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.

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.

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.

Increased expression of the sodium/iodide symporter in papillary thyroid carcinomas.

Iodide is concentrated to a much lesser extent by papillary thyroid carcinoma as compared with the normal gland. The Na+/I- symporter (NIS) is primarily responsible for the uptake of iodide into thyroid cells. Our objective was to compare NIS mRNA and protein expression in papillary carcinomas with those in specimens with normal thyroid. Northern blot analysis revealed a 2.8-fold increase in the level of NIS mRNA in specimens with papillary carcinoma versus specimens with normal thyroid. Immunoblot analysis using anti-human NIS antibody that was produced with a glutathione S-transferase fusion protein containing NIS protein (amino acids 466-522) showed the NIS protein at 77 kD. The NIS protein level was elevated in 7 of 17 cases of papillary carcinoma but was not elevated in the normal thyroid. Immunohistochemical staining revealed abundant NIS in 8 of 12 carcinomas, whereas NIS protein was barely detected in specimens with normal thyroid. Although considerable patient-to-patient variation was observed, our results indicate that NIS mRNA is elevated, and its protein tends to be more abundant, in a subset of papillary thyroid carcinomas than in normal thyroid tissue.

Targeted killing of carcinoembryonic antigen (CEA)-producing cholangiocarcinoma cells by polyamidoamine dendrimer-mediated transfer of an Epstein-Barr virus (EBV)-based plasmid vector carrying the CEA promoter.

The present study reports a novel nonviral method to efficiently and specifically target carcinoembryonic antigen (CEA)-producing cholangiocarcinoma (CC) cells in vitro. Epstein-Barr virus (EBV)-based and conventional plasmid vectors were constructed that possess the beta-galactosidase (beta-gal) or herpes simplex virus-1 (HSV-1) thymidine kinase (Tk) genes as well as tandem repeats of the human genomic sequence -82 to -42 bp from the transcriptional start site of the CEA gene. The plasmids were transfected by means of polyamidoamine dendrimer into CEA-positive (HuCC-T1) or -negative cell lines. Transfection of the conventional plasmid vector with the CEA promoter and beta-gal gene resulted in a very low or undetectable level of marker gene expression even in the CEA-positive cell line. Transferring the HSV-1 Tk gene by conventional plasmid did not affect the susceptibility of HuCC-T1 cells to ganciclovir. In marked contrast, strong beta-gal expression was specifically obtained in HuCC-T1 cells by transfecting the EBV-based plasmid in which the CEA promoter and a ubiquitous promoter (SRalpha) are employed to drive the EBV-encoded nuclear antigen 1 (EBNA1) and beta-gal genes, respectively (pTES.beta). Furthermore, CEA-positive but not -negative tumor cells were rendered highly susceptible to ganciclovir when transfected with the EBV-based vector that carries the CEA promoter-EBNA1 and SRalpha-HSV-1 Tk genes (pTES.Tk). These results strongly suggest that the EBV-based plasmid vector/cationic polymer system (EBV/polyplex) equipped with the CEA promoter provides an efficient nonviral method for the targeted gene therapy of CEA-producing malignancies.

Birefringent (calcium oxalate) crystals in thyroid diseases. A clinicopathological study with possible implications for differential diagnosis.

To elucidate the nature and significance of calcium oxalate crystals in the pathologic thyroid, we used polarized light microscopy to review 357 thyroid lesions. Under polarized light, calcium oxalate crystals had brilliant birefringence, and they were invariably identified within the colloid of follicles. The highest prevalence of crystals (87.9%) was in nodular goiters; they were also found in 60.0% of follicular adenomas and 33.3% of follicular carcinomas. The prevalence of crystals in papillary carcinomas was very low (5.4%). Therefore, the overall prevalence was 69.4% in benign nodules and 7.6% in malignant nodules. A heavy deposit of crystals was seen only in benign nodules except for one case of follicular carcinoma. Graves' disease, focal thyroiditis, and subacute thyroiditis showed low prevalence: 25.0, 46.9, and 40.0%, respectively. In cases of toxic nodules, the crystals were sparsely identified within nodules, but abundantly observed in surrounding inactive tissues. Immunohistochemistry for thyroid hormones confirmed that the crystals tended to appear in inactive follicles. On tissue x-ray film, the crystals appeared as microcalcifications. As a result of these findings, we suggest that examinations of crystals are likely to be useful in the differential diagnosis of thyroid diseases and in possible estimations of the functional state of lesions.

