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Biomedical subjects

S Weber

Publications and source records attributed to S Weber.

At least 325 records · Page 18Linked to original sources
PubMed1983

[Secondary neoplastic subacute constrictive pericarditis disclosing a bronchial cancer].

In a fifty-three-year-old man, constrictive metastatic carcinoma of the pericardium revealed a bronchial carcinoma. The subacute course was rapidly progressive. Only partial pericardiectomy could be performed. Death occurred 16 days after the peripheral signs of compression of the heart became patent. In such cases early diagnosis, before signs of constrictive pericarditis become obvious, is very important.

Adenocarcinoma↗
PubMed1983

Contrast bone cement.

The effects of adding 1.0 cc of aqueous methylene blue dye as a visual contrast agent to a standard 40 g pack of acrylic bone cement are determined. These cements are evaluated: Simplex P (Radiopaque), Zimmer Bone Cement, and Zimmer LVC Bone Cement. Seven tests were performed. Leach out is less than 2.0% and was undetectable after day 8. Biocompatibility using a rabbit model shows contrast and white cement to be equivalent. Tension, compression, and 3- and 4-point bending strengths are not significantly altered except for a slight increase in 4-point bending strength for contrast Zimmer (regular) bone cement. Dough, set, and working times are decreased by 30-150 s. The ASTM F451 intrusion standards are met for all three contrast cements. Viscosity increases more rapidly for contrast cement, but remains sufficiently low (less than 100 N-s/m2) early after mixing to allow good penetration into bone. Ease of removal and visualization of contrast cement are shown by revision of cemented femoral total hip components in synthetic and cadaver femurs and by debriding cement particles from a soft tissue background coated with blood. The use of contrast bone cement appears to be both safe and efficacious for use in initial and revision total joint replacements. Because of the decreased working times, its use is recommended only by experienced surgeons.

Animals↗
PubMed1983

Reticulocytopenia in severe autoimmune hemolytic anemia (AIHA) of the warm antibody type.

A patient with severe AIHA of the warm antibody type, absence of reticulocytes and red cell hyperplasia of the bone marrow is described. In order to maintain a reasonable hemoglobin level 38 units of washed packed red cells were required within 24 days. The treatment with high doses of steroids showed no permanent beneficial effect. After splenectomy the red cell destruction was immediately reduced and the patient went into a remission. Bone marrow culture studies during the acute phase of the disease and at the time of complete hemato- and immunological remission, i.e. 4 months after splenectomy suggested a circulating autoantibody directed to early erythroid progenitors (BFU-E). The inhibitory activity in the patient's plasma did not influence granulocytic or mixed colony formation (CFU-GEMM). In addition to autoantibodies directed to erythroblasts and erythropoietin involved in the pathogenic mechanisms leading to red cell aplasia type I and II the culture studies suggest an unusual autoantibody that might cause the observed reticulocytopenia and erythropoietic hyperplasia of the bone marrow in AIHA. After the splenectomy the patient recovered, he required no further blood transfusions and his disease has not recurred.

Adult↗
PubMed1983

Pharmacological interaction between nitroglycerin and aspirin after acute and chronic aspirin treatment of healthy subjects.

The interaction between nitroglycerin (NTG) and aspirin was investigated in 7 healthy subjects in order to test whether aspirin could block the haemodynamic response to NTG; the doses used were NTG 0.8 mg, and aspirin 0.5 g for chronic and 1 g for acute treatment. The plasma levels of NTG and various physiological parameters (heart rate, diastolic arterial pressure, end diastolic diameter, and end systolic diameter) were measured during the 30 minutes after the administration of NTG. An increase in NTG Cmax and AUC was observed after both aspirin treatment. The changes in physiological parameters produced by NTG were enhanced by the two treatments, although the differences were not statistically significant. The results indicate complex pharmacokinetic and pharmacodynamic interactions between NTG and aspirin.

Adult↗
PubMed1983

The lectin neuraminidase inhibition test: a new method for the detection of antibodies to neuraminidase.

Two methods for the detection of neuraminidase antibodies were compared. The lectin neuraminidase inhibition test (LNI-test) gave results comparable with those provided by the conventional neuraminidase inhibition test (NI-test). Reproducibility and repeatability were better with the LNI-test which used smaller amounts of materials, was less time consuming than the NI-test and was more sensitive.

Animals↗
PubMed1983

Nosocomial infections by chlorhexidine solution contaminated with Pseudomonas pickettii (Biovar VA-I).

Over a period of 10 days, six patients in a cardiac intensive care unit developed Pseudomonas pickettii (biovar VA-I) septicaemia after installation of a venous catheter. The organism was also recovered from all the vials of the aqueous solution of 0.05 per cent chlorhexidine ('Hibitane') prepared with contaminated bidistilled water. There were no further cases of infection when the use of this water was prohibited.

Adult↗
PubMed1983

Isolation and characterization of the RAD3 gene of Saccharomyces cerevisiae and inviability of rad3 deletion mutants.

The RAD3 gene of Saccharomyces cerevisiae is required for nicking of DNA containing pyrimidine dimers or interstrand crosslinks. We have cloned the RAD3 gene and physically mapped it to 2.6 kilobase of DNA. A DNA segment of the cloned RAD3 insert was ligated into plasmid YIp5, which transforms yeast by homologous integration, and shown to integrate at the RAD3 site in chromosome V, thus verifying the cloned DNA segment to be the RAD3 gene and not a suppressor. The RAD3 gene encodes a 2.5-kilobase mRNA, extending between the Kpn I site and the Sau3A1/BamHI fusion junction in plasmid pSP10, and the direction of transcription has been determined. The 2.5-kilobase transcript could encode a protein of about 90,000 daltons. We also show the deletions of the RAD3 gene to be recessive lethals, indicating that the RAD3 gene plays an important role in other cellular processes in addition to incision of damaged DNA.

