特发性血小板减少性紫癜患者血清白细胞介素11水平、淋巴细胞亚群及NK细胞变化的临床意义

目的 检测特发性血小板减少性紫癜(ITP)患者血清白细胞介素11(IL-11)水平、淋巴细胞亚群及NK细胞的变化,探讨相关因素在ITP发病中的作用.方法 应用酶联免疫吸附法(ELISA)、流式细胞术分别检测50例ITP(ITP组)和30例健康体检者(对照组)血清IL-11水平、淋巴细胞亚群及NK细胞的变化.结果 ITP组的血小板计数[(30.21±19.40)×109/L]明显低于对照组[(207.21±31.55)×109/L](P＜0.05),ITP组患者血清IL-11水平[(255.72±163.43)ng/L]明显高于对照组[(40.60±5.57)ng/L](P＜0.05),相关分析表明ITP患者血清IL-11水平与血小板计数呈负相关(r=-0.557,P＜0.05);ITP组患者CD3+、CD4+T淋巴细胞百分比及CD4+/CD8+明显低于对照组(P＜0.05),CD8+T淋巴细胞百分比明显高于对照组(P＜0.05);CD3-CD(16+56)+NK细胞百分比明显低于对照组(P＜0.05).结论 IL-11水平、淋巴细胞亚群及NK细胞变化与ITP的发病密切相关,且IL-11水平与血小板计数可能存在负反馈调节作用.

Abstract：

Objective To detect the serum level of interleukin (IL)-1 1, lymphocyte subsets and NK cells in patients with idiopathic thrombocytopenic purpura (ITP), and explore the related factors in the pathogenesis of ITP. Methods The serum level of IL-11, lymphocyte subsets and NK cells were detected by double antibody sandwich enzyme linked immunosorbent assay (ELISA) and flow cytometry in 50 ITP patients (ITP group) and 30 controls (control group). Results The platelet in ITP group [ (30.21 ± 19.40) ×109/L] was lower than that in control group [ (207.21 ± 31.55 ) × 109/L] obviously (P ＜ 0.05 ); the serum level of IL-11 in ITP group [(255.72 ± 163.43) ng/L] was significantly higher than that in control group [ (40.60 ± 5.57 ) ng/L ] (P ＜ 0.05 ). The correlation analysis indicated that the blood serum levels of IL- 11 had negative relationship with the platelet (r = -0.557 ,P ＜ 0.05). The percentage of CD3+ and CD4+ T lymphocyte percentage, CD4+/CD8+ in ITP group were lower and the percentage of CD8+ T lymphocyte was higher than those in control group obviously (P ＜ 0.05 ). The percentage of CD3- CD(16+56) +NK cell in ITP group was lower than that in control group (P ＜ 0.05). Conclusion IL-11, lymphocyte subgroup and NK cell change correlate with ITP morbidity closely, and the IL-11 level and the platelet possibly have the negative feedback control action.     

胃癌患者外周血淋巴细胞免疫功能的变化及临床意义

目的检测胃癌患者外周血淋巴细胞免疫功能的变化,探讨其与胃癌新临床病理分期(TNM)及组织病理学分级的关系。方法流式细胞仪测定胃癌患者及正常对照组外周血淋巴细胞亚群及NK细胞数量。结果胃癌患者外周血CD3+、CD4+、NK、CD19+细胞数量及CD4+/CD8+比值较正常对照组明显下降(P<0.01),而CD8+细胞水平显著升高(P<0.01)。Ⅲ～Ⅳ期患者的CD3+细胞数、CD4+/CD8+比值、NK细胞数降低(P<0.05)。胃癌组织的分化程度与细胞免疫功能无明显相关性。结论胃癌患者外周血淋巴细胞免疫功能低下,且临床病理分期越晚,其免疫功能越低。检测淋巴细胞亚群、NK细胞可用于胃癌患者的免疫状态监测。     

