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Biomedical subjects

S Sandor

Publications and source records attributed to S Sandor.

At least 37 records · Page 2Linked to original sources
PubMedDate not supplied

In vitro studies on normal and pathological preimplantation development. I. Events of normal mouse preimplantation development as revealed by microcinematography.

After briefly presenting the main historical data of in vitro culture of preimplantation mouse embryos and their filming, the first own observations on normal preimplantation development made by using microcinematography are presented: development from two-cell to eight-cell embryos; compaction and cavitation. The timing and the duration of various developmental events were recorded. Own observations were compared with previous cinematographic data reported by other authors. Some processes needing further investigations are evidenced: rotation within the zona pellucida, penetration of cytoplasmic emissions through the zona, contraction and reexpansion.

Animals↗
PubMedDate not supplied

Sulphonated phthalocyanine induced caudal malformative syndrome in the chick embryo.

Sulphonated phthalocyanine (Pht.) has been tested for its possible noxious effect on the developing chick embryo. When injected into the subembryonic cavity of 40-45 hours incubated chick embryos (mainly 10-20 somite pairs), Pht. induces a highly reproducible caudal malformative syndrome (trunk and taillessness, various anomalies of the limbs). The main effect is--in about 15% of the malformed specimens--associated with unilateral microphthalmy and, less frequently, with coelosomy. Microscopically developmental disturbances of the caudal axial organs, of the mesonephros and of the limbs are observed. The initial pathological changes, at microscopic level, are necrosis and hemorrhages in the caudal axial and paraxial area. The allantois is poorly developed or even absent. Skeletal changes involve anomalies of the ribs and of the vertebral column and total or partial absence of the pelvic girdle bones. The high mortality, mainly during the first week, is due--first of all--to the developmental disturbances including the poor development or absence of the allantois. Control experiments with CuCl2 suggest the ethiological role of Cu. Pathogenetic aspects are discussed.

Abnormalities, Drug-Induced↗
PubMedDate not supplied

The effect of ethanol upon early development in mice and rats. VIII. The effect of chronic consumption of some beverages upon preimplantation development in rats.

The effects of chronic consumption of some beverages (plum-brandy 24% and cognac 20%) upon preimplantation development in rats were studied. The control of possible effects was performed on day 5 by usual flushing, examination and photographying of oviductal and uterine embryos. In order to evaluate the effect of the beverage applied, the following criteria were used: mean litter size, migration of the embryos from the oviduct to the uterus, the developmental stage attained by the pre-implantation embryos and the appearance of pathological embryos. The main results were the following: both beverages applied influenced the preimplantation development; with respect to the developmental rate and to the induction of pathological changes, the effect of both beverages was similar (retardation and an increased, number of pathological morulae and blastocysts); a different action could be detected as to the mean litter size and to the migration of preimplantation embryos: plum-brandy reduced more substantially the mean litter size, whereas cognac had a more marked retarding effect upon the migration of embryos from the oviduct to the uterus: all the changes detected show a more or less marked "litter-effect". The present data were compared with the corresponding effects of chronic ethanol administration observed previously in our laboratory. No obvious potentiating effect of beverage congeners could be established. The findings are discussed in connection with other experimental models of alcohol embryo and fetopathy.

Alcohol Drinking↗
PubMedDate not supplied

Effect of alcoholization upon the maternal and fetal hepatic DNA and the maternal serum-proteins in pregnant albino rats.

Experiments were performed on pregnant albino rats (Wistar strain) of 150-200 g b.w. Biochemical investigations involved the determination of maternal and fetal hepatic DNA content (Spirin's method), of maternal serum proteins (total protein content and electrophoretic fractions). The mean litter size, early resorptions, fetal mortality, and some biochemical data of fetuses were also determined. The main statements were as follows: The chronic, peroral administration of 20% ethanol to pregnant albino rats before and during pregnancy induced changes of the biosynthesis of hepatic DNA: a nonsignificant increase as compared with the control group was recorded. The control of serum proteins revealed an increase of the total protein content and of the total electrophoretic serumglobulin fractions. Within the globulin fraction, a hyper-alpha-globulinemia, and a hypo-beta and gamma globulinemia were detected. In the fetuses of the experimental group a slight but statistically significant increase of the hepatic DNA content appeared. In the experimental group the early resorption rate (10.97%) and the fetal mortality (2.43%) was increased in comparison with the control group (0%). In the alcoholized mothers a nonsignificant decrease of the crown-rump length and a significant decrease of fetal and placental weight could be observed.

Alcoholism↗
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The effect of ethanol upon early development in mice and rats. IV. The effect of acute ethanol intoxication of day 4 of pregnancy upon implantation and early postimplantation development in mice.

Acute ethanol intoxication in albino mice (RAP) induced by intravenous administration of ethanol on day 4 of pregnancy delayed or inhibited implantation in about 25 per cent of the cases. The noxious action upon the implantation process showed a clear-cut "litter effect" and the mean litter was not affected by the experimental intervention. In very early postimplantation stage (day 6 of pregnancy) a statistically significant advance of some main morphogenetic indices was detected in treated specimens. As a possible explanation of this finding, a "selection" of more resistant and viable embryos by the acute ethanol intoxication is presumed. The data discussed in the present paper, together with authors' previous findings suggest a possible noxious action of acute ethanol intoxication during preimplantation stages upon implantation.

Animals↗
PubMedDate not supplied

The embryo as allograft.

The main problems and experimental results with respect to the mechanism by which the embryo, as "allograft", is tolerated within the maternal organism are reviewed. The following hypotheses are discussed: the immunological "immaturity" of the embryo and of its appendages; the immunological incompetence of the maternal organism; the uterus as an immunologically "privileged" area; the existence of an immunological barrier between the mother and the embryo.

