Gender disparity in radial and femoral arterial size: an ultrasound study.
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Biomedical subjects
Publications and source records attributed to Hiroshi Sekiguchi.
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A 41-year-old female attempted suicide by taking 7.8g acetaminophen and was transferred to our hospital four hours after ingestion. The patient was diagnosed as non-hepatic toxicity (below the line set by the Rumack Matthew nomogram). Laboratory data showed an elevation in serum liver enzymes and coagulation defects at 3 days after ingestion, therefore, the patient was treated with plasma exchange and an oral administration of N-acetylcysteine (NAC). The elevation of liver enzymes was maximal at 4 days after ingestion, and the laboratory data became normalized at approximately 9 days after ingestion. In this case, habitual alcohol intake may have exacerbated the severe liver injury. We should consider an exacerbation of hepatotoxicity and administer NAC in any case having a history of habitual alcohol intake, even if the case was diagnosed as non-hepatic toxicity by the nomogram.
Seven cases of Streptococcus suis infection in Japan during 1994 and 2006 were summarized. All cases had porcine exposure and five of them had hand skin injury during the exposure. Five cases presented symptoms of meningitis, three presented symptoms of sepsis, and one resulted in sudden death. All of the isolated S. suis belonged to Lancefield's group D and to serotype 2. They were susceptible to penicillin G, ampicillin, cefotaxime, and ciprofloxacin. However, six of them were resistant to both erythromycin and clindamycin, and four were also resistant to minocycline. Multilocus sequence typing of six isolates showed that they belonged to sequence type (ST) 1, and their pulsed-field gel electrophoresis (PFGE) patterns were similar. The remaining isolate was ST28 and its PFGE pattern was distinct from those of the others.
Two genes related to extremely early heading were identified in populations derived from crosses between Hoshinoyume, a variety adapted to the northernmost limit of rice cultivation (Hokkaido), and Nipponbare, a variety adapted to the temperate region of Japan. The segregations for heading date clearly revealed that a two-gene model determined the extremely early heading in the F(2) and BC(1)F(1) populations under natural field conditions in Hokkaido. Using molecular markers corresponding to ten known quantitative trait loci (QTLs) for heading date, we carried out QTL analysis in the BC(1)F(1) population and detected two QTLs, qDTH-7-1 and qDTH-7-2, both on chromosome 7, and observed epistatic interaction between them. We conclude that the recessive alleles of these two genes contribute to extremely early heading for the adaptation to Hokkaido environment and to stable rice production in Hokkaido. The relationships between the two QTLs identified in this study and known QTLs are discussed.
A transposable element that is active in intact plants has been identified in rice (Oryza sativa L.). The 607-bp element itself, termed nonautonomous DNA-based active rice transposon (nDart), has no coding capacity. It was found inserted in the gene encoding Mg-protoporphyrin IX methyltransferase in a chlorophyll-deficient albino mutant isolated from backcross progeny derived from a cross between wild-type japonica varieties. The nDart has 19-bp terminal inverted repeats (TIRs) and, when mobilized, generates an 8-bp target-site duplication (TSD). At least 13 nDart elements were identified in the genome sequence of the japonica cultivar Nipponbare. Database searches identified larger elements, termed DNA-based active rice transposon (Dart) that contained one ORF for a protein that contains a region with high similarity to the hAT dimerization motif. Dart shares several features with nDart, including identical TIRs, similar subterminal sequences and the generation of an 8-bp TSD. These shared features indicate that the nonautonomous element nDart is an internal deletion derivative of the autonomous element Dart. We conclude that these active transposon systems belong to the hAT superfamily of class II transposons. Because the transposons are active in intact rice plants, they should be useful tools for tagging genes in studies of functional genomics.
