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Biomedical subjects

R D Carter

Publications and source records attributed to R D Carter.

At least 55 records · Page 3Linked to original sources
PubMed1984

High carbohydrate-high fibre diets in poorly controlled diabetes.

Fifteen non-insulin-dependent diabetic patients with persistently elevated blood glucoses despite high doses of oral hypoglycaemic agents, were randomly allocated to a high carbohydrate-high fibre diet (HC) or a reinforced low carbohydrate diet (LC). After six weeks the diets were reversed for a similar period. Immediately preceding the study and at the end of each dietary period 24-h biochemical profiles were performed. In the 11 patients who completed the study, fasting and preprandial glucose, percentage glycosylated haemoglobin, VLDL cholesterol and mean 24-h triglycerides were significantly lower on HC than on LC or during the initial profile on their usual diet. There was no significant difference in any of the measurements on LC compared with the usual diet. Previous studies of high carbohydrate-high fibre diets in diabetes have been carried out in relatively well-controlled patients. These data show that poorly controlled non-insulin-dependent patients have an even more striking response.

Aged↗
PubMed1984

A comparison of isocaloric high carbohydrate and high fat test meals in diabetics.

Ten diabetic patients were given test meals at breakfast and lunch on successive days to compare the acute glycaemic responses to meals either high (65%) (HC) or extremely low (12%) in carbohydrate; the latter was very high (71%) in fat (HF). The meals were isocaloric and fibre content, though higher in HC, was within the range of the average British intake for both diets. The mean fasting blood glucose levels were similar on the 2 days (9.8 mmol/l; 9.6 mmol/l) but mean peak post-prandial levels were significantly greater after the HC meals (17.7 mmol/l after breakfast and 14.1 mmol/l after lunch) than after the HF meals (11.7 mmol/litre after breakfast; P less than 0.02; 8.1 mmol/l after lunch; P less than 0.02). Mean blood glucose value for the 6-hr study period was significantly higher after the HC meals (14.0 mmol/l) than after the HF meals (9.2 mmol/l; P less than 0.001). There was no significant difference in mean fasting, peak or total mean triglyceride level. In the short term, therefore, meals very low in carbohydrate and high in fat are followed by a lower glycaemic response than meals high in carbohydrate but with only a usual (22 g/day) fibre content. Delayed gastric emptying after HF meals may well contribute to the results but long-term use of such HF meals is not advised in view of the extremely high fat content.

Blood Glucose↗
PubMed1984

Practice characteristics of male and female physician assistants.

In a national survey of 3,294 non-military responding physician assistants, sociodemographic and practice characteristics of male and female physician assistants were compared. Differences by specialty, practice setting, size of community, and hours of work were generally similar in nature, but smaller in magnitude, than those reported for physicians, and may not be of practical significance.

Adult↗
PubMed1983

Low phospholipid arachidonic acid values in diabetic platelets.

Platelet aggregation is enhanced in diabetes mellitus, and platelets may be implicated in the pathogenesis of diabetic angiopathy. Increased platelet aggregation is probably mediated by the production of the proaggregatory prostaglandin thromboxane, which is synthesised from arachidonic acid (C20:4) by the action of the platelet enzymes cyclo-oxygenase and thromboxane synthetase. The fatty acid composition of platelet phospholipid was measured in 20 normal controls, 10 insulin-treated diabetics with no or minimal retinopathy, and 10 insulin-treated diabetics with proliferative retinopathy. The percentage of arachidonic acid was significantly higher in controls (mean 22.6%) than in the diabetics with no or minimal retinopathy (mean 18.5%; p less than 0.025) and the diabetics with proliferative retinopathy (mean 14.6%; p less than 0.001). The percentage of linoleic acid was lower in controls (mean 8.9%) than in the diabetics with no or minimal retinopathy (mean 12.6%; p less than 0.01) and diabetics with proliferative retinopathy (mean 13.1%; p less than 0.001). The mean percentage of linolenic acid was significantly lower in the diabetics with proliferative retinopathy (2.7%) than in the normal control group (4.4%; p less than 0.01). A significant negative correlation was found between the percentages of arachidonic acid and glycosylated haemoglobin (Rs = -0.58; p less than 0.001). A significant positive correlation was found between linoleic acid and the percentage of glycosylated haemoglobin (Rs = 0.51; p less than 0.01). The reciprocal correlation between percentages of arachidonic acid and glycosylated haemoglobin suggests that diabetic control may influence thromboxane release and platelet activity directly and that low percentages of arachidonic acid reflect the increased degree of in-vivo activation.

