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Biomedical subjects

J Weissgarten

Publications and source records attributed to J Weissgarten.

At least 37 records · Page 2Linked to original sources
PubMed1999

Sulpiride versus metoclopramide in nononcologic patients with vomiting or nausea.

Metoclopramide, a benzamide substitute, is used frequently as an antiemetic drug. Sulpiride, another benzamide substitute, was investigated and found to be safe and effective in a handful of studies involving only oncologic or other severely symptomatic patients. In this investigation the authors compared prospectively the antiemetic efficacy of sulpiride versus metoclopramide in a double-blind, randomized study involving 36 nononcologic patients with transient vomiting or nausea of various etiologies. Each group of 18 patients received oral metoclopramide or sulpiride (10 mg or 50 mg respectively) every 8 hours for a total of three doses each (24 hours of treatment). A 5-point score was used to evaluate symptomatic relief. Efficacy of the two drugs proved similar, and at the end of the study, 14 and 13 of 18 patients on sulpiride or metoclopramide respectively were asymptomatic. Only transient, minor side effects were reported in one patient in each group. The authors conclude that sulpiride is an effective and safe antiemetic drug that can be adopted legitimately in such cases as a first choice, or serve as an equipotent alternative to metoclopramide in patients sensitive to the latter.

Adolescent↗
PubMed1998

The effect of grapefruit juice on the pharmacokinetics of orally administered verapamil.

OBJECTIVE: To investigate the effect of grapefruit juice (GJ) on the pharmacokinetics of orally administered verapamil in hypertensive patients. METHODS: Ten hypertensive patients on chronic verapamil treatment participated in a two-day study. On day 1 200 ml of water was given 1 hour before, and together with the morning verapamil dose; on the day 2, water was replaced by GJ in the same order. Serial blood samples were collected and the concentrations of verapamil and its main dealkylated metabolite (D-617) were determined by high-performance liquid chromatography (HPLC). The area under the concentration versus time curve of verapamil (AUCv) and its metabolite D-617 (AUCM) were calculated before and after GJ ingestion. The peak serum concentration (Cmax) and the time until its appearance (tmax) were also determined. RESULTS: GJ did not affect Cmax, tmax, AUCv or AUVm. The AUCv/AUCm ratio (AUCR) was slightly, but significantly, increased after GJ (1.67 vs 1.92). CONCLUSIONS: A single administration of GJ with short-acting verapamil has no significant effect on the pharmacokinetics, of verapamil.

Administration, Oral↗
PubMed1998

Effects of captopril and enalapril on zinc metabolism in hypertensive patients.

OBJECTIVE: To investigate the effect of chronic captopril and enalapril treatment on zinc metabolism in hypertensive patients by assessing zinc levels in serum, urine and monocytes. METHODS: Patients with newly diagnosed essential hypertension were randomly divided into two treatment groups: those treated with captopril only (n = 16) and those treated with enalapril only (n = 18). Ten healthy subjects served as controls. Prior to the start of treatment and again 6 months later, zinc was assessed in the serum, in urine collected over 24 hours, and in peripheral blood monocytes. RESULTS: Significant enhancement of 24-hour urinary zinc excretion (micrograms/24 hour) after 6 months of treatment was observed only in the captopril-treated group (p < 0.01). However, intramonocytic zinc levels decreased significantly in both of the treated groups over the same period (p < 0.01 and P < 0.04 in the captopril- and enalapril-treated groups, respectively). CONCLUSION: Treatment of hypertensive patients with captopril or enalapril may result in zinc deficiency.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1998

The proliferative responsiveness of mesangial cells to postnephrectomy serum declines progressively with time elapsing after contralateral nephrectomy.

