A latent class model to multiply impute missing treatment indicators in observational studies when inferences of the treatment effect are made using propensity score matching

Analysts often estimate treatment effects in observational studies using propensity score matching techniques. When there are missing covariate values, analysts can multiply impute the missing data to create m completed data sets. Analysts can then estimate propensity scores on each of the completed data sets, and use these to estimate treatment effects. However, there has been relatively little attention on developing imputation models to deal with the additional problem of missing treatment indicators, perhaps due to the consequences of generating implausible imputations. However, simply ignoring the missing treatment values, akin to a complete case analysis, could also lead to problems when estimating treatment effects. We propose a latent class model to multiply impute missing treatment indicators. We illustrate its performance through simulations and with data taken from a study on determinants of children's cognitive development. This approach is seen to obtain treatment effect estimates closer to the true treatment effect than when employing conventional imputation procedures as well as compared to a complete case analysis.     

Some environmental factors affecting the reproduction of Aphanius dispar (Rüppell, 1828)

In order to determine the suitability of thecyprinodont fish Aphanius dispar as a biologicalcontrol agent for mosquito larvae, the effects oftemperature, salinity, feeding rate and photoperiod onits reproductive condition were studied. The factorsexamined were the gonado-somatic index (GSI) and fourdistinct stages of cell maturation in the ovaries(oogonia, primary oocytes, secondary oocytes andmature ova). The fish were found to be tolerant to awide range of the examined factors. GSI's were notaffected by ambient temperatures over the range of18 °C to 37 °C. However, oocyte maturationstages increased as temperatures rose from 18 °Cto 27 °C, with mature ova first being found at thelatter temperature. No significant differences amongmaturation stages were found between27 °C–37 °C. At salinities ranging from of0 ppt to 56 ppt, no significant differences were found betweenmean GSI's, except for the two extremes of the testrange. The ovaries of fish kept in distilled watercontained primordial germ cells only. In feedingexperiments, significant differences were found onlybetween the ovaries (GSI's and oocyte maturationstages) of fish deprived of food and those fed at1% body weight per day. Regarding photoperiod,a decrease in day length from 14L:10D (the longest dayof the year) to 10L:14D (the shortest) caused adecrease in oocyte maturation stages. Fish at theintermediate level (12L:12D) still had ovariessuitable for spawning, whereas those at 10L:14D didnot. The results of this study show that limitinglevels for adequate reproductive condition were foundfor some of the factors investigated, however, rangesof the factors above these levels were relativelylarge. That Aphanius dispar's reproductivecondition may be controlled in an artificialenvironment is essential for it to be mass produced,and a prerequisite for its use in the biologicalcontrol of mosquito larvae.     

Glutamine synthetase (GS) expression is reduced in senile dementia of the Alzheimer type

Glutamine synthetase (GS), a metabolic marker of the mature astrocyte, was investigated in the temporal neocortex of postmortem brain samples of 8 cases, either not demented or affected by senile dementia of the Alzheimer type. A negative correlation between the GS protein level and the density of both classical A4 deposits and senile plaques was evidenced. Such a correlation for GS underlies a dysfunction of the astroglial metabolism and particularly of the glutamate and ammonia neutralization. Since GS is sensitive to oxidative lesioning, the changes in GS level that were observed, occurring at the posttranslational stage, might reflect oxidative damage and have severe consequences on the pathological cascade of events.     

Taxonomic variation in total leaf protein amino acid compositions of grasses

Leaves of greenhouse grown grasses had free protein amino acid contents of generally less than 5 % total amino acids, while field collected grasses averaged 14.7 % free protein amino acid contents. Taxonomic patterns are detectable in the total leaf amino acid profiles of grasses from both sources, those of pooids being distinguishable from those of chloridoids and panicoids, and those of danthonioids showing an intermediate pattern. Leaf profiles of Oryza, Stipeae, and Ehrharteae resemble one another, and are more like those of pooids than those of panicoids. Variations in Thr and Leu are apparently associated with differences in photosynthetic pathway. Grass leaves are generally low in total amino acid contents (2.2 ? 1.0 g % fr. wt), with Ile, Val and Met + Cys identified as the limiting essential amino acids. However, the nutritional ‘chemical scores’ of grass leaf proteins are high (75 %, based on the WHO scoring pattern).     

