Evidence for progesterone synthesis by human umbilical cord blood erythrocytes

In order to determine whether human umbilical cord blood erythrocytes are capable of progesterone biosynthesis, sonicated preparations of plasma-free erythrocytes at the range of total cell numbers between 18.4 x 10(9) and 62.9 x 10(9) cells obtained from umbilical cord arterial and venous blood collected from normal pregnant women (n = 6, age 28-39 years) following spontaneous vaginal delivery were incubated with [7n-(3)H]-pregnenolone as substrate. The leucocyte content of the incubates was negligible (<0. 005%). Controls (n = 4, age 29-36 years; 27.6 x 10(9) to 42.7 x 10(9) erythrocytes) obtained from cord blood of normal pregnant women were heat-denatured preparations of cells. Using the reverse-isotope dilution technique, [(3)H]-progesterone was isolated and characterized yielding an overall enzymic conversion which ranged between 0.27 and 0.46%. The results indicate for the first time that cord blood erythrocytes possess the 3beta-hydroxysteroid dehydrogenase-5,4-en isomerase activity and are a source of progesterone in human pregnancy.     

Vasorelaxant properties of Vernonia amygdalina ethanol extract and its possible mechanism

Context: Vernonia amygdalina Del. (VA) (Asteraceae) is commonly used to treat hypertension in Malaysia.

Objective: This study investigates the vasorelaxant mechanism of VA ethanol extract (VAE) and analyzes its tri-step FTIR spectroscopy fingerprint.

Materials and methods: Dried VA leaves were extracted with ethanol through maceration and concentrated using rotary evaporator before freeze-dried. The vasorelaxant activity and the underlying mechanisms of VAE using the cumulative concentration (0.01–2.55?mg/mL at 20-min intervals) were evaluated on aortic rings isolated from Sprague Dawley rats in the presence of antagonists.

Results: The tri-step FTIR spectroscopy showed that VAE contains alkaloids, flavonoids, and saponins. VAE caused the relaxation of pre-contracted aortic rings in the presence and absence of endothelium with EC₅₀ of 0.057?±?0.006 and 0.430?±?0.196?mg/mL, respectively. In the presence of Nω-nitro-l-arginine methyl ester (EC₅₀ 0.971?±?0.459?mg/mL), methylene blue (EC₅₀ 1.203?±?0.426?mg/mL), indomethacin (EC₅₀ 2.128?±?1.218?mg/mL), atropine (EC₅₀ 0.470?±?0.325?mg/mL), and propranolol (EC₅₀ 0.314?±?0.032?mg/mL), relaxation stimulated by VAE was significantly reduced. VAE acted on potassium channels, with its vasorelaxation effects significantly reduced by tetraethylammonium, 4-aminopyridine, barium chloride, and glibenclamide (EC₅₀ 0.548?±?0.184, 0.158?±?0.012, 0.847?±?0.342, and 0.304?±?0.075?mg/mL, respectively). VAE was also found to be active in reducing Ca²⁺ released from the sarcoplasmic reticulum and blocking calcium channels.

Conclusions: The vasorelaxation effect of VAE involves upregulation of NO/cGMP and PGI₂ signalling pathways, and modulation of calcium/potassium channels, and muscarinic and β₂-adrenergic receptor levels.     

Morphological and biochemical changes of andrographolide-induced cell death in human prostatic adenocarcinoma PC-3 cells

Andrographolide was extracted and purified from Andrographis panicula using hexane and water partitioning followed by ethyl acetate extraction and chromatography. It showed selective cytotoxicity to prostate cancer PC-3 cells in vitro. The morphological and biochemical changes induced by the extract in carcinoma PC-3 cell death were studied. In andrographolide-treated cells, evidence of apoptosis such as cell shrinkage and surface microvilli loss after 4-hour treatment and chromatin condensation and fragmentation in H&E-stained cells between 4 to 8 hours after treatment were observed. Under electron microscopy, membrane blebbing and apoptotic bodies formation were seen after 8-hour treatment. Using immunocytochemistry staining and cellular caspase-3 activity assay, andrographolide-treated cells showed considerable caspase-3 activation and caspase-8 in PC-3 cells at 4 and 2 hours after treatment, respectively. This suggests andrographolide-induced cell death was achieved through the apoptotic pathway, via the activation of an extrinsic caspase cascade.     

Appropriateness of vancomycin therapeutic drug monitoring and its outcomes among non-dialysis patients in a tertiary hospital in Singapore

Background Vancomycin therapeutic drug monitoring (TDM) is commonly performed to ensure safe and effective use of the antibiotic. Aim of Study To evaluate appropriateness of vancomycin TDM and its outcomes in Singapore General Hospital. Method A retrospective, cross-sectional study was conducted between 1 January 2014 and 28 February 2014 involving patients who received?≥?1 dose of intravenous vancomycin with TDM. Patient demographics and relevant vancomycin TDM data were collected from medical records. Results Of 746 vancomycin troughs measured among 234 patients, 459 troughs (61.5%) were taken inappropriately, with a median time of 2.6 h (interquartile range 1.1–4.3) before the next scheduled dose. Inappropriate interpretation of vancomycin troughs resulted in 41 unnecessary dose suspensions, 24 dose changes, and 102 unchanged vancomycin doses. The cost incurred due to inappropriate interpretation and measurement after discontinuation of treatment was US$7286. No differences in rates of vancomycin related nephrotoxicity, ototoxicity, recurrent infection, development of infection secondary to vancomycin resistant microorganism and mortality were observed (p?>?0.05). Conclusion This study highlighted a high incidence of inappropriate vancomycin TDM which has led to increased healthcare cost.     

