Modeling subsurface contaminant transport from a former open-pit uranium mine in fractured granites (La Ribière, France): Reducing uncertainties with geophysics.

The long-term management of tailings from former uranium (U) mines requires an in-depth understanding of the hydrogeological processes and water flow paths. In France, most of the legacy U mines are located in fractured crystalline (plutonic) rocks, where the intrinsic subsurface heterogeneity adds to the uncertainties about the former extraction and milling activities and the state of the mine when production was ceased. U ores were mainly processed by sulfuric acid leaching, leading to high-sulfate-content mill tailings now contained in several tailing storage facilities (TSFs). The La Ribière site, located in western central France, is a former open-pit and underground U mine, closed in 1992 and used to store mill tailings. This site is being used as a test case to establish a workflow in order to explain and predict water flow and subsurface contaminant transport. A conceptual model of water flow and sulfate transport, at the scale of the La Ribière watershed, is first developed based on available information and hydrogeochemical monitoring. Recent geophysical investigations allows refining this model. Electrical Resistivity Tomography (ERT) proves to be efficient at localizing the extent of the highly conductive sulfate plume inherited from the U-mill tailings, but also at imaging the weathering profile. Magnetic Resonance Sounding (MRS), despite the limited signal intensity due to the low porosity in crystalline rocks, gives some insight into the porosity values, the depth of the fractured layer and the location of the low-porosity ore-processing muds. Based on this conceptual model, a 3D flow and non-reactive transport model with the METIS code is developed and calibrated. This model allows predicting the evolution of the sulfate plume, but will also be used in future investigations, to build reactive transport models with simplified hydrogeology for U and other reactive contaminants.

Embryonic death of Mek1-deficient mice reveals a role for this kinase in angiogenesis in the labyrinthine region of the placenta.

Mek is a dual-specificity kinase that activates the extracellular-signal-regulated (Erk) mitogen-activated protein (MAP) kinases upon agonist binding to receptors. The Erk MAP kinase cascade is involved in cell-fate determination in many organisms. In mammals, this pathway is proposed to regulate cell growth and differentiation. Genetic studies have shown that although a single mek gene is present in Caenorhabditis elegans, Drosophila and Xenopus, two mek homologs, Mek1 and Mek2, are present in the mammalian cascade. In the present study, we describe a mutant mouse line in which the mek1 gene has been disrupted by insertional mutagenesis. The null mutation was recessive lethal, as the homozygous mutant embryos died at 10.5 days of gestation. Histopathological analyses revealed a reduction in vascularization of the placenta that was due to a marked decrease of vascular endothelial cells in the labyrinthine region. The failure to establish a functional placenta probably explains the death of the mek1-/- embryos. Cell-migration assays indicated that mek1-/- fibroblasts could not be induced to migrate by fibronectin, although the levels of Mek2 protein and Erk activation were normal. Re-expression of Mek1 in the mutant mouse embryonic fibroblasts (MEFs) restored their ability to migrate. Our findings provide genetic evidence that establishes the unique role played by Mek1 in signal transduction. They also suggest that mek1 function is required for normal response to angiogenic signals that might promote vascularization of the labyrinthine region of the placenta.

Complement receptors in human renal glomeruli. Further evidence by immunofluorescence.

A new method is described for demonstrating the presence of glomerular receptors for the third component of complement in human kidney. Frozen sections are incubated together with normal human serum and inulin. Activated C3 is detected by a fluoresceinated anti-C3 antiserum. Glomeruli are labelled by C3-coated inulin particles while there is no labelling in tubules and interstitium. This method is easy and rapid and it allows the exact localization of C3 glomerular receptors.

Cholecystectomy by minilaparotomy without muscle section: a short-stay procedure.

