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Biomedical subjects

L Roth

Publications and source records attributed to L Roth.

At least 55 records · Page 3Linked to original sources
PubMed1980

A micropuncture study of urate excretion by Cebus monkeys employing high performance liquid chromatography with amperometric detection of urate.

Net renal reabsorption of endogenous urate was studied by the micropuncture technique in Cebus monkeys in the absence of osmotic diuresis. Most of filtered urate (more than 70%) was reabsorbed in the proximal convoluted tubules. Samples from early distal tubules contained 9% of filtered urate; approximately 18% being reabsorbed between the late proximal and early distal segments. There was no detectable reabsorption along the distal tubule. Fractional delivery of urate to late distal tubules was greater than fractional excretion, implying reabsorption of some 4% of filtered urate in the collecting system. However, we cannot exclude nephron heterogeneity as the cause of the difference. The foregoing results were obtained using the method of Pachla and Kissinger for the determination of urate. Urate is separated by high performance liquid chromatography and detected by an amperometric technique. We found the method to be sufficiently sensitive, precise and specific for renal micropuncture samples.

Animals↗
PubMed1980

Reaginic hypersensitivity in Otodectes cynotis infestation of cats and mode of mite feeding.

Otodectes cynotis infestations were induced in barrier-reared mite-free cats. By monitoring the infested cats, sequence of humoral and cellular immune reactions to the mites was determined. Delayed hypersensitivity was not demonstrated in vivo, using intradermal skin tests. Reaginic (immunoglobulin E) antibodies, as detected by 72-hour passive cutaneous anaphylaxic reactions, were the earliest form of immune expression. Precipitating antibodies developed later in the course of the experimental infestation. Hematologic indices, including eosinophil counts, were not affected by established infestations. Antibodies prepared against feline whole blood, lymph, epithelium, and RBC indicated that these regularly occurred in extracts prepared from whole mites. It was concluded, therefore, that the feeding mode of mites required that they ingest feline tissue fluids. This mode is the interface by which the host becomes exposed to, and immunized against, mite antigens.

Animals↗
PubMed1979

Laboratory diagnosis in a case of fatal progressive vaccinia due to manifest immunologic deficiencies.

A case of progressive vaccinia is described, in a 21 years old man, diagnosed after 8 months of vaccinial lesion's evolution. The area of vaccination developed progressive necrosis and metastatic lesions evolved on various regions of the body. The vaccinia virus was isolated on the chorioallantoic membrane of embryonated eggs, from the cutaneous lesions, blood, internal organs and even from the apparently intact skin.--The serological tests indicated hypogammaglobulinemia with absence of neutralizing antibodies.--The death occured after 366 days. The progressive vaccinia described above represents the case with the most prolonged evolution known until now.

Adult↗
PubMed1978

Literacy skills of long-term hospitalized mental patients.

The authors tested 48 patients who had lived in a state psychiatric hospital for extended periods to determine their literacy levels. Measures used were the reading test portion of the Adult Basic Learning Examination (ABLE) and selected questions from the Adult Performance Level (APL) test, which attempts to assess competencies necessary to function effectively in society. Nearly half of the patients scored at the fourth-grade level or below on the ABLE, and their scores on the APL were well below norms for other groups. No correlation was found between number of years of hospitalization and test performance. From the findings the authors conclude that both in-hospital and aftercare programs must recognize that literacy level is an important factor in the the rehabilitation or recidivism of patients.

Adolescent↗
PubMed1978

Salicylate excretion in the rat; free flow micropuncture experiments.

As in other animals, the renal clearance of salicylate in the rat is greater when the urine is alkaline than when it is acid. In none of the present experiments was the rate of salicylate excretion greater than the rate of its glomerular filtration. Nevertheless, net secretion of salicylate was observed in the proximal tubules of alkalotic, nonalkalotic diuretic, and normal hydropenic animals when the plasma concentration of salicylate was below 150 microgram/ml. Alkalosis enhanced the salicylate content of proximal tubular fluid (approximately 30%). The enhancement is less than would be expected from published reports of proximal tubular fluid pH, if non-ionized salicylate were the only permeant form of the drug. In the absence of alkalosis and at high plasma concentrations, net reabsorption in the proximal tubule was observed. In some circumstances there is net reabsorption of salicylate between the end of the accessible portion of the proximal tubule and the beginning of the distal. Salicylate is reabsorbed from the distal tubule. There was only a small difference in distal reabsorptive rate between normal and alkalotic animals.

Animals↗
PubMed1977

Effect of mutant host RNA polymerase on the bifunctional activities of P22 gene c1.

The product of phage P22 gene c1 has two functions: (1) it promotes synthesis of repressor and (2) during the first minutes of infection it retards expression of some lytic genes. We call the second, negative function "c1 retardation". We investigated c1 retardation in a mutant host of Salmonella typhimurium that is resistant to rifampicin and carries an altered RNA polymerase. No c1 retardation of DNA synthesis was detectable in this host after infection with wild-type phages. This elimination of the normally detectable c1 function leads to the conclusion that the mutant RNA polymerase interferes with the expression of c1 gene activity. Wild-type genes form clear plaques on the mutant host. Mutants of P22 called cly were isolated by others. These mutants form turbid plaques on the altered RNA polymerase host. Infections with P22 cly in the mutant host resulted in detectable c1 retardation. The cly mutation therefore restores c1 activity in a host which wild-type c1 is not expressed. Two spontaneous mutants were isolated from the mutant host. These two strains allowed partial expression of c1 retardation, although they remained rifampicin resistant. We interpret our data to indicate that expression of the normal functions of the gene c1 product requires an interaction of that product with the host RNA polymerase.

DNA-Directed RNA Polymerases↗
PubMed1975

[The india ink phagocytosis by monocytes and granulocytes during acute and chronic consumption coagulopathy].

During generalized intravascular coagulation (GIC) the polimerisation products of fibrinogen are phagocytized by the reticulo-endothelial system of the liver and spleen. Thus an inhibition of the clearance of RES could be detected in a progressed stage of the shock and GIC; this can also be represented by a decrease of India ink storage. In the present work the authors investigate the behavior of monocytes and granulocytes in the peripheral blood in GIC. Approximately 80% of cells will usually phagocytize and concentrate India ink granules, if heparinized blood mixed with India ink is incubated for two hours at 37 degrees C. A decrease of the India ink phagocytosis was detected in 6 patients and in 10 dogs during the shock. This observation corresponds to the behavior of hepatolienal RES during this condition.

Animals↗