High-Resolution Detection of Translocation of Oral Bacteria to the Gut

Ectopic enrichment of oral microbes in the gut is a notable alteration in gut microbial balance. These microbes are likely delivered from the oral cavity with saliva and food; however, evidence of oral-gut microbial transmission is insufficient and needs further investigation. In this observational study, we examined 144 pairs of saliva and stool samples collected from community-dwelling adults to verify the oral-gut microbial link and identify the relevant influencing factors on the increased abundance of oral microbes within the gut. The bacterial composition of each sample was determined using PacBio single-molecule long-read sequencing of the full-length 16S ribosomal RNA gene and amplicon sequence variant (ASV) analysis. Although the bacterial compositions of salivary and gut microbiota were distinctly different, at least 1 ASV was shared between salivary and gut microbiota in 72.9% of subjects. Shared ASVs accounted for 0.0% to 63.1% (median 0.14%) of the gut microbiota in each subject and frequently included abundant Streptococcus salivarius and Streptococcus parasanguinis. Their total relative abundance in the gut was significantly higher in older subjects or those with dental plaque accumulation. The gut microbiota with ≥5% of shared ASVs displayed a higher abundance of Streptococcus, Lactobacillus, and Klebsiella and a lower abundance of Faecalibacterium, Blautia, Megamonas, and Parabacteroides. Our study presents evidence for the translocation of oral bacteria to the gut in community-dwelling adults and suggests that aging and dental plaque accumulation contribute to an increased abundance of oral microbes in the gut, which might be relevant to the compositional shift in the gut commensals.

Cultivation and biogeochemical analyses reveal insights into methanogenesis in deep subseafloor sediment at a biogenic gas hydrate site

Gas hydrates deposited in subseafloor sediments are considered to primarily consist of biogenic methane. However, little evidence for the occurrence of living methanogens in subseafloor sediments has been provided. This study investigated viable methanogen diversity, population, physiology and potential activity in hydrate-bearing sediments (1–307 m below the seafloor) from the eastern Nankai Trough. Radiotracer experiments, the quantification of coenzyme F430 and molecular sequencing analysis indicated the occurrence of potential methanogenic activity and living methanogens in the sediments and the predominance of hydrogenotrophic methanogens followed by methylotrophic methanogens. Ten isolates and nine representative culture clones of hydrogenotrophic, methylotrophic and acetoclastic methanogens were obtained from the batch incubation of sediments and accounted for 0.5–76% of the total methanogenic sequences directly recovered from each sediment. The hydrogenotrophic methanogen isolates of Methanocalculus and Methanoculleus that dominated the sediment methanogen communities produced methane at temperatures from 4 to 55 °C, with an abrupt decline in the methane production rate at temperatures above 40 °C, which is consistent with the depth profiles of potential methanogenic activity in the Nankai Trough sediments in this and previous studies. Our results reveal the previously overlooked phylogenetic and metabolic diversity of living methanogens, including methylotrophic methanogenesis.

Long-term wheel-running prevents reduction of grip strength in type 2 diabetic rats

Diabetic skeletal muscles show reduced contractile force and increased fatigability. Hands are a target for several diabetes-induced complications. Therefore, reduced handgrip strength often occurs as a consequence of diabetes. The aim of this study was to examine whether long-term exercise can prevent reduction of grip strength in type 2 diabetes mellitus (T2DM) model OLETF rats, and to explore the mechanisms underlying diabetes-induced grip strength reduction. Ten 5-week-old OLETF rats were used as experimental animals, and five non-diabetic LETO rats as controls of OLETF rats. Half OLETF rats performed daily voluntary wheel-running for 17 months (OLETF + EXE), and the rest of OLETF and LETO rats were sedentary. Grip strength was higher in OLETF + EXE and LETO groups than in OLETF group. OLETF group with hyperglycemia showed an increase in HbA1c, serum TNF-α, and muscle SERCA activity, but a decrease in circulating insulin. Each fiber area, total fiber area, and % total fiber area in type IIb fibers of extensor digitorum longus muscles were larger in OLETF + EXE and LETO groups than in OLETF group. There was a positive correlation between grip strength and the above three parameters concerning type IIb fiber area. Therefore, type IIb fiber atrophy may be the major direct cause of grip strength reduction in OLETF group, although there seems multiple etiological mechanisms. Long-term wheel-running may have blocked the diabetes-induced reduction of grip strength by preventing type IIb fiber atrophy. Regular exercise may be a potent modality for preventing not only the progression of diabetes but muscle dysfunction in T2DM patients.

Effects of whole-body vibration on bone properties in aged rats

OBJECTIVE

This study aimed to explore optimal conditions of whole-body vibration (WBV) for improving bone properties in aged rats.

METHODS

Eighty-week-old rats were divided into baseline control (BC), age-matched control (CON) and experimental groups, which underwent WBV (0.5 g) at various frequencies (15, 30, 45, 60 or 90 Hz) or WBV (45 Hz) with various magnitudes (0.3, 0.5, 0.7 or 1.0 g) for 7 weeks. After interventions, femur bone size, bone mechanical strength and circulating bone formation/resorption markers were measured, and trabecular bone microstructure (TBMS) and cortical bone geometry (CBG) of femurs were analyzed by micro-CT.

RESULTS

Several TBMS parameters and trabecular bone mineral content were significantly lower in the 15 Hz WBV (0.5 g) group than in the CON group, suggesting damage to trabecular bone. On the other hand, although frequency/magnitude of WBV did not influence any CBG parameters, the 0.7 g and 1.0 g WBV (45 Hz) group showed an increase in tissue mineral density of cortical bone compared with the BC and CON groups, suggesting the possibility of improving cortical bone properties.

CONCLUSION

Based on these findings, it should be noted that WBV conditions are carefully considered when applied to elderly people.

