Reaction of selenomethionine with o-benzoquinone

A new reaction of selenomethionine with o-benzoquinone is described. This reaction can be used to distinguish between methionine and selenomethionine.     

Differential response of cycling and noncycling cells to inducers of DNA synthesis and mitosis

The objective of this study was to determine whether cells in G(0) phase are functionally distinct from those in G(1) with regard to their ability to respond to the inducers of DNA synthesis and to retard the cell cycle traverse of the G(2) component after fusion. Synchronized populations of HeLa cells in G(1) and human diploid fibroblasts in G(1) and G(0) phases were separately fused using UV-inactivated Sendai virus with HeLa cells prelabeled with [(3)H]ThdR and synchronized in S or G(2) phases. The kinetics of initiation of DNA synthesis in the nuclei of G(0) and G(1) cells residing in G(0)/S and G(1)/S dikaryons, respectively, were studied as a function of time after fusion. In the G(0)/G(2) and G(1)/G(2) fusions, the rate of entry into mitosis of the heterophasic binucleate cells was monitored in the presence of Colcemid. The effects of protein synthesis inhibition in the G(1) cells, and the UV irradiation of G(0) cells before fusion, on the rate of entry of the G(2) component into mitosis were also studied. The results of this study indicate that DNA synthesis can be induced in G(0)nuclei after fusion between G(0)- and S-phase cells, but G(0) nuclei are much slower than G(1) nuclei in responding to the inducers of DNA synthesis because the chromatin of G(0) cells is more condensed than it is in G(1) cells. A more interesting observation resulting from this study is that G(0) cells is more condensed than it is in G(1) cells. A more interesting observation resulting from this study is that G(0) cells differ from G(1) cells with regard to their effects on the cell cycle progression of the G(2) nucleus into mitosis. This difference between G(0) and G(1) cells appears to depend on certain factors, probably nonhistone proteins, present in G(1) cells but absent in G(0) cells. These factors can be induced in G(0) cells by UV irradiation and inhibited in G(1) cells by cycloheximide treatment.     

Glucosiduronidation and esterification of androsterone by human breast tumors invitro

The metabolism of ³H-androsterone was studied in homogenates (fortified with uridine 5'-diphosphoglucuronic acid and andenosine 3'-phosphate 5'-phosphosulfate) of eighteen breast tumors, one muscle underlying the primary breast carcinoma and metastatic axillary lymph nodes from a patient with suspected primary breast cancer. The major metabolites identified were less polar than androsterone. On saponification these lipoidal derivatives afforded androsterone as the only product (3 to 48%). Unmetabolized androsterone and lesser quantities of epiandrosterone, 5α-androstane-3α,17β-diol and 5α-androstane-3,17-dione comprised the free steroid fraction. Androsterone glucosiduronate was isolated (0.17–4.1%) from eight breast tumor homogenates and from the node tissue incubation (17%). There was no apparent correlation between glucuronyltransferase activity and histopathology or estrogen receptor content.     

Gametogenesis,endosperm development,and embryogeny inMicrocarpaea muscosa (Scrophulariaceae,Gratioleae)

InMicrocarpaea muscosa gametogenesis, embryo sac development (Polygonum type), endosperm development (cellular), embryogeny (Onagrad type), and seed structure are described. The different modes of endosperm development withinGratioleae are compared.     

Effect of extreme salinity conditions on the survival of Mytilopsis sallei Recluz (Pelecypoda)

Effects of salinity conditions, ranging from fresh water to 80, on the survival of marine molluscan fouling species, Mytilopsis sallei Recluz, have been studied in the laboratory. The results show that the species exhibits a wide tolerance to different salinity conditions including freshwater, showing normal activity up to 50 beyond which the higher salt concentration had a lethal effect. The effect of various salinity conditions on spawning has also been examined. The significance of wide range tolerance to salinity on the fouling in seawater cooling systems is discussed.     

