An Avicel-affinity Site in an Avicel-digesting Exocellulase from aTrichoderma virideMutant

A single form of exo-type cellulase (Exo I; MW, 65,000), purified from a Trichoderma viride protease-depressed mutant, HK-75, digested Avicel to cellobiose exowise, and hydrolyzed cellotriose, cellotetraose, and cellopentaose in the strict manner of splitting off by cellobiose units. Exo I, however, hydrolyzed cellohexaose by both cellobiose and cellotriose units. Exo I was proteolyzed by papain into two fragments; GPExo (MW, 9,000) and Exo I' (MW, 56,000). The GPExo intensively adsorbed onto Avicel but did not hydrolyze it. Exo I' had nearly identical activity to that of intact Exo I toward cellooligosaccharides but was almost inert to Avicel in digestion and adsorption. Sequence analysis of N-terminal and C-terminal amino acids showed that GPExo was between Gly435 and Leu496 and Exo I' between Glu1 and Gly434 in Exo I. Exo I therefore consists of two domains, one for adsorption to Avicel, as demonstrated by the Avicel-affinity site, GPExo and the other for the cleavage of glycosidic linkages as demonstrated in Exo I'.

Implementation of an operator intervention system for remote control of the RIKEN 28 GHz superconducting electron cyclotron resonance ion source

The control system for the RIKEN 28 GHz superconducting electron cyclotron resonance ion source (28 GHz SC-ECRIS) consists of a distributed control system based on the experimental physics and industrial control system. To maintain the beam quality for the long beam-service time at the radioactive isotope beam factory, beam tuning to prevent subtle changes in the 28 GHz SC-ECRIS conditions is required. Once this is achieved, it should then be possible to check conditions and operate the ion source at any time. We have designed a web-based operational interface to remotely control the ion source, but for access and control from several locations, suitable access security, policies, and methods are required. We thus implemented an operator intervention system that makes it possible to safely access the network externally with the permission of on-site accelerator operators in the control room.

Chylous ascites after hepatopancreatobiliary surgery

Background

Postoperative chylous ascites following abdominal surgery is uncommon. It potentially induces malnutrition and immunodeficiency, contributing to increased mortality. In the field of hepatopancreatobiliary (HPB) surgery, no large studies have been conducted that focused on postoperative chylous ascites. The aim of this study was to determine the incidence, risk factors and management of chylous ascites following HPB surgery, with particular emphasis on pancreatic resection.

Methods

Consecutive patients who had HPB surgery between 2000 and 2011 at a single institution were reviewed retrospectively. Chyle leak was defined as 100 ml/day or more of milky, amylase-free peritoneal fluid with a triglyceride concentration of 110 mg/dl or above. Risk factors for chylous ascites associated with pancreatic resection and the clinical efficacy of octreotide in treating chylous ascites were evaluated.

Results

Of 2002 consecutive patients who underwent HPB surgery during the study period, 21 (1·0 per cent) developed chylous ascites. Chylous ascites occurred relatively frequently in patients who had a pancreatic resection, such as pancreaticoduodenectomy (3·3 per cent) or distal pancreatectomy (3·8 per cent). Multivariable analysis revealed that manipulation of the para-aortic area (P < 0·001), retroperitoneal invasion (P = 0·031) and early enteral feeding after operation (P < 0·001) were independent risk factors for chylous ascites following pancreatic resection. Octreotide treatment decreased drainage output of chylous ascites on day 1 after initiation of treatment (P = 0·002).

Conclusion

Chylous ascites is a rare complication following HPB surgery. It is more common after pancreatic resection. Treatment with octreotide combined with total parenteral nutrition is recommended.

