Chemoautotrophy, symbiosis and sedimented diatoms support high biomass of benthic molluscs in the Namibian shelf.

The molluscs Lucinoma capensis, Lembulus bicuspidatus and Nassarius vinctus are highly abundant in Namibian oxygen minimum zone sediments. To understand which nutritional strategies allow them to reach such impressive abundances in this extreme habitat we investigated their trophic diversity, including a chemosymbiosis in L. capensis, focussing on nitrogen biochemical pathways of the symbionts. We combined results of bulk nitrogen and carbon (δ13C and δ15N) and of compound-specific isotope analyses of amino acid nitrogen (AAs-δ15NPhe and δ15NGlu), with 16S rRNA gene sequencing of L. capensis tissues and also with exploratory results of ammonium, nitrate and nitrite turnover. The trophic position (TP) of the bivalve L. capensis is placed between autotrophy and mixotrophy, consistent with its proposed symbiosis with sulfur-oxidizing Candidatus Thiodiazotropha sp. symbionts. The symbionts are here revealed to perform nitrate reduction and ammonium uptake, with clear indications of ammonium host-symbionts recycling, but surprisingly unable to fix nitrogen. The TP of the bivalve L. bicuspidatus is placed in between mixotrophy and herbivory. The TP of the gastropod N. vinctus reflected omnivory. Multiple lines of evidences in combination with current ecosystem knowledge point to sedimented diatoms as important components of L. bicuspidatus and N. vinctus' diet, likely supplemented at times with chemoautotrophic bacteria. This study highlights the importance of benthic-pelagic coupling that fosters the dietary base for macrozoobenthos in the OMZ. It further unveils that, in contrast to all shallow water lucinid symbionts, deeper water lucinid symbionts rely on ammonium assimilation rather than dinitrogen fixation to obtain nitrogen for growth.

Effect of glucosamine sulphate on the temporomandibular joint of ovariectomised rats.

Glycosamine is an amino-monosaccharide present in connective and cartilage tissues that contribute to the maintenance, resistance, flexibility, and elasticity of these tissues. This study aimed to determine the in vivo effects of glucosamine sulphate (GS) on the temporomandibular joint (TMJ) of ovariectomised rats (OVX).Thirty-two rats were distributed into four groups as follows: G1, sham-OVX+saline solution; G2, sham-OVX+glucosamine sulphate (80mg/kg) - oral administration; G3, OVX+saline solution; G4, OVX+glucosamine sulphate (80mg/kg) - oral administration. Animals were treated for seven days. The TMJ was removed and stained with toluidine blue. The thickness of the cartilage layers and cytokines IL-1ß, IL-6, and TNF-α levels were determined by histomorphometry and immunoassay, respectively. The administration of GS to OVX females did not change the thickness of condylar cartilage when compared with the other groups (p>0.05). There was an increase in the total cartilage thickness in sham-OVX females. IL-1ß and TNF-α levels were significantly lower in sham-OVX females than in OVX females, indicating that ovariectomy acts as potent cytokine inducer. IL-6 levels were significantly higher in sham-OVX females. GS did not affect cytokine production in OVX females (p>0.05). In conclusion, the administration of GS did not affect cytokine levels, but did induce an increase in the total thickness of the TMJ condylar cartilage in sham-OVX rats.

Effects of auriculotherapy and midazolam for anxiety control in patients submitted to third molar extraction.

Anxiety is common and still represents a barrier to appropriate professional care for patients requiring dental treatment. The aim of this study was to compare the effects of auriculotherapy and midazolam for the control of anxiety in patients submitted to third molar extractions. This was a randomized, double-blind, controlled, crossover clinical trial. Thirty healthy volunteers requiring bilateral third molar extraction received midazolam 15mg (oral) and sham auriculotherapy during one session, and a placebo tablet (oral) and auriculotherapy during the other; the sessions were randomized. The level of anxiety was assessed through questionnaires and physical parameters (blood pressure, heart rate, and oxygen saturation (SpO2)) at three time points: baseline, on the day of surgery, and at follow-up. No significant differences between the protocols were observed for blood pressure and SpO2. Auriculotherapy induced a lower heart rate than midazolam during some periods. Auriculotherapy induced more events remembered after surgery than midazolam (P<0.0001). More undesirable effects were observed with midazolam (P<0.0001). However, patient preference for auriculotherapy (53.3%) was not higher than preference for midazolam (46.7%). Auriculotherapy showed an anxiolytic effect equivalent to the midazolam effect, without the undesirable effects usually attributed to the benzodiazepine.

