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Biomedical subjects

J J Rohack

Publications and source records attributed to J J Rohack.

12 recordsLinked to original sources
PubMed2000

Influence of cholesterol status on blood lipid and lipoprotein enzyme responses to aerobic exercise.

To compare postexercise changes in plasma lipids and lipoprotein enzymes in 13 hypercholesterolemic (HC) and 12 normocholesterolemic men [total cholesterol (TC) 252 +/- 5 vs. 179 +/- 5 mg/dl], fasting blood samples were obtained 24 h before, immediately, 24, and 48 h after a single bout of treadmill walking (70% peak O(2) consumption, 500 kcal expenditure). Significant findings (P < 0.05 for all) for plasma volume-adjusted lipid and enzyme variables were that TC, low-density-lipoprotein cholesterol, and cholesterol ester transfer protein activity were higher in the HC group but did not influence the lipid responses to exercise. Across groups, TC was transiently reduced immediately after exercise but returned to baseline levels by 24 h postexercise. Decreases in triglyceride and increases in high-density-lipoprotein cholesterol (HDL-C) and HDL(3)-C were observed 24 h after exercise and lasted through 48 h. Lipoprotein lipase activity was elevated by 24 h and remained elevated 48 h after exercise. HDL(2)-C, cholesterol ester transfer protein activity, hepatic triglyceride lipase, and lecithin: cholesterol acyltransferase activities did not change after exercise. These data indicate that the exercise-induced changes in HDL-C and triglyceride are similar in HC and normocholesterolemic men and may be mediated, at least in part, by an increase in lipoprotein lipase activity.

Adult↗
PubMed1998

The effects of menopausal status and exercise training on serum lipids and the activities of intravascular enzymes related to lipid transport.

The study purpose was to compare the effect of exercise training on serum lipid and apolipoprotein concentrations and the activities of intravascular enzymes related to lipid transport in previously untrained eumenorrheic, premenopausal (PRM) women (n = 21; mean age, 36 +/- 3 years) and estrogen-free postmenopausal (POM) women (n = 16; mean age, 68 +/- 8 years). Subjects trained at a progressive intensity and duration (50% to 75% maximal O2 consumption [VO2max], 200 to 300 kcal/session) 4 d/wk for 12 weeks. Before and after training, VO2max, body weight, relative body fat, and fasting blood samples were obtained following 2 weeks on a standardized diet designed to maintain body weight and during the early follicular stage for the PRM group. Blood samples were analyzed for serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), the cholesterol content of the HDL3 subfraction, apolipoprotein (apo)A-I and apoB, lipoprotein(a), and the activity of lecithin:cholesterol acyltransferase (LCAT). Total and hepatic triglyceride lipase activity (HTGLA) were determined from plasma samples obtained after heparin administration. The cholesterol content of the low-density lipoprotein (LDL) and HDL2 subfractions and endothelial-bound lipoprotein lipase activity (LPLA) were calculated. A two (group) x two (time) multivariate ANOVA (MANOVA), with repeated measures for time indicated that the exercise-induced changes in physiological measurements, serum lipid or apolipoprotein concentrations, or enzyme activities did not differ between groups. Serum concentrations of TC, LDL-C, and HDL3 cholesterol, TG, and apo A-I and apoB were higher in POM women compared with the PRM group (P < .05 for all). For the combined groups, body weight and relative body fat did not change with training, but VO2max increased an average of 18.5% (P < .05). LPLA, HTGLA, and LCAT activity were unaltered with exercise training. Except for a small but significant decrease in HDL-C (-5.5%) and an elevation in apoB (4.3%; P < .05 for both), the concentrations of serum lipids and apolipoproteins did not change over the training period. We conclude that in previously untrained women, menopausal status does not influence the exercise training response of serum lipids or apolipoproteins or activities of intravascular enzymes related to lipid transport.

Adult↗
PubMed1998

Peak exercise hemodynamics in exercising postmenopausal women taking versus not taking supplemental estrogen.

