盐附子遗传毒性研究

[目的]选用目前新药遗传毒性评价中推荐使用的3种试验方法(小鼠骨髓微核试验、鼠伤寒沙门氏菌回复突变试验、体外CHL细胞染色体畸变试验)研究盐附子的遗传毒性. [方法]小鼠骨髓微核试验设3个盐附子给药剂量组(15.45、7.73、3.86 g生药/kg)、阴性对照组和阳性对照组(环磷酰胺40 mg/kg).Ames试验选用两种方法:直接法和代谢活化法.试验菌株为鼠伤寒沙门氏组氨酸缺陷型菌株TA97、TA98、TA100、TA102、TA1535,盐附子在试验中设6个剂量组(5.000、2.500、1.250、0.625、0313、0.156 mg生药/皿),同时设自发回复突变对照组、阳性对照组.体外CHL细胞染色体畸变试验也选用两种方法:直接法和代谢活化法.盐附子不加S9时处理终浓度为5、2.5、1.25、0.625、0.313 mg生药/ml,加S9时处理终浓度为2.5、1.25、0.625、0.313、0.156 mg生药/ml. [结果]小鼠骨髓微核试验盐附子各剂量组小鼠骨髓多染红细胞微核率与阴性对照组相比,差异无统计学意义(P>0.05).Ames试验盐附子在加或不加肝微粒体酶(S9)时均未见引起TA97、TA98、TA100、TA102、TA1535试验菌株基因突变,即Ames试验阴性,试验重复一次,所得结论相同.体外CHL细胞染色体畸变试验盐附子在加或不加S9时均未引起CHL细胞的染色体畸变,试验结果为阴性,试验重复一次,所得结果相同.[结论]在实验室条件下,盐附子在小鼠骨髓微核试验、Ames试验及体外CHL细胞染色体畸变试验中均为阴性结果,故认为盐附子无遗传毒性.     

丙烯腈对蝾螈睾丸精原细胞DNA的诱导损伤

目的探讨丙烯腈(ACN)对睾丸精原细胞DNA的损伤作用及经肝微粒体酶活化前后该损伤程度的差异。方法用体外培养方法分离蝾螈睾丸精原细胞,不同浓度(0,0.1,0.4,0.8,1.6μmol/ml)ACN染毒3 h,每个浓度分活化组(加S9)和非活化组(不加S9),另设2个阳性对照组(丝裂霉素C,1.6μg/ml,加S9)和(环磷酰胺,80μg/ml,不加S9),用单细胞凝胶电泳法检测DNA损伤程度。结果未活化ACN浓度≥0.8μmol/ml及活化后ACN浓度≥0.4μmol/ml时,蝾螈精原细胞DNA损伤程度明显升高,彗星发生率、长尾彗星率及彗星细胞平均尾长均明显高于对照组(P<0.05),并存在剂量-反应关系,经S9活化后,ACN对DNA损伤程度比同浓度未活化组明显增强。结论ACN能诱导蝾螈睾丸精原细胞DNA损伤,并且经肝微粒体酶活化后损伤能力明显增强。     

亚硝酸钠对大鼠睾丸支持细胞DNA损伤的研究

[目的]观察亚硝酸钠对大鼠睾丸支持细胞DNA的损伤作用.[方法]采用冷胰酶消化法分离培养大鼠睾丸支持细胞,采用单细胞凝胶电泳法检测亚硝酸钠对大鼠睾丸支持细胞DNA的损伤作用.试验共设6个剂量组,亚硝酸钠终浓度分别为1.5μg/ml、15μg/ml、150μg/ml和1500μg/ml,同时设PBS阴性对照组和丝裂霉素C阳性对照组(20μg/ml).[结果]当亚硝酸钠剂量为15μg/ml时,可引起支持细胞拖尾率的增加,与阴性对照组相比,其差异有统计学意义(x2=18.320, P=0.000),但共尾长、尾/头(长)、尾距等较为客观的距离指标与阴性对照组相比,则在亚硝酸钠剂量达150μg/ml时,差异才有统计学意义,随着染毒剂量的增加,DNA损伤程度明显加重,存在明显的剂量-效应关系.[结论]亚硝酸钠具有损伤睾丸支持细胞DNA的作用,并且在染毒剂量为150μg/ml时,能观察到明显的损伤效应.     

