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Biomedical subjects

C B Brown

Publications and source records attributed to C B Brown.

At least 127 records · Page 7Linked to original sources
PubMed1984

Azathioprine metabolism in kidney transplant recipients.

Azathioprine metabolite concentrations were studied in 54 kidney transplant recipients. Thirty-seven of these patients were studied over a 6 month period to investigate the intrapatient variation in metabolite concentrations. All patients had stable functioning grafts and normal peripheral white blood cell counts. The metabolites measured were plasma 6-mercaptopurine and red blood cell 6-thioguanine nucleotide. There was no correlation between azathioprine dose and plasma 6-mercaptopurine concentration but there was a significant correlation between dose and red blood cell 6-thioguanine nucleotide concentration (rs = 0.41, P less than 0.005). The individual transplant recipient showed little variation in metabolite concentrations over several months. Using this group as a control we studied metabolite concentrations in patients with kidney transplants who developed leucopenia. Our preliminary findings indicate that elevated red cell 6-thioguanine nucleotide concentrations, above the control range, can be associated with bone marrow depression.

Adult↗
PubMed1984

Vasculitis affecting the kidney: presentation, histopathology and long-term outcome.

Fifty-three patients who by clinical and/or histological criteria were judged to have vasculitis affecting the kidney were reviewed. Patients with systemic lupus or Schönlein-Henoch purpura were excluded. Segmental necrotising glomerulitis was taken as a manifestation of vasculitis ('microscopic polyarteritis'). Those patients in whom vasculitis was confined to glomerular capillaries were compared with those who in addition had vascular lesions outside the glomeruli. The two groups were found to have identical clinical features. Clinical presentation was predominantly extrarenal, and exclusively renal in only two. Three patients were classified histologically as Wegener's granulomatosis, four had malignant tumours and two relapsing polychondritis. Hepatitis B surface antigen was absent in all of 37 patients tested. Renal disease presented with microscopic haematuria and minor proteinuria in the majority (32) but 16 patients presented with rapid deterioration of renal function, including seven with anuria. Histologically 42 patients showed segmental necrotising glomerulitis ('microscopic polyarteritis'), six diffuse proliferative glomerulonephritis,and in five only minor or ischaemic glomerular changes were present. Crescents were found in 41/42 of those with segmental necrotising glomerulitis, nd involved more than 50 per cent of glomeruli in 15 patients. Immunohistochemical studies were generally negative except the fibrin. Electron microscopy showed no evidence of immune deposits in necrotising glomerulitis, but these were present in 2/6 patients with diffuse proliferative glomerulonephritis. Overall prognosis was poor, 35 patients having died, 20 early in the course of the disease and 15 later. Oligoanuria and extensive crescent formation were adverse signs. Survivals were 54, 38 and 34 per cent at one, five and 10 years respectively. Of those who survived the initial illness, 12 were stable with apparently inactive disease, whilst 16 continued to show clinical signs of activity and required treatment. A variety of treatments was employed including oral and intravenous corticosteroids, immunosuppressive agents, anticoagulants; only one patient was treated by plasmapheresis. It is difficult to draw any firm conclusions as to the efficacy of treatment and survival rates remain unsatisfactory.

Acute Disease↗
PubMed1984

Acute renal failure in essential mixed cryoglobulinemia: precipitation and reversal by plasma exchange.

A patient with essential mixed cryoglobulinemia was treated for deteriorating renal function with plasma exchange alone. This therapy was immediately followed by acute oliguric renal failure due to precipitation of the cryoglobulin within glomerular capillary loops, probably as a result of infusion of cold plasma. The composition of the intracapillary deposits reflected not only the variety of cryoglobulin but the rapidity of deposition. Renal function returned when plasma exchange was re-introduced, this time coupled with immunosuppressive chemotherapy. After resolution of the intraluminal caogula a membranoproliferative picture remained. Replacement fluids for plasma exchange in cryoglobulinemia should be warmed before infusion.

Acute Kidney Injury↗
PubMed1983

Genital oedema in patients treated by continuous ambulatory peritoneal dialysis: an unusual presentation of inguinal hernia.

Four patients receiving continuous ambulatory peritoneal dialysis presented with scrotal or labial oedema but no detectable cough impulse. Two of the patients later developed clinical evidence of inguinal hernia, and in the other two inguinal hernias were found at operation. These cases suggest that genital oedema occurring in a patient receiving continuous ambulatory peritoneal dialysis is a sign of a small inguinal hernia which may not be detectable clinically.

Adult↗
PubMed1983

High versus "low" dose corticosteroids in recipients of cadaveric kidneys: prospective controlled trial.

Corticosteroids have the major role in the immunosuppressive treatment of patients who have received renal transplants. Despite their extensive use there is still debate about the appropriate dose that will prevent rejection of the renal allograft with the least morbidity. From March 1979 to November 1981 a randomised controlled trial of high (33 patients) v low oral dose (34 patients) of prednisolone along with azathioprine was conducted in recipients of first cadaveric transplants who had received a blood transfusion within six months of transplantation. The main difference in outcome between the two groups was a high incidence of some infections in the high dose group. Patient mortality, graft survival, transplant function, and number of rejection episodes were indistinguishable in the two groups, but rejection episodes tended to occur later in the high dose group. These findings suggest that the use of lower doses of corticosteroids soon after cadaveric renal transplantation does not jeopardise graft survival and results in lower patient morbidity.

