Assessment of baroreflex sensitivity during isometric handgrip exercise and oscillatory lower body negative pressure.

Objectives: Baroreflex sensitivity (BRS) is an estimate of autonomic control of cardiovascular system via the baroreflex arc. It has been suggested that exercise pressure reflex and muscle metaboreflex override baroreflex during exercise to decrease baroreflex gain, which facilitates the simultaneous rise in blood pressure (BP) and heart rate during the exercise. This study investigated the effects of isometric handgrip exercise (IHE) on baroreflex gain and frequency dependence of baroreflex sensitivity while fluctuations in arterial BP were generated. Methods: Thirteen healthy men performed IHE at 20% and 30% of their maximum voluntary contraction (MVC), while oscillatory lower body negative pressure (OLBNP) of 40 mmHg was applied in 0.1 and 0.25 Hz frequencies. Results: Compared to the OLBNP at 0.25 Hz frequency alone, the baroreflex gain for diastolic BP (DBP) was significantly reduced with the addition of IHE at 20% and 30% of MVC in the high frequency band. At rest (without IHE and OLBNP) the baroreflex gain was significantly more in the high frequency band for DBP, but the baroreflex gain for DBP was not significantly different when IHE + OLBNP were applied at 20% and 30% of MVC in both frequencies. Conclusions: The significant reduction of DBP baroreflex gain with the addition of graded IHE might indicate that exercise pressure reflex and muscle metaboreflex override baroreflex during exercise to decrease baroreflex gain at a high frequency band (0.25 Hz). The frequency-dependent phenomenon of BRS was altered when IHE and OLBNP were applied, meaning that the frequency dependence of BRS was nullified during IHE.

Persistent Hyperglycemia Worsens the Oleic Acid Induced Acute Lung Injury in Rat Model of Type II Diabetes Mellitus.

Aim: This research aimed to study the impacts of persistent hyperglycemia on oleic acid (OA)-induced acute lung injury (ALI) in a rat model of type II diabetes mellitus. Materials and Methods: Healthy adult male albino rats that weigh 150 to 180 g were divided into four groups (n = 6). Group I-saline (75 µL i.v.) was injected and served as a control; group II-OA (75 µL i.v.) was injected to induce ALI. Group III-pretreated with a high-fat diet and streptozotocin (35 mg/kg), was injected with saline, and served as a control for group IV. Group IV was pretreated with a high-fat diet, and streptozotocin (35 mg/kg) was injected with OA (75 µL i.v). Urethane was used to anesthetize the animal. The jugular venous cannulation was done for drug/saline administration, carotid artery cannulation was done to record blood pressure, and the tracheal cannulation was done to maintain the respiratory tract's patent. Heart rate, mean arterial pressure, and respiratory frequency were recorded on a computerized chart recorder; an arterial blood sample was collected to measure PaO2/FiO2. Additionally, the pulmonary water content and lung histology were examined. Result: Hyperglycemic rats showed no significant change in the cardio-respiratory parameter. Histology of the lungs shows fibroblastic proliferation; however, rats survived throughout the observation period. There was an early deterioration of all the cardio-respiratory parameters in hyperglycemic rats when induced ALI (OA- induced), and survival time was significantly less compared to nonhyperglycemic rats. Conclusion: Persistent hyperglycemia may cause morphological changes in the lungs, which worsens the outcome of acute lung injury.

Comparison of two formats of journal club for postgraduate students at two centers in developing critical appraisal skills.

Journal club (JC) is an integral part of postgraduate medical education. Although several innovations have been attempted to improve its effectiveness, the influence of the number of sessions remains unexplored. The current study investigated the effect of the number of sessions (one vs. four) of conduction of journal club on critical appraisal skills of postgraduate students at two institutions. A quasi-experimental study was conducted comparing the effectiveness of JC in a one- versus four-session JC format using two objective tests: Critical Appraisal Skills Test (CAST) and Population, Intervention, Comparison, Outcome (PICO) score. The degree of changes (pre-JC vs. post-JC session) after each format exposure, association of prescores to postscores, and correlation between the CAST and PICO scores were discerned. CAST score was higher in the four-session format (P = 0.03), whereas PICO score increased in the single-session format of JC (P = 0.03). Also, the change in CAST score was higher in the four-session versus single-session JC format (P = 0.04). We conclude that a four-session format of JC is more effective in augmenting critical appraisal skills of postgraduate students, whereas a single session is sufficient for improving factual knowledge.

Effects of 6-Week Sprint-Strength and Agility Training on Body Composition, Cardiovascular, and Physiological Parameters of Male Field Hockey Players.

Sharma, HB and Kailashiya, J. Effects of 6-week sprint-strength and agility training on body composition, cardiovascular, and physiological parameters of male field hockey players. J Strength Cond Res 32(4): 894-901, 2018-Optimal physiological and cardiovascular characteristics are essential for optimal physical performance. Different types of training regimes affect these characteristics and lead to trainees' adaptation and changes in relevant parameters. In the present interventional study, we have evaluated the effects of 6-week sprint-strength and agility training on such parameters. Twenty-four young Indian national hockey players volunteered for this study. Body weight (BW), body mass index (BMI), percentage body fat, lean body mass (LBM), resting heart rate (rHR), resting blood pressure (rBP), resting double-product (rDP), P/power (using Running-based Anaerobic Sprint Test), vertical jump (VJ), seated shot put test (SP), ball-hitting speed (BS), Tm (505-agility test), and V[Combining Dot Above]O2max were measured, and changes (d) after specified training regime were studied. The training proved to be "short yet effective." Significant improvements after training were found in body composition, cardiovascular, aerobic, anaerobic, strength, agility, and performance-related parameters; but not in BW, BMI, P/LBM, SP/LBM, and V[Combining Dot Above]O2max/LBM. Change in VJ (dVJ) was associated with change in Tm (dTm); change in SP (dSP) with change in VO2max, which also related to change in rHR, rBP and rDP. Change in BS (dBS) was more among those with lower initial BW, BMI, and BF. dBS, along with change in VO2max/LBM, was more mainly among those with lower initial anaerobic-aerobic fitness. The findings will be useful for coaches, sports managers, players, and also for general population for better, individual, and sport-based designing of "short yet effective" training programs and monitoring of outcomes. Specific physiological parameter improvement-targeted training can also be designed based on this research.