P190-B, a Rho-GTPase-activating protein, is differentially expressed in terminal end buds and breast cancer.

Microdissection and differential display PCR were used to identify genes preferentially expressed in the highly proliferative terminal end buds (TEBs) in the mammary gland of 45-day-old virgin rats. One clone exhibited 87% homology to the human p190-B gene encoding a novel Rho-Gap. Using in situ hybridization, p190-B was detected in both the TEBs and the terminal ducts, with the highest expression observed in the outer layer of TEBs. During normal mammary gland development, p190-B mRNA expression was highest in the virgin mammary gland and decreased during late pregnancy and lactation. Interestingly, increased levels of p190-B mRNA relative to the normal mammary gland were seen in a subset of murine mammary tumors that appeared to be less well differentiated and potentially more aggressive. Transient transfection of a p190-B expression construct into MCF-10A human mammary epithelial cells resulted in disruption of the actin cytoskeleton, which suggests a role for p190-B in regulating the signaling pathways that influence cell migration and invasion. These results suggest that p190-B may be required for virgin mammary gland development, and its aberrant expression may occur in breast cancer.     

Structural and mass spectral studies on some multiply bonded diosmium tetracarboxylate compounds

The compounds Os₂(O₂CCH₃)₄Cl₂,1 and Os(O₂CC₂H₅)₄Cl₂, 2, have been structurally characterized. Both compounds crystallize in space group P2₁/n. For 1 the unit cell parameters are a = 6.546(1) Å, b = 8.950(1) Å, c = 12.533(1) Å, β = 90.17(1)° and Z = 2; for 2 they are a = 6.792(2) Å, b = 10.519(3) Å, c = 13.372(4) Å, β = 89.27(3)° and Z = 2. Both molecules have approximate D_4th symmetry with important dimensions as follows: for 1, Os≡Os 2.314(1) Å, OsCl 2.448(2) Å; for 2, Os≡Os 2.316(2) Å, OsCl 2.430(5) Å. The mass spectra of these compounds as well as that of Os₂(O₂CC₃H₇)₄Cl₂,3, are reported and discussed.     

The anthocyanin pigmentation pattern in Hibiscus sabdariffa L. and its mode of inheritance,with special reference to the variation intermedius

The anthocyanin pigmentation patterns of stem, epicalyx, calyx, fading corolla, colour of anthers and petal spot character were studied in Hibiscus sabdariffa L.The stem and epicalyx pigmentation are controlled by the c and r genes. The two genes C and R are involved so far as calyx pigmentation, fading corolla colour and the anther and spot colours are concerned but an additional factor f is assumed to explain the segregation of the calyx pigmentation and fading corolla colour. Thus, a total of three genes (c, r. f) is distinguished, segregating independently.The intermedius type resembles the green-light-red rype of altissima in stem and epicalyx pigmentation but shows distinct differences in calyx pigmentation and fading corolla colour.     

Indian aconites

Of the two dozen species of aconite native to India, thirteen are known to possess drug value. Some of the latter are in commercial trade and offer valuable substitutes for the more commonly used species of Europe. Their nomenclature is revised in this article, with proper consideration given to their habitats and chemical constituents in order to facilitate identification and standardization of this drug.     

Morphological changes in an acidophilic bacterium induced by heavy metals

The Acidiphilium strains inhabit acidic mine regions where they are subjected to occasional environmental stresses such as high and low temperatures, exposure to various heavy metals, etc. Change in morphology is one of the strategies that bacteria adopt to cope with environmental stresses; however, no study on this aspect has been reported in the case of Acidiphilium sp. This work is an attempt using the acidophilic heterotrophic bacterium Acidiphilium symbioticum H8. It was observed that the maximum alterations in size occurred when the bacterium was exposed to sub-inhibitory concentrations of Cu and Cd. Loosely packed coccobacillus-type normal cells formed characteristic chains of coccoidal lenticular shape with constrictions at the junctions between them in the presence of Cd; Cu induced transformation of cells to become round shaped; Ni caused the cells to aggregate, but Zn showed no effect. Respective metal depositions on the cell surface were confirmed by scanning electron microscopy equipped with energy dispersive X-ray analysis. Cell bound Ca²⁺ ions were replaced by these metal ions and measured by inductively coupled plasma mass spectrometry from the culture filtrate. Cell shape changed only after the addition of sub-inhibitory concentrations of the metals, but in growth inhibitory concentrations it was similar to the normal cells.     

Systematic analysis of the effect of multiple templates on the accuracy of comparative models of protein structure

Background  

Although multiple templates are frequently used in comparative modeling, the effect of inclusion of additional template(s) on model accuracy (when compared to that of corresponding single-template based models) is not clear. To address this, we systematically analyze two-template models, the simplest case of multiple-template modeling. For an existing target-template pair (single-template modeling), a two-template based model of the target sequence is constructed by including an additional template without changing the original alignment to measure the effect of the second template on model accuracy.     

