PubMed Health⌕ Search

Biomedical subjects

B M Fisher

Publications and source records attributed to B M Fisher.

70 records · Page 4Linked to original sources
PubMed1987

The effects of insulin-induced hypoglycaemia on cardiovascular function in normal man: studies using radionuclide ventriculography.

The cardiovascular effects of an intravenous injection of soluble insulin and of acute hypoglycaemia were examined in six normal male subjects using multiple-gated radionuclide ventriculography. The basal left ventricular ejection fraction rose significantly from 47 +/- 3% (mean +/- SEM) to 54 +/- 3% p less than 0.01, within 5 min of the intravenous injection of insulin, and before any significant changes occurred in the blood glucose concentration. The ejection fraction subsequently rose to a peak of 72 +/- 5% coinciding with the onset of the acute hypoglycaemic reaction. This corresponded to the nadir of blood glucose and was associated with rises in heart rate, stroke volume and cardiac output. The heart rate returned to the resting value within 30 min of the acute hypoglycaemic reaction, but the ejection fraction, stroke volume and cardiac output were still elevated 90 min later. The peak ejection fraction value immediately preceded the maximal increment of plasma catecholamines released in response to hypoglycaemia. Thus, administration of intravenous insulin had a small, immediate, discernible effect on the cardiovascular system. A subsequent rise in left ventricular ejection fraction of much greater magnitude was stimulated by the development of acute hypoglycaemia, and was associated temporally with sympatho-adrenal activation. The use of radionuclide ventriculography showed that the haemodynamic changes provoked by hypoglycaemia produced a sustained effect on cardiac contractility.

Acute Disease↗
PubMed1987

Plasma oxytocin, arginine vasopressin and atrial natriuretic peptide responses to insulin-induced hypoglycaemia in man.

The changes in blood glucose, plasma oxytocin, plasma vasopressin, plasma atrial natriuretic peptide, serum osmolality, haematocrit and blood pressure were measured in response to acute insulin-induced hypoglycaemia in six normal male subjects. After the i.v. administration of insulin (0.15 U/kg), plasma concentrations of oxytocin and vasopressin increased rapidly in all subjects and were maximal 15 min after the acute hypoglycaemic reaction (R). Haematocrit increased at the time of the hypoglycaemic reaction, but there was no change in serum osmolality. Systolic blood pressure rose and diastolic blood pressure fell, but mean arterial blood pressure remained unchanged. No changes were demonstrated in plasma concentrations of atrial natriuretic peptide. The release of oxytocin and vasopressin in response to acute hypoglycaemia in man is probably caused by stimulation of the posterior pituitary gland via hypothalamic activation, and not by stimulation of osmoreceptors or baroreceptors.

Adult↗
PubMed1987

Responses of peripheral blood cells and lymphocyte subpopulations to insulin-induced hypoglycaemia in human insulin-dependent (Type 1) diabetes.

Changes in counts of peripheral blood cells including lymphocytes and lymphocyte subpopulations were examined in response to acute insulin-induced hypoglycaemia in fourteen insulin-dependent diabetic patients of differing duration, and in eight normal subjects. In patients with a short duration of diabetes (less than 5 years) an initial lymphocytosis preceded a later granulocytosis, similar to changes in the normal group following hypoglycaemia. The lymphocytosis comprised increments in T11 (total), T4 (helper), and T8 (suppressor/cytotoxic) lymphocyte subsets, but B lymphocytes did not rise. In diabetic patients of longer duration (greater than 15 years) the initial lymphocytosis was attenuated, the T4 subset response being absent and the T11 subset response was diminished. The lower lymphocyte responses in the long-term diabetics were unrelated to differences in the hormonal responses to hypoglycaemia or to the rate of blood glucose recovery. Rapid mobilization of specific lymphocyte subpopulations appears to be abnormal in long-term insulin-dependent diabetes, and may indicate underlying immunological dysfunction.

Adolescent↗
PubMed1987

Effect of sodium depletion on pressor responsiveness in ACTH-induced hypertension in man.

1. Pressor responsiveness to angiotensin II (AII) and phenylephrine (PHE) was measured before and after 5 days of ACTH (1 mg i.m. daily) in six normal men maintained on low sodium diet (15 mmol daily). 2. ACTH caused a significant increase in systolic blood pressure of 9 mmHg. 3. There was no change in pressor responsiveness to AII with ACTH. 4. ACTH increased pressor responsiveness to PHE for both systolic and diastolic blood pressure, with a fall in the threshold for response from 0.9 to 0.6 micrograms/kg per min. 5. Increased pressor sensitivity to catecholamines during ACTH administration in man is not sodium-dependent.

Adrenocorticotropic Hormone↗
PubMed1987

Carriage of Candida species in the oral cavity in diabetic patients: relationship to glycaemic control.

