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Biomedical subjects

A Schaeffer

Publications and source records attributed to A Schaeffer.

At least 73 records · Page 4Linked to original sources
PubMed1990

Organic arsenic-induced Guillain-Barré-like syndrome due to melarsoprol: a clinical, electrophysiological, and pathological study.

A young woman suffering from sleeping sickness was treated with melarsoprol. Thirty-eight days after the first administration of this organo-arsenic compound, myalgias, distal paresthesias and rapidly progressive weakness developed in all four limbs. Electrophysiological studies were misleading for Guillain-Barré syndrome. Neuropathological data included massive distal wallerian degeneration in peripheral nerves and abnormalities in dorsal ganglia and spinal cord where vacuolation of anterior horn cells and axonal neurofilamentous masses were observed. Very high concentrations of arsenic were found in the spinal cord, contrasting with undetectable levels in peripheral nerves. Our findings are consistent with an arsenic neuronopathy manifested by initial proximal demyelination and delayed distal axonal damage. Renal and hepatic dysfunctions, which were implicated in the toxic arsenic accumulation, should be systematically detected before administration of melarsoprol. The diagnosis of Guillain-Barré syndrome must be considered with caution in patients treated with this compound.

Adult↗
PubMed1989

[Sheathing periostitis and Crohn's disease].

Periostitis is an uncommon extradigestive lesion in Crohn's disease. We report two cases. The first patient was a young man presenting with moderate digestive symptoms, intense bone pain and high fever simulating osteomyelitis. The second case was more similar to those previously reported in the literature as the periostal new bone formation occurred in a woman already treated for Crohn's disease. These observations show the importance for clinicians to be aware of the association of periostitis and Crohn's disease, especially as corticotherapy is susceptible to improve bone pain as well as digestive symptoms.

Adult↗
PubMed1989

[Comparative studies of cyclic 11, 12 erythromycin carbonate (davercin) and erythromycin a levels in lung tissue, serum and bronchial secretions].

A comparison of serum, pulmonary tissue and bronchial secretory levels of erythromycin and cyclic--11,12 carbonate of erythromycin (Davercin--Polfa) was carried out in 55 patients with lung cancer. All patients received erythromycin and Davercin 80 hours prior surgery, during which a small fragment of pulmonary tissue was removed for further evaluation. Concentration of both antibiotics was determined microbiologically. Better penetration of Davercin to the pulmonary tissue was found, as well as higher tissue concentration. The study demonstrates the advantage of Davercin over erythromycin in treating bacterial infections of the respiratory system.

Body Fluids↗
PubMed1988

[Value of a fraction of low molecular weight heparin, enoxaparine, in patients at high risk of hemorrhage and thrombosis].

Treatment of patients with both thromboembolic manifestations and acute bleeding episodes is poorly defined. The use of low molecular weight heparin fractions has been shown to provide prophylactic antithrombotic activity in humans, with the possibility of fewer hemorrhagic complications because of their low anticoagulant activity and weaker action on platelets. An open trial was carried out in 50 patients. 47 of whom had a recent history of thromboembolic accident (34 venous thrombosis, including 13 with pulmonary embolism, 9 systemic arterial episodes, 4 cardiac emboli) and 3 who required prophylaxis. Conventional heparin therapy was contraindicated in all patients: 30 because of major digestive or muscle hemorrhage and 20 with high hemorrhagic risk (neurosurgery, deep thrombocytopenia). Enoxaparine (Laboratoire Pharmuka, Gennevilliers) was administered as 1 mg/kg/24 hours as 2 divided injections with adjustment to maintain an anti-Xa activity of 0.1 to 0.4 IU/ml. Antithrombotic efficacy as function of type of pathology was rated excellent in all patients, while tolerance, evaluated similarly by tests chosen as a function of type of hemorrhage, was good: one patient had moderate bleeding after accidental overdose and 4 patients minor bleeding. Enoxaparine by subcutaneous injection could represent a new therapeutic approach by improving the efficacy/risk ratio in this type of patients.

Blood Coagulation Tests↗
PubMed1988

[Plasma exchange in polyradiculoneuritis in AIDS].

Plasma exchange was used in three cases of peripheral neuropathy of polyradiculoneuritis type in patients with AIDS. The neurologic lesion in the first case was due to a cytomegalovirus, and plasma exchange appeared to provide additional benefits (to antiviral treatment) during the first attack of polyradiculoneuritis. The peripheral neurologic disorders were probably related to the HIV itself in the other two cases, and plasma exchange was carried out only briefly because of the seriousness of the situation, which was unaffected. Although plasma exchange is possible, if particular technical precautions are taken, in patients with AIDS, the present series is too small for valid scientific evaluation.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Binding and processing of fibrinogen by rabbit hepatocytes.

We describe a specific fibrinogen-hepatocyte interaction. Rabbit 125I-labeled fibrinogen (125I-FGN) was incubated at 4 degrees C with suspensions of rabbit hepatocytes (approximately 1 X 10(6) cells/ml). Bound ligand was separated from free by centrifugation of cells through oil and quantitated by gamma-scintillation counting. Specific binding, determined by subtraction of nonspecific binding in the presence of 8 mM EDTA from total binding in the presence of 2 mM CaCl2, required 3 h to plateau and represented approximately 70% of total binding. Specific binding was calcium-dependent and was negligible in buffer containing 2 mM MgCl2. Half-maximal saturation occurred at approximately 30 nM 125I-FGN with approximately 480,000 molecules/cell at saturation. Dilution experiments revealed comparable affinities for labeled and unlabeled fibrinogen. Total binding was irreversible as determined by addition of excess unlabeled fibrinogen or EDTA. Specific binding of 25 nM 125I-FGN was inhibited, in a concentration-dependent fashion, by unlabeled fibrinogen or fibrinogen fragment D95 (Mr = 95,000), but not by fibrinogen fragment E or Arg-Gly-Asp-containing peptides. Unlabeled fibrinogen (3.1 microM) completely abolished specific binding, whereas greater than 80% inhibition was achieved with 10 microM fragment D95. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and autoradiography of 125I-FGN bound in the presence of calcium demonstrated disappearance of A alpha chains with formation of products of Mr greater than 200,000; EDTA or unlabeled fibrinogen prevented fibrinogen processing. These data describe a unique fibrinogen-hepatocyte interaction which differs considerably from the platelet-fibrinogen interaction, especially with regard to the processing of the fibrinogen molecule.

