Gender effect on beta-endorphin response to exercise

PURPOSE: Twelve healthy men (26.4 yr) and women (26.8 yr) were compared at rest and after cycling for 25 min at 60 and 80% VO2max to determine whether gender and menstrual cycle influenced circulating beta-endorphin concentration (BE). METHODS: VO2max was determined on a cycle ergometer, and subjects completed the exercise in a randomized order. Women were tested in both the luteal (L) and follicular (F) phases of their menstrual cycle, which was confirmed by their blood estrogen levels. All tests were conducted in the morning after a 30-min rest (12-h postabsorptive). An indwelling venous catheter placed in a forearm vein enabled blood sampling at rest, 25 min of cycling, and 25 min of recovery. RESULTS: Resting BE was similar for men before both 60 and 80% intensities of exercise, 5.27 +/- 0.43 and 5.30 +/- 0.33 pmol.mL-1, respectively. BE was not significantly changed at 60% VO2max (6.54 +/- 0.33 pmol.mL-1) but significantly increased at 80% VO2max (11.90 +/- 1.98 pmol.mL-1). Women tended to have slightly lower BE during the L compared with F, but this did not reach significance (L = 4.40 +/- 0.22, F = 4.73 +/- 0.30 pmol.mL-1). Cycling at 60% VO2max did not significantly increase BE in the L (5.41 +/- 0.42 pmol.mL-1) nor the F (5.35 +/- 0.40 pmol.mL-1). Cycling at 80% VO2max increased BE to a similar extent in both the L and F phase, respectively (10.44 and 10.96). Although the BE concentrations tended to be slightly lower in women compared with men at 80% VO2max, this did not reach statistical significance. CONCLUSIONS: These data suggest that women cycling at 80% VO2max will have a similar BE response to men independent of their menstrual cycle. BE in women at rest and who exercise at lower exercise intensities may have slightly lower BE levels then men independent of the time of the women's menstrual cycle.     

Perception of physical exertion during dynamic exercise: a tribute to Professor Gunnar A. V. Borg

Previous studies have shown that CD8 beta plays a role in both enhancing CD8 alpha-associated Lck kinase activity and promoting the development of CD8-lineage T cells. To examine the role of this enhancement in the maturation of CD8-lineage cells, we assessed CD8 alpha-associated Lck kinase activity in both T cell hybridomas and thymocytes of mice expressing CD8 beta mutations known to impair CD8 T cell development. Lack of CD8 beta expression or expression of a cytoplasmic domain-deleted CD8 beta resulted in a severalfold reduction in CD8 alpha-associated Lck kinase activity compared with that observed with cells expressing wild-type CD8 beta chain. This analysis indicated a critical role for the cytoplasmic domain of CD8 beta in the regulation of CD8 alpha-associated Lck activity. Decreased CD8 alpha-associated Lck activity observed with the various CD8 beta mutations also correlated with diminished in vivo cellular tyrosine phosphorylation. In addition, analysis of CD8 beta mutant mice (CD8 beta-/- or cytoplasmic domain-deleted CD8 beta transgenic) indicated that the degree of reduction in CD8 alpha-associated Lck activity associated with each mutation correlated with the severity of developmental impairment. These results support the importance of CD8 beta-mediated enhancement of CD8 alpha-associated Lck kinase activity in the differentiation of CD8 single-positive thymocytes.     

Influence of mode and carbohydrate on the cytokine response to heavy exertion

1. This experiment was carried out to evaluate the productive and physiological consequences of a slight but long term food restriction of male broiler chickens from 2 commercial strains. 2. Cobb-500 and Ross chickens were submitted to a 20% food restriction from 8 to 21 d of age. Strain, food programme and their interactive effects were analysed in terms of consequences upon performance, mortality, incidence of sudden death syndrome (SDS) and ascites syndrome (AS), index of right cardiac hypertrophy and plasma concentrations of hormones related to metabolism and growth (T3, T4, T3:T4 ratio, IGF-I and GH). 3. Although some catch-up growth was observed by refeeding previously restricted birds after 22 d of rearing, food restriction decreased (P < or = 0.05) body weight at market age (42 d) irrespective of the strain, but improved (P < or = 0.05) food conversion. 4. The incidence of mortality was not high in non-restricted birds but SDS and AS caused more than 50% of deaths. Hypertrophic cardiac index was observed in chickens of both strains after 4 weeks of age and was higher in ad libitum fed birds. 5. During the period of food restriction, plasma T3 and IGF-I concentrations decreased whereas plasma T4 and GH concentrations increased compared to those of the age-matched ad libitum fed counterparts. During the subsequent ad libitum feeding period, few differences in circulating hormone concentrations were observed, except for the higher mean GH litres in previously food-restricted chickens at 35 d of age. 6. These results indicate that even a non-severe food restriction negatively affects body weight of 42-d-old male broilers but these are benefits with improved food efficiency and diminished mortality from metabolic disturbances. The hormone results suggest that the degree of food restriction applied was not severe because there was a very fast adaptive response with small and transient alterations in T3, T4 and GH plasma concentrations during the period of compensatory growth.     

