Increased renal allograft thrombosis in CAPD patients

In a retrospective analysis of 202 renal transplant procedures in the years 1989-1992 we identified an excess of grafts lost from primary renovascular thrombosis in patients receiving continuous ambulatory peritoneal dialysis (CAPD) compared to haemodialysis (HD) patients (9 CAPD versus 0 HD, Chi-squared = 9.63; P < 0.01). All graft losses from thrombosis occurred within 16 days of surgery. Possible predisposing causes were identified in three patients. Donor age was greater in CAPD patients losing their kidneys from thrombosis compared to the overall CAPD group [mean (SD) years, 43.0(12.9) versus 29.1(15.8); P = 0.01] whereas no significant difference in haematocrit, platelet count, antibody status, cyclosporin use, peroperative hypotension, primary diagnosis, smoking, or diabetes mellitus was found. Data from the EDTA registry for 1990-91 show that graft loss from primary renovascular thrombosis in UK-treated patients was reported in 7.1% of CAPD recipients compared with 1.8% in haemodialysis. We suggest that CAPD patients are at greater risk of graft loss from renovascular thrombosis than HD patients and may require more intensive fluid and anticoagulant treatment in the perioperative period.

A Simple Kinetic Model of Polymer Adsorption and Desorption

A model of the desorption and adsorption of a polymer layer at a planar surface indicates a transition from exponential kinetics at high temperatures to nonexponential kinetics (stretched exponential with index one-half) at lower temperatures where these processes are diffusion-limited. Measurements of polystyrene desorption through polyisoprene overlayers show this predicted transition. Corroborative results are obtained for polystyrene desorption through polymethylmethacrylate overlayers. This identification of two distinct kinetic regimes suggests a unifying perspective from which to analyze polymer and biopolymer mobility at surfaces.

A neurotoxicity assessment of high flash aromatic naphtha

Catalytic reforming is a refining process that converts naphthenes to aromatics by dehydrogenation to make higher octane gasoline blending components. A portion of this wide-boiling range hydrocarbon stream can be separated by distillation and used for other purposes. One such application is a mixture of predominantly 9-carbon aromatic molecules (C9 Aromatics, primarily isomers of ethyltoluene and trimethylbenzene), which is removed and used as a solvent also known as High Flash Aromatic Naphtha (HFAN). A program was initiated to assess the toxicological properties of HFAN since there may be human exposure, especially in the workplace. The current study was conducted to assess the potential for neurotoxicity in the rat. Adult male Sprague-Dawley rats of approximately 300 grams body weight, in groups of twenty, were exposed by inhalation to HFAN for 90 days at concentrations of 0, 100, 500, and 1500 ppm. During this period the animals were tested monthly for motor activity and in a functional observation battery. After three months of exposure, for 6 hours/day, 5 days/week, 10 animals/group/sex were sacrificed and selected nervous system tissue was examined histopathologically. No signs of neurotoxicity were seen in any of the evaluated parameters, nor was there evidence of pathologic changes in any of the examined tissues.

Decreasing incidence of coronary disease in pediatric cardiac transplant recipients using increased immunosuppression

BACKGROUND

Coronary artery disease (CAD) is a limiting factor to long-term survival in cardiac transplant recipients, affecting from 30% to 50% of patients by 4 years after surgery. Can the incidence of CAD be lowered with augmentation of immunosuppression?

METHODS AND RESULTS

We compared the incidence of CAD in our pediatric transplant population with nine potential risk factors, including immunosuppressive regimen. The study group consisted of 55 patients who survived more than 1 year (or to first angiogram) or had autopsies. Coronary angiograms were performed yearly and compared sequentially. The mean follow-up of 55 patients was 36 months. Mean age was 10.3 +/- 6 years (range, 4 months to 18 years). Thirteen patients received double immunosuppression with cyclosporine and prednisone, and 42 received triple therapy with cyclosporine, prednisone, and azathioprine. Significant CAD occurred in 10 grafts (6 deaths and 3 retransplants). Cause for graft loss in 6 patients with CAD was acute rejection. CAD was detected by angiogram in only 2 patients. Nine of 10 patients received double therapy (P < .001). There was no difference in mean follow-up between immunosuppression groups. There was a higher rejection frequency for double therapy (0.19 +/- 0.16 rejections per patient month) compared with triple therapy (0.07 +/- 0.11). Ten patients were rejection free in the triple therapy group.