It is widely accepted that green plants evolved the capacity to synthesize the highly organized branched alpha-polyglucan amylopectin with tandem-cluster structure, whereas animals and bacteria continued to produce random branched glycogen. Although most previous studies documented that cyanobacteria accumulate glycogen, the present study shows explicitly that some cyanobacteria such as Cyanobacterium sp. MBIC10216, Myxosarcina burmensis and Synechococcus sp. BG043511 had distinct alpha-polyglucans, which were designated as semi-amylopectin. The semi-amylopectin was intermediate between rice amylopectin and typical cyanobacterial glycogen in terms of chain length distribution, molecular size and length of the most abundant alpha-1,4-chain. It was also found that Cyanobacterium sp. MBIC10216 had no amylose-type component in its alpha-polyglucans. The evolutionary aspect of the structure of alpha-polyglucan is discussed in relation to the phylogenetic evolutionary tree of 16S rRNA sequences of cyanobacteria.
Red-fluorescent, non-phycobilin-containing plastids were found in the heterotrophic dinoflagellate, Dinophysis mitra. Transmission electron microscopy showed that they contained a three-layer thylakoid, the absence of girdle lamella, and an embedded pyrenoid with thylakoid intrusions. These characteristics all coincide with haptophyte plastids. Phylogenetic analysis of the plastid small-subunit ribosomal DNA (SSU rDNA) revealed that the Dinophysis mitra sequences are distantly related to those of phycobilin-containing Dinophysis species and are positioned within a lineage of haptophytes belonging to Prymnesiophyceae. Because the plastid SSU rDNA sequences of Dinophysis mitra showed significant heterogeneity, despite being derived from a single species, it is highly likely that they were not established as plastids through an evolutionary process but are "kleptoplastids" (temporally stolen plastids) from multiple sources of haptophytes in the environment. We deduced that Dinophysis mitra takes up haptophytes myzocytotically and selectively retains the plastid with surrounding plastidal membranes, whereas other haptophyte cell components are degraded. This represents another type of kleptoplastidy in the Dinophysis species, which mostly harbor cryptophyte plastids, and is the first evidence of kleptoplastidy originating from haptophytes.
Lung epithelium plays a central role in modulation of the lung inflammatory response, and lung repair and airway epithelial cells are targets in asthma and viral infection. Activated T lymphocytes release cytokines such as interferon-gamma (IFN-gamma) that induce apoptosis, or programmed cell death, of damaged epithelial cells. Death-associated protein-3 (DAP3) is involved in mediating IFN-gamma-induced cell death. To assess the possible involvement of genetic variants of DAP3 with asthma, we searched for single-nucleotide polymorphisms (SNPs) in the gene and conducted a case-control study with 1,341 subjects. We found a strong association between bronchial asthma (BA) in adults (P=0.0051, odds ratio=1.87, 95% CI=1.20-2.92), whereas no association was found with childhood asthma. The tendency was more prominent in patients with higher serum total immunoglobulin E (IgE) (>250 IU/ml) (P=0.00061, odds ratio=2.40, 95% CI=1.44-4.00). DAP3 was expressed in normal bronchial epithelial cells, and the expression was induced by IFN-gamma. These results indicated that specific variants of the DAP3 gene might be associated with the mechanisms responsible for adult BA and contribute to airway inflammation and remodeling.
The dynamics of a single protein molecule subjected to forced mechanical unfolding was investigated in a millisecond time domain using a custom-made atomic force microscope (AFM) apparatus, which allows simultaneous measurements of an average tensile force applied to a single molecule and its mechanical response with respect to an external oscillation. Our target protein was genetically engineered bovine carbonic anhydrase II (BCA) which is a monomeric globular protein, and it has been shown that the as-expressed BCA from Escherichia coli contains two conformational isomers, one with enzymatic activity (type I) and the other without (type II). An interesting feature observed from the dynamic measurements was that when the type I BCA conformer was extended, it often exhibited a clear out-of-phase response against an external oscillation. The type II BCA conformer, however, always exhibited an in-phase response to the external oscillation. This relationship between different types of BCA and their dynamical behaviors was evidently observed around the discontinuous transition point from type I to II.
