Deletion of cytoplasmic sequences of the nerve growth factor receptor leads to loss of high affinity ligand binding

The nerve growth factor (NGF) receptor is a glycosylated transmembrane protein present on the cell surface as both high and low affinity forms, but biological responsiveness requires interactions of NGF with the high affinity site. We have tested the effects of mutations in the intracellular domain of the receptor upon its cell surface expression and equilibrium binding of 125I-NGF. Although mutant receptors lacking the entire cytoplasmic domain are processed and expressed at the cell surface and are capable of binding to NGF, the absence of cytoplasmic sequences leads to a loss of high affinity binding and to a lack of an appropriate cross-linking pattern as assessed by N-hydroxysuccinimidyl 4-azidobenzoate photoaffinity cross-linking. These results, taken together with the highly conserved nature of these cytoplasmic sequences, implies that the interaction of the receptor with an accessory molecule is necessary to form the high affinity receptor.     

Suppression of bioactive luteinizing hormone and testosterone by a progesterone antagonist ZK 98.734 in adult male common marmosets, Callithrix jacchus

The effects of a progesterone antagonist ZK 98.734 on release of bioactive luteinizing hormone (LH) and testosterone were studied in adult male common marmosets by using the following experimental protocols: (1) the blocking of the nocturnal rise in testosterone levels by ZK 98.734, (2) the pharmacodynamic effects of ZK 98.734 on testosterone and LH levels, (3) the reversal of ZK 98.734-induced decrease in testosterone by treatment with human chorionic gonadotropin (hCG), and (4) the blocking of estradiol-induced positive feedback release of LH by ZK 98.734. Sixteen adult male common marmosets were used for different experiments after resting them for at least 4 wk between experiments. Testosterone and bioactive LH levels were measured by specific radioimmunoassay and in vitro bioassay methods, respectively. Treatment (i.m.) of male common marmosets (n = 6/group) with ZK 98.734 (1 mg or 5 mg/day) at 1700 h for 3 consecutive days significantly (p less than 0.05) suppressed the nocturnal (2200 h) rise in testosterone levels. The effects of the two doses were not dose-related; however, the decrease on the first day of treatment was more pronounced with the 5-mg dose than with the 1-mg dose. Diurnal rhythms were restored during the post-treatment period. Similarly, treatment with ZK 98.734 (5 mg, n = 8/group) at 1000 h caused a decrease in testosterone and LH levels. The levels were significantly (p less than 0.05) lower at 3 and 6 h after treatment compared to pretreatment levels.(ABSTRACT TRUNCATED AT 250 WORDS)     

Degradation of carboxin and oxycarboxin in different soils

Summary Five different soils varying in physico-chemical properties were used for studying the persistence and degradation of carboxin and oxycarboxin. In one soil only both fungicides were degraded with accumulation of ammonium and nitrite. Under the conditions of forced circulation of air and continuous perfusion, oxycarboxin was found to be more susceptible to degradation than carboxin. Under simulated conditions of rice fields, conversion of carboxin to its sulphoxide and to a non-toxic derivative of oxycarboxin could only be seen in all the soils.The role of clay, humus and organic matter as protectants of fungicides against degradation indicated that the intermediary compound carboxin sulphoxide was strongly adsorbed probably on organic and inorganic colloids of most of the soils. Organic matter free soils delayed the degradation. Carboxin was rapidly converted to its sulphoxide on three forms of monoionic clays whereas oxycarboxin was transformed to an unidentified derivative.Part of Ph.D. thesis submitted to UAS, Bangalore-65.     

Assessment of genetic diversity and population structure in pomegranate (Punica granatum L.) using hypervariable SSR markers

Physiology and Molecular Biology of Plants - The present study investigates the genetic diversity and population structure among 42 diverse pomegranate genotypes using a set of twenty one class I...     

Gametic embryogenesis and callogenesis in Isolated microspore culture of Jatropha curcas L. a recalcitrant bioenergy crop

Plant Cell, Tissue and Organ Culture (PCTOC) - Jatropha curcas is an undomesticated crop and its plantations did not meet commercial expectation due to absence of high yielding commercial line with...     

Unraveling the camel rumen microbiome through metaculturomics approach for agriculture waste hydrolytic potential

Archives of Microbiology - Cellulose is the most abundant natural polymer present on Earth in the form of agriculture waste. Hydrolysis of agriculture waste for simple fermentable reducing sugars...     

Exogenous dsRNA-mediated field protection against Pigeonpea sterility mosaic emaravirus

Journal of Plant Biochemistry and Biotechnology - Pigeonpea sterility mosaic emaraviruses (PPSMVs) cause sterility mosaic disease in pigeonpea which significantly reduce the crop yield. Currently...