Aloe vera na criopreservação do sêmen de tambaqui (Colossoma macropomum) / Aloe vera in the cryopreservation of tambaqui (Colossoma macropomum) sperm

This study aimed to evaluate the extract of Aloe vera (AV) associated or not with 10% Dimethylsulfoxide (DMSO) in cryopreservation of tambaqui semen. For the formation of the pools (n= 14), 30 males were hormonally induced twice. Each pool had the objective motility, curvilinear velocity, straight-line velocity, average path velocity and morphology analyzed before and after cryopreservation of semen. The means for cryopreservation were constituted of Powder Coconut Water-104 diluent added DMSO and/or AV (5 or 10%). After cryopreservation, motility, velocities and morphology were reduced significantly when compared to fresh semen. For sperm motility the best treatment was that using only DMSO (20,86±8,31) and DMSO + 5% AV (15.71±9.77). For the velocities, the worse treatment was DMSO+10% AV. Treatment with only the addition of DMSO had a significantly higher effect than others on percentage of morphologically normal sperm. The mean correlation found was between motilityand the rate of morphologically normal sperm (r = 0.687). In conclusion, the addition of AV does not provide greater protection for spermatozoa during cryopreservation.

Influence of multiple sclerosis, age and degree of disability, in the position of the contrast sensitivity curve peak.

Context: Contrast sensitivity (CS) function is one of the most important tests available for evaluating visual impairment. Multiple sclerosis (MS) can produce highly selective losses in visual function and psychophysical studies have demonstrated CS deficits for some spatial frequencies. Aims: This work studies the differences in CS between a group of controls and a group of MS patients, focusing on the location of the maximum sensitivity peak, shape of the curve, and determination of the most affected spatial frequencies. Materials and Methods: Using a sinusoidal stimulus the authors assessed CS function in 28 subjects with definitive relapsing remitting MS, and in 50 controls with acuities of 20/25 or better. The peaks of the CS curves were studied by fitting third degree polynomials to individual sets of data. Results: Compared with the control group, the CS function curve for MS subjects showed more deficits in extreme points (low‑ and high‑spatial frequencies). Our results display significant CS losses, at the high‑frequencies band level, in the beginning of the disease. When the disease progresses and the disabilities appear, there are greater losses at the low‑frequencies band level. In average, the CS curve peaks for the MS group were shifted in relation to the control group. Conclusions: CS losses in the MS group suggest an association with ageing and disability level in the expanded disability status scale. The position of the CS function peak is influenced by MS, age, and degree of disability.

Is arterial stiffness in HIV-infected individuals associated with HIV-related factors?

We investigated the association between pulse wave velocity (PWV) and HIV infection, antiretroviral treatment-related characteristics, viral load, immune status, and metabolic changes in a cross-sectional study nested in a cohort of HIV/AIDS patients who have been followed for metabolic and cardiovascular changes since 2007. The study included patients recruited from the cohort (N = 261) and a comparison group (N = 82) of uninfected individuals, all enrolled from April to November 2009. Aortic stiffness was estimated using the carotid-femoral PWV (Complior-Artech, Paris, France). The groups were similar with respect to age, metabolic syndrome, diabetes mellitus, Framingham score, and use of antihypertensive and hypolipidemic medications. Hypertension was more frequent among the controls. Individuals with HIV had higher triglyceride, glucose and HDL cholesterol levels. Among individuals with HIV/AIDS, those with a nadir CD4+ T-cell count <200 cells/mm³ had a higher PWV (P = 0.01). There was no statistically significant difference when subjects were stratified by gender. Heart rate, age, male gender, and blood pressure were independently correlated with PWV. Nadir CD4+ T-cell count did not remain in the final model. There was no significance difference in PWV between HIV-infected individuals and uninfected controls. PWV was correlated with age, gender, and blood pressure across the entire population and among those infected with HIV. We recommend cohort studies to further explore the association between inflammation related to HIV infection and/or immune reconstitution and antiretroviral use and PWV.

Gene flow from transgenic to nontransgenic soybean plants in the Cerrado region of Brazil

Evaluation of transgenic crops under field conditions is a fundamental step for the production of genetically engineered varieties. In order to determine if there is pollen dispersal from transgenic to nontransgenic soybean plants, a field release experiment was conducted in the Cerrado region of Brazil. Nontransgenic plants were cultivated in plots surrounding Roundup Ready transgenic plants carrying the cp4 epsps gene, which confers herbicide tolerance against glyphosate herbicide, and pollen dispersal was evaluated by checking for the dominant gene. The percentage of cross-pollination was calculated as a fraction of herbicide-tolerant and -nontolerant plants. The greatest amount of transgenic pollen dispersion was observed in the first row, located at one meter from the central (transgenic) plot, with a 0.52% average frequency. The frequency of pollen dispersion decreased to 0.12% in row 2, reaching 0% when the plants were up to 10 m distance from the central plot. Under these conditions pollen flow was higher for a short distance. This fact suggests that the management necessary to avoid cross-pollination from transgenic to nontransgenic plants in the seed production fields should be similar to the procedures currently utilized to produce commercial seeds.