CONCLUSIONS

We experienced a significant decrease in the incidence of CAD in our pediatric cardiac transplant recipients using increased immunosuppressive therapy. Type of immunosuppressive regimen (double) and rejection frequency were independent predictors for CAD by multivariate analysis.

Accelerated retinopathy and nephropathy in diabetic pregnancy

We report a case of severe deterioration in sight despite good metabolic control in a pregnant diabetic patient which has not recovered at two years post-delivery. This was accompanied by a deterioration in renal function which similarly has not improved.

Recurrent acute hypersensitivity to quinine

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Live donor renal transplantation--the experience of the Belfast Renal Unit

Live donor renal transplants are often preferred to cadaver grafts because of better graft survival. In a retrospective study of 41 live donor transplants performed in the Belfast Renal Unit from 1971 until November 1988, actual graft survival at 2 and 5 years was 84% and 69% respectively. Corresponding patient survival rates were 87% and 81%. These results are no better than those of cadaver grafts. A subdivision of patients considered to be relatively poor risk for transplantation showed less favourable results than those who were good risk. 15% of the donors suffered post-operative complications, which occurred more often in older donors. Live donor transplantation is not necessarily preferable to cadaver organ graft, and is not recommended for poor risk recipients or donors aged over 50 years.

Visual recovery in orbital vasculitis

A 46-year-old woman with polyarteritis nodosa and chronic renal failure developed sudden loss of vision which was associated with orbital vasculitis. Treatment with cyclophosphamide produced rapid improvement in vision, which has been preserved with maintenance doses of cyclophosphamide and prednisolone.

Ten-year results of renal transplantation with azathioprine and prednisolone as only immunosuppression

93 patients received 102 renal transplants between 1968 and 1977. 99 grafts were from cadavers and 3 were from live donors; 93 were first grafts, 7 were second, and 2 were third. At 10 years total actual patient survival was 66.6%. 50 (55.5%) of 90 first cadaver grafts, and 52.2% of all cadaver grafts, survived at 10 years. Cardiovascular disease was the commonest cause of death, being responsible for 18 of 31 deaths (58%).

Renal replacement treatment for diabetic nephropathy in Northern Ireland 1979-1987

Twenty-three patients with end-stage renal failure due to diabetic nephropathy received renal replacement treatment. All patients had insulin-dependent diabetes mellitus. Nineteen transplants were performed in seventeen patients. Two-year graft survival for all transplants was 74% with a two-year patient survival post-transplantation of 81%. Overall two-year patient survival was 73%, compared with 82% in non-diabetic patients receiving renal replacement treatment. In diabetic patients accepted for treatment there was a high incidence of non-renal complications, particularly vascular disease. An aggressive approach to the treatment of vascular disease in these patients may improve overall survival rates.

Natural killer cells in viral arthritis

Changes in natural killer (NK) cell activity were studied in patients with polyarthritis associated with rubella or Ross River virus infections. In 30 of 32 Ross River virus patients, peripheral NK cell activity was depressed at some stage of the disease but returned to normal levels as patients recovered from arthritic symptoms. Similar changes did not occur in rubella patients and no difference was found between changes in peripheral NK activity and serum interferon (IFN) levels in rubella patients with arthritis and those without. Neither the peak of NK cell activity in peripheral blood lymphocytes (PBL) recovered early in Ross River virus and rubella infections, nor the depression of NK cell activity late in Ross River virus infections could be correlated with changes in serum IFN levels. The decrease in PBL-NK cell activity in epidemic polyarthritis (EPA) patients could not be attributed solely to loss of NK cells from the peripheral circulation because limiting-cell-dilution (LCD) analyses indicated changes in peripheral NK cell activity were due to changes in both the number and lytic activity of NK cells. Despite the association between HLA-DR7 and EPA no differences were found in levels of peripheral NK cell activity in DR7+ and DR7- EPA patients. The demonstration that peripheral NK cells could kill autologous synovial cells suggested that NK cells in joints of EPA patients may contribute to the arthritis associated with Ross River virus infection.