手术前后卵巢癌患者外周血T细胞亚群及CD4~+CD25~+调节性T细胞表达及临床意义

目的:探讨手术前后卵巢癌患者外周血T细胞亚群及CD4+CD25+调节性T细胞的变化及其临床意义。方法:采用流式细胞术检测80例卵巢癌患者外周血T淋巴细胞亚群、NK细胞及CD4+CD25+调节性T细胞水平。结果:与对照组相比,卵巢癌患者外周血中CD3+,CD4+,CD4+/CD8+比值及NK细胞含量均降低(P0.05),CD8+升高(P0.05);随着疾病进展Ⅲ期+Ⅳ期与Ⅰ期+Ⅱ期比较CD3+,CD4+,CD4+/CD8+比值及NK细胞含量均降低(P0.05),CD8+升高(P0.05)。卵巢癌患者外周血CD4+CD25+细胞比例高于正常对照组(P0.05);手术后卵巢癌患者T细胞亚群比例与术前比较并未明显恢复(P0.05),但CD4+CD25+调节性T细胞水平有所恢复(P0.05)。结论:卵巢癌患者免疫功能低下,术后短期并不能恢复,CD4+CD25+调节性T细胞水平升高,术后明显恢复,提示其在免疫耐受中起重要作用。     

妊娠期糖尿病对新生儿免疫功能的影响

目的监测并比较妊娠期糖尿病孕妇在不同血糖控制情况下,其新生儿免疫球蛋白IgG、IgM、IgA与T淋巴细胞亚群CD 3+、CD 4+、CD 8+、CD 4+/CD 8+的值以及自然杀伤(natural killer,NK)细胞的含量值。方法选取凉山彝族自治州第二人民医院210例经确诊为妊娠期糖尿病(gestational diabetes mellitus,GDM)患者分娩的新生儿作为研究组,以及同时期100例由正常孕妇分娩的新生儿作为对照组。根据血糖控制水平,将GDM患者分为血糖控制理想组(GDM-A组)115例患者和血糖控制不理想组(GDM-B组)95例患者。采用流式细胞仪监测外周血T细胞亚群和NK细胞的含量;采用散射比浊度法检测免疫球蛋白的含量。结果经流式细胞仪检测,对于GDM-B组的新生儿,外周血中CD 3+细胞[(52.35±11.17)%]、CD 8+细胞[(15.69±5.58)%]水平均低于对照组和GDM-A组,CD 4+/CD 8+比值[(1.58±0.39)%]高于对照组;而NK细胞(6.37±1.29)%水平明显低于对照组与GDM-A组,差异均有统计学意义(P0.05)。GDM-A组新生儿外周血中NK细胞水平为(8.44±2.05)%,低于对照组(11.19±1.74)%,差异有统计学意义(P0.05)。而其他外周血T淋巴细胞亚群水平与对照组相比,差异无统计学意义(P0.05)。经散射比浊法检测,GDM-B组新生儿外周血IgG水平为(6.45±1.25)g/L,低于对照组[(9.99±1.36)g/L]和GDM-A组[(9.47±1.58)g/L]水平,差异有统计学意义(P0.05)。其他数据3组比较差异无统计学意义(P0.05)。结论 GDM可能会影响新生儿非特异性免疫功能,若妊娠期间血糖控制不理想,则可能造成新生儿免疫功能低下。因此GDM孕妇应积极控制妊娠期间血糖水平。     

肺癌患者外周血T淋巴细胞亚群的变化

目的研究肺癌患者外周血T淋巴细胞亚群的水平及变化特点。方法采用流式细胞技术,对41例肺癌患者术前检测外周血T淋巴细胞亚群水平,并与50例健康献血者作对照研究。结果与对照组比较,肺癌患者CD3+、CD4+、CD8+和NK细胞减少,CD4+/CD8+降低,差异均有统计学意义(P均<0.01)。淋巴细胞亚群变化与分期相关:Ⅰ期肺癌患者T淋巴细胞亚群未见明显抑制;Ⅱ期CD3+、CD4+、CD8+和NK细胞减少,但较Ⅰ期差异无统计学意义;Ⅲ期肺癌患者所有亚群均降低,分别与Ⅰ期和Ⅱ期比较,差异均有统计学意义;随着分期增加,CD4+/CD8+明显降低,各期之间差异均有统计学意义。淋巴结转移组NK细胞和CD4+/CD8+均明显低于无淋巴结转移组,差异均有统计学意义(P均<0.01)。结论肺癌患者存在免疫功能低下,免疫功能随着肿瘤的进展进一步受到削弱。     

