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Biomedical subjects

R Taylor

Publications and source records attributed to R Taylor.

At least 631 records · Page 35Linked to original sources
PubMed1980

Blood pressure studies in rural and urban Western Samoa.

Blood pressure was measured in the rural and urban male and female Polynesian populations of Western Samoa to determine if differences existed in mean blood pressures or in the prevalence of hypertension between these groups. It was found that, in the urban population, both males and females had higher mean blood pressures and approximately double the prevalence of hypertension found in their rural counterparts. There was an age-related rise in mean blood pressure and in the prevalence of hypertension in all groups. Approximately half of the difference in mean blood pressure and hypertension prevalence between rural and urban groups appeared to be due to difference in adiposity. Age and body mass index were significantly and independently correlated with systolic and diastolic blood pressure in each group. The prevalence of hypertension was greater in obese subjects.

Adult↗
PubMed1980

The effects of diurnal rhythms on immune parameters in New Hampshire chickens.

The influence of diurnal rhythms on several immune parameters was studied. When thymic-derived lymphocytes were collected 4 times during a 24-hour period, a variation occurred in the migration ability of these cells. The migration of T cells at 2:00 a.m. was markedly lower than at other time periods. Similar results were noted employing other T-cell tests: phytohemagglutinin wattle responsiveness and the graft vs. host assay.

Animals↗
PubMed1980

The effects of a megalevel of vitamin C on the immune response of the chicken.

Birds fed diets supplemented with 1% vitamin C experienced significant increases in serum levels of vitamin C. Cell-mediated immunity and antibody response to sheep red blood cells, a T-cell dependent antigen, were not influenced by feeding megalevels of vitamin C. However, the antibody response to a T-independent antigen, Brucella abortus, was lower in neonates and higher in adults in the presence of increased levels of vitamin C.

Animals↗
PubMed1980

Evidence of complement catabolism in experimental acute pancreatitis.

Serum specimens from guinea pigs with experimentally induced acute pancreatitis were examined for evidence of protease-antiprotease imbalance and complement catabolism. Pancreatitis was induced in 22 male Hartley guinea pigs by the injection of sodium taurocholate into the pancreatic parenchyma. Only a laparotomy was performed in 6 control animals. In 10 experimental animals that survived for less than 24 hours, there was a significant, early reduction of serum trypsin inhibitory capacity (a measure of antiprotease activity). Levels of total hemolytic complement as well as titers of hemolytic C3 and C4 fell significantly in all experimental animals during the first 24 hours. Factor B activity, however, did not change. Only serum from experimental animals contained chemotactic activity for human polymorphonuclear leukocytes. These findngs indicate that circulating complement components are cleaved during the course of experimental acute pancreatitis. As a consequence, complement-derived peptides are generated that may mediate local and systemic tissue injury.

Acute Disease↗
PubMed1979

The influence of obstetric procedures and social and cultural factors on breast-feeding rates at discharge from hospital.

The influence of obstetric factors on breast-feeding rates at discharge from St. Thomas's Hospital in 1969 and 1970 has been examined in 1356 primiparous mothers delivering healthy babies. Induction of labour and assisted delivery were significantly associated with lower breast-feeding rates. The association could not be explained by differences in social class, country of origin, birthweight, anaesthesia in labour, or medical reasons for induction and assisted delivery. The most likely explanation is that induction and assisted delivery are associated with delay in starting breast-feeding. However, trends in obstetric management of labour and delivery are unlikely to have a large influence on the incidence of breast-feeding compared with the influence of social and cultural factors.

Anesthesia, Obstetrical↗
PubMed1979

Radiochromium distribution in hypophysectomized and adrenalectomized rats.

The effects of hypophyseal and adrenal ablation (HYPOX, ADX) on trivalent radiochromium (51Cr) distribution and of GH and T4 replacement in HYPOX rats were determined. Hypophysectomy increased body retention of 51Cr by 20--35%, and hormonal replacement restored body retention to normal. Serum 51Cr was increased 300--800%, resulting in depressed tissue to serum 51Cr ratios. GH replacement partially restored the 51Cr distribution abnormalities in HYPOX rats to normal. The combination of T4 with GH enhanced the restoration of normal 51Cr distribution, and tissue to serum 51Cr ratios returned to baseline levels. ADX had no effect on body retention of 51Cr but had a small effect on increases in serum and tissue 51Cr levels. As a result, tissue to serum 51Cr ratios did not change. These data indicate that in the HYPOX state there is a marked disturbance in Cr metabolism which is due to deficiencies of both GH and T4. Whether or not adrenal hormones are envolved in 51Cr distribution will require further study.

Adrenalectomy↗
PubMed1979

Effectiveness of insulin therapy on altered renal calcium transport in diabetic rats.

The uptake of 45Ca was measured in slices of kidney cortex from normal rats, streptozotocin-diabetic rats, and streptozotocin-diabetic rats treated early and late with insulin. Insulin therapy was performed such that blood glucose levels were controlled in half the treated diabetic animals but not in the others. Considerably earlier than evidence of nephropathy (i.e., proteinuria and increased BUN levels) in streptozotocin-diabetic rats, there was a significant decrease in active uptake of calcium by the kidney. Insulin therapy, begun immediately upon diagnosis of diabetes, maintained normal calcium transport even when blood glucose levels were not controlled. On the other hand, insulin therapy, begun 1 mo after diabetes was confirmed but before evidence of nephropathy, did not restore calcium transport to normal whether or not blood glucose was controlled. We conclude that this biochemical mechanism, which possibly may be implicated in the pathophysiology of diabetic nephropathy, is clearly influenced by duration of insulin deficiency and not by the degree in hyperglycemia.

Animals↗
PubMed1979

The reduction by training of CO2 output during exercise.

5 men underwent a 10-wk endurance training programme which resulted in an 18% increase in max VO2 from a mean of 3.1 l/min. Measurements were made at 2 submaximal O2 intakes of 1.2 and 2.0 l/min to examine the physiological interdependence of mechanisms changed by training. At both levels of VO2, reductions were observed following training in cardiac frequency (fc), CO2 output (VCO2), respiratory exchange ratio (R), ventilation (VE), alveolar-arterial PO2 difference (A-aPO2) and blood lactate (La); the changes were statistically significant at the higher VO2. No change was observed in cardiac output, blood free fatty acids (FFA) and blood glycerol (gly). A small increase was found in arterial PCO2 (PaCO2) and HCO3-. Changes in fc were not significantly related to changes in other variables. The reductions in La were related to falls in VCO2 and VE, and inversely related to increases in PaCO2. Only a portion of the fall in R could be ascribed to increased usage of fat as a fuel, the main factor being a fall in lactate production. Reductions in A-aPO2 were due to decreases in PAO2 and falls in R, with no change in venous admixture. Changes in FFA and gly were small and not related to changes in other variables. Training led to an increased usage of aerobic metabolic pathways. The resultant fall in lactic acid production led to a fall in VCO2 and maintained HCO3-. These changes accounted for a marked reduction in VE following training.

Adult↗