Koleobacter methoxysyntrophicus gen. nov., sp. nov., a novel anaerobic bacterium isolated from deep subsurface oil field and proposal of Koleobacteraceae fam. nov. and Koleobacterales ord. nov. within the class Clostridia of the phylum Firmicutes

An anaerobic thermophilic, rod-shaped bacterium possessing a unique non-lipid sheathed-like structure enveloping a single-membraned cell, designated strain NRmbB1^T was isolated from at the deep subsurface oil field located in Yamagata Prefecture, Japan. Growth occurred with 40-60°C (optimum, 55°C), 0-2% (2%), NaCl and pH 6.0-8.5 (8.0). Fermentative growth with various sugars was observed. Glucose-grown cells generated acetate, hydrogen, pyruvate and lactate as the main end products. Syntrophic growth occurred with glucose, pyruvate and 3,4,5-trimethoxybenzoate in the presence of an H₂-scavenging partner, and growth on 3,4,5-trimethoxybenzoate was only observed under syntrophic condition. The predominant cellular fatty acids were C_16:0, iso-C_16:0, anteiso-C_15:0, and iso-C_14:0. Respiratory quinone was not detected. The genomic G+C content was 40.8mol%. Based on 16S rRNA gene phylogeny, strain NRmbB1^T belongs to a distinct order-level clade in the class Clostridia of the phylum Firmicutes, sharing low similarity with other isolated organisms (i.e., 87.5% for top hit Moorella thermoacetica DSM 2955^T). In total, chemotaxonomic, phylogenetic and genomic characterization revealed that strain NRmbB1^T (=KCTC 25035^T, =JCM 39120^T) represents a novel species of a new genus. In addition, we also propose the associated family and order as Koleobacteraceae fam. nov and Koleobacterales ord. nov., respectively.

Relativistic magnetic reconnection in laser laboratory for testing an emission mechanism of hard-state black hole system

Magnetic reconnection in a relativistic electron magnetization regime was observed in a laboratory plasma produced by a high-intensity, large energy, picoseconds laser pulse. Magnetic reconnection conditions realized with a laser-driven several kilotesla magnetic field is comparable to that in the accretion disk corona of black hole systems, i.e., Cygnus X-1. We observed particle energy distributions of reconnection outflow jets, which possess a power-law component in a high-energy range. The hardness of the observed spectra could explain the hard-state x-ray emission from accreting black hole systems.

Unexpected diversity of acetate degraders in anaerobic membrane bioreactor treating organic solid waste revealed by high-sensitivity stable isotope probing

In anaerobic membrane bioreactor (AnMBR) treating organic solid waste, acetate is one of the most important precursors to CH₄. However, the identity and diversity of anaerobic acetate degraders are largely unknown, possibly due to their slow growth rates and low abundances. Here, we identified acetate-degrading microorganisms in the AnMBR sludges by high-sensitivity stable isotope probing. Degradation of the amended ¹³C-acetate coincided with production of ¹³CH₄ and ¹³CO₂ during the sludge incubation. High-throughput sequencing of RNA density fractions indicated that the aceticlastic and hydrogenotrophic methanogens, i.e., Methanosaeta sp. (acetate dissimilator) and Methanolinea sp. (acetate assimilator), incorporated ¹³C-acetate significantly. Remarkably, 22 bacterial species incorporating ¹³C-acetate were identified, whereas their majority was distantly related to the cultured representatives. Only two of them were the class Deltaproteobacteria-affiliated lineages with syntrophic volatile fatty acid oxidation activities. Phylogenetic tree analysis and population dynamics tracing revealed that novel species of the hydrolyzing and/or fermenting taxa, such as the phyla Bacteroidetes, Chloroflexi and Lentisphaerae, exhibited low relative abundances comparable to that of Methanolinea sp. (0.00011%) during the AnMBR operation, suggesting that these bacteria were involved in anaerobic acetate assimilation. Meanwhile, novel species of the phyla Firmicutes, Synergistetes and Caldiserica, the candidate phyla Aminicenantes and Atribacteria and the candidate division GOUTA4-related clade, as well as the known Deltaproteobacteria members, existed at relatively high abundances (0.00031%-0.31121%) in the reactor, suggesting that these bacterial species participated in anaerobic dissimilation of acetate, e.g., syntrophic acetate oxidation. The results of this study demonstrated the unexpected diversity and ecophysiological features of the anaerobic acetate degraders in the AnMBR treating organic solid waste.

Parasympathetic nervous activity is associated with oxytocin in multiparous, but not primiparous, women during the perinatal period

Oxytocin (OXT) is thought to have antidepressant/anxiolytic effects in postpartum women. Primiparous women tend toward an attenuated lactation compared with multiparous women. However, so far, little is known about the relationship between OXT and autonomic nervous activity (ANA) in perinatal women and whether it may be different in primiparous and multiparous women. Therefore, the objective of this study was to answer this question by determining both ANA and salivary OXT levels in primiparous and multiparous perinatal women. In 18 primiparous and 18 multiparous women, who underwent a physical and physiological examination, ANA measurement by heart rate variability and saliva sampling were performed during the perinatal period. Saliva OXT concentration was determined by a highly sensitive ELISA. OXT release into saliva was obtained from multiplying saliva OXT concentration by saliva flow rate. In the postpartum period, multiparous women had higher parasympathetic nervous activity (PNA) and lower physical stress index (PSI) compared with primiparous women. Furthermore, multiparous postpartal women had higher OXT compared with primiparous or multiparous prepartal women. In addition, in multiparous perinatal women, OXT correlated positively with PNA, but negatively with PSI. These results suggest that after parturition, multiparous mothers may switch over to the "feed and breed" system more quickly due to increased OXT compared with primiparous mothers. Our findings support antidepressant/anxiolytic and anti-stress effects of OXT. In postpartal women exposed to synthetic OXT, ANA measurement may provide a clue to clarify the effects of exogenous OXT on postpartum psychiatric disorders.

