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Biomedical subjects

F O Finkelstein

Publications and source records attributed to F O Finkelstein.

At least 73 records · Page 4Linked to original sources
PubMed1976

Influence of uremia and hemodialysis on the turnover and metabolic effects of glucagon.

To evaluate the mechanism and role of hyperglucagonemia in the carbohydrate intolerance of uremia, 19 patients with chronic renal failure (12 of whom had undergone chronic hemodialysis for at least 11 mo) and 35 healthy control subjects were studied. Plasma glucagon, glucose, and insulin were measured in the basal state, after glucose ingestion (100 g), after intravenous alanine (0.15 g/kg), and during a 3-h continuous infusion of glucagon (3 ng/kg per min) which in normal subjects, raised plasma glucagon levels into the upper physiological range. Basal concentrations of plasma glucagon, the increment in glucagon after infusion of alanine, and post-glucose glucagon levels were three- to fourfold greater in uremic patients than in controls. The plasma glucagon increments after the infusion of exogenous glucagon were also two- to threefold greater in the uremics. The metabolic clearance rate (MCR) of glucagon in uremics was reduced by 58% as compared to controls. In contrast, the basal systemic delivery rate (BSDR) of glucagon in uremics was not significantly different from controls. Comparison of dialyzed and undialyzed uremics showed no differences with respect to plasma concentrations, MCR, or BSDR of glucagon. However, during the infusion of glucagon, the increments in plasma glucose in undialyzed uremics were three- to fourfold greater than in dialyzed uremics or controls. When the glucagon infusion rate was increased in controls to 6 ng/kg per min to produce increments in plasma glucagon comparable to uremics, the glycemic response remained approximately twofold greater in the undialyzed uremics. The plasma glucose response to glucagon in the uremics showed a direct linear correlation with oral glucose tolerance which was also improved with dialysis. The glucagon infusion resulted in 24% reduction in plasma alanine in uremics but had no effect on alanine levels in controls. It is concluded that (a) hyperglucagonemia in uremia is primarily a result of decreased catabolism rather than hypersecretion of this hormone; (b) sensitivity to the hyperglycemic effect of physiological increments in glucagon is increased in undialyzed uremic patients; and (c) dialysis normalizes the glycemic response to glucagon, possibly accounting thereby for improved glucose tolerance despite persistent hyperglucagonemia. These findings thus provide evidence of decreased hormonal catabolism contributing to a hyperglucagonemic state, and of altered tissue sensitivity contributing to the pathophysiological action of this hormone.

Adolescent↗
PubMed1976

Marital discord, sexual problems, and depression.

Systematic studies of relationships among depression, sexual function, and martial discord in hemodialysis patients and their spouses arelacking; existing studies focus upon only one of these three topics, or deal with patient or spouse as individuals rather than as a couple. We studied 17 chronic, medically stable hemodialysis patients and their husbands or wives. Although couples rated their degree of marital discord as low, the investigators rated it as high, based on the number and type of specific problems reported by the couple. The couples' evaluation may not represent denial, as has been commonly assumed. Instead their evaluation may imply that the disease and its treatment overshadow marital problems, even though couples recognize and react to these problems. Couples showed a high prevalence of sexual problems--in terms of overall satisfaction, frequency of intercourse, and specific dysfunctional symptoms (difficulty becoming excited, maintaining excitement, or having orgasm). We found a strong relationship between severity of depression and severity of sexual dysfunction in patients, but not in their mates. No strong relationship existed between a patient's depression score and marital discord, although spouses showed a trend toward correlation between severity of depression and martial discord. Younger couples, especially, seem not to want intercourse when severe martial discord exists. Patients' depression scores were comparable to thoseof psychiatric patients, while spouses' depression scores resembled those of normals. While psychosocial phenomena such as marital discord, sexual dysfunction, and depression are clear, causal chains are not. Despite disadvantages inherent in using questionnaires, short, self-administered, easily scored instruments may elicit problems with sex, marriage, and mood which might otherwise be overlooked by caretaking personnel.

Adult↗
PubMed1976

The antecubital fossa fistula.

