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Biomedical subjects

S S Fenton

Publications and source records attributed to S S Fenton.

At least 19 recordsLinked to original sources
PubMed1990

Results from the Canadian Renal Failure Registry.

This report encompasses data collected from all Canadian patients starting treatment for end-stage renal failure (ESRF) from 1981 until the end of 1987. Gross mortality showed an initial decline, but has stabilized since 1985. The year of entry into the system did not change the survival rate. There was an increase in the rate of acceptance of new patients between 1982 and 1987. The largest increases were in the older age groups, and resulted in a concomitant increase in the number of registered patients in older age groups. Survival on dialysis by age group declined with age. There was no difference in patient survival on hemodialysis or peritoneal dialysis. The probability of death for all patients entering the ESRF system remained constant notwithstanding year of entry into the system. It was slightly higher for males than females, much higher for patients with diabetes or renal vascular disease, higher with age, and much higher for patients not undergoing transplant.

Adolescent↗
PubMed1988

Aluminum toxicity to the brain.

The association between elevated brain aluminum levels and Alzheimer's disease (AD) is examined and critically reviewed. We found elevated aluminum levels in the brains of patients with AD (greater than 4 micrograms/g dry wt.) compared with normal subjects (approximately 1.5 micrograms/g dry wt.). Nine laboratories from different geographical regions have confirmed this finding. Two laboratories did not find any differences between AD and control brains. This discrepancy is traced to differences in sample sizes used for the aluminum assay and the sample selection criteria. It is found that it is essential to use small sizes (approximately 10 mg dry wt.) and to ensure that control brains do not contain neurofibrillary tangles (NFT) and that AD brains do. The exact pathogenic role of aluminum in AD is, as yet, unclear. It is the only element (other than calcium, which non-specifically accumulates at all degenerating tissue sites) that is found in elevated concentrations in NFTs. It is found elevated at four loci in the brain, i.e. the DNA-containing structures of the nucleus, the protein moities of NFTs, the amyloid cores of senile plaques and cerebral ferritin. The evidence thus far indicates that aluminum is toxic to the brain and it is probable that it has a pathogenic role in Alzheimer's disease.

Aluminum↗
PubMed1988

Early function as the principal correlate of graft survival. A multivariate analysis of 200 cadaveric renal transplants treated with a protocol incorporating antilymphocyte globulin and cyclosporine.

We examined the factors determining graft survival in 200 consecutive cadaveric renal transplants managed on a quadruple-therapy protocol: Minnesota antilymphoblast globulin, cyclosporine, azathioprine, and low-dose prednisone. Perioperative central venous pressure monitoring and volume expansion were emphasized. To avoid CsA nephrotoxicity in the early posttransplant period, patients were treated with ALG until renal function was established (a mean of 7 days). Therapeutic CsA levels were achieved before ALG was discontinued. Azathioprine was used to supplement CsA in patients with nephrotoxicity or rejection. Twelve-month graft survival was 85% (first transplants 86%, retransplants 79%), with patient survival of 95%. ALG was not associated with excessive clinical cytomegalovirus infections, which occurred in 5% of patients, or with malignancy. When 3 technical failures were excluded, an analysis of numerous factors in the pretransplant and peritransplant period revealed that the strongest correlate of one-year graft survival was early renal function. Grafts with delayed function (DF) had 75% survival, compared with 91% for grafts with good early function (EF). A multivariate analysis confirmed this association: the relative risk of graft loss was increased 2.86 times for DF compared with EF. The mechanism of the deleterious effect of DF was apparently multifactorial: the DF group, by definition, contained all the kidneys that never functioned, but some risk also persisted in kidneys that achieved function. One reason for this may be that DF kidneys that achieved function had higher mean serum creatinine values at 1 month: elevated serum creatinine values at 1 month were strongly associated with increased risk of graft loss regardless of initial function. There was also a higher number of rejection episodes diagnosed in the DF group. These observations suggest that early renal function is a major determinant of graft outcome and should be a target for efforts to further improve renal graft survival.

Antilymphocyte Serum↗
PubMed1987

Right atrial ball thrombus as a complication of subclavian catheter insertion for hemodialysis access.

In two patients right atrial ball thrombi developed following prolonged subclavian cannulation for hemodialysis. One patient died, the other had the ball thrombus removed by open heart surgery. It appears that repeated friction of the catheter tip may have damaged the endothelium of the right atrial wall. This hitherto unrecognised complication might be prevented by ensuring that subclavian hemodialysis catheters are never allowed to reach as far as the right atrium.

