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Biomedical subjects

N Veall

Publications and source records attributed to N Veall.

At least 19 recordsLinked to original sources
PubMed1989

Treatment of heart failure with diuretics: body compartments, renal function and plasma hormones.

Body fluid compartments, renal function and plasma hormones were measured in 13 patients with severe chronic heart failure, when the referring physician considered the patient to be appropriately treated. Although renal function was substantially impaired and plasma noradrenaline, aldosterone and renin activity were elevated, fluid compartments were within the normal range. These results show that careful clinical assessment of patients by an experienced physician is a reliable method of assessing restoration of 'normal' body fluid volumes with diuretics.

Adult↗
PubMed1988

Cerebral anaerobic glycolysis and reduced cerebral oxygen transport in human cerebral malaria.

In 12 patients comatose with cerebral malaria, cerebral blood flow was 52.2 (SE 4.0) ml/100 g per min, within the reported range for healthy controls, but cerebral vascular resistance was raised at 1.66 (0.19) mm Hg/ml per 100 g per min. Cerebral oxygen consumption (1.90 [0.23] ml/100 g per min), and cerebral arteriovenous oxygen content difference (3.5 [0.43] ml/dl) were subnormal, while cerebral venous pO2 (5.7 [0.2] kpA) was raised. After recovery of consciousness there were significant decreases in arterial lactate concentration (2.44 [0.45] to 1.19 [0.45] mumol/l) and cerebral lactate production (17.4 [7.9] to 5.6 [1.1] mmol/100 g per minute). These results provide evidence of cerebral anaerobic glycolysis associated with inadequate oxygen delivery to the brain consistent with either inhibition of cerebral oxidative metabolism or the microcirculatory obstruction envisaged in the "mechanical" hypothesis for cerebral malaria.

Adolescent↗
PubMed1987

Skeletal blood flow in metabolic disorders of the skeleton.

Results are presented of measurements of skeletal blood flow made in 80 patients with painful benign or malignant diseases of the skeleton, excluding patients with Paget's disease. In crush fracture osteoporosis, total bone blood flow was slightly lower than normal although skeletal perfusion was normal. High values of bone blood flow were seen in 14/20 patients with osteomalacia and 3/12 patients with primary hyperparathyroidism. Very high values, comparable to those seen in the most severely affected patients with Paget's disease, were seen in polyostotic fibrous dysplasia, 2 out of 4 cases of Engelmann's disease and 1 out of 3 cases of renal osteodystrophy. Results were less elevated in myositis ossificans, secondary skeletal involvement with breast and prostatic carcinomata, myelomatosis and sympathetic osteodystrophy.

Adolescent↗
PubMed1987

Radiation absorbed dose from technetium-99m DTPA.

The whole-body retention of intravenously administered [99mTc]DTPA was measured by urine analysis and whole-body counting in eight normal subjects. On average, the elimination of [99mTc]DTPA was faster in these subjects than in 11 patients under study for hypertension whose whole-body retention data were used in MIRD Dose Estimate Report No. 12. The average residence time for [99mTc]DTPA in total body, less bladder contents, was only 65% of the MIRD value. However, despite this difference, the dosimetry is similar in both cases largely owing to the influence of radioactivity in bladder contents. Approximately 2-3% of the administered radioactivity was retained in the body for a time that was long relative to the physical half-life of 99mTc, and probably reflects a small amount of protein binding of the DTPA preparation.

Adult↗
PubMed1986

Uptake of 77Br-spiperone in the striata of schizophrenic patients and controls.

Twelve patients with a diagnosis of schizophrenia and thirteen control subjects were injected with 77Br-bromospiperone and scanned using single photon emission tomography after 16 h. Although a statistically significant increase in patients by comparison with controls could be demonstrated, wide variations in specific activity of the ligand preclude a firm conclusion. In two patients but no controls an asymmetry in striatal uptake was noted, the uptake on the left being less than that on the right.

Adult↗
PubMed1985

Isotope renography and urinary schistosomiasis: a study in a Gambian community.

A transportable apparatus for isotope renography, which allowed deconvolution analysis, was used to study the prevalence and prognosis of abnormalities associated with urinary schistosomiasis. Before carrying out studies in a heavily infected community, observations were made in a non-endemic area to allow derivation of criteria for abnormality. Comparison of the findings in the two areas showed that changes suggesting urinary tract obstruction were more common in the endemic area in subjects between nine and 45 years but not in older subjects. Measurements of effective renal plasma flow showed renal function was impaired in the endemic area in subjects older than 17 years but not in younger subjects. In the endemic area the results of renography were unrelated to the urinary egg count of the subjects examined, but there was an improvement in the abnormal renograms in a group of subjects aged between nine and 20 years who were re-examined a year after treatment with metrifonate. Follow-up data about 316 subjects was obtained two years after renography. Nine subjects had died, including four of the five subjects with abnormalities suggesting both obstruction and over-all loss of renal function. These findings, which are comparable to the results of similar studies using radiological techniques, suggest urinary schistosomiasis may be a significant cause of mortality in adults in intensely infected communities.

Adolescent↗
PubMed1985

The effect of pyridoxine on oxalate dynamics in three cases of primary hyperoxaluria (with glycollic aciduria).

