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Biomedical subjects

Hideo Hayashi

Publications and source records attributed to Hideo Hayashi.

At least 19 recordsLinked to original sources
PubMed2007

Otitis media in adults as a symptom of gastroesophageal reflux.

OBJECTIVE: To investigate the clinical relationship between gastroesophageal reflux (GER) and otitis media with effusion (OME) in adults. STUDY DESIGN AND SETTING: Sixty patients with OME with unknown causes were asked to answer a new questionnaire specific for the diagnosis of GER disease; pepsinogen (PG) levels in their middle-ear effusions (MEEs) were measured. RESULTS: The percentage of patients with high PG concentrations in their MEEs was significantly higher in those with questionnaire-positive GER than in those with questionnaire-negative GER. OME was present bilaterally in a significantly higher percentage of patients with questionnaire-positive GER. The PG levels decreased in some of the patients after receiving proton pump inhibitors, which also decreased the symptoms of GER. CONCLUSION: The presence of PG in MEEs supports the existence of GER; treatment for GER should be considered in patients with ear complaints, especially in those who have GER-related symptoms.

Adult↗
PubMed2006

Purification and structure determination of glucosides of capsaicin and dihydrocapsaicin from various Capsicum fruits.

Two new glucosides, capsaicin-beta-D-glucopyranoside (1) and dihydrocapsaicin-beta-D-glucopyranoside (2), were discovered in the fruit of the Capsicum annuum cultivar 'High Heat'. They were sequentially purified by acetone extraction, n-hexane extraction, and acetonitrile extraction, followed by medium-pressure liquid chromatography and high-performance liquid chromatography performed on an octadecylsilane column. Their chemical structures were elucidated by proton nuclear magnetic resonance, carbon nuclear magnetic resonance, and hydrolysis with alpha- and beta-glucosidases. The glucosides were also detected in various pungent cultivars of C. annuum, Capsicum frutescens, and Capsicum chinense by liquid chromatography-mass spectrometry. However, they were not detected in nonpungent cultivars of C. annuum. Furthermore, a positive correlation was observed between the quantity of the capsaicinoids, capsaicin, and dihydrocapsaicin and their glucosides.

Capsaicin↗
PubMed2006

Mice doubly deficient in the midkine and pleiotrophin genes exhibit deficits in the expression of beta-tectorin gene and in auditory response.

alpha-Tectorin and beta-tectorin are major noncollagenous proteins of the tectorial membrane, which plays a crucial role in the reception of sonic signals in the cochlea. Midkine and pleiotrophin are closely related proteins that serve as growth factors and cytokines. In mice doubly deficient in the midkine gene and pleiotrophin gene, expression of beta-tectorin mRNA was nearly abolished in the cochlea on day 1 and 7 after birth. Expression of alpha-tectorin mRNA was unaffected in the double knockout mice, and expression of beta-tectorin mRNA was not altered in mice deficient in only the midkine or pleiotrophin gene. In newborn wild-type mice, both midkine and pleiotrophin were expressed in the greater epithelial ridge of the cochlea, in which beta-tectorin mRNA was strongly expressed. These results indicate that either midkine or pleiotrophin is required for significant expression of beta-tectorin. In agreement with the view that beta-tectorin is essential for normal auditory function, mice doubly deficient in both midkine and pleiotrophin genes exhibited very severe auditory deficits. We observed that mice deficient in either midkine or pleiotrophin gene were also impaired in their auditory response, but the level of the deficit was generally low or moderate. The present finding illustrates the importance of growth factor expression in the cochlea for auditory function.

Animals↗
PubMed2006

Strigolactones: chemical signals for fungal symbionts and parasitic weeds in plant roots.