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.

The effect of Helicobacter pylori eradication therapy on dyspepsia symptoms in industrial workers in Japan.

BACKGROUND: The relationship between Helicobacter pylori infection and non-ulcer dyspepsia is still controversial. The potential benefits and risks of the treatment could depend on local conditions, such as the prevalence of the infection and the local rates of gastric cancer. AIM: To evaluate the effects of H. pylori eradication therapy on non-ulcer dyspepsia symptoms in industrial workers in Japan. METHODS: A total of 615 employees of an industrial corporation were examined for H. pylori infection and symptom scores; 215 H. pylori-positive non-ulcer dyspepsia cases underwent eradication therapy. Symptom scores were also analysed 12 months after the eradication therapy. Serum pepsinogen A and pepsinogen C levels were analysed and chronic atrophic gastritis was serologically diagnosed on the basis of the criteria of a pepsinogen A < 70 ng/mL and pepsinogen A : pepsinogen C ratio < 3.0. RESULTS: The symptom score improved significantly in the cured cases, but not in the non-cured cases. The effect of the cure of H. pylori infection on symptoms was analysed according to the serological diagnosis of chronic atrophic gastritis. In both groups, cases with atrophic gastritis and cases with chronic gastritis only, the cure of infection was effective in improving symptoms. CONCLUSION: The cure of H. pylori infection was effective in reducing non-ulcer dyspepsia symptoms in industrial workers in Japan.

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.

Senile degenerative brain lesions and dementia.

In a study of senile degenerative lesions-including Alzheimer's neurofibrillary changes, senile plaques and amyloid angiopathy-the hippocampal area of the brain was examined by thioflavine T fluorescence microscopy in 146 consecutive autopsy patients over the age of 49. The incidence and quantity of neurofibrillary changes and senile plaques rose with age, and an approximate positive correlation in quantity was noted among the three kinds of degenerative change. The quantity of neurofibrillary lesions and senile plaques was significantly different between the demented and non-demented patients, but not between the severely and less severly demented patients. The cause of dementia was studied retrospectively, based on the extent of morphologic changes in the brain, thus classifying dementia into three types: degenerative, vascular, and mixed. Clinically, the mixed type resembled the vascular type with regard to major neurologic signs, and there was some similarity to the degenerative type with regard to mental features.

Pyruvate dehydrogenase activity and energy metabolite levels following bilateral common carotid artery occlusion in rat brain.

The influence of chronic cerebral hypoperfusion on cerebral energy metabolism was studied. The bilateral common carotid arteries of Wistar rats were occluded for 0, 2, 7, and 28 days. Cerebral energy metabolism was evaluated by assaying adenosine triphosphate (ATP), phosphocreatine (PCr), and lactate levels and measuring pyruvate dehydrogenase (PDH) activity (each time point, n = 6). Pathological changes were assessed light-microscopically by Klüver-Barrera staining and immunohistochemical labeling for astroglia (each time point, n = 3). There were no changes in ATP and PCr levels or PDH activity; there was slight but significant transient lactate accumulation at 2 days. Myelin pallor and increase in immuno-reactive astroglia were only observed at 28 days. These results indicate that chronic cerebral hypoperfusion induces delayed white matter changes in the corpus callosum of rat brain, but does not affect energy production.

Effects of CYP2C19 gene polymorphism on cure rates for Helicobacter pylori infection by triple therapy with proton pump inhibitor (omeprazole or rabeprazole), amoxycillin and clarithromycin in Japan.

