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Biomedical subjects

M Allon

Publications and source records attributed to M Allon.

At least 55 records · Page 3Linked to original sources
PubMed1990

Albuterol and insulin for treatment of hyperkalemia in hemodialysis patients.

We evaluated in maintenance hemodialysis patients the potassium lowering effects of intravenous insulin with glucose, nebulized albuterol, and a regimen combining both modalities. There was a similar decrease in plasma potassium following either insulin with glucose (0.65 +/- 0.09 mmol/liter) or albuterol (0.66 +/- 0.12 mmol/liter), and a substantially greater fall with the combined regimen (1.21 +/- 0.19 mmol/liter, P less than 0.02 vs. either drug alone). Baseline plasma glucose concentrations were similar (about 4.8 mmol/liter) prior to all three treatments. Following insulin with glucose, plasma glucose increased transiently. but then fell to 2.8 +/- 0.3 mmol/liter at one hour, with concentrations below 3 mmol/liter in 9 of 12 patients. None of the patients had symptoms of hypoglycemia. Plasma glucose increased to 6.8 +/- 0.5 mmol/liter with albuterol. After the combined drug regimen plasma glucose rose transiently and was back to baseline (4.7 +/- 0.7 mmol/liter) at one hour. Treatment with insulin or albuterol produced trivial increases in heart rate, whereas the combined drug regimen was associated with a significant rise (15.1 +/- 6.0 min-1). These observations suggest that albuterol and insulin with glucose are equally efficacious in lowering plasma potassium in uremic patients, and that the hypokalemic effects of the two drugs is additive. The hypoglycemic effect of insulin is attenuated by coadministration albuterol. Combined therapy with insulin, glucose and albuterol is efficacious and safe for the acute treatment of hyperkalemia in hemodialysis patients.

Administration, Inhalation↗
PubMed1990

Sodium and water excretion in nephrotic patients: effects of changes in renal haemodynamics.

1. Eight nephrotic patients were studied in order to evaluate the effects of acute changes in renal plasma flow and glomerular filtration rate on renal solute and water handling, in the absence of plasma volume expansion. 2. The subjects were studied first after the administration of captopril, a manoeuvre that increased renal plasma flow without a significant change in glomerular filtration rate, and a second time after receiving combined therapy with captopril and ibuprofen, a manoeuvre that decreased glomerular filtration rate without a significant change in renal plasma flow. 3. After captopril therapy, despite the increase in renal plasma flow, there was no significant change in proximal sodium reabsorption (as estimated from fractional lithium reabsorption), urine volume or urine osmolality. 4. The decrease in glomerular filtration rate observed after the administration of captopril plus ibuprofen was associated with decreases in fractional excretion of sodium and urine volume, and an increase in urine osmolality. The changes in these parameters of tubular function were proportionate to the changes in glomerular filtration rate. Fractional proximal sodium reabsorption increased substantially. 5. These observations suggest that, in the absence of plasma volume expansion, an increase in renal plasma flow does not increase sodium or water excretion by the nephrotic kidney. Moreover, during acute decreases in glomerular filtration rate, glomerulotubular balance appears to be disrupted, resulting in disproportionately high rates of proximal tubule sodium reabsorption.

Adult↗
PubMed1990

Interaction of captopril and ibuprofen on glomerular and tubular function in humans.

Renal hemodynamics and tubular solute and water handling were evaluated in normal subjects during water diuresis, before and after the acute administration of captopril, ibuprofen, or the combination of both drugs. The glomerular filtration increased after captopril administration but did not change after ibuprofen alone or in combination with captopril. Renal plasma flow increased with captopril alone and captopril plus ibuprofen but did not change after ibuprofen alone. Urine volume and Na excretion increased with captopril and decreased after ibuprofen; coadministration of ibuprofen attenuated the tubular effects produced by captopril alone. FELi, fractional delivery of solute to the distal nephron, and FELi-FENa, fractional distal reabsorption of solute, both significantly increased after captopril and decreased after ibuprofen but did not change with the combined regimen. (FELi-FENa)/FELi, fractional reabsorption of distally delivered Na, significantly decreased after captopril and increased after ibuprofen but remained unchanged after captopril plus ibuprofen. Thus captopril and ibuprofen have opposing effects on tubular Na and water handling, which are attenuated by the addition of the other drug. This interaction may have clinical relevance in patients with heart failure or hypertension, in whom captopril is used to enhance Na and water diuresis.

Absorption↗
PubMed1990

Role of cigarette use in hyponatremia in schizophrenic patients.

Urine volume and osmolality were studied in two schizophrenic patients with hyponatremia and six normal subjects after they smoked or ingested cigarettes. The results suggest that cigarette use may contribute to the development of hyponatremia by impairing water excretion.

Adult↗
PubMed1990

Drug-induced meningitis.