Immune response to a single bout of exercise in young and elderly subjects

Mandibular advancement splints are successful in managing obstructive sleep apnoea (OSA) in selected subjects. For these to be effective, some improvement in the dimensions of the oropharyngeal airway must occur. Twenty subjects with proven obstructive sleep apnoea were examined using lateral cephalometric radiography and a fluoroscopic technique. Cephalograms were analysed, and assessed for both skeletal and soft tissue abnormalities known to be present in OSA subjects. On the basis of these, a prediction was made as to whether the subject's oropharyngeal airway would increase during mandibular protrusion. From the fluoroscopic sequences, the narrowest antero-posterior dimensions of the post-palatal and post-lingual airways were recorded as the mandible moved from the intercuspal position into maximal protrusion. The changes in airway size were noted and these were compared with the predictions made from the static films. In nine subjects, fluoroscopy indicated that the airway opened well during mandibular protrusion, seven did not improve and in four the changes were minimal. Post-palatally the mean airway increase was 2.6 mm, whilst behind the tongue a mean improvement of 3.1 mm was seen. In all but two instances, the cephalometric prediction agreed exactly with the outcome demonstrated by fluoroscopy. All subjects whose airways clearly increased were correctly identified by the cephalogram alone. Cephalometric features associated with a good airway response to protrusion were a reduced lower facial height, low maxillomandibular planes angle and a high hyoid position, accompanied by a normal anteroposterior relationship of the jaws, relatively normal mandibular body length and soft palate area. The more abnormal the skeletal and soft tissue dimensions, the poorer the prognosis. Thus, whilst a single radiograph could indicate whether a positive mandibular response to protrusion could be expected, where doubt existed, a fluoroscopic analysis could provide a useful adjunct to diagnosis.     

The effect of exogenous iron on levels of adenosinetriphosphate and 2,3-diphosphoglycerate in erythrocytes of men during extreme physical exertion

Nine men were examined during a three-week training requiring much physical effort. They were given nutrient, "LIVEX", enriched with iron. Hematological parameters as well as concentration of erythrocyte ATP and 2,3-DPG were determined before and after the experiment. Hematological parameters were determined using standard methods while Boehringer's test (Germany) was used for determining ATP and 2,3-DPG. The level of reticular cells was statistically higher after the experiment, and the increase in ATP and 2,3-DPG concentration was insignificant. A positive adaptation of energy metabolism after exogenous iron administration during physical effort was discussed.     

?[The effect of physical exercise on glycemia on healthy subjects following administration of glimepiride

OBJECTIVES: Pronounced infiltration of activated macrophages occurs in the peripheral nerves of patients with HIV distal symmetric polyneuropathy (DSPN). Mycobacterium avium complex (MAC) is a common facultative intracellular parasite of the macrophage in advanced HIV disease and may induce macrophage activation. Whether MAC disease is associated with DSPN was examined prospectively. METHODS: One hundred and fifty consecutive patients with HIV infection were assessed for the probability of DSPN. Blood cultures for MAC were performed, independently of neurological assessment, as part of the investigation of unexplained fever, anaemia, weight loss, or, less commonly, diarrhoea. RESULTS: There were 20 patients with possible, 14 with probable, and 22 with definite HIV DSPN. Blood cultures for MAC were performed on 80 patients, of whom 39 were positive and 41 negative. The test for trend, when corrected for CD4 count, disclosed a significant association (P = 0.01). There was no statistically significant association between DSPN and cytomegalovirus (CMV) disease. CONCLUSION: Coinfection of the macrophage by MAC may further activate the HIV infected macrophage thereby accelerating the elaboration of neural toxins or MAC infection of the macrophage itself may lead to the production of neural toxins.     