We have measured glomerular filtration rate (GFR), extracellular fluid volume (ECF), oxalate distribution volume (OxDV), plasma oxalate concentration (POx.), plasma total clearance of oxalate (PCOx.), oxalate metabolic pool size [(OxDV) X (POx.)], renal clearance of oxalate (RCOx.), oxalate excretion, tissue clearance of oxalate (TCOx.) and tissue oxalate accumulation rate [(TOx.A) = (TCOx.) X (POx.)] in three patients with type I primary hyperoxaluria (hyperoxaluria with hyperglycollic aciduria) when they were taking pyridoxine and after discontinuation of the vitamin. Seven days after stopping pyridoxine the plasma oxalate concentration, oxalate metabolic pool size and the urinary excretion of oxalate had all increased between seven- and eight-fold in two of the patients. The third patient showed no changes on stopping pyridoxine. These results support the view that pyridoxine acts by reducing oxalate biosynthesis in some patients with type I primary hyperoxaluria. The possible biochemical basis for this effect is discussed.

Adult↗
PubMed1985

Iodothyronine kinetics in the rabbit: an experimental model.

Turnover studies of thyroxine (T4), 3,5,3'-tri-iodothyronine (T3) and 3,3',5'-tri-iodothyronine (rT3) have been performed in the rabbit. A novel modification of a conventional radioimmunoassay has been used to measure specific 125I-labelled iodothyronines in small volumes of plasma in the presence of other 125I-labelled metabolites. Kinetic analysis of plasma disappearance of tracer was performed by a new theoretical approach. For T4 the mean (+/- S.D.) plasma concentration, clearance and production rates were 34 +/- 12 nmol/l, 109 +/- 19 ml/kg per day and 3.7 +/- 1.4 nmol/kg per day respectively (n = 9). For T3 the corresponding values were 2.04 +/- 0.42 nmol/l, 1.52 +/- 0.29 litres/kg per day and 3.07 +/- 0.76 nmol/kg per day (n = 8), and for rT3 0.12 +/- 0.04 nmol/l, 5.7 +/- 1.7 litres/kg per day and 0.69 +/- 0.23 nmol/kg per day (n = 8). The combination of these two new methodologies affords a simple and convenient means of studying iodothyronine metabolism under normal and abnormal conditions. The techniques employed may be generally applied to turnover studies of other compounds of physiological interest which can be measured by radioimmunoassay.

Animals↗
PubMed1985

Primary hyperoxaluria (type I): attempted treatment by combined hepatic and renal transplantation.

A case is reported of a patient with renal failure and developing systemic and renal oxalosis due to pyridoxine-resistant type I primary hyperoxaluria. In spite of vigorous haemodialysis and hydration before and after operation, an allografted cadaveric kidney failed because of oxalate deposits in the transplant. The patient was treated by combined hepatic and renal transplantation. The liver allograft functioned well but the kidney had poor function due to primary acute tubular necrosis aggravated by steroid-associated acute pancreatitis, systemic cytomegalovirus infection and high cyclosporin A levels. The patient died from generalised cytomegalovirus infection. The early course after operation was associated with a reduced rate of oxalate production, which would slow the rate of oxalate deposition in the tissues. The size of the oxalate metabolic pool was also diminished. These observations are compatible with the grafted liver having corrected the metabolic lesion.

Child↗
PubMed1984

Oxalate dynamics and removal rates during haemodialysis and peritoneal dialysis in patients with primary hyperoxaluria and severe renal failure.

We have measured the plasma oxalate concentration (POx), urinary oxalate excretion (UOx), oxalate equilibrium distribution volume (ODV), oxalate metabolic pool size [(ODV) X (POx)], total plasma oxalate clearance (PCOx), renal (or dialyser) oxalate clearance (RCOx), non-renal oxalate clearance (NRCOx) and the tissue oxalate accretion rate (TOA) = [(NRCOx) X (POx)] in three patients with severe renal failure due to primary hyperoxaluria who were being treated by peritoneal dialysis or haemodialysis, or by renal transplantation. The clearance (either GFR or dialyser) of [99mTc]diethylenetriaminepenta-acetate (DTPA) and the extracellular fluid volume (ECF) measured as [99mTc]DTPA distribution volume were also determined. Negligible amounts of 14C were found in faeces or as 14CO2 in expired air and hence (NRCOx) = (PCOx-RCOx). Haemodialysis removed oxalate more efficiently than peritoneal dialysis in the patient where a direct comparison was possible. Neither treatment could keep up with the TOA when performed for clinically acceptable times. The plasma oxalate concentrations calculated from 14C clearance through the dialyser and the chemically determined concentration of the oxalate in the dialysate were in the range 111-146 mumol/l. This is higher than in normals and in hyperoxaluric patients who are not in renal failure. Hence, although the ODV and ECF are similar to those of hyperoxaluric patients without renal failure and normal control subjects, the oxalate metabolic pool (ODV X POx) is grossly enlarged. In the patient treated by renal transplantation, the oxalate pool size diminished concurrently with the resumption of oxalate excretion but expanded again as renal function decreased due to oxalosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