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Biomedical subjects

D Bischoff

Publications and source records attributed to D Bischoff.

7 recordsLinked to original sources

[Congenital tubular supravalvular aortic stenosis with massive coronary artery dilatation in a 35-year-old man].

Supravalvular aortic stenosis is a rare cause of left ventricular outflow obstruction in adults. It occurs as an isolated defect sporadically or on a hereditary basis with an autosomal dominant trait without further phenotypical anomalies, or as part of the Williams syndrome with mental retardation and multiple other anomalies. This lesion was proved to result from a defect of the elastin coding gene. Supravalvular aortic stenosis is frequently associated with cardiovascular defects, particularly of the peripheral pulmonary arteries, thoracic aorta, carotid, subclavian, and coronary arteries and the aortic valve. The coronary arteries are subject to an increased perfusion pressure leading to dilatation, tortuosity and accelerated arteriosclerosis. We give details of a 35-year-old patient in whom a previously asymptomatic supravalvular aortic stenosis is associated with an excessive dilatation of the right coronary artery and the left anterior descending coronary artery as well as an ostium stenosis of the left common carotid artery. The patient did not present any phenotypical anomalies of the Williams syndrome.

Adult↗

Exon skipping truncates the PDZ domain of human erythroid p55 in a patient with chronic myeloid leukemia in acute megakaryoblastic blast crisis.

Human p55, the major palmitoylated protein associated with the cytoplasmic face of the erythrocyte membrane, is believed to modulate interactions between protein 4.1 and glycophorin C. It is the prototype of a newly described family of signaling molecules that includes hD1g, the human homologue of the Drosophila discs-large tumor suppressor protein. Chronic myeloid leukemia is characterized by transformation to a fulminating acute leukemia, heralded by evolution of the Philadelphia chromosome positive genotype (Ph +) to further abnormalities. RT-PCR of p55 mRNA from a patient with acute megakaryoblastic CML revealed a 69 base pair deletion in the PDZ domain, corresponding to exon 5 of the p55 gene. The deletion of constitutive exon 5 not only marks the first abnormality of the p55 cDNA in human disease but also the first abnormality of a PDZ domain in human disease and may represent another genetic abnormality associated with CML in blast crisis.

Amino Acid Sequence↗

Specific demonstration of rat brain adenylate cyclase in polyacryl amide microgels by a new histochemical procedure.

Adenylate cyclase from rat hippocampus was separated by electrophoresis in polyacryl amide microgels and stained for enzymatic activity using a new histochemical procedure. This method involves the use of AMP-PNP, aminophylline, dithiotreitole, and Sr2+ as "primary" capture ions, thus fulfilling all the demands for a really specific histochemical incubation medium for the enzyme. The incubation of the gels with this medium resulted in the inhibition of other enzymes, which are capable of splitting AMP-PNP (ATP: pyrophosphatase, alkaline phosphatase), whereas adenylate cyclase remained highly active under these conditions. The enzyme was found to be present in two forms in the gels. Both protein bands were stimulated by the addition of various biogenic amines to the incubation medium. One protein band was fully GMP-PNP dependent in its activity. It is reasonable to suppose that these forms are either differently high aggregated molecules of the enzyme or enzyme molecules bound to their regulatory sites.

Adenylyl Cyclases↗

[The influence of inhalation anaesthetics on catecholamine secretion from the adrenal medulla in vivo].

The influence of chloroform and ether on the catecholamine (CA) secretion from the adrenal medulla was investigated in cats in order to compare these effects to those of halothane and methoxyflurane studied previously. The CA concentrations in the blood of the adrenolumbar vein were measured spectrofluorometrically. During inhalation of chloroform (1.0-1.5%) no significant changes of spontaneous CA secretion were observed; contrary to that, the secretion evoked by splanchnic nerve stimulation was decreased. During inhalation of ether (4.0-6.0%) spontaneous CA output was increased and the CA release evoked by splanchnic nerve stimulation was inhibited. The results differ qualitatively from those obtained with methoxyflurane and halothane; these anesthetics caused a pronounced inhibition of spontaneous CA output. The inhibition by ether of CA secretion evoked by splanchnic nerve stimulation was less pronounced than that caused by the other anaesthetics. By comparison of the effects of four inhalation anaesthetics we evaluated, which circulatory side effects depend on changes of CA output.

Adrenal Medulla↗