Adult↗
PubMed1983

Effect of pregnancy upon malignant melanoma.

Results of this study suggest melanomas diagnosed, initiated or stimulated during pregnancy have worse prognoses than do those of patients not having this history. For those female patients who have had melanomas without a history of the preceding factors, it appears they can become pregnant following the diagnosis and treatment of melanoma without increased hazard. Further biochemical studies on hormone receptors and correlation with the clinical course are needed to clarify the influences of endocrines on malignant melanomas.

Adult↗
PubMed1983

Breast cancer as analyzed by the human tumor stem cell assay.

Patients with primary and recurrent carcinomas of the breast were studied by the human tumor stem cell assay to determine if (1) colonies would form from breast cancer specimens, (2) growth in the culture would equate with aggressiveness of disease, (3) the assay would yield specific information on drug responsiveness, and (4) the assay would yield nonspecific information on drug responsiveness. Colony counts ranged from 0 to 363. There was no significant difference in median colony counts by pathologic stage of disease or site. Among stage IV patients presenting for treatment with primary disease, those with colony counts greater than 10 had a mortality rate of 4.7/1000 person-days; there were no deaths among those with colony counts less than or equal to 10 (P = 0.042). Stage IV patients presenting with recurrent disease showed no association between colony counts and survival (P = 0.53). No significant relationship between colony counts and disease-free intervals was observed among stages I, II, and III patients (P = 0.10). Drug sensitivity in vitro was found in 14% of the cultures with colony counts greater than or equal to 30. The only complete clinical responses in stage IV patients occurred in two patients with 0 colony counts. These data demonstrate that colonies grow from breast cancer specimens, that colony formation in vitro may be related to aggressiveness of growth in vivo in patients presenting with stage IV disease, that drug sensitivity is demonstrated in few cultures, and that patients with metastatic disease who have complete response to systemic therapy may be identified by lack of growth in the culture.

Antineoplastic Agents↗
PubMed1982

Low dietary intake of linoleic acid predisposes to myocardial infarction.

Thirty-two men who had recently had a myocardial infarction were matched individually for age with controls who had no evidence of heart disease. The patients had a significantly lower proportion of linoleic acid and a higher proportion of palmitic acid in their plasma triglyceride fatty acids. Analysis of the composition of red-cell membrane phosphatidyl choline, which reflects long-term dietary fat intake, showed a significantly lower proportion of linoleic acid in the patients.These differences suggest that the type of dietary fat consumed might be an important factor in the genesis of ischaemic heart disease.

Adult↗
PubMed1982

Digestible carbohydrate--an independent effect on diabetic control in type 2 (non-insulin-dependent) diabetic patients?

Many studies have shown high carbohydrate, high fibre diets to benefit diabetic control, the improvement being attributed mainly to an effect of fibre. This study investigated the possible beneficial effects of the digestible carbohydrate component. A diet rich in carbohydrate was compared with a traditional low carbohydrate diet in 10 Type 2 (non-insulin-dependent) diabetic patients, using a crossover design; both diets contained less than 20 g dietary fibre/day. During 24-h metabolic profiles carried out after 4 weeks on each diet, the mean basal plasma glucose (mean of 03.00, 05.00 and 07.00 h values) was 5.3 mmol/l on the high carbohydrate diet and 5.9 mmol/l on the low carbohydrate diet (p less than 0.05), despite the 2-h post-prandial glucose (mean of three main meals) being higher on the high carbohydrate diet than on the low carbohydrate diet (8.7 versus 7.3 mmol/l, p less than 0.01). Overall diabetic control was the same throughout the study, as judged by a mean 24-h plasma glucose of 6.7 mmol/l on the high carbohydrate and 6.6 mmol/l on the low carbohydrate diet, and haemoglobin A1c percentage of 8.3 on both diets. Mean cholesterol was 4.55 mmol/l on both diets and fasting plasma triglyceride was 2.83 mmol/l on the high carbohydrate and 2.55 mmol/l on the low carbohydrate diet (p = NS). These results indicate that a diet rich in carbohydrate, but restricted in fibre, does not cause overall deterioration of diabetic control or lipid metabolism in stable Type 2 diabetic patients, and suggest that digestible carbohydrate has an effect on basal blood glucose independent of fibre.

