Hydrocarbon Cycling in the Tokamachi Mud Volcano (Japan): Insights from Isotopologue and Metataxonomic Analyses.

Understanding hydrocarbon cycling in the subsurface is important in various disciplines including climate science, energy resources and astrobiology. Mud volcanoes provide insights into biogeochemical processes occurring in the subsurface. They are usually associated with natural gas reservoirs consisting mainly of methane and other hydrocarbons as well as CO2. Stable isotopes have been used to decipher the sources and sinks of hydrocarbons in the subsurface, although the interpretation can be ambiguous due to the numerous processes involved. Here we report new data for hydrocarbon isotope analysis, including position-specific isotope composition of propane, for samples from the Tokamachi mud volcano area, Japan. The data suggest that C2+ hydrocarbons are being biodegraded, with indirect production of methane ("secondary methanogenesis"). Data from chemical and isotopic composition are discussed with regard to 16S rRNA analysis, which exhibits the presence of hydrogenotrophic and acetoclastic methoanogens. Overall, the combination of isotopologue analysis with 16S rRNA gene data allows refining of our understanding of hydrocarbon cycling in subsurface environments.

Determinism of microbial community assembly by drastic environmental change.

Microbial community assembly is shaped by deterministic and stochastic processes, but the relationship between these processes and the environment is not understood. Here we describe a rule for the determinism and stochasticity of microbial community assembly affected by the environment using in silico, in situ, and ex situ experiments. The in silico experiment with a simple mathematical model showed that the existence of essential symbiotic microorganisms caused stochastic microbial community assembly, unless the community was exposed to a non-adapted nutritional concentration. Then, a deterministic assembly occurred due to the low number of microorganisms adapted to the environment. In the in situ experiment in the middle of a river, the microbial community composition was relatively deterministic after the drastic environmental change caused by the treated wastewater contamination, as analyzed by 16S rRNA gene sequencing. Furthermore, by culturing microbial communities collected from the upstream natural area and downstream urban area of the river in test tubes with varying carbon source concentrations, the upstream community assembly became deterministic with high carbon concentrations while the downstream community assembly became deterministic with low carbon concentrations. These results suggest that large environmental changes, which are different from the original environment, result in a deterministic microbial community assembly.

A cross-sectional analysis from the Mykinso Cohort Study: establishing reference ranges for Japanese gut microbial indices.

The purpose of this study was to establish reference ranges for gut microbial indices by collecting real-world Japanese microbiome data from a Mykinso cohort. Although several large cohort studies have focused on the human gut microbiome, large cohort studies of the gut microbiome from Japanese populations are scarce, especially from healthy or non-diseased individuals. We collected stool samples and original survey lifestyle information from 5,843 Japanese individuals through the Mykinso gut microbiome testing service. From the obtained 16S rRNA sequence data derived from stool samples, the ratio and distribution of each taxon were analyzed. The relationship between different epidemiological attributes and gut microbial indicators were statistically analyzed. The qualitative and quantitative indicators of these common gut microbiota were confirmed to be strongly correlated with age, sex, constipation/diarrhea, and history of lifestyle-related diseases. Therefore, we set up a healthy sub-cohort that controlled for these attribute factors and defined reference ranges from the distribution of gut microbial index in that population. Taken together, these results show that the gut microbiota of Japanese people had high beta-diversity, with no single "typical" gut microbiota type. We believe that the reference ranges for the gut microbial indices obtained in this study can be new reference values for determining the balance and health of the gut microbiota of an individual. In the future, it is necessary to clarify the clinical validity of these reference values by comparing them with a clinical disease cohort.

Usefulness of Machine Learning-Based Gut Microbiome Analysis for Identifying Patients with Irritable Bowels Syndrome.

Irritable bowel syndrome (IBS) is diagnosed by subjective clinical symptoms. We aimed to establish an objective IBS prediction model based on gut microbiome analyses employing machine learning. We collected fecal samples and clinical data from 85 adult patients who met the Rome III criteria for IBS, as well as from 26 healthy controls. The fecal gut microbiome profiles were analyzed by 16S ribosomal RNA sequencing, and the determination of short-chain fatty acids was performed by gas chromatography-mass spectrometry. The IBS prediction model based on gut microbiome data after machine learning was validated for its consistency for clinical diagnosis. The fecal microbiome alpha-diversity indices were significantly smaller in the IBS group than in the healthy controls. The amount of propionic acid and the difference between butyric acid and valerate were significantly higher in the IBS group than in the healthy controls (p < 0.05). Using LASSO logistic regression, we extracted a featured group of bacteria to distinguish IBS patients from healthy controls. Using the data for these featured bacteria, we established a prediction model for identifying IBS patients by machine learning (sensitivity >80%; specificity >90%). Gut microbiome analysis using machine learning is useful for identifying patients with IBS.

