OSCE在全科医生实习出科考试中的应用研究

目的 为客观评价全科医学生实习后的综合能力,探讨客观结构化临床考核（objective structured clinical examination,OSCE）在全科医生实习出科考试中的应用效果。方法 选取2020年7月至2021年5月在重庆医科大学附属永川医院老年病科实习的全科医学生36名为研究对象,采用客观结构化临床考核方式进行出科考核,OSCE考核流程为建立标准化病人,设置多站式考核,包括医疗评估站点、分析站点、技能考核站点、医患沟通站点,制定各站评分标准等三部分,分析OSCE考核试题的难度、信度、效度及各站点的得分,运用SPSS 20.0统计学软件进行数据的统计分析。结果 对OSCE的各站点试题质量进行信度、效度、难度、区分度分析,试题的α信度系数为0.715,内部一致性信度较高;测度值（Kaiser-Meyer-Olkin,KMO）为0.713,表明效度适合;难度系数为0.478～0.797,平均难度0.654,试题中等难度;区分度0.593～0.733,平均区分度0.536,有较好的区分和鉴别能力。结论 客观结构化考核可应用于医学生实习出科考核,成绩客观体现了医学生临床能...     

客观结构化临床考试在麻醉学专业本科临床实习准入考试中的应用效果研究

目的检验客观结构化临床考试(OSCE)在麻醉本科临床实习准入考试中应用的可靠性和适宜性。方法分析OSCE成绩获得客观评价(包括信度、效度、难易度及区分度等),通过问卷调查获得主观评价(考生对OSCE的认可度)。结果 OSCE合格率为79.00%~96.80%,各考站合格率适宜;各考站内部一致性信度Cronbach’s α系数为0.240,技能操作类考站为0.675;OSCE成绩与麻醉临床技能培训成绩显著正相关(r=0.263,P=0.039),除标准化病人临床问诊考站外,各考站成绩与OSCE总成绩显著相关;总体难度系数为0.80,区分度为0.30。绝大多数考生对OSCE认可度较高,认为能客观评价其学习能力。结论 OSCE应用于麻醉学专业本科临床实习准入考试的可靠性和适宜性较高,值得推广。     

客观结构化临床考试在护理本科生毕业考核中的应用研究

目的：探讨OSCE在护理本科生毕业考核中应用的可行性,促进高等护理教育考试改革。方法：以我院65名2003级护理本科生为研究对象,于毕业实习结束后开展OSCE多站式考试,分为SP考站与非SP考站,对学生考试成绩进行统计,分析OSCE成绩与护理专业课程考试成绩的相关性,调查学生对OSCE的认同情况。结果：0SCE考试平均成绩为81．04±3．99,总难度系数为0．81,信度分析克伦巴赫系数α=0．705,OSCE成绩与5项专业课程考试成绩显著相关。结论：应用0SCE进行护理本科生考核是科学有效的临床护理技能评价方法。     

康复治疗学本科专业临床技能多站式考核的研究与应用

目的:探讨OSCE在康复治疗学本科专业毕业考核中应用的可行性,促进高等学校康复治疗学教育考试改革。方法:以我院2007级27名康复治疗学本科毕业生为研究对象,于毕业实习结束后开展OSCE多站式考试,分析OSCE成绩与康复治疗学专业课程考试成绩的相关性。结果:OSCE考试平均成绩为77.13±5.47,总难度系数0.771;问卷内容效度测量结果用人单位为r=0.76,临床实习带教教师为r=0.72;问卷信度测量结果用人单位Cronbach’a系数a=0.78,临床实习带教教师的Cronbach’a系数a=0.75;用人单位重测信度a=0.86,临床实习带教教师的重测信度a=0.83;OSCE成绩与3项专业课程考试成绩显著相关。结论:应用OSCE可以科学有效地对康复治疗学本科专业学生的临床技能进行评价。     

客观结构化临床考试OSCE在MBBS留学生儿科学期末考核中的应用和成绩分析

昆明医科大学第二临床医学院儿科教研室首次开展MBBS留学生全英文教学,并在期末考试中应用客观结构化临床考试(OSCE),设立病史询问、体格检查、医患沟通3个站点考核学生儿科临床技能,成绩分析果显示:OSCE考试的Cronbach’sα系数为0.727,各站点评定者信度为0.89~0.93,提示评分者之间的一致性较高。OSCE成绩与笔试成绩的相关系数为0.578(P<0.05)。本次OSCE初步探索和实践取得良好的信度和效度。     

