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Biomedical subjects

G Knight

Publications and source records attributed to G Knight.

At least 55 records · Page 3Linked to original sources
PubMed1987

Ethanol and aging effects on movement initiation can be dissociated from general behavioral impairment using a high-speed lever-release task in rats.

An animal model of human reaction time was used to assess the effects of ethanol on reactive capacity (RC) as a function of age. Three doses of ethanol (0.5, 1.0 & 1.5 g/kg of 20% v/v, i.p.) were confirmed by gas chromatographic analysis of blood samples taken immediately following every behavioral test. Fisher 344 rats were trained to use their forepaws to hold down a lever until the onset of a buzzer and light that signalled impending foot shock, which occurred within 200-1000 msec of the stimulus. All rats were shaped to release the lever faster than 200 msec, which permitted them to avoid all shock under saline treatment. In the first experiment, only young adult rats (3-4 mos) were tested. Ethanol caused a dose-dependent impairment of RC. In a second experiment, rats aged 4, 12 and 24 mos were tested. As in previous work, RC was reduced by age. Ethanol caused a dose-dependent impairment of response speed (as indicated by the average of the fastest five RTs) that was exaggerated in the 24 mo-old rats. Ethanol also appeared to amplify the trial-by-trial variability in RC that was typical of the old rats under saline conditions. Nevertheless, if given enough time (1000 msec) most rats (except for a few in the oldest group) were able to avoid shock under ethanol as reliably as under saline conditions, even at the highest dose. Thus, ethanol specifically slowed reaction time while sparing memory and motivational and motor capacities required for success in this task. Both extensive practice and pre-test warm up sessions modified the effects of ethanol; however they did not do so differentially across ages.

Aging↗
PubMed1986

Experience of continuous subcutaneous insulin infusion in the outpatient management of diabetic teenagers.

Of forty-five adolescent diabetic patients offered continuous subcutaneous insulin infusion (CSII) as part of a large feasibility study, 13 (28.9%) initially chose the treatment, but only 4 out of 11 who actually started CSII continued for one year (64% discontinuation rate). In contrast 30.4% of adults approached chose CSII, and 32% had discontinued after one year. Improvement in glycaemic control was poor, and clinical problems were more common in pump-treated teenagers than in adults. CSII does not appear to be a therapeutic solution for adolescents having difficult management problems.

Adolescent↗
PubMed1986

Long term glycaemic control by alternative regimens in a feasibility study of continuous subcutaneous insulin infusion.

Of 382 insulin-treated diabetic patients participating in a feasibility study of continuous subcutaneous insulin infusion (CSII) and alternative regimens in a large British clinic, 63 used CSII for a 2-yr period. Additionally 74 patients persisted with an intensified injection regimen and 85 continued on non-intensified therapy. There was no significant difference in mean glycosylated haemoglobin between the 3 groups at the study onset. At month 24 only the CSII group had significantly reduced mean glycosylated haemoglobin (11.0 +/- 1.8 (SD) at month 0; 9.8 +/- 1.9 month 24, p less than 0.001) although the intensified injection group experienced a significant reduction in mean glycosylated haemoglobin until month 18 (11.0 +/- 1.8 month 0; 10.1 +/- 1.4, p less than 0.001). Serious hypoglycaemia was not increased in the CSII-treated group compared with the intensified injection group. Thus it proved feasible to achieve sustained, improved glycaemic control in a large group of patients by the use of insulin pump therapy and the level of control was superior to that achieved by an intensified injection regimen.

Blood Glucose↗
PubMed1985

Severe hyperkalaemia and ketoacidosis during routine treatment with an insulin pump.

During a feasibility study of the use of insulin pumps to treat diabetes ketoacidosis occurred at a rate of 0.14 episodes/patient/year in the first year but was lower in subsequent years. A case of cardiac arrest secondary to hyperkalaemia during ketoacidosis occurred in a patient treated with a pump. The mean (SD) serum potassium concentration on presentation to hospital with ketoacidosis was significantly higher in patients treated with a pump (5.7 (1.1) mmol(mEq)/l) than those treated with conventional injections of insulin (4.9(0.9) mmol/l; p less than 0.01). The high rate of ketoacidosis and raised serum potassium concentrations during treatment with the pump creates doubt about the use of this treatment as an alternative regimen for large numbers of patients in a busy diabetic clinic.

Acidosis↗
PubMed1984

A feasibility study of the use of continuous subcutaneous insulin infusion in a diabetic clinic: patients' choice of treatment.

