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Biomedical subjects

J Shapira

Publications and source records attributed to J Shapira.

At least 109 records · Page 6Linked to original sources
PubMed1985

Effect of potassium loading on prostaglandin E2 and F2 alpha excretion in the Brattleboro rat.

In order to assess the relative roles played by potassium (K) and the antidiuretic hormone (ADH) on the renal production of prostaglandins (PG) E2 and F2 alpha, the 24 hour urinary excretion of these substances was measured in Brattleboro rats (devoid of ADH) and in control Long Evans heterozygote rats. Rats of each strain received either a normal K intake or a K load for 8 days. Urinary PGE2 and PGF2 alpha were measured by radioimmunoassay in three consecutive 24 h urine collections obtained after the above periods. K loading induced an increase in PGF2 alpha (p less than 0.01), PGE2 showing a non significant trend to decrease. The E/F ratio was decreased in K loaded animals. The changes were qualitatively similar in presence or absence of ADH, but animals with diabetes insipidus had lower levels of PGs than control animals. The results suggest the possibility that K loading induces an increase in the activity of the renal enzyme PGE2-9-ketoreductase. The resulting increase in PGF2 alpha could play a role in K excretion and this response is probably independent of ADH.

Animals↗
PubMed1985

Effect of sodium loading on the urinary excretion of prostaglandins E2 and F2 alpha in rats with hereditary diabetes insipidus (Brattleboro rats).

Current evidence suggests that the antidiuretic hormone (ADH) and changes in sodium balance influence renal prostaglandins (PGs). To separate these two mechanisms, the effect of sodium loading on the urinary excretion of PGE2 and PGF2 alpha was studied in female Brattleboro rats with diabetes insipidus (DIHO) and compared with that in female, age matched, heterozygous Long Evans controls (LEHE). Ten DIHO and ten LEHE rats had a normal sodium intake. In ten DIHO rats a 0.16% NaCl solution was supplied instead of drinking water for either 8 days (n = 5) or 14 days (n = 5). In two groups of LEHE rats, sodium loading was obtained with a 0.80% NaCl solution for the same study periods. Urine PGs were measured by radioimmunoassay in three 24 h urine collections for each rat. Urine PGs were significantly increased in the 8 day loaded but not in the 14 day loaded LEHE rats. In DIHO rats, a non-significant increase in both PGE2 and PGF2 alpha was present after 8 days of sodium loading, while PGE2 and the E/F ratio were decreased after 14 days of salt loading. The findings suggest that the natriuresis induced by sodium loading in the rat may be mediated in part by increased production of PGs. In addition, it seems that ADH plays a role in this response.

Animals↗
PubMed1985

Urinary prostaglandins E2 and F2 alpha in chronic renal failure. Influence of chronic and acute changes in Na balance.

The role played by renal prostaglandins E2 (PGE2) and F2 alpha (PGF 2 alpha) in the modification of sodium homeostasis in chronic renal failure (CFR) was studied. The 24-hour urinary excretion of PGE2 and PGF2 alpha was measured before and after 5 days of a diet containing less than 20 mmol/day of sodium in 6 patients with CRF. At the end of this period, an acute sodium load (77 mmol/h of NaCl for 4 h) was administered and prostaglandins measured in hourly urine collections. In contrast to the findings previously reported in normal subjects, PGE2 and PGF2 alpha decreased with the low-sodium diet. The ratio PGE2/PGF2 alpha (reflecting the activity of the enzyme PGE2-9-ketoreductase) was greatly increased and did not change with the low-sodium diet. The acute sodium load induced an increase in urinary prostaglandins. The results suggest that prostaglandins may contribute to natriuresis in CRF, under basal conditions, after a short-term sodium depletion and in response to an acute sodium load. The changes in prostaglandin excretion in CRF could be related to decreased activity of PGE2-9-ketoreductase.

Adult↗
PubMed1985

Occlusal composite restorations: 4-year results.

A study was performed to determine the success of a conservative cavity preparation using the principle of sealing for prevention rather than cavity extension for prevention. A total of 332 restorations were placed in 240 teeth of 110 subjects, aged 6 to 14, with a mean age of 8 years. After 4 years, 205 restorations were examined. Caries appeared in 13 teeth and sealant wear occurred in 14 restorations. Complete sealant loss was observed in eight restorations and partial loss in 38, leaving 156 restorations with complete retention of the sealant. These preliminary results show that conservative cavity preparation with sealing for prevention is a successful technique that conserves valuable tooth structure.

Adolescent↗
PubMed1983

Effect of atenolol treatment on urinary prostaglandins E2 and F2 alpha in essential hypertension.

The urinary excretion of prostaglandins (PG) E2 and F2 alpha was measured by radioimmunoassay in 15 patients with essential hypertension, before and after 2 and 4 weeks of treatment with the selective beta 1-adrenergic blocker, atenolol. Systolic and diastolic blood pressure, pulse rate and plasma renin activity decreased significantly during the treatment. No change was observed in renal function and electrolyte balance. The 24-hour excretion of PGE2 and PGF2 alpha was also unaffected by the antihypertensive treatment. The above findings, in contrast with those previously observed with another beta-blocker, propranolol, suggest that tubular beta-receptors are not involved in the synthesis of PGs. The different hemodynamic effects of the two drugs are the most likely explanation for the different responses in prostaglandin excretion.

Adult↗
PubMed1982

Prolonged dimethylsulphoxide treatment in 13 patients with systemic amyloidosis.

Continuous oral dimethylsulphoxide (DMSO) treatment (7-15 g/day) was given to 3 patients with amyloidosis of familial Mediterranean fever (FMF), 3 patients with idiopathic amyloidosis, and 7 patients with secondary amyloidosis. The nephrotic syndrome and various degrees of renal insufficiency were the major clinical manifestation in all case. Renal function was used as the main parameter for evaluation of therapy. DMSO treatment for 7-16 months produced no effect in the FMF patients and in the patient with idiopathic amyloidosis; they all ran the predictable clinical course of their disease and either died of cardiac failure or have been maintained on chronic haemodialysis. In the 7 patients with secondary amyloidosis an unequivocal improvement of renal function was observed following 3-6 months of DMSO treatment. It was shown by a 30-100% rise of creatinine clearance and a decline in proteinuria. This new equilibrium has been maintained as long as DMSO was administered. No serious side effects of DMSO wee encountered. Mild nausea and an unpleasant breath odour were the patients' main concern. We conclude that a therapeutic trial with oral DMSO is warranted in all patients with secondary amyloidosis. This treatment is unpleasant but bears no exceptional risks. It may significantly prolong life, though its effect on amyloid deposits themselves is doubtful.

Adult↗
PubMed1980

Detection of a fibroblast proliferation inhibitory factor from Capnocytophaga sputigena.

The addition of a sonic extract of Capnocytophaga sputigena to the culture fluid to human fibroblasts resulted in an inhibition of cell proliferation. The inhibition was dose-related (200 micrograms/ml caused a 90% inhibition, and 1,000 micrograms/ml caused a complete cessation of growth). The growth inhibition was not due to alterations in culture medium, pH or ionic strength, or to the effects of the C. sputigena lipopolysaccharide.

Cell Division↗