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J Launay

Publications and source records attributed to J Launay.

14 recordsLinked to original sources
PubMed1996

[Percutaneous angioplasty of the renal arteries. Long-term results of 222 operations].

OBJECTIVES: Determine the relative role of percutaneous angioplasty of the renal arteries in the treatment of renovascular hypertension. METHODS: From September 1984 to June 1993, we performed 222 angioplasties in 196 patients with renovascular hypertension. There were 186 atheromatous stenoses of the renal arteries and 36 fibromuscular dysplasias. Certain patients had associated moderate renal failure but variations in renal function were not considered in this study. RESULTS: The operation was hemodynamically successful in 180 cases (86%) including 165 cases with residual narrowing less than 30% and 27 between 30 and 50%. In 10 cases (4%), residual stenosis was greater than 50%. Complications at the site of angioplasty occurred in 13 cases (6%) including parietal damage (n = 10) due to hemodynamic pressure (n = 4), thrombosis (n = 2), and arterial rupture (n = 1). Mean follow-up in 131 patients was 2 years. Among these patients, clinical success was obtained in 93 (70%) including 12 complete cures (9%) and 81 improvements (62%). Cure of hypertension was better in patients with dysplasia (30% success rate) than in those with atheroma (5% success rate). Rate of clinical cure was higher for lesions of arterial branches (82%) than in main trunks (69%) or ostium (68%). Among the 38 cases of clinical failure (30%) there were 28 angiographically proven cases of restenosis including 16 which underwent redilatation leading to improvement in 6 (38%). CONCLUSION: These findings confirm the efficacy of percutaneous endoluminal angioplasty for the treatment of renovascular hypertension and suggest that this technique should be used as first line therapy.

Adult↗
PubMed1986

Murine aggression induced by a boar chemosignal: a stimulus presentation dependency.

Male mice were used to assess for the presence of aggression-promoting cues in the boar chemosignal, 5 alpha-androst-16-ene-3-one. The findings of Experiment 1 indicated that this steroid has no aggression-promoting properties when mixed in water. When mixed in urine from castrated males, however, the steroid was shown to induce agonistic behavior in aggressors. Thus, the steroid was shown to possess aggression-promoting cues when associated with urine. Experiment 2 was designed to assess the chemosignal properties of the steroid when mixed in urine or juxtaposed either proximally or distally to urine. It was determined that the steroid needed to be either adjacent to or mixed in urine for chemosignal activity to be evidenced. It was concluded that (1) urine may function as an orienting stimulus for the appropriate detection of the steroid or (2) the conjoint presentation of the steroid and urine provided a qualitatively different stimulus complex than either stimulus presented alone. The findings of both experiments question the species specificity of the boar chemosignal and have methodological implications for studies attempting to isolate a chemocommunicative substance. Appropriate stimulus presentation procedures need to be considered for future research projects.

Aggression↗
PubMed1983

[Platelet aggregation: a tool for clinical investigation and pharmacological study. Methodology].

Platelet aggregation can be measured quantitatively by continuous recording of the transmission of a beam of light across a suspension of platelets in constant agitation in an aggregometer. In routine clinical investigation, the study of platelet aggregation is performed on platelet-rich citrated plasma (PRPc). The blood sample has to be excellent to eliminate all traces of thrombin. The blood is collected in 3.8% sodium dihydrate citrate (1 volume for 9 volumes of blood). It is centrifuged at 190 g for 15 minutes at ambiant temperature. The PRPc obtained can be diluted with platelet-poor plasma (PPP) to adjust the concentration of platelets to 3 X 10(5)/microliters. The PRPc is stored at ambiant temperature in stoppered tubes under CO2 to avoid variations in pH. The maximal delay between the collection of the blood and the end of the study of aggregation is 3 hours. In certain cases, in order to define the platelet lesion and to eliminate the influence of plasma proteins, clotting factors and anti-coagulants, a suspension of washed platelets is used. The blood is collected on acid-citrate-dextrose (ACD) and centrifuged at + 37 degrees C to obtain the PRPc. The platelet deposit obtained by centrifugation of the PRPc is washed twice, according to Mustard's method, in Tyrode-albumin buffer at a concentration of 0.35% at + 37 degrees C. It is re-suspended in the same buffer solution at + 37 degrees C in the presence of apyrase and the platelet concentration is adjusted to 3 X 10(5)/microliters. The aggregation or agglutination of the platelets is induced by several agents: ADP, adrenalin, collagen, thrombin, arachidonic acid, ionophor A 23187, PAF-acether and ristocetin. The quantitative study of the aggregation curves of human platelets allows us to study the physiological and biochemical mechanisms control platelet aggregation, to recognize and classify the hereditary or acquired platelet abnormalities which lead to clinical haemorrhagic or thrombotic manifestations and to study the effect of drugs which inhibit platelet aggregation and to understand their mechanism of action.

Anticoagulants↗
PubMed1976

Hepatosplenography by intravenous injection of a new iodized oily emulsion.

Hepatosplenography with intravenously injected iodized lipid emulsion has been performed in 30 cases and the results reported. The side effects were minor and transient, as the elimination is rapid. The uptake in the liver was satisfactory and permitted tomography both of the liver and the spleen. Small neoplasms and splenic nodules in Hodgkin's disease could be detected and located accurately.

Emulsions↗
PubMedDate not supplied

[Incidence of cholesterol embolisms in 70 atheromatous patients hospitalized for cardiovascular evaluation].

Cholesterol crystal embolization must be considered in all atheromatous patients hospitalized for cardiovascular evaluation. Because this is a difficult and often belated diagnosis, between June 1989 and June 1990 a prospective study was conducted on 70 patients. Clinical monitoring, including examination of the fundus oculi, was performed before, and on the 5th day of cardiovascular investigations. The incidence of systemic emboli (12.8%) detected in this way corresponds to that reported in rare published series. Funduscopy is a simple, rapid and little expensive examination which should improve the investigative procedures and point to the best treatment.

Aged↗