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Hoang-Ngoc Minh

Publications and source records attributed to Hoang-Ngoc Minh.

12 recordsLinked to original sources
PubMed1993

[Histogenetic study of corpus luteum in the human ovary].

The authors present a histological study of the formation of the corpus luteum after follicular rupture. According to the classical conception, the corpus luteum is derived from luteinisation of the granulosa cells: the theca interna participates in its formation only to a lesser degree. The authors criticize this histogenesis and describe the corpus luteum as being entirely derived from thecal cells. Large and small luteal cells are all derived from mesenchymal elements of the ovarian stroma, which are the precursors of steroid-secreting cells. According to the authors, granulosa cells derived from the primary sex cords of coelomic mesothelial origin only play a support role for the oocyte. After expulsion of the oocyte from the dominant follicle, the granulosa cells which remain in the follicular cavity disappear without a trace.

Adult↗
PubMed1993

[Hormones and embryogenesis of the uterine cervix].

In the absence of the T.D.F. gene, differentiation of the genital tract follows the female development with Wolffian ducts regression, elaboration of Müllerian ducts, and homologous uro-genital sinus organization. Up to week 32, the fetal ovary secretes no organizing substance and no estrogen. Even if the maternal body is heavily impregnated by estrogens from the fetal-placental unit, the estrogenic and progestogenic activity of any steroid hormones which cross the placental barrier and enter the fetal body is reduced as a result of metabolic degradation within the fetal liver. It is only from week 32 that in normal pregnancies, phenomena of estrogenic action on the uterine cervix of the fetus are seen. This consists of hyperplasia of the endo-cervical epithelium and its emergence towards the exo-cervix. The slightest addition of non-steroid synthetic estrogens administered to the mother may interfere with this hormonal environment of the fetus and result in abnormal development of Müller's tract, particularly in the cervico-vaginal zone.

Cervix Uteri↗
PubMed1991

[From embryogenesis to female phenotype in subjects with XY karyotype].

On the basis of the findings of their investigation of the embryogenesis of the female genital tract, the authors advance a hypothesis concerning the origin of ambiguities between the genetic sex and the gonophoric sex which determine primary sexual characteristics observed in Morris' syndrome and in gonadoblastoma. According to the authors, in gonadoblastoma there is dysgenesis or even agenesis of the gonads, with a total absence of Sertoli cells and, therefore, no secretion of anti-Müller substance and this explains the development of the Müller canals into uterus and Fallopian tubes and the presence of a vagina in an XY subject. In the syndrome of the feminizing testis, XY subjects have testes containing Sertoli cells which have produced anti-Müller substance. However, the initiation of the production of this substance is delayed and it is this delay which has permitted the tendency towards feminization of the uro-genital sinus with the formation of a vagina. The authors thus refute the theory which holds that the Müller cells are involved in the genesis of the vagina.

Female↗
PubMed1989

[New findings on the embryogenesis of the uterus].

In this study including twelve embryos, aged 4 to 8 weeks, and twenty-one fetuses between 9 and 25 weeks, and a group of five still-born fetuses between 25 and 40 weeks, the authors used conventional techniques of histological preparations and immuno-chemistry according to the BSA technique (biotin-streptavidin with peroxidase labelling), in order to demonstrate that the uterus presents a "dual embryogenesis". The endometrium with its stroma and the transition zone endometrium-myometrium have a coelomic origin. The myometrium with the common connective tissue derive from primary mesenchyma. According to the authors, the "dual embryology" of the uterus, would permit simplifying the taxonomy of the histogenesis of uterine tumors.

Embryonic and Fetal Development↗
PubMed1989

[Histologic study of the gonads in ovarian differentiation during organogenesis].

