Identification and characterization of endo-α-, exo-α-, and exo-ß-D-arabinofuranosidases degrading lipoarabinomannan and arabinogalactan of mycobacteria.

The cell walls of pathogenic and acidophilic bacteria, such as Mycobacterium tuberculosis and Mycobacterium leprae, contain lipoarabinomannan and arabinogalactan. These components are composed of D-arabinose, the enantiomer of the typical L-arabinose found in plants. The unique glycan structures of mycobacteria contribute to their ability to evade mammalian immune responses. In this study, we identified four enzymes (two GH183 endo-D-arabinanases, GH172 exo-α-D-arabinofuranosidase, and GH116 exo-ß-D-arabinofuranosidase) from Microbacterium arabinogalactanolyticum. These enzymes completely degraded the complex D-arabinan core structure of lipoarabinomannan and arabinogalactan in a concerted manner. Furthermore, through biochemical characterization using synthetic substrates and X-ray crystallography, we elucidated the mechanisms of substrate recognition and anomer-retaining hydrolysis for the α- and ß-D-arabinofuranosidic bonds in both endo- and exo-mode reactions. The discovery of these D-arabinan-degrading enzymes, along with the understanding of their structural basis for substrate specificity, provides valuable resources for investigating the intricate glycan architecture of mycobacterial cell wall polysaccharides and their contribution to pathogenicity.

Machine Learning Estimation of Plateau Stress of Aluminum Foam Using X-ray Computed Tomography Images.

Owing to its lightweight and excellent shock-absorbing properties, aluminum foam is used in automotive parts and construction materials. If a nondestructive quality assurance method can be established, the application of aluminum foam will be further expanded. In this study, we attempted to estimate the plateau stress of aluminum foam via machine learning (deep learning) using X-ray computed tomography (CT) images of aluminum foam. The plateau stresses estimated by machine learning and those actually obtained using the compression test were almost identical. Consequently, it was shown that plateau stress can be estimated by training using the two-dimensional cross-sectional images obtained nondestructively via X-ray CT imaging.

Lactobacillus crispatus Strain KT-11 S-Layer Protein Inhibits Rotavirus Infection.

S-layer proteins (SLPs), which are present in the external layer of certain strains of lactic acid bacteria isolated from the intestinal tract, are known to recognize and bind to specific proteins and glycan structures and contribute to adsorption to the host intestinal mucosa. The binding properties of certain SLPs are considered to exert a competitive inhibitory effect on infection because similar properties are involved in the infection mechanisms of several viruses. However, little is known regarding whether SLPs directly inhibit viral infection. In the present study, we investigated the effect of an SLP of the Lactobacillus crispatus KT-11 strain, a probiotic strain isolated from a healthy human infant, on human rotavirus infection. The impact of KT-11 lithium chloride extract (KT-11 LE), which contains SLP, on the infection of the P[4] genotype human rotavirus strain DS-1 was evaluated by monitoring the amplification of viral protein 6 (VP6) expression in human intestinal epithelial Caco-2 cells by quantitative reverse transcription-polymerase chain reaction assay after infection. KT-11 LE showed a significant suppressive effect on DS-1 infection in a dose-dependent manner with pre-infection treatment, whereas post-infection treatment was not effective. A 45 KDa protein isolated from KT-11 LE was investigated for homology using the BLAST database and was found to be a novel SLP. KT-11 SLP concentrate (KT-11 SLP) significantly inhibited the proliferative process of the DS-1 strain but not that of the P[8] genotype human rotavirus strain Wa. KT-11 SLP exerted significant inhibitory effect on DS-1 infection by pre-infection treatment even after digestion with gastric juice up to 2 h. Our results provided crucial evidence that SLPs from certain Lactobacillus strains can inhibit human rotavirus infection of intestinal epithelial cells.

A protecting group-free approach for synthesizing C-glycosides through glycosyl dithiocarbamates.

The first protection/deprotection-free process for radical C-glycosylation has been achieved through one-step preparable glycosyl dithiocarbamates (GDTCs). The Giese-type reaction and radical allylation of unprotected GDTCs were successfully performed to obtain the corresponding α-C-glycosides stereoselectively under mild reaction conditions.

Body cooling effects of immersion of the forearms in high-concentration artificial carbonic acid water at 25°C.