Possible effects of whole body vibration on bone properties in growing rats

Objectives

To examine the effects of whole body vibration (WBV) on bone properties in growing rats, and to explore the optimal conditions for enhancing bone properties.

Methods

Thirty-six 4-week-old male rats were divided into 1 control and 5 experimental groups. Each experimental group underwent WBV at 15, 30, 45, 60, and 90 Hz (0.5 g, 15 min/d, 5 d/wk) for 8 weeks. We measured bone size, muscle weight and bone mechanical strength of the right tibia. Trabecular bone mass and trabecular bone microstructure (TBMS) of the left tibia were analyzed by micro-computed tomography. Serum levels of bone formation/resorption markers were also measured.

Results

WBV at 45 Hz and 60 Hz tended to enhance trabecular bone mass and TBMS parameters. However, there was no difference in maximum load of tibias among all groups. Serum levels of bone resorption marker were significantly higher in the 45-Hz WBV group than in the control group.

Conclusions

WBV at 45–60 Hz may offer a potent modality for increasing bone mass during the period of rapid growth. Further studies are needed to explore the optimal WBV conditions for increasing peak bone mass and TBMS parameters. WBV modality may be a potent strategy for primary prevention against osteoporosis.

Enhancing laser beam performance by interfering intense laser beamlets

Increasing the laser energy absorption into energetic particle beams represents a longstanding quest in intense laser-plasma physics. During the interaction with matter, part of the laser energy is converted into relativistic electron beams, which are the origin of secondary sources of energetic ions, γ-rays and neutrons. Here we experimentally demonstrate that using multiple coherent laser beamlets spatially and temporally overlapped, thus producing an interference pattern in the laser focus, significantly improves the laser energy conversion efficiency into hot electrons, compared to one beam with the same energy and nominal intensity as the four beamlets combined. Two-dimensional particle-in-cell simulations support the experimental results, suggesting that beamlet interference pattern induces a periodical shaping of the critical density, ultimately playing a key-role in enhancing the laser-to-electron energy conversion efficiency. This method is rather insensitive to laser pulse contrast and duration, making this approach robust and suitable to many existing facilities.

Enhanced coupling of laser energy to the target particles is a fundamental issue in laser-plasma interactions. Here the authors demonstrate increased photon absorption leading into higher laser to electron and proton energy transfer through the interference of multiple coherent beamlets.

Whole body vibration at low-frequency can increase trabecular thickness and width in adult rats

OBJECTIVE

This study aimed to examine whether WBV becomes a possible modality for the primary prevention of osteoporosis by exploring WBV frequency that has positive effects on bone properties in adult rats.

METHODS

Thirty-six 24-week-old rats were divided into one control and 5 experimental groups, which underwent WBV at various frequencies (15, 30, 45, 60 or 90 Hz), with a magnitude of 0.5 g, for 15 min/day, 5 days/week, for 8 weeks. Bone size, muscle weight and bone mechanical strength were measured at the end of experimental period. Bone mass, trabecular bone microarchitecture (TBMA) and cortical bone geometry were analyzed by micro-CT. Circulating bone formation/resorption markers were determined by ELISA.

RESULTS

Body weight-corrected soleus weight in all experimental groups and body weight-corrected extensor digitorum longus muscle weight in the 15 and 30 Hz groups were significantly higher than those of the control group, respectively. Femur trabecular thickness and width were significantly higher in the 15 Hz group than in the control group. However, there was no difference in bone mechanical strength or bone formation/resorption markers among all groups.

CONCLUSION

These results suggest that WBV at low-frequencies may become a potent modality for the primary prevention of osteoporosis in adults.

A large-aperture high-sensitivity avalanche image intensifier panel

A large-aperture high-sensitivity image intensifier panel that consists of an avalanche photodiode array and a light-emitting diode array is presented. The device has 40% quantum efficiency, over 10⁴ optical gain, and 80-ns time resolution. The aperture size of the device is 20 cm, and with the current manufacturing process, it can be scaled to arbitrarily larger sizes. The device can intensify the light from a single particle scintillation emission to an eye-visible bright flash. The image resolution of the device is currently limited by the size of the avalanche photodiode that is 2 mm, although it can be scaled to smaller sizes in the near future. The image intensifier is operated at a small voltage, typically +57 V. The device can be applied to various applications, such as scintillation imaging, night vision cameras, and an image converter from non-visible light (such as infrared or ultraviolet) to visible light.

Microbial community structure in deep natural gas-bearing aquifers subjected to sulfate-containing fluid injection

In the natural gas field located in central Japan, high concentrations of natural gases and iodide ions are dissolved in formation water and commercially produced in deep aquifers. In the iodine recovery process, the produced formation water is amended with sulfate, and this fluid is injected into gas-bearing aquifers, which may lead to infrastructure corrosion by hydrogen sulfide. In this study, we examined the microbial community in aquifers subjected to sulfate-containing fluid injection. Formation water samples were collected from production wells located at different distances from the injection wells. The chemical analysis showed that the injection fluid contained oxygen, nitrate, nitrite and sulfate, in contrast to the formation water, which had previously been shown to be depleted in these components. Sulfur isotopic analysis indicated that sulfate derived from the injection fluid was present in the sample collected from near the injection wells. Quantitative and sequencing analysis of dissimilatory sulfite reductase and 16S rRNA genes revealed that sulfate-reducing bacteria (SRB), sulfur-oxidizing bacteria, and anaerobic methanotrophic archaea (ANME) in the wells located near injection wells were more abundant than those in wells located far from the injection wells, suggesting that fluid injection stimulated these microorganisms through the addition of oxygen, nitrate, nitrite and sulfate to the methane-rich aquifers. The predominant taxa were assigned to the ANME-2 group, its sulfate-reducing partner SEEP-SRB1 cluster and sulfur-oxidizing Epsilonproteobacteria. These results provide important insights for future studies to support the development of natural gas and iodine resources in Japan.