Treatment of periodontal disease using xanthan based chlorhexidine gel

People of all ages are suffering from periodontal disease. It causes indirect damage in the oral cavity. It is of interest to evaluate the efficacy of xanthan-based chlorhexidine gel (Xan-CHX) in patients with mild-severe chronic periodontitis. Five patients with 60 sites were divided in two groups. Group A (treated with SRP) and group B (treated with Chlosite i.e., SRP + CHL). The recorded clinical parameters were Plaque index (PI), Gingival index (GI), Bleeding index (BI), and Clinical attachment Level (CAL) with sub gingival plaque subjected to microbial analysis. Significant reduction was observed in both groups. However, group B (treated with Chlosite i.e., SRP + CHL) showed statistically significant improvement on above mentioned parameters as compared to group A. Data suggest that in the treatment of periodontal disease (viz. PI, GI, BI and CAL) combination of SRP and Chlosite showed added benefits over only SRP.     

Study of trivalent samarium ion embedded lithium‐based borate glass for high‐density optical memory devices

Sm³⁺ ions doped strontium lithium lead borate glasses (SLLB:Sm) were prepared using a conventional melt‐quenching technique. The glasses were analyzed using X‐ray diffractometry and Fourier transform infrared spectroscopy, optical absorption, fluorescence spectral analysis, and fluorescence lifetime decay. The Judd–Ofelt (J–O) parameters and radiative parameters of the SLLB:Sm10 glass (1.0 mol% Sm³⁺ ion‐doped glass) were calculated using J–O theory. From the emission spectra, among all the synthesized glass, SLLB:Sm10 glass had the highest emission intensity for ⁴G_5/2→⁶H_11/2 transition (610 nm). Emission parameters, such as stimulated emission cross‐section and optical gain bandwidth, were calculated. For all concentrations of Sm³⁺ ions, the decay profile showed an exponential nature and decreased when the Sm³⁺ ion concentration was increased due to a concentration quenching effect. This result suggests that the synthesized SLLB:Sm10 glass could be used for application in high‐density optical memory devices.     

Deregulation of hepatic lipid metabolism associated with insulin resistance in rats subjected to chronic monocrotophos exposure

In our previous study, we demonstrated the potential of monocrotophos (MCP), an organophosphorus insecticide (OPI), to induce glucose intolerance, insulin resistance (IR), and dyslipidemia with hyperinsulinemia in rats after chronic exposure. As hyperinsulinemia is likely to exert an impact on hepatic lipid metabolism, we carried out this study to establish the effect of chronic MCP exposure (0.9 and 1.8 mg/kg/day for 180 days) on hepatic lipid metabolism in rats. The state of IR induced by MCP in rats was associated with an increase in the liver lipid content (triglyceride and cholesterol) and expression levels of sterol regulatory element‐binding proteins, PPARγ, acetyl‐CoA carboxylase, and fatty acid synthase in the liver. Similarly, activities of key enzymes (acetyl‐COA carboxylase, fatty acid synthase, lipin 1, malic enzyme, glucose‐6‐phosphate dehydrogenase, and glycerol‐3‐phosphate dehydrogenase), which regulate lipogenesis, were enhanced in livers of pesticide‐treated rats. A strong correlation was observed between insulin levels, hepatic lipid content, and plasma lipid profile in treated rats. Our study suggests that long‐term exposure to OPIs not only has a propensity to induce a state of hyperinsulinemic IR, but it is also associated with augmented hepatic lipogenesis, which may explain dyslipidemia induced by chronic exposure to MCP.     

A non‐canonical rhodopsin‐mediated insulin receptor signaling pathway in retinal photoreceptor neurons

We previously reported a ligand‐independent and rhodopsin‐dependent insulin receptor (IR) neuroprotective signaling pathway in both rod and cone photoreceptor cells, which is activated through protein–protein interaction. Our previous studies were performed with either retina or isolated rod or cone outer segment preparations and the expression of IR signaling proteins were examined. The isolation of outer segments with large portions of the attached inner segments is a technical challenge. Optiprep? density gradient medium has been used to isolate the cells and subcellular organelles, Optiprep? is a non‐ionic iodixanol‐based medium with a density of 1.320 g/mL. We employed this method to examine the expression of IR and its signaling proteins, and activation of one of the downstream effectors of the IR in isolated photoreceptor cells. Identification of the signaling complexes will be helpful for therapeutic targeting in disease conditions.     

Evaluation of photosynthetic efficiency of yam bean (Pachyrhizus erosus L.) at saturating photon flux density under elevated carbon dioxide

Physiology and Molecular Biology of Plants - The future CO2 concentration is projected to reach 900–1000 ppm levels by the end of twenty-first century, pertaining to global climatic...