Organic-inorganic hybrid-nanocarrier of siRNA constructing through the self-assembly of calcium phosphate and PEG-based block aniomer.

The development of siRNA delivery systems is a major key for practical RNA therapy that holds promise for the treatment of life-threatening human diseases, yet there still exists significant difficulties in their construction because of the various requirements including high transfection efficacy, tolerability in the biological medium, and low toxicity. Here we report the novel preparation route of organic-inorganic hybrid-nanocarriers entrapping siRNA based on the self-assembly of the block aniomer, poly(ethylene glycol)-block-poly(methacrylic acid), with calcium phosphate crystals. The nanocarriers have diameters in the range of several hundreds of nanometers and revealed excellent colloidal stability due to the steric stabilization effect of the PEG palisade. The biological activity of siRNA loaded in nanocarriers was assessed using 293 cells stably expressing luciferase gene, showing the remarkably high gene silencing-efficacy without the use of any adjuvant molecules such as chroloquin. Further advantage of the system is the serum tolerability, which is of a critical issue in in vivo application.     

Characteristics of Bile Duct Carcinoma with Superficial Extension in the Epithelium

Background  Longitudinal tumor extension from the main tumor involves intramural or superficial spread along the bile duct, which influences surgical curability. Identifying the range of superficial extension is difficult by preoperative imaging. To clarify specific characteristics of bile duct carcinoma (BDC) with superficial extension of epithelium in the bile duct, we examined clinicopathologic features and patient outcomes in BDC patients with or without superficial extension who underwent surgical resection. Methods  Between 1994 and 2008, we retrospectively examined clinicopathologic findings and outcomes for 42 BDC patients who underwent surgical resection and divided them into two groups: (1) superficial extension (SE) group (n = 10); and (2) non-SE group (n = 32). Results  In terms of macroscopic growth of the main tumor, the papillary type was more common in the SE group than in the non-SE group, whereas the nodular type was dominant in the non-SE group. The prevalence of cancer-positive findings at the cut end of the bile duct was higher in the SE group. Portal vein invasion was not observed in the SE group, and the prevalence of regional lymph node metastasis was significantly greater in the non-SE group than in the SE group. No patients died of cancer in the SE group, who tended to show better survival than the non-SE group. Conclusions  The present results suggest that a good prognosis may be achieved in BDC patients with SE when complete resection is accomplished.     

Relationship Between Microvessel Count and Postoperative Survival in Patients with Intrahepatic Cholangiocarcinoma

Background  The present study aimed to elucidate the relationship between microvessel count (MVC) according to CD34 expression and prognosis in intrahepatic cholangiocarcinoma (ICC) patients who underwent hepatectomy based on our preliminary study. Methods  Relationships between MVC and clinicopathological factors were examined in 37 ICC patients. CD34 expression was analyzed using immunohistochemical methods. Results  Median MVC for ICC patients was 140/mm², which was applied as a cutoff value. Lower MVC was significantly associated with larger tumor size, periductal infiltrating type, and advanced Japanese tumor–node–metastasis stage (p < 0.05). Univariate survival analysis identified higher carcinoembryonic antigen level, periductal infiltrating type, poor histological differentiation, and lower MVC as significantly associated with lower 5-year survival rates. The 5-year survival rate in the higher-MVC group was significantly greater than that in the lower-MVC group (44% vs. 7%, p = 0.048). According to Cox multivariate survival analysis, only periductal infiltrating type on macroscopic examination was identified as a significant independent risk factor for poor survival after hepatectomy (risk ratio 4.8; p = 0.006), not MVC (1.1; p = 0.82). Conclusion  Tumor MVC might offer a useful prognostic marker of ICC patient survival after hepatectomy and further investigation in a larger series is warranted.     

Comparative study of anastomosis in pancreaticogastrostomy and pancreaticojejunostomy after pancreaticoduodenectomy

BACKGROUND/AIMS: The relative advantages of pancreaticojejunostomy and pancreaticogastrostomy after pancreaticoduodenectomy remain to be established. To clarify differences between the two procedures, we examined 66 patients who underwent PD and compared clinical and histological parameters, surgical records and patient outcomes. METHODOLOGY: In this retrospective study, subjects were divided into a pancreaticojejunostomy group (n=48) and a pancreaticogastrostomy group (n=18). Pancreaticogastrostomy and pancreaticojejunostomy were performed using invagination technique and end-to-side anastomosis, respectively. RESULTS: There were no significant differences in patient demographics and surgical records between the two groups. Increases in serum amylase concentrations after operation were significantly greater in the pancreaticogastrostomy group (902 +/- 915 IU/L) than in the pancreaticojejunostomy group (326 +/- 761 IU/L) (p = 0.025). However, there were no significant differences in other postoperative laboratory data or complications between the two groups. CONCLUSIONS: In our study, the clinical and safety data associated with pancreaticojejunostomy and pancreaticogastrostomy procedures for anastomosis after pancreaticoduodenectomy were almost similar. Therefore, the anastomotic procedure used should depend on the surgeon's choice or the distance between the remnant stomach and pancreas.     

