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Biomedical subjects

S Bekaert

Publications and source records attributed to S Bekaert.

At least 19 recordsLinked to original sources
PubMed1992

Reversal of cold induced haemoconcentration.

Classically, cold induced plasma volume reduction is explained by an increased diuresis which is generated by an inhibition of antidiuretic hormone release. However, most of the haemoconcentration appears to be reversible during rewarming. This observation weakens the former statement. The aim of this study was to clarify the mechanisms involved in the reversal of the cold induced haemoconcentration. Six young males, resting in a dorsal reclining position, were exposed successively to a thermoneutral environment (30 min), a cold environment (1 degrees C; cold) or thermoneutrality (control) for 120 min, and during a 60-min recovery period in thermoneutral conditions. During cold stress, a reduction of 15% (i.e. 510 ml) of the plasma volume was observed, and osmolality was unchanged. After the 60-min recovery under thermoneutral conditions, plasma volume variation between the Cold and the Control experiments was reduced and reached 3% (i.e. 100 ml). This volume equalled the increased amount of urine production observed during the cold stress experiment. Haemoconcentration cannot be explained by increased urinary water loss (+/- 100 ml) alone. Therefore a transient shift of plasma water from vascular to interstitial spaces, due to an increase of blood pressure, could be involved in the reduction of plasma volume.

Adult↗
PubMed1990

Hematological variations at rest and during maximal and submaximal exercise in a cold (0 degree C) environment.

The affect of negative thermal stress on hematological variables at rest, and during submaximal (sub ex) and maximal exercise (max ex) were observed for young males who volunteered in two experimental sessions, performed in cold (0 degree C) and in normal room temperature (20 degrees C). At rest, hematological variables such as RBC and derivates Hb and Hct were significantly increased (P less than 0.05) during cold stress exposure, while plasma volume decreased. The findings of this study suggest that the major factor inducing hypovolemia during low thermal stress can be imputed to local plasma water-shift mechanisms and especially to a transient shift of plasma water from intra- to extravascular compartments. Rest values for WBC and platelets (Pla) were also slightly increased during cold stress exposure. However this increase can partly be related to hemoconcentration but also to the cold induced hyperventilation activating the lung circulation. Maximal exhaustive exercise induced, in both experimental temperatures, significant (P less than 0.05) increments of RBC, Hb, Hct, and WBC while plasma volume decreased. However, Pla increase was less marked. On the other hand, cold stress raised slightly the observed variations of the different hematological variables. Submaximal exercise induced a similar, though non-significant, pattern for the different hematological variables in both experimental conditions. Observed plasma volume (delta PV%) reduction appears during exercise. However cold stress induced resting plasma volume variations that are transferred at every exercise level. Neither exercise nor cold inducement significantly modified the hematological indices (MCH, MCV, MCHC). In conclusion hematological variables are affected by cold stress exposure, even when subjects perform a physical activity.

Acclimatization↗
PubMed1986

[Endurance bicycle ergometry at 0 degrees C: cardio-respiratory and metabolic course].

The purpose of the present study is to determine the physiological and metabolic variations during and after an exhaustive exercise in different thermal conditions (0 degree C and 20 degrees C). For the eleven experimental subjects, the maximal power output is the same at 0 degrees C and 20 degrees C: 330 +/- 30 W (Mean +/- s). The heart rate is lower (bradycardia) at rest, exhaustion, and recovery. However, these differences are only significant (p less than 0.05) at exhaustion. The oxygen consumption and pulmonary ventilation is higher at 0 degree C in comparison with the measurements at 20 degrees C. The blood lactate concentrations are significantly lower at 0 degree C and we observe the inverse phenomenon for the bicarbonates. The bases excess was significant at 4, 6 and 10th minute of recovery time. These values are higher for the measurements taken at 0 degree C. The results have shown that the cold stress after an exhaustive exercise and during recovery, can induce a physiological and metabolic response unlike of those at 20 degrees C.

Adolescent↗
PubMedDate not supplied

Minority integration in rural healthcare provision: an example of good practice.

To ensure that ethnic minority groups were receiving equality of treatment and service, Horton General Hospital in Banbury formed a multicultural consultation group. The group carried out a five-year plan to standardise health care for ethnic minority communities in Oxfordshire and to educate staff to enhance their cultural sensitivity.

Attitude of Health Personnel↗