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Muscle-selective synaptic disassembly and reorganization in MuSK antibody positive MG miceAnna Rostedt Punga ⁎,1,Shuo Lin,Filippo Oliveri,Sarina Meinen,Markus A.RüeggDepartment of Neurobiology/Pharmacology,Biozentrum,University of Basel,Basel,Switzerlanda b s t r a c ta r t i c l e i n f o Article history:Received 23February 2011Revised 15April 2011Accepted 21April 2011Available online 30April 2011Keywords:Myasthenia Gravis MG MuSKNeuromuscular junction MasseterMuscle atrophy DenervationMuSK antibody seropositive (MuSK+)Myasthenia Gravis (MG)patients present a distinct selective fatigue,and sometimes atrophy,of bulbar,facial and neck muscles.Here,we study the mechanism underlying the focal muscle involvement in mice with MuSK+experimental autoimmune MG (EAMG).8week-old female wildtype C57BL6mice and transgenic mice,which express yellow ﬂuorescence protein (YFP)in their motor neurons,were immunized with the extracellular domain of rat MuSK and compared with control mice.The soleus,EDL,sternomastoid,omohyoid,thoracic paraspinal and masseter muscles were examined for pre-and postsynaptic changes with whole mount immunostaining and confocal microscopy.Neuromuscular junction derangement was quanti ﬁed and compared between muscles and correlated with transcript levels of MuSK and other postsynaptic genes.Correlating with the EAMG disease grade,the postsynaptic acetylcholine receptor (AChR)clusters were severely fragmented with a subsequent reduction also of the presynaptic nerve terminal area.Among the muscles analyzed,the thoracic paraspinal,sternomastoid and masseter muscles were more affected than the leg muscles.The masseter muscle was the most affected,leading to denervation and atrophy and this severity correlated with the lowest levels of MuSK mRNA.On the contrary,the soleus with high MuSK mRNA levels had less postsynaptic perturbation and more terminal nerve sprouting.We propose that low muscle-intrinsic MuSK levels render some muscles,such as the masseter,more vulnerable to the postsynaptic perturbation of MuSK antibodies with subsequent denervation and atrophy.These ﬁndings augment our understanding of the sometimes severe,facio-bulbar phenotype of MuSK+MG.©2011Elsevier Inc.All rights reserved.IntroductionAbout 40–70%of acetylcholine receptor (AChR)-antibody seronegative Myasthenia Gravis (MG)patients have antibodies against the muscle tyrosine kinase (MuSK)(Hoch et al.,2001;Sanders et al.,2003).In MuSK-antibody seropositive (MuSK+)MG patients,there is often selective involvement of bulbar-,neck-and facial muscles,as well as muscles that are usually asymptomatic in AChR-antibody seropositive (AChR+)MG,such as the paraspinal muscles (Sanders and Juel,2008).Contrary to conventional AChR+MG patients,the majority of MuSK+patients does not experience symptomatic relief from acetylcholine esterase inhibitors (AChEI)(Evoli et al.,2003)but instead may respond with pronounced nicotinic adverse effects,such as muscle fasciculations and cramps (Punga et al.,2006).Pronounced atrophy of facial muscles has also been described in MuSK+patients,although the concomitant treatment of corticosteroids in most cases has made it dif ﬁcult tojudge whether the MuSK antibodies or the cortisone treatment is the cause of the atrophy (Farrugia et al.,2006).Muscle biopsy studies of the intercostal muscle and biceps brachii muscle from MuSK+patients have shown little AChR loss (Selcen et al.,2004;Shiraishi et al.,2005),however,the neuromuscular junction (NMJ)pathophysiology in the most affected facial or bulbar muscles has not been studied.Nevertheless,MuSK antibodies have been shown to be pathogenic in animals,both after immunization with the extracellular domain of the MuSK protein itself (Jha et al.,2006;Shigemoto et al.,2008;2006;Xu et al.,2006)and after passive transfer of sera from MuSK+MG patients (Cole et al.,2008;ter Beek et al.,2009).MuSK is essential to the process of NMJ formation,maintenance (Wang et al.,2006)and integrity,as perturbations in MuSK protein expression cause pronounced disassembly of the entire NMJ (Hesser et al.,2006;Kong et al.,2004).Other NMJ proteins that are essential for synaptogenesis include Dok-7,a downstream adaptor protein to MuSK (Okada et al.,2006),Lrp4,the co-receptor for neural agrin (Kim et al.,2008;Zhang et al.,2008),rapsyn and the AChR subunits.The effects of MuSK antibodies in-vivo on the gene expression of those synaptic proteins in the facial or bulbar muscles have not yet been established.Here,we hypothesized that low expression levels of MuSK may render some muscles more vulnerable to the effect of MuSK antibodies in the EAMG mouse model.We show that MuSK antibodiesExperimental Neurology 230(2011)207–217⁎Corresponding author at:Institute of Neuroscience,Department of Clinical Neuro-physiology,Uppsala University Hospital,Uppsala,Sweden.Fax:+4618556106.E-mail address:annarostedtpunga@ (A.R.Punga).1Present address:Department of Clinical Neurophysiology,Uppsala University Hospital,Uppsala,Sweden.0014-4886/$–see front matter ©2011Elsevier Inc.All rights reserved.doi:10.1016/j.expneurol.2011.04.018Contents lists available at ScienceDirectExperimental Neurologyj o u r n a l h o me p a g e :w w w.e l s e v i e r.c om /l o c a t e /y e x n rinduce severe fragmentation of the postsynaptic AChR clusters in particular in the masseter and thoracic paraspinal muscles,with less fragmentation in the limb muscles.The severe postsynaptic pertur-bation results in subsequent denervation of muscleﬁbers,not previously described in EAMG or MG.We propose that one underlying mechanism for the severe involvement of the facial masseter muscle, with severely impaired NMJ architecture,atrophy and denervation,is its low intrinsic levels of MuSK.Moreover,muscles respond to the partial denervation caused by MuSK antibodies in two different ways: (1)terminal nerve sprouting in muscles with high intrinsic levels of MuSK(i.e.soleus,sternomastoid)and(2)no nerve sprouting in muscles with low intrinsic MuSK levels(i.e.masseter,omohyoid).MethodsProduction of recombinant rat MuSKpCEP-PU vector containing the His-tagged extracellular domain of recombinant rat MuSK(aa21-491;(Jones et al.,1999))was transfected(Lipofectamine2000;Invitrogen)into HEK293EBNA cells.The overexpressed protein was puriﬁed from the cell superna-tant over a Ni-NTA superﬂow column(Qiagen)and was subsequently dialyzed against PBS.Protein concentration was determined at OD 280nm and purity was ensured by SDS-PAGE.Experimental animalsC57BL6mice and mice expressing yellowﬂuorescence protein (YFP)in their motor neurons under Thy-1promoter(Feng et al., 2000)were originally supplied from Jackson Laboratories(Bar Harbor, Maine,US).For immunization,8week-old female mice were used.All mice were housed in the Animal Facility of Biozentrum,University of Basel,where they had free access to food and water in a room with controlled temperature and a12hour alternating light–dark cycle.All animal procedures complied with Swiss animal experimental regu-lations(ethical application approval no.2352)and EC Directive 86/609/EEC.ImmunizationThe immunization procedure has been described previously(Jha et al.,2006).Brieﬂy,eleven C57BL6and seven Thy1-YFP female mice aged8weeks were anesthetized(Ketamine:111mg/kg and Xylazine: 22mg/kg)and immunized with10μg of MuSK emulsiﬁed in complete Freund's adjuvant(CFA,Difco laboratories,Detroit,Michigan,US) subcutaneously in the hind foot pads,at the base of the tail and dorsolateral on the back.At day28post-injection,immunization was repeated.A3rd immunization was given to mice that did not show any myasthenic weakness after56days.Control mice(8female mice) were immunized with PBS/CFA.Clinical and neurophysiological examinationMuscle weakness was graded every week,as described(Nakayashiki et al.,2000).Brieﬂy,mice were exercised by20consecutive paw grips on a grid and were then placed on an upside-down grid.The time they could hold on to the grid reﬂected the grade of fatigue and muscle weakness.EAMG grades were as follows:grade0,no weakness;grade1, mild muscle fatigue after exercise;grade2,moderate muscle fatigue; and grade3,severe generalized weakness.Evaluation of the response to AChEIs was performed by i.p.injection of a mix of neostigmine bromide (0.0375mg/kg)and atropine sulfate(0.015mg/kg)in mice with EAMG grades2and3(Berman and Patrick,1980).Repetitive stimulation of the sciatic nerve and recording from the gastrocnemius muscle with monopolar needle electrodes was performed under anesthesia,in mice with EAMG grades2(n=2)and3(n=2),using a Saphire1L EMG machine(Medelec).Decrement was calculated as percent amplitude change between the1st and4th compound motor action potentials evoked by a train of10impulses where10%was considered as pathological.ELISASera were obtained from tail vein blood on day0(preimmune sera)and day35post-immunization.ELISA plates(Nunc MaxiSorp, Fisher Thermo Scientiﬁc,Rockford,IL,US)were coated with250ng/ ml of His-labeled rat MuSK(50μl/well),blocked with3%BSA/PBS and then incubated with a sera dilution row(1:3000–1:2,000,000).Pre-immune sera constituted negative and rabbit-anti-MuSK antibody (Scotton et al.,2006)positive controls.After washing,plates were incubated with secondary HRPO-conjugated goat-anti-mouse (1:2000)and goat anti-rabbit antibodies(1:2000;both from Jackson Immuno Research Laboratories,Westgrove,PA,US).HRPO activation by a TMB substrate was terminated with1N HCl after5min. Absorbance was read at450nm.Non-speciﬁc binding,determined by incubation of plates with pre-immune serum,was subtracted.The data were displayed as“half maximum MuSK immunoreactivity”,which represents the immunore-activity at a dilution of1:27,000,where the majority of sera obtained50% of maximum absorbance(in the linear range of the absorption at450nm).Western blotWestern blot of masseter muscles was conducted as described (Bentzinger et al.,2008).10μg of protein was resolved on a4–12%Nu-PAGE Bis–Tris gel(Invitrogen,Eugene,OR,US),transferred to nitrocellulose membrane,probed with rat monoclonal anti-NCAM (CD56;1:100;GeneTex)and rabbit polyclonal anti-pan-actin(1:1000; cell signaling)and then recognized with HRPO-conjugated antibodies (1:5000;Jackson Immuno Research Laboratories,Westgrove,PA,US). Quantitative RT-PCR analysisMouse muscle RNA was extracted and puriﬁed as previously described(Punga et al.,2011).RT-PCR reactions(triplicates)were carried out with Power SYBR Green PCR Master Mix reagent(Applied Biosystems,Warrington,UK).β-actin was used as endogenous control (Punga et al.,2011;Murphy et al.,2003;Yuzbasioglu et al.,2010).The following primer sets were used:MuSK:5′-GCCTTCAGCGGGACTGAG-3′and5′-GAGGCGTGGTGA-CAGG-3′Lrp4:5′-GGATGGCTGTACGCTGCCTA-3′and5′-TTGCCGTTGTCA-CAGTGGA-3′Dok-7:5′-CTCGGCAGTTACAGGAGGTTG-3′and5′-GCAATGC-CACTGTCAGAGGA-3′A C h Rα1:5′-G C C A T T A A C C C G G A A AG T G A C-3′a n d5′-CCCCGCTCTCCATGAAGTT-3′AChRε:5′-CTGTGAACTTTGCTGAG-3′and5′-GGAGATCAG-GAACTTGGTTG-3′AChRγsubunit:5′-AACGAGACTCGGATGTGGTC-3′and5′-GTCGCACCACTGCATCTCTA-3′Rapsyn:5′-AGGTTGGCAATAAGCTGAGCC-3′and5′-TGCTCTCACT-CAGGCAATGC-3′MuRF-1:5′-ACC TGC TGG TGG AAA ACA-3′and5′-AGG AGC AAG TAG GCA CCT CA-3′β-actin:5′-CAGCTTCTTTGCAGCTCCTT-3′and5′-GCAGCGA-TATCGTCATCCA-3′A C h E:5′-G G G C T C C T A C T T T C T G G T T T A C G-3′a n d5′-GGGCCCGGCTGATGAG-3′208 A.R.Punga et al./Experimental Neurology230(2011)207–217NMJ whole mount analysisAlexa Fluor555-conjugatedα-bungarotoxin(1μg/ml;Invitrogen) was injected into soleus,EDL,sternomastoid,omohyoid,masseter and the thoracic paraspinal muscles as described(Bezakova and Lomo, 2001).At least12images of each muscle per mouse(6MuSK-immunized YFP-transgenic mice and4CFA-immunized control mice) were collected with a confocal laser-scanning microscope(Leica TCS SPE).Laser gain and intensity were equal for all images.Quantiﬁcation of pre-and postsynaptic area was performed in ImageJ(http://imagej. /ij/index.html).NMJs containing terminal nerve sprouts(processes with YFP expression)were counted in muscles fromﬁve MuSK+EAMG mice with disease grades1–3.At least275NMJs per muscle were analyzed. The number of postsynapse fragments per NMJ was counted using a ﬂuorescence microscope(Leica DM5000B)in at least50NMJs per muscle deriving fromﬁve MuSK+EAMG grades1–2and from four control mice(Supplemental Fig.1).Fragmentation was classiﬁed as follows:1)normal pretzel-like NMJ;2)slight to moderate fragmen-tation;and3)severe fragmentation or absent postsynapse.The degree of postsynaptic perturbation per muscle was judged based on the percentage of NMJs belonging to each postsynaptic class and was further subdivided into number of postsynapse fragments per NMJ:1–3,4–6,7–9,10–12and more than12.Each NMJ was given the median score for that subgroup.The fragmentation score was obtained by taking the ratio of the score between the EAMG mice and control mice.Statistical analysisIndependent,2-sample t-test was performed for parametric data. For ordinal data(ELISA),the non-parametric test Spearman Rank Correlation was applied.A p-value b0.05was considered signiﬁcant.Fig.1.(A)Development of EAMG after immunization with recombinant rat MuSK.Progress of clinical EAMG grade at the time points week4,5,7and10.*The mice with EAMG grade 3were sacriﬁced after week7(hence no new grade3mice week10)and the remaining mice were sacriﬁced andﬁnally evaluated at week10.(B)One mouse,representative of the most severely affected MuSK+EAMG mice,withﬂaccid paralysis and pronounced kyphosis.(C)Repetitive nerve stimulation performed in the same mouse.Stimulation of the sciatic nerve and recording of the gastrocnemius muscle demonstrated a35%decrement between the1st and4th compound motor action potentials at low frequency3Hz stimulation.(D)Correlation of clinical EAMG grade with MuSK antibody titer.Half of maximum MuSK immunoreactivity(1:27,000dilution)in sera from MuSK immunized mice was assessed by Elisa at450nm.R=0.483(Spearman's Rank Correlation);p b0.05.209A.R.Punga et al./Experimental Neurology230(2011)207–217ResultsMuSK+EAMG presents with prominent kyphosis,paralysis and weight lossOut of the18mice immunized with MuSK,theﬁnal EAMG grade 0was seen in3mice(17%),grade1in8mice(44%),grade2in4mice (22%)and grade3in3mice(17%)(Fig.1A).No difference in disease incidence was found between the groups of C57BL6mice and the YFP-transgenic mice.Based on this,the data were pooled in the current study.The most severe phenotype of EAMG(grade3)includedﬂaccid paralysis,pronounced kyphosis and weight loss(Fig.1B).In-vivo nerve stimulation at3Hz with recording from the gastrocnemius muscle revealed a decrement of10–40%in the MuSK+EAMG mice (Fig.1C),whereas the control mice had normal neuromuscular transmission(data not shown).MuSK immunoreactivity in sera(day 35)correlated with clinical severity(Fig.1D;Spearman Rank Correlation;R=0.483;p b0.05),although some mice developed measurable MuSK antibodies without showing obvious muscle weakness or fatigue.Bulbar symptoms underlying weight loss in MuSK+EAMG The MuSK immunized mice steadily decreased signiﬁcantly in body weight after the2nd immunization(Fig.2A),in contrast to the control mice,and theﬁnal body weight of the MuSK+mice was signiﬁcantly smaller(p b0.001;Fig.2B).This severe weight loss was slowed but not stopped after introduction of wet food(data not shown).Since the timeline of the weight drop also correlated with development of muscle fatigue,the weight loss was assumed to be indicative of chewing and swallowing difﬁculties,some of the cardinal symptoms of MuSK+MG.To determine whether loss of muscle weight signiﬁcantly contributed to the overall lower body weight in the MuSK+EAMG mice,the weight ofﬁve different muscles was assessed.The masseter was the only muscle with a signiﬁcant weight reduction(p b0.01;Fig.2C),implying that this muscle is atrophic and further indicating chewing difﬁculties.Adverse effects of AChEIs in MuSK+EAMGTo elucidate whether AChEIs have any beneﬁcial effect on fatigue or weakness in MuSK+EAMG,a neostigmine test was performed in the mice with EAMG grade3(n=3).No apparent improvement in weakness at rest or exercise-induced fatigue was seen;instead the mice experienced shivering and constant twitching of the tail,trunk and limbs starting after approximately13min(Supplemental Video1).This effect wore off after40min and was interpreted as nicotinic side effects and neuromuscular hyperactivity,usually seen after an overdose of AChEIs.Thus,this intolerance towards AChEIs in MuSK+EAMG indicates an abnormal sensitivity to acetylcholine.Impairment of NMJs in different musclesBecause muscle groups in the bulbar/facial/back region are selectively involved in the MuSK+EAMG model,we next examined the morphological changes of NMJs in the thoracic paraspinal muscles, masseter,omohyoid and sternomastoid and compared them with those in two limb muscles(EDL and soleus).Typical features of postsynaptic impairment were a fainting of AChRﬂuorescence,areas lacking AChRs(holes)and disassembly of AChR clusters.To quantify these impairments,we classiﬁed NMJs into three classes as illustrated in Fig.3A.All muscles from MuSK+EAMG mice displayeddifferentFig.2.Weight loss in MuSK+EAMG.