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Biomedical subjects

S S Fenton

Publications and source records attributed to S S Fenton.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1976

Defective triglyceride removal in lipemia associated with peritoneal dialysis and haemodialysis.

Plasma lipids were measured in 78 uremic patients receiving either chronic peritoneal dialysis or haemodialysis. Type IV hyperlipemia was found in 60% of patients. The lipid level was not influenced by dietary habits or patient's age. Patients on chronic peritoneal dialysis had a significantly higher and more sustained hyperlipemia than the patients on haemodialysis. Triglyceride turnover studies showed that all patients, regardless of the type of dialysis or lipid level, had impaired triglyceride removal as the cause of this lipemia. This defect in triglyceride metabolism was only partially corrected by increasing the efficiency of the dialysis.

Adult↗
PubMed1976

The elimination of tritiated doxycycline in normal subjects and in patients with severely impaired renal function.

Tritiated doxycycline was administered to four normals, four patients with renal failure interdialysis, and three patients in renal failure who were not on dialysis. Elimination was followed by collection of urine and feces up to eight days. It was demonstrated that renal failure reduced the urinary excretion of doxycycline. In normal individuals the total of 86% of the radioactivity was eliminated in five days, half in the urine and half in the feces. In patients, with renal failure on dialysis, 32% of the radioactivity was eliminated in that time, 9.3% in the urine and 23% in the feces. In renal failure patients not on dialysis 49% was eliminated in that time, 4% in the urine and 45% in the feces; when followed up to eight days a total of almost 70% of the radioactivity was eliminated and the increase elimination was accounted for by fecal elimination such that 64% was eliminated in the feces and 5% in the urine. The disappearance from the plasma compartment in all three groups was similar. Thus, although the plasma half-life of doxycycline is not significantly prolonged in renal failure, it appears likely that the drug is taken up into a compartment from which it may slowly be eliminated and when followed for a continual period of time a significant percentage can be recovered from the feces. There remains however, up to 30% of the administered dose which was not recovered and it must be assumed that a significant per cent of doxycycline would accumulate in a compartment, as yet unidentified, in patients with renal failure.

Administration, Oral↗