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Biomedical subjects

R Beetham

Publications and source records attributed to R Beetham.

31 records · Page 2Linked to original sources
PubMed1987

The effect of a synthetic polypeptide on the renal handling of protein in man.

Haemaccel is a synthetic polymer of partially degraded gelatin and a widely used plasma volume expander. The effect of a 17.5 g infusion of Haemaccel on protein excretion was investigated in four normal subjects. The urinary excretion of two low molecular weight proteins, retinol-binding protein and beta 2-microglobulin, increased 1000- and 500-fold respectively above the values found after administration of saline as a control. The urinary excretion of albumin did not change significantly (P greater than 0.5). In the hour after Haemaccel administration the excretion of the two low molecular weight proteins approached at least 50% of a predicted filtered load. This effect of Haemaccel may be due to inhibition of proximal tubular uptake or transport of the two proteins. Absence of any effect on albumin excretion suggests alternative mechanisms for its tubular reabsorption. Haemaccel may be a valuable new agent for the study of renal tubular protein metabolism.

Acetylglucosaminidase↗
PubMed1985

Studies on the mechanism of action of dioctyl sodium sulphosuccinate in the human jejunum.

An intestinal perfusion technique has been used to investigate the mechanism of action of the laxative, dioctyl sodium sulphosuccinate, in the human jejunum. Dioctyl sodium sulphosuccinate stimulated net secretion of water, sodium, chloride and potassium and inhibited net absorption of glucose and bicarbonate. These changes in water and solute transport were partially reversed by administration of indomethacin (4 mg/kg/day orally for three days), which suggests that they are mediated in part by endogenous prostaglandins.

Alkaline Phosphatase↗
PubMed1985

A radioimmunoassay for retinol-binding protein in serum and urine.

In this radioimmunoassay for human retinol-binding protein (RBP), sample (serum, diluted as much as 3600-fold; or urine, diluted or undiluted) or calibrant (purified RBP in phosphate buffer containing bovine serum albumin) is incubated with 125I-labeled RBP and rabbit anti-human RBP antiserum for 24 h before separation with second antibody/polyethylene glycol. The assay's sensitivity is 5 micrograms/L, its useful working range 10 to 200 micrograms/L. The between-batch CV is 12.5% at 12 micrograms/L, 7% at 120 micrograms/L. Results correlate well (r = 0.99) with those by radial immunodiffusion. The reference interval for RBP in serum of men is 39-75 mg/L (mean 57), significantly (p less than 0.01) broader than for women (29-66 mg/L; mean 48). The 2.5-97.5 centile interval for RBP in urine is from less than 0.5 to 12.2 micrograms per millimole of creatinine (median 5.8). RBP in urine is unstable below pH 5.0 at 37 degrees C.

Animals↗
PubMed1980

Calibrant solutions for continuous-flow urate analysis: interference by formaldehyde.

The use of formaldehyde to preserve aqueous urate calibration solutions has been recommended since 1913, but it interferes in some commonly used methods. At a pH below 8.5 formaldehyde affects the rate of dialysis of urate in Technicon AutoAnalyzer systems. This effect has been studied by variation of the pH at which dialysis takes place. The interference is attributed to the formation of pH-dependent addition products between uric acid and formaldehyde, which have been examined by thin-layer chromatography and mass spectrometry. Recovery experiments on protein-containing solutions show that a purely aqueous urate calibrant solution is satisfactory for use in AutoAnalyzer systems.

Autoanalysis↗
PubMed1977

Comparison of plasma disappearance and standard clearance techniques for measuring glomerular filtration rate in children with and without vesico-ureteric reflux.

The plasma disappearance rate, or slope clearance, after a single intravenous injection of 51Cr-EDTA was compared with simultaneously determined standard (UV/P) clearances of inulin, creatinine and 51Cr-EDTA in 4 healthy adults and 18 children with renal disease but no reflux. Slope clearance correlated well with standard inulin (r=0.99) and 51Cr-EDTA (r=0.97) clearances and was more accurate than creatinine clearance. Slope clearance x0.82 estimated standard 51Cr-EDTA clearance with +/- 12% accuracy in these subjects. In 18 children with vesico-ureteric reflux the correlations of the standard clearance methods with slope clearance were significantly reduced. Slope clearance may be measured with only two plasma samples and is recommended as the method of choice for determining glomerular filtration rate in children with gross reflux or impaired ability to empty their bladders.

