Community outreach as an iterative dialogue among scientists and communities in the Texas gulf coast region

In response to significant environmental health challenges in Southeast Texas, a National Institute for Environmental Health Sciences Center at the University of Texas Medical Branch at Galveston was created to promote and conduct inter-disciplinary research in the areas of: (1) the molecular biology of DNA repair, replication and mutagenesis, (2) asthma pathogenesis in response to oxidative stress and viral exposures, and (3) environmental toxicant biotransformation. In addition, the NIEHS Center maintains close ties with neighboring communities through an active Community Outreach & Education Program (COEP) that develops and disseminates translational materials for use in environmental health awareness outreach, toxicology consultation, K-12 curriculum enrichment and in developing site-specific Community Partnership projects. The COEP core service divisions include: Environmental Arts & Sciences, Asthma Outreach & Education, Theater Outreach & Education, and Public Forum & Toxics Assistance. Public Forums focus on the use of Augusto Boal's Forum Theater dramaturgy to include the voices and local knowledge of communities within the process of Participatory Research. Forums create the preconditions for significant partnerships that link the hazardous risk perceptions and environmental health needs of communities with the expertise of NIEHS Center investigators and translational services provided through COEP outreach programs. The Forum process also creates leadership cores within environmentally challenged communities that facilitate the ongoing translational process and maintain the vital linkage between the health needs of communities and the analytic tools and the field and clinical technologies of the environmental sciences.     

A missense mutation (GGC[435Gly]-->AGC[Ser]) in exon 8 of the CYP11B2 gene inherited in Japanese patients with congenital hypoaldosteronism

OBJECTIVES: To clarify the underlying molecular mechanism of corticosterone methyl oxidase type II (CMO II) deficiency, Japanese patients newly diagnosed with CMO II deficiency were investigated. METHODS: We analyzed the patients' genomic DNA sequence on all 9 exons of the CYP11B2 gene. In addition, restriction fragment length polymorphism (RFLP) analysis and expression studies were performed. RESULTS: The analysis showed that the patients homozygously retained a missense mutation, Gumacr;GC[435Gly]-->Aumacr;GC[Ser], in the CYP11B2 gene. Expression studies indicated that the steroid 18-hydroxylase/oxidase activities of the mutant enzyme were substantially reduced. CONCLUSION: These results support the hypothesis that this mutation causes CMO II deficiency in the patients, and are in accordance with our theory that the partial loss of P-450(C18) activities causes CMO II deficiency.     

Active intestinal chloride secretion in human carriers of cystic fibrosis mutations: an evaluation of the hypothesis that heterozygotes have subnormal active intestinal chloride secretion

To explain the very high frequency of cystic fibrosis (CF) mutations in most populations of European descent, it has been proposed that CF heterozygotes have a survival advantage when infected with Vibrio cholerae or Escherichia coli, the toxins of which induce diarrhea by stimulation of active intestinal chloride secretion. Two assumptions underlie this hypothesis: (1) chloride conductance by the CF transmembrane conductance regulator (CFTR) is the rate-limiting step for active intestinal chloride secretion at all levels of expression, from approximately zero in patients with CF to normal levels in people who are not carriers of a mutation; and (2) heterozygotes have smaller amounts of functional intestinal CFTR than do people who are not carriers, and heterozygotes therefore secrete less chloride when exposed to secretagogues. The authors used an intestinal perfusion technique to measure in vivo basal and prostaglandin-stimulated jejunal chloride secretion in normal subjects, CF heterozygotes, and patients with CF. Patients with CF had essentially no active chloride secretion in the basal state, and secretion was not stimulated by a prostaglandin analogue. However, CF heterozygotes secreted chloride at the same rate as did people without a CF mutation. If heterozygotes are assumed to have less-than-normal intestinal CFTR function, these results mean that CFTR expression is not rate limiting for active chloride secretion in heterozygotes. The results do not support the theory that the very high frequency of CF mutations is due to a survival advantage that is conferred on heterozygotes who contract diarrheal illnesses mediated by intestinal hypersecretion of chloride.     

Trichophyton simii in a "Caí" monkey (Cebus apella) colony in the province of Corrientes, Argentina.