Effects of a selection of histone deacetylase inhibitors on mast cell activation and airway and colonic smooth muscle contraction

Studies of histone deacetylase (HDAC) inhibitors, novel anticancer drugs, in models of autoimmune diseases, asthma, and inflammatory bowel disease suggest that HDAC inhibitors may also have useful anti-inflammatory effects. Accordingly, in vitro studies relevant to asthma and inflammatory bowel disease were conducted using a selection of HDAC inhibitors: suberoylanilide hydroxamic acid (SAHA, Vorinostat), and a related branched hydroxamic acid, diamide (1), MGCD0103 and two short chain fatty acid derivatives: sodium butyrate (of use in inflammatory bowel disease) and sodium valproate. The ability of those HDAC inhibitors to modulate antigen- or agonist-induced contraction of isolated guinea pig tracheal rings and colon, agonist-induced contraction of rat colon, and histamine release from rat peritoneal mast cells was examined. Pre-incubation (up to 6 h) with 10-40 microM of SAHA, diamide (1), or MGCD0103 caused significant inhibition of the antigen-induced contraction of sensitised guinea pig tracheal rings as well as inhibition of the contraction induced by histamine, 5-hydroxytryptamine and carbachol (G-protein coupled receptor agonists), while sodium butyrate (1 mM) and sodium valproate (100 microM) were weak inhibitors. Contraction of tracheal rings by sodium fluoride (NaF, a non-selective G-protein activator), KCl and a peroxyl radical generator was blocked by MGCD0103. Additionally, MGCD0103 significantly inhibited antigen-induced histamine release from IgE antibody-sensitised rat peritoneal mast cells, and NaF-induced histamine release, as well as inhibiting NaF-induced colon contraction. Those various effects appear to involve modulation of cell signaling, probably involving G-protein coupled pathways, and further support the development of HDAC inhibitors as anti-inflammatory agents.     

Polychlorinated Biphenyls Disrupt Intestinal Integrity via NADPH Oxidase-Induced Alterations of Tight Junction Protein Expression

Background

Polychlorinated biphenyls (PCBs) are widely distributed environmental toxicants that contribute to numerous disease states. The main route of exposure to PCBs is through the gastrointestinal tract; however, little is known about the effects of PCBs on intestinal epithelial barrier functions.

Objective

The aim of the present study was to address the hypothesis that highly chlorinated PCBs can disrupt gut integrity at the level of tight junction (TJ) proteins.

Methods

Caco-2 human colon adenocarcinoma cells were exposed to one of the following PCB congeners: PCB153, PCB118, PCB104, and PCB126. We then assessed NAD(P)H oxidase (NOX) activity and expression and the barrier function of Caco-2 cells. In addition, the integrity of intestinal barrier function and expression of TJ proteins were evaluated in C57BL/6 mice exposed to individual PCBs by oral gavage.

Results

Exposure of Caco-2 cells to individual PCB congeners resulted in activation of NOX and increased permeability of fluorescein isothiocyanate (FITC)-labeled dextran (4 kDa). Treatment with PCB congeners also disrupted expression of TJ proteins zonula occludens-1 (ZO-1) and occludin in Caco-2 cells. Importantly, inhibition of NOX by apocynin significantly protected against PCB-mediated increase in epithelial permeability and alterations of ZO-1 protein expression. Exposure to PCBs also resulted in alterations of gut permeability via decreased expression of TJ proteins in an intact physiological animal model.

Conclusions

These results suggest that oral exposure to highly chlorinated PCBs disrupts intestinal epithelial integrity and may directly contribute to the systemic effects of these toxicants.     

Specific detection of fungal pathogens by 18S rRNA gene PCR in microbial keratitis

Background  

The sensitivity and specificity of 18S rRNA polymerase chain reaction (PCR) in the detection of fungal aetiology of microbial keratitis was determined in thirty patients with clinical diagnosis of microbial keratitis.     

Sociodemographic determinants of Malaysian household’s use of and expenditure on alcohol: a regional comparison

Abstract

Aims: Alcohol consumption has become a serious public health concern. The objective of the present study is to investigate sociodemographic factors associated with alcohol consumption across regions of Malaysia.

Methods: Data are obtained from the Malaysian Household Expenditure Survey 2014, which contains 10,665 observations. Double-hurdle model is used to examine the consumption decision and amount decision of alcohol among households. Analyses are stratified by regions (Northern, East coast, Central and Southern).

Findings: Results show that age, household size, gender, ethnicity, marital status, education, employment status, location of residence and tobacco consumption are independently associated with alcohol consumption. Households headed by males and well-educated individuals are more likely to consume alcohol and also spend more compared with households headed by females and less-educated individuals. Being employed, non-Bumiputera and tobacco consumption seem to increase the likelihood of consuming alcohol. Household size is negatively associated with the amount spent on alcohol.

Conclusion: In conclusion, sociodemographic factors play an important role in determining alcohol consumption. It appears that factors associated with alcohol consumption vary across regions. Hence, policies that address regional differences in the sociodemographic factors associated with alcohol consumption are needed.     

Demographic and lifestyle factors associated with sexual activity among adolescents in Malaysia

Having a better understanding of the factors associated with sexual behaviour among adolescents is important as it may assist government in lowering the prevalence of teen pregnancy. The objective of the present study is to examine the effects of demographic and lifestyle factors on the likelihood of engaging in sexual intercourse with a focus on Malaysian adolescents. Using a nationally representative data collected by the Ministry of Health Malaysia, the present study finds that age, self-rated academic performance, parents’ marital status, alcohol consumption and cigarette smoking can significantly affect the sexual behaviour among adolescents. The present study concludes by discussing the policy implications of these findings. As a measure towards reducing underage sex, successful policies should be targeted primarily at adolescents who aged more than 16 years self-rate their academic performance as poor, have single parents, and adopt alcohol drinking and cigarette smoking behaviours.