The aim of this prospective study was to assess the results of cholecystectomy performed by an incision characterized by its small size and absence of muscle section, to minimize postoperative discomfort, and shorten hospital stay. Surgical access was via a transverse division of the linea alba extending 1.5-2 cm on the rectus sheath, on both sides, without section of muscle. One hundred and ninety-one patients were operated on. Only 1 (0.5%) peroperative complication (injury of cystic artery) and 4 (2%) benign postoperative complications occurred. The mean postoperative hospital stay was 4.4 +/- 1.7 days (range 2 to 12); for the 90 patients operated on in 1989-1990 it was 3.3 +/- 1.7 days (range 2 to 12). Long-term results were assessed in 113 patients. Only 1 (0.6%) complication occurred, namely migration of a retained common duct stone. Neither incisional hernias nor a need for reoperation occurred. The cosmetic results were assessed by the patients themselves as very good in 95 (84.1%) cases and good in 16 (14.2%) cases.

[Results of the surgical treatment of common bile duct calculi in aged patients]. / Résultats du traitement chirurgical de la lithiase de la voie biliaire principale chez le sujet âgé.

One hundred and two patients (median age: 76 years old; range: 70-91) underwent choledocotomy for biliary lithiasis. Seventy patients had at least one risk factor, 31 had at least 2 factors and 12 had 3 or 4 factors. The indication for surgical treatment was based on evolutive complications in 64 cases; an elective operation was performed in 38 cases. Common bile duct lithiasis was present in only 87 cases but associated lesions made a choledocotomy necessary in every case. A choledocoduodenostomy was performed in 40 cases and a choledocojejunostomy in 3 cases. No postoperative complications occurred in 86 patients. Of 16 patients with complications, 2 were fatal being due to hemiplegia and respiratory failure respectively. Two patients had residual lithiasis. Ninety-four patients were followed on a long-term basis (median follow-up time: 6 years): 34 died from underlying diseases, while 60 are still alive. Treatment failures were, in one case, recurrent lithiasis treated by choledocoduodenostomy and, in the other case, biliary anastomosis stenosis. These results show that the surgical treatment of choledocolithiasis does not necessarily increase the mortality rate in the elderly.

[Effect of proximal gastric vagotomy on the competence of the lower sphincter of the esophagus]. / Effet de la vagotomie fundique sur la compétence du sphincter inférieur de l'oesophage.

The aim of this prospective study was to assess the effects of highly selective vagotomy on lower esophageal sphincter pressure, and to determine whether or not it leads to increased gastroesophageal reflux. Fifteen patients (4 females, 11 males), mean age 43 years (22-63) suffering from duodenal ulcer without any clinical or pH evidence of gastroesophageal reflux were treated by highly selective vagotomy. All of them were studied before and 3-6 months after operation by history taking, pH reflux, manometric, and acid secretory pentagastrin tests. After operation none of the 15 patients had clinical evidence of duodenal ulcer or gastroesophageal reflux. The basal and stimulated acid outputs were decreased after vagotomy; pre and postoperative values were 6.8 +/- 8.9 mmol/h and 0.9 +/- 1.6 mmol/h; 42.2 +/- 10.3 mmol/h and 21.4 +/- 6.4 mmol/h, for BAO and PAO respectively (p less than 0.001). The lower esophageal sphincter pressure was 22.5 +/- 5.6 cm H20 before and 21.1 +/- 4.9 cm H20 after surgery (p less than 0.01). None of the values were lower than normal. There was no significant difference in pH reflux tests; the total duration of pH less than 5 reflux was 1.2 +/- 2.1 p. 100 before, and 1.9 +/- 2.8 p. 100 after vagotomy. These results suggest that an efficient highly selective vagotomy does not impair lower esophageal sphincter efficiency in patients-without gastroesophageal reflux, and that the routine addition of an antireflux procedure is not well advised.

[Malaise and brief losses of consciousness after 65 years of age. Clinical diagnosis and value of complementary studies in 512 patients]. / Malaises et pertes de connaissance brèves après 65 ans. Diagnostic clinique et valeur des explorations complémentaires chez 512 malades.

