Clustering of sex hormone disruptors in Singapore's marine environment.

Abnormal sexual differentiation and other reproductive abnormalities in marine animals indicate the presence in seawater of endocrine-disrupting compounds (EDCs) that perturb the function of the sex hormone signaling pathways. However, most studies to date have reported on EDC effects in freshwater and sewage samples, and there is a paucity of bioassay data on the effects of EDCs in marine waters. Our aims in this study were to devise robust methodologies suitable for extracting potential EDCs and to measure their summated effects on activities of androgen receptors (ARs) and estrogen receptors (ER-alpha and ER-beta) in marine samples from Singapore's coastal waters.

Fedbatch operation using Clostridium acetobutylicum suspension culture as biocatalyst for enhancing hydrogen production.

We demonstrated the feasibility of fedbatch operation using Clostridium acetobutylicum suspension culture as a biocatalyst for the continuous production of hydrogen. The optimum operating pH and temperature of the current cultivation system for hydrogen production were pH 6.0 and 37 degrees C, respectively.

Protein trans-splicing in transgenic plant chloroplast: reconstruction of herbicide resistance from split genes.

Inteins are intervening protein sequences that undergo self-excision from a precursor protein with concomitant joining of the flanking sequences. Here, we demonstrate intein trans-splicing in Nicotiana tabacum chloroplasts by using the naturally split Ssp DnaE intein. Trans-splicing occurred whether both intein fragments were encoded in the chloroplast or were separated into the chloroplast and nuclear genomes.

Modulation of the N-type calcium channel gene expression by the alpha subunit of Go.

Go, a heterotrimeric G-protein, is enriched in brain and neuronal growth cones. Although several reports suggest that Go may be involved in modulation of neuronal differentiation, the precise role of Go is not clear. To investigate the function of Go in neuronal differentiation, we determined the effect of Goalpha, the alpha subunit of Go, on the expression of Ca(v)2.

Deacetoxycephalosporin C synthase isozymes exhibit diverse catalytic activity and substrate specificity.

The biosynthesis of cephalosporins involving a thiozolidine ring expansion is catalyzed by deacetoxycephalosporin C synthase (DAOCS). In this study, three DAOCS isozymes were cloned and expressed as active enzymes together with Streptomyces jumonjinensis DAOCS that was newly isolated and partially characterized. The enzymes showed excellent substrate conversion for penicillin G, phenethicillin, ampicillin and carbenicillin, but they were less effective in the ring expansion of penicillin V, amoxicillin and metampicillin.

Applying the random effect negative binomial model to examine traffic accident occurrence at signalized intersections.

Poisson and negative binomial (NB) models have been used to analyze traffic accident occurrence at intersections for several years. There are however, limitations in the use of such models. The Poisson model requires the variance-to-mean ratio of the accident data to be about 1.

Cavernous sinus involvement by extramedullary plasmacytoma of the sphenoid sinus. An argument for the use of adjuvant chemotherapy.

A 63-year-old man with cavernous sinus involvement from extramedullary plasmacytoma (EMP) of the sphenoid sinus is described. Transient resolution of retro-orbital headache and continued progression of the locally extensive tumor were noted after chemotherapy was given following a poor response to 5400 cGy of local irradiation. To determine whether adjunctive chemotherapy will improve the outcome of these particular patients, we propose that a randomized trial comparing radiotherapy to chemoradiation be conducted.

An analysis of motorcycle injury and vehicle damage severity using ordered probit models.

Problem: Motorcycles constitute about 19% of all motorized vehicles in Singapore and are generally overrepresented in traffic accidents, accounting for 40% of total fatalities.

Method: In this paper, an ordered probit model is used to examine factors that affect the injury severity of motorcycle accidents and the severity of damage to the vehicle for those crashes. Nine years of motorcycle accident data were obtained for Singapore through police reports.

Must metabolic acidosis be associated with malnutrition in haemodialysed patients?

