Oligomeric Structural Transition of HspB1 from Chinese Hamster.

HspB1 is a mammalian sHsp that is ubiquitously expressed in almost all tissues and involved in regulating many vital functions. Although the recent crystal structure of human HspB1 showed that 24 monomers form the oligomeric complex of human HspB1 in a spherical configuration, the molecular architecture of HspB1 is still controversial. In this study, we examined the oligomeric structural change of CgHspB1 by sedimentation velocity analytical ultracentrifugation. At the low temperature of 4 °C, CgHspB1 exists as an 18-mer, probably a trimeric complex of hexamers. It is relatively unstable and partially dissociates into small oligomers, hexamers, and dodecamers. At elevated temperatures, the 24-mer was more stable than the 18-mer. The 24-mer is also in dynamic equilibrium with the dissociated oligomers in the hexameric unit. The hexamer further dissociates to dimers. The disulfide bond between conserved cysteine residues seems to be partly responsible for the stabilization of hexamers. The N-terminal domain is involved in the assembly of dimers and the interaction between hexamers. It is plausible that CgHspB1 expresses a chaperone function in the 24-mer structure.

PV1 Protein from Plasmodium falciparum Exhibits Chaperone-Like Functions and Cooperates with Hsp100s.

Plasmodium falciparum parasitophorous vacuolar protein 1 (PfPV1), a protein unique to malaria parasites, is localized in the parasitophorous vacuolar (PV) and is essential for parasite growth. Previous studies suggested that PfPV1 cooperates with the Plasmodium translocon of exported proteins (PTEX) complex to export various proteins from the PV. However, the structure and function of PfPV1 have not been determined in detail. In this study, we undertook the expression, purification, and characterization of PfPV1. The tetramer appears to be the structural unit of PfPV1. The activity of PfPV1 appears to be similar to that of molecular chaperones, and it may interact with various proteins. PfPV1 could substitute CtHsp40 in the CtHsp104, CtHsp70, and CtHsp40 protein disaggregation systems. Based on these results, we propose a model in which PfPV1 captures various PV proteins and delivers them to PTEX through a specific interaction with HSP101.

A low psoas muscle volume correlates with a longer hospitalization after radical cystectomy.

BACKGROUND: Recently, sarcopenia has been reported as a new predictor for patient outcomes or likelihood of post-operative complications. The purpose of this study was to evaluate the association of the psoas muscle volume with the length of hospitalization among patients undergoing radical cystectomy. METHODS: A total of 63 (80.8%) male patients and 15 (19.2%) female patients who underwent radical cystectomy for their bladder cancer in our institution from 2000 to 2015 were analyzed. The psoas muscle index (PMI) was calculated by normalizing the psoas muscle area calculated using axial computed tomography at the level of the umbilicus (cm2) by the square of the body height (m2). Longer hospitalization was defined as hospitalization exceeding 30 days after surgery. RESULTS: The median PMIs (mean ± standard deviation) were 391 (394 ± 92.1) and 271 (278 ± 92.6) cm2/m2 in men and women, respectively. Thus, the PMIs of male patients were significantly larger than those of females (p < 0.001). Based on the differences in gender, we analyzed 63 male patients for a further analysis. In male patients, those hospitalized longer showed a significantly smaller PMI than those normally discharged (377 ± 93.1 vs. 425 ± 83.4; p = 0.04). Similarly, male patients with a small PMI (<400) had a significantly worse overall survival (p = 0.02) than those with a large PMI (≥400). CONCLUSIONS: The presence of sarcopenia was found to be associated with significantly longer hospitalization after radical cystectomy in male patients. Furthermore, in men, a PMI <400 may suggest a significantly worse prognosis.

Neutrophil-to-lymphocyte ratio is a prognostic marker in bladder cancer patients after radical cystectomy.

