Identification of intracellular and extracellular domains mediating signal transduction in the inhibitory glycine receptor chloride channel

Fast synaptic neurotransmission is mediated by transmitter-activated conformational changes in ligand-gated ion channel receptors, culminating in opening of the integral ion channel pore. Human hereditary hyperekplexia, or startle disease, is caused by mutations in both the intracellular or extracellular loops flanking the pore-lining M2 domain of the glycine receptor alpha 1 subunit. These flanking domains are designated the M1-M2 loop and the M2-M3 loop respectively. We show that four startle disease mutations and six additional alanine substitution mutations distributed throughout both loops result in uncoupling of the ligand binding sites from the channel activation gate. We therefore conclude that the M1-M2 and M2-M3 loops act in parallel to activate the channel. Their locations strongly suggest that they act as hinges governing allosteric control of the M2 domain. As the members of the ligand-gated ion channel superfamily share a common structure, this signal transduction model may apply to all members of this superfamily.

Determination of trace elements in scalp hair of an elderly population by neutron activation analysis

Neutron activation analysis was applied to assess trace elements concentrations in head hair from healthy elderly people living in the Sao Paulo metropolitan area. Concentrations of As, Br, Ca, Cl, Co, Cr, Cu, Fe, K, La, Mn, Na, Sb, Se and, Zn were determined. Comparisons were made between the results obtained for dyed and non-dyed hair as well as for hair from females and males of two different age groups. The results were also compared with range values established by clinical laboratories and published data.

Intracellular free Ca2+ and basal Mn2+ influx in cultured aortic smooth muscle cells from spontaneously hypertensive and normotensive Wistar-Kyoto rats.

Numerous studies investigating the possible role of altered Ca2+ homeostasis in hypertension have compared resting and agonist-stimulated intracellular free Ca2+ ([Ca2+](i)) in cultured aortic smooth muscle cells from spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats. However, such studies have not given consistent results. Differences in the method used to load cells with the Ca2+-sensitive indicator fura-2 have been investigated here as a possible source of variability between studies. We also describe the adaptation of a fluorescence technique for the assessment of basal Ca2+ permeability in SHR and WKY through the measurement of Mn2+ influx. The results are consistent with the hypothesis that basal Ca2+ influx is elevated in cultured aortic smooth muscle cells from SHR compared to those from WKY. However, this was not reflected as a significant difference between the two strains in basal or angiotensin II (200 nmol/L)stimulated [Ca2+](i). Furthermore, this result was not dependent on the protocol used to load cells with fura-2. Hence, measurement of bulk [Ca2+](i) does not appear to be the most sensitive parameter for altered Ca2+ homeostasis in SHR. Other compartments of the cell may better reflect altered Ca2+ fluxes in hypertension and are discussed in this work.

Hydraulic tracer studies in a pilot scale subsurface flow constructed wetland

Current design procedures for Subsurface Flow (SSF) Wetlands are based on the simplifying assumptions of plug flow and first order decay of pollutants. These design procedures do yield functional wetlands but result in over-design and inadequate descriptions of the pollutant removal mechanisms which occur within them. Even though these deficiencies are often noted, few authors have attempted to improve modelling of either flow or pollutant removal in such systems. Consequently the Oxley Creek Wetland, a pilot scale SSF wetland designed to enable rigorous monitoring, has recently been constructed in Brisbane, Australia. Tracer studies have been carried out in order to determine the hydraulics of this wetland prior to commissioning it with sealed sewage. The tracer studies will continue during the wetland's commissioning and operational phases. These studies will improve our understanding of the hydraulics of newly built SSF wetlands and the changes brought on by operational factors such as biological films and wetland plant root structures. Results to date indicate that the flow through the gravel beds is not uniform and cannot be adequately modelled by a single parameter, plug flow with dispersion, model. We have developed a multiparameter model, incorporating four plug flow reactors, which provides a better approximation of our experimental data. With further development this model will allow improvements to current SSF wetland design procedures and operational strategies, and will underpin investigations into the pollutant removal mechanisms at the Oxley Creek Wetland. (C) 1997 IAWQ. Published by Elsevier Science Ltd.

