tRNA in developing human placenta

Summary Amino acid acceptor activity of tRNA in the human placenta as measured throughout gestation was found to be the lowest in post-term placenta. Aminoacylation of tRNA proceeded with maximum activity in the stage of formation of the placenta.     

Immunogenic potency of the zona pellucida

Summary New Zealand white rabbits were immunized with low doses of pig zona pellucida material with the aim of reducing nonspecific antibodies in the antiserum. The antibody levels were assayed by the standard precipitation and immunofluorescence methods. The titers produced were comparable with those obtained using large amounts of zona material.     

Isozymes of cathepsin B1 in developing human placenta

Summary Cathepsin B1 was purified from human placentas of different gestational ages and analyzed by isoelectric focusing on polyacrylamide gel. The enzyme was shown to consist of 3 or 4 isozymes with pI values between 5.1 and 5.7.     

Migratory patterns of clonally related cells in the developing central nervous system

Summary Neurons and glioblasts that arise in the ventricular zone migrate to form discrete nuclei and laminae as the central nervous system develops. By stably labeling precursor cells in the ventricular zone, pathways taken by different cells within an individual clone can be described. We have used recombinant retroviruses to label precursor cells with a heritable marker, theE. coli lacZ gene; clones of lacZ-positive cells are later mapped histochemically. Here we review results from three regions of the chicken central nervous system — the optic tectum, spinal cord, and forebrain - and compare them with previous results from mammalian cortex and other regions of the vertebrate CNS. In particular, we consider the relationship between migratory patterns and functional organization, the existence of multiple cellular sources of migratory guidance, and the issue of whether a cell's choice of migratory pathway influences its ultimate phenotype.     

Migratory patterns of clonally related cells in the developing central nervous system

Neurons and glioblasts that arise in the ventricular zone migrate to form discrete nuclei and laminae as the central nervous system develops. By stably labeling precursor cells in the ventricular zone, pathways taken by different cells within an individual clone can be described. We have used recombinant retroviruses to label precursor cells with a heritable marker, the E. coli lacZ gene; clones of lacZ-positive cells are later mapped histochemically. Here we review results from three regions of the chicken central nervous system--the optic tectum, spinal cord, and forebrain--and compare them with previous results from mammalian cortex and other regions of the vertebrate CNS. In particular, we consider the relationship between migratory patterns and functional organization, the existence of multiple cellular sources of migratory guidance, and the issue of whether a cell's choice of migratory pathway influences its ultimate phenotype.     

Aldose metabolism in developing human fetal brain and liver

Summary Aldose reductase, sorbitol dehydrogenase, and glucose-6-phosphate dehydrogenase enzyme activities were studied in human foetal brain and liver at different periods of gestation. Aldose reductase activity in liver disappears after 16 weeks of gestation whereas sorbitol dehydrogenase keeps on increasing in liver as well as in brain. In utero, some glucose metabolism may be mediated through an active sorbitol pathway in human fetuses.Acknowledgments. These studies were supported by the Indian Council of Medical Research.     

Aldose metabolism in developing human fetal brain and liver

Aldose reductase, sorbitol dehydrogenase, and glucose-6-phosphate dehydrogenase enzyme activities were studied in human foetal brain and liver at different periods of gestation. Aldose reductase activity in liver disappears after 16 weeks of gestation whereas sorbitol dehydrogenase keeps on increasing in liver as well as in brain. In utero, some glucose metabolism may be mediated through an active sorbitol pathway in human fetuses.     

Microelectrode studies of spontaneous potentials from chick embryo telencephalon in vitro

Résumé A l'aide de micro-électrodes, des potentiels rythmiques spontanés ont été enregistrés dans du tissu télencéphalique d'embryons de poulets âgès de 14 jours, in vitro. Ces potentiels sont semblables à ceux précédemment décrits en utilisant des électrodes de 80 en platine. La possibilité pour ces potentiels d'être produits par les neurones de l'explant est discuté.     

Aniline hydroxylation in the human red cells

Summary The aniline hydroxylation in human red cells was studied and the hydroxylating activity was much accelerated in the presence of methylene blue.     

Receptive fields of cells in the human visual cortex

Résumé Des microéléctrodes implantées dans le cortex humain visuel donnent des champs réceptifs de formes rectangulaires et circulaires qui ont des réponses d'excitation achromatiques, non influencées par les efforts mentaux volontaires ou par d'autres modalités sensorielles. Il y a inhibition quand les paupières sont fermées.     

Possible presence of autoantibodies to zona pellucida in infertile women

Summary Of 52 serum samples from infertile women tested against isolated porcine oocytes by immunofluorescence, 8 produced intense reactions in zonae pellucidae, while only one of 52 sera from control subjects showed the reaction. Autoantibodies to the zona may be present in these women.This work was supported in part by a grant from WHO Task Force on Immunological Methods for Fertility Regulation Project No. 76464.     

On the participation of the zona glomerulosa on the adrenal response to stress

Zusammenfassung Zwei Serien Ratten wurden durch Formalininjektion belastet. Die Zona glomerulosa der Nebennierenrinde reagierte durch Lipoidausscheidung nur in jener Serie, die durch hohe Lymphozytenzahl des Blutes, hohen Lipoidgehalt der Fasciculata, kleinere Aktivität der Lymphknötchen der Milz und auffallend intensive Stressreaktion der Fasciculata charakterisiert war. Bei Ratten, deren Glomerulosa ihre Lipoide ausgeschieden hatte, trat weder Schwellung noch Desintegration des lymphatischen Gewebes der Milz auf.