Adolescent↗
PubMed1983

Hyperimmune immunoglobulin therapy for cytomegalovirus infections in renal transplant patients.

Eleven renal transplant patients with CMV infection have been treated by passive immunisation, one with high-titre anti-CMV plasma and 10 with fractionated hyperimmune anti-CMV immunoglobulin. All were pyrexial for at least seven days before treatment with typical clinical and laboratory features of CMV infection. Seven of the 11 patients treated showed a striking and sustained response within 24-48 hours of therapy, with lysis of fever, resolution of pneumonitis, a rise in white cell count and improvement in renal function and liver function tests.

Adolescent↗
PubMed1983

Rapidly progressive glomerulonephritis with extensive glomerular crescent formation.

Thirty-nine patients with severe crescentic glomerulonephritis and rapidly progressive renal failure were reviewed. Nineteen patients had a focal necrotizing glomerulonephritis, they usually presented with signs of multi-system disease, and eight had histologically-proven microscopic polyarteritis. A second group of 20 patients presented with an acute nephritic syndrome, often with nephrotic features, and had only minor prodromal symptoms. Renal biopsy material showed various forms of proliferative glomerulonephritis in addition to crescents. The most important prognostic feature at admission was renal function: only four of 21 patients who required dialysis recovered any renal function. The prognosis was worse for those with necrotizing glomerulonephritis, of whom two-thirds had oliguria on admission. All patients who were not oliguric, and some with oliguria, were treated with high doses of corticosteroids, usually accompanied by azathioprine and anticoagulants. Seventeen of 18 patients who were not oliguric initially retained or regained renal function, although three subsequently went into renal failure, and three others died of non-renal causes. At the most recent review, 25 of the 39 patients were either dead (16 patients) on dialysis or transplanted (nine patients). Ten were alive with diminished renal function, one had normal renal function but persisting proteinuria, and three were well. Prompt treatment may have contributed to these favourable results in a very severe disease.

Adolescent↗
PubMed1982

Relationship between platelet aggregation, thromboxane synthesis and albumin concentration in nephrotic syndrome.

Increased platelet aggregability on stimulation with sodium arachidonate (NaAA), collagen and ADP was found in a group of 14 patients with nephrotic syndrome when compared with age and sex matched controls. Five of the group also exhibited spontaneous platelet aggregation (SPA), associated with synthesis of thromboxane B2 (TxB2), and which appeared to correlate with a markedly increased serum triglyceride concentration. Thromboxane B2 generation in response to NaAA was increased and reflected both the low serum albumin concentration and the platelet aggregation response to this agent. Addition of albumin in vitro decreased the amount of TxB2 generated for a given dose of NaAA and increased NaAA and collagen-induced platelet aggregation thresholds. However, albumin had no significant effect on collagen-induced TxB2 production. The results suggest that the hypoalbuminaemia and associated reduced binding of arachidonic acid and increased synthesis of TxA2 account in part for the increased platelet aggregability seen in the nephrotic syndrome but that other mechanisms are also involved.

Adenosine Diphosphate↗
PubMed1981

The role of vitamin D metabolites in the osteomalacia of renal disease.

Osteomalacia is commonly found in patients with severe renal impairment. Its aetiology is multifactional and not simply due to deficient production of active metabolites of vitamin D. Decreased availability of calcium and phosphate and the accumulation of aluminium is some dialysis-treated patients are also important aetiological factors. The treatment of osteomalacia depends, in part, upon its accurate diagnosis, and identifying and reversing the underlying cause.

Calcium↗
PubMed1981

High dose frusemide in acute renal failure: a controlled trial.

Fifty-eight patients in established acute renal failure following trauma or surgery were allocated in a prospective and random fashion to two different diuretic regimes. In the control group, 1 g frusemide was given as a single injection over four hours. In the test group, frusemide was then continued either intravenously or orally in a dose of 3 g/24 hr until a urine output of 200 ml/hr was sustained or until the plasma creatinine fell below 300 mumoles/l. Oliguria was reversed or prevented in 24 of 28 patients given sustained frusemide, but in only 2 patients given a single injection. However, the number of dialyses and duration of renal failure and mortality were not different in the two groups. The serious complication of deafness occurred in two patients and in one of them this was permanent.

Acute Kidney Injury↗
PubMed1978

Dynamic renal transplant imaging with Tc-99m DTPA (Sn) supplemented by a transplant perfusion index in the management of renal transplants.

We have performed 955 studies on 152 patients with 167 renal transplants. Images were recorded following bolus injection of 12-15 mCi Tc-99m DTPA (Sn). The data were stored on a computer and analyzed by generation of region-of-interest curves from (a) the iliac artery distal to the transplant, (b) the kidney, and (c) a background area. A perfusion index was adopted: formula see text. In 276 studies the patient clearly had acute tubular necrosis (ATN), rejection, or a normal kidney on retrospective analysis. The normal perfusion index has a value below 150, and it increases with falling perfusion, such as is seen in rejection and in renal-artery stenosis. The use of this index in addition to sequential images and changes in the region-of-interest curves usually allows separation of rejection from ATN and, particularly, rejection from normals. When serial studies are performed, the separation of rejecting from nonrejecting transplants is excellent, although renal-artery stenosis may cause similar changes in perfusion.

Acute Kidney Injury↗