A systemic parvo-like virus in the freshwater crayfish Cherax destructor

Systemic Cowdry Type A inclusions (CAs) were observed in a moribund Cherax destructor collected at an aquaculture farm in South Australia. Inclusions were most common in the gills and were associated with multifocal necrosis of the main gill axis and lamellae. The hepatopancreas was necrotic; however, only one CA was observed in the interstitial tissues. CAs were associated with necrosis in the abdominal and gut musculature. CAs were also observed in the spongy connective tissues and the epicardium. Empty capsids (17.5 +/- 0.5 nm) and microfilaments were most commonly observed within these inclusions by transmission electron microscopy. Complete icosahedral viral particles (20.8 +/- 1.2 nm) were difficult to distinguish within the viroplasm, but were visualised better in aggregates between the viroplasm and the inner nuclear membrane. The nucleolus was closely associated with the developing viroplasm, and was hypertrophied and segregated into its fibrillar and granular components. The virus was named Cherax destructor systemic parvo-like virus (CdSPV) on the basis of its histopathology, cytopathology and morphology. CdSPV is the first systemic virus described in a freshwater crayfish.

Molecular motion in miscible polymer blends .1. Motion in blends of PEO and PVPh studied by solid-state C-13 T-1 rho measurements

Changes in molecular motion in blends of PEO-PVPh have been studied using measurements of C-13 T-1 rho relaxation times. C-13 T-1 rho relaxation has been confirmed as arising from spin-lattice interactions by observation of the variation in T-1 rho with rf field strength and temperature. In the pure homopolymers a minimum in T-1 rho is observed at ca. 50 K above the glass transition temperatures detected by DSC. After blending, the temperature of the minimum in T-1 rho for PEO increased, while that for PVPh decreased, however, the minima, which correspond to the temperatures where the average correlation times for reorientation are close to 3.1 mu s, are separated by 45 K (in a 45% PEO-PVPh blend). These phenomena are explained in terms of the local nature of T-1 rho measurements. The motions of the individual homopolymer chains are only partially coupled in the blend. A short T-1 rho has been observed for protonated aromatic carbons, and assigned to phenyl rings undergoing large-angle oscillatory motion, The effects of blending, and temperature, on the proportion of rings undergoing oscillatory motion are analyzed.

Competing notions of social justice and contradictions in special education reform

In the past three decades, special education has been subjected to extensive critique and reform of practices. These critiques have been based on notions of social justice and equity. However, the field has suffered from inadequate attention to assumptions about social justice. Social justice is essentially a contested concept. Rather than representing a unitary and universally shared concept, social justice has variable meanings. Differing views of social justice can be seen to underlie apparent contradictions in continuing practice in response to pressures for reform. Reforms predicated on individual rights have been undermined by deep commitments to meritocratic practices in U.S. schools. Reforms based on more communitarian principles, however, ignore the need for structure and the tendency for communal values to marginalize people with disabilities. Special education reform today requires a different basis in a relational definition of the self, structures to support the qualities of relationships, and a belief in the mutability of social justice.

Resting energy expenditure in white and non-white severely obese women

This study aimed to compare the resting energy expenditure (REE) of white and non-white severely obese Brazilian women. REE was examined in 83 severely obese Brazilian women (n = 58 white and 25 non-white) with mean (+/- SD) age 42.99 +/- 11.35 and body mass index 46.88 +/- 6.22 kg/m(2) who were candidates for gastric bypass surgery. Body composition was assessed by air displacement plethysmography (ADP) BOD PODO body composition system (Life Measurement Instruments, Concord, CA) and REE was measured, under established protocol, with an open-circuit calorimeter (Deltatrac II MBM-200, Datex-Ohmeda, Madison, WI, USA). There was no significant difference between the REE of white and non-white severely obese women (1,953 +/- 273 and 1,906 +/- 271 kcal/d, respectively; p = 0.48). However, when adjusted for fat free mass (MLG), REE was significantly higher in non-white severely obese women (difference between groups of 158.4 kcal, p < 0.01). REE in white women was positively and significantly correlated to C-reactive protein (PCR) (r = 0.41.8; P < 0.001) and MLG (r = 0.771; P < 0.001). In the non-white women, REE was only significantly correlated to MLG (r = 0.753; P < 0.001). The multiple linear regression analysis showed that skin color, MLG and PCR were the significant determinants of REE (R(2) = 0.55). This study showed that, after adjustment for MLG, non-white severely obese women have a higher REE than the white ones. The association of body composition inflammation factors and REE in severely obese Brazilian women remains to be further investigated.

