The amniotic plaques in sheep of the Karagouniko breed.

The structure of amniotic plaques and adjacent epithelium of full term ewes of the Karagouniko breed were studied using scanning electron microscopy (SEM) and light microcopy. The amniotic plaques appeared as cauliflower-like structures mainly trifurcate or as single papillae. The wall of their stems possessed numerous foldings and round openings. Of interest to note was the abundant vascularization observed in sections of the amniotic plaques. The adjacent amniotic epithelium to the plaques revealed a heterogenous surface which was composed of cells of various forms.

Ossification and growth rates of the limb long bones during the prehatching period in the quail (Coturnix coturnix japonica).

The timing of ossification and the growth of six long bones of the prehatching period in the quail was studied. Ninety-nine quail eggs were incubated and in total nine fetuses were selected daily from the sixth to the sixteenth day of incubation. The fetuses were stained with alizarine and alcian blue double colouration. The fetuses were studied under the stereoscopic microscope and linear measurements were obtained from the humerus, ulna, radius, femur, tibia and fibula. The first appearance of the primary ossification centres in the diaphysis of the studied bones was found to occur between the sixth and the seventh day of incubation. Different growth patterns between the bones of the leg and of the wing were observed. Humerus and tibia showed the greatest growth rate while the radius and fibula showed the lowest.

The developmental relation among mesonephros, gonad and external genitalia in the fetus of goat (Capra prisca).

The mesonephros, the gonad, the external genitalia and the developmental relationships between them were examined on 21 goat fetuses, 29 to 92 days old. Three fetuses were not sexually differentiated, however 11 were males and 7 females. The development of the gonad could be divided in a not differentiated stage and a gonadal and external genitalia differentiation stage. A close relationship between the fetal gonad and the mesonephros was found during the stage of differentiation. The epicenter of this relation is the giant mesonephric nephron, a peculiar structure of mesonephros, from which epithelial cells presumably migrate into the gonad.

RF radiation-induced changes in the prenatal development of mice.

The possible effects of radiofrequency (RF) radiation on prenatal development has been investigated in mice. This study consisted of RF level measurements and in vivo experiments at several places around an "antenna park." At these locations RF power densities between 168 nW/cm2 and 1053 nW/cm2 were measured. Twelve pairs of mice, divided in two groups, were placed in locations of different power densities and were repeatedly mated five times. One hundred eighteen newborns were collected. They were measured, weighed, and examined macro- and microscopically. A progressive decrease in the number of newborns per dam was observed, which ended in irreversible infertility. The prenatal development of the newborns, however, evaluated by the crown-rump length, the body weight, and the number of the lumbar, sacral, and coccygeal vertebrae, was improved.

Formaldehyde vapour effects in chicken embryo.

A total of 763 fertile chicken eggs were divided in two groups. The eggs of the first group were manipulated intact. The shell of each egg of the second group was drilled at the air chamber position. The eggs of both groups were divided in 6 subgroups and they were placed in an automatic incubator. Between the second and the fourth day of incubation each subgroup of eggs was moved to another incubator saturated with formaldehyde vapour, and it was exposed for a certain time. The hatched chicks were examined, measured, and processed, in order to search for any external, visceral, and skeletal malformation. Although the chicks of the first group did not show any particular abnormalities after their exposure to formaldehyde vapours, those of the second group were found to be affected in a rate of about 29:100. The observed embryotoxic effects of the hatched chicks of the second group were mainly early and late prenatal deaths, extensive and limited congenital anomalies as well as reduction deformities.

Teratogenic effects of a mixture of scopolamine and hyoscyamine in chick embryos.

The effect of a mixture of scopolamine and hyoscyamine (98:2) on developing chick embryos was investigated. The embryos were exposed at 2 stages of development to various doses of this mixture via yolk sac injection. This resulted in deaths at different stages of prenatal development, as well as various malformations and reduction deformities. These findings suggest that the studied mixture has a teratogenic effect when injected into the yolk sac of developing chick embryos.

Anatomical study of the renal portal system in the duck (Anas platyrhincos).

Sixteen healthy mature ducks of both sexes were used in the present study. The injection of a polymerizing material was made via the posterior vena cava and, after a complete corrosion, casts were obtained for the examination of the entire venal network of the kidneys. Similar injections were made in a limited number of fowls, in order to facilitate the comparison between our findings in the duck and those in the fowl. The renal portal system as well as the renal veins of the duck were identified and illustrated in detail. The anatomical relation of the renal portal system to the renal veins and to the coccygomesenteric vein was examined and evaluated. From the comparison of the findings in the duck and fowl, the main differences in the duck were found to be the following: the cranial portal vein was rudimentary, the distance between the two caudal portal veins as well as that between the two renal veins was short, the posterior part of the caudal renal portal vein and the renal vein were located superficially and ventrally to the caudal lobe of the kidney, and the distance between the caudal renal portal vein and the homolateral vein was also short.

Vestibular afferents of the inferior olive and the vestibulo-olivo-cerebellar climbing fiber pathway to the flocculus in the cat.

The projection of the vestibular nuclei to the inferior olive was investigated by means of anterograde transport of tritiated leucine. Following injections in the medial and descending vestibular nuclei, terminal labeling was found ipsilaterally in the dorsomedial cell column, subnucleus beta and the caudal medial accessory olive, while the latter also received afferents from the nucleus prepositus hypoglossi. At the contralateral side termination in the dorsomedial cell column and the medial accessory olive was found after injections in the nucleus vestibularis superior and group Y. The ventrolateral outgrowth and different parts of the principal olive also received afferents from these two nuclei and also from ventral parts of the lateral cerebellar nucleus. The dorsal cap was labeled exclusively from the contralateral nucleus prepositus hypoglossi. The termination in the inferior olive of the vestibular afferents is compared with the projection from a number of pretectal nuclei. Furthermore the consequences of the divergence and convergence of both types of projections at the level of the inferior olive is discussed in relation to the subsequent climbing fiber projection to the flocculus.

Vestibular nuclear efferents to the nucleus raphe pontis, the nucleus reticularis tegmenti pontis and the nuclei pontis in the cat.

The projection of the vestibular nuclei to the pontine tegmentum was investigated by means of anterograde transport of tritiated leucine. Dense patches of terminal labeling were observed in the contralateral nucleus raphe pontis and the nucleus reticularis tegmenti pontis in cases where the injection involved the medial and descending vestibular nuclei. Following injections in the superior vestibular nucleus and group Y, weaker termination, also patchlike, was observed in the same tegmental nuclei, and in addition in the dorsomedial pontine nuclei proper. The results are discussed in relation to the position of the nucleus raphe pontis and the nucleus reticularis tegmenti pontis in the oculomotor pathways.

Distribution of the secondary vestibular fibers in the cerebellar cortex. An autoradiographic study in the cat.

Autoradiography of tritiated leucine, injected into the vestibular nuclei in 20 cats, was used to trace the projection of the secondary vestibular fibers in the cerebellum. The distribution of these fibers in the cerebellar cortex is described and discussed in relation to the findings from other experimental works.