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Biomedical subjects

S Khaled

Publications and source records attributed to S Khaled.

At least 19 recordsLinked to original sources
PubMed1999

Early hemorheologic aspects of overtraining in elite athletes.

A standardized questionnaire has been proposed by the French consensus group on overtraining of the Société Française de Médecine du Sport (SFMS) and allows the calculation of a 'score' that may help to quantify the early clinical symptoms of the overtraining syndrome in sportsmen submitted to a heavy training program. We investigated a possible relationship between this score and blood rheology in 36 male elite sportsmen (national level in football, volleyball and karate; age: 17-33 yr) who underwent a standardized check-up including biological measurements and an exercise-test. The overtraining score ranged between 0 and 21 items and was correlated with blood viscosity (r = 0.413, p < 0.02). This correlation was explained by a correlation of this score with plasma viscosity (r = 0.512, p < 0.01) and hematocrit (r = 0.387, p < 0.05). When subjects with a high score (>6) were compared to subjects with a lower score they appeared to have a higher blood viscosity at native (but not corrected) hematocrit (3.18 +/- 0.01 vs. 2.89 +/- 0.05 mPa.s, p < 0.02), explained by higher values in both plasma viscosity (1.39 +/- 0.02 vs. 1.31 +/- 0.02 mPa.s, p < 0.01) and hematocrit (42.8 +/- 0.45 vs. 41.1 +/- 0.44, p < 0.05). By contrast, there was no difference in RBC deformability and aggregation. Overtrained subjects have also lower levels of zinc (0.72 +/- 0.024 vs. 0.84 +/- 0.023 mg/l, p < 0.01), ferritin (55.1 +/- 7.3 vs. 92.3 +/- 9.4 ng/ml), and IGF-binding protein 3 (3.4 +/- 0.22 vs. 4.52 +/- 0.4 ng/ml). Neither zinc nor ferritin status were likely to explain the rheologic alterations since disturbances in zinc or iron are rather associated with abnormalities in erythrocyte deformability or aggregability. Therefore, the early signs of overtraining in elite sportsmen are associated with a hemorheologic pattern that suggests some degree of reversal of the 'autohemodilution' associated with fitness in athletes.

Adult↗
PubMed1998

Increased blood viscosity in iron-depleted elite athletes.

Since iron deficiency is associated with abnormal erythrocyte rheology, we investigated relationships between plasma ferritin and blood rheology in 36 male elite sportsmen (age: 22.38+/-0.9 years). On the whole, ferritin was negatively correlated with blood viscosity (r = -0.36, p < 0.05). When 23 subjects with low ferritin levels suggesting mild iron deficiency were compared with 13 matched sportsmen with normal ferritin levels, iron-deficient sportsmen were shown to have a higher blood viscosity at 1000 s(-l) (3.17+/-0.09 vs. 2.85+/-0.06 mPas, p < 0.05), explained by a higher plasma viscosity (1.38+/-0.02 vs. 1.31+/-0.02 mPa s, p < 0.05), while hematocrit and RBC rigidity index Tk were similar in the two groups. RBC aggregability index M (4.59+/-0.58 vs. 2.95+/-0.43 mPas, p < 0.05) and M1 (8.46+/-0.58 vs. 6.07+/-0.55, p < 0.01) were higher in iron-deficient subjects. Serum zinc was lower in iron-deficient sportsmen (0.73+/-0.02 vs. 0.83+/-0.02 mg/l, p < 0.01), but the score of early signs of overtraining was higher in this group (10.84+/-1.61 vs. 4.08+/-1.11, p < 0.01). These data suggest that mild iron deficiency as commonly seen in athletes, before anemia occurs, is associated with an increase in plasma viscosity and RBC aggregation, together with an increased subjective feeling of exercise overload.

Adult↗
PubMed1998

The triphasic effects of exercise on blood rheology: which relevance to physiology and pathophysiology?

The life-extending effects of regular exercise are related to a decrease in both coronary and peripheral vascular morbidity, associated with some improvements in cardiovascular risk factors. A possible link between the beneficial metabolic and hemodynamic effects of exercise could be blood rheology, which is markedly affected by exercise. We propose here a description of the hemorheological effects of exercise as a triphasic phenomenon. Short-term effects of exercise are an increase in blood viscosity resulting from both fluid shifts and alterations of erythrocyte rheologic properties (rigidity and aggregability). Increased blood lactate, stress, and acute phase play a role in this process. Middle-term effects of regular exercise are a reversal of these acute effects with an increase in blood fluidity, explained by plasma volume expansion (autohemodilution) that lowers both plasma viscosity and hematocrit. Long-term effects further improve blood fluidity, parallel with the classical training-induced hormonal and metabolic alterations. While body composition, blood lipid pattern, and fibrinogen improve (thus decreasing plasma viscosity), erythrocyte metabolic and rheologic properties are modified, with a reduction in aggregability and rigidity. On the whole, these improvements reflect a reversal of the so-called "insulin-resistance syndrome" induced by a sedentary lifestyle. Since impaired blood rheology has been demonstrated to be at risk for vascular diseases, the hemorheologic effects of exercise can be hypothesized to be a mechanism (or at least a marker) of risk reversal. This latter point requires further investigation. The physiological meaning of the triphasic pattern of exercise-induced alterations of blood rheology is uncompletely understood, but increased blood fluidity may improve several steps of oxygen transfer to muscle, as clearly demonstrated in hypoxic conditions. Increasing evidence emerges from the literature, that blood fluidity is a physiological determinant of fitness.