The purpose of this study was to determine whether supplemental estrogen influences cardiovascular hemodynamics at peak exercise in endurance trained and sedentary postmenopausal women. Subjects were 22 women between 3 and 10 yr past menopause who had engaged in endurance exercise at least three times per week for one or more years. Twelve of the women had taken estrogen replacement for at least 1 yr (ER) while the other 10 had never taken supplemental estrogen (NOER). Peak cardiac output (Qpeak) and, subsequently, peak cardiac index (QIpeak) were calculated by regressing submaximal cardiac output values on corresponding oxygen consumptions and extrapolating to peak exercise. Peak oxygen consumption in the two groups were almost identical; however, the ER group demonstrated a higher QIpeak in conjunction with a lower arteriovenous oxygen difference and a lower peripheral resistance. It was concluded that estrogen supplementation may be associated with higher peak cardiac outputs in exercise trained postmenopausal women via alterations in the peripheral vascular and oxygen kinetic responses to maximal exercise.

Cardiac Output↗
PubMed1997

Training intensity, blood lipids, and apolipoproteins in men with high cholesterol.

Twenty-six hypercholesterolemic men (mean cholesterol, 258 mg/dl; age, 47 yr; weight, 81.9 kg) completed 24 wk of cycle ergometer training (3 days/wk, 350 kcal/session) at either high (n = 12) or moderate (n = 14) intensity (80 and 50% maximal O2 uptake, respectively, randomly assigned) to test the influence of training intensity on blood lipid and apolipoprotein (apo) concentrations. All physiological, lipid, and apo measurements were completed at 0, 8, 16, and 24 wk. Lipid data were analyzed via two x four repeated-measures analysis of variance (alpha = 0.0031). Training produced a significant decrease in body weight and increase in maximal O2 uptake. No interactions between intensity and weeks of training were noted for any lipid or apo variable, and no between-group differences were significant before or throughout training. Therefore, intensity did not affect the training response. Regardless of intensity, apo AI and apo B fell 9 and 13%, respectively, by week 16 and remained lower through week 24 (P < 0.0003). Total cholesterol fell transiently (-5.5%) by week 16 (P < 0.0021) but returned to initial levels by week 24. Triglyceride, low-density-lipoprotein cholesterol, and high-density-lipoprotein (HDL) cholesterol did not change with training. In contrast, HDL2 cholesterol rose 79% above initial levels by week 8 and 82% above initial levels by week 24 (P < 0.0018); HDL3 cholesterol fell 8 and 13% over the same training intervals (P < 0.0026). These data show that changes in blood lipid and apo concentrations that accompany training in hypercholesterolemic men are not influenced by exercise intensity when caloric expenditure is held constant.

Adult↗
PubMed1997

Effects of training and a single session of exercise on lipids and apolipoproteins in hypercholesterolemic men.

To differentiate between transient (acute) and training (chronic) effects of exercise at two different intensities on blood lipids and apolipoproteins (apo), 26 hypercholesterolemic men (cholesterol = 258 mg/dl, age = 47 yr, weight = 81.9 kg) trained three times per week for 24 wk, 350 kcal/session at high (80% maximal O2 uptake, n = 12) or moderate (50% maximal O2 uptake, n = 14) intensity. Serum lipid and apolipoprotein (apo) concentrations (plasma volume adjusted) were measured before and immediately, 24, and 48 h after exercise on four different occasions corresponding to 0, 8, 16, and 24 wk of training. Data were analyzed using three-way repeated-measures multivariate analysis of variance followed by analysis of variance and Duncan's procedures (alpha = 0.05). A transient 6% rise in low-density-lipoprotein cholesterol measured before training at the 24-h time point was no longer evident after training. Triglycerides fell and total cholesterol, high-density-lipoprotein cholesterol (HDL-C), HDL3-C, apo A-I, and apo B rose 24-48 h after exercise regardless of training or intensity. Total cholesterol, HDL3-C, apo A-I, and apo B were lower and HDL2-C was higher after training than before training. Thus exercise training and a single session of exercise exert distinct and interactive effects on lipids and apolipoproteins. These results support the practice of training at least every other day to obtain optimal exercise benefits.

Adult↗
PubMed1995

Maximal exercise and acute mood response in women.