三羟异黄酮对细胞的致突变作用及DNA损伤研究

[目的]主要研究三羟异黄酮(Genistein ,GEN)对细胞的致突变效应及DNA的损伤作用,同时探讨细胞DNA损伤与氧化效应的关系。[方法]采用L5 178Ytk+ / -3 .7.2C小鼠淋巴瘤细胞基因突变试验(MLA)观察GEN在浓度为0、2 .1、4.2、6.3、8.4、10 .5 μmol/L(加S9)时或在浓度为0、12 .5、2 5、5 0、10 0、2 0 0 μmol/L(不加S9)时诱发细胞突变的情况;用单细胞凝胶电泳试验(即彗星试验)检测GEN在浓度为0、10、3 0、90、2 70 μmol/L时对中国仓鼠肺细胞(CHL细胞)和SMMC 772 1肝癌细胞DNA原始损伤,同时测定细胞内超氧化物歧化酶(SOD)和过氧化氢酶(CAT)酶的活性。[结果]GEN在加S9时诱发突变的浓度(≥2 .1μmol/L)显著低于不加S9的浓度(≥2 5 μmol/L)。GEN达到90 μmol/L浓度时作用18h ,可导致CHL细胞和SMMC 772 1肝癌细胞DNA断裂,但CHL细胞各处理组间CAT和SOD差异都无显著性。而SMMC 772 1肝癌细胞在GEN≥3 0 μmol/L时,SOD下降;GEN≥10 μmol/L时,CAT下降。[结论]在加S9时的诱发突变效应剂量远小于不加S9的剂量,表明GEN的代谢产物致突变效应更强。这可能与GEN的代谢产物具有氧化损伤效应有关。但GEN导致细胞DNA断裂,不是由其氧化损伤引起。     

氧化剂致CHL细胞DNA损伤及酪醇的保护作用

目的 检测阿霉素、重铬酸钾和过氧化氢所致中国仓鼠肺成纤维细胞（CHL）DNA的损伤效应及酪醇对真核细胞DNA氧化损伤的保护作用。方法 CHL细胞用不同浓度化学物作用一定时间后（阿霉素：1.25h；重铬酸钾：1.75h；过氧化氢：25min)，收获细胞用单细胞凝胶电泳技术检测DNA链断裂情况；CHL细胞先用不同浓度酪醇作用1.58h，再加入0.4mmol/L过氧化氢共同培养25min，然后用单细胞凝胶电泳技术测定DNA链断裂情况，分析酪醇的抗氧化损伤作用。结果 0.1μmol/L阿霉素、0.1mmol/L重铬酸钾及0.1mmol/L过氧化氢作用一定时间后，均可引起DNA链断裂，随着各组处理物浓度的增加，DNA迁移长度和拖尾细胞百分率也相应增加，两剂量－反应关系明显。10μg/ml、20μg/ml酪醇的预处理可使过氧化氢染毒细胞的拖尾百分率和DNA迁移长度显降低。结论 阿霉素、重铬酸钾和过氧化氢均是强烈的DNA链断裂剂；酪醇对真核细胞DNA氧化损伤具有抑制作用。     

生川乌提取物遗传毒性研究

[目的]选用目前新药遗传毒性评价中推荐使用的3种试验方法(小鼠骨髓微核试验、鼠伤寒沙门氏菌回复突变试验、体外CHL细胞染色体畸变试验)研究生川乌的遗传毒性.[方法]小鼠骨髓微核试验设3个生川鸟提取物给药剂量组(26.0、13.0、6.5 g生药/kg)、阴性对照组和阳性对照组(环磷酰胺40 mg/kg).Ames试验选用两种方法:直接法和代谢活化法.试验菌株为鼠伤寒沙门氏组氨酸缺陷型菌株TA97、TA98、TA100、TA102、TA1535,生川乌提取物在试验中设6个剂量组(5.000、2.500、11250、0.625、0.313、0.156 mg生药/皿),同时设自发回复突变对照组、阳性对照组.体外CHL细胞染色体畸变试验也选用两种方法:直接法和代谢活化法.试验设5个生川乌提取物浓度组(5.000、2.500、1.250、0.625、0.313 mg生药/ml),阴性对照及阳性对照组.[结果]小鼠骨髓微核试验生川乌提取物各剂量组小鼠骨髓多染红细胞微核率与阴性对照组相比,差异无统计学意义(P>0.05).Ames试验生川乌提取物在加或不加肝微粒体酶(S9)时均未见引起TA97、TA98、TA100、TA102、TA1535试验菌株基因突变,即Ames试验阴性,试验重复一次,所得结论相同.体外CHL细胞染色体畸变试验生川乌提取物在加或不加S9时均未引起CHL细胞的染色体畸变,试验结果为阴性,试验重复1次,所得结论相同.[结论]在本实验室条件下,生川乌提取物在小鼠骨髓微核试验、Ames试验及体外CHL细胞染色体畸变试验中均为阴性结果,故认为在本实验条件下,生川乌提取物无遗传毒性.     

