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The mammalian RYK is an orphan receptor that contains a catalytically inactive tyrosine-kinase-related domain. Its Drosophila homolog, Lio/Drl, is required for axon pathfinding in developing brain. Our previous study suggested that RYK mRNA is expressed in nestin-positive progenitor cells and neurons. In the present study, immunohistochemistry has been used to further localize RYK in the central nervous system of rats to identify the lineage of the RYK-expressing cells. In the embryonic forebrain, RYK colocalized with nestin in the ventricular zone and with MAP2 in the cortical plate, suggesting that RYK is expressed in neural progenitor cells and neurons. Localization of RYK in embryonic spinal cord also suggested its expression in both cell types. In primary cultures of rat cerebrum, RYK expression was observed in all neurons, as well as in a significant population of oligodendrocytes, O-2A progenitor cells, and type-2 astrocytes. However, no RYK expression was detected in type-1 astrocytes or microglia. Multipotent neural stem cell line MNS-70 was also analyzed for expression of RYK, and most of the cells were positive for both RYK and nestin in the undifferentiated stage. In the differentiated stage, expression of RYK was detected in the neurons, but not in type-1 astrocytes. In conclusion, RYK is expressed in nestin-positive progenitor cells and neurons, and in a certain population of oligodendrocytes, O-2A progenitor cells, and type-2 astrocytes in developing CNS. These findings show that expression of RYK in rat CNS is tightly regulated in a cell-type-specific manner.

We report a rare case of endometrial carcinoma arisen from both horns of an asymmetrical double uterus.

In this paper, we discuss the possibility of cytological judgment of radiosensitivity of uterine cervical cancer by comparison between pre and postirradiation smears given 1, 000 rads by telecobalt external test irradiation.The estimation of radiation effects on nuclei and the cytological presumption of histological typing in preirradiation smears have brought about satisfactory results;agreement between histological and cytological judgments of radiosensitivity was about 96.8%.Cytological criteria of good sensitivity are as follows;1) Disparity in size of chromatin particles and irregular distribution.2) Irregularity of nuclear membrane with nuclear wrinkling with diminution of thickness of nuclear membrane.3) Mature squamous cell carcinoma without pearlformation.Those of poor sensitivity are as follows;4) Existence of many unchanged viable cells and less disturbances of chromatines.5) Existence of cells exibiting adenocarcinoma and carcinoma of intermediate type.6) Clusters of cyanophilic cells having lacy, indistinct cell borders.

40 strains of Neisseria isolated from the oral cavity were investigated bacteriologically and immunologically.14 strains were identified as Neisseria sicca, 4 strains as Neisseria catarrhalis and only 1 strain was Neisseria crassus.The remainder were intermediate in many respects.

In this study the human decidua, chorion and amnion were incubated for short term. Only the decidua, secreted much prolactin clearly among them as a function of time. When the amounts of prolactin in the maternal blood, cord blood obtained from umbilical vein, or those released into decidual incubation medium were compared with the amniotic fluid prolactin levels, only the decidual prolactin correlated significantly with the amniotic fluid prolactin. The urine obtained from newborns showed a low concentration of prolactin. These results suggest that the origin of prolactin present in the amniotic fluid is not from the mother or fetus, but from the decidua which has the ability of producing prolactin, and that prolactin secreted from this tissue may be transported into the amniotic fluid through the fetal membrane and accumulated there.