Short communication: effect of oxygen on symbiosis between Lactobacillus bulgaricus and Streptococcus thermophilus

Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) and Streptococcus thermophilus are traditionally used for the manufacture of yogurt. It is said that a symbiotic relationship exists between Strep. thermophilus and L. bulgaricus and this decreases fermentation time. It is well known that L. bulgaricus is stimulated by the formate produced by Strep. thermophilus, and Strep. thermophilus is stimulated by free amino acids and peptides liberated from milk proteins by L. bulgaricus in symbiotic fermentation. We found that acid production by starter culture LB81 composed of L. bulgaricus 2038 and Strep. thermophilus 1131 was greatly accelerated by decreasing dissolved oxygen (DO) to almost 0 mg/kg in the yogurt mix (reduced dissolved oxygen fermentation) and that DO interferes with the symbiotic relationship between L. bulgaricus 2038 and Strep. thermophilus 1131. We attributed the acceleration of acid production of LB81 by reduced dissolved oxygen fermentation mainly to the acceleration of formate production and the suppression of acid production of LB81 by DO mainly to the suppression of formate production.

Construction of recombinant monoclonal antibodies from a chicken hybridoma line secreting specific antibody

The chicken is a useful animal for the development of the specificantibodies against the mammalian conserved proteins. We generated twotypes of recombinant chicken monoclonal antibodies (mAbs), using a phagedisplay technique from a chicken hybridoma HUC2-13 which secreted themAb to the N-terminal of the mammalian prion protein (PrP). Althoughthe mAb HUC2-13 is a useful antibody for the prion research, thehybridoma produces a low level of antibody production. In order to producea large amount of the mAb, we have constructed a single chain fragmentvariable region (scF(V)) mAb by using the variable heavy(V(H)) and light (V(L))genes which were amplified by using the two primer pairs and theflexible linker. The two phage display mAbs (HUC2p3 and HUC2p5)expressed on a M13 filamentous phage and their soluble type mAbs(HUC2s3 and HUC2s5) were reacted with the PrP peptide antigen in theELISA. In the Western blot analysis, the mAbs HUC2p3 and HUC2s3 wereas reactive to PrP(c) from mouse brains as the mAb HUC2-13 was. The nucleotide sequences of V(H) and V(L) genes from HUC2-13 and the two cloneswere identical except for only one residue. These results indicate that themethods presented here provide an effective tool for the improvement ofthe low levels of antibody production in the chicken hybridoma system.

IgG4-related inflammatory pseudotumor of the trigeminal nerve: another component of IgG4-related sclerosing disease?

IgG4-related IPTs have been reported in various sites and may form part of the spectrum of systemic IgG4-related sclerosing disease. Some pseudotumors are clinically and radiologically indistinguishable from malignant tumors. We present the first case of an IgG4-related IPT of the trigeminal nerve diagnosed histopathologically without involvement of any of the common sites. The trigeminal nerve pseudotumor may represent a component of IgG4-related sclerosing disease.

The long-term outcome of high tibial osteotomy: a ten- to 20-year follow-up

We carried out a prospective study of 132 patients (159 knees) who underwent closed-wedge high tibial osteotomy for severe medial compartment osteoarthritis between 1988 and 1997. A total of 94 patients (118 knees) was available for review at a mean of 16.4 years (16 to 20). Seven patients (7.4%) (11 knees) required conversion to total knee replacement. Kaplan-Meier survival was 97.6% (95% confidence interval 95.0 to 100) at ten years and 90.4% (95% confidence interval 84.1 to 96.7) at 15 years. Excellent and good results as assessed by the Hospital for Special Surgery knee score were achieved in 87 knees (73.7%). A pre-operative body mass index > 27.5 kg/m(2) and range of movement < 100 degrees were risk factors predicting early failure. Although our long-term results were satisfactory, strict indications for osteotomy are required if long-term survival is required.

alpha-particle condensation in 16O studied with a full four-body orthogonality condition model calculation

To explore the four-alpha-particle condensate state in 16O, we solve a full four-body equation of motion based on the four-alpha-particle orthogonality condition model in a large four-alpha-particle model space spanned by Gaussian basis functions. A full spectrum up to the 0_{6};{+} state is reproduced consistently with the lowest six 0;{+} states of the experimental spectrum. The 0_{6};{+} state is obtained at about 2 MeV above the four-alpha-particle breakup threshold and has a dilute density structure, with a radius of about 5 fm. The state has an appreciably large alpha condensate fraction of 61%, and a large component of alpha+12C(0_{2};{+}) configuration, both features being reliable evidence for this state to be of four-alpha-particle condensate nature.

