三种不同品系小鼠在肺肿瘤短期诱发试验中的敏感性比较

用不同剂量尿烷一次腹腔注射，对ＫＭ、ＢＡＬＢ／ｃ和Ａ／Ｊ系小鼠进行肺肿瘤短期诱导试验，以比较其敏感性，为环境化学物致癌性鉴定的实验条件提供依据。结果显示：以肺肿瘤发生率和平均发瘤数两项指数来衡量发瘤危险，Ａ／Ｊ系均在最低染毒剂量（２５ｍｇ／ｋｇ）即出现发瘤危险明显增高；ＫＭ系以发生率衡量时，１００ｍｇ／ｋｇ为发瘤危险增高的最低剂量，而以平均发瘤数衡量时，最低剂量为２００ｍｇ／ｋｇ；ＢＡＬＢ／ｃ系前     

眼内异物合并外伤性白内障的联合手术治疗：附88例分析

眼内异物合并外伤性白内障是眼外伤常见的致盲原因之一,各地报告的致盲率为20%～48.9%。本文对88例眼内异物合并外伤性白内障患者采用联合手术治疗,收到较好疗效,术前视力0.05以下占85.2%,术后矫正视力0.05以下占27.3%,矫正视力0.06～1.5占73.7%,其中矫正视力0.6～1.5者占22.8%。根据异物的性质、在眼内部位和晶体损伤情况选择不同的手术方式一次联合手术摘出异物和白内障,术后采用中西药配合治疗。联合手术可提高疗效,减少术后并发症.减少手术次数,减轻病人的痛苦,缩短病程,减少医疗费用.眼科学报1993;9:216—218.     

NF1 mutations in neurofibromatosis 1 patients with plexiform neurofibromas

Neurofibromatosis 1 (NF1) is an autosomal dominant disorder caused by genetic alterations of the NF1 gene on 17q11.2. About 30% of NF1 patients develop plexiform neurofibromas (PNFs), which often cause severe clinical deficits. To determine whether there is a certain genotype underlying PNFs or subtypes of PNFs, we screened 42 NF1 patients from 41 families with PNFs for mutations in the NF1 gene. In 33 out of the 41 (80%) unrelated patients NF1 mutations were found, 24 are novel while the other 9 have been described in previous studies. The 33 mutations included 23 nonsense and frameshift, six splice and four missense mutations. The tumors in these patients had various sizes and features/growth characteristics. No correlation was found between the type or location of the NF1 mutations and size, location or feature of the PNFs, suggesting that many types of NF1 mutations can lead to development of PNFs.     

Quantitative evaluation of recall and precision of CAT Crawler,a search engine specialized on retrieval of Critically Appraised Topics

Background

Critically Appraised Topics (CATs) are a useful tool that helps physicians to make clinical decisions as the healthcare moves towards the practice of Evidence-Based Medicine (EBM). The fast growing World Wide Web has provided a place for physicians to share their appraised topics online, but an increasing amount of time is needed to find a particular topic within such a rich repository.

Methods

A web-based application, namely the CAT Crawler, was developed by Singapore's Bioinformatics Institute to allow physicians to adequately access available appraised topics on the Internet. A meta-search engine, as the core component of the application, finds relevant topics following keyword input. The primary objective of the work presented here is to evaluate the quantity and quality of search results obtained from the meta-search engine of the CAT Crawler by comparing them with those obtained from two individual CAT search engines. From the CAT libraries at these two sites, all possible keywords were extracted using a keyword extractor. Of those common to both libraries, ten were randomly chosen for evaluation. All ten were submitted to the two search engines individually, and through the meta-search engine of the CAT Crawler. Search results were evaluated for relevance both by medical amateurs and professionals, and the respective recall and precision were calculated.

Results

While achieving an identical recall, the meta-search engine showed a precision of 77.26% (±14.45) compared to the individual search engines' 52.65% (±12.0) (p < 0.001).

Conclusion

The results demonstrate the validity of the CAT Crawler meta-search engine approach. The improved precision due to inherent filters underlines the practical usefulness of this tool for clinicians.

     

Butyrate increases production of human chimeric IgG in CHO-K1 cells whilst maintaining function and glycoform profile

The influence of sodium butyrate on the production and glycosylation of recombinant mouse/human chimeric antibody by transfected CHO-K1 cells was investigated. We selected cells expressing 'wild-type' antibody with a human IgG3 heavy chain and a mutant of this molecule in which Phe 243 is replaced by Ala. These proteins have previously been shown to exhibit very different glycoform profiles with the mutant IgG being comprised of glycoforms having a high galactose and sialic acid content. Cell culture with 0-5 mM butyrate was shown to effect a 2-4-fold increase in antibody production whilst the induction of apoptosis was observed in a dose-dependent manner. The optimal butyrate concentration was observed to be 2 mM. The glycoform profile of each antibody produced in the presence of butyrate was analyzed by HPAEC-PAD and shown to be unchanged, relative to that produced in the absence of butyrate. Biological activity was evaluated by the ability of the antibodies to trigger superoxide generation, through Fc gamma RI, and shown to be independent of production in the presence or absence of butyrate. A similar increase in production was observed for a high antibody-producing cell line when expanded in a hollow fibre bioreactor under low-serum conditions (1%). These results demonstrated that butyrate is of value for increasing the productivity of CHO-K1 for recombinant IgG and does not compromise either glycosylation or biological activity.     

抗人喉癌/抗VEGF双功能抗体制备及应用研究

目的：研制抗人喉癌／抗血管内皮因子（VEGF）双功能克隆抗体，用于喉癌抗血管生成治疗。方法：采用二次杂交瘤技术制备抗人喉癌／抗VEGF双功能抗体。经酶联免疫吸附试验法和SP法检测喉癌及癌前病患者血清及癌组织中VEGF的含量表达。结果：获得6株分泌抗人喉癌／抗VEGF双功能抗体的杂交瘤，经免疫组化证实与喉癌细胞特异性结合率为93％，而与血管内皮细胞结合率为89％。血清中VEGF含量表达，喉癌组与癌前病组及正常对照组相比差异均显著。IgG亚型鉴定为IgG2aBSAb抗体效价为1：25 600倍（ELISA法）。结论：二次杂交瘤法制备的双功能抗体具有均匀性、可控性、效价高、稳定性好，可用于喉癌抗血管生成治疗，动态检测可作为判断喉癌预后的客观指标。     

654—2对家兔红细胞膜Na^＋—K^＋—ATPase活性及血浆LPO含量的影响

日本大耳兔9只,其中6～8月龄5只,2～2.5年龄4只。均喂以2％654-2溶液1ml/天(即20mg)共43天。结果不分年龄统计,LPO含最下降0.827±1.048 nmol/ml(P<0.05)。Na~+-K~+-ATPase活性增加0.057±0.074μmol Pi/mg pro/hr(P<0.05)。认为654-2可能有抗衰老作用,并与普鲁卡因比较,讨论了其降低LPO的可能途径。