亚硝酸钠对中国仓鼠肺细胞染色体畸变率的影响

[目的]研究亚硝酸钠(NaNO2)致中国仓鼠肺细胞(CHL)染色体畸变的作用. [方法]测定NaNO2对CHL细胞的半数抑制浓度(IC50),根据IC50设立不同剂量组,进行正式实验,分别观察不加及加S9后的染色体畸变情况,根据标准进行结果判定. [结果]NaNO2染毒在不加S9时,128、12.8和1.28μg/ml 3个剂量组的染色体畸变率均＞5%而≤10%,为可疑阳性,而高剂量组(1.28 mg/ml)畸变率＞10%而＜20%,为阳性反应.NaNO2染毒在加入活化系统S9后,各剂量组引起CHL细胞染色体畸变率在12.8和1.28 μg/ml 2个剂量组的染色体畸变率均＞5%而≤100%,为可疑阳性,而中(128μg/ml)和高(1.28 mg/ml)剂量组畸变率均＞10%而＜20%,为阳性反应. [结论]NaNO2在1.28 mg/ml剂量下可引起CHL细胞染色体畸变率增高.     

甲苯二异氰酸酯对中国仓鼠肺细胞增殖及DNA损伤的影响

目的研究甲苯二异氰酸酯(TDI)对细胞增殖及DNA损伤的影响,为评价TDI类化合物的潜在生物学效应提供科学依据。方法以中国仓鼠肺细胞(CHL)为靶细胞,染毒组TDI浓度分别为0.01、0.02、0.04、0.08、0.16μmol/ml,同时设DMSO溶剂对照组,每组8个平行样,采用四甲基偶氮噻唑蓝(MTT)法检测细胞生长抑制率;染毒组TDI浓度分别为0.04、0.08、0.16μmol/ml,同时设二甲基亚砜(DMSO)溶剂对照组和阳性对照组(过氧化氢),采用单细胞凝胶电泳技术检测细胞DNA损伤程度。结果TDI能使细胞形态学发生改变,抑制细胞生长,呈剂量-时间-反应关系,0.16μmol/mlTDI染毒6d,细胞生长抑制率为88.6%。TDI能使细胞DNA发生断裂,TDI染毒组细胞拖尾率、彗星尾DNA百分含量和彗星尾长均增高,与对照组比较,差异均有统计学意义(P<0.01),呈剂量-反应关系;0.16μmol/mlTDI染毒组细胞拖尾率、彗星尾DNA百分含量和彗星尾长分别为86.30%,34.54%和7.18μm。结论TDI能抑制细胞生长,具有DNA损伤作用。     

丙烯腈对原代双室培养的大鼠睾丸支持细胞的毒性

[目的]研究丙烯腈(ACN)对原代双室培养的大鼠睾丸支持细胞(Sertolicell,Sc)的毒性,以探讨ACN诱导雄性生殖毒性机制。[方法]用已分离纯化的大鼠睾丸SC为材料,用原代双室培养方法,加和不加S9,以浓度为0、0.5、5.0、25.0μg/mlACN染毒,于4、12、24、48h后检测跨细胞上皮电阻(TER);染毒24、48h后检测转铁蛋白(Trf)浓度,评价ACN体外染毒对大鼠睾丸SC的损伤。[结果]ACN浓度≥5.0μg/ml时,对TER的形成有明显抑制作用;5.0μg/ml培养48h、25.0μg/ml培养12h后对已形成的TER引起下降;加S9( S9)与不加S9(-S9),TER值接近(如25.0μg/ml组培养12h后 S9组为480.3,-S9组为486.3),无明显差异。浓度为25.0μg/ml时,ACN染毒引起外室Trf浓度升高,明显高于对照及其他组(P<0.05),内室Trf浓度变化不明显,因此内室与外室之间Trf浓度差值缩小。[结论]结果表明ACN对双室培养的SCTER的形成有抑制作用,对已形成的TER有降低作用;提示ACN可能对SC形成的紧密连接和“血睾屏障”有影响。     