Relationship between physical exercise and health of the elderly people in a rural community

The significance of life style and regular physical exercise for health of elderly people in a rural community was evaluated by questionnaires. The subjects studied were a group who had been playing gate ball (such as croquet) for more than three years (N = 86) and a group who had not (N = 255). Significantly more males in the group playing gate ball (GB group) than in the group not playing gate ball (n-GB group) reported feeling healthier than three years before. The average overall score for life style which indicates a healthier life style was analyzed. The score for life style of males was significantly lower in the GB group than in the n-GB group. Significantly more males in the GB group did not take snacks or smoke than those in the n-GB group. Regarding regular physical exercise, significantly fewer females in the GB group went for a daily walk than those in the n-GB group. The average score for integrated regular physical exercise was significantly higher in the GB group than in the n-GB group. The scores for regular physical exercise of females in the GB group, even in spite of disability or hypertension, were significantly higher than those in the n-GB group. From this survey it appears that regular physical exercise including gate ball may be beneficial for health of elderly people in a rural community.     

Eccentric exercise augments the cardiovascular response to static exercise

High-force eccentric exercise induces neuromuscular dysfunction and may augment the cardiovascular response to exercise. This investigation sought to determine whether changes in strength and sense of force following high-force eccentric exercise alter heart rate and blood pressure responses during isometric contractions. Subjects (4F,6M) performed 50 maximum resistance eccentric actions with one arm (ECC arm). Contractions at 10% of the ECC arm maximum were held for 7 min on two pre-exercise days. The force output perceived to be the same as 10% of the pre-exercise maximum was determined using a force matching task. This force, 35.6, 27.2, and 21.1% lower on days 1, 3, and 5 post-exercise, was held during isometric contractions on these days, respectively. Despite a lowering of absolute contraction force, heart rate (P < 0.05) and blood pressure (P < 0.001) responses during contractions using the ECC arm were consistently elevated relative to the control arm. However, subjects perceived that they were exerting forces similar to those achieved before eccentric exercise-induced neuromuscular dysfunction. These findings suggest that perceived effort following strength loss induced by mechanically stressful exercise dictates the cardiovascular responses during isometric contractions.     

Does physical exercise at the workplace have any effect on sick leave?

The objective of the study was to ascertain whether physical activity at the workplace reduces the amount of sick leave. The databases Medline and Spri-line, reference lists, and professional expertise were consulted for information on the subject. We included random controlled trials, and controlled trials studying the effect on sick leave of physical activity at the worksite. Four trials were identified, including one carried out in Norway. The small number of trials limits the value of any conclusions and highlights the need for more research. The results of the four trials do not indicate that physical activity at the workplace reduces sick leave.     

Alcohol and its variable effect on human thermoregulatory response to exercise in a warm environment

The aim of this study was to observe the effect of alcohol ingestion on body temperature and local sweat rate during endogenous and exogenous heat stress. After ingesting either alcohol (1.2 g alcohol/kg of body weight) or a placebo drink, 8 subjects exercised for 60 minutes at 45% VO2max in a warm environment (35 degrees C, 45% RH). Varying patterns of response were observed in these subjects, with no consistent effect on the thermoregulatory response seen. The absence of any significant change in skin and body temperature and in sweat rate suggests that the capacity of the body to struggle against exogenous and endogenous heat is not fundamentally altered by alcohol ingestion. The difference in individual response observed in our experiment is in accord with the previous lack of clearcut effect of alcohol reported in the literature.     

The role of adrenocortical response to physical stress on the body's work capacity

Adrenocortical reaction to muscular exertion was inhibited by the intramuscular injection of 125mg of dexamethasone for 2 days of every week of the training. The maximal swimming time in the water (33--34 degrees C) with an additional load of 3 per cent of body weight failed to increase after 5 weeks of training in the animals to which dexamethasome was infected. In these animals the blood corticosterone level increased less after the maximal swimming test than in rats trained without any dexamethasone administration.     

Effect of prosthesis type and size on the hemodynamic response of mitral valve prostheses to exertion

