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Biomedical subjects

R W Smith

Publications and source records attributed to R W Smith.

At least 127 records · Page 7Linked to original sources
PubMed1985

Gaseous acidity and basicity scales as guides to chemical ionization in reversed-phase liquid chromatography-mass spectrometry with direct liquid introduction.

During direct liquid introduction (DLI) liquid chromatography-mass spectrometry (LC-MS), the detectability of acetone is shown to be predictable, based on consideration of the gas-phase acidities and basicities of solvents methanol and acetonitrile and modifiers formic acid and ammonium formate. Consequently, ion formation in DLI LC-MS resembles gas-phase chemical ionization processes; since the order of acidities is altered in solution, solution ionization must be much less important than gas-phase. Ion populations could be predicted on the basis of gas-phase proton affinities and acidities: acetone could be detected in all solvent mixture by positive ions, but it was not readily detected by negative ions when acid was also present. In solvents without additives it was always detected.

Acetonitriles↗
PubMed1985

Identification of the major metabolite of 4,4'-thio-bis-(6-t-butyl-m-cresol).

Metabolism of 4,4'-thio-bis-(2-t-butyl-5-methylphenol)(TBBC) in rats resulted in the formation of a glucuronide conjugate of TBBC. This conjugate was identified by a combination of high-performance liquid chromatography (HPLC) and mass spectrometry and a tandem mass spectrometric method employing a fast particle ionization technique. A comparison of mass spectral data from the in-vivo metabolite of TBBC and an enzymically synthesized glucuronide conjugate of TBBC showed the metabolite to be the monoglucuronide.

Animals↗
PubMed1985

External cardiac pacing for out-of-hospital bradyasystolic arrest.

Cardiac pacing has been used successfully in patients with asystole or bradycardia compromising hemodynamics when it was applied soon after the onset of the event. An external cardiac pacemaker was used as part of initial resuscitative efforts for patients in primary, out-of-hospital, cardiac arrest who arrived in the emergency department in asystole, agonal rhythm, pulseless idioventricular rhythm, or bradycardia with hemodynamic compromise. A pulse was successfully generated in only one of twelve patients. That patient developed complete atrioventricular dissociation while in the emergency department. The nonresponding patients were in asystole or pulseless idioventricular rhythm when the pacemaker was applied. Pacing was initiated 1-13 minutes (mean 7 minutes) after arrival in the emergency department, but 27-90 minutes (mean 59 minutes) after arrest. The interval between arrest and application of the pacemaker was prolonged because of long periods for ambulance response, field resuscitation, and transport. It is concluded that the external cardiac pacemaker is a useful instrument for the treatment of bradyarrhythmias. While it may also be useful in the first few minutes after development of asystole, pulseless idioventricular rhythm, or agonal rhythm, it is of no benefit if applied long after the event.

Adult↗
PubMed1985

Effects of vinblastine, etoposide, cisplatin and bleomycin on rodent wound healing.

Chemotherapy for malignant disease is usually deferred for three weeks postoperatively to prevent interference with wound healing. Recently, aggressive perioperative combination chemotherapy has improved survival rates in patients with germ cell tumors. Facial dehiscence at one month in a young man on combination chemotherapy for a pure choriocarcinoma prompted this experimental study. Laboratory rats receiving bleomycin, perioperatively and a combination of bleomycin, etoposide and cisplatin had a significant decrease in wound breaking strength five weeks after injection. These data suggest that patients receiving bleomycin alone or in combination should have fascial closure with nonabsorbable sutures.

Animals↗
PubMed1984

Burn injury: sunlight and a single dose of methoxsalen.

A patient is described in whom burn injury, caused by moderate exposure to sunlight in the U.K., was precipitated by undue sensitivity to a photosensitizing agent methoxsalen. This drug, although withdrawn in the UK, is freely available in the Republic of Ireland and many EEC countries for the treatment of psoriasis and acne vulgaris.

Adult↗
PubMed1984

An analysis into childhood burns.

A retrospective study was conducted into all the children admitted to a regional burns unit over a 6-year period. The whole childhood age group (up to 16 years of age) was examined epidemiologically. The study highlighted differences in the injuries and their acquisition, between the older children (10-16 years of age) and the younger children (up to 10 years of age). The study included data on the social background of the families, and points to the shortcomings of such retrospective material. Aspects of the epidemiology illustrated in the study are discussed with a view to their influence on programmes aimed at the prevention of such injuries to children.

Accidents↗
PubMed1984

Effect of lactation on the metabolism of sheep adipose tissue.

The rates of incorporation of 14C glucose and 14C acetate into triglycerides by slices of omental adipose tissue were much lower in tissues from sheep in early lactation than in tissues from dry, non-pregnant sheep. The rates of oxidation of both substrates were also much lower in early lactation but increased again in late lactation. There was an increase in the incorporation of 14C acetate into triglycerides in late lactation and a further increase after the lambs were weaned. Lipoprotein lipase activity was lower in omental adipose tissue from lactating sheep than in tissue from dry, non-pregnant sheep. There were marked increases in the concentrations of nonesterified fatty acids in plasma and in adipose tissue during early lactation. The rate of release of glycerol by adipocytes in vitro also increased during lactation. These results suggest that there was a change from lipid deposition to lipid mobilisation during lactation.

Acetates↗
PubMed1982

Induction of resistance to tuberculosis in mice with defined components of Mycobacteria and with some unrelated materials.

Factors contributing to protection against experimental tuberculosis have been studied with refined and well-characterized fractions from mycobacteria and with certain unrelated antigens. Mice were vaccinated intravenously with various combinations of materials presented on minute oil droplets in saline emulsion and were later challenged by aerosol. The minimal composition of an effective vaccine was P3 (a trehalose mycolate similar to cord factor) plus an antigen, which could be tuberculo-protein, or a low-molecular-weight tuberculin-active peptide, or unrelated antigen such as bovine serum albumin or bacterial endotoxin. Development of a hypersensitivity granuloma in the lungs appeared to be essential to protection in this laboratory model.

Animals↗
PubMed1982

Induction of resistance to tuberculosis in mice with defined components of mycobacteria and with some unrelated materials.

Factors contributing to protection against experimental tuberculosis have been studied with refined and well characterized fractions from mycobacteria and with certain unrelated antigens. Mice were vaccinated intravenously with various combinations of materials presented on minute oil droplets in saline emulsions and were later challenged by aerosol. The minimal composition of an effective vaccine was P3 (a trehalose mycolate similar to cord factor) plus an antigen, which could be tuberculoprotein, or a low-molecular-weight tuberculin-active peptide, or unrelated antigen such as bovine serum albumin or bacterial endotoxin. Development of a hypersensitivity granuloma in the lungs appeared to be essential to protection in this laboratory model.

Animals↗