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Biomedical subjects

C Chryssanthopoulos

Publications and source records attributed to C Chryssanthopoulos.

17 recordsLinked to original sources

Influence of a carbohydrate-electrolyte solution ingested during running on muscle glycogen utilisation in fed humans.

This study investigated whether the ingestion of a carbohydrate-electrolyte solution during running would influence muscle glycogen utilisation in subjects who had consumed a carbohydrate meal 3 hours before exercise. Eight men completed two 60-min treadmill runs at 70% VO(2)max. Before each run they consumed a carbohydrate meal (183 +/- 7 g) 3 hours before exercise and either 1) a carbohydrate-electrolyte solution during the run (46 +/- 1 g) (M+C), or 2) water during the run (M + W). Biopsy samples were obtained from the vastus lateralis muscle at rest and after 60 min of running. Serum insulin concentrations were higher (p < 0.01) in both trials at the start of exercise compared with fasting values, whereas blood glucose concentrations were higher (p < 0.01) after 60 min of running in the M+C trial. Pre-exercise muscle glycogen concentrations were similar in both trials (M+C: 321.9 +/- 27.2 vs M+W: 338.8 +/- 32.8 mmol x kg x dry weight (-1) [dw]; NS). There was no difference in the amount of glycogen used during exercise (M+C: 96.1 +/- 22.1 vs M+W: 77.9 +/- 11.7 mmol x kg x dw (-1); NS). In conclusion, a carbohydrate-electrolyte solution ingested during treadmill running at 70 % VO(2)max does not influence muscle glycogen use during the first hour of exercise when a carbohydrate meal is consumed 3 hours before exercise.

Adult↗

Fatal disseminated intravascular coagulation caused by Mycoplasma pneumoniae.

We report fatal disseminated intravascular coagulation caused by Mycoplasma pneumoniae infection in a 7-year-old white boy. The diagnosis was based on relevant clinical material, absence of any other infections, a 4-fold rise in titer of complement fixation for M. pneumoniae and open lung biopsy findings. We discuss the association between M. pneumoniae and autoimmune mechanism.

Child↗

Pre-exercise carbohydrate meal and endurance running capacity when carbohydrates are ingested during exercise.

This study examined whether combining a pre-exercise carbohydrate meal with the ingestion of a carbohydrate-electrolyte solution during exercise is better in improving endurance running capacity than a carbohydrate-electrolyte solution alone. Ten men completed three treadmill runs at 70% VO2max to exhaustion. They consumed 1.) a carbohydrate meal three hours before exercise and a carbohydrate-electrolyte solution during exercise (M + C), or 2.) a liquid placebo three hours before exercise and the carbohydrate-electrolyte solution during exercise (P + C), or 3.) a placebo three hours before exercise and placebo during exercise (P + P). When the meal was consumed (M + C) serum insulin concentrations were higher at the start of exercise, and carbohydrate oxidation rates were higher during the first 60 min of exercise compared with the values found in the P + C and P + P trials (p < 0.01). Exercise time was longer in the M + C (147.4+/-9.6 min) compared with the P + C (125.3+/-7 min) (p < 0.01). Also, exercise time was longer in M + C and P + C compared with the P + P (115.1+/-7.6 min) (p < 0.01 and p < 0.05 respectively). These results indicate that the combination of a pre-exercise carbohydrate meal and a carbohydrate-electrolyte solution further improves endurance running capacity than the carbohydrate-electrolyte solution alone.

Adult↗

Comparison between carbohydrate feedings before and during exercise on running performance during a 30-km treadmill time trial.

The purpose of this study was to compare the effects of a carbohydrate-electrolyte solution, ingested during exercise, with the effects of a preexercise carbohydrate meal on endurance running performance. Ten endurance-trained males completed two 30-km treadmill runs. In one trial subjects consumed a placebo solution 4 hr before exercise and a carbohydrate-electrolyte solution immediately before exercise and every 5 km (C). In the other trial, subjects consumed a 4-hr preexercise high-carbohydrate meal and water immediately before exercise and every 5 km (M). Performance times were identical for M and C, and there was no difference in the self-selected speeds. Oxygen uptake, heart rates, perceived rate of exertion, and respiratory exchange ratios were also similar. However, blood glucose concentration was higher in C during the first 20 km of the 30-km run. In M, blood glucose concentration was maintained above 4.5 mmol.L-1 throughout exercise. Thus, the two conditions produced the same 30-km treadmill running performance time.