ZnG、MnCl2对SiO2致CHL细胞DNA损伤的影响

目的:观察葡萄糖酸锌(ZnG)、氯化锰(MnCl2)及其联合作用对二氧化硅(SiO2)致中国仓鼠肺成纤维细胞(CHL)DNA损伤的影响,寻找两者的最佳剂量组合。方法:常规培养CHL细胞,按实验分组:①生理盐水对照组(阴性对照);②SiO2组:SiO2100μg/ml;③ZnG(2·25μg/ml)组;④MnCl2(1·0μg/ml组);⑤SiO2 ZnG组:内含100μg/mlSiO2外,ZnG1·0μg/ml、1·5μg/ml、2·25μg/ml;⑥SiO2 MnCl2组:内含100μg/mlSiO2外,MnCl20·25μg/ml、0·5μg/ml、1·0μg/ml;⑥ZnG、MnCl2联合作用组:每组内含SiO2100μg/ml外,采用两因素三水平正交设计,ZnG Mn-Cl2共设9个剂量组。培养2h后收获细胞,通过彗星试验检测CHL细胞DNA损伤情况。结果:与二氧化硅组比,葡萄糖酸锌、氯化锰可以显著减轻二氧化硅致DNA链断裂作用(P<0·05);1·0μg/mlZnG与0·5μg/mlMnCl2联合作用效果最好。结论:葡萄糖酸锌、氯化锰及两者联合应用在体外可有效减轻二氧化硅粉尘致CHL细胞的DNA损伤作用。     

The human drama of genetics: 'hard' and 'soft' media representations of inherited breast cancer

This paper examines media coverage of 'breast cancer genetics', and explores its implications for public understanding. We present a content analysis of coverage in British newspapers and look at a variety of popular forms, including women's magazines, television soap opera and radio drama. Genetic/inherited risk receives a great deal of coverage across a wide range of media formats and outlets. Much of this attention has focused on individuals from 'high risk families' and dilemmas around prophylactic mastectomies. Through examining media coverage, combined with interviews with media personnel and their sources, we show why this story proved so attractive to the media and highlight the different production values which influence coverage. Finally, we introduce preliminary findings from focus group discussions to demonstrate how such 'human interest' framing has engaged audience attention and influenced public understandings. The paper concludes by highlighting the implications for analysing, predicting, and engaging with, media representations of science.     

Worker education in the primary prevention of occupational dermatoses

This paper reports the evaluation of a skin care education programmeconducted on a fine chemicals manufacturing site where over1,000 employees are located. Approximately 60% are involvedin chemical manufacture. Over a 12 month period production staffreceived training in prevention of occupational dermatoses linkedto a site-wide poster initiative. The incidence of new casesof occupational dermatoses fell from 0.055 (70 cases in 1,277employees) to 0.021 (27 cases in 1,277 employees) before andafter the intervention respectively (p<0.0001). After otherfactors such as chemicals handled, observer bias and changesin reporting related to socioeconomic climate were taken intoaccount it is concluded that this study demonstrates the importanceof worker education as a tool for primary prevention of disease.Training materials such as video and poster presentations maybe effectively used in the chemical manufacturing industry asan adjunct to prevention and control of exposure to substanceshazardous to the skin. Such methods may also be used in otherindustries where there are significant risks of dermatoses.     

Regional Variation in Travel-related Illness acquired in Africa,March 1997–May 2011

To understand geographic variation in travel-related illness acquired in distinct African regions, we used the GeoSentinel Surveillance Network database to analyze records for 16,893 ill travelers returning from Africa over a 14-year period. Travelers to northern Africa most commonly reported gastrointestinal illnesses and dog bites. Febrile illnesses were more common in travelers returning from sub-Saharan countries. Eleven travelers died, 9 of malaria; these deaths occurred mainly among male business travelers to sub-Saharan Africa. The profile of illness varied substantially by region: malaria predominated in travelers returning from Central and Western Africa; schistosomiasis, strongyloidiasis, and dengue from Eastern and Western Africa; and loaisis from Central Africa. There were few reports of vaccine-preventable infections, HIV infection, and tuberculosis. Geographic profiling of illness acquired during travel to Africa guides targeted pretravel advice, expedites diagnosis in ill returning travelers, and may influence destination choices in tourism.     

