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Biomedical subjects

B H Scribner

Publications and source records attributed to B H Scribner.

At least 37 records · Page 2Linked to original sources
PubMed1982

Clinical studies of a continuous extracorporeal cyanate treatment system for patients with sickle cell disease.

An extracorporeal carbamylation system was evaluated in two patients with sickle cell disease. Access was achieved with existing veins in one patient and an AV fistula in the second. Modifications in the treatment procedure were made as experience indicated. Levels of carbamylation of greater than 1 mol/mol of hemoglobin tetramer were achieved with 4 to 6 hr of treatment every 2 weeks. Cyanate returned to the patient averaged 68.5 mg per treatment. As expected, P50 values decreased and hemoglobin levels increased as the treatment progressed. Patterns of cyanate distribution among the red cell population were those predicted by computer calculations. These observations document the safety and reliability of the treatment system but do not permit conclusions as to efficacy.

Adult↗
PubMed1981

The middle molecule hypothesis in perspective.

The middle molecule (MM) hypothesis states that molecules in the molecular weight range of 500 to 2000 daltons/molecule accumulate in uremia and are one cause of peripheral neuropathy. Evidence for and against this hypothesis is reviewed and evaluated. The course of events in the core of early hemodialysis patients who developed neuropathy provides important support ofr the hypothesis. Failure of early peritoneal dialysis patients to develop neuropathy suggested that the peritoneum is more permeable to MM's than early hemodialysis membranes, a fact that was later hemodialysis membranes, a fact that was later confirmed by appropriate investigations. Several investigators have demonstrated that MM's actually do accumulate in uremia and disappear rapidly following a renal transplant, which suggests a high clearance by the human kidney. Retrospective and prospective studies have demonstrated a protective effect of residual renal function against MM intoxication. Our prospective studies to produce MM intoxication are reviewed and their strengths and weaknesses delineated. Similarly, the investigations of others that are cited as evidence against the MM hypothesis are reviewed. It is the opinion of hte authors that the weight of evidence supports the validity of the MM hypothesis; but that final proof still is lacking. A protocol for more definitive studies is discussed.

Humans↗
PubMed1981

Creatinine production rate measured by whole body counting of 40K.

The creatinine production rate in dialysis patients was measured by potassium-40 whole body counting and carbon-14 creatinine injection. The correlation coefficient for the two methods was 0.96, p less than 0.005. An equation predicting whole body potassium (WBK) for normal subjects was found to accurately predict the WBK of dialysis patients as well. Two equations predicting creatinine production from WBK were compared with measured production rates and were found to agree within experimental error. It is thus possible to use the predictive equations to accurately estimate creatinine production without resorting to experimental measurements. These findings should simplify the use of computer models of the patient-artificial kidney system where accurate estimations of creatinine production rates are essential.

Carbon Radioisotopes↗
PubMed1981

Creatinine degradation I: the kinetics of creatinine removal in patients with chronic kidney disease.

The existence of an alternative route of excretion for creatinine in subjects with chronic renal failure has been demonstrated. The data presented in this study confirm the hypothesis that creatinine is converted into other metabolites, probably by action of the gut flora. Creatinine degradation was quantitated in a group of subjects that spanned a wide range of kidney functions from normal to no renal function. Five patients were analyzed who were on maintenance dialysis, five were predialysis and two subjects were normal with respect to kidney function. Creatinine degradation expressed as a percentage of production varied from 13.9 to 27.7% in the dialysis patients, 0 to 42.3% in the pre-dialysis patients and was 0% in the controls. Creatinine degradation was correlated with plasma creatinine degradation was correlated with plasma creatinine levels in predialysis (r = 0.73, p less than 0.01), but not in dialysis patients. No correlation was found between creatinine degradation and production in either group. It is concluded that significant amounts of creatinine are degraded in dialysis patients, and this removal mechanism must be accounted for in models of the patient-artificial kidney system.

Adult↗
PubMed1981

Creatinine degradation. II: Mathematical model including the effect of extra-renal removal rates.

Previous models of the patient-artificial kidney system have neglected the contribution of creatinine degradation as a pathway for creatinine removal. Creatinine degradation can remove significant amounts of creatinine from dialysis patients, and models which neglect this mechanism are susceptible to error in predicting creatinine concentrations. In this study three models of the patient-artificial kidney system have been developed. The single pool model is the easiest to use since it requires a minimum of patient information, but it is the least accurate in predicting creatinine plasma concentrations. A two-pool model predicts experimental data within 5 percent, and appears to be the most useful model from the consideration of ease of use and accuracy. A three-pool model was derived that is suitable for use on a mini-computer or programmable calculator providing the device is capable of inverting a 3 x 3 matrix. The three-pool model predicts the measured plasma concentrations with 0.5 percent. These models provide a means to account for creatinine degradation and accurately predict creatinine concentrations in dialysis patients.

Creatinine↗
PubMed1980

Experience with an indwelling right atrial catheter for home parenteral nutrition.

In 94 patients, 137 permanent Silastic central venous catheters were inserted. Of these, 53 catheters were removed because of catheter related problems. The average duration of catheter use was 12 months. However, the catheter was only removed once every 31 patient months because of catheter dysfunction and once every 82 months because of catheter related sepsis. None of the patients died from catheter related septicemia. We believe this low complication rate of catheter related complications represents an acceptable risk for those patients who will benefit from home parenteral nutrition.

Activities of Daily Living↗
PubMed1979

Effect of hypertonic glucose on the muscular cramps of hemodialysis.

The effect of hypertonic (50%) glucose injected for relief of hemodialysis-induced muscular cramps was studied in 15 chronically uremic, nondiabetic patients who experienced a total of 44 cramp episodes. In a double-blind trial either 50 mL (or less) of hypertonic glucose or physiologic (0.9%) saline solution was injected, and the therapeutic response was evaluated. Of a total of 44 episodes of cramps, 26 were treated with hypertonic glucose and 18 with normal saline. Treatment with hypertonic glucose relieved 17 of 26 episodes, in contrast to only five of 18 episodes relieved with 50 mL of normal saline (P less than 0.016). No complications related to hypertonic glucose administration were observed. Hypertonic glucose seems to be safe and effective for the relief of dialysis-induced cramps. It also avoids undesirable loading with sodium and mannitol, which have been suggested for treatment of dialysis-induced cramps.

Clinical Trials as Topic↗
PubMed1979

The influence of acetate versus bicarbonate on patient symptomatology during dialysis.

The effect of large-surface area dialysis (LS) using dialysate containing both acetate and bicarbonate (LS-C) on a patient's symptomatology was compared with that noted with acetate (LS-A) or bicarbonate (LS-B) in the dialysis fluid. Patients experienced significantly more symptoms and deterioration of objective performance test scores with both LS-A and LS-C than LS-B. Furthermore, a correlation was seen between plasma acetate level at the end of dialysis and decrement in the performance test scores. The results suggest that accumulation of acetate rather than acute alteration in acid-base status is primarily responsible for the morbidity.

Acetates↗