BACKGROUND: Doppler echocardiography is current tool for hemodynamic evaluation of mitral prosthetic heart valves. It's accepted that the area and the gradients by Doppler echocardiography are not influenced at rest by valvular type and valvular size. We evaluated the influence of valvular type, mechanical-biological, and size on exercise hemodynamic of normally-functioning mitral prosthesis. Thirty-seven patients with mitral prosthesis, mean age 56 +/- 10 years, underwent exercise Doppler echocardiography. Peak and mean prosthetic gradient were obtained at rest, during and at maximal exercise with a nonimaging transducer. Mechanical prosthesis were 23 and biological valves 14. Valvular size was less than 26 mm in 7 patients and more than 28 mm in 20 patients. Exercise increased the heart rate from 80 +/- 14 to 143 +/- 22 (p < 0.001), peak gradient from 11.4 +/- 4 to 26.1 +/- 7 mm Hg (p < 0.001) and mean gradient from 4.8 +/- 1 to 13.7 +/- 5 mm Hg (p < 0.001). We found similar peak (11.4 +/- 3 & 11.3 +/- 4) and mean gradient (3.4 +/- 1 & 2.9 +/- 0.7) at rest between mechanical and biological valves; at maximum exercise, peak (26 +/- 7 & 26 +/- 6) and mean gradient (13.9 +/- 6 & 13.2 +/- 4) were also similar. Prosthesis with > 28-mm-size compared with prosthesis < 26-mm-size showed minor peak gradient at second step (21.3 +/- 4 & 26.4 +/- 6, p < 0.05) and at peak exercise (25.4 +/- 7 & 29.8 +/- 8, ns). Hemodynamics on exercise using Doppler echocardiography was not influenced by valvular type (mechanical-biological) in normal mitral prosthesis. However, mitral prosthesis of small size showed worse on hemodynamics exercise than bigger ones.     

The effect of adrenergic agonists on the systemic response to hemorrhage

An in vivo antitumor screening of extracts of Gomphrena martiana indicated positive activity in the petroleum ether extract, and its further bioactivity-directed fractionation resulted in a lipophilic flavonoid fraction. Upon inoculation of various doses of 5,6,7-trisubstituted flavones on two murine tumor lines, Sarcoma 180 and Ehrlich's carcinoma, a decrease of tumor growth was observed. An in vitro KB cultured cell screen indicated cytotoxicity.     

The role of exercise and physical modalities in the treatment of osteoarthritis

Physical rehabilitation is a valuable and often underutilized part of the overall management of small animals with OA. A team consisting of the veterinarian, physical therapist, veterinary technician, and owner is vital to determine and carry out an appropriate therapeutic regimen. To maintain enthusiasm for the program, measurements should be regularly obtained to document progress. In addition, controlled studies should be performed to determine the degree of improvement that may be expected with physical rehabilitation programs.     

The effect of physical training on lipid parameters in the blood

Physical training leads to an improved metabolic capacity of musculature. At the same time through a decreased liberation of catecholamines a reduction of the increased lipolysis develops. The two factors together condition an improved glucose tolerance and a decrease of the reactive insulin secretion. Thus, among others, the synthesis of triglycerides is reduced and an essential factor of risk is favourably influenced for the development of arteriosclerosis.     

Epidemiologic study on physical conditions related to work among the elderly]

The present study was conducted in order to examine the epidemiologic factors related to work capacity among the elderly. As study area, Ogimi Village in Okinawa Prefecture was selected by reason of the long life expectancy of the inhabitants. Medical examination and interview were conducted on 756 inhabitants aged 65 yr and older. Working status was classified into two groups, that is, working group and non-working group. The association between working status and related factors was examined by using multiple logistic regression analysis. The examined factors were as follows: sex, age, history of apoplexy, history of being down, history of falls, history of fracture, chewing ability, pain, exercise habit, hobby, education, number of family members, alcohol, smoking, food intake frequencies and medical indicators (blood pressure, ECG, Quetlet index, skinfold thickness, grip strength, one-leg test with eyes opened, albumin, total cholesterol, hemoglobin and HDL-cholesterol). The results of the analysis revealed that grip strength and one-leg test with eyes opened had a statistically significant correlation with working status (p < 0.01). From the results, maintenance of muscle strength and equilibrium function were found to be the physical conditions related to work among the elderly in the agricultural area.     

Effect of physical exercise in fibromyalgia

The aim of the present study was to review and discuss the literature on exercise-induced pain and physical fitness training in patients with fibromyalgia. Normal muscle metabolism during exercise and no muscle damage after physical activity are reported from recent studies. However, no rise in blood noradrenaline concentration during exercise was found in fibromyalgia patients as compared with a many-folded rise in healthy subjects. Exercise has been used in the treatment of fibromyalgia. Training has shown little benefit as regards pain, but has improved the physical fitness of the patients. Since pain may be exacerbated by physical activity, many patients become physically inactive, with possible development of reduced physical fitness. In the long run, fibromyalgia patients who exercise report less symptoms than sedentary patients do. Thus, exercise should be aimed at preventing physical inactivity and improving the patients' physical fitness.