客观结构化临床考试在医学影像学专业临床教学考核中的应用

为探讨适合医学影像技术学专业临床教学考核的客观结构化临床考试（OSCE ）模式,本研究对我院2007级～2009级4年制医学影像学专业104人在实习结束后进行OSCE技能考核,运用统计学方法评估技能考核成绩难度系数、信度,正态分布情况,并进行问卷调查,分析OSCE在临床技能考核教学评价中的可行性,从而为应用型医学影像技术人才培养考核的评价方式改革提供一些参考依据。     

客观结构化临床考试在住院医师规范化培训年度考核中的应用

  目的  通过开展对客观结构化临床考试(objective structured clinical examination, OSCE)在住院医师规范化培训年度考核中应用的研究,指导今后OSCE的试题设置,使试题更规范、合理。  方法  选取参加2020年蚌埠医学院第一附属医院住院医师规范化培训年度考核的内科专业学员2018级62人、2019级64人的考核成绩为研究对象,分别分析OSCE设置的信度、效度、难度、区分度,并比较2个年级学员各站考试分数,讨论OSCE试题设置的合理程度及培训时间对成绩的影响。  结果  OSCE设置的信度选择评价者信度进行分析,结果良好;效度使用内容效度进行评价,效度较高;OSCE试题对于2018级学员的难度在0.55~0.78、总难度为0.72,对于2019级学员的难度在0.49~0.79、总难度为0.67,2个年级的单站难度、总体难度基本达到适宜标准;OSCE试题对于2018级学员的区分度为0.18,对于2019级学员的区分度为0.19,稍嫌不足;比较2个年级学员各站考试分数,2018级学员有5站(共6站)成绩高于2019级学员,差异有统计学意义(P < 0.001)。  结论  本次OSCE考站设置较为合理,可以客观反映学员的培训水平及临床实践能力,考核区分度有上升空间,培训时间与成绩呈正相关。      

OSCE在评价护理本科生临床能力的实证研究

目的：OSCE模式能够更加客观的反应学生的综合能力.方法：采用便利整群抽样法抽取我校2007级127名护理专业本科生为研究对象,接受OSCE模式的考核.考核结束后,立即对研究对象进行考试效果自评问卷调查.同时,把学生OSCE模式考试成绩与其自身的综合测评成绩进行分析比较.结果：OSCE模式的考核效果总体评价、认同感均较高.OSCE成绩和学生的综合测评保持一致.结论：OSCE考核模式能够更加全面、客观的反应学生的综合素质和教学目标,并能够提高学生理论联系实践的能力.     

OSCE在临床实习管理中内科出科考试的应用

目的探讨客观结构化临床技能考试(OSCE)在临床实习管理中内科出科考试的具体应用。方法以2014级昆明医科大学第二临床学院本科207名临床实习同学为研究对象,构建OSCE具体考核方案,对学生考试成绩进行统计学分析,评估OSCE运用于临床出科考试的应用效果。结果考生成绩符合正态分布,各考站试题难度,区分度适宜,客观反映了临床实习学生的实习质量,考生OSCE考试成绩与平时实习成绩高度相关。结论 OSCE考试体系引入内科实习出科考试,改变了重理论轻技能的传统考评方式,更为客观全面的反应了学生的临床实习质量,有利于医学生过渡到住院医师规范化培训体系。     

OSCE考试模式在临床药学本科实践技能考核中的应用

目的 评估客观结构化临床考试(OSCE)在临床药学本科实践技能考核中的应用效果。方法 选取2021年3月至2021年12月在我院实习的50名皖南医学院药学院临床药学本科生进行OSCE 5个站点的实践技能考核,并对OSCE考试满意度进行问卷调查,采用多元线性回归分析OSCE考试满意度的影响因素。结果 问卷信度检验Cronbach′s α为0.929,KMO为0.818。回收问卷50份,临床药学本科生对OSCE考试的总体满意度为97.2%。多元线性回归分析表明站点数目、就业压力和考研压力、心理因素是OSCE考试满意度的影响因素(P<0.05)。结论 OSCE考试模式应用于临床药学本科实践技能考核,有助于提升学生的综合素质和临床药学实践能力。     

