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Biomedical subjects

G Proud

Publications and source records attributed to G Proud.

At least 91 records · Page 5Linked to original sources
PubMed1986

Aspirate cellularity as a rapid indicator of renal allograft rejection.

No rapid and unequivocal test exists to diagnose renal allograft rejection. Despite advances in immunosuppression over the last 20 years, rejection is still the major problem in clinical organ transplantation. Most transplant centres report a renal graft survival rate of about 60 per cent at 5 years and the majority of graft losses are due to rejection. An influx into the graft of various cell types has been implicated in the diagnosis of rejection but it takes up to 24 h to obtain such information histologically. We have carried out fine needle aspiration biopsy of the allografts and estimated the number of white cells in the aspirate using a fluorescence activated cell sorter. Studies were performed in 34 cases of normal allograft function, 8 of rejection, 8 of acute tubular necrosis and 8 of cyclosporin nephrotoxicity. There was a statistically significantly higher cell number in the group undergoing rejection (P less than 0.01; Wilcoxon unpaired test) when compared to each of the other three groups. We believe that this technique, which takes only a few minutes to perform, could yield much valuable information. It deserves further study.

Biopsy, Needle↗
PubMed1986

Effect of perioperative blood transfusion on recurrence of colorectal cancer.

The aim of the present study was to examine the outcome of 517 patients undergoing curative surgery for colonic and rectal cancer, and to compare the recurrence and mortality rates in transfused and non-transfused groups of patients. The two groups were evenly matched for age, sex, Dukes' stage and histological differentiation. There were significantly more rectal tumours in the transfused group (P less than 0.01), but the distribution of colonic lesions did not differ. Life table analysis revealed that the transfused patients had a 20 per cent greater probability of recurrence at 5 years (P less than 0.005) and there were 16 per cent more cancer related deaths (P less than 0.01). Even when all rectal cancers were excluded, a similar trend was seen for the colonic lesions: a 24 per cent greater probability of recurrence at 5 years (P less than 0.025) and 15 per cent more cancer related deaths (P less than 0.02). We conclude that blood transfusion may be associated with increased mortality and recurrence in patients undergoing curative surgery for colorectal cancer.

Aged↗
PubMed1986

Subpopulations of thyroid autoantibody secreting lymphocytes in Graves' and Hashimoto thyroid glands.

Lymphocytes isolated from Graves' and Hashimoto thyroid tissue by enzymatic (dispase) digestion or mechanical disaggregation were markedly different in terms of their ability to synthesize thyroid autoantibodies in culture. Dispase digestion, followed by removal of thyroid follicular cells, gave a lymphocyte population with a high T:B cell ratio (6:1). However, the ability of these cell suspensions to synthesize microsomal (Mic) and thyroglobulin (Tg) antibodies spontaneously was significantly increased compared with lymphoid suspensions isolated by mechanical means. Spontaneous synthesis of thyroid autoantibodies was not markedly enhanced in cell suspensions prepared from patients' lymph node tissue by digestion compared with mechanical disaggregation. Further, Mic and Tg antibody production by thyroid lymphocytes prepared using dispase was inhibited by pokeweed mitogen (PWM) whereas in most cases suspensions prepared from the same tissues by mechanical dispersion synthesized low or undetectable levels of autoantibodies whether PWM was present or absent. Digestion of tissue debris remaining after mechanical removal of lymphocytes gave suspensions which had an increased proportion of suppressor/cytotoxic T cells compared with suspensions produced mechanically or by digestion alone; however, in terms of spontaneous autoantibody synthesis and PWM induced inhibition, these suspensions were similar to these obtained by digestion alone. It would therefore seem that enzymatic digestion of thyroid tissue resulted in the isolation of a lymphoid population which was different from that extracted by mechanical disaggregation. The digestion process appears to permit the recovery of lymphocytes closely associated with thyroid follicular cells and our studies suggest that it is this population which makes the major contribution to autoantibody synthesis.

Adult↗
PubMed1985

Continuous ambulatory peritoneal dialysis and renal transplantation: a five year experience.

Continuous ambulatory peritoneal dialysis is a new and increasingly popular method of routine dialysis, but its effect on renal transplantation is uncertain. A non-randomised comparison was made of the outcome of grafting in patients who had been treated before transplantation with continuous ambulatory peritoneal dialysis with that in patients treated with haemodialysis. During the five years, 1979-84, after continuous ambulatory peritoneal dialysis was introduced to Newcastle upon Tyne 220 patients have received transplants after either continuous ambulatory peritoneal dialysis (61 patients) or haemodialysis (159 patients). During follow up no significant differences occurred in survival of patients or grafts between the two treatment groups. One year after transplantation the percentages of survivors who had received continuous ambulatory peritoneal dialysis and haemodialysis were 88% and 91% respectively, and overall graft survival was 66% and 72%, respectively. A multiple regression model was used to allow for differences among patients--for example, duration of dialysis and number of preoperative transfusions--on the survival of grafts. When only first cadaver grafts were considered (in 152 patients) graft survival (non-immunological failures excluded) was not significantly different between the patients treated with continuous ambulatory peritoneal dialysis and haemodialysis. Continuous ambulatory peritoneal dialysis is not a risk factor in renal transplantation, and its continued use in treatment of potential renal graft recipients is recommended.

Adolescent↗
PubMed1985

Cystic adventitial disease of the common femoral and popliteal arteries.

