Study of the mechanism of initiation of enzymatic NADPH-dependent lipid peroxidation in membranes of the endoplasmic reticulum

The localization and mechanism of generation of active oxygen species in the enzymatic NADPH-dependent lipid peroxidation system in liver microsomes were studied. Using the spin-trapping method, the key role of active oxygen species in the initiation of NADPH-dependent enzymatic lipid peroxidation was confirmed. It was shown that active oxygen species are generated via consecutive one-electron reduction of the oxygen molecule by NADPH-cytochrome P-450 reductase.     

Vertical trends in morphological variability of sea urchins of the genus Echinus from the Northeast Atlantic and Arctic

A study of the morphological variability of seven species of sea urchins of the genus Echinus from the Northeast Atlantic and Arctic with different depth preferences showed that in the group of species E. tenuispinus, E. esculentus, E. melo, E. acutus, E. elegans, E. affinis, and E. alexandri, arranged based on increasing depth of occurrence, the maximum test diameter decreases, the diameter of the apical system increases, the ratio of the number of interambulacral plates to the number of ambulacral plates increases, buccal and periproctal spines tend to disappear, and the number of ambulacral plates lacking a primary tubercle sharply decreases. At the same time, the test height decreases, while the number of secondary tubercles on coronal plates and number of lateral teeth on the valves of the globiferous pedicellariae increases. The change in the first six characters reflects the process of retention of juvenile features in deep-water Echinus. Similar trends in test height, apical system diameter and the ratio of the number of interambulacral plates to the number of ambulacral plates are recorded while comparing shallow-water and deep-sea populations of the eurybathic species E. acutus. This suggests that this species may currently be in the process of speciation.     

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.      

Change in the activity of creatine kinase and its MB isoenzyme as affected by partial and complete occlusion of the coronary artery in rats

A model of different degree left coronary artery (LCA) occlusion in rats has been developed. The activity of creatine kinase and its cardiospecific MB isoenzyme was determined both in the cardiac muscle and blood plasma of 62 animals at different time after complete or partial LCA occlusion. A direct dependence of the decrease in the enzyme activity in the heart and hyperfermentemia on the degree of LCA occlusion has been established. It is concluded that the model of LCA occlusion in rats could be useful for the study of different forms and stages of myocardial ischemia.     

Role of vimentin in cell migration

Cell migration plays a crucial role in embryonic development, wound healing, regeneration, inflammation, and immune response, as well as in dissemination of malignant tumors. Vimentin is the marker of migrating cells, but its role in cell migration is still unclear. However, recent studies have revealed novel functions for vimentin related to the migration, such as determination of cellular polarity, regulation of cell contact formation, and arrangement and transport of signal proteins involved in cell motility. The review sums up the latest data on vimentin functions and its involvement in molecular mechanisms underlying cell migration. Early studies demonstrated that vimentin expression during embryonic development is associated with cell migration. However, having obtained vimentin knockout mice without apparent impairments in development and ability to reproduce, doubts have appeared if vimentin is required for cell migration during embryonic development. In the present review, we also discuss involvement of vimentin in migration processes at different stages of development and try to resolve current contradictions concerning the role of vimentin in various events of cell migration.     

Study of localization of the protein-synthesizing machinery along actin filament bundles.

Indirect immunofluorescent microscopy was used to study the distribution of elongation factor 2 (eEF-2) in fixed human skin diploid and mouse embryo fibroblasts. It was found earlier that some of the eEF-2 ribosomes and initiation factor 2 (eIF-2) are co-localized with a part of the actin microfilament bundles in these cells (Gavrilova et al., 1987; Shestakova et al., 1991). Here it has been shown that inhibition of protein synthesis either by inactivation of eEF-2 itself with diphtheria toxin or by inactivation of ribosomes with ricin does not abolish the distribution of eEF-2 along the actin microfilament bundles. At the same time, the disassembly of actin microfilaments by cytochalasin D results also in the disappearance of eEF-2-carrying threads. This means that the eEF-2-carrying threads do not exist per se, and that the organization of eEF-2 in visible "filaments" depends upon the integrity of the actin cytoskeleton.     

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.     

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.     

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。