Adult↗
PubMed1986

Analysis of biological thiols: determination of thiol components of disulfides and thioesters.

This report describes a method for using selective cleavage of thioesters to allow differentiation between thioesters and disulfides. The method identifies thiol components (including glutathione, coenzyme A, and cysteine) of low-molecular-weight thioesters and disulfides in cell extracts, as well as thiols bound to protein via thioester or disulfide links. Thioesters were cleaved with 200 mM hydroxylamine under a nitrogen atmosphere in the presence of monobromobimane (mBBr), which forms a fluorescent derivative with the released thiol. For analysis of disulfides, thioesters were cleaved with hydroxylamine in the presence of N-ethylmaleimide to block released thiols: disulfides were then reduced with 10 mM dithiothreitol and subsequently labeled with mBBr. The bimane derivatives were identified and quantified using previously described HPLC methods (G. L. Newton, R. Dorian, and R. C. Fahey, 1981, Anal. Biochem. 114, 383-387). Traditional methods using dithiothreitol and sodium borohydride to cleave disulfides can also cleave thioesters and thus should not be used for specific analysis of disulfides.

Animals↗
PubMed1985

The reduction in the peritonitis rate among high-risk CAPD patients with the use of the Oreopoulos-Zellerman connector.

We have described a prospective controlled study of the Oreopoulos-Zellerman peritoneal dialysis connection system which is based on the principle of chemical sterilization of the connector between each dialysis exchange. This system, in a short-term study of 27 high-risk patients, has resulted in a fourfold difference in the peritonitis rate between the concurrent control group (1/8.8 patient months) and the O-Z group (1/35.7 patient months). The probability of developing peritonitis by 6 mos was 0.15 using the O-Z connector and 0.46 in the control group.

Adult↗
PubMed1981

Symptomatic exacerbation of peripheral vascular disease with chronic ambulatory peritoneal dialysis.

Details of five patients with exacerbation of the symptoms of peripheral vascular disease on chronic ambulatory peritoneal dialysis (CAPD) are presented. The mechanisms of their vascular complications are discussed and the peripheral arterial sequelae of hypotension induced by CAPD are emphasized. These patients are compared with the other patients in the series of 121 patients. Suggestions for diagnosis and treatment of exacerbations of peripheral vascular disease in patients on CAPD are given.

Arteriosclerosis↗
PubMed1980

Dialysis hyperlipemia: response to dietary manipulations.

The effects of dietary manipulations on plasma lipid concentrations were studied over a 3 month period in 8 stable uremic patients on dialysis. Each of the 4 diets was of 3 weeks' duration, and consisted of the following periods: Control (regular diet), high carbohydrate (60% of total calories ingested), control, and a low carbohydrate diet (20% of total calories ingested). The patients' weight remained stable throughout the study. A 33% reduction in plasma triglyceride concentration was observed during the low carbohydrate period (P less than 0.05, paired analysis), and a 33% increase above control values was observed during the high carbohydrate period (P less than 0.05, paired analysis). Cholesterol concentrations did not vary and remained within normal limits throughout the study. There was no significant correlation observed between either insulin or glucagon levels and variations in triglyceride concentration. Reduction in the proportion of carbohydrate in the diet of dialysis patients, may be an effective long-term therapeutic approach to their hypertriglyceridemia.

Adult↗
PubMed1979

Initial experiences with continuous ambulatory peritoneal dialysis.

Continuous ambulatory peritoneal dialysis (CAPD) has been initiated on 51 patients: 27 females (mean age -- 43.9 years) and 24 males (mean age -- 46.4 years). This group has been observed for a total of 1420 patient weeks of treatment (27.3 patient years). Thirty-six episodes of peritonitis have been noted among 19 patients. The overall incidence was one episode per 39.4 patient weeks. Recurrent episodes of peritonitis resulted in discontinuation of CAPD in five (9.8%) of the patients. Three (5.9%) of the patients were unable to continue with CAPD because of its inability to control extracellular fluid balance. In the patients who transferred from intermittent peritoneal dialysis to CAPD, there was a 4.5 mg/dl drop in serum creatinine and a 34 mg/dl drop in mean BUN values. There was a rise of approximately 2 gm in the hemoglobin levels of this group of patients. If the problem of peritonitis can be solved, CAPD will become the dialytic treatment of choice for the majority of patients with end-stage renal disease.