Genetic Characterization of Hepatitis B Virus in Peripheral Blood Leukocytes: Evidence for Selection and Compartmentalization of Viral Variants with the Immune Escape G145R Mutation

The compartmentalization of viral variants in distinct host tissues is a frequent event in many viral infections. Although hepatitis B virus (HBV) classically is considered hepatotropic, it has strong lymphotropic properties as well. However, unlike other viruses, molecular evolutionary studies to characterize HBV variants in compartments other than hepatocytes or sera have not been performed. The present work attempted to characterize HBV sequences from the peripheral blood leukocytes (PBL) of a large set of subjects, using advanced molecular biology and computational methods. The results of this study revealed the exclusive compartmentalization of HBV subgenotype Ae/A2-specific sequences with a potent immune escape G145R mutation in the PBL of the majority of the subjects. Interestingly, entirely different HBV genotypes/subgenotypes (C, D, or Aa/A1) were found to predominate in the sera of the same study populations. These results suggest that subgenotype Ae/A2 is selectively archived in the PBL, and the high prevalence of G145R indicates high immune pressure and high evolutionary rates of HBV DNA in the PBL. The results are analogous to available literature on the compartmentalization of other viruses. The present work thus provides evidence in favor of the compartment-specific abundance, evolution, and emergence of the potent immune escape mutant. These findings have important implications in the field of HBV molecular epidemiology, transmission, transfusion medicine, organ transplantation, and vaccination strategies.Hepatitis B virus (HBV) is the prototype member of the Hepadnaviridae family and classically has been described to be hepatotropic, causing a wide range of clinical and subclinical manifestations of liver disease (57). Nevertheless, studies of HBV-infected human subjects and woodchucks infected with Woodchuck hepatitis virus (WHV; an animal model of hepadnaviral infection) have reported different molecular forms of replicative intermediates in the lymphatic cells and have established that hepadnaviruses are strongly lymphotropic in nature (29). Moreover, the results of studies of human subjects as well as with animal models have revealed that the life-long occult persistence of replication- and transmission-competent viruses in lymphatic cells is a strict consequence of hepadnaviral infections (29).More interestingly, in animal models, lymphatic system-restricted occult hepadnaviral infection has been found to be transmissible vertically as an asymptomatic, serologically occult infection exclusively confined to the lymphatic system (29). Earlier we provided evidence that occult HBV persisting in the lymphatic cells are transmissible, specifically to the PBL through horizontal intrafamilial modes (9). These observations clearly indicate important immunological, pathogenic, and epidemiological implications of lymphatic system-restricted hepadnaviral infections. Although the involvement of specific viral variants has been suggested to explain this lymphatic system-restricted hepadnaviral infection and transmission (29), the classical belief that hepatocytes are the primary target and only reservoir of HBV has precluded the genetic characterization of hepadnaviruses from extrahepatic sites.Fascinatingly, despite being classically considered a hepatotropic virus, hepatitis C virus (HCV), belonging to the family Flaviviridae, also shows occult persistence and lymphotropism very similar to that of hepadnaviruses (37). Similarly to WHV, HBV, and HCV, other viruses, including HIV (human immunodeficiency virus), small ruminant lentivirus, and Epstein-Barr virus, also have been shown to infect and persist in different anatomical compartments of the body in addition to their classical target cells (38, 40, 43, 45, 50). Furthermore, recent molecular evolutionary analyses based on envelope sequences of these viruses (e.g., HIV, HCV, small ruminant lentivirus, Epstein-Barr virus, etc.) have established clearly that these viruses undergo selection and independent evolution in diverse tissues, leading to the tissue-specific compartmentalization of viral populations (38, 40, 43, 45, 50). In contrast to other viruses, to the best of our knowledge, methodical molecular evolutionary studies to characterize HBV sequences isolated from extrahepatic sites of HBV-infected subjects have not been reported in the literature.We hypothesized that similar to other viruses, HBV also undergo independent evolution in different compartments of the body under the influence of differential immune pressure. To examine our hypothesis, we used the most easily available lymphatic cells, the peripheral blood leukocytes (PBL), determined the HBV envelope sequences from HBV DNA isolated from these cells, and performed advanced genetic, phylogenetic, and mutational analysis. The results of this work demonstrate a highly compartment-specific preponderance of HBV genetic variants in serum and PBL of the same study population, providing evidence in favor of the compartmentalization of HBV genetic variants. The results and important implications of these findings are discussed in this work.     

Identification of isothiazole-4-carboxamidines derivatives as a novel class of allosteric MEK1 inhibitors

The development of potent, orally bioavailable, and selective series of 5-amino-3-hydroxy-N(1-hydroxypropane-2-yl)isothiazole-4-carboxamidine inhibitors of MEK1 and MEK-2 kinase is described. Optimization of the carboxamidine and the phenoxyaniline group led to the identification of 55 which gave good potency as in vitro MEK1 inhibitors, and good oral exposure in rat.     

A series of novel, potent, and selective histone deacetylase inhibitors

Histone deacetylase (HDAC) inhibitors offer a promising strategy for cancer therapy and the first generation HDAC inhibitors are currently in clinical trials. A structurally novel series of HDAC inhibitors based on the natural cyclic tetrapeptide Apicidin is described. Selected screening of the sample collection looking for L-2-amino-8-oxodecanoic acid (L-Aoda) derivatives identified a small acyclic lead molecule 1 with the unusual ketone zinc binding group. SAR studies around this lead resulted in optimization to potent, low molecular weight, selective, non-hydroxamic acid HDAC inhibitors, equipotent to current clinical candidates.