[Physical performance and thermoregulatory study of subjects with sickle cell trait during a sub-maximal exercise]. / Etude de la performance physique et de la thermoregulation des sujets porteurs du trait drepanocytaire au cours d'un exercice sous maximal.

The sickle cell trait is a genetic abnormality of red blood cells. It is due to the mutation of a parental gene, which rest Its to the substitution of glutamic acid by valin on beta globin chain of haemoglobin. The possibility for sickle cell trait carriers (SCT) to present any disturbance during predominantly anaerobic and aerobic exercises is unclear. Ten (10) subjects with sickle cell trait and 10 subjects control were studied during exercise test on cycloergometer. They were all students of the National Institute of Popular Education and Sport of Dakar. The mean of environmental temperature was 26 degrees C and humidity was 60 to 80%. After haematological analysis, a submaximal muscular exercise for one hour with 75% of maximal heart rate was done. We have determined heart rate, blood pressure, rectal and skin temperature during exercise. Haematological parameters shown any significant difference between the two groups. No significant difference was found in cardiocirculatory variables during maximal exercise in cycloergometer between control group and sickle cell trait group. The two groups have done submaximal exercise during 1 hour without particular difficulty. We have not observed a significant difference between the two groups in cardiovascular variables, rectal and skin temperature during exercise, and after 3 minutes of rest. These results show that subjects with SCT have physical capacity comparable with control subjects during a sub maximal exercise for 1 hour. We can assure that subjects with SCT in our country may participate in sports competition, as well as normal subjects (HbAA).

Quantitative Doppler blood flow measurement method and in vivo calibration.

Femoral blood flow (FBF) was measured in seven dogs, simultaneously with both an electromagnetic perivascular probe and a transcutaneous range gated Doppler velocimeter. Measurements were made in basal conditions and during intraarterial infusions of noradrenaline (10 to 400 ng . kg-1 . min-1) and isoprenaline (10 to 400 ng . kg-1 . min-1) thus allowing comparisons of ultrasonic (DBF) and electromagnetic (EMBF) blood flow at 91 different blood flow rates ranging from 5 to 300 cm3 . min-1. The linear regression line through the data of ultrasonic and electromagnetic simultaneous measurement was: DBF = 0.8 + 1.016 EMBF +/- 19.0 cm3 . min-1 with a highly significant correlation (r = 0.96, p less than 0.001) but there was a wide scattering about the mean. Errors in DBF were mainly due to positioning of the probe and determination of arterial diameter.

Vasomotor effects of transcutaneous CO2 in stage II peripheral occlusive arterial disease.

Vasomotor effects of skin exposure to carbon dioxide (CO2) have been described in normal subjects. It was of interest, therefore, to determine whether percutaneous CO2 is of therapeutic benefit. In a randomized, double-blind study, 10 patients with lower limb arteriopathy (stage II) were investigated before and after local exposure for twenty minutes to CO2-rich spa gas or to water-vapor-saturated air at the same temperature as that CO2-rich spa gas. Brachial and femoral blood flows, brachial and posterior tibial artery pressures, heart rate, and chest and foot transcutaneous oxygen tensions (tcPO2) were determined. Femoral blood flow, tibial pressure, and foot tcPO2 were significantly increased after exposure of the skin to CO2-rich spa gas. This effect was not accompanied with systemic hemodynamic modifications. Water-vapor-saturated air had no effect. These results suggest that transfer of CO2 across the skin can have beneficial local vasomotor effects in patients with lower limb stage II arteriopathy.

[Non-invasive test for aortic compliance in man]. / Détermination non invasive de la compliance aortique chez l'homme.

We determined the compliance of the aortic "Windkessel" using a non-invasive method. The occlusion of the lower extremities (5 min, 180 mm Hg) elicited reactive hyperemia. An abrupt change in pressure in the occluding cuffs from 180 to 60 mm Hg increased femoral blood flow (measured by pulsed Doppler) and decreased blood pressure (measured by Penaz continuous method). During abrupt decrease in blood pressure, the compliance was calculated as a ratio of the blood volume flowing out of the aorta via the femoral arteries to the decrease of blood pressure. The measurements were made repeatedly in eight healthy men, and in patients with essential hypertension (ten patients with essential hypertension, IInd degree-WHO without treatment and six patients with essential hypertension, IInd degree-WHO treated with slow released verapamil). Compliance in the first group was 1.18 +/- 0.25 ml. mm Hg-1, in the second 0.96 +/- 0.21 ml. mm Hg-1, and in the third group 0.90 +/- 0.11 ml. mm Hg-1. We found a negative correlation between compliance and arterial blood pressure. However the relative large scatter requires repeated measurements.

