Multiple imputation technique applied to appropriateness ratings in cataract surgery

Missing data such as appropriateness ratings in clinical research are a common problem and this often yields a biased result. This paper aims to introduce the multiple imputation method to handle missing data in clinical research and to suggest that the multiple imputation technique can give more accurate estimates than those of a complete-case analysis. The idea of multiple imputation is that each missing value is replaced with more than one plausible value. The appropriateness method was developed as a pragmatic solution to problem of trying to assess "appropriate" surgical and medical procedures for patients. Cataract surgery was selected as one of four procedures that were evaluated as a part of the Clinical Appropriateness Initiative. We created mild to high missing rates of 10%, 30% and 50% and compared the performance of logistic regression in cataract surgery. We treated the coefficients in the original data as true parameters and compared them with the other results. In the mild missing rate (10%), the deviation from the true coefficients was quite small and ignorable. After removing the missing data, the complete-case analysis did not reveal any serious bias. However, as the missing rate increased, the bias was not ignorable and it distorted the result. This simulation study suggests that a multiple imputation technique can give more accurate estimates than those of a complete-case analysis, especially for moderate to high missing rates (30 - 50%). In addition, the multiple imputation technique yields better accuracy than a single imputation technique. Therefore, multiple imputation is useful and efficient for a situation in clinical research where there is large amounts of missing data.     

IBA损伤老化鼠脑Meynert核的AD模型动物研究

目的研究定位损伤脑胆碱能系Alzheimer病(AD)模型大鼠学习能力及相关脑神经肽免疫组化改变.方法用兴奋性毒素鹅膏蕈氨酸(IBA)定位损伤大鼠脑右侧Meynert核,观察模型动物学习能力改变(Y型迷宫法),并用分光光度法和免疫组化染色法观察动物脑胆碱酯酶(AchE)活性和皮层及海马β-淀粉样肽前体(β-APP)、生长抑素(SOM)及P物质(SP)的表达情况.结果模型组老化大鼠经损伤后,学习能力及脑AchE活性显著低于对照组(P均＜0.05).β-APP在额叶皮层和海马的表达均升高,而S()M表达则显著减少,用IBA及β-AP25-35同时损伤鼠脑时,可显示脑皮质区SP表达增加(P均＜0. 01).单独用IBA注射无效.结论IBA损伤老化大鼠脑Meynert核建立的动物模型,显示胆碱能系统损伤,学习能力障碍,β-APP过表达而神经肽SOM表达降低,一定条件下SP表达增加,与AD病人某些临床和病理特征基本一致.     

肢体负压对周围动脉闭塞性病变犬皮肤SP免疫反应阳性神经纤维影响

目的　观察肢体负压对周围动脉闭塞性病变犬皮肤中 SP免疫反应阳性神经纤维的影响 .方法　犬 17只 ,随机分治疗组 10只、非治疗组 5只和正常对照组 2只 ,治疗组和非治疗组均将动物制作左后肢缺血模型 ,治疗组在模型制作后 14d,开始行患肢负压治疗 10 d(15 min·次 - 1 ) ;非治疗组不做负压治疗 ;正常对照组不行缺血模型制作及负压治疗 . 3组均行左后肢趾皮肤免疫组化染色 ,检测 SP免疫反应阳性纤维 .结果　非治疗组皮肤中 SP免疫反应阳性神经纤维均较正常对照组明显增多 (P<0 .0 1) ,治疗组较非治疗组减少(P<0 .0 1) ,但仍较正常对照组增多 .结论　肢体负压疗法可促进皮肤感觉神经纤维中 SP的释放     

术中应用丝裂霉素C预防翼状胬肉术后复发的疗效观察

OBJECTIVE: To explore the feasibility of intraoperative application of mitomycin C (MMC) in pterygium and observe the ultrastructure change of pterygium with or without intraoperative application of MMC. METHODS: Sixty two eyes of 57 patients with primary pterygium were randomly divided into MMC group and control group, 29 patients (32 eyes) in MMC group underwent transposition with intraoperative application of MMC (0.4 mg.ml-1 for 1 minute), whereas 28 patients (30 eyes) in control group underwent transposition. The recurrence rate, complications and side effects were observed and compared between the two groups. The ultrastructure of pterygium with or without intraoperative application of MMC was studied with transmission electron microscopy. The mean follow-up was(7.6 +/- 3.4) months (1-13 minths). RESULT: Eleven eyes of the 30 eyes in control group (36.%) showed recurrence, whereas only 2 of 32 eyes (6.3%) in MMC group showed recurrence (P < 0.005). No severe complication and side effect appeared during the follow-up. Most of fibroblasts in pterygium that underwent intraoperative MMC occurred the change of rough endoplasmic reticulum (RER) dilatation. CONCLUSION: Intraoperative MMC appears to be an effective treatment in preventing recurrence of primary pterygium. The fibroblasts in pterygium have RER dilatation after application of MMC for 1 minute during the operation.     