The design of hazard risk assessment matrices for ranking occupational health risks and their application in mining and minerals processing

Two hazard risk assessment matrices for the ranking of occupational health risks are described. The qualitative matrix uses qualitative measures of probability and consequence to determine risk assessment codes for hazard-disease combinations. A walk-through survey of an underground metalliferous mine and concentrator is used to demonstrate how the qualitative matrix can be applied to determine priorities for the control of occupational health hazards. The semi-quantitative matrix uses attributable risk as a quantitative measure of probability and uses qualitative measures of consequence. A practical application of this matrix is the determination of occupational health priorities using existing epidemiological studies. Calculated attributable risks from epidemiological studies of hazard-disease combinations in mining and minerals processing are used as examples. These historic response data do not reflect the risks associated with current exposures. A method using current exposure data, known exposure-response relationships and the semi-quantitative matrix is proposed for more accurate and current risk rankings.     

Psychopathological features of a patient population of targets of workplace bullying

BACKGROUND: A strong association between workplace bullying and subsequent anxiety and depression, indicated by empirical research, suggests that bullying is an aetiological factor for mental health problems. AIMS: To evaluate levels of stress and anxiety-depression disorder developed by targets of workplace bullying together with outcome at 12 months and to characterize this population in terms of psychopathology and sociodemographic features. METHODS: Forty-eight patients (36 women and 12 men) meeting Leymann Inventory of Psychological Terror criteria for bullying were included in a prospective study. Evaluations were performed at first consultation and at 12 months using a standard clinical interview, a visual analogue scale of stress, the Hospital Anxiety and Depression (HAD) scale, the Beech scale of stress in the workplace and a projective test (Picture-Frustration Study). RESULTS: At first consultation, 81% of patients showed high levels of perceived stress at work and 83 and 52% presented with anxiety or depression, respectively. At 12 months, only 19% of working patients expressed a feeling of stress at work. There was a significant change in symptoms of anxiety while there was no change in symptoms of depression. Stress at work and depression influenced significatively capacity to go back to work. At 12-month assessments, workers showed a significantly better score on the HAD scale than non-workers. Over half the targets presented a neuroticism-related predominant personality trait. CONCLUSION: Workplace bullying can have severe mental health repercussions, triggering serious and persistent underlying disorders.     

The rise and fall in incidence of malignant mesothelioma from a British Naval Dockyard, 1979-1999

BACKGROUND: The incidence of malignant mesothelioma in Britain is predicted to rise over the next 15-25 years because of past failure to protect the workforce against inhalation of asbestos. In British Naval dockyards, alternative insulation materials and respiratory protection were introduced from the mid-1960s. Aims This study was carried out to investigate the effects of these control measures on mesothelioma deaths in dockyard workers. METHODS: Cases of mesothelioma of the pleura and peritoneum between 1979 and 1999 in workers from the Devonport Naval Dockyard, south-west England, were sought from coroners' and medico-legal records. RESULTS: Three hundred and one cases were identified, 7% peritoneal. The peak incidence occurred in 1991 with 25 cases per annum (quadratic model fit R(2) = 74.2%, P < 0.001) and we predict that by 2003 the incidence will fall to fewer than five cases per annum. The mean time between first exposure and presentation was 48.5 years [95% confidence interval (CI) = 47.3-49.8], but this was significantly shorter in the more heavily exposed trades, when compared with the less heavily exposed (42 years, 95% CI = 39.0-45.0, versus 49.5 years, 95% CI = 48.2-50.9). Those with higher exposure were also at significantly greater risk of peritoneal disease (P < 0.023, Fisher's exact test). CONCLUSION: The reduction in incidence of mesothelioma is greater than can be accounted for by reduction in numbers of dockyard workers over the last 50 years. Changes in insulation materials and improved industrial hygiene measures introduced into the Devonport Dockyard from the mid-1960s have resulted in an earlier decline in the incidence of malignant mesothelioma than that predicted for the British workforce as a whole.     

Die sogenannte Vinylchlorid-Krankheit—eine berufsbedingte Systemsklerose?