High-fat/high-sucrose diet results in higher bone mass in aged rats

Intake of high-fat/high-sucrose (HFS) diet or high fat diet influences bone metabolism in young rodents, but its effects on bone properties of aged rodents still remain unclear. This study aimed to examine the effects of HFS diet intake on trabecular bone architecture (TBA) and cortical bone geometry (CBG) in aged rats. Fifteen male Wistar rats over 1 year were randomly divided into two groups. One group was fed a standard laboratory diet (SLD) and the other group was fed a HFS diet for six months. The femur/tibia, obtained from both groups at the end of experimental period, were scanned by micro-computed tomography for TBA/CBG analyses. Serum biochemical analyses were also conducted. Body weight was significantly higher in the HFS group than in the SLD group. In both femur and tibia, the HFS group showed higher trabecular/cortical bone mass in reference to bone mineral content, volume bone mineral density and TBA/CBG parameters compared with the SLD group. In addition, serum calcium, inorganic phosphorus, total protein, triacylglycerol, HDL and TRACP-5b levels were significantly higher in the HFS group than in the SLD group. There were good correlations between body weight and bone parameters in the femur and tibia. These results suggest that HFS diet intake results in higher bone mass in aged rats. Such effects of HFS diet intake might have been induced by increased body weight.

Long-Term Intake of Green Tea Extract Causes Mal-Conformation of Trabecular Bone Microarchitecture in Growing Rats

The purpose of this study was to examine the effects of green tea extract (GTE) intake on bone structural and physiological properties, such as bone mass, trabecular bone microarchitecture, cortical bone geometry, and bone mechanical strength, in growing rats. Four-week-old male Wistar rats were divided into the following four groups: standard diet feeding for 85 days (S-CON) or 170 days (L-CON), and GTE diet feeding for 85 days (S-GTE) or 170 days (L-GTE). At the end of the experiment, in addition to measurement of circulating bone formation/resorption markers, bone mass, trabecular bone microarchitecture, and cortical bone geometry were analyzed in the left femur, and bone mechanical strength of the right femur was measured. There was no difference in all bone parameters between the S-CON and S-GTE groups. On the other hand, the L-GTE group showed the decrease in some trabecular bone mass/microarchitecture parameters and no change in cortical bone mass/geometry parameters compared with the L-CON group, and consequently the reduction in bone weight corrected by body weight. There was no difference in bone formation/resorption markers and bone mechanical strength between the S-CON and S-GTE groups and also between the L-CON and L-GTE groups. However, serum leptin levels were significantly lower in the L-GTE group than in the L-CON group. Thus, the long-term GTE intake had negative effects on bone, especially trabecular bone loss and microarchitecture mal-conformation, in growing rats.

Guiding of relativistic electron beams in dense matter by laser-driven magnetostatic fields

Intense lasers interacting with dense targets accelerate relativistic electron beams, which transport part of the laser energy into the target depth. However, the overall laser-to-target energy coupling efficiency is impaired by the large divergence of the electron beam, intrinsic to the laser-plasma interaction. Here we demonstrate that an efficient guiding of MeV electrons with about 30 MA current in solid matter is obtained by imposing a laser-driven longitudinal magnetostatic field of 600 T. In the magnetized conditions the transported energy density and the peak background electron temperature at the 60-μm-thick target's rear surface rise by about a factor of five, as unfolded from benchmarked simulations. Such an improvement of energy-density flux through dense matter paves the ground for advances in laser-driven intense sources of energetic particles and radiation, driving matter to extreme temperatures, reaching states relevant for planetary or stellar science as yet inaccessible at the laboratory scale and achieving high-gain laser-driven thermonuclear fusion.

Petrothermobacter organivorans gen. nov., sp. nov., a thermophilic, strictly anaerobic bacterium of the phylum Deferribacteres isolated from a deep subsurface oil reservoir

A novel thermophilic, anaerobic, chemoheterotrophic, acetate-oxidizing and iron(III)-, manganese(IV)-, nitrate- and sulfate-reducing bacterium, designated strain ANA^T, was isolated from a deep subsurface oil field in Japan (Yabase oil field, Akita Pref.). Cells of strain ANA^T were Gram-stain-negative, non-motile, non-spore forming and slightly curved or twisted rods (1.5-5.0 µm long and 0.6-0.7 µm wide). The isolate grew at 25-60 °C (optimum 55 °C) and pH 6.0-8.0 (optimum pH 7.0). The isolate was capable of reducing iron(III), manganese(IV), nitrate and sulfate as an electron acceptor. The isolate utilized a limited range of electron donors such as acetate, lactate, pyruvate and yeast extract for iron reduction. Strain ANA^T also used pyruvate, fumarate, succinate, malate, yeast extract and peptone for fermentative growth. The major respiratory quinones were menaquinone-7(H8) and menaquinone-8. The strain contained C18 : 0, iso-C18 : 0 and C16 : 0 as the major cellular fatty acids. The G+C content of the genomic DNA was 34.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain ANA^T was closely related to Calditerrivibrio nitroreducens in the phylum Deferribacteres with low sequence similarities (89.5 %), and formed a distinct clade within the family Deferribacteraceae. In addition, the isolate is the first sulfate-reducing member of the phylum Deferribacteres. Based on phenotypic, chemotaxonomic and phylogenetic properties, a novel genus and species, Petrothermobacter organivorans gen. nov., sp. nov., is proposed for the isolate (type strain=ANA^T= NBRC 112621^T=DSM 105015^T).