Preparation of decellularized meniscal scaffolds using sonication treatment for tissue engineering

Scaffolds play a key role in the process of regeneration and morphogenesis of tissue or organ. We have developed a novel sonication decellularization system to prepare decellularized bio-scaffolds in a short treatment time. The aim of the study is to investigate sonication decellularization condition that completely decellularize meniscus can be changed as well as to maintain the biomechanical parameters of scaffolds. The meniscus samples were decellularized using sonication treatment. The treated samples were evaluated histologically by EVG for cell removal, picrosirius red for content of collagen type I and III, and safranin-O/fast green staining for content of glycosaminoglycan, and SEM for observation of scaffold surface. Indentation apparatus was used to analyze the unconfined deformation under load of native and decellularized menisci. The load parameters which are stiffness, compression and residual force were not significantly different compare with native and sonicated scaffolds. However, the content of extracellular matrix and its fiber alignment changed significantly due to sonication treatment as observed by SEM and safranin-O/fast green staining, respectively. The removal of immunogenic cell components by sonication decellularization as well as maintain its biomechanical strength of decellularized scaffolds, so that it has potential to use as an implant material for tissue engineering of menisci.

CD44 with variant exons 8-10 in colorectal tumors

Using a fusion protein encoded by variant exon (v) 8-10 of CD44, a monoclonal antibody (mAb) 44-1V reactive with v9 product was generated. Western immunoblots and reverse transcriptase-polymerase chain reaction/Southern blot revealed that a 130 kilodalton component containing v8-10 products was specifically expressed in colorectal and gastric cancer cell lines. Immunohistological examination of 179 pairs of colorectal cancer and normal tissues revealed that about 47% of cancers expressed the CD44 variant (CD44v8-10), and its expression correlated with hematogenous and lymph node metastasis. These findings suggest the usefulness of CD44v8-10 in the prediction of colorectal cancer metastasis.

Human nm23-h1-protein and h2-protein have similar nucleoside diphosphate kinase-activities

The nucleoside diphosphate kinase activity of nm23-H1 and nm23-H2 proteins was examined. Full length nm23-H1 and nm23-H2 proteins were produced in E.coli in fusion form with a 26 kDa glutathione S-transferase (GST). Affinity purified nm23-H1 and nm23-H2 formed phosphoenzyme intermediates when incubated with [gamma-P-32]ATP. The formation of GTP from GDP was also demonstrated by these two proteins by thin layer chromatography. The 26 kDa GST alone did not show similar activity. Both nm23-H1 and nm23-H2 shared very similar biochemical characteristics, namely, time kinetics, pH, temperature and cation dependency for the formation of the phosphoenzyme intermediates.

Differential effects of a murine monoclonal antibody reactive with the disialylgalactosyl residue on the growth of melanoma cells and T cell activation

A murine monoclonal antibody, S2-566, was generated by immunization with a melanoma line, SK-MEL-28. Although AbS2-566 showed a similar reaction pattern with that of anti-GD3 mAbR24 in cell surface serology, it recognized a disialyl galactosyl structure not only in GD3 but in GT1a and GQ1b. The suppression of the growth of cultured melanoma cells by AbS2-566 was not obvious, in contrast with AbR24. However, the mitogenic effects of AbS2-566 on peripheral lymphocytes were observed showing similar kinetics to those of mAbR24, suggesting different signaling effects based on the different epitope structures.

Up-regulation of nm23/NDP kinase expression in regenerating hepatocytes

We analyzed the kinetics and subcellular localization of nm23-M1 and nm23-M2 in in vivo proliferating mouse liver cells after partial hepatectomy. Along with the regenerative growth rate measured by mitotic index, the expression of both nm23-M1 and nm23-M2 was altered with distinct kinetics. Among the subcellular fractions of regenerating hepatocytes, the increase in the quantity of nm23-M1 and nm23-M2 was the most dominant in the nuclear fractions. In in vitro proliferating human hepatocellular carcinoma cells (PLC/PRF/5) stimulated by hepatocyte growth factor, both nm23-H1 and nm23-H2 were dominantly accumulated around nuclear membranes.