Adult↗
PubMed1977

Home peritoneal dialysis: 3 years' experience in Toronto.

From November 1972 to November 1975, 52 males and 39 females aged 11 to 71 years were trained for home peritoneal dialysis. Dialysis was performed through a permanent catheter 4 nights a week. The first 11 patients used the manual system, exchanging 2 / of dialysate solution every 50 to 60 minutes. Subsequently 73 patients used the automatic cycler and commercially available dialysate and 7 patients used Tenckhoff's reverse osmosis peritoneal dialysis machine. The average duration of training was 15, 11.6 and 15 dialysis days, respectively, for the three methods. For the 83 patients followed up, the average duration of home dialysis was 8.3 months (range, 0.5 to 33 months); the total number of dialyses at home was 10 571. Ten received a transplant, 20 were transferred to hospital peritoneal dialysis or hemodialysis, 8 died and 48 continued with home dialysis. Twenty-three patients had a total of 33 episodes of peritonitis, an incidence of 27.7% among the patients in the program for up to 3 years or 0.3% among all the dialyses. By November 1975, 46 patients had returned to their predialysis lifestyle, 18 were working part-time, 10 were able to work but were not doing so, and 9 were unable to work or care for themselves.

Adolescent↗
PubMed1977

A controlled trial of nondrolone decanoate in the treatment of uremic anemia.

Thirty-seven male dialysis patients, from three university hospital centers known to have adequate iron B12, and folate stores, were entered into a controlled trial to study the effects of nandrolone decanoate (200 mg i.m. weekly) on their anemia. An initial six-month stabilization period was followed by a randomized 12-month study, with crossover between treatment and control groups occurring at six months. Patients received parenteral iron therapy plus oral folate throughout the trial. All serious illnesses or major blood losses excluded the patients from analysis. The 24 patients with remnant kidneys showed an increase in hemoglobin and hematocrit of 24% by the end of six months of treatment (P less than 0.005), with a corresponding decrement during the six months of control, but the five anephric patients showed no statistically significant change compared to those patients whose kidneys were in place during the study. Complications of treatment were minimal, with injection site hematoma the only significant local effect and a rise in triglyceride the only significant systemic disturbance. Despite the improvement in anemia, the disadvantages, including the high cost of treatment, the apparent plateauing of benefits by five months, the minimal subjective improvement in life style, the risk of i.m. injection, plus the long term effects of increased lipids, should limit this therapy to patients with remnant kidneys who have severe symptomatic anemia or frequent transfusion requirements.

Adult↗
PubMed1977

Home peritoneal dialysis. A major advance in promoting home dialysis.

The institution of a home peritoneal dialysis program has allowed us to increase the number of patients with end-stage renal failure entering our home dialysis program from 42.5% to 67.5% of the total population. This represents a 56.5% increase over the rate achieved by home hemodialysis alone. Twenty-four percent of the home peritoneal dialysis patients could have managed home hemodialysis, but 38 could not and this represents 48% of the total patients who entered our home dialysis program, for the period of the study. These patients would have required institutional dialysis which would not have been practical for 52.6% of them because of the distance they live from Toronto. The results of home peritoneal dialysis have compared favorably with home hemodialysis in the 2 concurrent but unmatched series in respect of training time, failure rate, need for in-hospital back-up and patient survival. A long-term study of matched patients randomized to either treatment group such as that described by Blumenkrantz will finally answer the question as to how valid is our contention that peritoneal dialysis compares favourably to hemodialysis for the treatment of end-stage renal failure.

Adolescent↗
PubMed1977

Urine fibrin degradation products in detection and management of acute and chronic renal transplant rejection.

Detection of rejection by serial determinations of urine FDP using the latex agglutination slide test proved to be a reliable, simple and inexpensive method. In the absence of infection, clinical and biochemical acute rejection was preceded by a two-titer rise in excretion of urine FDP in 80% of 26 patients studied. It was not useful in predicting rejection in 44 stable long-term allograft recipients, although persistent elevation of urine FDP after anti-rejection therapy in these patients or those in the immediate post-transplant period implies ongoing rejection. Maintenance immunosuppression should be continued in these patients, but repeated high-dose steroid therapy should be limited because of their poor-term prognosis. Persistent increase in urine FDP may allow selection of those patients who would benefit from a trial of anticoagulant or antiplatelet therapy.

Creatinine↗