Isolation and characterization of endocellulase-free multienzyme complex from newly isolated Thermoanaerobacterium thermosaccharolyticum strain NOI-1

An endocellulase-free multienzyme complex was produced by a thermophilic anaerobic bacterium, Thermoanaerobacterium thermosaccharolyticum strain NOI-1, when grown on xylan. The temperature and pH optima for growth were 60 degrees C and 6.0, respectively. The bacterial cells were found to adhere to insoluble xylan and Avicel. A scanning electron microscopy analysis showed the adhesion of xylan to the cells. An endocellulase-free multienzyme complex was isolated from the crude enzyme of strain NOI-1 by affinity purification on cellulose and Sephacryl S-300 gel filtration. The molecular mass of the multienzyme complex was estimated to be about 1,200 kDa. The multienzyme complex showed one protein on native PAGE, one xylanase on a native zymogram, 21 proteins on SDS-PAGE, and 5 xylanases on a SDS zymogram. The multienzyme complex consisted of xylanase, beta-xylosidase, alpha-L-arabinofuranosidase, beta-glucosidase, and cellobiohydrolase. The multienzyme complex was effective in hydrolyzing xylan and corn hulls. This is the first report of an endocellulase-free multienzyme complex produced by a thermophilic anaerobic bacterium, T. thermosaccharolyticum strain NOI-1.     

Induction of autophagy by B cell antigen receptor stimulation and its inhibition by costimulation

Autophagy is a major pathway for degradation of cytoplasmic components, and is induced by some apoptotic stimuli mostly in cancer cells under the condition in which apoptosis is blocked. Ligation of the B cell antigen receptor (BCR) induces apoptosis and plays a crucial role in self-tolerance. However, whether BCR ligation induces autophagy is not clear. Here, we demonstrate that autophagosomes are extensively formed in normal mouse B cells as well as the WEHI-231 B cell line upon induction of BCR ligation-induced apoptosis regardless of whether apoptosis is blocked by overexpression of Bcl-2. In contrast, autophagosomes were not formed during apoptosis of spleen B cells cultured with medium alone or in BCR-ligated BAL17 cells which do not undergo apoptosis. Moreover, autophagy is not induced when apoptotic BCR signaling is abrogated by CD40 signaling. These results indicate that autophagy is induced specifically by apoptotic BCR signaling even in unmanipulated normal B cells.     

In vivo kinematics of two-component total ankle arthroplasty during non-weightbearing and weightbearing dorsiflexion/plantarflexion

Relatively high rates of loosening and implant failure have been reported after total ankle arthroplasty, especially in first and second generation implants. Abnormal kinematics and incongruency of the articular surface may cause increased loads applied to the implant with concomitant polyethylene wear, resulting in loosening and implant failure. The purpose of this study was to measure three-dimensional kinematics of two-component total ankle arthroplasty during non-weightbearing and weightbearing activities, and to investigate incongruency of the articular surfaces during these activities. Forty-seven patients with a mean age of 71 years were enrolled. Radiographs were taken at non-weightbearing maximal dorsiflexion and plantarflexion, and weightbearing maximal dorsiflexion, plantarflexion, and neutral position. 3D-2D model-image registration was performed using the radiographs and the three-dimensional implant models, and three-dimensional joint angles were determined. The implanted ankles showed 18.1±8.6° (mean±standard deviation) of plantarflexion, 0.1±0.7° of inversion, 1.2±2.0° of internal rotation, and 0.8±0.6mm of posterior translation of the talar component in the non-weightbearing activity, and 17.8±7.5° of plantarflexion, 0.4±0.5° of inversion, 1.8±2.0° of internal rotation, and 0.7±0.5mm of posterior translation in the weightbearing activity. There were no significant differences between the non-weightbearing and weightbearing kinematics except for the plantarflexion angle. Incongruency of the articular surface occurred in more than 75% of the ankles. Our observations will provide useful data against which kinematics of other implant designs, such as three-component total ankle arthroplasty, can be compared.     

Hyperthermostable Endoglucanase from Pyrococcus horikoshii

An endoglucanase homolog from the hyperthermophilic archaeon Pyrococcus horikoshii was expressed in Escherichia coli, and its enzymatic characteristics were examined. The expressed protein was a hyperthermostable endoglucanase which hydrolyzes celluloses, including Avicel and carboxymethyl cellulose, as well as β-glucose oligomers. This enzyme is the first endoglucanase belonging to glycosidase family 5 found from Pyrococcus species and is also the first hyperthermostable endoglucanase to which celluloses are the best substrates. This enzyme is expected to be useful for industrial hydrolysis of cellulose at high temperatures, particularly in biopolishing of cotton products.     

