Role for connexin 26 in metastasis of human malignant melanoma: communication between melanoma and endothelial cells via connexin 26

BACKGROUND: Connexins form the intercellular channels of the gap junction and play an integral part in a variety of biological functions, such as maintaining tissue homeostasis, cell growth control, and development. Previously it was demonstrated that the expression of connexin 26 (Cx26) can increase the metastatic potential of mouse melanoma cells. The objective of the study was to investigate the role Cx26 plays in the metastasis of human melanoma cells, focusing on the communication between melanoma cells and endothelial cells. METHODS: Immunostaining was used to examine Cx26 expression in the melanoma lesions and in the endothelial cells around the melanoma cell nests. In all, 33 melanomatous tissue samples from 16 patients were studied, as well as nevocellular nevus (NCN) and normal skin samples. Cx26 mRNA and protein expression was also examined in the cultured endothelial cells. A dye-transfer assay was performed to examine gap junction formation between melanoma cells and endothelial cells. RESULTS: Immunohistochemistry demonstrated that Cx26 was clearly expressed by the endothelial cells of the small vessels surrounding the melanoma cell nests as well as the melanoma cells. Cx26 mRNA and protein expression was detected in cultured endothelial cells. In a coculture system with human malignant melanoma cell line (HMY-1) and endothelial cells (HMVEC), immunohistochemistry indicated Cx26 expression in both types of cells and dye-transfer assay demonstrated dye-coupling from HMY-1 into HMVEC. CONCLUSIONS: Cx26 may contribute to the metastasis of melanoma by facilitating communication between melanoma cells and their surrounding endothelial cells.     

Specific Antibiotic Prophylaxis Based on Bile Cultures Is Required to Prevent Postoperative Infectious Complications in Pancreatoduodenectomy Patients Who Have Undergone Preoperative Biliary Drainage

Background Preoperative biliary drainage (PBD) is associated with bacterial contamination of bile, but the effects of PBD on morbidity after pancreatoduodenectomy remain controversial. The aim of this study was to characterize bile contamination to develop successful specific antibiotic prophylactic strategies for pancreatoduodenectomy. Methods Ninety-one consecutive patients who underwent pancreatoduodenectomy for periampullary tumor were prospectively evaluated. Prophylactic antibiotics were selected based on preoperative bile cultures. Bile cultures and postoperative complications were compared in 46 patients who underwent PBD (drainage group) versus 45 patients who did not (nondrainage group). Results The incidence of positive bile cultures was higher in the drainage group (78%) than in the nondrainage group (36%) (P < 0.001). In the drainage group, positive bile cultures were frequently polymicrobial (61%) and demonstrated resistance to several antibiotics, including cefazolin (83%), cefmetazole (72%), and cefpirome (64%). Overall morbidity (30% and 22%) and infectious morbidity (13% and 11%) did not differ significantly between the drainage and nondrainage groups, respectively. Conclusions PBD had a notable influence on bile microbial contamination, including a higher rate of antibiotic resistance. Therefore, specific antibiotic prophylaxis based on bile culture is required for preventing infectious complications in pancreatoduodenectomy patients who undergo PBD.     

Alpha 1-adrenoceptor agonists protect against stress-induced death of neural progenitor cells

Here, we show that alpha(1)-adrenoceptor agonists suppress stress-induced death of mouse embryonic brain-derived neural progenitor cells (NPCs). NPCs highly expressed both alpha(1A)- and alpha(1B)-adrenoceptor genes, whereas the gene encoding alpha(1D)-adrenoceptor was expressed at low levels. Application of the alpha(1)-adrenoceptor agonists phenylephrine and cirazoline significantly promoted cell survival of embryonic NPCs that had been exposed to stress, as measured by a lactate dehydrogenase release assay, but had no remarkable effect on differentiation of the NPCs. Both phenylephrine and cirazoline protected NPCs from death induced by growth factor deprivation, N2 nutrient deprivation, tunicamycin treatment or staurosporine treatment. Phenylephrine and cirazoline treatments both maximally reduced stress-induced cell death by approximately 60% but did not change the percentage of undifferentiated cells as measured by nestin staining. Moreover, phenylephrine and cirazoline treatments did not affect the cellular activities of caspase-3 and caspase-7 but markedly reduced propidium iodide penetration into the cytoplasm, suggesting that alpha(1)-adrenoceptor agonists inhibit caspase-3/7-independent death of the embryonic NPCs.     

YM-58483, a selective CRAC channel inhibitor, prevents antigen-induced airway eosinophilia and late phase asthmatic responses via Th2 cytokine inhibition in animal models

T cells play a regulatory role in the pathogenesis of various immune and allergic diseases, including human asthma. Recently, it was reported that a pyrazole derivative, YM-58483 (BTP2), potently inhibits Ca²⁺ release-activated Ca²⁺ (CRAC) channels and interleukin (IL)-2 production in T cells. We investigated the effects of YM-58483 on T helper type 2 (Th2) cytokine production in vitro and antigen-induced airway asthmatic responses in vivo. YM-58483 inhibited IL-4 and IL-5 production in a conalbumine-stimulated murine Th2 T cell clone (D10.G4.1), and IL-5 production in phytohemagglutinin-stimulated human whole blood cells with IC₅₀ values comparable to those reported for its CRAC channel inhibition (around 100 nM). YM-58483 inhibited antigen-induced eosinophil infiltration into airways, and decreased IL-4 and cysteinyl-leukotrienes content in inflammatory airways induced in actively sensitized Brown Norway rats. Furthermore, orally administered YM-58483 prevented antigen-induced late phase asthmatic broncoconstriction and eosinophil infiltration in actively sensitized guinea pigs. These data suggest that the inhibition of Ca²⁺ influx through CRAC channel leads to the prevention of antigen-induced airway inflammation, probably via the inhibition of Th2 cytokine production and inflammatory mediators release. YM-58483 may therefore be useful for treating airway inflammation in bronchial asthma.     