Meningitis is usually produced by an infectious agent, but there are multiple noninfectious causes. Medications may produce both acute and recurrent meningitis. We present a patient with 3 episodes of aseptic meningitis due to trimethoprim-sulfamethoxazole, and then review the topic of drug-induced meningitis.

Adult↗
PubMed1990

Renal sodium and water handling in hypothyroid patients: the role of renal insufficiency.

The mechanism responsible for renal tubular abnormalities in sodium and water excretion in hypothyroid patients is poorly understood. To evaluate the possible contribution of the reduced glomerular filtration rate of hypothyroidism to these abnormalities, tubular function in hypothyroid patients was compared with that in patients with chronic renal failure and in normal subjects. The lithium clearance method and oral water loading were used to evaluate parameters of tubular sodium and water handling, respectively. The hypothyroid and the chronic renal failure patients were selected to have similar reductions in glomerular filtration rate. As compared to the normal subjects, the hypothyroid and chronic renal failure patients had a decrease in proximal sodium reabsorption and an increase in distal sodium reabsorption. The changes in tubular handling of sodium were not different in the hypothyroid and the chronic renal failure patients. Maximal urinary flow rate and free water clearances were similarly reduced in the hypothyroid patients and the chronic renal failure patients. For all subjects studied, proximal sodium reabsorption and maximal urinary volume were directly correlated with the glomerular filtration rate, and distal nephron sodium reabsorption was proportionate to delivery of sodium from the proximal tubule. The results suggest that the abnormalities in tubular sodium and water handling in hypothyroid patients are comparable to those present in other patients with a similar degree of renal insufficiency. Thus, the tubular abnormalities in hypothyroidism may be a consequence of the associated decrease in glomerular filtration rate.

Adult↗
PubMed1990

Effect of cardiac catheterization on renal function.

Sensitive acute renal clearance methodology was used to investigate the incidence of radiocontrast-induced nephrotoxicity in patients undergoing cardiac catheterization. Patients at the University of Oklahoma Teaching Hospitals scheduled for elective cardiac catheterization had their creatinine clearance measured on the day preceding and the day following their procedure. All patients had a serum creatinine concentration lower than 175 mumol/l. The creatinine clearance was calculated from the mean of four consecutive 30-minute renal clearance periods obtained in the fasted state during water loading. The change in renal function following the catheterization was evaluated. There was no significant change in the creatinine clearance after the cardiac catheterization (Ccr 101.5 +/- 6.4 ml/min before and 111.6 +/- 7.4 ml/min after the procedure). A decrease in Ccr exceeding 25% occurred in 1 of 23 subjects (4.3%. Patient age, presence of diabetes, and volume of contrast agent were not adverse risk factors. The results suggest a low risk of nephrotoxicity in low-risk patients undergoing elective cardiac catheterization, even when very sensitive measures of glomerular filtration rate are utilized.

Acute Kidney Injury↗
PubMed1990

Severe hypophosphatemia in hospitalized patients.

Although severe hypophosphatemia has been associated with significant morbidity, little quantitative information is available on the magnitude of the risk. The objective of this study was to determine the frequency and timing of severe hypophosphatemia, the relative risk associated with various medical diagnoses, and the choice of therapy. Among 10,197 patients hospitalized over a 1-year period, the incidence of severe hypophosphatemia (serum phosphate less than or equal to 0.33 mmol/l) was 0.43%. The incidence was 0.91% in alcoholics, 2.42% in septic patients, 10.4% in patients with malnutrition, and 14.6% in patients with diabetic ketoacidosis. The odds ratio for developing the metabolic abnormality was 4.2 (95% confidence interval 2.2-8.1) in alcoholics, 6.4 (1.9-18.9) in septic patients, 46.9 (16.6-125.6) in patients with diabetic ketoacidosis, and 60.7 (31.4-117.5) in malnourished patients. There was a 4-fold increase in mortality in patients with severe hypophosphatemia (18.2 vs. 4.6%; p less than 0.001). The metabolic abnormality was not recognized or was inappropriately treated in 42% of patients. Severe hypophosphatemia is a relatively common finding in hospitalized patients, especially in those with certain well-defined medical conditions. It is associated with significant excess mortality. Its recognition and treatment remain suboptimal.

Alcoholism↗
PubMed1990

Renal abnormalities in sickle cell disease.

