妊娠期糖尿病患者肠道微生态失衡与炎症因子的相关性

目的探讨妊娠期糖尿病(GDM)妊娠妇女肠道微生态失衡与炎症因子的相关性。方法选择2017年3月至2018年8月于我院产科门诊建立产检完整档案的妊娠妇女,其中确诊为GDM妊娠妇女78例作为研究组,正常妊娠妇女99例作为对照组;定性、定量分析2组妊娠妇女肠道肠杆菌、肠球菌、双歧杆菌、乳杆菌、拟杆菌和梭杆菌数量,分析肠道微生态失衡情况并比较肠道失衡组、非肠道失衡组临床资料,分析肠道失衡发生危险因素;Spearman相关分析明确肠道微生态失衡与炎性因子白细胞介素-2(IL-2)、肿瘤坏死因子-α(TNF-α)、C-反应蛋白(CRP)水平相关性。结果研究组SBP(收缩压)、DBP(舒张压)、FBG(空腹血糖)、HbA_(1c)(糖化血红蛋白)、IL-2、CRP、TNF-α水平高于对照组(均P0.05),肠杆菌、肠球菌、拟杆菌、梭杆菌数量大于对照组,而双歧杆菌、乳杆菌数量小于对照组(均P0.05)。研究组发生肠道微生态失衡例数23例(29.49%),对照组发生肠道微生态失衡例数10例(10.10%),研究组肠道微生态失衡发生率高于对照组(P0.05)。IL-2≥34.10 pg/mL、CRP≥19.33 mg/L、TNF-α≥89.96 ng/L、肠杆菌≥8.42 logN/g、肠球菌≥7.46 logN/g、双歧杆菌8.49 logN/g、乳杆菌6.32 logN/g、拟杆菌≥8.87 logN/g、梭杆菌≥3.13 logN/g是GDM妊娠妇女妊娠期发生肠道微生态失衡危险因素(均P0.05)。GDM妊娠妇女IL-2、CRP、TNF-α水平均与双歧杆菌、乳杆菌数量呈负相关(均P0.05),与肠杆菌、肠球菌、拟杆菌和梭杆菌数量呈正相关(均P0.05)。结论高炎性应激状态下的GDM患者表现出更明显的肠道微生态失调,可导致或加剧GDM发生或发展;妊娠期注意益生菌补充对防治GDM有重要价值。     

Limiting Mrs2-dependent mitochondrial Mg2+ uptake induces metabolic programming in prolonged dietary stress

1. Download : Download high-res image (232KB)
2. Download : Download full-size image

     

Ordered Biochemical Program of Gene Expression in Cancer Cells

Our introduction of the molecular correlation concept and the key enzyme concept and the use of biologically meaningful tumor models and control systems resulted in the discovery of an ordered pattern of enzymic and metabolic imbalance and the elucidation of the linkage with transformation and progression. We showed that the biochemical and enzymic pattern of alterations was the result of a reprogramming of gene expression that was both quantitative and qualitative and was characteristic to neoplasia, since no similar pattern of imbalance was observed in any of the control normal, regenerating, or differentiating tissues. Important aspects of gene logic were identified. These include demonstration of operation of reciprocal control of activities of opposing key enzymes and antagonistic pathways of synthesis and catabolism in pyrimidine, purine, ornithine, and carbohydrate metabolism and recently in signal transduction. The extent of increase in the activities of key enzymes of pyrimidine and purine biosynthesis related to the absolute activity of the enzymes in resting liver. The qualitative alterations in gene expression included the isozyme shift of key regulatory enzymes. We identified a segment of gene expression that is essential for neoplasia. We pointed out the selective advantages that reprogramming of gene expression confers to cancer cells. Understanding these alterations in the enzymology and biochemistry of cancer cells made it possible to identify potentially sensitive targets for anticancer chemotherapy. In recent clinical studies we targeted the increased IMP dehydrogenase activity in leukemic blast cells by an inhibitor drug, tiazofurin, and achieved 77% responses, including complete remissions.     

Productivity and vitality of spruce stands: dynamic feedback simulation for responses to different annual and seasonal levels of magnesium supply from soil

Responses of Norway spruce stands to gradually decreased annual magnesium supply from soil, with two seasonal courses, are evaluated by computer simulation. At low supply, magnesium concentrations in the needles are reduced to levels inducing chlorosis, but annual growth of new needles remains at the same level as stands with adequate magnesium. Above-ground permanent biomass shows a decreased annual production with lower supply, mainly because of shorter net carbon gain caused by decreased assimilation which is due to magnesium deficiency in needles. An additional but less important reason is the magnesium deficiency in stem and branch cambium, which is most severe during summer at low magnesium supply rates. The interaction of magnesium and carbon balance is emphasized.Modeling and simulation are not used for prediction but to test the consistency of scientific hypotheses.     

