Reduced sensitivity of peripheral cells to glucocorticoids in hypercholesterolemia

It has been found that lymphocytes of hypercholesterolemic (HCh) subjects are characterized by a reduced number of glucocorticoid receptors (GcR) as compared with the cells of normolipidemics (N). Addition of HCh-sera or very low density lipoproteins, or low density lipoproteins isolated both from HCh-sera and N-sera to cultured human skin fibroblasts brought about a fall in the number of GcR in the cells. High density lipoproteins had no effect on GcR level. Dexamethasone was less effective in inhibiting cholesterol synthesis from [14C]acetate in the lymphocytes and fibroblasts with a reduced number of GcR. In the presence of dexamethasone (I x 10(-8)M) in fibroblast growth medium, reduced number of GcR (due to preincubation with very low density lipoproteins) led to a substantial increase in cholesterol synthesis. These findings indicate that the sensitivity of peripheral cells to glucocorticoids is decreased in HCh which might be one of the trigger mechanisms of atherogenesis.     

The taxonomic composition of macrozoobenthos in central Russian small karst lakes

The macrozoobenthos taxonomic composition in small karst lakes of Vladimir oblast is studied for the first time. In the structure of bottom communities, 149 taxa one rank below the genus have been found. Chironomid larvae and other amphibiotic animals, as well as oligochaetes, prevail. Most of them are species widely distributed in the surface waters of European Russia. The highest macrozoobenthos species diversity was recorded in neutral lakes, and the lowest diversity was in lakes with weakly acidic waters.     

Big flies, small repeats: the "Thr-Gly" region of the period gene in Diptera

The region of the clock gene period (per) that encodes a repetitive tract of threonine-glycine (Thr-Gly) pairs has been compared between Dipteran species both within and outside the Drosophilidae. All the non- Drosophilidae sequences in this region are short and present a remarkably stable picture compared to the Drosophilidae, in which the region is much larger and extremely variable, both in size and composition. The accelerated evolution in the repetitive region of the Drosophilidae appears to be mainly due to an expansion of two ancestral repeats, one encoding a Thr-Gly dipeptide and the other a pentapeptide rich in serine, glycine, and asparagine or threonine. In some drosophilids the expansion involves a duplication of the pentapeptide sequence, but in Drosophila pseudoobscura both the dipeptide and the pentapeptide repeats are present in larger numbers. In the nondrosophilids, however, the pentapeptide sequence is represented by one copy and the dipeptide by two copies. These observations fulfill some of the predictions of recent theoretical models that have simulated the evolution of repetitive sequences.      

Excitation of System I and System II in Photosynthesis as a Possible Control Mechanism of Glycolate Metabolism in the Blue-Green Alga Anacystis nidulans

Photosynthetic enhancement studies performed at 619 nm (excitation of Systems I and II) and at 446 nm (mainly excitation of System I) revealed an 18% photosynthetic enhancement simultaneously with a 31% reduction in glycolate excretion. This observation supports the hypothesis that some glycolate may be consumed in an oxidation process associated with System I when System II is poorly excited and the supply of electrons from the water splitting process of photosynthesis is low.     

土壤中棉花黄萎病菌SYBR Green Ⅰ荧光RT-PCR定量检测技术研究

为实现田间土壤棉花黄萎病菌的早期检测,建立了土壤中棉花黄萎病菌的SYBR Green I荧光定量PCR检测方法。以含342bp PCR扩增产物的阳性质粒为参考,构建了标准曲线,并对该曲线的特异性、敏感性、可重复性进行了评价。结果表明,该方法具有快速、特异性强、敏感度高等特点。检测范围在3.8×103-3.8×108copies/μL之间有良好的线性关系,相关系数R2为0.996,扩增效率为101.5%,灵敏度比常规PCR方法高102倍。     

The anabolic action of intermittent parathyroid hormone on cortical bone depends partly on its ability to induce nitric oxide‐mediated vasorelaxation in BALB/c mice

There is strong evidence that vasodilatory nitric oxide (NO) donors have anabolic effects on bone in humans. Parathyroid hormone (PTH), the only osteoanabolic drug currently approved, is also a vasodilator. We investigated whether the NO synthase inhibitor L‐NAME might alter the effect of PTH on bone by blocking its vasodilatory effect. BALB/c mice received 28 daily injections of PTH[1–34] (80 µg/kg/day) or L‐NAME (30 mg/kg/day), alone or in combination. Hindlimb blood perfusion was measured by laser Doppler imaging. Bone architecture, turnover and mechanical properties in the femur were analysed respectively by micro‐CT, histomorphometry and three‐point bending. PTH increased hindlimb blood flow by >30% within 10 min of injection (P < 0.001). Co‐treatment with L‐NAME blocked the action of PTH on blood flow, whereas L‐NAME alone had no effect. PTH treatment increased femoral cortical bone volume and formation rate by 20% and 110%, respectively (P < 0.001). PTH had no effect on trabecular bone volume in the femoral metaphysis although trabecular thickness and number were increased and decreased by 25%, respectively. Co‐treatment with L‐NAME restricted the PTH‐stimulated increase in cortical bone formation but had no clear‐cut effects in trabecular bone. Co‐treatment with L‐NAME did not affect the mechanical strength in femurs induced by iPTH. These results suggest that NO‐mediated vasorelaxation plays partly a role in the anabolic action of PTH on cortical bone. © 2016 The Authors. Cell Biochemistry and Function published by John Wiley & Sons, Ltd.     

