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Biomedical subjects

R L Kirkman

Publications and source records attributed to R L Kirkman.

At least 73 records · Page 4Linked to original sources
PubMed1986

The use of percutaneous nephrostomy in patients with ureteric obstruction undergoing renal transplantation.

The use of percutaneous nephrostomy with or without placement of a ureteric stent has been of increasing aid in treating both acute and chronic ureteral obstruction in recipients of renal allografts. Eight patients who underwent transplantation, had ureteric obstruction develop and were treated by this means are reported herein. The technique is standard and can be performed in an arteriography suite. Once a catheter is inserted into the allograft collecting system, a nephrostomy tube or a stent, or both, is easily inserted. Three of the patients had acute ureteric obstruction secondary to clot forming after needle biopsy of the transplant kidney. Percutaneous nephrostomy tubes were passed, the renal pelvis and ureter irrigated and the clots lysed. Operation was unnecessary. In five patients with declining renal function secondary to chronic obstruction, percutaneous nephrostomy placement allowed return of renal function to base line levels, while placement of a stent through the ureter into the bladder facilitated location of the ureter at operation for ureteral reimplantation. The technique of percutaneous nephrostomy is simple, convenient and allows patient recovery preoperatively. It has become part of our standard armamentarium in transplant recipients.

Adult↗
PubMed1985

Administration of an anti-interleukin 2 receptor monoclonal antibody prolongs cardiac allograft survival in mice.

Administration of the monoclonal antibody M7/20, which binds to the murine interleukin-2 (IL) receptor, significantly prolongs cardiac allograft survival in two H-2-incompatible strain combinations of inbred mice. The results support the important role of the IL-2 receptor in the mechanism of graft rejection, and suggest its suitability as a target for immunosuppressive therapy.

Animals↗
PubMed1985

Failure of cyclosporine to prevent small bowel allograft rejection in pigs.

The effect of cyclosporine (CyS) on survival and function of 250 cm intraabdominal heterotopic small bowel allografts was studied in outbred pigs. Experimental animals received oral CyS alone (25 mg/kg/day), or oral CyS, donor bowel radiation, and recipient splenectomy; controls were untreated. Excluding technical failures, no significant differences in graft survival were observed, although one relatively long-term survivor occurred in each treated group. Rejection was not related to cyclosporine levels. These data show that CyS as a single agent as well as when used with supplemental therapy does not uniformly prevent rejection of small bowel allografts in pigs, although an occasional long-term survivor will occur. The failure to achieve consistently successful engraftment may reflect the large quantity of lymphoid tissue in small bowel. Further experimentation is required before human transplantation is again attempted.

Animals↗
PubMed1985

Clinical experience with cyclosporine and azathioprine at Brigham and Women's Hospital.

Cyclosporine (CsA) immunosuppressive therapy of renal allograft recipients at Brigham and Women's Hospital yielded a 20% increase in 12- and 24-month allograft survival over azathioprine (Aza) treated controls. A trend towards increased allograft survival with better HLA-A,B, or DR matching in recipients of cadaver allografts treated with CsA was appreciated, but it fell short of statistical significance. Nephrotoxicity is common in CsA-treated patients and is manifested by a largely reversible increase in the serum creatinine. It is possible to convert patients from CsA to Aza without adverse effects on allograft survival or allograft function.

Adult↗
PubMed1985

Liver disease in recipients of long-functioning renal allografts.

After noting that hepatic failure was the leading cause of death in our transplant recipients whose renal allografts had functioned for more than five years, we reviewed retrospectively the post-transplant course of these patients to assess the long-term effect of liver disease in this population. Sufficient data was available to evaluate 184 of 217 long-term survivors (85%). Twenty-six patients (14%) experienced a doubling of SGOT and/or SGPT of greater than six months' duration and were defined as having chronic liver disease. The etiology of chronic liver disease was identified in 14 patients (54%), of whom 11 were HBsAg positive. Evidence of chronic hepatitis developed in only six of 26 patients (22%) during the first four years post transplant. Once enzyme abnormalities occurred, they were unremitting until death or end of the study in 73% of patients. Actuarial survival of patients with chronic liver disease was markedly decreased compared to long-surviving transplanted controls. Ten of the 12 deaths in patients with hepatocellular abnormalities were due to hepatic failure, of which eight occurred in the setting of extrahepatic sepsis. Chronic liver disease is a late complication of transplantation and is associated with significant mortality due to an increased susceptibility to overwhelming sepsis.

