Suppressive effect of ascorbic acid on the mutagenesis induced by the bystander effect through mitochondrial function.

Here, we focused on suppressive effect of ascorbic acid (AsA) on changes in mitochondrial function and mutagenesis by the radiation- induced bystander effect (RIBE). In mammalian cell lines, medium transfer assay was performed and conditioned medium including secreted factors after X-irradiation were examined to detect the RIBE. We found that the membrane potential and increased levels of superoxide radical (O2(-)) in mitochondria were modulated in cells treated with conditioned medium from irradiated cells. The result of the present study also demonstrated that increases in reactive oxygen species (ROS) levels led to the induction of gene mutations. Interestingly, the modulations in mitochondria, in addition to mutation inductions by RIBE, were completely suppressed by treatment with AsA in cells treated with conditioned medium. These results suggest that mutagenesis, which may have resulted from secreted factors involving the RIBE, may be induced by ROS that are localized in mitochondria and may be relieved by AsA.

Independent histological risk factors for lymph node metastasis of superficial esophageal squamous cell carcinoma; implication of claudin-5 immunohistochemistry for expanding the indications of endoscopic resection.

Endoscopic resection is curative for superficial esophageal squamous cell carcinoma (ESCC) limited to the lamina propria. Endoscopic resection is not recommended for superficial ESCC invading muscularis mucosa or submucosa, however, because of the high frequency of lymph node metastasis (LNM) in such patients. Methods to more accurately predict LNM by analysis of endoscopically resected specimens are needed. Patients with superficial ESCC who underwent surgery without prior chemoradiotherapy (n= 110) were retrospectively examined to determine whether LNM correlated with immunohistochemical parameters and conventional histological parameters, including depth of invasion and vascular permeation. Cancer cell expression of claudins-1, 5, and 7, E-cadherin, beta-catenin, and matrix metalloproteinase 7 was evaluated. Univariate analysis revealed that LNM correlated with claudin-5 expression, but not any other immunohistochemical parameter examined. Multivariate analysis revealed three independent risk factors for LNM: aberrant claudin-5 expression in cancer cells (odds ratio; OR [95% confidence interval]= 4.61[1.44-14.77]), depth of submucosal invasion greater than 200 microm (3.55 [1.02-13.17]), and positive lymphatic permeation (3.34 [1.22-9.15]). LNM was found in one of 29 (3.4%) patients with none of these three risk factors, and in 32 of 81 (39.5%) patients with one or more of these risk factors. In superficial ESCC, routine analysis of claudin-5 expression in cancer cells together with depth of invasion and lymphatic permeation may be useful for predicting LNM and thereby reducing the number of patients undergoing additional surgery after successful endoscopic resection.

Relation between outcomes and localisation of p-mTOR expression in gastric cancer.

The mammalian target of rapamycin (mTOR), a Ser/Thr protein kinase that mediates intracellular signalling related to cell growth, proliferation, and differentiation, has received considerable interest as a possible target for cancer treatment. We evaluated the correlation of mTOR expression with clinicopathological features, outcomes, and the expression of Akt, an upstream regulator of mTOR, in gastric cancer. Tumour samples were obtained from 109 patients with gastric adenocarcinomas who underwent a radical gastrectomy. The expressions of phosphorylated mTOR (p-mTOR) and phosphorylated Akt (p-Akt) in the cytoplasm and in the nucleus were analysed by immunohistochemical staining. Cytoplasmic p-mTOR expression positively correlated with the depth of tumour invasion (T1 vs T2-4, P=0.003), involved lymph nodes (P=0.010), and tumour stage (I vs II-IV, P=0.002). In contrast, nuclear p-mTOR expression negatively correlated with these variables (P<0.001,=0.035, and <0.001). Cytoplasmic p-mTOR expression was associated with significantly poorer relapse-free survival (RFS, P=0.037) and overall survival (OS, P=0.024), whereas nuclear p-mTOR expression was associated with better RFS and OS (P=0.029, 0.059). Neither cytoplasmic nor nuclear p-Akt expression was associated with any clinicopathological factor or with survival. Localisation of p-mTOR may play an important role in tumour progression and outcomes in patients with gastric cancer.

