Oxidation of Guanosine Monophosphate with O2 via a Ru-peroxo Complex in Water.

Oxidative damage of DNA by reactive oxygen species (ROS) is responsible for aging and cancer. Although many studies of DNA damage by ROS have been conducted, there have been no reports of the oxidation of RNA components, such as guanosine monophosphate, by metal-based species in water. Here, we report the first case of oxidation of guanosine monophosphate to 8-oxoguanosine monophosphate by a metal-based oxygen bound species, derived from O2 and in water.

Acetyl-CoA production by encapsulated pyruvate ferredoxin oxidoreductase in alginate hydrogels.

Pyruvate ferredoxin oxidoreductase from Citrobacter sp. S-77 (PFORS77) was purified in order to develop a method for acetyl-CoA production. Although the purified PFORS77 showed high O2-sensitivity, the activity could be remarkably stabilized in anaerobic conditions. PFORS77 was effectively immobilized on ceramic hydroxyapatite (PFORS77-HA) with an efficiency of more than 96%, however, after encapsulation of PFORS77-HA in alginate, the rate of catalytic acetyl-CoA production was highly reduced to 36% when compared to that of the free enzyme. However, the operational stability of the PFORS77-HA in alginate hydrogels was remarkable, retaining over 68% initial activity even after ten repeated cycles. The results suggested that the PFORS77-HA hydrogels have a high potential for biotechnological application.

Decrease in fungal biodiversity along an available phosphorous gradient in arable Andosol soils in Japan.

Andosols comprise one of the most important soil groups for agricultural activities in Japan because they cover about 46.5% of arable upland fields. In this soil group, available phosphorus (P) is accumulated by application of excessive fertilizer, but little is known about the influence of increasing P availability on microbial community diversity at large scales. We collected soil samples from 9 agro-geographical sites with Andosol soils across an available P gradient (2048.1-59.1 mg P2O5·kg(-1)) to examine the influence of P availability on the fungal community diversity. We used polymerase chain reaction - denaturing gradient gel electrophoresis to analyze the fungal communities based on 18S rRNA genes. Statistical analyses revealed a high negative correlation between available P and fungal diversity (H'). Fungal diversity across all sites exhibited a significant hump-shaped relationship with available P (R(2) = 0.38, P < 0.001). In addition, the composition of the fungal community was strongly correlated with the available P gradient. The ribotype F6, which was positively correlated with available P, was closely related to Mortierella. The results show that both the diversity and the composition of the fungal community were influenced by available P concentrations in Andosols, at a large scale. This represents an important step toward understanding the processes responsible for the maintenance of fungal diversity in Andosolic soils.

Combined analyses of bacterial, fungal and nematode communities in andosolic agricultural soils in Japan.

We simultaneously examined the bacteria, fungi and nematode communities in Andosols from four agro-geographical sites in Japan using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and statistical analyses to test the effects of environmental factors including soil properties on these communities depending on geographical sites. Statistical analyses such as Principal component analysis (PCA) and Redundancy analysis (RDA) revealed that the compositions of the three soil biota communities were strongly affected by geographical sites, which were in turn strongly associated with soil characteristics such as total C (TC), total N (TN), C/N ratio and annual mean soil temperature (ST). In particular, the TC, TN and C/N ratio had stronger effects on bacterial and fungal communities than on the nematode community. Additionally, two-way cluster analysis using the combined DGGE profile also indicated that all soil samples were classified into four clusters corresponding to the four sites, showing high site specificity of soil samples, and all DNA bands were classified into four clusters, showing the coexistence of specific DGGE bands of bacteria, fungi and nematodes in Andosol fields. The results of this study suggest that geography relative to soil properties has a simultaneous impact on soil microbial and nematode community compositions. This is the first combined profile analysis of bacteria, fungi and nematodes at different sites with agricultural Andosols.

Effect of soil type and fertilizer management on archaeal community in upland field soils.

