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Biomedical subjects

R Zaidenstein

Publications and source records attributed to R Zaidenstein.

34 records · Page 2Linked to original sources

Erythrocyte Na+, K+ and Ca2+, Mg(2+)-ATPase activities in hypertensives on angiotensin-converting enzyme inhibitors.

OBJECTIVE: To investigate erythrocyte membrane Na+, K(+)- and Ca2+, Mg(2+)-ATPase activities in newly diagnosed hypertensive patients before and after 2, 4, and 6 months of treatment with enalapril or captopril as monotherapy. METHODS AND RESULTS: Na+, K(+)-ATPase activity (nmol ATP hydrolysed/min per mg protein) rose by 6 months of treatment in both groups when values were compared in each treated group over time (4.5 +/- 0.8 to 9.9 +/- 1.2; 4.9 +/- 0.8 to 10.5 +/- 1.7, respectively, p < 0.001 for both). When the treated groups were compared with controls at each period of time, Na+, K(+)-ATPase activity was higher at months 4 and 6 (p < 0.001) for both groups, respectively). Ca2+, Mg(2+)-ATPase activity (nmol ATP hydrolyzed/min per milligram protein) in the absence and in the presence of calmodulin increased in the enalapril (6.4 +/- 0.7 to 8.9 +/- 0.95, p < 0.05; 13.4 +/- 1.2 to 17.2 +/- 1.2, p < 0.05, respectively) and captopril (7.0 +/- 0.6 to 8.5 +/- 0.7; 14.4 +/- 1.1 to 16.0 +/- 1.0, p < 0.05, respectively) groups after 6 months of treatment compared within each treated group over time. When patient groups were compared with controls at time 0, 2, 4, and 6 months, the pump activity was higher in the treated groups at 6 months. CONCLUSION: The long-term enhancement of cell membrane Na+, K(+)-and Ca2+, Mg(2+)-ATPase activity associated with enalapril and captopril therapy may represent a specific effect of these agents or alternatively, a nonspecific outcome of blood pressure reduction.

Angiotensin-Converting Enzyme Inhibitors↗

Effects of Various Modalities of Oral Furosemide Administration in Mild or Severe Congestive Heart Failure.

BACKGROUND: This study evaluated the optimal formulation (tablet vs solution) and frequency (once vs twice daily) of maintenance oral furosemide in compensated congestive heart failure (CHF). METHODS AND RESULTS: Eighteen patients with mild (group 1) and 18 with severe (group 2) CHF were studied. On 2 consecutive days each patient's individual fixed oral furosemide daily dosage was administered in tablet or solution in a crossover design. In an additional study, 14 patients with severe CHF received the daily dosage in tablet or solution form in two divided doses. Pharmacokinetic data were obtained in six randomly allocated patients of each group, during the once daily administration periods of either formulation. Twenty-four-hour urinary sodium and 12-hour volume were significantly greater in group 1 following furosemide solution versus tablets. In group 2, all parameters were comparable in response to single identical doses in tablets or solution, as well as to once versus twice daily administration of either formulation. These results coincided with a higher C(max) and a shorter t(max) following solution. CONCLUSIONS: A once-daily oral furosemide solution is more effective than the same dosage in tablet form in patients with mild, but not those with severe, CHF. In patients with severe CHF, the natriuretic and diuretic effects are similar whether oral furosemide in tablet or solution is administered in a once or twice daily schedule.

Journal Article↗

Effect of furosemide oral solution versus furosemide tablets on diuresis and electrolytes in patients with moderate congestive heart failure.

Oral furosemide solution was claimed to produce a greater diuretic response than furosemide tablets in patients with congestive heart failure. The aim of this study was to assess this observation and to further investigate the effects on the electrolyte balance. We compared the effects of oral furosemide in tablets versus oral furosemide solution on serum levels as well as on 4- and cumulative 24-hour urinary volume and sodium, potassium, calcium, magnesium and zinc excretions in 10 patients with moderate congestive heart failure due to ischemic heart disease. Oral furosemide (40-80 mg) was given at the usual once-daily dosage. No change in serum electrolyte levels has been found. All urinary parameters, except zinc, were significantly greater during the first 4 h following oral solution as compared with tablets (volume p < 0.001, sodium p < 0.001, potassium p < 0.05, calcium p < 0.003, magnesium p < 0.05). However, after 24 h, significant differences were found in urinary volume (p < 0.03) and sodium excretion (p < 0.004) only. We conclude that: (1) oral furosemide solution provides a more potent 24-hour diuretic and natriuretic effect than an identical dosage in tablet form, without entailing greater cumulative urinary losses of potassium, calcium, magnesium, and zinc; (2) following the first 4 h of furosemide solution, brisk diuresis, kaliuresis, and magnesiuria are produced, and (3) despite the urinary losses, serum electrolytes remained within normal limits at 4 and 24 h.

Aged↗

Acute subdural hematoma following disseminated intravascular coagulation associated with an obstetric catastrophe.

