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Biomedical subjects

D M Roxe

Publications and source records attributed to D M Roxe.

18 recordsLinked to original sources
PubMed1992

Reversibility of long-standing urinary tract obstruction requiring long-term dialysis.

Urinary tract obstruction of longer than 4 to 6 weeks' duration is usually said to be irreversible. Older reports of unilateral obstruction have documented return of kidney function after longer periods of obstruction. The duration of bilateral obstruction compatible with return of life-sustaining renal function is poorly defined. We report herein three cases of long-standing urinary tract obstruction leading to apparent dialysis-dependent end-stage renal disease, where relief of obstruction eventually led to discontinuation of dialysis.

Aged↗
PubMed1991

A comparison of cutaneous testing and ELISA testing for assessing reactivity to ethylene oxide-human serum albumin in hemodialysis patients with anaphylactic reactions.

In five patients who have experienced anaphylaxis and in 29 patients who have not had such episodes during hemodialysis, we have performed two immunologic studies: cutaneous testing with ethylene oxide-human serum albumin (ETO-HSA) and ELISA for IgE against ETO-HSA. Four of five patients with reactions had positive cutaneous tests, whereas only one nonreactor had a positive skin test (p less than 0.0002). The same four of five patients with reactions also had positive ELISA results, whereas three nonreactors has positive ELISA results (p less than 0.003). In this group of patients, the positive predictive value of cutaneous testing (80%) is somewhat higher than that of ELISA testing (57%). However, the sensitivity, specificity, and negative predictive values are similar. We conclude that cutaneous testing with ETO-HSA probably offers a small advantage over IgE against ETO-HSA as determined by ELISA.

Anaphylaxis↗
PubMed1991

Aging and renal function.

Reflection on the circumstances of the elderly permits one to understand the risk factors for renal disease that are present in that population; to consider what impact impairment of the primary functional capacities of the kidney will have; to structure a diagnostic work-up; and finally, to close the loop by modifying care in order to protect the elderly from renal insufficiency.

Aged↗
PubMed1990

Parathyromatosis in hyperparathyroidism.

Recurrent hyperparathyroidism after parathyroidectomy may present a difficult diagnostic problem. A rare etiology is parathyromatosis (multiple nodules of hyperfunctioning parathyroid tissue scattered through the neck and mediastinum) due to spillage of otherwise benign parathyroid tissue during surgery. We present a case of recurrent hyperparathyroidism and parathyromatosis due to tissue spillage during surgical removal of probable double adenomas, a rare cause of primary hyperparathyroidism. Thus, parathyromatosis must be included in the differential diagnosis of recurrent or persistent hyperparathyroidism, distinguished from parathyroid carcinoma by histologic criteria. The surgeon must be careful of parathyroid spillage during surgery, even of benign tumors of the parathyroids.

Adenoma↗
PubMed1990

Failure of deferoxamine to improve iron overload in chronic hemodialysis patients.

We prospectively studied the in vivo dialytic clearance of iron after deferoxamine (DFO) administration in four stable iron-overloaded chronic hemodialysis patients by quantifying iron concentration in blood entering and leaving the dialyzer and in dialysate after infusions of DFO. No significant arteriovenous iron differences were demonstrated. The mean ratio of venous to arterial iron approached identity at 1.005. All dialysate concentrates used contained large amounts of iron (300-610 micrograms/dl). No changes in efferent versus afferent dialysate iron concentration could be demonstrated. We conclude (a) iron removal during dialysis with DFO was not demonstrated; (b) the dialysate concentrate tested contained large amounts of iron; (c) in view of potentially significant toxicity, and lack of demonstrable therapeutic benefit, caution in prescribing DFO chelation therapy for iron overload is recommended.

Deferoxamine↗
PubMed1989

Phosphate-binding effects of sucralfate in patients with chronic renal failure.

Sucralfate has been reported to reduce serum phosphate concentration in patients with chronic renal failure. To evaluate whether sucralfate could be used to treat hyperphosphatemia secondary to chronic renal failure and whether this treatment resulted in a reduced exposure to aluminum, an open-label crossover study was designed to determine the efficacy, relative potency, safety, and cost of sucralfate v aluminum hydroxide. Of the 21 hemodialysis patients completing both phases of the crossover study, serum phosphate could be maintained below 4.5 mg/dL (1.45 mmol/L) in 16 with sucralfate and in 14 with aluminum hydroxide. The 16 patients controlled on sucralfate consumed 1,694 +/- 190 mg/d of aluminum to maintain a serum phosphate concentration of 3.91 +/- 0.17 mg/dL (1.27 +/- 0.05 mmol/L) compared with the 14 patients controlled on aluminum hydroxide with an aluminum intake of 2,678 +/- 294 mg/d (P less than 0.025) and a serum phosphate concentration of 3.94 +/- 0.13 mg/dL (1.27 +/- 0.04 mmol/L). Thus sucralfate was an effective, albeit expensive, alternative to aluminum hydroxide for the treatment of hyperphosphatemia associated with chronic renal failure. Although the difference in aluminum intake was significant, use of sucralfate did not result in lower serum aluminum concentrations.

Adult↗
PubMed1987

Acidotic alterations in oxidative metabolism influencing rat renal slice ammoniagenesis.