Effect of MDR1 C3435T polymorphism on cure rates of Helicobacter pylori infection by triple therapy with lansoprazole, amoxicillin and clarithromycin in relation to CYP 2C19 genotypes and 23S rRNA genotypes of H. pylori.

BACKGROUND: Polymorphism in MDR1 is associated with variation in the plasma level of a proton pump inhibitor. AIM: To investigate whether MDR1 polymorphism is associated with eradication rates of Helicobacter pylori by a triple therapy with lansoprazole, amoxicillin and clarithromycin in relation to CYP2C19 genotype status and bacterial susceptibility to clarithromycin. METHODS: A total of 313 patients infected with H. pylori completed the treatment with lansoprazole 30 mg b.d., clarithromycin 200 mg b.d. and amoxicillin 750 mg b.d. for 1 week. MDR1 C3435T polymorphism and CYP2C19 genotypes of patients and sensitivity of H. pylori to clarithromycin were determined. RESULTS: Logistic regression analysis revealed that the MDR1 polymorphism as well as CYP2C19 genotypes of patients and clarithromycin-resistance of H. pylori were significantly associated with successful eradication. Eradication rates for H. pylori were 82% (83/101: 95% CI = 73-89), 81% (112/139: CI = 73-87), and 67% (44/73: CI = 48-72) in patients with the MDR1 3435 C/C, C/T and T/T genotype, respectively (P = 0.001). CONCLUSIONS: Polymorphism of MDR1 is one of the determinants of successful eradication of H. pylori by the triple therapy with lansoprazole, amoxicillin and clarithromycin, together with CYP2C19 genotype and bacterial susceptibility to clarithromycin.

The role of leptin during the development of mouse preimplantation embryos.

Leptin is known to regulate diverse reproductive functions, and recent studies have implicated involvement of leptin in the early mouse embryo development. The aim of the present study was to investigate the expression of leptin and its functional receptor (OB-Rb) in mouse oocyte and preimplantation embryo, and to examine whether leptin influenced the early embryo development. Leptin mRNA was detected in blastocyst and hatched blastocyst, and OB-Rb mRNA was detected in oocytes, 1-cell, 2-cell, morula, blastocyst and hatched blastocyst. As for the origin of leptin, leptin mRNA was identified in both the oviduct and uterus of the pregnant mouse. Furthermore, in the pregnant mouse, the levels of leptin in uterine fluid were higher than those in the non-pregnant mouse. Supplementation of culture medium with leptin promotes the development of preimplantation embryos from 2-cell stage to the blastocysts, fully expanded blastocysts and hatched blastocysts. Leptin significantly increased the total cell number of blastocysts, and the effect was preferentially observed in the trophectoderm. These findings raise the possibility that leptin regulates the development of mouse preimplantation embryo through a paracrine pathway.

Impaired Delta Np63 expression associates with reduced beta-catenin and aggressive phenotypes of urothelial neoplasms.

p63, a homologue of the p53 gene, is considered to be essential for the normal development of stratified epithelia including urothelium. To examine possible roles of p63 in urothelial tumorigenesis, p63 expression was systematically examined in normal urothelium, low-grade papillary noninvasive (LPN) urothelial tumours, and high-grade or invasive carcinomas, using either an isoform-nonspecific or a Delta N-isoform-specific antibody. Expression profiles of p63 were also analysed in cultured cells. Immunoreactivity with the two antibodies was virtually identical in tissue samples examined. Basal and intermediate cell layers of normal urothelium showed intense nuclear p63 immunostaining. This normal staining pattern was preserved in a majority of LPN tumours, whereas it was frequently impaired in high-grade or muscle-invasive carcinomas. At the mRNA level, Delta Np63 expression predominated over TAp63, and amounts of Delta Np63 mRNA correlated with p63 immunoreactivity, confirming that Delta Np63 accounts for p63 expressed in urothelial tissues. In cultured cells, Delta Np63 was also expressed in low-grade tumour cells as well as normal urothelial cells, but undetectable in high-grade aggressive carcinoma cells. Interestingly, impaired Delta Np63 expression significantly associated with reduced beta-catenin expression that was possibly related to progression of urothelial neoplasms. Thus, impaired Delta Np63 expression characterises aggressive phenotypes of urothelial neoplasms.

