Effect of some carbamate pesticides on nodulation,plant yield and nitrogen fixation byPisum sativum andVigna sinensis in the presence of their respective rhizobia

Summary Six carbamate pesticides namely 1-naphthol, sevin, dimetilan, trematan, NaDDC and dymid were studied to see their effect on nodulation and nitrogen fixation inPisum sativum andVigna sinensis. Low concentrations of the pesticides have little effect on nodulation and nitrogen fixation, whereas higher concentrations adversely effect these processes. The results also indicate that then sensitivity depends upon the species of the Rhizobium and also the type of the pesticide. Pesticides belonging to the carbamate group differ in their capacity to affect nodulation and nitroge fixation.     

Characterization of specific high affinity receptors for human tumor necrosis factor on mouse fibroblasts

Mouse L-929 fibroblasts, an established line of cells, are very sensitive to lysis by human lymphotoxin (hTNF-beta). Specific binding of a highly purified preparation of hTNF-beta to these cells was examined. Recombinant DNA-derived hTNF-beta was radiolabeled with [3H]propionyl succinimidate at the lysine residues of the molecule to a specific activity of 200 microCi/nmol of protein. [3H]hTNF-beta was purified by high performance gel permeation chromatography and the major fraction was found to be monomeric by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The labeled hTNF-beta was fully active in causing lysis of L-929 fibroblasts and bound specifically to high affinity binding sites on these cells. Scatchard analysis of the binding data revealed the presence of a single class of high affinity receptors with an apparent Kd of 6.7 X 10(-11) M and a capacity of 3200 binding sites/cell. Unlabeled recombinant DNA-derived hTNF-beta was found to be approximately 5-fold more effective competitive inhibitor of binding than the natural hTNF-beta. The binding of hTNF-beta to these mouse fibroblasts was also correlated with the ultimate cell lysis. Neutralizing polyclonal antibodies to hTNF-beta efficiently inhibited the binding of [3H]hTNF-beta to the cells. We conclude that the specific high affinity binding site is the receptor for hTNF-beta and may be involved in lysis of cells.     

Synthesis of 2-acetamido-2-deoxy-4-O-β-d-galactopyranosyl-3-O-methyl-d-glucopyranose (N-acetyl-3-O-methyllactosamine) and its benzyl α-glycoside

Benzyl 2-acetamido-2-deoxy-3-O-methyl-α-d-glucopyranoside (3) was obtained by deacetalation of its 4,6-O-benzylidene derivative (2). Compound 2 was prepared by methylation of benzyl 2-acetamido-4,6-O-benzylidene-2-deoxy-α-d-glucopyranoside with methyl iodide-silver oxide in N,N-dimethylformamide. Diol 3 was selectively benzoylated and p-toluenesulfonylated, to give the 6-benzoic and 6-p-toluenesulfonic esters (4 and 5, respectively). Displacement of the sulfonyl group of 5 with sodium benzoxide in benzyl alcohol afforded the 6-O-benzyl derivative (6). Glycosylation of 4 with 2,3,4,6-tetra-O-acetyl-α-d-galactopyranosyl bromide (7) in dichloromethane, in the presence of 1,1,3,3-tetramethylurea, furnished the disaccharide derivative 8. Similar glycosylation of compound 6 with bromide 7 gave the disaccharide derivative 10. O-Deacetylation of 8 and 10 afforded disaccharides 9 and 11. The structure of compound 9 was established by ¹³C-n.m.r. spectroscopy. Hydrogenolysis of the benzyl groups of 11 furnished the disaccharide 2-acetamido-2-deoxy-4-O-β-d-galactopyranosyl-3-O-methyl-d-glucopyranose (N-acetyl-3-O-methyllactosamine).     

Fine needle aspiration cytologic diagnosis of the solitary cold thyroid nodule. Comparison with ultrasonography, radionuclide perfusion study and xeroradiography

Thirty-six cases of solitary and scintigraphically "cold" thyroid nodules were studied by fine needle aspiration (FNA) cytology, ultrasonography, radionuclide perfusion study (RPS) and xeroradiography with the aim of differentiating the neoplastic from the nonneoplastic nodules. Histologic study of the excised specimens provided the definitive diagnosis in all cases. Of the techniques used in this study, FNA cytology and RPS had the highest sensitivities and specificities. Ultrasonography and xeroradiography were of limited use due to their low sensitivity rates.     

Age-mediated gut microbiota dysbiosis promotes the loss of dendritic cells tolerance

The old age-related loss of immune tolerance inflicts a person with a wide range of autoimmune and inflammatory diseases. Dendritic cells (DCs) are the sentinels of the immune system that maintain immune tolerance through cytokines and regulatory T-cells generation. Aging disturbs the microbial composition of the gut, causing immune system dysregulation. However, the vis-à-vis role of gut dysbiosis on DCs tolerance remains highly elusive. Consequently, we studied the influence of aging on gut dysbiosis and its impact on the loss of DC tolerance. We show that DCs generated from either the aged (DC^Old) or gut-dysbiotic young (DC^Dysbiotic) but not young (DC^Young) mice exhibited loss of tolerance, as evidenced by their failure to optimally induce the generation of Tregs and control the overactivation of CD4⁺ T cells. The mechanism deciphered for the loss of DC^Old and DC^Dysbiotic tolerance was chiefly through the overactivation of NF-κB, impaired frequency of Tregs, upregulation in the level of pro-inflammatory molecules (IL-6, IL-1β, TNF-α, IL-12, IFN-γ), and decline in the anti-inflammatory moieties (IL-10, TGF-β, IL-4, IDO, arginase, NO, IRF-4, IRF-8, PDL1, BTLA4, ALDH2). Importantly, a significant decline in the frequency of the Lactobacillus genus was noticed in the gut. Replenishing the gut of old mice with the Lactobacillus plantarum reinvigorated the tolerogenic function of DCs through the rewiring of inflammatory and metabolic pathways. Thus, for the first time, we demonstrate the impact of age-related gut dysbiosis on the loss of DC tolerance. This finding may open avenues for therapeutic intervention for treating age-associated disorders with the Lactobacillus plantarum.     

