Biomedical subjects

F Tremollières

Publications and source records attributed to F Tremollières.

5 recordsLinked to original sources

PubMed2006

Understanding the oestrogen action in experimental and clinical atherosclerosis.

Whereas hormone replacement/menopause therapy (HRT) in postmenopausal women increases the coronary artery risk, epidemiological studies (protection in premenopaused women) suggest and experimental studies (prevention of the development of fatty streaks in animals) demonstrate a major atheroprotective action of oestradiol (E2). The understanding of the deleterious and beneficial effects of oestrogens is thus required. The immuno-inflammatory system plays a key role in the development of fatty streak deposit as well as in the rupture of the atherosclerotic plaque. Whereas E2 favours an anti-inflammatory effect in vitro (cultured cells), it rather elicits in vivo a proinflammation at the level of several subpopulations of the immuno-inflammatory system, which could contribute to plaque destabilization. Endothelium is another important target for E2, as it potentiates endothelial NO and prostacyclin production, thus promoting the beneficial effects as vasorelaxation and inhibition of platelet aggregation. Prostacyclin, but not NO, appears to be involved in the atheroprotective effect of E2. E2 also accelerates endothelial regrowth, thus favouring vascular healing. Finally, most of these effects of E2 are mediated by oestrogen receptor alpha, and are independent of oestrogen receptor beta. In summary, a better understanding of the mechanisms of oestrogen action not only on the normal and atheromatous arteries, but also on innate and adaptive immune responses is required and should help to optimize the prevention of cardiovascular disease after menopause. These mouse models should help to screen existing and future selective oestrogen receptor modulators.

Animals↗

PubMed1993

[Postmenopausal bone loss: results of a topographic study by X-ray absorptiometry].

Bone density was determined in six areas (head, arms, thorax, spine, legs, and pelvis) using total body dual photon X-ray absorptiometry. Values were compared with the conventional anterior-posterior lumbar spine (L2-L4) absorptiometry measurement in 20 young females (25 +/- 4.2 years), 41 perimenopausal females (51 +/- 2 years), and 39 postmenopausal females (time since menopause 2.7 +/- 1.9 years). The two older groups were of similar age and physical characteristics. Total body bone mineral density and leg bone mineral density were significantly lower in the perimenopausal women than in the younger women, but this difference was no longer apparent after adjustment for height. Postmenopausal women exhibited diffuse bone loss with a particularly marked decrease in the lumbar spine measurement. Lumbar bone mineral density was significantly correlated with bone mineral densities at other sites; correlation coefficients ranged from r = 0.56 for the head to r = 0.83 for the total skeleton. However, one third of females with a lumbar measurement predictive of a high fracture risk had normal bone mineral density at another site, and vice versa. Our findings show that postmenopausal bone loss affects the entire skeleton and that measurements should be performed at several sites in order to identify high-risk women at cessation of menses.

Absorptiometry, Photon↗

PubMed1992

[Fracture of the upper extremity of the femur in elderly women: respective role of fall and bone demineralization].

Fractures of the proximal femur in elderly individuals are becoming increasingly common in the industrialized world and represent a heavy burden in both socioeconomic and human terms. Two factors are key to the pathophysiology of these fractures: falls and decreased bone strength due to osteoporosis. Femoral and vertebral bone density was measured in 40 elderly women (83 +/- 5 years) who experienced a fall; in those who developed a femoral fracture as a result of the fall, femoral bone density was lower by 12 to 21% (z score: -0.7 to -1.04) than in those with no fracture, after adjustment for age, height and weight. Femoral neck and trochanteric area measurements had the best predictive value (area under the RoC curve: 75% +/- 8%). These was no difference by anatomic fracture type (neck or trochanter). Patients with pertrochanteric fractures had lower vertebral bone densities than controls. These findings, together with recent prospective data, demonstrate that in addition to falls, bone loss (osteoporosis) promotes the occurrence of fractures of the proximal femur in elderly patients. This has important practical implications for the detection and prevention of these fractures.

Accidental Falls↗

PubMed1989

[Non-neoplastic hypercalcemia].

Hypercalcaemia is a frequent situation in clinical practice. An earlier detection is facilitated by routine analysis of serum calcium. The clinical manifestations depend on severity and the rate of onset of hypercalcaemia. Paucisymptomatic and asymptomatic presentations are the most frequent. Causes of hypercalcaemia are numerous and the mechanisms are various. PTH and vit. D play a preponderant part. In first of all iatrogenic cause are eliminated (all vit D preparations, thiazide diuretics, milk-alkali syndrome). Among non neoplastic hypercalcaemia primary hyperparathyroidism is the first diagnosis. Nephrolithiasis and asymptomatic forms are the most frequent presentations actually. The biochemical profile is not always typical. Generally the association of echography and tomodensitometry lead to the topographic diagnosis. Parathyroid surgical exploration is often necessary in difficult cases. Secondary, the other rare causes of hypercalcaemia are studied: sarcoidosis and granulomatosis disease, thyrotoxicosis and dome endocrinopathies, immobilisation hypercalcaemia, familial hypocalciuric, hypercalcaemia. All of this causes of hypercalcaemia are potentially reversible.

Humans↗

PubMed1989

Femoral bone density in young male adults with stress fractures.

Femoral bone mineral density (BMD) was measured by dualphoton absorptiometry in 41 young military recruits who had one or several stress fractures, during their physical training program. These fractures involved the following locations: Femur (neck: n = 10, diaphysis: n = 2), calcaneus (n = 10), tibia (n = 8), fibula (n = 3), metatarsus (n = 8). The stress fracture group generally had a lower bone density than that of a control group, consisting of 48 young military recruits matched for age, height and weight. However, the BMD was significantly lower (-10%) in patients with femoral and calcaneal locations, but it did not differ for other locations. To determine the possible effect of this intense physical activity on bone mineral mass, bone mass was measured again in 35 subjects from the control group at the end of their training. The BMD remained stable or increased in 28 subjects, but decreased significantly (greater than 2%) in 7 subjects, demonstrating the individual variability in the adaptation of bone to this stress. Our results suggest that lowered bone mass could be a factor that encourages the development of stress fractures (femoral and calcaneal) in young subjects submitted to intense physical activity to which they are not accustomed.

Adolescent↗