Zusammenfassung Es wurden 13 Arbeiter untersucht, die zwischen 1 3/4 und 18 Jahren in einem PVC-herstellenden Betrieb beschäftigt waren. 8 von ihnen wiesen sklerodermieartige Hautveränderungen (Abb. 2) auf, die histologisch charakterisiert sind durch Verbreiterung und Homogenisierung der kollagenen Faserbündel (Abb. 3 u. 4) sowie Fragmentation und Rarefizierung der elastischen Fasern (Abb. 5). Bei 7 Patienten bestanden trommelschlegelartige Auftreibungen einzelner Fingerendphalangen (Abb. 1). 11 Patienten zeigten Durchblutungsstörungen der Extremitäten (4 von diesen ein Raynaud-Syndrom) und 6 Patienten Acroosteolysen einzelner Fingerendphalangen (Abb. 6, Tabellen 1–3).Darüber hinaus bestand bei allen Patienten eine Thrombocytopenie, bei 12 Patienten eine Splenomegalie, bei 11 Patienten eine Einschränkung der Leberfunktion (erhöhte BSP-Retention). An der Leber ließ sich histologisch bei den 5 laparoskopierten Patienten eine deutliche Fibrosierung der Portalfelder nachweisen. Bei 4 Patienten bestanden Oesophagusvaricen (Tabellen 4 u. 5). 8 Patienten zeigten eine Partialinsuffizienz mit Hinweisen für vorwiegend restriktive Veränderungen.Die hier beschriebenen Veränderungen gehen weit über das bisher bekannte Acroosteolysesyndrom hinaus. Es wird der dringende Verdacht geäußert, daß langfristige Vinylchlorid-Exposition dieses komplexe Krankheitsbild verursacht. Daher wird für diese systemische Krankheit die Bezeichnung Vinylchlorid-Krankheit vorgeschlagen.Wir danken Frau E. Voigtländer für die Herstellung der klinischen und histologischen Abbildungen.     

Organophosphate toxicity and occupational exposure

The ubiquitous organophosphates present a continuing health hazard in agriculture, public health eradication programmes and as chemical warfare agents. Despite significant progress in understanding the potential mechanisms of toxicity far beyond the commonly accepted mechanism of cholinesterase inhibition in intentional exposures, the precise health effects following occupational exposures are yet to be completely defined. A much greater understanding exists of the clinical features of organophosphate poisoning. These are characterized by a triphasic response involving an initial acute cholinergic phase, an intermediate syndrome (both associated with high mortality) and a disabling but non-lethal delayed polyneuropathy. The delayed polyneuropathy may occur in the absence of the cholinergic or intermediate phases. However, progress is still required in order to improve the quantification and assessment of occupational exposures and the implementation of appropriate preventive measures. Finally, evidence-based guidelines for appropriate or optimal therapeutic interventions following poisoning are required urgently and collaborative work with colleagues in developing countries, where the occurrence of organophosphate exposures is more frequent, may provide the answers.     

Miliaria rubra of the lower limbs in underground miners

This report documents a case series of miliaria rubra of the lower limbs in miners at a deep underground metalliferous mine in tropical arid Australia. During the summer months of February and March 1999, all cases of miliaria rubra of the lower limbs in underground miners seen at the mine's medical centre were clinically examined and administered a questionnaire. Twenty-five patients were seen, an incidence of 56.4 cases per million man-hours. Miliaria rubra was most often located between the ankle and knee (88% of cases). Twenty-four percent had concurrent folliculitis and 20% had concurrent tinea. Thirty-two percent had a personal history of asthma. Walking through ground-water and splashing of the legs was common. Three to 4 weeks of sedentary duties in air conditioning was generally required to achieve resolution of miliaria rubra. The incidence of miliaria rubra of the lower limbs is 38% of the incidence of heat exhaustion at the same mine. The length of disablement is greater, however. Atopics may be at increased risk of miliaria rubra. Control measures are discussed.     

Empathic processes: perception by medical students of patients'' anxiety and depression

Perceptions by medical students of patients' affective states were investigated, and the effect of the students' own emotions on such perceptions. One hundred and one fourth-year medical students rated the levels of anxiety and depression of three women patients presented on videotape, rated their own levels of anxiety and depression and completed a questionnaire on aspects of the rating process. Students had widely different and often inappropriate perceptions of patients' levels of anxiety and depression. Students who consistently overrated anxiety or depression in patients, compared to those who consistently underrated, were themselves significantly more anxious or depressed. These data suggest a need in medical education for systematic teaching of empathic skills and for recognition of potential bias in clinical decision-making arising from the clinician's own emotional state.