Chemodiversity and α-Glucosidase Activity of Eucalyptus Species from Northwestern Himalaya,India

The aim of current work was to determine essential oils (EOs) composition from three Eucalyptus species, including E. citriodora, E. camaldulensis and E. globulus and assess their α-glucosidase inhibitory activity. The EOs were collected using the hydrodistillation technique and characterized by GC/MS, GC-FID and NMR. The isolated EOs from leaves parts of Eucalyptus species varied from 0.56 to 1.0 % on fresh weight basis. The content of the EOs was distinct according to the species. The most abundant metabolites were identified as citronellal (0–83.0 %), 1,8-cineole (0.2–44.8 %), spathulenol (0.4–16.1 %) α-pinene (0.4–15.9 %), p-cymene (3.7–11.9 %), citronellol (0–8.6 %), β-eudesmol (5.3–8.6 %) and β-pinene (0–7.1 %). The EOs obtained from targeted samples exhibited strong α-glucosidase inhibitory activity. These results are encouraging and underline that the EOs of Eucalyptus species may be a promising alternative source of natural antidiabetic.     

Effect of cell cycle on the regulation of the cell surface and secreted forms of type I and type II human tumor necrosis factor receptors

The cell cycle has been shown to regulate the biological effects of human tumor necrosis factor (TNF), but to what extent that regulation is due to the modulation of TNF receptors is not clear. In the present report we investigated the effect of the cell cycle on the expression of surface and soluble TNF receptors in human histiocytic lymphoma U-937. Exposure to hydroxyurea, thymidine, etoposide, bisbensimide, and democolcine lead to accumulation of cells primarily in G₁/S, S, S/G₂/M, G₂/M, and M stages of the cell cycle, respectively. Whilie no significant change in TNF receptors occurred in cells arrested in G₁/S or S/G₂ stages, about a 50% decrease was observed in cells at M phase of the cycle. Scatchard analysis showed a reduction in receptor number rather than affinity. In contrast, cells arrested at S phase (thymidine) showed an 80% increase in receptor number. The decrease in the TNF receptors was not due to changes in cell size or protein synthesis. The increase in receptors, however, correlated with an increase in total protein synthesis (to 3.8-fold of the control levels). A proportional change was observed in the p60 and p80 forms of the TNF receptors. A decrease in the surface receptors in cells arrested in M phase correlated with an increase in the amount of soluble receptors. The cellular response to TNF increased to 8- and 2-fold in cells arrested in G₁ and S phase, respectively; but cells at G2/M phase showed about 6-fold decrease in response. In conclusion, our results demonstrate that the cell cycle plays an important role in regulation of cell-surface and soluble TNF receptors and also in the modulation of cellular response. © 1995 Wiley-Liss, Inc.     

Differences in water relations and physiological characteristics in leaves of wheat associated with leaf position on the plant

The seasonal change in leaf water potential and its components, stomatal resistance, specific leaf weight, photosynthesis rate, the activities of ribulose-1,5-bisphosphate carboxylase and nitrate reductase, and soluble proteins were measured in flag leaves (ninth from base in position), seventh and fifth leaves of wheat Triticum aestivum L. cv Kalyansona. Flag leaves had a lower water and solute potential and lower or equal turgor pressure than seventh and fifth leaves. These differences were found to be independent of environment. The rate of photosynthesis and nitrate reductase activity were always lower in fifth and seventh leaves than in flag leaf. The photosynthetic efficiency in flag leaves appeared to be associated with lower stomatal resistance and higher specific leaf weight. The relations between leaf water potential and relative water content showed a change with leaf position. This change possibly allows flag leaf to maintain its functional efficiency despite its lower water potential.     

Determination of cobalt in urine by gas chromatography—mass spectrometry employing nickel as an internal standard

A gas chromatographic—mass spectrometric method for the determination of cobalt in biological materials employing stable enriched ⁶²Ni as an internal standard and using lithium bis(trifluoroethyl)dithiocarbamate as a chelating agent is described. The method involves the addition of a known amount (1 μg) of ⁶²Ni to the sample, the formation of the chelate and the determination by selected-ion monitoring of the m/z ratio, which corresponds to . No appreciable memory effect was observed, and an acceptable dynamic range of 100 was found. There was good agreement between the cobalt concentration values determined by gas chromatography—mass spectrometry and electrothermal atomic absorption spectrometry. The present method has high sensitivity and can be used for the quantitation of cobalt at concentrations as low as 1 μg/l. The use of enriched ⁶²Ni circumvents the problem caused by endogenous nickel and simultaneously provides data on the nickel concentration in the biological sample without any additional experimental effort.