A retrospective study of the diagnosis and causes of malaise and loss of consciousness has been conducted under the aegis of the French National Society of Internal Medicine. This multicentric and retrospective enquiry, which involved 512 patients, revealed that up to 44% of the malaise had no diagnostic label and that those of known aetiology were frequently due to cardiovascular disorders, such as postural hypotension (11.7%) or arrhythmia (9.5%). The study also demonstrated that the clinical enquiry was more important than complementary examinations which yielded few useful data.

[Sentinel networks. The national public health network. State information]. / Les réseaux sentinelles. Le réseau national de santé publique. L'information de l'Etat.

In the area of health, the information system used by the authorities is based on a series of networks that need to be coordinated. 1. State information: State information as regards health epidemiology was for a long time fragmented. The reasons for this relative ignorance are varied, and are based both on professional and technical factors (preference of physicians for personal exchange rather than for statistical analysis, difficulties in data collection and mathematical processing), and on socio-political factors (the euphoria of years of economic growth). For a long time only the causes of death were appropriately documented (cf. Mme Facy's report). In the last decade, a variety of initiatives has been directed towards all fields, and morbidity is becoming better defined thanks to the ORS (Regional Health Observatories) (cf. M. Garro's speech) and health registers (cf. M. Schaffer). Warning systems are becoming a principal preoccupation for most people in positions of authority, and explain the proliferation of surveillance networks. 2. Sentinel networks: A 'sentinel network' is an interactive surveillance system involving the collection of health data on a routine basis by a group of doctors (general physicians, biologists, etc.). Initially conceived for the surveillance of communicable diseases, they are also used for all diseases requiring early warning and rapid intervention (effects of sudden pollution, surveillance of drugs and poisons, etc.). These sentinel networks have expanded in our countries to complement the compulsory notification systems for infectious diseases, whose 'passive' nature often leads to under-notification (and therefore a non-representative selection) and delayed notification of cases, and whose range of influence does not cover all communicable diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

[Medico-administrative aspects of medically assisted reproduction techniques]. / Aspects médico-administratifs des techniques de procréation médicalement assistée.

Artificial procreation techniques raise many ethical questions. The National Consultative Ethics Committee has pronounced on two occasions on this subject. Apart from ethical considerations, the rapid development of various techniques has required regulations aimed at ensuring the quality of the medical activities performed. The decree of April 8, 1988 concerning medically assisted procreation limits the practice of these activities to hospitals and medical biology laboratories. These regulations do not apply to fundamental questions which fall in the realm of legislation. A bill has already been drafted; if it passes it might provide a few guiding marks on this subject for practitioners and for society as a whole.

[Inguinal herniorrhaphy under local anesthesia with short hospitalization]. / Herniorraphie inguinale sous anesthésie locale avec hospitalisation brève.

This prospective study gives short-term results of 208 inguinal herniorrhaphy performed under local anaesthesia. The median age of the 201 patients (186 M, 15 F) was 57 years (17-87). Local anaesthesia could not be achieved in 1 (0.5%) patient because he was panic-stricken. No serious complications occurred. Peroperative systemic hypotension with bradycardia occurred in 6 (3%) cases. Two (1%) benign postoperative sepsis and 9 (4%) hematoma occurred. The median postoperative hospital stay was 2.8 days (1-10). Twenty seven (13%) patients were discharged on the first postoperative day, 93 (46%) in a period of time less than or equal to 2 days, 147 (73%) in a period less than or equal to 3 days and 184 (91%) in a period less than or equal to 4 days.

[Recurrence of vascular prosthesis infection: treatment by bypass of the lower part of the thoracic aorta using abdominal approach]. / Récidive d'infection de prothèse vasculaire: traitement par pontage à partir de l'aorte thoracique basse abordée par voie abdominale.