Macroevolution of hoverflies (Diptera: Syrphidae): the effect of using higher‐level taxa in studies of biodiversity,and correlates of species richness

We test a near‐complete genus level phylogeny of hoverflies (Diptera: Syrphidae) for consistency with a null model of clade growth having uniform probabilities of speciation and extinction among contemporaneous species. The phylogeny is too unbalanced for this null model. Importantly, the degree of imbalance in the phylogeny depends on whether the phylogeny is analysed at the genus level or species level, suggesting that genera ought not to be used uncritically as surrogates for species in large‐scale evolutionary analyses. Tests for a range of morphological, life‐history and ecological correlates of diversity give equivocal results, but suggest that high species‐richness may be associated with sexual selection and diet breadth. We find no correlation between species‐richness and either body size or reproductive rate.     

Changes in hepatic branched-chain α-keto acid dehydrogenase activity in response to isoleucine imbalance in growing chickens

Three experiments were carried out to determine the influence of isoleucine imbalance on hepatic branched-chain α-keto acid dehydrogenase (BCKAD) activity in growing chickens. An isoleucine imbalance was induced by adding a 5% imbalancing amino acid mixture to a basal diet that contained adequate concentrations of all indispensable amino acids except isoleucine, which was marginally adequate (0.64–0.76% of the diet). The imbalancing mixture caused depressions (P < 0.05) in feed intake and growth rate. The depression in feed intake appeared to occur prior to the depression in growth rate. The isoleucine concentration in plasma decreased (P < 0.05), but not consistently, among experiments in response to the imbalancing mixture of amino acids. Basal and total activities of hepatic BCKAD were increased (P < 0.05) 21% and 28%, respectively, within 24 hours in one experiment and were elevated (P < 0.05) 19% and 14%, respectively, at the end of the 13 days of a second experiment. The moisture, protein, and fat contents of whole body and liver were not affected by the imbalancing mixture of amino acids. It appears likely that broiler chicks did not adapt to the imbalanced diets because the depressed feed intake and growth rate and alterations in plasma isoleucine and hepatic BCKAD activity persisted through 13 days of experiment. The isoleucine requirement, expressed as percent of diet, was increased by the imbalancing mixture of amino acids, and the efficiency of isoleucine utilization for growth (grams of weight gain per milligram of isoleucine intake) was decreased in two of three experiments. These results suggest that BCKAD may have a play in the increased isoleucine requirement of broiler chicks under conditions of isoleucine imbalance.     

Influence of excess nitrogen deposition on a white spruce (Picea glauca) stand in southern Alaska

Excess N delivered to forest ecosystems has been shown to alterinternal ecosystem biogeochemical cycles, contribute to forestdecline, and negatively affect the health of receiving waters.In the vicinity of the Nikiski Industrial Complex, Kenai Peninsula,Alaska, there has been recent concern about the influence ofNH3 emissions that have occurred for over twodecades on local soils and vegetation. The study site representedan opportunity to examine the influence of elevated N depositionon a northern coniferous ecosystem in an area with a low backgroundof N deposition. Overstory vegetation in the area is dominated bywhite spruce (Picea glauca Moench. Voss) and paper birch (Betulapapyrifera Marsh.). Mortality of both species has occurred adjacent(<2 km) to the industrial complex. Average annual Ndeposition rates ranged from 0.7 to 21.0 kg ha-1 y-1in the area, with the highest rates closest to the complex. Sulfatedeposition at the site was low. Due to the high NH3deposition, precipitation near the complex was less acidic thanprecipitation in general; bulk precipitation pH ranged from 5.51to 7.06. Within 1.80 km of the facility there was an increase inKCl- and resin- extractable soil NH4+ andNO3- in the O horizon, and a decrease in soil pHcompared to soils further from the facility. Spruce near thefacility had chlorotic foliage and thinning crowns, higherconcentrations of N, but lower foliar Ca and Mg. Foliar Mglevels approached deficiency levels, but foliar Ca was wellabove reported deficiency levels at all sites. Both Mg:N andCa:N ratios, however, suggest nutrient imbalances in the highN deposition zone. Canopy death and fertilization by N appearto have encouraged growth of the native bluejoint grass. Thepresence of elevated NO3- in O horizon soilextracts, elevated NO3- in resin bags placed betweenthe O and E horizons, and nutritional imbalances in the foliagesuggest that N saturation may be occurring in soils adjacent to thefacility.     

The Propensity Score in the Analysis of Therapeutic Studies

A method for reducing bias in observational studies proposed by ROSENBAUM and RUBIN (1983, 1984) is discussed with a view to applications in studies designed to compare two treatments. The data are stratified on a function of covariates, called the propensity score. The propensity score is the conditional probability of receiving a specific treatment given a set of observed covariates. Some insight into how this kind of stratification works in theory is given. Within strata, the treatment groups are comparable with respect to the distribution of covariates incorporated into the score, hence a corresponding stratified analysis can be considered. The method is different from other strategies in that the sub-classes are not intended to comprise patients with similar prognosis. In practice, estimated grouped scores are used. Problems concerning the interpretation of the proposed stratified approach are illustrated by an application in oncology, and the results are compared to those from an analysis in a standard regression model.     

Measures of Imbalance for Higher Order Designs

In this paper we consider a generalization of the measures of imbalance given by AHRENS and PINCUS (1981) considering the cases: m-fold hierarchical model and m-way classification model in order to quantify the degree of imbalance in an unbalanced design. These measures of imbalance satisfy the same properties as those for the one-way classification model.