Increased Immunoglobulin G Anti-Paracoccidioides brasiliensis Serum Antibody Avidity as a Predictor of Favorable Posttherapeutic Evolution in Paracoccidioidomycosis

Paracoccidioidomycosis is endemic in Latin America, and ca. 80% of all cases occur in Brazil. Little is known about antibody avidity or the evolution of such avidity in the posttherapeutic period for the different clinical presentations of the disease. In the present study, we evaluated 53 patients with paracoccidioidomycosis and calculated the avidity index. Medium-and high-avidity antibodies were found in 79.5% of patients with chronic presentation (n = 39). Among patients with the acute form (n = 14), 57.1% of the antibodies presented low avidity. In the posttherapeutic period, there was a significant increase in antibody avidity in patients presenting with the chronic multifocal form. In our preliminary study, which needs to be confirmed using a larger number of samples, the optimized method for studying antibody avidity detected differences among the clinical presentations of the mycosis and indicated the value of the avidity index as a marker of posttherapeutic evolution of patients with a multifocal chronic form of the disease.

Limited Ca(2+) and PKA-pathway dependent neurogenic differentiation of human adult mesenchymal stem cells as compared to fetal neuronal stem cells

The ability of mesenchymal stem cells to generate functional neurons in culture is still a matter of controversy. In order to assess this issue, we performed a functional comparison between neuronal differentiation of human MSCs and fetal-derived neural stem cells (NSCs) based on morphological, immunocytochemical, and electrophysiological criteria. Furthermore, possible biochemical mechanisms involved in this process were presented. NF200 immunostaining was used to quantify the yield of differentiated cells after exposure to CAMP. The addition of a PKA inhibitor and Ca(2+) blockers to the differentiation medium significantly reduced the yield of differentiated cells. Activation of CREB was also observed on MSCs during maturation. Na(+)-, K(+)-, and Ca(2+)-voltage-dependent currents were recorded from MSCs-derived cells. In contrast, significantly larger Na(+) currents, firing activity, and spontaneous synaptic currents were recorded from NSCs. Our results indicate that the initial neuronal differentiation of MSCs is induced by CAMP and seems to be dependent upon Ca(2+) and the PKA pathway. However, compared to fetal neural stem cells, adult mesenchymal counterparts are limited in their neurogenic potential. Despite the similar yield of neuronal cells, NSCs achieved a more mature functional state. Description of the underlying mechanisms that govern MSCs` differentiation toward a stable neuronal phenotype and their limitations provides a unique opportunity to enhance our understanding of stem cell plasticity. (C) 2009 Elsevier Inc. All rights reserved.