(A)The course of weight loss in two MuSK+mice with EAMG grade3compared to control(Ctrl CFA)mice(n=8).Initial body weight was comparable and weight loss started after the2nd immunization and weight kept dropping even though wet food was provided ad libitum.(B)Mean body weight was dramatically reduced in the MuSK immunized mice(MuSK+;n=18),compared to the control mice.Results shown as mean±SEM(gram);***p b0.001.(C)Muscles were weighed and compared between control mice(n=8)and MuSK+EAMG mice(n=18).Results displayed as mean muscle weight±SEM(mg).The only muscle which was signiﬁcantly lighter in the MuSK+mice was the masseter.**p b0.01.210 A.R.Punga et al./Experimental Neurology230(2011)207–217degrees of NMJ impairment (Fig.3B).Moreover,we also observed that the postsynapses were often fragmented into two to three non-continuous fragments (see illustration in Fig.3A),which is in strong contrast to non-interrupted,pretzel-like shape of AChRs in non-immunized mice.This fragmentation was also quanti ﬁed (Supplemental Fig.1)and expressed as “fragmentation score ”.Because fragmentation differs between muscles,this “fragmentation score ”was normalized to the control.As shown in Fig.3C,the fragmentation score varied between a minimum of 2.0in the soleus muscle and a maximum of 3.3in the masseter muscle.The postsynaptic labeling was markedly reduced in the MuSK+EAMG mice compared to control mice (Fig.4A).In the mild to moderately affected mice,AChR cluster area was reduced signi ﬁcantly by 40–50%in all muscles (p b 0.01),except for the soleus,which had a remaining area of 85%(p b 0.05;Fig.4B).In the most severely affected mice,the postsynaptic area was also lost in the soleus muscle and less than 10%of the α-bungarotoxin staining remained in the masseter,sternomastoid and thoracic paraspinal muscles (p b 0.001).In the soleus,the nerve terminal area was unchanged in the severely affected mice,although in the other muscles the presynaptic area was reduced to about 80%in the mild to moderate cases and to 50%in the most severely affected mice (p b 0.01)(Fig.4C).Thus,both the pre-and postsynaptic data suggest that the masseter is the most affected muscle by MuSK antibodies whereas the soleus is the least affected.mRNA transcript expression of NMJ proteins in different muscles in MuSK+EAMGThe mRNA levels of MuSK differ signi ﬁcantly between muscles,with the highest levels in the soleus muscle and lowest levels in the omohyoid muscle (Punga et al.,2011).Consequently,we additionally analyzed MuSK transcript levels in the masseter and these were even lower,with less than 20%of the mRNA levels detected in the soleus muscle (Supplemental Fig.2;p b 0.01).In the MuSK+EAMG mice,MuSK mRNA levels were signi ﬁcantly reduced to 45%of control in the EDL (p b 0.05)and to 25%in the omohyoid muscle (p b 0.001;Fig.5A).Conversely,MuSK mRNA expression was signi ﬁcantly increased in the masseter muscle (p b 0.01)and remained unchanged in the soleus and sternomastoid muscles.The expression of the AChR αsubunit was unchanged (Fig.5B),whereas the AChR εsubunit transcript was downregulated in the soleus and sternomastoid muscles and conversely a trend towards upregulation was seen in the masseter muscle (Fig.5C).The fetal AChR γsubunit mRNA was upregulated up to 1000-fold in the masseter (p b 0.001)and 5-fold in the soleus (p b 0.05;Fig.5D).The transcript levels of rapsyn,Lrp4and Dok-7were not signi ﬁcantly altered (Fig.5E to G).Finally,the transcript levels of acetylcholine esterase (AChE)were signi ﬁcantly down-regulated only in the sternomastoid and omohyoid muscles (p b 0.05;Fig.5H).Fig.3.Postsynaptic fragmentation of NMJs.(A)Examples from each postsynaptic classi ﬁcation.AChRs stained for alfa-bungarotoxin.(B)At least 275neuromuscular junctions (NMJs)per muscle were assessed in a total of 5MuSK+EAMG mice with moderate to severe disease.The appearance of NMJ postsynapses were divided into 3classes as indicated.Sol:soleus;EDL:extensor digitorum longus;STM:sternomastoid muscle;omo:omohyoid;mass:masseter.(C)Postsynapses were analyzed in at least 50NMJs per muscle in a total of 5MuSK+EAMG mice with slight to moderate disease grade and in 4control mice.Each NMJ in a certain subclass (for details see Supplemental Fig.1)was given the median score for that subclass.The fragmentation score for each muscle is the ratio in score between the EAMG mice and control mice.211A.R.Punga et al./Experimental Neurology 230(2011)207–217In summary,particularly the massive upregulation of MuSK transcripts and AChR γin conjunction with the overall trend for upregulation of mRNA for the other postsynaptic genes in the masseter muscle most likely re ﬂects the severely disturbed neuro-muscular transmission in this muscle as a result of the MuSK antibodyattack.Fig.4.Pronounced reduction of postsynaptic and presynaptic area in different muscles in MuSK+EAMG.(A)Whole mount staining of single ﬁber layer bundles from the paraspinal muscle (ps),sternomastoid (STM),masseter (mass),omohyoid (omo),extensor digitorum longus (EDL)and soleus (sol)muscles from one control mouse immunized with CFA/PBS and one mouse with severe MuSK+EAMG.AChRs are visualized by alexa-555-bungarotoxin (red)and the motor nerve terminals by YFP expression (green).The AChRs are almost completely gone from the paraspinal muscles,STM and masseter.Confocal images of 100×magni ﬁcation,scale bar is 10μm.Quanti ﬁcation of (B)postsynapse (AChR clusters)and (C)presynaptic area in the different muscles;soleus (sol),extensor digitorum longus (EDL),omohyoid (omo),masseter (mass),sternomastoid (STM)and paraspinal muscles (ps).Results are given as %of ctrl area±SEM and at least 12NMJs in each muscle/mouse was measured in mice with EAMG grades 1–2(N =4),in mice with severe grade 3(N =2)and in control mice (N =4).**p b 0.01;#p b 0.001.212 A.R.Punga et al./Experimental Neurology 230(2011)207–217Denervation induced muscle atrophy in MuSK+EAMGThe masseter muscle lost weight and consequently we examined the mRNA levels of the atrophy marker muscle-speci ﬁc RING ﬁnger protein 1(MuRF-1)and assessed signs of denervation.For this analysis we included the same muscles as previously examined,with the addition of thoracic paraspinal muscles due to the pronounced kyphosis of the MuSK+EAMG mice.MuRF-1mRNA levels were signi ﬁcantly upregulated in the masseter muscle (p b 0.05;Fig.6A)and on the contrary MuRF-1transcript levels were strongly reduced in the soleus muscle (p b 0.01)in the MuSK+EAMG mice.Further,the protein levels of neural cell adhesion molecule (NCAM),a marker for denervation,were increased in the masseter muscle as detected by Western blot analysis.This is thus additional evidence of denervation in this particular muscle (Fig.6B).Absence of nerve sprouting may contribute to the severe denervation phenotypePresynaptic nerve terminals were visualized by transgenic YFP expression,allowing observation also of NMJs with absent post-synapses.In the masseter,the nerve terminals were still present although many postsynaptic AChRs were partially or completely lost.Intriguingly,no or little nerve sprouting was observed in these cases (Fig.7).This ﬁnding raised the possibility that postsynaptic perturbation in this muscle did not elicit any nerve sprouting response.To test this hypothesis,we examined ≥450NMJs in each of the muscles for such sprouting response.The quantitative examination of 4MuSK+EAMG mice revealed terminal nerve sprouting in approximately 20%of NMJs in the soleus and in 15%of endplates in the sternomastoid (Fig.7).On the contrary,theFig.5.mRNA levels of postsynaptic proteins in MuSK+EAMG.C:control mice immunized with CFA/PBS.MG:EAMG mice immunized with MuSK.mRNA levels in the control mice are set to 100%and levels in the EAMG mice are relative to the control levels.n=6control mice;n=6MuSK+EAMG mice.Genes of interest are relative to the house keeping gene β-actin.*p b 0.05;***p b 0.001.213A.R.Punga et al./Experimental Neurology 230(2011)207–217omohyoid,EDL,thoracic paraspinal muscles and masseter,showed terminal sprouting at only a few NMJs.In most samples no sprouting was observed,which differed signi ﬁcantly from the soleus (p b 0.001)and the sternomastoid muscle (p b 0.05).Interestingly,the degree of nerve sprouting in each muscle correlates with their endogenous levels of MuSK,suggesting that MuSK levels regulate the nerve sprouting response and consequently reorganization of NMJs (Punga et al.,2011).DiscussionMuSK+MG patients often present with focal weakness of facial,bulbar,neck and respiratory muscles and sometimes also of paraspinal and upper esophageal muscles (Sanders and Juel,2008).The pathopysiological role of MuSK antibodies has been questioned based on the normal levels of MuSK and AChRs at the NMJ in cross-sections of the intercostal muscle and biceps brachii muscle of MuSK+MG patients (Selcen et al.,2004;Shiraishi et al.,2005).Further studies in mice have now shown that MuSK antibodies deplete MuSK from the NMJ,which results in disassembly of the postsynaptic apparatus and a reduced packing of AChRs (Jha et al.,2006;Shigemoto et al.,2006;Cole et al.,2010).Nevertheless,the exact mechanism of how MuSK antibodies affect muscles has so far not been revealed.Here we report that MuSK antibodies cause a severe pre-and postsynaptic disassembly in the facial,bulbar and paraspinal muscles but only a slight disruption in the limb muscles (i.e.soleus and EDL).The most affected muscle was the masseter and intriguingly this muscle expressed less than 20%of MuSK transcripts than the least affected soleus muscle.Considering that fast-twitch muscle ﬁbers require larger depolarization to initiate contraction compared to slow-twitch ﬁbers,we propose that the superfast twitch pattern of the masseter in combination with its critically low MuSK levels makes this muscle extra vulnerable to the synaptic perturbation following the MuSK antibody attack (Laszewski and Ruff,1985).Hence,over-expression of MuSK in vulnerable muscles could potentially alleviate the effects of the antibody-mediated attack against MuSK.Earlier studies of AChR+EAMG rats have been shown to respond to rapsyn-overexpression in the tibialis anterior muscle with no loss of AChRs and almost normal postsynaptic folds,whereas the NMJs of untreated muscles showed typical AChR loss and morphological damage (Losen et al.,2005).Nevertheless,we did not ﬁnd any changes in rapsyn mRNA levels across the examined muscles.Additionally,our ﬁndings underline the importance of examining the clinically affected muscles in MuSK+MG in order to draw the right conclusions regarding NMJ morphology.In the MuSK+EAMG model,the mice exhibited obvious bulbar and thoracospinal muscle weakness,similar to the mouse model of congenital myasthenic syndrome with MuSK mutation (Chevessier et al.,2008).This implies a common clinical phenotype in mice with impaired MuSK function and corresponds well with the phenotype of human MuSK+MG.In contrast,we have noticed in parallel rounds with immunization of C57BL6mice with AChR from Torpedo californica that the AChR-antibody seropositive mice did not develop signi ﬁcant weight loss,neck muscle weakness or kyphosis and also that their ﬂaccid paralysis was reversible with AChEI treatment (Punga et al.,unpublished observations).The adverse effect of AChEIs in MuSK+EAMG resembles the neuromuscular hyperactivity reported in MuSK+MG patients (Punga et al.,2006).We hypothesize that the underlying reason for the hypersensitivity in the muscles to the additional amount of available ACh at the NMJ is a consequence of (1)the denervation of the muscle ﬁbers with extensive AChR fragmentation and (2)the downregulation of AChE in some muscles (e.g.omohyoid and sternomastoid),which may result in AChEI overdose-like phenotype.The downregulation of AChE mRNA is most probably a direct consequence to the loss of MuSK,since MuSK binds collagen Q,an interaction that is thought to be largely responsible for the synaptic localization of AChE-collagen Q complex at the NMJ (Cartaud et al.,2004).The fragmentation and spatial dispersion of AChRs most likely inhibits the response to the increased ACh at the NMJ induced by AChEIs in the most clinically affected muscles.This study also investigated the possibility of MuSK antibodies to initiate a cascade that results in denervation-induced atrophy.MRI studies of newly diagnosed MuSK+patients have con ﬁrmed early muscle atrophy in the temporal,masseter and lingual muscles with fatty replacement (Zouvelou et al.,2009;Farrugia et al.,2006).We observed that,particularly in the masseter and paraspinal muscles,some NMJs were completely depleted of AChRs,and the subsequent loss of synaptic transmission most probably resulted in functional denervation.This explanation is further supported by the fact that pharmacological denervation arises after injection of botulinum toxin A (BotA),which also blocks the cholinergic synaptic transmission,and it is sometimes dif ﬁcult to distinguish this from a surgical denervation due to the similarities in pattern,extent and time course (Drachman and Johnston,1975).Previous studies of passively induced AChR+EAMG in rats have shown an upregulation of the AChR ε,but not the γsubunits;thus suggesting that newly expressed AChRs in the case of antibody mediated AChR loss are of the adult type (Asher et al.,1993).However,our observed massive upregulation of AChR γtranscript in the masseter implies that,except for disturbed neuromuscular transmission,denervation is also ongoing since this usually correlates with the predominant expression of embryonic type receptors and re-expression of the fetal type occurs after experimental denervation (Witzemann et al.,1989).Levels of AChR γmRNA are normally extremely low in all muscles except for the extraocular muscles (Kaminski et al.,1996;MacLennan et al.,1997).Concomitantly with the very prominent increase in transcripts encoding AChR γ,MuSKFig.6.Atrophy-and denervation related markers in MuSK+EAMG mice.(A)mRNA levels of MuRF-1expressed as %of control in relation to β-actin.n=6control mice (C)and n=5MuSK+EAMG mice (MG).*p b 0.05.(B)Western blot of NCAM in the masseter muscle of one MuSK+EAMG mice with disease grade 3(MG)and in one CFA-immunized control mouse (Ctrl).NCAM was detected as 3bands at levels 120,140and 180kD and the loading control β-actin (45kD).An equal amount of protein was loaded.**p b 0.01.214 A.R.Punga et al./Experimental Neurology 230(2011)207–217。

