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Biomedical subjects

L Segal

Publications and source records attributed to L Segal.

33 records · Page 2Linked to original sources
PubMed1990

Fate of oleate in the colon of the rat.

To study the fate of oleate in the colon, oleate labeled with carbon 14 was instilled into the cecum of four rats through chronically implanted cecal cannulas. Fecal recovery of 14C and 14CO2 excretion were measured over a 3-day period. A mean of only 57% +/- 6% of the dose of [14C(U)]oleate was recovered as 14C in fecal lipid. About 8% was recovered in the aqueous phase of feces and 4% was recovered as 14CO2. Occlusion of the terminal ileum did not diminish 14CO2 excretion, excluding ileal reflux with small bowel absorption. Studies in two germ-free rats showed no conversion of [14C(U)]oleate to fecal water-soluble compounds, indicating that [14C]oleate is converted into water-soluble compounds by bacterial metabolism. The metabolism of [14C]oleate to 14CO2 was also observed in germ-free rats, indicating oxidation in the colon or other host tissues. We conclude that the colonic absorption of lipid or lipid metabolites plus conversion to water-soluble fecal compounds or volatile metabolites results in a fecal fat measurement that appreciably overestimates small bowel absorption of lipid.

Animals↗
PubMed1989

[Vasectomy and its reversibility].

The authors report their experience of 2000 vasectomies. They discuss the indications, the technical aspects, the complications, the immunological consequences and the pathological results on the vas deferens, the epididymis and the testis. They report thereafter their experience of vaso-vasostomies (320 cases). They discuss their results on a mechanical (repermeabilization) and functional (% of pregnancies) point of view.

Adult↗
PubMed1987

Morphological anomalies in the placentae of IVF pregnancies: preliminary report of a multicentric study.

Macroscopic characteristics of 100 fetal adnexae from pregnancies obtained by in-vitro fertilization and embryo transfer (IVF-ET) were compared with data for normal pregnancies taken from the literature. Material was obtained from 63 singleton, 15 twin, one triplet and one quadruplet pregnancies. The fetal and placental weights as well as the fetal:placental weight ratio were within the normal range for gestational age. Whilst placental morphology was normal, the insertion of the umbilical cord was frequently abnormal. Marginal (15%) and velamentous (14%) insertions of the umbilical cord were found more frequently than in a general obstetrical population (6% and 1% respectively). Excluding placentae from multiple pregnancies (which are known to have a higher incidence of abnormal cord insertion) the frequency did not decrease and remained significantly higher than in a normal population (P less than 0.01 and P less than 0.001, for marginal and velamentous insertion respectively). Abnormal insertion of the cord is of major clinical importance because of its association with vasa praevia and fetal haemorrhage (Benkiser Syndrome). Since this condition is thought to be caused by disturbed orientation of the blastocyst at implantation it is probably related to the IVF-ET procedure.

Embryo Implantation↗
PubMedDate not supplied

Iatrogenic causes of infertility.

The Authors review the list of the iatrogenic causes of infertility. In their opinion the more delicate the structure, the more heavy the price paid to clumsy or erroneous investigation. Such eventual incompetence may lead to further damage of the already existing situation. The Authors however look at the future with relative optimism: incidents become rarer, specialists in gynecology and infertility pay more attention to the delicacy of genital structures and there is an encouraging tendency to refer to infertility specialists those cases who need adequate work-up of their condition.

Humans↗
PubMedDate not supplied

Pregnancy obtained with human testicular spermatozoa in an in vitro fertilization program.

The fertilizing capacity of human testicular spermatozoa and the positive outcome of an in vitro fertilization program open a wide range of opportunities for men suffering from obstructive and inoperable azoospermia. In six cases, subzonal sperm injection or intracytoplasmic sperm injection techniques were applied to inject testicular spermatozoa into human oocytes. The fertilization rate after testicular sperm injection reached 45%. Normal cleavage was observed and replacement of 10 embryos in 6 patients resulted in one chemical and one ongoing pregnancy.

Cell Separation↗
PubMedDate not supplied

Assisted fertilization with epididymal spermatozoa.

In vitro fertilization is used for several years as a technique for resolving infertility problems due to moderate or severe oligospermia. More recently, techniques of micro-insemination of oocytes have also become available for cases of extremely severe oligospermia which cannot be resolved by classical I.V.F. Nevertheless, although these particular techniques have already led to results which have gone far beyond initial hopes, they are not able to resolve all cases of male sterility. There are indeed many situations of excretory azoospermia associated with normal spermatogenesis; the spermatozoa remain trapped in a more or less extensive part of the epididymis because its passage is blocked, either because of post-infectious sclerosis, or of agenesis of a variably extensive area of the Wolffian duct. Post-inflammatory occlusions can be treated by micro-surgery, whereas in cases of agenesis, attempts to collect spermatozoa by means of an artificial spermatocele have led to far too many failures, and this technique has now been abandoned, in spite of some successful pregnancies. The extraordinary development of in vitro fertilization techniques has led to the logical idea that it might be possible to collect epididymal spermatozoa for oocyte fertilization.

Epididymis↗
PubMedDate not supplied

New therapeutic possibilities handling residual azoospermia.

Obviously, medical therapy of secretory azoospermia or microsurgical therapy of excretory azoospermia are not always successful. The unsolvable cases therefore can be grouped as residual azoospermias. Both the medical and microsurgical approaches are reviewed and their success rates analyzed. Some problems are unsolvable after work-up of the diagnosis. Till the early nineties, such patients were discouraged to undergo further medical therapeutic approaches and were advised to consider either adoption or donor insemination. At the present time, new possibilities have risen since the use of epididymal spermatozoa for performing assisted fertilization has considerably altered the picture. Furthermore, the last breakthrough of using testicular spermatozoa combined with the ICSI procedures have offered solutions that were unthinkable only a few years ago. The impact of these new approaches is discussed and the future development of microsurgery versus assisted reproduction techniques is also considered.

Atrophy↗