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Biomedical subjects

J Roth

Publications and source records attributed to J Roth.

At least 631 records · Page 35Linked to original sources
PubMed1981

[Comparing investigations of the valence of acetylcholine test and the closing volume for the early detection of non-specific lung diseases (author's transl)].

Investigations in 77 healthy persons and 94 patients with a manifest obstructive lung disease have led to the result that not only the central but also the peripheral part of the bronchial system are influenced by the bronchial reactivity. Accordingly the examination of the bronchial reactivity (0.01% acetylcholine solution as ultrasonic aerosol) enable in healthy persons a certain differentiation between smokers and non-smokers if the single breath test by means of the slope index are used. Therefore the method of investigation may be recommended for the early detection of functional disorders of persons with inhalatory exposure to noxious substances.

Acetylcholine↗
PubMed1981

The regenerating fascial sheath in lipectomized Osborne-Mendel rats: morphological and biochemical indices of adipocyte differentiation and proliferation.

We investigated the cellular and enzymatic changes that occur as adipose tissue regenerates following bilateral lipectomy of Osborne-Mendel rats. At 6, 8, 10, 12 and 14 days after surgery regenerating fascial sheaths regrowing at the site of the inguinal fat depots were fixed in situ and removed for studies of cellular and tissue morphology at both light and electron microscopic levels. Additional tissue from some animals was prepared for measurement of thymidine kinase and lipoprotein lipase activity. Six days after surgery, fascial sheaths had regrown at the site and contained a few mature unilocular adipocytes as well as numerous other cells, some of which contained non-membrane bound lipid droplets, and which were tentatively identified as pre-adipoblasts and adipoblasts. Over the period from day 6 to day 14 the number of unilocular adipocytes in the tissue doubled and the average cell size increased. These changes in cellular morphology were accompanied by correlative changes in enzyme activity.

Adipose Tissue↗
PubMed1981

Rarity of diabetic retinopathy in patients with acromegaly.

We studied 44 acromegalic patients with the use of fluorescein angiography to detect the presence of diabetic retinopathy. We found elements of diabetic retinopathy in only one patient (2.2%). The average patient had a growth hormone concentration of 32 ng/mL (range, 1 to 275 ng/mL) for a duration of 10.5 years (range, three to 26 years). Forty-five percent (20) of our group had glucose intolerance and 14% (six) had elevated fasting blood glucose levels for an average duration of two years (range, one to four years). We conclude that diabetic retinopathy is an uncommon finding in patients with acromegaly and that fluorescein angiography does not reveal cases that were not detected by conventional funduscopic examination.

Acromegaly↗
PubMed1980

Insulin-induced loss of the insulin receptor in IM-9 lymphocytes. A biological process mediated through the insulin receptor.

Exposure of cultured lymphocytes of the IM-9 line to insulin results in a rapid, time-dependent reduction in the number of insulin receptors to a new steady state concentration. Both the rate of loss and the net loss of receptors were directly related to the ambient insulin concentration. The insulin-induced loss of receptors was mediated by binding of insulin to the receptor itself; insulins, which varied 200-fold in biopotency, produced receptor loss in direct proportion to the ability of each insulin to occupy the receptor. The residual insulin receptors were normal following insulin-mediated receptor loss by a variety of sensitive binding criteria. While insulin binding to its receptors was a necessary condition to induce receptor loss, it was not sufficient. Thus, reduction in the temperature of the preincubation from 37 degrees C to 20 degrees C (which enhanced the total amount of insulin bound to the receptor) abolished the loss of insulin receptors. Likewise, cycloheximide prevented the insulin-induced loss of receptors. Furthermore, turkey erythrocytes, which lack active macromolecular synthesis, had no change in the concentration of insulin receptors when exposed to insulin for similar periods. Interestingly, the turkey erythrocytes, when exposed to insulin or to proinsulin, showed a time- and concentration-dependent increase in the affinity of the insulin receptor over a restricted part of the insulin-binding isotherm, which was reversed over a period of several hours following removal of hormone. The insulin-mediated decrease in receptor number on IM-9 lymphocytes was reversible. Following removal of insulin from the growth medium, about one-half of the receptors were restored within 10 h and the full complement of insulin receptors was restored within 24 h. Cycloheximide prevented restoration of the insulin receptor.

Cell Line↗
PubMed1980

Characterization of insulin receptors in patients with the syndromes of insulin resistance and acanthosis nigricans.

This report analyzes the in vitro characteristics of 125I-insulin binding to the monocytes of nine patients with the syndromes of acanthosis nigricans and insulin resistance. The 3 Type A patients (without demonstrable autoantibodies to the insulin receptor) had decreased binding of insulin due to a decreased concentration of receptors. In these patients the residual receptors demonstrated normal dissociation kinetics, negative cooperativity, and were blocked by anti-receptor antibodies in a manner similar to normal cells. In contrast, monocytes from the 6 Type B patients (with circulating anti-receptor autoantibodies) had decreased binding of insulin due to a decrease in receptor affinity. Insulin binding to monocytes of Type B patients demonstrated accelerated rates of dissociation with no evidence of cooperative interactions among insulin receptors. When coupled with previous data, the present studies further suggest that different mechanisms account for the defects in insulin binding and insulin resistance observed in these patients.

