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Biomedical subjects

J P Martineaud

Publications and source records attributed to J P Martineaud.

At least 19 recordsLinked to original sources
PubMed2005

[Physical performance and thermoregulatory study of subjects with sickle cell trait during a sub-maximal exercise].

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).

Blood Pressure↗
PubMed1997

Evidence of fetal cerebral vasodilatation induced by submaximal maternal dynamic exercise in human pregnancy.

To investigate the relationship between maternal exercise and fetal circulatory responses in humans during the third trimester of pregnancy, changes in uterine, umbilical and fetal cerebral circulations were measured by pulsed-Doppler ultrasound method in 14 healthy volunteer pregnant women before and just after a moderate non-exhaustive exercise. Maternal heart rate increased significantly reaching 80% of the theoretical maximal heart rate (TMHR) while uterine resistance indices did not change. The fetal heart rate and umbilical mean velocity were unchanged while umbilical resistance index decreased slightly (0.58 +/- 0.06 versus 0.62 +/- 0.07, P < 0.05). The fetal internal carotid artery mean velocity increased (23.2 +/- 5.3 versus 20.4 +/- 4.1 cm/s, P < 0.02) and the cerebral resistance index decreased (0.71 +/- 0.11 versus 0.80 +/- 0.10, P < 0.01). We conclude that submaximal maternal exercise at 80% of TMHR does not significantly alter uterine perfusion but involves a slight fetal cerebral vasodilation which could be due to a moderate fetal hemoglobin desaturation.

Adult↗
PubMed1997

[Rectal temperature trends during 24 hours in a hot climate with and without nutritional support].

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.

Adult↗
PubMed1996

[Maximal exercise in spinal cord injured subjects: effects of an antigravity suit].

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.

Abdomen↗
PubMed1996

[Non-invasive test for aortic compliance in man].

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.

Adult↗
PubMed1996

[Method for recovering and concentrating lactic acid during interval training].

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.

Adult↗
PubMed1996

[Effects of water deprivation on rectal and skin temperature and on performance in sustained muscular exercise in a hot climate].

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.

Adult↗
PubMed1995

Influence of posture on middle cerebral artery mean flow velocity in humans.

We determined middle cerebral artery, common carotid artery and temporal superficial artery Doppler derived flow velocities in ten subjects for 10 min after change in posture. Maximal changes were observed after about 3 min. The 10 degrees head-down tilt position increased blood velocities in the common carotid artery by 13% (SD 4)% (P < 0.001), in the middle cerebral artery by 6% (SD 3)% (P < 0.001) and in the superficial temporal artery by 70% (SD 26)% (P < 0.001). In the standing position, there was an 18% (SD 9)% (P < 0.001) decrease in the common carotid blood velocities, with 14% (SD 6)% (P < 0.001) and 53% (SD 23)% (P < 0.001) reductions in the middle cerebral and superficial temporal artery velocities, respectively. At 9 min after the changes in posture, velocities in the middle cerebral artery were at the value of supine rest, whereas the common carotid blood velocity was not completely restored and deviations in the temporal artery velocity persisted. The data would suggest that cerebral blood flow is regulated with some delay and that such regulation is partially reflected in the common artery blood flow, since changes in a branch of the external carotid artery flow velocity remained.

Adult↗
PubMed1995

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.

Administration, Cutaneous↗
PubMed1995

[Growth and ventilatory function in Black children and adolescents].

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.

Adolescent↗
PubMed1993

Relationship between birth weight and umbilical Doppler blood flow velocity waveforms during the third trimester of pregnancy.

OBJECTIVES: The Doppler ultrasound method for recording blood flow velocity waveforms in the fetal umbilical arteries is now widely used as an indicator of fetal well-being. This study was conducted to investigate the impact of umbilical placental resistance level on fetal growth development. METHODS: Maximal flow velocity waveforms were recorded from the umbilical artery in 108 pregnant women including 50 with normal pregnancies, 3 with previous death in utero, and 55 with moderate arterial hypertension corrected by resting only. All the newborn infants had a normal birth weight (BW between the 10th and the 90th percentile for the gestational age at birth). Doppler measurements were performed between 25 to 38 weeks of gestation. The placental resistance index (PRI) derived from blood flow velocity measurements was determined. RESULTS: Data were grouped in two-week intervals according to the age of gestation at Doppler examination. We found an inverse close relationship between BW and PRI which can be described by a linear function of PRI in each interval. BW increased with the decrease in PRI. CONCLUSIONS: Our findings suggest that umbilical placental resistance level determines fetal growth development and birth weight during pregnancies without placental insufficiency.

Birth Weight↗
PubMed1992

Relationship between umbilical and fetal cerebral blood flow velocity waveforms and umbilical venous blood gases.