Dose-dependent effect of an oral adsorbent, AST-120, in patients with early chronic renal failure.

We evaluated the dose dependence of an oral adsorbent, AST-120, in 31 patients with early chronic renal failure (baseline serum creatinine: 1.2-3.0 mg/dl). Twenty-three patients were given AST-120 and eight patients were not. AST-120 was administered at three different maintenance doses, < 3.0 g, 3.0 g and 6.0 g/day, according to patients' ability to tolerate treatment. The treatment period was 12 months. The slope of the reciprocal of serum-creatinine concentration versus time was calculated to assess the progression of renal failure. This slope became significantly less steep after AST-120 treatment at 6.0 g/day, but did not change significantly at the other doses. These findings suggest that 6.0 g/day of AST-120 may delay the initiation of dialysis in patients with early chronic renal failure.

Invasive subglottal aspergillosis in a patient with severe aplastic anemia: a case report.

A 19-year-old female with aplastic anemia who developed subglottal aspergillosis is reported. She presented with fever, cough and stridor. Inspiratory dyspnea progressed rapidly and emergent tracheostomy was performed, which confirmed the diagnosis. In spite of intensive anti-fungal treatment combined with adoptive immunotherapy, Aspergillus infection expanded and she died of pulmonary aspergillosis. Autopsy revealed the fungal mass obstructing the trachea and disseminated pulmonary aspergillosis. Difficulties in diagnosis and management of subglottal Aspergillus infection are discussed.

Histopathological diagnosis of biopsy samples from early esophageal carcinoma.

Carcinoma of the esophagus is frequently diagnosed in advanced clinical stages. When an esophagic carcinoma has infiltrated the submucosa or the muscular or serosa, metastases are a common finding. Thus, early diagnosis and opportune treatment are vital for patients with this type of neoplasm. Timely diagnosis can be done through endoscopic or X-ray studies and confirmed through a histopathological study by directed biopsy. We presently report the case of a 65 year old man with precedents of achalasia who underwent an endoscopic study using the Lugol staining technique for suspected malignant lesion classified as 0-IIc. After two biopsies it was diagnosed as early carcinoma of the esophagus and was subjected to mucosectomy. Histopathological findings are reviewed at architectural and cellular level and are essential to establish the diagnosis of early neoplastic lesions of the esophagus epithelium. These cellular changes are corroborated by immunohistochemical studies with nuclear expression of p53. The relevant literature was reviewed and experiences by Japanese and North American pathologists compared with emphasis on the need for multidisciplinary management to make an early diagnosis by endoscopic studies, Lugol staining, X-rays, biopsy and conservative treatment based on mucosectomy.

Early gastric carcinoma: evaluation with high-spatial-resolution MR imaging in vitro.

PURPOSE: To determine signal intensity characteristics of the gastric wall layers and to assess the accuracy of the evaluation of early gastric carcinomas in vitro by using resected specimens studied with high-spatial-resolution magnetic resonance (MR) imaging. MATERIALS AND METHODS: Fifteen gastric specimens obtained from patients suspected of having early gastric carcinoma were studied with a 1.5-T MR system with a 4-cm-diameter loop coil. High-spatial-resolution spin-echo MR images were obtained with a field of view of 50 mm, a matrix of 256 x 256, and a section thickness of 2 mm, resulting in a voxel size of 0.08 mm(3). Findings from MR images were compared with histopathologic findings. RESULTS: T1- and T2-weighted MR images clearly depicted the normal gastric wall as consisting of four and six layers, respectively, which corresponded well to the histologic layers. In 14 (93%) of 15 gastric carcinomas, the depth of mural invasion visualized with MR imaging correlated well with the histopathologic stage. The stage determined with MR imaging, however, was lower in one instance (7%) than the histopathologic stage. MR imaging also depicted the gross features of the tumor, presence of ulceration, and adjacent lymph node swelling. CONCLUSION: High-spatial-resolution MR imaging has a high diagnostic accuracy in the evaluation of the mural invasion of early gastric carcinoma in vitro and thus potentially enables preoperative histopathologic staging.