Adult↗

The influence of pre-exercise glucose ingestion on endurance running capacity.

Drinking a concentrated glucose solution less than 1 h before the start of prolonged submaximal exercise has been reported to reduce endurance capacity during cycling. The purpose of this study was to re-examine the influence of pre-exercise ingestion of a concentrated glucose solution on endurance running capacity. Nine recreational runners (five men and four women) ran to exhaustion on a level treadmill, at speeds equivalent to 70% VO2max, on two occasions separated by at least 1 week. The runners ingested either a solution containing 75 g of glucose in 300 ml of water (G trial), or 300 ml of sweetened water (P trial) 30 min before each trial. As a consequence, the blood glucose concentrations were 55% higher at the beginning of the G trial compared with those recorded for the P trial (G trial, mean(s.e.) blood glucose = 6.3(0.7) mmol l-1 versus P trial, mean(s.e.) blood glucose = 4.1(0.3) mmol l-1; P < 0.01). Nevertheless, there were no differences in the running times to exhaustion between the two trials (G trial, mean(s.e.) 133.79(11.0) min versus P trial, mean(s.e.) 121.16(8.1) min). The results of this study show that ingesting a 25% glucose solution 30 min before exercise does not reduce the endurance capacity of recreational runners when the exercise intensity is equivalent to 70% VO2max.

Adult↗

A comparative study on aztreonam, ceftazidime and amikacin in the treatment of complicated urinary tract infections.

In a prospective, randomized trial, aztreonam (1 g intravenously or intramuscularly, twice daily) was compared with ceftazidime (1 g intravenously or intramuscularly, twice daily) and amikacin (500 mg intravenously or intramuscularly, twice daily) in 76 patients aged 24 to 84 years (mean, 59.7 years) with complicated urinary tract infections. Initial pathogens included Escherichia coli (47.5%), Pseudomonas aeruginosa (22.5%), Klebsiella spp. (9%), Proteus spp. (7.5%) and Enterobacter spp (6%). In four patients initial urine cultures yielded more than one organism. All pathogens were sensitive to the three study drugs. Including performance of 4- to 6-week follow-up cultures, eradication of the pathogens occurred in 72% of patients treated with aztreonam, in 74% of those treated with ceftazidime and in 71% treated with amikacin (p greater than 0.05). Clinical success was observed in 84% of patients treated with aztreonam, in 82% of those treated with ceftazidime and in 85% treated with amikacin (p greater than 0.05). All drugs were well tolerated. It is concluded that aztreonam, ceftazidime and amikacin are equally effective and safe for the treatment of complicated urinary tract infections due to susceptible organisms.

Adult↗

The determination of the eosinophil count: comparison of two techniques.

The total eosinophil count obtained by use of the standard hemacytometer is considered by several investigators to be the most reliable method for the determination of the circulating eosinophil levels in the blood because it is believed to be less subject to error than the calculated eosinophil count obtained with Wright stained blood smears from the differential count. We compared the two techniques in outpatients as well as inpatients with and without allergies (total of 514 patients). Our results demonstrate that the eosinophil count by the two methods are similar.

Eosinophils↗

Cardiopulmonary responses of asthmatic children to strenuous exercise. Effect of theophylline.

The purpose of the study were to investigate the cardiopulmonary adaptations of asthmatic children to physical exercise and to evaluate the effects of theophylline. Two groups of children were evaluated. Eight asthmatic children participated in two exercise sessions. Half of the patients received theophylline in predetermined doses during the first session and half prior to the second session. Seventeen normal children matched for age, height, and weight served as controls. Various cardiorespiratory parameters were measured every 2 minutes during exercise and prior to termination of maximal physical effort. The results indicate that children with chronic asthma reach the range of predicted maximal aerobic capacity for their age. Theophylline increases the endurance of asthmatic children to maximal physical efforts without improving the cardiorespiratory parameters that were measured. The use of theophylline in therapeutic doses appears safe under conditions of vigorous exercise.

