Cyclic GMP-dependent protein kinase II plays a critical role in C-type natriuretic peptide-mediated endochondral ossification

Longitudinal bone growth is determined by endochondral ossification at the growth plate, which is located at both ends of long bones and vertebrae, and involves many systemic hormones and local regulators. C-type natriuretic peptide (CNP), a third member of the natriuretic peptide family, occurs at the growth plate and acts locally as a positive regulator of endochondral ossification through the intracellular accumulation of cyclic GMP (cGMP). The increase in cGMP concentrations is known to activate different signaling mediators, such as cyclic nucleotide phosphodiesterases, cGMP-regulated ion channels, and cGMP-dependent protein kinases (cGKs). The type II cGK (cGKII)-deficient mice (Prkg2(-/-) mice) develop dwarfism as a result of impaired endochondral ossification, suggesting that cGKII is important for the CNP-mediated endochondral ossification. However, given that Prkg2(-/-) mice differ from CNP-deficient mice (Nppc(-/-) mice) in the growth plate histology, which downstream mediator(s) of cGMP play key roles in the process is still an enigma. Here we show that targeted expression of CNP in the growth plate chondrocytes fails to rescue the skeletal defect of Prkg2(-/-) mice. Using cultured fetal mouse tibias, an in vitro model system of endochondral ossification, we also demonstrated that CNP cannot increase the longitudinal bone growth, and chondrocytic proliferation and hypertrophy, and cartilage matrix synthesis in Prkg2(-/-) mice. This study provides in vivo and in vitro genetic evidence that cGKII plays a critical role in CNP-mediated endochondral ossification.     

Effects of Inflammatory Cytokines Induced by Helicobacter pylori Infection on Aminopyrine Accumulation in Parietal Cells Isolated from Guinea Pigs

The effects of inflammatory cytokines induced byHelicobacter pylori infection on acid secretion have notbeen well defined. The purpose of this study was toinvestigate the direct effects of these cytokines on parietal cells isolated from guinea pigs. Weexamined the effects of human recombinant IL-1(0.05-100 ng/ml), IL-8 (2-256 ng/ml), and TNF-(0.625- 80 ng/ml) on acid secretion stimulated by three secretagogues (10^-4 M histamine,10^-4 M carbachol, and 10^-5 Mtetragastrin) and on basal acid secretion from isolatedparietal cells, which was measured by the aminopyrineaccumulation method. None of three cytokines showed any significant effects onstimulated or basal acid secretion from isolated guineapig parietal cells. We concluded that inflammatorycytokines induced by Helicobacter pylori infection may affect acid secretion through mechanismsother than direct actions on parietal cells.     

Decreased expression of intestinal chemokine TECK/CCL25 in experimental obstructive jaundice and its reversal following internal biliary drainage

BACKGROUND: Although bacterial translocation is a significant problem in patients with obstructive jaundice, how translocation is promoted in this situation is not clearly understood. We previously reported the recovery of gut mucosal T-lymphocyte numbers in jaundiced rats following internal biliary drainage. This suggests that bile in the intestinal lumen promotes T-lymphocyte redistribution into the gut mucosa. To test this hypothesis, we have examined the expression patterns of chemokines that play an important role in lymphocyte recruitment into the small intestine. METHODS: Four groups of rats receiving one of the following surgical procedures were studied: a sham operation (SHAM), common bile duct ligation (CBDL), CBDL followed by external drainage, or CBDL followed by internal drainage. Expression levels of intestinal mRNAs encoding TECK, MECK, and LARC chemokines were assessed using real-time polymerase chain reaction. Distribution of chemokine mRNA in the rat ileum was examined using in situ hybridization (ISH). RESULTS: Following surgery, the expression levels of TECK mRNA decreased significantly in the CBDL group compared with in the SHAM group. While TECK expression did not recover after external drainage, it recovered to a near-normal level after internal drainage. Expression levels of MECK and LARC mRNAs were similar among all groups. ISH confirmed strong expression of TECK mRNA in the epithelial cells of the small intestine. CONCLUSIONS: These results indicate that bile may contribute to high expression levels of TECK/CCL25 mRNA in the small intestine. Bile may also have a role in regulating the distribution of gut mucosal T lymphocytes by promoting TECK production from epithelial cells.     

Clinical features of adult acute leukemia with 11q23 abnormalities in Japan: a co-operative multicenter study

To clarify the clinical features of adult patients with acute leukemia (AL) with 11q23 abnormalities, we performed a retrospective analysis of data from 58 adult Japanese patients: 51 with acute myeloid leukemia (AML), and 7 with acute lymphoblastic leukemia (ALL). The incidences according to fusion partners in AML were: t(9;11), 31.3%; t(11;19), 27.4%; t(6;11), 21.5%. The incidence of patients with t(11;19) was higher than those in the US and Europe, and the incidence of t(4;11) was lower than that in childhood. The results indicated the poor prognosis of AML with 11q23 abnormalities regardless of the fusion partners. AML patients with 11q23 aged <60 years in the first CR who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) showed a more favorable outcome than those treated without allo-HSCT, although the differences were not statistically significant (P = 0.322 for DFS, P = 0.138 for OS). This result suggests that treatment strategies including allo-HSCT may be considered in the first CR in cases of AML with 11q23 abnormalities. However, further studies involving a large number of cases are required to assess the effect of allo-HSCT on adult AL with 11q23 abnormalities.     