BACKGROUND: This study examined the effects of immersion in stirred, high-concentration, artificial carbonic acid water on body cooling. METHODS: Seven healthy male students (23 ± 2 years old) participated in the experiment. Signed informed consent was obtained from all subjects before the experiment. The subjects changed into shorts and T-shirts and entered an experimental room (with room temperature controlled at 30 °C and relative humidity maintained at 70%) at least 30 min before starting the experiment. After starting the experiment, the subjects were asked to rest on an exercise bike for 5 min and then pedal for 20 min. The exercise load was set to reach 50% of each subject's presumed maximum oxygen intake at 5 min after starting exercise. Subjects then continued pedaling for 1 min to cool down. After this exercise, subjects sat on a chair and immersed forearms in tap water or artificial carbonic acid water (CO2 water) at 25 °C for 20 min. During immersion, tap water or CO2 water was stirred slowly with a pump. After immersion, subjects rested for 10 min. Skin temperature and skin blood flow (left forearm), as well as heart rate and ear canal temperature, were measured continuously. Thermal sensation and thermal comfort were measured intermittently. RESULTS: Skin blood flow of the immersed forearms was higher in CO2 water than in tap water during immersion. The blood flow in the last 5 min (average at rest was 100%) was significantly higher in CO2 water (290.85 ± 84.81%) than in tap water (104.80 ± 21.99%). Thermal sensation and thermal comfort were not different between conditions. Ear canal temperature significantly declined more in CO2 water (- 0.56 ± 0.31 °C) than in tap water (- 0.48 ± 0.30 °C) during immersion. CONCLUSIONS: Our study suggests that immersion of the forearms in slowly stirred CO2 water at 25 °C reduces core temperature elevated by heat stress or exercise more effectively than does tap water at the same temperature. Immersion of the forearms in stirred CO2 water at 25 °C could be useful as a preventive measure against heat stroke from summer work or exercise.

Association of the Serum Endostatin Level, Renal Function, and Carotid Atherosclerosis of Healthy Residents of Japan: Results from the Kyushu and Okinawa Population Study (KOPS).

AIM: To analyze associations among the serum endostatin level, renal function, and carotid atherosclerosis of healthy residents of Japan. METHODS: Among 1,057 Japanese residents who attended free public physical examinations between 2010 and 2011, we evaluated the data of 648 healthy residents (200 men and 448 women, age 24 to 84 years) for whom the serum endostatin level and common carotid intima-media thickness (IMT) were measured. Renal function was assessed by estimated glomerular filtration rate (eGFR). Multiple linear regression analysis was done to determine the association of eGFR and serum endostatin level after adjustment for known covariates. Mediation analysis was done using Baron and Kenny's regression approach. RESULTS: The median endostatin level was 63.7 ng/mL (interquartile range: 49.7-93.2). The mean eGFR was 78.4±14.8 mL/min/1.73m2. Univariate analysis showed that age (r=－0.37, P＜0.01), non current smoking (85.8±13.0 vs. 77.5±14.8 mL/min/1.73 m2, P＜0.01), hemoglobin A1c (r=－0.08, P=0.05), low-density lipoprotein-cholesterol (r=－0.13, P＜0.01), uric acid (r=－0.15, P＜0.01), carotid IMT (r=－0.11, P＜0.01), and log-transformed endostatin (r=－0.36, P＜0.01) were significantly associated with eGFR. In multiple linear regression analysis, log-transformed endostatin was significantly associated with eGFR (beta=－0.24, P＜0.01). While, carotid IMT was no longer significant. Mediation analysis showed serum endostatin level to be a mediator in the association between carotid IMT and eGFR. CONCLUSIONS: The association between carotid IMT and eGFR is mediated by the serum endostatin level of healthy individuals.

The Relation between Serum Endostatin Level and Carotid Atherosclerosis in Healthy Residents of Japan: Results from the Kyushu and Okinawa Population Study (KOPS).

AIM: To examine the association between the serum endostatin levels and subclinical atherosclerosis independent of traditional risk factors in a healthy Japanese population. METHODS: Among 1,057 residents who attended free public physical examinations between 2010 and 2011, we evaluated the data of 648 healthy residents for whom the serum endostatin level and common carotid intima-media thickness (IMT) were successfully measured. RESULTS: The median endostatin level was 63.7 ng/mL (interquartile ranges: 49.7-93.2 ng/mL), and the mean carotid IMT was 0.68±0.12 mm. Residents with above median endostatin had significantly higher carotid IMT than did those with below median endostatin (0.71±0.14 vs. 0.65±0.09 mm, P＜0.001). Multiple linear regression analysis demonstrated that increased serum endostatin is significantly associated with carotid IMT (above vs. below median endostatin level; beta=0.11, P=0.03), independent of the known covariates of age, sex, body mass index, drinking and smoking status, systolic blood pressure, diastolic blood pressure, hemoglobin A1c, low density lipoprotein cholesterol, estimated glomerular filtration rate, and log-transformed high sensitive C-reactive protein. CONCLUSIONS: A higher serum endostatin level reflected subclinical atherosclerosis in this Japanese population.

