Vitamin D status in a sunny country: Where has the sun gone?

Background & aims: Hypovitaminosis D [serum 25 vitamin D < 30 ng/ml] is related to the development of metabolic bone disease and greater risk of chronic illnesses. However, it is frequently under-diagnosed, mainly in countries where UV radiation is abundant. We prospectively determined the prevalence and the predictors of serum 25 vitamin D (s25(OH)D) in a healthy Brazilian population after the winter and after the summer. Methods: 603 (118M and 485F) healthy Brazilian volunteers aged 18-90 years from a universitary hospital were selected after the winter of 2006. From the initial sample, 209 volunteers (31M and 178F) accepted to participate in a second health check after the subsequent summer. Results: After the winter, median s25(OH)D was 21.4 ng/mL and 77.4% of the population presented hypovitaminosis D. s25(OH)D was significantly related to age, BMI, PTH and race. In multivariate linear regression analysis, s25(OH)D was significantly and independently dependent on age, glycemia and skin color. Significant increase in s25(OH)D was verified after summer [10.6 (3.7-19.3 ng/ml); p < 0.001] and this improvement was dependent on age. We also observed a significant decrease in hyperparathyroidism prevalence (20.8% vs. 4.9%; P < 0.0001). Conclusion: In Sao Paulo, at the end of winter, we observed a high prevalence of hypovitaminosis D and secondary hyperparathyroidism in healthy adults. s25(OH)D was dependent on age and skin color. After summer, we observed a decrease in the prevalence of hypovitaminosis D. This unexpected finding emphasizes the need for a strong recommendation to monitor s25(OH)D, even in a sunny country such as Brazil. (C) 2010 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Neither Molecular Diversity of the Envelope, Immunosuppression Status, Nor Proviral Load Causes Indeterminate HTLV Western Blot Profiles in Samples From Human T-Cell Lymphotropic Virus Type 2 (HTLV-2)-Infected Individuals

Although human T-cell lymphotropic virus type 2 (HTLV-2) is considered of low pathogenicity, serological diagnosis is important for counseling and monitoring. The confirmatory tests most used are Western blot (WB) and PCR. However, in high-risk populations, about 50% of the indeterminate WB were HTLV-2 positives by PCR. The insensitivity of the WB might be due to the use of recombinant proteins of strains that do not circulate in our country. Another possibility may be a high level of immunosuppression, which could lead to low production of virus, resulting in low stimulation of antibody. We found one mutation, proline to serine in the envelope region in the position 184, presented at least 1/3 of the samples, independent the indeterminate WB profile. In conclusion, we found no correlation of immune state, HTLV-2 proviral load, or env diversity in the K55 region and WB indeterminate results. We believe that the only WB kit available in the market is probably more accurate to detect HTLV-1 antibodies, and some improvement for HTLV-2 detection should be done in the future, especially among high-risk population. J. Med. Virol. 82:837-842,2010. (C) 2010 Wiley-Liss, Inc.

Executive dysfunction correlates with impaired functional status in older adults with varying degrees of cognitive impairment

Background: Previous studies have reported an association between executive dysfunction and the ability to perform activities of daily living (ADL)s among older adults. This study aims to examine the association between executive functions and functional status in a cross-section of older adults with varying degrees of cognitive impairment. Methods: 89 individuals (mean age 73.8 years) were recruited at a memory clinic in Sao Paulo, Brazil. Subjects underwent evaluation, and were allocated into three diagnostic groups according to cognitive status: normal controls (NC, n = 32), mild cognitive impairment (MCI, n = 3 1) and mild Alzheimer`s disease (AD, n=26). Executive functions were assessed with the 25-item Executive Interview (EXIT25), and functional status was measured with the Direct Assessment of Functional Status test (DAFS-R). Results: Significantly different total DAFS-R scores were observed across the three diagnostic groups. Patients with AD performed significantly worse in EXIT25 compared with subjects without dementia, and no significant differences were detected between NC and MCI patients. We found a robust negative correlation between the DAFS-R and the EXIT25 scores (r=-0.872, p < 0.001). Linear regression analyses suggested a significant influence of the EXIT-25 and the CAMCOG on the DAFS-R scores. Conclusion: Executive dysfunction and decline in general measures of cognitive functioning are associated with a lower ability to undertake instrumental ADLs. MCI patients showed worse functional status than NC subjects. MCI patients may show subtle changes in functional status that may only be captured by objective measures of ADLs.

Characterization of acid-base status in maintenance hemodialysis: physicochemical approach

Acidosis is a common and deleterious aspect of maintenance dialysis. Traditionally, it is considered to be an elevated anion gap acidosis caused by the inability to excrete nonvolatile anions. Stewart`s approach made it possible to identify real determinants of the acid-base status and allowed quantification of the components of these disturbances, especially the unmeasured anions. We performed a cross-sectional study to identify and quantify each component of acidosis in hemodialysis maintenance patients. Sixty-four maintenance hemodialysis patients and 14 controls were enrolled in this study. Gasometrical and biochemical analysis were performed before the midweek dialysis session. Quantitative physicochemical analysis was carried out using the Stewart methodology. Hemodialysis patients were found to have mild acidemia (mean pH: 7.33 +/- 0.06 versus 7.41 +/- 0.05) secondary to metabolic acidosis (serum bicarbonate: 18.8 +/- 0.26 versus 25.2 +/- 0.48 mEq/l). The metabolic acidosis was due to retention of unmeasured anions (6.5 +/- 0.29 versus 3.1 +/- 0.62 mEq/l), hyperchloremia (105.1 +/- 0.5 versus 101.8 +/- 0.7 mEq/l), and hyperphosphatemia (5.90 +/- 0.19 versus 3.66 +/- 0.14 mg/dl). Compared with control values, the unmeasured anions and hyperchloremia had a similar acidifying effect (3.4 and 3.3 mEq/l), corresponding to almost 90% of the metabolic acidosis. Unmeasured anions and hyperchloremia are important components of acidosis in maintenance hemodialysis, in addition to phosphorus. Future studies to determine the etiology and consequences of hyperchloremic acidosis are warranted.