Clinical factors predictive of spontaneous remission or relapse in cases of autoimmune pancreatitis

BACKGROUND: The rates of spontaneous remission and relapse of autoimmune pancreatitis (AIP) are not known. OBJECTIVE: To study the clinicopathologic factors predictive of remission and relapse in cases of AIP. DESIGN: Retrospective study. PATIENTS: Of the 20 patients with AIP, complete response to steroid therapy was recognized in 12 patients, and the remaining 8 patients improved without steroid therapy. Seven patients experienced a relapse. RESULTS: Patients who were seronegative for immunoglobulin (Ig) G4, had no obstructive jaundice, no diabetes mellitus, no swelling of the duodenal papilla, negative staining of the duodenal papilla for IgG4, and focal pancreatic swelling showed a greater tendency toward spontaneous remission (P < .05). The results of multivariate analysis revealed that negative staining of the duodenal papilla for IgG4 was the only independent predictor of spontaneous remission of AIP (odds ratio [OR] 1.395, P = .0304). Seropositivity for IgG4, diffuse swelling of the pancreas, and the presence of stricture in the lower part of the bile duct were significantly associated with a relapse of AIP (P < .05) according to the results of univariate analysis, whereas the results of multivariate analysis revealed only diffuse pancreatic swelling as an independent predictor of a relapse of AIP (OR 26.197, P = .0331). CONCLUSIONS: Endoscopic findings are of useful prognostic value, because patients with AIP and with negative staining of the duodenal papilla for IgG4 appeared to have a higher frequency of remission without steroid therapy. Patients with AIP and with diffuse pancreatic swelling were found to be at an increased risk of relapse after the initial steroid administration.     

Capillary angiogenesis and remodeling induced in rat limb by arteriovenous shunting

Capillary angiogenesis and remodeling induced by arteriovenous (AV) shunting in rat hind limb was investigated by evaluating changes in capillary density and diameter in the skeletal muscle subject to retrograde flow and high pressure. Wistar rats were used, and an AV anastomosis was created in the hind limb. Two weeks after AV shunting, the microvasculature in the limb was visualized by GS-lectine, and the samples were observed using confocal laser microscopy. The capillary density were increased by approximately 150% for small vessels (<13 microm in diameter) under retrograde flow condition, but no change appeared for large vessels (>13 microm in diameter). The capillary diameters were not significantly different between control and chronic condition. In conclusion, retrograde flow produced by AV shunting increased capillary density but it did not change the capillary diameter significantly.     

Clinical significance of the duodenal papilla in patients with separate orifices for the bile and pancreatic ducts

BACKGROUND: There have been few reports of separate orifices (SPO) for the bile and pancreatic ducts. The aim of this study was to elucidate the clinical significance of SPO. METHODS: Clinical data of patients with SPO (n = 21) were compared with those of 324 patients without SPO. The duodenal papillae in the patients with SPO were classified endoscopically into three types. Furthermore, we compared three subgroups (n = 221) among 345 patients (group A, 10 patients with bile duct stones with SPO; group B, 66 patients with bile duct stones without SPO; and group C, 145 patients without bile duct dysfunction) to evaluate the bile stasis of SPO. Various factors were retrospectively analyzed to identify any relationship in patients with SPO. RESULTS: Univariate analysis revealed that the diameter of the common bile duct, cholangiographic angulation, and the presence of common bile duct stones (CBDS) were significantly associated with the presence of SPO. Multivariate analysis of the different risk factors for SPO in all patients revealed that the presence of CBDS (relative risk, 3.000; 95% confidence interval, 1.083-8.313; P = 0.0346) and cholangiographic angulation (relative risk, 1.041; 95% confidence interval, 1.010-1.072; P = 0.0085) were independent risk factors. Moreover, univariate analysis among the three subgroups revealed that age, the presence of periampullary diverticula, the diameter of the common bile duct, and the length of the short narrow distal segment were significantly associated with the presence of SPO. CONCLUSIONS: CBDS and cholangiographic angulation are independent risk factors for SPO. This result suggests that SPO may be associated with an elevated risk of CBDS owing to bile stasis.     

Prognostic factors in hepatic metastases of colorectal carcinoma: immunohistochemical analysis of tumor biological factors

The present study was designed to provide a systemic analysis of prognosis in 62 patients who underwent hepatic resection for colorectal liver metastasis. The analyzed factors included microvessel counts stained by CD34 and expression of two adhesion molecules, E-cadherin and CD44 variant exon 6-(v6) in these tumors. No significant factors related to recurrence were identified and only negative expression of CD44v6 tended to correlate with recurrence (P = 0.075). A short disease-free period to recurrence was noted in patients with high CEA levels (>10 ng/ml) and H2/3 classification. A short surgical margin, H2/3 classification, high microvessel counts (>60/field, x200), and negative expression of CD44v6 and E-cadherin tended to be associated with poor prognosis. A high microvessel count was the most significant prognostic factor by multivariate Cox proportional hazards regression model. Hepatic resection without tumor exposure and a careful follow-up in cases identified with poor prognostic factors are necessary.