Search PubMed⌕ Search

Biomedical subjects

R M Freeman

Publications and source records attributed to R M Freeman.

At least 55 records · Page 3Linked to original sources
PubMed1983

The effect of sulfate on serum ionized calcium.

Serum sulfate concentrations may reach five to ten times normal in renal failure patients dialyzed on a sorbent cartridge system, and these patients have elevated alkaline phosphatase levels suggesting an increased incidence of renal oseodystrophy. We studied the effect of adding sulfate on ionized calcium (Ca2+) in human serum in vitro and in rat serum in vivo. K2SO4 or Na2SO4:NaCl mixtures were added to aliquots of serum from normal subjects to reproduce the observed biologic range of sulfate concentrations up to 10 mmol. Serum Ca2+ concentration was found to decrease linearly as serum sulfate concentration increased, for each subject. The weighted mean slope estimates of the effect of sulfate on ionized calcium in two experiments were -.0197 and -.0181. Rats were infused through the inferior vena cava with 2 mL of either 200 mmol NaCl (N = 5) or 100 mmol Na2SO4 (N = 6), after ligation of the renal arteries and veins and withdrawal of 2 mL blood for baseline studies. The animals were killed by exsanguination from the aorta after a five-minute equilibration period. In rats administered NaCl, no difference in Ca2+ or sulfate concentration was found between pre- and postinfusion sera. In the Na2SO4 treated rats, however, a significant mean increase of 0.635 mmol (p less than .005) in serum sulfate concentration was associated with a significant mean decrease of -0.062 mmol (p less than .01) in serum Ca2+ concentration. We conclude that the acute in vitro and in vivo addition of sulfate results in a decrease in serum Ca2+ concentration. Thus, hypersulfatemia, which is present chronically in patients on sorbent dialysis systems, may contribute to elevated alkaline phosphatase levels in these patients.

Animals↗
PubMed1982

Hypnotherapy for incontinence caused by the unstable detrusor.

Fifty incontinent women with proved detrusor instability completed 12 sessions of hypnosis (symptom removal by direct suggestion and "ego strengthening") over one month. This was continued at home with a prerecorded cassette, and all patients were followed up for at least six months. At the end of the 12 sessions 29 patients were entirely symptom free, 14 improved, and seven unchanged. Three months later cystometry in 44 of the patients showed conversion of the cystometrogram to stability in 22 and a significant improvement in a further 16; only six showed no objective improvement. Seven patients relapsed (three after bereavement). Further treatment was given and five out of six patients were rendered symptom free again. Patients with detrusor instability were not found to have a noticeably increased susceptibility to hypnosis. It is concluded that psychological factors are very important in "idiopathic" detrusor instability and that hypnotherapy is effective for incontinence due to this disorder.

Adolescent↗
PubMed1980

Transfusion and renal allograft survival: beneficial effect of transfusions given on day of transplantation.

To determine if the beneficial effect of blood transfusion on renal allograft survival can be obtained without risk of presensitization, we examined the effect of transfusions given on the day of transplant surgery in a series of 180 primary cadaveric renal allografts. Three-month graft survival of those transfused only on the day of transplant was significantly better than the graft survival of those never transfused, and was not significantly different from graft survival of those transfused during the dialysis waiting period. Maximal beneficial effect was achieved by administration of as few as two to three units. We conclude that the benefits of transfusion can be obtained while minimizing the risks of presensitization if transfusion is minimized during the dialysis waiting period and patients are electively transfused at the time of transplant.

Adolescent↗
PubMed1979

Bicarbonate hemodialysis using a sorbent regenerative system.

In light of the concern about the use of acetate in dialyzate a simplified means of performing acetate-free hemodialysis has been developed using the sorbent regenerative system (RED). Fifteen sorbent bicarbonate hemodialyses free of acetate were performed on two patients for 4 or 6 hours. The initial dialyzate mixture contained 135 mEq/l NaHCO3 only. The infusate cations of K, Ca and Mg were in the form of chloride salts. A 30-minute titration of the sorbent cartridge with the bicarbonate dialyzate was necessary to release the excessive hydrogen ion from the cartridge which allowed the dialyzate bicarbonate to stabilize. The dialyzate Na fell during titration but rose during dialysis. The dialyzate Cl rose throughout titration and dialyses. The plasma bicarbonate rose significantly by the end of 4 and 6 hour dialyses. The blood pO2 and pCO2 did not change during dialysis and a significant rise in blood pH resulted. We conclude that bicarbonate dialysis is feasible and relatively easily accomplished in the sorbent system.

Bicarbonates↗
PubMed1978

Critical comparison of renal transplant survival between recipients of live related donor and cadaver organs.

Survival statistics of 163 cadaver and 60 live related donor renal transplants from a single center were analyzed. Survival rates at one, two and three years for 38 first cadaver transplants matched for a haplotype and 34 first live related donor haplotype matched kidneys were virtually the same. In addition, nine, four antigen matched cadaver transplants had a comparable survival rate at one, two and three years to the larger group of 25 HL-A identical live related donor kidneys. When poor risk cadaver recipients were excluded from the entire cadaver group, the graft survival rate approached that of the live related group at one year but declined more rapidly at two and three years than did the live related donor group. Thus, cadaver renal transplantation in this series appears to be an alternative to comparably matched live related donor transplants. An increased effort should be made to identify and use brain death cadaver donors for transplantation. As more donors become available and national sharing systems are improved, a strong case can be made to avoid the use of live related donor kidneys, except in instances of a perfect match.

Brain Death↗
PubMed1978

Home hemodialysis review in Iowa: 1970--1977.