The influence of HLA-A, B, and DR matching on graft survival in primary cadaveric renal transplantation in Belfast

HLA-DR matching has been shown in a retrospective study of 72 renal transplant patients to significantly enhance graft survival at 12 months. HLA-A and -B antigen matching also increased the graft survival rate significantly. Analysis of combined HLA-A, -B and -DR matching suggested an improvement in graft survival rate with better matching, but this did not attain statistical significance. It is now our policy to use HLA-DR matching prospectively and to ensure that all recipients receive a kidney with a maximum of 1 HLA-DR incompatibility and a minimum of 2 HLA-A and -B antigens shared.

Mismatching for HLA-A, -B antigens and renal graft survival

One hundred and seventy five recipients of a kidney graft were analyzed to see if mismatching for certain HLA-A, -B antigens was detrimental to graft survival. No association was found between graft survival and a specific mismatched HLA-A, -B antigen.

Two-year inhalation toxicity study of propylene in F344/N rats and B6C3F1 mice

Chronic toxicity studies of propylene were conducted by exposing groups of 50 F344/N rats and 50 B6C3F1 mice of each sex in chambers to air containing the chemical in concentrations of 5000 and 10,000 ppm, 6 hr per day, 5 days per week, for 103 weeks. Groups of 50 rats and 50 mice of each sex in similar chambers received clean air only on the same schedule and served as controls. Survival and mean body weights of exposed and control male and female rats and mice were similar. In exposed rats, increased incidences of nonneoplastic lesions were observed in the nasal cavity. These consisted of epithelial hyperplasia in female rats exposed to the high concentration, and squamous metaplasia in female rats exposed to both concentrations and in male rats exposed to the low concentration. In addition, inflammatory changes characterized by an influx of lymphocytes, macrophages, and granulocytes into the submucosa and by granulocytes into the lumen occurred in male rats of both exposure groups. There was no evidence of nasal cavity lesions in exposed mice, suggesting a species difference in sensory irritation to propylene. There were no treatment-related increases or decreases in tumor incidence in the exposed groups relative to controls for either rats or mice. These data suggest that inhaled propylene induces signs of nasal cavity toxicity in rats but not in mice, and that the chemical is not carcinogenic to either species at the concentrations tested.

Pre-transplantation immunological monitoring and graft survival in recipients of renal allografts

Various immunological parameters were measured pre-transplantation in 82 renal transplant recipients. The results were compared with the clinical course of the recipient post-transplantation and with the results of 40 controls. Only one test C3 inactivation products (C3i) was associated with transplant outcome in that 0/30 patients with no rejection episodes had C3i whereas 9/38 patients with rejection episodes, including 3/12 patients whose graft failed, had C3i.

No evidence of carcinogenicity for L-ascorbic acid (vitamin C) in rodents

Carcinogenesis studies of L-ascorbic acid were conducted by offering diets containing 0, 25,000 or 50,000 ppm L-ascorbic acid to groups of 50 F344/N rats and 50 B6C3F1 mice of each sex for 103 wk. Survival of dosed and control female rats and of dosed and control female mice were comparable. Survival of high-dose male rats was slightly greater than that of the controls, whereas survival of high-dose male mice was significantly greater than that of the controls. There was no observed differences in neoplasms between treated and control groups that were considered related to L-ascorbic acid. In female rats, several lesions usually seen in aged animals showed a dose-related decline. Under the conditions of these studies, L-ascorbic acid given at 2.5% or 5.0% in the diet for 103 wk was not toxic or carcinogenic for male and female F344/N rats or for male and female B6C3F1 mice.