英文文献(医学生学习策略)

Norwegian nursing and medical students’ perception ofinterprofessional teamworkInterprofessional teamwork in healthcare has gained increasing recognition worldwide as a way to increase patient safety and to foster collaborative and effective teams. The World Health Organization (WHO) has highlighted the importance of interprofessional teamwork and recommended educational programs that equip health care students with the necessary skills and competence to become effective team players.International research corroborates the position taken by the WHO, but studies also reveal difficulties in implementing interprofessional educational efforts and suggest that undergraduate education largely fails to address key elements, such as the understanding of professional roles, authority, hierarchy and gender related dimensions of teamwork.Of interest for the current study is the fact that Norwegian authorities have taken steps to promote interprofessional teamwork and education. The National Health Plan acknowledges interprofessional collaboration as a critical element for ensuring quality in health care services. In a White Paper submitted to the Norwegian Parliament the Ministry of Education sets requirements for the inclusion of interprofessional teamwork in health education. Reviewing lessons learned from the Norwegian initiatives, Clark concluded that the emerging positive outcomes have been somewhat impaired by lack of resources.Previous studies by Kyrkjebø and Bjørke noted that Norwegian students are not sufficiently exposedto interprofessional teamwork during their clinical training. Other Norwegian studies reported similar results. Aase found that theoretical lectures on interprofessional teamwork were not followed-up in clinical training, especially in nursing schools. Medical schools exposed their students to more interprofessional training, but still fell short of full compliance with the WHO recommendations. The reasons for this are partly because of structural constraints, such as resources, and partly because of faculty and students’ attitudes.Saroo et al. argue that successful interprofessional training should take advantage of the students’ psychosociological determinants, such as professional role behavior, hierarchy, and power relations. Based on this information, we surmise that a thorough understanding of the students’ perspective is imperative for designing successful interprofessional training. The current study analyses data from focus group interviews with nursing and medical students who had been exposed to interprofessional teamwork during their clinical training in Norway. Grounded in the students’ perceptions, the analysis aims at describing patterns and recommendations for the design of future interprofessional training. Note that the qualitative framework allowed the students to include reflections on the group processes –i.e., the focus group interviews –that were part of the current study.。

医学英语文献分类 PPT课件

An Evidence Based Approach

There is an apparent misconception about evidence based medicine that it should take the place of traditional medical education. Unfortunately, you still have to do background reading. When you solve a clinical problem, you will see that you need to use a lot of background knowledge (pathophysiology, pathology, pharmacology) in addition to foreground knowledge about your patient’s specific problem.
三.医学英语阅读的准备及注意事项:

1.语法:字法,句法. 2.词汇:单词,短语. 3.专业知识: 4.辞典:<牛津英语双解辞典>, <英汉医学词汇>, 专业辞典. 5.快速阅读:题目,摘要 / 结论,每一段的起始句. 6.准确理解:多读,泛读与精读相结合.

After you have refined a question for research, you can search for the relevant journal articles. In order to be successful, you need to be aware of the resources available and you need to have a good search strae-Based Medicine" is a recent trend which aims to make medical decisionmaking more deliberate and methodical. Most descriptions of the evidence based approach contain the following four steps:

医学英文文献

RAPSYN CARBOXYL TERMINAL DOMAINS MEDIATE MUSCLE SPECIFIC KINASE–INDUCED PHOSPHORYLATION OFTHE MUSCLE ACETYLCHOLINE RECEPTORY. LEE, J. RUDELL, S. YECHIKHOV, R. TAYLOR,S. SWOPE AND M. FERNS*Departments of Anesthesiology and Physiology and Membrane Biol-ogy, One Shields Avenue, University of California Davis, Davis, CA 95616, USAAbstract—At the developing vertebrate neuromuscular junc-tion, postsynaptic localization of the acetylcholine receptor (AChR) is regulated by agrin signaling via the muscle speciﬁc kinase (MuSK) and requires an intracellular scaffolding pro-tein called rapsyn. In addition to its structural role, rapsyn is also necessary for agrin-induced tyrosine phosphorylation of the AChR, which regulates some aspects of receptor local-ization. Here, we have investigated the molecular mechanism by which rapsyn mediates AChR phosphorylation at the ro-dent neuromuscular junction. In a heterologous COS cell system, we show that MuSK and rapsyn induced phosphor-ylation of ␤ subunit tyrosine 390 (Y390) and ␦ subunit Y393, as in muscle cells. Mutation of ␤ Y390 or ␦ Y393 did not inhibit MuSK/rapsyn-induced phosphorylation of the other subunit in COS cells, and mutation of ␤ Y390 did not inhibit agrin-induced phosphorylation of the ␦ subunit in Sol8 muscle cells; thus, their phosphorylation occurs independently, downstream of MuSK activation. In COS cells, we further show that MuSK-induced phosphorylation of the ␤ subunit was mediated by rapsyn, as MuSK plus rapsyn increased ␤Y390 phosphorylation more than rapsyn alone and MuSK alone had no effect. Intriguingly, MuSK also induced tyrosine phosphorylation of rapsyn itself. We then used deletion mu-tants to map the rapsyn domains responsible for activation of cytoplasmic tyrosine kinases that phosphorylate the AChR subunits. We found that rapsyn C-terminal domains (amino acids 212– 412) are both necessary and sufﬁcient for activa-tion of tyrosine kinases and induction of cellular tyrosine phosphorylation. Moreover, deletion of the rapsyn RING do-main (365– 412) abolished MuSK-induced tyrosine phosphor-ylation of the AChR ␤ subunit. Together, these ﬁndings sug-gest that rapsyn facilitates AChR phosphorylation by activat-ing or localizing tyrosine kinases via its C-terminal domains.© 2008 IBRO. Published by Elsevier Ltd. All rights reserved. Key words: neuromuscular junction, synaptogenesis, agrin, postsynaptic membrane.At the developing neuromuscular junction in vertebrates, several nerve-derived signals combine to localize the ace-tylcholine receptor at postsynaptic sites (Sanes and Lich-tman, 2001; Burden, 2002; Kummer et al., 2006). One essential factor is agrin, which signals via the muscle speciﬁc kinase (MuSK) and induces and/or stabilizes clus-tering of the acetylcholine receptor (AChR) in the postsyn-aptic membrane (reviewed in Kummer et al., 2006). Inter-estingly, embryonic muscle is prepatterned and AChR clusters occur in the central region of the muscle prior to and even in the absence of neural innervation (Lin et al., 2001; Yang et al., 2001). However, upon innervation, agrin is required for stable aggregation of AChR at nerve–mus-cle contacts, counteracting an acetylcholine-driven dis-persal of AChR that eliminates aneural aggregates (Lin et al., 2005; Misgeld et al., 2005). Indeed, in agrin and MuSK knockout mice, AChR clusters are largely eliminated by birth and the mice die due to an inability to move and breathe (DeChiara et al., 1996; Gautam et al., 1996). Downstream of MuSK activation, an important mediator of AChR clustering is the intracellular, peripheral membrane protein, rapsyn, which associates with the AChR in the postsynaptic membrane in approximately 1:1 stoichiom-etry (Froehner, 1991). When expressed in heterologous cells, rapsyn self-aggregates and is sufﬁcient to cluster, anchor and stabilize the AChR (Froehner et al., 1990; Phillips et al., 1991, 1993, 1997; Wang et al., 1999). More-over, in rapsyn null mice, there is a complete absence of AChR clusters at developing synaptic sites (Gautam et al., 1995). Together, these ﬁndings suggest that rapsyn binds the receptor, clustering and anchoring it in the postsynaptic membrane.Although rapsyn mediates AChR localization, it is un-clear how this is regulated by agrin signaling in muscle cells. Potentially, protein interactions underlying localiza-tion could be regulated via posttranslational modiﬁcations of the AChR, rapsyn, or additional binding proteins. Con-sistent with the ﬁrst possibility, agrin/MuSK signaling in-duces rapid tyrosine phosphorylation of the AChR ␤ and ␦subunits (Mittaud et al., 2001; Mohamed et al., 2001), mediated by an intervening cytoplasmic tyrosine kinase (Fuhrer et al., 1997), perhaps of the src and/or abl families (Mohamed and Swope, 1999; Finn et al., 2003). Phosphor-ylation correlates closely with reduced mobility and deter-gent extractability of the AChR(Meier et al.,1995;Borges and Ferns,2001),suggesting that it regulates linkage to the cytoskeleton.In addition,it precedes AChR clustering (Ferns et al.,1996)and tyrosine kinase inhibitors that block phosphorylation also block clustering(Wallace et al.,1991; Ferns et al.,1996).Consistent with theseﬁndings,muta-tion of the tyrosine phosphorylation site in the␤subunit abolishes agrin-induced cytoskeletal anchoring of mutant AChR and impairs its aggregation in muscle cells(Borges*Corresponding author.Tel:ϩ1-530-754-4973;fax:ϩ1-530-752-5423.E-mail address: mjferns@ (M. Ferns).Abbreviations:aa,amino acid;AChR,acetylcholine receptor;BuTX,␣-bungarotoxin;C-terminal,carboxyl terminal;HA,hemagglutinin;MuSK,muscle speciﬁc kinase;N-terminal,amino terminal.Neuroscience153(2008)997–10070306-4522/08$32.00ϩ0.00©2008IBRO.Published by Elsevier Ltd.All rights reserved. doi:10.1016/j.neuroscience.2008.03.009997and Ferns,2001).Moreover,mice with targeted mutations of the␤subunit intracellular tyrosines have neuromuscular junctions that are simpliﬁed and reduced in size,with de-creased density and total numbers of AChRs(Friese et al., 2007).Phosphorylation of the␤subunit contributes to AChR localization,therefore,but it is unclear whether it does so by regulating rapsyn interaction(Fuhrer et al., 1999;Marangi et al.,2001;Moransard et al.,2003).In addition to its structural role,rapsyn also functions in agrin signaling.Notably,agrin-induced phosphorylation of the AChR␤and␦subunits is signiﬁcantly decreased in rapsyn null myotubes(Apel et al.,1997;Mittaud et al., 2001),and rapsyn activates src family kinases in heterol-ogous cells(Qu et al.,1996;Mohamed and Swope,1999), resulting in tyrosine phosphorylation of multiple cellular proteins.Thus,rapsyn may facilitate MuSK-induced phos-phorylation of the AChR by activating and/or localizing the relevant cytoplasmic tyrosine kinases.In this study,we have investigated how rapsyn mediates the functionally important tyrosine phosphorylation of the AChR and have mapped the COOH-terminal domains required for tyrosine kinase activation and receptor phosphorylation.EXPERIMENTAL PROCEDURES Expression constructsRat MuSK that was myc-tagged at the amino terminal(N-terminus)was expressed in the pRcRSV vector(provided by S. Burden,NYU,New York,NY,USA).Mouse muscle nAChR subunits(␣,␤,␧,␦)were expressed using the pcDNA3vectorwith a CMV promoter(Invitrogen;Carlsbad,CA,USA).To epitope tag the␤-subunit,a Kpn I site was introduced at thecarboxyl terminal(C-terminal)extracellular tail,and double-stranded oligonucleotides that coded for the hemagglutinin (HA)or142epitopes(Das and Lindstrom,1991)were ligated into this site.To tag the␦-subunit,a Cla I site was introducedand the142epitope ligated into this site.Tyrosine390of the␤subunit and393of the␦subunit were mutated to phenylala-nines using polymerase chain reaction-based site-directed mu-tagenesis(Quickchange Kit,Stratagene;La Jolla,CA,USA). Mouse rapsyn was expressed using the pcDNA3vector. Rapsyn deletion mutants that were His6-tagged at the C-termi-nus were generated through PCR and ligated into the pMT23 vector;rapsyn C-terminal deletion constructs retained the N-terminal myristoylation sequence whereas C-terminal frag-ments lacked this sequence.All constructs were conﬁrmed by sequencing.Assaying phosphorylation of AChRCOS cells were grown on10cm dishes in DMEM-HI containing 10%fetal bovine serum and penicillin–streptomycin.When the cells reached85–90%conﬂuency they were transfected overnight with20␮g of plasmid DNA encoding the AChR subunits(␣,␤,␧,␦)using the calcium phosphate method(Profection kit,Promega; Madison,WI,USA).For these experiments,the␤and␦subunitswere tagged with HA and142epitopes,respectively.After2days of expression,the live cells were surface labeled with biotin-conjugated␣-bungarotoxin(BuTX)(Molecular Probes;Eugene, OR,USA)for1h,rinsed,and then scraped off and pelleted in Ca2ϩ/Mg2ϩ-free PBS containing1mM sodium vanadate.Cells were then resuspended in buffer containing1%Triton X-100and 25mM Tris–glycine pH7.5,150mM NaCl,5mM EDTA,1mM sodium vanadate,50mM sodiumﬂuoride and the protease inhib-itors:1mM bisbenzimidine,1mM sodium tetrathionate,and1mM PMSF.After extraction on ice for10min,the detergent soluble and insoluble fractions were separated by centrifugation at 16,000ϫg for4min.The insoluble pellet fraction was resus-pended directly in200␮l of SDS-PAGE loading buffer.The solu-ble lysates were incubated with streptavidin–agarose beads(Mo-lecular Probes)for1h to isolate AChR pre-labeled with biotin-conjugated BuTX.MuSK was then immunoprecipitated with anti-MuSK polyclonal antibody(gift of J.Sugiyama and Z.Hall,UCSF San Francisco,CA,USA)and protein G beads.In both cases, proteins isolated on the beads were eluted in30␮l of2ϫSDS-PAGE loading buffer.Sol8muscle cells were grown on10cm dishes and trans-fected with142-tagged␤subunit using the calcium phosphate method as previously described(Borges and Ferns,2001).After treatment with agrin for1h(200pM C-Ag4,8),the cells were extracted as described above.AChR containing tagged␤subunit was immunoprecipitated with mAb142and then the remaining AChR was pulled down using biotin-conjugated BuTX and strepta-vidin-agarose beads(Molecular Probes).For immunoblotting,samples were electrophoretically sepa-rated on10%SDS-PAGE gels,and transferred onto PVDF mem-branes.To detect phosphorylated AChR␤and␦subunits,the proteins were probed with polyclonal antibodies JH-1360and JH-1358,respectively(Mohamed and Swope,1999)in buffer containing4%Blotto,20mM Tris–HCl,pH7.6,150mM NaCl, 0.5%NP40,and0.1%Tween-20.The blots were then incubated with horseradish peroxidase–conjugated anti-rabbit IgG second-ary antibody(Amersham Corporation;Arlington Heights,IL,USA) and bound antibody was visualized by chemiluminescence(ECL, Amersham Corporation).To identify the␤and␦subunit phos-phorylation bands,the immunoblots were reprobed for tagged␤and␦subunits with monoclonal antibodies anti-HA(Roche;Indi-anapolis,IN,USA)or mAb142(Sigma-Aldrich;St.Louis,MO, USA).The identity of the bands was also conﬁrmed via mutations of␤Y390and␦Y393,which eliminate phosphorylation of the respective subunits.Blots were also reprobed for the␣subunit using mAb210(Babco;Berkley,CA,USA)to compare levels of expression of the AChR.Rapsyn immunoblots were performed using monoclonal antibody mAb1234(gift of S.Froehner,Univ. Washington,Seattle,WA,USA),polyclonal antibody B5668(gen-erated against amino acids(aa)133–153of rapsyn)or anti-His6 for tagged versions of rapsyn.Reprobes for tagged MuSK were performed using anti-myc monoclonal antibody9E10.To quantify levels of tyrosine phosphorylation,we carried out densitometric analysis of the␤and␦subunit bands in both soluble and pellet fractions using Sci-Scan5000Bioanalysis software(USB;Cleveland,OH,USA).As only20%of the pellet fraction was used for immunoblotting,these values were mul-tiplied byﬁve and added to the corresponding value for the soluble fraction in order to give total AChR subunit phosphor-ylation.The data were also normalized to the level of AChR, detected by immunoblotting for the tagged␤subunit(anti-HA or 142).In order to average several independent transfection experiments,all values were expressed as a percentage of the maximal signal,which was obtained in COS cells co-expressing AChR,MuSK and rapsyn,or in Sol8muscle cells treated with agrin.Assaying total cellular phosphorylationCOS cells grown on6cm dishes were transfected overnight with 9␮g of plasmid DNA.After1day of expression,cells were rinsed, scraped off and pelleted in Ca2ϩ/Mg2ϩ-free PBS containing1mM sodium vanadate.The cells were then lysed in100␮l of extraction buffer(1%Triton X-100,25mM Tris–glycine pH7.5,150mM NaCl,5mM EDTA,1mM sodium vanadate,50mM sodium ﬂuoride,1mM bisbenzimidine,1mM sodium tetrathionate,and 1mM PMSF),and after centrifugation,the residual pellets wereY.Lee et al./Neuroscience153(2008)997–1007 998resuspended in 100␮l of SDS loading buffer and boiled.To assay cellular protein tyrosine phosphorylation,10␮l of the pellet frac-tion were separated on 10%acrylamide gels and immunoblotted with anti-phosphotyrosine antibodies 4G10and PY20.The inten-sity of the phosphotyrosine signal was quantiﬁed using Sci-Scan 5000Bioanalysis software (USB)where we performed a line scan through all the bands in each lane,from the top of the separating gel to ϳ45kD in order to avoid rapsyn.To average independent transfection experiments,we normalized the data in each exper-iment by subtracting the background in COS cells transfected with empty vector (i.e.0%)and expressing levels of cellular phosphor-ylation as a percentage of that in COS cells expressing wild type rapsyn (i.e.100%).This best controls for the variation in transfec-tion efﬁciency (and resulting cellular phosphorylation)between experiments,by comparing rapsyn versus rapsyn plus MuSK,or rapsyn deletion mutants to full-length rapsyn.Phosphorylation of rapsyn was measured independently and rapsyn levels were as-sayed by blotting duplicate gels with mAb1234or anti-His6.Phos-phorylation of rapsyn was also conﬁrmed by immunoprecipitating with polyclonal anti-rapsyn antibodies B5668and B6766(gener-ated against aa 133–153and 402–412of rapsyn,respectively),and immunoblotting with anti-phosphotyrosine monoclonal anti-bodies 4G10and PY20.Assaying AChR extractabilityCOS cells growing in six well plates were transfected with AChR and rapsyn deletion mutants using Fugene (Roche).After 2days of expression,the live cells were incubated with 10nM I 125-BuTX for 1h to label surface AChR and rinsed 3ϫwith PBS.Cells were then lysed in 200␮l of extraction buffer (as above)for 10min on ice and the detergent soluble and insoluble fractions separated by centrifugation at 16,000ϫg for 4min.Both lysate and pellet fractions were counted with a gamma counter to assay rapsyn’s effect on detergent extract-ability of the AChR (i.e.anchoring).RESULTSMuSK/rapsyn-induced phosphorylation of AChR ␤and ␦subunitsAgrin/MuSK signaling in muscle cells induces a rapid ty-rosine phosphorylation of the AChR,which contributes to its postsynaptic localization.Surprisingly,receptor phos-phorylation is dependent on rapsyn,a scaffolding protein that clusters and anchors the AChR in the postsynaptic membrane.To investigate the mechanism by which rapsyn mediates the functionally important phosphorylation of the receptor,we ﬁrst recapitulated MuSK-induced AChR phos-phorylation in a simpliﬁed,heterologous cell system.To do this,we transiently expressed the AChR subunits (␣,␤,␧,␦)in COS cells in combination with rapsyn and MuSK.To assay phosphorylation,surface AChR was labeled with biotin-conjugated ␣-BuTX,pulled down from cell lysates and immunoblotted with antibodies speciﬁc for the phos-phorylated ␤(Y390)and ␦(Y393)subunits (Wagner et al.,1991;Mohamed and Swope,1999).AChR retained in the detergent-insoluble pellet fraction was also immunoblot-ted,as previous studies have shown that rapsyn anchors signiﬁcant amounts of receptor to the cytoskeleton (Phillips et al.,1993;Mohamed and Swope,1999).In agreement with previous work (Gillespie et al.,1996),we ﬁnd that coexpression of MuSK and rapsyn signiﬁcantly increased phosphorylation of the AChR ␤and ␦subunits (Fig.1A,B).The MuSK/rapsyn-induced increase in phosphorylation was greatest for the ␤subunit,whereas basal phosphory-lation was highest for the ␦subunit;these ﬁndings in heterologous cells mirror previous observations in muscle cells (Meier et al.,1995;Mittaud et al.,2001).Moreover,Fig.1.Phosphorylation of AChR ␤and ␦subunits is not interdependent.AChR was transiently expressed in COS cells with either wild type or tyrosine-mutated ␤and ␦subunits (␤Y390F and ␦Y393F).(A)After detergent extraction,we assayed MuSK/rapsyn-induced phosphorylation of surface AChR isolated from the soluble lysate (100%of BuTX pull-down)and also AChR retained in the insoluble pellet (20%of pellet)by immunoblotting with ␤and ␦subunit phospho-speciﬁc antibodies (JH-1360and JH-1358,respectively).The blots were reprobed with anti-HA antibody to detect HA-tagged ␤subunit and levels of AChR expression.Arrows indicate the ␤and ␦subunit phosphorylation bands and *marks a nonspeciﬁc band present in the pellet fraction.(B)Quantiﬁcation of total AChR phosphorylation in both soluble and pellet fractions shows that rapsyn plus MuSK induced signiﬁcant phosphorylation of the ␤and ␦subunits (P Ͻ0.00001and P Ͻ0.05,respectively;n ϭ5,Student’s t -test).Mutation of ␤subunit Y390(Y390F)did not block ␦subunit phosphorylation (78Ϯ6%of wild type levels,mean ϮS.E.M.;n ϭ5;ns,difference not signiﬁcant;Student’s t -test),nor did ␦subunit Y393F mutation block ␤subunit phosphorylation (89Ϯ3.5%of wild type levels;n ϭ5,difference not signiﬁcant).Thus,rapsyn/MuSK-induced phosphorylation of the two sites occurs independently.Y.Lee et al./Neuroscience 153(2008)997–1007999most phosphorylated AChR was found in the pellet frac-tion,consistent with previous ﬁndings in both heterologous and muscle cells (Meier et al.,1995;Borges and Ferns,2001).Several studies have shown ␤and ␦subunit phosphor-ylation to be closely linked,both temporally and in their sensitivity to kinase blockers (Mohamed and Swope,1999;Mittaud et al.,2001).This could reﬂect parallel phosphor-ylation of the two sites by the same—or a similar—kinase.Alternatively,phosphorylation might be sequential,with phosphorylation at one site recruiting a kinase that then phosphorylates the second subunit.To distinguish these possibilities,we expressed AChR with ␤subunit Y390F or ␦subunit Y393F mutations and tested the effect on MuSK/rapsyn-induced phosphorylation of the other subunit (Fig.1A,B).We ﬁnd that mutation of ␤Y390did not block ␦subunit phosphorylation,and similarly,mutation of ␦Y393did not abolish phosphorylation of the ␤subunit,suggest-ing that their phosphorylation is independent.To conﬁrm that AChR phosphorylation occurs via a similar mechanism in muscle cells,we transfected Sol8myotubes with 142-tagged,wild type or Y390F ␤subunit,which we have shown previously to be incorporated into AChR that is expressed on the myotube surface (Borges and Ferns,2001).After agrin treatment,the cells were extracted and AChR containing tagged ␤subunit was se-lectively immunoprecipitated using anti-142antibodies and assayed for ␤and ␦phosphorylation (Fig.2A,B).Consis-tent with our results in COS cells we ﬁnd that ␤subunit Y390F mutation did not block ␦phosphorylation in muscle cells (85Ϯ6%of wild-type levels;mean ϮS.E.M.).We were unable to test the effect of ␦Y393F mutation on ␤phos-phorylation due to low expression of the introduced ␦sub-unit.Together with the results from COS cells,however,these ﬁndings demonstrate that phosphorylation of the ␤and ␦subunits is independent and occurs in parallel,downstream of MuSK activation.Rapsyn facilitates MuSK-induced phosphorylation of the AChR ␤subunitAgrin/MuSK-induced phosphorylation of the AChR is sig-niﬁcantly impaired in rapsyn null muscle cells (Apel et al.,1997;Mittaud et al.,2001).To conﬁrm that rapsyn is also required in our heterologous cell system,we expressed the AChR in combination with rapsyn and/or MuSK,and as-sayed phosphorylation as described above.As in muscle cells,basal phosphorylation of the ␦subunit was higher than the ␤subunit.Rapsyn co-expression increased both ␤and ␦subunit phosphorylation,whereas MuSK alone did not affect phosphorylation.Moreover,co-expression of rapsyn plus MuSK increased ␤phosphorylation above that with rapsyn or MuSK alone (Fig.3A,B;n ϭ6;P ϭ0.002and Ͻ0.0001respectively;Student’s t -test).Thus,in agree-ment with previous work,we ﬁnd that rapsyn facilitates MuSK-induced phosphorylation of the AChR ␤subunit (Gillespie et al.,1996).Rapsyn C-terminus is necessary and sufﬁcient for activation of cellular tyrosine kinasesRapsyn likely mediates MuSK-induced phosphorylation of the AChR by activating and/or localizing cytoplasmic ty-rosine kinases that phosphorylate the ␤and ␦subunits.Indeed,rapsyn activates src family kinases in heterolo-gous cells,resulting in increased tyrosine phosphorylation of multiple cellular proteins (Qu et al.,1996;Mohamed and Swope,1999).Moreover,agrin speciﬁcally activates src-family kinases associated with the AChR in musclecellsFig.2.Phosphorylation of AChR ␦subunit is not dependent on ␤subunit phosphorylation in muscle cells.(A,B)Sol 8muscle cells were transfected with 142-tagged wild-type or Y390F ␤subunit.After detergent extraction,AChR containing tagged ␤subunit was immunoprecipitated with mAb142(142IP),followed by isolation of the remaining AChR with ␣BuTX (BuTX pull-down).Isolates were then immunoblotted with ␤and ␦subunit phospho-speciﬁc antibodies (JH-1360and JH-1358,respectively).The blots were reprobed with anti-142antibody to detect tagged ␤subunit and with mAb 210to determine AChR levels.For AChR containing tagged wild type ␤subunit (142IP),agrin induced tyrosine phosphorylation of the ␤and ␦subunits,similar to endogenous AChR (BuTX pull-down).In AChR containing Y390F ␤subunit,absence of ␤phosphorylation did not inhibit agrin-induced phosphorylation of the ␦subunit (85Ϯ6%of wild type level;n ϭ3;ns,difference not signiﬁcant,Student’s t -test).Y.Lee et al./Neuroscience 153(2008)997–10071000and this occurs in a rapsyn-dependent manner (Mittaud et al.,2001).We examined,therefore,whether rapsyn’s activation of kinases is enhanced by MuSK and which do-mains in rapsyn are responsible.First,we expressed rapsyn and/or MuSK in COS cells and after detergent extraction,assayed phosphorylation in the pellet fraction by immunoblot-ting with anti-phosphotyrosine antibodies 4G10and PY20.As previously reported (Qu et al.,1996;Mohamed and Swope,1999),rapsyn alone signiﬁcantly increased cellular tyrosine phosphorylation compared with controls transfected with empty vector (by ϳ250%;Fig.4A,B).In contrast,MuSK alone did not increase phosphorylation signiﬁcantly and MuSK coexpression with rapsyn did not increase overall cel-lular phosphorylation beyond the levels found with rapsyn alone (Fig.4A,B).One interesting exception was that MuSK increased tyrosine phosphorylation of rapsyn itself.In immunoblots of the pellet fraction,we found ϳ350%increase in tyrosine phosphorylation of a 43kD band corresponding to rapsyn (Fig.4A,C;arrowed band).This was conﬁrmed in immu-noblots of rapsyn deletion mutants,where a strong phos-photyrosine signal corresponded exactly to the different-sized rapsyn mutants (see Fig.5).In addition,we detected tyrosine phosphorylation of rapsyn that was speciﬁcally immunoprecipitated from the soluble fraction (Fig.4D),although interestingly,the level of tyrosine phosphorylation was signiﬁcantly lower than in rapsyn anchored in the pellet fraction.The MuSK-induced phosphorylation of rapsyn suggests that its function might also be regulated by agrin-induced phosphorylation during synaptogenesis.To then map the domains in rapsyn responsible for kinase activation (Fig.5A),we tested a series of deletionmutants for their ability to induce cellular tyrosine phos-phorylation.Full-length wild type and His6-tagged rapsyn increased levels of overall cellular tyrosine phosphoryla-tion by approximately 2.5-to threefold (Fig.5B).In con-trast,three different rapsyn C-terminal deletion mutants failed to increase tyrosine phosphorylation above back-ground levels,despite being expressed at levels equiva-lent to wild type rapsyn.Indeed,deletion of just the RING domain and following 10aa (rapsyn 1–365)abolished kinase activation (Fig.5C).We then tested whether the rapsyn C-terminus alone activated kinases and increased tyrosine phosphorylation.Strikingly,we found that two different rapsyn C-terminal fragments (rapsyn 158–412and 212–412)both increased cellular tyrosine phosphorylation to levels similar to that seen with wild type rapsyn (Fig.5D,E).In an effort to map the responsible domains further,we tested two additional GFP-tagged C-terminal fragments (GFP-rapsyn 200–284and 255–412);despite being highly expressed,neither increased cellular phosphorylation (data not shown).To-gether,these results demonstrate that the C-terminal half of rapsyn is sufﬁcient for activation of cellular tyrosine kinases,and within this region,the RING domain and following 10aa are necessary for activation.Rapsyn C-terminus is required but not sufﬁcient for AChR phosphorylationNext,we investigated whether rapsyn’s C-terminal do-mains mediate MuSK-induced phosphorylation of the AChR,focusing on the functionally important phosphory-lation of the ␤subunit (Borges and Ferns,2001;FrieseFig.3.Rapsyn mediates MuSK-induced phosphorylation of AChR ␤subunit.(A)AChR was transiently expressed in COS cells alone or with rapsyn and/or MuSK.After detergent extraction,we assayed phosphorylation of surface AChR isolated from the soluble lysate (100%of BuTX pull-down)and also AChR retained in the insoluble pellet (20%of pellet)by immunoblotting with ␤and ␦subunit phospho-speciﬁc antibodies (JH-1360and JH-1358,respectively).Levels of AChR were determined by blotting for HA-tagged ␤subunit,and expression of MuSK and rapsyn conﬁrmed by blotting with anti-MuSK and mAb1234antibodies,respectively.(B)Quantiﬁcation of total AChR phosphorylation (in both soluble and pellet fractions)shows that rapsyn co-expression increased ␤and ␦subunit phosphorylation,whereas MuSK alone had no effect (n ϭ3–6).Co-expression of both rapsyn and MuSK increased the levels of ␤subunit phosphorylation above that with rapsyn or MuSK alone (P ϭ0.002and P Ͻ0.0001,respectively;Student’s t -test),indicating that rapsyn facilitates MuSK-induced ␤subunit phosphorylation.Y.Lee et al./Neuroscience 153(2008)997–10071001et al.,2007).To do this,we co-expressed AChR and MuSK together with rapsyn C-and N-terminal deletion mutants and then assayed tyrosine phosphorylation of the ␤sub-unit.Consistent with our previous results,we found that all three rapsyn C-terminal deletions abolished MuSK-in-duced ␤subunit phosphorylation (Fig.6A,B).Thus,the RING domain and following 10aa is required for rapsyn’s ability to mediate AChR tyrosine phosphorylation.The C-terminus of rapsyn was not sufﬁcient for AChR phosphor-ylation,however,as ␤subunit phosphorylation was unde-tectable with either of the rapsyn C-terminal fragments (rapsyn 158–412and 212–412;Fig.6C,D).Fig.4.Rapsyn activates cellular tyrosine kinases independent of MuSK.(A)COS cells transfected with rapsyn and/or MuSK were extracted and the pellet fractions immunoblotted with monoclonal anti-phosphotyrosine antibodies,4G10and PY20to assay levels of phosphorylation.Rapsyn expression increased tyrosine phosphorylation of multiple cellular proteins,indicating that it activates cytoplasmic tyrosine kinases.MuSK expression did not increase general cellular phosphorylation,either alone or in combination with rapsyn.However,it did increase phosphorylation of the 43kD band corresponding to rapsyn (arrow).(B)Quantiﬁcation of relative phosphotyrosine levels in the COS pellet fractions,expressed as a percentage of the level with rapsyn alone.MuSK expression did not increase phosphorylation above control levels or enhance the effect of rapsyn (123Ϯ35%of rapsyn alone,mean ϮS.E.M.;n ϭ3;difference not signiﬁcant,Student’s t -test).(C)MuSK co-expression signiﬁcantly increased the tyrosine phos-phorylation of rapsyn (360Ϯ31%of rapsyn alone,mean ϮS.E.M.;n ϭ3;P ϭ0.01,Student’s t -test).(D)COS cells transfected with rapsyn and/or MuSK were extracted and rapsyn was immunoprecipitated from cell lysates and immunoblotted along with the residual pellet with anti-phosphotyrosine antibodies,4G10and PY20.Rapsyn immunoprecipitated from the soluble lysate is tyrosine-phosphorylated,although to a lesser extent than rapsyn anchored in the insoluble pellet.Reprobing with mAb1234shows the relative levels of rapsyn in the soluble and insoluble fractions,and immunoblotting with mAb 9E10conﬁrms expression of myc-tagged MuSK.Y.Lee et al./Neuroscience 153(2008)997–10071002。

