Maternal HIV infection and other factors associated with growth outcomes of HIV-uninfected infants in Entebbe, Uganda.

OBJECTIVE: To assess the associations between maternal HIV infection and growth outcomes of HIV-exposed but uninfected infants and to identify other predictors for poor growth among this population. DESIGN: Within a trial of de-worming during pregnancy, the cohort of offspring was followed from birth. HIV status of the mothers and their children was investigated and growth data for children were obtained at age 1 year. Length-for-age, weight-for-age and weight-for-length Z-scores were calculated for each child; Z-scores ,22 were defined as stunting, underweight and wasting, respectively. SETTING: The study was conducted in Entebbe municipality and Katabi subcounty, Uganda. SUBJECTS: The sample consisted of 1502 children aged 1 year: HIV-unexposed (n 1380) and HIV-exposed not infected (n 122). RESULTS: Prevalence of stunting, underweight and wasting was 14.2%, 8.0% and 3.9%, respectively. There was evidence for an association between maternal HIV infection and odds of being underweight (adjusted OR52.32; 95% CI 1.32, 4.09; P=0.006) but no evidence for an association with stunting or with wasting. Young maternal age, low maternal education, low birth weight, early weaning and experiencing a higher number of episodes of malaria during infancy were independent predictors for stunting and underweight. A higher number of living children in the family was associated with wasting. CONCLUSIONS: Maternal HIV infection was associated with being underweight in HIV-exposed uninfected infants. The success of programmes for prevention of mother-to-child HIV transmission means that an increasing number of infants will be born to HIV-infected women without acquiring HIV. Therefore, viable nutritional interventions need to be identified for this population

Pulse pressure and age at menopause

BACKGROUND: The objective of this study was to study the association of early age at menopause with pulse pressure (PP), a marker of arterial stiffness, and PP change. METHODS: The effect of natural menopause was studied in 2484 women from the Atherosclerosis Risk in Communities (ARIC) Study who had not used hormone replacement therapy and who had not had a hysterectomy. The cross-sectional association of age with PP was evaluated in the entire cohort. The cross-sectional association of recalled age at menopause was evaluated in the 1688 women who were postmenopausal at baseline. PP change over 6 years was assessed in relation to menopausal age separately in women who were postmenopausal at baseline and in those whose menopause occurred during the 6-year interval. RESULTS: Chronological age was strongly and positively associated with PP in cross-sectional analyses, but not independently associated with PP change. While menopausal age was not associated cross-sectionally with PP, early age at menopause (age<45) was significantly and independently associated with a slightly larger increase in PP (8.4, 95% CI 7.0–9.8) than later menopause (6.5, 95% CI 5.8;7.2). However, among normotensive women the difference was not statistically significant (p = 0.07, 6.1 vs 4.7). CONCLUSIONS: Early age at menopause may be related to a greater increase in arterial stiffness, but the effect appears to be small and further evidence is needed

High-throughput crystallography reveals boron-containing inhibitors of a Penicillin-binding protein with di- and tricovalent binding modes

The effectiveness of β-lactam antibiotics is increasingly compromised by β-lactamases. Boron-containing inhibitors are potent serine-β-lactamase inhibitors, but the interactions of boron-based compounds with the penicillin-binding protein (PBP) β-lactam targets have not been extensively studied. We used high-throughput X-ray crystallography to explore reactions of a boron-containing fragment set with the PBP3 (PaPBP3). Multiple crystal structures reveal that boronic acids react with PBPs to give tricovalently linked complexes bonded to Ser294, Ser349, and Lys484 of PaPBP3; benzoxaboroles react with PaPBP3 via reaction with two nucleophilic serines (Ser294 and Ser349) to give dicovalently linked complexes; and vaborbactam reacts to give a monocovalently linked complex. Modifications of the benzoxaborole scaffold resulted in a moderately potent inhibition of PaPBP3, though no antibacterial activity was observed. Overall, the results further evidence the potential for the development of new classes of boron-based antibiotics, which are not compromised by β-lactamase-driven resistance

Analysis of SEC9 Suppression Reveals a Relationship of SNARE Function to Cell Physiology

BACKGROUND:Growth and division of Saccharomyces cerevisiae is dependent on the action of SNARE proteins that are required for membrane fusion. SNAREs are regulated, through a poorly understood mechanism, to ensure membrane fusion at the correct time and place within a cell. Although fusion of secretory vesicles with the plasma membrane is important for yeast cell growth, the relationship between exocytic SNAREs and cell physiology has not been established. METHODOLOGY/PRINCIPAL FINDINGS:Using genetic analysis, we identified several influences on the function of exocytic SNAREs. Genetic disruption of the V-ATPase, but not vacuolar proteolysis, can suppress two different temperature-sensitive mutations in SEC9. Suppression is unlikely due to increased SNARE complex formation because increasing SNARE complex formation, through overexpression of SRO7, does not result in suppression. We also observed suppression of sec9 mutations by growth on alkaline media or on a non-fermentable carbon source, conditions associated with a reduced growth rate of wild-type cells and decreased SNARE complex formation. CONCLUSIONS/SIGNIFICANCE:Three main conclusions arise from our results. First, there is a genetic interaction between SEC9 and the V-ATPase, although it is unlikely that this interaction has functional significance with respect to membrane fusion or SNAREs. Second, Sro7p acts to promote SNARE complex formation. Finally, Sec9p function and SNARE complex formation are tightly coupled to the physiological state of the cell