PD-1在弥漫性大B细胞淋巴瘤患者外周血CD4~+T细胞和CD8~+T细胞上的表达和临床意义

目的探讨PD-1在弥漫性大B细胞淋巴瘤外周血CD4+T细胞和CD8+T细胞上的表达及临床意义。方法以32例DLBCL患者为研究对象,同期健康志愿者18例为对照组。应用流式细胞技术比较2组CD4+T细胞和CD8+T细胞PD-1的表达水平的差异,分析CD4+T细胞和CD8+T细胞的PD-1表达与DLBCL患者各临床病理因素的相关性。结果外周血CD4+T细胞和CD8+T细胞的PD-1表达水平在DLBCL组均显著高于对照组,2组间差异有统计学意义(P0.01)。在DLBCL组中,Ann Arbor分期Ⅰ期~Ⅱ期患者CD4+T细胞和CD8+T细胞的PD-1表达水平均低于Ⅲ期~Ⅳ期患者,差异亦有统计学意义(P0.05)。5例DLBCL患者在化疗期间PD-1在CD4+T细胞和CD8+T细胞的表达水平较化疗前有下降趋势。结论 DLBCL患者外周血PD-1表达水平升高,与临床分期和治疗存在一定的相关性。     

乙型肝炎后肝硬化T细胞亚群、肿瘤坏死因子-α、白细胞介素-6、白细胞介素-8的临床研究

目的 探讨乙型肝炎病毒(HBV)携带者及乙型肝炎后肝硬化患者T细胞亚群、肿瘤坏死因子(TNF)-α、白细胞介素(IL)-6、IL-8的变化及意义.方法 利用流式细胞仪方法和酶联免疫吸附试验法分别检测30例HBV携带者(HBV携带者组)及27例乙型肝炎后肝硬化患者(乙型肝炎后肝硬化组)的T细胞亚群、TNF-α、IL-6、IL-8含量,并与20例正常对照者(正常对照组)进行比较.结果 乙型肝炎后肝硬化组及HBV携带者组与正常对照组比较,CD3+显著下降(0.5900±0.0305、0.6500±0.0502比0.7000±0.0554,P＜ 0.01);CD4+显著下降(0.2900±0.0283、0.3800±0.0306比0.4400±0.0411,P＜ 0.01);CD8+显著升高(0.2900±0.0152、0.2700±0.0238比0.2500±0.0459,P＜ 0.01或＜0.05);CD4+/CD8+乙型肝炎后肝硬化组显著低于正常对照组(1.03±0.10比1.73±0.16,P＜ 0.01),但HBV携带者组与正常对照组比较差异无统计学意义(1.71±0.18比1.73±0.16,P＞0.05);乙型肝炎后肝硬化组与正常对照组相比NK(CD16+ CD56)显著下降(0.1300±0.0541比0.1900±0.0742,P＜0.01),但HBV携带者组与正常对照组比较差异无统计学意义(0.1600±0.0539比0.1900±0.0742,P＞ 0.05),乙型肝炎后肝硬化组与HBV携带者组比较差异有统计学意义(P＜0.05);乙型肝炎后肝硬化组和HBV携带者组TNF-α显著升高[(307.00±38.28)、(113.00±18.61)μg/L比(101.00±13.90) μg/L,P＜ 0.01];IL-6显著升高[(184.60±18.86)、(68.10±7.58) μg/L比(63.40±7.04)μg/L,P＜0.01或＜0.05];IL-8显著升高[(1710.00±158.05)、(926.00±61.82) μg/L比(814.00±45.91)μg/L,P＜0.01].结论 T细胞亚群、TNF-α、IL-6和IL-8水平的高低,能够反映肝细胞损害的程度,可以作为临床上判断乙型肝炎严重程度和预后的重要指标.     

