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Biomedical subjects

M Sagiv

Publications and source records attributed to M Sagiv.

At least 37 records · Page 2Linked to original sources
PubMed1992

Effect of body position on the afterload response during sustained exercise.

Hemodynamic and cardiovascular responses were studied in 80 males (age: 30 +/- 2 years) at rest, and during separate three minute trials of upright and supine isometric deadlift exercise at 30% of maximum voluntary contraction (MVC). MVC did not differ significantly between supine and upright deadlift exercise. In comparison to values at rest, both forms of isometric exercise resulted in significant increases (p less than 0.05) in heart rate, systolic blood pressure, diastolic blood pressure, mean arterial blood pressure, oxygen uptake, oxygen pulse and double product. In the upright exercise, the values obtained for all of the physiological variables were found to be significantly higher (p less than 0.05) than in the supine exercise. These findings indicate that the upright isometric deadlift produces a higher after-load than the supine maneuver, and that this response may be a good indicator of cardiovascular functioning.

Adult↗
PubMed1991

Comparison of hemodynamic and left ventricular responses to increased after-load in healthy males and females.

Hemodynamic and left ventricular responses were studied echocardiographically in 20 males (31.5 +/- 4.5 yrs) and 20 females (30.4 +/- 4.3 yrs) at rest and during 3 min of isometric deadlift exercise at 30% of maximum voluntary contraction. Maximal tension exerted was significantly (P less than .001) lower in the female group (87.4 +/- 8.1 kg) compared with the male group (127.3 +/- 15 kg). Significant (P less than .001) increases in heart rate and contractility index were noted in both groups during exercise compared to the resting values. Mean arterial blood pressures were significantly (P less than .05) higher in the males at rest and during exercise. Ejection fraction and fractional shortening, both at rest and during exercise, differed significantly (P less than .05) between the two groups. It was raised by exercise only in the males (from 62 +/- 5% to 65 +/- 5% and 32 +/- 4% to 35 +/- 4%, respectively) but remained unchanged in the females. No significant changes in end diastolic dimension and stroke volume were observed in either group during exercise. End systolic dimension was significantly (P less than .001) lower during exercise in females and males (from 3.25 +/- .23 to 3.1 +/- .26 and 3.12 +/- .33 to 3.00 +/- .32 cm, respectively). These data indicate that hemodynamic and left ventricular function in normal male and female subjects were augmented during submaximal isometric exercise. However, females do so with lower after-load than males.

Adult↗
PubMed1991

Smoking effect on exercise response kinetics of oxygen uptake and related variables.

The effects of smoking on the kinetics of oxygen uptake (VO2), carbon dioxide production (VCO2), ventilation (Ve) and heart rate (HR) in the transition from rest to steady-state submaximal exercise was investigated in 6 female and 4 male smokers (32 +/- 8 yrs). The subjects underwent two counter-balanced treadmill tests at 60% of their maximal VO2, lasting 10 min each: one following a 24-hr smoking abstinence, and one immediately after smoking three cigarettes without prior abstinence. Physiological variables were measured at rest and every 30 sec throughout each test. The time required for a given variable to rise from its respective resting baseline to half of its steady-state value (t1/2) was calculated for VO2, VCO2, Ve and HR. Smoking abstinence was associated with t1/2 values of 32 +/- 8, 42 +/- 12, 43 +/- 10, and 30 +/- 9 sec for VO2, VCO2, Ve, and HR, respectively. Smoking significantly (p less than 0.01) lengthened those values to 51 +/- 12, 58 +/- 11, 54 +/- 8, and 41 +/- 10 sec. Concurrently, smoking raised the baseline (resting) values of HR (p less than 0.01) and of Ve, VCO2, O2 pulse (O2P), and both systolic and diastolic blood pressures (p less than 0.05). During steady-state exercise only HR values were elevated by smoking (p less than 0.01), while O2P values were lowered (p less than 0.05). These findings indicate that smoking considerably retards physiological responses to submaximal exercise.

