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Biomedical subjects

C Sawyer

Publications and source records attributed to C Sawyer.

9 recordsLinked to original sources
PubMed1992

Preliminary assessment of the Dex Frame for assisting children with specific learning difficulties.

A device called the Dex Frame has recently been marketed as an aid for children with specific learning difficulties. Using a test of reading speed and a test of reading accuracy we have attempted to evaluate the device. Two groups of children with learning difficulties were used, one having sole use of the device and being allowed to carry it with them and a second group who only used the device when attending for remedial tuition and assessment. The results show that no significant improvement occurred in reading performance of the groups with learning difficulties using the Dex Frame as compared with a control group. The teachers of the groups did, however, feel that on an individual basis some children (< 10%) expressed that they felt more comfortable using the device.

Audiovisual Aids↗
PubMed1991

An inducible gene expression system for Neurospora crassa.

Neurospora crassa acetyl CoA synthetase is highly induced when the growing mycelium is transferred from sucrose- to acetate-based medium. The inducible promoter of this gene has been isolated and used to control the expression of glutamate dehydrogenase. Transformants containing this expression cassette show gdh levels up to 25 times higher than the nontransformed host strain. This expression cassette will form the basis of a system of heterologous gene expression.

Acetate-CoA Ligase↗
PubMed1989

Mild cystic fibrosis in a consanguineous family.

Cystic fibrosis is an autosomal recessive genetic disorder linked to chromosome 7q in all families studied. Expression of the disease varies, but the genetic basis for clinical heterogeneity is unknown. We describe an extended consanguineous family with pulmonary disease and the sweat gland phenotype of cystic fibrosis. In the members of this family, clinical expression of the disease was mild, as manifested by the absence of severe childhood lung disease and increased longevity with better functional status than that expected for age. The degree of pancreatic exocrine insufficiency varied (4/10), but the older patients had normal pancreatic function. The pedigree suggested the likelihood of common ancestry, and eight of the ten affected persons were clearly related. At least three of the family members with the mildest clinical disease had consanguineous parents and may therefore have been homozygous for a variant cystic fibrosis gene. The mild expression of cystic fibrosis in this family provides evidence for a form of cystic fibrosis that is intrinsically less debilitating than the classic form.

Adolescent↗
PubMed1988

Bacterial survival and thermal responses of beef loaf after microwave processing.

The effects of wrapping product in polyvinylidene chloride (PVDC) film, load size (150, 600 and 1200 g loaves), microwave output power (713 +/- 5 W and 356 +/- 3 W at 2450 MHz) and processing time on bacterial survival were evaluated in beef loaf. Specifically the survival of aerobic flora, and inoculated Staphylococcus aureus (ATCC 6538) and Escherichia coli (O157:H7) were assessed. Results showed that beef loaf wrapped in PVDC film had lower levels of survival for aerobic bacteria, S. aureus and E. coli than unwrapped beef loaf. When beef loaf was exposed to the same microwave dose (watts x minutes processed/grams of food), the percent of survival remained the same, regardless of load size or microwave output power. Exposed microwave dose, which correlated highly to percent of bacterial survival (R2 = 0.8-0.83) and end point temperature (R2 = 0.84), is suggested in place of output power, time or temperature as a predictor of microbial quality in foods that have been microwave processed.

Animals↗
PubMed1984

Calculation of carcinogenic potency from long-term animal carcinogenesis experiments.

An index of carcinogenic potency for chemicals tested in chronic animal experiments is described. By analogy with the well-known 'lethal dose 50' (LD50) of quantal bioassay, a 'tumorigenic dose 50' (TD50) may be defined (in the absence both of tumors in the control group and of intercurrent deaths) as that (daily) dose of chemical which gives 50% of the test animals tumors by some fixed age. Tumors in the control (zero-dose) group are handled exactly as for the LD50, and intercurrent deaths are handled by life-table methods. Nonparametric procedures are developed for estimating the TD50 and for constructing confidence intervals. These are based on likelihoods which assume that the tumor hazard is linear in dose.

Aniline Compounds↗