Exercise↗
PubMed1990

[A therapeutic trial of a combination of 3 essential drugs in a short course of chemotherapy in tuberculosis. Results 6 months after the end of treatment].

250 patients suffering from pulmonary tuberculosis who were smear positive received a chemotherapy regime for 6 months combining Rifampicin and Isoniazid every day with a daily supplement of Pyrazinamide for the first 8 weeks. The three drugs given in the initial phase of treatment were administered either separately or in combined preparations according to the 2 controlled randomised groups. During the maintenance phase the drugs were given in a combined form in fixed proportions in the 2 groups. 6 months after the end of treatment the bacteriological results were similar in the 2 groups in the 144 cases which were analysed. Amongst 137 cases with bacilli which were initially sensitive to Isoniazid (68 cases with separate medicines at the beginning and 69 with combined drugs) there was no failure at 6 months, nor any relapse during the course of the first period of surveillance. Amongst 7 cases with bacilli which were originally resistant to Isoniazid (4 and 3 respectively), there were 2 failures at 6 months one in each group with acquired resistance to Rifampicin observed at the time of the failure. There was no difference in the therapeutic results observed whatever the presentation of drugs used during the initial phase of treatment.

Drug Combinations↗
PubMed1989

[Therapeutic trial of a combination of isoniazid, rifampicin and pyrazinamide in the first 2 months of treatment of pulmonary tuberculosis].

250 patients suffering from smear positive pulmonary tuberculosis who had never been treated before, received a six-month regimen combining isoniazid and rifampicin every day with a supplement of pyrazinamide for the first eight weeks of treatment. The three drugs given during the initial phase of therapy were administered in two different forms: either as separate tablets or in a form combining all three drugs in fixed proportions (each tablet contained 50 mg of isoniazid, 120 mg of rifampicin and 300 mg of pyrazinamide). The patients were randomised into two groups of 125 receiving one or other combination of medications with the dose adapted for their weight. An analysis of the results at the end of the second month of treatment was carried out on 240 cases who could be analysed for tolerance and acceptability and in 193 cases who were analysed for the efficacy of therapy as judged by negative cultures. The treatment results were excellent in both groups, as was patient acceptability. The level of side effects was significantly lower in the group receiving combined medication (p less than 0.02). Both groups gave a similar proportion of negative cultures at the end of two months. The combined medicaments studied are thus well tolerated and at least as effective as individual drugs. They may thus replace them.

Adolescent↗
PubMed1989

Anti-leishmanial antibodies during natural infection of Psammomys obesus and Meriones shawi (Rodentia, Gerbillinae) by Leishmania major.

Sera from 77 rodents (Psammomys obesus: 64; Meriones (M.) shawi: 10; M. libycus: 3) trapped in a focus of zoonotic cutaneous leishmaniasis (ZCL) (Leishmania (L.) major) were examined for the presence of anti-leishmanial antibodies by the indirect fluorscence antibody technique (IFAT) (L. major antigens) using homologous antiglobulins and/or anti-Rattus conjugates. Sera from 21 animals were positive with titres that ranged from 1: 20 up to 1: 640. The investigation revealed that a good correlation existed between the occurrence of antileishmanial antibodies in the sera and amastigotes in the rodents' ears. The data also suggest the suitability of the IFAT as an epidemiological tool to estimate rates of infection by L. major in Psammomys obesus and Meriones Spp. in foci of ZCL.

Animals↗
PubMed1985

[Epidemiology of hydatid cyst in Tunisia. Value of mass serologic surveys of hydatid cyst].

Three serological surveys were conducted for mass detection of hydatidosis in Tunisia. Microtubes were used for sampling of serum and plasma eluates were tested by the E. L. I. S. A. technique. More than 2,500 persons, mainly originating from rural areas (Souks, primary schools, military recruits, village dispensaries) were studied. 2/3 of individuals examined simultaneously underwent abdominal echotomography the findings of which were compared to those of serology. The whole data were discussed with respect to current status of hydatidosis in Tunisia.

Echinococcosis↗