To study the possible relationship between the quality of glycaemic control in diabetes mellitus and the carriage of Candida species, the candidal carrier status of 412 diabetic patients was examined using an oral rinse technique and correlated with measurements of random blood glucose and total glycosylated haemoglobin. Candida was isolated in 210 diabetics (51%) with 13 patients (6%) carrying more than one species. The positive isolates were: Candida albicans (89%), Candida krusei (2.8%), Candida glabrata (2.8%), Candida tropicalis (6.2%), Candida stellatoidea (2.8%) and Candida parapsilosis (0.5%). No association was identified between carriage rates and the type of treatment of diabetes, or with the quality of glycaemic control. As in non-diabetic subjects, the carriage rates were higher in diabetic patients wearing dentures. Thus, the oral carriage of Candida in diabetic patients was independent of glycaemic control but in certain sub-groups the carriage rates were higher, and involved uncommon candidal species.

Blood Glucose↗
PubMed1987

Nocturnal convulsions and insulin-induced hypoglycaemia in diabetic patients.

Convulsions may occur as a consequence of insulin-induced hypoglycaemia. We report three patients with insulin-dependent diabetes, who presented with generalized tonic-clonic seizures associated with nocturnal hypoglycaemia. None of the patients had experienced hypoglycaemia during waking hours and the convulsions were mistakenly diagnosed as idiopathic epilepsy. Recognition of the possible hypoglycaemia aetiology of these convulsions permitted appropriate alteration of the insulin regimens with no recurrence of convulsions. In one case, the seizure was associated with bilateral fractures of the neck of the humerus. Unrecognized hypoglycaemia should be considered as a possible cause of convulsions in insulin-dependent diabetic patients.

Adult↗
PubMed1987

A case of watery diarrhoea syndrome due to an adrenal phaeochromocytoma secreting vasoactive intestinal polypeptide with coincidental autoimmune thyroid disease.

A 40 year old woman presented with a 10 year history of watery diarrhoea and an acute quadriparesis. On clinical examination there was severe muscle weakness and a nodule was palpable in the thyroid gland. Biochemical testing revealed a hypokalaemia at 1.6 mmol/l. Plasma levels of VIP were raised at 202 pmol/l. CT scanning demonstrated a mass in the area of the left adrenal gland, and isotope scanning of the thyroid gland showed a 'cold' nodule. The plasma catecholamines and calcitonin were elevated. The patient also presented with psychiatric symptoms, and the relevance of these to her condition has been discussed. At operation a left adrenal tumour was removed. Post-operatively the patient's symptoms disappeared and the plasma hormone levels returned to normal values. Histological examination of the tumour revealed a well differentiated phaeochromocytoma which contained VIP and calcitonin. The thyroid nodule was excised and showed histological features of autoimmune thyroid disease. It is suggested that in all cases of the WDHA syndrome where the tumour is in an extra-pancreatic site patients should be screened for phaeochromocytoma.

Adrenal Gland Neoplasms↗
PubMed1987

Glycaemic control in diabetic patients transferred from therapy with animal insulins to human crystalline zinc insulin of recombinant DNA origin: a multicentre study.

87 stable insulin-dependent diabetic patients from 6 diabetic clinics within the UK were transferred from their existing once or twice daily regimen of subcutaneous animal insulin to a similar regimen of human insulin of recombinant DNA origin in neutral soluble and crystalline zinc suspension formulations. Seven point blood glucose profiles, glycosylated haemoglobin concentrations and insulin dose were examined, in each patient, before and after 6 weeks therapy with human insulins. The 67 patients on twice daily insulin showed no significant change in mean blood glucose values or glycosylated haemoglobin but required a significantly higher dose of human crystalline zinc suspension than their previous long-acting animal insulin. In contrast the 17 patients on a once daily regimen experienced a significant deterioration in glycaemic control without a significant change in insulin dose or glycosylated haemoglobin. Three patients on twice daily insulin withdrew shortly after transfer to human insulin. The combination of human soluble and crystalline zinc suspension appears to be a more satisfactory substitute for animal insulin when used in a multi-dose regime rather than on a once daily basis.

Animals↗
PubMed1986

Cardiac function and coronary arteriography in asymptomatic type 1 (insulin-dependent) diabetic patients: evidence for a specific diabetic heart disease.

Cardiac function was examined in 63 asymptomatic Type 1 (insulin-dependent) diabetic patients, aged 30-50 years, using radionuclide ventriculography and exercise electrocardiography to investigate the possible existence of a specific diabetic heart disease. Comparisons were made with 45 age- and sex-matched non-diabetic controls. Radionuclide ventriculography was performed at rest and during the physiological stresses of isometric exercise, cold-pressor testing and dynamic exercise. Scans were technically satisfactory in 56 of the diabetic patients and 38 of the control subjects. The resting left ventricular ejection fractions and the responses to isometric exercise and cold-pressor testing were similar in the diabetic patients and controls. A smaller rise in the left ventricular ejection fraction during dynamic exercise was observed in male diabetic patients compared with male control subjects (9 +/- 1% (mean +/- SEM) vs 14 +/- 1% (p less than 0.005)). A similar trend was observed in female diabetic patients, with a rise of 5 +/- 1% on dynamic exercise compared with a rise of 8 +/- 1% in the control group. Sixteen diabetic patients (29%) demonstrated an abnormal response to dynamic exercise, and 5 of these had an abnormal exercise electrocardiogram. Cardiac catheterisation and coronary arteriography were performed in eight of these 16 patients, and all 8 had normal coronary arteries. Endomyocardial biopsy revealed arteriolar thickening and interstitial fibrosis in 5 patients, and in 2 patients basement membrane thickening was conspicuous. Thus, in diabetic patients cardiac function may be abnormal without evidence of coronary heart disease, and some patients appear to have the histological changes consistent with a diabetic microangiopathy involving the heart.