EtAlCl2/2,6-Disubstituted Pyridine-Mediated Carboxylation of Alkenes with Carbon Dioxide.

α-Arylalkenes and trialkyl-substituted alkenes undergo carboxylation with CO2 in the presence of EtAlCl2 and 2,6-dibromopyridine to afford the corresponding α,ß- and/or ß,γ-unsaturated carboxylic acids. This reaction is suggested to proceed via the electrophilic substitution of EtAlCl2 with the aid of the base, followed by the carbonation of the resulting ate complex. This reaction can be applied to terminal dialkylalkenes by using a mixture of 2,6-di-tert-butylpyridine and 2,6-dibromopyridine.

The relation of postprandial plasma glucose and serum endostatin to the urinary albumin excretion of residents with prediabetes: results from the Kyushu and Okinawa Population Study (KOPS).

BACKGROUND: Previous clinical studies have shown that the circulating level of endostatin is related to kidney injury. We hypothesized that the impact of HbA1c, fasting, and postprandial plasma glucose on urinary albumin excretion would be related to the serum endostatin level. METHODS: A cross-sectional, community-based population study of 1057 Japanese residents was conducted. Of these subjects, 162 with a fasting plasma glucose value between 5.5 and 6.9 mmol/L and an HbA1c level of <6.5 % received an oral glucose tolerance test, had serum endostatin measured, and had the urinary albumin/creatinine ratio (UACR) calculated. RESULTS: In multivariate analysis, 2-h postprandial plasma glucose (ß = 0.26, P < 0.01) was significantly associated with log-transformed UACR, independently of fasting plasma glucose (ß = 0.14, P = 0.28) and HbA1c (ß = -0.08, P = 0.57). When divided by the median value of endostatin (82.2 ng/mL), 2-h postprandial plasma glucose (ß = 0.38, P = 0.01) remained significantly associated with the log-transformed UACR of the participants below the median, while the fasting plasma glucose (ß = 0.34, P = 0.046) was independently associated with the log-transformed UACR of participants above the median. CONCLUSION: Postprandial plasma glucose was independently associated with the urinary albumin excretion of the residents with prediabetes. Moreover, this relationship was limited to residents with a serum endostatin level below the median.

Synthesis of rocaglamide derivatives and evaluation of their Wnt signal inhibitory activities.

Rocaglamides are bioactive natural compounds which have a cyclopenta[b]benzofuran core structure. The total synthesis of a reported natural product, 3'-hydroxymethylrocaglate (5), was achieved using [3 + 2] cycloaddition between 3-hydroxyflavone and methyl cinnamate. We also describe the synthesis of rocaglamide heterocycle derivatives and evaluate their Wnt signal inhibitory activities. Compounds 4, 5, 22a, 22b, 22c and 23c showed potent Wnt signal inhibitory activity.

Fontan completion following flow adjustable bilateral pulmonary artery banding.

We have performed bilateral pulmonary artery banding operations combined with planned percutaneous balloon dilatation at banding sites for patients with hypoplastic left heart syndrome and related anomalies. Here, we report a case of Fontan completion in a patient who underwent aortic arch repair and a bidirectional Glenn procedure following flowadjustable bilateral pulmonary artery banding. The patient had a double-inlet left ventricle, a hypoplastic right ventricle, a hypoplastic aortic arch, and coarctation of the aorta. She underwent banding at 9 days of age and balloon dilatation at 2 months. The Damus-Kaye-Stansel anastomosis, aortic arch repair, and bidirectional Glenn procedure were performed at 5 months of age, and the extracardiac Fontan procedure was performed at 1.5 years.

Microwave-assisted acid hydrolysis of konjac products for determining the konjac powder content.

The complete hydrolysis of konjac glucomannan (KGM) with an acid or enzyme generally takes a long time. To accelerate KGM hydrolysis without diminishing the conventional quality, a diluted acid hydrolysis of KGM with sulfuric acid was conducted using a microwave digestion system. The optimum conditions of microwave-assisted acid hydrolysis for KGM were: 10 mL of 0.25 M sulfuric acid, hydrolysis temperature of 135°C (microwave power of 600 W), and total microwave-irradiation time of 45 min. The yields of the component sugars, mannose and glucose, from two konjac powders were similar to those by conventional acid hydrolysis with 1 M sulfuric acid in a boiling water bath for 5 h. Furthermore, a pretest for microwave-assisted acid hydrolysis using mixtures of konjac powder and starch at different ratios proved that their konjac content can be calculated by determining the mannose generated by the new rapid hydrolysis method, if the raw materials are provided.