Postnephrectomy serum has been proved to enhance proliferation of mesangial cells in culture. Studies in offspring to uninephrectomized (UNx) mothers indicate that it remains active for a long period following UNx. On the other hand, postnephrectomy renal compensatory growth in vivo is known to be completed within a short period. In this study we assessed the proliferative responses of mesangial cells from single kidneys of rats which were cultured 48 h or 4 months following contralateral nephrectomy. The proliferative stimulus was provided by different postnephrectomy sera. Proliferation of both experimental cell populations was significantly greater than that of controls. Moreover, the proliferation rate of early postcontralateral nephrectomy mesangial cells was greater than those harvested 4 months after nephrectomy. We, therefore, propose that the early in vivo completion of single kidney compensatory hypertrophy, at least in part, is due to progressive blunting of renal cell responsiveness to the mitotic stimulus of the animal's serum.

Animals↗
PubMed1998

High-protein diet or unilateral nephrectomy induces a humoral factor(s) that enhances mesangial cell proliferation in culture.

BACKGROUND: A high-protein diet is one of the maneuvers which produce hypertrophy of kidney mass. The underlying mechanism(s) has not been elucidated. In the present study, we investigated the possibility that a humoral factor may be involved. METHODS: Twenty-eight 3-week-old Charles River rats were studied. Fourteen underwent right nephrectomy and 14 sham operation. Each of these groups was divided into two equal subgroups (n = 7 in each): one maintained on a regular diet (20% protein) and the other on a high-protein diet (60% protein) for 7 days. Following this period the animals were sacrificed. Sera from the animals were added to mesangial cell cultures from kidneys of intact 3-week-old rats, and the thymidine incorporation was assessed. RESULTS: The parameters of kidney mass indicated that the high-protein diet indeed produced kidney hypertrophy. Sera from the sham-nephrectomized animals fed a high-protein diet produced a significantly greater proliferative effect on mesangial cells in culture than sera from the respective animals on a normal-protein diet. Sera from either nephrectomized group or from the high-protein sham-operated group all had similar magnitudes of enhancement of mesangial cell proliferation. CONCLUSION: We conclude that the renal hypertrophy produced by a high-protein diet is mediated, at least in part, by a humoral factor(s).

Animals↗
PubMed1997

Increased toxicity of high-dose furosemide versus low-dose dopamine in the treatment of refractory congestive heart failure.

OBJECTIVE: To evaluate the safety and efficacy of low-dose dopamine, high-dose furosemide, and their combination in the treatment of refractory congestive heart failure. METHODS: Twenty consecutive patients with refractory congestive heart failure were randomized to receive intravenous low-dose (4 micrograms/kg/min) dopamine combined with low-dose (80 mg/day) oral furosemide (group A; n = 7), intravenous low-dose dopamine with medium-dose furosemide (5 mg/kg/day through continuous intravenous administration; group B; n = 7), or high-dose furosemide (10 mg/kg/day through continuous intravenous administration; group C; n = 6). RESULTS: The three groups showed similar improvement in signs and symptoms of congestive heart failure, urinary output (2506 +/- 671 ml/24 hr, mean +/- SD) and weight loss (3.3 +/- 2.3 kg) after 72 hours of therapy. Mean arterial blood pressure (MAP) decreased by 14% +/- 8% and 15% +/- 6% in groups B and C, respectively, but increased by 4% +/- 15% in group A (p = 0.017). Renal function deteriorated significantly in groups B and C: creatinine clearance decreased by 41% +/- 23% and 42% +/- 23%, respectively, but increased by 14% +/- 35% in group A (p = 0.0074). MAP decrease was positively correlated with the decrease in creatinine clearance (r = 0.7; p = 0.0007). Patients in group B and C had more hypokalemia than group A. Two patients in group C sustained acute oliguric renal failure and one patient in group B died suddenly while sustaining severe hypokalemia. CONCLUSION: Combined low-dose intravenous dopamine and oral furosemide have similar efficacy but induce less renal impairment and hypokalemia than higher doses of intravenous furosemide taken either alone or with low-dose dopamine. The renal impairment induced by intravenous furosemide is probably related to its hypotensive effect in patients with refractory congestive heart failure.

Acute Kidney Injury↗
PubMed1997

Pulse oxymetry evaluation of oxygen saturation in the upper extremity with an arteriovenous fistula before and during hemodialysis.

