PubMed Health⌕ Search

Biomedical subjects

J A Mendez

Publications and source records attributed to J A Mendez.

5 recordsLinked to original sources

Synthesis and gastric antisecretory properties of allenic 16-phenoxy-omega-tetranor prostaglandin E analogs.

In order to improve the modest oral activity of PGE2 as an inhibitor of gastric acid secretion, analogs were prepared and tested orally in histamine-challenged rats. Insertion of a double bond at C-4, resulting in the 4,5-allene analog of PGE1, gave a small increase in activity. Introduction of the omega-tetranor-16-phenoxy lower sidechain, a modification known to enhance activity in the PGF series, gave an eight-fold increase in activity. The analog having both modifications (enprostil, 2) showed a six hundred-fold increase in oral antisecretory activity over PGE2, which may reflect a potentiation effect. Modification of enprostil at C-1 (various esters) and at C-11 (11-methyl, 11-deoxy) generally resulted in compounds of high activity while modifications at other sites generally resulted in significant reductions in activity.

Animals↗

The effect of commercial policy on international migration flows: the case of the United States and Mexico.

"Microeconomic simulations are performed to determine the impact of liberalized commodity trade on Mexican immigrant supply to the United States. The results suggest that a removal of trade barriers will reduce migration flows, but that the reduction will be fairly modest. Specifically, if both countries move from the levels of protection characteristic of the mid-1960s to completely free trade, the ratio of real U.S.-Mexican wages falls by roughly 18 percent. Using an upper bound for the range of empirical estimates of the wage elasticity of immigrant supply, this implies a maximum reduction in migration flows of 35 percent. A unilateral elimination of trade barriers by the United States reduces Mexican immigrant supply by a maximum of 14 percent."

Americas↗

The seminiferous tubules of the testis before, around and after birth.

A study has been carried out on the width of the seminiferous tubules, and the proportion of pre-germinal cells, in 174 stillborn children between 24 and 40 weeks of gestation, and in 146 children dying between the ages of birth and six years. There was a general diminution in the diameter of the seminiferous tubule throughout the last trimester and immediately before birth, followed by a slow and steady increase in the diameter of the tubule throughout childhood. The germinal cells within the seminiferous tubules appear to be under some slightly increased stimulatory influence during the last few weeks prior to delivery, and under considerable stimulation in the first 4 or 5 weeks after birth. Following this these cells appear to diminish in size and become hidden among the Sertoli cells, to be re-stimulated around the time of puberty.

Aging↗

Carcinoma in situ of the Fallopian tube associated with cervical carcinoma. Case report.

A case of carcinoma in situ of the fallopian tube in a 55-year-old woman, associated to cervical carcinoma is described. The necessary criteria for the diagnosis of pre-invasive carcinoma of the fallopian tube, among which the number of mitoses seems to be of great importance, are discussed. This previously unreported association of carcinoma in situ of the fallopian tube, with carcinoma of the uterine cervix, emphasizes the notion of the multicentric neoplastic possibilities of the müllerian tract derivatives.

Carcinoma in Situ↗