BACKGROUND: There is no reliable biomarker for predicting the prognosis of patients who undergo radical cystectomy for bladder cancer. Recent studies have shown that the neutrophil-to-lymphocyte ratio (NLR) could function as a useful prognostic factor in several types of malignancies. This study aimed to assess the usefulness of NLR in bladder cancer. METHODS: A total of 74 patients who underwent radical cystectomy in our institutions from 1999 to 2014 were analyzed. The NLR was calculated using the patients' neutrophil and lymphocyte counts before radical cystectomy. An immunohistochemical analysis was also performed to detect tumor infiltrating neutrophils (CD66b) and lymphocytes (CD8) in bladder cancer specimens. RESULTS: A univariate analysis showed that the patients with a high NLR (≥2.38; HR = 4.84; p = 0.007), high C-reactive protein level (>0.08; HR = 10.06; p = 0.030), or pathological lymph node metastasis (HR = 4.73; p = 0.030) had a significantly higher risk of cancer-specific mortality. Kaplan-Meier and log-rank tests further revealed that NLR was strongly correlated with overall survival (p = 0.018), but not progression-free survival (p = 0.137). In a multivariate analysis, all of these were found to be independent risk factors (HR = 4.62, 10.8, and 12.35, respectively). The number of CD8-positive lymphocytes was significantly increased in high-grade (p = 0.001) and muscle-invasive (p = 0.012) tumors, in comparison to low-grade and non-muscle-invasive tumors, respectively. CONCLUSIONS: The NLR predicted the prognosis of patients who underwent radical cystectomy and might therefore function as a reliable biomarker in cases of invasive bladder cancer.

[Metastatic collecting duct carcinoma with relatively long-term survival treated with sunitinib: a case report].

A 51-year-old man visited our hospital with a chief complaint of left renal mass detected by ultrasonography in another hospital. Enhanced computed tomography (CT) revealed a hypovascular tumor measuring about 9 cm in the left kidney, tumor thrombus in the inferior vena cava and paraaortic lymph nodes metastases. Radical left transperitoneal nephrectomy with removal of the thrombus from the left renal vein were performed. Paraaortic lymph nodes dissection was partially performed because of the solid adhesion to aorta. Histological examination revealed collecting duct carcinoma (CDC). He was treated with systemic chemotherapy (gemcitabine plus nedaplatin) followed by sunitinib. Duration of stable disease after initiation of therapy was seventeen months, and survival after surgery was 31 months. It would be worthwhile to prospectively evaluate the antitumor activity of tyrosine kinase inhibitors against metastatic CDC.

[Non-gated vessel wall imaging of the internal carotid artery using radial scanning and fast spin echo sequence: evaluation of vessel signal Intensity by flow rate at 3.0 tesla].

Vessel wall imaging using radial scanning does not use a blood flow suppression pulse with gated acquisition. It has been proposed that there may not be a flow void effect if the flow rate is slow; however, this has yet to be empirically tested. To clarify the relationship between the signal intensity of the vessel lumen and the blood flow rate in a flow phantom, we investigated the usefulness of vessel wall imaging at 3.0 tesla (T). We measured the signal intensity while changing the flow rate in the flow phantom. Radial scanning at 1.5 T showed sufficient flow voids at above medium flow rates. There was no significant difference in lumen signal intensity at the carotid artery flow rate. The signal intensity of the vessel lumen decreased sufficiently using the radial scan method at 3.0 T. We thus obtained sufficient flow void effects at the carotid artery flow rate. We conclude this technique to be useful for evaluating plaque if high contrast can be maintained for fixed tissue (such as plaque) and the vessel lumen.

[Optimal scan parameters for a method of k-space trajectory (radial scan method) in evaluation of carotid plaque characteristics].

The purpose of this study was to optimize scan parameters for evaluation of carotid plaque characteristics by k-space trajectory (radial scan method), using a custom-made carotid plaque phantom. The phantom was composed of simulated sternocleidomastoid muscle and four types of carotid plaque. The effect of chemical shift artifact was compared using T1 weighted images (T1WI) of the phantom obtained with and without fat suppression, and using two types of k-space trajectory (the radial scan method and the Cartesian method). The ratio of signal intensity of simulated sternocleidomastoid muscle to the signal intensity of hematoma, blood (including heparin), lard, and mayonnaise was compared among various repetition times (TR) using T1WI and T2 weighted imaging (T2WI). In terms of chemical shift artifacts, image quality was improved using fat suppression for both the radial scan and Cartesian methods. In terms of signal ratio, the highest values were obtained for the radial scan method with TR of 500 ms for T1WI, and TR of 3000 ms for T2WI. For evaluation of carotid plaque characteristics using the radial scan method, chemical shift artifacts were reduced with fat suppression. Signal ratio was improved by optimizing the TR settings for T1WI and T2WI. These results suggest the potential for using magnetic resonance imaging for detailed evaluation of carotid plaque.

[Can fruits and vegetables be used as substitute phantoms for normal human brain tissues in magnetic resonance imaging?].

