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Biomedical subjects

D Modai

Publications and source records attributed to D Modai.

At least 37 records · Page 2Linked to original sources

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↗

Conservative treatment for Brucella endocarditis.

Endocarditis is the most devastating complication of brucellosis. The accepted treatment for Brucella endocarditis (BE) is a combination of valve replacement and antibiotics. Conservative antibiotic treatment alone is not recommended by most authors, as it is considered ineffective, risking fatality. We describe a patient with BE, in whom antibiotic treatment alone resulted in complete recovery. On reviewing the literature, we found 12 additional such cases. We compared this group of 13 patients with data from 49 published cases treated with a combination of surgery and antibiotics, with a favorable outcome. Absence of congestive heart failure or a prosthetic valve, relatively mild extravalvular cardiac involvement, and a somewhat shorter disease history until initiation of treatment were characteristic of the group treated conservatively in comparison with patients who underwent surgery. In selected patients with BE, conservative antibiotic treatment may be a valid alternative to surgery.

Anti-Bacterial Agents↗

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↗

Chylothorax following median sternotomy.

Reports of chylothorax (CT) following median sternotomy are rare, amounting so far to 16 cases in the English literature, of which 6 were cases of postcoronary artery bypass grafting (CABG). This report deals with an additional case of a 70-year-old woman who developed left pleural chylous effusion following CABG. It is suggested that the incidence of this type of pleural effusion is considerably greater than the few cases hitherto reported. Moreover, as CT may produce serious pulmonary and/or pleural functional impairment, it is proposed that a diagnostic tap be performed more often in cases of post CABG pleural effusion and that preventive drainage be instituted when CT is diagnosed.

Aged↗

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↗

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↗

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↗

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↗

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↗

[Bronchiolitis obliterans organizing pneumonia].

Bronchiolitis obliterans organizing pneumonia (BOOP) is an uncommon condition of unknown etiology which often responds to corticosteroids. It is characterized by cough, patchy pulmonary infiltrations and intra-alveolar organizing fibrosis. We report a 45-year-old man and a 70-year-old woman with BOOP and elevated liver enzymes. Corticosteroid therapy led to complete recovery.

Adrenal Cortex Hormones↗

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↗