Adult↗
PubMed1985

Vascular access for hemodialysis. Patency rates and results of revision.

Over a 4-year interval, 324 arteriovenous conduits were created in 256 patients with end-stage renal disease as access for chronic hemodialysis. These included 154 Cimino fistulae, 163 polytetrafluoroethylene (PTFE) grafts, and seven miscellaneous grafts. Satisfactory patency rates were demonstrated for as long as 4 years for both Cimino fistulae and PTFE grafts by life-table analysis. Failures of Cimino fistulae usually occurred early in the postoperative period, secondary to attempts to use inadequate veins. Thrombosis caused the majority of PTFE graft failures and was generally the result of venous stenosis. Correction of such venous stenosis is mandatory to restore graft patency and can result in prolonged graft survival.

Adolescent↗
PubMed1985

The detection of cardiac allograft rejection by alterations in proton NMR relaxation times.

The ability of proton NMR relaxation times to detect cardiac allograft rejection was studied in an inbred rat heterotopic cardiac transplantation model. Hearts from 25 Lewis X Brown Norway F1 hybrid rats were anastomosed to the abdominal aorta and vena cava of Lewis recipients; 25 Lewis donor hearts served as isograft controls. Groups of five allografts and five isografts were harvested daily between two and six days post-transplant. The relaxation times T1 and T2 of the transplanted hearts were determined in vitro with a 10 MHz spectrometer. T1 and T2 values in allografts did not differ significantly from those in isografts at days 2 and 3 post-transplant. However, at days 4, 5, and 6 T1 and T2 of the allografts were significantly prolonged. This finding correlated with an elevation in tissue water content and the onset of rejection as determined histologically. An additional 21 allografts, treated with cyclosporine, were studied in the same way from four to more than 100 days post-transplant. T1 and T2 values of these treated allografts did not change significantly during the observation period and were similar to the relaxation values obtained in the isografts at days 2 to 6. These data suggest that serial measurements of myocardial T1 and T2 may be useful in detecting acute cardiac allograft rejection and monitoring the effect of antirejection treatment.

Animals↗
PubMed1985

The effect of anti-interleukin-2 receptor monoclonal antibody on allograft rejection.

During immune response to an allograft, activated T cells express a number of cell surface activation antigens, among them the membrane receptor for the lymphokine interleukin 2 (IL-2). As the IL-2 receptor is not present on resting T cells, it offers an attractive target for potentially specific immunosuppressive therapy. The rat monoclonal antibody M7/20, which binds to the murine IL-2 receptor, was studied for its effect on allograft survival in two H-2-incompatible strain combinations in inbred mice. Treatment with M7/20 for 10 days markedly prolonged survival of vascularized, heterotopic heart allografts in both strain combinations, with indefinite graft survival in 50% of recipients. The same treatment significantly prolonged skin allograft survival in one of the two combinations. The results support the important role of the IL-2 receptor in the mechanism of graft rejection and confirm its suitability as a target for immunosuppressive therapy in transplantation.

Animals↗
PubMed1985

Structural and functional evolution of jejunal allograft rejection in rats and the ameliorating effects of cyclosporine therapy.

We assessed the structural and functional evolution of small intestinal transplant rejection in a rat model by use of 1-micron section, electron microscopic, and in vitro electrophysiologic techniques to study jejunal mucosa 3, 6, and 9 d posttransplantation. The earliest structural abnormalities detected in jejunal loops transplanted from Lewis X Brown Norway F1 hybrids into Lewis rats occurred within 3 d posttransplantation and consisted of focal endothelial cell injury of the microvasculature and focal injury of crypt epithelial cells. Both alterations were associated with adjacent infiltration of large lymphoid cells, and both markedly progressed and became rather diffuse over the following 6 d. In contrast, villus absorptive cells were not markedly altered in structure until the 9th postoperative day. As compared with host jejuna, allograft jejunal epithelium demonstrated multiple functional abnormalities. Transepithelial resistance declined progressively by days 6 and 9 (both P less than 0.05), although baseline transepithelial spontaneous potential difference was only affected at day 9 (P less than 0.01). Stimulated absorption by allograft jejuna, as assessed by measuring electrical response to mucosal glucose, was not significantly diminished until day 9 (P less than 0.05). In contrast, stimulated secretion assessed by measurement of electrical response to serosal theophylline was diminished by day 6 (P less than .01). These data suggest that the earliest epithelial injury during rejection, as judged both structurally and functionally, occurs in the crypt and is paralleled by endothelial injury at the level of the microvasculature. Thus, the primary targets for rejection are most likely endothelial cells and crypt epithelial cells. In contrast, structural and functional impairment of villus epithelium is detectable only at substantially later times during rejection and are most likely secondary processes related to either ischemia produced by microvascular injury or decreased epithelial regenerative ability secondary to crypt injury. Last, we show that the detrimental structural and functional sequellae of jejunal transplantation across the major histocompatibility complex in this model is strikingly ameliorated with cyclosporine therapy.