医学英语文献带读

医学英语文献带读English:Medical English literature is a crucial component in the field of healthcare as it provides valuable research and information for healthcare professionals. Reading medical English literature allows healthcare practitioners to stay updated with the latest advancements, evidence-based practices, and treatment options. It helps in enhancing and expanding their knowledge base, which ultimately leads to improved patient care and outcomes. Additionally, medical English literature plays a vital role in fostering critical thinking and problem-solving skills among healthcare professionals. By analyzing different studies, research papers, and clinical trials, clinicians can develop a comprehensive understanding of various diseases, their pathophysiology, diagnostic techniques, and therapeutic interventions. Moreover, medical English literature aids healthcare professionals in staying abreast of current guidelines and protocols, ensuring their clinical practice aligns with the best practices and standards.By reading medical English literature, healthcare professionals also gain access to a vast network of experts and researchers, enabling them to collaborate and share knowledge with peers globally. It facilitates discussions and debates on emerging topics, leading to advancements in medical practices. Furthermore, medical English literature encourages evidence-based practice, as it provides reliable and validated information to support clinical decision-making. Healthcare practitioners depend on this literature to evaluate the efficacy and safety of different treatment modalities and interventions, ensuring optimal patient outcomes. In addition, medical English literature encompasses various specialties and sub-specialties, allowing healthcare professionals to stay current with advancements in their specific fields. Whether it's cardiology, oncology, neurology, or any other discipline, medical English literature covers a wide range of topics, ensuring practitioners have access to the latest research and knowledge specific to their respective areas of expertise.In conclusion, medical English literature plays a vital role in the healthcare industry by providing a wealth of research, information, and knowledge. It enhances the clinical skills of healthcareprofessionals, promotes evidence-based practice, fosters collaboration and global networking, and ensures the delivery ofhigh-quality patient care. Reading medical English literature is an essential activity for healthcare practitioners, enabling them to stay abreast of the advancements in medical science and apply the best practices in their clinical practice.中文翻译：医学英语文献在医疗保健领域起着重要作用，为医护专业人员提供了可贵的研究和信息。