Evidence of brain overgrowth in the first year of life in autism

Context  Autism most commonly appears by 2 to 3 years of life, at which time the brain is already abnormally large. This raises the possibility that brain overgrowth begins much earlier, perhaps before the first clinically noticeable behavioral symptoms. Objectives  To determine whether pathological brain overgrowth precedes the first clinical signs of autism spectrum disorder (ASD) and whether the rate of overgrowth during the first year is related to neuroanatomical and clinical outcome in early childhood. Design, Setting, and Participants  Head circumference (HC), body length, and body weight measurements during the first year were obtained from the medical records of 48 children with ASD aged 2 to 5 years who had participated in magnetic resonance imaging studies. Of these children, 15 (longitudinal group) had measurements at 4 periods during infancy: birth, 1 to 2 months, 3 to 5 months, and 6 to 14 months; and 33 (partial HC data group) had measurements at birth and 6 to 14 months (n = 7), and at birth only (n = 28). Main Outcome Measures  Age-related changes in infants with ASD who had multiple-age measurements, and the relationship of these changes to brain anatomy and clinical and diagnostic outcome at 2 to 5 years were evaluated by using 2 nationally recognized normative databases: cross-sectional normative data from a national survey and longitudinal data of individual growth. Results  Compared with normative data of healthy infants, birth HC in infants with ASD was significantly smaller (z = –0.66, P<.001); after birth, HC increased 1.67 SDs and mean HC was at the 84th percentile by 6 to 14 months. Birth HC was related to cerebellar gray matter volume at 2 to 5 years, although the excessive increase in HC between birth and 6 to 14 months was related to greater cerebral cortex volume at 2 to 5 years. Within the ASD group, every child with autistic disorder had a greater increase in HC between birth and 6 to 14 months (mean [SD], 2.19 [0.98]) than infants with pervasive developmental disorder-not otherwise specified (0.58 [0.35]). Only 6% of the individual healthy infants in the longitudinal data showed accelerated HC growth trajectories (>2.0 SDs) from birth to 6 to 14 months; 59% of infants with autistic disorder showed these accelerated growth trajectories. Conclusions  The clinical onset of autism appears to be preceded by 2 phases of brain growth abnormality: a reduced head size at birth and a sudden and excessive increase in head size between 1 to 2 months and 6 to 14 months. Abnormally accelerated rate of growth may serve as an early warning signal of risk for autism.      

Incidence of diabetes in youth in the United States

Context  Data on the incidence of diabetes mellitus (DM) among US youth according to racial/ethnic background and DM type are limited. Objective  To estimate DM incidence in youth aged younger than 20 years according to race/ethnicity and DM type. Design, Setting, and Participants  A multiethnic, population-based study (The SEARCH for Diabetes in Youth Study) of 2435 youth with newly diagnosed, nonsecondary DM in 2002 and 2003, ascertained at 10 study locations in the United States, covering a population of more than 10 million person-years. Main Outcome Measure  Incidence rates by age group, sex, race/ethnicity, and DM type were calculated per 100 000 person-years at risk. Diabetes mellitus type (type 1/type 2) was based on health care professional assignment and, in a subset, further characterized with glutamic acid decarboxylase (GAD65) autoantibody and fasting C peptide measures. Results  The incidence of DM (per 100 000 person-years) was 24.3 (95% confidence interval [CI], 23.3-25.3). Among children younger than 10 years, most had type 1 DM, regardless of race/ethnicity. The highest rates of type 1 DM were observed in non-Hispanic white youth (18.6, 28.1, and 32.9 for age groups 0-4, 5-9, and 10-14 years, respectively). Even among older youth (10 years), type 1 DM was frequent among non-Hispanic white, Hispanic, and African American adolescents. Overall, type 2 DM was still relatively infrequent, but the highest rates (17.0 to 49.4 per 100 000 person-years) were documented among 15- to 19-year-old minority groups. Conclusions  Our data document the incidence rates of type 1 DM among youth of all racial/ethnic groups, with the highest rates in non-Hispanic white youth. Overall, type 2 DM is still relatively infrequent; however, the highest rates were observed among adolescent minority populations.      

