Blepharophimosis sequence and de novo balanced autosomal translocation [46, XY,t(3;4)(q23;p15.2)]: Possible assignment of the trait to 3q23

We report on a boy with the blepharophimosis sequence and de novo, apparently balanced reciprocal translocation between 3q23 and 4p15.2 [46, XY,t(3;4)(q23;p15.2)de novo]. Possible assignment of this autosomal dominant disorder is discussed. A 3q23 band is a more preferable gene locus of the blepharophi mosis sequence, based on the comparison of clinical manifestations between 4p- and 3q-syndromes.     

Hydrogen peroxide augments eosinophil adhesion via beta2 integrin

During eosinophil (EOS) accumulation at sites of allergic inflammation, an initial step is the binding of EOS to adhesion molecules expressed on vascular endothelial cells (EC). We have previously observed that adhesion of peripheral blood EOS to recombinant human vascular cell adhesion molecule-1 (rh-VCAM-1) stimulates the respiratory burst of EOS. Although the biological consequence of this activation remains to be elucidated, reactive oxygen species such as hydrogen peroxide (H2O2) may modify the adhesive property of EOS. In the present study, we examined whether H2O2 modifies the adhesive property of EOS. EOS were isolated from the peripheral blood of healthy subjects. Adhesion of the EOS to paraformaldehyde-fixed human umbilical vein EC (HUVEC), stimulated or not stimulated with tumour necrosis factor-alpha (TNF-alpha; 100 pM for 24 hr), was examined in the presence or absence of H2O2. H2O2 significantly enhanced adhesion of EOS to both resting and TNF-alpha-stimulated fixed HUVEC (P < 0.01, respectively). Such enhancing effects were inhibited by anti-beta2 integrin antibody or anti-CD11b antibody, but not by anti-CD11a or anti-alpha4 integrin antibody. H2O2 also enhanced EOS adhesion to rh-intracellular cell adhesion molecule-1 (ICAM-1) but not to rh-VCAM-1. Finally, H2O2 enhanced the expression of both CD11b and CD18 on EOS. These results indicate that H2O2 directly augments the adhesive property of EOS through beta2 integrin.     

Colchicine-induced Inhibition of Fat Globule Development in Hepatocytes of Rats Injected with Ethionine

To examine the effect of colchicine on ethionine induced fatty liver, adult female rats were starved overnight and then injected i.p. with 1 g kg ethionine at 11th hour of fasting; then a half of the rats were also injected i.p. with 2.5 mg kg colchicine twice at 3 and 6 h after the single administration of ethionine. Similarly, fasted control rats were injected i.p. with vehicle alone at the above times. All of the rats were sacrificed after a 20 h fast, and the hepatocytes in periportal areas were observed ultra-structurally. In addition, total lipids in the liver tissue were extracted and determined biochemically. Although similar significant increases of triglyceride were observed in the liver tissue of all ethionine-injected rats, the hapatocytes in the group treated with both chemicals had fewer cytoplasmic fat globules (CFG) than those in the group treated with ethionine only. On the other hand, the diameters of markedly increased membrane-bound lipid particles (MLP) in the double treated group were distributed mainly in the range 0.2–0.4 μm, compared with those (0.1-0.2 μm) in the other groups. These findings indicate that colchicine inhibits the development of CFG in ethionine injured hapatocytes. Acta Pathol Jpn 39: 281∼288, 1989.     

Primrose syndrome associated with unclassified immunodeficiency and a novel ZBTB20 mutation

Primrose syndrome is a congenital malformation syndrome characterized by intellectual disability, developmental delay, progressive muscle wasting, and ear lobe calcification. Mutations in the ZBTB20 gene have been established as being accountable for this syndrome. In this study, a novel de novo ZBTB20 mutation, NM_001164342.2:c.1945C>T (p.Leu649Phe), has been identified through whole exome sequencing (WES) in a female patient presenting a typical Primrose phenotype. Because the present patient exhibited recurrent otitis media, detailed immunological examinations were performed in this study and subnormal immunoglobulin levels were firstly identified in a Primrose patient. Anatomical anomaly of the inner ear has never been reported in this patient and WES data did not include any relevant variants causally linked with the immunologic defect. Thus, there is a possibility of a relation between an unclassified immunodeficiency with selective IgG2 deficiency and Primrose syndrome and this may be the reason of recurrent otitis media frequently observed in Primrose patients. Because subnormal levels of IgG2 in this patient might be caused by an unrelated and still uncharacterized genetic cause, further studies are required to prove the causal link between aberrant ZBTB20 function and immunodeficiency.     

