Plutonium, 137Cs and uranium isotopes in Mongolian surface soils.

Plutonium (238Pu and 239,240Pu), 137Cs and plutonium activity ratios (238Pu/239,240Pu) as did uranium isotope ratio (235U/238U) were measured in surface soil samples collected in southeast Mongolia. The 239,240Pu and 137Cs concentrations in Mongolian surface soils (<53 µm of particle size) ranged from 0.42 ± 0.03 to 3.53 ± 0.09 mBq g-1 and from 11.6 ± 0.7 to 102 ± 1 mBq g-1, respectively. The 238Pu/239,240Pu activity ratios in the surface soils (0.013-0.06) coincided with that of global fallout. The 235U/238U atom ratios in the surface soil show the natural one. There was a good correlation between the 239,240Pu and 137Cs concentrations in the surface soils. We introduce the migration depth to have better understanding of migration behaviors of anthropogenic radionuclides in surface soil. We found a difference of the migration behavior between 239,240Pu and 137Cs from 137Cs/239,240Pu - 137Cs plots for the Mongolian and Tsukuba surface soils; plutonium in surface soil is migrated easier than 137Cs.

Peroral video cholangioscopy to evaluate indeterminate bile duct lesions and preoperative mucosal cancerous extension: a prospective multicenter study.

BACKGROUND AND STUDY AIMS: Despite the development of peroral video cholangioscopy (PVCS), no prospective multicenter studies have been undertaken to investigate the diagnostic accuracy of PVCS in biliary tract diseases. Therefore, the aim of this study was to clarify the accuracy of PVCS in evaluating biliary tract lesions. PATIENTS AND METHODS: This study was a prospective multicenter study at five tertiary referral centers in Japan and included 87 eligible patients with biliary tract diseases who underwent PVCS. The study evaluated the ability of PVCS to diagnose indeterminate biliary tract diseases, detect mucosal cancerous extension preoperatively in extrahepatic bile duct cancers, and predict adverse events. RESULTS: The use of PVCS appearance alone correctly distinguished benign from malignant indeterminate biliary lesions in 92.1 % of patients whereas biopsy alone was accurate in 85.7 %. In extrahepatic bile duct cancer, mucosal cancer extended histologically at least 20 mm in 34.7 % (17/49) of patients. The accuracy rate of PVCS to evaluate the presence or absence of mucosal cancerous extension by endoscopic retrograde cholangiography (ERC) alone, ERC with PVCS, and ERC with PVCS + biopsy were 73.5 %, 83.7 %, and 92.9 %, respectively. Adverse events were seen in 6.9 % of PVCS patients, but no serious complications were observed. CONCLUSION: PVCS enhanced the accurate diagnosis of biliary tract lesions by providing excellent resolution in combination with biopsy.

Etiology of recurrent acute pancreatitis, with special emphasis on pancreaticobiliary malformation.

PURPOSE: This study was aimed to investigate etiology and clinical profiles of recurrent acute pancreatitis (RAP), particularly from the morphology of the pancreaticobiliary duct system. MATERIAL AND METHODS: Pancreaticobiliary morphology was examined in 230 of 381 patients with acute pancreatitis (AP) using endoscopic retrograde cholangiopancreatography. We analyzed factors associated with RAP including the pancreaticobiliary duct system. RESULTS: RAP was diagnosed in 74 patients (19%). Major etiologies of RAP were alcoholic (38%), idiopathic (26%) and pancreaticobiliary malformation (22%). Patients with alcoholic RAP were significantly younger (47.2±11.6 years) than those with gallstone RAP (67.3±16.8; p<0.05). RAP with pancreaticobiliary malformation (male-to-female ratio: 1:4.3; p<0.01) and gallstone RAP (1:1.7; p<0.05) occurred predominantly in females in comparison with alcoholic RAP (1:0.2). Recurrence rate was 80% for AP with pancreaticobiliary malformation, significantly higher than for the others (p<0.01). Pancreas divisum was suspected as the etiology of mild RAP in 7 patients. Four RAP patients with pancreas divisum underwent endoscopic minor papilla sphincterotomy and improved. Pancreaticobiliary maljunction with biliary dilatation (choledochal cyst) was suspected as the etiology of mild RAP in 3 patients. The 3 RAP patients with choledochal cyst underwent prophylactic flow diversion surgery with complete resection of the dilated common bile duct, and achieved improvement. High confluence of pancreaticobiliary ducts was suspected as the etiology of mild RAP in 6 patients. CONCLUSION: Pancreaticobiliary malformation is one of the major causes of RAP. As some of them benefit from endoscopic or surgical treatment, morphology of the pancreaticobiliary duct system should be examined where possible in RAP patients.

