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Biomedical subjects

J Ben-Ari

Publications and source records attributed to J Ben-Ari.

At least 37 records · Page 2Linked to original sources
PubMed1990

Adaptive myocardial hypertrophy in the renal ablation model.

We have previously reported downregulation of the vascular alpha 1-receptor in the 5/6 renal ablation model. In this investigation we have examined the adaptive response of the heart following 5/6 renal ablation. Renal ablated and sham rats were maintained under identical conditions for 6 weeks. Despite the presence of systemic hypertension in renal ablated rats (185 +/- 10 mm Hg, P less than .01), heart weight did not differ from sham. [125I] +/- CYP binding was performed and myocardial norepinephrine (NE) content determined to evaluate myocardial sympathetic neuroeffector mechanisms. Scatchard analysis and 1-isoproterenol competition curves did not reveal a difference in the binding properties of the myocardial beta-receptor. No difference in myocardial NE was found in renal ablated and sham rats. Unexpectedly, 1-isoproterenol stimulation of adenylate cyclase was impaired in renal ablated rats (32.6 +/- 6 v 58.6 +/- 5 pmol/mg/min, P less than .01) and the dose response curve shifted to the right. We conclude that despite systemic hypertension an adaptive hypertrophic response was not present in hearts of renal ablated rats; myocardial sympathetic neuroeffector mechanisms are not altered in this model; and impaired stimulation of adenylate cyclase appears to be the result of a post-receptor defect.

Adaptation, Physiological↗
PubMed1990

Intraperitoneal phosphate administration in hungry bone syndrome.

Hypophosphatemia complicating parathyroidectomy for secondary hyperparathyroidism in renal failure is usually corrected by the oral or intravenous routes. We present a case in which those methods of treatment were not possible, and the phosphate was administered intraperitoneally. Phosphate was added as one molar sodium diphosphate solution to the dialysis fluid. In our case the procedure was well tolerated, phosphate blood levels were rapidly corrected, no alterations in calcium, magnesium or other parameters were detected and the patient was discharged in good condition. In selected cases of hungry bone syndrome after parathyroidectomy, intraperitoneal phosphate can be used safely.

Adult↗
PubMed1989

The prevalence of high insertion of scrotum, hydrocele and mobile testis in the newborn infant (36-42 weeks gestation).

The prevalence of some minor abnormalities of the male genitalia was studied in 271 boys born over a period of 2 months. The scrotal insertion on the ventral side of the penis was determined in an objective manner by measuring the ratio of the ventral and dorsal length of the unstretched penis. A scrotal insertion ratio of less than 0.48 defined high insertion of the scrotum which was found in 2.7% of our newborn infants. This anatomical finding has an important clinical significance for the performance of early circumcision. The prevalence of hydrocele in all male newborn infants was 57.9%. Extravaginal (communicating) type was present in 86% of all infants, intravaginal (noncommunicating) in 9.5%, while both types of hydrocele in the same neonate was observed in 4.5%. The relatively high frequency of mobile testes (22%) is of interest. The natural history of this entity is not fully understood and the question of follow-up remains open.

Anthropometry↗
PubMed1988

Myocardial hypertrophy: the effect of sodium and the role of sympathetic nervous system activity.

Dietary sodium and the myocardial alpha 1-receptor have been implicated in the hypertrophic response of myocardial tissue. Alterations in sodium homeostasis have been demonstrated to influence sympathetic nervous function, centrally and peripherally. In this investigation, we have examined the effect of dietary sodium on the development of myocardial hypertrophy; and the role of sympathetic neuroeffector mechanisms in the hypertrophic response. Studies were performed in three groups of uninephrectomized rats: A-regular diet; B-1% saline/regular diet; C-1% Saline/doca/regular diet. Groups A and B did not develop systemic hypertension (SHT). Saline treatment increased heart weight and the density of surface alpha 1-receptors; myocardial norepinephrine (NE) was reduced. Group C developed SHT. Heart weight was greatest in Group C; and myocardial NE was severely depleted. Downregulation of myocardial alpha 1-receptors, a finding consistent with the hyperadrenergic state, was observed in Group C. Our results suggest dietary sodium may modulate hypertrophic response in myocardial tissue, by altering sympathetic neuroeffector mechanisms.

Animals↗
PubMed1988

Amelioration of systemic hypertension by converting enzyme inhibition in the renal ablation model.

Hypertension associated with a reduction in renal mass has been traditionally thought of as a volume-dependent state. Recent investigations suggest important roles for systemic and glomerular resistance vessels in the pathogenesis of systemic hypertension (SHT) and progression of end-stage renal disease. To examine this relationship, investigations were performed in two groups of rats maintained for 6 weeks following 5/6 renal ablation. Group A received converting enzyme inhibition (CEI) for 6 weeks. Group B received no treatment. Systolic blood pressure and weight of remnant kidney tissue were both increased in group B (P less than 0.01). BUN did not differ in groups A and B; however, renal PGI2 excretion was increased in group A (P less than 0.01). Renal morphology was preserved in group A, with little or no evidence of glomerular sclerosis. CEI prevents SHT and enhances renal PGI2 excretion in this model. The selective increase in PGI2 may mediate systemic and renal effects of this agent.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1988

Upregulation of the vascular alpha-1 receptor in malignant DOCA-salt hypertension.