Various custom-made phantoms designed to optimize magnetic resonance imaging (MRI) sequences have been created and subsequently reported in JSRT. However, custom-made phantoms that correctly match the T1-value and T2-values of human brain tissue (gray matter and white matter) cannot be made easily or quickly. The aim of this project was to search for alternative materials, such as fruits and vegetables, for optimizing MRI sequences. The following eight fruits and vegetables were investigated: apple, tomato, melon, apple mango (Mangifera indica), banana, avocado, peach, and eggplant. Their potential was studied for use in modeling phantoms of normal human brain tissues. MRI (T1- and T2-weighted sequences) was performed on the human brain and the fruits and vegetables using various concentrations of contrast medium (gadolinium) in the same size tubes as the custom-made phantom. The authors compared the signal intensity (SI) in human brain tissue (gray matter and white matter) with that of the fruits and the custom-made phantom. The T1 and T2 values were measured for banana tissue and compared with those for human brain tissue in the literature. Our results indicated that banana tissue is similar to human brain tissue (both gray matter and white matter). Banana tissue can thus be employed as an alternative phantom for the human brain for the purpose of MRI.

Clinical Presentation and Characteristics of the Upper Extremity in Patients with Musculocontractural Ehlers-Danlos Syndrome.

Musculocontractural Ehlers-Danlos syndrome (mcEDS) is a subtype of EDS caused by defective dermatan sulfate biosynthesis, characterized by multiple malformations (craniofacial features, ocular and visceral malformations) and progressive cutaneous, skeletal, vascular, and visceral fragility-related manifestations. Repeated dislocations and deformities of the joints due to joint relaxation are observed, causing serious damage to the musculoskeletal system of the whole body; however, the motor function of the upper limbs and the morphology of the bone joints have not been systematically investigated. In this study, we present a detailed and comprehensive report on upper limb lesions of 13 patients with a mean age at the first visit of 21 years. Twelve patients (92.3%) had a history of dislocation. Eleven patients (84.6%) had shoulder dislocations, and two patients (15.4%) had elbow dislocations. Four patients (30.8%) had elbow osteoarthritis, and three patients (23.1%) had distal radioulnar joint (DRUJ) osteoarthritis. The phalanges and metacarpals are thin, and the ratio of medullary cavity of the metacarpal bone decreases with age. As bone and joint deformity progresses, patients with mcEDS should be recommended to receive regular follow-up, including radiology. The present findings suggest an important role for dermatan sulfate in the maintenance of the skeletal system.

Microwave aided conversion of cellulose to glucose using polyoxometalate as catalyst.

The viability of biorefining technology primarily depends on the facile cellulose conversion route with adequate conversion efficiency. Here we have demonstrated the microwave-assisted hydrolysis of cellulose to glucose using polyoxometalate (POM) clusters as acid catalysts. Two different types of POM, including Wells-Dawson and Keggin were justified as catalysts in the cellulose conversion process. In particular, the cellulose to glucose catalytic conversion using Wells-Dawson type POMs has not been reported to date. Also, even though there have been some previous reports about the catalytic biomass conversion of Keggin type POMs, the systematic study to optimize the conversion efficiency in terms of catalyst amount, reaction temperature, reaction time, and the amount of solvent is lacking. Under the experimental conditions employed, the Keggin-type catalyst showed higher cellulose conversion and glucose yield than the Wells-Dawson-type catalyst. Furthermore, the cellulose conversion efficiency and glucose yields were optimized by tuning the reaction conditions including temperature, reaction time, and the amount of solvent. Under optimized conditions, the Keggin-type POM catalyst shows a remarkably high glucose yield of 77.2% and a cellulose conversion of 90.1%. The unique complex properties of the POM catalyst, including being (i) strong acids with extremely high Brønsted and Lewis acidity and (ii) efficient microwave adsorbants which enhanced interaction between substrate and the catalyst can be attributed to the outstanding efficacy of the conversion process.

Microwave-assisted catalytic conversion of chitin to 5-hydroxymethylfurfural using polyoxometalate as catalyst.