Animals↗
PubMed1985

Stability of renal allograft recipients after conversion from cyclosporine to azathioprine.

Forty-eight patients with stable renal function after allotransplantation have been converted from CsA/prednisone to azathioprine/prednisone to assess the short- and long-term effects upon renal function. Virtually all patients show an initial improvement in serum creatinine levels. Three patients developed chronic renal failure after 12 to 21 months, and three died of pneumonia 7, 12, and 19 months later. The mean serum creatinine level at latest follow-up (seven to 36 months) was 2.5 +/- 1.5 mg/dL for all 48 patients. Of interest, a control group of 21 patients not converted to azathioprine had serum creatinine levels of 2.5 +/- 0.8 mg/dL, over a follow-up period of five to 25 months. It is not immediately apparent that either group will have a superior overall outcome, although patients on azathioprine seem to have more of a risk for graft loss. More data are needed with various dosage schedules, and with randomized controls.

Acute Disease↗
PubMed1984

Renal artery stenosis in transplant patients.

Although hypertension appears not infrequently among recipients of kidney transplants, renal artery stenosis is relatively rare as a causative factor. A 23-year experience of patients receiving kidney grafts at the Brigham and Women's Hospital was reviewed to ascertain the incidence of renal artery stenosis and its surgical management. Risk factors leading to the condition and selection of patients for operation are emphasized. The incidence of arterial stenosis severe enough to require operation was 2.7% of 914 kidney transplants; the overall incidence in these patients is unknown, although operated patients comprise about one-half of those undergoing arteriography to diagnose hypertension. The mean time for development of the condition was 21.4 months from date of engraftment. A successful outcome as measured by fall in blood pressure and/or serum creatinine was achieved in 14 of 21 patients (67%) in whom surgical repair of the effected artery was undertaken. Reparative surgery was unsuccessful in seven patients, although hypertension was improved in one of these individuals following transplant nephrectomy. Surgery was never undertaken in four patients because of chronic rejection noted on biopsy. There was no mortality. Operative repair should be offered to patients with renal artery stenosis leading to unmanageable hypertension or renal dysfunction, but withheld from those with documented chronic rejection regardless of major arterial compromise.

Adult↗
PubMed1984

Experience with cyclosporine and steroids in clinical renal transplantation.

We have reviewed the results of patient survival and transplant function of the last 100 recipients of renal allografts treated with cyclosporine (CyA) plus low-dose steroids since November 1981; the follow-up varies between 3 months and 2 years. A group of 56 individuals transplanted between January 1980 and October 1982 and immunosuppressed with azathioprine (Aza) and steroids were used as comparison. There were five deaths among 100 patients treated with CyA and two among 56 treated with Aza. There were, however, marked differences in allograft function. Using actuarial curves, 2-year allograft survival from 24 living, related, one haplotype matched donors was 83%, as compared to an unsatisfactory 60% graft function among 24 nonrandomized, comparable, Aza-treated recipients. The 2-year actuarial survival of 76 allografts from cadaver donors was 76%; that of 36 grafts in patients treated with Aza, 48%. Interestingly, function of first cadaver allografts was 84% at 2 years, far better (p less than 0.002) than cadaver graft function (58%) in patients who had been previously transplanted; these latter results are comparable to Aza-treated cadaver recipients. Side effects and complications of this difficult drug, as well as its benefits, have been stressed in this article.

Actuarial Analysis↗
PubMed1984

Conversion from cyclosporine to azathioprine in renal allograft recipients.

