Comparison of the hemodynamic effects of exercise and isoproterenol infusion in patients with pulmonary valvar stenosis

In children with congenital cardiac anomalies, isoproterenol has been used to simulate exercise. To determine if these states are comparable, 28 children with pulmonary valvar stenosis were studied by cardiac catheterization at rest, during supine submaximal exercise, and during isoproterenol infusion. Similar heart rates were obtained during exercise (142/min) and isoproterenol infusion (139/min). Cardiac index, right ventricular systolic pressure and oxygen consumption were measured during each physiologic state. The change in pulmonary valve area from rest was calculated. At similar heart rates, cardiac index was significantly greater with exercise than with isoproterenol and right ventricular systolic pressure was similar in the two states. Thus, the calculated pulmonary valve area was significantly smaller with the pharmacologically induced stress. The study indicates that several of the hemodynamic effects of isoproterenol are not comparable to those produced by exercise in patients with pulmonary valvar stenosis.

Human skeletal muscle glycogen branching enzyme activities with exercise and training

Sixteen healthy male subjects classified as sedentary (8) or active (8), exercised to exhaustion on a bicycle ergometer at a load requiring 70% of their maximal aerobic capacity. Biopsy samples of the vastus lateralis muscle were taken at rest and at the time of fatigue. A 12 week training program increased skeletal muscle glycogen content and branching enzyme activities twofold. The exhaustive submaximal exercise reduced the glycogen levels of the trained group to values similar to the fatigue levels of the non-trained subjects. Skeletal muscle glycogen branching enzyme activities decreased with submaximal exercise to fatigue in all groups. Maximal exercise to fatigue resulted in small increases in the activities of the enzyme. The results of the present study and a previous study (Taylor et al. 1972. Can. J. Physiol. Pharmacol. 50, 411–415) indicate that the activities of the glycogen synthesizing enzymes are highly correlated with the skeletal muscle resting glycogen concentration and the relative fitness of the subjects.

Rat blood and muscle lactate after prolonged exercise

The effects of reserpine upon skeletal muscle and blood lactate levels have been studied in exercised and control rats. The exercise program consisted of 12 weeks of running on a motor-driven treadmill at 26.8 m/min for 1 h per day, 5 days per week. Animals received reserpine doses of 2.5, 5.0, and 12.5 mg/kg (i.p.) 24 h prior to sacrifice. Skeletal muscle and blood lactate levels were measured from animals sacrificed at rest or immediately after a fatiguing run. Tissue lactate levels were elevated only in those animals receiving 2.5 mg/kg of reserpine and exhaustive exercise. Blood lactate levels were unaffected by the drug and by the run to exhaustion. The results indicate that elevated muscle lactate levels are not the sole cause of muscular fatigue.

Exercise hemodynamics of pulmonary valvular stenosis. Study of 64 children

Sixty-four children with pulmonary stenosis were studied by cardiac catheterization both at rest and on exercise. Whereas milder degrees of stenosis were associated with normal right ventricular function, more severe stenosis was associated with fixed stroke index and elevated RVEDP, and suboptimal response of cardiac index. These changes result from altered right ventricular compliance. In several the compliance abnormality was related to myocardial hypertrophy, whereas in four patients it was most likely caused by myocardial fibrosis.

Human skeletal muscle phosphorylase activities with exercise and training

Fifteen healthy male subjects classified as sedentary (7) or active (8), exercised to exhaustion on a bicycle ergometer at a work load requiring 70% of their maximal aerobic capacity. Biopsy samples of the vastus lateral is muscle were taken at rest, at the time of fatigue, and after a 10 min recovery. Training increased [Formula: see text], [Formula: see text], work time to fatigue, skeletal muscle glycogen levels, and phosphorylase a activity (P < 0.01). An exhaustive submaximal exercise reduced the glycogen levels of the trained group to values similar to the fatigue levels of the nontrained subjects: the higher the initial glycogen levels, the longer the subjects were able to exercise before the onset of fatigue. Skeletal muscle phosphorylase a activities decreased with exercise to fatigue in all groups whereas phosphorylase b activities were maintained. Training had no effect on resting phosphorylase b activity.