A Century of Change in Coral Reef Status in Southeast and Central Pacific: Polynesia Mana Node, Cook Islands, French Polynesia, Kiribati, Niue, Tokelau, Tonga, Wallis and Futuna

The Polynesia Mana Node of the southeast and central Pacific contains 7 independent or autonomous countries or territories with only 6,000 km2 of land on 347 islands, but surrounded by 12 million km2 of EEZ. These seas contain 13,000 km2 of coral reefs as the main natural ecosystem providing food resources and opportunities for development, especially for tourism and pearl culture for 500,000 inhabitants. During the 19th and first half of the 20th centuries, there was major exploitation by the colonial powers of mother-of-pearl oysters for the button industry, as well as guano, sandalwood and trepang. The Polynesian people were largely involved in a subsistence economy and all coral reefs and lagoons were healthy. During the last two decades of the 20th, all countries experienced rapid development and urbanization, rising populations, and some increased agriculture. These developments were limited to a few islands of each country (i.e. 15 islands amongst the 347) with resulting degradation of the coral reefs around these sites. The other islands remained mostly uninhabited and pristine, and continued with a subsistence economy. Generally, there was more damage to the coral reefs through natural events such as cyclones and coral bleaching, than by human activities. There is however, an urgent need to combat the threats on some islands from increased sedimentation, over-fishing, dredging and nutrient pollution.

Effects of a Low-Protein Diet on Plasma Amino Acid and Homocysteine Levels and Oxidative Status in Rats

Background/Aims: Transmethylation reactions and antioxidant metabolism are linked by transsulfuration, where homocysteine (Hcy) is converted to cysteine and reduced glutathione (GSH). Low protein intake can modulate the balance of this metabolic reaction. The aim of the present investigation was to study the effect of a low-protein diet on Hcy metabolism by monitoring levels of the amino acids involved in these pathways, and relating these levels to GSH levels and lipid peroxidation in rats. Methods: Sixteen rats were divided into 2 groups: control (C; standard AIN-93 diet, 20% protein) and low-protein diet (LPD; 8% protein diet). Rats in both groups were placed on the diets for 28 days. Results: A significant reduction (p < 0.05) in plasma Hcy concentration was found in LPD rats (0.16 +/- 0.04 mu mol/mg protein) versus C rats (0.25 +/- 0.03 mu mol/mg protein). Methionine levels were not significantly different between the 2 groups (C: 1.24 +/- 0.22 mu mol/mg protein; LPD: 1.03 +/- 0.27 mu mol/mg protein). A significant reduction (p ! 0.05) in hepatic GSH concentrations (C: 44 8 10 mu mol/mg protein; LPD: 17.4 +/- 4.3 mu mol/mg protein) was accompanied by an increase in lipid peroxidation (C: 0.13 +/- 0.01 mu mol/mg protein; LPD: 0.17 +/- 0.02 mu mol/mg protein; r = -0.62, p < 0.01). Conclusion: Hcy levels were reduced under a low-protein diet, resulting in modulated methyl balance and reduced GSH formation leading to increased susceptibility of hepatic cells to oxidative events. Copyright (C) 2009 S. Karger AG, Basel

Comparative neuroanatomical and temporal characterization of FluoroJade-positive neurodegeneration after status epilepticus induced by systemic and intrahippocampal pilocarpine in Wistar rats

The aims of this study were to characterize the spatial distribution of neurodegeneration after status epilepticus (SE) induced by either systemic (S) or intrahippocampal (H) injection of pilocarpine (PILO), two models of temporal lobe epilepsy (TLE), using FluoroJade (FJ) histochemistry, and to evaluate the kinetics of FJ staining in the H-PILO model. Therefore, we measured the severity of behavioral seizures during both types of SE and also evaluated the FJ staining pattern at 12, 24, and 168 h (7 days) after the H-PILO insult. We found that the amount of FJ-positive (FJ+) area was greater in SE induced by S-PILO as compared to SE induced by H-PILO. After SE induced by H-PILO, we found more FJ+ cells in the hilus of the dentate gyrus (DG) at 12 h, in CA3 at 24 h, and in CA1 at 168 h. We found also no correlation between seizure severity and the number of FJ+ cells in the hippocampus. Co-localization studies of FJ+ cells with either neuronal-specific nuclear protein (NeuN) or glial fibrillary acidic protein (GFAP) labeling 24 h after H-PILO demonstrated spatially selective neurodegeneration. Double labeling with FJ and parvalbumin (PV) showed both FJ+/PV+ and FJ+/PV- cells in hippocampus and entorhinal cortex, among other areas. The current data indicate that FJ+ areas are differentially distributed in the two TLE models and that these areas are greater in the S-PILO than in the H-PILO model. There is also a selective kinetics of FJ+ cells in the hippocampus after SE induced by H-PILO, with no association with the severity of seizures, probably as a consequence of the extra-hippocampal damage. These data point to SE induced by H-PILO as a low-mortality model of TLE, with regional spatial and temporal patterns of FJ staining. (C) 2010 Elsevier B.V. All rights reserved.