In this investigation we describe regulation of the vascular alpha-1 receptor and functional properties of resistance vessels in malignant hypertensive DOCA-salt rats (DOCA-salt). Uninephrectomized control and DOCA-salt rats were maintained for 6 weeks; microscopic renal morphology provided an index of vascular injury. Radioligand binding studies indicated a striking increase in the density of mesenteric alpha-1 binding sites in DOCA-salt (542 +/- 44 fm/mg) vs. salt control (206 +/- 4 fm/mg) and water control (223 +31 fm/mg) P less than .01. The affinity of the receptor for the radioligand [125I] (+/-) BE 2254 was reduced in DOCA-salt rats. Electrical nerve stimulation and agonist dose response curves were performed on isolated perfused mesenteric arteries. A singular correlation between increased receptor density and vascular responses in DOCA-salt rats could not be demonstrated. The norepinephrine (NE) content of mesenteric arteries was reduced in DOCA-salt (1001 +/- 32 ng/g) vs. water control (1522 +/- 44 ng/g) and saline control (1538 +/- 30 ng/g) P less than .01. Our results indicate, upregulation of the mesenteric alpha-1 receptor occurs in DOCA-salt rats, however, additional factors participate in the vascular response to adrenergic stimulation in this model.

Animals↗
PubMed1987

Externally applied abdominal vibration as a method for improving efficiency of peritoneal dialysis.

We studied the effect of externally applied vibration onto the abdominal wall on the efficiency of peritoneal dialysis (PD). Ten patients were studied. Three consecutive PD exchanges (control sessions, CS) were compared with vibration sessions (VS). Samples of blood and dialysate were analyzed for urea nitrogen (UN), creatinine (Cr) and potassium (K). Mean clearance was calculated. We found that vibration increased significantly the mean UN, Cr and K clearances.

Abdominal Muscles↗
PubMed1986

Effect of chronic uremia on the cardiovascular alpha 1 receptor.

Adrenergic dysfunction in uremia has been well described. Several lines of evidence suggest disorders of blood pressure regulation and myocardial response may occur secondary to adrenergic dysfunction; attenuated pressor response to norepinephrine (NE) in uremia; attenuated chronotropic responses during dialysis induced hypotension. Since the adrenergic receptors are the effector component of the adrenergic nervous system, we have employed the partially nephrectomized uremic rat, to examine the effect of chronic uremia (4-6 weeks) on the binding properties of alpha 1 receptors in rat mesenteric artery and myocardial tissue. The results indicate that moderate levels of uremia alter the binding properties of both the alpha 1 vascular and myocardial receptor.

Animals↗
PubMed1985

Characteristics of the male genitalia in the newborn: penis.

During a 2-month period all male newborns were examined prospectively to determine the normal characteristics of the penis. Of the 274 neonates examined 3 were excluded because of hypospadias with chordee. The spontaneous direction of the shaft was in the midline in 76.8 per cent, to the left side in 15.5 per cent and to the right side in 7.7 per cent. Partial absence of the prepuce was observed in 10 per cent of the patients, while an unretractable foreskin was seen in 23.2 per cent. The mean meatal aperture was 2.6 plus or minus 0.8 mm. Deviation of the median raphe was present in 10 per cent of the newborns and was associated with deviation of the meatus in 2.2 per cent. Mild torsion of the penis was noted in 1.5 per cent, while isolated torsion of 90 degrees was seen in 0.7 per cent of the patients. Early diagnosis and followup of these newborns might be helpful in determining further treatment.

Humans↗
PubMed1985

Hepatitis associated with propylthiouracil treatment.

A 12-year-old girl with hyperthyroidism who had started treatment with propylthiouracil (PTU) 100 mg tid developed hepatitis. The drug was stopped, and the clinical and laboratory findings of hepatitis disappeared within a week. She was not receiving other drugs that could cause hepatic damage, and investigations for various viral agents were negative. This is the ninth report of PTU-induced hepatitis. The clinical picture is similar to that of viral hepatitis. Recovery usually occurs after withdrawal of the drug, but there have been two fatal cases of PTU-induced hepatitis.

Chemical and Drug Induced Liver Injury↗
PubMed1983

A spot sample test for the estimation of urinary or nephrogenous cAMP in the evaluation of parathyroid function.

The measurement of urinary or nephrogenous cAMP is considered to be a reliable index of parathyroid function. This test usually involves timed urine collections which renders it logistically burdensome. We have therefore assessed the validity of using spot urine samples for this purpose, 2-hour urine collections were compared to spot samples for the estimation of urinary and nephrogenous cAMP in 10 patients with hypercalcemic primary hyperparathyroidism and 22 control subjects. The results demonstrated: (1) a considerable overlap between the primary hyperparathyroid and control groups when the urinary and nephrogenous cAMP values were expressed as a function of creatinine excretion. (2) A satisfactory separation between the two groups when the 2-hour urine and spot sample levels of urinary cAMP--and even more so nephrogenous cAMP--were expressed as a function of glomerular filtrate (i.e. nmol cAMP/100 ml glomerular filtrate). (3) An excellent correlation (r = 0.91, p less than 0.001, n = 32) between 2-hour urine collections and spot samples for both urinary and nephrogenous cAMP levels. The feasibility of using a spot sample for measuring urinary or nephrogenous cAMP without impairing its diagnostic efficacy considerably simplifies the logistics of the test. This is of particular importance for ambulatory patients.

Adult↗
PubMed1977

Near drowning in the Dead Sea.

Seven cases of submersion in the Dead Sea are described. The clinical picture varied in severity and consisted of signs of pulmonary edema, chemical bronchitis, hypermagnesemia and hemoconcentration. Two of the patients died of hypotension and cardiac arrhythmia. The clinical findings were similar to those found in cases of drowning in seawather, but the presence of hypermangesemia is unique to this entity. The amount of aspirated water causing severe clinical signs seemed to be much smaller than is seen with ordinary seawater. Therapeutic guidelines, including assisted respiration, infusion of hypotonic solutions and corticosteroid therapy, are suggested.

Aged↗