Oral tolerance in EAE: reversal of tolerance by T helper cell cytokines

Oral administration of myelin basic protein (MBP) inhibits clinical and histopathological manifestations of experimental autoimmune encephalomyelitis (EAE), but only partially reduces serum anti-MBP antibody titers. We report here that orally administered MBP alters the isotypic distribution of anti-MBP antibody-forming cells (AFC) among various lymphoid tissues, with the most profound differences seen in mucosal tissues. We observed an isotype-selective reduction in anti-MBP IgA but not IgM AFC frequencies in Peyer's patches. The anti-MBP IgA AFC frequencies could be reconstituted by addition of interleukin 4 (IL-4) and interleukin 5 (IL-5). The cytokines did not appear to generate de novo responses since no increases in anti-MBP IgA AFC frequencies were observed in control cultures. These results indicate that decreased antibody production, as a result of oral antigen administration, can be reversed by exposure to the appropriate cytokines.     

蕲蛇酶减轻大鼠局灶性脑缺血再灌注损伤的实验研究(Ⅱ)

目的 从病理形态学观察蕲蛇酶对大鼠局灶性脑缺血再灌注损伤的保护作用并探讨其机制。方法 采用线栓法制备大鼠大脑中动脉栓塞后再灌注模型，光镜及电镜观察缺血3h恢复血流再灌24h后脑组织形态学变化。TTC染色观察脑梗死面积，免疫组织化学方法检测脑组织碱性成纤维细胞生长因子（bFGF）的表达。用药组分别在缺血即刻或再灌即刻静脉给予不同剂量的蕲蛇酶，观察比较模型组和蕲蛇酶所有给药组之间上述指标的变化。结果 缺血即刻给蕲蛇酶4U／kg组较再灌即刻给蕲蛇酶同剂量组显著减小梗死灶（P〈0．001），减轻脑组织病理改变，并使脑组织中bFGF蛋白表达明显增多。结论 蕲蛇酶对脑缺血再灌注损伤的神经保护作用可能与脑组织中bFGF表达增高有关；提示该药早期使用更为有效。     

Benefits from peer teaching in the dental gross anatomy laboratory

This study examined the impact of implementing a rotating dissection schedule on the attitudes and performance of first-year dental students in the gross anatomy laboratory at the University of Kentucky. In 2002-2003, half of the students assigned to each cadaver dissected the assigned objectives during the first 90 min of the laboratory session. During the last 30 min, the non-dissecting group members came into the laboratory and had the day's dissection demonstrated and explained to them via peer instruction. Dissection responsibilities rotated with each laboratory session. Eighty-eight percent of student participants were satisfied with the rotating dissection approach according to a mid-term survey, and this satisfaction level remained unchanged at the end of the semester for most students. Students' perceptions of the quality of peer laboratory presentations varied, with only 44% rating them as good or better. Eighty percent of students perceived that rotating dissection did not impede their performance, and this was confirmed by analysis of grade data. Student satisfaction and the ability to devote additional weekly curriculum time to studying anatomy in a very compressed curriculum were the main student-described benefits.     

某部性病基本知识调查分析

目的　探讨部队性病防治情况。方法　设计 10个与性病有关的问题 ,对随机抽样某师 4个营官兵现场无记名调查。结果　有关性病的基本知识已被大部分官兵所认知 ,但也有一部分官兵对性病缺乏了解 ,甚至误解。结论　在官兵中加强性病基本知识的宣传 ,强调性病的危害对部队防治性病很有必要。     

Comparison of the enzymatic and edema-produscing activities of two venom phospholipase A2 enzymes

The edema-producing activity of NNAVPLA₂, an acidic phospholipase A₂ (PLA₂) enzyme from Naja naja atra venom (NNAV), was less potent than that of TMVPLA₂ II, a basic PLA; from Trimeresurus mucrosquamatus venom (TMV). These edema-forming effects were greatly suppressed by pretreatment of rats with diphenhydramine/ methysergide or compound 48/80, which reduced the tissue content of histamine and serotonin. Heparin abolished and suppressed the paw edema caused by protamine and TMVPLA₂ II, respectively, but had no effect on the NNAVPLA₂-induced response. In isolated rat peritoneal mast cells, both PLA₂ concentration dependently induced the release of histamine and β-glueuronidase. Again, TMVPLA₂ II was more potent than NNAVPLA₂. This degranulation effect of mast cells caused by TMVPLA₂ II and protamine was inhibited by heparin, while that caused by NNAVPLA₂ was unaffected. The edema-forming and mast cell degranulation effects were greatly decreased in both PBPB-modified NNAVPLA₂ and PBPB-modified TMVPLA₂ II, in which the catalytic activity of the enzymes was completely lost. PBPB-modified TMVPLA₂ II-induced paw edema was also suppressed by heparin. Furthermore, this edematous response was totally reversed in rat pretreated with aspirin in combination with diphenhydramine and methysergide. These results suggest that the edema-forming effect of PLA₂ is probably dependent on the presence of catalytic, positive charge and pharmacological sites on its molecule.     