Adolescent↗

Prognostic criteria in idiopathic pulmonary hemosiderosis in children.

An epidemiologic survey was undertaken of 30 children in whom idiopathic pulmonary hemosiderosis (IPH) had been identified. In determining the prognostic significance of various parameters, a clinical severity score was used. This included the year of onset of IPH, fever, difficulty in breathing, the severity of the anemia, the roentgenographic findings and therapeutic modalities such as transfusions, administration of steroids, antibiotic treatment and splenectomy. Eighteen patients had died. The results of this investigation suggest that: (1) The severity of the disease at its onset does not determine the survival; (2) Females survived longer; (3) Young age of the patients at the onset of IPH seems to carry a less favorable prognosis; (4) The common therapeutic modalities in use have not proved to be beneficial. We believe that some environmental insult to the developing lung in genetically predisposed persons may contribute to a higher morbidity in the younger patients.

Adolescent↗

Epidemiologic observations in idiopathic pulmonary hemosiderosis.

We did an epidemiologic survey of 30 children in whom idiopathic pulmonary hemosiderosis was diagnosed. Eighteen patients had died; 12 patients were still living. The majority of the cases were diagnosed in between 1962 and 1971, mainly in the spring and fall. Eighty percent of the patient lived in villages, whereas only 30% of the total population resided in the same type of rural area. Only one (5%) of the deceased children lived in the city, whereas four (33%) of the living children were city dwellers. The socioeconomic conditions were poor, and in 50% of the cases continuous exposure to highly toxic insecticides was elicited by history and investigation of housing conditions. The incidence of newly diagnosed cases decreased with the improvement of living conditions and the prohibition of the use of certain insecticides. We believe that environmental factors, perhaps insecticides, may cause idiopathic pulmonary hemosiderosis in genetically predisposed persons. An epidemiologic history and genetic investigation should be included in the evaluation of patients with any disease when the cause is obscure.

Child↗

Assessment of acute asthma in the emergency room: evaluation of compliance and combined drug therapy.

Thirty-three chronic asthmatic children and adolescents on predetermined doses of theophylline preparations who arrived at the Emergency Room with an acute episode of wheezing were evaluated to determine compliance, and if therapeutic plasma theophylline levels (PTLs) facilitate the effectiveness of epinephrine. Patients were divided into three groups based on the requirement of one, two, or three doses of epinephrine. In the total group of patient visits, only 25% took the theophylline preparations as prescribed. The poor responders group requiring three injections of epinephrine was characterized by the lowest compliance and the highest unacceptable PTLs. It appears that therapeutic PTLs enhance the response to epinephrine. The evaluation of compliance in case of epinephrine failure is recommended.

Adolescent↗

Listeria meningitis in an immunocompetent child.

We report a case of Listeria monocytogenes meningitis in an apparently healthy 3-year-old boy. This is the first case reported in English literature where adequate evaluation of immune status did not reveal an immunologic defect. The patient is in the age group least affected by an opportunistic organism and has been living in a district known for a high incidence of Listeria in livestock. The epidemiologic implication of this observation is discussed.

Animals↗

An assessment of cardiorespiratory adjustments of asthmatic adults to exercise.

The cardiorespiratory adjustments of asthmatic adults to submaximal and maximal workloads were investigated. Cardiorespiratory variables were measured every 2 min during exercise and at the end of maximal physical effort. Exercise-induced asthma (EIA) occurred in all asthmatic subjects while normal subjects maintained normal spirometry. The results suggest that asthmatic adults have no cardiac reserve or oxygen delivery limitations. They work under less efficient ventilatory conditions at submaximal workloads and have a significantly lower functional work capacity. The high degree of correlation between preexercise maximal midexpiratory flow rate (MMF) and maximum O2 consumption (max Vo2) suggests that the smaller airways contribute significantly to the observed abnormalities. We recommend that evaluation of antiasthmatic medications in exercise-induced asthma should take into consideration their effect upon smaller airways and cardiorespiratory variables.

Adult↗