The effects of soil and fertilizer types on archaeal communities were evaluated by real-time PCR and PCR-denaturing gradient gel electrophoresis (DGGE) targeting the 16S rRNA gene of total DNA directly extracted from upland field soils. Twelve experimental upland field plots containing four different soil types, i.e., Cumulic Andosol, Low-humic Andosol, Yellow Soil and Gray Lowland Soil, were maintained under three different fertilizer management systems for 8 years (chemical fertilizer, rice husks and cow manure, and pig manure, respectively). Two-way ANOVA and RDA analyses showed that the copy number and PCR-DGGE profile of archaeal 16S rRNA gene were affected mainly by soil type, especially between Andosol and non-Andosol, but were also influenced by fertilizer type. Among several soil chemical properties, total N content showed a significant correlation to archaeal community. Sequence analyses showed that most of the major DGGE bands corresponded to uncultured Crenarchaeota of Group I.1b that contained ammonia-oxidizing archaea (AOA). These sequences were separated into two clusters in the phylogenetic tree and each lineage showed a different response to total N content.

Quantitative analyses of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in fields with different soil types.

Soil type is one of the key factors affecting soil microbial communities. With regard to ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB), however, it has not been determined how soil type affects their community size and soil nitrification activity. Here we quantitatively analyzed the ammonia monooxygenase genes (amoA) of these ammonia oxidizers in fields with three different soil types (Low-humic Andosol [LHA], Gray Lowland Soil [GLS], and Yellow Soil [YS]) under common cropping conditions, and assessed the relationships between soil nitrification activity and the abundance of each amoA. Nitrification activity of LHA was highest, followed by that of GLS and YS; this order was consistent with that for the abundance of AOB amoA. Abundance of AOB amoA showed temporal variation, which was similar to that observed in nitrification activity, and a strong relationship (adjusted R(2)=0.742) was observed between the abundance of AOB amoA and nitrification activity. Abundance of AOA amoA also exhibited a significant relationship (adjusted R(2)=0.228) with nitrification activity, although this relationship was much weaker. Our results indicate that soil type affects the community size of AOA and AOB and the resulting nitrification activity, and that AOB are major contributors to nitrification in soils, while AOA are partially responsible.

Estimation of the mechanical property of meniscus using ultrasound: examinations of native meniscus and effects of enzymatic digestion.

We previously developed a novel ultrasound assessment system featuring wavelet transform to evaluate the material properties of articular cartilage. We aimed in this study to demonstrate the feasibility of quantitative evaluation of meniscus using ultrasound and to elucidate the relationships between its acoustic, mechanical, and biochemical properties. Meniscal disc specimens from mature pigs were assessed by ultrasound and compression testing, and their correlation was analyzed. A positive correlation was found between the ultrasound signal intensity and apparent Young's modulus (r=0.61). Subsequently, the porcine meniscal discs were treated with various enzymes and then characterized by ultrasound, by compression tests, by biochemical analyses, and by histology and immunohistochemistry. The signal intensity was decreased not by hyaluronidase but by collagenase treatment. Hyaluronidase-treated menisci showed a discrepancy between acoustic and mechanical properties, suggesting that the ultrasound reflection could not detect a reduction in proteoglycan content. Also, ultrasound signal intensity could only reflect superficial layers of the material. Several limitations exist at present, and further studies and improvements of the device are required. However, given the noninvasive nature and the requirement of only small equipment, this ultrasound assessment system will be an instrumental diagnostic tool for meniscal function in both research and clinical fields.

Acoustic stiffness and change in plug cartilage over time after autologous osteochondral grafting: correlation between ultrasound signal intensity and histological score in a rabbit model.