Journal Article↗
PubMed1983

Calcium entry blocking agents in digital vasospasm (Raynaud's phenomenon).

We have evaluated the therapeutic effect of the calcium entry blocking agent nifedipine in Raynaud's phenomenon associated with connective tissue diseases and in idiopathic digital vasospasm. In a preliminary study 16 patients with a digital vasospasm that could be induced by hand-immersion in cold water (4 degrees C) were challenged a second time with cold water 1 and 6h after 20 mg oral nifedipine. Nifedipine provided an effective protection against this cold-induced vasospasm in 14 of the 16 patients. Thirty patients were included in a short-term ambulatory study: Raynaud's phenomenon was associated with progressive systemic sclerosis (PSS) in 10 patients, systemic lupus erythematosus (SLE) in five and rheumatoid arthritis (RA) in three; it was idiopathic (I) in 12 patients. Each patient received, in a double-blind manner and random order, on two consecutive weeks, nifedipine (20 mg three times daily) and placebo. Nifedipine proved to be effective: the mean number of digital vasospastic attacks per week decreased from 27.3 to 5.8 (P less than 0.01). The results in the SLE and RA groups were similar and were pooled. The improvement (in % decrease) was better in the idiopathic group (90.9) than in the SLE and RA group (78.6, P less than 0.02) and the PSS group (64.0, P less than 0.01).

Adult↗
PubMed1983

[Clinical significance and pathogenesis of drug- or microbe-induced autoimmune hemolytic anemias].

Methyldopa and several other drugs, continuously taken over months or years, may induce autoimmunity in persons having a probably genetic predisposition. The autoimmunity is reversible after discontinuation of the drug. A number of infectious agents may lead to the same effect. The autoantibodies can react with different autologous targets, for instance red blood cells. This may occasionally cause an autoimmune haemolytic anaemia. The two pathogenetic cardinal points are discussed in the case of the methyldopa-induced autoimmune haemolytic anaemia: the induction of the process results very probably by inhibiting or blocking of the competent suppressor-T-lymphocytes, which normally prevent an autoantibody production, representing a form of chemical "contrasuppression". This has been demonstrated in cultures of peripheral human blood lymphocytes of patients on methyldopa therapy. The second pathogenetic cardinal point is the effect of the autoantibody after its binding to the drugs investigated up to now. Rarely it is pathogenic. This relation is exactly contrary to the idiopathic warm autoantibody anaemia and remains an unsolved problem. A reversible selective deficiency of suppressor-T-cells has also to be postulated for other autoimmune haemolytic anaemias and autoimmune diseases induced by drugs or infectious agents.

Adult↗
PubMed1983

[Molsidomine prevention of coronary artery spasm caused by alkalosis].

A test provocation of coronary artery spasm by alkalosis was used to evaluate a possible anti-coronary artery spasm effect of molsidomine. The rapid infusion of an alkaline buffer followed by maximal voluntary hyperventilation in 10 patients with angina at rest led to the appearance of angina pain and significant, transient ischaemic changes of the ST segment, due to alkalosis induced coronary spasm. A second provocation test was performed under the same conditions, 24 hours later, after the prior administration of 4 mg of molsidomine. Molsidomine prevented the development of coronary artery spasm in 8 of the 10 patients in the study group. These preliminary results justify further clinical evaluation of molsidomine in the treatment of vasospastic angina.

Alkalosis↗
PubMed1983

[Comparative effects of dopamine and dobutaine in subendocardial perfusion in the acute phase of myocardial infarct].

Dobutamine, a selective agonist of beta I adrenergic receptors was proposed as an inotropic support of the failing left ventricle in the acute phase of myocardial infarction. We studied the action of Dobutamine (10 micrograms/kg/min) on subendocardial perfusion, compared to the effects of an equipotent dose of Dopamine, in 10 patients with acute transmural infarction. Subendocardial perfusion was assessed by subendocardial viability ratio (EVR), ratio of the diastolic pressure-time index to the systolic pressure-time index. A mean 35 p. cent increase in cardiac index was observed with 10 micrograms/kg/min Dopamine, and with 6,75 micrograms/kg/min Dobutamine; heart rate increased by 13 p. cent with both drugs; with Dobutamine, systolic arterial pressure increased by 9,6 p. cent while pulmonary wedge pressure decreased by 34 p. cent; Dopamine increased systolic arterial pressure by 19 p. cent while pulmonary wedge pressure remained unchanged. Subendocardial viability ratio decreased by 25 p. cent with Dopamine (p less than 0,01) but only by 14 p. cent with Dobutamine (p less than 0,01). Thus, there was significantly less impairment of subendocardial perfusion with Dobutamine and its use is preferable when inotropic support of the failing left ventricle is necessary in the acute stage of myocardial infarction.

Aged↗
PubMed1982

Evidence for cellular mediated immunity in an animal model of autoimmune pituitary disease.

The anterior pituitary gland can be involved in an inflammatory reaction mediated by lymphocytes that leads to various degrees of dysfunction. In seven rabbits immunized with homologous pituitary tissue in complete Freund's adjuvant, a focal lymphocytic infiltrate, and increased fibrosis was observed in five. These changes were patchy in distribution and limited to the anterior pituitary. No inflammation was observed in five control animals. When incubated with pituitary extract, partially purified lymphocytes from four of the five animals with altered pituitary histology demonstrated a significant (p less than 0.05) stimulation of 3H-thymidine incorporation. Measures of antipituitary antibodies using indirect immunofluorescence were negative in experimental as well as control animals. The present studies characterize the histologic changes and suggest that cellular immunity plays a role in the pathogenesis of experimentally induced autoimmune pituitary disease.

Animals↗