We believe that two findings are interconnected and help to comprehend a major mechanism behind the regulation of renal ammonia production during acidosis. First, slices from acidotic compared to control and alkalotic rats produce more ammonia from glutamine. Second, inhibition of renal oxidative metabolism at various points by metabolic inhibitors augments slice ammoniagenesis. Based on this, our purpose was to determine whether enhanced renal ammoniagenesis during acidosis could occur through the same mechanism as the metabolic inhibitors. However, metabolic inhibitors (malonate; arsenite; 2,4-dinitrophenol) usually decrease while acidosis increases slice gluconeogenesis. There is one known exception. Fluorocitrate, which blocks citrate metabolism, simulates the acidotic condition by enhancing both ammonia and glucose production. Accordingly, a block of oxidative metabolism if located prior to citrate oxidation in the tricarboxylic acid cycle could theoretically augment ammoniagenesis during acidosis. Lactate, is a major renal fuel whose oxidative metabolism would be blocked by fluorocitrate. There, we concentrated on the effects of acidosis on lactate as well as glutamine metabolism. Lactate decarboxylation decreases in the face of increased glucose production during acidosis, and lactate inhibition of glutamine decarboxylation decreases in slices from acidotic rats. Also, we found lesser oxygen consumption in the presence of lactate by kidney slices from acidotic rats compared to control and alkalotic rats. We postulate that relatively less incorporation of lactate into the TCA cycle, causing decreased citrate formation and citrate oxidation during acidosis, contributes, at least in part, to acidotic adaptation of ammoniagenesis.

Acidosis↗
PubMed1985

Severe anaphylactoid reactions to cuprammonium cellulose hemodialyzers.

Twenty-one severe reactions to hemodialysis occurred in approximately 260,000 dialysis treatments at three centers within a 10 1/2-year period. Reactions typically appeared within minutes of initiating dialysis, and were characterized by cardiopulmonary, mucocutaneous, and/or gastrointestinal tract symptoms highly suggestive of anaphylaxis. Four respiratory arrests and one death resulted. Analysis of dialyzer use patterns and of each patient's dialyzer exposure history strongly implicated hollow-fiber dialyzers made of cuprammonium cellulose (CC) as a cause of these reactions. No obvious factors could be found to identify predisposed patients. Less than optimal rinsing of the CC hollow-fiber dialyzers prior to use may have been responsible for some, but not all, of these reactions.

Anaphylaxis↗
PubMed1979

Severe hypernatremia caused by age, isolation, and obstructive uropathy.

Although this is an extremely interesting case report from a medical viewpoint, inasmuch as it presents an unusual cause of hypernatremia, it is probably even more important because of its sociologic implications. The basic underlying causes are common in the aged, and as the number of senior and ultimately senior senior citizens increases, a repetition of the events enumerated here can be predicted in increasing numbers of patients.

Aged↗
PubMed1978

The regulations of renal ammoniagenesis in the rat by extracellular factors. I. The combined effects of acidosis and physiologic fuels.

Substrate oxidation by rat kidney slices regulates renal ammoniagenesis from glutamine. At concentrations close to those expected in plasma, lactate alone, or combined with other renal fuels, inhibits ammoniagenesis markedly; glucose and citrate decrease ammoniagenesis slightly. However, lactate, citrate, and glucose inhibit ammoniagenesis of kidney slices from acidotic rats less than ammoniagenesis of kidney slices from control rats. Lesser inhibition of ammoniagenesis is seen also when acidotic slices rather than control slices are incubated in the presence of all the tested substrates combined in the same medium. In addition to decreasing the ammoniagenesis of renal slices from control rats, the presence of lactate causes an augmented accumulation of glutamate. In contrast, adding lactate to acidotic slices does not increase glutamate accumulation nearly as much. When glutamate is substituted for glutamine in the medium, lactate still decreases ammonia production, but to a lesser extent with acidotic slices. Changes in medium pH from 7.0 to 7.8 have no, or only small, overall effects on net renal slice ammonia production from glutamine under any of the circumstances tested. We conclude that lactate alone and combined with other substrates decreases ammoniagenesis primarily at the glutamate dehydrogenase step and that slices from acidotic rats are relatively resistant to substrate mediated inhibition.

Acidosis↗
PubMed1976

Complications of peritoneal dialysis.

Peritoneal dialysis is an easily available therapeutic procedure. The complications noted in 490 dialyses over a six-year period in a university hospital have been reviewed. Seventeen major and 624 minor complications occurred. Only four deaths could be attributed to the procedure itself. Peritoneal dialysis is an effective procedure but one with a significant incidence of complications, though few of these are associated with mortality or morbidity for the patient. Various safeguards against these are discussed.

Acute Kidney Injury↗
PubMedDate not supplied

Reagent strip glucose monitoring methods in chronic hemodialysis.

Reagent strip blood glucose testing methods have not been extensively validated in dialysis patients, a serious omission as thousands of diabetic patients are now entering dialysis. Severe anemia and uremia are potentially confounding variables that might impair those testing methods. Various methods were tested pre- and postdialysis, and compared with standard laboratory results. In general, strip methods (SM) underestimated laboratory results by approximately 15%. Extremes of blood urea nitrogen, hematocrit, or blood glucose levels did not affect this reliability. Such methods appear to be suitable for use in chronic hemodialysis patients.

Blood Glucose↗