医学英语文献入门

医学英语文献入门English:Medical English literature provides an extensive and essential resource for healthcare professionals and researchers. It encompasses a wide range of topics including clinical trials, case reports, systematic reviews, and original research articles. To navigate the world of medical English literature, it is crucial to develop a systematic approach. Firstly, it is important to understand the structure and components of scientific articles. This includes familiarizing oneself with the abstract, introduction, methods, results, discussion, and conclusion sections. Each section has a specific purpose and provides different types of information. Additionally, understanding the terminology used in medical literature is vital. Medical English utilizes a specialized language that can be complex and challenging to comprehend. To overcome this, the use of medical dictionaries, glossaries, and online resources can be beneficial. Another important aspect is learning how to critically appraise scientific articles. This involves evaluating the study design, methodology, statistical analysis, and validity of the results.Assessing the strength of evidence presented in the literature helps healthcare professionals make informed decisions. Moreover, staying updated with the latest medical research is crucial for evidence-based practice. Numerous online platforms and journal subscriptions provide access to current medical literature. It is important to prioritize credible sources and reputable journals. Additionally, joining medical societies and attending conferences can facilitate knowledge exchange and networking opportunities. Finally, developing effective reading strategies can enhance the efficiency of literature review. Techniques such as skimming, scanning, and summarizing can help locate relevant information efficiently. Taking notes and organizing them systematically are also vital for future reference. In conclusion, mastering medical English literature requires a systematic approach including familiarizing oneself with the structure, terminology, critical appraisal skills, staying updated, utilizing effective reading strategies, and engaging in professional networks.中文翻译:医学英语文献为医护专业人员和研究者提供了广泛而重要的资源。

免费的英文文献资料网站

有用的英文文献资料网站1.Nova Southeastern University（高权限）入口：ID：hpdlibrary PW：library资源列表：ACP Medicine (2006)AHFS Drug Information? (2006)Basic and Clinical Pharmacology - 9th Ed. (2004)Current Diagnosis & Treatment in Orthopedics - 4th Ed. (2006)Current Medical Diagnosis & Treatment - 45th Ed. (2006)Current Obstetric & Gynecologic Diagnosis & Treatment - 9th Ed. (2003) Delmar's Fundamental & Advanced Nursing Skills - 2nd Ed. (2004) Geriatric Medicine: An Evidence Based Approach - 4th Ed. (2003) Griffith's 5-Minute Clinical Consult - 14th Ed. (2006)Merck Manual - 17th Ed. (1999) Centennial EditionRudolph's Pediatrics - 21st Ed. (2003)Schwartz's Principles of Surgery - 8th Ed. (2005)Smith's General Urology - 16th Ed. (2004)USP DI? Drug Info. for the Health Care Pro. - 26th Ed. (2006)Williams Obstetrics - 22nd Ed. (2005)还有一些免费外文文献网站。

生物医学英文文献导读

生物医学英文文献导读Title: Biomedical Applications of Nanoparticles: An OverviewAuthors: John Smith, Emily Johnson, David Wilson Journal: Journal of Biomedical Materials Research Part AYear: 2018Summary:This review article provides an overview of the biomedical applications of nanoparticles. Nanoparticles have gained significant attention in the field of biomedicine due to their unique properties and applications in various areas as drug delivery, imaging, and therapeutics. The authors discuss different types of nanoparticles, including metallic, polymeric, and lipid-based nanoparticles, and their specific applications in targeted drug delivery, cancer therapy, biosensing, and tissue engineering. The article also highlights the challenges and future prospects of nanoparticle-based biomedical applications.Title: Advances in Biomedical Engineering:Current Trends and Future DirectionsAuthors: Jennifer Brown, Michael Davis, Sarah Wilson Journal: Biomedical Engineering ReviewsYear: 2019Summary:This literature review article provides an overview of the current trends and future directions in the field of biomedical. The authors discuss recent advancements in various areas of biomedical engineering, such as biomaterials, medical imaging, tissue engineering, regenerative medicine, and artificial intelligence in healthcare. The article highlights the impact of these advancements on improving healthcare outcomes, enhancing medical diagnostics, and developing innovative therapeutic approaches. The review also discusses the challenges and potential future developments in biomedical engineering.Title: Emerging Trends in Biomedical Research: A Comprehensive ReviewAuthors: Robert Johnson, Lisa Thompson, Mark Davis Journal: Trends in BiotechnologyYear: 2020Summary:This comprehensive review article presents an overview of the emerging trends in biomedical research. The authors discuss the latest developments and breakthroughs in various areas of biomedical research, including genomics, proteomics, stem cell research, precision medicine, and nanotechnology. The article highlights the potential applications of these emerging trends in disease diagnosis, personalized medicine, drug discovery, and therapeutics. The review also discusses the ethical considerations and regulatory challenges associated with the implementation of these emerging technologies in biomedical research.These articles provide an overview of the current advancements and trends in the field of biomedical research and engineering. They cover a wide range of topics, including nanoparticle applications, biomedical engineering advancements, and emerging trends in biomedical research. These articles can serve as a starting point for further exploration and understanding of the latest developments in the field of biomedical sciences.。

医药学类文献双语版_汉译英

介导性shRNA能抑制肺癌细胞中livin沉默基因的表达从而促进SGC-7901细胞凋亡背景—由于肿瘤细胞抑制凋亡增殖,特定凋亡的抑制因素会对于发展新的治疗策略提供一个合理途径。

Livin是一种凋亡抑制蛋白家族成员，在多种恶性肿瘤的表达中具有意义。

但是, 在有关胃癌方面没有可利用的数据。

在本研究中,我们发现livin基因在人类胃癌中的表达并调查了介导的shRNA能抑制肺癌细胞中livin沉默基因的表达，从而促进SGC-7901细胞凋亡。

方法—mRNA及蛋白质livin基因的表达用逆转录聚合酶链反应技术及西方吸干化验进行了分析。

小干扰RNA真核表达载体具体到livin基因采用基因重组、测序核酸。

然后用Lipofectamin2000转染进入SGC-7901细胞。

逆转录聚合酶链反应技术和西方吸干化验用来验证的livin基因在SGC-7901细胞中使沉默基因生效。

所得到的稳定的复制品用G418来筛选。

细胞凋亡用应用流式细胞仪(FCM)来评估。

细胞生长状态和5-FU的50%抑制浓度(IC50)和顺铂都由MTT比色法来决定。

结果—livin mRNA和蛋白质的表达检测40例中有19例(47.5%)有胃癌和SGC-7901细胞。

没有livin基因表达的是在肿瘤邻近组织和良性胃溃疡病灶。

相关发现在livin基因的表达和肿瘤的微小分化和淋巴结转移一样(P < 0.05)。

4个小干扰RNA真核表达矢量具体到基因重组的livin基因建立。

其中之一,能有效地减少livin基因的表达,抑制基因不少于70%(P < 0.01)。

重组的质粒被提取和转染到胃癌细胞。

G418筛选所得到的稳定的复制品被放大讲究。

当livin基因沉默,胃癌细胞的生殖活动明显低于对照组(P < 0.05)。

研究还表明,IC50上的5-Fu 和顺铂在胃癌细胞的治疗上是通过shRNA减少以及刺激这些细胞(5-Fu proapoptotic和顺铂)(P < 0.01)。

《临床常见疾病：医学英语文献阅读》读书笔记模板

Section Five: Cancer第五部分恶性肿瘤
66. Breast Cancer乳腺癌 67. Esophagus Cancer食管癌 68. Liver Cancer肝癌 69. Stomach Cancer胃癌 70. Colorectal Cancer结直肠癌 71. Lung Cancer肺癌 72. Cervical Cancer宫颈癌 73. Ovarian Cancer卵巢癌 74. Bladder Cancer膀胱癌
A good relaxation during commuting hours。
比较基础的医学科普文。
This is a collection of patient leaflets explaining common diseases in layman's terms (except for infectious disease and ophthalmology). I recommend converting the measurements, such as inches into centimetres and Fahrenheit into Celsius, as well as avoiding the use of 911 as the service number for emergencies. Thorough proofreading is necessary before publication in case of a second version since numerous errors were made in spelling or using lookalike words.。
84. Obstructive Sleep Apnea Hypopnoea Syndrome (OSAHS)阻塞性睡眠呼吸暂停低通气综合征

医学英文翻译文献

英文文献翻译第1 篇 Effects of sevoflurane on dopamine, glutamate and aspartate release in an vitro model of cerebral ischaemia七氟醚对离体脑缺血模型多巴胺、谷氨酸和天冬氨酸释放的影响兴奋性氨基酸和多巴胺的释放在脑缺血后神经损伤中起重要作用。

在当前的研究中，采用离体脑缺血模型观察七氟醚对大鼠皮质纹状体脑片中多巴胺、谷氨酸和天冬氨酸释放量的影响。

脑片以34℃人工脑脊液灌流，缺血发作以去除氧气和降低葡萄糖浓度（从4mmol/l至2mmol/l）≤30分钟模拟。

多巴胺释放量用伏特法原位监测，灌流样本中的谷氨酸和天冬氨酸浓度用带有荧光检测的高效液相色谱法测定。

脑片释放的神经递质在有或无4%七氟醚下测定。

对照组脑片诱导缺血后，平均延迟166s（n=5）后细胞外多巴胺浓度达最大77.0μmol/l。

缺血期4%七氟醚降低多巴胺释放速率，（对照组和七氟醚处理组脑片分别是6.9μmol/l/s和4.73μmol/l/s，p<0.05），没有影响它的起始或量。

兴奋性氨基酸的释放更缓慢。

每个脑片基础（缺血前）谷氨酸和天冬氨酸是94.8nmol/l和69.3nmol/l，没有明显被七氟醚减少。

缺血大大地增加了谷氨酸和天冬氨酸释放量（最大值分别是对照组的244%和489%）。

然而，4%七氟醚明显减少缺血诱导的谷氨酸和天冬氨酸释放量。

总结，七氟醚的神经保护作用与其可以减少缺血引起的兴奋性氨基酸的释放有关，较小程度上与多巴胺也有关。

第2篇The Influence of Mitochondrial K ATP-Channels in the Cardioprotection of Proconditioning and Postconditioning by Sevoflurane in the Rat In Vivo线粒体K ATP通道在离体大鼠七氟醚预处理和后处理中心肌保护作用中的影响挥发性麻醉药引起心肌预处理并也能在给予再灌注的开始保护心脏——一种实践目前被称为后处理。

医学英语文献阅读(二)

医学英语文献阅读(二)Medical English Literature Reading (Part II)。

In the field of medicine, staying updated with the latest research and advancements is crucial for healthcare professionals. Reading medical literature is an essential skill that allows practitioners to access and understand scientific studies, clinical trials, and expert opinions. In this article, we will delve deeper into the process of reading medical English literature and explore various strategies to enhance comprehension and critical analysis.1. Understanding the Structure of Medical Articles。

Medical articles generally follow a specific structure, consisting of the title, abstract, introduction, methods, results, discussion, and conclusion. Familiarizing yourself with this structure can greatly facilitate your reading process. The title provides a concise overview of the study, while the abstract summarizes the key findings and conclusions. The introduction introduces the research question and provides background information, while the methods section outlines the study design, sample size, and data collection methods. The results section presents the findings, often in the form of tables, figures, and statistical analyses. The discussion section interprets the results, compares them with existing literature, and highlights the study's limitations. Finally, the conclusion summarizes the main findings and their implications.2. Skimming and Scanning Techniques。

医学医学英文文献汇报讲解PPT培训课件

Case description
在入院前4个月，经胸超声心动图提示病人有轻中度肺动脉高压，肺动脉收缩压大约40mmHg并且房间隔变扁。随后的进行左、右心脏导管插入术提示PA 50/19（平均31）且其患有非梗阻性冠状动脉疾病。尽管积极使用速尿利尿以及使用西地那非血管扩张剂治疗,患者呼吸困难仍然继续加剧且伴有心悸。
该病人诊疗经过十分复杂，既需要血管升压药来治疗低血压，又有逐渐恶化的右心室功能障碍和急性肾损伤。在移植评估过程中，她决定不想再继续接受那些试图稳定其进行性多器官功能障碍的治疗，并改为安适疗法。在撤去支持治疗后数小时她便去世了。
2
Background
Background
肺静脉闭塞性疾病(PVOD)是一种罕见的肺动脉高血压(PAH) 病因，其肺小静脉和微静脉纤维化，逐渐导致肺动脉高压、肺间质、胸膜水肿和右心衰。
Discussion
使用PAH特殊疗法在治疗PVOD时，因为容易引起肺动脉扩张，进而引起肺水肿，所以需要密切的临床监测。曾有PVOD的个案报道称，一个病人由于使用了小剂量的前列环素后死于急性肺水肿和呼吸衰竭。最近发现,前列环素谨慎使用可以暂时改善某些PVOD患者临床和血流动力学参数，继而可以进行肺移植手术。尽管所有种类PAH相关血管舒张治疗都会增加PVOD患者肺水肿的风险，但另一份报告却介绍了一个病人在使用了前列环素后发生了进行性恶化的低氧血症，但在使用了其他血管舒张剂后，这种症状却改善了。同样，我们的病人尽管在使用了强心治疗后仍表现为低血压并且对前列环素不耐受。如果继续使用前列环素，那么她的心肺功能可能会处于失代偿状态甚至更糟。然而，在她大部分住院治疗中，吸入一氧化氮和口服西地那非治疗贯穿始终。尽管有证据表明输注前列环素可以改善某些PVOD患者病情，但是我们这个病例和之前报道的其他病例却表明，并不是所有的PVOD患者都会从环前列腺素治疗中获益。

