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Biomedical subjects

G Walters

Publications and source records attributed to G Walters.

At least 55 records · Page 3Linked to original sources
PubMed1986

Sodium retention in response to saline infusion in uncomplicated diabetes mellitus.

The response to a 21 infusion of physiological saline infusion was studied in 7 male uncomplicated insulin-dependent diabetics and in 7 non-diabetic male controls. The urinary sodium excretion in the diabetics in each of the 4 hr following the infusion was approximately half that of the controls. The total induced sodium excretion in controls was 34 +/- 4 mmols (mean +/- SEM) but only 14 +/- 4 mmols in the diabetics (p less than 0.005). The hourly creatinine clearance rate was higher in diabetics than in controls indicating a mechanism of reduced sodium excretion via enhanced tubular reabsorption rather than impaired filtration. This propensity to sodium retention in diabetics may play a role in the tendency to cardiovascular and renal complications.

Blood Glucose↗
PubMed1985

Abrupt withdrawal of atenolol in patients with severe angina. Comparison with the effects of treatment.

The effects of abrupt withdrawal of atenolol, a long acting cardioselective beta blocker, were studied in 20 patients with severe stable angina pectoris admitted to hospital for coronary arteriography. During the 144 hour postwithdrawal period no serious coronary events occurred. Mean and maximal daily heart rates rose steadily for at least 120 hours. No important arrhythmias were noted on ambulatory electrocardiographic monitoring. Treadmill exercise testing at 120 hours showed little reduction in the times to angina, ST depression, and maximal exercise when compared with those recorded at 24 hours. This deterioration was small when contrasted with the improvements in these indices produced by atenolol treatment in a similar group of patients not admitted to hospital. No change in catecholamine concentrations or acceleration of the heart rate response to exercise occurred after atenolol withdrawal, suggesting that rebound adrenergic stimulation or hypersensitivity was absent or insignificant. Catastrophic coronary events after beta blockade withdrawal (the beta blockade withdrawal syndrome) have occurred almost exclusively in patients taking propranolol, many of whom had unstable angina at the time of withdrawal. This study showed that in patients with stable angina, even when severe, the abrupt withdrawal of atenolol can be expected to result in only minor clinical consequences. The risk to any patient of so called rebound events after withdrawal of beta blockade seems to be related to both the clinical setting and the agent being used.

Adult↗
PubMed1982

Complement activation and complement control proteins in acute pancreatitis.

Serum levels of the complement proteins C3, C4, C1 inhibitor (C1 INH), factor I (C3b inactivator) and factor H (BIH) and plasma levels of cleavage products of C3 (C3c) and factor B were measured in 26 patients with acute pancreatitis. Breakdown of C3 occurred in 19 patients, as shown by a reduction in C3 level and the presence of C3c. C4 levels, however, did not fall and factor B breakdown products were not detected, thus suggesting that enzymatic cleavage of C3 occurred without significant involvement of either the early classical pathway or the alternative pathway. C1 INH and factor H both showed increases, presumably reflecting an acute phase response. Factor I showed an initial fall followed by a rise. There was no correlation between the presence or extent of C3 breakdown and the clinical condition of the patients. It is concluded that C3 cleavage in pancreatitis probably results from tryptic activity and that the measurement of complement components has no part to play in the management of the disease.

Acute Disease↗
PubMed1982

Effect of total dose infusion of iron dextran on the storage iron content of the human placenta.

In a series of pregnant women with iron deficiency anaemia treated by a total dose infusion of iron dextran, the non-haem iron content of the placenta at term was studied histochemically and by chemical analysis. Within a few days of the infusion the Prussian blue reaction on the placenta was very strong, but was negative by ten days after the infusion. Chemical analysis showed that both the water-insoluble fraction (haemosiderin) and the water-soluble fraction (ferritin) of the non-haem iron were increased soon after the infusion, but three weeks after the infusion they were almost the same as in untreated controls. Pinocytosis of iron dextran by the trophoblast and increased transport of transferrin-bound iron to the placenta are considered as possible causes for this large uptake of iron by the placenta.

Anemia, Hypochromic↗
PubMed1982

Estimation of the saturation of serum transferrin by an electrophoretic technique.

An electrophoretic method is described for estimating the saturation of serum transferrin. After first precipitating most of the other proteins with Rivanol, the apo-, mono-, and di-ferric transferrins are separated by electrophoresis in urea-polyacrylamide gel. Densitometric scanning enables the percentage saturation to be calculated.

Antibodies↗
PubMed1980

LSD 'flashback' as a cause of diagnostic error.

An emaciated, but otherwise physically normal young man presented with an acute psychosis resembling hallucinogenic drug abuse. His behaviour was so strange that the underlying pathology of severe pyloric stenosis was only detected when a chance measurement of urea and electrolytes was made, revealing gross biochemical abnormalities. His abnormal mental state persisted for more than one week and an LSD 'flashback' was postulated as the cause of the prolonged psychosis

Adult↗
PubMed1980

A comparison of urine free cortisol (RIA) with cortisol metabolites (GLC) for detecting increased cortisol secretion.

A comparison of the estimation of urine free cortisol by radioimmunoassay with the measurement of cortisol metabolites by gas-liquid chromatography (GLC) for detecting increased adrenal cortical activity has been made. Urine samples were examined from adults with normal or increased adrenal cortical function. Urine free cortisol showed a proportionately greater increase than cortisol metabolites when levels of cortisol were above twice normal, but both procedures led to the same qualitative conclusion about adrenal cortical activity. Their precision, ease of performance, assay time, and cost were similar. It is concluded that the greater sensitivity of the free cortisol does not warrant foregoing the additional information provided by the GLC method.

Adrenal Cortex↗
PubMed1979

Resetting of osmoreceptor response as cause of hyponatraemia in acute idiopathic polyneuritis.

In a patient with hyponatraemia associated with acute idiopathic polyneuritis plasma concentrations of antidiuretic hormone increased when hypertonic saline was infused intravenously, and urine osmolality rose concomitantly. A water load was excreted normally, while the plasma remained extremely hypo-osmolal. It is concluded that osmoregulation was functioning normally but was set abnormally low, possibly owing to a disturbance of the peripheral volume receptors.

Acute Disease↗
PubMed1979

Hyponatraemia in patients with head injury.

Three patients with head injury are described to illustrate certain features of the development, treatment and recovery of hyponatraemia. The hyponatraemia is initially due to water retention but true sodium depletion may develop because of an associated urine sodium loss. The mechanism of the latter is discussed.

Adult↗
PubMed1978

Use of laser nephelometry in the measurement of specific antibody to lamb's quarters antigen.

Laser nephelometry was used to measure specific antibody to lamb's quarters antigen. It was demonstrated that the same specific antibody detected by indirect hemagglutination could readily be measured by this sensitive technique. Current investigations are being conducted to determine if this system might be validated for the measurement of blocking antibody in human serum.

Animals↗