Repeated immunostaining of the same tissue section using alkaline phosphatase as a reporter

One can determine the best dilution of a primary antibody for immunohistochemistry that uses horseradish peroxidase conjugated to a secondary antibody by testing increasing concentrations sequentially on the same tissue section. When the same tissue section is incubated repeatedly with increasing concentrations of primary antibodies to epithelial membrane antigen, smooth muscle α-actin, or vimentin using alkaline phosphatase conjugated to a secondary antibody as the reporter, the best staining was obtained with a less concentrated primary antibody than was optimal for a single staining test. The best concentration of primary antibody for single run staining using an alkaline phosphatase reporting system is usually four times the best concentration for staining with multiple runs. The optimal concentration can be determined by denaturing the residual alkaline phosphatase and extracting residual stain by incubating the section in 4:1 diglyme:phosphate buffered saline for 20 min at 80^o C between tests of primary antibody concentrations. I tested the method for four chromogens from one supplier and one chromogen from a different supplier.     

Barley microgreen incorporation in diet-controlled diabetes and counteracted aflatoxicosis in rats

Increased environmental pollution and unhealthy lifestyle are blamed for escalated chronic diseases. Exposure to aflatoxins was recently suggested to have a role in the increased incidence of type 2 diabetes mellitus. Diet modification and consumption of different functional food are now gaining attention, especially in diabetes management. This study investigates the effect of a diet containing barley microgreen against diabetes induced by streptozotocin with or without aflatoxin administration in rats. Barley microgreen was rich in 3′-Benzyloxy-5,6,7,4′-tetramethoxyflavone (48.8% of total) followed by 5β,7βH,10α-Eudesm-11-en-1α-ol (18.46%). Streptozotocin injection and/or aflatoxin administration significantly elevated glucose level, decreased insulin level, decreased β-cell function, deteriorated liver and kidney function parameters, and induced oxidative stress in the liver. Histopathology revealed irregular small-sized islets and decreased area % of insulin-positive beta cells in the pancreas, hepatic degeneration, nephropathy, and neuropathy in diabetic and/or aflatoxin administered rats compared to control. Barley microgreen diet fed to diabetic rats with or without aflatoxin alleviated all evaluated parameters. Barley microgreen diet also ameliorated the toxic effect of aflatoxin. In conclusion, exposure to aflatoxin aggravated diabetes and its complication. The incorporation of barley microgreen in the diet was able to control type 2 diabetes mellitus and the improved outcomes observed with barley microgreen treatments involved or occurred in conjunction with improved biomarkers of oxidative stress.     

Effects of alcohol on the major steps of reverse cholesterol transport

The effects of moderate alcohol consumption on the capacity of blood sera to promote acceptance of cholesterol (C) from Fu5AH hepatoma cells, esterification of delivered free C, and transfer of produced cholesteryl esters to apolipoprotein (apo) B-containing lipoproteins have been studied. Twenty male subjects with relatively high (>50 mg/dl, n = 10) and low (<50 mg/dl, n = 10) high density lipoprotein (HDL) C levels consumed for eight weeks red grape wine (0.3 g ethanol/kg body mass per day). Alcohol consumption reduced total C and low density lipoprotein C levels in both groups of subjects. Low HDL C subjects showed an increase in HDL C, apo AI, apo AII, and lipoprotein (Lp) AI particle levels after alcohol consumption. Alcohol did not affect free C efflux from the cells. However, after the following period of substitution of alcohol with an isocaloric amount of red grape juice, cellular C efflux markedly reduced. While lecithin:cholesterol acyltransferase (LCAT) activity increased during alcohol consumption only in subjects with low HDL C, high HDL C subjects showed a significant decrease in cholesteryl ester transfer protein (CETP) activity. At the same time, alcohol consumption reduced the endogenous C esterification rate and increased the transfer of endogenous cholesteryl esters to apo B-containing lipoproteins in both groups. Thus, alcohol consumption in moderate doses enhanced the anti-atherogenicity of the serum lipoprotein spectrum, supporting more effective C efflux from peripheral cells and transport of accepted C to apo B-containing lipoproteins. The effects of alcohol on the reverse cholesterol transport depend on the initial HDL C level.