We have reviewed our experience with 19 proximal forearm arteriovenous fistulas used in chronic hemodialysis. Thirteen functioned adequately, and of these 10 were complicated by dislodge needles during dialysis, arm edema or hematomas. Although 3 patients developed symptoms of arterial steal, none required ligation of the fistula. This experience suggests that antecubital fossa fistulas might best be used as a second line angioaccess when distal forearm fistulas have been unsuccessful or are impossible to contruct.

Adolescent↗
PubMed1975

Pharmacokinetics of digoxin and digitoxin in patients undergoing hemodialysis.

The pharmacokinetics of digoxin and digitoxin in patients undergoing long-term hemodialysis were examined to determine which is the preferred cardiac glycoside in this patient population. Absorption curves from 0 to 24 hours after an oral dose of digitoxin were similar in dialyzed patients and in control patients. Serum glycoside concentrations after an oral dose of digoxin were higher in dialyzed patients than in control patients, significantly so from 2 to 24 hours, reflecting the absence of the predominantly renal route of excretion of digoxin. When nine dialyzed patients were placed on a maintenance dose of digoxin, 0.125 mg 5 days a week, serum levels plateaued at 30 days at a mean concentration (plus or minus SE) of 0.84 plus or minus 0.05 ng/ml. Maintenance therapy with 0.1 mg digitoxin 5 days a week resulted in stabilization of serum levels within 30 days at a mean concentration of 19 plus or minus 1 ng/ml. Variability in the serum glycoside concentrations was determined after stabilization of levels during 2 to 19 week follow-up periods with each drug. Variability in serum levels was somewhat increased during maintenance therapy with digitoxin. On the basis of the parmacokinetic data obtained in this study, no clear cut preference for one glycoside over the other could be established.

Adult↗
PubMed1975

Effect of peritoneal dialysis on serum levels of tobramycin and clindamycin.

The pharmacokinetics of tobramycin and clindamycin were examined in patients undergoing peritoneal dialysis for chronic renal failure. Peak serum levels of tobramycin in functionally anephric patients were less than expected, probably secondary to a larger volume of distribution. Peritoneal dialysis resulted in a significant clearance of tobramycin, with a resultant reduction in serum half-life. The present data suggest that, if bactericidal serum levels of tobramycin are to be maintained in patients undergoing peritoneal dialysis, a parenteral loading dose be administered, followed by either (i) an identical dose every third half-life or (ii) one-half the loading dose every half-life. However, optimal therapy is best achieved by monitoring serum levels to insure appropriate drug dosage. Peak serum levels of clindamycin in functionally anephric patients were approximately twofold greater than those expected in normals after an identical parenteral dose. It is, therefore, recommended that the administered dose of this agent in functionally anephric patients be one-half of that required to produce desired peak serum levels in patients without renal impairment. Peritoneal clearance of clindamycin during dialysis was shown to be essentially zero, indicating that dialysis does not affect clindamycin disposition.

Anti-Bacterial Agents↗
PubMed1975

Role of medullary Na-K-ATPase in renal potassium adaption.

Since recent studies have shown that chronic potassium loading stimulates the specific activity of Na-K-ATPase in renal tissue, experiments were performed to determine whether increased enzyme acitivity correlated with renal adaptation for accelerated potassium excretion. The Na-K-ATPase activity in different renal zones was correlated with the maximum rate of potassium excretion during the intravenous infusion of KCl in animals with normal and reduced renal function, animals on a varied potassium diet and animals treated with methylprednisolone or deoxycorticosterone acetate. The enhanced ability to excrete a potassium load was associated with increased enzyme activity in the outer or red medulla, whether the change in Na-K-ATPase was caused by chronic potassium loading, methylprednisolone treatment, or partial nephrectomy. There was no evidence that a rise in enzyme activity in the cortex influenced the rate of potassium secretion. Moreover, stimulation of Na-K-ATPase in the inner medulla-papilla did not augment the rate of potassium excretion above that found in animals with an increase in enzyme in the outer medulla alone. These experiments provide evidence that links Na-K-ATPase to the mechanism of renal potassium adaptation and suggest that the major increment in potassium secretion by the adapted kidney occurs in the outer medulla.