AIMS: Arbuscular mycorrhizae are formed between >80 % of land plants and arbuscular mycorrhizal (AM) fungi. This Botanical Briefing highlights the chemical identification of strigolactones as a host-recognition signal for AM fungi, and their role in the establishment of arbuscular mycorrhizae as well as in the seed germination of parasitic weeds. SCOPE: Hyphal branching has long been described as the first morphological event in host recognition by AM fungi during the pre-infection stages. Host roots release signalling molecules called 'branching factors' that induce extensive hyphal branching in AM fungi. Strigolactones exuded from host roots have recently been identified as an inducer of hyphal branching in AM fungi. Strigolactones are a group of sesquiterpenes, previously isolated as seed germination stimulants for the parasitic weeds Striga and Orobanche. Parasitic weeds might find their potential hosts by detecting strigolactones, which are released from plant roots upon phosphate deficiency in communication with AM fungi. In addition to acting as a signalling molecule, strigolactones might stimulate the production of fungal symbiotic signals called 'Myc factors' in AM fungi. CONCLUSIONS: Isolation and identification of plant symbiotic signals open up new ways for studying the molecular basis of plant-AM-fungus interactions. This discovery provides a clear answer to a long-standing question in parasitic plant biology: what is the natural role for germination stimulants? It could also provide a new strategy for the management and control of beneficial fungal symbionts and of devastating parasitic weeds in agriculture and natural ecosystems.

Germination↗
PubMed2006

Genome sequence of the cat pathogen, Chlamydophila felis.

Chlamydophila felis (Chlamydia psittaci feline pneumonitis agent) is a worldwide spread pathogen for pneumonia and conjunctivitis in cats. Herein, we determined the entire genomic DNA sequence of the Japanese C. felis strain Fe/C-56 to understand the mechanism of diseases caused by this pathogen. The C. felis genome is composed of a circular 1,166,239 bp chromosome encoding 1005 protein-coding genes and a 7552 bp circular plasmid. Comparison of C. felis gene contents with other Chlamydia species shows that 795 genes are common in the family Chlamydiaceae species and 47 genes are specific to C. felis. Phylogenetic analysis of the common genes reveals that most of the orthologue sets exhibit a similar divergent pattern but 14 C. felis genes accumulate more mutations, implicating that these genes may be involved in the evolutional adaptation to the C. felis-specific niche. Gene distribution and orthologue analyses reveal that two distinctive regions, i.e. the plasticity zone and frequently gene-translocated regions (FGRs), may play important but different roles for chlamydial genome evolution. The genomic DNA sequence of C. felis provides information for comprehension of diseases and elucidation of the chlamydial evolution.

Adaptation, Biological↗
PubMed2006

Association between cupular deposits and otosclerosis.

OBJECTIVE: To evaluate whether otosclerosis is an underlying mechanism for the production of cupular deposits and to study the association between cupular deposits and dysequilibrium in otosclerosis. DESIGN: Retrospective human temporal bone (TB) study. The incidence of cupular deposits in these 70 TBs was analyzed. Correlations between cupular deposits and vestibular symptoms, endosteal involvement of the otosclerotic focus, stapedial fixation, and clinical history of stapes surgery were evaluated. SETTING: Otolaryngology laboratory in a tertiary academic medical center. PATIENTS: The study material consisted of 35 human TBs with otosclerosis and 35 age-matched controls. MAIN OUTCOME MEASURES: Morphometric evaluations of the incidence of cupular deposits, endosteal involvement of the otosclerotic focus, and stapedial fixation were made by light microscopy. Clinical records were reviewed retrospectively for clinical history of stapes surgery and prevalence of vestibular symptoms. The incidence of cupular deposits was compared between the otosclerotic and control groups. Correlations between cupular deposits and vestibular symptoms, endosteal involvement of the otosclerotic focus, stapedial fixation, and clinical history of stapes surgery were evaluated in the subjects with otosclerosis. RESULTS: The incidence of cupular deposits in TBs with otosclerosis was significantly higher than in those without whereas there was no correlation between the incidence of the deposits and dysequilibrium in cases of otosclerosis. An increase in deposits did not correlate with stapedial fixation, stapes surgery, or endosteal involvement. CONCLUSIONS: Our results suggest otosclerosis as an underlying mechanism for the production of cupular deposits; however, we did not find an association between these deposits and vestibular symptoms.

Adult↗
PubMed2006

Vascular evaluation in laryngeal diseases: comparison between contact endoscopy and laser Doppler flowmetry.