Effect of light wavelength on hot spring microbial mat biodiversity.

Hot spring associated phototrophic microbial mats are purely microbial communities, in which phototrophic bacteria function as primary producers and thus shape the community. The microbial mats at Nakabusa hot springs in Japan harbor diverse photosynthetic bacteria, mainly Thermosynechococcus, Chloroflexus, and Roseiflexus, which use light of different wavelength for energy conversion. The aim of this study was to investigate the effect of the phototrophs on biodiversity and community composition in hot spring microbial mats. For this, we specifically activated the different phototrophs by irradiating the mats with different wavelengths in situ. We used 625, 730, and 890 nm wavelength LEDs alone or in combination and confirmed the hypothesized increase in relative abundance of different phototrophs by 16S rRNA gene sequencing. In addition to the increase of the targeted phototrophs, we studied the effect of the different treatments on chemotrophic members. The specific activation of Thermosynechococcus led to increased abundance of several other bacteria, whereas wavelengths specific to Chloroflexus and Roseiflexus induced a decrease in >50% of the community members as compared to the dark conditions. This suggests that the growth of Thermosynechococcus at the surface layer benefits many community members, whereas less benefit is obtained from an increase in filamentous anoxygenic phototrophs Chloroflexus and Roseiflexus. The increases in relative abundance of chemotrophs under different light conditions suggest a relationship between the two groups. Aerobic chemoheterotrophs such as Thermus sp. and Meiothermus sp. are thought to benefit from aerobic conditions and organic carbon in the form of photosynthates by Thermosynechococcus, while the oxidation of sulfide and production of elemental sulfur by filamentous anoxygenic phototrophs benefit the sulfur-disproportionating Caldimicrobium thiodismutans. In this study, we used an experimental approach under controlled environmental conditions for the analysis of natural microbial communities, which proved to be a powerful tool to study interspecies relationships in the microbiome.

Comparison between solid component size on thin-section CT and pathologic lymph node metastasis and local invasion in T1 lung adenocarcinoma.

OBJECTIVES: To correlate the tumor size and solid component size on thin-section CT (TS-CT) with pathological findings including lymph node (LN) metastasis and local invasion in T1 lung adenocarcinoma. METHODS: 188 patients with surgically resected T1 lung adenocarcinoma were retrospectively analyzed. Two chest radiologists measured the long-axis and short-axis dimensions of nodules and solid components with a lung and/or a mediastinal window setting (WS) on TS-CT. After analyzing interobserver agreement, average long-axis dimensions of the measured tumors and solid components were correlated with pathological findings. RESULTS: Seven of 188 patients (3.7%) had pathologic LN-positive metastasis. In patients in whom the long axis of the solid component was <5 mm with a mediastinal WS or <8 mm with a lung WS on TS-CT, no LN metastases were observed, resulting in a positive predictive value (PPV) for predicting a pathologic LN-negative status of 100% with each WS. Based on the same diagnostic criteria, the PPVs for a pathological local invasion (LI)-negative status were 91 (40/44) and 90% (55/61), respectively. CONCLUSION: Solid component size on TS-CT may have the potential to predict LN-negative or LI-negative status.

Clinicoradiological outcomes of 33 cases of surgically resected pulmonary pleomorphic carcinoma: correlation with prognostic indicators.

OBJECTIVES: To retrospectively review the clinical, radiological and pathological data in patients who underwent surgical resection for pulmonary pleomorphic carcinoma (PC), and to analyse the prognostic predictors of survival. METHODS: The data were retrospectively examined for 33 consecutive patients (28 males and five females) who had undergone surgical resection for pulmonary PC. Cox's proportional-hazards model was used to analyse the prognostic predictors of survival. RESULTS: The size of the tumours ranged from 1.1 to 12.0 cm (mean 5.4 cm). The majority (26) of the tumours were located at the lung periphery, five tumours had cavitation, two had calcification and 14 had peritumoral ground-glass opacity. Most of the tumours showed heterogeneous enhancement and contained a low-density area (LDA) within the tumour. The 5-year overall survival of surgically resected PC was 36 % (standard error = 0.093). A multivariate analysis revealed the LDA grade [hazard ratio (HR), 2.019], pathological stage (HR, 7.552) and pathological N factor (HR, 0.370) to be significant predictors of a poorer prognosis. CONCLUSIONS: A greater component of LDA within the tumour on contrast-enhanced CT is associated with a poorer prognosis in patients with PC. KEY POINTS: PC has a poorer prognosis than other conventional NSCLC. The five-year OS of surgically resected PC was 36 %. A greater component of LDA on contrast-enhanced CT suggests a poorer prognosis.

