Tumor protein D52 (TPD52): A novel B-cell/plasma-cell molecule with unique expression pattern and Ca2+-dependent association with annexin VI

We generated a murine monoclonal antibody (B28p) detecting an antigenic determinant shared by the immunoglobulin superfamily receptor translocation-associated 1 (IRTA1) receptor (the immunogen used to raise B28p) and an unrelated 28-kDa protein that was subsequently subjected to extensive characterization. The expression of the 28-kDa protein in normal lymphohematopoietic tissues was restricted to B cells and plasma cells and clearly differed from that expected for IRTA1 (selectively expressed by mucosa-associated lymphoid tissue [MALT] marginal zone B cells). Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE)/mass-spectrometry analysis identified the 28-kDa protein as human tumor protein D52 (TPD52), whose expression had been previously described only in normal and neoplastic epithelia. Specific B28p reactivity with TPD52 was confirmed by immunostaining/immunoblotting of TPD52-transfected cells. TPD52 expression pattern in normal and neoplastic B cells was unique. In fact, unlike other B-cell molecules (paired box 5 [PAX5], CD19, CD79a, CD20, CD22), which are down-regulated during differentiation from B cells to plasma cells, TPD52 expression reached its maximum levels at the plasma cell stage. In the Thiel myeloma cell line, TPD52 bound to annexin VI in a Ca2+-dependent manner, suggesting that these molecules may act in concert to regulate secretory processes in plasma cells, similarly to what was observed in pancreatic acinar cells. Finally, the anti-TPD52 monoclonal antibody served as a valuable tool for the diagnosis of B-cell malignancies

Lung colonization and metastasis of murine mammary tumors: relationship to various characteristics of the primary tumors

The ability to metastasize via the bloodstream of mammary tumors occurring in Balb/cfC3H and Balb/cfRIII mice (two substrains of identical Balb/c genotype carrying milk-transmitted C3H or RIII murine mammary tumor virus (MuMTV) infection, respectively) has been compared in MuMTV-free Balb/c virgin female recipients given intravenous tumor cell suspensions or subcutaneous solid tumor transplants from mammary tumor-bearing Balb/cfC3H and Balb/cfRIII breeding female donors. Tumor cell suspensions different for MuMTV inducing variant, growth rate, tumor size, and clinical duration, injected intravenously to Balb/c virgin female recipients, have been compared with respect to the foci of lung colonization induced in recipient hosts. The results obtained indicate that MuMTV variant, growth rate and clinical duration of the primary mammary tumor, but not the size of the primary tumor, significantly influence the lung colonization. Similar results were obtained with solid subcutaneous transplants of the same mammary tumors. The significance of these results for the understanding of the general mechanisms of tumor metastases is discussed

[H-3]Ro 15-1788 binding sites to brain membrane of the saltwater Mugil cephalus

The equilibrium binding parameters of the benzodiazepine antagonist [3H]Ro 15-1788 (8-fluoro-3-carboethoxy-5,6-dihydro-5-methyl-6-oxo-4H-imidazol-[1,5-a]-1,4 benzodiazepine) were evaluated in brain membranes of the saltwater teleost fish, Mugil cephalus. To test receptor subtype specificity, displacement studies were carried out by competitive binding of [3H]Ro 15-1788 against six benzodiazepine receptor ligands, flunitrazepam [5-(2-fluoro-phenyl)-1,3-dihydro-1-methyl-7-nitro-2H-1,4-benzodiazepin-2-one], alpidem [N,N-dipropyl-6-chloro-2-(4-chlorophenyl)imidazo[1,2-a]pyridine-3-acetamide], zolpidem [N,N-6 trimethyl-2-(4-methyl-phenyl)imidazo[1,2-a]pyridine-3-acetamide hemitartrate], and beta-CCM (methyl beta-carboline-3-carboxylate). Saturation studies showed that [3H]Ro 15-1788 bound saturatably, reversibly and with a high affinity to a single class of binding sites (Kd value of 1.18-1.5 nM and Bmax values of 124-1671 fmol/mg of protein, depending on brain regions). The highest concentration of benzodiazepine recognition sites labeled with [3H]Ro 15-1788 was present in the optic lobe and the olfactory bulb and the lowest concentration was found in the medulla oblongata, cerebellum and spinal cord. The rank order of displacement efficacy of unlabelled ligands observed suggested that central-type benzodiazepine receptors are present in one class of binding sites (Type I-like) in brain membranes of Mugil cephalus. Moreover, the uptake of 36Cl- into M. cephalus brain membrane vesicles was only marginally stimulated by concentrations of GABA that significantly enhanced the 36Cl- uptake into mammalian brain membrane vesicles. The results may indicate a different functional activity of the GABA-coupled chloride ionophore in the fish brain as compared with the mammalian brain

Decreasing expression of NM23 gene in metastatic murine mammary tumors of viral etiology (MMTV).

Murine mammary tumors induced by the Murine Mammary Tumor Virus (MMTV) were chosen to study the expression of the NM23 gene during the metastatic process because of their viral etiology, different from that of the previously reported experimental tumor systems. NM23 mRNA levels are higher in non metastatic tumors than in metastatic ones. Moreover, the NM23 expression is higher in tumors induced by the C3H variant of the MMTV than in tumors induced by the RIII variant. These data are a further support to the hypothesis of a basic role of the NM23 gene in the down-regulation of tumor progression

Current knowledge of Umbrian macrofungi (central Italy)

An annotated checklist of 1016 species of fungi (Ascomycota and Basidiomycota), which have been recorded in 95 different localities, from 1990 to 2015, is presented for Umbria (Italy). The checklist was compiled from records of Umbrian fungi in scientific publications, unpublished lists and personal observations. This work represents the first comprehensive checklist of macrofungi for Umbria. Even if not complete, an exhaustive overview of the current knowledge of the mycobiota of Umbria is presented. Although a large amount of the regional territory has still to be explored for mycological diversity, this study offers an important support in compiling red-lists of endangered macrofungi, as well as to identify indicator species of particular habitats to be considered for wildlife reserves, as is currently done in many European countries

Autoradiographic distribution of peripheral benzodiazepine receptors in the retina of the albino rabbit, Lepus cunicula

The distribution of peripheral benzodiazepine receptors (PBRs) in the retina of the albino rabbit, Lepus cunicula, was studied by autoradiography using [H-3]-PK11195, a isoquinoline carboxamide, as a tracer. Autoradiograms obtained by directly placing the slides containing the retina sections on tritium-sensitive film provide evidence for the presence of PBRs in rabbit retina. Furthermore, the dark field examination of photomicrographs taken from autoradiograms showed two dense horizontal bands corresponding to the outer and inner photoreceptor segments, and to the inner plexiform layer. The retinal regions where [3H]-PK11195 binding was more-dense are rich in mitochondria, suggesting that as in other-neuronal tissues, retinal PBRs are involved in the mitochondrial activity. (C) 2000 Published by Elsevier Science Ireland Ltd. All rights reserved