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Biomedical subjects

R G Wilson

Publications and source records attributed to R G Wilson.

At least 109 records · Page 6Linked to original sources
PubMed1982

Human colorectal tumours in short-term organ culture. A stathmokinetic study.

Short-term organ culture, using a technique to preserve epithelial/stromal interaction and metabolism, is a useful technique for carrying out kinetic studies on human colorectal carcinoma and adjacent normal mucosa, providing initial perturbations of proliferative indices are allowed to settle. Tumours require 3.0 micrograms/ml vincristine for complete metaphase arrest compared with mucosa, which needs 0.5 microgram/ml, a 6-fold difference. Using a stathmokinetic technique, the birth rate of tumour cells is 10.21 cells/1000 cells per hr, compared with 7.73 cells/1000 cells per hr for mucosa, a statistically significant difference (P less than 0.01).

Adenocarcinoma↗
PubMed1982

Urine cyclic nucleotide concentrations in cancer and other conditions; cyclic GMP: a potential marker for cancer treatment.

Cyclic guanosine 3',5' monophosphate (cyclic GMP) and cyclic adenosine 3',5' monophosphate (cyclic AMP) have been determined in random urine specimens from 95 healthy individuals, 60 patients with non-cancerous conditions, 52 patients with benign tumours, and 74 patients with malignant tumours. Concentrations of cyclic GMP have also been determined in a number of other groups, including some undergoing cancer treatment. Ninety-three per cent of cancer patients had raised urinary cyclic GMP concentrations compared to the reference range for healthy subjects. For the non-cancerous and benign groups, 33% and 42% respectively had raised concentrations. The urine cyclic AMP concentrations were similar in all groups. Urine cyclic GMP appeared to rise early in the onset of malignant growth. Successful cancer treatment was accompanied by a dramatic fall in the urine cyclic GMP concentrations, whereas if the treatment was unsuccessful the level did not change. It is concluded that urine cyclic GMP may have important applications in the monitoring of cancer treatment.

Adolescent↗
PubMed1981

Two types of adriamycin inhibition of a homologous RNA synthesizing system from L1210 cells.

Purified L1210 RNA polymerase II was utilized to study the effect of adriamycin on the kinetics of RNA synthesis. In this study it was found that the adriamycin induced two types of inhibition of RNA synthesis with native DNA as a template. At low drug/DNA-P molar ratios, adriamycin functions as an uncompetitive inhibitor, whereas at high drug/DNA-P molar ratios adriamycin inhibits RNA synthesis competitively. However, when denatured DNA was utilized as template, only competitive inhibition was observed. It is proposed that two modes of inhibition of native DNA-dependent RNA synthesis represents two types of adriamycin-DNA complexes.

Animals↗
PubMed1981

Comparative inhibition of nuclear RNA synthesis in cultured mouse leukemia L1210 cells by adriamycin and 4'-epi-adriamycin.

Adriamycin and 4'-epi-adriamycin were compared as to their effect on nRNA synthesis. 4'-Epi-adriamycin was a more effective inhibitor than the parent compound of RNA synthesis as measured by incorporation of [3H]-uridine. Adriamycin inhibited all three species of nRNA (ribosomal, non-poly(A)hnRNA, poly(A)hnRNA) to approximately the same extent. 4'-Epi-adriamycin on the other hand inhibited the nRNA species in the following order: non-poly(A)hnRNA greater than ribosomal RNA greater than poly(A)hnRNA. The inhibitory effects of both drugs on incorporation of uridine into RNA were reversible at low concentrations (5 microgram/ml).

Animals↗
PubMed1981

Simple estimation of macrophage activity in tumour-bearing animals treated with Corynebacterium parvum.

The effects of Corynebacterium parvum on the reticuloendothelial system and on tumour growth have been known for many years. The causes of these effects have been the subject of many hypotheses and we here discuss a new method of evaluating macrophage activity and some of its components. These studies show that in macrophage activation the degree of enzymic activity and the cell size are more important than the number of cells present and that by giving silica concurrently it is macrophage enzyme activity and cell size that one affects and not cell number. Consequently, it is of no use simply to count macrophages in a section in studies of this system.

Animals↗
PubMed1980

Cell wall appositions and plant disease resistance: Acoustic microscopy of papillae that block fungal ingress.

Plant cells react to localized stress by forming wall appositions outside their protoplasts on the inner surface of their cellulose walls. For many years it has been inferred that appositions elicited by encroaching fungi, termed "papillae," may subsequently also deter them and thus represent a disease-resistance mechanism. Recently, it has been shown that preformed, oversized papillae, experimentally produced in coleoptile cells of compatible barley, Hordeum vulgare, can completely prevent direct entry of Erysiphe graminis f. sp. hordei that ordinarily penetrates and causes disease. To discover how these papillae may function, acoustic microscopy was used to contrast their in vivo elastic properties with those of ineffective normal papillae and contiguous cell wall. Raster and line scans showed intense acoustic activity at sites of preformed papillae; scans in selected focal planes identified this activity with the papillae, not with subtending cell wall. Minimal acoustic activity was found in normal papillae. It is suggested that some wall appositions could serve in disease resistance as viscoelastic barriers to mechanical forces exerted by the special penetration structures of advancing pathogenic fungi.

Journal Article↗