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Biomedical subjects

M Gough

Publications and source records attributed to M Gough.

At least 55 records · Page 3Linked to original sources
PubMed1991

Weight of the evidence on the human carcinogenicity of 2,4-D.

The phenoxy herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is widely used to control the growth of weeds and broadleaf plants. We convened a panel of 13 scientists to weigh the evidence on the human carcinogenicity of 2,4-D. The panel based its findings on a review of the toxicological and epidemiological literature on 2,4-D and related phenoxy herbicides. The toxicological data do not provide a strong basis for predicting that 2,4-D is a human carcinogen. Although a cause-effect relationship is far from being established, the epidemiological evidence for an association between exposure to 2,4-D and non-Hodgkin's lymphoma is suggestive and requires further investigation. There is little evidence of an association between use of 2,4-D and soft-tissue sarcoma or Hodgkin's disease, and no evidence of an association between 2,4-D use and any other form of cancer. Scientists on the panel were asked to categorize 2,4-D as a "known," "probable," "possible," or "unlikely" carcinogen or as a noncarcinogen in humans. The predominant opinion among the panel members was that the weight of the evidence indicates that it is possible that exposure to 2,4-D can cause cancer in humans, although not all of the panelists believed the possibility was equally likely: one thought the possibility was strong, leaning toward probable, and five thought the possibility was remote, leaning toward unlikely. Two panelists believed it unlikely that 2,4-D can cause cancer in humans.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1988

Review of interspecies risk comparisons.

Use of laboratory animal data to make quantitative predictions of the risks of toxic effects in humans assumes that a relationship exists between the potencies in animals and humans and that its parameters can be estimated adequately. Such "scaling rules" have been used to predict the risks of carcinogenicity or other effects. A survey of the literature yielded only a modest number of papers devoted to the validity of these interspecies risk extrapolations, of which approximately 25 attempt quantitative comparisons for either radiation or chemical hazards. Some authors have investigated relatively large data sets in an attempt to identify the scaling rule that provides the best correlation of risks in two or more species. Others have selected a scaling rule and investigated whether its predictions from data in laboratory species match the risks found in humans. Opinion is divided on the validity of specific extrapolation rules and the utility of animal experiments for quantitative risk assessment. Correlations exist among risk levels in various species, but many factors appear to influence toxicity that are not captured in a simple scaling rule such as dose per unit weight or per unit surface area. Although scaling rules are useful, better projections will be made if case-specific factors such as pharmacokinetics can be considered. Further careful comparisons of quantitative risk estimates are needed.

Animals↗
PubMed1988

Science policy choices and the estimation of cancer risk associated with exposure to TCDD.

United States regulatory agencies use no-threshold models for estimating carcinogenic risks. Other countries use no-threshold models for carcinogens that are genotoxic and threshold models for carcinogens that are not genotoxic, such as 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD or "dioxin"). The U.S. Environmental Protection Agency has proposed a revision of the carcinogenic potency estimate for TCDD that is based on neither a threshold nor a no-threshold model; instead, it is a compromise between risk numbers generated by the two irreconcilably different models. This paper discusses the revision and its implications.

Carcinogens↗
PubMed1988

Fructooligosaccharides: a review.

Fructooligosaccharides are naturally occurring compounds that have been reported in a variety of plants. Neosugar is a fructooligosaccharide mixture of 1F-(1-beta-fructofuranosyl)-sucrose polymers which is produced on a commercial scale from sucrose using a fungal fructosyltransferase. The resulting product is 0.4 to 0.6 times as sweet as sugar and is resistant to digestion by mammalian alpha-amylase, sucrase and maltase. Although Neosugar is non-digestible in humans, it is selectively utilized by bifidobacteria. Neosugar has been examined extensively in human and animal studies which indicate a lack of toxicity, carcinogenicity and genotoxic effects. Neosugar is used as a feed additive for poultry and swine in Japan and has been approved in foods as a raw material. Additional studies in progress in the US suggest that it could provide an economic alternative as an additive to poultry and swine feed.

Animals↗
PubMed1983

The presence of polysaccharide in normal human gastric mucus.

Polysaccharide material was found in the proteolysis glycopolypeptide fraction from normal human gastric mucus. The polysaccharide was identified by carbohydrate and amino acid analyses, by elemental analysis and from its behaviour on density-gradient ultracentrifugation. The polysaccharide is polydisperse with a weight-average molecular mass of 300 000 Da. Over 85% of the polysaccharide consists of galactose, and this represents 26% of all the galactose present in the fractions after beta-elimination with reduction of the glycopolypeptide material.

Amino Acids↗
PubMed1983

The effect of naloxone and morphine on convulsions in mice following withdrawal from nitrous oxide.

The incidence of withdrawal convulsions was determined in mice following removal from a 70 per cent nitrous oxide environment. Groups of 20 mice received saline (control), naloxone or morphine subcutaneous injections five minutes prior to withdrawal. The observer was blind to the treatments. In comparison to the control group, the proportion convulsing was significantly (p less than 0.05) increased following naloxone 0.125 mg (n = 40), 0.25 mg, but not 0.5 mg. The proportion convulsing was significantly decreased following morphine 0.4 mg. Overall proportions of mice convulsing was 0.55 for the saline control group; 0.73 for naloxone 0.125 mg; 0.80 for naloxone 0.25 mg; 0.60 for naloxone 0.50 mg; and 0.38 for morphine 0.4 mg. Modification of this phenomenon by both an opiate antagonist and agonist suggests endorphin withdrawal as a possible mechanism. However, this should be regarded as indirect evidence pending further study of this area.

Animals↗
PubMed1979

Study of the oligosaccharide units from mucus glycoproteins of meconium from normal infants and from cases of cystic fibrosis with meconium ileus.

1. The mucus glycoproteins in meconium from normal infants and from infants having cystic fibrosis with meconium ileus have been studied. 2. Whereas normal meconium contained about 50% protein-bound carbohydrate, the meconium from cystic fibrosis contained only about 10%. 3. Glycopolypeptides were prepared from the mucus of glycoproteins. The oligosaccharide units from this material were released and fractionated. The fractions ranged widely in size and composition. 4. The fractions from cystic fibrosis specimens had a significantly higher content of fucose than those from normal specimens.

Carbohydrate Metabolism↗