[The Study of a Relaxed Patient Position in Whole Lower Limb Radiography].

PURPOSE: In whole lower limb radiography, a position of the patella is the center of the knee with a leg slight internal rotation (a knee frontal position). However, we revised the positioning to stand naturally so that we can evaluate the lower limb alignment while standing more naturally (a relaxed patient position). In this study, we compared a lower limb alignment of a relaxed patient position and a knee frontal position. METHODS: The images of 84 patients who underwent artificial joint replacement surgery were analyzed, separately for the group with artificial joint and without it. The Mikulicz line (the functional axis of the lower limb connecting the center of the femoral bone and the ankle joint) is drawn on the image of the whole lower limb radiography. The intersection between the proximal tibia joint surface and the Mikulicz line defines the percentage of mechanical axis (%MA). Furthermore, we compared the %MA between a relaxed patient position and a knee frontal position and assessed them by the Bland-Altman analysis. RESULTS: The correlation coefficient (R) was 0.792 in the group with artificial joint and 0.856 in the group without artificial joint. There was a fixed error between the relaxed patient position and the knee frontal position. CONCLUSION: The %MA tends to be smaller in a relaxed patient position than in a knee frontal position. Besides, it is found that there is a correlation between them.

"Duckweed-Microbe Co-Cultivation Method" for Isolating a Wide Variety of Microbes Including Taxonomically Novel Microbes.

We herein described a new microbial isolation method using the interaction between the floating aquatic plant, duckweed, and microbes. We harvested microbial cells from Japanese loosestrife roots and co-cultivated these cells with aseptic duckweed using artificial inorganic medium for the plant for four weeks. During the co-cultivation, some duckweeds were collected every week, and the roots were used for microbial isolation using a low-nutrient plate medium. As a result, diverse microbial isolates, the compositions of which differed from those of the original source (Japanese loosestrife root), were obtained when the roots of duckweed were collected after 2 weeks of cultivation. We also successfully isolated a wide variety of novel microbes, including two strains within the rarely cultivated phylum, Armatimonadetes. The present study shows that a duckweed-microbe co-cultivation approach together with a conventional technique (direct isolation from a microbial source) effectively obtains more diverse microbes from a sole environmental sample.

Isolation of Novel Bacteria Including Rarely Cultivated Phyla, Acidobacteria and Verrucomicrobia, from the Roots of Emergent Plants by Simple Culturing Method.

A number of novel bacteria including members of rarely cultivated phyla, Acidobacteria and Verrucomicrobia, were successfully isolated from the roots of two emergent plants, Iris pseudacorus and Scirpus juncoides, by a simple culturing method. A total of 47.1% (66 strains) for I. pseudacorus and 42.1% (59 strains) for S. juncoides of all isolates (140 strains from each sample) were phylogenetically novel. Furthermore, Acidobacteria and Verrucomicrobia occupied 10.7% (15 strains) and 2.9% (4 strains) of I. pseudacorus isolates, and 2.1% (3 strains) and 3.6% (5 strains) of S. juncoides isolates, respectively, indicating that plant roots are attractive sources for isolating rarely cultivated microbes.

[Study on the effect of setting the region of interest for exposure index computing].

Exposure index (EI) is expected as important standard for the optimization of image quality and exposed dose in digital radiography. It is set a region of interest (ROI) in a radiograph, to obtain a histogram of pixel values within an ROI, it is computed as EI of the image representative value of the histogram. In this study, we examined the effects of setting the ROI for EI computing. We set five different ROIs in chest or cervical spine frontal radiograph, and compared the computed EI in each ROIs. From the result, in some cases, we found that EI varied greatly as those compared to the case of ROI set in full image. We should consider about setting the ROI for EI computing when we use EI as standard for optimization of image quality and exposed dose in digital radiography.

Optimization of dual-energy subtraction chest radiography by use of a direct-conversion flat-panel detector system.

