Cosmic-Ray Exposure Histories of Gas-rich Brecciated Meteorites

72nd Annual Meeting of the Meteoritical Society, held July 13-18, 2009 in Nancy, France

Regolith history of the aubritic meteorite parent body revealed by neutron capture effects on Sm and Gd isotopes

Enstatite achondrites (aubrites) when compared to other stone meteorites have unusually long cosmic-ray exposure (CRE) ages. We report here the 150Sm/149Sm and 158Gd/157Gd ratios in six different structural phases, i.e., light and dark (shocked) grains and in matrix materials of Pesyanoe, in three different fragments from Pena Blanca Spring, and in one from Norton County, Shallowater, and Khor Temiki, to investigate the regolith history on the aubrite parent body. The results from phases components of Pesyanoe confirm earlier reported evidence for regolith irradiation of several aubrites. The inferred neutron fluences for six Pesyanoe separates vary between (2.13 and 2.82) × 1016 n cm-2. The fluences also significantly exceed those expected from cosmic-ray irradiation during transit to Earth and approach those observed in the lunar regolith. These observations confirm that the brecciated Pesyanoe meteorite, which contains solar wind (SW) gases only in dark phases, was processed in a regolith and that structural phases were differentially irradiated before compaction. On the other hand, in some aubrites (Mt. Egerton, Shallowater, Pena Blanca Spring, Norton County) neutron capture effects may entirely be due to space irradiation

Portal Vein Anastomosis with Parachute Method in Hepatectomy and Pancreatectomy

In advanced cancers of hepatobiliary and pancreatic lesions, major vascular resection and reconstruction are necessary to accomplish curative resection. Stenosis of vascular anastomosis is a concern in case of portal or superior mesenteric venous anastomosis with different vascular calibers. We attempted to apply parachute anastomosis in such a situation, which has often been used in the field of cardiovascular surgery. We applied this procedure in 4 cases of two hepatectomies in intrahepatic cholangiocarcinomas and two pancreatectomies in pancreatic carcinomas, in which combined vascular resection was necessary. After anastomosis, the orifice of anastomotic veins was well matched and did not show stenosis or poor blood flow on ultrasonographic examination. Parachute anastomosis in the portal or superior mesenteric vein is a useful procedure to prevent vascular stenosis, particularly in case of anastomosis with different calibers

Comparison of Outcome of Hepatectomy with Thoraco-abdominal or Abdominal Approach

Background/Aims: Thoraco-abdominal approach is a suitable choice for hepatectomy to secure good view for mobilization. The aim of this study was to assess efficacy of thoraco-abdominal approach (TAA) for hepatectomy. Methodology: There were compared clinicopathological data, surgical results and postoperative complications of 425 consecutive patients who underwent hepatectomy via abdominal (AA) (n=147) or TAA (n=278). Results: Blood loss and operating time were significantly higher in TAA than AA group (970 vs. 830ml and 408 vs. 372 min.)(p<0.05). Prevalence of pleural effusion was significantly higher in TAA than AA group (24 vs. 9%) (p<0.01). However, proportions of patients who developed hepatic complications such as biloma (14 vs. 23%), and wound infection (8 vs.25%) were significantly less in TAA than AA group (p<0.05). Hospital stay after hepatectomy and mortality were similar between both groups. Presence of chronic viral hepatitis, lower platelet count, higher level of serum hyaluronic acid, larger blood loss and TAA correlated significantly with thoracic complications (p<0.05). Multivariate analysis showed that increased blood loss (p=0.011), but not TAA, was a significant determinant of thoracic complications (p=0.08). Conclusions: TAA can be considered a relatively safe approach for hepatectomy with minimal abdominal complications nevertheless of frequent pleural effusion

ABCC11/MRP8 Expression in the Gastrointestinal Tract and a Novel Role for Pepsinogen Secretion

