Realized heritability of resistance to dicrotophos in greenhouse whitefly

Realized heritability (h ²) of resistance to dicrotophos in greenhouse whitefly,Trialeurodes vaporariorum Westwood, was estimated from a laboratory selection experiment. Five generations of selection increased the LC₅₀ approximately 13-fold. Estimatedh ² of resistance to dicrotophos was 0.40 when calculated with the method of Tabashnik (1992) and 0.35 with the method of Tanaka & Noppun (1989). These results suggest that 35 to 40% of the total phenotypic variation in resistance was caused by additive genetic variation. For thirteen previously reported estimates ofh ² of insecticide resistance in other insect pests, the mean was 0.29. The relatively highh ² of dicrotophos resistance forT. vaporariorum is consistent with rapid resistance development in field populations.     

Vanadate enhances insulin-receptor binding in gestational diabetic human placenta

Although vanadium is found abundantly in animal and plant kingdoms its biological effects are not clear. Vanadate compounds have been shown to normalize blood glucose levels in streptozotocin treated rats, enhance glucose oxidation and improve the sensitivity to insulin by enhanced receptor binding in rat adipocytes. The aim of the present study was to investigate the effect of vanadate, at high (0–8 mmol l^?1) and low (0–1·0 mmol l^?1) physiological concentrations, on [¹²⁵I]-insulin binding in the placenta of three groups of pateints, namely from normal (N) controls, gestational diabetics (GDM) and women with risk factors in their medical history for developing diabetes mellitus (RF). Vanadate at low concentrations (0·2–0·6 mmol l^?1) enhanced the maximal binding 2-fold in GDM placenta but only increased (up to 1·2-fold) the binding slightly at high cncentrations (5 mmol l^?1). However with placenta from normal or women at risk, vanadate increased the [¹²⁵I]-insulin binding up to 1·2-fold both at low and high concentrations. Thus it appears that vanadate augements insulin binding in the placenta from women with gestational diabetes mellitus.     

α-Synuclein expression selectively affects tumorigenesis in mice modeling Parkinson's disease

Alpha Synuclein (α-Syn) is a protein implicated in mechanisms of neuronal degeneration in Parkinson's disease (PD). α-Syn is primarily a neuronal protein, however, its expression is found in various tumors including ovarian, colorectal and melanoma tumors. It has been hypothesized that neurodegeneration may share common mechanisms with oncogenesis. We tested whether α-Syn expression affects tumorigenesis of three types of tumors. Specifically, B16 melanoma, E0771 mammary gland adenocarcinoma and D122 Lewis lung carcinoma. For this aim, we utilized transgenic mice expression the human A53T α-Syn form. We found that the in vivo growth of B16 and E0771 but not D122 was enhanced in the A53T α-Syn mice. The effect on tumorigenesis was not detected in age-matched APP/PS1 mice, modeling Alzheimer's disease (AD), suggesting a specific effect for α-Syn-dependent neurodegeneration. Importantly, transgenic α-Syn expression was detected within the three tumor types. We further show uptake of exogenously added, purified α-Syn, by the cultured tumor cells. In accord, with the affected tumorigenesis in the young A53T α-Syn mice, over-expression of α-Syn in cultured B16 and E0771 cells enhanced proliferation, however, had no effect on the proliferation of D122 cells. Based on these results, we suggest that certain forms of α-Syn may selectively accelerate cellular mechanisms leading to cancer.     

Comparative morphometric analysis of intraepidermal and dermal lymphocytes in early mycosis fungoides and some inflammatory dermatoses

OBJECTIVE: Early stage mycosis fungoides (MF) may be indistinguishable from some inflammatory dermatoses (IDs) histopathologically. Various morphologic features of lymphocytes in epidermis and dermis may help to differentiate early-stage MF from other IDs. STUDY DESIGN: We studied 25 cases of early-stage MF and 30 cases of various IDs with prominent exocytosis. The following nuclear variables were measured on dermal and epidermal lymphocytes in MF and IDs (control) groups: nuclear area and perimeter, area convex hull, perimeter convex hull, diameter equivalent circle, minimum feret, maximum feret and form factor. All measurements were done using routinely prepared and hematoxylin-eosin-stained slides. RESULTS: There were statistically significant differences (p < 0.01) for all of the morphometric variables between early-stage MF and IDs. CONCLUSION: Our results revealed that the nuclear contour irregularities of intraepidermal lymphocytes are higher than those of dermal lymphocytes in MF. Their nuclear geometry is also different. Comparison of the nuclear features of intraepidermal with dermal lymphocytes may provide additional support in the diagnosis of early-stage MF.     

β-d-glucosidase-catalysed transfer of the glycosyl group from aryl β-d-gluco- and β-d-xylo-pyranosides to phenols

The effect of phenols on the hydrolysis of substituted phenyl β-d-gluco- and β-d-xylo-pyranosides by β-d-glucosidase from Stachybotrys atra has been investigated. Depending on the glycon part of the substrate and on the phenol substituent, the hydrolysis is either inhibited or activated. With aryl β-d-xylopyranosides, transfer of the xylosyl residue to the phenol, with the formation of new phenyl β-d-xylopyranosides, is observed. With aryl β-d-glucopyranosides, such transfer does not occur when phenols are used as acceptors, but it does occur with anilines. A two-step mechanism, in which the first step is partially reversible, is proposed to explain these observations. A qualitative analysis of the various factors determining the overall effect of the phenol is given.     

Effect of fish oil supplementation on plasma oxidant/antioxidant status in rats

The aim of this study was to investigate effect of dietary omega-3 fatty acid supplementation on the indices of in vivo lipid peroxidation and oxidant/antioxidant status of plasma in rats. The plasma thiobarbituric acid reactive substances (TBARS) and nitric oxide (NO) levels, and activities of xanthine oxidase (XO), superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) were studied in male Wistar Albino rats after ingestion of 0.4 g/kg fish oil (rich in omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid) for 30 days and compared to untreated control rats. The rats in the treated group had significantly higher SOD activity (P < 0.001), NO levels (P < 0.01) and decreased TBARS levels (P < 0.05) with respect to controls whereas GSH-Px and XO activities were not significantly different between the groups. None of the measured parameters had significant correlation with each other in both groups. We conclude that dietary supplementation of omega-3 fatty acids may enhance resistance to free radical attack and reduce lipid peroxidation. These results support the notion that omega-3 fatty acids may be effective dietary supplements in the management of various diseases in which oxidant/antioxidant defence mechanisms are decelerated.