Blastocystis in Côte d'Ivoire: molecular identification and epidemiological data.

Blastocystis is an enteric protozoan infecting humans and animals in both developed and developing countries at all latitudes. Despite this, data on Blastocystis infection are not available for several geographical areas, including many African countries. In this study, a survey was conducted on Blastocystis among humans and domestic animals in rural and urban localities in Côte d'Ivoire, in order to investigate the prevalence, the subtype distribution, and the zoonotic potential in association with sociodemographic factors, seasonality, symptoms, and co-infections. A total of 110 fecal samples were collected from patients living in four localities. Molecular and phylogenetic analyses were conducted for Blastocystis detection and subtyping. Positive samples from symptomatic patients were tested by Luminex xTAG® Gastrointestinal Pathogen Panel (GPP) to evidence the presence of other common intestinal pathogens. Overall, a prevalence of 58.2% was observed in humans and subtypes ST1(50.0%), ST2 (22.0%) and ST3 (28.1%) were identified. The prevalence values varied significantly among the sites but not in relation to the subtype. The seasonal rains significantly increase the infection rate in all localities. No significant differences in the ST distribution between asymptomatic and symptomatic subjects were observed. As regard the zoonotic transmission, an additional sampling was conducted in another village where fecal samples were simultaneously collected from humans and animals. Blastocystis STs 1-3 and ST7 were identified in eight humans and four chickens, respectively. This study provides the first exhaustive data on the prevalence and molecular epidemiology of Blastocystis in Côte d'Ivoire.

Social determinants associated with Giardia duodenalis infection in southern Côte d'Ivoire.

The purpose of this investigation was to analyze the association between different social determinants of health at the local scale and Giardia duodenalis infection in diverse settlements in southern Côte d'Ivoire. Stool samples from 306 individuals aged 1-16 years were collected from six rural villages and a small town. Five variables were categorized to classify the increasing risk levels of acquiring intestinal parasites. Giardia prevalences (%) and odds ratios (ORs) were evaluated. Correlation and regression analyses were conducted to determine the correlation coefficients and to propose predictive models based on social determinants to forecast the risk of giardiasis. The overall observed prevalence of Giardia was 21.6 %. When the analysis was conducted at the local level, the percentage of infected people varied from a minimum of 12.7 up to 36.4 %. A significant association (p < 0.001) was found between the selected social determinants and G. duodenalis prevalence in the different localities. Correlation and regression analyses allowed us to describe two predictive models to estimate the OR of Giardia transmission. This study helps to clarify the possible impact of different social determinants of health on the risk of giardiasis at the local scale. Both predictive models could be suitable in order to assess the likelihood of the transmission of intestinal parasitic infection in developing countries.

Sub-cellular localization of manganese in the basal ganglia of normal and manganese-treated rats An electron spectroscopy imaging and electron energy-loss spectroscopy study.

We have studied at the ultrastructural level the presence of manganese (Mn) in rat basal ganglia, which are target regions of the brain for Mn toxicity. The rats underwent a moderate level of Mn exposure induced per os for 13 weeks. Mn was detected by means of electron spectroscopy imaging (ESI) and electron energy-loss spectroscopy (EELS) analyses on perfusion fixed samples embedded in resin. While no significant contamination by exogenous Mn occurred during the processing procedures, less than 50% of endogenous Mn was lost during fixation and dehydration of the brain samples. The residual Mn ions in the samples appeared as discrete particles, localized in selected sub-cellular organelles in a cell, suggesting that no significant translocation had occurred in the surrounding area. In control rats, the Mn sub-cellular localization and relative content were the same in neurons and astrocytes of rat striatum and globus pallidus: the Mn level was highest in the heterochromatin and in the nucleolus, intermediate in the cytoplasm, and lowest in the mitochondria (p<0.001). After chronic Mn treatment, while no ultrastructural damage was detected in the neurons and glial cells, the largest rate of Mn increase was noted in the mitochondria of astrocytes (+700%), an intermediate rate in the mitochondria of neurons (+200%), and the lowest rate in the nuclei (+100%) of neurons and astrocytes; the Mn level in the cytoplasm appeared unchanged. EELS analysis detected the specific spectra of Mn L(2,3) (peak at DeltaE = 665 eV) in such organelles, confirming the findings of ESI. Although a consistent loss of Mn occurred during the processing of tissue samples, ESI and EELS can be useful methods for localization of endogenous Mn in embedded tissues. The high rate of Mn sequestration in the mitochondria of astrocytes in vivo may partly explain the outstanding capacity of astrocytes to accumulate Mn, and their early dysfunction in Mn neurotoxicity. The high level of Mn in the heterochromatin and nucleoli of neurons and astrocytes in basal conditions and its further increase after Mn overload should provide insight into new avenues of investigating the role of Mn in the normal brain and a baseline for future Mn toxicity studies.

DXA vs QCT: in vitro and in vivo studies.