Two years before admission a 72-year-old woman received an aortobifemoral bypass graft. When the graft became infected it was replaced by an axillofemoral bypass graft. This also became infected. In another attempt at revascularization, a bypass was installed between the lower part of the thoracic aorta and the two distal parts of the superficial femoral arteries, passing through the obturator foramen. Access to the lower part of the thoracic aorta was made through an abdominal incision, lowering the risk factors associated with such an intervention. At 18-month follow-up, the results were satisfactory; the graft was patent and not infected.

Experimental immune glomerulonephritis induced in the rabbit with streptococcal vaccine.

Heavy C3 glomerular deposits were observed in rabbits injected intravenously with C5 streptococcal vaccine. Immunoglobulin deposits appeared later in a few rabbits. Although some data favour the presence of circulating immune complexes during the course of this glomerulonephritis, no evidence for their initiating role could be demonstrated. Streptococcal components are known to activate the alternative pathway of complement. It is suggested that complexes made of streptococcal components and activated C3 might deposit in glomerular tufts.

The cofactors required by C3 nephritic factor to generate a C3 convertase in vitro.

The mechanisms by which a C3 convertase is generated by C3 nephritic factor (NeF) were investigated using purified NeF, C3, C3b, factor B and factor D of the alternative pathway of complement activation. NeF could generate a C3 convertase with C3 and B in the absence of D, and without cleavage of B. At lower concentrations of NeF the addition of D was required to generate a C3 convertase, and B cleavage now occurred. The generation of both the D-independent and D-dependent C3 convertases with NeF was inhibited by preincubation of the C3 source with C3b inactivator (KAF); isolated C3b was more efficient than the C3 preparations used in generating the D-independent C3 convertase with NeF. These experiments indicate that C3b is required for the formation of both convertases, and that the reaction occurring with apparently native C3 is due to trace amounts of C3b. It is concluded that the C3 convertase generated by NeF in the absence of D is C3bB (NeF), and that generated in the presence of D is the feedback convertase C3bBb. The relevance of these experiments to reactions which may occur in vivo is discussed.

[Lethal forms of connective tissue disease with antiribonucleoprotein antibodies (author's transl)]. / Formes fatales de connectivites avec anticorps anti-ribonucléoprotéines.

Following Sharp's initial findings, the presence of antiribonucleoprotein antibodies in patients with connective tissue disease has long been considered as a sign of favourable prognosis. However, the long-term follow-up of such patients has revealed an increase in the number of severe or lethal cases. The authors report one lethal case and review 22 other published cases. Attention is drawn to the frequency of forms with onset in childhood and of scleroderma-like forms. Most deaths are due to pulmonary lesions, but the heart and kidneys may also be involved. Histological lesions of visceral vasculitis are extremely common.

Hepatodiaphragmatic interposition of the colon--an unusual case of combined anterior and posterior types treated with an original operative technique: report of a case.

Hepatodiaphragmatic interposition of the colon is rare. The posterior type is rarer than the anterior type. We observed a case of combined anterior and posterior types and used an original operative technique with a Prolene mesh to exclude the dead space and prevent recurrence.

Complement studies in BN rats with mercuric chloride-induced immune glomerulonephritis.

Whole complement haemolytic activity (CH50) changes were examined in 71 rats, developing and HgCl2-induced biphasic immune glomerulonephritis. In some rats, serum C4 level was also studied. Whole CH50 level was compared with proteinuria and C3 glomerular deposits. In control rats or in rats injected with low doses of HgCl2, there was no complement decrease. In rats injected with a high dose, after an initial increase (also observed in controls), CH50 level decreased between day 12 and day 20, sometimes dramatically. This decrease, observed during the first phase, was transient, CH50 levels returning to normal before day 30. Serum C4 level varied in accordance with CH50, indicating a classical pathway activation of complement. Fall in CH 50 and proteinuria was correlated: the heavier the proteinuria, the greater the fall in complement (p < 0.01). Whether proteinuria is or is not the consequence of the complement activation, remains to be demonstrated.