Publications by authors named "Taku Uchiyama"

Background: Recurrent cases of spontaneous spinal epidural hematoma are rare, and there are no reports of spontaneous resolution and recurrence in toddlers.

Case Presentation: We present a case of a toddler with a cervical spontaneous spinal epidural hematoma, characterized by three episodes of sudden-onset transient torticollis with subsequent natural recovery. The patient was referred to our hospital after the second episode, during which symptoms were already improving.

View Article and Find Full Text PDF

Introduction: Ultrasonography (US) is used as a real-time dynamic imaging modality during neurosurgery. A novel Doppler US technique, Superb Microvascular Imaging (SMI), can be used to visualize low-velocity flow of small vessels at high resolution with high frame rates. We visualized vessel flow using this US SMI technique and contrast agent during cerebrovascular surgery.

View Article and Find Full Text PDF

Efficient depolymerization of crystalline cellulose requires cooperation between multiple cellulolytic enzymes. Through biochemical approaches, molecular dynamics (MD) simulation, and single-molecule observations using high-speed atomic force microscopy (HS-AFM), we quantify and track synergistic activity for cellobiohydrolases (CBHs) with a lytic polysaccharide monooxygenase (LPMO) from . Increasing concentrations of LPMO (AA9D) increased the activity of a glycoside hydrolase family 6 CBH, Cel6A, whereas the activity of a family 7 CBH (Cel7D) was enhanced only at lower concentrations of AA9D.

View Article and Find Full Text PDF

Rosette-forming glioneuronal tumors (RGNTs) are benign WHO grade 1 tumors that occur in the ventricular system, particularly the fourth ventricle. RGNTs and dysembryoplastic neuroepithelial tumors (DNTs) are both categorized as neuronal and mixed neuronal-glial tumors and may be difficult to distinguish. Coexistence of the two tumor types has been reported.

View Article and Find Full Text PDF

The authors report a case of a rare, large, nodular pseudogout which developed from the temporomandibular joint (TMJ).An 83-year-old female was referred to the hospital with swelling on her left cheek. Imaging studies revealed a large calcified mass surrounding the left mandibular condyle, partially destroying the adjoining bone and extending to the skull base.

View Article and Find Full Text PDF

Cellobiohydrolases directly convert crystalline cellulose into cellobiose and are of biotechnological interest to achieve efficient biomass utilization. As a result, much research in the field has focused on identifying cellobiohydrolases that are very fast. Cellobiohydrolase A from the bacterium (CfCel6B) and cellobiohydrolase II from the fungus (TrCel6A) have similar catalytic domains (CDs) and show similar hydrolytic activity.

View Article and Find Full Text PDF

Cellulose is the most abundant biomass on Earth, and many microorganisms depend on it as a source of energy. It consists mainly of crystalline and amorphous regions, and natural degradation of the crystalline part is highly dependent on the degree of processivity of the degrading enzymes (i.e.

View Article and Find Full Text PDF

An epileptic seizure during the course of driving can result in a serious car accident. However, basic data on how epileptic seizures actually affect driving performance is significantly lacking. To understand the relationship, it is crucial to conduct not only behavioral but also electroencephalogram (EEG) analysis during epileptic seizures.

View Article and Find Full Text PDF

Certain methanogens deteriorate steel surfaces through a process called microbiologically influenced corrosion (MIC). However, the mechanisms of MIC, whereby methanogens oxidize zerovalent iron (Fe), are largely unknown. In this study, Fe-corroding Methanococcus maripaludis strain OS7 and its derivative (strain OS7mut1) defective in Fe-corroding activity were isolated.

View Article and Find Full Text PDF

Background: Random mutagenesis is a powerful technique to obtain mutant proteins with different properties from the wild-type molecule. Error-prone PCR is often employed for random mutagenesis in bacterial protein expression systems, but has rarely been used in the methylotrophic yeast Pichia pastoris system, despite its significant advantages, mainly because large (μg-level) amounts of plasmids are required for transformation.

Results: We developed a quick and easy technique for random mutagenesis in P.

View Article and Find Full Text PDF

Trichoderma reesei Cel6A (TrCel6A) is a cellobiohydrolase that hydrolyzes crystalline cellulose into cellobiose. Here we directly observed the reaction cycle (binding, surface movement, and dissociation) of single-molecule intact TrCel6A, isolated catalytic domain (CD), cellulose-binding module (CBM), and CBM and linker (CBM-linker) on crystalline cellulose I The CBM-linker showed a binding rate constant almost half that of intact TrCel6A, whereas those of the CD and CBM were only one-tenth of intact TrCel6A. These results indicate that the glycosylated linker region largely contributes to initial binding on crystalline cellulose.

View Article and Find Full Text PDF

Unlabelled: β-Glucosidase Td2F2 isolated from a compost metagenome has high glucose tolerance and transglycosylation activity. In this study, we determined the high-resolution crystal structure of Td2F2. It has a unique structure at the -1 subsite that is important for substrate specificity but not for glucose tolerance.

View Article and Find Full Text PDF

Aplastic or twig-like middle cerebral artery (Ap/T-MCA) is a rare anatomical anomaly, which can be associated with intracranial hemorrhage and cerebral ischemia. A 52-year-old woman who presented with sudden headache was admitted to our hospital. Computed tomography (CT) and magnetic resonance imaging showed no abnormality; however, magnetic resonance angiogram revealed an occlusion or severe stenosis in the left middle cerebral artery.