职业接触柴油机尾气作业人员外周血白细胞变化研究

目的了解柴油机尾气对作业工人外周血白细胞的影响。方法采用血细胞自动分析计数和流式细胞分析法,对某柴油机生产企业接触柴油机尾气的46名作业人员(接触组)进行白细胞分类计数和淋巴细胞亚群检测,并与同一地区自来水生产厂等3家企业43名作业人员(对照组)比较。结果两组白细胞总数无明显差异,在分类计数中,接触组中性粒细胞比率[(53.4±8.4)%]低于对照组[(58.0±8.0)%],且差异有统计学意义(P0.05),淋巴细胞比率[(38.3±7.9)%]高于对照组[(33.9±7.3)%],差异有统计学意义(P0.01);接触组CD3+细胞、CD4+细胞和B细胞绝对数分别为(2 211.0±624.3)×106/L,(1 232.6±372.0)×106/L,(419.3±172.7)×106/L,均高于对照组(1 869±540.6)×106/L,(1 007.4±316.7)×106/L,(353.2±172.5)×106/L,且差异有统计学意义(P0.01或P0.05)。结论职业接触柴油机尾气可能刺激机体产生免疫反应,其产生机制和相关病理效应需要做进一步的研究。     

镍职业暴露对作业工人外周血淋巴细胞亚群的影响

[目的]探讨镍职业暴露对作业工人外周血淋巴细胞亚群的影响。[方法]选择70名镍作业工人为暴露组,126名非镍作业工人为对照组,使用硫酸镍斑贴实验将暴露组分为斑贴阴性组和斑贴阳性组。乙炔-空气火焰原子吸收光谱法检测暴露工厂车间空气中镍浓度,电感耦合等离子体质谱法及外标法获得皮肤暴露镍浓度,分光光度法检测研究对象尿镍浓度。EDTA抗凝静脉血做常规分析,流式细胞技术检测外周血淋巴细胞亚群百分比,并结合二者获得外周血淋巴细胞亚群绝对值。t检验比较暴露组与对照组、斑贴阴性组与斑贴阳性组淋巴细胞亚群等指标的差异,Pearson相关分析尿镍水平、暴露工龄与淋巴细胞亚群等指标的相关性,一般线性模型分析吸烟与暴露的交互作用。[结果]暴露组作业工人斑贴阳性者共14人(阳性率20%),尿镍水平[M(P_(25),P_(75))]高于对照组[13.60(7.35,28.76)vs 6.02(3.93,10.97)μg/L,P=0.000],外周血白细胞、中性粒细胞及CD4~+/CD8~+高于对照组[分别为(7.03±1.67)×10~9/L vs(6.23±1.35)×10~9/L,(4.54±1.45)×10~9/L vs(3.71±1.07)×10~9/L,(1.68±0.72)vs(1.27±0.43),均P0.05],CD8~+T细胞、NK细胞和血小板低于对照组[分别为(0.52±0.26)×10~9/L vs(0.60±0.22)×10~9/L,(0.34±0.18)×10~9/L vs(0.45±0.25)×10~9/L,(200.66±69.01)×10~9/L vs(229.85±51.48)×10~9/L,均P0.05]。总人群CD4~+/CD8~+与尿镍水平呈正相关(r=0.152,P=0.037);未发现暴露工龄长短与外周血淋巴细胞亚群等指标存在相关关系(P0.05)。[结论]镍职业暴露可致作业工人外周血CD4~+/CD8~+增高,CD8~+T细胞、NK细胞降低。     

