Changes in psychosocial adjustment of adolescent girls in the lessons of physical education.

OBJECTIVE: The aim of the present study was to establish the changes in psychosocial adjustment of adolescent girls in the modified lessons of physical education. MATERIAL AND METHODS: An experimental design was used in the study. The experimental group included 14- to 15-year-old adolescent girls (n=128), and the control group comprised adolescent girls of the same school and the same age (n=137). The girls of the experimental group participated in modified physical education lessons. Once a month, they had a theory class where they received knowledge on communication disorders among adolescents and ways of preventing them by means of physical activities. In practical classes, the girls of the experimental group had sports games (basketball, volleyball, and football), enhancing physical abilities, and Pilates exercises. For the estimation of the level of adolescents' psychosocial adjustment and its components (self-esteem and domination), an adapted questionnaire developed by Rogers and Dymond was applied. An adapted questionnaire developed by Huebner was administered to measure students' satisfaction with life. RESULTS: The analysis of the data demonstrated that when comparing the psychosocial adjustment of the adolescent girls in the experimental group before and after the experiment, a significant differences in the score of the psychosocial adjustment scale was established (53.81±8.34 vs. 59.41±7.66, P<0.05). After the experiment, high life satisfaction was reported by 42.19% of the girls (P<0.05). CONCLUSIONS: After the educational experiment, the index of the psychosocial adjustment scale in the experimental group improved statistically significantly.

The effect of heating and cooling on time course of voluntary and electrically induced muscle force variation.

UNLABELLED: The aim of this study was to investigate the effect of heating and cooling on time course of voluntary and electrically induced muscle force variation. MATERIAL AND METHODS: Ten volunteers performed 50 maximal voluntary and electrically induced contractions of the knee extensors at an angle of 120 degrees under the control conditions and after passive lower body heating and cooling in the control, heating, and cooling experiments. Peak torque, torque variation, and half-relaxation time were assessed during the exercise. RESULTS: Passive lower body heating increased muscle and core temperatures, while cooling lowered muscle temperature, but did not affect core temperature. We observed significantly lower muscle fatigue during voluntary contraction compared with electrically induced contractions. Body heating (opposite to cooling) increased involuntarily induced muscle force, but caused greater electrically induced muscle fatigue. In the middle of the exercise, the coefficient of correlation for electrically induced muscle torque decreased significantly as compared with the beginning of the exercise, while during maximal voluntary contractions, this relation for torque remained significant until the end of the exercise. CONCLUSION: It was shown that time course of voluntary contraction was more stable than in electrically induced contractions.

[Cooling makes recovery of muscle faster after eccentric-concentric than concentric exercise]. / Pasaldymas labiau pagreitina raumens atsigavima po ekscentrinio-koncentrinio fizinio kruvio nei po koncentrinio.

The aim of the study was to establish the influence of muscle cooling on muscle recovery after concentric and eccentric-concentric exercise. Healthy untrained males (n=40) took part in this study. During the first experiment, subjects performed concentric and during the second--eccentric-concentric exercise. During both experiments, the subjects were divided into the groups. In the first group, the muscles of the lower limbs were cooled down after the physical load, while the muscles of the subjects of the second group were not cooled. The rectal, skin, and muscle temperature was repeatedly measured immediately after physical load and after cooling of the muscle. Before exercise and after 2 min and 4, 8, 24, 48, 72 hours after performing exercise, quadriceps muscle strength, generated by electrical stimulation at frequencies of 20 Hz and 50 Hz, and maximal voluntary contraction force were registered. Serum creatine kinase levels were measured before and 24 hours after exercise. In addition, the subjects subjectively rated their muscle pain on a 10-point scale 24, 48, 72 hours after exercise. The results show that cooling applied to muscles after concentric and eccentric-concentric exercise affected the indicators of muscle damage--the activity of creatine kinase was decreased and muscle strength recovered faster. The cooling effect is greater when it is applied after eccentric-concentric exercise.

[The structure of myocardial nerve plexus of human auricle of the right atrium and its relation to myocardial ischemia, functional status of the heart, and age]. / Zmogaus desiniojo priesirdzio ausytes miokardo nervinio rezginio sasajos su miokardo isemija, sirdies funkcine bukle ir amziumi.

The aim of this study was to investigate and evaluate morphometrically the relationship between changes in the structure of myocardial nerve plexus of the right atrium auricle and myocardial ischemia, parameters reflecting functional status of the heart, and age. A total of 56 females and males aged 20-94 years were investigated. Ischemic heart disease group consisted of 39 persons (their mean age was 63.83+/-15.67 years). The control group comprised 17 persons (the mean age was 60.53+/-9.89 years). Control group consisted of deceased persons who according to the pathologic and anatomic examination were not diagnosed with cardiac pathology leading to heart lesions or overload. Ischemic heart disease group consisted of patients who underwent aorta-coronary artery bypass grafting surgery. In ischemic heart disease group, degree of coronary artery stenosis was evaluated as well as the major indicators reflecting the size of atria and formation of postinfarction scar. After examination, postinfarction scars were found in 18 (46.2%) persons; no scars were found in 21 (53.8%) persons. Neurohistochemical method and video microscopy were employed for the evaluation of quantitative changes in the structure of the myocardial nerve plexus. In ischemic heart disease group, the structures of nerve plexus occupied 5.0+/-1.0% of the area, perimeter was 10 488+/-2134 microm, and number of the structures was 2698+/-981; the same parameters in the control group were 6.0+/-1.4%, 13 008+/-443 microm, and 3469+/-1511, respectively. In persons with postinfarction scar, the number of nerve plexus structures was lower by 9.3%, area by 8.9%, perimeter by 9.7% on average as compared to ischemic heart disease group without a scar. Regression analysis did not reveal any statistically significant correlation between the degree of coronary artery stenosis and quantitative parameters of nerve plexus (P>0.05). Changes in quantitative parameters of nerve plexus were not related to compensatory dilation of the atria--echoscopy parameters of long and short axes. The results showed that the number, area, and perimeter of nerve plexus structures decreases at the same rate both in healthy subjects and patients with ischemic heart disease starting the fifth decade of life.

