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Biomedical subjects

H Courtois

Publications and source records attributed to H Courtois.

At least 109 records · Page 6Linked to original sources
PubMed1994

Endothelins. A potential target for pharmacological intervention in diseases of the elderly.

The existence of vasoconstrictive factors originating from the endothelium was confirmed by the description of endothelin, a 21-amino-acid peptide derived from a series of precursors, preproendothelin and a 38-amino-acid big endothelin. Three isoforms of endothelin, endothelin-1, -2 and -3, and 3 receptors (ETA, ETB and ETC) have been described and cloned. The cellular mode of action of endothelin seems to involve the modulation of intracellular calcium (through inositol trisphosphate, diacylglycerol and phospholipase C) and activation of calcium channels. The effects of endothelin are predominantly on the cardiovascular system. Its major effect is vasoconstriction, both systemic and pulmonary, with additional positive chronotropic and inotropic effects on the heart. It has also been implicated in homeostatic regulation of kidney microcirculation, and has powerful mitogenic effects on fibroblasts and smooth muscle cells. Many additional effects have been described on the endocrine system and on other systems. However, the clinical relevance of such effects is uncertain. Increased plasma endothelin levels have been reported in many diseases, but as yet it is not certain whether they are a cause or a consequence of the pathology. Pathologies most probably related to endothelin dysfunction are the vasospastic diseases, especially vasospasm after subarachnoid haemorrhage. Endothelin could be implicated to a lesser measure in diseases typical of the elderly population, such as hypertension or atherosclerosis. Drugs are being developed which act on endothelin metabolism, the most promising of which appear to be the inhibitors of endothelin converting enzyme and endothelin receptor antagonists. Some already existing drugs, such as calcium channel blockers or angiotensin converting enzyme inhibitors, probably act at least in part by interfering with endothelin metabolism or effects.

Aged↗
PubMed1994

[Major hypercalcemia revealing sarcoidosis].

We reported a new case of sarcoidosis disclosed by a symptomatic severe hypercalcemia. Increase of 1,25-dihydroxyvitamin D is secondary to an extrarenal production by alveolar macrophages and sarcoid granuloma. Glucocorticoid administration produces a prompt and persistent decrease in serum and urinary levels of calcium.

Adrenal Cortex Hormones↗
PubMed1994

[Digital necrosis of the arm excluding scleroderma. Retrospective study of 45 cases].

UNLABELLED: The causes of digital necrosis are so diverse that it should be considered not as a surgical but as a medical emergency. In women, digital necrosis first suggests connective tissue disease, and especially Progressive Systemic Sclerosis. In men the causes are more diverse. In this retrospective study, we have tried to identify and categorize the cause of digital necrosis in patients without Progressive Systemic Sclerosis. The medical files of all patients admitted from 1/1/89 to 1/1/93 for digital necrosis were retrospectively reviewed. All patients with Progressive Systemic Sclerosis, either diagnosed at that time or know before, were excluded. All 45 patients in the study had an evaluation of coagulation, vascular risk factors, a cardiac examination and nailfold capillary microscopy, as well as tests for antinuclear antibodies, and cryoglobulinaemia. Other tests were done according to the clinical presentation. Upper limb angiography was done 26 times. RESULTS: there were 10 women and 35 men, mean age 53 years (24-85 years). In the women, the following diagnosis were found: atherosclerosis 1, paraneoplastic syndrome 1, one thrombocythemia, and 6 connective tissue diseases (one dermatopolymyositis, 1 essential cryoglobulinaemia, 2 lupus erythematous and two suspected secondary Raynaud's phenomenon. Twelve men had arterial diseases: 6 thromboangiitis obliterans and 6 obliterans atherosclerosis. Seven times, the cause was local: 5 hammer's syndromes, 2 thoracic outlet syndrome. In the other patients, the causes were extremely diverse: cardiac embolism (4), primary antiphospholipid syndrome (3), polyarteritis nodosa (1), leprosy seroconversion (1), connective tissue disease (3). In 4 patients (3 of whom were smokers) no cause was found.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Hormone replacement therapy in menopause, hemostasis and thromboembolic risk].

The association between oral contraceptives and the risk of thrombosis is now well documented. Conversely, post-menopausal hormonal therapy with doses and types of estrogen vastly different, seems not conducive of venous thromboembolism. Clotting factor abnormalities which have occasionally been observed in patients receiving hormone replacement therapy appear to be relatively unimportant clinically. Since no study is available on the assessment of the risk of thrombosis with these treatment, any hormone replacement therapy should be contraindicated as a principle, in both patients with recurrent venous thrombosis with or without known hemostatic abnormality. This attitude could be modified, if the therapy is justified by osteopenia or clinical complaints, after consulting specialist in gynecology, endocrinology, angiology or rheumatology, informed of the risk arising from such hormonal therapies. In theses particular cases, hormonal therapy with the fewest metabolic effects could be used.

Blood Coagulation Factors↗
PubMed1993

[Remission under treatment of cutaneous xanthomatosis disclosing myeloma: apropos of a case with a three-year course].

We report a case of IgG lambda multiple myeloma with inaugural cutaneous xanthomatosis. A three years follow up showed parallel evolution of xanthomatosis and monoclonal gammapathy during therapy suggesting that the association is not coincidental. A decrease in IDL catabolism could be responsible. The monoclonal gammapathy could react with IDL and disturb the recognition of apolipoprotein E by its hepatic receptor.

Cyclophosphamide↗
PubMed1993

Acquired von Willebrand's syndrome associated with decrease of plasminogen activator and its inhibitor during hypothyroidism.

