人脂肪干细胞复合脱细胞软骨基质支架在生物反应器中构建组织工程软骨

目的:观察人脂肪干细胞复合脱细胞软骨基质支架在生物反应器中初步构建组织工程软骨的可行性。方法:实验于2005-04/2006-05在解放军总医院骨科研究所完成。脂肪组织和关节软骨均来自膝关节置换术中切除的组织,并经患者知情同意。关节软骨冻干后经粉碎机粉碎,过筛,选取25～38μm大小的软骨微粒。在样品中先加入2.5g/L胰蛋白酶,37℃消化24h,再加入1%Triton X-100震荡72h。将软骨微粒和蒸馏水按1∶3的比例混合后滴加在模板中,置入冷冻干燥机冻干后行紫外线交联。紫外线照射8h完成。最后经25kGy 60Co辐照灭菌完成支架制备。取膝关节置换术中切除的髌下脂肪垫,酶消法获得脂肪干细胞,扩增后复合于脱细胞软骨基质制成圆柱状三维支架上(细胞密度5×1010L-1),置于生物反应器中进行诱导培养,同时设静态培养组作为对照,3周后观测大体形态和组织学形态变化,同时进行组织化学(包括番红花O,阿利新蓝染色)和Ⅱ型胶原免疫组织化学分析。结果:生物反应器组诱导培养3周苏木精-伊红染色显示支架结构消失,只有中心区域残存少量支架结构;静态培养组支架结构尚存在,有少量基质分泌。番红花O染色显示生物反应器组细胞外有大量蛋白聚糖沉积,阿利新蓝染色表明有软骨特异性蛋白多糖的聚集;而静态培养组只有部分区域染色且淡于生物反应器组。Ⅰ型胶原免疫组化的结果显示,在生物反应器组细胞能够合成大量软骨细胞特异性胶原成分,而静态培养组呈弱阳性。结论:生物反应器培养明显促进了脂肪干细胞的增殖与软骨分化,是体外构建组织工程软骨的良好方法。     

应用遥测肌电技术实测分析人体助行带的生物力学作用

目的:人体助行带为一种随身佩带的动力装置,应用遥测肌电技术测定和分析自行研制的人体助行带的生物力学作用机制。方法:实验于2005-12/2006-06在天津体育大学运动生物力学实验室进行。选取天津市天津医院30名受试对象,均对本实验知情同意。按照生物力学的测试要求,首先对受试者进行5次以上行走状态下的遥测肌电测定,然后在同等条件下对受试者佩带助行带实施对照研究。实验采用的助行带为自行研制的,由腰至足以双层弹力带作为动力装置的弹性结构。结果:行走摆动相大腿肌肌电:佩带助行带后肌内侧肌、肌二头肌、半腱肌肌电高于佩带前(P<0.01)。支撑相小腿肌肌电:佩带助行带后胫前肌、腓骨长肌、腓肠肌肌电高于佩带前(P<0.01)。结论:通过弹力带施加于下肢的外部载荷,能够起到增强下肢肌电以及产生助行的生物力学功效。     

蒿甲醚对大鼠肺泡Ⅱ型上皮细胞DNA的影响

目的:蒿甲醚除了具有良好的临床治疗作用外,对正常组织有极大的副作用。实验拟观察蒿甲醚对大鼠肺泡Ⅱ型上皮细胞的影响。方法:实验于2005-09-20/2007-03-10在山东省泰山医学院生命科学研究所、中心实验室和机能实验室完成。①实验材料:蒿甲醚购自昆明制药厂,分析纯,使用前先进行预处理,处理方法:研磨后用溶液配成1g/L的母液,超声助溶解后供实验用。Wistar大鼠70只,体质量(70±15)g,雌雄不拘,由山东大学医学院实验动物中心提供。实验过程中对动物处置符合动物伦理学标准。②实验方法:将大鼠随机分为普通饲料对照组(n=10)和实验组(n=60),实验组分6个亚组,分别在饲料中加入0.1,0.2,0.4,0.8,1.6,3.2mg/kg的蒿甲醚。采用单细胞凝胶电泳技术观察大鼠肺泡Ⅱ型上皮细胞DNA的改变。结果:70只大鼠,饲养过程中实验组死亡6只,死亡原因为饲料添加蒿甲醚造成。当饲料中的蒿甲醚浓度为0.1mg/kg时,大鼠肺泡Ⅱ型上皮细胞DNA损伤率与对照组相比,差异无统计学意义;饲料中的蒿甲醚浓度超过0.2mg/kg时,大鼠肺泡Ⅱ型上皮细胞DNA损伤率明显增加,与对照组相比,差异有统计学意义。且损伤程度与饲料中蒿甲醚含量呈正相关。结论:当饲料中的蒿甲醚浓度超过0.2mg/kg时,蒿甲醚可在一定程度上改变肺泡Ⅱ型上皮细胞的DNA生物学特性。且随着蒿甲醚浓度的升高,这种损害更为明显。     

