Search PubMed⌕ Search

Biomedical subjects

I Brosens

Publications and source records attributed to I Brosens.

119 records · Page 7Linked to original sources
PubMedDate not supplied

Trophoblastic invasion of human decidua from 8 to 18 weeks of pregnancy.

Trophoblastic invasion of the human decidua has been studied in 48 intact uteri with pregnancies ranging from 8 to 18 weeks after the last menstrual period. Some cytotrophoblast invades the distal segments of the spiral arteries to become endovascular while the rest diffusely infiltrates the decidua as an interstitial invader. The interstitial cytotrophoblast reaches the myometrium and gives rise to the characteristic placental bed giant cells. As the placental site enlarges the lateral spiral arteries come to lie obliquely; new openings into the intervillous space are created but this readjustment of the placental blood supply may cause focal superficial decidual necrosis. The physiological changes converting the spiral to the uteroplacental arteries are effected in the upper decidua by the action of endovascular and perivascular cytotrophoblast, whereas in the deeper decidua endovascular trophoblast is principally involved. Endometrial granulocytes aggregate in the region of maternal tissue degeneration with the heaviest trophoblast invasion but the role played by these cells in placentation is unknown.

Arteries↗
PubMedDate not supplied

The pattern of interstitial trophoblastic invasion of the myometrium in early human pregnancy.

The human placental bed myometrium, studied in 42 intact hysterectomy specimens ranging from 8 to 18 weeks' gestation, is characterized by the presence of large numbers of non-villous invasive cytotrophoblastic cells. Quantitative morphometric analysis reveals a tendency for maximal invasive activity to occur at the centre and, subsequently, to extend centrifugally to produce an annular pattern. Morphological observations suggest that the intimate mixture of cytotrophoblast with myometrial tissue must affect the mechanical properties of the myometrium. Local hormone production by trophoblast may induce or enhance these and other changes in uterine tissues that are essential for the establishment of human placentation. Cytotrophoblastic invasion into the myometrium appears to be restricted to the earlier stages of gestation and morphological evidence indicates that, subsequently, clumps of cytotrophoblast fuse to form multinuclear syncytiotrophoblast, the characteristic placental bed giant cells.

Female↗
PubMedDate not supplied

Review article: trophoblast invasion and the establishment of haemochorial placentation in man and laboratory animals.

Trophoblast invasion is an essential component of haemochorial placentation and has to be considered to relation to reactive changes in the maternal uterine tissues. Some comparative aspects of human and laboratory rodents are discussed and, although there is an obvious phylogenetic gap between the two, many characteristics of placental development are found to be analogous. Trophoblast growth into the uterus is different in different species: localized trophoblast growth forming a bulky tissue (mouse, rat, hamster) contrast with a dispersion of independent trophoblastic elements, forming an interstitial invasion (guinea pig, man). In the rat, mouse, hamster and man retrograde intra-arterial trophoblast migration occurs in maternal vessels supplying blood to the developing placenta. Early changes in maternal tissue might influence trophoblast behaviour. Decidualization probably is a key phenomenon, and the relation of decidual necrosis to trophoblast invasion is considered. Some kind of controlled immune response by the mother also may be involved. These considerations apply to stromal or interstitial invasion as well as to intravascular trophoblast migration but, for the latter, haemodynamic factors probably influence tissue reactions.

Adaptation, Physiological↗
PubMedDate not supplied

Uteroplacental arterial changes related to interstitial trophoblast migration in early human pregnancy.

Morphometric and statistical techniques were used to assess the relation of myometrial interstitial trophoblast to the uteroplacental vasculature in 27 intact hysterectomy specimens ranging from 8 to 18 weeks' gestation. It was found that the volume density of cytotrophoblast in the myometrium and in particular the proximity of such trophoblast to the placental bed spiral arteries correlated significantly with morphological alterations in these vessels. The changes included swelling of endothelium, hypertrophy of individual medial smooth muscle cells, and oedema and disruption of the architecture of the vessel wall as a time-related continuum. Some of the changes, such as swollen endothelium and basophilia of medial smooth muscle cells were noted also in spiral arteries in the non-placental bed endometrium but to a considerably less extent than in the placental bed. Intimal vacuolation was common to placental bed and non-placental bed arteries, increased with gestational age and can be considered as a non-specific feature. The migration of endovascular trophoblast into the myometrial spiral arteries in the second trimester occurred only when these arteries had been considerably altered in their morphology. These findings indicate that migratory interstitial cytotrophoblast probably has a role to play in the preparation of the myometrial segments of the uteroplacental arteries for the second wave of endovascular trophoblast migration that occurs in the second trimester of human pregnancy.

Arteries↗
PubMedDate not supplied

Decidual changes in the endometrium and morphological adaptation of the associated supplying arteries in the normal and diabetic pseudopregnant rat.