Complex vascular reconstruction using donor's vessel grafts in orthotopic liver transplantation.

The vascular abnormalities of recipients are associated with reconstructive difficulties with an increased risk of postoperative complications. We performed an orthotopic liver transplantation that required a complex vascular reconstruction using donor vascular grafts. A patient with hepatitis B virus cirrhosis received a liver from a brain-dead donor. Dynamic computed tomography revealed complete obstruction of the portal vein due to thrombosis as well as narrowing of the hepatic arteries. We employed orthotopic liver transplantation using the piggy-back technique with complex reconstruction of the portal vein and the hepatic arteries. For portal vein reconstruction, we used the donor's iliac vein as an interpositional conduit from the recipient's gastric coronary vein to graft the portal vein. The hepatic arteries of the graft were reconstructed at the back-table before anastomosis to the side of superior mesenteric artery using an interpositional conduit of the donor's external iliac artery. All postoperative studies revealed good graft function with an excellent blood flow through all vascular anastomoses during the first year postoperatively.

N-acetyl cysteine protects osteoblastic function from oxidative stress.

We tested the protective potential of an antioxidant amino acid derivative, N-acetyl cysteine (NAC), in controlling oxidative stress against osteoblasts. Osteoblastic cells extracted from rat bone marrow were cultured. Oxidative stress was induced by adding 100 µM H2O2 into the culture media. Then, some H2O2-treated cultures were cotreated with 2.5 or 5 mM NAC. Addition of H2O2 decreased the number of cells to 50% of untreated cultures at days 2. Addition of 5 mM NAC into H2O2 cultures resulted in a dose-dependent increase in the number of cells, with the cell number being 50% greater than that in the 100 µM H2O2 culture. The gene expression levels of type I collagen, osteopontin, and osteocalcin were downregulated threefold by H2O2 on day 7. The H2O2-suppressed gene expression was fully recovered by NAC cotreatment. The mineralizing capability, assessed by Von Kossa staining on day 15, were approximately 1.8 times greater in the NAC + H2O2 cotreated group than in the culture with H2O2 alone. These NAC-mediated restorations were associated with an NAC dose-dependent increase of intracellular glutathione and a NAC dose-dependent decrease of intracellular reactive oxygen species. In conclusion, oxidative stress induced by H2O2 substantially impairs the proliferation, differentiation, and mineralization of osteoblasts. More importantly, the addition of NAC into the culture was found to restore these damages to a near normal level due to the improved redox balance, warranting further in vivo studies to test its therapeutic potential as a local antioxidative stress drug.

Scattered radiation from dental metallic crowns in head and neck radiotherapy.

We aimed to estimate the scattered radiation from dental metallic crowns during head and neck radiotherapy by irradiating a jaw phantom with external photon beams. The phantom was composed of a dental metallic plate and hydroxyapatite embedded in polymethyl methacrylate. We used radiochromic film measurement and Monte Carlo simulation to calculate the radiation dose and dose distribution inside the phantom. To estimate dose variations in scattered radiation under different clinical situations, we altered the incident energy, field size, plate thickness, plate depth and plate material. The simulation results indicated that the dose at the incident side of the metallic dental plate was approximately 140% of that without the plate. The differences between dose distributions calculated with the radiation treatment-planning system (TPS) algorithms and the data simulation, except around the dental metallic plate, were 3% for a 4 MV photon beam. Therefore, we should carefully consider the dose distribution around dental metallic crowns determined by a TPS.