Analysis of the relationship between age and treatment response in migraine

In migraine, headache severity varies with age. As a consequence, the effectiveness of medication may also depend on a patient's age. The purpose of this study was to assess the combined effect of age and drug treatment on headache characteristics. Using data from clinical trials of sumatriptan in adolescents and adults, we show how the interaction between age and drug exposure can be parameterised as a covariate on a Markov model that describes the decline of headache severity over three clinically defined stages (no relief, relief and pain-free status). The model explains important clinical observations: (i) the rates at which the pain relief and pain-free status were attained were found to be inversely related to age; (ii) in placebo-treated patients, the mean transit time from 'no relief' to 'relief' is 3 h for young adolescents and increases to 6 h for patients aged ≥ 30 years; and (iii) sumatriptan reduces the transit time to 2 h, irrespective of age. These findings indicate that the therapeutic gain over placebo increases with age. Prospective studies of antimigraine drugs should take this relationship into account when extrapolating efficacy data from adults to adolescents.     

Symptoms of ＂Heat＂ as a Pattern of Physiopathology

Objective： The guiding criteria are considered the backbone of Chinese medicine. They have previously been described as functional features （symptoms） leading to the overall assessment of human functions on the basis of a regulatory （cybernetic） model referring to the I Ging. Methods： The Heidelberg model can explain symptoms such as created by ＂heat＂ on a rational physiological level. Results ＆ Conclusion： The overall of physiological symptoms are shown as a schematic draft. The basis of ＂heat＂ is considered to be a general increase of microcirculation in the periphery. This leads to a couple of local pathophysiological consequences and sensations like 1） red tongue （the tongue is considered an embryological somatotopic system）. 2） Sensation of warmth （by increase of capillary flow）. 3） pre-inflammatory state, leading to pain modalities like ＂worse if pressed＂, as inflammations tend to be increasingly painful under pressure; 4） reddish skin, the mechanisms by which this is induced may include the release of substance P, therefore accompanied by burning sensation. Systemic pathophysiological consequences may include. Relative lack of fluid in the larger vessels, as fluid supplies peripheral capillary flow. This may lead to water saving mechanisms like thirst, dry mucosa with do, mouth, dry nose, dry lips, dry skin, and also dry stool, yellow and sparse urine.     

Novel dual inhibitors of AChE and MAO derived from hydroxy aminoindan and phenethylamine as potential treatment for Alzheimer's disease

