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Biomedical subjects

R Richards

Publications and source records attributed to R Richards.

At least 127 records · Page 7Linked to original sources

Reducing the hazards in Sydney's the Sun City-to-Surf runs, 1971 to 1979.

The hazards experienced by fun runners in Sydney's The Sun City-to-Surf run are principally physical, environmental and medical. The organizers of the event, advised by a representative of the Australian Sports Medicine Federation (N.S.W.), have progressively increased the implementation of the recommendations which were made after the inaugural run in 1971 in the areas of improved organization, competitor education, medical support, recording of competitor data, and conducting the event in cool weather. To ensure the maximum safety of the runners, the number of whom has increased from approximately 1650 in 1971 to 16200 in 1979, additional measurees have been taken. These were (i) the introduction of "spotters" with experience in sports medicine to identify and advise exhausted runners before they collapse; (ii) staffing the run's medical centre with medical and nursing specialists in intensive care; (iii) improved management of heat exhaustion; and (iv) conducting education seminars after the run to make recommendations for improving subsequent events. Since 1971, there has been a progressive reduction in the number of casualties. The incidence of casualties treated in the medical centre fell from 1.76% in 1971 to 0.1% in 1979; and the incidence of those requiring further treatment in hospital fell from 0.42% in 1971 to 0.01% in 1979. None of the participants had suffered severe complications of heat exhaustion. Improvements in the management of heat exhaustion (the most common cause of collapse) which made the use of iced water (hiterto traditional method of cooling casualties with hyperthermia) unnecessary have reduced the risk of using electrical equipment in wet surroundings. The over-all reduction in the incidence and morbidity of collapse casualties is due to a combination of factors. These factors and possibilities of further reduction of hazards are discussed.

Accident Prevention↗

Elevated levels of carcinoembryonic antigen in cord plasma.

41.5% of 200 newborn infants had levels of carcinoembryonic antigen (CEA) in excess of 2.5 ng/ml in their cord plasma. There was no direct correlation with the maternal CEA level although the frequency of elevated CEA was significantly greater among infants born to mothers with CEA levels greater than 2.5 ng/ml. There was no preponderance of high CEA levels among infants with low birth weights and there was no influence of maternal smoking on a cord CEA level. There was a tendency toward an increased incidence of cancer in families with infants who had elevated CEA levels and a reverse trend was noted with respect to diabetes; however, these associations were not statistically significant. We were unable to define clearly the factors accounting for the persistent elevation of this oncofetal antigen at birth; however, the possible association with susceptibility to the development of neoplasia merits further study.

Adult↗

Diseases of aquarium fish--4: treatment.

Prevention and treatment of aquarium fish diseases is described. A variety of husbandry factors may predispose to disease development and these should always be considered. Any treatment should first be tried on a small sample of fish as toxicity does vary between species.

Acriflavine↗

Diseases of aquarium fish--2: skin diseases.

Brief descriptions are given of the common skin diseases in aquarium fishes. Many of these diseases are secondary to poor water quality and aquarium conditions and this primary cause should always be considered.

Animals↗

Studies of the metabolic fate of p-hydroxybenzoic acid in male and female cats.

Metabolic studies conducted on p-hydroxybenzoic acid orally administered at dose levels of 13 and 26 mg/kg to male and female cats have shown that the compound is rapidly excreted in the urine exclusively in the form of the glycine conjugate p-hydroxyhippuric acid. Similar results were obtained following either single administration or 7-day treatment. The metabolite in the urine was characterised by thin-layer chromatography, amino acid analysis and mass spectrometry.

Amino Acids↗

Kinetics of assembly of a parvovirus, minute virus of mice, in synchronized rat brain cells.

The rates of assembly of the three classes of particles of minute virus of mice were examined in synchronized rat brain cells by a combination of electron microscopy and biochemical techniques. We observed a burst of virus assembly beginning about 8 h after the end of cellular S phase. Labeled thymidine incorporated into the 1.46 g/cm3 class of full virus particles was transferred almost quantitatively to the 1.42 g/cm3 class. The 1.46 g/cm3 virus appeared to be an immediate precursor to the 1.42 g/cm3 class. Conversion of the 1.46 density virus to the 1.42 density particles was observed at the time of virus assembly. The processing was rapid and occurred primarily in the nucleus. Infected cells did not contain significant pools of viral DNA in a form that could be encapsulated in the absence of DNA synthesis. The role of the empty virus capsids in the assembly process is discussed.

Animals↗

Preliminary studies with L-asparaginase bound to implantable bovine collagen heterografts: a potential long-term, sustained dosage, antitumor enzyme therapy system.

In this study, L-Asparaginase has been bound to collagen heterografts derived from carotid bovine arteries. The immobilization procedure utilizes both non-covalent and covalent interactions to fix the enzyme. Binding of the enzyme to the graft material was shown to the pH dependent, with optimum binding occurring at pH 6.0 and pH 8.5. Amidohydrolysis by the bound enzyme exhibited zero-order kinetic behavior at substrate saturating conditions. Total apparent asparaginase activity expressed by the grafts as a function of the number of repeated in vitro assay trials demonstrated that over a span of 3 months of intermittent storage and use, the enzyme-grafts retained as much as 62% of their initial activities. Implantation of 4 asparaginase-collagen grafts in various locations of the thoracic and abdominal aorta resulting in prolonged reductions of plasma asparagine levels in 3 of the 4 implants. Presence of plasma asparaginase was checked in one of the four implants and determined to be less than 2 X 10(-4) I.U./ml. Removal of grafts from 3 of the 4 animal subjects showed reductions in the apparent asparaginase activity expressed by the grafts of 7 to 70 percent after in vivo contact times which varied from 6 to 15 days.

Animals↗

Characterization of pulmonary surfactant from ox, rabbit, rat and sheep.

1. Pulmonary surfactants from ox, rabbit, rat and sheep were isolated and analysed. 2. All preparations had a high anenoic phosphatidylcholine content and would produce stable surface tensions of 0.01 Nm-1 or less. 3. Protein content was 8-18% of the dry weights. A number of proteins were observed; their overall composition were high in hydrophobic amino acid residues. 4. Lipid content varied from 79% (ox) to 90% (rabbit) with phosphatidylcholine representing from 58% (sheep) to 83% (rabbit) of the total lipid. The surfactant preparations were rather similar in lipid composition except that sheep surfactant contained about 10% lysophosphatidylcholine. 5. Hexadecanoic acid was the principal fatty acid. It was particularly high in phosphatidylcholine. 6. Phosphatidylglycerol was a minor constituent of all surfactants but phosphatidyldimethylethanolamine was not detected.

Amino Acids↗

Name-printing as a test of developmental maturity.

An attempt to derive a practical scoring technique for name-printing by children in kinderten (age-range 5 1/2 to 6 1/2 years) as a quick test of skills and maturity is reported. The relationship of the Print-Your-Name test scores to other established tools of developmental assessment is examined. Teachers' assessments of the study children's readiness for academic promotion and of those children with school problems tended to correlate with the test scores.

Canada↗