The key challenges for converting chitin to 5-hydroxymethylfurfural (5-HMF) include the low 5-HMF yield. Moreover, the disadvantages of traditional acid-base catalysts including complex post-treatment processes, the production of by-products, and severe equipment corrosion also largely limit the large-scale conversion of chitin to 5-HMF. In this view, herein we have demonstrated a microwave aided efficient and green conversion of chitin to 5-HMF while using polyoxometalate (POM) as a catalyst and DMSO/water as solvent. Chitin treated with H2SO4 followed by ball-milling (chitin-H2SO4-BM) was selected as the starting compound for the conversion process. Four different POMs including H3[PW12O40], H3[PMo12O40], H4[SiW12O40] and H4[SiMo12O40] were used as catalysts. Various reaction parameters including reaction temperature, amount of catalyst, mass ratios of water/DMSO and reaction time have been investigated to optimize the 5-HMF conversion. The H4[SiW12O40] catalyst exhibited the highest catalytic performance with 23.1% HMF yield at optimum operating conditions which is the highest among the literature for converting chitin to 5-HMF. Significantly, the disadvantages of the state of the art conversion routes described earlier can be overcome using POM-based catalysts, which makes the process more attractive to meet the ever-increasing energy demands, in addition to helping consume crustacean waste.

Microwave-assisted catalytic conversion of glucose to 5-hydroxymethylfurfural using "three dimensional" graphene oxide hybrid catalysts.

Hybrids of reduced graphene oxide (rGO) and metal/metal oxide (Pt, NiO/Ni(OH)2, CoO, Fe3O4) nano particle were prepared by reduction of graphene oxide (GO) and metal ion (Pt2+, Ni2+, Co2+, Fe2+) hybrids. The M-rGO hybrids (M = Pt, Ni-, Co and Fe) were justified for the transformation of glucose to 5-hydroxymethylfurfural (5-HMF). High glucose → 5-HMF conversion was yielded depending on the nature of the M-rGO catalyst. The Ni-rGO showed the highest 5-HMF yield. The conversion reaction tuned to the optimized state under a microwave-assisted reaction accomplished by using Ni-rGO. In such case, the conversion rate was 99% with a 5-HMF yield of 75%. In order to improve both the conversion and yield, NiGO-FD was prepared by a freeze-dry method. The NiGO-FD remarkably showed the highest conversion of 99% and 5-HMF yield of 95%. Beside the biomass transformation process, the physico-chemical strategy employed herein for multiplying the catalytic efficiency might be justified for catalyzing similar reactions.

Correction: Microwave-assisted catalytic conversion of glucose to 5-hydroxymethylfurfural using "three dimensional" graphene oxide hybrid catalysts.

[This corrects the article DOI: 10.1039/D0RA01009J.].

[Applicability of the 3D-VIBE sequence to whole brain imaging].

The VIBE method has been developed imaging also holds its breath in an abdomen, and to do three-dimensional T1WI in possible time in gradient echo sequence, and applied to dynamic study mainly and planning for time reduction using an interpolation and partial fourier. We considered the condition for imaging to do whole brain as high resolution image using VIBE. Even if base matrix was maintained when an interpolation and partial fourier were used too much excessively by Phantom experiment, the resolution of MPR image fell. There was a limit of the interpolation therefore to maintain the resolution as voxel. SNR fell by FA increase by the applicability to the head, and peak existed in about 15 degrees in CNR of white matter and gray matter. Therefore by it's clinical and optimizing the imaging condition of VIBE, whole brain, it was imaging possible in about 3 minutes as high resolution image.

A Liquid-core Liquid-cladding Optical Waveguide Based on Thermal Gradients across the Laminar Flow of Water in Capillary Tubing.

A liquid-core liquid-cladding optical waveguide based on thermal gradients across laminar flow was built with the laminar flow of water in a stainless capillary tube placed in a heat source. Its characteristics were studied with both experiments and a computational fluid dynamics simulation, firstly showing that it had the nature of a graded index optical fiber.

Functional and structural characterization of HspB1/Hsp27 from Chinese hamster ovary cells.

Small heat shock proteins (sHsps) endow cells with stress tolerance. Of the various sHsps in mammals, HspB1, also known as Hsp27, is the most ubiquitous. To examine the structure and function of HspB1, we expressed, purified, and characterized HspB1 from Chinese hamster (Cricetulus griseus) ovary cells (CgHspB1). CgHspB1 forms a large oligomeric structure. We observed a monodisperse 16-mer with an elongated sphere, but this is affected by changes in various conditions, including temperature. Under dilute conditions, CgHspB1 dissociates into small oligomers at elevated temperatures. The dissociated conformers interacted with the gel filtration column through hydrophobic interactions. In contrast, dissociation of the oligomer was not observed by small-angle X-ray scattering at 55 °C. The result partially coincides with the results of size exclusion chromatography, showing that dissociation did not occur at high protein concentrations. However, a significant structural change in the oligomeric conformations appears to occur between room and higher temperatures. Reflecting their status as homeotherms, mammalian sHsps are regulated by phosphorylation. A phosphorylation mimic mutant of CgHspB1 with the replacement of Ser15 to Asp exhibited relatively lower oligomer stability and greater protective ability against thermal aggregation than the wild-type protein. The result clearly shows a correlation between oligomer dissociation and chaperone activity.