Assessment of cyclobenzaprine in the treatment of spasticity

The efficacy of cyclobenzaprine 60 mg/day in the treatment of spasticity was assessed in a double-blind crossover trial of two weeks' duration in 15 patients suffering from cerebral or spinal spasticity. Independent clinical and electromyographic methods were used. The effects of cyclobenzaprine did not differ significantly from those of placebo. The administration of a higher dosage, 150 mg/day, to one patient revealed a dose-related response, but the degree of improvement was clinically small. Apart from a skin rash there were no significant untoward effects of therapy.

Human skeletal muscle glycogen synthetase activities with exercise and training

A 5 month training program increased skeletal muscle glycogen synthetase activities of both the 'I' and 'D' forms in human subjects. The level of activity of the enzyme appears to be directly related to the physical fitness level of the subjects tested.

Action of L- -methyldopa-hydrazine on the blood pressure of patients receiving levodopa

The blood pressure and pulse rate have been compared in a 'double blind, cross over' study involving twenty patients with idiopathic Parkinsonism receiving maximum tolerated dosage of levodopa with and without an extracerebral decarboxylase inhibitor, L-alpha-methyldopahydrazine. The supine and erect systolic pressures were significantly higher and the erect pulse rate significantly lower during administration of L-alpha-methyldopahydrazine. The implications of these observations are discussed.

Idiopathic Parkinsonism treated with an extracerebral decarboxylase inhibitor in combination with levodopa

The clinical actions of levodopa in Parkinsonism, given with and without an extracerebral decarboxylase in hibitor, L-alpha-methyldopahydrazine, were compared. Twenty-one patients were investigated in a "double-blind cross-over" study, administering levodopa in maximum tolerated dosage. L-Alpha-methyldopahydrazine failed to augment the overall therapeutic actions of levodopa but it consistently alleviated nausea. It is concluded that L-alpha-methyldopahydrazine will prove useful in the management of some Parkinsonian patients who have difficulty in taking levodopa alone.

Evaluation, Awareness, Practice and Management of Cold Chain at the Primary Health Care Centers in Coastal South India

Introduction: Vaccination is one of the most effective disease prevention strategies and potency of vaccines is dependent on effective management of cold chain at all levels of vaccine handling. The objective was to assess the status of cold chain at the primary health centers and to assess the knowledge and practices of medical officers at these centers regarding cold chain management.Materials and Methods: This cross sectional study was conducted at 70 primary health centers of Dakshina Kannada District of Coastal South India. Cold chain equipment and maintenance process was noted following direct observation on uninformed visits. Data regarding the knowledge and practices of cold chain management was obtained by interviewing the medical officers using structured pretested questionnaire.Results: Ice lined refrigerators and deep freezers were available in 69 (98.6%) and 67(95.8%) of centers. Dial thermometer was present in all the centers. Cold boxes, frozen packs and automated voltage stabilizers were available in 68(97.2%) centers. Improper vaccine storage was observed in 7 (10%) centers. Majority of medical officers had knowledge and correct practices in fields like ideal equipment, OPV administration, vaccine requiring diluents but only 47 (61.8%) medical officers had correct practice of defrosting the deep freezers.Conclusions: The availability of equipment is near universal. Improper vaccine storage practices and poor knowledge in some fields of cold chain management may adversely affect the quality of administered vaccine. Relevant training for those handling the cold chain is recommended.Key words: Cold Chain; India; Primary health center; Temperature monitoring   DOI: http://dx.doi.org/10.3126/jnps.v32i1.5946  J. Nepal Paediatr. Soc. Vol.32(1) 2012 19-22