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Biomedical subjects

T M Hayes

Publications and source records attributed to T M Hayes.

At least 37 records · Page 2Linked to original sources
PubMed1987

The effects of glucose-dependent insulinotropic polypeptide infused at physiological concentrations in normal subjects and type 2 (non-insulin-dependent) diabetic patients on glucose tolerance and B-cell secretion.

The effects of porcine glucose-dependent insulinotropic polypeptide given by continuous intravenous infusion in normal subjects (n = 6) and Type 2 (non-insulin-dependent) diabetic patients (n = 6) have been investigated. The subjects were studied on 2 separate days after overnight fasts. On each day 25 g of glucose was infused from 0-30 min plus an infusion of either porcine glucose-dependent insulinotropic polypeptide (0.75 pmol . kg-1 . min-1) or control solution. During the glucose-dependent insulinotropic polypeptide infusion plasma glucose values were reduced in normal subjects from 30-60 min (p less than 0.01) and in Type 2 diabetic patients at 45 and 60 min (p less than 0.05). In the normal subjects insulin concentrations were greater from 10-35 min (p less than 0.01) following glucose-dependent insulinotropic polypeptide infusion and peak values were increased by 123%. In the Type 2 diabetic patients following glucose-dependent insulinotropic polypeptide infusion insulin levels were increased from 4-40 min (p less than 0.01) but peak values were only increased by 27%. In the normal subjects C-peptide values were greater from 25-45 min (p less than 0.01) following glucose-dependent insulinotropic polypeptide infusion and peak C-peptide levels were increased by 82%. In the Type 2 diabetic patients following the glucose-dependent insulinotropic polypeptide infusion C-peptide levels were increased from 6-55 min (p less than 0.01) and peak values were increased by 20%. Plasma glucose-dependent insulinotropic polypeptide levels were within the physiological post prandial range during the glucose-dependent insulinotropic polypeptide infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Renal response to intravenous somatostatin in insulin-dependent diabetic patients and normal subjects.

The acute effects of iv somatostatin (SRIH; 100 micrograms/h) on the urinary flow (Uvol), effective renal plasma flow (RPF), and glomerular filtration rate (GFR) were compared with those of a control infusion of 0.15 M NaCl in nine insulin-dependent diabetic (IDD) patients of less than 10 yr disease duration and six normal subjects (NS). RPF and GFR were measured using a standard primed constant isotope infusion of [125I]iodohippurate and [51Cr]chromium EDTA. Uvol, RPF, and GFR were measured during 20-min clearance periods. During the NaCl infusion mean Uvol, RPF, and GFR were 14.1 +/- 0.2 (+/- SEM), 708 +/- 4, and 150 +/- 1 mL/min in the IDD group and 12.7 +/- 0.4, 568 +/- 5, and 110 +/- 2 mL/min in the NS group, respectively. In the IDD patients Uvol, RPF, and GFR decreased from 16.6 +/- 1.8, 670 +/- 30, 146 +/- 4 mL/min pre-SRIH to 9.2 +/- 1 (P less than 0.001), 553 +/- 25 (P less than 0.001), and 130 +/- 5 (P less than 0.001) mL/min, respectively, at 120 min during the SRIH infusion. Similarly, in the NS group mean Uvol, RPF, and GFR were 14.2 +/- 0.6, 552 +/- 15, and 112 +/- 5 mL/min pre-SRIH and decreased to 7.4 +/- 0.6 (P less than 0.001), 422 +/- 7 (P less than 0.001), and 93 +/- 3 (P less than 0.001) mL/min, respectively, after 120 min of the SRIH infusion. SRIH, therefore, had a profound effect on renal function in both IDD patients and NS, resulting in a reduction in RPF, GFR, and, as a consequence, Uvol.

Adult↗
PubMed1986

Effect of somatostatin on renal function.

Somatostatin has profound effects on both splanchnic and portal vascular beds. The effects of intravenous somatostatin (100 micrograms/h) on urinary volume, effective renal plasma flow, and glomerular filtration rate were compared with the effects of a control infusion of physiological saline in six normal subjects. Renal plasma flow and glomerular filtration rate were measured by primed constant isotope infusions of iodine-125 iodohippurate and chromium-51 edetic acid. Urinary volume, renal plasma flow, and glomerular filtration rate were measured during 20 minute clearance periods. During the control infusion urinary volume, renal plasma flow, and glomerular filtration rate remained essentially unchanged at 254 (SEM 3) ml/20 min, 568 (5) ml/min/1.73 m2, and 110 (2) ml/min/1.73 m2 respectively. From similar basal values the infusion of somatostatin led to a rapid decrease in all three variables. After 120 minutes of infusion of somatostatin urinary volume, renal plasma flow, and glomerular filtration rate were reduced to 148 (17) ml/20 min (p less than 0.01), 422 (7) ml/min/1.73 m2 (p less than 0.001), and 93 (3) ml/min/1.73 m2 (p less than 0.05) respectively. This effect on renal function should be borne in mind whenever somatostatin is used.

