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Biomedical subjects

V Parsons

Publications and source records attributed to V Parsons.

At least 109 records · Page 6Linked to original sources

Experience in the diagnosis of glomerulonephritis using combined light microscopical, ultrastructural and immunofluorescence techniques--an analysis of 134 cases.

The contribution of electron and immunofluorescence microscopy to renal biopsy diagnosis is illustrated by the results obtained in a personal series of patients with various types of glomerulonephritis. Introductory notes on the ultrastructure of the glomerular capillary and on immunological processes are also included. Immunofluorescent staining has particular value in demonstrating IgG-containing deposits in early membranous glomerulonephritis at a stage when ordinary microscopy is inconclusive. It is capable of throwing light on the mechanism of glomerular damage in severe extracapillary proliferation and in some cases of recurrent haematuria, but is less successful in separating minimal change disease from proliferative processes. Electron microscopy reveals the precise site of immune deposits and fibrin together with basement membrane changes, the microtubular structures common in SLE, and other details. It is concluded that for the accurate diagnosis of kidney disease it is essential to supplement light microscopy by one, or preferably both these methods.

Adolescent↗

Dialysis in the treatment of renal failure in patients with liver disease.

The value and effects of treating renal failure by dialysis are analyzed in a series of 84 patients with various types of liver disease. Although none of the 25 patients with cirrhosis survived, six of 50 with fulminant hepatic failure recovered completely as did seven of nine patients with renal failure secondary to extrahepatic biliary tract obstruction or with liver and renal damage following episodes of severe hypotension. Dialysis was required for seven weeks before diuresis occurred in one patient in the latter group. Both peritoneal and hemodialysis satisfactorily controlled plasma urea and creatinine levels, except in patients with fulminant hepatic failure in whom this was only achieved by hemodialysis. Complications of dialysis were most common in patients with cirrhosis and fulminant hepatic failure and included hypotension, gastrointestinal bleeding, and intraperitoneal sepsis. Overall, the results show that dialysis is only worth attempting in those patients in whom recovery of the underlying liver lesion is possible, and even then treatment for prolonged periods may be necessary.

Acute Kidney Injury↗

Immune response to HBsAg and the spectrum of liver lesions in HBsAg-positive patients with chronic renal disease.

Evidence of chronic hepatitis was found on histological examination in nine out of 15 patients positive for hepatitis-B surface antigen (HBsAg) who had either chronic renal failure or a functioning renal transplant. Cirrhosis had already developed in three of the patients, who deteriorated rapidly and died. Liver biopsies from the remaining 12 patients showed the features of chronic aggressive hepatitis in two, chronic persistent hepatitis in four, and minor histological lesions in six. The persistence of HBsAg in patients with renal failure or in those receiving immunosuppressive drugs after a transplant must indicate some impairment of the normal immune response to hepatitis-B viral antigens. Nevertheless, cellular or humoral immunity to HBsAg was detected in all eight patients with chronic hepatitis tested compared with only one out of five with minimal liver lesions, which suggests that the severity of the liver damage may be directly related to the degree of immunocompetence.

Adult↗

Role of thyroid hormones in an abnormal grooming behavior in thyroidectomized cats and cats with pontile lesions.

Thyroidectomized cats and cats with pontile lesions exhibit the same abnormal grooming behavior. Investigations were conducted to determine whether the abnormal grooming behavior in cats with pontile lesions was attributable to a hypothyroid condition. Administration of thyroid hormones abolished the abnormal behavior of thyroidectomized cats but was without effect in cats with pontile lesions. Studies of brain and blood levels of thyroid hormones in cats with pontile lesions failed to detect any differences from normal cats, and normal effects of thyroid hormones on evoked potentials to light flashes and to clicks were obtained in cats with pontile lesions. It was concluded that any thyroid dysfunction that may exist in the cats with pontile lesions was not involved in the genesis of the abnormal grooming behavior. Because the abnormal grooming behavior fluctuates rhythmically during the year, an endocrine hypothesis was entertained as the source of the fluctuations; endocrine concomitants of the abnormal behavior were investigated with longitudinal studies. The urinary excretion of 11-hydroxycorticoids exhibited a significant negative correlation with the abnormal behavior. When compared with that of normal cats, the plasma level of 11-hydroxycorticoids of thyroidectomized cats was significantly decreased. Intramuscular injections of 11-hydroxycorticoids abolished the abnormal behavior in both thyroidectomized cats and cats with pontile lesions. These results considered together with previous findings indicate that thyroidectomy and pontile lesions induce similar changes in 11-hydroxycorticoid and serotonergic functions-changes that are critical features of the physiological bases of the abnormal grooming behavior in both groups.