Nineteen women (mean +/- SD: 28 +/- 5 years) with small fetuses relative to gestational age (mean +/- SD: 32 +/- 2.2 weeks of gestation) were referred to our unit for cordocentesis for the determination of fetal karyotyping. Four of these 19 patients had small-for-gestational-age ultrasound-derived measurements under the third centile for gestational age. Fetal blood gases were measured in the umbilical vein. Umbilical artery and fetal internal carotid artery Doppler examinations were performed 15 min before cordocentesis. The results showed a progressive and proportional increase in umbilical artery resistance index with hypoxia (p < 0.001), hypercapnia (p < 0.025) and acidosis (p < 0.005). Moreover, the results showed a progressive and proportional decrease in fetal internal carotid artery resistance index with hypoxia (p < 0.01), hypercapnia (p < 0.01) and acidosis (p < 0.025). Fetal blood gases are therefore related to umbilical circulatory function and cerebral vasodilatation, suggesting fetal vascular redistribution.

Journal Article↗
PubMed1992

[Effect of water fasting on sport performances in the laboratory].

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.

Adult↗
PubMed1992

[Central temperature and its circadian rhythm in men acclimated to the intertropical zone].

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)

Acclimatization↗
PubMed1991

[Central temperature during chronic exposure to a warm climate].

Rectal temperature was determined at rest in 603 healthy melanoderm african men, in their natural environment. The ambient temperatures were noted between 20 and 38 degrees C on the morning and 23 to 46 degrees C on the afternoon, according to the season and place. On the morning results a significant positive correlation was found between rectal and ambient temperatures. On the afternoon results the situation was more complex: there was a positive correlation only with comfortable and warm ambient temperatures (23-35 degrees C), but not with higher temperatures (36-46 degrees C). Furthermore 28 young sportmen performed a submaximal 30 min exercise test on a cycloergometer at 2 ambient temperatures (comfortable and hot) and the difference in rectal temperature was appreciated between the beginning and the end of each activity. Results showed the same increase in the body temperature during the 2 tests. These results suggest that human thermoregulation remains effective in the subtropical area but can be adapted to the climatic conditions in permanent residents. Then the internal temperature is modified by the increasing ambient temperature, but there is a superior limit of this deep body temperature: when it is overpassed, a strong corrective mechanism is applied.

Adaptation, Physiological↗
PubMed1991

Circadian cycles of central temperature in hot climate in man.

In order to appreciate eventual changes of the circadian rhythm of the body core temperature induced by hot climates, we measured for 24 h periods in summer (June) and in winter (December), in Senegal (latitude, 25 degrees north), the central temperature in two groups of 45 and 58 young soldiers living permanently in the Sahelian area. The subjects were free-running but without any strong activity during the experiments. Rectal temperatures were measured at rest each 3 h, in natural environment: in winter ambient temperature varied from 21 to 25 degrees C and in summer from 28 to 42 degrees C. We observed no change in the shape of the circadian cycle: minimal values were seen at 3 AM and maximal at 3 or 6 PM. But during the hot season, we observed increase of the mesor (36.85 and 37.10 degrees C, in december and june respectively) and of the amplitude of the nycthemeral variation (0.85 and 1.37 degrees C respectively). These results demonstrate a clear adaptation to high ambient temperatures in man, similar to that observed in other mammals.

Adaptation, Physiological↗
PubMed1990

[Changes in the blood flow of the primary carotid and its branches during modifications of the O2 and CO2 composition of alveolar gas].

We measured common carotid blood flow using a range gated Doppler velocimeter, and internal and external blood velocities using a continuous Doppler in 20 lowlanders at sea level, under normal barometric pressure, in 10 subjects in an altitude chamber under a barometric pressure of 462 Torr (61.6 KPa) and then in 5 of them over a 3-weeks period at 3850 m of elevation (475 Torr = 63.3 KPa). The same measurements were also performed in 20 permanent residents at 3850 m. Common carotid blood flow was 15% higher in all subjects exposed to high altitude, due to a lowering in downstream resistances since systemic blood pressure did not change at high altitude. The increase in common carotid blood flow was the result of an immediate increase in internal carotid blood velocities observed in the altitude chamber as well as after the arrival at high altitude, but a few days later those velocities in the internal carotid artery declined to values similar to those observed at sea level. In the same time velocities in external carotid artery rose at high altitude, remained steadily elevated and the result is a permanent increase in common carotid blood flow at altitude. In all subjects we performed the same measurements, during an acute inhalation of gas mixtures to try to quantify the mechanisms controlling the changes in common carotid blood flow while changing gas inhalation. In the limits of the variations in PO2 (60 to 400 Torr) and in PCO2 (30 to 50 Torr) the stimulation by CO2 is twice more efficient than the O2 stimulation on vasomotion.

Adult↗