The objective is to describe an outbreak of Trichophyton simii in a Cebus apella monkey colony in Argentine. During summer, alopecic zones appeared on dorsal regions from head to base of the tail of the animals. The hair and skin of nine animals were streaked onto Sabouraud dextrose with cloramphenicol and incubated at 25 degrees C. By the 10th day, white, filamentous colonies, which turned pale pink, developed from simples of four animals. Microscopical examinations were carried out and, because of colony and macroconidia morphology, were classified as Trichopyton simii. Although infection with T. simii is considered a zoonosis, we did not find human cases.     

Fluorescence anisotropy assay for pharmacological characterization of ligand binding dynamics to melanocortin 4 receptors

Fluorescence anisotropy assay was implemented for characterization of ligand binding dynamics to melanocortin 4 (MC₄) receptors. This approach enables on-line monitoring of reactions that is essential for estimation of more correct binding parameters, understanding of ligand binding and its regulation mechanisms, and design of new drugs with desirable properties. Two different red-shifted fluorophore-labeled peptide ligands, Cy3B-NDP-α-MSH and TAMRA-NDP-α-MSH, were used and compared in assays that monitored their binding to MC₄ receptors in membranes of Sf9 insect cells. The Cy3B dye-labeled ligand exhibited improved performance in assays when compared with the TAMRA-labeled ligand, having higher photostability, insensitivity to buffer properties, and better signal/noise ratio. The binding of both ligands to membranes of Sf9 cells expressing MC₄ receptors was saturable and with high affinity. All studied MC₄ receptor-specific nonlabeled ligands displaced fluoroligands’ binding in a concentration-dependent manner with potencies in agreement with their pharmacological activities. On-line monitoring of the reactions revealed that equilibrium of peptide binding was not reached even after 3 h. Real-time monitoring of ligand binding dynamics enabled us to find optimal experimental conditions for each particular ligand and an improved estimate of their binding parameters.     

pRb-dependent cyclin D3 protein stabilization is required for myogenic differentiation

The expression of retinoblastoma (pRb) and cyclin D3 proteins is highly induced during the process of skeletal myoblast differentiation. We have previously shown that cyclin D3 is nearly totally associated with hypophosphorylated pRb in differentiated myotubes, whereas Rb-/- myocytes fail to accumulate the cyclin D3 protein despite normal induction of cyclin D3 mRNA. Here we report that pRb promotes cyclin D3 protein accumulation in differentiating myoblasts by preventing cyclin D3 degradation. We show that cyclin D3 displays rapid turnover in proliferating myoblasts, which is positively regulated through glycogen synthase kinase 3beta (GSK-3beta)-mediated phosphorylation of cyclin D3 on Thr-283. We describe a novel interaction between pRb and cyclin D3 that maps to the C terminus of pRb and to a region of cyclin D3 proximal to the Thr-283 residue and provide evidence that the pRb-cyclin D3 complex formation in terminally differentiated myotubes hinders the access of GSK-3beta to cyclin D3, thus inhibiting Thr-283 phosphorylation. Interestingly, we observed that the ectopic expression of a stabilized cyclin D3 mutant in C2 myoblasts enhances muscle-specific gene expression; conversely, cyclin D3-null embryonic fibroblasts display impaired MyoD-induced myogenic differentiation. These results indicate that the pRb-dependent accumulation of cyclin D3 is functionally relevant to the process of skeletal muscle cell differentiation.     

Synthesis and anti-aromatase activity of some new steroidal D-lactones

Starting from D-seco derivatives of 5-androstene 1-3, the D-homo lactones, 4 and 5, were synthesized. By the Oppenauer oxidation and/or by dehydration of 4 and 5 with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) or 2,3,5,6-tetrachloro-1,4-benzoquinone (chloranil), the corresponding D-lactones 6-12 were obtained. The structures of 6 and 10 were unambiguously proved by the appropriate X-ray structural analysis. Anti-aromatase assay showed that tested compounds possess inhibition potency, however, two to four times smaller (IC50 from 0.2 to 0.7 microM, respectively) in comparison to aminoglutethimide (AG).