Age-related changes in bone density, geometry and biomechanical properties of the proximal femur: CT-based 3D hip structure analysis in normal postmenopausal women.

The geometry as well as bone mineral density (BMD) of the proximal femur contributes to fracture risk. How and the extent to which they change due to natural aging is not fully understood. We assessed BMD and geometry in the femoral neck and shaft separately, in 59 normal Japanese postmenopausal women aged 54-84 years, using clinical computed tomography (CT) and commercially available software, at baseline and 2-year follow-up. This system detected significant reductions over the 2-year interval in total BMD (%change/year = -0.900 ± 0.257, p < 0.0005), cortical cross-sectional area (CSA) (-0.800 ± 0.423%/year, p < 0.05) and cortical thickness (-1.120 ± 0.453%/year, p < 0.01) in the femoral neck. In the femoral shaft, cortical BMD decreased significantly (-0.642 ± 0.188%/year, p < 0.005). Regarding biomechanical parameters in the femoral neck, the cross-sectional moment of inertia (CSMI) and section modulus (SM) decreased (-1.38 ± 3.65%/year, p < 0.01 and -1.37 ± 2.96%/year, p < 0.005) and the buckling ratio (BR) increased significantly (1.48 ± 4.81%/year, p < 0.05), whereas no changes were found in the femoral shaft. The distinct patterns of age-related changes in the geometry and biomechanical properties in the femoral neck and shaft suggest that improved geometric measures are possible with the current non-invasive method using clinical CT.

[Measurement of bone mineral density is unnecessary for monitoring of bisphosphonate treatment].

A monitoring period in osteoporosis treatment should be considered in accordance with the efficacy of medicine as well as the precision of monitoring tool, because a significant bone gain should be larger than the precision error of the measurement. Regarding bisphosphonate treatment in osteoporosis, 2-5 years'period is required to detect a significant change in bone mineral density (BMD) using dual-energy x-ray absorptiometry. Furthermore, the degree of increase in BMD by bisphosphonate treatment cannot account for the degree of reduction in the risk of fracture. It therefore makes no sense to determine how much BMD increases during the treatment.

Endovascular treatment of iliac artery aneurysms.

Endovascular treatment is now an alternative to surgery for the treatment of iliac artery aneurysms (IAAs). A variety of minimally invasive therapeutic options are available (eg, coil embolization, stent-graft placement), and choosing an appropriate option is essential for achieving excellent long-term results and reducing potential complications. Preprocedural imaging with multi-detector row computed tomography or magnetic resonance imaging is necessary for evaluating patient eligibility and planning the interventional procedure. An imaging classification system for IAAs that is based on anatomic features and endovascular treatment options has been developed and may help determine therapeutic strategies for affected patients. Early experience indicates that endovascular treatment is safe and effective in treating IAAs, and it is expected that various devices that will make endovascular treatment easier to perform will soon become commercially available. However, large, long-term follow-up studies will be needed to determine whether this approach is a practical alternative to open surgery.

Effects of risedronate on trabecular microstructure and biomechanical properties in ovariectomized rat tibia.

We determined the effect of risedronate on the trabecular microstructure of ovariectomized rat tibiae, using micro-computed tomography, in order to investigate how changes in microstructure contribute to biomechanical properties. Fifty 18-week-old rats underwent sham operation (n=10) or ovariectomy (OVX) (n=40). The OVX rats were further divided into four groups (n=10 for each group) and treated with risedronate at doses of 0, 0.1, 0.5 or 2.5 mg/kg for 9 months. OVX caused deterioration of three-dimensional trabecular microstructure, notably structure model index (SMI) and connectivity density, while treatment of OVX rats with risedronate at 0.5 and 2.5 mg/kg improved those deleterious microstructural changes. Biomechanical property, as assessed by finite element analysis (FEA), correlated significantly with trabecular bone volume fraction (BV/TV), and the correlation further increased substantially when microstructural parameters were added, especially SMI and connectivity density, with risedronate therapy. Thus, it is suggested that, in addition to increasing bone mass, risedronate improves biomechanical property by maintaining a plate-like structure as well as connectivity of trabeculae.