One hundred fifty-two patients were accepted for home hemodialysis training from 1970 to 1976. Duration of training varied from 4 to 22 weeks. The primary reason for discontinuing home dialysis was patient and assistant psychological adjustment problems. Patient medical and technical problems were not related to the distance from the home dialysis training unit. Cumulative probability of survival was .948 at one year and .637 at five years. Cardiovascular disease accounted for 80% of the patients who died while receiving long-term hemodialysis. Fifty-three percent of the deaths in patients after renal transplantation were secondary to infectious causes.

Adaptation, Psychological↗
PubMed1977

Salt substitutes as a source of potassium.

Chemical analysis of commercially obtained potassium-containing salt substitutes was performed. The potassium content was remarkably uniform from sample to sample of each brand and even among different brands. When hypertensive outpatients ranked these products, several were shown to differ considerably in taste characteristics and in overall preference. A cost comparison showed salt substitutes to be less costly than prescription (pharmaceutical) potassium supplements.

Costs and Cost Analysis↗
PubMed1977

Influence of histidine administration on zinc metabolism in the rat.

The influence of intravenous and oral histidine administration on zinc metabolism in the rat has been investigated. Acute studies: histidine (250 mg/hr) was given by constant intravenous infusion to rats with paired control animals receiving diluent alone. During the hour preceding histidine the urinary zinc excretion averaged 0.435 +/- 0.37 (SE) microng/hr. During the hours of histidine infusion the urinary zinc excretion averaged 7.58 +/- 0.97, 20.21 +/- 2.07, and 16.78 +/- 1.90 microng/hr. These values were all higher than the prehistidine infusion value and higher than in the rats receiving diluent alone. Plasma zinc at the end of the infusion was 76 +/- 5 microng/100 ml compared to control levels of 110 +/- 9 microng/100 ml, P less than 0.001. Chronic studies: histidine (500 mg/day) was given by gavage for 43 days to rats. Urinary zinc excretion in histidine treated rats was 3 to 6 times that of controls throughout the study. Despite this there was no difference in the plasma, testicular, or kidney zinc content. No histological lesions of zinc deficiency were noted in the esophagus. In conclusion, histidine increased urinary excretion in the rats whether administered orally or parenterally. Evidence for zinc deficiency, however, was not apparent after 43 days of histidine administration.

Administration, Oral↗
PubMed1977

Phosphorus metabolism in potassium-deficient rats.

Hypophosphatemia as a consequence of potassium deficiency has been reported sporadically. Most cases have been complicated by other factors which might lead to decreased serum phosphorus levels. Therefore, the serum phosphorus in this study was measured in Sprague-Dawley rats with nutritionally induced potassium deficiency. Severe potassium depletion was manifested by hypokalemia (2.4 mEq/liter versus 3.9 mEq/liter in controls) and decreased muscle potassium content. Statistically significant hypophosphatemia did not develop, although decreased muscle phosphorus content was observed. Therefore, hypophosphatemia is not a regular accompaniment of severe potassium deficiency in the rat.

Animals↗
PubMed1977

Acetate-free hemodialysis with a sorbent regenerative system.

We conclude from this study that acetate-free, bicarbonate hemodialysis is well suited to the sorbent regenerative system. It can be performed safely and gives postdialysis patient values similar to standard dialysis. Long-term trials are presently being conducted at our institution. With modification of the cartridge pH by the manufacturer, it should prove simple and practical.

Acid-Base Imbalance↗
PubMed1977

Glucose tolerance tests and their insulin and growth hormone responses in hemodialysis patients: are they reproducible?

The concept that carbohydrate intolerance improves after hemodialysis has been challenged. Critical to this issue is the reproducibility of GTT in a dialysis population. Thirty-nine oral or i.v. GTT were performed on ten stable hemodialysis patients at weekly intervals for three weeks. Blood glucose was determined by both oxygen consumption rate during glucose oxidation and the ferricyanide method. The coefficient of variation of blood glucose ratios (Glucose at time X/Fasting glucose) by glucose oxidase varied considerably. With the i.v. GTT the coefficients of variation at 90 and 120 minutes were 27.9 and 36.8 percent in one patient but below 15 percent at 60, 90, and 120 minutes in the other four patients. Three of the five patients who received oral GTT displayed coefficients of variation greater than 20 percent at one or more sampling times. The coefficients of variation of the growth hormone ratio (Growth hormone at time X/Fasting growth hormone) during i.v. and oral GTT ranged from 2.1 to 83.6 percent. Coefficients of variation of insulinogenic indexes ranged from 16.3 to 59.3 percent. In summary, large variations in glucose, growth hormone and insulin occur during both oral and i.v. GTT when repeated on a weekly basis in stable hemodialysis patients.

Administration, Oral↗
PubMed1976

Goodpasture syndrome: recovery after severe renal insufficiency.

A 22-year-old woman developed the sudden onset of cough, dyspnea, blood-tinged sputum, and bilateral fluffy infiltrates on her chest x-ray film, together with severe iron deficiency anemia. Urinalysis initially revealed normal values, but gross hematuria developed on the 12th day. Linear deposits of IgG and C3 were present in the GBM; circulating anti-GBM antibodies were also observed initially but had disappeared 13 months later. Hemodialysis was performed because of oliguria and a rising serum creatinine value. She subsequently had a diuresis; 18 months later, the creatinine clearance was 63 ml/min. The anti-GBM antibody response appears to be transient, lasting only a few months, so that if the patient survives the initial insult, stabilization and even some recovery may ensue. Had this patient undergone immediate nephrectomy as part of her initial therapy, the observed favorable outcome would have been denied.

Acute Kidney Injury↗