We aimed to optimize the exposure conditions in the acquisition of soft-tissue images using dual-energy subtraction chest radiography with a direct-conversion flat-panel detector system. Two separate chest images were acquired at high- and low-energy exposures with standard or thick chest phantoms. The high-energy exposure was fixed at 120 kVp with the use of an auto-exposure control technique. For the low-energy exposure, the tube voltages and entrance surface doses ranged 40-80 kVp and 20-100 % of the dose required for high-energy exposure, respectively. Further, a repetitive processing algorithm was used for reduction of the image noise generated by the subtraction process. Seven radiology technicians ranked soft-tissue images, and these results were analyzed using the normalized-rank method. Images acquired at 60 kVp were of acceptable quality regardless of the entrance surface dose and phantom size. Using a repetitive processing algorithm, the minimum acceptable doses were reduced from 75 to 40 % for the standard phantom and to 50 % for the thick phantom. We determined that the optimum low-energy exposure was 60 kVp at 50 % of the dose required for the high-energy exposure. This allowed the simultaneous acquisition of standard radiographs and soft-tissue images at 1.5 times the dose required for a standard radiograph, which is significantly lower than the values reported previously.

High-throughput DNA microarray detection of pathogenic bacteria in shallow well groundwater in the Kathmandu Valley, Nepal.

Because of heavy dependence on groundwater for drinking water and other domestic use, microbial contamination of groundwater is a serious problem in the Kathmandu Valley, Nepal. This study investigated comprehensively the occurrence of pathogenic bacteria in shallow well groundwater in the Kathmandu Valley by applying DNA microarray analysis targeting 941 pathogenic bacterial species/groups. Water quality measurements found significant coliform (fecal) contamination in 10 of the 11 investigated groundwater samples and significant nitrogen contamination in some samples. The results of DNA microarray analysis revealed the presence of 1-37 pathogen species/groups, including 1-27 biosafety level 2 ones, in 9 of the 11 groundwater samples. While the detected pathogens included several feces- and animal-related ones, those belonging to Legionella and Arthrobacter, which were considered not to be directly associated with feces, were detected prevalently. This study could provide a rough picture of overall pathogenic bacterial contamination in the Kathmandu Valley, and demonstrated the usefulness of DNA microarray analysis as a comprehensive screening tool of a wide variety of pathogenic bacteria.

Microbial community analysis in the roots of aquatic plants and isolation of novel microbes including an organism of the candidate phylum OP10.

A number of molecular ecological studies have revealed complex and unique microbial communities in various terrestrial plant roots; however, little is known about the microbial communities of aquatic plant roots in spite of their potential use for water quality improvement in aquatic environments (e.g. floating treatment wetland system). Here, we report the microbial communities inhabiting the roots of emerged plants, reed (Phragmites australis) and Japanese loosestrife (Lythrum anceps), collected from a floating treatment wetland in a pond by both culture-independent and culture-dependent approaches. Culture-independent analysis based on 16S rRNA gene sequences revealed that the microbial compositions between the two aquatic plant roots were clearly different (e.g. the predominant microbe was Betaproteobacteria for reed and Alphaproteobacteria for Japanese loosestrife). In comparisons of microbial communities between the plant roots and pond water taken from near the plants, the microbial diversity in the plant roots (e.g. 4.40-4.26 Shannon-Weiner index) were higher than that of pond water (e.g. 3.15 Shannon-Weiner index). Furthermore, the plant roots harbored 2.5-3.5 times more phylogenetically novel clone phylotypes than pond water. The culture-dependent approach also revealed differences in the microbial composition and diversity among the two plant roots and pond water. More importantly, compared to pond water, we succeeded in isolating approximately two times more novel isolate phylotypes, including a bacterium of candidate phylum OP10 (recently named Armatimonadetes) from the plant roots. These findings suggest that aquatic plants roots are significant sources for a variety of novel organisms.

[Relationship between the effect of medial rotation of the foot axis by ankle dorsiflexion and the ability to visualize the femoral neck axis in the hip joint anterio-posterior radiography: evaluation by magnetic resonance images].

