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Biomedical subjects

S Roth

Publications and source records attributed to S Roth.

At least 379 records · Page 21Linked to original sources
PubMed1976

Parathyroid hyperplasia in primary hyperparathyroidism: a review of 85 cases.

Parathyroid hyperplasia of all four glands was found to be the cause of primary hyperparathyroidism in 85 of 557 cases seen at the Massachusetts General Hospital between 1930 and 1973. There were 66 cases of chief cell hyperplasia and 19 cases of clear cell hyperplasia that were grossly, microscopically, and ultrastructurally distinct. Although the clinical findings overlap, there are several differences in the signs and symptoms between these two forms of hyperplasia. Both types are treated by subtotal removal of all the parathyroid tissue. Removal of insufficient tissue has left residual hyperparathyroidism in 45% of those with chief cell hyperplasia and 11% of those with clear cell hyperplasia after what was thought to be definitive surgery. Postoperative hypoparathyroidism was found in 15% of the patients with chief cell hyperplasia and in none with clear cell hyperplasia. These findings further suggest that removal of three and one-half glands in the more than 86% of patients with one gland involvement (adenoma or carcinoma) as the cause of primary hyperparathyroidism is unwarranted.

Adult↗
PubMed1976

[Indirect lymphography of the retrosternal lymphatics and of the thoracic duct (author's transl)].

Successful demonstration of the retrosternal lymphatics and of the thoracic duct after infradiaphragmatic injection is reported, using a contrast medium developed by the author. The lymphatics opacify after 45 minutes. After fourteen days the substance can no longer be seen radiogically. Following some preliminary investigations, it is proposed to try the method in humans. The importance of the lymphatic pathways in medial carcinomas of the breast and in the movement of carcinoma cells from the peritoneal cavity and the liver is stressed.

Animals↗
PubMed1976

Assay of intercellular adhesiveness using cell-coated Sephadex beads as collecting particles.

A simple, rapid and precise method, based on a previous method, for measuring relative rates of intercellular adhesion is described. DEAE-Sephadex beads were treated with nitrocellulose in order to allow cells to grow on their surfaces. Balb/c 3T3 and Balb/c 3T12 cells were used to characterize the assay. They formed confluent cell layers on nitrocellulose-treated DEAE-Sephadex. These cell-coated beads were employed to collect 32P-labelled cells from single cell suspensions. Since they formed statistically uniform, large collecting surfaces, the collection of labelled cells was markedly improved as compared to the original assay. The cell-coated beads collected a large percentage of the labelled cells in a short time. The percentage of cells collected was independent of the concentration of labelled cells in the assay mixture, and the collection was linear for approximately 60 min. The variability between replicate assays was usually +/- 5%. The assay allows the rapid and precise determination of intercellular adhesion in large numbers of individual samples. These features make it useful to screen for effects of different treatments on intercellular adhesions.

Cadmium↗
PubMed1976

Studies on avian erythrocyte metabolism. 5. Relationship between the major phosphorylated metabolic intermediates and while blood oxygen affinity in embryols and poults of the domestic turkey (Meleagris gallopavo).

The changes in organic phosphates of turkey erythrocytes (RBC) have been determined in relation to the changes in oxygen affinity of whole blood during growth of the embryo and poult. On a molar basis, 2,3 diphosphoglyceric acid (2,3-DPG) is the predominant organic phosphate of erythrocytes from turkey embryos during the last week of incubation. However, on the basis of relative % phosphate, 2,3-DPG is the major organic phosphate of the erythrocytes from turkey embryos on day 23 and 25 of incubation only. With the exception of day 23 and 25 incubation, adenosine triphosphate (ATP) represents the major organic phosphate of the erythrocytes of the turkey embryo and poult during the last week of embryonic development and through the first 29 days after hatching. The whole blood P50 during the last week of incubation and the first 8 days after hatching correlates best with the amount of ATP in the erythrocytes. The effects of inositol pentaphosphate on P50 of the whole blood is much more gradual and appears to become of major influence after 2-3 weeks post-hatching.

Adenosine Diphosphate↗
PubMed1975

A molecular approach to retinotectal specificity.

An assay is described to examine the hypothesis that retinal neurons adhere preferentially to that part of the optic tectum near theri normal synaptic termini. The method measures the adherence of isotopically labelled cell bodies from either the dorsal or ventral half of the neural retina of chick embryos to dorsal and ventral tectum halves. When a labelled cell suspension is prepared from a dorsal half-retina, more cells adhere to the ventral half of the tectum. When the cells are from the ventral part of the retina, more bind to the dorsal half of the tectum. This preferential adhesion mimics the retinotectal projection found in vivo and supports an interpretation of neuronal specificity dependent on cell surface adhesive properties. Molecular mokels are presented that utilize glycosyltransferases and their substrates as the basis for adhesive recognition. Two of these models suggest that quantitative changes in the distribution of transferases and their substrates determine retinotectal specificity. The third proposes qualitative variations in these molecules across the retina and tectum.

Animals↗
PubMed1974

Cell contact dependence of surface galactosyltransferase activity as a function of the cell cycle.

Mitotic, nonmalignant Balb/c 3T3 cells exhibit endogenous, surface galactosyltransferase activity that does not require intercellular contact throughout the assay period. In this respect, mitotic 3T3 cells resemble malignant Balb/c 3T12 cells which similarly show no contact requirement for optimum transferase activity in any phase of their cell cycle. Previously, it was shown that randomly growing populations of 3T3 cells have lower galactosyltransferase activity when assayed under conditions which decreased cell contact. This led to the conclusion that these normal (3T3) and malignant (3T12) cells differed in that intercellular contact is required for optimum activity of surface galactosyltransferases on the normal cell type. The present data indicate that mitotic 3T3 cells may be capable of expressing enzyme activities exhibited at all times by malignant cells. That is, mitotic 3T3 cells and randomly growing 3T12 cells may readily catalyze galactosyltransferase reactions between enzymes and acceptors on the same cell. Interphase 3T3 cells, on the other hand, might require that enzymes glycosylate acceptors on adjacent cells. A model is proposed that suggests that changes in the spatial arrangement of surface enzymes and acceptors or variations in the fluidity of the cell membrane can account for this contact-related glycosylation.

Animals↗
PubMed1973

Adhesive recognition and retinotectal specificity.

An assay has been developed to test the hypothesis that neurons from a limited area of the retina will adhere preferentially to that part of the optic tectum near their normal synaptic termini. The method measures the adherence of (32)P-labeled cell bodies from either the dorsal or ventral half of the neural retina of chick embryos to dorsal and ventral tectal halves. When a labeled, single-cell suspension is prepared from dorsal half-retina, more cells bind to the ventral half of the tectum. When the labeled cells are from ventral half-retina, more bind to dorsal half-tecta. This preferential adhesion mimics the retinotectal projection found in vivo. Dorsal retinal cells show this preference shortly after dissociation with crude trypsin, and maintain it for at least 9 hr. Ventral retinal cells, however, require incubation in nutrient medium after trypsinization in order to display this selectivity. Comparable results are obtained when the cell suspension is prepared from pigmented retina. The data support an interpretation of neuronal specificity dependent on cell-surface interactions and demonstrate a clear correlation between selective adhesion and biological function.

Animals↗