Angiopreventive Efficacy of Pure Flavonolignans from Milk Thistle Extract against Prostate Cancer: Targeting VEGF-VEGFR Signaling

The role of neo-angiogenesis in prostate cancer (PCA) growth and metastasis is well established, but the development of effective and non-toxic pharmacological inhibitors of angiogenesis remains an unaccomplished goal. In this regard, targeting aberrant angiogenesis through non-toxic phytochemicals could be an attractive angiopreventive strategy against PCA. The rationale of the present study was to compare the anti-angiogenic potential of four pure diastereoisomeric flavonolignans, namely silybin A, silybin B, isosilybin A and isosilybin B, which we established previously as biologically active constituents in Milk Thistle extract. Results showed that oral feeding of these flavonolignans (50 and 100 mg/kg body weight) effectively inhibit the growth of advanced human PCA DU145 xenografts. Immunohistochemical analyses revealed that these flavonolignans inhibit tumor angiogenesis biomarkers (CD31 and nestin) and signaling molecules regulating angiogenesis (VEGF, VEGFR1, VEGFR2, phospho-Akt and HIF-1α) without adversely affecting the vessel-count in normal tissues (liver, lung, and kidney) of tumor bearing mice. These flavonolignans also inhibited the microvessel sprouting from mouse dorsal aortas ex vivo, and the VEGF-induced cell proliferation, capillary-like tube formation and invasiveness of human umbilical vein endothelial cells (HUVEC) in vitro. Further studies in HUVEC showed that these diastereoisomers target cell cycle, apoptosis and VEGF-induced signaling cascade. Three dimensional growth assay as well as co-culture invasion and in vitro angiogenesis studies (with HUVEC and DU145 cells) suggested the differential effectiveness of the diastereoisomers toward PCA and endothelial cells. Overall, these studies elucidated the comparative anti-angiogenic efficacy of pure flavonolignans from Milk Thistle and suggest their usefulness in PCA angioprevention

Isolation and localization of a cytosolic 10 S triacylglycerol biosynthetic multienzyme complex from oleaginous yeast

Triacylglycerol is one of the major storage forms of metabolic energy in eukaryotic cells. Biosynthesis of triacylglycerol is known to occur in membranes. We report here the isolation, purification, and characterization of a catalytically active cytosolic 10 S multienzyme complex for triacylglycerol biosynthesis from Rhodotorula glutinis during exponential growth. The complex was characterized and was found to contain lysophosphatidic acid acyltransferase, phosphatidic acid phosphatase, diacylglycerol acyltransferase, acyl-acyl carrier protein synthetase, and acyl carrier protein. The 10 S triacylglycerol biosynthetic complex rapidly incorporates free fatty acids as well as fatty acyl-coenzyme A into triacylglycerol and its biosynthetic intermediates. Lysophosphatidic acid acyltransferase, phosphatidic acid phosphatase, and diacylglycerol acyltransferase from the complex were microsequenced. Antibodies were raised against the synthetic peptides corresponding to lysophosphatidic acid acyltransferase and phosphatidic acid phosphatase sequences. Immunoprecipitation and immunolocalization studies show the presence of a cytosolic multienzyme complex for triacylglycerol biosynthesis. Chemical cross-linking studies revealed that the 10 S multienzyme complex was held together by protein-protein interactions. These results demonstrate that the cytosol is one of the sites for triacylglycerol biosynthesis in oleaginous yeast

Purification and characterization of acyl-acyl carrier protein synthetase from oleaginous yeast and its role in triacylglycerol biosynthesis

Fatty acids are activated in an ATP-dependent manner before they are utilized. We describe here how the 10S triacylglycerol biosynthetic multienzyme complex from Rhodotorula glutinis is capable of activating non-esterified fatty acids for the synthesis of triacylglycerol. The photolabelling of the complex with [32P]azido-ATP showed labelling of a 35kDa polypeptide. The labelled polypeptide was identified as acyl-acyl carrier protein (ACP) synthetase, which catalyses the ATP-dependent ligation of fatty acid with ACP to form acyl-ACP. The enzyme was purified by successive PAGE separations to apparent homogeneity from the soluble fraction of oleaginous yeast and its apparent molecular mass was 35kDa under denaturing and reducing conditions. Acyl-ACP synthetase was specific for ATP. The Km values for palmitic, stearic, oleic and linoleic acids were found to be 42.9, 30.4, 25.1 and 22.7μM, respectively. The antibodies to acyl-ACP synthetase cross-reacted with Escherichia coli acyl-ACP synthetase. Anti-ACP antibodies showed no cross-reactivity with the purified acyl-ACP synthetase, indicating no bound ACP with the enzyme. Immunoprecipitations with antibodies to acyl-ACP synthetase revealed that this enzyme is a part of the 10S triacylglycerol biosynthetic complex. These results demonstrate that the soluble acyl-ACP synthetase plays a novel role in activating fatty acids for triacylglycerol biosynthesis in oleaginous yeast.</jats:p