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Biomedical subjects

H Márquez Monter

Publications and source records attributed to H Márquez Monter.

At least 19 recordsLinked to original sources
PubMed1994

[Mitochondrial heredity in hydatidiform moles].

A mitochondrial DNA study of seven hydatidiform moles and seven full term placentas as controls was carried out to determine the role played by mitochondrial DNA as the only maternal genome participating in the pathogenesis of these trophoblastic growths. Mitochondrial DNA was digested by restriction enzymes Eco R1 and Hind III, processed by electrophoresis and stained by ethidium bromide. Molar mitochondrial DNA showed two restriction bands at 9416 and 2322 kbs with Eco R1 and one band at 2322 kbs with Hind III, whereas the controls showed three bands of 9416, 4361 and 2322 kbs with Eco 1, and two bands at 4361 and 2322 kbs with Hind III. The results were interpreted as a DNA alteration consistent with a mutation at level of tARN genes, initiating the reading of gen ND2 of Complex I, NADH dehydrogenase and affecting Complex CO III that transcribe cytochrome c and oxidoreductase genes. The alterations are considered as mutations probably resulted from folic acid deficiency at threshold levels during nuclear and mitochondrial DNA synthesis in oogenesis and meiosis that renders anucleated ova (cytoplasts), fertilized, and further accelerated development of a zygote bearing an entire androgenic genome.

DNA, Mitochondrial↗
PubMed1977

Fine structure of mule testes: light and electron microscopy study.

Testes of 3 mules, 3 stallions, and 3 donkeys were studied by light and electron microscopic techniques. Mule testes were firm, with an average weight less than that of stallion or donkey testes. As expected, mule seminiferous tubules had few cell elements. There were 2 cell populations within the seminiferous tubules: (a) Only basal spermatogonia and Sertoli's cells in 70% of the tubules and, (b) the cells in (a) plus leptotene and pachytene primary spermatocytes in 30% of the tubules. Degenerative changes occurred at the pachytene stage and began with the appearance of nuclear vesicles and chromatin condensation. The last stages disclosed pyknotic nuclei and cytoplasmic vesicles. The interstitia were filled by connective tissue elements and few Leydig's cells. Interstitial cells had well-developed, smooth endoplasmic reticula and mitochondria, indicating a normal steroidogenic activity. Epididymides in the mule had morphologic features similar to those of the stallion or donkey, except for the presence of intertubular fibrosis. Degenerative changes in primary spermatocytes indicate metabolic alterations which could be explained by the blockage of meiosis.

Animals↗