Changes of type I collagen in the lungs of rats with hypoxic pulmonary hypertension]

The changes of type I collagen in the lung tissues of rats with hypoxic pulmonary hypertension (HPH) and its relationship to the mean pulmonary arterial pressure (mPAP) were investigated. The blood dynamic indexes of pulmonary circulation were measured by using Swan-Ganz. The distribution of type I collagen in pulmonary arteries, bronchi and plumonary interstitial was observed by using streptavidin peroxidase method (SP). The morphologic changes of small pulmonary arteries and the level of type I collagen were determined by image pattern analysis technique and gray scale scanning, respectively. The results showed, compared with the controls, mPAP of the hypoxic rats elevated (from 2.12 +/- 0.25 to 3.95 +/- 0.43 kPa, P < 0.01), their small pulmonary arteries, walls thickened (MT% from 16.35 +/- 2.64 to 35.83 +/- 3.55, MA% from 26.83 +/- 3.40 to 59.68 +/- 4.90, P < 0.01) and lumen narrowed. The distribution of type I collagen was mainly in the external layer of pulmonary arterial walls; the positive degrees of gray scale scanning increased and had a positive linear relationship to the mPAP and MT%. These findings suggest that the increase of type I collagen contents in pulmonary arteries is closely related to the development of HPH.     

Transcriptome analysis of Armillaria gallica 012 m in response to auxin

Gastrodia elata is an achlorophyllous and fully mycoheterotrophic orchid which obtains carbon and other nutrients from Armillaria species in its life cycle. Many researchers suggested that plant hormones, as signing molecules, play a central role in the plant–fungi interaction. In the process of Armillaria gallica 012 m cultivation, both exogenous indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) distinctly stimulated the growth of mycelia in solid media. The differential expression genes (DEGs) of A. gallica 012 m with IAA versus blank control (BK) and IBA versus BK were investigated. The results showed that more than 80% of DEGs of the IAA group were coincident with the DEGs of the IBA group, and more than half of upregulated DEGs and most of the downregulated DEGs of the IAA group coincided with those DEGs of the IBA group. Above research implied that A. gallica 012 m could perceive IAA and IBA, and possess similar responses and signaling pathways to IAA and IBA. The overlapping differential genes of the IAA group and IBA group were analyzed by GO term, and the results showed that several DEGs identified were related to biological processes including positive regulation of the biological process and biological process. The downregulated NmrA-like and FKBP_C genes might be benefit to the growth of mycelia. Those results can explain that exiguous IAA and IBA improved the growth of A. gallica to some extent. We speculate that IAA and IBA are signaling molecules, and regulate the expression of growth-related genes of A. gallica 012 m by the same signaling pathway.     

骨肉瘤细胞核因子кB免疫组化研究

细胞核因子ＮＦ－кＢ在肿瘤血管生成中可能具有核心调节作用,本文选择８０例有随访结果的骨肉瘤,应用免疫组化方法检测 ＮＦ－кＢ ｐ６５亚单位以及血管内皮细胞生长因子（ＶＥＧＦ）的表达,同时观察肿瘤内微血管密度（ＭＶＤ）,旨在探讨 ＮＦ－кＢ表达与骨肉瘤血管生成的关系。结果：８０例骨肉瘤中 ４８例 ＮＦ－кＢ ｐ６５阳性,阳性产物主要定位于肿瘤细胞浆。ＮＦ－кＢ表达与ＶＥＧＦ表达和ＭＶＤ呈显著正相关,而且ＮＦ－кＢ阳性组病人存活时间显著低于阴性组。该结果表明：①ＮＦ－кＢ ｐ６５是骨肉瘤相关的一种癌蛋白,在骨肉瘤的发生和发展中发挥重要的作用;②ＮＦ－кＢ对ＶＥＧＦ可能有正向调节作用,进而影响骨肉瘤血管生成;③ＮＦ－кＢ　对肿瘤血管生成的作用,可能是影响骨肉瘤预后的主要原因之一。     

国产房水引流物置入术治疗难治性青光眼远期疗效观察

１９９３年７月～１９９８年１月为１０３例（１０６只眼）难治性青光眼患者施行国产房水引流物（ＨＡＤ）置入术。术后平均随访３２８月。术后１年时平均眼压２２±１．４ｋＰａ。术后１～５年的手术成功率分别为８３８％,８０４％,７７１％,７１０％及６４３％。术中联合应用丝裂霉素Ｃ的病例,其术后１年时的成功率为８９５％。术后常见的并发症有持续性浅前房,局限性脉络膜脱离及眼压升高等。认为ＨＡＤ可用于治疗难治性青光眼。     

Periodontitis, a risk factor for cardiovascular diseases?

Exist a statistically significant association between a diagnosis of coronary heart disease and certain oral health parameters. These parameters are independent and more strongly associated with coronary heart disease than were recognized risk factors, such as serum cholesterol levels, body mass index, diabetes and smoking status. The correlation between serum and salivary cholesterol concentration and the role of salivary lipids in oral health have been poorly characterized. Lipids in saliva are mostly glandular in origin, through some may diffuse diffuse directly from the serum. The surface of the enamel (in case of dietary fat which have an cariostatic effect) is protected against demineralization by a mixture of salivary lipids and proteins. Salivary lipids may have anucleating role in the early mineralization of the dental plaque. The prevalence of periodontal disease may be increased in patients with atherosclerosis, and dental and periodontal infections have been shown to be associated with occurrence of acute and chronic coronary heart disease. Among the known risk factors of atherosclerosis, high serum lipid levels, especially cholesterol may be important with regard to periodontal health.