Genomic architecture of autism from comprehensive whole-genome sequence annotation

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一个以前列腺特异抗原密度和穿刺评分为基础的中国人群中前列腺癌根治术后病理升级预测模型的建立

目的：分析前列腺癌根治术后病理得分较穿刺得分增加的原因，并建立一个可以预测中国人群中前列腺癌根治术后病理升 级的模型。方法：以2008 年8 月至2013 年12 月在我院泌尿科行前列腺癌根治性切除术的264例患者的临床资料为基础，根据 术前和术后患者病理得分的变化将其分为升级组和未升级组。运用单因素和多因素logistic 回归分析病理升级的原因，并通过多 因素回归系数建立预测病理升级的诺模图。结果：264 例患者中，共238 例最终纳入统计分析，多因素logistic 回归分析显示前列 腺特异抗原密度(0R=3.854，P=0.001 )和穿刺Gleason(≤ 6)评分是中国人群中前列腺癌根治术后病理升级的独立危险因素。前列腺 特异抗原密度和穿刺得分的ROC 最佳截断取值为0.37 ng/ml 2和8 分。运用上述两个变量建立了一个可用于预测病理升级的诺 模图。结论：前列腺特异抗原密度和穿刺Gleason 评分是预测中国人群中前列腺癌根治术后病理升级的独立危险因素，本研究所 得的诺模图可以很好地预测前列腺癌根治术后的病理升级。     

Sirtuin 5 regulates the proliferation,invasion and migration of prostate cancer cells through acetyl‐CoA acetyltransferase 1

Sirtuin 5 (SIRT5) is a NAD⁺‐dependent class III protein deacetylase, and its role in prostate cancer has not yet been reported. Therefore, to explore the diagnosis and treatment of prostate cancer, we investigated the effect of SIRT5 on prostate cancer. Sirtuin 5 was assessed by immunohistochemistry in 57 normal and cancerous prostate tissues. We found that the tissue expression levels of SIRT5 in patients with Gleason scores ≥7 were significantly different from those in patients with Gleason scores <7 (P < .05, R > 0). Further, mass spectrometry and pathway screening experiments showed that SIRT5 regulated the activity of the mitogen‐activated protein kinase (MAPK) pathway, which in turn modulated the expression of MMP9 and cyclin D1. Being a substrate of SIRT5, acetyl‐CoA acetyltransferase 1 (ACAT1) was regulated by SIRT5. SIRT5 also regulated MAPK pathway activity through ACAT1. These results revealed that SIRT5 promoted the activity of the MAPK pathway through ACAT1, increasing the ability of prostate cancer cells to proliferate, migrate and invade. Overall, these results indicate that SIRT5 expression is closely associated with prostate cancer progression. Understanding the underlying mechanism may provide new targets and methods for the diagnosis and treatment of the disease.     

Circulating exosome‐derived bona fide long non‐coding RNAs predicting the occurrence and metastasis of hepatocellular carcinoma

Although the diagnosis and therapy approach developed, techniques for the early diagnosis of HCC remain insufficient which results in poor prognosis of patients. The traditional biomarker AFP, however, has been proved with low specificity. Circulating exosomal ncRNAs revealed different profiles reflecting the characteristics of tumour. In this study, we mainly focused on circulating exosomal ncRNAs which might be the fingerprint for HCC, especially for the diagnosis or metastasis prediction. A high throughput lncRNA microarray in exosomes extracted from cell‐free plasma was applied. The risk score analysis was employed to screen the potential exosome‐derived lncRNAs in two independent sets based on different clinical parameters in 200 paired HCC patients. After a multi‐stage validation, we finally revealed three lncRNAs, ENSG00000248932.1, ENST00000440688.1 and ENST00000457302.2, increased in HCC comparing with the both chronic hepatitis (CH) patients and cancer‐free controls. ROC curve revealed a higher sensitivity and specificity in predicting the occurrence of HCC from cancer‐free controls and CH patients with the area under curve (AUC) of 0.905 and 0.879 by combining AFP. The three lncRNA panel combined with AFP also indicted a fingerprint function in predicting the metastasis of HCC with the AUC of 0.870. In conclusion, ENSG00000248932.1, ENST00000440688.1 and ENST00000457302.2 might be the potential biomarker for the tumorigenesis prediction from CH patients or healthy controls and may also be applied for dynamic monitoring the metastasis of HCC.