BACKGROUND: Omeprazole is mainly metabolized by cytochrome P450 2C19 (CYP2C19) in the liver. Rabeprazole, on the other hand, is mainly metabolized to thioether-rabeprazole via a non-enzymatic pathway and partially metabolized to demethylated-rabeprazole by CYP2C19 in liver CYP2C19 status may affect cure rate for Helicobacter pylori infection with proton pump inhibitor triple therapy. AIM: To investigate whether genetic polymorphism of CYP2C19 and selected proton pump inhibitors (omeprazole or rabeprazole) were associated with cure rate for Helicobacter pylori infection using triple therapy with omeprazole or rabeprazole, amoxicillin, and clarithromycin. METHODS: A total of 170 Helicobacter pylori-positive patients with chronic gastritis were randomized to receive one of the following Helicobacter pylori eradication regimens; OAC (omeprazole 20 mg bd, amoxycillin 750 mg bd and clarithromycin 400 mg bd for 1 week) and RAC (rabeprazole 20 mg bd, amoxycillin 750 mg bd and clarithromycin 400 mg bd for 1 week). The CYP2C19 genotype; wild-type or two mutant genes (ml in exon 5 and m2 in exon 4), or both, were identified by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: In DAC regimen, cure rate (per protocol analysis) was 73.3% in homozygous extensive metabolizers, 86.1% in heterozygous extensive metabolizers, and 85.0% in poor metabolizers. In RAC regimen, the cure rate was 81.0% in homozygous extensive metabolizers, 82.9% in heterozygous extensive metabolizers, and 87.5% in poor metabolizers. Cure rate was not significantly different between the CYP2C19 genotypes in both regimens. CONCLUSION: Triple therapy with proton pump inhibitor (omeprazole or rabeprazole), amoxycillin, and clarithromycin is sufficiently effective in cure of Helicobacter pylori infection regardless of CYP2C19 status.

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.

Parenchymal cells proliferate and differentiate in an organotypic slice culture of the neonatal liver.

We applied organotypic slice culture of neonatal mouse liver tissues to maintain the parenchymal cells in ontogenesis and to investigate their proliferation and differentiation. Cultured tissue spread gradually over 3 weeks. Small basophilic cells formed several layers in the center of the cultured tissues, and a monolayer of polygonal cells was seen at the periphery. Albumin- and alpha-fetoprotein-immunoreactions were seen in polygonal cells, as were proliferating cell nuclear antigen-immunoreactions. Connexin 32- and 26-immunoreactions were observed in small plaques on the membrane of the polygonal cells, and electron microscopy showed gap junctional complexes. Ultrastructurally, polygonal cells had a round nucleus and abundant cytoplasmic organelles, and bile canaliculi were seen on the cytoplasmic membrane. Cytokeratin 19-immunoreactions were scattered in clusters. There were ultrastructurally bile-duct-like structures with microvilli on the inner surface of the cavity and tight junctions between their constituent cells. Quantitative analysis of albumin-, alpha-fetoprotein- and cytokeratin 19- or proliferating cell nuclear antigen-immunoreactivity in parenchymal cells showed changes of their phenotypes or maintenance of their proliferation in tissue culture. Our slice-culture system enabled us to maintain and to develop parenchymal cells in the liver tissue for at least 3 weeks. The findings suggest that organotypic slice culture applied to liver tissues in ontogenesis may be a useful tool not only to maintain parenchymal cells but also to investigate their proliferation and differentiation.

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.

Unilateral meningoencephalitis with hemispheric slowing on EEG.

We report a 12-year-old boy with unilateral meningoencephalitis due to non-herpes simplex virus. He experienced secondarily generalized partial seizures of the left extremities with loss of consciousness. In contrast with normal neuroimaging findings, interictal electroencephalograms (EEGs) showed prolonged slowing in the right hemisphere. This laterality agreed with the right brain dysfunction verified on neuropsychological examination. Follow-up EEG is important in such a subtle case with normal neuroimaging.

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.

[A case of ACTH-producing thymic carcinoid tumor with Cushing syndrome].

ACTH-producing thymic carcinoid tumor with Cushing syndrome in a 41-year-old male was reported. Plasma ACTH and cortisol was high, and chest X-ray film and CT scan revealed a tumor mass in the anterior mediastinum. Extended thymectomy with pretracheal lymph node dissection was performed. The microscopic findings revealed that the mass was carcinoid tumor with metastasis of anterior mediastinal lymph node. ACTH and cortisol were restored to normal range 1 week after operation. Unfortunately, he admitted seven months later because of high level of ACTH and right supraclavicular lymph nodes swelling. He underwent right neck dissection. Pathological examination proved metastatic carcinoid tumors in the dissected nodes. It is important to perform supraclavicular lymph node dissection together with extended thymectomy for thymic carcinoid tumor.