Frequent activation of mitogen-activated protein kinase relative to Akt in extrahepatic biliary tract cancer

BACKGROUND

Lack of effective adjuvant therapy against advanced extrahepatic biliary tract carcinoma (BTC) requires that new therapeutic methods, such as molecular targeted therapy, be developed. The mitogen-activated protein kinase (MAPK) and Akt signaling pathways, which activate cell proliferation and suppress apoptosis, respectively, may function as important targets for such therapies. The aim of this study was to examine the expression patterns of phosphorylated MAPK (p-MAPK) and phosphorylated Akt (p-Akt) proteins in BTC cell lines and clinical specimens.

METHODS

Expression of p-MAPK and p-Akt proteins in four human BTC cell lines and in frozen sections of 20 advanced extrahepatic BTC specimens was analyzed by Western blotting. Thirty formalin-fixed BTC specimens were immunohistochemically stained for p-MAPK and p-Akt using labeled streptavidin-biotin conjugates.

RESULTS

Expression of p-MAPK was observed in three of four (75%) BTC cell lines, whereas no expression of p-Akt was observed. Twenty-three of 30 formalin-fixed specimens stained positive for p-MAPK (77%), whereas only 47% stained positively for p-Akt. Expression of p-MAPK relative to that of p-Akt was also seen more frequently in the frozen specimens.

CONCLUSIONS

The results of this study suggest that MAPK is activated more frequently than Akt in extrahepatic biliary tract carcinoma.

Frequent occurrence of abnormal E-cadherin/beta-catenin protein expression in advanced gallbladder cancers and its association with decreased apoptosis

OBJECTIVE

Our aim is to assess the clinicopathological significance of E-cadherin and beta-catenin expression, as well as their association with apoptosis in gallbladder cancers.

METHODS

The expression of E-cadherin and beta-catenin proteins was examined in 4 biliary tract cancer cell lines and 49 gallbladder cancer specimens by immunofluorescent or immunohistochemical methods and Western blotting. The apoptotic status was evaluated in the cell lines by poly(ADP-ribose) polymerase Western blotting and in the tumors by the TdT-mediated dUTP nick end labeling assay.

RESULTS

Expression of poly(ADP-ribose) polymerase (apoptosis) was only seen in cell lines that expressed both E-cadherin and beta-catenin. Reduced expression of E-cadherin and beta-catenin was frequently seen in advanced gallbladder cancer cases (61 and 83%, respectively) relative to pT1 cases (25 and 63%, respectively). The 5-year survival rate in cases with reduced E-cadherin expression was 26%, significantly lower than in cases with preserved E-cadherin expression (70%; p = 0.017). Cases with reduced expression of both had lower apoptotic indices and showed a worse prognosis compared with cases with reduced expression of either E-cadherin or beta-catenin (p = 0.04 and 0.049, respectively).

CONCLUSIONS

The expression of E-cadherin or beta-catenin frequently diminishes as the tumor progresses, and abnormalities of E-cadherin and beta-catenin expression were associated with decreased apoptosis in gallbladder cancers. E-cadherin expression might be a useful prognostic marker in this tumor.

Antitumor Effect of Gemcitabine on Orthotopically Inoculated Human Gallbladder Cancer Cells in Nude Mice

BACKGROUND

The prognosis of gallbladder carcinoma is poor; therefore, investigating the efficacy of new chemotherapy agents is essential for the treatments for this tumor. Recently, several studies have reported clinical trials using gemcitabine as treatment for advanced gallbladder cancers. However, the antitumor effects of gemcitabine on gallbladder carcinoma have not been examined in in vitro and in vivo model systems.