Human parathyroid hormone (1-34) increases mass and structure of the cortical shell, with resultant increase in lumbar bone strength, in ovariectomized rats.

Estrogen deficiency causes reduction of bone mass and abnormal bone microarchitecture, consequently reducing bone strength. Human parathyroid hormone (hPTH) (1-34) increases bone mass and strength. To clarify the factors that determine the recovery of bone strength in the lumbar vertebrae of ovariectomized rats by intermittent hPTH administration, we analyzed the relationship between skeletal measurements and bone strength. Human PTH (1-34) administration resulted in recovery of cortical bone mineral content (BMC) and cortical bone area to sham the levels, but in resulted in a less pronounced recovery of trabecular BMC and no increase in the total cross-sectional area of the vertebral body. Of the three-dimensional (3D) trabecular bone parameters, hPTH (1-34) increased trabecular thickness (Tb.Th). The cortical shell area of L4, determined by histomorphometry, was also increased. In hPTH-treated rats, the only determinant of the compressive load of L5 was the cortical shell BMC, in the early recovery period (days 42-84). Our data suggest that increased cortical bone mass contributes more than trabecular bone mass and structure to the recovery of bone strength in response to hPTH therapy in the rat lumbar vertebral body after ovariectomy.

Effect of etidronate on three-dimensional trabecular structure in ovariectomized or sciatic neurectomized rats.

The purpose of this study was to evaluate the effect of etidronate (EHDP) on three-dimensional (3D) trabecular structure in ovariectomized (OVX) and sciatic neurectomized (NX) rats. Eight-week-old female Lewis rats received ovariectomy ( n = 19) or sham operation (OVX-sham; n = 10). OVX rats received either vehicle (OVX-control; n = 9) or EHDP (OVX-EHDP; n = 10). Eight-week-old female Lewis rats received NX ( n = 20) or sham operation (NX-sham; n = 10). NX rats received either vehicle (NX-control; n = 10) or EHDP (NX-EHDP; n = 10). EHDP at 5 mg/kg or vehicle was subcutaneously injected 5 days a week. The treatment was initiated 2 weeks after surgery and was continued for 2 weeks. At 12 weeks of age, the rats were killed, and we scanned the proximal metaphysis of the tibia; this was done using micro-CT; (micro CT20; SCANCO Medical). The recovery of structural parameters was not complete in NX rats compared to OVX rats. The 3D micro-CT images showed that the subcortical spongiosa, which was preserved in OVX rats, had marked loss in NX rats. Furthermore, these trabeculae were not restored after the EHDP treatment. In conclusion, the mechanical driving of the control of trabecular structure is inactive in NX, and EHDP treatment for 2 weeks does not restore this condition.

Chronic aortic dissection complicated by disseminated intravascular coagulation: successful treatment with endovascular stent-grafting.

PURPOSE: To report endovascular repair of a chronic aortic dissection complicated by disseminated intravascular coagulation (DIC). CASE REPORT: A 61-year-old man developed DIC associated with a chronic Stanford type B aortic dissection that occurred during cardiac catheterization 12 years earlier. At the current admission, computed tomography showed a partially thrombosed false lumen extending from the aortic arch to the left common iliac artery. On angiography, entry and re-entry tears were identified at the right subclavian and left common iliac arteries, respectively. After stent-graft implantation at the entry and re-entry sites, not only was the false lumen completely thrombosed but the DIC also resolved. The patient is doing well with no complication at 16 months after treatment. CONCLUSIONS: Endovascular stent-grafting is an acceptable alternative to surgical repair for aortic dissection accompanied by DIC.

Which bone densitometry and which skeletal site are clinically useful for monitoring bone mass?