OBJECTIVES: In a prospective study we searched for von Willebrand's syndrome during hypothyroidism and investigated the effects of treatment with thyroid hormones on plasma concentrations or activities of the factors involved in von Willebrand's disease in addition to tissue plasminogen activator and plasminogen activator inhibitor 1. METHODS: Eleven patients with hypothyroidism were tested. Factor VIII coagulant activity (VIIIc), von Willebrand factor (vWf:Ag), von Willebrand factor activity (vWf:RCo), tissue plasminogen activator antigen (tPA) and plasminogen activator inhibitor activity (PAI) was monitored before and after correction of hypothyroidism by hormone supplementation. RESULTS: Five patients had laboratory evidence of type I von Willebrand's disease. The other six patients had concentrations or activities of the factors involved in von Willebrand's disease within the normal range. In all cases except one, during thyroxin treatment, von Willebrand factors returned to normal if initially low, or increased clearly if initially normal. With the correction of hypothyroidism, an increase of tPA was noted in the eleven patients, associated with a significant increase of PAI. CONCLUSION: Laboratory evidence of von Willebrand's disease is common during hypothyroidism. Study of plasminogen activator and its inhibitor suggest a decrease of von Willebrand factor synthesis during hypothyroidism.

Adult↗
PubMed1993

[Evaluation and utilization patterns of antibiotic therapy. A study in 4 hospital departments].

The use of antibiotics in 480 cases in 4 hospital wards during 1988 was assessed by examination of medical records. Only the first antibiotic therapy administered during the first stay in the ward for each patient was included. Antibiotics were administered to 163 in-patients (37% of hospitalizations) for infections in 113 (26%) cases. Amoxycillin and macrolides were the drugs most frequently used. Sixty-eight percent of the treatments were administered in the absence of microbiological data. Single drug therapy was used in 60% of treatments. Fifty in-patients (11% overall; 41% of patients undergoing surgery) received antibiotics for prophylaxis. The exact indication(s) for the choice of therapy was not given in the medical records of 39% of cases. Treatment started within 48 hours of infection in 15% of the cases. Overall, 93% of the treatments given were indicated, but 53% were inappropriate because they were too expensive, unlikely to be effective or were multiple drug therapy without justification. There are a variety of factors that cause such inappropriate administration of antibiotics.

Adult↗
PubMed1992

A low molecular weight heparin decreases plasma aldosterone in patients with primary hyperaldosteronism.

Four patients with primary hyperaldosteronism were treated with nadroparin 4100 or 6150 antiXa IU daily for 4 days. Plasma and urine sodium and potassium, and plasma aldosterone and renin were monitored before, during and after the study. After four days of treatment, and for the following two days, plasma aldosterone was decreased (by a mean of 49% on Day 6), and urinary Na/K was increased (3.7-fold). The direction of the changes was reversed on Day 8. The study has confirmed the effect of low molecular weight heparin on aldosterone, and makes it unlikely that it is related to inhibition of angiotensin II stimulation in these patients, as renin could not be detected in their plasma.

Aged↗
PubMed1992

[Erythromelalgia in adults. Apropos of 16 cases].

The authors report sixteen consecutive cases of erythromelalgia, an infrequent disease in which local heat, redness, and pain develop in the hands and/or feet in recurrent attacks. The disease was essential in nine patients; in the remaining seven, the cause was a myeloproliferative syndrome (polycythemia vera in 3 cases and thrombocythemia in 1 case) or a drug (bromocriptine, nicardipine, and nifedipine, one case each). Acetylsalicylic acid was effective in only six of the nine essential cases. Intravascular platelet activation and aggregation with plugging of the arterioles has been suggested as the mechanism of erythromelalgia in patients with myeloproliferative disorders. Other, as yet unelucidated pathophysiologic events underlie the juvenile-onset forms, which usually fail to respond to acetylsalicylic acid.

Adult↗
PubMed1992

[Horton's disease with involvement of the arterial trunks of the arms. Pathogenic role of anticardiolipin antibodies? Report of two cases].

Diffuse arterial involvement in temporal arteritis is well known but the intimate mechanisms of vasculopathy is unknown. Recently the presence of anticardiolipin antibodies (aCL) has been recognized in giant cell arteritis. We report two cases of temporal arteritis with diffuse arterial involvement associated with aCL (axillary arteries in the two cases associated with femoral arteries in one). During corticosteroid and anticoagulant therapy, a rapid improvement was noted with regression of upper-limb ischemia. One month later, the aCL were absent. These cases confirm the presence of aCL in giant cell arteritis with diffuse arterial involvement. These antibodies might imply severe vascular damage and could play a role in pathogenesis of the vasculopathy of temporal arteritis. Their presence suggests the necessity of anticoagulant therapy at the beginning of corticosteroid therapy.

Adrenal Cortex Hormones↗
PubMed1991

[Hypocholesterolemia: prevalence, diagnostic and prognostic value. Study in a department of internal medicine].

Serum cholesterol was measured in all patients admitted to the Department of Internal Medicine over one year. 6.2 percent had hypocholesterolaemia defined as total serum cholesterol level below 4 mmol/l. Comparison with non-hypocholesterolaemic patients showed male predominance and indirect arguments for increased morbidity: longer duration of hospital stay, greater number of rehospitalizations, greater number of associated diseases. In over a quarter of the cases, hypocholesterolaemia was associated with malignant disease. These results should entice physicians to caution when finding a low serum cholesterol level: this could be a marker of associated disease, especially malignant.

Adult↗