Adolescent↗
PubMed1976

Immunoelectrophoretic study of proteins in middle ear effusion. A study of secretory otitis media in children.

An immunoelectrophoretic study of the proteins of middle ear effusions in children with secretory otitis media is described. The findings support the view that the effusion is an exudate as a result of mucosal reaction. The protein content of the fluid appears to decrease as the condition becomes more chronic, and this seems to be enhanced by antibiotic treatment. In cases of bilateral disease, the ears may be in a quite different pathological phase, thus each ear should be treated independently.

Anti-Bacterial Agents↗
PubMed1976

Faecal composition after surgery for Hirschsprung's disease.

Diarrhoea and perianal excoriation occur frequently after the endorectal pull-through operation for Hirschsprung's disease. A new method of faecal analysis was performed on 3-day stool collections in 17 postoperative Hirschsprung patients and in 14 normal children, in order to define the faecal abnormality and to establish the cause of perianal excoriation in these patients. Loose stools in postoperative patients were deficient in dry solid content and contained an excess of extractable faecal water. This also had a raised electrolyte concentration, particularly with respect to sodium. Total daily output of faecal water was normal. Formed stools from postoperative patients were also deficient in drysolids but had a normal extractable water content. Excess extractable faecal water, the main abnormality of loose stools in these patients, is the result of abnormal water absorption from the distal colon. Perianal excoriation in these patients is most closely associated with the concentration of sodium in faecal water.

Anal Canal↗
PubMed1975

The significance of variation in the selectivity of proteinuria.

The selectivity of proteinuria has been determined immunochemically at least 4 times over periods of 3 years or more in 27 children and adolescents who had been investigated by renal biopsy. Variations of the selectivity outside the limits of experimental error were observed in 14 patients, in 8 of whom there was a progressive decline. Six of these 8 had focal and segmental glomerular lesions, including one case of Alport's syndrome, and 2 had proliferative glomerulonephritis. Two different anomalies of relative IgG clearance were noted: in proliferative glomerulonephritis there was a constantly low clearance, and in focal glomerulosclerosis an elevated clearance increasing with time. Indirect evidence suggests that the latter may be due to the presence of low molecular weight IgG fragments in serum and urine.

Adolescent↗
PubMedDate not supplied

Trans-femoral lumbar epidural venography.

Epidural venography is a relatively simple, safe and highly accurate method of diagnosing lumbar disc herniations. Good opacification of the epidural venous plexus can be obtained by selective catheterization of the ascending lumbar vein or pre-sacral branches of the internal iliac veins. Experience with 100 cases of lumbar disc herniations is described. The authors think that epidural venography is a more sensitive technique than myelography, particularly with lateral disc herniation at the L5-S1 level. It is not associated with the morbidity or complications of myelography and can be performed as an outpatient procedure. Epidural venography is recommended as the examination of choice in patients with suspected lumbar disc herniation.

Epidural Space↗
PubMedDate not supplied

The assessment of subclinical ifosfamide-induced renal tubular toxicity using urinary excretion of retinol-binding protein.

The excretion of retinol-binding protein in early morning urine samples, expressed as a ratio to urinary creatinine (RBPCR), was used as a measure of proximal renal tubular toxicity in children during or after treatment with ifosfamide-containing chemotherapy. The results showed a progressive increase in renal tubular leak after exposure to ifosfamide that persisted after treatment. The toxic effect appeared to be greatest in younger children and at least partly dose-dependent, although partially reversible after each course of chemotherapy. However, few patients had related symptoms and none experienced major metabolic difficulty. RBPCR appears to offer a sensitive and noninvasive way of monitoring sequential change in renal tubular function after exposure to ifosfamide. Further studies are required to define more clearly the effect of cumulative dose, age, and drug scheduling and to identify whether a level of renal tubular dysfunction, measured by RBPCR or a similar noninvasive technique, can identify a threshold beyond which further exposure to ifosfamide is likely to be significantly and permanently damaging.

Age Factors↗