Comparison of magnetic resonance imaging sequences for depicting the subthalamic nucleus for deep brain stimulation.

Electrodes are surgically implanted into the subthalamic nucleus (STN) of Parkinson's disease patients to provide deep brain stimulation. For ensuring correct positioning, the anatomic location of the STN must be determined preoperatively. Magnetic resonance imaging has been used for pinpointing the location of the STN. To identify the optimal imaging sequence for identifying the STN, we compared images produced with T2 star-weighted angiography (SWAN), gradient echo T2*-weighted imaging, and fast spin echo T2-weighted imaging in 6 healthy volunteers. Our comparison involved measurement of the contrast-to-noise ratio (CNR) for the STN and substantia nigra and a radiologist's interpretations of the images. Of the sequences examined, the CNR and qualitative scores were significantly higher on SWAN images than on other images (p < 0.01) for STN visualization. Kappa value (0.74) on SWAN images was the highest in three sequences for visualizing the STN. SWAN is the sequence best suited for identifying the STN at the present time.

[Analysis of dot-like hemosiderin spots using brain dock system].

BACKGROUND AND PURPOSE: Dot-like low intensity spots (a dot-like hemosiderin spot: dotHS) on T2*-weighted MR images (T2*WI), which is regarded as a sensitive method for hemosiderin detection, have been histologically diagnosed as old microbleeds associated with microangiopathies. The clinical significance of the dotHS, however, is still under debate. Therefore, we investigated the factors associated with dotHS. METHODS: We investigated 209 healthy volunteers in our hospital (sex: 106 males, 103 females; age: 38 to 78 years old, mean age: 56.4 +/- 8.3 years old) using "Brain Dock", a formalized screening system for asymptomatic brain diseases. The Odds ratio (OR) was estimated from multiple logistic regression analyses using the dotHS and variables. RESULTS: T2*WI demonstrated dotHS in 7.7% of volunteers, and the mean number of dotHS was 0.16 +/- 0.78. The hemosiderin was preferentially deposited in the basal ganglia and thalamus. Age > or = 65 years old (OR: 5.9; 95% confidence interval [CI]: 1.4-25.9; p = 0.02), hypertension (OR: 7.0; 95% CI: 1.4-34.7; p = 0.02), and headache (OR: 5.8; 95% CI: 1.4-24.6; p = 0.02) were all found to be independently associated with dotHS. CONCLUSIONS: The dotHS was significantly associated with several factors, including age, hypertension and headache.

[Dynamic changes in magnetic resonance diffusion-weighted and fluid-attenuated images of cerebral fat embolism: a case report].

Cerebral fat embolism (CFE) is serious complication of a long-bone fracture. We reported magnetic resonance (MR) diffusion-weighted (DWI) and fluid attenuated inversion recovery (FLAIR) images in a patient suffered with CFE. A 26-year-old man with a right femoral bone fracture lapsed into a semicoma eight hours later. Eighteen hours after the depressed consciousness, DWI and FLAIR images on MR imaging showed multiple high-intensity spots in corona radiata, basal ganglia, thalamus, corpus callosum, brain stem and cerebellum. Thereby, he was diagnosed as CFE. These multiple lesions were more detectable on FLAIR images than DWI, particularly in posterior fossa. Eight days after the onset, follow-up DWI, FLAIR, and T 2-weighted MR image (T 2 WI) showed most of the lesions disappeared or shrunk. The resolution of the lesions suggests that most of the lesions were brain edema as a result of the unique pathophysiological condition of CFE. The remained lesions were diagnosed as cerebral infarctions. The consciousness of the patient improved alert. Three months later, follow-up MRI showed almost complete resolution of the abnormal intensities. Follow up DWI and FLAIR images observed in the patient indicated that many small lesions occurs throughout the whole brain without a preferential region, and many of the lesions can subside or attenuate in CFE.