Mortality in a cohort of street youth in Montreal

Context  Many studies have shown a high prevalence of sexually transmitted diseases, human immunodeficiency virus (HIV) infection, viral hepatitis, drug dependence, and mental health problems among street youth. However, data on mortality among these youth are sparse. Objectives  To estimate mortality rate among street youth in Montreal and to identify causes of death and factors increasing the risk of death. Design, Setting, and Population  From January 1995 to September 2000, 1013 street youth 14 to 25 years of age were recruited in a prospective cohort with semi-annual follow-ups. Original study objectives were to determine the incidence and risk factors for HIV infection in that population; however, several participants died during the first months of follow-up, prompting investigators to add mortality to the study objectives. Mortality data were obtained from the coroner's office and the Institut de la Statistique du Québec. Main Outcome Measures  Mortality rate among participants and factors increasing the risk of death. Results  Twenty-six youth died during follow-up for a mortality rate of 921 per 100 000 person-years (95% confidence interval [CI], 602-1350); this represented a standardized mortality ratio of 11.4. The observed causes of death were as follows: suicide (13), overdose (8), unintentional injury (2), fulminant hepatitis A (1), heart disease (1); 1 was unidentified. In multivariate Cox regression analyses, HIV infection (adjusted hazard ratio [AHR] = 5.6; 95% CI, 1.9-16.8), daily alcohol use in the last month (AHR = 3.2; 95% CI, 1.3-7.7), homelessness in the last 6 months (AHR = 3.0; 95% CI, 1.1-7.6), drug injection in the last 6 months (AHR = 2.7; 95% CI, 1.2-6.2), and male sex (AHR = 2.6; 95% CI, 0.9-7.7) were identified as independent predictors of mortality. Conclusions  Current heavy substance use and homelessness were factors associated with death among street youth. HIV infection was also identified as an important predictor of mortality; however, its role remains to be clarified. These findings should be taken into account when developing interventions to prevent mortality among street youth.      

Patterns of participation of patients in cancer clinical trials in Ireland

Background  In the United States the overall participation in cancer clinical trials (CCT) is less than 3% [Avis et al. in J Clin Oncol 24:1860–1867 (2006); Lara et al. in J Clin Oncol 19:1728–1733 (2001)]. In Europe there is little data on participation in such trials. Aim  We aim to gather information on factors influencing CCT enrolment in Ireland. Methods  From November 2005 to 28 February 2006 all consecutive patients considered for systemic therapy were assessed for eligibility re participation in available CCTs. Results  A total of 290 patients were included. Overall 2.4% of patients were recruited to one of the available CCTs. The main reasons for failure of trial recruit were: no trial for cancer type (60%), no trial for stage (21%), ineligible by trial criteria (16.1%), patient declined (0.3%), and physician discretion (2.6%). Only one patient, who was otherwise eligible, declined entry into a clinical trial. Conclusions  Irish patients with cancer are very willing to participate in CCTs. Current levels of recruitment compare favourably with international levels. Presented in part for a poster presentation at the 31st European Society of Medical Oncology (ESMO) congress. Poster number 619. Annals of Oncology 17 (Supplement 9): ix191, 2006. The Cancer Centre Beaumont Hospital is affiliated to NSABP, ECOG, ICORG, HRB.     

Assessment of dyslipidemia in pre-dialysis patients in south-west Nigeria

Background:

Majority of chronic kidney disease (CKD) patients are more likely to die of cardiovascular complications before reaching end stage renal disease. The Kidney Disease Outcomes Quality Initiative (K/DOQI) recommends that all CKD patients should be evaluated for dyslipidemia and for treatment to reduce the risk of cardiovascular events.

Patients and Methods:

A cross-sectional case control study to determine the frequency of occurrence of lipid abnormalities in patients with CKD and compare these abnormalities with that of normal controls. A total of 100 patients and 100 controls were recruited for the study. Demographic and clinical data were obtained using structured questionnaire. Weight, height and waist circumference, body mass index (BMI) and blood pressure were also obtained. Subjects had their fasting lipid profile and fasting plasma glucose assayed after overnight fast of 8-14 hours. Low-density lipoprotein (LDL) was obtained using Friedwald formula.