We investigated the interaction between GroEL and a denatured protein from a mechanical point of view using an atomic force microscope. Pepsin was bound to an atomic force microscope probe and used at a neutral pH as an example of denatured proteins. To measure a specific and delicate interaction force, we obtained force curves without pressing the probe onto GroEL molecules spread on a mica surface. Approximately 40 pN of tensile force was observed for approximately 10 nm while pepsin was pulled away from the chaperonin after a brief contact. This length of force duration corresponding to the circumference of GroEL's interior cavity was shortened by the addition of ATP. The relation between the observed mechanical parameters and the chaperonin's refolding function is discussed.
OBJECTIVE: This clinical study compares the diagnostic value of interactive 3-dimensional tuned-aperture computed tomography (TACT) with conventional dentoalveolar radiographic examinations of impacted maxillary incisors. STUDY DESIGN: TACT was compared variously with conventional intraoral, occlusal, rotational panoramic, and lateral cephalographic examinations. Sixteen dentists independently evaluated the clarity of anatomic structures of impacted anterior maxillary teeth and surrounding tissues. Estimation of confidence in clinical assessment of the patient was made together with a determination of the diagnostic potential of the studied modalities for altering treatment plans. RESULTS: TACT was found to significantly improve depiction of the buccal/palatal position of the impacted tooth and its relationship with adjacent teeth (P < .0001) irrespective of the availability of lateral cephalograms. Subjective assessments for clinical decision making approximated a 10% increase in confidence ratings with TACT. The added diagnostic value with TACT varied from case to case. CONCLUSIONS: The interactive 3-dimensional TACT display was perceived to be more informative for assessing impacted teeth and their relation to surrounding tissues than conventional methods in some cases but not in others. TACT altered treatment-option selection in some instances.
The atomic force microscope has been extensively used not only to image nanometer-sized biological samples but also to measure their mechanical properties by using the force curve mode of the instrument. When the analysis based on the Hertz model of indentation is applied to the approach part of the force curve, one obtains information on the stiffness of the sample in terms of Young's modulus. Mapping of local stiffness over a single living cell is possible by this method. The retraction part of the force curve provides information on the adhesive interaction between the sample and the AFM tip. It is possible to functionalize the AFM tip with specific ligands so that one can target the adhesive interaction to specific pairs of ligands and receptors. The presence of specific receptors on the living cell surface has been mapped by this method. The force to break the co-operative 3D structure of globular proteins or to separate a double stranded DNA into single strands has been measured. Extension of the method for harvesting functional molecules from the cytosol or the cell surface for biochemical analysis has been reported. There is a need for the development of biochemical nano-analysis based on AFM technology.
Based on technical studies and clinical examinations, the clinical value of a new three-dimensional dento-alveolar imaging system, Tuned-Aperture Computed Tomography (TACT), were examined for dental applications. TACT is a conventional and low-cost tomosynthesis method in which the benefit of digitization is fully utilized. The clinical information yield of TACT has been examined for the detection of dental caries, periodontal defects and radicular fractures, and also for the pre-surgical assessment of implant placement and impacted teeth. In this article, we introduce basic TACT technology, review the literature pertaining to in vitro and in vivo studies, and describe the outline of our study of TACT to determine its clinical value in the assessment of impacted maxillary teeth.
Two heterotrophic members of the Dictyochophyceae (stramenopiles), Pteridomonas danica and Ciliophrys infusionum, were investigated. An undescribed organelle bounded by four membranes and closely associated with the nucleus was detected in P. danica. The outermost membrane was continuous with the outer nuclear membrane. These features strongly suggested that this organelle was a vestigial chloroplast. A photosynthetic gene, rbcL, was successfully amplified by polymerase chain reaction (PCR) from P. danica and C. infusionum. These sequences were readily and well aligned with those of photosynthetic stramenopiles. Phylogenetic trees of 18S rDNA and rbcL were constructed. In all the trees obtained, P. danica and C. infusionum appeared in two different clades, the Pedinellales clade and the Ciliophryales/Rhizochromulinales clade, each of which contained photosynthetic members as well as heterotrophic members. The results indicated that the loss of photosynthetic ability occurred independently in P. danica and C. infusionum. This is the first report of the presence of a vestigial chloroplast (leucoplast) in colorless dictyochophytes.