Interleukin-1beta causes acute lung injury via alphavbeta5 and alphavbeta6 integrin-dependent mechanisms

Interleukin (IL)-1beta has previously been shown to be among the most biologically active cytokines in the lungs of patients with acute lung injury (ALI). Furthermore, there is experimental evidence that lung vascular permeability increases after short-term exposure to IL-1 protein, although the exact mechanism is unknown. Therefore, the objective of this study was to determine the mechanisms of IL-1beta-mediated increase in lung vascular permeability and pulmonary edema following transient overexpression of this cytokine in the lungs by adenoviral gene transfer. Lung vascular permeability increased with intrapulmonary IL-1beta production with a maximal effect 7 days after instillation of the adenovirus. Furthermore, inhibition of the alphavbeta6 integrin and/or transforming growth factor-beta attenuated the IL-1beta-induced ALI. The results of in vitro studies indicated that IL-1beta caused the activation of transforming growth factor-beta via RhoA/alphavbeta6 integrin-dependent mechanisms and the inhibition of the alphavbeta6 integrin and/or transforming growth factor-beta signaling completely blocked the IL-1beta-mediated protein permeability across alveolar epithelial cell monolayers. In addition, IL-1beta increased protein permeability across lung endothelial cell monolayers via RhoA- and alphavbeta5 integrin-dependent mechanisms. The final series of in vivo experiments demonstrated that pretreatment with blocking antibodies to both the alphavbeta5 and alphavbeta6 integrins had an additive protective effect against IL-1beta-induced ALI. In summary, these results demonstrate a critical role for the alphavbeta5/beta6 integrins in mediating the IL-1beta-induced ALI and indicate that these integrins could be a potentially attractive therapeutic target in ALI.     

IgA-lambda/IgG-kappa biclonal myeloma in which two clones proliferated in individual sites

A 72-year-old man was admitted to our hospital because of lumbago and numbness of legs. Tumor invasion at the fourth lumbar vertebra was revealed. Immunohistochemistry using specific antibodies against each heavy and light chain of immunoglobulin revealed that the myeloma cells in bone marrow were all IgA-lambda type whereas they were all positive for IgG-kappa type in a tumor of the fourth lumbar vertebra. These data indicate that the patient had IgG-kappa/IgA-lambda biclonal myeloma. Different phenotypes of M-proteins and distinct proliferating sites for two clones suggest that they may have resulted from two independent transforming events.     

Rabeprazole treatment attenuated Helicobacter pylori-associated gastric mucosal lesion formation in Mongolian gerbils

BACKGROUND AND AIM: Although rabeprazole (RPZ), a proton pump inhibitor, has been reported to have a bactericidal effect on Helicobacter pylori (H. pylori), no studies have been conducted regarding the effect of RPZ on gastric mucosal lesion formation caused by this bacterium. In the present study, we investigated the effect of RPZ on H. pylori-associated gastric mucosal lesion formation. METHODS: Sixty-two male Mongolian gerbils were inoculated with H. pylori (ATCC43504) (Hp group) and 60 gerbils with the culture media alone (control group). Some gerbils in the Hp group and in the control group were injected with RPZ (1 mg/kg/day, for 7 days) at the 5th week. Gerbils were evaluated at the 12th, 24th and 48th weeks. RESULTS: In the Hp group, all gerbils were persistently infected for 24 weeks, but 36% became negative for H. pylori at the 48th week. In the Hp + RPZ group, 18% of gerbils at the 12th week, 40% at the 24th week, and 80% at the 48th week, became negative for H. pylori. The level of neutrophil infiltration was significantly decreased in the Hp + RPZ group in comparison to the Hp group, possibly through the effects of RPZ on initial bacterial colonization and resultant inflammation. Even in the gerbils that became H. pylori-negative, the level of neutrophil infiltration was lower in the Hp + RPZ group than in the Hp group. RPZ treatment significantly increased the level of the reduced form of glutathione (GSH) at the 48th week. The elevated levels of the reduced form of GSH may have been reduced by an antioxidation process in the H. pylori-positive Hp + RPZ group. CONCLUSION: Administration of RPZ not only inhibited gastric H. pylori colonization, but also reduced gastric mucosal inflammation in gerbils, possibly through its antibacterial action as well as pharmacological recruitment of the reduced form of GSH.     

Carcinoma of the Ampulla of Vater: Expression of Cancer-Associated Antigens Inversely Correlated with Prognosis

To obtain some useful pathologic indicators for predicting the prognosis in carcinomas of the ampulla of Vater, we analyzed 24 surgically resected ampullary carcinomas pathologically with immunohistochemistry of cancer-associated antigens. Pancreatic invasion, lymph node metastasis, and histology of the tumor were significantly correlated with poor prognosis (p less than 0.01), but the size or ulceration of the tumor did not significantly affect the prognosis (p less than 0.05). Immunohistochemically, diffuse positivity for anti-CA19-9 monoclonal antibody was demonstrated in 10 carcinomas and that for anti-carcinoembryonic antigen (CEA), in 10. Eight of them showed synchronously diffuse immunoreactivities for both antigens. Although there was no significant correlation between diffuse positivity for CA19-9 and pathologic factors, CA19-9-positive cases exhibited significantly poor prognoses (p less than 0.01). Diffuse positivity for CEA was correlated with pancreatic invasion (p less than 0.05) and poor prognosis (p less than 0.05). Immunohistochemical study of cancer-associated antigens may disclose some malignant potential of ampullary carcinoma other than that expressed in the morphology. Furthermore, because of the consistency of staining results, immunohistochemistry of cancer-associated antigens may also be useful in predicting preoperatively the prognosis of ampullary carcinoma in biopsied materials.