Aged↗
PubMed1982

Low density lipoprotein cholesterol: an association with the severity of diabetic retinopathy.

Diurnal profiles of total and lipoprotein cholesterol and triglycerides were measured in 11 insulin-dependent diabetic subjects without retinopathy, 10 with background and 10 with proliferative retinopathy. The groups were closely matched for age and duration of diabetes. Total cholesterol levels were higher in patients with proliferative (5.6 +/- 0.5 mmol/l) than background (5.1 +/- 0.7 mmol/l) or no retinopathy (4.6 +/- 0.8 mmol/l, trend test; p less than 0.003), due to raised levels of low density lipoprotein (LDL) cholesterol (3.8 +/- 0.9, 3.2 +/- 0.6 and 2.8 +/- 0.8 mmol/l respectively; p less than 0.02). High density lipoprotein (HDL) levels were similar in patients with and without retinopathy and HDL/LDL ratios were lower with more severe retinopathy (p less than 0.025). Cholesterol levels were similar in diabetic subjects without retinopathy and in 12 normal subjects. Triglyceride levels were not related to retinopathy and no measure of plasma lipids correlated with HbA1 or 24-h mean plasma glucose. Total and LDL cholesterol were weakly inversely correlated with creatinine clearance but the association with retinopathy was independent of this effect.

Adult↗
PubMed1982

Acral lentiginous melanoma. A clinicopathologic entity.

Acral lentiginous melanoma (ALM) is the fourth clinicopathologic variant of malignant melanoma. It occurs on volar surfaces of hands and feet, subungual sites, and fingers or toes. It is characterized by slow lentiginous radial growth and central plaque-like thickening, heavily pigmented tumor cells, markedly thickened papillary dermis, and diffuse reticular infiltration. Lesions are unusually large and, in most cases, thick and ulcerated. There were 180 patients with acral melanoma (AM), which includes 67 in whom the specific features of ALM could be documented. One hundren sixty had primary lesions on ;the foot, and 20 occurred on the hand. There were 104 men and 76 women. There were 41 black patients and 139 whites. Five-year survivals following all modalities of therapy in 122 patients with Stage I acral melanoma is 63% for planter/palmar lesions, 58% for subungual lesions, and 27% for skin of digits. For the subgroup of Stage I patients with ALM treated by surgery and regional chemotherapy by perfusion, the five-year survival for all sites is 72% and 56% at 10 and 15 years, respectively. Survival in ALM is essentially the same as for all AM lesions.

Adult↗
PubMed1981

A high carbohydrate leguminous fibre diet improves all aspects of diabetic control.

In a randomised cross-over study 18 nondependent (NIDDM) and 9 insulin-dependent (IDDM) diabetics were put on to a high carbohydrate diet containing leguminous fibre (HL) for 6 weeks, and also a standard low carbohydrate diet (LC) for 6 weeks. During two identical 24 h metabolic profiles mean preprandial and mean 2 hour postprandial blood glucoses were significantly lower on HL in both groups, as were also several overall measures of diabetic control, including the degree of glycosuria. Total cholesterol was reduced significantly on HL in both groups, and the HDL/LDL cholesterol ratio increased significantly on HL in the NIDDM group. A diet high in complex carbohydrate and leguminous fibre improves all aspects of diabetic control, and continued use of a low carbohydrate diet no longer appears justified.

Adult↗
PubMed1980

Diurnal changes in plasma lipoproteins in normal subjects and diabetics.

Significant diurnal variations in levels of total plasma cholesterol, HDL cholesterol and LDL cholesterol were found in the majority of 12 normals, 13 maturity onset and 14 insulin requiring diabetics. The variations in total cholesterol and its lipoprotein subfraction were more marked in diabetics. These variations were not correlated in either diabetic group with glucose control as assessed by the level of glycosylated haemoglobin. The significance of the diurnal changes in total plasma cholesterol and the lipoprotein subfractions in relation to arteriovascular disease is discussed.

Adult↗