[Comparison of humeral blood flow during rewarming and recooling of the hand in normal subjects or presenting Raynaud's phenomenon]. / Comparaison des débits sanguins huméraux lors du réchauffement et du refroidissement de la main chez des sujets sains ou présentant un phénomène de Raynaud.

Vascular reactivity to heat and cold was studied in 11 normal subjects without vascular disease and in 23 patients with Raynaud's phenomenon (etiologies: Raynaud's disease, scleroderma, thoracic outlet syndrome). The study of hand and digital temperatures and brachial artery blood flow was performed in ambiant conditions (room temperature 23.5 +/- 1 degree C) and after thermal (cold or warm exposure: 10, 33 and 40 degrees C), mechanical and metabolic modifications (with a wrist tourniquet). In these conditions, blood flow was studied at each temperature, before, during and after 3 minutes ischemia of the hand. Analysis of results showed that vasomotricity possibilities were preserved but that responses were not identical. Patients with primary Raynaud's phenomenon, and even more those with scleroderma as well, had reduced brachial artery blood flow after cooling (10 degrees C). After ischemia, maximal blood flow was also reduced. The microcirculatory disease existing in Raynaud's phenomenon limits the vasodilator capacity of hand vessels, but probably more in tissues with vascular lesions. Vasodilation seems to be limited during exposure to low well as high temperatures, but vasoconstriction capacity is not disturbed.

[Value of functional vascular study during endoluminal angioplasty in patients with obliterative arteriopathy of the legs]. / Intérêt de l'exploration fonctionnelle vasculaire au cours de l'angioplastie endoluminale chez des malades atteints d'artériopathie oblitérante des membres inférieurs.

Femoral blood flow, circulation time and arterial pressure at different levels, at rest and after a supervised treadmill test, were measured in 20 patients with obliterating arteriopathy of the lower limbs treated by percutaneous transluminal angioplasty (PTA), in a context of non-invasive vascular functional investigation. These haemodynamic parameters were measured pre-operatively, on the 1st post-operative day and in some case up to 18 months subsequently. Results on the whole were most satisfactory. In 18 patients, the haemodynamic improvement which was observed on the first post-operative day and confirmed by the clinical course persisted long after PTA; in one patient, with relapse of his haemodynamic signs, repeat angioplasty was carried out; another patient was referred for surgery after further clinical and haemodynamic deterioration. In the diagnosis and haemodynamic monitoring of patients with vascular stenoses, particularly those that have been treated by PTA, non-invasive functional investigation constitutes an important step, which is both effective and simple to carry out.

[Cardiac effects of the flow in the arteriovenous fistula. Study in 66 chronic hemodialysis patients]. / Retentissement cardiaque du débit de la fistule artério-veineuse. Etude chez 66 hémodialysés chroniques.

The effect on the heart of blood flow in the arterio-venous fistula created for haemodialysis was investigated in 66 patients with chronic renal impairment. Blood flow was measured by pulsed Döppler flowmetry. A significant (p less than 0.001) correlation was established between the signs of cardiac insufficiency and the fistula blood flow x fistula duration product. The arterio-venous fistula therefore constitutes a cardiac risk which should be quantified in chronically uraemic patients undergoing repeated haemodialysis.

[Can respiratory tolerance to beta-blockers be predicted?]. / Peut-on prévoir la tolérance respiratoire d'un bêta-bloqueur?

Adverse effects on respiratory function is one of the main problems associated with the use of beta-adrenoceptor antagonists. Studies on this subject in healthy volunteers or patients with obstructive airway disease have been performed by measuring air flow at rest and after exercise, but no attention has been paid to the repercussions on pulmonary circulation. The lack of standardized protocol, the inhomogeneity of groups and the absence of long-term studies preclude objective comparisons between the different beta-adrenoceptor antagonists. On the whole, cardioselective beta-blockers are better tolerated than the others, but any classification based on the respiratory effects to cardiovascular effectiveness ratio is, for the moment, impossible to establish.

[Growth and ventilatory function in Black children and adolescents]. / Croissance et fonction ventilatoire chez l'enfant et l'adolescent noirs.

