Formate-producing capacity provided by reducing ability of Streptococcus thermophilus nicotinamide adenine dinucleotide oxidase determines yogurt acidification rate.

Yogurt is made by fermenting milk with 2 lactic acid bacteria, Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus. To comprehensively understand the protocooperation mechanism between S. thermophilus and L. bulgaricus in yogurt fermentation, we examined 24 combinations of cocultures comprising 7 fast- or slow-acidifying S. thermophilus strains with 6 fast- or slow-acidifying L. bulgaricus strains. Furthermore, 3 NADH oxidase (Nox)-deficient mutants (Δnox) and one pyruvate formate-lyase deficient mutant (ΔpflB) of S. thermophilus were used to evaluate the factor that determines the acidification rate of S. thermophilus. The results revealed that the acidification rate of S. thermophilus monoculture determined the yogurt fermentation rates, despite the coexistence of L. bulgaricus, whose acidification rate was either fast or slow. Significant correlation was found between the acidification rate of S. thermophilus monoculture and the amount of formate production. Result using ΔpflB showed that the formate was indispensable for the acidification of S. thermophilus. Moreover, results of the Δnox experiments revealed that formate production required Nox activity, which not only regulated dissolved oxygen, but also the redox potential. The Nox provided the large decrease in redox potential required by pyruvate formate-lyase to produce formate. A highly significant correlation was found between formate accumulation and Nox activity in S. thermophilus. In conclusion, the formate production ability provided by the action of Nox activity determines the acidification rate of S. thermophilus, and consequently, regulates yogurt coculture fermentation.

Cultivation of rice for animal feed with circulated irrigation of treated municipal wastewater for enhanced nitrogen removal: comparison of cultivation systems feeding irrigation water upward and downward.

To achieve enhanced nitrogen removal, we modified a cultivation system with circulated irrigation of treated municipal wastewater by using rice for animal feed instead of human consumption. The performance of this modified system was evaluated through a bench-scale experiment by comparing the direction of circulated irrigation (i.e. passing through paddy soil upward and downward). The modified system achieved more than three times higher nitrogen removal (3.2 g) than the system in which rice for human consumption was cultivated. The removal efficiency was higher than 99.5%, regardless of the direction of circulated irrigation. Nitrogen in the treated municipal wastewater was adsorbed by the rice plant in this cultivation system as effectively as chemical fertilizer used in normal paddy fields. Circulated irrigation increased the nitrogen released to the atmosphere, probably due to enhanced denitrification. Neither the circulation of irrigation water nor its direction affected the growth of the rice plant and the yield and quality of harvested rice. The yield of rice harvested in this system did not reach the target value in normal paddy fields. To increase this yield, a larger amount of treated wastewater should be applied to the system, considering the significant amount of nitrogen released to the atmosphere.

Establishment of pure NOTES procedure using a conventional flexible endoscope: review of six cases of gastric gastrointestinal stromal tumors.

An increasing number of reports have recently been published on hybrid natural orifice transluminal endoscopic surgery (NOTES). These reports do not address how to complete an operation with a flexible endoscope alone (pure NOTES), but rather how to combine use of an endoscope and a laparoscope. Surgical procedures using flexible and rigid endoscopes have been developed using different processes and concepts. Recognizing this conceptual difference, we conducted a study to address how to establish a pure NOTES procedure. Six patients with gastric gastrointestinal stromal tumors (GISTs) underwent hybrid NOTES. Each case was retrospectively reviewed to determine the appropriateness of the treatment and the usefulness of the endoscopic submucosal dissection (ESD) method, double-scope method, spaced perforation method, duodenal balloon occlusion method, and loop clip technique. The development of operative procedures that take advantage of the characteristics of flexible endoscopes, even with conventional flexible endoscopic devices and conventional endoscopes alone, may contribute to the realization of pure NOTES.

Quantum spin liquid emerging in two-dimensional correlated Dirac fermions.

At sufficiently low temperatures, condensed-matter systems tend to develop order. A notable exception to this behaviour is the case of quantum spin liquids, in which quantum fluctuations prevent a transition to an ordered state down to the lowest temperatures. There have now been tentative observations of such states in some two-dimensional organic compounds, yet quantum spin liquids remain elusive in microscopic two-dimensional models that are relevant to experiments. Here we show, by means of large-scale quantum Monte Carlo simulations of correlated fermions on a honeycomb lattice (a structure realized in, for example, graphene), that a quantum spin liquid emerges between the state described by massless Dirac fermions and an antiferromagnetically ordered Mott insulator. This unexpected quantum-disordered state is found to be a short-range resonating valence-bond liquid, akin to the one proposed for high-temperature superconductors: the possibility of unconventional superconductivity through doping therefore arises in our system. We foresee the experimental realization of this model system using ultra-cold atoms, or group IV elements arranged in honeycomb lattices.

