Isolation and characterization of a highly divergent HIV-2[GH-2]: generation of an infectious molecular clone and functional analysis of its rev-responsive element in response to primate retrovirus transactivators (Rev and Rex).

A highly divergent HIV-2 designated as HIV-2[GH-2] was obtained from an AIDS-related complex (ARC) patient in Ghana. A full-length molecular clone of this isolate was obtained and a biologically active clone was constructed. Its restriction pattern differed from that of prototype HIV-2[GH-1] in 25 of 35 restriction sites, but was strikingly similar to a previously characterized HIV-2 isolate from a Ghanaian (HIV-2ALT). The conserved integrase region (288-bp fragment) previously displayed 95% identity with that of ALT but 17-20% divergence from the HIV-2 prototype member, and a new distinct subgroup (HIV-2b) of HIV-2 consisting of GH-2 and ALT was postulated (Miura et al. 1991.) These isolates, however, were biologically distinguishable from each other by its replication capacity in a monocyte line, U937, in which GH-2 could not grow but ALT grew well. In addition, the nucleotide sequence of the LTR of this new isolate displays 21% divergence from that of prototype HIV-2[GH-1], but the core enhancer, Sp1 binding sites and TATA box were conserved. Although the 3' half of the env gene sequence which is deleted in HIV-2ALT clone showed 27% diversity from the prototype, functional differences in the rev-responsive element were not observed.     

Distribution and co-existence of Met-enkephalin-like and mesotocin-like immunoreactivity in the neural lobe of the pituitary of the frog

Content and distribution of Met-enkephalin (Met-ENK)-like immunoreactivity in the hypothalamo-hypophysial system of bovine, rat and frog were examined using specific radioimmunoassay and immunohistochemistry. Ultrastructural localization and co-existence of Met-ENK-, mesotocin (MT)- and vasotocin (VT)-like immunoreactivity in the neural lobe of the frog pituitary was examined by a method combining pre-embedding peroxidase-antiperoxidase immunostaining for Met-ENK with post-embedding immunocolloidal gold staining for MT or VT. The highest concentrations of immunoassayable Met-ENK were present in the neural lobe of the pituitary of the frog. In addition to nerve fibers showing only MT-like or Met-ENK-like immunoreactivity, nerve fibers containing neurosecretory granules showing both MT- and Met-ENK-like immunoreactivities were very rich. But VT-like and Met-ENK-like immunoreactivity was confirmed separately in different axon terminals.     

An autopsy case of acquired immune deficiency syndrome (AIDS) with preceding aplastic anemia

A case of acquired immunodeficiency syndrome (AIDS) with preceding aplastic anemia is reported. The patient was a 36 year old female who had been diagnosed as having aplastic anemia 10 years before and thereafter had received multiple transfusions. Human immunodeficiency virus (HIV)-seropositivity was revealed 10 months prior to her death, but no particular clinical signs indicating HIV infection, pre-AIDS or onset of AIDS were recognized before serological diagnosis, although the slow progression of leukopenia was noted along with thrombocytopenia. Her general condition deteriorated during the last 10 months accompanied by an acute decrease In the CD4/CD8 ratio. Autopsy revealed full-blown AIDS: systemic aspergillosis, progressive multifocal leukoencephalopathy, Epstein-Barr virus-related B cell lymphoma arising in the diaphragm and severe lymphocyte depletion in the lymph nodes and spleen. Markedly hypo-plastic bone marrow was considered to be primarily attributable to the aplastic anemia but the affection of AIDS was not excluded. The possible transmission route of HIV and the effect of the preceding aplastic anemia on the infection and clinical course of AIDS are discussed.     

Polymorphous low-grade adenocarcinoma of submandibular gland origin

A case of polymorphous low-grade adenocarcinoma (PLGA) in the submandibular gland is reported. A 72 year old woman presented with a 5 year history of a gradually expanding tumor in the submandibular region. The surgical specimen revealed a relatively well demarcated tumor, 35 × 35 × 20 mm in size. Macroscopically, necrosis and hemorrhage were not seen in the solid tumor. Histologically, the tumor growth pattern was variable, composed of tubular, papillary, solid, trabecular and cribriform structures. Immunohistochemically, some tumor cells were positive for epithelial membrane antigen (EMA), S-100 protein, keratin, and carcino-embryonic antigen (CEA). Electron microscopically, prominent microvilli projected into the luminal spaces, and basal lamina and hemidesmosomes were seen in the tumor cells adjacent to the connective tissues. The submandibular gland is an extremely rare location for PLGA. To the authors' knowledge, this is the first case of its kind reported in the English literature.     