Background: Metabolic acidosis was evaluated in the past as an independent variable of catabolism in haemodialysis (HD) patients. Nevertheless, it could in theory reflect a higher acid production from protein oxidation. The aim of this study was to evaluate the incidence and basis of metabolic acidosis in conjunction with a nutritional assessment in a HD population (n=120).

C-terminus modification of Streptomyces clavuligerus deacetoxycephalosporin C synthase improves catalysis with an expanded substrate specificity.

The biosynthesis of cephalosporins is catalyzed by deacetoxycephalosporin C synthase (DAOCS). Based on computational, biochemical, and structural analyses, it has been proposed that modification of the C-terminus of DAOCS might be a constructive strategy for engineering improvement in enzyme activity. Therefore, five hydrophilic residues namely N301, Y302, N304, R306, and R307 located in proximity to the C-terminus of Streptomyces clavuligerus DAOCS (scDAOCS) were selected and each substituted with a hydrophobic leucine residue.

Effect of pH on high-temperature production of bacterial penicillin acylase in Escherichia coli.

High-temperature-oriented production of bacterial penicillin acylase (PAC), which is usually expressed at low temperatures (less than 30 degrees C), was demonstrated in this study via heterologous expression of the Providencia rettgeri (P. rettgeri) pac gene in Escherichia coli (E. coli).

Molecular basis of R-type calcium channels in central amygdala neurons of the mouse.

R-type Ca2+ channels play a critical role in coupling excitability to dendritic Ca2+ influx and neuronal secretion. Unlike other types of voltage-sensitive Ca2+ channels (L, N, P/Q, and T type), the molecular basis for the R-type Ca2+ channel is still unclear, thereby limiting further detailed analyses of R-type Ca2+ channel physiology. The prevailing hypothesis is that alpha(1E) (Ca(V)2.

Sox-9 and cDachsund-2 expression in the developing chick telencephalon.

The expression patterns of the transcription factor, Sox-9, and of the nuclear factor, cDachsund-2, were examined in the developing chick telencephalon. Both genes were expressed in the ventricular zone and in the subventricular zone of the telencephalon during the period of neurogenesis. Whereas Sox-9 was not expressed in postmitotic tissues, cDachsund-2 was specifically expressed in the neostriatum and in subdivisions of the hyperstriatum embryonically and in posthatch chicks.

High vegetable and fruit diet intervention in premenopausal women with cervical intraepithelial neoplasia.

Objective: To examine whether diet intervention can promote increased vegetable and fruit intake, as reflected in increased plasma carotenoid and decreased plasma total homocysteine concentrations, in premenopausal women with cervical intraepithelial neoplasia, a precancerous condition.

Design: Randomized controlled diet intervention study.

Subjects: Fifty-three free-living premenopausal women who had been diagnosed with cervical intraepithelial neoplasia, were randomly assigned to an intervention (n = 27) or a control (n = 26) group.

Requirement for the L-type Ca(2+) channel alpha(1D) subunit in postnatal pancreatic beta cell generation.

Pancreatic beta cells are the source of insulin, which directly lowers blood glucose levels in the body. Our analyses of alpha(1D) gene-knockout (alpha(1D)(-/-)) mice show that the L-type calcium channel, alpha(1D), is required for proper beta cell generation in the postnatal pancreas. Knockout mice were characteristically slightly smaller than their littermates and exhibited hypoinsulinemia and glucose intolerance.

Photoaffinity labeling of insect nicotinic acetylcholine receptors with a novel [(3)H]azidoneonicotinoid.

The nicotinic acetylcholine receptor (nAChR) is a ligand-gated ion channel in the insect CNS and a target for major insecticides. Here we use photoaffinity labeling to approach the functional architecture of insect nAChRs. Two candidate 5-azido-6-chloropyridin-3-yl photoaffinity probes are evaluated for their receptor potencies: azidoneonicotinoid (AzNN) with an acyclic nitroguanidine moiety; azidodehydrothiacloprid.

