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Biomedical subjects

P Cowan

Publications and source records attributed to P Cowan.

35 records · Page 2Linked to original sources
PubMed1986

Reversal of insulin resistance in type 1 diabetes following initiation of insulin treatment.

The biological action and pharmacokinetics of insulin were assessed in nine type 1 (insulin-dependent) diabetic patients before and after 3 months conventional insulin treatment, and in seven age and weight-matched non-diabetic controls, by means of the euglycaemic insulin clamp technique. The mean (+/- S.E.) metabolic clearance rate of insulin, when infused at 1 mU/kg/min, was similar in untreated and treated diabetic patients and in controls (22.7 +/- 2.0, 19.3 +/- 3.8, and 22.9 +/- 3.3 ml/kg/min) but, when infused at 6 mU/kg/min, was greater (p less than 0.01 and less than 0.01) in untreated patients (18.0 +/- 2.5 ml/kg/min) than in treated patients (11.5 +/- 1.4 ml/kg/min) and controls (12.7 +/- 1.3 ml/kg/min). Insulin-mediated glucose disposal was reduced (p less than 0.01 and less than 0.01) at insulin infusion rates 1 and 6 mU/kg/min in untreated patients (18.5 +/- 1.9 and 33.8 +/- 4.5 mumol/kg/min) when compared with controls (35.8 +/- 3.4 and 62.0 +/- 4.7 mumol/kg/min) and was improved (p less than 0.01 and less than 0.01) following insulin treatment (36.1 +/- 4.6 and 64.8 +/- 4.2 mumol/kg/min). Daily insulin requirement fell by 33% following 3 months insulin treatment with improvement in mean HbA1 from 16.3 +/- 0.7 to 8.2 +/- 0.4%, but without significant increase in endogenous insulin secretion. The 'honeymoon phenomenon', which has traditionally been attributed exclusively to resurrection of endogenous insulin release, may also be related to normalization of insulin action following institution of insulin treatment.

3-Hydroxybutyric Acid↗
PubMed1985

Influence of insulin antibodies on pharmacokinetics and bioavailability of recombinant human and highly purified beef insulins in insulin dependent diabetics.

Sixteen insulin dependent diabetics of long standing, with undetectable fasting plasma C peptide concentrations, and eight non-diabetic controls were each infused intravenously with biosynthetic human and highly purified beef insulin (1 mU/kg/min) while euglycaemia was maintained by a Biostator. No difference was observed between the two insulins in respect of insulin pharmacokinetics or biological action. The diabetics showed appreciable insulin resistance, manifested by a 40% reduction in the rate of insulin mediated glucose disposal, which was unrelated to the presence of insulin antibodies. Insulin binding antibodies, however, increased insulin's clearance rate and distribution space and prolonged its pharmacological and biological half lives. The rate at which insulin action was lost, after an intravenous infusion, was more rapid in diabetics without insulin antibody binding than in controls. In respect of their influence on insulin pharmacokinetics, moderate concentrations of insulin antibodies may be of positive advantage to all diabetics without endogenous insulin secretion and are not responsible for the insulin resistance of type 1 diabetes.

Adult↗
PubMed1984

Insulin action and pharmacokinetics in insulin treated diabetics during the third trimester of pregnancy.

Insulin action and pharmacokinetics were compared, using the euglycaemic insulin clamp technique, in seven insulin-treated diabetics during the third trimester of pregnancy and one to three weeks post-partum. At an insulin infusion rate of 1 mU/kg/min, insulin mediated glucose disposal was significantly greater (p less than 0.02) following delivery (1.194 +/- 0.138 mmol/m2/min) than in pregnancy (0.761 +/- 0.072 mmol/m2/min) and the rate of decline in insulin mediated glucose disposal, at the end of the insulin infusion, was significantly greater (p less than 0.02) following delivery (24.78 +/- 4.22 mumol/m2/min2) than in pregnancy (15.17 +/- 2.00 mumol/m2/min2). The metabolic clearance rate, distribution space and pharmacological half-life of insulin were not significantly altered by pregnancy. These findings show that the third trimester of pregnancy is associated with steady state insulin resistance accompanied by a reduced rate of insulin deactivation, but normal insulin pharmacokinetics.

Adult↗
PubMed1984

A comparison of the biological actions and pharmacokinetics of intravenously infused highly purified beef and biosynthetic human insulins in normal man.

By means of the euglycaemic insulin clamp technique the rate of insulin-mediated peripheral glucose disposal (GDR) was compared in response to intravenous infusions of highly purified beef insulin (BI) and biosynthetic human insulin (BHI), infused at 1 and 6 mU/kg/min, in healthy volunteers. The metabolic clearance rates of BI and BHI were similar at the lower insulin infusion rate and were both greater than those observed at the higher insulin infusion rate, which were also similar, implying the process of insulin clearance to be saturable. The GDRs were similar in response to infusions of BI and BHI at each insulin infusion rate. The rates of insulin deactivation were similar, having discontinued BI and BHI infusions at 1 mU/kg/min.