Inhibition of liver metastasis formation by anti-CD44 variant exon 9 monoclonal antibody

The overexpression of variants of the glycoprotein CD44 is thought to be associated with the tumorigenesis and progression of human cancers. We examined the role of the variant CD44v8-10 in the metastasis of the human colon cancer cell line HT29 using a monoclonal antibody (mAb 44-1V) reactive with the v9 product. After immunization with mAb 44-1V, the growth of HT29m cells in vitro was not retarded. Six-to 8-week-old mice were divided into 4 groups for liver metastasis assay. All animals in control groups injected with intrasplenic HT29m developed metastases. In contrast, only one of the animals injected with HT29m that reacted with mAb 44-1V developed a metastatic tumor in the liver. The intravenous administration of mAb 44-1V after intrasplenic HT29m injection did not inhibit the formation of liver metastasis. In addition, the adhesiveness of the HT29m cells to the basement membrane matrix was decreased by treatment with the anti-CD44v9 mAb. These findings indicated that a CD44 variant containing the products of variants of exons v8-10 may play an important role in adhesion of tumor cells to the capillaries of distant organs in the metastatic process.

Enhancement of productivity of recombinant alpha-amidating enzyme by low temperature culture

We have produced a recombinant C-terminal alpha-amidating enzyme (799BglIIalpha-AE) derived from Xenopus laevis by culturing a CHO cell line named 3mu-1S. Recently, we demonstrated that culturing 3mu-1S cells at a temperature below 37 degrees C led to the following phenomena: inhibited cell growth with high viability, enhanced cellular productivity (maximally at 32 degrees C), and suppressed medium consumption and release of impurities from the cells. Therefore, it is suggested that the 799BglIIalpha-AE production will be increased by culturing a sufficient number of the cells at a low temperature (especially at 32 degrees C). To assess this effect on batch and perfusion cultures, the culture temperature was shifted from 37 to 32 degrees C in the mid-exponential phase in the case of batch culture and from 37 to 34 degrees C when the cell density became high enough in the case of perfusion culture. Application of the low temperature culture to batch and perfusion cultures was effective in comparison with the culture at 37 degrees C: the productivity per medium and the productivity per time were increased severalfold with enhanced cellular productivity at a low culture temperature. The low temperature culture also increased the relative content of 799BglIIalpha-AE in the supernatant and reduced the glucose consumption. The method presented here would contribute to production of bioactive proteins using other recombinant cell lines.

Effect of culture temperature on a recombinant CHO cell line producing a C-terminal α-amidating enzyme

In order to seek an efficient method for producing a recombinant protein by using animal cell culture, we investigated various effects of the culture temperature on a recombinant CHO cell line (3µ-1S), producing a C-terminal α-amidating enzyme (799BglIIα-AE) originating from Xenopus laevis. The results revealed that a low culture temperature (below 37 °C) led to the following phenomena: [1] inhibited cell growth, [2] enhanced cellular productivity of the recombinant protein, [3] maintained high cell viability, [4] suppressed medium consumption, and [5] suppressed release of impurities from the cells. These findings indicate that a quite simple method, the culture at low temperature, will contribute to the total improvement of the industrial process for the production of the recombinant protein, 799BglIIα-AE.

Treatment of domestic sewage by a metal membrane bioreactor

A submerged flat metal MBR (membrane bioreactor) was used to treat synthetic domestic sewage in this study. The experiment was continued for 270 days and ran under two modes as AMBR (aerobic membrane bioreactor) and A/O-MBR (anoxic/aerobic membrane bioreactor) at a permeate flux of 0.4-1 m³/(m² d). PVA (polyvinyl alcohol) gel beads were added to the aeration tank with a volume ratio of 10% at the end of the A/O-MBR mode. The mean COD and TN removal efficiencies achieved 96.69 and 32.12% under the AMBR mode, and those were 92.17 and 72.44% under the A/O-MBR mode, respectively. SND (simultaneous nitrification and denitrification) occurred at high MLSS (mixed liquor suspended solids) concentration. The metal membranes reduced effluent COD during filtration. The system ran stably for 115 days at a permeate flux of 0.8-1 m³/(m² d) without changing membranes under the AMBR mode, but the membrane filterability decreased gradually under high MLSS or A/O-MBR mode, and the addition of PVA worsened the membrane filterability on the contrary. PSD (particle size distribution) and sludge fractions had evident influence on membrane fouling. The main fouling mechanism was cake formation under the AMBR mode, and that was pore blocking under the A/O-MBR mode.