The present study was designed to characterize and assess the reliability of acute mood responses to maximal exercise in women. All subjects (N = 22; age = 45 +/- 2.5 yr; BMI = 24.3 +/- 0.9 kg/m2) participated in two maximal walking tests spaced approximately one month apart. The abbreviated Profile of Mood States (POMS) questionnaire was administered immediately prior to and within 5 min following maximal exercise at both occasions. Maximal heart rate, rating of perceived exertion, and functional aerobic capacity responses indicated compliance to maximal exertion at both tests. Using repeated measures ANOVA, no significant (p < .05) differences were noted between the two tests for any of the POMS subscales. Significant pre to postexercise increases were noted for fatigue and self-esteem subscales while the tension and vigor affects significantly decreased. Because no interactions were found, these effects are concluded to be independent of the order in which the tests were performed. Additionally, intraclass correlations computed for each respective POMS subscale, ranged between 0.69 and 0.81 for fatigue, tension, vigor, self-esteem, confusion, and total mood disturbance. The anger and depression subscales were noted to have intraclass correlations of 0.29 and 0.43, respectively, and may have been influenced by a floor effect in this study population. It is concluded that the abbreviated POMS questionnaire may be reliably used to assess acute mood responses to maximal exercise in women and that even maximal exertion has the potential to acutely benefit mood by decreasing tension and increasing self-esteem.

Affect↗
PubMed1995

Changes in serum lipids and apolipoproteins after exercise in men with high cholesterol: influence of intensity.

The purpose of this study was to characterize the short-term changes in blood lipid and apolipoprotein concentrations in healthy hypercholesterolemic men after high-intensity [80% maximal O2 uptake (VO2max); n = 20] or moderate-intensity (50% VO2max; n = 19) cycle ergometer exercise balanced for caloric expenditure (350 kcal). The men's age, height, weight, %fat, and VO2max were 46 +/- 2 yr, 173 +/- 7 cm, 82.7 +/- 2.2 kg, 28 +/- 1%, and 31.1 +/- 1.0 ml O2.kg-1.min-1, respectively. Blood samples were drawn before exercise, immediately after exercise, then 24 and 48 h later, and concentrations of all variables were adjusted for changes in plasma volume. Significant changes (P < 0.0016) were as follows: total and low-density lipoprotein cholesterol fell by 4% immediately after exercise and then rose by 5-8% by 48 h. Triglycerides were 18 and 15% lower at 24 and 48 h, respectively. HDL-cholesterol, high-density lipoprotein3-cholesterol, and apolipoprotein B rose 8-9% by 24 h and remained elevated. High-density lipoprotein2-cholesterol rose by 27% by 48 h after exercise, but this change was not significant. Apolipoprotein A-I did not change with exercise. The response patterns were not affected by exercise intensity. These data show that a single session of exercise performed by untrained hypercholesterolemic men alters blood lipid and apolipoprotein concentrations. Furthermore, the postexercise response patterns are not influenced by exercise intensity, as long as caloric expenditure is held constant.

Adult↗
PubMed1995

Acute effects of walking on serum lipids and lipoproteins in women.

The purpose of this study was to characterize and evaluate the acute effects of walking performed of fairly light (50% VO2max) and moderate (70% VO2max) intensities on serum lipids and lipoproteins in a group of premenopausal (n = 11) and a group of postmenopausal (n = 10) women. Premenopausal women were (x +/- SEM) 34.5 +/- 1.1 years of age, had 22.8 +/- 1.7% body fat and a 2.47 +/- 0.08 l.min-1 VO2max. Postmenopausal women were 54.8 +/- 2.5 years of age, had 37.9 +/- 0.9% body fat and a 2.06 +/- 0.15 l.min-1 VO2max. All subjects walked on a motor-driven treadmill at each respective intensity of exercise for a total duration sufficient to expend 350 kcal of energy. Dependent variables included total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and its subfractions HDL2-C and HDL3-C, low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG). Blood samples were obtained at baseline (pre-exercise), immediately post-exercise (IPE), and at 24 hours and 48 hours post-exercise. A repeated measures design was employed controlling for diet, menstrual cycle periodicity, natural menopause, and plasma volume shifts. A 2 x 4 ANOVA was used to test for differences among means for each group separately. Significant (p < 0.05) time exercise intensity interactions were found for TC and LDL-C for the premenopausal women. This non-parallel change across exercise intensity condition created significant differences at IPE for both TC and LDL-C. Furthermore, an IPE increase in TG (p < 0.05) was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1995

What's new in stroke?