Impact of simulated three-dimensional perception on precision of depth judgements, technical performance and perceived workload in laparoscopy

Background

This study compared precision of depth judgements, technical performance and workload using two‐dimensional (2D) and three‐dimensional (3D) laparoscopic displays across different viewing distances. It also compared the accuracy of 3D displays with natural viewing, along with the relationship between stereoacuity and 3D laparoscopic performance.

Methods

A counterbalanced within‐subjects design with random assignment to testing sequences was used. The system could display 2D or 3D images with the same set‐up. A Howard–Dolman apparatus assessed precision of depth judgements, and three laparoscopic tasks (peg transfer, navigation in space and suturing) assessed performance (time to completion). Participants completed tasks in all combinations of two viewing modes (2D, 3D) and two viewing distances (1 m, 3 m). Other measures administered included the National Aeronautics and Space Administration Task Load Index (perceived workload) and the Randot^® Stereotest (stereoacuity).

Results

Depth judgements were 6·2 times as precise at 1 m and 3·0 times as precise at 3 m using 3Dversus2D displays (P < 0·001). Participants performed all laparoscopic tasks faster in 3D at both 1 and 3 m (P < 0.001), with mean completion times up to 64 per cent shorter for 3Dversus2D displays. Workload was lower for 3D displays (up to 34 per cent) than for 2D displays at both viewing distances (P < 0·001). Greater viewing distance inhibited performance for two laparoscopic tasks, and increased perceived workload for all three (P < 0·001). Higher stereoacuity was associated with shorter completion times for the navigating in space task performed in 3D at 1 m (r = − 0·40, P = 0·001).

Conclusion

3D displays offer large improvements over 2D displays in precision of depth judgements, technical performance and perceived workload.

Many advantages for 3D

Methane production from coal by a single methanogen

Coal-bed methane is one of the largest unconventional natural gas resources. Although microbial activity may greatly contribute to coal-bed methane formation, it is unclear whether the complex aromatic organic compounds present in coal can be used for methanogenesis. We show that deep subsurface-derived Methermicoccus methanogens can produce methane from more than 30 types of methoxylated aromatic compounds (MACs) as well as from coals containing MACs. In contrast to known methanogenesis pathways involving one- and two-carbon compounds, this "methoxydotrophic" mode of methanogenesis couples O-demethylation, CO₂ reduction, and possibly acetyl-coenzyme A metabolism. Because MACs derived from lignin may occur widely in subsurface sediments, methoxydotrophic methanogenesis would play an important role in the formation of natural gas not limited to coal-bed methane and in the global carbon cycle.

Long-term wheel-running can prevent deterioration of bone properties in diabetes mellitus model rats

OBJECTIVES

The purpose of this study was to examine the effects of long-term wheel-running on tibia bone properties in T2DM Otsuka Long-Evans Tokushima Fatty (OLETF) rats.

METHODS

Ten five-week-old male OLETF rats were used as experimental animals and 5 Long-Evans Tokushima Otsuka (LETO) rats as controls. Half of OLETF rats performed daily voluntary wheel-running for 17 months (OLETF-EXE), while neither the remainder of OLETF nor LETO rats had exercise. At the end of experiment, in addition to serum biochemical and bone formation/resorption marker analyses, bone mass, trabecular bone microarchitecture and cortical bone geometry were analyzed in left tibia, and bone mechanical strength of right tibia was measured.

RESULTS

Tibia bone mass, trabecular bone microarchitecture, cortical bone geometry and bone mechanical strength deteriorated in diabetic OLETF rats. However, such deterioration was obviously attenuated in OLETF-EXE rats, which maintained normal levels of blood glucose, HbA1c and blood urea nitrogen.

CONCLUSIONS

Daily wheel-running could prevent the deterioration of bone properties in OLETF rats. This would be induced mainly by suppressing the development of T2DM. Regular physical exercise may be a potent strategy for preventing not only the development of diabetes but also the deterioration of bone properties in patients with chronic T2DM.

Methanomicrobium antiquum sp. nov., a hydrogenotrophic methanogen isolated from deep sedimentary aquifers in a natural gas field

A mesophilic, hydrogenotrophic methanogen, designated strain MobHT, was isolated from sediments derived from deep sedimentary, natural-gas-bearing aquifers in Japan. Strain MobHT utilized H2/CO2 or formate, but not ethanol, 1-propanol, 2-propanol, 2-butanol or cyclopentanol, for growth and methane production. In addition, acetate and tungsten were required for growth. Yeast extract stimulated the growth, but was not required. The cells were weakly motile with multiple flagella, presented as a curved-rod-shaped (0.8×2.0 µm) and occurred singly or in pairs. Strain MobHT grew at 15-40 °C (optimum 35 °C) and at pH 5.9-7.9 (optimum pH 7.0-7.5). The sodium chloride range for growth was 0-5.8 % (optimum 2 %). The G+C content of the genomic DNA was 37.6 mol%. In the phylogenetic tree based on the 16S rRNA gene sequences, strain MobHT clustered together with Methanomicrobium mobile (95.4 % in sequence similarity), and formed a distinct clade from Methanolacinia petrolearia SEBR 4847T (95.6 %) and Methanolacinia paynteri G-2000T (95.4 %). The two species of the genus Methanolacinia utilized 2-propanol, whereas strain MobHT and Methanomicrobium mobile, the sole species of the genus Methanomicrobium, do not. Based on phenotypic and phylogenetic features, we propose a novel species for the isolate with the name, Methanomicrobiumantiquum sp. nov. The type strain is MobHT (=DSM 21220T=NBRC 104160T).