The authors realized an anthropometric and spirometric study in Senegalese children and adolescents, 119 males and 82 females were selected. They studied the statural and thoracic rate of growth with age and the consequences on lung function growth. The correlations between each spirometric parameter and each anthropometric parameter were calculated in order to determine the best regression equations of pulmonary volumes and flows according to height, weight and other anatomical parameters. Results were compared to literature. The spirometric values were very close to Black American and African ones but the spirometric volumes were about 20% less than Caucasian values. The differences in forced expiratory flows were smaller (10%). The explanation is mainly anatomic: African children have smaller thorax with long limbs as it was shown largely in adults. The rate of somatic and lung growth was not similar to Caucasian children, thus we have proposed our regression equations as spirometric reference values for African children and adolescents.

[Maximal exercise in spinal cord injured subjects: effects of an antigravity suit]. / Exercice physique maximal chez le blesse medullaire: interet de la contention veineuse sous-lesionnelle.

Paraplegics have low aerobic capacity because of the spinal cord injury. Their functional muscle mass is reduced and usually untrained. They have to use upperbody muscles for displacements and daily activities. Sympathic nervous system injury is responsible of vasomotricity disturbances in leg vessels and possible abdominal vessels, proportionally to level injury. If cord injury level is higher than T5, then sympathic cardiac efferences may be damaged. Underbody muscles atrophy and vasomotricity disturbances contribute to phlebostasis. This stasis may decrease venous return, preload and stroke volume (Starling). To maintain appropriate cardiac output, tachycardia is necessary, especially during exercise. Low stroke volume, all the more since it is associated with cardio-acceleration disturbances, may reduce cardiac output reserve, and so constitutes a limiting factor for adaptation to exercise. The aim of this study was to verify if use of an underlesional pressure suit may increase cardiac output reserve because of lower venous stasis, and increase performance. We studied 10 able-bodied and 14 traumatic paraplegic subjects. Able-bodied subjects were 37 +/- 6 years old, wellbeing, not especially trained with upperbody muscles: there were 2 women and 8 men. Paraplegics were 27 +/- 7 years old, wellbeing except paraplegia, five of them practiced sport regularly (athletism or basket for disabled), and the others just daily propelled their wheelchair; there were 5 women and 9 men. For 8 of them, cord injury levels were located below T7, between T1 and T6 for the others. The age disability varied from 6 months to 2 years for 9 of them, it was approximately five years for 4 of them, and 20 years for one. We used a maximal triangular arm crank exercise with an electro-magnetic ergocycle Gauthier frame. After five minutes warm up, it was proceeded in one minute successive stages until maximal oxygen consumption is raised. VO2, VCO2, RER were measured by direct method with an Ergostar analyser every 30 seconds. Heart rate was registered continuously using a cardio-frequence-meter Baumann, and ECG was observed on a Cardiovit electro-cardiograph. Each subject reached maximal exercises on different days: one without any contention, and the other one with abdomen and legs contention using an antigravity suit, inflated to 45-50 mm Hg for legs and 30-40 mm Hg for abdomen. The able-bodied subjects VO2 peak was 24 +/- 5.8 mL min-1 kg-1, without any change on peak VO2 and on cardiac frequency when pressure suit was used. Results were different for paraplegics: peak VO2 was significantly higher (21.5 +/- 6.5 mL min-1 kg-1 without contention and 23.8 +/- 6.3 mL min-1 kg-1 with contention), heart rate was significantly lower at all stages of exercise with antigravity suit and comfort was better during exercise and rest. In our study, contention contributed to increase paraplegics's performances, but responses depend also on spinal cord level, injury age, spasticity. Therefore, testing paraplegics using an antigravity suit may be useful to determine if neurovegetative disturbances significantly modify their cardiac adaptation and capability. If gravity suit is efficient, contention tights might be prescribed, with respect to subject's legs measurements. But, because these tights are very difficult to put on, their efficiency has to be proved before, the motivation of the subject is essential too.

[Central temperature and its circadian rhythm in men acclimated to the intertropical zone]. / La température centrale et son rythme circadien chez l'homme acclimaté à la zone intertropicale.