METHODS

We examined the cytotoxicity of gemcitabine in four biliary tract cancer cell lines using the WST-1 assay. In addition, we examined the effect of gemcitabine on gallbladder cancers resulting from orthotopic inoculation of NOZ gallbladder tumor cells into nude mice. One week after transplantation, the mice were randomized into two groups: In Group A, the mice were treated by an intra-peritoneal injection of 0.9% sodium chloride for three weeks after inoculation (control). In Group B, the mice were treated by an intra-peritoneal injection of gemcitabine (125 mg / kg) for three weeks. All mice were sacrificed one week after the end of treatment, and macroscopic and histological findings were evaluated. The expression levels of proliferating-cell nuclear antigen (PCNA) were examined to investigate cellular proliferation activity, and Tunnel assays were performed to determine apoptotic status. Survival duration of the mice after gemcitabine treatment was compared to that of untreated mice.

RESULTS

The gemcitabine sensitivity of the four biliary tract cancer cell lines was similar in a dose dependent manner. In the in vivo models, the Group A mice showed huge tumors of the gallbladder, with liver invasion and lymph node metastases. However, there were no abdominal tumors in the Group B mice, and microscopic gallbladder cancer could only be detected from histological findings. The mean percent of PCNA-positive tumor cells was significantly higher in tumors from mice in Group A (71.9%) compared to those of Group B (34.7%). The mean percent of Tunnel-positive tumor cells was significantly lower in mice from Group A (2.0%) than those from Group B (5.7%). Survival duration was prolonged significantly in the gemcitabine-treated mice relative to untreated mice.

CONCLUSIONS

Gemcitabine treatment may inhibit tumor progression and prolong survival in gallbladder cancer by inhibiting cell proliferation and inducing apoptosis.

Specific and quantitative detection of PCR products from Clostridium piliforme, Helicobacter bilis, H. hepaticus, and mouse hepatitis virus infected mouse samples using a newly developed electrochemical DNA chip

We developed a microfabricated electrochemical DNA chip for detection of polymerase chain reaction (PCR) products from 16S rRNA sequences of Clostridium piliforme (Cp), Helicobacter bilis (Hb) and Helicobacter hepaticus (Hh), and the nucleocapsid protein gene of mouse hepatitis virus (MHV). This chip does not require DNA labeling, and the hybridization signal can be detected as an anodic current. The average anodic currents of 9 (Cp), 5 (Hb), 8 (Hh) and 7 (MHV) PCR positive samples derived from feces of spontaneously infected mice (Cp, Hb and Hh) and MHV-contaminated tumor cells were 27.9+/-7.2, 31.9+/-8.1, 29.3+/-10.1, and 27.6+/-3.0 nA, respectively. On the other hand, the average anodic currents of 19 (Cp), 27 (Hb), 18 (Hh), and 13 (MHV) PCR negative samples were 0.3+/-2.9, 3.7+/-2.4, -1.0+/-1.7, and -2.3+/-2.7 nA, respectively. The anodic current increased with increasing concentrations of pathogens. For experimentally infected samples, the results of PCR/electrophoresis were in complete accord with those of this system when anodic currents of 6.1 (Cp), 8.5 (Hb), 2.4 (Hh), and 3.1 nA (MHV) were taken as the cut-off value. The results suggested that the electrochemical DNA chip system is useful for specific and quantitative detection of PCR products.

