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Biomedical subjects

R E Robinson

Publications and source records attributed to R E Robinson.

11 recordsLinked to original sources
PubMed1991

Free radical formation in the oxidation of malondialdehyde and acetylacetone by peroxidase enzymes.

Malondialdehyde, a product of lipid peroxidation, and acetylacetone undergo one-electron oxidation by peroxidase enzymes to form free radical metabolites, which were detected with ESR using the spin-trapping technique. The structures of the radical adducts were assigned using isotope substitution. With both malondialdehyde and acetylacetone and the enzymes myeloperoxidase and chloroperoxidase, carbon-centered radicals were detected. With horseradish peroxidase, a carbon-centered radical was initially trapped and then disappeared with the concomitant appearance of an iminoxyl radical.

Chloride Peroxidase↗
PubMed1991

Control of nausea and autonomic dysfunction with terfenadine, a peripherally acting antihistamine.

Terfenadine (Seldane) was administered to 14 male subjects in a randomized, double-blinded, and crossed-over design to assess the efficacy of this peripherally active antihistamine as an anti-motion sickness drug. Terfenadine possesses practically no central side effects. A Staircase Profile Test was administered 4 h following placebo or a single oral dose of terfenadine (300 mg). The study revealed a statistically significant therapeutic effect from terfenadine (p less than 0.05). This led us to conclude that because the drug does not or only poorly crosses the blood-brain barrier, a selective peripheral antihistamine (H1) action may be sufficient in the control of motion sickness induced through cross-coupled accelerative semicircular canal stimulation using a rotating chair. This finding implies that other peripherally acting agents might be found that possess even greater anti-motion sickness efficacy. The present research raises additional questions regarding current theories on the etiology of motion sickness, its associated autonomic system dysfunction, and the validity of assumptions that effective pharmacological agents must act centrally.

Autonomic Nervous System↗
PubMed1987

Virulence of iron transport mutants of Shigella flexneri and utilization of host iron compounds.

Mutants of Shigella flexneri defective in aerobactin-mediated iron transport were assayed for virulence in several model systems. A Tn5 insertion mutant was invasive in HeLa cells, lethal in the chicken embryo, and produced keratoconjunctivitis in the guinea pig, indicating little or no loss of ability to invade and multiply intracellularly. Although the mutant failed to grow in low-iron medium in vitro, growth equivalent to that of the wild type was observed in HeLa cell lysates. Thus, there appears to be sufficient available iron inside the HeLa cell to allow growth in the absence of siderophore synthesis. Possible host iron sources were tested, and both the mutant and wild type utilized hemin or hematin as a sole source of iron. Only the wild-type, aerobactin-producing strain could remove iron from transferrin or lactoferrin. Two deletion mutants were also assayed for virulence and were found to be avirulent for the chicken embryo. These deletions encompass flanking sequences as well as the aerobactin genes; therefore, adjacent genes may be required for virulence.

Animals↗
PubMed1985

Prevalence of human papillomavirus type 16 DNA in cervical carcinoma samples in East Anglia.

A substantial increase in the incidence of severely dysplastic cervical lesions (CIN 3) has been observed during the period 1975-1982 in the East Anglian region of England. Since patients with severe dysplasia have an enhanced risk of developing cervical carcinoma, it seems possible that a substantial increase in the rate of cervical carcinoma is likely to occur in the near future. Evidence of a relationship between human papillomavirus (HPV) infection and cervical carcinoma has accumulated recently. We have studied the incidence of HPV16 DNA in cervical tissue samples from patients with cervical carcinoma, severe dysplasias and normal controls. Five out of 11 invasive squamous carcinomas of the cervix, 3/4 dysplasias and 0/12 normal samples were positive in Southern blot assays for HPV16 DNA. Some of the tissue samples had as many as 500 copies of HPV16 DNA per cell. The amount of HPV16 DNA present correlated with the aggressiveness of tumour growth.

Animals↗
PubMed1979

Clinical aspects of diabetes in pregnancy.

The introduction of insulin produced a rapid improvement in the maternal prognosis in pregnancy associated with diabetes mellitus. Within years, maternal mortality fell from 50% and has become a rarity. Improvement in fetal survival was less dramatic until the work of Pedersen (1952); Peel and Oakley (1950) and White (1949) demonstrated that with determined antenatal control of diabetes the fetal outcome was greatly improved. Further improvement in the care of the fetus of the pregnant diabetic with fetal monitoring, both ante- and intra-partum, together with modern neonatal expertise, had brought the perinatal and neonatal morbidity and mortality for this group of patients close to that of the non-diabetic. An account is given of the author's present day practice in this group of patients.

Delivery, Obstetric↗