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Biomedical subjects

R J Oliver

Publications and source records attributed to R J Oliver.

26 records · Page 2Linked to original sources
PubMed1986

Dyspepsia: incidence of a non-ulcer disease in a controlled trial of ranitidine in general practice.

Patients who presented to their family doctors with previously uninvestigated dyspepsia of at least two weeks' duration were recruited into a placebo controlled trial of treatment with ranitidine (150 mg twice daily) for six weeks. All patients were examined by endoscopy before treatment, and for those with macroscopical abnormalities the examination was repeated after treatment. Of the 604 patients recruited, 559 had endoscopy, of whom 171 (30%) had no apparent abnormality. Of the 388 patients remaining, one third had two or more lesions. The high incidence of underlying disease was coupled with low accuracy in unaided clinical diagnosis. After endoscopy 496 patients with persistent symptoms (median duration six to eight weeks) were randomly allocated to treatment and then reviewed every two weeks. Complete remission of symptoms occurred in 76% of patients who were taking ranitidine and in 55% who were taking placebo (p less than 0.000004). Of those with non-ulcer dyspepsia, significantly more became symptom free taking ranitidine compared with placebo (p less than 0.002). Ranitidine healed most duodenal ulcers (80%) and gastric ulcers (90%) within four weeks. Tolerance to ranitidine was good, and the incidence of complaints was similar on placebo.

Adolescent↗
PubMed1984

A portable instrument for quantifying erythema induced by ultraviolet radiation.

The design and performance of an instrument for quantifying ultraviolet-induced cutaneous erythema are discussed. If the instrument is used to record an 'erythema index' at a site on the skin before and after irradiation, the difference between those two readings is essentially related to an increase in vasodilation and is largely independent of the melanin content of the epidermis.

Dermatology↗
PubMed1979

In Vitro Study of Mitochondrial Protein Synthesis during Mitochondrial Biogenesis in Excised Plant Storage Tissue.

Mitochondrial biogenesis was induced in Jerusalem artichoke (Helianthus tuberosus) tuber by aging tissue discs in distilled water for up to 26 hours. Changes in the purified mitochondrial fraction during aging included an increase in both protein content and specific respiratory activity. Using intact isolated mitochondria, conditions were optimized for incorporation of radioactive amino acid into protein. Incorporation was dependent upon the supply of an oxidizable substrate or an external ATP-generating system and showed characteristic sensitivity to inhibitors of protein synthesis. Aging of the tissue resulted in a 3-fold increase in the rate of in vitro incorporation of [(35)S]methionine into mitochondrial protein. An analysis of the free amino acid pool in the mitochondrial fraction showed that the decrease in methionine level during aging of intact tissue was sufficient to account for the increased rate of protein labeling. The activation of mitochondrial biogenesis which occurs after slicing is not dependent on an increase in the capacity of mitochondria to synthesize protein as assayed in vitro.Analysis, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography, showed that isolated mitochondria synthesized about 15 polypeptides in the molecular weight range 8,000 to 55,000. As aging proceeded, significant changes were observed in the relative rates of labeling of three out of the eight major polypeptides synthesized by mitochondria in vitro.

Journal Article↗
PubMed1978

Variation in mitochondrial translation products associated with male-sterile cytoplasms in maize.

Mitochondria were isolated under sterile conditions from maize lines with normal cytoplasm and with T, C, and S sources of cytoplasmic male sterility. Protein synthesis by these mitochondria was dependent upon the presence of ADP and an oxidizable substrate or an energy generating system and displayed characteristic sensitivity towards inhibitors of protein synthesis. Approximately 20 polypeptides were detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis of the [(35)S]methionine-labeled mitochondrial translation products. Mitochondria from the T and C cytoplasms were characterized by the synthesis of a single additional or variant polypeptide.These observations are discussed with reference to the possible mechanisms of male sterility and the susceptibility of plants with T cytoplasm to Helminthosporium maydis, race T. Our results also suggest a potentially rapid method of classifying sources of cytoplasmic male sterility that could be used in conjunction with existing methods, which depend on patterns of fertility restoration after an extended breeding program.

Journal Article↗
PubMed1972

Machine for automatic bacteriological pour plate preparation.

A fully automatic system for preparing poured plates for bacteriological analyses has been constructed and tested. The machine can make decimal dilutions of bacterial suspensions, dispense measured amounts into petri dishes, add molten agar, mix the dish contents, and label the dishes with sample and dilution numbers at the rate of 2,000 dishes per 8-hr day. In addition, the machine can be programmed to select different media so that plates for different types of bacteriological analysis may be made automatically from the same sample. The machine uses only the components of the media and sterile polystyrene petri dishes; requirements for all other materials, such as sterile pipettes and capped bottles of diluents and agar, are eliminated.

Automation↗