Induction of β-Defensin Expression by Porphyromonas gingivalis-Infected Human Gingival Graft Transplanted in nu/nu Mouse Subdermis

It is important to understand the onset of periodontal disease in terms of bacterial infection and host factors. Host-bacteria interactions can be elicited in human cultured cells and animal models, but these models provide only limited biological information about human host reactions against bacterial attacks. Development of an in vivo model using human gingival tissue is needed. We established an in vivo model using nu/nu mice and evaluated host defense following bacterial infection in human gingiva. Human gingival samples were collected from periodontitis patients and transplanted in nu/nu mouse subdermis. After 2 weeks, human characteristics were confirmed by positive immunohistochemical reactions for human-specific markers. We used this model to investigate human β-defensin-2 (hBD-2), an antimicrobial peptide that contributes to initial defense against bacterial invasion. Using real-time polymerase chain reaction, in situ hybridization, and immunohistochemistry, we investigated whether hBD-2 expression was induced in human gingiva as a response to Porphyromonas gingivalis as a periodontal pathogen. Two hours after infection with bacteria, we detected increased expression of hBD-2 mRNA, which was localized in the epithelium of human gingiva. Using our in vivo model, we concluded that increased hBD-2 may play an important role in early defense from bacterial infection in human gingival epithelium.     

Higher expression of EpCAM is associated with poor clinical and pathological responses in breast cancer patients undergoing neoadjuvant chemotherapy

Neoadjuvant chemotherapy (NAC) is a standard regimen in treatment of breast cancer patients, but some are resistant to NAC. We hypothesized that breast cancer cells overexpressing epithelial cell adhesion molecule (EpCAM) could be resistant to NAC, contributing to a poor prognosis. Seventy patients with breast cancer were treated with NAC. Core needle biopsy (CNB) specimens and resected tumors before and after NAC, respectively, were examined for expression of EpCAM. In resected tumors, high EpCAM expression correlated with lymphovascular invasion status and nuclear grade (P = 0.01 and 0.008, respectively), and was associated with poor pathological and clinical responses (P < 0.001). High tumoral EpCAM expression in resected tumor was independently related to a poor pathological response. Patients with high EpCAM expression before and after NAC (high‐to‐high group) showed worse pathological and clinical responses (P = 0.008 and <0.001, respectively) than the patients with high and low EpCAM expression before and after NAC, respectively (high‐to‐low group). The overall survival rate of the high‐to‐high group appeared shorter compared with the high‐to low‐group (P = 0.049). Our findings imply that higher levels of EpCAM in breast cancer may be associated with poor response to NAC via a potential chemoresistant effect.     

Sentinel lymph node mapping for gastric cancer using a dual procedure with dye- and gamma probe-guided techniques

BACKGROUND: Increasing evidence supports the sentinel lymph node (SN) concept for melanoma and breast cancers. SN biopsy may replace routine lymph node dissection in the treatment of these cancers. But there are little data evaluating this concept in patients with gastric cancer. The objective of this study was to test the feasibility of SN mapping in gastric cancers by using the dual-mapping procedure with dye and radioactive colloid. STUDY DESIGN: Thirty-one consecutive patients preoperatively diagnosed as T1-2 and N0 underwent SN biopsy using the dual-mapping procedure. Distributions of SNs identified by the dye-guided technique (blue nodes; BNs) were compared with those identified by the gamma probe guided technique (hot nodes; HNs). RESULTS: Among the 31 patients, 7 were found to have lymph node metastases. All positive nodes were detected by SN biopsy using the dual method. So, an accuracy rate of 100% was achieved in predicting the status of regional lymph nodes. Both BNs and HNs were identified in 28 of 31 patients (90%), but significant discrepancy of distribution was noted between BNs and HNs. Among the 28 patients with identified BNs, there was one metastasis in a non-BN. So the accuracy rate was 96% for the dye-guided technique. In contrast, among the 28 patients with identified HNs, 2 patients had metastasis in non-HNs, making the accuracy rate 93% for the gamma probe-guided technique. CONCLUSIONS: SN mapping is feasible in gastric cancer, but the dye-guided and gamma probe-guided techniques are complementary. So we recommend the dual-mapping procedure.     

