Involution of the mesonephros and differentiation of the epididymis in chickens: immunohistological study]

By means of purified rabbit anti-adult chicken kidney antibodies two types of antigens have been identified in the mesonephros: one, localised in the cells of the proximal segment of the secretory tubules, the other characteristic of the collecting segments derived from the Wolffian duct. During the transformation of certain mesonephric tubules into ductuli efferentes and conjugentes of the epididymis the collecting tubule antigen disappears whereas the proximal secretory tubule antigen not only persists but can also be detected in the parietal layer of Bowman's capsules as they transform before connecting with the rete testis.     

Releasable GABA in tubular epithelium of rat kidney

The distribution of gamma-aminobutyric acid (GABA) in the rat kidney was examined by immunocytochemical techniques. GABA-like immunoreactivity (GABA-LI) was predominantly confined to the renal tubules, including the ascending parts of the distal tubules, and the loops of Henle, the collecting tubules and ducts, and the connective parts of the convoluted tubules. In GABA-positive cortical tubules, about half of the epithelial cells were labelled. The labelled cell type showed the ultrastructural features of principal cells. Depolarizing stimulation by ouabain and high K+ concentration evoked the efflux of endogenous GABA from kidney slices. The present findings, along with previous results, suggest that GABA released from renal tubular epithelium, and transported with the urine, might be involved in the modulation of contractility in the urinary tract.     

Releasable GABA in tubular epithelium of rat kidney

Summary The distribution of gamma-aminobutyric acid (GABA) in the rat kidney was examined by immunocytochemical techniques. GABA-like immunoreactivity (GABA-LI) was predominantly confined to the renal tubules, including the ascending parts of the distal tubules, and the loops of Henle, the collecting tubules and ducts, and the connective parts of the convoluted tubules. In GABA-positive cortical tubules, about half of the epithelial cells were labelled. The labelled cell type showed the ultrastructural features of principal cells. Depolarizing stimulation by ouabain and high K⁺ concentration evoked the efflux of endogenous GABA from kidney slices. The present findings, along with previous results, suggest that GABA released from renal tubular epithelium, and transported with the urine, might be involved in the modulation of contractility in the urinary tract.     

Localization of brain type creatine kinase in kidney epithelial cell subpopulations in rat

Summary Immunoperoxidase studies of rat kidney using antibody to brain type isoenzyme of creatine kinase (BB) revealed a specific staining in the epithelial cells of the thick ascending limb of the Henle's loop and collecting tubule. Occasional epithelial cells in cortical tubules that lack brush border were also positive for BB. Renal glomeruli and proximal tubules showed no immunoreactivity to this enzyme.     

Localization of brain type creatine kinase in kidney epithelial cell subpopulations in rat

Immunoperoxidase studies of rat kidney using antibody to brain type isoenzyme of creatine kinase (BB) revealed a specific staining in the epithelial cells of the thick ascending limb of the Henle's loop and collecting tubule. Occasional epithelial cells in cortical tubules that lack brush border were also positive for BB. Renal glomeruli and proximal tubules showed no immunoreactivity to this enzyme.     

Phospholipid and fatty acid composition of lamellar bodies isolated from chicken lungs at different stages of development]

In order to elucidate whether the lamellar body content represents functional surfactant as soon as these bodies appear in lung epithelium during fetal development, lamellar bodies were isolated from lungs of Chicken at various developmental stages. Their content was analyzed and compared to extra-cellular functionnal surfactant. The results show that this content undergoes gradual changes in the phospholipid/protein ratio, as well as in the relative phosphatidylcholine amount. Thus, in the Chicken, nascent lamellar bodies do not represent the final form of extracellular surfactant.     

Androgen levels in the rete testis fluid during sexual development

Summary The concentrations of testosterone (T) and 5-dihydrotestosterone were measured in fluid collected from the rete testis of immature and adult rats. The results indicate that adult levels of T are attained in the seminiferous tubules much earlier than in the peripheral circulation.This work was performed at the Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts, USA and supported by the National Institutes of Health through grants HD12641 and HD12642. We thank Dr B.V. Caldwell for antiserum to testosterone.     

