ABSTRACT
Three cases of eosinophilic granuloma of bone exhibited intercellular attachments between histiocytes, with a pentalaminar structure identical to that seen in nearby intracellular Birbeck granules (BG). It is proposed that the term "lattice junction" be coined to describe this organelle, which seems to be expressed only by cells of monocytic-histiocytic lineage. While this finding confirms the ability of the surface membrane to form such structures, it does not necessarily preclude other intracytoplasmic sites of origin for some BG. The previously suggested role of BG in membrane storage and regulation is reiterated as a supportable model for their function.
Subject(s)
Cytoskeleton/ultrastructure , Eosinophilic Granuloma/pathology , Histiocytes/ultrastructure , Intercellular Junctions/ultrastructure , Adolescent , Child, Preschool , Cytoskeleton/pathology , Female , Histiocytes/pathology , Humans , Intercellular Junctions/pathology , Langerhans Cells/pathology , Langerhans Cells/ultrastructure , Male , Microscopy, ElectronABSTRACT
A new rapid method for the processing of biopsy specimens for electron microscopy is described. The method uses standard reagents and media and employs ultrasonic cleaning bath agitation to accelerate fluid exchange. The procedure takes approximately 2.5 h from specimen excision to polymerized block and gives excellent results.
Subject(s)
Histological Techniques , Microscopy, Electron , Ultrasonics , Humans , Liver/ultrastructure , Skin/ultrastructure , Time FactorsABSTRACT
Melanotic neuroectodermal tumor of infancy is a specific but unusual tumor of infancy for which only sporadic cases have been reported in the literature. This paper presents a case in an infrequent site, the epididymis, and summarizes the literature on the subject.
Subject(s)
Neoplasms, Germ Cell and Embryonal/ultrastructure , Adult , Aged , Child , Child, Preschool , Female , Histocytochemistry , Humans , Infant , Infant, Newborn , Male , Microscopy, Electron , Middle Aged , Neoplasms, Germ Cell and Embryonal/congenital , Neoplasms, Germ Cell and Embryonal/metabolism , Prognosis , Vanilmandelic Acid/urineABSTRACT
1. Adenosine diphosphate (ADP) and adrenaline caused the aggregation of human platelets suspended in plasma containing citrate anticoagulant and stirred at 37 degrees C. The aggregation occurred in two phases and the second phase was associated with the appearance in the plasma of up to 30% of the ATP and 55% of the ADP present in the platelets. The concentration of ADP appearing in the plasma was up to 7 times the concentration added.2. Radioactivity was released by ADP and by adrenaline from platelets labelled with radioactive 5-hydroxytryptamine; this release was closely correlated with the second phase of aggregation and with the release of nucleotides.3. Acid phosphatase, beta-glucuronidase and adenylate kinase were released to a small extent during second phase aggregation by ADP or adrenaline; thrombin and collagen particles caused significantly greater release of beta-glucuronidase than of either acid phosphatase or of adenylate kinase.4. Morphological changes indicating degranulation of the platelets were observed during the second phase of aggregation produced by adrenaline and by ADP.5. The second phase of aggregation, degranulation of platelets, and the release of nucleotides, of labelled 5-hydroxytryptamine and of enzymes, were all inhibited by concentrations of amitriptyline which did not inhibit aggregation.