Adult↗
PubMed1986

The metabolic response to glucagon and glucagon-(1-21)-peptide in normal subjects and non insulin dependent diabetics.

The metabolic effects of glucagon leading to hyperglycaemia are well recognised. However, the spasmolytic properties of glucagon have only relatively recently been utilised in clinical medicine. The marked hyperglycaemia accompanying the smooth muscle relaxant action of glucagon has led to the development of smaller peptides derived from glucagon which may retain the spasmolytic effects without the metabolic consequences. This study compares the metabolic and hormonal response to one such peptide, glucagon-(1-21)-peptide, with the parent peptide glucagon. The results demonstrate that glucagon-(1-21)-peptide has no metabolic effects comparable to glucagon. In normal subjects and non-insulin dependent diabetics, glucagon-(1-21)-peptide has no stimulatory effect on the pancreatic beta-cell.

Blood Glucose↗
PubMed1985

Possible new method to improve detection of diabetic retinopathy: Polaroid non-mydriatic retinal photography.

Two retinal cameras (Canon CR2 45NM and CR3 45NM) have recently become available and are capable of producing an instant colour photography of a 45 degree field of retina, including the macula and optic disc, without dilatation of the pupils being necessary. The ability of each camera to detect diabetic retinopathy was compared with that of doctors in diabetic clinics using ophthalmoscopy during busy clinic hours. The CR3 was found to be considerably superior to the CR2 in terms of quality of photograph because it can use a smaller pupil. Overall, the detection rate of the camera was more than four times higher than that of ophthalmoscopy through undilated pupils and more than twice as high as that of ophthalmoscopy through dilated pupils. Lesions missed by ophthalmoscopy but detected by the camera included soft exudates and circinate rings of hard exudates, sometimes encroaching on the macula. Though various aspects of this system of screening for diabetic retinopathy, in particular its ability to detect new retinal vessels, have not yet been assessed, the system may prove beneficial in the detection and monitoring of diabetic retinopathy.

Diabetic Retinopathy↗
PubMed1984

How soon after myocardial infarction should plasma lipid values be assessed?

Because acute myocardial infarction may affect plasma lipid concentrations it is commonly recommended that assessment of these concentrations should be delayed until about three months after the acute event. A study was therefore conducted of fasting plasma lipid concentrations in 58 patients with acute myocardial infarction. Measurements were made during their stay in hospital (days 1, 2, and 9) and three months later. Triglyceride concentrations remained unchanged throughout. Values of total cholesterol, low density lipoprotein, and high density lipoprotein all fell significantly between the first two days and day 9. Total cholesterol and low density lipoprotein also showed significant falls between days 1 and 2. Nevertheless, fasting plasma lipid concentrations showed no significant difference at any time during the first 48 hours from values measured three months later. After the infarction 26 patients changed to eating less fat or less energy, or both. More patients had hypercholesterolaemia in the first 48 hours than at three months. These results suggest that lipid state may be assessed as accurately, and possibly more accurately, during the first 48 hours after acute myocardial infarction than at three months.

Adult↗
PubMed1984

Randomised controlled trial of routine hospital clinic care versus routine general practice care for type II diabetics.

Two hundred patients with type II diabetes were entered into a randomised controlled trial lasting five years to compare routine care of this condition by a hospital diabetic clinic with routine care in general practice. Fewer patients in the group being cared for by their general practitioner (general practice group) were regularly reviewed or had regular estimations of blood glucose concentration. More patients in the general practice group than in the hospital group were admitted to hospital for medical reasons during the study (25 (24%) compared with 17 (18%] and more patients in the general practice group died (18) than did in the hospital group (6). At the end of the study mean concentrations of haemoglobin A1 were higher in the general practice group (10.4%) than in the hospital group (9.5%). Routine care in general practice for patients with type II diabetes was less satisfactory than care by the hospital diabetic clinic.

Adult↗
PubMed1984

Conservative management of pregnancy in diabetic women.

In 1979 the obstetric management of pregnancies in diabetic women in Cardiff was changed from elective delivery at 37-38 weeks to delivery at term. This change was facilitated by home monitoring of blood glucose concentrations and improved techniques for assessing fetal wellbeing. There were 35 pregnancies in insulin dependent diabetics in 1972-8 and 45 in 1979-82. The quality of diabetic control during pregnancy was equally good in both periods. The average gestation at final admission to hospital increased from 30 to 37 weeks. Amniocentesis to assess fetal pulmonary maturity was necessary in 26 patients (74%) in the first period of study and in only four (9%) in the second. Gestational age at delivery increased from 37.4 to 39.4 weeks after the change in policy. The proportion of mothers entering spontaneous term labour and delivering vaginally increased from 14.3% to 37.8%. The mean birth weight of live born, singleton infants increased from 3090 g to 3650 g, the feeding pattern improved, and respiratory problems were less common. Morbidity was reduced and perinatal mortality was not increased with conservative management of pregnancy in diabetic women.

Apgar Score↗
PubMed1984

Pharmacokinetics of subcutaneously administered human, porcine and bovine neutral soluble insulin to normal man.