Long-term precision, as well as reproducibility, is important for monitoring bone mineral density (BMD) alteration in response to aging or therapy. In order to investigate which bone densitometry and which skeletal site are clinically useful for monitoring bone mass, we examined the standardized long-term precision of several bone density measurements in 83 healthy Japanese women. Annual BMD measurements were performed for 5 or 6 years using dual X-ray absorptiometry (DXA) on the lumbar spine, radius (EXP5000) and calcaneus (HeelScan); peripheral quantitative computed tomography (pQCT) on the radius (Densiscan1000); and quantitative ultrasound (QUS) on the calcaneus (Achilles+). The long-term precision error for the individual subject was given by the standard error of estimate (SEE), and the standardized long-term precision was defined as the percentage coefficient of variation (CV%) divided by the percentage ratio of the annual bone-loss rate. Based on the CV% of spinal DXA, speed of sound (SOS) and diaphyseal pQCT showed significantly higher precision than others, while radial ultradistal (UD) DXA and heel DXA showed significantly lower precision. The long-term precision errors of other measurements were statistically the same as that of the spinal DXA. The spinal DXA, the radial DXA, and pQCT at both the distal metaphysis and diaphysis showed high rates of annual bone loss. The radial trabecular BMD (pQCT) was significantly higher than that of spinal DXA. The annual rates of bone loss of QUS and of heel DXA were significantly lower than that of spinal DXA. Taken together, standardized long-term precision was obtained in the spinal DXA and radial pQCT. In conclusion, spinal DXA and radial pQCT were considered the most useful monitoring method for osteoporosis, while QUS was considered less useful.

Bone structure and mineralization demonstrated using synchrotron radiation computed tomography (SR-CT) in animal models: preliminary findings.

We investigated the ability of synchrotron radiation computed tomography (SR-CT) to demonstrate trabecular microstructure, detail of trabecular surfaces, and mineralization of bones. Eight rat vertebrae, six rat tibiae, and eight minipig vertebrae were scanned using SR-CT at the synchrotron radiation facility Super Photon ring-8GeV (SPring-8). Images obtained using conventional micro-CT, scanning electron microscopy (SEM), and contact microradiography (CMR) were compared with the SR-CT images. SR-CT showed high image quality without visible partial volume effect. Three-dimensional SR-CT revealed shallow concavities in the bone surface, which were considered to correspond to osteoclastic resorption areas, as well as the connectivity, anisotropy, and shape (rod- or platelike) of trabeculae. Two-dimensional SR-CT showed different density along the surface of the trabecular bone, indicating the degree of bone mineralization. In conclusion, SR-CT seems to be a useful tool for delineating trabecular surfaces, evaluating bone mineralization, and revealing precise trabecular structure.

Bilateral elastofibroma of the thighs with concomitant subscapular lesions.

We report a case of elastofibroma that occurred in both thighs and subscapular regions. The MR signal intensity of the lesions was typical for elastofibroma. Although bilateral involvement of the thighs is exceptional, the presence of concomitant characteristic bilateral subscapular lesions was helpful in making the diagnosis of elastofibroma.

Coil embolization of iliac artery aneurysms developing after abdominal aortic aneurysm repair with a conventional bifurcated graft.

PURPOSE: To evaluate the efficacy of embolizing iliac artery aneurysms (IAAs) developing after abdominal aortic aneurysm (AAA) repair. METHODS: The records of 6 patients (5 men; mean age 79 years, range 61-87) with unilateral (n=3) or bilateral (n=3) IAAs that had developed after AAA repair were reviewed. In all patients, the limbs of the bifurcated graft were anastomosed end-to-end or end-to-side with the external iliac arteries during AAA repair. Before embolization, superior mesenteric artery (SMA) arteriography was done in all patients to evaluate collateral pathways to the inferior mesenteric artery (IMA). RESULTS: The unilateral IAAs were treated by proximal and distal embolization. In 2 patients with bilateral IAAs, SMA angiography showed sufficient collateral flow to the IMA, so the aneurysms were treated by proximal embolization and packing. In the other bilateral IAA case, the left 6-cm IAA was treated by proximal and distal embolization, while the contralateral 3-cm IAA was not embolized because angiography demonstrated inadequate collateral flow to the IMA, indicating a possible risk of colon ischemia if both IAAs were embolized. Immediate postprocedural angiography in all patients showed complete exclusion of the IAAs. Mild buttock claudication occurred in 1 patient. There were no episodes of rupture over a mean 46-month follow-up. CONCLUSIONS: Embolization is a safe and effective alternative to open surgery for the treatment of IAAs that develop after AAA repair. However, before embolization, angiographic evaluation of collateral pathways to the IMA is essential to reduce the risk of colon ischemia.