Because HRV and BPV response is different when induced by static or dynamic exercise, differences in the autonomic activity can be advised. Instead of the vagal withdrawal and sympathetic augmentation observed during dynamic exercise, the increase in the overall HRV and the MF component during static exercise suggest an increased activity of both autonomic branches.

Gas chromatography was utilized to determine triacylglycerol profiles in milk and non-milk fat. The values of triacylglycerol were subjected to linear discriminant analysis to detect and quantify non-milk fat in milk fat. Two groups of milk fat were analyzed: A) raw milk fat from the central region of Mexico (n = 216) and B) ultrapasteurized milk fat from 3 industries (n = 36), as well as pork lard (n = 2), bovine tallow (n = 2), fish oil (n = 2), peanut (n = 2), corn (n = 2), olive (n = 2), and soy (n = 2). The samples of raw milk fat were adulterated with non-milk fats in proportions of 0, 5, 10, 15, and 20% to form 5 groups. The first function obtained from the linear discriminant analysis allowed the correct classification of 94.4% of the samples with levels <10% of adulteration. The triacylglycerol values of the ultrapasteurized milk fats were evaluated with the discriminant function, demonstrating that one industry added non-milk fat to its product in 80% of the samples analyzed.

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One hundred and twenty-five HIV-infected patients, of whom 49 (39%) were at early stages of the infection (CDC-II & III) and 76 (61%) in CDC IV, were prospectively examined. In 100 (80%) one or more oral mucosal lesions were observed; candidiasis (51%) and hairy leukoplakia (43%) were the commonest. Erythematous candidiasis was more often seen (35%) than the pseudomembranous type (16%), and appeared with the higher values at early than later stages. The prevalence of hairy leukoplakia, oral hyperpigmentation and xerostomia were incremented in groups CDC-IV. Pseudomembranous candidiasis and exfoliative cheilitis increased significantly with severity of disease. Our study demonstrates that oral alterations associated to HIV are a frequent finding, both at early (76%) and late (83%) stages of the infection in Mexican patients.

In the present study, we examined two baroreflex sensitivity (BRS) issues that remain uncertain: the differences among diverse BRS assessment techniques and the association between BRS and vagal outflow. Accordingly, the electrocardiogram and non-invasive arterial pressure were recorded in 27 healthy subjects, during supine with and without controlled breathing, standing, exercise, and recovery conditions. Vagal outflow was estimated by heart rate variability indexes, whereas BRS was computed by alpha-coefficient, transfer function, complex demodulation in low- and high-frequency bands, and by sequence technique. Our results indicated that only supine maneuvers showed significantly greater BRS values over the high frequency than in the low-frequency band. For maneuvers at the same frequency region, supine conditions presented a larger number of significant differences among techniques. The plots between BRS and vagal measures depicted a funnel-shaped relationship with significant log-log correlations (r=0.880-0.958). Very short latencies between systolic pressure and RR interval series in high-frequency band and strong log-log correlations between frequency bands were found. Higher variability among different baroreflex measurements was associated with higher level of vagal outflow. Methodological assumptions for each technique seem affected by non-baroreflex variation sources, and a modified responsiveness of vagal motoneurons due to distinct stimulation levels for each maneuver was suggested. Thus, highest vagal outflows corresponded to greatest BRS values, with maximum respiratory effect for the high-frequency band values. In conclusion, BRS values and differences across the tested techniques were strongly related to the vagal outflow induced by the maneuvers.

In studies of autonomic regulation during orthostatic challenges only a few nonlinear methods have been considered without investigating the effect of gender in young controls. Especially, the temporal development of the autonomic regulation has not yet been explicitly analyzed using short-term segments in supine position, transition and orthostatic phase (OP). In this study, nonlinear analysis of cardiovascular and respiratory time series was performed to investigate how nonlinear indices are dynamically changing with respect to gender during orthostatic challenges. The analysis was carried out using shifted short-term segments throughout a head-up tilt test in 24 healthy subjects, 12 men (26  ±  4 years) and 12 age-matched women (26  ±  5 years), at supine position and during OP at 70°. The nonlinear methods demonstrated statistical differences in the autonomic regulation between males and females. Orthostatic stress caused significantly decreased heart rate variability due to increased sympathetic activity mainly in men, already at the beginning and during the complete OP, revealed by (a) increased occurrence of specific word types with constant fluctuations as pW111 from symbolic dynamics, (b) augmented fractal correlation properties by the short-term index alpha1 from detrended fluctuation analysis, (c) increased slope indices (21ati and 31ati) from auto-transinformation and (d) augmented time irreversibility indices demonstrating more temporal asymmetries and nonlinear dynamics in men than in women. After tilt-up, both men and women increased their sympathetic activity but in a different way. Time-dependent gender differences during orthostatic challenge were shown directly between men and women or indirectly comparing baseline and different temporal stages of OP. The proposed dynamical study of autonomic regulation has the advantage of screening the fluctuations of the sympathetic and vagal activities that can be quantified by the temporal behavior of nonlinear indices. The findings in this paper strongly suggest the need for gender separation in studies of the dynamics of autonomic regulation during orthostatic challenge.

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