The aim of the present study was to compare the modulation of heart rate in a group of postmenopausal women to that of a group of young women under resting conditions on the basis of R-R interval variability. Ten healthy postmenopausal women (mean ± SD, 58.3 ± 6.8 years) and 10 healthy young women (mean ± SD, 21.6 ± 0.82 years) were submitted to a control resting electrocardiogram (ECG) in the supine and sitting positions over a period of 6 min. The ECG was obtained from a one-channel heart monitor at the CM5 lead and processed and stored using an analog to digital converter connected to a microcomputer. R-R intervals were calculated on a beat-to-beat basis from the ECG recording in real time using a signal-processing software. Heart rate variability (HRV) was expressed as standard deviation (RMSM) and mean square root (RMSSD). In the supine position, the postmenopausal group showed significantly lower (P<0.05) median values of RMSM (34.9) and RMSSD (22.32) than the young group (RMSM: 62.11 and RMSSD: 49.1). The same occurred in the sitting position (RMSM: 33.0 and RMSSD: 18.9 compared to RMSM: 57.6 and RMSSD: 42.8 for the young group). These results indicate a decrease in parasympathetic modulation in postmenopausal women compared to young women which was possibly due both to the influence of age and hormonal factors. Thus, time domain HRV proved to be a noninvasive and sensitive method for the identification of changes in autonomic modulation of the sinus node in postmenopausal women.
The similarity between the iICP and nICP monitoring methods was higher than the similarity between the nICP and the recordings of the radial ABP for all seven patients. Despite the possible differences between the shape of the ABP waveform at radial and parietal arteries, the results indicate-based on the similarities of iICP and nICP as functions of time-that the nICP method can be applied as an alternative method for ICP monitoring.
Exercise can generate alterations in body composition and modulate the immune system. The objective of this study was to verify whether a circuit resistance training (CRT) protocol can increase lean body mass (LM), and reduce fat body mass (FM) and the percent of FM (%FM) of sedentary women, without inducing inflammatory responses, indicated by serum cytokine levels. The initial hypothesis was that CRT would improve body composition, without changing serum cytokine levels. The study consisted of 14 healthy, sedentary women, aged 33-45 years (mean +/- SD, 40.23 +/- 3.98 years), with a normal body mass index. They participated in 3 sessions per week of CRT, which included 2 rounds in 9 stations with 1 set of 8-12 repetition maximum at each station, for 10 weeks. During the 10-week CRT period, participants maintained their pretraining nutritional standard. Body composition was analysed with dual-energy X-ray absorptiometry both pre- and post-training. Blood samples were collected after 96 h of rest pre- and post-training, and 5 min, 24 h, and 48 h after the second and last training sessions to measure serum cytokine levels by flow cytometry. The nutritional standard was accompanied throughout the study period with 24-h dietary recall. Increases in LM (35.937 +/- 4.926 to 39.130 +/- 4.950 kg) and decreases in FM (21.911 +/- 8.150 to 17.824 +/- 4.235 kg) and %FM (37.10 +/- 10.84 to 31.19 +/- 6.06), without concurrent changes in serum cytokine levels, and in the nutritional standard (alpha = 0.05). The proposed CRT improved body composition and did not induce any changes in serum cytokine levels characteristic of the inflammatory response in women.
SynopsisEcologically distinct species of Hoplias were studied as to the cardio-respiratory responses to graded hypoxia. Hoplias malabaricus maintained a constant oxygen uptake down to a PiOZ of 20 mmHg. Oxygen uptake declined markedly at lower PiO, and, concomitantly, cardiac frequency decreased. Concurrent reductions of oxygen uptake and heart rate also occurred in Hoplias lacerdae but at the considerably higher Pi02 of 35 mmHg. These species-specific differences are consistent with the respective habitats: H. malabarices occurs in stagnant hypoxic water, whereas H. lacerdae inhabits well-oxygenated rivers.
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