A Hydrothermal-Sedimentary Context for the Origin of Life.

Critical to the origin of life are the ingredients of life, of course, but also the physical and chemical conditions in which prebiotic chemical reactions can take place. These factors place constraints on the types of Hadean environment in which life could have emerged. Many locations, ranging from hydrothermal vents and pumice rafts, through volcanic-hosted splash pools to continental springs and rivers, have been proposed for the emergence of life on Earth, each with respective advantages and certain disadvantages. However, there is another, hitherto unrecognized environment that, on the Hadean Earth (4.5-4.0 Ga), would have been more important than any other in terms of spatial and temporal scale: the sedimentary layer between oceanic crust and seawater. Using as an example sediments from the 3.5-3.33 Ga Barberton Greenstone Belt, South Africa, analogous at least on a local scale to those of the Hadean eon, we document constant permeation of the porous, carbonaceous, and reactive sedimentary layer by hydrothermal fluids emanating from the crust. This partially UV-protected, subaqueous sedimentary environment, characterized by physical and chemical gradients, represented a widespread system of miniature chemical reactors in which the production and complexification of prebiotic molecules could have led to the origin of life. Key Words: Origin of life-Hadean environment-Mineral surface reactions-Hydrothermal fluids-Archean volcanic sediments. Astrobiology 18, 259-293.

[Virilizing ovarian tumors in the menopausal patient]. / Tumeurs virilisantes de l'ovaire chez la femme ménopausée.

Virilizing ovarian tumors are rare and can occur at any age. In postmenopausal women, they commonly present with signs of masculinization. These tumors should be suspected in any patient with virilization and high testosterone levels (>1ng/mL). Tumor localization is sometimes difficult. These tumors are usually benign; surgical resection is the accepted treatment. Masculinizing consequences of hormonal secretions may be managed by cosmetologic treatments which should not be overlooked.

[Urodynamics and uterine fibroid. Is there a specific parameter?]. / Urodynamique et fibrome utérin. Existe-t-il un paramètre spécifique?

AIM OF STUDY: To search for a urodymamical parameter and/or a VBN parameter (deduced from a modelized analysis of uroflows) which could characterize the voiding dysfunctions due to a uterine fibroid. POPULATION AND METHODS: Thirty women (31-69 years) with a uterine fibroid (exclusion criteria: neurological disease, diabetes mellitus, previous pelvic surgery, grade > I prolapse) underwent one urodynamic session which included the successive tests: free uroflow, urethral profilometry, cystometry and, if possible, a second free uroflow. Twenty-eight patients complained from stress urinary incontinence. Modelized analysis of the flow curves was performed in order to determine the value of two VBN parameters: urethral parameter g and recruitment ratio rr (which quantify the ratio of firing motor neurons during detrusor contraction). RESULTS: The fibroid (known for 23 subjects) was detected during gynaecological examination in seven cases. No significant change of the value of one urodynamical parameter which could be linked to the uterine fibroid rather than the urinary disorder has been found. Some urethral constrictive obstruction exists for 18 patients (g = 0.40 +/- 0.15) but is not meaningful. In the whole population, an effective abdominal pressure is found in 78% of the analyzed micturitions. CONCLUSION: Some urinary disorders result from the presence of a uterine fibroid; they are significantly improved by simple hysterectomy. If urodynamics does not have any specificity, concomitant physical examination allows to detect fibroids with only urinary symptomatology.

[Rendu-Osler-Weber disease and intracranial hemorrhage during pregnancy. A case report]. / Maladie de Rendu-Osler-Weber et hémorragie intra-crânienne pendant la grossesse. A propos d'un cas.

A 24-year-old woman with Rendu-Osler-Weber disease presented an intracranial hematoma during pregnancy. The main localizations of the Rendu-Osler-Weber disease, an inborn disease, are discussed. Neurological complications are rare. Vascular malformations are more fragile during pregnancy. The obstetrical attitude depends on the organ involved and the severity of the complications.

[Anti-infective prophylactic measures in cesareans]. / Mesures prophylactiques anti-infectieuses dans les césariennes.

Septic complications remain important in obstetrical surgery due to the serious threat they pose to life and the sequelae which they may leave. The authors have therefore attempted to identify which of the anti-infectious prophylactic treatments used in cesareans were the most effective. This analysis was based on cases in their unit seen from 1984 to 1988 and on a review of the literature. Of the patients who underwent a cesarean (9.4 percent out of 7,855 deliveries), 2 percent were infected, with and incidence of 0.65 percent serious infections (0.4 percent septicemia). On the basis of the literature, the following risk factors were identified: 1st cesarean, cesarean during labor, rupture of the membranes, surgical problem, anemia, obesity and low socio-economic level. The local fundamental and systemic prophylactic measures taken were special antibiotic prophylaxis in the patients with a risk of infection only. The short protocol, with a single injection of penicillin A or a first generation cephalosporin, after clamping the umbilical was preferable and, according to all the studies, had the advantage of avoiding the selection of resistance.

[Hormone effects of the administration of 50 mg of dehydroepiandrosterone (DHEAS) intravenously in pregnant women (author's transl)]. / Effets hormonaux de l'administration intraveineuse de 50 mg de déhydroépiandrostérone (DHEAS) chez la femme enceinte.

The DHEAS overload test has been regarded by C. Lauritzen as reflecting the conditions of placental function. Some will support and some will oppose that test. We have merely concerned ourselves with conducting an examination into the metabolic outcome of the DHEAS overload. --by defining the way in which oestriolury variations are best express themselves. --by estimating how reliable such variations are in cases where foetal pain and hypotrophy are diagnosed. --by going through a statistical analysis of other hormonal variations.