Interregional cytogenetic comparisons in Halichoeres and Thalassoma wrasses (Labridae) of coastal and insular regions of the southwestern Atlantic.

The distribution patterns of marine biodiversity are complex, resulting from vicariant events and species dispersion, as well as local ecological and adaptive conditions. Furthermore, the wide geographic distribution of some species may be hindered by biogeographical barriers that can interfere in the gene flow. Cytogenetic analyses in marine fishes, especially those involving populations in small remote insular environments, remain scarce. In the Western Atlantic, species of wrasses from the genera Halichoeres and Thalassoma occur in biogeographic arrangements that make it possible to analyze cytogenetic patterns between coastal and widely separated island populations. Species of these genera were punctually analyzed in some Atlantic regions. In this study, we compared several chromosomal features, such as karyotype macrostructure, heterochromatic patterns, patterns of base-specific fluorochromes, Ag-NORs, and 18S and 5S ribosomal sites in Thalassoma noronhanum, Halichoeres poeyi, and Halichoeres radiatus individuals from distinct coastal or insular regions of Atlantic. Notably, all of them are characterized by multiple 18S and 5S rDNA sites with syntenic arrangements in some chromosome pairs. Individuals of T. noronhanum (between the insular regions of Rocas Atoll and Fernando de Noronha Archipelago - FNA) and H. poeyi (coastal areas from Northeastern Brazil) show no detectable differences among their cytogenetic patterns. On the other hand, H. radiatus from FNA and São Pedro and São Paulo Archipelago exhibit differences in the frequency of rDNA sites that could suggest some level of population structuring between these insular regions. Interregional cytogenetic inventories of marine species with wide geographic distribution need to be rapidly expanded. These data will allow a better understanding of the level of chromosomal stability between vast oceanic spaces, which may be less than previously thought.

[Critical analysis of respiratory infectious disease investigations related to children attending day care centers] / Análise crítica de investigações sobre doenças infecciosas respiratórias em crianças que freqüentam creche.

OBJECTIVE: Social-economic and cultural changes are increasingly leading families to share the children's care and education with daycare centers. Nevertheless, this practice is being widely criticized. Medical literature, for example, points to the high risk of illnesses in these environments. Searching to assess theoretical- methodological aspects underlying disease/daycare research, a bibliography review was done. METHOD: The last five years production was reviewed, through Current Contents, Med-Line and Lilacs, using creche / daycare center as keywords. RESULTS: 665 papers were obtained and organized in subgroups. Selecting the group of papers on respiratory infectious diseases, 34 papers were obtained, being 22 of them empirical, and 12 theoretical or review article, etc. The empirical studies used large populations; data were collected by interviews, medical reports and laboratory analyses; 50% were cross-sectional. Disease/daycare relation was obtained mainly by quantitative analysis, based on a multivariate model and logistic regression. Seventy per cent concluded that attending daycare implies an illness high risk, especially for youngers than 2 years. The papers with a preventive character, and-in more subtler ways - 50% of the others point alternative solutions for this clinical and social problem (vaccination, immunity stimulation, environmental organization). CONCLUSION: The structure and the discussion of the majority of the studies seem to be guided by implicit assumptions, based on conceptions of an ideal situation of care (at house, by the mother). The results are legitimized by large populations and sophisticated statistic systems. Nevertheless, they express a prediction risk, which highlights static aspects, not the dynamic ones, of health/ disease processes. At last, they treat a social problem on clinical individual assumptions.