5′-O-Alkyl and Acyl Prodrugs of 1-β-D-Arabinofuranosyl-E-5-(2-Bromovinyl)Uracil

5′- O-Alkyl derivatives of 1-β-D-arabinofuranosyl- E-5-(2-bromovinyl)uracil (BV-araU) were synthesized by selective alkylation and deprotection of 2′,3′-bis- O-tetrahydropyranyl BV-araU to enhance metabolic stability and evaluated for efficacy as oral prodrugs of BV-araU. For comparison, their acyl congeners, and 3′- O- and 2′- O-ethyl BV-araU, were also prepared by direct acylation of BV-araU and by selective protection, alkylation, and deprotection, respectively. The 5′- O-alkyl prodrugs were stable in acidic solutions, whereas the 5′- O-acyl analogues were unstable under the same conditions. When incubated with enterobacteria, the 5′- O-acyl derivatives resulted in the formation of BV-uracil through non-enzymatic hydrolysis of BV-araU, but the 5′- O-alkyl prodrugs did not. 5′- O-Short-chain aliphatic alkyl (not longer than butyl) and generally acyl prodrugs gave higher blood concentrations of BV-araU than the aromatic derivatives. Plasma concentrations of BV-araU were equal or slightly higher than those after equivalent oral doses of BV-araU. 5′- O-Ethyl BV-araU was effective against intracerebral, intraperitoneal, and cutaneous infections with herpes simplex virus type 1 in mice. 5′- O-Short-chain aliphatic alkyl derivatives may prove to be useful oral prodrugs of BV-araU because of increased metabolic stability.

In vitro Anti-Herpesvirus Activities of 5-Substituted 2′-Deoxy-2′-Methylidene Pyrimidine Nucleosides

New pyrimidine deoxyribonucleoside analogues, 2′-deoxy-2′-methylideneuridine (DMDU), 2′-deoxy-2′-methylidenecytidine (DMDC), and their 5-substituted derivatives were tested for the anti-herpesvirus activities and anti-proliferative activity. E-5-(2-Bromovinyl)uracil derivative (BV-DMDU) and its cytosine congener were synthesized from 1-β-D-arabinofuranosyl- E-5-(2-bromovinyl)uracil (BV-araU). 5-Bromo, 5-iodo, 5-methyl, and 5-ethyl derivatives of DMDU and BV-DMDU showed activities against herpes simplex virus type 1 (HSV-1) and varicella-zoster virus (VZV). The corresponding DMDC derivatives had no or only weak antiviral activity. Among the 2′-deoxy-2′-methylidene pyrimidine nucleosides, BV-DMDU showed the most potent and selective anti-VZV activity. BV-DMDU was more potent than acyclovir, but less active than BV-araU. BV-DMDU was inactive against human diploid and tumour cells. DMDC and F-DMDC (5-fluoro derivative) were potent inhibitors of HSV-1, herpes simplex virus type 2, VZV, and human cytomegalovirus (HCMV) and also had significant anti-proliferative activity. Their potency against HCMV was better than that of ganciclovir and araC. Some DMDU derivatives also showed anti-HCMV activity, but they had anti-proliferative activity. The anti-HCMV activity of these DMDC and DMDU compounds was generally more potent than those against HSV-1 and VZV thereof, suggesting the participation of cellular kinase in their antiviral action.

Femoral bone structure in Otsuka Long-Evans Tokushima Fatty rats

Objectives

Type 2 diabetes mellitus (T2DM) increases fracture risk despite normal to high levels of bone mineral density. Bone quality is known to affect bone fragility in T2DM. The aim of this study was to clarify the trabecular bone microstructure and cortical bone geometry of the femur in T2DM model rats.

Methods

Five-week-old Otsuka Long-Evans Tokushima Fatty (OLETF; n = 5) and Long-Evans Tokushima Otsuka (LETO; n = 5) rats were used. At the age of 18 months, femurs were scanned with micro-computed tomography, and trabecular bone microstructure and cortical bone geometry were analyzed.

Results

Trabecular bone microstructure and cortical bone geometry deteriorated in the femur in OLETF rats. Compared with in LETO rats, in OLETF rats, bone volume fraction, trabecular number and connectivity density decreased, and trabecular space significantly increased. Moreover, in OLETF rats, cortical bone volume and section area decreased, and medullary volume significantly increased.

Conclusions

Long-term T2DM leaded to deterioration in trabecular and cortical bone structure. Therefore, OLETF rats may serve as a useful animal model for investigating the relationship between T2DM and bone quality.

Are we burying our heads in the sand? Preventing small bowel obstruction from the V-loc® suture in laparoscopic ventral rectopexy

AIM

There have been increasing reports in the literature highlighting the complication of V-loc® associated small bowel obstruction in patients after laparoscopic ventral rectopexy.

METHODS AND RESULTS

Using clinical and experimental evidence, we demonstrate that bowel obstruction from the V-loc® following laparoscopic ventral rectopexy will still occur despite the technical recommendations to bury or cut its barbed end flush.

CONCLUSION

The risk of bowel obstruction from the V-loc® following laparoscopic ventral rectopexy is not negated by burying or cutting its barbed end flush. We have proposed its pathogenesis to refute commonly held assumptions about its prevention.

Tepidicaulis marinus gen. nov., sp. nov., a marine bacterium that reduces nitrate to nitrous oxide under strictly microaerobic conditions

A moderately thermophilic, aerobic, stalked bacterium (strain MA2T) was isolated from marine sediments in Kagoshima Bay, Japan. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain MA2T was most closely related to the genera Rhodobium , Parvibaculum , and Rhodoligotrophos (92–93 % similarity) within the class Alphaproteobacteria . Strain MA2T was a Gram-stain-negative and stalked dimorphic bacteria. The temperature range for growth was 16–48 °C (optimum growth at 42 °C). This strain required yeast extract and NaCl (>1 %, w/v) for growth, tolerated up to 11 % (w/v) NaCl, and was capable of utilizing various carbon sources. The major cellular fatty acid and major respiratory quinone were C18 : 1ω7c and ubiquinone-10, respectively. The DNA G+C content was 60.7 mol%. Strain MA2T performed denitrification and produced N2O from nitrate under strictly microaerobic conditions. Strain MA2T possessed periplasmic nitrate reductase (Nap) genes but not membrane-bound nitrate reductase (Nar) genes. On the basis of this morphological, physiological, biochemical and genetic information a novel genus and species, Tepidicaulis marinus gen. nov., sp. nov., are proposed, with MA2T ( = NBRC 109643T = DSM 27167T) as the type strain of the species.