Adult↗
PubMed1991

Exercise tolerance of end-stage renal disease patients.

The purpose of this study was to evaluate the exercise tolerance of end-stage renal disease patients, and to examine pulmonary function and blood lactate as its possible limiting factors. Ten end-stage renal disease patients (age 30 +/- 11) were tested at rest and in a subsequent graded treadmill test to exhaustion. Velocity was 4.8 km/h and the grade was incremented by 2.5% every 4 min. One minute of rest, used for blood sampling, separated successive stages. Pulmonary functions (FVC, FEV1) at rest were both 76% of predicted. Resting heart rate, systolic and diastolic blood pressures, and ventilatory equivalent values were higher than normal. At peak exercise, heart rate, oxygen uptake, oxygen pulse and blood lactic acid were lower than normally predicted for maximal exercise, while ventilatory equivalent and diastolic blood pressure were higher. Only six patients reached blood lactate levels beyond 4 mM.l-1 (onset of blood lactic acid), at which point they utilized 88 +/- 5% of their respective peak Vo2. The results suggest that the low exercise tolerance demonstrated in end-stage renal disease patients is not limited by the somewhat compromised pulmonary capacity or by excessive blood lactate levels.

Adult↗
PubMed1991

Physiological responses to wrist weights during endurance cycling in normal subjects.

Cardiopulmonary and metabolic responses were studied in 12 healthy males aged 45 +/- 7 yr (mean +/- SD) during 25 min of cycling exercise with (WW) and without (NW) arm swing with wrist weights at 60% and 75% of their maximal heart rate reserve (MHRR). Cycling leg work was adjusted in order to produce a constant 60% and 75% of MHRR during WW and NW sessions. The results revealed that during both exercises the cardiopulmonary and hemodynamic responses were similar. However, during the NW sessions lactic acid (LA) levels were significantly (P less than 0.01) higher than those observed during WW sessions (3.2 +/- 0.9 and 5.4 +/- 1.5 mm.l-1, vs 2.9 +/- 0.9 and 3.8 +/- 1.3 mm.-1), as were ratings of perceived exertion (RPE) (13.2 +/- 1 and 14.4 +/- 0.6, vs 12.2 +/- 1 and 13.4 +/- 1.5). These data indicated a similar pattern of hemodynamic and respiratory responses to NW and WW cycling exercises, while LA and RPE were lower in WW cycling. It is therefore suggested that arm swing with wrist weights may be a beneficial mode of exercise, distributing the workload on a larger muscle mass while maintaining the target heart rate. Thus, it enables a lower reliance on anaerobic metabolism and a lower perceived exertion.

Adult↗
PubMed1990

Comparative analysis of cardiopulmonary responses during dynamic exercise with wrist weights in the elderly versus young hypertensive responders.

Endurance exercise is usually prescribed with caution for hypertensive patients because of the possible adverse effects of increased blood pressure on cardiorespiratory function. Cardiopulmonary responses were studied in 11 young (37 +/- 4 years) and 10 elderly (65 +/- 4 years) male subjects during treadmill exercise with wrist weights (WW) and with no weights (NW) at constant 60% of their maximal heart rate for 8 min at each exercise condition. The results revealed that both groups had similar responses at rest. During maximal stress test, heart rate, oxygen consumption and minute ventilation were significantly (p less than 0.01) higher in the younger subjects. During 60% WW and NW exercises heart rate, oxygen consumption and minute ventilation were significantly (p less than 0.01) lower in the elderly than in the younger group. Diastolic and mean arterial blood pressures were significantly (p less than 0.01) higher in both groups during WW compared to NW exercise. However, minute ventilation and rate-perceived exertion were significantly (p less than 0.01) higher during NW compared to WW exercise. These measurements indicated a similar pattern of hemodynamics in younger and elderly hypertensive responders, with variable respiratory responses to endurance exercise. In addition, careful observation of blood pressure during exercise with WW is recommended for both groups where an increased afterload is contraindicated. We recommend the usage of controlled WW exercise for hypertensive responders of all age groups as part of their rehabilitative program.

