Ultrastructural identification of human tonsil T-lymphocytes by peroxidase-conjugated anti-HTLA serum

Summary A horse anti-serum rendered specific for human T-lymphocytes was conjugated with peroxidase and used for ultrastructural identification of human tonsil T-lymhocytes. With T- and B-enriched suspensions, virtually all T-lymphocytes were labelled with Po-anti-HTLA, whereas no B-cells were stained with this conjugate. The labelling was found to be irregularly distributed on the plasma membrane of T-cells. Direct identification with specific Po-anti-HTLA conjugate confirm the ultrastructural characteristics of thymus-dependant cells.This work was supported by I.N.S.E.R.M. grants No. 74-5-027-01 and A.T.P. No. 73-16.Acknowlegments. We are indebted toMartine Blanc who prepared the cell suspensions and toDanielle Germain who did the preparations for electron microscopic examination.     

Ultrastructural identification of human tonsil T-lymphocytes by peroxidase-conjugated anti-HTLA serum.

A horse anti-serum rendered specific for human T-lymphocytes was conjugated with peroxidase and used for ultrastructural identification of human tonsil T-lymphocytes. With T- and B-enriched suspensions, virtually all T-lymphocytes were labelled with Po-anti-HTLA, whereas no B-cells were stained with this conjugate. The labelling HTLA conjugate confirm the ultrastructural characteristics of thymus-dependant cells.     

Ultrastructure of human myeloma cells studied by peroxidase conjugated antibodies directed to human immunoglobulin component chains

Zusammenfassung Menschliche Myelomazellen wurden immunchemischelektronenoptisch untersucht. Durch die Behandlung mit peroxidasekonjugiertem Antikörper gegen die Immunoglobuline H- oder L-Kette wurde keine H-Kette beobachtet.     

Ultrastructural localization of vanadium in the blood cells of Ascidiacea

Summary X-ray histospectrographic analysis at the scanning and transmission electron microscope (STEM) are made on the blood cells ofPhallusia mamillata Cuvier andCiona intestinalis, to study the direct intracellular sites of accumulation of vanadium. The results show a clear accumulation of vanadium on the membrane and in the granules of vacuoles of amebocytes, signet ring cell, compartment cell and traces of metal in the vanadophores of vanadocytes.We thank Dr C. Weichan and Mr G. Hubert for kind hospitality and for technical assistance in the Department of Electron Microscopy of Siemens Laboratory in Karlsruhe (BRD). We thank also Dr V. Andria of Siemens Elettra in Rome (Italy).     

Ultrastructural localization of vanadium in the blood cells of Ascidiacea.

X-ray histospectrographic analysis at the scanning and transmission electron microscope (STEM) are made on the blood cells of Phallusia mamillata Cuvier and Ciona intestinalis, to study the 'direct' intracellular sites of accumulation of vanadium. The results show a clear accumulation of vanadium on the membrane and in the granules of vacuoles of amebocytes, signet ring cell, compartment cell and traces of metal in the 'vanadophores' of vanadocytes.     

Ultrastructural localization of newcastle disease virus surface antigen in infected Hela cells as revealed by an enzyme-labelled antibody method

Zusammenfassung Nach indirekter peroxidasekonjugierter Antikörpermethode wurden elektronenmikroskopisch mit Newcastle-Disease-Virus infizierte HeLa-Zellen geprüft, und in den frühen Infektionsstadien an den Ribosomen des endoplasmatischen Retikulums solcher Zellen und in den späten Infektionsstadien an den «Spikes» des spriessenden Viruskörperchens das Antigen der Virusoberflächen gezeigt.     

Ultrastructural localization of glucose 6-phosphatase activity in the cells of the epididymis of the mouse

Summary Glucose 6-phosphatase activity is localized in the endoplasmic reticulum and nuclear envelope of all cell types composing mouse epididymis. It is higher in the principal cell than in other cell types in the terminal and caudal half of the middle segment.     

Ultrastructural localization of acid phosphatase in the yeastCryptococcus neoformans

Résumé La localisation de la phosphatase-acide dans la levureCryptococcus neoformans est étudiée ici par des méthodes cytochimiques au niveau ultrastructural. On a trouvé que l'enzyme se concentrait exclusivement dans les vacuoles, ce qui s'accorde avec les résultats que d'autres auteurs ont obtenus sur la localisation de l'enzyme dans les cellules végétales.     

Ultrastructural localization of 5-methylcytosine on DNA and RNA

DNA methylation is the major epigenetic modification and it is involved in the negative regulation of gene expression. Its alteration can lead to neoplastic transformation. Several biomolecular approaches are nowadays used to study this modification on DNA, but also on RNA molecules, which are known to play a role in different biological processes. RNA methylation is one of the most common RNA modifications and 5-methylcytosine presence has recently been suggested in mRNA. However, an analysis of nucleic acid methylation at electron microscope is still lacking. Therefore, we visualized DNA methylation status and RNA methylation sites in the interphase nucleus of HeLa cells and rat hepatocytes by ultrastructural immunocytochemistry and cytochemical staining. This approach represents an efficient alternative to study nucleic acid methylation. In particular, this ultrastructural method makes the visualization of this epigenetic modification on a single RNA molecule possible, thus overcoming the technical limitations for a (pre-)mRNA methylation analysis.     

The potency of heparin-like activity of glycosaminoglycans released by human endothelial cells in culture

Summary Glycosaminoglycans isolated from culture medium conditioned by human endothelial cells showed heparin-like antithrombin III cofactor activity measured by Xa inhibition. Their activity was relatively weak, 0.1% of the potency of heparin, but was approximately 5-fold more potent than that of glycosaminoglycans derived from vascular smooth muscle cells.