Adenosine Triphosphatases↗
PubMed1975

Rejection episodes and patient and graft survival after renal transplantation.

The occurrence of acute rejection episodes following renal transplantation was correlated with one-year patient mortality and graft failure rates in a series of 102 consecutive transplant recipients. Twenty-one patients had two or more rejection episodes in the first two months post transplantation; 17 of these expired or lost their kidney compared to only 5 of 28 patients with no rejection episodes in this time period. Similarly, of the 14 patients who developed a second rejection episode 2--6 months post transplantation, 8 died or lost the graft compared to only 2 of 21 patients who had no rejection episodes in this time period. Thus, the development of a second rejection episode early after transplantation necessitating treatment with high dose prednisone therapy carries an ominous prognosis and suggests that serious consideration must be given to graft removal and subsequent retransplantation.

Cell Biology↗
PubMed1975

Leukocyte responses to acute renal transplant rejection.

A retrospective study of the response of the leukocyte count to renal transplant rejection was performed in 159 rejection episodes. Results of the study showed that 1. contrary to what is commonly thought leukocytosis is the least common response to acute rejection and a decrease in leukocyte count is far more common, 2. a sudden decrease in leukocyte count in a previously stable patient can be an early sign of rejection, 3. there is a significantly greater incidence of graft loss in rejection episodes characterized by leukopenia and 4. the risk of infection following rejection is greatest in patients with rejection characterized by leukopenia.

Graft Rejection↗
PubMed1975

Influence of rejection on graft survival after renal transplantation.

The clinical course was reviewed of 102 renal allograft recipients between December 1967 and December 1973. Only 4 of 21 patients (19 per cent) who had 2 or more episodes of rejection during the first 2 months had a functioning graft at the end of 1 year, compared to 24 of 30 patients (83 per cent) who had no rejection episodes. A similar trend was seen 2 to 6 months after transplantation. During the first 2 years vigorous immunosuppressive therapy for rejection in the first few months resulted in 12 deaths (44 per cent) of 27 patients. Subsequent to this immunosuppressive therapy was modified and grafts were removed if there was not a prompt recovery of function after treatment, which resulted in a significant decrease in mortality rate to 16 per cent. There also was improvement in the over-all survival of patients with functioning grafts from 37 to 56 per cent. Serious complications and mortality could be related to high dosage of steroids and severe leukopenia. A white blood count of less than 1,000 m m.3 on 3 successive days was associated with a mortality rate of 52 per cent, compared to 15 per cent in those without leukopenia. Serious consideration should be given to early graft removal in patients who have 2 or more episodes of rejection in the first few months after transplantation, particularly when there is not a prompt improvement in renal function after immunosuppressive therapy. High doses of steroids (greater than 1 mg. per kg. for more than 26 days during the first 60 days) should be avoided to decrease morbidity and mortality rates from serious infections. The results of histocompatibility (HL-A) matching in 72 donor-recipient pairs indicated an improved graft survival when there was a match of 2 or more antigens, which is supported by the results recently reported by the Transplant Registry. The results of mixed lymphocyte reactions in 20 live donor-recipient pairs showed a marked improvement in graft survival when there was less than 20 per cent stimulation and it appeared that this reaction was of more important prognostic significance than the results of histocompatibility (HL-A) matching in these patients.

Acute Disease↗
PubMedDate not supplied

Assessment of marital relationships of hemodialysis patients.

In addition to the somatic problems associated with uremia and dialysis it is apparent that successful hemodialysis is dependent upon psychological adjustment to this type of therapy. While previous studies have focused on the patient or spouse as individuals, patterns of marital interactions and conflicts have not been systematically evaluated. These factors ere examined in 17 medically stable patients maintained on hemodialysis for a mean duration of 22 +/- 4 SE months. Standardized pssychiatric evaluation forms ere used to examine mood and cognition disturbances in all patients and spouses, and a deailed marital questionnaire, which each patient and spouse filled out independently, was used to evaluate fundamental aspects of the marital relationship...

Adult↗