托吡酯对慢性癫(癎)大鼠海马碱性成纤维细胞生长因子表达的影响

目的研究托吡酯（TPM）对慢性癫痫大鼠海马碱性成纤维细胞生长因子（bFGF）表达的影响。方法制作戊四氮（PTZ）慢性癫痫点燃大鼠模型，分为PTZ组、TPM组及正常对照组，每组又以5d、10d、15d3个时间点各分为3小组。免疫组化法观察各组海马CAl、CA3区及齿状回bFGF表达，HE染色观察病理形态学改变。结果（1）行为学观察：PTZ组和TPM组在癫痫发作上无明显差别。（2）bFGF表达：①各组齿状回区bFGF表达：PTZ组和TPM组各时点表达不断增高，与正常对照组比较差异有统计学意义（均P〈0．01），尤以10d及15d时增高更明显，与5d时比较差异有统计学意义（均P〈0．05）。②各组CAl区bFGF表达：PTZ组各时点均有明显表达，且随时间延长而表达不断增高，各时点比较差异有统计学意义（均P〈0．01），与正常对照组比较差异有统计学意义（均P〈0．01）；TPM组在5d时与正常对照组比较差异有统计学意义（P〈0．01），而10d、15d时逐渐下降，接近正常对照组水平。③各组CA3区bFGF表达：5d时3组比较差异无统计学意义。但PTZ组和TPM组在10d时与正常对照组比较差异有统计学意义（P〈0．01），PTZ组在15d时和TPM组及正常对照组比较差异有统计学意义（均P〈0．01）。（3）病理形态学改变：PTZ组和TPM组的海马CAl、CA3区尤其是CAl区可见较多神经元发生变性和坏死，PTZ组更显著。结论PTZ点燃过程中海马bF-GF表达增高，尤其在CAl区，且随时间延长有表达不断增高的趋势。TPM可能通过减少海马神经元损伤而明显下调海马CAl、CA3区bFGF的表达。     

碱性成纤维细胞生长因子治疗猫急性脑梗死的作用机制研究

目的:观察碱性成纤维生长因子(bFGF)处理的缺血再灌注不同时程的猫脑组织中微管相关蛋白(MAP-2)和神经丝蛋白(NTP)的表达,探讨bFGF治疗缺血性脑损伤的可能作用机制。方法:健康家猫30只,随机分为生理盐水对照组和bFGF治疗组。采用左侧眼眶入路制作大脑中动脉缺血再灌注模型。于术前和再灌注24h、48h和7d,采用Philip的猫脑缺血神经功能评分标准进行神经功能缺损评分;应用免疫组织化学SP法检测缺血再灌注不同时程的脑组织MAP-2及NTP蛋白表达,进行免疫阳性细胞计数。结果:缺血再灌注48h后,治疗组动物神经功能受损程度较对照组明显减轻,MAP-2及NTP蛋白阳性细胞数目较对照组也显著增加。结论:bFGF通过诱导MAP-2及NTP蛋白的表达,减轻了缺血再灌注脑组织的神经元损伤和促进了神经纤维生长,从而改善受损的神经功能。     

论中医病因、致病因素、邪气、邪之关系

邪是一切不正常、不正当的因素,邪气是邪的一部分,主要指六气异常以及疫疠之气等外感因素。两者可以独立于人体而存在,也可以进入人体,成为可能导致疾病的因素,即致病因素,邪(邪气)进入人体是致病因素,未进入人体不是致病因素。未导致疾痛的致病因素不是病因,已经引起疾病的致病因素是病因。     

Competitive dissociation of encephalitogenic complexes between antigen presenting cells and myelin basic protein

Splenic T cells from myelin basic protein (MBP)-immunised Lewis rats were activated to transfer experimental autoimmune encephalomyelitis (EAE) by co-culture with MBP-pulsed lymphoid dendritic cells (DC). MBP-pulsed DC could be kept for at least 24 h at 37 degrees C in antigen-free medium without affecting their ability subsequently to activate encephalitogenic T cells. However, MBP-pulsed DC were rendered much less stimulatory after a 6 h, but not 2 h, secondary incubation with ovalbumin. Thus, although encephalitogenic complexes between MBP and DC appear very stable in the absence of competing antigens, in their presence, antigen exchange can take place over a period of a few hours; this has positive implications for therapy of EAE by antigen competition.     

The need for basic sciences in the understanding and practice of anaesthesia

We conducted a survey using an unstructured, then a structured, questionnaire to determine the attitudes of 78 postfellowship anaesthetists to the Basic Sciences component of the part I examination for the FRCA. Seventy-two per cent replied. These anaesthetists felt that about 65% of the basic science syllabus was essential to the understanding and practice of everyday anaesthesia, but there was varying opinion as to the importance of specific topics. Cardiovascular, respiratory, central nervous system and renal physiology were all regarded as essential, as was the pharmacology of anaesthetic drugs. Topics regarded as irrelevant included biochemistry, endocrinology, membrane theory and immunology. Paradoxically, there were many topics which anaesthetists regarded as essential but on which they were unable to give a tutorial. There was little difference between the responses of consultants and trainees. This survey may help to identify a core syllabus on which the majority of anaesthetists agree but also suggests that the current syllabus is overloaded with detail that has no place in clinical practice.