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Biomedical subjects

I B Kerr

Publications and source records attributed to I B Kerr.

At least 37 records · Page 2Linked to original sources
PubMed1986

The relation of ras family oncogene expression to conventional staging criteria and clinical outcome in colorectal carcinoma.

The elevated levels of ras-related cellular RNA in a series of colorectal carcinomata (n = 12) was correlated with conventional staging criteria (tumour morphology and Dukes' staging) and with clinical outcome with particular reference to the development of metastatic disease. No direct relationship was evident between these parameters suggesting that although abnormal expression of ras oncogenes may be critical in the development of malignancy, variations in the level of their expression do not appear to be directly related to clinically evident phenotypic differences.

Aged↗
PubMed1985

Immunocytochemical demonstration of p21 ras family oncogene product in normal mucosa and in premalignant and malignant tumours of the colorectum.

Study of the distribution of the p21 ras oncogene product as demonstrated by monoclonal antibody Y13-259 shows this protein to be apparently present in all epithelial populations of both premalignant and malignant tumours and throughout the normal foetal and adult epithelial crypt population in the colorectum. Metastatic tumour in liver shows a similar staining pattern which is less intense however than in the surrounding normal hepatocytes. Our results suggest that the presence of this protein is a widespread feature of normal cellular metabolism in certain cell types and is not restricted to those actively involved in cellular proliferation. It appears, furthermore, that neither cells at different stages of carcinogenesis nor those representing variants of a malignant phenotype can be identified using this particular antibody.

Antibodies, Monoclonal↗
PubMed1984

Sex hormones and susceptibility of the rat to paracoccidioidomycosis.

The development of intraperitoneal paracoccidioidomycosis was studied in groups of female and male rats: a) Under normal conditions (intacts), b) After castration and c) After castration but submitted to a treatment with, respectively, testosterone and estradiol. The criterion of susceptibility to infection was based on: 1) Spontaneous mortality of the animals and 2) Number of metastatic pulmonary lesions. The results showed that: the unique deaths and the more severe pulmonary lesions were found among the intact females, representing the animals most susceptible to the infection in these experiments; the intact females showed more numerous lesions than the castrated; the intact males had less lesions than the castrated, and than those castrated which were treated with estradiol.

Animals↗
PubMed1984

Elevated expression of the human ras oncogene family in premalignant and malignant tumours of the colorectum.

Study of expression of ras-related oncogenes in human premalignant polyps and malignant tumours of the colorectum, as well as in normal colorectal mucosa, shows a significant elevation in the premalignant and malignant tissues as compared to their respective colorectal mucosa. These results suggest that activation of the ras oncogene family occurs in the development of colorectal tumours and that elevated expression at a premalignant stage may well be critical in the process of carcinogenesis but not in itself sufficient.

Cell Line↗
PubMed1983

Paracoccidioidomycosis in silica-treated rats.

An attempt is made to evaluate the importance of macrophages in the early local reaction to infection caused by the fungus Paracoccidioides brasiliensis. With this purpose, an attempt was made to impair macrophagic activity in the site of the fungal inoculum, by means of previous injections of silica. Twenty male rats were intraperitoneally infected with yeast cells of the fungus. Ten of the rats were injected intraperitoneally with silica particles twice, namely 24 and 4 h before the infection. All the animals were killed 4 wk after fungal inoculum. The results showed that the disease was aggravated in rats pre-treated with silica, clearly demonstrated by the 100% metastatic pulmonary involvement, in contrast with only 40% observed in the non-treated controls.

Animals↗
PubMed1982

Experimental paracoccidioidomycosis in immunosuppressed mice.

Mice were immunosuppressed by means of wholebody irradiation or cyclophosphamide, in order to investigate the influence on the initial phase of infection induced by a strain of the fungus, Paracoccidioides brasiliensis, in the yeast phase and inoculated intraperitoneally. A group of mice was irradiated with 600 rad (cobalt gamma-irradiation) 24 h before infection. Two groups were treated with cyclophosphamide (200 mg/kg intravenously), one two days before, and the other, one day after infection. A control group received the fungus, but no radiation or cyclophosphamide. All animals developed lesions at the site of inoculation. Metastatic lesions were observed in 100% of the animals in the irradiated group, 67% in each of the cyclophosphamide-treated groups and 33% in the control group. These lesions were found both in the liver and lungs, being more numerous in the irradiated group, followed by the cyclophosphamide-treated group in which the drug was given after the infection; they were slight in both viscera in the other cyclophosphamide-treated group and also slight in the liver and absent in the lungs of the controls.

Animals↗
PubMed1975

Growth inhibition of sarcoma 180 induced by silica and talc.

In applying amorphous silica and talc in the site of solid Sarcoma 180 implants, the authors found a suppression and delay of tumor growth which was proveked by peritumoral foreign-body granulomas. Correlating these findings which those experiments which resulted in granulomas of hypersensitivity type, it may be suggested that any kind of peritumoral chronic inflammation enables an anti-tumor effect.

Animals↗
PubMed1975

Local effects of silica on tumor growth inhibition. A histological study.

The subcutaneous implant of a fibrosarcoma covered with silica, in rats, resulted in a temporary retardation of tumor growth. The histological study demonstrated that the silica provoked, within and at the periphery of the tumor, inflammatory foci which altered the composition of the fundamental substance and which promoted the accumulation of principally macrophages in the interior as well as on the surface of the tumoral mass. Besides the macrophages of the host, a number of tumor cells do also phagocyte silica crystals, leading to destruction of all those cells. The authors are of the opinion that the local modifications provoked by silica, could have interfered in the adaptation of the tumor with its nutrient stroma. Of these modifications, the stroma sclerosis seems to be the most effective in the inhibition of tumor growth. Some correlations were suggested between the here described results and those obtained by other workers who have used other inflammatory agents of different nature.

Adaptation, Biological↗