Adult↗
PubMed1986

Reduced number of angiotensin II receptors on platelets in insulin-dependent diabetes.

Angiotensin II receptors on platelets were studied in 13 patients with uncomplicated type I diabetes mellitus and in 15 age-matched normal subjects. Receptor density on cells from the diabetic patients was 15% lower than the normal subjects (5.2 +/- 0.8 SD sites/platelet in diabetic patients and 6.4 +/- 0.8 in normals, P less than 0.001), but there were no differences in receptor affinity as measured by Kd (4.9 +/- 1.5 X 10(-10) mol/l in diabetic patients and 5.4 +/- 1.4 X 10(-10) mol/l in normals). Plasma concentrations of renin and angiotensin II were similar in both groups. The reduced density of angiotensin II receptors on platelets from patients with insulin-dependent diabetes may reflect a generalized abnormality of angiotensin II receptor regulation.

Adult↗
PubMed1985

Diabetes, driving, and the general practitioner.

The medical fitness of drivers who have diabetes is assessed primarily by general practitioners. A survey was made of the knowledge of driving and diabetes of 105 general practitioners in Glasgow. Ninety four (90%) knew that people who were insulin dependent were required by law to declare their condition to the Driver and Vehicle Licensing Centre in Swansea, but most were unaware that people with diabetes should not hold a "till 70" driving licence. Seventy one doctors (69%) claimed that patients were recalled individually for fitness to drive. The minimum visual acuity for driving was stated correctly by 37 (35%). Only eight respondents knew that a hypoglycaemic diabetic driver can be charged with driving under the influence of a drug (Road Traffic Act 1972), and the practical advice that was given to patients about hypoglycaemia and driving was unsatisfactory. As a group the general practitioners showed deficiencies in knowledge regarding diabetes and driving, suggesting a need for further postgraduate education.

Automobile Driving↗
PubMed1985

Cardiac function and insulin-dependent diabetes: radionuclide ventriculography in young diabetics.

We have compared left ventricular function in 40 insulin-dependent diabetic patients (30 male, 10 female) aged 16-30 years (mean 23 years) with duration of diabetes 3 months to 25 years (mean 10 years) with 19 healthy age and sex-matched controls using radionuclide ventriculography at rest, during cold-pressor stimulation, isometric exercise, and dynamic exercise. There were no differences in exercise or smoking habits in the two groups. All subjects had a normal resting electrocardiogram and a normal electrocardiographic response to dynamic exercise using the Bruce protocol on the Marquette Computer Assisted System of Exercise. Left ventricular ejection fraction was similar at rest and fell in diabetics and controls, respectively, by 2.3 +/- 1.0% and 3.0 +/- 0.08% (NS) and by 2.4 +/- 0.8% and 2.2 +/- 0.8% (NS) during isometric exercise, and cold pressor testing. During supine dynamic exercise on a bicycle ergometer ejection fraction rose in both groups by 13.9 +/- 1.7% and 13.7 +/- 1.6%, respectively (NS). No statistically significant differences were found in peak ventricular filling and emptying rates and abnormalities of regional wall motion did not develop. Two female patients with diabetes for more than 10 years had an abnormal response to dynamic exercise manifested by a fall in ejection fraction. In comparison to the higher frequency of abnormalities reported in diabetics using echocardiography and the measurement of systolic time intervals, abnormal left ventricular function assessed by radionuclide ventriculography is uncommon in young patients.

Adolescent↗
PubMedDate not supplied

The effects of diabetes and autonomic neuropathy on parotid salivary flow in man.

Stimulated parotid salivary flow studies were performed on 20 non-diabetic subjects and on 30 patients with insulin-dependent diabetes mellitus who had been screened for autonomic neuropathy using tests of cardiovascular reflexes. Electrical gustometry was performed to detect the taste threshold. The stimulated parotid salivary flow rates of diabetics with no autonomic neuropathy or early parasympathetic autonomic dysfunction alone were similar to those of non-diabetic subjects. Diabetic patients with established parasympathetic autonomic neuropathy had significantly higher salivary flow rates as did those with combined sympathetic and parasympathetic neuropathies. Taste thresholds did not correlate either with the duration of the diabetes or with the presence of autonomic neuropathy. The cause of the increased salivary flow associated with diabetic autonomic neuropathy is unclear. It may represent the removal of a neural inhibitory mechanism which modulates salivary flow, or the effects of long-standing diabetes on salivary secretion.

Adult↗