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Biomedical subjects

A Sobel

Publications and source records attributed to A Sobel.

At least 181 records · Page 10Linked to original sources
PubMed1976

Mast cell sensitizing antibodies in experimental myositis.

Mast cell sensitizing antibodies, direct mast cell degranulation and positive delayed skin tests were detected in guinea pigs and rats during experimental paralysis provoked by inoculation with acetylcholine receptors from the Electrophorus electricus. The animals also developed fluorescent antibodies to the sarcolemma, and massive myositis with histological changes in muscles similar to those characterizing clinical polymyositis.

Acetylcholine↗
PubMed1975

Delayed hypersensitivity to mono-azobenzene-arsonate-N-acetyl-L-tyrosine. I. Induction of cellular sensitivity in the rat.

In the guinea pig, mono-ABA-Tyrosone (ABA-Tyr) has been extensively studied as a hapten capable of inducing delayed type hypersensitivity in the absence of circulating antibodies. This model has been extented to the rat, and cellular sensitivity has been assessed both "in vivo" (skin reaction) and "in vitro" (cellular proliferation and lymphocyte migration inhibition). All the reactions studied follow a reproducible pattern with maximal positivity between 4 and 13 days, and negative responses after 20 days. Circulating antibodies were not detectable at any period after immunization. In view of the original properties of ABA-Tyr, and of the advantage of the rat as an experimental animal, the proposed model can be expected to facilitate further studies on the cellular mechanisms of delayed hypersensitivity.

Animals↗
PubMed1975

A vascular permeability factor in lymphocyte culture supernants from patients with nephrotic syndrome. II. Pharmacological and physicochemical properties.

Pharmacological properties of the "Skin Reactive Factor" demonstrated in nephrotic patients are similar to guinea-pig Skin Reactive Factor. This biological activity is not antagonized by anti-histaminic and anti-serotonin drugs. It is inhibited by meclofenamate and pyridinolcanbamate. It is enhanced by diethyldithiocarbamate and normal human serum. According to this results it could be an activator of the kinin system. Biochemical studies indicate that it is a pepsin destroyed protein, unaffected by Rnase and Dnase. Its electrophoretic mobility is that of an albumin or an alpha1 globulin.

Blood Proteins↗
PubMed1975

Synthesis of acetylcholine receptor during differentiation of cultured embryonic muscle cells.

Acetylcholine receptor, a component of the specialized muscle membrane, appears during the differentiation of embryonic myogenic cells in tissue culture. Demonstration of incorporation of the radioactive precursor L-[35S]methionine into purified receptor polypeptides is presented as evidence for its synthesis de novo. The identity of the purified radioactive species is established by cosedimentation of the [35S]receptor with [3H]alpha-toxin binding activity on sucrose gradients and by crossreaction with antiserum to purified acetylcholine receptor of Electrophorus electricus.

Acetylcholine↗
PubMed1973

Dopaminergic terminals in the rat cortex.

The destruction of ascending noradreniergic pathways by bilateral microinjections of 6-hydroxydopamnine made laterally to the pedunculus cerebellaris superior completely abolished the in vitro synthesis of [(3)H]norepinephrine from L-[(3)H]tyrosine in slices and in synaptosomes of the rat cortex. However, normal [(3)H]dopamine synthesis could still be observed in both cortical preparations from animals with lesions. These results provide the first biochemical support for the existence of dopaminergic terminals independent of noradrenergic terminals in the rat cortex.

Animals↗
PubMedDate not supplied

Neurofibrillary tangle-associated alteration of stathmin in Alzheimer's disease.

Stathmin (p19), a 19-kDa cytosolic phosphorotein, plays a key role in converting extracellular signals into intracellular biochemical changes. Antibodies and cDNA specific for stathmin were used to study its levels and localization in normal and Alzheimer's disease (AD) brain tissue. The stathmin protein concentration was reduced in AD neocortex as assessed by Western blotting, whereas the concentration of its mRNA detected by both in situ hybridization and slot blot were increased in AD. The alteration of the stathmin protein concentration was negatively correlated with neurofibrillary tangle numbers but not with plaque numbers. Immunoreactivity was evenly localized to the cytoplasm of neurons in control cortical sections, whereas in AD it was preferentially localized to some of the neurofibrillary tangle-bearing neurons. Numbers of stathmin-positive neurons were inversely correlated with tangle numbers but not with plaque numbers in the frontal cortex of AD patients.

Alzheimer Disease↗
PubMedDate not supplied

Hyperdense CT foci in treated AIDS toxoplasmosis encephalitis: MR and pathologic correlation.

Five AIDS patients with previously diagnosed and treated toxoplasmosis presented with hyperdense precontrast CT approximately 6 months after the CNS infection. An MR study was performed in all cases. The CT hyperdensities were characterized on MR by a high signal intensity on T1 images in four cases. In two of these, pathological correlation confirmed hemorrhage. In the fifth case, MR findings were consistent with calcification, which was verified by pathological examination.

Acquired Immunodeficiency Syndrome↗