Adult↗
PubMed1990

Immunosuppressive activity and polyamine levels of seminal plasma in azo-ospermic, oligospermic, and normospermic men.

Seventy specimens of human seminal plasma obtained from azo-ospermic, oligospermic, and normospermic men were tested for immunosuppressive activity on normal donor lymphocytes. Spermine and spermidine levels in acidic extracts were determined in 32 specimens of seminal plasma from the three groups. The original seminal plasma as well as the neutralized spermine extracts were examined for their effect on the functional activity of the lymphocytes. Seminal plasma obtained from the normospermic and oligospermic semen showed significant immunosuppressive activity, whereas no immunosuppressive activity was induced by seminal plasma from azo-ospermic semen. The latter finding was in accordance with the low spermine levels in azo-ospermic semen, which were about 50% of those found in normospermic and oligospermic seman. Acidic extraction of the seminal plasma of azo-ospermic origin resulted in an increase in spermine levels and also in immunosuppressive activity, demonstrating that in azo-ospermic men spermine is bound probably to a protein and is released after acidification, exerting its immunosuppressive activity only when unbound.

Graft vs Host Reaction↗
PubMed1990

Andrological parameters in men with high sperm counts and possible correlation with age.

Two hundred eighty six human semen samples with sperm counts above 200 million/ml, were divided into 3 groups according to semen volume: (1) less than 1 ml (low), (2) 1 ml-5 ml (normal), and (3) greater than or equal to 6 ml (high). Each group was examined for routine andrological parameters. Also examined was a possible correlation between sperm counts, semen volumes, and ages of patients. The quality of motility (percent and grade) and viability of sperm were generally lowest in specimens with a volume below 1 ml and highest in those of normal volume. Proportions of morphological normality exhibited a similar trend, lacking, however, statistical significance. The mean fructose content of low-volume semen was significantly decreased in comparison with those of normal volume. Patients with low-volume semen and sperm counts above 200 million/ml were older than those with similar sperm counts and normal volume. The mean ages of all patients with high sperm counts of semen were higher than of those with lower sperm counts. It was assumed that in contradiction to specimens with high sperm counts and low volume, those whose volumes range from 1 ml-5 ml should be considered normal with respect to motility, viability, and morphological normality.

Adult↗
PubMed1989

Effect of running versus isometric training programs on healthy elderly at rest.

Left ventricular function and hemodynamic alterations at rest were measured echocardiographically following running or isometric training in 40 healthy elderly. They were randomly assigned into two groups. Twenty (67 +/- 4 years) were engaged in running and 20 (67.8 +/- 3.8 years) in isometric training programs. All subjects underwent a 12-week program, 3 times a week 30 min each session. The running exercise (REX) group had an aerobic exercise conditioning program at 70% of their VO2max. The program for the isometric exercise (IEX) group included weight lifting utilizing large muscle mass at 30% of their maximal voluntary contraction. After training, the REX group increased significantly (p less than 0.05) their VO2max from 2.08 +/- 0.37 to 2.36 +/- 0.41 liter/min and ejection fraction 56 +/- 5.9 to 62 +/- 6.1%. They decreased significantly their heart rate, from 73 +/- 7 to 65 +/- 7 beats/min. No change occurred in the IEX group in left ventricular function and hemodynamic parameters. These data suggest that left ventricular responses at rest differ between the two groups following a short-term training with a favorable response after REX training. In addition, this study demonstrated that a controlled aerobic training program is a better way to improve physical capacity than is a weight lifting program for trained healthy elderly.

Aged↗
PubMed1989

Doppler assessment of the effects of isometric stress on left ventricular filling in hypertensive young adults.