Immunomodulatory Effects of Polysaccharides Produced by Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1

The extracellular polysaccharides (EPS) produced by lactic acid bacteria (LAB) are associated with the rheology, texture, and mouthfeel of fermented milk products, including yogurt. This study investigated the immunomodulatory effects of EPS purified from the culture supernatant of Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) OLL1073R-1. The crude EPS were prepared from the culture supernatant of L. bulgaricus OLL1073R-1 by standard chromatographic methods, and were fractionated into neutral EPS and acidic EPS (APS). Acidic EPS were further fractionated into high molecular weight APS (H-APS) and low molecular weight APS (L-APS). High molecular weight APS were shown to be phosphopolysaccharides containing D-glucose, D-galactose, and phosphorus. Stimulation of mouse splenocytes by H-APS significantly increased interferon-gamma production, and, moreover, orally administered H-APS augmented natural killer cell activity. Oral administration of yogurt fermented with L. bulgaricus OLL1073R-1 and Streptococcus thermophilus OLS3059 to mice showed a similar level of immunomodulation as H-APS. However, these effects were not detected following administration of yogurt fermented with the starter combination of L. bulgaricus OLL1256 and S. thermophilus OLS3295. We conclude from these findings that yogurt fermented with L. bulgaricus OLL1073R-1, containing immunostimulative EPS, would have an immunomodulatory effect on the human body.

Thymidylate synthase and dihydropyrimidine dehydrogenase expressions in gallbladder cancer

BACKGROUND

Although 5-Fluorouracil (5-FU) is widely used in chemotherapeutic treatment for gallbladder cancer, there is little evidence of its effectiveness. Thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) are the major determinants of individual sensitivity to 5-FU, and the impact of TS and DPD expression on prognosis and 5-FU efficacy has been studied in gastrointestinal carcinomas.

MATERIALS AND METHODS

TS and DPD enzymatic activities in frozen samples of 7 gallbladder cancer tissues and immunohistochemical TS and DPD protein expressions in 53 resected gallbladder cancers were evaluated.

RESULTS

The DPD activity of gallbladder cancers was significantly higher than that of gastric and colon cancers (p=0.041). TS and DPD protein expressions increased in pT2 and pT3 cases compared to those in pT1 cases, and cases both with high TS and DPD expressions had a worse prognosis than both low TS and DPD expressions. However, TS and DPD expressions were not independent prognostic factors.

CONCLUSION

TS and DPD protein expressions in gallbladder cancers were frequently high in pT2 and pT3 gallbladder cancers and control of high TS or DPD levels may be important for advanced gallbladder cancer therapy.

Genomic sequence of the pathogenic and allergenic filamentous fungus Aspergillus fumigatus

Aspergillus fumigatus is exceptional among microorganisms in being both a primary and opportunistic pathogen as well as a major allergen. Its conidia production is prolific, and so human respiratory tract exposure is almost constant. A. fumigatus is isolated from human habitats and vegetable compost heaps. In immunocompromised individuals, the incidence of invasive infection can be as high as 50% and the mortality rate is often about 50% (ref. 2). The interaction of A. fumigatus and other airborne fungi with the immune system is increasingly linked to severe asthma and sinusitis. Although the burden of invasive disease caused by A. fumigatus is substantial, the basic biology of the organism is mostly obscure. Here we show the complete 29.4-megabase genome sequence of the clinical isolate Af293, which consists of eight chromosomes containing 9,926 predicted genes. Microarray analysis revealed temperature-dependent expression of distinct sets of genes, as well as 700 A. fumigatus genes not present or significantly diverged in the closely related sexual species Neosartorya fischeri, many of which may have roles in the pathogenicity phenotype. The Af293 genome sequence provides an unparalleled resource for the future understanding of this remarkable fungus.

The wide distribution of endornaviruses, large double-stranded RNA replicons with plasmid-like properties

The International Committee on Taxonomy of Viruses (ICTV) recently accepted Endornavirus as a new genus of plant dsRNA virus. We have determined the partial nucleotide sequences of the RNA-dependent RNA polymerase regions from the large dsRNAs (about 14 kbp) isolated from barley (Hordeum vulgare), kidney bean (Phaseolus vulgaris), melon (Cucumis melo), bottle gourd (Lagenaria siceraria), Malabar spinach (Basella alba), seagrass (Zostera marina), and the fungus Helicobasidium mompa. Phylogenetic analyses of these seven dsRNAs indicate that these dsRNAs are new members of the genus Endornavirus that are widely distributed over the plant and fungal kingdoms.