Immunohistochemical analysis of hepatic interferon alpha-beta receptor level: relationship between receptor expression and response to interferon therapy in patients with chronic hepatitis C

Background/Aims: This study aimed to determine the expression level of interferon alpha/beta (IFN-α/β) receptor in the liver immunohistochemically and evaluate its usefulness in predicting the outcome to IFN therapy in patients with chronic hepatitis C.Methods: The level of IFN-α/β receptor expression was determined in immunoperoxidase-stained pretreatment sections of 55 chronic hepatitis C patients later treated with IFN. We used liver biopsy specimens and mouse monoclonal anti-human IFN-α/β receptor antibody. Quantitative analysis of immunostaining was performed by image analysis software. The level of IFN-α/β receptor was expressed as Unit (U). Sustained responders were patients who showed persistent disappearance of serum HCV-RNA during the 6-month period after treatment, while non-responders showed persistence of viremia after therapy.Results: Positive immunostaining was observed in the cytoplasm of hepatocytes. The mean expression level of hepatic IFN-α/β receptor in sustained responders (2.65±1.11 U, n=15) was significantly (p<0.001) higher than in non-responders (1.61±1.05 U, n=40). A significant decrease in IFN-α/β receptor expression level was observed in patients with advanced liver fibrosis. In patients with low level viremia (pretreatment serum HCV-RNA <1 Meq/ml, n=18), the level of IFN-α/β receptor in sustained responders (2.89±1.12 U, n=11) was significantly (p<0.01) higher than in non-responders (0.93±0.33 U, n=7).Conclusions: Our results suggest that measurement of the level of hepatic IFN-α/β receptor in patients with chronic hepatitis C might be useful for predicting the response to IFN therapy. Resistance to IFN therapy in patients with chronic hepatitis C might be due to low levels of hepatic IFN-α/β receptor.     

One-year clinical outcomes of dialysis patients after implantation with sirolimus-eluting coronary stents

Background The efficacy of sirolimus-eluting stents (SESs) has not been established in dialysis patients. Methods and Results This study was a non-randomized observational single-center registry in a community hospital: data for 80 consecutive dialysis patients who underwent percutaneous coronary intervention (PCI) with SES were compared with those of a historical group of consecutive 124 dialysis patients treated with bare-metal stents (BMS). After 1 year, the cumulative incidence of major adverse cardiac events (MACE), comprising cardiac death, nonfatal myocardial infarction, stent thrombosis, or target lesion revascularization (TLR), was 25.2% in the SES group and 38.2% in the BMS group (p=0.048). In multivariate analysis, use of SES remained an independent predictor of MACE at 1 year after PCI (risk ratio 0.70, 95% confidence interval 0.52-0.93, p=0.015). Rates of TLR were 21.7% in the SES group and 30.9% in the BMS group and (p=0.15). Subgroup analysis showed that use of SES was effective in patients with small vessels, non-diabetic patients, and patients without highly calcified lesions. Conclusions In dialysis patients, the implantation of SES was moderately effective in reducing MACE at 1 year after PCI as compared with BMS. However, the TLR rate at 1 year was relatively higher than previously reported. (Circ J 2008; 72: 1430 - 1435).     

Gene manipulation in the field of surgery

Recent advances in molecular biology have led to expectations for the use of gene therapy or gene manipulation as a radical treatment strategy. I described the research projects and results, in the field of organ transplantation and cancer treatment in which we have been involved.     

Cytoplasmic expression of laminin gamma2 chain correlates with postoperative hepatic metastasis and poor prognosis in patients with pancreatic ductal adenocarcinoma

BACKGROUND: The laminin gamma2 chain is involved in tumor invasion and metastasis, but the significance of laminin gamma2 chain expression remains unclear in patients with pancreatic carcinoma. METHODS: Laminin gamma2 chain expression was examined immunohistochemically in 48 patients with pancreatic ductal adenocarcinoma who were followed closely to elucidate the correlations between clinicopathologic factors, postoperative recurrence, and overall survival. Prognostic factors for postoperative survival were examined comparing clinicopathologic factors and laminin gamma2 chain expression. RESULTS: Two different staining patterns of laminin gamma2 chain expression, cytoplasmic expression and basement membrane expression, were detected in tumors from all 48 patients. Tumors were then classified into two types according to the dominant pattern of laminin gamma2 chain expression: the cytoplasmic expression dominant type (CYT; n = 26 patients) and the basement membrane expression dominant type (BM; n = 22 patients). Tumor differentiation was associated statistically with the BM type of laminin gamma2 chain expression (P = 0.0002). The CYT type of laminin gamma2 chain expression was associated significantly with the occurrence of postoperative hepatic metastasis (P = 0.0011) and also was the strongest predictive factor for poorer overall survival in patients with pancreatic ductal adenocarcinomas (P = 0.0161). CONCLUSIONS: The cytoplasmic expression of the laminin gamma2 chain represents the high invasive potential of the tumor and is correlated with distant metastasis, especially hepatic metastasis, and with a poorer prognosis in patients with pancreatic ductal adenocarcinoma.