Strongly correlated fermions after a quantum quench.

Using the adaptive time-dependent density-matrix renormalization group method, we study the time evolution of strongly correlated spinless fermions on a one-dimensional lattice after a sudden change of the interaction strength. For certain parameter values, two different initial states (e.g., metallic and insulating) lead to observables which become indistinguishable after relaxation. We find that the resulting quasistationary state is nonthermal. This result holds for both integrable and nonintegrable variants of the system.

Evaluation of treatment for gastro-oesophageal reflux disease with a proton pump inhibitor, and relationship between gastro-oesophageal reflux disease and Helicobacter pylori infection in Japan.

BACKGROUND: Effective therapy for gastro-oesophageal reflux disease (GERD) is associated with improvement in health-related quality of life. It remains unclear whether Helicobacter pylori infection protects against GERD. AIM: We evaluated the relationship between GERD and H. pylori, and whether the health-related quality of life score improved after medical treatment. METHODS: We enrolled 151 outpatients with upper abdominal symptoms; 81 patients received omeprazole 20 mg/day for 2 weeks. Health-related quality of life was assessed using the Gastrointestinal Symptom Rating Scale (GSRS) and the Psychological General Well-Being (PGWB) index. H. pylori infection was diagnosed by serum antibody or endoscopy and the relationship between GERD and H. pylori was evaluated. RESULTS: In GERD patients, the mean GSRS score improved from 2.20 to 1.67 following treatment (P < 0.01). The mean GSRS reflux symptom score improved from 2.96 to 1.67 (P < 0.01). The mean PGWB score improved from 96.36 to 107.34 (P < 0.01). All scores in GERD patients significantly improved compared with non-GERD patients. The H. pylori-positive ratio was 66.15% in GERD patients and 65.21% in non-GERD patients (P = 0.94). CONCLUSIONS: Health-related quality of life is useful for evaluation of proton pump inhibitor treatment in GERD. The presence of H. pylori was not associated with the prevalence of GERD.

[Mucosa-associated lymphoid tissue lymphoma; report of two cases].

Primary pulmonary malignant lymphoma is a rare disease that is thought to belong to a category of malignant lymphomas arising from mucosa-associated lymphoid tissue (MALT). We presented 2 cases of MALT lymphoma. Case 1: In a 39-year-old woman, an abnormal shadow was detected in chest radiography in the left S3. The diagnosis was organizing pneumonia in consequence of the further examination. One year after an growing abnormal shadow was detected again, we performed the tumor resection with the thoracoscopy in the possibility of malignancy. The pathological diagnosis was MALT lymphoma. Case 2: In a 70-year-old man, middle lobe syndrome was detected in chest radiography. As a result of the bronchial biopsy, the lesion was suspected of MALT lymphoma. Right middle lobectomy was performed, and the tumor was diagnosed as a MALT lymphoma histologically. He underwent an effective postoperative radiotherapy and has had no evidence of recurrence.

Local quantum criticality in confined fermions on optical lattices.

Using quantum Monte Carlo simulations, we show that the one-dimensional fermionic Hubbard model in a harmonic potential displays quantum critical behavior at the boundaries of a Mott-insulating region. A local compressibility defined to characterize the Mott-insulating phase has a nontrivial critical exponent. Both the local compressibility and the variance of the local density show universality with respect to the confining potential. We determine a generic phase diagram, which allows the prediction of the phases to be observed in experiments with ultracold fermionic atoms trapped on optical lattices.

Autoimmune hepatitis in a patient with systemic lupus erythematosus.

We report a female patient with systemic lupus erythematous (SLE), hyperbilirubinemia and high serum value of ALT. International autoimmune hepatitis (AIH) score showed definite AIH before treatment, but autoantibodies could not make a differential diagnosis of AIH and SLE-associated hepatitis. Liver biopsy showed periportal hepatitis with lymphoplasmacytic infiltration, but neither parenchymal collapse nor rosette formation could be found. Pericarditis, pleuritis and nephritis were improved as well as liver injury after administration of prednisolone, and no repeated attack has been present these 4 years. Our case suggested invalidity of AIH score among patients of SLE, and liver histology should be inferred most important at present to make a differential diagnosis of lupus hepatitis or AIH in patients with SLE.