Cell-specific expression and subcellular localization of neurophysin-CAT-fusion proteins expressed from oxytocin and vasopressin gene promoter-driven constructs in transgenic mice.

The cell-specific expression of both the oxytocin (OT) and vasopressin (VP) genes in magnocellular neurons (MCNs) of the hypothalamus has been proposed to be under the control of cis-elements in an intergenic region downstream of the VP gene. We examined this hypothesis using transgenic mice containing mouse genomic DNA-derived constructs linked to chloramphenicol acetyltransferase (CAT) reporters. VP gene expression was studied using constructs containing 3.

Mutation of N304 to leucine in Streptomyces clavuligerus deacetoxycephalosporin C synthase creates an enzyme with increased penicillin analogue conversion.

Superimposition of deacetoxycephalosporin C synthase (DAOCS) and isopenicillin N synthase (IPNS) structures revealed that R74, R160, R266 and N304 are strategically located in the catalytic cavity of Streptomyces clavuligerus DAOCS (scDAOCS) and are crucial for orchestrating different substrates. Substitutions at these sites to a hydrophobic leucine residue were expected to stabilize the hydrophobic substrate bound state. Substantial improvements in the biotransformation of penicillin G, ampicillin and amoxicillin to their respective cephalosporin moieties were observed using the N304L mutant scDAOCS.

Altered nociceptive response in mice deficient in the alpha(1B) subunit of the voltage-dependent calcium channel.

Calcium influx through N-type calcium channels mediates synaptic transmission at numerous central synapses and transduces nociceptive information in the spinal dorsal horn. However, the precise role of N-type calcium channels in pain perception is not fully elucidated. To address this issue, we generated and analyzed knockout mice for alpha(1B,) the pore-forming subunit of the N-type calcium channel.

Palliative radiotherapy for synchronous bilateral lung cancers.

Scant information is available about the outcomes of patients with synchronous bilateral lung cancers (SBLC) treated with radiation. We report on 32 patients with SBLC who were treated for palliation by external beam irradiation during a 19-year period. The overall median survival was 7 months; 20 individuals (63%) survived at least 6 months.

Trans-NIH neuroscience initiatives on mouse phenotyping and mutagenesis.

In the post-genomic era, the laboratory mouse will excel as a premier mammalian system to study normal and disordered biological processes, in part because of low cost, but largely because of the rich opportunities that exist for exploiting genetic tools and technologies in the mouse to systematically determine mammalian gene function. Many robust models of human disease may therefore be developed, and these in turn will provide critical clues to understanding gene function. The full potential of the mouse for understanding many of the neural and behavioral phenotypes of relevance to neuroscientists has yet to be realized.

Practice development credentialing in the United Kingdom - a unique framework for providing excellence, accountability and quality in nursing and healthcare.

This paper will describe the purpose, process and value of an international Practice Development Program by which clinical units can choose to be credentialed. It will describe how the fourteen criteria that a Unit is credentialed against takes them along a journey of practice, personal and professional development that equips them to not only positively respond to, but to proactively influence, the challenges and changes that healthcare is facing globally. It explains how The Program focuses on credentialing sustainable practice development that then contributes to the development of both the capability and capacity of healthcare services.

Utero-tubal transfer of mouse embryos.

A successful embryo transfer depends on the quality of the transferred embryos, recipients, and the transfer techniques. Among these, transfer techniques are often the limiting factor because transfer methodologies and personal skills vary. Suboptimal embryo transfer procedures can compromise transgenic experiments (pronuclear microinjection and gene targeting) and critical steps of mouse colony maintenance (embryo cryopreservation and mouse line rederivation).

Development of glaucoma in the course of interferon alpha therapy for chronic hepatitis B.

Previous reported ocular complications of interferon alfa administration are extremely rare. These include oculomotor palsy, corneal allograft rejection, retinal hemorrhage and cotton wool patches. A 15-year-old boy with chronic hepatitis B was treated with interferon alpha for six months, and then developed glaucoma.