We investigated quantitative changes over time in ultrasound signal intensity (an index of stiffness), signal duration (an index of surface irregularity), and interval between signals (an index of thickness) of plug cartilage in an animal model of autologous osteochondral grafting. A full-thickness osteochondral plug was surgically removed and replaced in male Japanese white rabbits (n = 22). Specimens obtained at day 0 and weeks 2, 4, 8, 12 and 24 postoperatively were assessed using an ultrasound system and by macroscopic and histological evaluation (modified Mankin's score). Histology revealed that the plug sank until 2 weeks postoperatively, and that newly formed cartilage-like tissue covered the plug, but at 24 weeks the tissue detached. The plug itself survived well throughout the period of observation. Although the signal intensity at the plug site was same as that in the sham operated contralateral knee at day 0, from 2 to 24 weeks postoperatively it was less than that in the sham knee. At 8 weeks, this difference was significant (P < 0.05). Modified Mankin's score revealed early degenerative changes at the site, but macroscopic examination did not. Signal intensity correlated significantly with score (both at day 0 and at the five postoperative time points [P < 0.05, r = -0.91] and as a whole [P < 0.05, r = -0.36]). Signal intensity also significantly correlated with the individual subscores for 'cartilage structure' (P < 0.05, r = -0.32) and 'cartilage cells' (P < 0.05, r = -0.30) from the modified Mankin's score, but not significantly with subscores for 'staining' and 'tidemark'. Signal duration correlated significantly with total score (as a whole [P < 0.05, r = 0.34]), but not significantly with the score for cartilage structure (P = 0.0557, r = 0.29). The interval between signals reflected well the actual thickness of the plug site. The significant relationships between ultrasound signal intensity and scores suggest that early degenerative changes in plug cartilage and cartilage-like tissue, especially in the superficial layer, are detectable by high-frequency ultrasound assessment.

Ultrasonographic features of the masseter muscle in female patients with temporomandibular disorder associated with myofascial pain.

OBJECTIVE: The purpose of the present study was to examine ultrasonographic appearances in female patients with temporomandibular disorder (TMD) associated with myofascial pain in comparison with healthy volunteers. STUDY DESIGN: The thickness of the masseter muscle in 25 female patients with TMD was measured at rest and at maximum contraction using ultrasonography. The visibility and width of the internal echogenic bands of the masseter muscle were also assessed and the muscle appearance was classified as 1 of 3 types: type I, characterized by the clear visibility of the fine bands; type II, thickening and weakened echo-intensity of the bands; type III, disappearance or reduction in number of the bands. RESULTS: There were significant differences in the thickness at rest and the increase ratio by contraction between the patient and control groups. The distribution of muscle types showed a significant difference between the 2 groups. CONCLUSION: The ultrasonographic features of the masseter muscle in TMD patients with myofascial pain were clarified and they might be related to muscle edema.

Remodeling of the Nauplius Eye into the Adult Ocelli during Metamorphosis of the Barnacle, Balanus amphitrite hawaiiensis: (Crustacea/cypris larva/photoreceptor/rhabdom/Ultrastructure).

The planktonic barnacle larva has a single median ocellus (nauplius eye), while the adult possesses two distinct sets of photoreceptors; a pair of lateral ocelli and a single median ocellus. The nauplius eye of the cypris larva of Balanus amphitrite hawaiiensis is composed of 14 visual cells grouped into three components (a pair of lateral components and a single ventral component) surrounding two centrally located pigment cells; each lateral component consists of 5 visual cells and the ventral component, 4 visual cells. In each component, the rhabdom is made up of apposing microvilli arising directly from the neighboring visual cell bodies. During metamorphosis into the adult form, the three components of the median ocellus become separated. Each lateral component migrates laterally on the mantle and is remodeled into the adult lateral ocellus, losing two visual cells but gaining new pigment and tapetum cells in the process. The ventral component remains in the mid portion and becomes the adult median ocellus without fundamental modification in composition. The visual cells in both ocelli undergo a marked increase in volume and form many finger-like dendrites. Rhabdomes are made up of interdigitating microvilli arising from the the dendrite tips.