Depositional behaviors of plutonium and thorium isotopes at Tsukuba and Mt. Haruna in Japan indicate the sources of atmospheric dust.

Monthly plutonium and thorium depositions at Tsukuba (28m asl) and Mt. Haruna (1370m asl) were measured during 2006 and 2007 (Jan 2006-Dec 2007 at Tsukuba, Nov 2006-Dec 2007 at Mt. Haruna). The monthly (239,240)Pu depositions ranged from 0.044 to 2.67mBq m(-2) at Tsukuba and from 0.05 to 0.9mBq m(-2) at Mt. Haruna during the measurement periods. Monthly (239,240)Pu deposition did not differ markedly between the two sites except in April 2007. Seasonal pattern of monthly (239,240)Pu depositions at both sites showed high in spring and low in summer, and typical of seasonal variations in northeastern Asia. Thorium deposition at Tsukuba was higher than that at Mt. Haruna except in May and June 2007. (230)Th/(232)Th activity ratios were used to partition deposition samples into locally and remotely derived fractions. The results revealed that a major proportion of total (239,240)Pu and Th deposits are derived from remote sources, especially in spring.

Quantitative analysis of mast cells in benign and malignant colonic lesions: immunohistochemical study on formalin-fixed, paraffin-embedded tissues.

BACKGROUND: Comparison of the number of mast cells in the active stage and that in remission in the same patients with ulcerative colitis with immunohistochemical staining remains to be elucidated, and analysis of the number of mast cells in benign and malignant colonic lesions is insufficient. METHODS: Using immunohistochemical methods, morphological examinations of mast cells were undertaken in colonic tissues from 8 patients with ulcerative colitis and 10 patients with colonic primary cancer, which were formalin-fixed and paraffin-embedded. Changes in the number of mast cells in the active stage and in remission in the same patients with ulcerative colitis were investigated. Then, the number of mast cells in malignant tissues and adjacent healthy tissues obtained from the same patients with colonic primary cancer were compared, and finally the number of mast cells was compared among the samples from benign and malignant colonic lesions. RESULTS: Accumulation of mast cells was found to be significant in the active stage of ulcerative colitis compared with remission in the same patients. The number of mast cells in colonic primary cancer was significantly increased compared with that in adjacent healthy tissues. The number of mast cells in ulcerative colitis was significantly greater than that in adjacent healthy tissues from patients with colonic primary cancer, irrespective of the stages of ulcerative colitis. CONCLUSIONS: We were the first to analyse mast cells in the active stage and in remission in the same patients with ulcerative colitis using immunohisto-chemical methods, and compared the number of mast cells between benign and malignant colonic lesions.

Comparison of food mixing ability among mandibulectomy patients.

Many papers have been published on surgical mandibulectomy and reconstruction. However, only a few reports refer to masticatory function after prosthodontic treatment in mandibulectomy patients. The aim of this study was to investigate the masticatory function of mandibulectomy patients. Twenty-three subjects (10 males and 13 females, with an average age of 63 years) participated in this study: 11 subjects who had undergone unilateral marginal mandibulectomy, six subjects with unilateral segmental mandibulectomy with reconstruction and six subjects with hemimandibulectomy without reconstruction. Mixing Ability Index (MAI) was used to measure masticatory function on the non-defect side and on the defect side with a prosthesis installed. Comparisons were carried out among the marginal, segmental and hemimandibular groups and between the non-defect side and the defect side. Consequently, our study indicates these results. On the non-defect side, a significant difference was found between the marginal and the segmental groups, and between the marginal and the hemimandibular groups. In the marginal and the segmental groups, a significant difference was found between the non-defect and the defect sides. In conclusion, our study suggests that MAI is an adequate tool to study the masticatory function in mandibulectomy patients, the masticatory function of the mandibulectomy patients is more impaired than that of the ordinary removable partial denture patients, and that surgical intervention affects the masticatory function on not only the defect side but also the non-defect side in mandibulectomy patients.

Accumulation of mast cells in the interstitium of eosinophilic colitis.

