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Diaw M.,Laboratoire Of Physiologie Et Explorations Fonctionnelles | Diop S.,Laboratoire dHemato immunologie | Soubaiga F.Y.W.,Laboratoire dHemato immunologie | Seck M.,Laboratoire dHemato immunologie | And 7 more authors.
Clinical Hemorheology and Microcirculation | Year: 2015

The aim of this study was to compare blood and plasma viscosities, as well as the hematocrit/blood viscosity ratio (HVR), between trained and sedentary SCT carriers. Thirty African male SCT carriers from the city of Dakar (Senegal) participated in the study: one group composed of 15 trained SCT carriers (TSCTc) and one group composed of 15 sedentary individuals (SSCTc). Blood was sampled in resting condition and blood and plasma viscosities were measured using a cone-plate viscometer. After the determination of hematocrit by microcentrifugation, HVR was determined for each subject. Blood and plasma viscosities, as well as hematocrit, were significantly reduced in TSCTc compared to SSCTc. As a consequence, HRV was greater in TSCTc. These findings provide evidence that SCT carriers should be encouraged to practice regular physical activity to limit the cardiovascular strain usually caused by their blood hyperviscosity. © 2015 - IOS Press and the authors.


Sarr F.B.,Laboratoire Of Physiologie Et Explorations Fonctionnelles | Sarr F.B.,Societes T University Bamako | Sarr M.,Laboratoire Of Physiologie Et Explorations Fonctionnelles | Sarr M.,Societes T University Bamako | And 14 more authors.
Journal of Medicinal Plants Research | Year: 2010

Scientific validation of pharmacological actions of 7 Senegalese plants used in traditional medicine for the treatment of respiratory illness was carried out. Changes in contractility of isolated rat trachea were assessed in organ chambers. Rings were allowed to equilibrate for 60 min before experiments were carried out, during which time the resting tension was adjusted, as required. Rings were first exposed to methanolic plants extracts (10 -2 and 10 -1 mg/ml) or solvent. After a 30 min incubation period, they were contracted with acetylcholine in a cumulative manner (10 -9 to 10 -3M). Extracts from leaves of Guiera senegalensis, Melaleuca leucodendron and Hymenocardia acida elicited a significant dose-dependant inhibition of the contractile agonist, suggesting further investigations on its chemical composition, the underlying mechanisms involved and its potential health value. However, in rings pre-incubated with extracts from Cymbopogon giganteus leaves and Salvadora persica roots, effect of the contractile agonist was not affected. Moreover, a hypereactivity was observed with extracts from Gossypium barbadense leaves and Cassia occidentalis seeds. These results provide evidence that Senegalese herbals may be of interest as valuable source of information for the selection of plants for focussed screening programmes and for therapeutically useful products. © 2010 Academic Journals.


Diaw M.,Laboratoire Of Physiologie Et Explorations Fonctionnelles | Samb A.,Laboratoire Of Physiologie Et Explorations Fonctionnelles | Diop S.,Laboratoire dHematoimmunologie | Sall N.D.,Laboratoire Of Biochimie Et Of Biologie Moleculaire | And 3 more authors.
British Journal of Sports Medicine | Year: 2014

The present study compared the changes in blood viscosity, hydration status, body temperature and heart rate between a group of sickle cell trait (SCT) carriers and a control (Cont) group before and after a soccer game performed in two conditions: one with water offered ad libitum (hydration condition; Hyd) and the other one without water (dehydration condition; Dehyd). Blood viscosity and haematocrit per blood viscosity ratio (HVR; an index of red blood cell oxygen transport effectiveness) were measured before and at the end of each game. Resting blood viscosity was greater in the SCT carriers than in the Cont group. The increase of blood viscosity over baseline at the end of the game in the Cont group was similar in the two conditions. In contrast, the change in blood viscosity occurring in SCT carriers during soccer games was dependant on the experimental condition: (1) in Dehyd condition, blood viscosity rose over baseline; (2) in Hyd condition, blood viscosity decreased below resting level reaching Cont values. The Cont group had higher HVR than SCT carriers at rest. HVR remained unchanged in the Cont group at the end of the games, whatever the experimental condition. Although HVR of SCT carriers decreased below baseline at the end of the game performed in Dehyd condition, it increased over resting level in Hyd condition reaching the values of the Cont group. Our study demonstrated that ad libitum hydration in exercising SCT carriers normalises the blood hyperviscosity.


Diaw M.,Laboratoire Of Physiologie Et Explorations Fonctionnelles | Connes P.,University of the French West Indies and Guiana | Connes P.,University of Paris Pantheon Sorbonne | Samb A.,Laboratoire Of Physiologie Et Explorations Fonctionnelles | And 7 more authors.
Chronobiology International | Year: 2013

The goal of the present study was to test whether fasting during the holy period of Ramadan may disturb blood rheology in sickle cell trait (SCT) carriers more than in a group of subjects with normal hemoglobin. Twenty African male students participated in the study: 10 SCT carriers and 10 subjects with normal hemoglobin (CONT). Biochemical parameters (plasma glucose and lipids levels), hematocrit, blood viscosity, and urine specific gravity were measured in the two groups on the 14th day of the Ramadan period (Ramadan condition) and 6 wks after the end of Ramadan (baseline condition). All the measurements were performed twice for each experimental day to measure intraday variation: 8:00 and 18:00 h. Plasma glucose level and lipid profile were not significantly different between the two groups. Although Ramadan did not affect the lipid profile, the plasma glucose concentration was lower during the Ramadan period compared with the baseline condition in the two groups. Hematocrit and urine specific gravity did not differ between the two groups and was greater in the evening than in the morning, independently of the condition. SCT carriers had higher blood viscosity than the CONT group. However, whereas blood viscosity remained unchanged through the day in the CONT group, whatever the condition, SCT carriers were characterized by a large increase of blood viscosity in the evening during the Ramadan period, indicating higher risk for microcirculatory blood flow impairments. Specific medical recommendations are needed for SCT carriers engaged in religious fasting. © Informa Healthcare USA, Inc.