11-Hydroxycorticosteroids↗

Immunopathology of penicillamine-induced glomerular disease.

Four patients with rheumatoid arthritis developed heavy proteinuria after five to 12 months of treatment with D-penicillamine. Light microscopy of renal biopsy samples showed minimal glomerular capillary wall thickening and mesangial matrix increase, or no departure from normal. Electron microscopy, however, revealed subepithelial electron-dense deposits, fusion of epithelial cell foot processes, and evidence of mesangial cell hyperactivity. Immunofluorescence microscopy demonstrated granular capillary wall deposits of IgG and C3. The findings were similar to those in early membranous glomerulonephritis, differences being observed however in the results of staining for the early-acting complement components C1q and C4. It is tentatively concluded that complement was activated by the classical pathway.

Arthritis, Rheumatoid↗

A study of labetalol in patients of European, West Indian and West African origin.

1 Hypertension in West Indians and Africans is common and has an unacceptably high mortality in the younger patients. 2 Fifty-three patients received labetalol (a combined alpha- and beta-adrenoreceptor antagonist) as part of an open evaluation of its anti-hypertensive effect. Ten non-caucasian patients were included. 3 Significant reductions in systolic and diastolic pressures were obtained in the caucasian patients, the African and West Indian patients remaining refractory to therapy.

Adult↗

Arsine toxicity aboard the Asiafreighter.

Eight sailors on board the Asiafreighter were exposed to arsine that had escaped from a cylinder in the cargo hold. Four suffered severe toxicity and within a few hours had developed fever, weakness, nausea, vomiting, diarrhoea, abdominal pain, and haemoglobinuria. These patients had pronounced intravascular haemolysis, which in one patient was complete. This patient was also stuporose and anoxic, a condition attributed to failure of oxygen transport and sludging of red cell debris in the cerebral and pulmonary circulations, but he regained a normal level of consciousness after exchange transfusion. Evidence of marrow depression was present: the reticulocyte response to the haemolysis was poor and there was a thrombocytopenia. All four patients developed renal failure, one being totally anuric for five weeks. Two patients developed peripheral neuropathy, and one was still severely disabled six months after the incident. The other four patients had a similar, though less severe, illness.

Acute Kidney Injury↗

Renal excretion of fluoride in renal failure and after renal transplantation.

We have compared the renal excretion of fluoride in a variety of patients with chronic renal failure maintained with and without protein restriction before and during regular dialysis treatment and after transplantation. The patients tended to continue to excrete normal dietary loads of fluoride quite well until renal function was seriously reduced. From a regression of function on excretion the mean level of creatinine clearance when a normal dietary load of fluoride 0.0526 plus or minus 0.019 mmol/2 h (1.0 plus or minus 0.36 mg/24h) has a 90% chance of being excreted lies around 16 ml/min, a level when most patients with renal failure will be symptomatic. Acute loading of such patients with additional fluoride in the form of sodium fluoride from 40 mg to 60 mg/day showed a twofold to threefold increase of serum fluoride concentrations, slight increases in urinary fluoride excretion, and heavy tissue absorption, suggesting that prior fluoride loading of the skeleton had not taken place. These effects contrasted with those in one patient with normal renal function and with those in one patient with skeletal saturation due to prolonged loading. After renal transplantation fluoride excretion increased but reached normal levels within three months of satisfactory function, suggesting that fluoride loading in renal failure and during regular dialysis therapy had not been excessive.

Calcium↗

Intrarenal platelet consumption in the diffuse proliferative nephritis of systemic lupus erythematosus.

1. Platelet survival and an index of the localization of platelets in the kidney were studied in patients with the proliferative nephritis of systemic lupus erythematosus, either focal or diffuse, and in control subjects. Platelet survival was reduced in patients with proliferative lupus nephritis, more in those with diffuse rather than focal renal involvement. 2. The index of renal platelet localization in patients with diffuse proliferative nephritis suggested an intrarenal platelet consumption not found in other groups. 3. A patient with the classical platelet autoantibody disease, idiopathic thrombocytopenic purpura, also showed reduced platelet survival but localization of platelets was in the spleen rather than the kidney. 4. Intrarenal platelet consumption in diffuse proliferative lupus nephritis may be an epiphenomenon of pre-existing scarring or platelet aggregation secondary to immune complex-formation, which contributes to the progressive sclerosing lesions of this form of nephritis.

Adult↗