Alkaloids of the leaves of Voacanga grandifolia

Besides vobtusine and vobtusine-lactone, deoxyvobtusine was isolated from the leaves of Voacanga grandifolia (Miq. Rolfe. Spectral and chemical evi     

Socioeconomic, demographic and environmental determinants of infant mortality in Nepal

The Nepal Fertility and Family Planning Survey of 1986 demonstrated that demographic variables, previous birth interval and survival of preceding child, still predominated as determinants of infant mortality, particularly in rural areas of Nepal. However, in urban Nepal, where the level of socioeconomic development is higher, an environmental variable, along with previous birth interval and survival of preceding child emerges as important in determining infant mortality. Separate policy measures for child survival prospects in rural and urban Nepal are suggested.     

Correlation between nuclear glucocorticoid receptor levels and casein gene expression in murine mammary gland in vitro

The relationship between nuclear binding of glucocorticoid-receptor complex and casein gene expression was studied in organ culture of the whole mammary gland of the mouse. Pyridoxal 5'-phosphate was used as a modulatory agent for measuring nuclear binding of the receptor complex. Addition of 2 mM and 5mM pyridoxal-5'-P in the medium (Waymouth's MB752/1) resulted in 4- and 12-fold increase of its concentration in the glands incubated with insulin, prolactin, and hydrocortisone. Pyridoxal-5'-P also caused a 52% and 92% inhibition of nuclear binding of [3H]dexamethasone in the glands at 2 mM and 5 mM concentration in the presence of the same hormones in the medium. Corresponding to the reduced nuclear binding of the receptor complex casein mRNA levels, measured by a specific cDNA probe was reduced 86% and over 90% in the glands exposed to 2 mM and 5 mM pyridoxal-5'-P, respectively, in presence of insulin, prolactin, and hydrocortisone in the medium. Withdrawal of pyridoxal-5'-P from the medium restored nuclear binding of the receptor complex near the level of control glands incubated only with the hormones. mRNA casein levels also increased in the gland in the pyridoxal-5'-P-free medium containing the same hormones. This indicates that pyridoxal-5'-P does not alter the specific hormone responsiveness of the mammary cells and its action mediated at the level of the glucocorticoid receptor can influence hormone-inducible expression of the casein genes. Thus, glucocorticoid plays a major role in the multiple hormone regulation of the milk protein gene(s). The findings also suggest that the breast tissue concentration of the vitamin B6 derivative may influence the physiology of lactation in nursing mothers.     

Purification and properties of cyclic AMP-dependent protein kinase from rat epididymis

Two protein kinases (I and II: EC 2.7.1.37) that show a high degree of substrate specificity for protamine rather than histones, phosvitin and casein were partly purified from rat epididymal tissue. The enzymes were present in the cytosol because greater than 80% of the enzymic activity was recovered in the soluble fraction. The kinases required Mg2+ for activity although Co2+ and Mn2+ were partial substitutes. Zn2+ (1 mM) inhibited nearly completely the activity of the enzymes. Both the kinases showed high affinity for activation with cyclic AMP compared to other cyclic nucleotides. Amino acid analysis of 32P-labelled protamine product revealed that the kinases transfer the terminal phosphate of ATP to serine residues of the protein. The isoenzymes I and II showed certain differences in relation to their hydroxyapatite-chromatography profiles, pH activation profiles, heat sensitivity and Km for ATP and cyclic AMP.     

A Puzzle Unsolved: Failure to Observe Different Effects of God and Religion Primes on Intergroup Attitudes

Religious priming has been found to have both positive and negative consequences, and recent research suggests that the activation of God-related and community-related religious cognitions may cause outgroup prosociality and outgroup derogation respectively. The present research sought to examine whether reminders of God and religion have different effects on attitudes towards ingroup and outgroup members. Over two studies, little evidence was found for different effects of these two types of religious primes. In study 1, individuals primed with the words “religion”, “God” and a neutral control word evaluated both ingroup and outgroup members similarly, although a marginal tendency towards more negative evaluations of outgroup members by females exposed to religion primes was observed. In study 2, no significant differences in attitudes towards an outgroup member were observed between the God, religion, and neutral priming conditions. Furthermore, the gender effect observed in study 1 did not replicate in this second study. Possible explanations for these null effects are discussed.     

VDAC3 regulates centriole assembly by targeting Mps1 to centrosomes

Centrioles are duplicated during S-phase to generate the two centrosomes that serve as mitotic spindle poles during mitosis. The centrosomal pool of the Mps1 kinase is important for centriole assembly, but how Mps1 is delivered to centrosomes is unknown. Here we have identified a centrosome localization domain within Mps1 and identified the mitochondrial porin VDAC3 as a protein that binds to this region of Mps1. Moreover, we show that VDAC3 is present at the mother centriole and modulates centriole assembly by recruiting Mps1 to centrosomes.     

Topoisomerases of kinetoplastid parasites as potential chemotherapeutic targets

The protozoan parasites Trypanosoma, Leishmania and Crithidia, which belong to the order kinetoplastidae, emerge from the most ancient eukaryotic lineages. The diversity found in the life cycle of these organisms must be directed by genetic events, wherein topoisomerases play an important role in cellular processes affecting the topology and organization of intracellular DNA. Topoisomerases are valuable as potential drug targets because they have indispensable function in cell biology. This review summarizes what is known about topoisomerase genes and proteins of kinetoplastid parasites and the roles of these enzymes as targets for therapeutic agents.     

Characterization of nuclear phosphoprotein phosphatases from goat testis

Two nuclear phosphoprotein phosphatases (PPases I and II) that cause dephosphorylation of [32P]histone, have been partially purified from goat testis. The enzymic activity is associated with nucleoplasm and chromatin. PPase I is markedly stimulated (approx. 200-600%) by Mg2+ or Mn2+ (1 mM) whereas Ca2+ (1 mM) causes slight stimulation (approx. 35%) of the enzyme. On the contrary, PPase II is only slightly activated (20-40%) by these metal ions (5 mM). Both the phosphoprotein phosphatase isoenzymes are maximally active at pH 6-7. PPases I and II are strongly inhibited (approx. 60-100%) by ZnCl2 (1 mM), P1 (5 mM) and thiol reagents. NaF (5 mM) inhibits (approx. 40%) specifically the activity of PPase I rather than PPase II. PPases are strongly inhibited by relatively high concentration of NaCl (0.4 M), isoenzyme II being more sensitive (approx. 80%) than isoenzyme I (approx. 50%). In addition to histones, both the isoenzymes can as well cause dephosphorylation of protamine, casein, and testicular nuclear proteins. Enzymic characteristics of the testicular nuclear PPases are clearly different from those of the cytosolic enzyme previously characterized.