Byelyankacin: a novel melanogenesis inhibitor produced by Enterobacter sp. B20

A novel melanogenesis inhibitor, byelyankacin (1), was isolated from the fermentation broth of a bacterial strain. The producing organism, designated B20, was identified as a member of the genus Enterobacter based on taxonomic characteristics. 1 was obtained as a white powder from the culture medium by solvent extraction and serial chromatographic purification. The structure of 1 was determined as (E)-4-(2-isocyanovinyl)phenyl alpha-L-rhamnopyranoside on the basis of spectroscopic data. 1 potently inhibited mushroom tyrosinase and melanogenesis of B16-2D2 melanoma cells with IC50 value of 2.1 nM and 30 nM, respectively.     

Transplantation of culture expanded bone marrow cells and platelet rich plasma in distraction osteogenesis of the long bones

Longer treatment period in distraction osteogenesis (DO) leads to more frequent complications. We developed a new technique of transplantation of culture expanded bone marrow cells (BMC) and platelet rich plasma (PRP) in DO of the long bones. Retrospective comparative study was conducted between the bones treated with and without BMC and PRP in DO to assess the efficacy of this new technique of transplantation. Ninety-two bones (46 patients) that were lengthened in our hospital and followed up until removal of the pins were divided into two groups according to the cell (BMC+PRP) treatment. The BMC-PRP(+) group consisted of 32 bones (14 femora, 18 tibiae) in 17 patients (10 boys and 7 girls), while the BMC-PRP(-) group consisted of 60 bones (25 femora, 35 tibiae) in 29 patients (13 boys and 16 girls). The clinical outcome including the age at operation, amount of length gained, the healing index, the delay in consolidation, and complications were compared between the two groups. The healing between the femoral and the tibial lengthening was also assessed. The average age at operation was 15.8 years in the BMC-PRP(+) group and 15.5 years in the BMC-PRP(-) group. Although there were no significant differences in the age at operation and the length gained between the two groups, the average healing indices of the BMC-PRP(+) group in short stature and in limb length discrepancy were significantly lower than those of the BMC-PRP(-) group (P=0.0019 and P=0.0031, respectively). A delay in consolidation was seen in 45% of the BMC-PRP(-) group but never observed in the BMC-PRP(+) group (P<0.0001). The rate of complications was 23% of the BMC-PRP(-) group and only 6% of the BMC-PRP(+) group (P=0.0406). The femoral lengthening showed significantly faster healing than the tibial lengthening by the BMC and PRP transplantation (P=0.0004) In conclusion, transplantation of BMC and PRP shortened the treatment period and reduced associated complications by accelerating new bone formation in DO.     

Prognostic significance of lymph node metastasis and surgical margin status for distal cholangiocarcinoma

BACKGROUND AND OBJECTIVES: Prognostic indicators for patients with distal cholangiocarcinoma have not been confirmed because of its rarity. The aim of this study was to identify useful prognostic factors in patients undergoing surgical resection for distal cholangiocarcinoma. METHODS: Charts of 43 patients with distal cholangiocarcinoma who underwent surgical resection were retrospectively reviewed. Pancreatoduodenectomy was performed in 35 patients, and segmental bile duct resection in 8. Potential clinicopathological prognostic factors were examined by univariate and multivariate survival analysis. RESULTS: Postoperative complications occurred after surgery in 19 patients (44%), but there was no mortality. Overall survival rates were 72%, 53%, and 44% for 1, 3, and 5 years, respectively (median survival time, 26.0 months). Univariate analysis found that older age, pathological pancreatic invasion, lymph node metastasis, perineural invasion, positive surgical margin, and TNM stages II and III were significant predictors of poor prognosis (P < 0.05). Furthermore, lymph node metastasis and positive surgical margin were found to be significant independent predictors of poor prognosis with a Cox proportional hazards regression model (P < 0.05). CONCLUSIONS: These results suggest that lymph node metastasis and positive surgical margin as determined by surgical resection might be useful in predicting post-surgical outcome in patients with distal cholangiocarcinoma.     

Clinical significance of a blood eosinophilia in adult T-cell leukemia/lymphoma: a blood eosinophilia is a significant unfavorable prognostic factor

We investigated the clinical significance of a blood eosinophilia in a cohort of 158 consecutive patients with adult T-cell leukemia/lymphoma (ATLL), and multivariate analysis revealed that a blood eosinophilia was an independent and a significant unfavorable prognostic factor. Interestingly, a blood eosinophilia was independent of serum LDH level, which might reflect the tumor burden. The present study shows that measurement of the blood eosinophil count is useful for predicting the prognosis and for determining a suitable treatment strategy for ATLL patients.