We noticed that some patients with arteriovenous (AV) fistula on chronic hemodialysis experience pain in the limb with the fistula a short time after being connected to the dialysis machine. We postulated that the pain is caused by relative ischemia and therefore performed this study to determine whether oxygen saturation (SaO2) of the extremities with AV fistula decreases during hemodialysis. Seventy-two patients with a side-to-side primary AV fistula were evaluated by pulse oxymetry. SaO2 was measured before hemodialysis and 20 minutes after initiation of dialysis. The contralateral arm served as a control. In 48 patients, SaO2 difference between the arms of each patient before hemodialysis was less than 4%. SaO2 values of this group of patients did not change significantly 20 minutes after initiation of dialysis. In 24 patients, SaO2 differences between the hands of each patient before hemodialysis were 4% or more. In this group of patients, SaO2 values of the hands with the AV fistula decreased significantly 20 minutes after hemodialysis from a mean of 90.85 +/- 2.84% to 81.60 +/- 3.94 (P < 0.001). SaO2 remained unchanged in the contralateral arm. Nine patients in this group complained of pain and change in sensation in the arm with the fistula during hemodialysis. One patient complained of severe pain in the arm with the fistula before hemodialysis, and SaO2 was unmeasurable. We conclude that, in some patients, SaO2 of the arm with the AV fistula decreases only during hemodialysis. This phenomenon may be symptomatic. A predialysis SaO2 difference of 4% or more between the arms predicts decreased SaO2 of the arm with the AV fistula during hemodialysis.

Arm↗
PubMed1997

Benign familial microcytic thrombocytosis with autosomal dominant transmission.

Familial thrombocytosis is an extremely rare disorder, so far reported in only a handful of families. In the majority of cases the characteristics were of essential thrombocythemia. Most patients presented with a platelet count above 800,000/mm3, were diagnosed as having a myeloproliferative disease, and some required chemotherapy. We describe a benign form of familial thrombocytosis with autosomal dominant inheritance in five healthy members of three generations of a family, all of whom had moderate thrombocytosis within the range 422,000-662,000/mm3, characterized by low mean platelet volume. A careful medical history and a 5-year follow up of the subjects did not reveal any untoward clinical development. This variant of familial thrombocytosis is therefore of a benign nature. Possible mechanisms linking thrombocytosis with platelet microcytosis in this family are discussed.

Adolescent↗
PubMed1996

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↗
PubMed1996

Asthma mortality in Israel 1971-1990.

BACKGROUND: One of the enigmas in asthma is that our improved understanding of the pathophysiology and the introduction of new modalities to treat asthma has not led to a parallel decrease in asthma mortality. On the contrary, morbidity and mortality from asthma have increased since the mid-seventies in most of the western countries. This trend of increased asthma mortality rate was not observed in Israel in a survey that examined the changes in asthma mortality rate in Israel during 1960-1986. A small but statistically insignificant increase in asthma mortality rate during the last years of that survey solicited for reexamination and extension of the survey. OBJECTIVES: The purpose of the present study was to evaluate the changes in the asthma mortality rate in Israel during the years 1971-1990. METHODS: We extracted the statistical data on asthma mortality rate in Israel during the 1971-1990 period. Because of the small numbers each year and the variations in asthma mortality rate between years, the data were analyzed after grouping the asthma mortality rate into 5-year periods. RESULTS: The rates, expressed as deaths per 100,000 population per year, were 0.43, 0.18, 0.39, and 0.40 in the 5- to 34-year-old group for the periods 1971-1975. 1976-1980, 1981-1985, and 1986-1990, respectively. We found a statistically significant increase in asthma mortality rate during the 1981-1985 and 1986-1990 periods as compared with 1975-1980 in the young (<34 years old) population. The increase in asthma mortality rate was greater among males. The mortality rate in the older population (35-64 year olds) decreased during 1976-80 as compared with 1971-1975 but did not change thereafter. The rates were 10.4, 4.8, 4.5, and 4.4 cases per 100,000 for 1971-1975, 1976-80, 1981-85, and 1986-90, respectively. CONCLUSIONS: Asthma mortality rate increased in Israel in the young age group (5-34 years) during 1980-1990. This is similar to reports from many other countries with advanced medical care systems. The decrease of asthma mortality rate in 1976-80 probably reflect the general improvement in medical care in Israel during these years.