Association of the HLA-DRB1 gene locus with gastric adenocarcinoma in Japan.

BACKGROUND AND AIM: Helicobacter pylori infection is associated with gastric adenocarcinoma, however, the odds ratio is relatively low. The aim of the present study was to investigate host genetic factors that increase the risk of gastric adenocarcinoma among H. pylori-infected individuals. METHODS: A total of 70 patients with early gastric adenocarcinoma and 121 unrelated healthy controls were examined for H. pylori infection and HLA-DRB1 genotyping. The frequencies of HLA-DRB1 alleles were compared among groups. RESULTS: The allele frequency of DRB1*04051 was significantly higher in patients with gastric adenocarcinoma (17.9%) than in controls (7.9%) (P(correct) = 0.045). The odds ratio of gastric adenocarcinoma associated with the presence of the HLA-DRB1*04051 allele compared with its absence was 2.55 (95% confidence limits, 1.35-4.83). This genetic risk was not associated with H. pylori infection. There was no significant difference in the HLA-DRB1 allele frequency between H. pylori-positive and H. pylori-negative controls. The frequency of genotypes that possessed the DRB1*04051 allele in gastric adenocarcinoma patients (34.3%) was significantly higher than that in H. pylori-negative controls (11.9%) (p = 0.0089) and H. pylori-positive controls (15.2%) (p = 0.0066). CONCLUSION: These findings suggest that immunogenetic factors for susceptibility to gastric adenocarcinoma are present in the host, the HLA-DRB1*04051 allele is a host genetic risk factor for gastric adenocarcinoma, and that this genetic risk is independent of H. pylori infection.

Antiholons in one-dimensional t-J models.

Using a newly developed hybrid Monte Carlo algorithm for the nearest-neighbor (nn) t-J model, we show that antiholons identified in the supersymmetric inverse squared (IS) t-J model are clearly visible in the electron-addition spectrum of the nn t-J model at J=2t and also for J=0.5t, a value of experimental relevance.

Mott domains of bosons confined on optical lattices.

In the absence of a confining potential, the boson-Hubbard model exhibits a superfluid to Mott insulator quantum phase transition at commensurate fillings and strong coupling. We use quantum Monte Carlo simulations to study the ground state of the one-dimensional bosonic Hubbard model in a trap. Some, but not all, aspects of the Mott insulating phase persist. Mott behavior occurs for a continuous range of incommensurate fillings, very different from the unconfined case, and the establishment of the Mott phase does not proceed via a traditional quantum phase transition. These results have important implications for interpreting experiments on ultracold atoms on optical lattices.

Investigation of parenchymal cell differentiation in organotypic slice culture of mouse fetal liver under administration of sodium butyrate.

The fetal mouse liver tissues in our organotypic slice culture were spread and flattened for at least 3 weeks; small, round cells were distributed in the center and polygonal cells were seen in the periphery. Ultrastructurally, polygonal cells showed abundant rough endoplasmic reticulum and mitochondria. They expressed albumin (ALB) and alpha-fetoprotein (AFP) for at least 3 weeks, and Cx32-immunoreactivity was also seen in a plaque on the cells. Many proliferating cell nuclear antigen (PCNA)-positive cells were observed at the periphery, and there were scattered CK-19-positive cells. The spreading of the fetal liver tissue in organotypic slice culture was reduced in medium containing sodium butyrate (SB). The expression of ALB was well maintained in polyglonal cells of the SB(+) group 3 weeks after culture and AFP-immunoreactivity was decreased in the SB(+) group. The concentration of ALB in the medium was significantly higher in the SB(+) than in the SB(-) group. CK-19-positive cells in the SB(+) group were increased in number more than those in the SB(-) group. PCNA-positive cells were less numerous in the SB(+) group, and Cx32-positive plaques were increased. SB can help immature hepatocytes to differentiate into the mature type and the cholangiocytic lineage, reducing their proliferation. These findings suggest that parenchymal cells in our organotypic slice culture of the fetal mouse liver can maintain structure and function as in vivo for the long term, and SB is shown to be a differentiation inducer of parenchymal cells in the slice culture.