Tripette J.,National Institute of Health and Nutrition | Hardy-Dessources M.-D.,French Institute of Health and Medical Research | Hardy-Dessources M.-D.,University of the French West Indies and Guiana | Hardy-Dessources M.-D.,University of Paris Pantheon Sorbonne | And 10 more authors.
Clinical Hemorheology and Microcirculation | Year: 2013

This review presents the epidemiological data regarding the exercise-related complication in exercising sickle cell trait carriers, and focuses on the different potential mechanisms that could be involved in these adverse events, such as hemorheological alterations, inflammation, vascular adhesion of circulating blood cells, oxidative stress and impaired nitric oxide metabolism. We also discuss the effects of different modulating factors such as vascular function, environment (hot temperature), hydration status, physical fitness, exercise intensity and genetic factors. © 2013 - IOS Press and the authors. All rights reserved.


PubMed | Laboratoire dhemato immunologie, Hopital Ricou and Laboratoire Of Physiologie Et Explorations Fonctionnelles
Type: Journal Article | Journal: Clinical hemorheology and microcirculation | Year: 2015

The aim of this study was to compare blood and plasma viscosities, as well as the hematocrit/blood viscosity ratio (HVR), between trained and sedentary SCT carriers. Thirty African male SCT carriers from the city of Dakar (Senegal) participated in the study: one group composed of 15 trained SCT carriers (TSCTc) and one group composed of 15 sedentary individuals (SSCTc). Blood was sampled in resting condition and blood and plasma viscosities were measured using a cone-plate viscometer. After the determination of hematocrit by microcentrifugation, HVR was determined for each subject. Blood and plasma viscosities, as well as hematocrit, were significantly reduced in TSCTc compared to SSCTc. As a consequence, HRV was greater in TSCTc. These findings provide evidence that SCT carriers should be encouraged to practice regular physical activity to limit the cardiovascular strain usually caused by their blood hyperviscosity.


PubMed | Laboratoire Of Physiologie Et Explorations Fonctionnelles
Type: Journal Article | Journal: Chronobiology international | Year: 2013

The goal of the present study was to test whether fasting during the holy period of Ramadan may disturb blood rheology in sickle cell trait (SCT) carriers more than in a group of subjects with normal hemoglobin. Twenty African male students participated in the study: 10 SCT carriers and 10 subjects with normal hemoglobin (CONT). Biochemical parameters (plasma glucose and lipids levels), hematocrit, blood viscosity, and urine specific gravity were measured in the two groups on the 14th day of the Ramadan period (Ramadan condition) and 6 wks after the end of Ramadan (baseline condition). All the measurements were performed twice for each experimental day to measure intraday variation: 8:00 and 18:00h. Plasma glucose level and lipid profile were not significantly different between the two groups. Although Ramadan did not affect the lipid profile, the plasma glucose concentration was lower during the Ramadan period compared with the baseline condition in the two groups. Hematocrit and urine specific gravity did not differ between the two groups and was greater in the evening than in the morning, independently of the condition. SCT carriers had higher blood viscosity than the CONT group. However, whereas blood viscosity remained unchanged through the day in the CONT group, whatever the condition, SCT carriers were characterized by a large increase of blood viscosity in the evening during the Ramadan period, indicating higher risk for microcirculatory blood flow impairments. Specific medical recommendations are needed for SCT carriers engaged in religious fasting.


PubMed | Laboratoire Of Physiologie Et Explorations Fonctionnelles
Type: Comparative Study | Journal: British journal of sports medicine | Year: 2014

The present study compared the changes in blood viscosity, hydration status, body temperature and heart rate between a group of sickle cell trait (SCT) carriers and a control (Cont) group before and after a soccer game performed in two conditions: one with water offered ad libitum (hydration condition; Hyd) and the other one without water (dehydration condition; Dehyd). Blood viscosity and haematocrit per blood viscosity ratio (HVR; an index of red blood cell oxygen transport effectiveness) were measured before and at the end of each game. Resting blood viscosity was greater in the SCT carriers than in the Cont group. The increase of blood viscosity over baseline at the end of the game in the Cont group was similar in the two conditions. In contrast, the change in blood viscosity occurring in SCT carriers during soccer games was dependant on the experimental condition: (1) in Dehyd condition, blood viscosity rose over baseline; (2) in Hyd condition, blood viscosity decreased below resting level reaching Cont values. The Cont group had higher HVR than SCT carriers at rest. HVR remained unchanged in the Cont group at the end of the games, whatever the experimental condition. Although HVR of SCT carriers decreased below baseline at the end of the game performed in Dehyd condition, it increased over resting level in Hyd condition reaching the values of the Cont group. Our study demonstrated that ad libitum hydration in exercising SCT carriers normalises the blood hyperviscosity.

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