OBJECTIVE: To determine the efficacies of 2 methods for evaluating vascular changes in laryngeal diseases. DESIGN: Prospective comparative study. SETTING: University hospital. PATIENTS: Twenty-four adults planning to undergo laryngomicrosurgery for unilateral lesions in their vocal cords. INTERVENTION: Vascular evaluation was performed using contact endoscopy and laser Doppler flowmetry during laryngomicrosurgery. MAIN OUTCOME MEASURES: Morphological and physiological variables of the vascular changes. RESULTS: Contact endoscopy examinations revealed changes in the fine vascular network patterns in the vocal cords. Hypervascularity was present in patients with polyps but not in those with nodules, and the degree of vascularity was variable in patients with malignant neoplasms. Patients with papillomas and patients in the postradiation therapy group showed hypovascularity with losses in the capillary network. Laser Doppler flowmetry revealed high mean blood flows in patients with polyps, dysplasia, and malignant neoplasms, whereas patients with papillomas and those in the postradiation therapy group had low blood flows. The variables measured by laser Doppler flowmetry and endoscopy were strongly correlated. CONCLUSION: Evaluations of morphological and physiological changes of vascularity in laryngeal diseases are important for understanding their pathophysiology, and combining contact endoscopy and laser Doppler flowmetry is useful in such evaluations.

Adult↗
PubMed2006

Large vestibular aqueduct syndrome: a human temporal bone study.

OBJECTIVES/HYPOTHESIS: Large vestibular aqueduct syndrome (LVAS) is one of the common causes of hearing loss (HL). All prior studies have reported some anomalies associated with LVAS by imaging techniques. This study was undertaken to determine prevalence of LVAS in our temporal bone (TB) collection and its relationship to other systemic or otologic anomalies. STUDY DESIGN: Retrospective, TB histopathologic study. METHODS: Anteroposterior diameters of internal (IA) and external (EA) apertures were measured in 40 normal TBs (40 cases). TBs were considered as large vestibular aqueduct (LVA) if width of apertures was 95% greater than "normals." Systemic and otologic anomalies and histopathology of ears with LVAS were noted. RESULT: Of 1,608 non-"normal" TBs, 63 had LVA. There was negative correlation between IA and EA in 48 TBs with only enlarged IA. Fifteen TBs with enlarged EA always had enlarged IA and were therefore considered as LVAS. The most common pathologic condition was congenital heart anomaly. The most common syndrome or dysplasia was Mondini's. The most common anomalies of external and middle ears were dehiscent facial nerves, low set auricles, and ossicular deformities. Inner ear anomalies included modiolar deficiencies, hair cell loss, interscalar septum defects, and strial atrophy. There was no record of family history of HL, head injury, or craniofacial, branchial, or thyroidal abnormalities. CONCLUSION: Because HL associated with LVAS may be attributed to other ear anomalies, it is important to investigate other inner ear problems and system diagnoses that may indicate a syndrome in patients with radiologically diagnosed LVAS.

Adolescent↗
PubMed2005

Staphylococcal Drp35 is the functional counterpart of the eukaryotic PONs.

Drp35 has been identified as a protein that is induced in Staphylococcus aureus in response to exposure to certain antibiotics. Here we demonstrate that Drp35 is a lactonase that does not contribute directly to the resistance to the inducer antibiotics except for bacitracin. The detailed analysis on the expression of Drp35 revealed that in addition to a broad range of antibiotics, agents such as detergents that perturb the membrane integrity could induce its expression. The significance of this characteristic expression is discussed in relation to its activity similarity to the eukaryotic counterparts, paraoxonase family proteins.

Amino Acid Sequence↗
PubMed2005

Plant sesquiterpenes induce hyphal branching in arbuscular mycorrhizal fungi.

Arbuscular mycorrhizal (AM) fungi form mutualistic, symbiotic associations with the roots of more than 80% of land plants. The fungi are incapable of completing their life cycle in the absence of a host root. Their spores can germinate and grow in the absence of a host, but their hyphal growth is very limited. Little is known about the molecular mechanisms that govern signalling and recognition between AM fungi and their host plants. In one of the first stages of host recognition, the hyphae of AM fungi show extensive branching in the vicinity of host roots before formation of the appressorium, the structure used to penetrate the plant root. Host roots are known to release signalling molecules that trigger hyphal branching, but these branching factors have not been isolated. Here we have isolated a branching factor from the root exudates of Lotus japonicus and used spectroscopic analysis and chemical synthesis to identify it as a strigolactone, 5-deoxy-strigol. Strigolactones are a group of sesquiterpene lactones, previously isolated as seed-germination stimulants for the parasitic weeds Striga and Orobanche. The natural strigolactones 5-deoxy-strigol, sorgolactone and strigol, and a synthetic analogue, GR24, induced extensive hyphal branching in germinating spores of the AM fungus Gigaspora margarita at very low concentrations.