The fishermen were right: experimental evidence for tributary refuge hypothesis during floods.

Fishermen often anecdotally report an unexpected increase of fish caught in small tributary streams during floods, presumably due to refuge-seeking behavior from the main stem. From a population perspective, this implies the significance of refuge habitats and connectivity for population viability against natural disturbances. Despite the plausibility, however, surprisingly few studies have examined the tributary refuge hypothesis, mainly due to the difficulty in field survey during floods. Here, we made use of a large-scale controlled flood to assess whether fishes move into tributaries during flooding in the main stem. A planned water release from the Satsunai River Dam located on Hokkaido Island in Japan rapidly increased the main stem discharge by more than 20-fold. Before, during, and after flooding censuses in four tributaries provided evidence of the refuge-seeking behavior of fishes from the main stem. For example, more than 10 Dolly Varden char, a salmonid fish, were caught in a tributary during the flood, even though almost no individuals were captured before or after the flood. The fish responded immediately to the flooding, suggesting the need for studies during disturbances. In addition, the likelihood of refuge movements varied among tributaries, suggesting the importance of local environmental differences between tributary and the main stem habitats. This is the first study to experimentally confirm the tributary refuge hypothesis, and underscores the roles of habitat diversity and connectivity during disturbances, even though some habitats are not used during normal conditions.

Stimulatory effects of testosterone and progesterone on the NADH- and NADPH-dependent oxidation of 7beta-hydroxy-delta8-tetrahydrocannabinol to 7-oxo-delta8-tetrahydrocannabinol in monkey liver microsomes.

Microsomal alcohol oxygenase catalyzes the stereoselective oxidation of 7alpha- and 7beta-hydroxy-delta8-tetrahydrocannabinol (7alpha- and 7beta-hydroxy-delta8-THC) to 7-oxo-delta8-THC in monkey liver, and the activity for 7beta-hydroxy-delta8-THC is relatively higher than that for 7alpha-hydroxy-delta8-THC. We previously reported that purified P450JM-E, assumed to be CYP3A8, is a major enzyme responsible for the oxidation of 7-hydroxy-delta8-THC to 7-oxo-delta8-THC in monkey liver and is capable of catalyzing the oxidative reaction by NADH as well as NADPH. In the present study, we demonstrated that some steroids such as testosterone and progesterone stimulated both the NADH- and NADPH-dependent conversions of 7beta-hydroxy-delta8-THC to 7-oxo-delta8-THC in monkey liver microsomes. Kinetic analyses revealed that both the NADH- and NADPH-dependent 7-oxo-delta8-THC formation showed sigmoid kinetics. Testosterone caused a decrease in S50 and an increase in V(max) for the NADH-dependent activity, and resulted in a decrease in S50 without changing the V(max) for the NADPH-dependent activity. On the other hand, NADH-dependent testosterone 6beta-hydroxylation activity showed Michaelis-Menten kinetics and was also inhibited by 7beta-hydroxy-delta8-THC, resulting in a decrease in V(max) with no effect on the K(m). NADPH-dependent testosterone 6beta-hydrozylation activity was also inhibited by 7beta-hydroxy-delta8-THC, resulting in a decrease in both S50 and V(max). In order to explain the metabolic interaction between 7beta-hydroxy-delta8-THC and testosterone, we propose a kinetic model involving at least three binding sites, for the mechanism of activation by testosterone.

An epidemiological study of HBV, HCV and HTLV-I in Sherpas of Nepal.

An epidemiological study of hepatitis viruses type B (HBV) and type C (HCV) and human T-cell leukemia virus type I (HTLV-I) was carried out among 103 residents (male:female=61:42) regarded as Sherpas, at Lukla (Solukhumbu district), Nepal in 2004. Blood was drawn from apparently healthy volunteers at ages of 28.8+12.3 (range 15-66) years. HBsAg, HBsAb, HBcAb, and HCV Ab were measured by microparticle enzyme-immunoassay, and HTLV-I Ab was measured by particle agglutination. Prevalence of HBsAg(+), HBsAb(+), HBcAb(+), and HBsAb(+) or HBcAb(+) were 1.9% 22.3%, 24.3%, and 28.2%, respectively. For HCV Ab, only a borderline reaction was observed in one sample, and for HTLV-I Ab all samples were negative. Nucleotide sequencing of the PreS1, PreS2, and S genes revealed that HBV among Sherpas to be of the A' (or Aa) genotype, which is prevalent among Nepalese but rare in native Tibetans, suggesting transmission within Nepal rather than association with ancestors' migration from Tibet as the origin. This is the first report of Himalayan Sherpas' state of infection with HBV, HCV, and HTLV-I.