Cystic adventitial arterial disease (CAAD) is usually situated in the popliteal artery and is a well recognized cause of intermittent claudication in otherwise healthy, young, non-smokers. Three cases of CAAD have recently been encountered, involving the popliteal artery in two patients and the common femoral in one. Two of these patients were hypertensive smokers in their sixth decades and only one was an otherwise healthy non-smoker, but all three had a characteristically rapid onset of symptoms. All had angiographic appearances suggestive of CAAD, confirmed by ultrasound and CAT scanning in one patient. Two were treated by resection of the affected artery and a replacement graft, both with excellent results. One popliteal lesion was bypassed with a vein graft which occluded after 3 months. CAAD may occur more commonly than generally realized. It can present in patients whose condition suggests an atheromatous cause for their symptoms. Since good results can be expected from appropriate surgical treatment in most cases, CAAD should be considered in the diagnosis of all patients with claudication, particularly when the onset has been rapid.

Arterial Occlusive Diseases↗
PubMed1985

The influence of surgical operations on components of the human immune system.

Surgical operations have been shown to cause a variety of immunological disturbances in man both in vivo and in vitro. With few exceptions the overall picture is one of a generalized state of immunodepression in the postoperative period. The implications of these observations are that host defences may be compromised by surgical procedures, thus providing a 'fertile soil' for bacterial invasion and tumour cell metastasis at the very time when risks from invading pathogens and viable tumour cells are maximal. We have studied the effects of surgical operations on the immune system in 35 patients with benign disease. Surgical procedures were classified as either minor (n = 15) or major (n = 20). A panel of monoclonal antibodies was used to identify peripheral blood lymphocyte subpopulations and analysis was performed using flow cytometry. Simultaneous estimations of plasma alpha-1 proteinase inhibitor (alpha-1-PI), alpha-2-macroglobulin (alpha-2-M), alpha-2-pregnancy-associated glycoprotein (alpha-2-PAG) and plasma suppressive activity (PSA) on stimulated allogeneic lymphocytes were performed before operation and on postoperative days 1, 3, 7, 17 and 21. Circulating numbers of all lymphocyte subpopulations fell significantly following surgery, except for B lymphocytes which did not change. The magnitude, and duration of the reduction in cell numbers and the subpopulation affected was significantly related to the degree of surgical trauma, and returned to pre-operative values by postoperative day 7. Changes in alpha-1-PI, alpha-2-M, alpha-2-PAG and PSA were also significantly related to the degree of surgical trauma, and these plasma changes persisted longer than the cellular disturbances. Surgical operations induce a reversible depression of cellular immunity which precedes plasma suppressive activity in its return to pre-operative levels. Immunostimulating agents such as interferon and the interleukins deserve evaluation as prophylactic agents pre-operatively.

Blood Proteins↗
PubMed1985

The detection of renal allograft rejection by fine-needle intrarenal manometry.

The causes of early renal allograft malfunction include rejection, acute tubular necrosis, cyclosporin nephrotoxicity and vascular complications. Fine-needle intrarenal manometry is a potential method of distinguishing rejection from the other causes of malfunction and has been used by Salaman and Griffin in patients' treated with cyclosporin. The technique involves inserting a fine-needle, which is connected to a specially designed manometer, into the substance of the transplant kidney. One hundred and six measurements of intrarenal pressure have been made in 28 patients immunosuppressed with either azathioprine and prednisolone or cyclosporin. Thirteen rejection episodes were identified and confirmed by biopsy. These were treated by pulse steroid (methylprednisolone) therapy. Seven episodes of cyclosporin toxicity were identified and there were fifteen episodes of acute tubular necrosis. The mean intrarenal pressure in the rejecting group was 52.8 mmHg compared with 22.3, 24.1 and 24.3 mmHg for the normal function, acute tubular necrosis and cyclosporin nephrotoxicity groups, respectively (P less than 0.01; Wilcoxon unpaired test). There were no differences within these groups related to the type of immunosuppression used. There were no clinical complications associated with the procedure. Thus in newly transplanted patients, fine-needle intrarenal manometry accurately identified rejection and distinguished it from normal function, acute tubular necrosis and cyclosporin nephrotoxicity in all the patients regardless of the immunosuppressants used.

Cyclosporins↗
PubMed1985

CAPD and renal transplantation.

Continuous ambulatory peritoneal dialysis (CAPD) is believed to improve the immune competence of end-stage renal failure patients and to increase the risk of graft rejection following subsequent renal transplantation. At this centre, 220 consecutive renal transplants have been studied in patients treated by either CAPD or haemodialysis (HD). Patient and graft survival was not significantly different for the two treatment groups over a five year follow-up. When only first cadaver recipients were considered (152 grafts) one-year graft survival (non-immunological failures excluded) was 77 per cent for CAPD and 79 per cent for HD patients (P greater than 0.05). Time on dialysis and number of pre-operative transfusions were significantly greater for the HD patients (P less than 0.05). A group of HD and CAPD patients were identified as being matched for age, sex, HLA, A, B, DR antigen matches, pre-operative transfusions and time-on dialysis. One-year graft survival of the CAPD patients was 82 per cent and for the HD patients 61 per cent. Studies of patient lymphocyte function and plasma suppressive activity in vitro revealed no differences between CAPD and HD treated patients. CAPD is not an immunological risk factor in renal transplantation and its continued use in the preparation of patients for transplantation is recommended.

Adolescent↗