The clinical, laboratory, radiological and operative recordings of a patient with disseminated intravascular coagulation (DIC) related to therapeutic abortion is reported. During a comatose state following respiratory arrest, anisocoria with right dilated unreactive pupil and decerebration signs appeared. A brain CT scan showed a right frontotemporal hemorrhage. On surgical intervention a subdural hematoma was found and removed. The patient remained in a persistent vegetative state. The rarity of subdural hematoma complicating DIC is presented and the causes of intracranial bleeding in obstetrics are reviewed.

Abortion, Therapeutic↗

Pancreatic enzyme elevation in measles.

During an outbreak of measles in the period from May 1993 through February 1994, a 23-year-old woman with measles was admitted because of abdominal pain and vomiting. Moderately elevated levels of serum and urinary amylase were found. We investigated prospectively the next nine consecutive young adults hospitalized with severe measles. Pancreatic and other organ involvement was determined by serum and urinary amylase, serum lipase, and additional appropriate biochemical and hematological data. Four patients had elevated amylase levels in both serum and urine, whereas in one, serum amylase alone was increased. Serum lipase determined in eight patients was elevated in seven. In all patients elevated serum levels of aspartate aminotransferase and alanine aminotransferase or lactate dehydrogenase were found. In seven patients serum calcium concentrations were below the lower limit of normal. Four patients had mild to moderate thrombocytopenia. This is the first detailed report of pancreatic involvement in young adults with measles. This abnormal finding, its possible underlying mechanisms, and the clinical significance are discussed.

Adult↗

Renal uric acid handling in non-insulin-dependent diabetic patients with elevated glomerular filtration rates.

1. Hypouricaemia is prevalent in diabetic patients. In most of the studies, the diabetic patients had some degree of diabetic nephropathy as evidenced by a decreased glomerular filtration rate and proteinuria. Therefore we studied renal uric acid handling in a group of type II diabetic patients with elevated glomerular filtration rates. 2. Eighteen type II diabetic patients with normal kidney functions and elevated glomerular filtration rate and a group of 18 healthy, age- and weight-matched control subjects, were studied. Serum fructosamine, creatinine and uric acid levels were determined. Twenty-four hour urine collections were obtained, and microalbumin, glucose, creatinine and uric acid, were measured. 3. The creatinine clearance was higher and the serum uric acid concentration was lower in the diabetic patients (P < 0.05). The 24 h urinary uric acid excretion and filtered uric acid load were similar in both groups. However, the derived parameters of uric acid clearance and fractional excretion were significantly higher in the diabetic patients (P < 0.002 and P < 0.05, respectively). A negative correlation was apparent between serum fructosamine concentration and serum uric acid concentration (r = -0.76). A positive correlation was found between serum fructosamine concentration and fractional uric acid excretion (r = 0.64) and between serum fructosamine concentration and filtered uric acid load (r = 0.66). A positive correlation was found between creatinine clearance and 24 h uric acid excretion (r = 0.61) and between creatinine clearance and filtered uric acid load (r = 0.82).(ABSTRACT TRUNCATED AT 250 WORDS)

Creatinine↗

Hereditary angioneurotic edema with severe hypovolemic shock.

Hereditary angioneurotic edema (HAE) is characterized by recurrent attacks of edema of the upper airways, face, and limbs, and/or abdominal pains sometimes mimicking surgical abdomen. Our patient, a 24-year-old woman, had undergone laparotomy on a previous attack, at which a large amount of serious peritoneal fluid and edema of the intestinal wall were found. This time she presented with severe abdominal pain and profound hypovolemic shock requiring replacement of great amounts of fluids in addition to fresh frozen plasma. There was no evidence of bleeding, and the patient recovered rapidly. Based on clinical and ultrasonographic grounds and findings on previous laparotomy, we concluded that the shock was produced by fluid sequestration in the peritoneal cavity and intestinal wall. We propose that patients with HAE who present with abdominal pain, hypotension, hemoconcentration, and leukocytosis form a distinct subgroup with a high risk of hypovolemic shock. This dangerous development should be anticipated in these patients.

Abdomen, Acute↗

[Cimetidine hepatitis].

A 41-year-old man with rheumatoid arthritis developed severe acute hepatitis 3 days after starting cimetidine for duodenal ulcer. Other causes were ruled out and he recovered after cimetidine was discontinued. Mild transient elevations of hepatic enzymes have been reported in 3.6% of patients taking cimetidine. However, only 12 cases of severe acute hepatitis associated with cimetidine, mostly secondary to idiosyncrasy, have been reported in the English literature. This rare but serious complication of cimetidine should be kept in mind.

Acute Disease↗

Hydrochlorothiazide-amiloride causes excessive urinary zinc excretion.

Serum zinc levels and urinary zinc excretion were compared in 15 patients with essential hypertension taking chronically a combination of hydrochlorothiazide and amiloride as monotherapy, eight patients maintained with hydrochlorothiazide alone, and eight control subjects. Serum zinc values were statistically comparable in all three groups. However, urinary zinc excretion was abnormally elevated in the two patient groups. In the dosage used, amiloride did not have a zinc-sparing effect.

Adult↗

An unusual case of POEMS syndrome.