Acanthosis Nigricans↗
PubMed1980

Insulin is ubiquitous in extrapancreatic tissues of rats and humans.

Insulin has been detected, at levels higher than those in plasma, in a broad range of extrapancreatic tissues in both rats and humans. Rat liver insulin was shown to be indistinguishable from genuine insulin by radioimmunoassay, Sephadex chromatography, bioassay, and antibody neutralization. Liver insulin (like brain insulin) was unchanged in ob/ob mice, in rats treated with streptozotocin, or in fasted rats, despite marked alterations in pancreatic secretion of insulin and in liver content of insulin receptors. Insulin was found in cultured human IM-9 lymphocytes and cultured fibroblasts at concentrations greater than 100 times the levels in the media. IM-9 lymphocyte insulin also was shown to be indistinguishable from genuine insulin, by the same criteria used for liver insulin. The insulin concentration in cultured human cells was unaffected by depletion of insulin from the culture medium or by addition of beef insulin to the medium. The data suggest that a part, if not all, of the extrapancreatic tissue insulin is independent of plasma insulin and may be synthesized by the tissues themselves.

Animals↗
PubMed1980

Evolutionary origins of vertebrate hormones: substances similar to mammalian insulins are native to unicellular eukaryotes.

Tetrahymena pyriformis, Neurospora crassa, and Aspergillus fumigatus that had been grown in simple defined media were extracted with acid ethanol by a classic method for recovering insulin from pancreas. After filtration of the extracts on Sephadex G-50, distinct peaks of insulin immunoreactivity were recovered in the region typical of insulin. The gel-filtered material from the Tetrahymena had reactivity in the pork insulin radioimmunoassay about equal to its reactivity in the insulin bioassay (stimulation of lipogenesis in isolated rat adipocytes), and the gel-filtered material from neurospora had an immunoreactivity-to-bioactivity ratio of about 1:3. The material that stimulated lipogenesis could be neturalized by anti-insulin sera (i.e., 75-95% of the Tetrahymena material and 60% of the Neurospora material). Bioactive and immunoactive insulin was found in the conditioned medium equal in amount to that in the cells. The findings suggest that insulin did not arise evolutionarily in the intestinal or neural tissues of primitive vertebrates or complex invertebrates but rather has its molecular origins at least as far back as the simplest unicellular eukaryotes.

Aspergillus↗
PubMed1980

Identification and mapping of a second proline permease Salmonella typhimurium.

In this paper we demonstrate the existence of a second proline permease, gene proP, in Salmonella typhimurium. Uptake assays demonstrate that this second proline permease has 5 to 10% the uptake rate of the putP permease, the cell's major proline permease, when assayed at 20 microM proline. Genetic mapping by Hfr and P22-mediated genetic crosses placed the second proline permease gene at 92 min on the S. typhimurium genetic map, near the genes for melibiose utilization. F'-mediated complementation tests indicated that Escherichia coli also has the proP gene.

Chromosome Mapping↗
PubMed1980

Quantitative immunocytochemical localization of pancreatic secretory proteins in subcellular compartments of the rat acinar cell.

The recently developed protein A-gold technique for the detection of intracellular antigenic sites on thin sections was utilized to localize nine different secretory proteins in the rat exocrine pancreas. Amylase, chymotrypsinogen, trypsinogen, lipase, elastase, carboxypeptidases A and B, RNase and DNase, were detected at the level of the rough endoplasmic reticulum, the Golgi area, and the zymogen granules of the acinar cells, as well as in the acinar lumen. A quantitative evaluation of the labeling showed that its intensity was not identical for all enzymes studied nor in all cellular compartments analyzed. An increasing gradient of the labeling from the rough endoplasmic reticulum to the Golgi and to the zymogen granules was found for amylase, carboxypeptidases A and B, chymotrypsinogen, trypsinogen, and RNase, while a comparable low degree of labeling in the Golgi apparatus and in the zymogen granules was observed for DNase, lipase, and elastase. These results suggest that the nine enzymes are processed through the same intracellular compartments, but that they may be concentrated to different degrees in the zymogen granules before being released in the acinar lumen.

Animals↗
PubMed1980

Protein A-gold complex for postembedding staining of intracellular antigens.

The use of protein A-gold complex for electron microscopic demonstration of intracellular antigenic sites in thin sections of glutaraldehyde and Epon-embedded tissue is reported. The method is carried out in two steps: thin sections are incubated with specific antisera and the antigen-antibody complexes are then visualized with protein A-gold solution. So far several exocrine pancreatic enzymes as well as polypeptide hormones from the endocrine pancreas have been revealed by this technique.

Amylases↗