View Article and Find Full Text PDF

β-glucosidases (BGLs) hydrolyze cello-oligosaccharides to glucose and play a crucial role in the enzymatic saccharification of cellulosic biomass. Despite their significance for the production of glucose, most identified BGLs are commonly inhibited by low (∼mM) concentrations of glucose. Therefore, BGLs that are insensitive to glucose inhibition have great biotechnological merit.

View Article and Find Full Text PDF

Double origin of the posterior inferior cerebellar artery (DOPICA) is a rare anatomical variation, and can be associated with intracranial aneurysm formation. We describe a 66-year-old woman case of a ruptured aneurysm involved in a DOPICA. We performed aneurysmal coil embolization for the ruptured aneurysm involved in the cranial channel of DOPICA, but the aneurysm relapsed two months later.

View Article and Find Full Text PDF

Processivity refers to the ability of synthesizing, modifying and degrading enzymes to catalyse multiple successive cycles of reaction with polymeric substrates without disengaging from the substrates. Since biomass polysaccharides, such as chitin and cellulose, often form recalcitrant crystalline regions, their degradation is highly dependent on the processivity of degrading enzymes. Here we employ high-speed atomic force microscopy to directly visualize the movement of two processive glycoside hydrolase family 18 chitinases (ChiA and ChiB) from the chitinolytic bacterium Serratia marcescens on crystalline β-chitin.

View Article and Find Full Text PDF

We applied a metagenomics approach to screen for transcriptional regulators that sense aromatic compounds. The library was constructed by cloning environmental DNA fragments into a promoter-less vector containing green fluorescence protein. Fluorescence-based screening was then performed in the presence of various aromatic compounds.

View Article and Find Full Text PDF

A 29-year-old woman complained of headache and nausea several hours after delivery, followed by mild disturbance of consciousness. Physical examination revealed hypertension, systemic edema, nystagmus, dysarthria, and cerebellar ataxia. Computed tomography showed low attenuation areas in the cerebellum, and MR imaging revealed vasogenic edema in the cerebellum.

View Article and Find Full Text PDF

The β-glucosidase encoded by the td2f2 gene was isolated from a compost microbial metagenomic library by functional screening. The protein was identified to be a member of the glycoside hydrolase family 1 and was overexpressed in Escherichia coli, purified, and biochemically characterized. The recombinant β-glucosidase, Td2F2, exhibited enzymatic activity with β-glycosidic substrates, with preferences for glucose, fucose, and galactose.

View Article and Find Full Text PDF

We report a case of blood blister-like aneurysm(BBA)on the posterior wall of the internal carotid artery(ICA)causing subarachnoid hemorrhage(SAH). A 45-year-old man suffering from SAH(WFNS grade 5)was referred to our hospital. 3D-CT angiography showed a BBA on the posterior wall of the ICA.

View Article and Find Full Text PDF

We report the case of a 24-year-old woman with cervicothoracic subpial lipoma not associated with spinal dysraphism. She complained of back pain, gait disturbance, and sensory disturbance of the both lower extremities. MRI revealed a hyperintense mass lesion that was dorsolateral to the spinal cord in the intradural region between C7 and Th4 on both T1 and T2 weighted images.

View Article and Find Full Text PDF

A reporter assay-based screening method for enzymes, which we named product-induced gene expression (PIGEX), was developed and used to screen a metagenomic library for amidases. A benzoate-responsive transcriptional activator, BenR, was placed upstream of the gene encoding green fluorescent protein and used as a sensor. Escherichia coli sensor cells carrying the benR-gfp gene cassette fluoresced in response to benzoate concentrations as low as 10 μM but were completely unresponsive to the substrate benzamide.

View Article and Find Full Text PDF

The SIGEX (substrate-induced gene expression) method is a novel approach for the screening of gene (genome) libraries. In addition to the commonly used function- and sequence-driven approaches to screening, SIGEX provides a third option; in SIGEX, positives are identified using a reporter gene, and the library is constructed using an "operon-trap" vector. This vector contains the reporter gene immediately downstream of the cloning site for the genomic insert so that the expression of the inserted gene(s) is coupled with that of the reporter gene.

View Article and Find Full Text PDF

Microbiologically influenced corrosion of steel in anaerobic environments has been attributed to hydrogenotrophic microorganisms. A sludge sample collected from the bottom plate of a crude-oil storage tank was used to inoculate a medium containing iron (Fe(0)) granules, which was then incubated anaerobically at 37 degrees C under an N(2)-CO(2) atmosphere to enrich for microorganisms capable of using iron as the sole source of electrons. A methanogen, designated strain KA1, was isolated from the enrichment culture.

View Article and Find Full Text PDF
Article Synopsis
  • Metagenomics offers a new way to comprehensively explore microbial genomes in their natural habitats, moving beyond traditional microbial screening methods.
  • A major challenge with metagenomics is that the cloned genes often don't express well in E. coli, leading to difficulties in analyzing their functions.
  • The review discusses recent research on metagenomic library screening and suggests potential solutions to improve gene expression during functional screening.
View Article and Find Full Text PDF