Many renal structural and functional abnormalities have been associated with sickle cell disease. The patients have an impaired urinary concentrating ability but an intact diluting capacity. There are defects in both urinary acidification and potassium excretion, although overt metabolic acidosis and hyperkalemia occur infrequently. Proximal tubular function is supranormal, as manifested by increased reabsorption of phosphate and increased secretion of creatinine. The former results in mild hyperphosphatemia, while the latter causes substantial overestimation of the glomerular filtration rate (GFR) by creatinine clearance. Both GFR and renal plasma flow are increased in young patients with sickle cell disease, but prostaglandin inhibitors decrease the GFR. The GFR progressively decreases with increasing age. Proteinuria, and even nephrotic syndrome, are relatively frequent; the most common renal lesion in children is focal glomerular sclerosis, which may be associated with progressive deterioration in renal function. Glomerular hyperfiltration has been implicated in the pathogenesis of the glomerular lesions, as well as in the development of renal failure. In patients with end-stage renal disease, both hemodialysis and kidney transplantation have been successful. Recurrent hematuria is a relatively common problem in patients with sickle cell disease. The bleeding usually remits spontaneously, but occasionally requires therapy with aminocaproic acid. Papillary necrosis may occur, and is thought to result from medullary ischemia.

Anemia, Sickle Cell↗
PubMed1990

Acute effects of captopril and ibuprofen on proteinuria in patients with nephrosis.

Captopril decreases protein excretion in patients with nephrosis. To evaluate whether captopril has an acute antiproteinuric effect and to evaluate the role of changes in renal hemodynamics or glomerular permselectivity on this effect, renal clearance studies were performed in patients without diabetes but with nephrosis. Protein excretion and renal hemodynamics were measured at baseline and after the administration of captopril. To measure the contribution of renal prostaglandins, patients were restudied on a separate day, after the combined administration of captopril and the prostaglandin synthetase inhibitor ibuprofen. Both treatments significantly reduced mean protein excretion, but the change was greater with combined therapy than with captopril alone (40.6% vs 20.0%). Mean glomerular filtration rate (GFR) decreased by 4.8% (not significant) and 16.5% (p less than 0.001), and filtration fraction (FF) decreased by 13.6% (p less than 0.001) and 14.9% (p less than 0.001) after captopril alone and combined therapy, respectively. No significant correlation was found between changes in proteinuria and changes in GFR or FF after treatment with captopril alone. In contrast, the decrease in proteinuria correlated with the change in GFR after combined drug administration (r = 0.68, p = 0.06). The ratio of immunoglobulin G to albumin clearance, an index of glomerular permselectivity, was unaffected by captopril but decreased significantly (by 43%) after combined drug administration. The results suggest that the acute antiproteinuric effect of captopril is not due to changes in FF, GFR, or glomerular perselectivity. The addition of ibuprofen enhances the antiproteinuric effect of captopril by decreasing the GFR as well as by enhancing the permselectivity of the glomerular capillary membrane.

Captopril↗
PubMed1990

Acute renal failure due to ciprofloxacin.

Acute renal failure developed in three patients within a few days of starting ciprofloxacin hydrochloride therapy. An allergic interstitial nephritis was suggested by fever and eosinophiluria in one patient and by erythema multiforme in another. A kidney biopsy specimen confirmed this diagnosis in one patient. Renal function improved shortly after withdrawal of the drug in all three patients. Literature survey revealed an additional three patients with a similar complication. Allergic manifestations, such as fever or rash, were a feature in most reported cases. In view of this potential complication, renal function should be closely monitored in patients receiving ciprofloxacin therapy, especially if other potentially nephrotoxic drugs are prescribed concomitantly.

Acute Kidney Injury↗
PubMed1989

Nebulized albuterol for acute hyperkalemia in patients on hemodialysis.

STUDY OBJECTIVE: To determine the efficacy and safety of nebulized albuterol in the acute treatment of hyperkalemia in patients on chronic hemodialysis. DESIGN: Prospective, double-blind, and placebo-controlled study. SETTING: Outpatient hemodialysis clinic at a university medical center. PATIENTS: Ten patients on maintenance hemodialysis who had chronic hyperkalemia. INTERVENTIONS: Patients received nebulized albuterol therapy (10 mg or 20 mg) or placebo (saline) on three separate occasions, serial measurements of plasma potassium levels, blood pressure, and pulse were then taken for a 2-hour period. MEASUREMENTS AND MAIN RESULT: Patients had a significant decrease in plasma potassium concentrations that was evident by 30 minutes and sustained for at least 2 hours after albuterol treatment. After the administration of 10- and 20-mg doses of albuterol, the maximal decrease in the plasma potassium levels was 0.62 +/- 0.09 and 0.98 +/- 0.14 mmol/L (SE), respectively. Nebulized saline administration did not produce a significant change in the plasma potassium concentrations. Patients did not develop symptoms or significant changes in blood pressure or heart rate with albuterol treatment. CONCLUSIONS: In the doses used, nebulized albuterol therapy resulted in a prompt and significant decrease in the plasma potassium concentrations in patients on hemodialysis, and caused no adverse cardiovascular effects. This treatment should be considered as an important adjunct for acute treatment of serious hyperkalemia in this population of patients.