CD69+/NKG2D+比值在保健食品评价中应用

目的研究小鼠外周血自然杀伤细胞(NK)细胞分化抗原CD 69+/NKG2D+检测在保健食品免疫调节作用评价中的应用.方法以左旋咪唑25mg(kg·bw)连续灌胃3 d设立左旋咪唑阳性对照;进行小鼠外周血自然杀伤细胞(NK)亚群CD69+/NKG2D+检测和脾NK细胞活性测定试验,观察0.83,1.67g/(kg·bw)剂量组蛋白粉对小鼠NK细胞免疫功能的影响.结果与阴性对照组比较,左旋咪唑对照组和0.83,1.67g/(kg·bw)剂量组蛋白粉剂量组外周血NK细胞CD69-/NKG2D+、CD69+/NKG2D+比值以及脾NK细胞活性均明显升高.结论外周血NK细胞CD69+/NKG2D+检测与传统的NK细胞免疫检测结果有较好一致性,且方法敏感性较好,在保健食品免疫调节功能评价中有较好应用价值.     

女性生殖器结核的临床表现及腹腔镜与宫腔镜检查特点分析

目的探讨女性生殖器结核(FGT)的临床表现,以及在腹腔镜、宫腔镜检查的表现特点,提高临床对FGT的诊断和鉴别诊断能力。 方法选择2010年1月至2016年12月,于首都医科大学附属北京妇产医院妇科微创中心进行腹腔镜和(或)宫腔镜检查,并经抗酸染色法和(或)活组织病理学检查,以及腹水培养病原学检查确诊为FGT的33例患者为研究对象。其年龄为17～73岁,平均为(31.4±5.6)岁。采用回顾性分析方法,收集所有患者的不孕、腹部异常症状、月经改变等临床表现,胸部X射线摄片、CT检查等影像学辅助检查结果,以及腹腔镜探查、宫腔镜检查、活组织病理学检查结果,并进行统计学分析。对于患者的不孕、腹部异常症状、月经改变等临床表现发生率,以及腹腔镜、宫腔镜检查结果所占比例等计量资料,采用率(%)表示。 结果①本研究33例FGT患者的临床表现中,以不孕最为多见,为21例(63.6%,21/33)。其他临床表现包括：下腹胀痛为7例(21.2%,7/33),腹水为5例(15.2%,5/33),盆腔包块为5例(15.2%,5/33),月经量过少或闭经为4例(12.1%,4/33),月经不规律为2例(6.1%,2/33),痛经为1例(3.0%,1/33),绝经后出血为1例(3.0%,1/33)。②本研究33例FGT患者中,经活组织病理学检查确诊为FGT者为26例,其中,17例确诊为输卵管结核,3例确诊为输卵管结核合并卵巢结核,6例确诊为子宫内膜结核,病理学诊断FGT阳性率为78.8%(26/33);1例(3%,1/33)抗酸染色结果呈强阳性,确诊为输卵管结核;4例(12.1%,4/33)经腹部X射线摄片检查确诊为输卵管结核;2例(6.1%,2/33)经诊断性抗结核治疗后,确诊为输卵管结核。③本研究33例FGT患者的影像学辅助检查结果提示,该检查对诊断FGT的符合率为21.2%(7/33)。④本研究33例FGT患者的腹腔镜检查结果如下：合并腹水者为7例(21.2 %,7/33),腹膜粟粒样改变者为16例(48.5%,16/33),输卵管积水与周围组织包裹成团者为10例(30.3%,10/33),输卵管增粗,呈串珠样、腊肠样改变者为13例(39.4%,7/33),输卵管伞端有黄色脓液流出者为1例(3.0%,1/33),卵巢呈苍白样改变、质硬者为2例(6.1%,2/33),盆、腹腔内可见干酪样坏死物者为13例(39.4%,13/33)。⑤本研究33例FGT患者中,25例因合并不孕或月经改变,接受腹腔镜检查的同时进行宫腔镜检查的结果显示,6例(24.0%,6/25)宫角局部子宫内膜增厚不平,输卵管开口细小;1例(4.0%,1/25)子宫内膜变薄,呈不规则苍白样改变;4例(16.0%,4/25)为宫腔黏连,其中1例(4.0%,1/25)可见干酪样钙化灶;其余14例(56.0%,14/25)宫腔镜检查结果均为正常宫腔形态。 结论腹腔镜和(或)宫腔镜检查可清晰显示FGT病灶的部位、大小、形态及病变周围情况,对于FGT的诊断和鉴别诊断具有重要意义。     