Tidal volume and diaphragm muscle activity in rats with cervical spinal cord injury

[Purpose] The purpose of this study was to make an experimental model of cervical spinal cord injury (CSCI) using Wistar rats, in order to analyze the influence of CSCI on the respiratory function. [Subjects] Thirty-two male 12-week-old Wistar rats were used. [Methods] The CSCI was made at the levels from C3 to C7, and we performed pneumotachography and electromyography (EMG) on the diaphragm. Computed tomography was used to determine the level of spinal cord damage. [Results] After the operation, the tidal volume of the rats with a C3 level injury decreased to approximately 22.3% of its pre-injury value. In addition, in the same rats, the diaphragmatic electromyogram activity decreased remarkably. Compared with before CSCI, the tidal volume decreased to 78.6% of its pre-injury value in CSCI at the C5 level, and it decreased to 94.1% of its pre-injury value in CSCI at the C7 level. [Conclusion] In the rats that sustained a CSCI in this study, the group of respiratory muscles that receive innervation from the thoracic spinal cord was paralyzed. Therefore, the EMG signal of the diaphragm increased. These results demonstrate that there is a relationship between respiratory function and the level of CSCI.

Response measurement of single-crystal chemical vapor deposition diamond radiation detector for intense X-rays aiming at neutron bang-time and neutron burn-history measurement on an inertial confinement fusion with fast ignition

A neutron bang time and burn history monitor in inertial confinement fusion with fast ignition are necessary for plasma diagnostics. In the FIREX project, however, no detector attained those capabilities because high-intensity X-rays accompanied fast electrons used for plasma heating. To solve this problem, single-crystal CVD diamond was grown and fabricated into a radiation detector. The detector, which had excellent charge transportation property, was tested to obtain a response function for intense X-rays. The applicability for neutron bang time and burn history monitor was verified experimentally. Charge collection efficiency of 99.5% ± 0.8% and 97.1% ± 1.4% for holes and electrons were obtained using 5.486 MeV alpha particles. The drift velocity at electric field which saturates charge collection efficiency was 1.1 ± 0.4 × 10(7) cm/s and 1.0 ± 0.3 × 10(7) cm/s for holes and electrons. Fast response of several ns pulse width for intense X-ray was obtained at the GEKKO XII experiment, which is sufficiently fast for ToF measurements to obtain a neutron signal separately from X-rays. Based on these results, we confirmed that the single-crystal CVD diamond detector obtained neutron signal with good S/N under ion temperature 0.5-1 keV and neutron yield of more than 10(9) neutrons/shot.

Effects of different fatty acid chain lengths on fatty acid oxidation-related protein expression levels in rat skeletal muscles

Skeletal muscles can adapt to dietary interventions that affect energy metabolism. Dietary intake of medium-chain fatty acids (MCFAs) enhances mitochondrial oxidation of fatty acids (FAO) in type IIa skeletal muscle fibers. However, the effect of MCFAs diet on mitochondrial or cytoplasmic FAO-related protein expression levels in different types of muscle fibers remains unclear. This study aims to examine the effects of a high-fat diet, containing MCFAs, on mitochondrial enzyme activities and heart-type fatty acid-binding protein (H-FABP) levels in different types of skeletal muscle fibers. Five-week-old male Wistar rats were assigned to one of the following three dietary conditions: standard chow (SC, 12% of calories from fat), high-fat MCFA, or high-fat long-chain fatty acids (LCFAs) diet (60% of calories from fat for both). The animals were provided food and water ad libitum for 4 weeks, following which citrate synthase (CS) activity and H-FABP concentration were analyzed. The epididymal fat pads (EFP) were significantly smaller in the MCFA group than in the LCFA group (p < 0.05). MCFA-fed group displayed an increase in CS activity compared with that observed in SC-fed controls in all types of skeletal muscle fibers (triceps, surface portion of gastrocnemius (gasS), deep portion of gastrocnemius (gasD), and soleus; p < 0.05,). H-FABP concentration was significantly higher in the LCFA group than in both the SC-fed and MCFA-fed groups (triceps, gasS, gasD, and soleus; p < 0.05,). However, no significant difference was observed in the H-FABP concentrations between the SC-fed and MCFA-fed groups. The results of this study showed that the MCFA diet can increase the expression of the mitochondrial enzyme CS, but not that of H-FABP, in both fast- and slow-twitch muscle fibers, suggesting that H-FABP expression is dependent on the chain length of fatty acids in the cytoplasm of skeletal muscles cells.

Photonuclear reaction based high-energy x-ray spectrometer to cover from 2 MeV to 20 MeV

A photonuclear-reaction-based hard x-ray spectrometer is developed to measure the number and energy spectrum of fast electrons generated by interactions between plasma and intense laser light. In this spectrometer, x-rays are converted to neutrons through photonuclear reactions, and the neutrons are counted with a bubble detector that is insensitive to x-rays. The spectrometer consists of a bundle of hard x-ray detectors that respond to different photon-energy ranges. Proof-of-principle experiment was performed on a linear accelerator facility. A quasi-monoenergetic electron bunch (Ne = 1.0 × 10(-6) C, Ee = 16 ± 0.32 MeV) was injected into a 5-mm-thick lead plate. Bremsstrahlung x-rays, which emanate from the lead plate, were measured with the spectrometer. The measured spectral shape and intensity agree fairly well with those computed with a Monte Carlo simulation code. The result shows that high-energy x-rays can be measured absolutely with a photon-counting accuracy of 50%-70% in the energy range from 2 MeV to 20 MeV with a spectral resolution (Δhν/hν) of about 15%. Quantum efficiency of this spectrometer was designed to be 10(-7), 10(-4), 10(-5), respectively, for 2-10, 11-15, and 15-25 MeV of photon energy ranges.

