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Biomedical subjects

J Pereda

Publications and source records attributed to J Pereda.

36 records · Page 2Linked to original sources
PubMed1984

Ultrastructure of the cumulus cell mass surrounding a human egg in the pronuclear stage.

The cumulus cell mass enclosing a penetrated human egg was studied. The egg, recovered from the Fallopian tube approximately 80 h after luteinizing hormone peak and 35 h after insemination, was surrounded by a large, expanded and dissociated cumulus. Dispersions of the outermost cumulus cell layers occurred during processing, the innermost cell layers remained attached enclosing the egg. The photomicrographs showed that the follicular cells were embedded in an intercellular matrix and contact via gap-junction-like structures between neighboring cells existed. Cumulus cell processes traversing the zona pellucida were not found. Two types of follicular cells coexisted within the cumulus, light and dark cells. These cellular types, were different in morphology and size. Light cells displayed cytoplasmic organelles normally associated with protein synthesis and steroidogenesis. Dark cells with long cytoplasmic processes were involved in sperm phagocytosis. It is suggested from the characteristics of the cytoplasmic organelles that dark cells seem to be modified light follicular cells.

Female↗
PubMed1983

Adenosinetriphosphatase (Mg-ATPase) activity in the plasma membrane of preimplantation mouse embryo as revealed by electron microscopy.

The ultrastructural localization of Mg2+-ATPase activity was investigated in unfertilized eggs and in preimplantation mouse embryos. Enzyme activity was detected on the entire surface of unfertilized eggs and in one-cell embryos. From the two-cell stage up to the 12-cell embryo the reaction product was localized both at the exposed surface of the embryo and between blastomeres. At the late morula stage, activity was only present on the free surface of the peripheral cells outside the apical tight junctions. In the early blastocyst the membranar reaction was observed both on the outside membrane of the trophoblastic cells and on the inner surface facing the blastocoele, whereas in the late blastocyst the reaction remained unchanged on the outer surface of the embryo but was absent from the membranes bordering the blastocoele. These results are discussed with reference to the modification of the cell surface membrane during preimplantation development.

Adenosine Triphosphatases↗
PubMed1979

Human listeriosis in Peru.

In a survey on listeriosis in Peru a study was made of 653 stool samples; material from 8 cases of perinatal death, in which a macroscopic diagnosis of listeriosis had been made at autopsy; 1 sample of vaginal secretion from a woman with abortion due to listeriosis; and 1 case of abscess which turned out to be an hematometra. The following results have been obtained: 1. From the faeces 7 isolates of Listeria (1.07%) were obtained: 3 belonged to L. monocytogenes serovar 4ab, 3 to L. innocua (the former "4g"--nownow serovar 6b) and 1 to L. monocytogenes serovar 4a. 2. The 8 strains of autopsy materials belonged to L. monocytogenes: 6 serovar 4b and 2 serovar 4d. 3. From the vaginal secretion L. monocytogenes serovar 4b was cultured. 4. The strain from the hematometra was identified as L. monocytogenes serovar 4b. The serovars 4a, 4ab and 4d are at this time the only ones identified in Peru as cause of human listeriosis. The serovars of serogroup 1/2 frequent in Western and primarily in Central Europe, were so far never cultivated.

Abortion, Spontaneous↗
PubMed1978

Congenital syphilis of the eye with lens involvement.

Pathological examination of a girl with congenital syphilis revealed a focal granulomatous reaction involving the anterior uvea and lens. Krajian's (silver) stain exhibited spiral forms that were morphologically compatible with Treponema pallidum within the lens cortex. These findings have been rarely reported in early congenital lues.

Eye↗
PubMed1976

Numerical X-chromosome anomalies at the maternity hospital of Lima.

Screening nuclear sex in buccal mucosa cells in 2,213 apparently normal newborns up to 24 hours from the Maternity Hospital of Lima showed that 3 newborn males out of 1,124, had chromatin-positive cells (2.66 per thousand). X-chromosome anomalies were not detected in 1,089 females examined.

Female↗
PubMed1975

A seven-cell human egg recovered from the oviduct.

A seven-cell human egg recovered from the proximal middle quarter of the oviduct is described. Whether or not it is a normal representative of this stage of human development cannot be established at the present time. The specimen was recovered 83 hours after intercourse and 77 hours after the first significant elevation of the luteinizing hormone level in the urine. According to these data and the results of the endometrial and corpus luteum biopsies, the age of the egg was estimated to be approximately 72 hours. An analysis of size and the reaction of the blastomeres to toluidine blue suggests that they already show some differentiation at this early stage of development. The addition of these findings to previous reports of eggs recovered from human oviducts and uteri gives support to the concept that human eggs are delivered to the endometrial cavity when they contain between 7 and 12 blastomeres.

Adult↗