Hypoxia and Cold Stress on Pulmonary Venous Obstruction

Hemodynamic changes induced by hypoxia and cold stress were examined on the model of pulmonary venous obstruction (PVO) to investigate the mechanism of pulmonary hypertensive crisis. Bilateral pulmonary venous stenosis was surgically created in 7 newborn piglets of the PVO group. Sham operations were performed on 6 piglets of the control group. Following the baseline hemodynamic measurement (FiO₂= 0.3) at 8 weeks after the operation, the piglets were exposed to hypoxia (FiO₂= 0.14) for 10 minutes, and were also exposed to cold stress for 20 minutes. Hypoxia significantly increased mean pulmonary arterial pressure in the PVO group. Hypoxia increased not only pulmonary arterial resistance, but also pulmonary venous resistance in the PVO group. Cold stress did not change pulmonary arterial resistance or pulmonary venous resistance in each group. In the lungs of the PVO group, the medial muscular layer of the pulmonary arteries and pulmonary veins were thickened. This probably accelerates hypoxia-induced vasoconstriction, which in turn increases pulmonary arterial and venous resistances.     

Inhibition of tumor invasion and extracellular matrix degradation by ubenimex (bestatin)

We have investigated the effect of the immunomodulator ubenimex (hereafter referred to as bestatin) on the enzymatic degradation of the extracellular matrix by human renal cell carcinoma SN12M cells during the invasive process. The invasion of SN12M cells into reconstituted basement membrane (Matrigel) was inhibited by the presence of bestatin in a concentration-dependent manner. However, bestatin did not have any effect on tumor cell adhesion and migration to the extracellular matrices which may be involved in tumor cell invasion. Bestatin inhibited the degradation of type IV collagen by tumor cells, but not by tumor-conditioned medium (TCM), in a concentration-dependent manner. We also found that bestatin inhibited hydrolysing activities towards substrates of aminopeptidases in SN12M cells. Since bestatin was found to inhibit aminopeptidase activity, the inhibition of tumor invasion by bestatin is likely to be associated with its action as an enzyme inhibitor. Bestatin only slightly inhibited tumor cell plasmin activity, which can lead to the conversion of the latent collagenase to the active form, but this slight effect was not significant. The zymography of TCM from SN12M cells showed that the treatment of tumor cells with bestatin resulted in the disappearance of the 68 kDa type IV collagenase-enzyme level (active form) and slight reduction of the 72 kDa type IV collagenase-enzyme level (latent form). These results indicated that bestatin may inhibit tumor cell invasion through a mechanism involving its inhibitory action on aminopeptidases in tumor cells, suggesting that the aminopeptidase may partly be associated with the conversion of a latent form of type IV procollagenase to an active form or the secretion of the collagenases from tumor cells.     

Age-related changes of the function of T cell subsets: predominant defect of the proliferative response in CD8 positive T cell subset in aged persons

The proportion of CD8 positive cells in the peripheral blood AET-rosette forming T cells from aged persons was significantly reduced than that from young persons. The difference in the proportion between aged and young groups became more significant after proliferative response to a mitogen phytohemagglutinin (PHA) or a specific antigen tuberculin active peptide (TAP). The purified macrophage-deprived T cells (Twp), CD4 (T4) positive cells or CD8 positive cells were prepared from aged or young persons. These cell preparations lost proliferative response to PHA or TAP but showed marked proliferative response to the combined stimulation to 1 microM of ionomycin and 1 nM of phorbol-12-myristate-13-acetate (PMA) at usual culture cell density (2.5 X 10(5)/ml). Proliferative responses of these cell preparations to the combined stimulation were significantly reduced in the aged than those in the young and the magnitude of the difference in the proliferative responses between aged and young groups was more pronounced in CD8 positive cell population than in CD4 positive cell population. Although the cell preparations were relatively independent of exogenous IL-2 for the proliferative response to the combined stimulation of ionomycin and PMA at usual culture cell density, they needed exogenous IL-2 for sustained proliferation at lower culture cell density (5 X 10(3)/ml). These IL-2-dependent proliferative responses to the combined stimulation in the aged were significantly lower than those in the young and again the difference in the proliferative magnitude between aged and young groups was greater in CD8 positive population. The mechanism(s) of age-related change of the proportion and proliferative ability of T subsets were discussed.     

Age-associated changes in proliferative and differentiative response of human B cells and production of T cell-derived factors regulating B cell functions

The abilities of highly purified B cells to repeat replication for clonal expansion and to differentiate into immunoglobulin secreting cells (ISC) were examined in the aged and young groups. B cells from the aged showed twofold less proliferative response to B cell mitogen Cowan 1 (SAC) than those from the young. The original clone size of SAC responding B cells determined by colchicine block and [3H] thymidine [( 3H] TdR) uptake was not significantly reduced in the aged whereas the ability to repeat replication to expand clonal size was significantly reduced. B cells from aged and young persons were induced into ISC by combined stimulation with SAC and partially purified B cell differentiation factor (BCDF) free of IL-2 activity. ISCs for IgG and IgA were rather increased or at least not reduced in number in the aged as compared with those in the young. We also determined the IL-2 and BCDF activity produced by T cells from aged and young persons. Upon PHA stimulation, the aged T cells produced tenfold less IL-2 activity and threefold higher BCDF activity than did young T cells. Approximately threefold increase in spontaneous secretion of BCDF activity by aged T cells was found as compared with young T cells. The inverse correlation between the IL-2 activity and BCDF activity was found when both activities were determined in the same samples.     

