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Biomedical subjects

N Hunter

Publications and source records attributed to N Hunter.

At least 235 records · Page 13Linked to original sources
PubMed1978

Dibutryl cyclic adenosine monophosphate: effect on radiosensitivity of tumors and normal tissues in mice.

The effect of dibutryl cyclic adenosine monophosphate (db-cAMP, 30 mg/kg), injected into mice before irradiation, on the radiation sensitivity of various tissues was investigated. Survival of proliferating hair follicles, small gut stem cells, fibrosarcoma (FSa) micrometastases in the lungs, and two different mammary carcinomas, as assayed by the TCD50 method, were studied. Intraperitoneal injection of db-cAMP before irradiation resulted in higher survival of hair follicles irradiated on the third day after plucking. Stem cells in the small gut showed increased survival if irradiated 4 hours after injection. There was no effect on the survival of FSa micrometastases by preinjection and the TCD50/120 days of the mammary carcinomas was not altered.

Animals↗
PubMed1977

Focal infection in perspective.

In this article some of the theoretical possibilities arising as a result of focal infection are discussed. Rheumatic fever is discussed as an example of a disease in which a number of possible mechanisms may act to produce tissue damage at a target area. The mechanisms examined are direct dissemination of organisms from the focus to the target area, the induction of L-phase bacteria, and toxic damage to target tissue. Host-mediated tissue damage by hypersensitivity or auto-immune mechanisms is considered as well.

Bacteria↗
PubMed1975

Combination of C. parvum and specific immunization against artificial pulmonary metastases in mice.

We have studied whether specific immunization administered intraperitoneally can augment the activity of C. parvum (0.25 mg intraperitoneally or intravenously) against intravenously injected cells of a syngeneic fibrosarcoma in C3Hf/Bu mice as expressed by the reduction of pulmonary metastases (nodules, colonies) and/or by the prolongation of the survival of recipients. Combination of specific immunization and C. parvum, applied either before or after IV inoculation of viable tumor cells, was more effective than the single treatments. IV injection of a mixture of heavily irradiated and viable tumor cells gave more tumor nodules in the lungs of normal mice than injection of viable cells alone. The metastasis-enhancing effect of admixed irradiated cells was not found in mice previously treated with C. parvum, and was abolished if the immunostimulant was injected after tumor cells. Generation of lung metastases by IV inoculation of fibrosarcoma cells was reduced in mice already having this tumor in the leg. This concomitant immunity to metastases was increased by treating the recipients with C. parvum, but not with irradiated cells; also, the injection of irradiated cells together with C. parvum did not augment the efficiency of the latter. C. parvum was not as effective in T-cell deprived as in control mice, which suggests that in this system, T-cells are required for optimal anti-tumor activity of this immunostimulant. Specific immunization was not effective in T-cell-deprived mice and did not augment the efficiency of C. parvum.

Animals↗
PubMedDate not supplied

Prophylaxis and treatment of experimental lung metastases in mice after treatment with liposome-encapsulated 6-O-stearoyl-N-acetylmuramyl-L-alpha-aminobutyryl-D-isoglutamine.

A new lipophilic muramyl dipeptide analog, 6-O-stearoyl-N-acetylmuramyl-L-alpha-aminobutyryl-D-isoglutamine, when incorporated in liposomes, was effective in both the prevention and eradication of experimental pulmonary metastases in mice. Multilamellar vesicles composed of synthetic phospholipids (phosphatidylglycerol and phosphatidylcholine) containing saturated myristoyl or unsaturated dioleoyl acyl chains were found to potentiate the antimetastatic activity of this glycopeptide. Prophylactic and therapeutic efficacy was observed against the three murine tumors tested: FSa, an immunogenic fibrosarcoma; NFSa, a nonimmunogenic fibrosarcoma; and B16 melanoma. Neither the administration of empty liposomes or free glycopeptide, nor their coadministration, had a significant antimetastatic effect. This approach is promising for the therapy of cancer metastases in humans, particularly in the prevention of metastatic seeding and in the treatment of micrometastases.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMedDate not supplied

Enhancement by misonidazole of metastatic tumor nodule formation in the lungs of mice.

Investigations were performed to determine whether misonidazole, a hypoxic cell radiosensitizer, influences formation of tumor nodules in the lung of C3Hf/Kam mice and whether it affects the enhancement of tumor nodule formation caused by local thoracic irradiation (LTI). Cells from a chemically-induced fibrosarcoma (FSa) and a spontaneously-developed fibrosarcoma (NFSa) formed twice as many tumor colonies in the lungs of mice that received misonidazole as in untreated mice. The effect was observed only with doses of misonidazole of 1 mg/g or higher given within 2 days prior to i.v. injection of tumor cells. A similar twofold amplification of the effect of LTI occurred when 1 mg/g misonidazole was given 30 min before or 0.5 to 2 hours after irradiation. This increase was independent of the dose of LTI and the absolute number of tumor nodules in the lung. The mechanistic possibilities and clinical relevance of the misonidazole effect are discussed.

Animals↗