Acute Disease↗
PubMed1989

Protein S and C antigen levels in proteinuric patients: dependence on type of glomerular pathology.

The cause of the thrombotic tendency in nephrotic patients is unknown. Recent reports of thrombotic complications in patients with deficiencies of protein C or protein S (natural inhibitors of coagulation) have raised the possibility that decreased levels of these proteins may play a role in the hypercoagulable state of nephrotic patients. We measured the levels of protein C, total protein S, and free protein S antigens in 42 patients (21 nephrotic and 21 non-nephrotic) with one of four types of glomerular pathology: diabetic nephropathy (DM), focal glomerular sclerosis (FGS), membranous glomerulonephritis (MGN), and chronic renal failure due to hypertension (CRF). Protein C and total protein S antigen levels were significantly higher in FGS and MGN than they were in DM or CRF. Free protein S levels were lower in DM than they were in MGN. Protein C, total protein S, and free protein S levels did not significantly correlate with either serum albumin or degree of proteinuria. The mean levels of the three proteins did not differ between nephrotic and non-nephrotic patients. Free protein S and protein C were, however, significantly correlated (P less than .005 and P less than .002, respectively) with the type of glomerular pathology, independent of differences in age, sex, serum albumin, or degree of proteinuria. These data suggest that abnormalities of free protein S and protein C are related to the nature of the underlying renal disease, rather than to the degree of proteinuria.

Glycoproteins↗
PubMed1989

Tubulointerstitial nephritis due to vancomycin.

Vancomycin was used to treat a patient with Staphylococcus aureus endocarditis. After 3 weeks of therapy, the patient developed a diffuse maculopapular rash, which resolved upon stopping the drug. Rechallenge with vancomycin several days later resulted in reappearance of the rash and rapid onset of acute anuric renal failure. Renal biopsy revealed acute granulomatous interstitial nephritis. This is the first report of biopsy-proven vancomycin-induced acute interstitial nephritis. Renal function should be monitored closely in patients receiving vancomycin therapy.

Aged↗
PubMed1989

Effects of physiologic hyperinsulinemia on renal phosphate handling in the rat: a role for calcium.

In a recent study in acutely parathyroidectomized, fasted rats, infused with parathyroid hormone (PTH), superimposition of euglycemic hyperinsulinemia within the physiologic range completely reversed the decline in tubular reabsorption of Pi (TRPi) induced by PTH. As an extension of these observations on insulin as a counterregulator of Pi homeostatis, the present results demonstrated that similar insulin administration prevented a decrease in TRPi when PTH infusion was superimposed. This was, moreover, observed in the fed state and at doses of insulin which did not stimulate renal cortical Na-K-ATPase activity. Subsequent studies addressed the role of insulin in a PTH-independent phosphaturic state, namely that induced by Pi loading. Under such conditions and while the resultant hypocalcemia of hyperphosphatemia was circumvented by the addition of calcium to the infusate, insulin substantially increased the renal tubular reabsorptive capacity for Pi, thereby demonstrating an antiphosphaturic action of insulin independent of PTH. Furthermore, when increased filtered loads of Pi and PTH administration were combined during insulin infusion, TRPi was greater than when PTH was administered alone during similar insulin infusion. When calcium infusion did not accompany Pi loading with a resultant fall in serum calcium, euglycemic hyperinsulinemia did not affect TRPi, indicating abolition of the antiphosphaturic action of insulin by hypocalcemia.

Animals↗
PubMed1989

Indomethacin in the treatment of lithium-induced nephrogenic diabetes insipidus.

Nephrogenic diabetes insipidus (NDI) is a frequent complication in patients receiving long-term lithium therapy. Both thiazide diuretics and amiloride may reduce the polyuria, but the use of each is associated with problems. We report the results of a clinical trial using the nonsteroidal anti-inflammatory drug indomethacin to treat a patient with well-documented lithium-induced NDI that persisted following cessation of lithium treatment. The administration of a single dose of indomethacin resulted in a dramatic decrease in urine volume and increase in urine osmolality that persisted for several hours, and was independent of renal hemodynamic changes. Subsequently, the patient experienced a sustained, favorable effect on her polyuria during long-term (3 months) indomethacin therapy without a deleterious effect on her renal function. Indomethacin may be a useful therapeutic tool for the amelioration of lithium-induced NDI.

Adult↗
PubMed1988

Minimal change glomerulonephropathy and interstitial infiltration with mycosis fungoides.

The nephrotic syndrome developed in a patient with mycosis fungoides shortly after systemic involvement by his tumor occurred. Renal biopsy examination revealed atypical lymphocytic interstitial infiltration and changes consistent with minimal change glomerulonephropathy. The patient's proteinuria decreased following steroid therapy. This is the first report of an association between minimal change glomerulonephropathy and a proven T-cell malignant lymphoma. The implications are discussed with reference to the literature.

Humans↗