Morphology of ribosomal RNA in chicken fibroblasts]

It is shown with the electron microscope that the 28 S RNA component of the ribosomal RNA extracted from Chicken fibroblasts contains secondary structures which are not present in the 18S component.     

5-Bromodeoxyuridine inhibition of the transformation of Rous sarcoma virus-infected chicken cells]

The transformation of Rous-Sarcoma-Virus-infected synchronized Chicken cells is prevented when 5-bromodeoxyuridine is added for 3 hrs. at time of the peak of the first S phase following infection. Virus progeny is normally released. The inhibitory effect of BrdU is reversed by simultaneous addition of thymidine, but not by that of deoxyuridine. Hence, the inhibition of the transformation seems to result from the incorporation of the analogue into the nuclear DNA.     

Xanthindehydrogenase in Organen vonDrosophila melanogaster

Summary High activity of the enzyme, xanthindehydrogenase, was detected in larval fat-body of wild typeDrosophila melanogaster. The Malpighian tubules of both larvae and adults exhibit activity, too, though rather little. No activity was detected in larval testes, while probably insignificant traces were found in adult testes. The results are discussed with regard to non-autonomy of mutants deficient in the enzyme.

---

---

Ausgeführt mit Unterstützung des Schweizerischen Nationalfonds zur Förderung der wissenschaftlichen Forschung.     

In vivo occupation of estrogen receptors by hydroxylated metabolites of tamoxifen]

We report that after in vivo administration of (3H) tamoxifen, the cytosol and nuclear estrogen receptor sites of Rat uterus and Chicken oviduct are mostly occupied by polar metabolites. One of the major metabolites is 4-hydroxy-tamoxifen which we have identified by cocrystallisation withe non radioactive compound and which is known to display a high affinity for the estrogen receptor. In the Rat uterus, the proportion of the metabolites versus tamoxifen, increases with time with a maximum at 8 hrs. for the 4-hydroxy-tamoxifen. Other hydroxylated metabolites (M2) became predominant after 24 hrs. We propose that in vivo, the synthetic antiestrogens act mostly via their transformation into hydroxylated metabolites.     

Implication of GABA in the spatial organization of the receptive fields of retinal ganglia cells of frogs]

An histoautoradiographic study of the Chicken and Frog retinae was made following an intravitreal injection if tritiated GABA. This amino acid was especially fixed at the amacrine and horizontal cell level. It has been suggested (Werblin, 1974) that horizontal cells might be responsible for the spatial organization of the receptive fields of retinal ganglion cells. GABA could thus be involved in bringing about of the centre-surround arrangement of the latter receptive fields. We have shown that picrotoxin, a specific GABA-antagonist, does indeed provoke marked changes in the activity of retinal ganglion cells. It provokes a decrease in the response threshold, a facilitation of spontaneous activities, and a marked increase in the receptive field area of the ON-OFF ganglion cells: from 12 at the start, it reaches 24 under the effect of picrotoxin.     

Synaptosomal adenosine triphosphatase (ATPase) inhibition by organophosphates.

Chicken spinal cord adenosine triphosphatases (both Na+, K+ stimulated and ouabain insensitive) were inhibited by tri-o-tolyl phosphate (TOTP, a neurotoxic organophosphate which is not a cholinesterase inhibitor) and mevinphos (a non-neurotoxic compound but inhibitor of cholinesterases). The inhibition was concentration and time dependent, with an initial rapid drop in activity followed by a gradual exponential decline.     