ATP-binding cassette (ABC) transporters are involved in chemotherapy resistance. Multidrug-resistance protein 8 (ABCC11/MRP8) is also involved in 5-fluorouracil (5-FU) metabolism. 5-FU and its derivatives are widely used in the treatment of gastrointestinal tract cancers, but little is known about the contribution of ABCC11/MRP8 to gastrointestinal tract and related cancers. Here, we report our investigation of ABCC11/MRP8 expression in normal and cancerous gastrointestinal tract tissues and reveal its novel role in the gastric mucosa. In tissue microarray and surgically resected cancer specimens, immunohistochemical (IHC) staining revealed significantly reduced expression of ABCC11/ MRP8 in gastrointestinal tract cancers compared with other cancers. In contrast, strong ABCC11/MRP8 expression was observed in normal gastric mucosa. Additional immuno-fluorescence assays revealed co-localization of ABCC11/MRP8 and pepsinogen I in normal gastric chief cells. Quantitative PCR and Western blot analysis also revealed significant expression of ABCC11/MRP8 in fundic mucosa where the chief cells are mainly located. Furthermore, the ABCC11 mRNA-suppressed NCI-N87 gastric cancer cell line failed to secret pepsinogen I extracellularly. Thus, low expression of ABCC11/MRP8 is consistent with chemotherapeutic regimens using 5-FU and its derivatives in gastrointestinal tract cancers. Our results indicated a novel function of ABCC11/MRP8 in the regulation of pepsinogen I secretion in the normal gastric chief cells

Usefulness of measuring hepatic functional volume using technetium-99m galactosyl serum albumin scintigraphy in hilar bile duct carcinoma

This case involved a 75-year-old woman with obstructive jaundice who was diagnosed with hilar bile duct carcinoma. After endoscopic retrograde biliary drainage, the total bilirubin level was normalized. The indocyanine green test retention rate at 15 min (ICGR15) was 26%. The liver uptake ratio (LHL15) by technetium-99m galactosyl human serum albumin (99mTc-GSA) liver scintigraphy was 0.87. Left hepatectomy was scheduled by CT volumetry. However, biliary drainage was insufficient, and the functional liver volume showed functional deterioration of the left liver. After percutaneous transhepatic biliary drainage, future remnant liver volume by 99mTc-GSA liver scintigraphy changed to 52% from 42%, and ICGR15 and LHL15 were improved to 16% and 0.914, respectively. Scheduled left hepatectomy was performed following the results of functional liver volume. The measurement of functional volume by 99mTc-GSA liver scintigraphy provides useful information with respect to segmental liver function for deciding operative indications

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.The original publication is available at www.springerlink.co

Vascular transection using endovascular stapling in hepatic resection

In anatomical resection of the liver, transection of the hepatic vein or Glisson\u27s pedicle is necessary. We examined the surgical records and outcome of 25 patients who underwent hepatectomy. An endovascular stapler with 36 and 60 mm staples was used for transection of the hepatic vein or Glisson\u27s pedicle, and hepatic parenchyma including vessels. Surgery included also left lateral sectorectomy in 6 patients, right lateral sectorectomy in one, right hepatectomy in 12, left hepatectomy in two and trisegraenteetomy in 4. Endovascular stapling was used for transection of hepatic veins (n=25) in all patients and Glisson\u27s pedicle (n=8). No failure of firing occurred during cutting. Injury of an aberrant bile duct occurred in one patient, but none suffered bleeding or bile leakage from the transected parts. Vascular transection using vascular stapler could be performed safely and rapidly during anatomical hepatic resection

Expressions of Vascular Endothelial Growth Factor (VEGF)-D and VEGF Receptor-3 in Colorectal Cancer: Relationship to Lymph Node Metastasis

Angiogenic factors play a major role in tumor growth and metastasis. Vascular endothelial growth factor (VEGF)- D is a ligand for VEGF receptor-3 (VEGFR-3/Flt-4), which mainly expressed on the lymphatic endothelium. Recent experimental studies have shown that VEGF-D induces tumor lymphangiogenesis and promote metastatic spread of tumor cells via lymphatic vessels. However, the contribution of VEGFD to lymph node metastasis in human colorectal cancer is less understood. We therefore examined VEGF-D and VEGFR-3 expression in patients with colorectal cancer. Sections of formalin-fixed and paraffin-embedded specimens from 76 colorectal cancers were immunohistochemically stained for VEGF-D and VEGFR-3. Staining for VEGF-D was positive in the cytoplasm of tumor cells in 43 of 76 examined tumors (56.6%). Staining for VEGFR-3 was positive in endothelial cells in 38 (50.0%) tumors. Univariate analysis showed that both VEGF-D and VEGFR-3 expressions correlated significantly with lymph node metastasis, histological type and depth of tumor invasion. However, logistic regression analysis indicated that VEGF-D expression, but not that of VEGFR-3, was an independent predictor for lymph node metastasis. Our data suggest that VEGF-D plays an important role in lymph node metastasis in colorectal cancer