Chromatography, High Pressure Liquid↗
PubMed2005

Identification and characterization of a cell-wall anchored DNase gene in Clostridium perfringens.

Completion of the whole genome sequence of Clostridium perfringens strain 13 revealed the presence of an extracellular nuclease gene, cadA. Transcriptional analysis showed that the cadA gene is negatively regulated by the two-component VirR/VirS system and its secondary regulator VR-RNA. The CadA protein possesses an N-terminal signal sequence and a Gram-positive cell wall anchoring motif consisting of a sorting signal (LPXTG motif), a hydrophobic domain, and positively charged residues at the end of C-terminus. By comparing the DNase production between the wild type and the cadA mutant, and DNase activity assay with the recombinant truncated CadA protein, we confirmed that the cadA gene product is one of the DNases produced by C. perfringens.

Bacterial Proteins↗
PubMed2005

Malnutrition and disease progression in patients with rheumatoid arthritis.

To examine the changes in nutritional status during the progression of rheumatoid arthritis (RA), we studied anthropometric and biochemical variables in 97 Japanese patients with RA. Anthropometric data included body mass index (BMI), triceps skinfold thickness (TSF), and arm muscle area (AMA). Levels of albumin and cholesterol in serum, and lymphocyte count were studied as biochemical variables. The prevalence of malnutrition defined as hypoalbuminemia less than 3.4 g/dl was 24.7%, similar to the reports in other countries. Analysis of the data according to disease stage showed that malnutrition in RA was characterized by a progressive reduction in body protein. Body mass index and TSF were increased in patients with stage 1 disease, whereas serum albumin and AMA were within normal range. Stage 2 patients had normal BMI with decreased body protein, albumin, and AMA. Progression to stages 3 and 4 was associated with a stepwise decrease in AMA; serum albumin and BMI remained in the same range as stage 2. Albumin values and AMA were significantly lower in patients with poor functional class and high C-reactive protein. The characteristic progression of malnutrition in RA is attributed to excessive protein catabolism evoked by inflammatory cytokines and by disuse atrophy due to functional impairment.

Journal Article↗
PubMed2005

Upregulation of HSP by geranylgeranylacetone protects the cochlear lateral wall from endotoxin-induced inflammation.

We investigated whether an acyclic polyisoprenoid antiulcer drug, geranylgeranylacetone (GGA), induces the expression of HSP70 in the rat cochlea. Immunoblotting revealed upregulation of HSP70 in the cochlea at 12 h after transtympanic (local) or oral (systemic) administration of GGA, and this increased at 24 h after administration. Positive immunohistochemical staining of HSP70 was observed in the hair cells, the spiral ganglion, the stria vascularis, the spiral ligament, and the perivascular portion of modiolar vessels. We therefore subsequently studied the effects of GGA as an HSP-inducer on inner ear trauma due to inflammation. Damage to the lateral wall due to inflammation induced by lipopolysaccharide inoculation was protected against by pretreatment with GGA, as assessed physiologically by measurement of cochlear blood flow and morphologically by electron microscopy. The results of the present study suggest that GGA can protect the cochlea against other injuries including those induced by noise, ototoxic drugs, and ischemia by upregulating HSP70.

Animals↗
PubMed2005

Laser ablation and low-pressure helium-ICP-MS for the analysis of alumina powder dispersed in glycerol.

A combined method of laser ablation (LA) and ICP-MS has gained much attention as a direct analytical method for solid samples. The determination of some elements, however, is seriously disturbed by isobaric interferences, mainly caused by argon and ambient air constituents. The use of low-pressure helium-ICP is a promising solution of the problem. A 1:1 mixture of alumina powder and glycerol was deaerated and irradiated with a pulsed laser beam (150 mJ) for 10 s. The sample aerosol was transported to the ICP with a stream of helium. Indium was used as an internal standard for correcting the ablated sample amount. Calibration curves were prepared from glycerol containing high-purity alumina, trace metals and indium. The detection limits for Cr, Mn, Fe, Co, Ni, and Cu approached the fractional ppm levels. The proposed method was successfully applied to the analysis of different alumina samples (99 - 99.995% purity).

Journal Article↗