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R S Harding

Publications and source records attributed to R S Harding.

17 recordsLinked to original sources
PubMed1993

Diabetes, glaucoma, sex, and cataract: analysis of combined data from two case control studies.

Data from two case control studies in Oxfordshire were combined and analysed. The combined study covered 1940 subjects, 723 cases, and 1217 controls, between the ages of 50 and 79 with a response rate of 97% for cases and 94% for controls. Diabetes was shown to be a powerful and highly significant risk factor for cataract with a relative risk of 5.04. More than 11% of cataracts in Oxfordshire are attributable to diabetes. The relative risk did not increase significantly with age within the range 50 to 79 years but was higher in females than in males. For females with diabetes the relative risk was 7.85 with 95% confidence interval from 4.30 to 14.3 compared with 3.42 with confidence interval from 2.05 to 5.71 for males with diabetes. Diabetes remained a powerful risk factor when other identified risk factors had been controlled for. No known mechanism for the development of diabetic complications provides an explanation for the excess risk in females. Combination of the two studies led to better estimates of the relative risk of glaucoma as a risk factor for cataract (3.96 with 95% confidence interval from 2.35 to 6.68). The relative risk appeared to be greater in women than in men but this difference was not statistically significant. There was no significant change in risk with age. Glaucoma is a powerful and independent risk factor for cataract in both sexes and may be responsible for 5% of all cataracts in our area.

Aged↗
PubMed1993

Annual birth patterns of savanna baboons (Papio cynocephalus anubis) over a ten-year period at Gilgil, Kenya.

Most cercopithecines reproduce on a seasonal basis, but the proximate mechanisms influencing birth periodicity are often unclear. We analyze 10 years of data from the Gilgil Baboon Project (Kenya) in order to examine the relationship between annual birth patterns and rainfall. Savanna baboons at Gilgil copulated in all months of the year, and births did not occur on a seasonal basis. Annual rainfall patterns showed no association with annual birth patterns, but the chances of conception were significantly greater following the end of the long rainy season than at other times of the year. Nonseasonal reproduction is a general characteristic of savanna baboons (Papio cynocephalus subsp.) throughout Africa. The extreme dietary diversity of baboons enables them to utilize a wide variety of resources and facultatively manipulate the timing of different stages in the reproductive cycle in accordance with resource availability. We predict that nonseasonality of reproduction will be more likely to occur among species with a large dietary diversity than among species with a more restricted diet.

Animals↗
PubMed1989

Risk factors for cataract in Oxfordshire: diabetes, peripheral neuropathy, myopia, glaucoma and diarrhoea.

423 cataract patients and 608 controls between the ages of 50 and 79 were interviewed in a case-control study in Oxfordshire. Diabetes, myopia, glaucoma, peripheral neuropathy and severe diarrhoea were identified as risk factors. The excess risk experienced by females with diabetes was confirmed. The trauma of surgery for glaucoma may be largely responsible for the appearance of glaucoma as a risk factor. Severe diarrhoea has now been identified as a risk factor in England and in India. The risk associated with peripheral neuropathy may indicate a common aetiology at least for some proportions of the two conditions.

Aged↗
PubMed1989

Protection against cataract by aspirin, paracetamol and ibuprofen.

Results of a case-control of 423 cataract patients and 608 controls in Oxfordshire shows that the protective effect against cataract associated with consumption of aspirin-like analgesics (aspirin, paracetamol and ibuprofen family) is manifest even at low doses. Less than 150 g total dose was associated with a halving of the risk of cataract extraction.

Acetaminophen↗
PubMed1988

Decreased postoperative myocardial fatty acid oxidation.

Myocardial substrate preferences following cardioplegic arrest for coronary bypass surgery have not been established. Fatty acids are believed to be the major fuel source for aerobic metabolism. Following cardioplegic arrest arterial fatty acid levels are elevated and myocardial fatty acid accumulation without oxidation may contribute to reperfusion injury. Perioperative fatty acid metabolism was evaluated in 18 patients undergoing elective coronary bypass surgery who were randomized to receive either blood (n = 11) or crystalloid (n = 7) cardioplegia. Palmitate labeled with 14carbon was infused perioperatively and arterial and coronary sinus blood samples were obtained to calculate myocardial fatty acid extraction and oxidation before and after cardioplegic arrest. Lactate and glycerol were released from the heart during both blood and crystalloid cardioplegia, suggesting ischemic glycolysis and lipolysis. Myocardial oxygen consumption was depressed and the myocardial consumptions of lactate, glucose, and fatty acids were minimal during the first 60 min after aortic clamp removal in both groups despite high arterial concentrations. Fatty acid oxidation was minimal after blood cardioplegia and was not found after crystalloid cardioplegia. Fatty acids were extracted by the heart, but were not aerobically metabolized following cardioplegic arrest. Myocardial fatty acid accumulation without oxidation may have been deleterious. The inability of the heart to oxidize exogenous fatty acids may reflect altered myocardial exogenous substrate preferences during reperfusion following coronary bypass surgery.

Cardioplegic Solutions↗
PubMed1986

Accelerated myocardial metabolic recovery with terminal warm blood cardioplegia.

Although blood cardioplegia provides excellent protection, myocardial metabolic recovery is delayed. To evaluate the benefits of a terminal warm cardioplegic infusion after cold blood cardioplegia, we performed a prospective randomized trial in 20 patients undergoing elective coronary bypass grafting. Eleven patients received cold blood cardioplegia and nine patients received cold blood cardioplegia and warm blood cardioplegia before cross-clamp removal (hot shot). The hot shot provided oxygen and removed excess lactate from the arrested heart. After the hot shot lactate was extracted by the heart and tissue adenosine triphosphate and glycogen concentrations were preserved. Atrial pacing and volume loading 3 and 4 hours postoperatively decreased myocardial lactate extraction after cold blood cardioplegia but increased lactate extraction after the hot shot. Left atrial pressures were higher at similar end-diastolic volumes (by nuclear ventriculography), which suggested decreased diastolic compliance after cold blood cardioplegia. Terminal warm blood cardioplegia accelerated myocardial metabolic recovery, preserved high-energy phosphates, improved the metabolic response to postoperative hemodynamic stresses, and reduced left atrial pressures.

Adenosine Triphosphate↗
PubMed1980

Agonism, ranking, and the social behavior of adult male baboons.

An ingrained technique in primatological analysis is to rank individual animals in a hierarchical system that is usually but not always based on the outcome of agonist encounters. An explication of group structure and function is then sought by correlating these rankings with aspects of behavior. When the behavior of the adult males in a free-ranging troop of olive baboons is examined, ranking is found to be inadequate to represent the behavioral variability existing between individuals. The relationships maintained by these animals is analyzed, emphasizing amounts of time devoted to specific activities, and it is recommended that affiliative rather than agonistic behavior be stressed in future studies.

Age Factors↗
PubMed1976

Ranging patterns of a troop of baboons (Papio anubis) in Kenya.

A troop of olive baboons, Papio anubis, was studied for 11 months in an open-country habitat near Gilgil, Kenya. Detailed mapping of troop movements was undertaken and provided a precise picture of range usage, showing that a small part of the range was used intensively. Gradations of home range use are described quantitatively. Tendencies to spread out and coalesce in different parts of the range are investigated. Shifting ranging patterns are examined together with meteorological factors, seasonal food supplies and water availability.

Age Factors↗