Immunohistochemical localization of CEA, CA19-9 and DU-PAN-2 in hepatitis C virus-infected liver tissues.

AIMS: We investigated expression of CEA, CA19-9 and DU-PAN-2 in liver tissues of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma, measuring their serum value to clarify their clinical significance, and proliferating cell nuclear antigen (PCNA) was assessed in serial sections to determine whether expression of these molecules in chronic liver disease was related to regeneration of biliary ducts. METHODS AND RESULTS: Liver tissues were biopsied under peritoneoscopy or echo-guidance and resected surgically among 63 patients with anti-hepatitis C virus-positive sera. There were 26 cases of chronic hepatitis, 21 cases of liver cirrhosis and 16 cases of hepatocellular carcinoma (four cases of mixed type). They were simultaneously used for immunocytochemistry for CEA, CA19-9 and DU-PAN-2, and PCNA was demonstrated in serial liver tissues by immunohistochemistry. Serum CEA, CA19-9 and DU-PAN-2 were measured by radioimmunoassay or enzyme immunoassay. In chronic hepatitis and liver cirrhosis CEA immunoreactivity was seen on membranes facing bile canaliculi and in bile ductules. Both CA19-9 and DU-PAN-2 immunoreactivity were observed in bile ductules in chronic hepatitis liver cirrhosis and non-neoplastic areas surrounding hepatocellular carcinoma, and CA19-9 was also present in interlobular bile ducts. PCNA immunoreactivity was not detected in marker-positive bile ductules or interlobular bile ducts. In hepatocellular carcinoma CEA immunoreactivity was seen on membrane facing dilated bile canaliculi in glandular structures, and CEA, CA19-9 and DU-PAN-2 immunoreactivity was observed in cholangiolar areas in mixed type of hepatocellular carcinoma. CONCLUSIONS: CEA in chronic hepatitis and liver cirrhosis is expressed not only in bile ductules but also on membrane facing bile canaliculi, and both CA19-9 and DU-PAN-2 were seen in different levels of biliary ducts. These molecules were expressed in bile ductules in surrounding non-neoplastic areas of hepatocellular carcinoma, and their expression was not associated with regeneration of biliary ducts. CEA expression was present in the trabecular type of hepatocellular carcinoma, and CA19-9 and DU-PAN-2 were observed in cholangiolar areas in mixed type of hepatocellular carcinoma.

Thoracoscopic treatment for spontaneous hemopneumothorax.

Spontaneous hemopneumothorax is a rare clinical entity sometimes requiring an operation in the early stage. Two patients who underwent successful video-assisted thoracic surgery (VATS) for spontaneous hemopneumothorax are presented. In both cases, the bleeding point was clearly identified, and hemostasis was easily obtained by clipping the point and placing three access ports in the usual fashion. Furthermore, the evacuation of clotted blood and resection of bulla were performed with no difficulties. The postoperative courses were smooth, and no complications occurred, although the preoperative general condition in the second case was hemodynamically unstable. The advantages of VATS over conventional thoracotomy include less time required to access the pleural cavity, a better view, and more facilitated manipulation during surgery. Because spontaneous hemopneumothorax is a benign disease, VATS should be considered an initial treatment option in all patients with this condition, even those with active bleeding.

Eradication of Helicobacter pylori infection induces an increase in body mass index.

BACKGROUND: The relationship between H. pylori infection and body mass indices is controversial. AIM: To investigate the relationship between H. pylori infection and body indices, and to examine the effect of H. pylori eradication therapy on body indices. METHODS: Nine-hundred and thirty-two employees of an industrial corporation were examined for H. pylori infection and body mass indices. Three hundred and two H. pylori-positive cases diagnosed with chronic gastritis by upper gastrointestinal endoscopy or radiography underwent eradication therapy. Body mass indices, serum total cholesterol levels and symptom scores were obtained before and at 12 months after eradication therapy. RESULTS: There was no significant difference in body weight, body mass index (BMI) or serum total cholesterol level between the H. pylori-positive and H. pylori-negative groups. However, body weight and BMI increased significantly 12 months after eradication of H. pylori infection. In contrast, there was no significant difference in body weight and BMI 12 months after eradication therapy in the non-eradication group. Serum total cholesterol levels did not change after eradication therapy in either the eradication or non-eradication groups. CONCLUSION: Eradication of H. pylori infection induced an increase in BMI in industrial workers with chronic gastritis in Japan.