Mutation of alanine 623 in the third cytoplasmic loop of the rat thyrotropin (TSH) receptor results in a loss in the phosphoinositide but not cAMP signal induced by TSH and receptor autoantibodies.

Thyrotropin (TSH) and IgG preparations from patients with Graves' disease increase inositol phosphate as well as cAMP formation in Cos-7 cells transfected with rat TSH receptor cDNA. Mutation of alanine 623 in the carboxyl end of the third cytoplasmic loop of the TSH receptor, to lysine or glutamic acid, results in the loss of TSH- and Graves' IgG-stimulated inositol phosphate formation but not in stimulated cAMP formation. There is no effect of the mutations on basal or P2-purinergic receptor-mediated inositol phosphate formation. The mutations do not affect transfection efficiency or the synthesis, processing, or membrane integration of the receptor, as evidenced by the unchanged amount and composition of the TSH receptor forms on Western blots of membranes from transfected cells. The mutations increase the affinity of the TSH receptor for [125I]TSH and decrease Bmax; however, cells with an equivalently decreased Bmax as a result of transfection with lower levels of wild type receptor do not lose either TSH-induced inositol phosphate formation or cAMP signaling activity. Thus, in addition to discriminating between ligand-induced phosphatidylinositol bisphosphate and cAMP signals, the mutation appears to cause an altered receptor conformation which affects ligand binding to its large extracellular domain.     

Insulin sensitivity in pancreatitis, liver diseases, steroid treatment and hyperthyroidism assessed by glucose, insulin and somatostatin infusion

In order to assess insulin sensitivity for glucose utilization in the other type of diabetes, insulin sensitivity tests were performed in subjects with pancreatitis, liver disease, steroid treatment and hyperthyroidism. Insulin sensitivity for glucose utilization decreased in subjects with liver disease, steroid treatment and hyperthyroidism irrespective of the presence or absence of glucose intolerance. Hyperinsulinism was associated in most of the subjects with liver disease and steroid treatment, but even in normo-insulinemic subjects, insulin insensitivity was observed. Obesity was associated with only 2 cases in both pancreatitis and liver diseases and therefore was excluded as a major cause for insulin insensitivity in subjects studied. In subjects with pancreatitis, insulin sensitivity was not significantly decreased. It is to be noted that 4 out of 5 subjects with diabetic OGTT (oral glucose tolerance test) exhibited normal insulin sensitivity. The results indicate that in pancreatitis, tissue insulin sensitivity for glucose metabolism is not altered and therefore can be used as a marker to differentiate the other type of diabetes due to pancreatitis from type 1 or 2 diabetes. Although hyperinsulinemia may be attributable to insulin insensitivity in subjects studied at least in part, steroid and thyroid hormone are thought to act directly antagonistically with insulin for glucose metabolism.     

Mastication and Risk for Diabetes in a Japanese Population: A Cross-Sectional Study

Background

Associations between mastication and insufficient nutrient intake, obesity, and glucose metabolism have been shown in previous studies. However, the association between mastication and diabetes has not been clarified. Our objective was to examine the association between mastication, namely masticatory performance or rate of eating, and diabetes in a population-based cohort.

Methods

We conducted a cross-sectional study of the association between mastication and diabetes in the Nagahama Prospective Cohort Study, an ongoing study which recruits citizens of Nagahama City in Shiga Prefecture, central Japan. 2,283 male and 4,544 female residents aged 40–74 years were enrolled from July 2009 to November 2010. Masticatory performance was evaluated by spectrophotometric measurement of color changes after masticating color-changeable chewing gum. Categorical rate of eating (fast, intermediate or slow) was self-assessed using a questionnaire.

Results

177 males (7.7%) and 112 (2.4%) females were diagnosed with diabetes. We divided participants into four groups by quartile of masticatory performance, namely Q1 (lowest), 2, and 3 and 4 (highest). Compared to the lowest performance group, the multivariable adjusted odds ratio (OR) of diabetes was 0.91 (95% confidence interval (CI), 0.58–1.4) in Q2, 0.77 (95% CI, 0.48–1.2) in Q3, and 0.53 (95% CI, 0.31–0.90) in the highest group in males, and 1.2 (95% CI, 0.73–2.0), 0.95 (95% CI, 0.54–1.6) and 0.56 (95% CI, 0.30–1.0) in females. We also estimated ORs of diabetes by rate of eating. Compared to the fast eating group, ORs in males were 0.87 (95% CI, 0.61–1.2) in the intermediate group and 0.38 (95% CI, 0.16–0.91) in the slow group, and ORs in females were 0.92 (95% CI, 0.59–1.4) and 1.5 (95% CI, 0.73–3.0).

Conclusions

These findings support the hypothesis that higher masticatory performance and slow eating prevent the occurrence of diabetes.