INTRODUCTION: The mechanism of eosinophilic colitis remains unclear, and no case has been reported in which the number of mast cells was examined. CASE REPORT: A 35-year-old man presented to our hospital with chief complaints of chills and consistent watery diarrhea after eating raw fresh-water fish. In blood examination, peripheral blood eosinophilia was found. Histological examination from biopsy specimens of both the ascending colon and rectum showed a prominent eosinophilic infiltration in the intestinal mucosa. Although a provocation test could not be performed due to lack of informed consent, a diagnosis of eosinophilic colitis was made on the basis of other findings. Immunohistochemical staining for human mast cell tryptase using monoclonal antibody against human mast cell tryptase showed an accumulation of mast cells in the colonic interstitium. CONCLUSIONS: We report a case of eosinophilic colitis in which an accumulation of mast cells in the colonic interstitium was demonstrated.

Can a bone marrow cell contribute to organ regeneration? In vivo analysis using transgenic rats with reporter genes.

Although implantation of multipotent bone marrow-derived stem cells represents an attractive new cell therapy to repair damaged tissues, recent reports have raised serious concerns over the feasibility of using stem cells deriving from the bone marrow to promote cell transdifferentiation. We established transgenic (Tg) rats with reporter genes as specific molecular tags to examine the effect of bone marrow cells (BMCs) on transdifferentiation into tissues/organs. To monitor transdifferentiation events of locally transplanted BMCs into hepatocytes or capillary endothelial cells, a liver injury model and an ischemic hind-limb model were developed in rats. To test the ability of circulating bone marrow-derived cells to give rise to myocytes after skeletal muscle injury, we used a bone marrow cell transplantation model from Tg rats, which showed ubiquitous expression of beta-galactosidase (lacZ), into lethally irradiated non-Tg rats. Our results show that there was little transdifferentiation of BMCs into the targeted cells in these tissue injury models. However, in the ischemic hind-limb model, laser Doppler imaging and histologic analysis showed that both implantation of BMCs and treatment with microspheres incorporating basic fibroblast-like growth factor (bFGF), which enables the release of bFGF at the site of action over a period of time, effectively induced angiogenesis. In conclusion, rat BMCs with specific marker genes could be a useful tool for detecting transdifferentiation events in vivo.

Wet and dry deposition patterns of plutonium in Daejeon, Korea.

Plutonium in wet and dry deposition samples collected monthly at the Korea Institute of Nuclear Safety (KINS), Daejeon, Korea was determined during the period from January 2000 to August 2000. Monthly 239,240Pu deposition in Korea showed a maximum in the spring season (March to May), which was several times greater than that in Japan and corresponds to a seasonal cycle of soil dust fallout originating from the East Asian arid areas. The trajectory analysis of dust storms suggests that 239,240Pu deposition in Korea in spring is originating from plutonium-bearing surface soil particles from the East Asian arid areas. A significant part of the 239,240Pu deposition in spring in Korea is attributable to dry deposition.

Plutonium isotopes in seas around the Korean Peninsula.

239+240Pu concentrations and 240Pu/239Pu atom ratios in coastal seas adjacent to the Korean Peninsula were determined, during the period 1999 to 2002, to assess the current distribution and to identify sources of Pu isotopes. 239+240Pu concentrations in surface waters ranged from 3.1 to 22.3 mBq m(-3) with higher concentrations in winter than in summer. 239+240Pu concentrations in seawaters around the Korean Peninsula are greater than that in the western North Pacific. 240Pu/239Pu atom ratios ranged from 0.18 to 0.33 with an average value of 0.25+/-0.03, which is significantly higher than the global fallout average. The 240Pu/239Pu atom ratios of the 2000 m deep entire water column in the south western part of the East Sea (Sea of Japan) was comparable to that observed in waters near Bikini Atoll. The higher 240Pu/239Pu atom ratios than that of global fallout may be explained by the hypothesis that the earlier input signal of low 240Pu/239Pu atom ratio (0.18-0.19) of global fallout plutonium in seas adjacent to the Korean Peninsula is being gradually diluted by the high 240Pu/239Pu atom ratio plutonium transported from the tropical Pacific Proving Grounds via prevailing ocean current.