Development of multichannel low-energy neutron spectrometer

A multichannel low-energy neutron spectrometer for down-scattered neutron (DSN) measurements in inertial confinement fusion (ICF) experiments has been developed. Our compact-size 256-channel lithium-glass-scintillator-based spectrometer has been implemented and tested in ICF experiments with the GEKKO XII laser. We have performed time calibration of the 256-channel analog-to-digital convertor system used for DSN measurements via X-ray pulse signals. We have clearly observed the DD-primary fusion neutron signal and have successfully studied the detector's impulse response. Our detector is soon to be implemented in future ICF experiments.

Characterizing a fast-response, low-afterglow liquid scintillator for neutron time-of-flight diagnostics in fast ignition experiments

The characteristics of oxygen-enriched liquid scintillators with very low afterglow are investigated and optimized for application to a single-hit neutron spectrometer for fast ignition experiments. It is found that 1,2,4-trimethylbenzene has better characteristics as a liquid scintillator solvent than the conventional solvent, p-xylene. In addition, a benzophenon-doped BBQ liquid scintillator is shown to demonstrate very rapid time response, and therefore has potential for further use in neutron diagnostics with fast time resolution.

Methylocaldum marinum sp. nov., a thermotolerant, methane-oxidizing bacterium isolated from marine sediments, and emended description of the genus Methylocaldum

An aerobic, methane-oxidizing bacterium (strain S8T) was isolated from marine sediments in Kagoshima Bay, Japan. Phylogenetic analysis based on 16S rRNA gene sequences indicated that this strain is closely related to members of the genus Methylocaldum (97.6–97.9 % similarity) within the class Gammaproteobacteria . Strain S8T was a Gram-staining-negative, non-motile, coccoid or short rod-shaped organism. The temperature range for growth of strain S8T was 20–47 °C (optimum growth at 36 °C). It required NaCl (>0.5 %), tolerated up to 5 % NaCl and utilized methane and methanol. The major cellular fatty acid and major respiratory quinone were C16 : 0 and 18-methylene ubiquinone 8, respectively. The DNA G+C content was 59.7 mol%. Strain S8T possessed mmoX, which encodes soluble methane monooxygenase, as well as pmoA, which encodes the particulate methane monooxygenase. On the basis of this morphological, physiological, biochemical and genetic information, the first marine species in the genus Methylocaldum is proposed, with the name Methylocaldum marinum sp. nov. The type strain is S8T ( = NBRC 109686T = DSM 27392T). An emended description of the genus Methylocaldum is also provided.

Methanohalophilus levihalophilus sp. nov., a slightly halophilic, methylotrophic methanogen isolated from natural gas-bearing deep aquifers, and emended description of the genus Methanohalophilus

A mesophilic, slightly halophilic, obligately methylotrophic, methanogenic archaeon, designated strain GTA13(T), was isolated from natural gas-bearing confined aquifers in the Minami-Kanto gas field, Japan. The cells were non-motile, slightly irregular cocci, 0.7-1.0 µm in diameter and occurred singly, in pairs or as small aggregates. The cells grew with tri- or dimethylamine but not with H2/CO2, formate, acetate, methanol or dimethyl sulphide. Vitamins, sodium and magnesium were required for growth. Optimal growth occurred at pH 7.0-7.5, 35 °C, 0.35-0.40 M NaCl and 15-50 mM MgCl2. The NaCl range for growth was 0.2-1.3 M. The DNA G+C content was 43.7 mol%. Strain GTA13(T) showed highest levels of 16S rRNA gene sequence similarity with Methanohalophilus portucalensis FDF-1(T) (96.4% sequence similarity) and Methanohalophilus halophilus DSM 3094(T) (96.0%). On the basis of physiological and phylogenetic features, strain GTA13(T) is considered to represent a novel species of the genus Methanohalophilus, for which the name Methanohalophilus levihalophilus sp. nov. is proposed. The type strain is GTA13(T) ( = NBRC 110099(T) = DSM 28452(T)). An emended description of the genus Methanohalophilus is also proposed.

Methyloceanibacter caenitepidi gen. nov., sp. nov., a facultatively methylotrophic bacterium isolated from marine sediments near a hydrothermal vent

A moderately thermophilic, methanol-oxidizing bacterium (strain Gela4(T)) was isolated from methane-utilizing mixed-culture originating from marine sediment near a hydrothermal vent. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain Gela4(T) was closely related to members of the genus 'Methyloligella' (94.7% similarity) within the class Alphaproteobacteria. Strain Gela4(T) was a Gram-staining-negative and aerobic organism. Cells were rod-shaped and non-motile. The temperature range for growth of strain Gela4(T) was 19-43 °C (optimal growth at 35 °C). Strain Gela4(T) tolerated up to 9% NaCl with an optimum at 1%. The organism was a facultative methylotroph that could utilize methanol, methylamine, trimethylamine and a variety of multi-carbon compounds. The major cellular fatty acid and major respiratory quinone were C18 : 1ω7c and ubiquinone-10, respectively. The predominant phospholipids were phosphatidylcholine, phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content was 63.9 mol%. On the basis of the morphological, physiological, biochemical and genetic information, a novel genus and species, Methyloceanibacter caenitepidi is proposed, with Gela4(T) ( = NBRC 109540(T) = DSM 27242(T)) as the type strain.