Insulin-treated diabetic patients attending a busy diabetic clinic were approached to determine their interest in using continuous subcutaneous insulin infusion (CSII) via a portable pump. Three hundred and eighty-two patients were offered the choice of CSII, intensified conventional therapy (ICT) or continuation of less intensified treatment. One hundred and sixteen patients (30.4%) chose CSII, 169 (44.2%) chose ICT, 97 (25.4%) chose the less intensive regimen. Those choosing CSII represented a broad cross section of the clinic population, though older patients with a longer duration of diabetes tended to continue with less intensified therapy. There were no differences between groups in the level of blood glucose control or the prevalence of complications at the outset of the study. Of 104 patients not previously using CSII, 86 have so far commenced the therapy. Twenty-seven (32.6%) of these discontinued within one year, 23 doing so in the first three months of treatment. Metabolic control, assessed by glycosylated haemoglobin, was significantly improved in the CSII group after three months and in the other treatment groups by six months. Glycosylated haemoglobin levels achieved with CSII were significantly lower at three and six months when compared with the other treatments.

Adolescent↗
PubMed1983

Diabetic ketoacidosis associated with outpatient treatment using continuous subcutaneous insulin infusion.

The occurrence of ketoacidosis in out-patient diabetics treated with continuous subcutaneous insulin infusion (CSII) has received little attention. We report two such cases of ketosis, each precipitated by infection and occurring in patients previously well controlled on CSII. This report illustrates that the risk of ketoacidosis is ever present in insulin-treated patients, whether the insulin is infused by pump or injected intermittently.

Diabetes Mellitus↗
PubMed1983

Venous distension in the diabetic neuropathic foot (physical sign of arteriovenous shunting).

A new physical sign is described in the feet of a group of diabetic patients with ulcerating neuropathic problems, in which major venous distension of the veins on the dorsum of the foot and lower calf is seen. Elevation of the leg is required to an average height of 32.3 cm to cause collapse of these distended veins. It is suggested that this clinical sign indicates the presence of arteriovenous shunting in such neuropathic legs, and as such is a simple and useful measure of this abnormality.

Adult↗
PubMed1982

Biosynthetic human insulin in the treatment of diabetes. A double-blind crossover trial in established diabetic patients.

94 diabetic patients established on treatment with porcine (n = 47) or bovine (n = 47) insulin took part in a double-blind crossover trial, in which 6-week periods of treatment with the appropriate animal insulin were compared with periods of treatment with biosynthetic human insulin (BHI). 6 patients withdrew during the trial, in 3 cases because of hypoglycaemia while taking BHI. In bovine-insulin-treated patients, the mean glucose level (mean of seven capillary-blood samples over 1 day), the modified M index, and total daily insulin requirement were the same on BHI and bovine-insulin treatment. For porcine-insulin-treated patients, mean glucose level and the modified M index were slightly higher on BHI than on porcine-insulin treatment (9.7 vs 9.0 mmol/l and 79.6 vs 65.0, respectively), despite an average increase of 2.3 units/day of BHI after 6 weeks of such treatment. Hypoglycaemic episodes were not significantly more or less frequent on BHI in either group of patients. In both groups fasting blood glucose was higher during BHI treatment than during animal-insulin treatment (14.2 vs 12.8 mmol/l [bovine group]; 12.1 vs 9.6 mmol/l [porcine group]). In bovine-insulin-treated patients blood glucose before the evening insulin injection was higher on BHI than on bovine insulin (11.6 vs 10.0 mmol/l). BHI appears to be a safe alternative to porcine or bovine insulin. Differences in the pharmacokinetics of BHI may account for the observed differences in blood-glucose responses.

Adult↗
PubMed1982

Comparison of respirable dust specifications with recent lung data.

This paper compares the two major respirable dusts size specifications with lung models derived from a recent review using computer simulation in logarithmic normal dust clouds. It was found that either specification gives reasonable reproductibility with respect to either the nose or mouth breathing lung models over the usual range of industrial dust clouds, and either could be chosen as a standard with only a slight adjustment in the corresponding dust control limit.

Air Pollutants, Occupational↗
PubMed1975

Overlap problems in counting fibers.

The probabilities of certain errors in counting fibers due to accidental overlaying during sampling are calculated and shown to be significant. Justification is given for simple rules to get agreement in counting between microscopists.

Air Pollution↗