We report the results of a histologic study of the differentiating ovary carried out in human embryos and fetuses. Up to the sixth week, the anlage of the gonad is formed by the proliferation of cells originating from the coelomic mesothelium; this proliferation starts with the migration of the primordial germ cells. Between the sixth and the tenth weeks, the primary mesenchyma invades the epithelial mass and divides it into "cords"; by division, the germ cells contained within the mass become ovocytes. At the tenth week, the gonad takes shape and is separated from the mesonephros. At the twelfth week, the gonad is formed of two zones; an outer zone formed of epithelial clusters arranged in rosettes around the ovocytes; and an inner, mesenchymal, zone that becomes the medulla and separates the outer epithelial zone from the remnants of the mesonephros. At the sixteenth week, the gonad becomes the ovary that contains millions of primordial follicles; each follicle consists of an ovocyte surrounded by a ring of granulosa cells originating from the coelomic epithelium; the follicles are separated from each other by mesenchymal cells that form the cortical stroma. The remnants of the mesonephros are clearly separated from the ovary by the medulla.(ABSTRACT TRUNCATED AT 250 WORDS)

Embryonic and Fetal Development↗
PubMed1989

[New findings on the embryogenesis of the vagina].

The authors have studied a series of twelve embryos between 4 and 8 weeks of age and 21 fetuses between 9 and 25 weeks of gestation. From this material they have made a study of the embryogenesis of the vagina, which shows that the whole of the vagina, and not only the lower third or fifth, is derived from the vaginal plate, this latter is the result of proliferation and fusion of the two sino-vaginal bulbs. This study supports the unitary theory ascribing formation of the vagina to ascension and extension of the vaginal plate which is derived from the cloacal sinus.

Embryonic and Fetal Development↗
PubMed1987

[Tissue changes caused by the diathermy loop].

An attempt of classification of the effects induced by electro-resection on the squamous epithelium of the cervix is presented. It has been founded on predominant features observed on histologic material notably: acantholysis, cells segregation by lysis of intercellular bridges and dislodgment of basal cells from basement membrane by dissolution of reticulin fibers.

Adult↗
PubMed1985

[Structure and function of the fetal umbilical vessels].

A morphological study carried out using electron microscopy has shown that there is an endothelium in the umbilical blood vessels consisting of intercellular spaces which interdigitate with one another and that are not specialization in junction complex. The endothelial cells are rich in their typical organ structure and have pinocytotic vesicles. There media contains a muscular coat which is thicker in the artery than in the veins. The smooth muscle cells also show pinocytotic vesicles. This morphological state leads the authors to two groups of thought: There is active diffusion by a process of "plasma perfusion" from the lumen of the vessels through the vascular wall which forms a physiological system for taking up fluids which in turn is capable of providing for the energy and plastic requirements of the umbilical vessels: The umbilical arteries, because of their thick muscular tunic and because of the ability of the lumen to dilate as there is an absence of an internal elastic membrane, can function not only as tubes for conducting blood but also as organs that regulate the blood flow. On the other hand the umbilical vein, which cannot stretch and cannot retract because its wall is so thin, behaves as an organ to return the blood flow, particularly because it does have an inner limiting layer preventing over-stretching.

Diffusion↗
PubMed1984

[Reflections on endometrial osteogenesis. Apropos of 3 cases].

The authors report three cases of endometrial ossification. They believe that the presence of bone in the uterus is associated with two very distinct situations. One is the retention in utero of fragments of foetal bone after a late abortion. In this case, the bone fragments have a recognisable morphology and a well differentiated structure. The other situation is osseous metaplasia of elements which they believe to be of Mullerian origin, arising in the myo-endometrial transitional zone.

Abortion, Induced↗
PubMedDate not supplied

[Genital sites of giant-cell arteritis].

Temporal arteritis is one of the localisation of the giant cell arteritis. The involvement of the female genital tract had been rarely reported with only 16 cases in the literature. We report 3 cases revealed by a tumor of the genital tract. Histologic features are found in the vessels of ovaries, fallopian tubes and myometrium. Only one patient had symptoms suggestive of temporal arteritis.

Aged↗