Result:

The study revealed that total cholesterol (TC) was elevated above normal levels in 44% of cases compared with 6% in controls (P < 0.001), with the mean (SD) value of 5.82 ± 3.28 mmol/l for cases compared with 3.9 ± 1.0 mmol/l (P < 0.001) in controls. Low density lipoprotein was elevated in 48% of cases compared with 14% in controls (P < 0.001), with the mean (SD) values of 4.15 ± 2.74 mmol/l and 2.57 ± 0.95 mmol/l for cases and controls, respectively, (P < 0.001). Triglyceride (TG) was elevated above normal level in 26% of cases compared with none in the controls (P < 0.001), with the mean (SD) values of 1.41 ± 1.10 mmol/l and 0.64 ± 0.24 mmol/l for cases and controls, respectively (P < 0.001). All Lipid fractions except HDL also correlated significantly with levels of proteinuria TC (r = 0.345, P = 0.001), TG (r = 0.268, P = 0.011) LDL (r = 0.366, P = 0.001).

Conclusion:

Dyslipidemia is common among patients with CKD. Regular evaluation of all CKD patients for dyslipidemia and treatment need be instituted.     

Incidence of hepatitis A in the United States in the era of vaccination

Context  In the United States, hepatitis A is a frequently reported vaccine-preventable disease. Vaccination has been recommended for persons at increased risk since 1996. In 1999, it was recommended that children living in 11 states with the highest incidence of hepatitis A be routinely vaccinated, and that children living in 6 additional states, with incidence above the national average, be considered for routine vaccination. Objective  To assess impact of the current vaccination strategy by evaluating trends in reported cases of hepatitis A since implementation. Design, Setting, and Cases  A longitudinal analysis of characteristics of cases of hepatitis A reported in the United States since 1990 to the National Notifiable Diseases Surveillance System. Main Outcome Measure  Incidence rates of reported cases of hepatitis A. Incidence rates in 2003 were compared with those for the prevaccination baseline period (1990-1997) overall and in the 17 states in which children should be routinely vaccinated or considered for routine vaccination (vaccinating states). Incidence rates in vaccinating states were also compared with those in the remaining states where there is no recommendation for statewide vaccination of children (nonvaccinating states). Results  Between the baseline period (1990-1997) and 2003, overall hepatitis A rates declined 76% to 2.6 per 100 000, significantly lower than previous nadirs in 1983 (9.2/100 000) and 1992 (9.1/100 000). The rate in vaccinating states declined 88% to 2.5 per 100 000 compared with 53% elsewhere (to 2.7/100 000). In 2003, cases from vaccinating states accounted for 33% of the national total vs 65% during the baseline period. Declines were greater among children aged 2 to 18 years (87%) than among persons older than age 18 years (69%); the proportion of cases in children dropped from 35% to 19%. Since 2001, rates in adults have been higher than among children, with the highest rates now among men aged 25 through 39 years. Conclusions  Following implementation of routine hepatitis A vaccination of children, hepatitis A rates have declined to historic lows, accompanied by substantial changes in the epidemiologic profile. Greater decreases in the age groups and regions where routine vaccination of children is recommended likely reflect the results of implementation of this novel vaccination strategy. Continued monitoring is needed to verify that implementation continues to proceed and that low rates are sustained.      

Therapeutic Effect of Propofol in the Treatment of Endotoxin-induced Shock in Rats

Lipopolysaccharide (LPS) ,amaincomponentofgram negativebacterialendotoxin[1] ,istheleadingcauseofsepsisorendotoxicshock ,andwhenadmin isteredexperimentallytoanimals ,mimicsthesameinflammatoryresponse The pathophysiologicalchangesseeninsepsisareoftennotduetotheinfec tiousorganismitselfbuttotheuncontrolledproduc tionofinflammatorymediators ,includingtumornecrosisfactor (TNF) α ,nitricoxide (NO)andneu trophilaccumulation Accumulationoftheseleadstotissuedamage ,ultimately producingthelethalit…     