An Immunohistochemical Study

C cell proliferation of the thyroid, which was designated as primary C cell hyperplasia (PCCH), was demonstrated in aged Fischer 344 rats in high incidence using the immunohistochemical method for calcitonin. It developed from mild to severe PCCH and resulted in nodular PCCH and tumor formation. The combined incidence of PCCH and nodular PCCH was increased with age and appeared in 60.7% of 7–15 month old group and 92.7% of 16–24 month old group possibly as a preneoplastic C cell lesion. It is almost an equivalent C cell lesion reported in the human thyroid with familial C cell carcinoma and therefore this Fischer 344 rat can provide a useful animal model to study familial C cell tumor of the thyroid.     

TAK1 Expression in the Cochlea: A Specific Marker for Adult Supporting Cells

Transforming growth factor-β-activated kinase-1 (TAK1) is a mitogen activated protein kinase kinase kinase that is involved in diverse biological roles across species. Functioning downstream of TGF-β and BMP signaling, TAK1 mediates the activation of the c-Jun N-terminal kinase signaling pathway, serves as the target of pro-inflammatory cytokines, such as TNF-α, mediates NF-κβ activation, and plays a role in Wnt/Fz signaling in mesenchymal stem cells. Expression of TAK1 in the cochlea has not been defined. Data mining of previously published murine cochlear gene expression databases indicated that TAK1, along with TAK1 interacting proteins 1 (TAB1), and 2 (TAB2), is expressed in the developing and adult cochlea. The expression of TAK1 in the developing cochlea was confirmed using RT-PCR and immunohistochemistry. Immunolabeling of TAK1 in embryonic, neonatal, and mature cochleas via DAB chromogenic and fluorescent immunohistochemistry indicated that TAK1 is broadly expressed in both the developing otocyst and periotic mesenchyme at E12.5 but becomes more restricted to specific types of supporting cells as the organ of Corti matures. By P1, TAK1 immunolabeling is found in cells of the stria vascularis, hair cells, supporting cells, and Kölliker’s organ. By P16, TAK1 labeling is limited to cochlear supporting cells. In the adult cochlea, TAK1 immunostaining is only present in the cytoplasm of Deiters’ cells, pillar cells, inner phalangeal cells, and inner border cells, with no expression in any other cochlear cell types. While the role of TAK1 in the inner ear is unclear, TAK1 expression may be used as a novel marker for specific sub-populations of supporting cells.     

IgG4‐related disease of the paratestis with the scrotal fluid: A case report

IgG4‐related disease (IgG4‐RD) can affect various organs, and the pancreas and salivary gland are representative examples. We report a rare case of IgG4‐RD of the paratestis. A 74‐year‐old man presented with left scrotal swelling. Scrotopuncture drainage and cytology confirmed a clear, yellow retention liquid (130 mL) with many small, similar lymphocytes and a few plasmacytes. Many lymphoid cells were immunopositive for CD3 on a cell block section, indicating that a predominant type of lymphoid cells was T cell. There were also some CD20 immunopositive cells and a few IgG4 immunopositive cells. Two months later the left scrotal swelling had returned, and he underwent radical inguinal orchiectomy. Microscopically, there was considerable lymphoplasmacytic inflammatory infiltration, fibrosis and abundant IgG4 immunopositive cells in the paratesticular region. The histopathologic and immunohistochemistry findings were consistent with IgG4‐RD. However, the abundant T cells in the scrotal fluid complicated the cytological diagnosis in our case.     

Adhesion polypeptides are useful for the prevention of peritoneal dissemination of gastric cancer

We examined the effect of adhesion polypeptides on the adhesion and invasiveness of gastric cancer cell lines. We previously reported the establishment of an extensively peritoneal-seeding cell line, OCUM-2MD3, from a poorly seeding human scirrhous gastric carcinoma cell line, OCUM-2M. Both 21 and 31 integrin expression was markedly increased on OCUM-2MD3 cells compared with OCUM-2M cells, and the ability of OCUM-2MD3 cells to bind to the extracellular matrix (ECM) was also significantly higher than that of OCUM-2M cells. The adhesion polypeptides, YIGSR and RGD, and two RGD derivatives significantly inhibited the adhesion of OCUM-2MD3 cells to the submesothelial ECM, while not inhibiting the adhesiveness of OCUM-2M cells and two well differentiated human gastric cell lines, MKN-28 and MKN-74. The YIGSR and RGD peptides also significantly inhibited the invasiveness of OCUM-2MD3 cells. The survival of nude mice with peritoneal dissemination given YIGSR sequenc e intraperitoneally was obviously longer than that of untreated mice. The survival of mice treated with RGD was also improved, and this effect was increased using the RGD derivatives, poly(CEMA-RGDS) and CM-chitin RGDS. These polypeptides appear to block the binding of integrins, which are expressed on OCUM-2MD3 cells, to the submesothelial ECM, and consequently inhibit peritoneal implantation. The peritoneal injection of adhe-sion polypeptides may be a new therapy against the dissemination of scirrhous gastric cancer, and may be useful for the prevention of dissemination in high-risk patients. © Rapid Science Ltd.