In scanning of the hip joint anterio-posterior radiography, by changing the lower extremities to the extension position and moving the foot axis (base line of the foot) by medial rotation, the angle of anteversion of the femoral neck is corrected. In this study, we assessed the effects on medial rotation of the femoral neck when keeping the planta vertically-positioned by ankle dorsiflexion (intermediate position of the ankle) and making change of the medial rotation angle of the foot axis by scanning the magnetic resonance (MR) images of knee joints and hip joints. The subjects in this study were 12 males (age: 37.9±13.8, weight: 67.3±5.5 kg) and 7 females (age: 27.6±5.1, weight: 50.0±4.5 kg). We measured the medial rotation angles of knee joints and femoral necks on MR images. Also, differences of these angles between males and females were compared. Although the gender differences were not found in medial rotation angle of both joints at all leg positions (P>0.05), the medial rotation angles increased by approximately 1.5 to 2.0 times larger by putting them at the intermediate position, and there were significant differences between the naturally plantar-flexed position and the intermediate position (P<0.05). In conclusion, our results showed that the optimal leg position for correcting the angle of anteversion was 20 degrees medial rotation of the foot axis at the naturally plantar-flexed position, or 10 degrees medial rotation of the foot axis at the intermediate position, regardless of gender.

Armatimonas rosea gen. nov., sp. nov., of a novel bacterial phylum, Armatimonadetes phyl. nov., formally called the candidate phylum OP10.

A novel aerobic, chemoheterotrophic bacterium, strain YO-36(T), isolated from the rhizoplane of an aquatic plant (a reed, Phragmites australis) inhabiting a freshwater lake in Japan, was morphologically, physiologically and phylogenetically characterized. Strain YO-36(T) was Gram-negative and ovoid to rod-shaped, and formed pinkish hard colonies on agar plates. Strain YO-36(T) grew at 20-40 °C with optimum growth at 30-35 °C, whilst no growth was observed at 15 °C or 45 °C. The pH range for growth was 5.5-8.5 with an optimum at pH 6.5. Strain YO-36(T) utilized a limited range of substrates, such as sucrose, gentiobiose, pectin, gellan gum and xanthan gum. The strain contained C(16 : 0), C(16 : 1), C(14 : 0) and C(15 : 0) as the major cellular fatty acids and menaquinone-12 as the respiratory quinone. The G+C content of the genomic DNA was 62.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain YO-36(T) belonged to the candidate phylum OP10 comprised solely of environmental 16S rRNA gene clone sequences except for two strains, P488 and T49 isolated from geothermal soil in New Zealand; strain YO-36(T) showed less than 80 % sequence similarity to strains P488 and T47. Based on the phylogetic and phenotypic findings, a new genus and species, Armatimonas rosea gen. nov., sp. nov., is proposed for the isolate (type strain YO-36(T)  = NBRC 105658(T)  = DSM 23562(T)). In addition, a new bacterial phylum named Armatimonadetes phyl. nov. is proposed for the candidate phylum OP10 represented by A. rosea gen. nov., sp. nov. and Armatimonadaceae fam. nov., Armatimonadales ord. nov., and Armatimonadia classis nov.

Culture-dependent and independent analyses of the microbial communities inhabiting the giant duckweed (Spirodela polyrrhiza) rhizoplane and isolation of a variety of rarely cultivated organisms within the phylum Verrucomicrobia.