Benefiting from clinical experience: the influence of learning style and clinical experience on performance in an undergraduate objective structured clinical examination

OBJECTIVE: To assess the relationship between clinical experience, learning style and performance in an objective structured clinical examination (OSCE) in medical students at the end of their first clinical year. DESIGN: Prospective study of undergraduate students taking an OSCE examination at the end of their first clinical year. SUBJECTS: 194 undergraduate medical students (95 male). MAIN OUTCOME MEASURES: Performance in the OSCE examination, the Entwhistle Learning Style Inventory1 and a composite self-reported score of clinical activity during the students first clinical year. RESULTS: Performance in the OSCE examination was related to well-organized study methods but not to clinical experience. A significant relationship between clinical experience and organized deep-learning styles suggests that knowledge gained from clinical experience is related to learning style. CONCLUSIONS: The relationship between clinical experience and student performance is complex. Well-organized and strategic learning styles appear to influence the benefits of increased clinical exposure. Further work is required to elucidate the most beneficial aspects of clinical teaching.     

The clinical and educational experiences of pre-registration house officers in general practice

AIMS: To describe aspects of the clinical experience and educational supervision gained by pre-registration house officers (PRHOs) in general practice, and to relate these to the current General Medical Council (GMC) aims for general clinical training in general practice. DESIGN: Qualitative evaluation, part of which involved semistructured interviews with 12 PRHOs who were experiencing a general practice rotation. Interviews were conducted at the beginning and the end of the pre-registration year, and following return to hospital work after completion of the general practice placement. SETTINGS: Three teaching hospitals, two district general hospitals and six general practices in south-east England. PARTICIPANTS: 12 PRHOs who were involved in rotations incorporating a general practice placement. RESULTS: To varying degrees, the GMC aims for training in general practice were met for all the participants. All PRHOs recognized the value of the clinical experience and educational supervision they received in general practice. They particularly valued aspects such as having an individual training programme based on their own needs, and the interlinking of theory and practice, which aided learning. Most felt that having responsibility for their own patients acted as an important incentive for learning, and in general, PRHOs appreciated having the time to learn which general practice allowed. CONCLUSIONS: For the majority of PRHOs, the time spent in general practice was seen as a positive clinical and educational experience. In a variety of ways, the general practice placement encouraged PRHOs to develop the self-directed learning skills seen as essential to the lifelong learning advocated by the GMC. A number of recommendations are made to help improve the integration of the hospital and general practice components of these rotations.     

温岭市病毒性肝炎的病原学与临床类型

了解温岭市散发性病毒性肝炎的病原和临床特征,为制定科学的预防措施提供依据。方法对2000年1月至2009年12月在温州医学院附属温岭医院住院的3317例病毒性肝炎患者资料进行回顾性分析。结果在3317例患者中,甲、乙、丙、丁、戊、庚型病毒性肝炎分别占1.63％、64.97％、0.66％、0.12％、9.52％、0.06...     

Some problems in teaching clinical decision-making

Evaluation of a number of courses in clinical decision-making (CDM) indicates that there are well-defined problems in teaching this subject. This paper describes some of the difficulties and proposes appropriate remedies. Problems in teaching undergraduates are different from those in the postgraduate years. Three areas where the principles of CDM are particularly useful to undergraduates relate to the structuring of clinical problems, clarifying the place of value judgements and developing new concepts regarding test ordering, particularly the importance of false positive rates and the overwhelming power of prior probabilities. In postgraduate teaching the most important areas relate to the origin of probability and of utility estimates. The complexity of decision analysis also needs critical comment. Two remedies are suggested which will help course developers when faced with these problems. Firstly, the early introduction of concepts regarding sensitivity analysis, making it clear that with the aid of CDM we are able to deal with a wide range of probability estimates, precision rarely being required in clinical medicine. Secondly, the availability of educational support systems will help expert clinicians teach CDM concepts within their own field.     