Fifty seven recipients of renal allografts initially treated with CsA and low-dose prednisone were switched to azathioprine and low-dose steroids. Ten had prolonged (greater than 28 days) allograft nonfunction after transplantation (group 1), 8 had ongoing, poorly controlled rejection (group 2), and 39 had stable functioning grafts (group 3). With a mean follow-up period of 5 +/- 3 months after conversion, 50 grafts remained functional including 6 of 10 in group 1, 6 of 8 in group 2, and 38 of 39 in group 3. Thirty-seven (65%) had improved function, 12 (21%) had stable function, and 8 (14%) experienced declining renal function. Three of these latter 8 patients required reinstitution of CsA therapy. There were 20 episodes of acute rejection in 18 patients; one graft lost function because of acute rejection unresponsive to therapy. Reasons for the 6 other graft losses were persistent primary nonfunction in 3 patients from group 1, untreated rejection in 2 patients who had multiple prior rejection episodes while on CsA, and chronic rejection in one patient. Although renal function has improved or stabilized in the majority (86%) of individuals changed to azathioprine therapy, there was substantial risk of acute rejection (32%) complicating this procedure. Patients most likely to benefit from conversion to azathioprine therapy are those with prolonged graft nonfunction after transplantation and those with serum creatinines greater than 2.0 mg/dl.

Adult↗
PubMed1984

Small intestine transplantation in the rat--immunology and function.

Heterotopic, vascularized small intestine transplants were performed in inbred strains of rats to investigate the structural, functional, and immunologic consequences of intestinal transplantation with and without immunosuppression with cyclosporine (CyA). Lewis X Brown Norway F1 intestine was rejected by untreated Lewis recipients in 7 to 10 days. Structurally, rejected intestine was characterized by shortened crypts and villi lined by damaged attenuated epithelial cells. Functionally, rejection was associated with impaired epithelial active ion transport as indicated by decreased potential difference and with diminished epithelial barrier function as reflected by decreased transepithelial resistance. Administration of CyA for 7 days prevented clinical rejection and partially prevented the structural and functional defects. Lewis intestine transplanted into Lewis X Brown Norway F1 recipients caused fatal graft versus host disease (GVHD) in 9 to 17 days. Treatment with CyA for 7 days failed to prevent GVHD routinely, but prolonged administration delayed fatal GVHD until CyA was discontinued. Intestine from Lewis "B" rats made deficient of T cells by thymectomy, irradiation, and reconstitution with syngeneic T cell-depleted bone marrow failed to cause GVHD in Lewis recipients. Reconstitution of the "B" rats with T cells before transplantation restored the GVHD response. These results may be relevant in the consideration of clinical small intestinal transplantation.

Animals↗
PubMed1983

Treatment of acute renal allograft rejection with monoclonal anti-T12 antibody.

Nineteen patients with acute rejection of a renal allograft were treated with the monoclonal antibody anti-T12, directed against a determinant present on all post-thymic T cells. Seven patients had a good response, four had an equivocal response, and eight failed to respond. Histologic studies demonstrated that the good responders had primarily cellular rejection. The nonresponders included 4 patients with moderate-to-severe humoral rejection, one patient with an inadequate dose of antibody, one patient who withdrew before completing the study, and one patient with late end-stage rejection. All eleven patients with good or equivocal responses have functioning kidneys in a follow-up of 1-15 months (mean 7 months). Only one patient has had a subsequent acute rejection episode, which responded to a steroid pulse. No significant complications of anti-T12 therapy occurred.

Adult↗
PubMed1983

Monoclonal anti-T12 antibody as therapy for renal allograft rejection.

Nineteen renal allograft recipients experiencing rejection were infused with monoclonal mouse anti-human T12 directed to a T lymphocyte differentiation antigen expressed on mature post-thymic cells. Patients were offered this therapy as an alternative to high-dose methylprednisolone after diagnosis of an acute rejection episode within 3 months of transplantation. Seven patients had clear-cut reversals of rejection activity within the 10-day period of treatment. Four additional patients had delayed responses in association with acute tubular necrosis and/or cyclosporine toxicity, and they received other therapies according to protocol when anti-T12 alone had not caused a response after 5 days. All but one of these responding patients have been free of subsequent acute rejection over a 1-15 month follow-up period. Treatment failures appear to be related to the presence of allo-antibody-mediated vasculitis. Therapy was well tolerated. These preliminary studies have revealed the existence of a T12 negative subpopulation of extrathymic T cells, usually undetectable in peripheral blood.

Antibodies, Anti-Idiotypic↗