The aim of this study was to evaluate the discrepancy between bone mineral density (BMD) results when using dual X-ray absorptiometry and quantitative computed tomography both in vitro and in vivo. Using these two techniques, we found that the T-score densitometric index values were discrepant in the BMD qualitative evaluation, which can affect the diagnosis of osteopenia or osteoporosis, thus we propose its modification.

Validity and reliability of a new portable telemetric calorimeter designed to measure oxygen consumption and carbon dioxide production.

OBJECTIVE: The purpose of the present study was to evaluate the precision and the accuracy of a new portable telemetric calorimeter developed for the measurement of oxygen consumption, carbon dioxide production and pulmonary ventilation. DESIGN: An in vitro validation study. METHODS: An experimental protocol was designed to generate a series of tidal volumes (from 100 ml to 6000 ml at 200 ml steps) at different respiratory rates (5, 8, 14, 20, 40, 60, 75 breaths-min(-1)). For this purpose, a standardized pulmonary waveform generator system was utilized. Moreover, in order to evaluate the measure of O2 and CO2 concentrations at different temperatures (-10 degrees, 0 degrees, 15 degrees, 25 degrees, 40 degrees C), the instrument was placed inside an adjustable temperature and humidity chamber. RESULTS: The accuracy of flow measurements was within +/-3% in respect to the real values throughout the entire range of physiological values, whereas the measurements of gas concentrations were within +/-1% between 0 and 25 degrees C. CONCLUSIONS: The new portable telemetric calorimeter represents an easy to use instrument for the measure of energy expenditure during the activities of daily living.

Plasma 5alpha-androstane-3alpha,17betadiol, an endogenous steroid that positively modulates GABA(A) receptor function, and anxiety: a study in menopausal women.

We tested the hypothesis that changes in endogenous neuroactive steroids acting as positive allosteric modulators of gamma-aminobutyric acid (GABA)(A) receptors may be related to the menopause-associated mood alterations. The study sample consisted of twenty five drug-free menopausal women, 1-3 years since the onset of menopause, homogeneous for age and body mass index (BMI) and without personal history of psychiatric, metabolic or endocrine disorders. Depression and anxiety-related symptoms were assessed with the Zung Self-administered Depression Scale (ZSDS) and the Cornell's Dysthymia Rating Scale (CDRS). The cut-off value predicted by the ZSDS index defined two groups of women (asymptomatic [35.5+/-4.6, n=12] and symptomatic [60.8+/-7.9, n=13]), that were also significantly different according to the CDRS scores (10.6+/-3.4 and 31.5+/-12, respectively, P<0.05). Upon evaluation of the scores relative to the anxiety factor of the CDRS (items 11-15) the symptomatic, but not the asymptomatic, group showed a moderate level of anxiety. The plasma concentrations of several neuroactive steroids were measured, after extraction and HPLC purification, by radioimmunoassay with specific antisera. Only dehydroepiandrosterone and its metabolite 5alpha-androstane-3alpha,17betadiol (3alpha-ADIOL), a positive allosteric modulator of GABA(A) receptors, were significantly (P<0.05 and P<0.005) higher (+110% and +64%, respectively) in the asymptomatic group. A highly significant and negative correlation (r=-0.672, P=0.003) was found between the plasma 3alpha-ADIOL concentrations and the scores of the anxiety factor of the CDRS. These data suggest that endogenous 3alpha-ADIOL modulates the central GABAergic tone and that higher 3alpha-ADIOL concentrations could have a role in preventing the expression of anxiety in the asymptomatic women.

New insights into body composition assessment in obese women.

During treatment of patients with non-insulin-dependent diabetes mellitus, there may be marked body weight loss. Therefore, body composition should be monitored to check for a decrease in fat mass alone, without an excessive decrease of both fat-free mass and total body water. Accordingly, it is useful to monitor the hydration of these patients. One method that allows us to check the status of body hydration is the multifrequency bioelectric impedance analysis (MFBIA). It makes use of formulas that estimate total body water on the basis of the concept that the human body may be approximated to a cylinder of length equal to body height. In normal subjects body water estimates are sufficiently accurate, but in obese subjects the true hydration status may be overestimated. In this report, we describe the accuracy of mathematical models previously described in the literature, and correct for the overestimation of total body water in obese subjects by means of a new equation based on a new model. The coefficients for each model have been recalculated by the weighing of our sample in order to test the accuracy of estimates obtained with the equations. This new model includes both body volume and two impedances at appropriate frequencies useful for identifying two terms strictly related to extra- and intra-cellular water. The new formulas do not include body weight, but they include the body volume, a parameter more closely related to the biophysical reference model. Fifty-five overweight females, body mass index ranging from 26.8 to 50.2 kg/m2, were enrolled in the study. The proposed equations, taking advantage of two impedance values at appropriate frequencies, better predict total body water in obese women. This was particularly evident when the results obtained with the multifrequency bioelectric impedance analysis and deuterium isotopic oxide dilution method were compared. Although this last method is considered the "gold standard," it is not suitable for use in routine clinical practice. In conclusion, evaluation of total body composition by means of bioelectric impedance analysis might be included in programs for the prevention of non-insulin-dependent diabetes and for monitoring weight loss during overt pathology.