High serum follistatin levels in women with ovarian endometriosis

Follistatin is an activin-binding protein produced by several tissues, including endometrium and endometriotic implants. We aimed to quantify follistatin in patients with ovarian endometriosis and investigate its value as a diagnostic marker. Women undergoing laparoscopic excision of ovarian endometrioma (n = 52) or other benign ovarian cysts (n = 52) were studied, plus women with non-ovarian endometriosis (n = 11) and healthy controls (n = 27). Serum was collected from all subjects, and peritoneal and cystic fluid from a subset with endometrioma. Follistatin was measured by enzyme-linked immunosorbent assay. The diagnostic accuracy of follistatin to detect endometrioma was evaluated by receiver operating characteristic (ROC) curve and compared with cancer antigen (CA)-125. Serum follistatin was increased in women with ovarian endometrioma (2080 +/- 94 pg/ml) compared with controls (545 +/- 49 pg/ml, P < 0.001), other benign ovarian cysts (795 +/- 60 pg/ml, P < 0.001) or non-ovarian endometriosis (1271 +/- 115 pg/ml, P < 0.001). Cystic fluid showed a higher concentration of follistatin (9850 +/- 4461 pg/ml) than peritoneal fluid (1885 +/- 261 pg/ml, P < 0.001) and serum (P < 0.001). Follistatin levels detected 48/52 cases of endometrioma (92% sensitivity) at 1433 pg/ml cut-off, corresponding to 92% specificity. CA-125 detected only 44% of endometriomas with 90% specificity. ROC curve comparison showed follistatin was more accurate than CA-125 to discriminate women with endometrioma either from controls or women with other benign ovarian cysts (P < 0.0001). Serum follistatin is increased in women with endometriosis and allows clear distinction between endometrioma and other benign ovarian cysts. Follistatin has the sensitivity and specificity to become a useful clinical marker of ovarian endometrioma.

Involuntary smoking and head and neck cancer risk: Pooled analysis in the International Head and Neck Cancer Epidemiology Consortium

Although active tobacco smoking has been identified as a major risk factor for head and neck cancer, involuntary smoking has not been adequately evaluated because of the relatively low statistical power in previous studies. We took advantage of data pooled in the International Head and Neck Cancer Epidemiology Consortium to evaluate the role of involuntary smoking in head and neck carcinogenesis. Involuntary smoking exposure data were pooled across six case-control studies in Central Europe, Latin America, and the United States. Adjusted odds ratios (OR) and 95% confidence interval (95% CI) were estimated for 542 cases and 2,197 controls who reported never using tobacco, and the heterogeneity among the study-specific ORs was assessed. In addition, stratified analyses were done by subsite. No effect of ever involuntary smoking exposure either at home or at work was observed for head and neck cancer overall. However, long duration of involuntary smoking exposure at home and at work was associated with an increased risk (OR for >15 years at home, 1.60; 95% CI, 1.12-2.28; P(trend) <0-01; OR for >15 years at work, 1.55; 95% CI, 1.04-2.30; P(trend) = 0.13). The effect of duration of involuntary smoking exposure at home was stronger for pharyngeal and laryngeal cancers than for other subsites. An association between involuntary smoking exposure and the risk of head and neck cancer, particularly pharyngeal and laryngeal cancers, was observed for long duration of exposure. These results are consistent with those for active smoking and suggest that elimination of involuntary smoking exposure might reduce head and neck cancer risk among never smokers.

VKORC1 polymorphisms in Brazilians: comparison with the Portuguese and Portuguese-speaking Africans and pharmacogenetic implications

Aims: The heterogeneity of the Brazilian population renders the extrapolation of pharmacogenomic data derived from well-defined ethnic groups inappropriate. We investigated the influence of self-reported `race/color`, geographical origin and genetic ancestry on the distribution of four VKORC1 SNPs and haplotypes in Brazilians. Comparative data were obtained from two major ancestral roots of Brazilians: Portuguese and Africans from former Portuguese colonies. Materials & methods: A total of 1037 healthy adults Brazilians, recruited at four different geographical regions and self identified as white, brown or black (race/color categories), 89 Portuguese and 216 Africans from Angola and Mozambique were genotyped for the VKORC1 3673G>A (rs9923231), 5808T>G (rs2884737), 6853G>C (rs8050894) and 9041G>A (rs7294) polymorphisms using TaqMan (R) (Applied Biosystems, CA, USA) assays. VKORC1 haplotypes were statistically inferred using the haplo.stats software. We inferred the statistical association between the distribution of the VKORC1 polymorphisms among Brazilians and self-reported color, geographical region and genetic ancestry by fitting multinomial log linear models via neural networks. Individual proportions of European and African ancestry were used to assess the impact of genetic admixture on the frequency distribution of VKORC1 polymorphisms among Brazilians, and for the comparison of Brazilians with Portuguese and Africans. Results: The frequency distribution of the 3673G>A and 5808T>G polymorphisms, and VKORC1 haplotypes among Brazilians varies across geographical regions, within self-reported color categories and according to the individual proportions of European and African genetic ancestry. Notably, the frequency of the warfarin sensitive VKORC1 3673A allele and the distribution of VKORC1 haplotypes varied continuously as the individual proportion of European ancestry increased in the entire cohort, independently of race/color categorization and geographical origin. Brazilians with more than 80% African ancestry differ significantly from Angolans and Mozambicans in frequency of the 3673G>A, 5808T>G and 6853G>C polymorphisms and haplotype distribution, whereas no such differences are observed between Brazilians with more than 90% European ancestry and Portuguese individuals. Conclusion: The diversity of the Brazilian population, evident in the distribution of VKORC1 polymorphisms, must be taken into account in the design of pharmacogenetic clinical trials and dealt with as a continuous variable. Warfarin dosing algorithms that include `race` terms defined for other populations are clearly not applicable to the heterogeneous and extensively admixed Brazilian population.

