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Biomedical subjects

R Hunter

Publications and source records attributed to R Hunter.

At least 109 records · Page 6Linked to original sources
PubMed1981

The adjuvant activity of nonionic block polymer surfactants. I. The role of hydrophile-lipophile balance.

We developed an experimental model for studying the physicochemical basis of the adjuvant activity of surface-active agents. Pluronic polyols are chemically similar but physicochemically diverse surface-active agents composed of polymers of hydrophilic polyoxyethylene and lipophilic polyoxypropylene. One of them, L121, was found to be a powerful adjuvant for increasing antibody formation to BSA in mice when injected in an oil-in-water emulsion. Another, L101, was less effective in increasing antibody formation, but was more effective in inducing granulomatous inflammation. Three others had little effect on either response. The ability of these and other surface active agents to serve as adjuvants correlated with a physicochemical parameter, the hydrophile-lipophile balance (HLB). All of the surfactants with strong adjuvant activity have HLB values of less than 2. They are strongly lipophilic and promote the retention of macromolecules by oil drops in oil-in-water emulsions. We propose that the adjuvant activity of these compounds is dependent on their ability to concentrate the adjuvant, immunogen, and host proteins on hydrophobic surfaces, where they are more effectively presented to cells of the immune system.

Adjuvants, Immunologic↗
PubMed1981

Biologic properties of iscador: a Viscum album preparation I. Hyperplasia of the thymic cortex and accelerated regeneration of hematopoietic cells following X-irradiation.

We demonstrated that a preparation of Viscum album (Iscador) has unusual effects on the immune system. In CD-1 mice, the mean weight of the thymus increased from 45 to 85 mg. following six daily intraperitoneal injections of 2.5 mg. of Iscador. The thymic trophic influence was maintained over a long period of time. Sprague-Dawley rats treated with Iscador for 16 weeks showed an increase of 78% in thymic weight over controls. The increased weight of the thymus was due to increased proliferation of cortical thymocytes. The number of blast cells in the outer cortex of the thymus increased within 2 days of the first injection and remained at high levels. Thymocytes of Iscador-treated animals were 29 times more responsive to Concanavalin A than those of untreated controls. Iscador increased the amount of antibody produced by animals injected with sheep red blood cells if it was injected after the antigen. Iscador also had effects on hematopoietic cells. It accelerated the recovery of hematopoietic tissue in bone marrow and spleens of irradiated animals. We believe that V. album preparations may be valuable reagents for perturbing thymus function.

Animals↗
PubMed1980

Steroid secretion by the postmenopausal ovary.

The concentrations of certain steroids in arterial and ovarian venous blood were measured in 42 postmenopausal women undergoing hysterectomy for uterine disease. A concentration gradient across the ovary was found for testosterone in 21 women, for androstenedione in 16, for estradiol in 15, for estrone in 8, and for dehydroepiandrosterone in 3. On the basis of postualated ovarian blood blow the gradient would result in a major contribution to the blood production rate for testosterone in about 50% of women and for estradiol in less than 20%. For androstenedione, dehydroepiandrosterone, and estrone the gradients did not signify important ovarian secretion. There was no evidence for secretion of dihydrotestosterone, estrone sulfate, or dehydroepiandrosterone sulfate. There were no apparent clinical correlates to indicate in which women the ovary was secreting steroids.

Androstenes↗
PubMed1979

Chromosomal aberrations induced by Dispersion Yellow 3 in Rana clamitans larvae during tail regeneration.

Azo dyes have been shown to be mutagenic and toxic in a variety of organisms. The azo dye, Dispersion Yellow 3 is a pollutant in the river water supply of Northern Georgia. Preliminary and definitive studies have indicated that it is mutagenic in micro-organisms and causes several malformations in chicken embryos. The present study revealed that when larvae are exposed to the dye during tail regeneration, several aberrations are seen in the squash preparations from regenerates. Included are gaps (the most frequent abnormality), dicentrics, rings and breaks. The data suggest that this azo dye deserves more detailed study to determine its mutagenicity.

Animals↗
PubMed1978

Studies on an oncofetal antigen, POA.

This paper describes the purification and partial characteristics of a putative oncofetal antigen, POA, which appears to be associated with the pancreas. POA is a glycoprotein of molecular weight between 800,000 and 900,000 daltons. It is found in fetal pancreas and pancreas cancer tissue, but not in normal adult pancreas. It is clearly different from carcinoembryonic antigen, other known tumor associated antigens, acute phase reactants and normal serum proteins. A quantitative rocket immunoelectrophoresis assay was developed for POA. Its specificity was monitored routinely by double immunodiffusion against known fetal and adult standards. The assay was performed on sera from over 700 patients. The results demonstrate that POA is found in the sera of most individuals. However, by far the highest absolute levels and the highest frequency of elevated levels was found in sera of patients with carcinoma of the pancreas. Elevated levels of POA were also found in the serum of a proportion of patients with carcinomas of the lung, stomach, colon, biliary tract, and breast and in a few other individuals with benign conditions. The spectrum of patients who have elevated levels of POA in their serum is quite different from that found with CEA or other known tumor markers.

Antigens, Neoplasm↗