Glomerular expression of cell-cycle-regulatory proteins in human crescentic glomerulonephritis

To elucidate the mechanism underlying crescentic formation, we assessed the phenotypic characterization and cell-cycle protein expression in human crescentic glomerulonephritis (CRGN). Kidney tissue specimens taken from CRGN patients (10 patients with pauci-immune type rapidly progressive glomerulonephritis (RPGN), 2 patients with Henoch-Schönlein purpura nephritis, and 1 patient with IgA nephropathy) were examined immunohistochemically. Most of the cellular components of the crescents expressed cytokeratin, whereas few cells expressed PHM-5. CD68-positive cells were minor components of cellular crescents, indicating that the major principal cellular component of the crescents is made up of cells with the parietal glomerular epithelial cell (PEC) phenotype. Additionally, serial section analysis revealed that Ki-67-positive cells in the crescents were frequently cyclin-A positive and Bcl-2 positive, but seldom cyclin-B₁ positive. Moreover, the expression of cyclin-dependent kinase inhibitor p27^Kip1 was low in the cellular crescents, despite being exclusively positive in podocytes within the same section. We concluded that the major component of the cellular crescents is made up of PECs and that apparent expression of cyclins and Bcl-2 and restrained expression of p27^Kip1 may be synergistically associated with the development of cellular crescents in human CRGN.     

Induction of Thymus-Derived γδ T Cells by Escherichia coli Enterotoxin B Subunit in Peritoneal Cavities of Mice

We examined the activation of intraperitoneal T cells in BALB/c mice by the Escherichia coli enterotoxin B subunit, which induced a specific Th2 type of T-cell response to intraperitoneally coadministered bovine immunoglobulin G. The numbers of both γδ and αβ T cells increased significantly after intraperitoneal administration of the B subunit in a time-dependent manner; these numbers were not affected by the B-subunit G33D mutant, which is defective in GM₁ ganglioside-binding ability. Early after administration a small number of γδ T cells produced either interleukin-4 (IL-4) or gamma interferon, while late after administration primarily IL-10-producing γδ T cells were detected. γδ T cells induced by the B subunit did not express a characteristic V gene over the time course of the study. The induction of γδ T cells did not occur in athymic nu/nu mice but could be induced upon transplantation of fetal AKR thymus-like αβ T cells. γδ T cells in athymic nu/nu mice with a fetal thymic graft predominantly expressed the donor Thy-1.1 antigen but not the host Thy-1.2 antigen. The induction of these T cells, however, could not be restored by coadministration of the B subunit with peritoneal cells from normal mice. These results suggest that the B subunit activates intraperitoneal γδ and αβ T cells in a manner dependent upon its ability to bind to GM₁ ganglioside. γδ T cells induced by the B subunit are Th2-type cells derived from the thymus. These γδ T cells may be functionally involved in specific Th2 responses to the B subunit, which possibly acts as an adjuvant through the influence of αβ T cells.     

Cell Cycle Regulation and Differentiation in the Human Podocyte Lineage

Mature podocytes are regarded as growth-arrested cells with characteristic phenotypic features that underlie their function. To determine the relationship between cell cycle regulation and differentiation, the spatiotemporal expression of cyclin A, cyclin B1, cyclin D1, the cyclin-dependent kinase inhibitors (CKIs) p27 and p57, and markers of differentiating podocytes in developing human kidneys was investigated by immunohistochemistry. In S-shaped body stage, Ki-67, a cell proliferation marker that labels the G1/S/G2/M phase, was expressed in the majority (more than 80%) of presumptive podocytes, along with cyclin A (~20% of the Ki-67-positive cells) and cyclin B1 (less than 5% of Ki-67-positive cells) expression. Among these cells, cyclin D1 and CKIs were markedly down-regulated. At the capillary-loop stage, by contrast, CKIs and cyclin D1 were intensely positive in podocytes, whereas no Ki-67, cyclin B1, or cyclin A expression was seen. Moreover, double-immunolabeling and serial-section analysis provided evidence that CKIs and markers specific for differentiating podocytes, namely PHM-5 (podocalyxin-like protein in humans), synaptopodin (a foot process-related protein), and C3b receptor, were co-expressed at the capillary-loop stage. Podocytes were the only cells within the glomeruli that expressed CKIs at immunohistochemically detectable levels. Furthermore, bcl-2 (an apoptosis inhibitory protein) showed a reciprocal expression pattern to that of CKI. These results suggest that 1) the cell cycle of podocytes is regulated by cyclin and CKIs, 2) CKIs may act to arrest the cell cycle in podocytes at the capillary-loop stage, and 3) the specific cell cycle system in podocytes may be closely correlated with their terminal differentiation in humans.