Doppler interrogation at the in-flow of the left ventricle was used to test the effects of isometric stress on ventricular filling in 7 hypertensive subjects with mild to moderate left ventricular hypertrophy, aged forty-two +/- seven years, compared with 9 matched healthy control males. In the hypertensive patients at rest, peak early diastolic (E) velocity was lower, and atrial (A) velocity higher, with lower E/A peak velocity ratios than in normals (p less than 0.05). These differences were more accentuated during isometric stress. Atrial filling fractions were higher in hypertensives (37 +/- 6%) than in normals (24 +/- 7%) at rest, p less than 0.05, and this difference increased during isometric stress (44 +/- 9% versus 30 +/- 11%). Thus, isometric stress accentuated the reliance of left ventricular filling on atrial contribution and may be applied for the detection of early ventricular filling abnormalities in patients with mild hypertension. The systolic blood pressure and the hypertrophic process were both important determinants of left ventricular diastolic filling.

Adult↗
PubMed1989

Beta-endorphin and calcitonin in human semen.

The levels of beta-endorphin (beta-E) and calcitonin were estimated in 36 samples of seminal plasma from semen of normospermic, oligozoospermic, and azoospermic origins and in pools of isolated sperm. The mean levels in plasma calculated for all samples examined were 192 +/- 224 pg/ml for beta-E and 754 +/- 397 pg/ml for calcitonin. The amounts in sperm were as follows: for beta-E in pools with sperm counts of 0.1-10 x 10(6)/ml, 157.2 +/- 99.7 pg/10(8) and 27.9 +/- 23.6 pg/ml protein; in pools of greater than 10-30 x 10(6)/ml, 71.2 +/- 41.5 pg/10(8) and 6.5 +/- 1.2 pg/mg protein; in pools of greater than 30-200 x 10(6)/ml, 24.9 +/- 9.7 pg/10(8) and 61 +/- 1.9 pg/mg protein. For calcitonin the amounts were: 501.2 +/- 170.8 pg/10(8) and 27.4 +/- 21.5 pg/mg protein, correspondingly. It was suggested that beta-E and calcitonin present in seminal plasma are synthesized mostly in a compartment of the male reproductive system. The high cellular beta-E and calcitonin levels would be involved in the process of motility through their effect on calcium transport.

Calcitonin↗
PubMed1988

Cardiovascular response during upright isometric dead lift in young, older, and elderly healthy men.

Isometric exercises raise the mean arterial blood pressure and impose serious stress on left ventricular function. It may be more dangerous for older than for younger people. The effect of aging on blood pressure response was studied in 75 subjects, 25 normal young men aged 25 +/- 4 years, 25 older men aged 51 +/- 3.2 years, and 25 elderly men aged 68 +/- 4 years, during upright isometric dead lift at 30% maximal voluntary effort for 3 min. The heart rate, systolic blood pressure, and diastolic blood pressure were measured during the 3rd min of dead lift contraction. Tension exerted was significantly lower in the older group (33 +/- 4 kg) and lowest in the elderly group (26.9 +/- 6 kg) compared with the young group (43 +/- 8 kg). All groups showed similar and significant increases in heart rate, systolic and diastolic blood pressure during dead lift (p less than 0.01). These data indicate a similar pattern of blood pressure response to acute pressure overload in young, older, and elderly normal men.

Adult↗
PubMed1988

Left ventricular and hemodynamic responses during upright isometric exercise in normal young and elderly men.

Cardiovascular responses were studied echocardiographically in 10 young (23 +/- 3 years) and 10 elderly (67 +/- 4 years) men, during upright isometric handgrip and deadlift. During handgrip and deadlift both groups showed significant increases in systolic and diastolic blood pressure. Those responses were significantly greater in both groups during deadlift. Heart rate was significantly higher in both groups during deadlift than resting and handgrip values. Oxygen uptake increased progressively and significantly across conditions, and was significantly higher for the younger subjects. Ejection fraction remained unchanged during handgrip in both groups. During deadlift it remained unchanged in the elderly while it increased significantly in the younger. Both groups increased significantly heart volumes from rest to handgrip. During deadlift end systolic volume was significantly lower from resting and handgrip values only in the young group. These data indicate a similar cardiovascular response to acute pressure overload in both groups.