The central temperature has been measured at rest over 623 black men who are between 18 and 78 years old, and perfectly fit to warm weather in the intertropical areas. The measures have been taken according to two protocols: dealing with the ambiant temperature and the humidity (ambiant temperature varying from 20 degrees C to 42 degrees C, the humidity from 70% to 80%). dealing with the daily cycle: The central temperature was recorded every 3 hours by 24 hours at two different periods in the year, on June (the ambiant temperature varying from 28 degrees C to 42 degrees C and the humidity from 33 to 42%), and on December (the ambiant temperature varying from 21 degrees C to 25 degrees C and the humidity from 70 to 90%). On the one hand, the results showed an influence of the external temperatures on the circadian curves of the central temperature (maximal central temperature taken in the afternoon was 37.2 degrees C in winter and 37.6 degrees C in summer). On the other hand, there's a linear relation between central temperature and ambiant temperature, at least on certain limit and apart from the weather. In spite of two modifications, the thermoregulator system of some designed individual remain efficiency but would work rather than according to the mechanism of the "following" systems.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effects of water deprivation on rectal and skin temperature and on performance in sustained muscular exercise in a hot climate]. / Effets de la privation hydrique sur les températures rectale, cutanée et sur la performance lors de l'exercice musculaire de longue durée en climat chaud.

This study was performed on 16 Senegal young soldiers well trained in physical activities. Experimentation was done in tropical zone in Kedougou (Oriental Senegal) during Scorching period if the year, diurnal-room temperature 34 degrees 9 average. The subject had to ride on a cyclo ergometer to a force corresponding to 75% maximum. The central cutaneous temperature, the provided force, and the cardiac frequence were measured at the end of the muscular's exercise. For each subject that effort's test was once in normal alimentation and the other one after 24 hours' hydric privation. We noticed a significant low of the provided power for having 75% of the maximal cardiac frequence, after half hours (30 mn) of exercise during the hydric restriction compared to normal alimentation. In other respects, a regular increase was observed of the rectal temperature in the course of the activity in any case. That rise was more important to subject in hydric restriction. On the other hand there wasn't any significant difference of the cutaneous temperatures in both situations. The hydric privation has caused a hypohydration in origin of the significant decrease of the performance even if they remain moderated.

[Effect of water fasting on sport performances in the laboratory]. / Effet du jeûne hydrique sur les performances sportives au laboratoire.

15 sport men heart rate and central temperature were measured at rest and at the end of a progressive maximal exercise. Maximum consumption of oxygen (VO2 max) was estimated after the effort. The experience began in the morning from 9 to 11 a.m. and the afternoon from 4 to 6 p.m. In the first time subjects had a normal alimentation and in the second they observed a rigorous fast. The comparison of the results doesn't show difference induced by fast on VO2 max and maximal heart rate. However heart rate at rest and capacity of work decrease during fast and permit to think that a more intensive and long exercise in more strenuous climates than this one should give significative modifications.

[Rectal temperature trends during 24 hours in a hot climate with and without nutritional support]. / Evolution de la température rectale sur 24 heures en climat chaud avec et sans apport nutritionnel.

A group of 22 young subjects staying in rest was studied in the aim to follow the nycthemeral evolution of the rectal temperature, according to two situations: 1) normal feeding, 2) absence of feeding. The use of drinking water was not limited. The experimentation was carried out in tropical area, Kédougou (Eastern Senegal), during a high period of temperature. The mean of day temperature was 38 degrees C and the night temperature, 22 degrees C. The skin and rectal temperature, the arterial pressure and the cardiac frequency were measured every three hours. The results showed a significant difference in the nycthemeral rythm of the rectal temperatures. The nocturnal temperatures were not different in the two conditions. We observed a significant elevation (delta = 0.31 +/- 0.18 degree C) of the diurne post prandial temperature. The results supported that the thermic modification observed during the experience were linked to the feed.

[Method for recovering and concentrating lactic acid during interval training]. / Mode de récupération et concentration d'acide lactique au cours d'un entraînement par intervalles.

Sixteen athletes were divided into 2 equal groups, A and B. Then, they were put through a series of repetitive trial exercises consisting in a sequence of 400 m races run to a sub-maximum speed (75% of maximum speed) and with pauses of a length of time equal to race time, and repeated to exhaustion, i.e., inability to keep up required speed. Recuperation in between races varied: Group A was completely passive, motionless; Group B was still going, albeit rather slowly. The parameters measured included blood concentration of lactic acid at rest and on completion of exercise and overall distance covered. At rest, there was a significant difference of lactatemia between the two groups. During the exercise, the distance run by Group B was longer (by 187.5 m) that that covered by Group A, though the difference was not significant (0.05 < P < 0.10), but his lactatemia was significantly much lower (P < 0.05). On average, the race speed and the time for recuperation which were alternatively measured were just the same for the two groups.