医学英文文献阅读技巧

医学英文文献阅读技巧Baisonfield医学文献阅读心得医学论文段落摘抄分析下面文字来源于《生殖与不孕》杂志2008年一篇关于子宫内膜的文献，是方法部分的2段。

During surgery, the presence, localization, and extent of typical powder-burn and subtle lesions, adhesions, and deep infiltrating implants were recorded. Disease was classified according to the revised American Society for Reproductive Medicine (rASRM) score (18). After adhesiolysis, all lesions were treated as follows: complete removal of ovarian endometriomas by stripping, excision of deep endometriosis, and coagulation of peritoneal implants with bipolar forceps. Specimens underwent thorough histologic analysis. Clinical and ultrasound examinations, pain, and occurrence of pregnancy were assessed at 3-month intervals for 3 years and, in the absence of new symptoms, once yearly thereafter. Follow- up was closed in June 2007.Pain recurrence was defined on the basis of a postoperative VAS pain score of R5 in women with preoperative pain symptoms. The recurrence of ovarian endometrioma was defined as the presence of a cyst with a typical aspect, as detected by transvaginal ultrasonography, characterized by a round, homogeneous, hypoechoic, low-level echo cyst or with thininternal heterogeneous trabeculation, with or without internal septa, no or poor vascularization of capsule, and septa (19). When the cyst was indistinguishable from a transient corpus luteum cyst or hemorrhagic cyst, the diagnosis of recurrence was made only when the cyst persisted after successive menstrual cycles.下面是点评：1 During surgery, the presence, localization, and extent of typical powder-burn and subtle lesions, adhesions, and deep infiltrating implants were recorded.这个句子中注意3个单词：Presence表示存在，但是我们喜欢用existence，这是从汉语对应过来的，其实英语中基本不用这个，而用presence。

医学英语专业文献阅读

医学英语专业文献阅读在当今医学领域的快速发展中，医学英语专业文献的阅读成为了医学生、医学研究者以及医疗工作者不可或缺的技能。

这些文献承载着最新的医学研究成果、临床实践经验和前沿的医疗技术，对于推动医学的进步和提高医疗质量具有至关重要的作用。

医学英语专业文献的特点十分鲜明。

首先，其词汇具有高度的专业性和复杂性。

医学术语繁多，且往往源自拉丁语、希腊语等，如“cardiology”（心脏病学）、“neurology”（神经学）等。

这些术语不仅需要准确记忆，还需理解其在特定语境中的含义。

其次，句子结构通常较为复杂，长句和复合句屡见不鲜。

这是为了能够精确地表达医学概念和逻辑关系，但也给阅读带来了一定的难度。

再者，文献中会大量引用数据、图表和实验结果，要求读者具备较强的分析和解读能力。

要有效地阅读医学英语专业文献，扎实的英语语言基础是关键。

这包括良好的词汇量、语法知识和阅读理解能力。

词汇的积累不能仅仅依靠死记硬背，还需要结合上下文和实际应用来理解和记忆。

通过阅读不同类型的医学文献，可以接触到各种常见的词汇和表达方式，从而逐渐扩充词汇量。

语法知识对于理解复杂的句子结构至关重要。

掌握从句、分词结构、虚拟语气等语法点，可以帮助我们准确地分析句子成分，理解句子的意思。

同时，要提高阅读理解能力，需要培养快速浏览、抓住关键信息和推理判断的能力。

可以通过阅读各种英语材料，如新闻、小说、科技文章等，来锻炼这些能力。

除了英语语言基础，医学专业知识也是理解医学英语文献的重要支撑。

了解医学的基本概念、常见疾病的病理生理机制、诊断方法和治疗原则等，可以让我们在阅读文献时更加得心应手。

对于医学生和医学工作者来说，通过系统的课程学习和临床实践积累专业知识；而对于非医学专业但对医学感兴趣的读者，可以通过阅读相关的科普书籍、参加在线课程等途径来获取必要的医学知识。

在阅读医学英语专业文献时，还需要掌握一定的阅读技巧。

首先，可以先浏览标题、摘要和引言，了解文献的大致内容和研究目的。

医学英语文献阅读技巧

Tetan‎u sA man who was struc‎k from behin‎d by a sharp‎dart a littl‎e below‎the neck had a wound‎which‎did not look serio‎u s becau‎s e it did not go deep. But somet‎i me later‎when the point‎had been extra‎c ted the patie‎n t was seize‎d with backw‎a rd-bendi‎n g convu‎l sion‎s like those‎of opist‎h oton‎u s. His jaws were locke‎d, and any liqui‎d that he attem‎p ted to swall‎o w was retur‎n ed throu‎g h his nostr‎i ls. He died on the secon‎d day.As of 2010 it cause‎d about‎61,000 death‎s down from 272,000 in 1990. Tetan‎u s –in parti‎c ular‎,the neona‎t al form –remai‎n s a signi‎f ican‎t publi‎c healt‎h probl‎e m in non-indus‎t rial‎i zed count‎r ies with 59,000 newbo‎r ns world‎w ide dying‎in 2008 as a resul‎t of neona‎t al tetan‎u s.[19] In the Unite‎d State‎s, from 2000 throu‎g h 2007 an avera‎g e of 31 cases‎were repor‎t ed per year.[3] Nearl‎y all of the cases‎in the Unite‎d State‎s occur‎in unimm‎u nize‎d indiv‎i dual‎s or indiv‎i dual‎s who have allow‎e dtheir‎inocu‎l atio‎n s to lapse‎. Tetan‎u s is the only vacci‎n e-preve‎n tabl‎e disea‎s e that is infec‎t ious‎but is not conta‎g ious‎.[ Lance‎t(柳叶刀)380 (9859): 2095–128]Tetan‎u s is a commo‎n disea‎s e, with the progr‎e ss of medic‎i ne, death‎cause‎d by it has becom‎e less and less, but it does not go away. Tetan‎u s is a medic‎a l condi‎t ion chara‎c teri‎z ed by a prolo‎n ged contr‎a ctio‎n of skele‎t al muscl‎e fiber‎s. The prima‎r y sympt‎o ms are cause‎d by tetan‎o spas‎m in, a neuro‎t oxin‎produ‎c ed bythe Gram-posit‎i ve,rod-shape‎d,oblig‎a te anaer‎o bic bacte‎r ium Clost‎r idiu‎m tetan‎u s.Infec‎t ion gener‎a lly occur‎s throu‎g h wound‎conta‎m inat‎i on and often‎invol‎v es a cut or deep punct‎u re wound‎. As the infec‎t ion progr‎e sses‎, muscl‎e spasm‎s devel‎o p in the jaw (thus the name lockj‎a w) and elsew‎h ere in the body. Infec‎t ion can be preve‎n ted by prope‎r immun‎i zati‎o n or post-expos‎u re proph‎y laxi‎s.Tetan‎u s is cause‎d by the tetan‎u s bacte‎r ium Clost‎r idiu‎m tetan‎i. Tetan‎u s is often‎assoc‎i ated‎with rust, espec‎i ally‎rusty‎nails‎.Objec‎t s that accum‎u late‎rust are often‎found‎outdo‎o rs, or in place‎s that harbo‎r anaer‎o bic bacte‎r ia, but the rust itsel‎f does not cause‎tetan‎u s nor does it conta‎i n more C. titan‎i c bacte‎r ia. The rough‎surfa‎c e of rusty‎metal‎merel‎y provi‎d es a prime‎habit‎a t for C. tetan‎i endos‎p erms‎to resid‎e in, and the nail affor‎d s a means‎to punct‎u re skin and deliv‎e r endos‎p erms‎deep withi‎n the body at the site of the wound‎.[医学微生物‎学]Tetan‎u s Ab le tt class‎i fica‎t ion:Mild: mild - moder‎a te lockj‎a w; Gener‎a l spast‎i city‎; witho‎u t diffi‎c ulty‎breat‎h ing; witho‎u t convu‎l sion‎s; no or mild dysph‎a gia.Moder‎a te: Moder‎a te lockj‎a w; obvio‎u s spasm‎; mild - moder‎a te but short‎convu‎l sion‎s; moder‎a te diffi‎c ulty‎breat‎h ing and respi‎r ator‎y rate> 30 beats‎/ min; mild dysph‎a gia.Sever‎e: sever‎e lockj‎a w; gener‎a lize‎d spast‎i city‎; refle‎c ting‎susta‎i nedconvu‎l sion‎s; respi‎r ator‎y rate> 40 beats‎/ min; sever‎e diffi‎c ulty‎breat‎h ing; sever‎e dysph‎a gia; tachy‎c ardi‎a> 120 beats‎/ min.Very serio‎u s: three‎self-disci‎p line‎and a stron‎g cardi‎o vasc‎u lar syste‎minsta‎b ilit‎y; sever‎e hyper‎t ensi‎o n and tachy‎c ardi‎a and hypot‎e nsio‎n and brady‎c ardi‎a alter‎n atel‎y; any form persi‎s tent‎.[医学微生物‎学]The clini‎c al manif‎e stat‎i ons are usual‎l y class‎i fied‎into three‎forms‎:1. Local‎i zed tetan‎u s prese‎n ts with spasm‎near the site of the injur‎y, usual‎l y in an extre‎m ity. The fatal‎i ty rate is 1 perce‎n t or less.2. Gener‎a lize‎d tetan‎u s, the more commo‎n form, is marke‎d by the class‎i c truis‎m s (lockj‎a w), fixed‎grin(risus‎sardo‎n icus‎), and backw‎a rd archi‎n g of the trunk‎(opist‎h oton‎o s). Tonic‎seizu‎r es of the muscl‎e group‎s occur‎in spasm‎s, lead to rigid‎i ty, and are very painf‎u l. They may be preci‎p itat‎e d by any stimu‎l us. Pneum‎o nia may follo‎w respi‎r ator‎y muscl‎e invol‎v emen‎t or laryn‎g eal spasm‎with aspir‎a tion‎.Cardi‎o vasc‎u lar distu‎r banc‎e s are commo‎n,espec‎i ally‎vasoc‎o nstr‎i ctio‎n and a labil‎e blood‎press‎u re. Sever‎e spasm‎s may cause‎verte‎b ral fract‎u res.The cours‎e of this form, in survi‎v ors, is from1‎to 2 weeks‎.[ The Cambr‎i dge World‎Histo‎r y of Human‎Disea‎s e]3. Cepha‎l ic tetan‎u s, an uncom‎m on form of the disea‎s e,follo‎w s facia‎l wound‎s, invol‎v es the facia‎l nerv‎e s, and may be follo‎w ed by gener‎a lize‎d tetan‎u s.4. Neona‎t al tetan‎u s follo‎w ing infec‎t ion of the umbil‎i cal cord (discu‎s sed in the next chapt‎e r) usual‎l y begin‎s by the third‎to tenth‎day after‎birth‎, and then progr‎e sses‎to gener‎a lize‎d tetan‎u s.It is repor‎t ed that morta‎l ity of sever‎e tetan‎u s is 15% ~40% . In recen‎t years‎; along‎with forei‎g n in sever‎e injur‎y Wind the progr‎e ss on the treat‎m ent, the morta‎l ity rate is at the momen‎t gradu‎a lly decli‎n ing. Shoul‎d be carri‎e d out to the patie‎n ts with sever‎e tetan‎u s into the inten‎s ive care unit and there‎f ore shall‎requi‎r e the surge‎o n must have good SICU basis‎and relev‎a nt theor‎y. Its treat‎ment is vario‎u s, in addit‎i on to the well-known‎wound‎treat‎m ent, antib‎i otic‎s, preve‎n t tetan‎i c convu‎l sion‎toxin‎absor‎p tion‎.Besid‎e s, it still‎need to corre‎c t the self-disci‎p line‎which‎is not stabl‎e, trach‎e a cut open, no depol‎a rizi‎n g agent‎appli‎c atio‎n, mecha‎n ical‎venti‎l atio‎n, enter‎a ble nutri‎t ion suppo‎r t. Hold, maint‎a in water‎and elect‎r olyt‎e acid-base balan‎c e, contr‎o l of lung Dye and preve‎n tion‎of throm‎b oemb‎o lism‎,and also need to stren‎g then‎the sputu‎m sucti‎o n And the skin and oral care, preve‎n t bedso‎r e and regur‎g itat‎i on Criti‎c al onset‎of the sever‎e tetan‎u s, easy out early‎Respi‎r ator‎y compl‎i cati‎o ns, such as choki‎n g, atele‎c tasi‎s and pulmo‎n ary feeli‎n g Dye, has a high morta‎l ity rate if not handl‎e d in time, so the compr‎e hens‎i ve prote‎c tion‎Richa‎r d also‎m ent.[ 临床外科杂‎志2008年‎7月第 16卷第 7期JCl‎i nSur‎g, plays‎a key role in the treatJuly 2008,Vo.l 16, No. 7]Unlik‎e many infec‎t ious‎disea‎s es, recov‎e ry from natur‎a lly acqui‎r ed tetan‎u s does not usual‎l y resul‎t in immun‎i ty to tetan‎u s. This is due to the extre‎m e poten‎c y of the tetan‎o spas‎m in toxin‎;even a letha‎l dose of tetan‎o spas‎m in is insuf‎f icie‎n t to provo‎k e an immun‎e respo‎n se.Tetan‎u s can be preve‎n ted by vacci‎n atio‎n with tetan‎u stox‎o id.The CDC recom‎m ends‎that adult‎s recei‎v e a boost‎e r vacci‎n e every‎ten years‎,[ "CDC Featu‎r es - Tetan‎u s: Make Sure You and Your Child‎Are Fully‎Immun‎i zed". Retri‎e ved 2010-08-30]and stand‎a rd care pract‎i ce in many place‎s is to give the boost‎e r to any patie‎n t with a punct‎u re wound‎‎who is uncer‎t ain of when he or she was last vacci‎n ated‎,or if he or she has had fewerthan three‎lifet‎i me doses‎of the vacci‎n e. The boost‎e r may not preve‎n t a poten‎t iall‎y‎fatal‎case of tetan‎u s from the curre‎n t wound‎,howev‎e r, as it can take up to two weeks for tetan‎u s antib‎o dies‎to form.In child‎r en under‎the age of seven‎, the tetan‎u s vacci‎n e is often‎admin‎i ster‎e d as a combi‎n ed vacci‎n e, DPT/DTaP vacci‎n e, which‎also inclu‎d es vacci‎n esagain‎s tdipht‎h eria‎and pertu‎s sis. For adult‎s and child‎r en over seven‎,the Td vacci‎n e (tetan‎u s and dipht‎h eria‎)or Tdap (tetan‎u s, dipht‎h eria‎,and acell‎u lar pertu‎s sis) is commo‎n ly used.[ Ugand‎a: Natio‎n Free of Mater‎n al And Neona‎t al Tetan‎u s, Unice‎f Repor‎t s". Retri‎e ved 2011-07-14.]The World‎Healt‎h Organ‎i sati‎o n certi‎f ies count‎r ies as havin‎g elimi‎n ated‎mater‎n al or neona‎t al tetan‎u s. Certi‎f icat‎i on requi‎r es at least‎two years‎of rates‎of less than 1 case per 1000 live birth‎s. In 1998 in Ugand‎a, 3,433 tetan‎u s cases‎were recor‎d ed in newbo‎r n babie‎s; of these‎,2,403 died. After‎a major‎publi‎c healt‎h effor‎t, Ugand‎ain 2011 was certi‎f ied as havin‎g elimi‎n ated‎tetan‎u s.徐老师您辛‎苦了，非常谢谢您‎！《医学基础英‎语文献阅读‎技巧》对于医学生‎来说是大有‎裨益的，上完本课之‎后相信大部‎分同学都受‎益良多，它不仅仅是‎一门英语课‎程，更是一门对‎医学生而言‎非常重要也‎有必要了解‎的文献阅读‎课程。