CD27/CD70 interaction directly drives B cell IgG and IgM synthesis

CD27 is a T cell activation antigen expressed on a majority of peripheral blood T cells. CD27 is also expressed on a subpopulation of human B cells, and it is reported that CD27⁺ B cells secrete both IgG and IgM. CD70, a ligand for CD27, is expressed on activated T and B cells, suggesting an interaction between T and B cells via CD27/CD70 ligation. Here, we analyze B cell immunoglobulin synthesis using a CD70 transfectant and present functional data showing that B cells secrete large amounts of IgG and IgM as a result of the CD27/CD70 interaction. A flow cytometric analysis showed that CD27 expression was increased and CD70 was expressed on tonsillar and peripheral blood B cells after activation with Staphylococcus aureus Cowan strain (SAC) plus interleukin (IL-2). In addition, the proliferation of B cells was enhanced mildly by the addition of CD70 transfectant, and its proliferation was blocked by anti-CD70 mAb. More importantly, the CD70 transfectant enhanced IgG and IgM production by purified B cells greatly in the presence of SAC plus IL-2. The enhancement was completely blocked by the addition of either anti-CD70 mAb or anti-CD27 mAb. Strongly suggesting that the interaction of CD27 with its ligand, CD70, on B cells plays an important role in B cell growth and differentiation to produce IgG and IgM.     

Association of genetic variation of the RIL gene,encoding a PDZ-LIM domain protein and localized in 5q31.1, with low bone mineral density in adult Japanese women

Twin and family studies had shown that genetic factors are important determinants of bone mass. Multiple genes might be involved. One candidate gene, the reversion-induced LIM gene (RIL), is a PDZ and LIM-domain-containing protein and has been localized within the cytokine cluster of chromosome 5 (5q31.1). In a genetic study of 370 adult Japanese women, we investigated the correlation between radial bone mineral density (BMD) and a genetic variation (−3333T→C) of the 5'-flanking region of RIL gene. A significant association was identified between the RIL variation −3333T→C and radial BMD (r=0.15, P=0.003). The variation of the RIL locus may be an important determinant of osteoporosis.     

Immunoelectron microscopic localization of carcinoembryonic antigen in gastric adenocarcinoma cell lines

The distribution of carcinoembryonic antigen (CEA) in human gastric adenocarcinoma cell lines (HPE-GAC-3 cells and HPE-GAC-2 cells) was determined immunohistochemically by indirect peroxidase-labeled antibody method at the light and electron microscopic levels. In GAC-3 cells that proliferated as non-adherent single cells, CEA was located in the perinuclear spaces, the endoplasmic reticulum, Golgi apparatus, vesicles, multivesicular body (MVB) and entire plasma membrane. Membrane CEA was shown to be internalized into MVB in GAC-3 cells. In GAC-2 cells that form an acinus, CEA was predominantly present along the microvilli of the lumina) surface and in glycocalyceal bodies, the vesicles which bud from the microvilli into the lumen. These results suggest that in poorly differentiated cancer cells CEA is transported over the entire cell surface, retained on the membrane and accumulated Into the cell by way of the MVB, but in well differentiated cancer cells the newly synthesized CEA is rapidly and predominantly transported to the luminal surface and rapidly released from the membrane into the lumen by way of the glycocalyceal body.     

Possible role of autoantibodies against nephrin in an experimental model of chronic graft-versus-host disease

Nephrin, a product of the NPHS1 gene, is a component of the slit diaphragms that are found between glomerular foot processes and is a crucial element for glomerular filtration barrier. Recently, nephrin has been focused in a number of studies of proteinuria development including various types of acquired glomerular diseases including minimal change nephrotic syndrome and membranous nephropathy. However, the precise role of nephrin in such acquired glomerular diseases is still unknown. To analyse the role of nephrin further, two kinds of anti-nephrin antibodies were raised in the rabbits and applied to an experimental mouse model of chronic graft-versus-host disease, in which (C57BL/10 x DBA/2) F1 mice developed clinically apparent severe proteinuria with significant glomerular lesions 7 weeks after parental DBA/2 cell transfer. Antibody-sandwich ELISA detected anti-nephrin antibodies during week 2 to week 6, with the peak at week 2 or week 4. Colocalization of nephrin and IgG on week 4, week 6, and week 8 was revealed by confocal microscopic analysis, suggesting that in situ immune complex formation with nephrin in glomerular lesion. Taken together, it seems to be suggested nephrin and its autoantibody have a certain role in the development of glomerular lesion in our model mice.     

Effects of food deprivation and high fat diet on opioid receptor binding in rat brain

The effect of food deprivation for 72 h or a high fat diet on [3H]naloxone binding in the discrete brain regions of male lean Zucker rats was studied. In the midbrain, both treatments increased Bmax for the high-affinity site with no change in Kd. In the cortex, the high fat diet increased Bmax for the high-affinity site. These results suggest that dietary manipulations could produce significant changes in the endogenous opioid system.