Cellular contaminants and structural proteins of Rous sarcoma virus (RSV), studied by polyacrylamide gel electrophoresis]

The number of polypeptides in highly purified preparations of RSV, of two different subgroups, produced in culture, has been compared to the polypeptides present in the supernatant of uninfected cultures and processed in identical manner. The analysis of PAGE-SDS shows that from 13 to 18 polypeptides present in viral preparations may be cellular contaminants. Fewer contaminating polypeptides are found in the myeloblastosis virus purified from plasma of Chicken.     

Synthesis of a ubiquitously present new HSP60 family protein is enhanced by heat shock only in the Malpighian tubules ofDrosophila

A homologue of the chaperonin protein of the HSP60 family has not been shown so far inDrosophila. Using an antibody specific to HSP60 family protein in Western blotting and immunocytochemistry, we showed that a 64-kDa polypeptide, homologous to the HSP60, is constitutively present in all tissues ofDrosophila melanogaster throughout the life cycle from the freshly laid egg to all embryonic, larval and adult stages. A 64-kDa polypeptide reacting with the same antibody in Western blots is present in all species ofDrosophila examined. Using Western blotting in conjunction with³⁵S-methionine labeling of newly synthesized proteins and immuno-precipitation of the labeled proteins with HSP60-specific antibody, it was shown that synthesis of the 64-kDa homologue of HSP60 is appreciably increased by heat shock only in the Malpighian tubules, which are already known to lack the common HSPs.     

Ultrastruttura della calcificazione distrofica renale da sublimato

Summary Carrying on the researches on the biological process of calcium deposition, the role of the substructures in the precipitation of calcium salts in the loci of distrophic calcification of kidney tubules following sublimate injections has been investigated. In agreement with the histochemical data previously found, the presence of collagen fibres in these sites is excluded; the morphological appearance of crystal deposits is described. The importance of mitochondria in the calcium ion deposition in kidney tubules is discussed.     

Synaptosomal adenosine triphosphatase (ATPase) inhibition by organophosphates

Summary Chicken spinal cord adenosine triphosphatases (both Na⁺, K⁺ stimulated and ouabain insensitive) were inhibited by tri-o-tolyl phosphate (TOTP, a neurotoxic organophosphate which is not a cholinesterase inhibitor) and mevinphos (a non-neurotoxic compound but inhibitor of cholinesterases). The inhibition was concentration and time dependent, with an initial rapid drop in activity followed by a gradual exponential decline.     

Identification of 2 phosphorylated amino acids in chicken bone phosphoproteins]

Phosphoproteins of Chicken bone have been extracted by 0.5 M EDTA pH 7.5. Their amino acid composition was similar to that of phosphoproteins of other calcified tissues. The crude EDTA extract contained 80 to 90% proteins, only 70% of the total organic phosphorus was bound to the proteins. We have studied and identified two phosphorylated components. o-phosphoserine and o-phosphothreonine have been identified by amino acid analysis at pH 1.7 from a partial acid hydrolysate, and confirmed by the liberation of the parent amino acids after total hydrolysis. In addition, phosphorus was found equimolecular to both of them. The presence of these phosphorylated groups is important for an understanding of the role of these proteins in the mechanism of mineralization.     

Forecasting car expenditures using household survey data

Surveys collecting data on consumer attitudes and buying intentions have been performed in Sweden since 1973. This paper examines the usefulness of these data as quick indicators of the development of household expenditures on automobiles. In the evaluation we are considering the explanatory power as well as the prediction accuracy. It turns out that the best single indicator is among the plan indices. However, an indicator based on car registration statistics is found to be at least as good. By combining plan/attitude indices with car registrations our study shows that considerable improvements can be obtained.     

Analysis of the tissue interactions responsible for the mesonephogenic determination in amphibians, by the in vitro culture technic]

The cultivation of mesonephric lateral mesoblast, in combination with the dorso-caudal endoblast, with or without cordomesoderm, leads to the differentiation of mesonephric tubules in Bufo bufo and Pleurodeles waltlii. Then, the nephric duct does not seem to be necessary to nephric differentiation under in vitro cultivation conditions.