Technical modifications and strategies for stenting gastric outlet strictures using esophageal endoprostheses.

BACKGROUND AND STUDY AIMS: The outcome of stenting gastric outlet stricture is favorable compared with a bypass operation which has significant morbidity and mortality. In Japan, this procedure is particularly complicated by a lack of enteral stents. We report some technical stratagems for stent placement for gastric outlet strictures. PATIENTS AND METHODS: Between February 1993 and July 2001, 23 patients with gastric outlet strictures (14 men, nine women; mean age 72 years) underwent stent placement using an esophageal stent system. The Ultraflex or Z-stents were used in 18 or five patients, respectively. With the Ultraflex, we increased the length of the delivery system. Some patients underwent stent placement with the help of endoscopic assistance with a grasping forceps or a home-made sheath. RESULTS: The metal stent was successfully inserted in all patients. There were no complications during the procedure. Migration occurred in two out of five patients treated with the Z-stent, whereas there was no migration in patients treated with the Ultraflex stent. In two patients, curable pancreatitis was caused by pressure on the duodenal papilla. One of these patients also experienced bile stasis which required biliary decompression. There were three cases of obstruction, caused by tumor ingrowth (1), hyperplasia (1) and stent fracture (1); recanalization by an additional stent placement and/or cutting stent filaments was successful. All the patients died, with a median survival period of 52 days. There was no procedure-related mortality. CONCLUSIONS: With some technical modification, stent placement for gastric outlet stricture, even using an esophageal stent, is feasible. This procedure offers good palliation with no major complications.

Successful repair of a damaged duodenal stent by cutting stent wires and placement of a second stent.

Duodenal stenting has been gradually established in recent years because it is less invasive than standard surgical procedures and produces a rapid therapeutic response. For palliation of both duodenal and biliary stenoses, double stenting may be performed. Duodenal stents offer a great advantage in allowing endoscopic retrograde cholangiopancreatography (ERCP) without the need for balloon dilation. When biliary stent dysfunction occurs, the patient undergoes diagnostic and/or therapeutic ERCP across the duodenal stent. We encountered a duodenal stent fracture in a patient who required repeated ERCPs for stent dysfunction. Duodenal stent fractures have not previously been reported. The damaged stent was successfully repaired by using a cutting wire filament and placing another duodenal stent coaxially with the first. Clinicians should be aware of the possibility of stent fracture following endoscopic procedures, such as an ERCP, that require passage through the stent. The procedure described in this report would be of significant benefit if a gastrointestinal stent is fractured and occluded by a broken part.

Microwave coagulation versus insertion of a second stent for occluded biliary metal stent.

BACKGROUND/AIMS: There is no consensus regarding optimal management of self-expandable metallic stent occlusion. We investigated the efficacy of microwave coagulation therapy for recanalization as compared to second stent placement. METHODOLOGY: Sixty patients with malignant obstruction of the common bile duct were treated with metal stent placement from January 1992 to July 1999. Of these, 13 patients subsequently developed stent occlusion due to tumor ingrowth. We compared stent patency and patient survival rates after microwave coagulation to those after insertion of a second stent. The influence of the duration of patency of the first stent on the second stent patency was also evaluated. RESULTS: Of the 13 patients with stent occlusion, 7 were treated with microwave coagulation therapy, and 6 with insertion of a second metal stent. In all cases, occluded stents were successfully recanalized without any complications. There was no significant difference in duration of first stent patency between the two groups. The median duration of second stent patency was prolonged in microwave-treated patients (152 days vs. 104 days, P > 0.05). The median duration of patient survival after last recanalizing procedure was also prolonged in microwave-treated patients (131 days vs. 78 days, P > 0.05). Microwave energy did not induce destruction of the stent filament. CONCLUSIONS: Microwave coagulation did not offer significantly longer duration of stent patency and patient survival compared to insertion of a second metal stent. However, this procedure is safe, feasible, and certainly as good as a second stent placement. It may be an alternative to insertion of a second stent within the occluded stent.