Carbamate derivatives of N-propargylaminoindans (Series I) and N-propargylphenethylamines (Series II) were synthesized via multistep procedures from the corresponding hydroxy precursors. The respective rasagiline- and selegiline-related series were designed to combine inhibitory activities of both acetylcholine esterase (AChE) and monoamine oxidase (MAO) by virtue of their carbamoyl and propargylamine pharmacophores. Each compound was tested for these activities in vitro in order to find molecules with similar potencies against each enzyme. Compounds with such dual AChE and MAO inhibitory activities are expected to have potential for the treatment of Alzheimer's disease. The observed SAR also offers insight into the requirements of the active sites on these enzymes. A carbamate moiety was found to be essential for AChE inhibition, which was absent in the corresponding hydroxy precursors. The propargyl group caused 2-70-fold decrease in AChE inhibitory activity (depending on the position of the carbamoyl group) of Series I, but had little or no effect in Series II. Thus, the 6- and 7-carbamyloxyphenyls in Series I were either equipotent to, or slightly (2- to 5-fold) less active as AChE inhibitors than, the corresponding compounds in Series II, while the 4-carbamyloxyphenyls were more potent. The presence of the carbamate moiety in 6- and 7-carbamyloxyphenyls of Series I, considerably decreased MAO-A and -B inhibitory activity, compared to that of the parent hydroxy analogues, while the opposite was true for Series II. Thus, the 6- and 7-carbamyloxyphenyls in Series I were 2-3 orders of magnitude weaker MAO inhibitors while the 4- carbamyloxyphenyls were equipotent with the corresponding compounds in Series II. In both series, N-methylation of the propargylamine enhanced the MAO (A and B equally) inhibitory activities and decreased the AChE inhibitory activity. Two candidates belonging to the indan and tetralin ring systems (24c, 27b) and one phenethylamine (53d) were identified as possible leads for further development based on the following criteria: (a) comparable AChE and MAO-B inhibitory activities, (b) good to moderate AChE inhibitory activity, and (c) lack of strong MAO-A selectivity. However, it is likely that these compounds will be metabolized to the corresponding phenols, with inhibitory activities against AChE and/or MAO-A or -B, different from those of the parent carbamates. Thus, the apparent enzyme inhibition will be a result of the combined inhibition of all of these individual metabolites. The results of our ongoing in vivo screening programs will be published elsewhere.     

One-year audit of admissions to the Intensive Care Unit of the Queen Elizabeth Central Hospital,Blantyre

The intensive care unit at Queen Elizabeth Central Hospital (QECH) has 4 beds and offers level 2 care. A retrospective audit of all admissions to the unit during 2002 was carried out. There were a total of 339 admissions giving a bed occupancy rate of 82 %. Surgical patients made up 81 % of admissions. 45% of all admissions were ventilated. Overall mortality was 38%. Ventilated patients had a mortality of 71% compared with 10% for non-ventilated. Data are also presented for mortality within the surgical and paediatric surgical admissions.     

Use of E mu-PIM-1 transgenic mice short-term in vivo carcinogenicity testing: lymphoma induction by benzo[a]pyrene, but not by TPA

E mu-pim-1 transgenic mice are predisposed to develop lymphomas. Due to their low spontaneous tumour incidence and their increased sensitivity towards the lymphomagen ethylnitrosourea these mice may present an interesting model for short-term carcinogenicity testing. Here, we report on the further exploration of this transgenic mouse model with two additional carcinogens known to have, among others, the lymphohaematopoietic system as target, i.e. benzo[a]pyrene (B[a]P) and 12-O-tetradecanoylphorbol-13-acetate (TPA). B[a]P, given three times a week (by gavage) for 13 weeks at 4.3, 13 or 39 mg/kg body weight, resulted in a dose-related increase in lymphomas up to a 90% incidence in E(mu)-pim-1 mice during the observation period of 40 weeks. B[a]P also induced tumours of the forestomach within this observation period, though at a lower incidence and apparently equally effective in wildtype and transgenic mice. TPA, on the other hand, was unable to induce lymphomas (or tumours in any other organ) in either transgenic or wildtype animals within the observation period of 44 weeks, when applied dermally at the maximum tolerated dose of 3 microg/mouse, twice a week for 35 weeks. Molecular analysis showed that B[a]P-induced lymphomas in transgenic mice were of T-cell origin, 80% of which had elevated levels of c-myc expression. None of the lymphomas had increased N-myc expression and mutation analysis of the ras-gene family revealed a K-ras mutation in only one out of eight tumours investigated. Also, none of the lymphomas showed aberrant expression of p53 as determined by immunohistochemistry. It is concluded that the E mu-pim-1 mouse model will not be very suitable for short-term carcinogenicity testing in general: only genotoxic chemicals that have the lymphohaematopoietic system as target for carcinogenesis in wild- type mice, appear to be efficiently identified.