Animals↗
PubMed1977

Prevalence of antibody to hepatitits B surface antigen among staff in an Edinburgh hospital.

Antibody to hepatitis B surface antigen was detected by radioimmunoprecipitation in 74 (5-5%) of 1336 staff members in a large general hospital in Edinburgh, in 14 (2-9%) of 480 volunteer blood donors in the area, and in 12 (6-1%) of 197 pregnant women attending for the first time at the ante-natal clinic in the hospital. Rates of antibody prevalence rose with age in the sample of hospital staff and in that of the blood donors, particularly among males. On the other hand, in the ante-natal patients antibody prevalence declined with age. The rates in hospital staff were higher than those in blood donors of comparable age and sex, and high titres of antibody were more common in the staff group. However, no association was found between antibody prevalence and a history of clinical hepatitis, blood transfusion, or recognized contact with cases of hepatitis. Staff who had previously worked in an infectious disease hospital did not show increased antibody prevalence, indicating that simple isolation measures have been adequate to minimize exposure to hepatitis B. No particular prevalence of infection was seen in physicians and surgeons, in the nursing staff, or in workers in clinical diagnostic laboratories, hospital administration or other areas. One group clearly showing increased antibody prevalence was staff currently working, or who had worked, in the Haemodialysis Unit; this correlated with the outbreak of dialysis-associated hepatitis in 1969--70. However, no evidence suggested that significant dissemination of infection had occurred to other defined groups of hospital staff. Elevated rates were also observed in a small sample of kitchen and portering staff, and in obstetric medical and nursing staff; the latter observation indicate a need for further investigation to identify unsuspected exposure to hepatitis B virus.

Adolescent↗
PubMedDate not supplied

American Chronic Pain Association: strategies for surviving chronic pain.

The American Chronic Pain Association (ACPA) is a nonprofit, self-help organization designed to help individuals suffering with chronic nonmalignant pain. The program is directed toward educating the individual about a multidimensional view of pain, identifying pain-illiciting and pain-aggravating situations and behaviors, and teaching various coping skills. The techniques that are used include exercise, relaxation instruction, goal selection, priority setting, self-awareness sensitization, and assertiveness training.

Humans↗
PubMedDate not supplied

Blood glucose control determines the renal haemodynamic response to angiotensin converting enzyme inhibition in type 1 diabetes.

Elevation of glomerular filtration rate (GFR) is a feature of diabetes mellitus in humans and in animal models. Angiotensin II has been implicated as a mediator of GFR in diabetes. The acute effect of inhibition of angiotensin converting enzyme with captopril on renal haemodynamic and endocrine parameters was therefore studied in 14 normotensive male Type 1 diabetic patients, and the responses compared with those in five normal male control subjects. Following captopril 12.5 mg orally the diabetic patients exhibited an acute fall in GFR from 122 +/- 3.8 to 113 +/- 4.5 ml min-1 1.73-m-2 (p less than 0.02) and a rise in renal plasma flow (RPF) from 670 +/- 57 to 797 +/- 46 ml min-1 1.73-m-2 (p less than 0.01) which resulted in a fall in filtration. This did not occur in normal control subjects. Natriuresis occurred only in normal control subjects. There was no change in urinary excretion of PGE2 or kallikrein in either group but excretion of 6-keto-PGF1 alpha fell in the diabetic patients. There was a significant correlation between glycosylated haemoglobin and baseline RPF (rs = -0.79, p less than 0.001) and filtration fraction (rs = 0.83, p less than 0.001) that persisted when the change in these variables following captopril was analysed. Our results are compatible with the response to ACE inhibition in diabetic patients being secondary to inhibition of angiotensin II and suggest that this response may be related to blood glucose control.

Adult↗
PubMedDate not supplied

Managing faecal retention and incontinence in neurodisability.

The large number of patients with faecal retention and/or incontinence in continuing care wards and rehabilitation units presents a considerable challenge. In order to maintain dignity and minimize the unpleasant odour so commonly associated with these wards and units, effective bowel management should be planned for individual patients. For an effective bowel management regime a team approach should be adopted, involving, where possible, the patient and carer as well as all the health professionals administering the care. Two case studies illustrate the use of assessment and management of bowel problems in patients with severe complex neurodisability. Bowel dysfunction in this patient population, in general, is poorly covered in the literature. The present article, by relating theory to practice, offers information and guidance for nurses working with patients who have bowel-related problems.

Aged↗