Expression of Fas and Fas ligand mRNA in rat and human preimplantation embryos.

The Fas-Fas ligand (L) system is one of the major signalling pathways to induce apoptosis in various cells and tissues. The aim of this study was to investigate the expression of the Fas-Fas L system in rat and human oocytes and preimplantation embryos. We determined the expression of Fas and Fas L mRNA of rat oocytes and embryos up to the blastocyst stage, and of human embryos at the 2- or 4-cell stage, using reverse transcription polymerase chain reaction (PCR) and nested PCR techniques. Moreover, we investigated the expression of Fas mRNA in human fragmented embryos. In rat embryos, Fas mRNA was expressed at the 2-cell stage only, whereas Fas L mRNA was expressed in oocytes, and at the pronuclear (1-cell) and 2-cell stages. In human embryos, Fas mRNA was expressed at the 4-cell stage only, whereas Fas L mRNA was expressed at both 2- and 4-cell stages. Human fragmented embryos expressed both Fas and Fas L mRNA. Because simultaneous expression of Fas and Fas L mRNA occurred in 2-cell rat embryos and in 4-cell human embryos, the Fas-Fas L system might be involved in the apoptotic pathway in the early embryos of these species.

Improvement in atrophic gastritis and intestinal metaplasia in patients in whom Helicobacter pylori was eradicated.

BACKGROUND: Glandular atrophy and intestinal metaplasia are precancerous lesions; whether Helicobacter pylori eradication affects these lesions is controversial. OBJECTIVE: To determine whether H. pylori eradication is associated with improvement in glandular atrophy and intestinal metaplasia after at least 1 year. DESIGN: Single-blind, uncontrolled prospective trial. SETTING: Academic gastroenterology clinic in Japan. PATIENTS: 163 consecutive patients with dyspepsia and H. pylori infection. INTERVENTION: One-week course of a proton-pump inhibitor and antibiotic therapy. MEASUREMENTS: Endoscopic examination with antral and corporal biopsy was done before treatment and at 1 to 3 and 12 to 15 months after treatment. Gastritis, atrophy, and metaplasia were graded according to the updated Sydney System. RESULTS: In the 115 patients in whom H. pylori was eradicated, inflammation and mean neutrophil activity had decreased by 1 to 3 months, and both glandular atrophy in the corpus and intestinal metaplasia in the antrum had decreased by 12 to 15 months. Glandular atrophy in the corpus improved in 34 (89%) of 38 patients with atrophy before treatment, and intestinal metaplasia in the antrum improved in 28 (61%) of 46 patients who had metaplasia at baseline. In the 48 patients in whom eradication was unsuccessful, no significant histologic changes were observed. CONCLUSION: In the year after successful H. pylori eradication, precancerous lesions improved in most patients.

Fibrous dysplasia with cystic appearance in maxillary sinus.

Fibrous dysplasia (FD) in the paranasal sinuses is uncommon, and its management may be difficult. We report the case of a 25-year-old female with FD exhibiting a cystic appearance in the maxillary sinus. The patient had been complaining of facial swelling for few years. Imagery study showed a cystic lesion and dense bone changes in the maxillary bone. Inferior meatal antrostomy with a nasal endoscope failed to confirm a histological diagnosis. After a 3-year follow-up, the degree of facial swelling was unchanged, and the patient underwent middle meatal antrostomy and was diagnosed with FD.

Electron spin echo study of long-lived radicals which cause mutation in gamma-ray irradiated mammalian cells.