A 58-year-old woman presented with a history of premature onset of menopause, longstanding hepatosplenomegaly, monoclonal gammopathy, lower limb polyneuropathy of recent onset, diabetes mellitus, excessive perspiration and leg edema. Polyneuropathy and excessive perspiration improved following a course of prednisone and melphalan. The clinical and pathophysiological features fit the rare entity known as POEMS syndrome.

Drug Therapy, Combination↗

Should acute gold overdose be invariably treated?

Acute gold overload is rare and its clinical and pathophysiological consequences are not well delineated. Consequently the therapeutic approach has not been formulated. We describe 2 patients with rheumatoid arthritis in whom an acute gold overload was inadvertently administered. Their subsequent course, without specific treatment, was benign and uneventful. We suggest that with similar cases a conservative approach of watchful expectancy be adopted.

Acute Disease↗

Adverse drug events in hospitalized patients treated with cardiovascular drugs and anticoagulants.

PURPOSE: To evaluate the incidence of serious adverse drug events (ADEs) caused by cardiovascular drugs during hospitalization in a department of internal medicine, and to identify patients at highest risk. PATIENTS AND METHODS: All the patients treated with cardiovascular drugs and/or anticoagulants in the department between November 1999 and January 2000 were recruited into the study. During hospitalization the patients' charts were reviewed by a pharmacist and a clinician, and the occurrence of serious ADEs was assessed using the Naranjo algorithm. 'Possible' and 'doubtful' ADEs were not counted. RESULTS: Of 496 patients who were enrolled in the study, 20 (4%) had serious ADEs. Compared to patients without ADEs, patients in the ADE group were older (72 +/- 12.6 years (mean +/- SD) vs. 65 +/- 13 years, p = 0.048), their average stay in hospital was longer (7.3 +/- 5.5 days vs. 5.2 +/- 3.7 days, p = 0.018) and their mean urea levels were higher (10.8 +/- 9.3 mmol/l vs. 7.8 +/- 5.3 mmol/l, p = 0.027). The most frequent background pathologies of the 20 patients with ADEs were hypertension (in 18 (90%)) and atrial fibrillation (in nine (45%)). In 50% of the the ADE group there was a history of drug allergies. The ADEs recorded were bleeding in four (20%), arrhythmias in six (30%), orthostatic hypotension in six (30%) and skin necrosis, paranoid reaction, acute hepatitis and acute renal failure in four (20%). The causative drugs were warfarin (which accounted for 25% of the ADEs), beta-blockers (15%), propafenone (5%), amiodarone (5%), and Ca(2+)-channel blockers, nitrates and diuretics (together accounting for 50% of ADEs). Drug combinations were implicated in 50% of ADE. CONCLUSIONS: Serious ADEs were developed by 4% of hospitalized patients taking cardiovascular drugs. Those at highest risk were older, were receiving multiple drug therapy and had higher urea levels. Warfarin and beta-blockers were the drugs causing the largest number of adverse effects. ADEs are an important cause of preventable morbidity, often with serious economic implications and special attention should be given to their prevention.

Adverse Drug Reaction Reporting Systems↗

Pharmacokinetics of intraperitoneal piperacillin/tazobactam in patients on peritoneal dialysis with and without pseudomonas peritonitis.

OBJECTIVE: The objective of this study was to assess the pharmacokinetics of intraperitoneal (IP) administration of the antibiotic combination piperacillin/tazobactam (PIP/TAZ) to patients on chronic ambulatory peritoneal dialysis (CAPD) with and without pseudomonas peritonitis. DESIGN: Open-labeled study. SETTING: The study was carried out in the CAPD unit of Assaf Harofeh Medical Center, Zerifin, Israel. PATIENTS AND METHODS: Six patients participated in the study, 4 had pseudomonas peritonitis, all were given an IP loading dose of 4 g/0.5 g PIP/TAZ. Twenty-four hours after the initial dose, a maintenance dose of 0.5 g/0.0625 g PIP/TAZ was administered with each dialysate exchange for a period of 1 week. The patients without peritonitis received only the loading dose. High performance liquid chromatography was used to determine the concentrations of PIPITAZ in plasma obtained at 0, 30, 60, 90, 120, 360, 480, 600, 720, and 1440 minutes after administration. Samples of the dialysate fluid for determination of PIP/TAZ concentration were collected at 6,10,14, 24, and 72, 120, and 168 hours. RESULTS: After the loading dose, the highest plasma PIP concentration (Cmax) was 51.6 t 21.25 Lig/mL and appeared at 1.5 = 0.45 hours (t,,a). During the maintenance period plasma PIP concentration was 5.2 t 4.75 Lg/mL. Tazobactam was detected in the plasma of 1 patient only. The concentration of TAZ in the dialysate fluid during the maintenance period was 2.3 t 0.5 ig/mL. CONCLUSIONS: Piperacillin administered IP at 4 g reached plasma concentrations comparable to intravenous administration and considered therapeutic (above the MIC90 for Pseudomonas aeruginosa) in CAPD patients with or without peritonitis. The maintenance dose, however, should be augmented. Tazobactam could not be detected in the plasma of most patients and the therapeutic implications of IP administration of TAZ cannot be directly correlated to intravenous administration.

Aged↗