[Influence of heating and cooling on muscle fatigue and recovery]. / Sildymo ir saldymo itaka raumenu nuovargiui ir atsigavimui.

SUMMARY: The aim of the present study was to establish the influence of muscle heating and cooling on knee flexors and extensors during fatiguing exercise. The participants of the study were 10 healthy males aged 19-23 years. The participants of the study were tested with the isokinetic dynamometer. Control measurements were done before the load as well as 10 min, 30 min, 60 min, and 24 h after the load. The participants performed concentric exercise bouts: 50 knee extensions and flexions at the fixed speed of 180 degrees /s, when femoral muscles before concentric load were of normal temperature, were heated or cooled. Creatine kinase activity in blood serum was estimated 1 h before the load and 24 h after it. Internal temperature of the muscle quadriceps femoris after muscle heating for 45 min increased to 39.5+/-0.2 degrees C (P<0.001) and after muscle cooling for 30 min decreased to 32.5+/-0.3 degrees C (P<0.05) as compared to baseline temperature (before heating - 36.9+/-0.1 degrees C, before cooling - 36.8+/-0.2 degrees C). Creatine kinase activity in blood serum 24 h after concentric load was significantly increased as compared to control values. Passive muscle warming increased muscle contraction force of knee extensors, but did not cause any changes either in the rate of muscle fatigue or in the rate of muscle recovery. Muscle cooling did not decrease muscle contraction force and did not increase muscle fatigue resistance. The findings of this study showed that both, muscle warming and muscle cooling, brought about a decrease in an indirect parameter of muscle damage - the amount of creatine kinase 24 h after concentric load.

Inotropic and lusitropic effects of Perilla frutescens (L.) Britton extract on the rabbit myocardium.

BACKGROUND: Common perilla (Perilla frutescens (L.) Britton) is a plant cultivated in many countries around the world. Although its immunomodulating and antioxidative properties are well known, there is a lack of data about the cardiotropic activity of the plant. The objective of this study was to determine the influence of Perilla frutescens extract on the myocardial contractility in vitro and as a food supplement in vivo. MATERIAL AND METHODS: Rabbits of the experimental group were fed with a supplement of 100 mg/kg of Perilla frutescens extract for 14 days. Rabbits of control group were fed with ordinary food. The maximal mechanical activity of isolated myocardial preparations, obtained from the rabbits of both groups, was tested during the perfusion with Ringer's solution containing 5 microM of adrenaline and 4.5 mM of CaCl2. For the assessment of the direct influence of Perilla frutescens extract on the myocardial contractility in vitro isolated heart preparations were perfused with 0.01, 0.1, and 1.0 mg/ml of Perilla frutescens extract. RESULTS: The maximum force of isometric contraction, maximum velocity of force development, and maximum velocity of relaxation were higher among the atrial and ventricular preparations from the experimental group, as compared with the control group. Perfusion of the myocardial preparations with different concentrations of Perilla frutescens extract revealed slight dose-dependent increase in the parameters of contraction and relaxation. CONCLUSIONS: The consumption of Perilla frutescens extract as a food supplement leads to an increase in the contractility of the rabbit myocardium. Perilla frutescens extract in vitro had a dose-dependent positive inotropic and lusitropic effect on the rabbit myocardium.

[Trace elements, cholesterol and ultrastructural alterations of aorta in hypodynamic stress]. / Mikroelementu, cholesterolio ir aortos intimos strukturiniai pakitimai esant hipodinamijai.

Hypodynamic stress of 48-day duration was provoked by permanent and periodically recurrent intervention (the hypodynamics periodically exchanged to physically activity) for Chinchilla rabbits (weight 2.5-3.0 kg) (n=19) by placing them in metal hutches according to B. V. Fiodorow. Rabbits (n=10) of the control group which had no intervention were kept in vivarium conditions. The concentration of trace elements (Zn, Mn, Cu) in the blood plasma and thoracic aorta was assessed by atomic absorption spectrophotometer (Perkin-Elmer 503, USA). The level of cholesterol was determined by enzymatic analysis. Ultrathin sections of thoracic aorta were examined with electron microscope "Tesla BS-500" (Italy). After 48 days of permanent hypodynamic stress the concentration of Zn and Mn in blood plasma of rabbits was found to be significantly decreased while the cholesterol and Cu level was greater than before the stress. In case of permanent stress significant decrease also was found in the concentration of Cu and Mn in aorta in comparison with that in the case of periodically recurrent stress. The mentioned changes of the trace elements and cholesterol concentration in tissues of rabbits in case of permanent hypodynamic stress were accompanied by ultrastructural alterations in endothelium--desintegration of cells, and winding and fragmentation of internal elastic lamina, accumulation of lipids. In case of periodically recurrent hypodynamic stress of the some duration these changes were less expressed.