Long-lived radicals, produced by gamma-ray irradiation of mammalian cells at room temperature, cause mutation and morphological transformation in the cells. The local environment near the long-lived radicals in irradiated cells was investigated here by the analysis of electron spin echo envelope modulation (ESEEM) spectra. The number of hydrogen (deuterium) atoms surrounding the long-lived radical, which may correspond to the number of water molecules, was estimated roughly as one or two. It is postulated that the long-lived radicals are generated in the interior of biopolymers. The radicals are not produced by the reaction of OH radicals, but mainly by the decomposition of biopolymer which absorbed directly the energy of the ionizing radiation.

Chaperonin 10 in the rat oocytes and early embryos: its expression and activity for early pregnancy factor.

PROBLEM: The aim of this study was to investigate the expression of chaperonin (cpn) 10 and cpn 60 mRNA in oocytes or embryos, and to further explore the possibility that early pregnancy factor (EPF) is identical with cpn 10. METHOD OF STUDY: The expressions of cpn 10 and cpn 60 mRNA in oocytes and embryos at the different stages (1-cell, 2-cell, 8-cell, and morula) were examined by polymerase chain reaction techniques. The EPF activity of native rat cpn 10 isolated from rat livers was evaluated by the rosette inhibition test. RESULTS: Similar levels of mRNA of cpn 10 and cpn 60 were detected in oocytes and embryos at every stage. There were no detectable EPF activities in the native cpn 10. Immunoprecipitation using polyclonal antibodies against cpn 10 did not affect the activity of EPF in the pregnant rat serum. CONCLUSION: Our results do not support the hypothesis that cpn 10 is identical with EPF.

Endoscopic and histological comparison of nonulcer dyspepsia with and without Helicobacter pylori infection evaluated by the modified Sydney system.

OBJECTIVE: Our aim was to identify endoscopic features associated with Helicobacter pylori (H. pylori) infection in patients with nonulcer dyspepsia. METHODS: A total of 50 infected patients with nonulcer dyspepsia who underwent endoscopy with antral and corporal biopsies and 50 patients matched for age and sex but with nonulcer dyspepsia without H. pylori were reviewed retrospectively by three endoscopists blinded to the H. pylori status and the patient's history. The endoscopic findings of gastritis, classified by a modification of the Sydney system as present or absent, were evaluated, and the histological severity was graded by the updated Sydney system. RESULTS: For endoscopic features, the odds ratio was 53.1 (95% confidence interval, 6.8-414.9) for edema, 18.8 (5.8-60.5) for erythema with reddish streaks excluded, 0.0275 (0.0002-0.477) for reddish streaks, 17.4 (0.97-313.7) for friability, 14.2 (5.1-40.0) for exudate, 17.2 (2.2-137.6) for flat erosions, 2.54 (0.81-7.94) for raised erosions, 40.1 (2.3-694.5) for rugal hypertrophy, 19.1 (2.4-151.6) for rugal atrophy, 96.2 (23.4-395.9) for a vascular pattern, 0.125 (0.010-1.06) for bleeding spots, and 21.0 (2.6-166.5) for nodularity. The histological severity of inflammation, neutrophil activity, and atrophy in the antrum and corpus and of metaplasia in the antrum was greater in the infected patients than in the noninfected patients. CONCLUSIONS: Endoscopic features associated with H. pylori were a vascular pattern, edema, rugal hypertrophy, nodularity, rugal atrophy, erythema with reddish streaks excluded, flat erosions, and exudate. These endoscopic features were associated with the histological findings of inflammation, neutrophil activity, atrophy, and metaplasia.

Direct infusion of ascites into the blood circuit during hemodiafiltration in uremic patients with cirrhosis.

Two chronic dialysis patients with massive ascites caused by cirrhosis were treated by infusion of their ascites directly into the blood circuit. This stabilized their hemodynamics during dialysis, facilitating the control of weight gain and ascites, and thus markedly improving their general condition. Long-term use of this therapy was able to prevent the accumulation of ascitic fluid. Interestingly, fever occurred when this therapy was performed with hemodialysis, but not with hemofiltration or hemodiafiltration, suggesting that a pyrogen in the ascites was removed by filtration.