Highly purified neutral soluble human, porcine and bovine insulin (0.075 U/kg body weight) were administered randomly by subcutaneous injection to six normal men. Somatostatin by continuous intravenous infusion (100 micrograms/h) was used to suppress endogenous insulin secretion. The effects of the three species of insulins on plasma glucose, immunoreactive insulin (IRI), C-peptide and intermediary metabolite concentrations were essentially similar. The onset of hypoglycaemic action of bovine insulin was delayed compared to human and porcine insulin due possibly to a lower receptor binding of the bovine insulin. No local or systemic adverse reactions to the insulins were observed.

3-Hydroxybutyric Acid↗
PubMed1984

Comparison of highly purified semi-synthetic insulin and highly purified porcine insulin in the treatment of type I diabetes: interim report of a multi-centre randomised single blind study.

This is an interim report of a long term single-blind study of the effects of changing diabetic patients treated with highly purified porcine insulin to semi-synthetic human insulins of identical formulation. Twenty four insulin dependent diabetics were randomly allocated to continue with porcine insulin (n = 11) or human insulin (n = 13). There were no significant changes within the groups nor differences between the groups in mean preprandial capillary blood glucose, glycosylated haemoglobin or insulin dose during the first 24 weeks of the study. Insulin antibody levels remained low and did not differ between the groups. No local or systemic adverse reactions were observed. In this group of patients conversion to human insulin did not result in a change in diabetic control or insulin dose.

Adolescent↗
PubMed1983

Determinants of plasma lipoproteins and coagulation factors in men from Caerphilly, South Wales.

Dietary, social, and constitutional determinants of plasma concentrations of some major risk factors for ischaemic heart disease were investigated in a cross sectional study among 711 men from the general population aged 30-69. For high density lipoprotein cholesterol (HDL-C) six variables were significantly associated with plasma concentrations, and these variables explained 12.6% of the variance. For low density lipoprotein cholesterol (LDL-C), total cholesterol (T-C), and triglyceride 8.4%, 7.5%, and 18.5% of the variance was explained by significantly associated variables. Fibrinogen concentrations determined chemically were significantly associated with age, smoking habit, body mass index, alcohol consumption, and intake of cereal fibre (24.2% variance). These data provide some encouragement for the possibility of dietary intervention to influence plasma concentrations of major risk factors for ischaemic heart disease in men.

Adult↗
PubMed1982

Dietary determinants of lipoproteins, total cholesterol, viscosity, fibrinogen, and blood pressure.

High-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol, viscosity, fibrinogen, and blood pressure were determined in 117 men aged 44 to 60 yr selected from the general population who also completed 7-day weighed dietary records. Associations between these measurements and a number of dietary factors were assessed by multiple regression analysis, allowing where necessary for the effects of age, body mass index, and smoking habit. High-density lipoprotein cholesterol was associated positively with both alcohol and fish consumption and negatively with saturated fat intake. High-density lipoprotein cholesterol expressed as a percentage of total cholesterol was associated negatively with the percentage of energy from fat and positively with fish consumption. Low-density lipoprotein cholesterol was associated positively with the percentage of energy from fat and negatively with fish consumption. Fibrinogen and systolic blood pressure were inversely related to cereal fiber intake.

Adult↗
PubMed1982

Determinants of high density lipoprotein and total cholesterol in women.

An epidemiological study was carried out among a random sample of women aged 18 to 69 years to examine possible determinants of plasma high density lipoprotein and total cholesterol (HDL-C and T-C). In a multiple regression analysis consumption of alcohol, fatty fish, and parental longevity showed positive associations with HDL-C, which were statistically significant. Smoking habit, sucrose consumption, and a family history of ischaemic heart disease showed significantly negative associations. In contrast, T-C was associated significantly only with age and Quetelet's index of body mass. Five variables having significant associations with HDL-C explained only 8% of the total variance; in the case of T-C 17% of the variance was explained by age and body mass.

Adolescent↗
PubMed1982

A study of the comparative safety and efficacy of neutral soluble human (semi-synthetic) and porcine monocomponent insulin in non-diabetic subjects.

Neutral soluble human (semi-synthetic) and porcine insulin and diluting medium were administered subcutaneously in a randomized fashion to six fasting normal male subjects. The plasma glucose, C-peptide and insulin response was observed for a period of two hours before and six hours after injection of insulin (0.075 m/kg) into the anterior abdominal wall. The hypoglycaemic response was identical for the two insulins with the plasma glucose values reaching a nadir at 90--120 minutes and returning to within 10% of basal levels by six hours. Also similar peak plasma insulin values were achieved with human and porcine insulin by 50--60 minutes post-injection. The C-peptide response following the administration of both insulins suggested equal suppression of endogenous beta cell secretion. The two insulins were well tolerated with no immediate or delayed allergic reactions in any subject. These results suggest that human (semi-synthetic) and porcine soluble monocomponent insulins under the described experimental conditions are bioequivalent.

Adult↗