Adolescent↗
PubMed1996

Interrelationship between renal mass and renotropin activity in consecutive generations of uninephrectomized mice.

In offspring of uninephrectomized mouse mothers at ages 3, 5 and 7 weeks (n = 8 in each group) fresh and dry kidney weights, protein content, mean number of glomeruli per microscopic field (GN), mean cumulative fractional glomerular area per microscopic field (GA) and mean number of nuclei per glomerulus (GC) were all significantly increased compared to age-matched control offspring of sham nephrectomized mothers. Sera from mice at ages 3 and 5 weeks, offspring of uninephrectomized mothers, stimulated mesangial cell proliferation in culture. Surprisingly, fresh and dry renal weight, GN, GA and GC were all significantly increased in offspring of sham nephrectomized mothers, daughters of uninephrectomized grandmothers. We speculate that elevated maternal renotropin transferred via the placenta introduces a modification in the embryonal interrelationship between renal mass and endogenous renotropin. This modification results in exaggerated embryonal serum renotropic activity extending to puberty. Whether the humoral agent responsible for enhanced mesangial cell proliferation in vitro is identical to renotropin remains to be elucidated.

Animals↗
PubMed1996

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↗
PubMed1996

Nerve conduction abnormalities in the arms of patients with arteriovenous fistula.

Fifteen patients with unilateral functioning arteriovenous fistula were assessed clinically and electromyographically to identify local neurologic changes. Ten of the patients were symptomatic (motor and/or sensory) and 5 were asymptomatic. Clinically, 11 patients had signs of a mild polyneuropathy, 2 patients of ulnar neuropathy, and 1 patient had signs of median neuropathy. A decrease of the above-elbow ulnar conduction velocity was noted in the study group on the side of the functional fistula, and in the symptomatic patients only on the side of the nonfunctional/nonexisting fistula. We suggest that ulnar nerve vulnerability should be taken into consideration during construction of the fistula, as well as during dialysis.

Adult↗
PubMed1996

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↗
PubMed1995

Age-related ANP release in response to acute vs. chronic sodium loading.

Atrial natriuretic peptide (ANP) levels were studied in young (2-week-old) and old (age 20 months) rats following acute (20 mL/kg bolus of normal saline i.v.) vs. chronic sodium loading (high-salt diet for 21 days). In both groups serum ANP rose significantly 1 h post i.v. loading. However, the increment was greater in the old animals. On chronic sodium load, in the young group, ANP rose significantly on days 3 and 7, subsequently declining to baseline. In the old animals, no increase in ANP was noted throughout the chronic experiment. Twenty-four-hour urinary sodium excretion was similar in the two groups following acute or chronic salt load. The results suggest that: (1) The old kidney requires a greater ANP stimulus to excrete a given acute i.v. sodium load. (2) The relatively diminished elasticity of the old heart plays a major role in the exaggerated ANP release in response to a bolus i.v. load of saline. (3) The role of ANP in maintaining homeostatic renal sodium excretion during short-term sodium oral loading is different in the two age groups.

Aging↗
PubMed1995

Atrial natriuretic peptide inhibits mesangial cell proliferation induced by early postnephrectomy serum.

Rat kidney mesangial or tubular cells were grown in tissue culture medium supplemented with sera of 20 sham-operated vs. 20 nephrectomized Charles River rats. Each cell sample was grown with or without addition of atrial natriuretic peptide (ANP) to the medium. ANP completely abolished the growth stimulatory effect of postnephrectomy serum [i.e., effect of renotropic factor(s) present in the serum] on mesangium cells. Tubular cell proliferation was unchanged. We propose that interaction between renotropin and atrial natriutetic peptide activity might be one of the possible mechanisms regulating compensatory renal growth following nephrectomy.

Animals↗