[Basophilic differentiation of leukemic cells in a patient with acute leukemia carrying minor bcr/abl chimeric mRNA].

A 77-year-old woman was referred to our hospital because of leukocytosis and leukoblastosis in September 1999. She was healthy except for hypertension, and no abnormal findings in the peripheral blood had been observed up to December 1998. Physical examination revealed neither hepatosplenomegaly nor superficial lymphadenopathy. A bone marrow film showed massive proliferation of blast cells (87.8%), some of which contained coarse basophilic granules (38.6%). The cells were negative for peroxidase and esterase (alpha-naphtyl butyrate and ASD-chloroacetate) staining, but the granules showed metachromasia upon toluidine blue staining. As immunophenotypic analysis of the cells showed double positive for CD13/CD19 but negativity for CD33, this case did not meet the diagnostic criteria for biphenotypic acute leukemia. Chromosome and gene analysis showed positivity for the Ph1 chromosome with minor bcr/abl chimeric mRNA. A homogenate of the peripheral mononuclear cells demonstrated a high concentration of histamine. Electron microscopy analysis confirmed that some of the blast cells contained dense granules, which closely resembled "immature basophil granules" morphologically. These results suggested that the blast cells showed basophilic differentiation. As the clinical course and peripheral blood findings were different from blastic crisis of chronic myelogenous leukemia (CML) and CML with minor bcr/abl chimeric mRNA, the present case was diagnosed as "multiphenotypic acute leukemia", a type of acute basophilic leukemia classified by Duchayne.

Transpapillary microwave coagulation therapy for recanalizing self-expandable metallic stents occluded by tumor ingrowth: initial experience.

Percutaneous microwave coagulation for recanalizing stents occluded by tumor ingrowth has been reported. With this technique, however, the percutaneous drain diminishes the quality of life in patients with unresectable tumors and a limited prognosis. Transpapillary microwave ablation was attempted in three patients with occluded stents. After a sheath had been inserted into the proximal hepatic duct across the occluded region, a microwave electrode was introduced into the intrahepatic duct via the sheath. We used microwave therapy with an output power of 40 W, based on our previous in vitro study. Except in one patient, the stents were successfully recanalized with one or two attempts. In one patient who underwent ablation in the intrahepatic duct, a 1.8-mm electrode enabled recanalization of the stent. In another who underwent ablation in the extrahepatic duct, however, a larger electrode was required. There were no procedure-related complications. Transpapillary microwave coagulation of occluded stents appears to be an alternative to percutaneous microwave coagulation with an electrode fitting the stent size. The technique might be easier with the use of a redesigned electrode with a guide wire lumen.

Knitted nitinol stent insertion for various intestinal stenoses with a modified delivery system.

BACKGROUND: Insertion of metallic stents for esophageal stenoses is well established, but these stents are technically difficult to place elsewhere in the GI tract. Moreover, major complications have occurred when metal stents with sharp ends have been placed in these locations. The currently available flexible, blunt-ended, knitted nitinol stent is intended for use only in the esophagus. Because its short delivery system cannot reach segments of the gut distal to the esophagus, the delivery device was modified to facilitate intestinal access, and its performance was evaluated in the treatment of malignant intestinal obstructions. METHODS: The Ultraflex delivery system was modified by connecting an additional plastic tube and a suture cord; the length was increased from 95 cm to 150 cm or more. Stents used were 18 to 23 mm in diameter, and 10 to 15 cm in length. A knitted metal stent was inserted by using the modified delivery system in 10 patients (7 men, 3 women, mean age 68 years); 8 with gastric outlet, 1 with jejunal, and 1 with proximal colonic obstruction. RESULTS: Metal stent insertion was successful in all patients with significant relief of symptoms and restoration of the ability to eat. The patient with a jejunal stent required placement of a second stent because of bending of the initial stent. No major complications (migration or perforation) occurred. CONCLUSION: This technique appears to facilitate placement of a metal stent with blunt ends in the duodenum, small intestine, and proximal colon. Manufacturers should offer blunt-ended stents with long delivery devices.