More than 30,000 strokes occur each year in Texas, even though most strokes can be prevented by currently available and well-tolerated therapies. Antiplatelet therapy with aspirin or ticlopidine reduces stroke by about 25% in many patients with transient ischemic attack or initial stroke. Warfarin should not be used routinely for primary cerebrovascular disease but is useful to prevent cardioembolic stroke. Carotid endarterectomy is highly beneficial for patients with symptomatic, high-grade carotid stenosis, but its value for lesser degrees of symptomatic carotid plaque and for asymptomatic stenosis is less clear. Patients with nonvalvular atrial fibrillation have a substantial risk for stroke; most should be treated with warfarin. Risk-factor management (eg, control of hypertension, cessation of smoking, and treatment of hyperlipidemia) is as important as antithrombotic or surgical therapies for most patients with threatened stroke. Treating isolated systolic hypertension in elderly patients reduces stroke risk. Determining the cause of threatened stroke strongly influences preventive management. The tools are at hand to prevent most strokes; the challenge remains to apply them optimally.

Acute Disease↗
PubMed1992

Cardiac structure and function in women basketball athletes: seasonal variation and comparisons with nonathletic controls.

To characterize hypertrophy and quantify seasonal changes in cardiac structure and function of women collegiate basketball (BB) athletes (n = 15), echocardiographic (echo) measurements were made in the fall (FALL1), winter (WIN), and spring (SPR), then again during the subsequent fall (FALL2; n = 10). Comparisons were made to age-matched nonathletes (NA) measured during FALL1 (n = 22) and SPR (n = 5). Left ventricular (LV) internal dimension-diastole (LVIDd), LV end-diastolic volume (LVEDV), stroke volume (SV), LV mass (LVM), septal thickness (IVS), LV posterior wall thickness (LVPW), right ventricular (RV) internal dimension-diastole (RVIDd), and aortic root diameter (AOD) were significantly larger (12-70%) in the athletes; RVIDd-, LVEDV-, SV-, and LVM-index were also significantly greater (8-46%). From FALL1 to SPR measurement periods, LVIDd, RVIDd, LVEDV, SV, IVS, and LVM-index increased significantly (7-18%) in the athletes. Over the same period of time, LVIDd, LAD, AOD, LVEDV, and SV measured in the five NA subjects increased significantly. In the athletes, LVIDs, RVIDd, IVS, LVPW, and LVM decreased significantly (5-30%) from the SPR to FALL2 measurement period. These data characterize the general nature of the cardiac hypertrophy noted in women BB athletes compared to NA controls and show that distinct changes in heart structure corresponding to different periods of the competitive season can occur in these athletes.

Adult↗
PubMed1979

Stimulus similarity and order as factors in visual short-term memory in nonhuman primates.

The short-term retention of nonhuman primates for a single sample or for two successively presented samples was assessed in four delayed matching-to-sample experiments with delays of .03, 4, 8, 16, and 32 sec. The single sample tasks included one (Experiment 1) or two (Experiment 4) distractor stimuli in the choice set (matching test). In the two successive samples tasks, the animals matched (reconstructed) the order of presentation of two samples with (Experiment 3) and without (Experiment 2) a distractor stimulus. Also, the possible combinations of eight stimuli (four colors and four shapes) were arranged to test the effects of sample set and choice set similarity. Taken together, analyses of the errors indicated that both sample and choice set similarity were significant sources of confusions in delayed matching. Order errors occurred independently of similarity but were a source of forgetting primarily at the longest delays (16 and 32 sec). Two exceptions to the similarity effect (second response errors in Experiment 3 and errors of an inexperienced group in Experiment 4) were observed. Possible reasons for the exceptions and several implications of these findings for theories of short-term memory are discussed.

Animals↗