The microbial communities of the rhizoplane, the surface part of roots, in aquatic plants are not understood at all. In this study, we analyzed microbial communities in the rhizoplane of a floating aquatic plant, giant duckweed (Spirodela polyrrhiza), based on cultivation-dependent and independent analyses. The cultivation-based analysis using agar and gellan gum plates revealed that the rhizoplane isolates were affiliated with four bacterial lineages; the Alphaproteobacteria, Betaproteobacteria, Bacteroidetes and Verrucomicrobia. Interestingly, microbes belonging to the phylum Verrucomicrobia accounted for 24% of all the isolates, suggesting that the rhizoplane of S. polyrrhiza forms a specific habitat for the organisms within this phylum. Culture-independent 16S rRNA gene cloning showed that the clonal sequences were affiliated with eight bacterial classes and phyla: the classes Alphaproteobacteria (14% total clones), Betaproteobacteria (45%), Gammaproteobacteria (2%) and Deltaproteobacteria (2%), and the phyla Bacteroidetes (11%), Verrucomicrobia (2%), Planctomycetes (2%) and Cyanobacteria (22%). Comparative analysis of the microbial communities in the rhizoplane between culture-dependent and independent methods revealed that 33% of the taxonomic groups of bacterial species detected in the molecular analysis were cultivable. Our findings suggest that the microbes in the rhizoplane of giant duckweed are comprised of a diverse array of readily cultured organisms including a variety of strains within the Verrucomicrobia, a well-known phylum that contains a number of yet-to-be cultivated organisms.

[Observer performance of PACS-oriented digitized mammography in the detection of fibrils, microcalcifications, and masses: a phantom study].

The film digitizer plays an important transitory role as an analog-to-digital bridge for the implementation of PACS on screen-film mammography. The objective of this phantom study was to compare the observer performance of a digitized mammogram on liquid crystal displays (LCDs) with that of the original film mammogram, and to clarify which matrix size of LCDs is adequate for the interpretation of digitized mammography. The American College of Radiology mammographic accreditation phantom containing variously sized fibrils, simulated microcalcifications, and tumor-like masses was radiographed with a screen-film mammographic system. The original film was digitized with a sampling pitch of 50 mum and a density depth of 12 bit. Six observers who were trained in mammography individually viewed digitized images on LCDs and original film. Observer performance of a digitized mammogram with a 2-megapixel LCD was compared with that of original film. The observers were asked to rate the detectability of each test object according to a three-point scale (obviously visible=2, barely detectable=1, undetectable=0). The difference in the mean score between two systems at each object was evaluated by the Wilcoxon's test. In addition, the dependence of observer performance on the matrix size of LCDs ranging from 1-to 5-megapixel was tested with Scheffé's multiple comparison. The observers also judged the detectability according to the three-point scale. The results show that the digitized mammogram provides acceptable but slightly inferior detectability than original film. There was no dependence of matrix size in observer performance with more than 2-megapixel LCDs.

Assessment of acetazolamide reactivity in cerebral blood flow using spectral analysis and technetium-99m hexamethylpropylene amine oxime.

Cerebral blood flow (CBF) can be quantified noninvasively using the brain perfusion index (BPI), determined from radionuclide angiographic data generated with technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO). Previously, the BPI has been calculated using graphical analysis (GA); however, the GA method is greatly affected by the first-pass extraction fraction and retention fraction, which are not only variable, but lower in cases with an increased CBF, such as after the administration of acetazolamide. Thus, GA-calculated BPI values (BPIG) may not reflect the absolute CBF. The objective of this study was to use the spectral analysis of radionuclide angiographic data collected using 99mTc-HMPAO to examine changes in the BPI after the administration of acetazolamide. We studied the CBF of both cerebral hemispheres in six healthy male volunteers; the BPI was measured at rest and after the intravenous administration of 1 g of acetazolamide. In all participants, an H215O positron emission tomography (PET) examination was also performed, and the spectral analysis-calculated BPI values (BPIS) and BPIG values were compared with the actual CBF measured using H215O PET (mCBFPET). The BPIS was 1.070 +/- 0.051 (mean +/- SD) at rest and 1.497 +/- 0.098 after acetazolamide; the corresponding BPIG values were 0.646 +/- 0.073 and 0.721 +/- 0.107. The BPIS values were significantly correlated with the mCBFPET values, whereas the BPIG values were not. According to the BPIS values, the increase in BPI after the intravenous administration of acetazolamide was 40.1 +/- 8.4%, as opposed to an increase of only 11.3 +/- 6.5% according to the BPIG values. These results suggest that the spectral analysis of 99mTc-HMPAO-generated data yields a more reliable BPI than GA for the quantification of CBF after acetazolamide administration.