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Biomedical subjects

D Jarvis

Publications and source records attributed to D Jarvis.

69 records · Page 4Linked to original sources
PubMed1985

Isolation and identification of actinomycetes from women using intrauterine contraceptive devices.

Of 259 women using intrauterine contraceptive devices 80 (31%) had visible actinomyces-like filaments in their cervical smears. Actinomycetes were cultured from a total of 31 women. Suspicious cultures were identified with the aid of a commercially available kit in conjunction with a computer data base. Culture was found to be less sensitive than microscopical examination of cervical smears in detecting actinomycetes in these women.

Actinomyces↗
PubMed1979

4-pyridylmethyl, a thiol-protecting group suitable for the partial synthesis of proteins.

Cysteine is converted into S-4-pyridylmethylcysteine [Gosden, Stevenson & Young (1972) J. Chem. Soc. Chem Commun. 1123-1124] by 4-pyridylmethyl chloride in aqueous propanol at pH 8.3. The derivative is stable to the conditions of total acid hydrolysis. Reduction and alkylation of bovine insulin (pH 8.3, aq. 50% propanol) gives fully S-substituted derivatives in excellent yields. The S-pyridylmethylated A- and B-chains of insulin were separated by gel filtration: each of them has good solubility properties. The pyridylmethyl group is cleaved by electrolysis in a dilute acid medium, pH 2.6, to give reduced chains. They can be recombined to give insulin in the same yield and with the same degree of biological activity as chains which had not been subjected to the protection and de-protection steps. The results indicate that pyridylmethyl satisfactorily meets requirements for partial synthesis and suggest that it warrants more general use.

Amino Acids↗
PubMed1979

2-Sulphobenzyl, a new solubilizing and reversible protecting group for cysteine in proteins. Its scope and limitations.

S-2-Sulphobenzylcysteine and S-2-(sulphomethyl)benzylcysteine are prepared by alkylation of cysteine with omega-toluenesultone and 2,3-benzo-1,4-butanesultone respectively. Owing to the presence of the sulphonic acid group, these protected cysteine derivatives are extremely water-soluble and are stable to acid hydrolysis. The groups can be removed by treatment with sodium in liquid NH3. Reduction with tributylphosphine and simultaneous alkylation of insulin with toluenesultone under mild conditions (pH 8.3, aq. 50% propanol) gives the fully S-substituted derivatives in excellent yield; they can be separated by isoelectric precipitation of the S-sulphobenzylated B-chain. Treatment of the latter with sodium in liquid NH3 led simultaneously to the removal of the protecting groups and to the well-documented cleavage at the threonine-proline bond which can be prevented by addition of sodium amide. When deprotected A-chain was recombined with B-chain, insulin was isolated in the same yield and with the same degree of biological activity as that in the control experiment.

Amino Acids↗
PubMed1977

Femoral artery pressure monitoring. Use of the Seldinger technique.

A case of bilateral femoral arterial occlusion following the Seldinger technique of arterial puncture for monitoring blood pressure is described. Sixty patients were closely studied for possible complications of this technique, using pedal blood pressure, and skin temperature to supplement clinical observation. Despite the occasional complications which are described we consider this to be a safe and valuable technique in selected circumstances.

Adult↗
PubMedDate not supplied

Effect of passive smoking on respiratory symptoms, bronchial responsiveness, lung function, and total serum IgE in the European Community Respiratory Health Survey: a cross-sectional study.

BACKGROUND: Passive smoking is widespread, and environmental tobacco smoke contains many potent respiratory irritants. This analysis aimed to estimate the effect of passive smoking on respiratory symptoms, bronchial responsiveness, lung function, and total serum IgE in the European Community Respiratory Health Survey. METHODS: This analysis included data from 7882 adults (age 20-48 years) who had never smoked, from 36 centres in 16 countries. Information on passive smoking, respiratory symptoms, asthma, and allergic rhinitis was gathered through a structured interview. Spirometry and methacholine challenge were carried out, and total and specific IgE were measured. The effect of passive smoking was estimated by means of logistic and multiple linear regression for each country and combined across countries by random-effects meta-analysis. FINDINGS: In 12 of the 36 centres, more than half the participants were regularly involuntarily exposed to tobacco smoke. The prevalence of passive smoking in the workplace varied from 2.5% in Uppsala, Sweden, to 53.8% in Galdakao, Spain. Passive smoking was significantly associated with nocturnal chest tightness (odds ratio 1.28 [95% CI 1.02 to 1.60]), nocturnal breathlessness (1.30 [1.01 to 1.67]), breathlessness after activity (1.25 [1.07 to 1.47]), and increased bronchial responsiveness (effect -0.18 [-0.30 to -.05]). Passive smoking in the workplace was significantly associated with all types of respiratory symptoms and current asthma (odds ratio 1.90 [95% CI 0.90 to 2.88]). No significant association was found between passive smoking and total serum IgE. INTERPRETATION: Passive smoking is common but the prevalence varies widely between different countries. Passive smoking increased the likelihood of experiencing respiratory symptoms and was associated with increased bronchial responsiveness. Decreasing involuntary exposure to tobacco smoke in the community, especially in workplaces, is likely to improve respiratory health.

Adult↗