After an electrically induced pseudopregnancy in rats in which deciduomas were produced by an intraluminal oil injection, the decidual tissue was studied morphologically on days 7, 10 and 13. A constant and dynamic wave of mitotic figures was found, which started on day 7 in the antimesometrial decidua, moving to the mesometrial decidua on day 10 and finally to the mesometrial triangle area on day 13 of pseudopregnancy. This and other morphological changes were compared with those found in pseudopregnant rats with streptozotocin-induced diabetes. On days 7 and 10 the incidence and distribution of mitotic figures were practically identical in both groups and statistically no significant difference was found in the uterine weight between the two groups on these two days. On day 13, two statistically significant differences were observed in the diabetic group: a fall in the uterine weight and a fall in the incidence of mitotic figures in the mesometrial triangle decidual cells. Associated with decidualization, a series of histological changes were studied in the arteries of the mesometrial triangle. Although the difference was not statistically significant, changes seemed to occur to a lesser degree in the diabetic group. It is concluded that the diabetic state has no influence in the early decidualization period, but it does have influence late in pseudopregnancy: a fall in the mitotic activity in the decidual tissue, a fall in the uterine weight and a less marked change in the spiral arteries which during pregnancy would supply the developing placenta with maternal blood.

Animals↗
PubMedDate not supplied

Office mini-hysteroscopy.

The technique of diagnostic hysteroscopy has not yet been accepted generally as an ambulatory, well-tolerated office procedure. Especially in the infertile patient the standard hysteroscopic procedure is poorly tolerated in an office environment. Our prospective registration of 530 diagnostic office mini-hysteroscopies in infertile patients demonstrates that using an atraumatic insertion technique, watery distention medium and the new generation of mini-hysteroscopic endoscopes, hysteroscopy can be performed in an office set-up without any form of anaesthesia and with a high patient compliance. The significant number of abnormal findings (28.5%), the absence of complications and the low failure rate (2.3%) indicate that diagnostic office mini-hysteroscopy should be a first-line diagnostic procedure. Those results are compared with the registration of 4204 consecutive conventional diagnostic hysteroscopies in a routine gynaecological population performed between 1982 and 1989. We conclude that the mini-hysteroscopic system offers a simple, safe and efficient diagnostic method in the office for the investigation of abnormal uterine bleeding, to evaluate the cervix and uterine cavity in the infertile patient, for screening of endometrial changes in patients under hormone replacement therapy or anti-oestrogens as (adjuvant) treatment and, lastly, it may be very helpful for the interpretation of uncertain findings in other diagnostic techniques such as ultrasound, magnetic resonance imaging, blind biopsy or hysterosalpingography.

Ambulatory Surgical Procedures↗
PubMedDate not supplied

Carbon dioxide pneumoamnios causes acidosis in fetal lamb.

Recently developed techniques of video-endoscopic surgery may offer new hope for the future of fetal surgery. To allow this approach, the amniotic cavity has to be temporarily enlarged, either by carbon dioxide (CO2) insufflation or by amnioinfusion. In 6 anesthetized ewes, CO2 insufflation of the amniotic cavity produced severe fetal hypercapnia (from 57.6 +/- 1.6 to 87.0 +/- 7.0 torr) and acidosis (from 7.22 +/- 0.03 to 7.11 +/- 0.08) despite normal maternal CO2 pressure and pH. CO2 pneumoamnios does not therefore appear to be an ideal working medium. Fetal endoscopic surgery through amnioinfusion of physiologic fluid may be a safer alternative.

Acidosis↗
PubMedDate not supplied

Vasoepididymostomy to the head of the epididymis: a comparative study of two microsurgical techniques in the rabbit.

In an experimental animal study, two different microsurgical techniques of vasoepididymostomy to the caput epididymidis are compared: an end-to-side anastomosis with the epididymal tubule and an end-to-end anastomosis with a section of a cluster of the epididymal tubule. The patency rates are respectively 50 per cent and 26.3 per cent, as controlled by deferentography and histology. Examination with scanning electron microscopy, shows that the superiority of the first method is due to the better apposition of both mucosas .

Animals↗
PubMedDate not supplied

[Microsurgery in 1982. Importance of the technique in the different surgical specialties and training possibilities (author's transl)].

Recently microsurgical techniques have become standard procedures in microvascular surgery especially in plastic surgery and hand surgery and peripheral nerve surgery. In gynecology and urology microsurgery has improved the results of infertility surgery by two or three times. Microsurgical training in vascular and nerve repair should be undertaken by every fellow in plastic and reconstructive surgery of handsurgery. Gynecologists and urologists should be aware of the possibilities of microsurgery and have the opportunity during their training to participate on these procedures. They should however not need to have full knowledge of the technical details and refer patients to specialized infertility microsurgery centers.

Education, Medical, Continuing↗
PubMedDate not supplied

Microsurgery in gynecology.

Microsurgical techniques have changed the outcome of infertility surgery. Tubal anastomosis for reversal of sterilization has resulted in pregnancy rates of up to 65%. In cases of salpingostomy, the ectopic pregnancy rate is quite high. In ovarian microsurgery, postoperative adhesions can be avoided and a 54% pregnancy rate achieved with endometriosis surgery.

Endometriosis↗