Animals↗
PubMedDate not supplied

The shaping of the mesometrial proamniotic cavity in the mouse. Are there various mechanisms?

The existence of an alternative pathway of the shaping of the mesometrial proamniotic cavity (based upon the examination of several hundreds 6-day mouse embryos), which occurs more frequently than mentioned by other authors, is described. The observed pathway begins with the invagination of the mesometrial pole of the implanted blastocyst, the early proamniotic cavity thus communicating with the uterine lumen. Subsequently, it is occluded by the ectoplacental cone. The phylogenetic aspects of these observations are discussed.

Animals↗
PubMedDate not supplied

The effect of ethanol upon early development in mice and rats. V. In vivo effect of acute preimplantation intoxication with or without previous chronic alcoholization.

Albino rats (Wistar) and albino mice (RAP) were either injected intravenously with ethanol during the preimplantation period (day 4 and 3, respectively) or injected in the same way after a previous chronic alcoholization (peroral consumption of 20% ethanol for 50-60 and 32-35 days, respectively before mating, adding the days until killing). The control of possible effects was performed on day 5 (rats) and 4 (mice) by usual flushing, examination and photographing of oviductal and uterine embryos. A group of albino rats, with chronic alcoholization, was controlled for late, fetal effects (resorption rate, skeletal control, possible ocular anomalies). The main results obtained were as follows: Acute ethanol intoxication. Rats: significant increase of pathological, fragmented preimplantation embryos with a marked "litter effect". Mice: no deleterious effect upon preimplantation development. Chronic alcoholization + acute ethanol intoxication. Rats: significant retardation of the preimplantation development rate and a significant increase of the number of pathological, fragmented embryos with a marked "litter effect". Mice: demonstrable advance of preimplantation development and migration rate. Chronic alcoholization--late fetal control in rats: the increase of resorption rate; the more frequent absence of sacral vertebrae; very rare rib anomalies and the absence of ocular malformations.

Alcoholism↗
PubMedDate not supplied

Researches on the formation of axial organs in the chick embryo. XI. Experimental investigations into the role of Hensen's node in somitogenesis.

In order to obtain new data with respect to the role of the node area in somitogenesis and to its "individuality" and real regression, three experimental models were applied to 1-7 somite chick embryo 1) UV irradiation of the node area (in vitro); 2) subnodal transsection (in vitro and in ovo); 3) combination of the two interventions. The main results obtained were as follows: The UV irradiation of the node area in chick embryos of early somite stage (1-7 somites) prevents, by necrotizing the cell population of the irradiated zone, the further regression of the node. This result attests the existence of a real, distinct, node cell population and the real character of regression movement. The subnodal transsection of similar embryos of about 0.1-0.2 mm caudal of the node leads (as observed also by several other authors) to the development of a "tail", projecting into the hole formed after the intervention. The "tail" contains axial organs and results from an "autonomous" regression of the node area. The previous irradiation of the node area prevents the shaping of the "tail". In both experimental models, segmentation and somite differentiation is possible caudal of the stopped node area (with the development of median somite blocks) and on the edges of the hole, respectively. Thus the node seems not to be an absolute contributor--by its regression--to the determination (to the second morphogenetic "wave") of somitogenesis (Cooke and Zeeman, 1976; Bellairs, 1980). The arrest of the node area regression does not influence (during the developmental stages studied) the rate of somitogenesis in the anterior part of the segmental plate.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Experimental embryology and teratology--its relevance for medical practice.

Some main aspects (but by no means all) of the strong relation between experimental embryology and teratology and practical medicine are discussed. As a matter of fact, the spectacular modern tool used in sterility therapeutics--the transfer of preimplantation embryos--has been developed on the basis of a considerable experience in embryo transfer on laboratory animals. Preventive teratological screening, its increasing development is the plausible consequence of the increasing importance of prenatal pathology. The present status of the problem, its real efficiency, some directions of research trying to find more efficient methodologies and some personal opinions as to the perspectives are discussed.

Animals↗
PubMedDate not supplied

The effect of ethanol upon early development in mice and rats. VI. In vivo effect of acetaldehyde upon preimplantation stages in rats.

In completion of the previously outlined "experimental alcohol blastopathy", the role of acetaldehyde in the induction of preimplantation pathological changes in rat embryos has been controlled. Two experimental models were used: the direct administration of acetaldehyde by gavage and the blockage of acetaldehyde metabolization by ANTALCOL (an aldehyde-dehydrogenase blocking compound). The main results were as follows: The exogenous acetaldehyde in the blood of pregnant animals has an obvious effect upon the developmental rate during the late preimplantation period (retarding segmentation, blastulation), and in one of the experimental models upon the oviductal-uterine migration rate. The increase of the blood acetaldehyde level by blockage of its further metabolization has a more marked effect as compared with the direct intravenous administration of the substance. According to our previous observations the intravenous application of ethanol on the same day (day 4) has no such effect. The direct noxious influence upon the developing preimplantation embryos (fragmentation) of the increased level of acetaldehyde obtained by ANTALCOL treatment is similar but more marked than this effect obtained previously by ethanol administration. The same effect observed after the direct administration of the substance is less marked than the effect of ANTALCOL treatment but more marked than the effect of intravenous ethanol administration. These results attest that acetaldehyde may contribute (alone or together with the effect of ethanol) to the induction of "experimental alcohol blastopathy". The less marked action of the substance proper introduced into the blood stream may be due--in our opinion--to its possible alteration during the period between distillation and application.

Acetaldehyde↗