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Biomedical subjects

R C Brown

Publications and source records attributed to R C Brown.

At least 19 recordsLinked to original sources
PubMed1979

An evaluation of nutrition centre effectiveness by measurement of younger siblings.

Thirty children were measured when they entered nutrition centres. Their younger siblings were later measured at the same age. Over the same period, a matched group of control children and their siblings were measured. The younger siblings of Centre participants showed the same growth patterns as the younger siblings of control children. Centre teaching had evidently not affected the way mothers fed their younger children, and thus it had no effect on their growth.

Body Height↗
PubMed1979

The effect of wheat bran and pectin on paracetamol absorption in the rat.

1. The absorption of an oral dose of paracetamol was measured in rats given either a basal fibre-free diet, or the basal diet with either pectin or bran added. 2. Urinary excretion of the oral dose was significantly greater during the first 8 h in the pectin-fed rats compared with those on basal diet, though cumulative excretion after 72 h was the same. 3. Free paracetamol levels in the plasma were significantly higher in the pectin-fed rats compared with those on basal diet at 30, 60, 90 and 120 min after the oral dose. 4. The plasma half-life of intravenously-injected paracetamol was shorter in the pectin-fed rats than in those on basal diet alone, but the antipyrine half-lives were not significantly different. 5. Pectin feeding had no effect on either the apparent volume of distribution of paracetamol and antipyrine, or on the rate of gastric empyting. 6. Perfusion of the whole length of the small bowel showed a significantly greater capacity for paracetamol absorption in the pectin-fed rats. 7. Bran had no effect on paracetamol absorption. 8. It was concluded that dietary fibre intake affects drug absorption and that the effect varies with the type of fibre. Unexpectedly pectin accelerates rather than retards absorption of paracetamol, though the mechansim of this effect is unknown.

Acetaminophen↗
PubMed1979

The effect of pectin on the structure and function of the rat small intestine.

1. The effect of pectin on the structure and function of the rat small intestine was compared with that of a standard pellet diet and of a fibre-free basal diet. 2. The length and wet weight of the small bowel was significantly greater inpect in-fed rats than in either pellet- or basal-diet-fed rats. 3. Histological measurements of longitudinal sections from the small bowel showed a significantly greater crypt depth and muscle layer thickness in the mid-jejunum and ileum of the pectin fed rats. Villous height showed less variation. 4. The specific activity of alkaline phosphatase (EC 3.1.3.1) and leucyl-beta-naphthylamidase (EC 3.4.11.1) in mucosal scrapings was significantly lower in the upper jejunum of pectin-fed rats compared with either of the other dietary groups. The differences were not so marked in mid-jejunum or ileum. 5. Glucose absorption measured in vivo from jejunal and ileal loops was similar in all three dietary groups. 6. With two minor exceptions there were no significant differences in any of these measurements between the pellet- and basal-diet-fed rats. 7. These findings could be explained by increased epithelial cell turnover caused by pectin. The possible mechanisms of this are discussed. 8. The effect of pectin on the human small bowel requires study before it can be widely prescribed in man.

Alkaline Phosphatase↗
PubMed1979

In vitro prediction of the pathogenicity of mineral dusts.

Eight mineral dusts, of which 7 were fibrous, were tested in 3 in vitro systems. The dusts had previously been tested for their ability to produce mesotheliomata in rats. The in vivo and in vitro biological activities of these dusts are compared with the number and size of fibres they contain. It is concluded that all the in vitro systems would predict which dusts are pathogenic in vivo, and that both in vivo and in vitro biological activities are determined by the number of long, fine fibres.

Aluminum↗
PubMed1979

Accuracy of lymphangiography in the diagnosis of paraaortic lymph node metastases from carcinoma of the cervix.

A study was undertaken to evaluate the use of lymphograms as a method of diagnosing cancer of the cervix metastatic to the paraaortic lymph nodes. Twenty-one patients underwent lymphograms, surgical biopsy, and histologic examination of the paraaortic nodes. The specificity of lymphangiographic examinations is not accurate enough to be of clinical significance in the detection of paraaortic lymph node metastasis from carcinoma of the cervix. Lymphangiography can be of assistance in locating suspicious lymph nodes. These nodes should then be biopsied. The final therapeutic decisions should be based on tissue diagnosis.

Aorta↗
PubMed1978

The effect of fibre size on the in vitro biological activity of three types of amphibole asbestos.

Three standard (UICC) samples of amphibole asbestos were subjected to ball-milling; the main effect of this procedure was to reduce the length of the fibres present in each sample. The numbers of fibres in unit masses, and the distribution of fibre sizes in all the samples, both parent and milled, were estimated from electron micrographs. The ability of all the samples to reduce the plating efficiency of V79-4 cells is compared, on the basis of mass, fibre number and fibre number number above various length thresholds. This biological activity of all the samples correlated best with the number of fibres above a threshold length of 6.5 micron. This is compared with the sizes of fibre previously reported to induce mesotheliomata when implanted into the pleural cavities of rats.

Asbestos↗
PubMed1978

Isolation and identification of the fluorescent degradation product of some beta-lactam antibiotics.

A fluorescent degradation product of cephalexin, recently employed in the determination of this antibiotic in aqueous solution and human plasma, has been isolated and identified as 2-hydroxy-3-phenyl-6-methylpyrazine. Spectroscopically and chromatographically the product is indistinguishable from that obtained by the same method from a series of other cephalosporins and penicillins bearing an alpha-amino group on the side-chain, and from the pyrazine structure produced by synthesis. Two reported methods for the fluorimetric determination of ampicillin have also been found to yield the same degradation product and not the suggested diketopiperazine structure.

Cephalosporins↗
PubMed1978

Amoebic hepatic abscess--potential causes of delay in diagnosis.

Delay in diagnosis can be serious in amoebic hepatic abscess, which is readily treatable. Two cases are presented to illustrate potential causes of delay. The first case had never been to an endemic area, apparently contracting the infection from his wife. The second case had negative serological tests.

Adult↗
PubMed1978

The cytotoxic effects of asbestos and other mineral dust in tissue culture cell lines.

The cytotoxic effects of 15 dusts have been tested in 2 cell lines. Experimental animal data are available for 11 of the 15 dusts. There is a correlation between the cytotoxic activities of the dusts and the ability to induce mesothelial tumours following intrapleural injection of the dusts. Some preliminary observations on the nature of interaction between the dusts, medium components and the cells are reported. It is suggested that the study of the interactions between cells and dusts in culture may lead to an understanding of the pathogenesis of these dusts in man and animals.

Asbestos↗