Animals↗
PubMed1986

Catabolic properties of aglycofibrinogen synthesized by tunicamycin-treated human hepatoma (HepG2) cells and rabbit hepatocytes.

Human hepatoma cell (HepG2) or rabbit hepatocyte monolayers were incubated with [35S]methionine in presence or absence of tunicamycin, a potent inhibitor of asparagine-linked glycosylation. The 35S-labeled nonglycosylated and control fibrinogens purified from the media were used to evaluate the influence of the oligosaccharide on the catabolic properties of this glycoprotein. Plasmin, pronase, cathepsin D or cathepsin B each degraded the nonglycosylated and control fibrinogens similarly, as evidenced by the release of trichloroacetic acid-soluble radioactivity and by SDS-polyacrylamide gel electrophoresis and autoradiography of plasmic digests. Nonglycosylated and control fibrin clots also showed no differences in susceptibility to plasmic digestion. The two forms of fibrinogen demonstrated the same plasma half-life in rabbits. These data indicate that the oligosaccharide does not influence the proteolytic stability or the in vivo plasma survival of fibrinogen, and suggest that other biochemical determinants may influence the catabolic properties of this molecule.

Animals↗
PubMed1986

Allopurinol hypersensitivity syndrome as a cause of hepatic fibrin-ring granulomas.

Hepatic fibrin-ring granulomas were found in a 35-yr-old man who developed fever, myalgias, rash, eosinophilia, and abnormal liver function tests 4 wk after the beginning of allopurinol treatment. All clinical and biochemical abnormalities spontaneously resolved within 6 wk after cessation of therapy. There was no evidence for Q fever or Hodgkin's disease, which are the recognized causes of hepatic fibrin-ring granulomas. It is suggested that allopurinol hypersensitivity might be an additional cause of these peculiar granulomas.

Adult↗
PubMed1986

Blood-borne pulmonary infection with Nocardia asteroides in a heroin addict.

Nocardia asteroides frequently causes primary lung infection with possible hematogenous dissemination to various organs, especially in patients with altered immune responses. The preponderance of pulmonary infections suggests an airborne route of contamination. We report a case of pulmonary nocardiosis in a previously healthy intravenous heroin abuser. The clinical and epidemiologic data strongly suggest a paraphernalia blood-borne infection in this patient, a mode of contamination which has not been previously reported.

Adolescent↗
PubMed1986

Orthostatic hypotension from a cerebellar gangliocytoma (Lhermitte-Duclos disease). Case report.

A 49-year-old woman presented with orthostatic hypotension. Vertebral angiography and ventriculography revealed a tumor of the left cerebellar hemisphere. Ventriculoperitoneal shunting was followed by complete disappearance of the orthostatic hypotension. The tumor was subsequently removed and microscopic study showed Lhermitte-Duclos disease. Orthostatic hypotension has been rarely reported in association with tumors of the posterior fossa except for those tumors destroying the medullary centers and interrupting the baroreceptor reflex arc. This case is of interest because the tumor was restricted to the cerebellum. The authors have found no previous case in which orthostatic hypotension was a presenting symptom of Lhermitte-Duclos disease.

Cerebellar Neoplasms↗
PubMed1986

[Acute ischemia of the extremities and drug addiction].

It is not unusual to find ischemia of limbs in drug addicts and two new cases are reported, together with a literature review, allowing analysis of physiopathologic mechanisms and therapeutic modalities. The first case was a 20 year old man who presented with sensory-motor ischemia of the right hand after injection of heroin into the radial artery. Arteriography showed partial occlusion of the deep palmar arch and all collateral arteries of fingers. Regression of ischemia followed administration of thrombolytics, heparin and vasodilators, arteriography showing restoration of palmar arch and digital arteries flow apart from that of the 4th finger. The latter developed distal necrosis which required, in spite of thoracic sympathectomy, amputation of the 3rd phalanx. Histology of amputation piece showed presence of intra-arterial foreign bodies. The second case was a 30 year old man who presented with an acute sensory-motor ischemia of left calf and foot after injection of heroin into the retromalleolar groove. Arteriography showed absence of opacification of vascular axes in the middle third of leg and an atheromatous plaque in left main iliac artery. Heparin therapy plus lumbar sympathectomy resulted in reheating of the foot, but ischemia recurred one month later. A repeat arteriography with oblique images demonstrated that the plaque in the main iliac artery was larger than it appeared in frontal images and that an embolus had developed in the deep femoral artery. Final treatment in this patient involved an inter-femoral saphenous vein bypass and amputation of 4th toe. Histology of amputation piece showed only a banal arterial thrombosis without foreign body.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Protease susceptibility of zinc- and apo-carboxypeptidase A.

Proteases in preparations of carboxypeptidase A progressively inactivate solutions of the apoenzyme but not the metal-containing enzyme. Free amino acids generated by proteolysis interfere with spectral studies after reconstituting the apoenzyme with cobalt. Purification by affinity chromatography eliminates this effect. Affinity-purified apoenzyme is susceptible to digestion with chymotrypsin but the metalloenzyme is not.

Apoenzymes↗