艾司氯氨酮复合丙泊酚在小儿肠套叠复位术中的应用研究

目的 探讨艾司氯氨酮复合丙泊酚在小儿肠套叠复位术中的应用效果。方法 选取2019年6月—2021年6月南通大学第二附属医院收治的86例拟行肠套叠复位术患儿为研究对象,按随机数字表法分为观察组和对照组,每组43例。两组患儿均行水压灌肠复位,对照组术中采用丙泊酚（2.5 mg/kg）进行静脉麻醉;观察组术中采用艾司氯氨酮（0.5～1.0 mg/kg）联合丙泊酚（2.0 mg/kg）静脉麻醉。比较两组患儿的复位情况、住院时间、Ramsay镇静评分、苏醒时间及与麻醉相关的不良反应;比较手术前后两组疼痛行为量表（FLACC）评分差值;随访6个月,比较两组复发情况。结果 两组患儿的复位成功率比较,差异无统计学意（P>0.05）;两组患儿住院时间比较,差异无统计学意义（P>0.05）;观察组苏醒时间短于对照组（P <0.05）;观察组Ramsay镇静评分低于对照组（P <0.05）;观察组手术前后FLACC评分差值高于对照组（P <0.05）;两组与麻醉相关的总不良反应发生率比较,差异无统计学意义（P>0.05）;两组复发率比较,差异无统计学意义（P>0.0...     

Discussion Sections in Reports of Controlled Trials Published in General Medical Journals: Islands in Search of Continents?

Context.— Several journals have adopted the Consolidated Standards of Reporting Trials (CONSORT) recommendations to make assessment of the quality of randomized controlled trials (RCTs) easier. One of these recommendations is that the trial's results be discussed in light of the totality of the available evidence. Objective.— To assess the extent to which reports of RCTs published in 5 general medical journals have discussed new results in light of all available evidence. Design.— Assessment of the discussion sections in all 26 reports of RCTs published during May 1997 in Annals of Internal Medicine, BMJ, JAMA, The Lancet, and The New England Journal of Medicine. Main Outcome Measure.— The inclusion or mention of a systematic review in the discussion section of each article. Results.— In only 2 articles were the RCT's results discussed in the context of an updated systematic review of earlier trials. In a further 4 articles, references were made to relevant systematic reviews, but no attempts were made to integrate the results of the new trials in updated versions of these reviews. One article was probably the first published trial to address the question studied. The remaining 19 articles included no evidence that any systematic attempt had been made to set the reported trial's results in the context of previous trials. Conclusion.— There is little evidence that journals have adequately implemented the CONSORT recommendation that results of an RCT be discussed in light of the totality of the available evidence.      

Role of osteopontin in diet-induced brown gallstone formation in rats

Background:Although osteopontin (OPN) is expressed in the liver and pigment gallstones of patients with hepatolithiasis, its role in pigment gallstone formation remains unclear. This study aimed to explore the function of OPN in pigment gallstone formation.Methods:Rats were fed a chow diet (CD) or lithogenic diet (LD) for 10 consecutive weeks; blocking tests were then performed using an OPN antibody (OPN-Ab). Incidence of gallstones and levels of several bile components, OPN, tumor necrosis factor alpha (TNF-α), and cholesterol 7 alpha-hydroxylase (CYP7A1) were analyzed. To determine TNF-α expression in hepatic macrophages and both CYP7A1 and bile acid (BA) expression in liver cells, recombinant rat OPN and recombinant rat TNF-α were used to treat rat hepatic macrophages and rat liver cells, respectively. Chi-square or Fisher exact tests were used to analyze qualitative data, Student t-test or one-way analysis of variance were used to analyze qualitative data.Results:Incidence of gallstones was higher in LD-fed rats than in CD-fed rats (80% vs. 10%, P < 0.05). BA content significantly decreased in bile (t = −36.08, P < 0.01) and liver tissue (t = −16.16, P < 0.01) of LD-fed rats. Both hepatic OPN protein expression (t = 9.78, P < 0.01) and TNF-α level (t = 8.83, P < 0.01) distinctly increased in the LD group; what''s more, CYP7A1 mRNA and protein levels (t = −12.35, P < 0.01) were markedly down-regulated in the LD group. Following OPN-Ab pretreatment, gallstone formation decreased (85% vs. 25%, χ² = 14.55, P < 0.01), liver TNF-α expression (F = 20.36, P < 0.01) was down-regulated in the LD group, and CYP7A1 expression (F = 17.51, P < 0.01) was up-regulated. Through CD44 and integrin receptors, OPN promoted TNF-α production in macrophage (F = 1041, P < 0.01), which suppressed CYP7A1 expression (F = 48.08, P < 0.01) and reduced liver BA synthesis (F = 119.4, P < 0.01).Conclusions:We provide novel evidence of OPN involvement in pigmented gallstone pathogenesis in rats.