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Biomedical subjects

B Dixon

Publications and source records attributed to B Dixon.

At least 199 records · Page 11Linked to original sources
PubMed1977

[Time factor in local radiotherapy (author's transl)].

This study was aimed at determining the influence of time factor in local radiotherapy in patients with spindle cell neoplasms of the skin or basal cell carcinomas of the face, treatable in a single plane. These neoplasma were treated using identical doses (6,000 rads distributed over the envelope isodose), but divided at random into two groups corresponsing to two different spreads (60 +/- 12 hours and 156 +/- 12 hours). The biological effects observed (rate of disappearance of the lesion, intensity of skin reaction, duration of skin reaction) showed no difference between the two types of treatment. This results is unexpected considering the important influence of time factor in the case of fractionated irradiation. In fact, if it is accepted that between 60 and 156 hours, cellular multiplication phenomena are equivalent to approximately 30 rads per day, the difference in spread the two types of treatment is not sufficient to give a significant result.

Basal Cell Carcinoma↗
PubMed1976

The effect of Corynebacterium parvum on the humoral and cellular immune systems in patients with breast cancer.

Corynebacterium parvum, a Gram-positive anaerobic bacillus thought to be a strong immunological stimulant, has been shown to decrease tumour growth and prolong survival in patients with metastatic disease. Study of the effect of a single injection of a strain of C. parvum (CN. 6134) in six patients with stage IV metastatic breast cancer is reported. Results of laboratory tests to judge the physical and immunological effects of the drug infusion 24 hr post-treatment and weekly thereafter for 3 weeks are evaluated. Within 24 hr after C. parvum administration, most patients experienced fever and nausea. Blood counts and differential counts exhibited increased values 24 hr after treatment with a strong shift to the left. Lymphocyte and monocyte counts were greatly depressed at 24 hr. T-cell numbers in peripheral blood did not appear to be altered, but the picture with regard to B cells was less clear. Normal count was recovered by day 8. It appears that intravenous administration of C. parvum produces a temporary marked immunological depression which returns to essentially normal values in 8 days. The return to normal may be accompanied by resolution of the endotoxin-like syndrome of side-effects. Further study of patients receiving this therapeutic agent is important to detect enhancement of the anti-tumour immunological response precipitated.

Aged↗
PubMed1975

Experimental paracetamol-induced hepatic necrosis: a light- and electron-microscope, and histochemical study.

Rats were killed at various time-intervals up to 48 hr after a single large dose of paracetamol (3 g per kg) and their livers examined by light and electron microscopy. In general, this revealed glycogen depletion, loss of ribosomes, and cytoplasmic matrix swelling commencing 3-6 hr after administration which in centrilobular hepatocytes progressed to frank coagulative necrosis at 12-24 hr. Midzonal cells showed more prominent aqueous swelling with besiculation of the endoplasmic reticulum, and in some cells, gross hydropic vacuolation.

Acetaminophen↗
PubMed1966

A specific requirement for biotin in the synthesis of ornithine carbamoyltransferase by yeast.

1. Growth of a biotin-requiring strain of Saccharomyces cerevisiae in a medium containing a suboptimum concentration of biotin for growth caused a decreased synthesis of ornithine carbamoyltransferase as compared with yeast grown in a medium containing an optimum concentration of biotin. Inclusion of the biotin homologues norbiotin or homobiotin, but not bishomobiotin, in the biotin-deficient medium caused an appreciable increase in ornithine carbamoyltransferase synthesis without affecting growth or synthesis of total RNA and protein. The addition of norbiotin to biotin-deficient medium had no effect on the respiratory activity of the yeast or on the synthesis of aspartate carbamoyltransferase, acid phosphatase, beta-fructofuranosidase or malate dehydrogenase. 2. Synthesis of acetylornithine deacetylase and acetylornithine acetyltransferase was slightly diminished by the imposition of biotin deficiency, but the effect was not as great as on ornithine carbamoyltransferase synthesis. Incorporation of norbiotin in the biotin-deficient medium had no marked effect on the synthesis of any other arginine-pathway enzyme except ornithine carbamoyltransferase. 3. l-Ornithine induced synthesis of ornithine carbamoyltransferase in yeast grown in biotin-deficient medium, but in yeast grown in this medium supplemented with norbiotin it repressed synthesis of the enzyme. l-Arginine had no detectable effect on ornithine carbamoyltransferase synthesis by the yeast grown in biotin-deficient medium with or without norbiotin. l-Aspartate repressed synthesis of ornithine carbamoyltransferase in biotin-deficient yeast and completely nullified the stimulatory effect of norbiotin on synthesis of the enzyme in this yeast. 4. There was no increase in ornithine carbamoyltransferase synthesis in biotin-deficient yeast incubated in phosphate buffer, pH4.5, containing glucose and biotin or norbiotin. In biotin-deficient yeast suspended in complete medium containing an optimum concentration of biotin, there was an increase in ornithine carbamoyltransferase synthesis only after the onset of growth.

Acid Phosphatase↗
PubMedDate not supplied

The pattern and timing of lymphatic metastasis of the rat carcinoma LMC.

The distribution pattern and latency of lymphatic metastases naturally disseminated by the Leeds Mammary Carcinoma (LMC1) when transplanted subcutaneously in isogeneic Johns' Strain Wistar rats has been determined. After the curative local irradiation and excision of the primary tumour in 210 rats, 55 +/- 3 per cent developed either local (26 +/- 3 per cent), and/or regional (28 +/- 3 per cent) and/or distant (37 +/- 3 per cent) lymph node metastases. Analysis of their pattern of distribution suggests that metastasis to local (inguinal and lumbar) and distant (axillary and mediastinal) nodes results mainly from the radial dissemination, trapping and nodal proliferation of cells released by the primary tumour. Although direct metastasis to the para-aortic node may have occurred, in the main seeding of this site and thence to other, regional, i.e. iliac and/or adrenal nodes, resulted from the dissemination of tumour cells from the local nodes. The latency of metastases appearing at different sites after primary tumour ablation, although highly variable, was site dependent and for local, regional and distant nodes was 30 +/- 14, 48 +/- 16, 56 +/- 17 days respectively. In addition, the latency of metastases at regional and distant nodes was directly correlated with the latency of local metastases. The latency of adrenal and iliac metastases also correlated with para-aortic node metastasis, as did mediastinal with axillary lymph node metastasis. From the data, a semi-quantitative model of lymphatic metastasis has been developed for further evaluation and adjuvant chemotherapy testing.

Adrenal Glands↗