Adult↗
PubMed1988

Aging and the effect of increased after-load on left ventricular contractile state.

Hemodynamic and contractile states were studied echocardiographically in 10 young (28 +/- 3 yr) and 10 elderly (67 +/- 4 yr) male subjects at rest and during upright isometric exercise which involved the hands, hips, legs, and lower back muscle groups (deadlift) at 30% of maximum voluntary contraction for 3 min. During deadlift, both groups showed similar and significant increases in blood pressure and heart rate, compared to the resting values. Ejection fraction at rest did not differ significantly between the two groups. During deadlift, it remained unchanged in the elderly white ejection fraction increased significantly in the younger subjects. No significant changes in left ventricular end-diastolic volume occurred in either group during deadlift. End-systolic volume remained unchanged in the elderly while it decreased significantly in the younger subjects. These data indicate that cardiovascular responses and contractile state in normal young men and normal exercise-trained elderly subjects were augmented during upright sub-maximal isometric deadlift exercise, utilizing large muscle mass. However, left ventricular contractility increased less in the elderly subjects compared to the younger subjects.

Adult↗
PubMed1988

Pattern of psychological fitness as related to pattern of physical fitness among older adults.

The purpose of the present study was to investigate psychological fitness as well as physical fitness among late middle-aged normal men and women before, during, and after a 12-wk. physical activity program. Heart-rate of each subject was measured on a graded treadmill four times, and four psychological measures were taken: self-esteem, body-image, trait-anxiety, and well-being. Improvement of fitness was gradual and significant for both sexes, whereas no effects of time or sex were found on the first three psychological measures. Significant differences in pattern of change between women and men on well-being confirm previous findings that women report more depression and less satisfaction than men and thus are more sensitive to change.

Anxiety↗
PubMed1988

Sialyl transferase in human semen.

The activity of the enzyme sialyl transferase, which is responsible for the transfer of sialic acid, has been examined in the following human seminal plasma: (1) originating from semen with sperm counts above 30 X 10(6)/ml and exhibiting normal values of other andrological parameters; (2) from semen with sperm counts below 25 X 10(6)/ml and with other andrological parameters of poor quality; (3) from semen devoid of sperm. Additionally, enzyme activity was examined in fractionated (split) semen. The activity in plasma based on measurement of radioactivity incorporated into asialofetuin, following incubation in the presence of 14C sialic acid, was expressed as cpm both per volume and per mg protein. There was a tendency for decreased activity with the decrease in sperm density of semen. The difference, however, lacked statistical significance. Enzyme activity in split semen was significantly lower in the first than in the second fraction.

Humans↗
PubMed1988

Endocrinological parameters and cell-mediated immunity postoperation for cryptorchidism.

Andrological and endocrinological parameters and cell-mediated immunity (CMI) were assessed in 25 postpubertal males who had undergone repair of unilateral or bilateral cryptorchidism in childhood or early adolescence. Among 20 patients with unilateral cryptorchidism, approximately 30% had decreased sperm density, whereas among 5 bilaterally affected, 1 was azoospermic and 2 oligozoospermic. In most patients the motility and viability values were normal, although the percentage of morphologically pathological sperm was higher than normal. Levels of testosterone, dihydrotestosterone, LH, and prolactin were within normal ranges in all the patients. Levels of FSH were slightly elevated. These findings may suggest a better fertility prognosis of postcryptorchid oligozoospermic patients than in patients with oligozoospermia of other etiology. CMI toward autologous semen revealed a positive reaction in 80% of the bilateral group and in 45% of the unilateral group. This response might be due to the damage of seminiferous tubules of undescended testis causing unmasking and exposure of antigenic determinants.

Adolescent↗