Centella asiatica water extract inhibits iPLA(2) and cPLA(2) activities in rat cerebellum

Centella asiatica (L.) Urb an is distributed widely in South America and Asia and is known as a therapeutic agent in folk medicine, capable of improving memory and treating several neurological disorders. Asiaticoside is one of the compounds found in C asiatica leaves that is suggested to be responsible for its pharmacological potential. Phospholipase A(2) (PLA(2)) is a group of enzymes that has abnormal activity in the central nervous system in some neuropsychiatric diseases. In this work, the asiaticoside present in C asiatica water extract was quantified by HPLC analysis. We also evaluated the activity of subtypes of PLA(2) in cerebellar samples from rats after C asiatica water extract treatment using a radioenzymatic assay. Asiaticoside was the major compound (84%) found in Centella water extract. We found a dose-dependent inhibitory effect of C asiatica water extract on the activity of Ca(2+)-independent PLA(2) (iPLA(2)) and cytosolic PLA(2) (cPLA(2)). The inhibition of these enzymes in the brain suggests that C asiatica may be useful to treat conditions associated with increased PLA(2) activity in the brain, such as epilepsy, stroke, multiple sclerosis and other neuropsychiatric disorders. (C) 2008 Elsevier GmbH. All rights reserved.

Correlation of fungi and endotoxin with PM2.5 and meteorological parameters in atmosphere of Sao Paulo, Brazil

Particulate matter, especially PM2.5, is associated with increased morbidity and mortality from respiratory diseases. Studies that focus on the chemical composition of the material are frequent in the literature, but those that characterize the biological fraction are rare. The objectives of this study were to characterize samples collected in Sao Paulo, Brazil on the quantity of fungi and endotoxins associated with PM2.5, correlating with the mass of particulate matter, chemical composition and meteorological parameters. We did that by Principal Component Analysis (PCA) and multiple linear regressions. The results have shown that fungi and endotoxins represent significant portion of PM2.5, reaching average concentrations of 772.23 spores mu g(-1) of PM2.5 (SD: 400.37) and 5.52 EU mg(-1) of PM2.5 (SD: 4.51 EU mg(-1)), respectively. Hyaline basidiospores, Cladosporium and total spore counts were correlated to factor Ba/Ca/Fe/Zn/K/Si of PM2.5 (p < 0.05). Genera Pen/Asp were correlated to the total mass of PM2.5 (p < 0.05) and colorless ascospores were correlated to humidity (p < 0.05). Endotoxin was positively correlated with the atmospheric temperature (p < 0.05). This study has shown that bioaerosol is present in considerable amounts in PM2.5 in the atmosphere of Sao Paulo, Brazil. Some fungi were correlated with soil particle resuspension and mass of particulate matter. Therefore, the relative contribution of bioaerosol in PM2.5 should be considered in future studies aimed at evaluating the clinical impact of exposure to air pollution. (C) 2010 Elsevier Ltd. All rights reserved.