农村社区儿童犬伤情况调查与处理

目的 调查农村社区儿童犬伤现状，分析创口的临床处理，预防人兽共患疾病。方法 调查2010年1月-2012年12月，某农村社区儿童犬伤的临床特点、创面急诊处理的临床疗效，组间数据率的比较，用χ²检验。结果 470例儿童犬伤患者，夏秋季节发生338例，冬春季节132例，夏秋季节和冬春季节比较差异有统计学意义(χ²=218.0，P＜0.01)。470例儿童犬伤患者创面全部愈合。随访至今，470例患者中无破伤风与狂犬病的病例发生。结论 农村社区儿童犬伤是儿童意外严重伤害的重要原因，及时处理创口，预防接种，健康教育，加强犬类管理，有利于预防人兽共患疾病。     

Informed consent in clinical training--patient experiences and motives for participating

The purpose of this study was to assess patients' attitudes to and experiences of participating in the clinical training of medical students. Samples of patients (n = 582) selected at random from six different departments (gynaecology, psychiatry, internal medicine, paediatrics, urology and a health care centre with general practitioners) were interviewed by means of a questionnaire. The patients were selected from those who had consulted the actual departments in the last six months of 1995. Four hundred and forty-one patients (76%) answered the questionnaire. Seventy-one per cent of all patients had experience of participating; of these 41% had estimated that they had once or several times participated without being informed. Eighty per cent felt aggrieved if they were not informed. On average 88% were, in principle, positive to participating. Of those who were, in principle, negative a majority had negative experiences of participating. Elderly patients tended to accept participating more often without being informed. Almost all patients seemed to be positive to participating in the education of medical students, although a silent precondition might be that patients should be informed and given the opportunity to abstain.     

Conceptual frameworks in preclinical and clinical textbooks

This is an exploratory attempt to investigate the organization of knowledge in preclinical and clinical textbooks. A theoretical framework to understand the role of textbooks in medical education is developed. An analysis of preclinical and clinical textbooks indicates that preclinical textbooks organize the same field of knowledge differently to clinical ones. In clinical textbooks two different types of organization are indicated. The implication of these findings is discussed.     

舒张期反向血流在腹部和外周血管中出现的意义

目的探讨舒张期反向血流在腹部和外周血管中出现的意义。方法对2000年1月至2009年3月行腹部和外周血管超声检查患者的多普勒频谱形态进行回顾性分析。结果在腹部和外周血管超声检查中共发现舒张期反向血流患者68例,包括锁骨下动脉窃血综合征21例,肾移植并发症22例,中晚期妊娠重度子痫前期3例,人工血液透析动静脉瘘血栓形成20例,其他2例。舒张期反向血流在腹部和外周血管中出现,其病因可被分为血管型（41例）、器官型（22例）、妊娠型（3例）和其他（2例）。结论舒张期反向血流在腹部和外周血管中的出现因部位不同而病因不同,对其病因分型有助于提高对舒张期反向血流的认识。     

舒张期反向血流在腹部和外周血管中出现的意义

目的 探讨舒张期反向血流在腹部和外周血管中出现的意义.方法 对2000年1月至2009年3月行腹部和外周血管超声检查患者的多普勒频谱形态进行回顾性分析.结果 在腹部和外周血管超声检查中共发现舒张期反向血流患者68例,包括锁骨下动脉窃血综合征21例,肾移植并发症22例,中晚期妊娠重度子痫前期3例,人工血液透析动静脉瘘血栓形成20例,其他2例.舒张期反向血流在腹部和外周血管中出现,其病因可被分为血管型(41例)、器官型(22例)、妊娠型(3例)和其他(2例).结论 舒张期反向血流在腹部和外周血管中的出现因部位不同而病因不同,对其病因分型有助于提高对舒张期反向血流的认识.