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S Obeid

Publications and source records attributed to S Obeid.

6 recordsLinked to original sources
PubMed1997

The interaction of diadenosine polyphosphates with P2x-receptors in the guinea-pig isolated vas deferens.

1. The site(s) at which diadenosine 5',5"'-P1,P4-tetraphosphate (AP4A) and diadenosine 5', 5"'-P1,P5-pentaphosphate (AP5A) act to evoke contraction of the guinea-pig isolated vas deferens was studied by use of a series of P2-receptor antagonists and the ecto-ATPase inhibitor 6-N,N-diethyl-D-beta,gamma-dibromomethyleneATP (ARL 67156). 2. Pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) (300 nM - 30 microM), suramin (3-100 microM) and pyridoxal-5'-phosphate (P-5-P) (3-1000 microM) inhibited contractions evoked by equi-effective concentrations of AP5A (3 microM), AP4A (30 microM) and alpha,beta-methyleneATP (alpha,beta-meATP) (1 microM), in a concentration-dependent manner and abolished them at the highest concentrations used. 3. PPADS was more potent than suramin, which in turn was more potent than P-5-P. PPADS inhibited AP5A, AP4A and alpha,beta-meATP with similar IC50 values. No significant difference was found between IC50 values for suramin against alpha,beta-meATP and AP5A or alpha,beta-meATP and AP4A, but suramin was more than 2.5 times more potent against AP4A than AP5A. P-5-P showed the same pattern of antagonism. 4. Desensitization of the P2xi-receptor by alpha,beta-meATP abolished contractions evoked by AP5A (3 microM) and AP4A (30 microM), but had no effect on those elicited by noradrenaline (100 microM). 5. ARL 67156 (100 microM) reversibly potentiated contractions evoked by AP4A (30 microM) by 61%, but caused a small, significant decrease in the mean response to AP5A (3 microM). 6. It is concluded that AP4A and AP5A act at the P2xi-receptor, or a site similar to the P2xi-receptor, to evoke contraction of the guinea-pig isolated vas deferens. Furthermore, the potency of AP4A, but not AP5A, appears to be inhibited by an ecto-enzyme which is sensitive to ARL 67156.

Adenosine Triphosphatases↗
PubMed1976

Congenital choledochal cysts.

Cystic dilation of the common bile duct is a rare congenital anomaly. The cases of two patients, 2 1/2 and 18 years old, respectively, illustrate the difficulty in preoperative diagnosis, as well as the value of long-term postoperative follow-up. Ascending cholangitis developed in one of the patients after a Roux-en-Y cystojejunostomy nine years after operation. A follow-up of three years after cystoduodenostomy and 14 years after a hepaticojejunostomy is reported. In infants and small children, a cystoduodenostomy is usually done; otherwise, cystojejunostomy should be the preferred initial operation. Excision may be attempted if the cyst is very small, and in selected cases.

Adolescent↗
PubMedDate not supplied

Mammary carcinoma with osteoclastlike giant cells cytologically mimicking benign breast disease. A case report.

BACKGROUND: Mammary carcinoma with osteoclastlike giant cells (OCLGCs) is a rare tumor. Few reports on the fine needle aspiration (FNA) findings are available. This case had cytologic findings overlapping with benign breast disease. CASE: A 50-year-old woman presented with multiple masses in her right breast and a 2-cm right axillary lymph node. Cytologic scrapings and FNA of the same breast mass showed large cohesive, two-dimensional epithelial cells with a uniform distribution of small, bland nuclei. Discohesion, single cells with features of malignancy, cytologic atypia and mitosis were lacking. Many OCLGCs were present. CONCLUSION: The cytologic features of this rare type of breast carcinoma need to become familiar to pathologists to avoid a false negative diagnosis.

Biopsy, Needle↗