Drug-induced differentiation of a rat glioma in vitro: II. The expression of S-100, a glial specific protein and steroid sulfatase

Amethopterin and 5-bromodeoxyuridine (BUdR) were used to induce morphological changes in cloned rat glioma (C6). The expression of S-100 protein, an acidic protein localized in glial cells, and steroid sulfatase, an ubiquitously distributed enzyme found in high concentration in glial cells, were followed during cell growth, from subculture to well into the stationary phase of control and drug-treated cultures. Amethopterin and BUdR differed in their effects on glioma morphology and in the expression of the biochemical parameters. Amethopterin coordinately stimualted both the production of S-100 protein and steroid sulfatase activity when cell division was inhibited during early logarithmic growth phase. BUdR stimulated steroid sulfatase activity but repressed production of S-100 protein. The results are discussed with respect to the mechanism of regulation of the differentiated state of tumor cells.     

Energy landscape of amyloidogenic peptide oligomerization by parallel-tempering molecular dynamics simulation: significant role of Asn ladder

Recent evidence suggests that amyloidogenic oligomers may be the toxic species in cell cultures. Thus, it is crucial to understand their structure and oligomerization mechanism in atomistic detail. By employing tens of fast central processing units and an advanced phase-space sampling algorithm, parallel-tempering molecular dynamics, we have explored the energy landscape of amyloidogenic peptide oligomerization in explicit water. A pentapeptide, DFNKF, derived from human calcitonin and its mutant, DFAKF, was simulated with a total simulation time of approximately 500 ns. The detailed oligomerization process of a DFNKF parallel beta-sheet formation at 300 K has been characterized. The assembly of a parallel beta-sheet from the amorphous state mainly occurs via a "bottleneck" channel where the interstrand Asn-Asn stacking is the major interaction. The interactions of Asn-Asn stacking include both backbone and side-chain hydrogen bonds. The Asn-Asn interactions work like "glue" by sticking the DFNKF strands together and assist the "on-pathway" oligomerization. The Asn-Asn stacking observed here is similar to the Asn ladder commonly found in globular beta-helix proteins. A control run shows that when Asn is mutated to Ala, the stability and population of the DFAKF parallel beta-sheet is decreased. Furthermore, our in vitro mutagenesis experiments show that the ability of DFAKF peptides to form amyloid fibrils is significantly reduced, in agreement with the simulations. Knowledge of the energy landscape of oligomerization may provide hints for rational drug design, preventing amyloid-associated diseases.     

Monosodium glutamate affects the temporal characteristics of biochemical variables in Wistar rats

Monosodium glutamate (MSG) was administrated chronically for 60 days to Wistar rats and 24 h rhythms of glucose, cholesterol, total protein and alkaline phosphatase were studied. MSG treatment was found to cause acrophase delays in the glucose and alkaline phosphatase rhythms and advances in acrophases of cholesterol and total protein levels. Amplitude and mesor values of these rhythms were found to be altered during MSG treatment. Glutamate levels in the brain were found to be significantly increased, which could alter these biochemical rhythms by modulating the transmission in retinohypothalamic tract and in the hypothalamic nuclei, probably including suprachiasmatic nuclei.     

Evaluation of analgesic, antipyretic activity and toxicity study of Bryonia laciniosa in mice and rats

Analgesic, antipyretic activity and toxicity study of the leaves of Bryonia laciniosa Linn. (Family: Cucurbitaceae) was evaluated in the standard animal models. The methanol extract of Bryonia laciniosa (MEBL) was evaluated by hot plate and acetic acid-induced writhing methods to assess analgesic activity. The antipyretic activity of the extract was also evaluated by normal body temperature and yeast-induced hyperpyrexia. The extract showed significant analgesic and antipyretic activity. The MEBL was further evaluated for toxicity at the doses of 125 and 250 mg/kg administered orally for 14 days in rats. At the end of experiments, the blood, liver function and kidney metabolism were observed. The hematological profile and different biochemical parameters such as SGOT, SGPT and ALP were estimated. The present study revealed that MEBL exhibited significant analgesic and antipyretic activity in the tested experimental animal models. The toxicity study indicates that the extract is not toxic at the tested doses.     