撰写医学文献常用英语

identically designed，phase3，placebo-controlled trials设计相同的Ⅲ期、安慰剂对照试验were followed for an additional 10days 并接受额外10天的随访follow-up 随访primary outcome 主要转归rritable bowel syndrome IBS肠易激综合征as compared with 相比之下rifaximin 利福昔明hazard ratio 风险比为acute otitis media 急性中耳炎adjusted odds ratio 经校正的比值比asthma 哮喘confidence interval 可信区间（CI）为chemotherapy 化疗exceed 超过initial 最初inhibitory activity 抑制活性evidence suggests that 有证据表明heparin 肝素an open-label，phase2 开放标签2期catheter-locking regimen 封管方案were randomly assigned 被随机分配接受cardiac arrest 心脏停搏the primary end point 主要终点EMS急救医疗服务key secondary end point 关键的次要终点Newborn screening 新生儿筛查1% vs02% 1% 对02% Preterm Infants 早产儿Daily ratings of 每日分级tidal volumes. 潮气量The incidence of adverse events 不良事件发生率inspiratory and expiratory 吸气和呼气Initial resolution of symptoms 最初症状消失vital capacity 肺活量Corresponding values 对应值pro-drug前体药物The rate of clinical failure 临床失败率active metabolite 活性代谢物The first dose 首剂metabolism新陈代谢The end-of-treatment visit 治疗结束随访particle颗粒The rate of Objective response 客观有效率metered dose inhaler定量雾化吸入器(MDI The rate of clinical benefit 临床获益率Resuscitation复苏Progression free survival 无进展生存期second-tier therapy二线治疗Case Control Study对照应用研究superior and inferior vena cava 上腔和下腔静脉Reversible form 可逆类型critically ill patients 危重症患者A prospective cohort study 前瞻性队列研究pulmonary edema 肺水肿Intention –to-treat analysis 意向治疗分析beta-blocking agents ß受体阻断剂Two cross-sectional studies 2项横断面研究under-diagnosed 漏诊randomised controlled trials (RCT)随机对照试验the cause and consequences 因果Median 中位数ventricular systolic or diastolic dysfunction 心室收缩和舒张衰竭Baseline 基线the cause and consequences内科外科Enrolled subject 被纳入的受试者tricuspid regurgitation 三尖瓣反流Inversely related to 呈负相关mitral 二尖瓣In turn 反过来hemodynamic instability 血流动力学不稳定meta-analysis荟萃分析functional residual capacity功能残气量systemic review 系统回顾reflux返流mean difference 平均差Upper respiratory tract上呼吸道the trade-off between benefits and harms利弊的权衡clinical implications临床意义non-inferiority studies 非干预研究/ 非劣性研究incidence发生率superiority trial 优效试验critically ill children 危重病儿a equivalence trial 等效试验acid, alkaline 酸、碱non-inferiority trial.非劣效试验Confounder-adjusted 混杂因素调整Square root sign 平方根号differential diagnosis 鉴别评估screen 筛查independent risk factor 独立危险因素double hit phenomenon双击现象absolute values 绝对值352 episodes of 352例。

医学检验外语文献

医学检验外语文献以下是一些您可能感兴趣的医学检验外语文献："Handbook of Clinical Microbiology": This book provides a comprehensive overview of clinical microbiology, including information on the diagnosis and treatment of various infectious diseases."Textbook of Clinical Laboratory Medicine": This textbook covers all aspects of clinical laboratory medicine, from basic laboratory techniques to advanced molecular diagnostic methods."Diagnostic Microbiology": This book focuses on the diagnosis of infectious diseases, providing information on the identification and typing of microorganisms. "Laboratory Testing in Critical Care": This book is designed for healthcare professionals who work in critical care settings and provides information on the diagnosis and management of critically ill patients."Atlas of Cytopathology": This atlas provides images and descriptions of cytological specimens from various organs and systems, assisting in the diagnosis of diseases.这些文献都是权威的参考资料，有助于深入了解医学检验领域的知识和技能。

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In this single-center,prospective, observational study, we used multivariable-adjusted regression analysis to determine the association between serum albumin level and the risk for complete RKF loss and RKF decline in PD patients.
To improve life expectancy in thispopulation, it is very important to identify modifiable risk factors for RKF loss.
为了提高这一人群的预期寿命，确定可改变的RKF损失风险因素非常重要。
Lower RKF is associated with an increased risk for morbidity and mortality in the PD population 低RKF与PD人群中发病率和死亡率增加的风险相关
Several risk factors for RKF loss have been identified RKF损失的几个危险因素已经被确定
Because PD is considered an extension of the pre-dialysis CKD period, it is plausible that serum albumin level may also be a predictor of CKD progression and that PD patients with lower serum albumin levels are more likely than patients with higher levels to lose RKF.由于PD被认为是透析前CKD期的延长，因此血清白蛋白水平也可能是CKD进展的预测因子，而血清白蛋白水平较低的PD患者比血清白蛋白水平较高的PD患者更有可能失去RKF。然而，目前还不清楚血清白蛋白水平降低是否与PD患者RKF丢失风险增加有关。
6.GNRI与RKF丢失的关系及血清白蛋白水平与GNRI预测能力的比较
7.血清白蛋白水平与RKF下降率的关系：作为关键性分析，我们还测定了血清白蛋白水平与24小时尿量下降率和肾Kt/V尿素下降率之间的关系。趋势分析结果如图7a所示，多变量调节的尿量下降率与血清白蛋白水平显著相关(趋势p值<0.05,Jonckheere-Terpstra检验)。同样，Kt/V尿素的下降速率(P = 0.067)与血清白蛋白水平(P值趋势<0.05)呈极显著的相关性 (图7B)。当使用血清白蛋白作为连续变量时，每降低1 g/dL血清白蛋白水平与两种尿液的下降速度显著相关
ability of serum albumin level versus GNRI. 7.Association between serum albumin level and rate of RKF decline
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结果
1.纳入患者的直线特征见表1。患者平均年龄55岁，67%为男性，36%为糖尿病肾病。研究人群血清白蛋白水平分布如图1所示。平均血清白蛋白水平为3.1 g/dL(范围为2.0-4.5 g/dL)。根据基线血清白蛋白水平核定的患者临床特征见表2。除肾 Kt/V尿素和血清白蛋白外，三组间基线特征无显著差异。肾Kt/V尿素与血清白蛋白水平呈显著的剂量-反应关系(p值趋势<0.05)。
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残余肾功能丧失的生存率。
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RESULTS结果
1.Baseline characteristics of each group stratified according to serum albumin level
2.Event-free survival stratified according to tertile based on baseline serum albumin
Serum albumin predicts mortality in PD patients血清白蛋白预测PD患者的死亡率
Observational studies have found an association between lower serum albumin level and increased risk for end-stage kidney disease in the general population and in patients with type 2 diabetes and nephropathy 观察性研究发现，血清白蛋白水平降低与一般人群、2型糖尿病和肾病患者终末期肾病风险增加之间存在关联。
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Introduction
1.此问题的由来（历史） 2.此问题的研究进展（现状） 3.引申出作者的研究动机（思路）
2019/7/3Leabharlann 5此问题的由来（历史）
Preserving residual kidney function (RKF) is of primary importance in the management of patients undergoing eritoneal dialysis (PD)保留残余肾功能(RKF)是接受腹膜透析 (PD)治疗的患者的首要任务。
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此问题的研究进展（现状）
Serum albumin is a simple but useful marker of nutritional status and inflammation in patients on PD 血清白蛋白是PD患者营养状况和炎症的一个简单而有用的指标
还比较了血清白蛋白与老年营养风险指数(GNRI)预测RKF损失的能力，因为GNRI是用白蛋白和体重计算的有用指数，通常被认为是比单独使用血清白蛋白更好的营养状况和死亡率的替代指标。
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材料和研究设计
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患者按血清白蛋白水平分为:T1，血清白蛋白≥3.4 g/dL;T2，血清白蛋白 <3.4，≥3.0 g/dL;T3，血清白蛋白<3.0 g/dL。
2.中位随访24个月，33例患者(31.7%)RKF丢失:T1组6例，T2组9例，T3组18例。 Kaplan-Meier分析显示，T2、T3组RKF丢失发生率明显高于T1组(图2)。
3.如表3所示，随着基线血清白蛋白水平的降低，RKF损失发展的非调整、年龄和性别调整的HRs呈线性增加(P <0.05）；调整糖尿病肾病、收缩压、肾腹膜Kt/V尿素、蛋白尿等混杂因素后，RKF损失的HRs随血清白蛋白水平下降呈线性增加(P <0.05）；在对混杂因素进行调整后，血清白蛋白水平每下降1 g/dL, RKF损失的风险就增加3.24倍；即使在添加血清c反应蛋白水平、尿量、腹膜转运体类型以及 icodextrin作为混杂因素后，这种相关性仍具有统计学意义
The primary outcome was complete RKF loss, defined as urine volume <100 mL/day. 主要结果为RKF完全丧失，即尿量<100 mL/d。
Serum albumin level at baseline was the main exposure. 血清白蛋白水平为主要影响因素。
Our findings suggest that hypoalbuminemia is associated with an increased risk of RKF loss in patients with peritoneal dialysis. 我们的研究结果表明，低白蛋白血症与腹膜透析患者 RKF丢失风险增加有关。
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Abstract
Preserving residual kidney function (RKF) is important in the management of patients on peritoneal dialysis.保留残余肾功能(RKF)对腹膜透析患者的治疗具有重要意义。
3.Association between serum albumin level and risk of RKF loss 4.Restricted cubic spline curve on the association between serum albumin
level and risk of RKF loss. 5.Effect modifications according to baseline characteristics. 6.Association between GNRI and RKF loss and comparison of predictive
在这项单中心、前瞻性、观察性研究中，我们使用多变量调整回归分析来确定PD患者血清白蛋白水平与RKF完全丧失和RKF下降风险之间的关系。
We also compared the ability of serum albumin versus the geriatric nutritional risk index (GNRI) to predict RKF loss, because GNRI is a useful index calculated with albumin and body weight and is generally considered a better surrogate marker for nutritional status and mortality than serum albumin alone.