Enhancement of circulatory antioxidants by alpha-ketoglutarate during sodium valproate treatment in Wistar rats

The effects of alpha-ketoglutarate (alpha-KG) on sodium valproate-induced hyperammonemia and hepatotoxicity were studied in biochemical experiments in rats. The levels of ammonia, urea, serum transaminases, hydroperoxides and thiobarbituric acid reactive substances were significantly increased in sodium valproate-treated rats. These levels were significantly decreased in alpha-KG- and sodium valproate-treated rats. Further, non-enzymatic (vitamins C and E) and enzymatic (superoxide dismutase and catalase) antioxidants were significantly decreased in sodium valproate-treated rats and were increased in alpha-KG- and sodium valproate-treated rats. These biochemical alterations during alpha-KG treatment could be due to (i) its ability to act as an ubiquitous collector of amino groups in body tissues, (ii) the participation of alpha-KG in the non-enzymatic oxidative decarboxylation in the hydrogen peroxide decomposition process and (iii) enhancing the proper metabolism of fats which could suppress oxygen radical generation and, thus, prevent the lipid peroxidative damages in rats.     

Effect of chronic vibration on the immune state of albino rats

A study was undertaken to investigate the effects of whole body chronic vibration on the immune system. Albino rats were exposed to whole body horizontal vibration acceleration 5.0 g, frequency 20 Hz for 3 hours per day for 3 months and changes were observed in plasma corticosterone level, total leucocyte count and differential leucocyte count. Neutrophil functions were accessed by candida phagocytosis and Nitroblue tetrazolium reduction test. The total leucocyte count was significantly decreased. A marked lymphopenia was observed in the differential count of the leucocytes. A significant increase in the plasma corticosterone level, candida phagocytosis and Nitroblue tetrazolium reduction was observed, indicating chronic whole body vibration to be a potent stressor in albino rats.     

Uptake and Distribution of Trace Elements in Dominant Mangrove Plants of the Indian Sundarban Wetland

Absorption, accumulation and translocation of 12 trace elements in nine dominant mangrove plants in the Indian Sundarban Wetland revealed both organ-specific and site-specific characteristics. An overall enrichment of elements was recorded in rhizosediment, exceeding the prescribed effects range-low (ER-L) of consensus based sediment quality guidelines (SQGs) for Cu and Pb. Avicennia officinalis, A. alba, Ceriops decandra and Excoecaria agallocha exhibited unique potential for accumulating Al, Cd, Co, Cr, Cu, Ni, Mn and Zn and could be considered efficient accumulators. Maximum element accumulation in trunk bark (As 6.16, Cr 49.9, Co 2.67, Cu 91.00 and Zn 85.5 mg kg^?1) and root/pneumatophore (Al 1000 and Fe 2430 mg kg^?1) was recorded. Maximum bioconcentration factor (6.23) in A. officinalis and translocation factor (17.5 for Mn) in C. decandra distinguished their phytoremediation capacity. These halophytes could be used for trace element phytoremediation in stressed sites of Sundarban.     

A highly efficient metal oxide incorporated metal organic framework [Nd2O3-MIL(Fe)-88A] for the electrochemical detection of dichlorvos

In this study, a Nd₂O₃@MIL(Fe)-88A composite was prepared through a hydrothermal method and used to detect dichlorvos. The XRD result demonstrated that the prepared sensor is highly crystalline in nature. The affinity of metal oxide and MIL(Fe)-88A could be utilised to overcome low stability and sensitivity owing to their synergistic and electronic effects. Differential pulse voltammetry (DPV) exhibits the electrocatalytic behaviour of Nd₂O₃@MIL(Fe)-88A; it functions at a lower potential at −0.5 to 0.8 V and has a wide linear range of 1–250 nM. It shows a very low detection limit of 0.92 nM with good sensitivity (4.42 mA nM⁻¹) and selectivity. The developed Nd₂O₃@MIL(Fe)-88A sensor was successfully applied to detect dichlorvos in real analysis. The recovery range calculated for cabbage and orange extracts was 96–97% and 99.5–103.4%, respectively, and RSD% calculated for cabbage and orange extracts was from 1.40 to 3.39% and from 0.64 to 2.26%, respectively.

A Nd₂O₃@MIL(Fe)-88A composite was prepared through a hydrothermal method and used to detect dichlorvos.