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Biomedical subjects

Haruo Takahashi

Publications and source records attributed to Haruo Takahashi.

At least 19 recordsLinked to original sources

Cochlear implantations in visually impaired patients.

We retrospectively review the cases to evaluate the outcome of cochlear implantation (CI) in patients with severe-to-profound hearing loss and visual impairment (VI). Six adults with severe or profound hearing loss and significant VI underwent multichannel CI. Follow-up period ranged from 17 months to 7 years. Case history, etiology of visual and hearing loss, and benefit from CI were evaluated. To measure the outcomes, we selected the pure-tone thresholds with CI, the speech discrimination scores (SDS) using the Japanese video SDS system, the speech perception rates using the Japanese CD SDS system by monosyllable and word, and the open-set and closed sentence score using live voice. All the patients live happily after CI. There was no significant difference between the present six patients and the patients with profound hearing loss without VI in evaluations of hearing and quality of life. CI can play a significant rehabilitative role in patients with severe hearing loss and VI.

Adult↗

Ligation of eustachian tube for intractable patulous eustachian tube: a preliminary report.

Pharyngeal orifice of the eustachian tube was ligated on ten patients, 15 ears with intractable patulous eustachian tube. While the eustachian tube orifice was observed by an endoscope inserted through the contralateral nostril, the orifice was ligated transnasally and/or transorally using instruments usually used in the endoscopic nasal surgery. Now 13-27 months after the surgery, the outcome was excellent (both symptoms and sonotubometry were normalized) in two ears, good (either symptoms or sonotubometry was improved) in seven ears, and unchanged in the remaining six ears. In one of the ears with an outcome of unchanged, the ligation was found to be spontaneously released soon after surgery, but the symptom was improved after the second operation 2.5 months after the first operation. Temporary otitis media with effusion was seen in one ear, mild inflammation around the ligated site also in one ear, but no other serious complication has been observed. Although further improvement in the surgical procedure and further discussion about its long-term outcome should be required, this procedure appeared to be one of the therapeutic options for intractable patulous eustachian tube.

Adult↗

Correlation between middle-ear pressure-regulation functions and outcome of type-I tympanoplasty.

OBJECTIVES: To examine the correlation between the middle-ear pressure-regulation functions including active eustachian tube (ET) functions and transmucosal gas exchange function, and outcome of tympanoplasty. PATIENTS AND METHODS: Seventy five patients (78 ears) with non-cholesteatomatous chronic otitis media with eardrum perforation but without ossicular damage or middle-ear anomaly participated in this study. Before surgery, patency of the ET was examined by applying positive pressure to the middle ear through the eardrum perforation, and then the ET pressure-regulation functions were examined using the inflation-deflation test. Also their transmucosal gas exchange function was evaluated by examining the presence or absence of aeration in the mastoid on the CT before surgery or through the microscope during the surgery. All of them underwent type-I tympanoplasty, and their postoperative conditions including the hearing were followed for more than 6 months. The outcome of the surgery was judged as poor outcome when they had any of the following conditions; more than 20 dB of mean air-bone gap, spontaneous perforation within 6 months, or persistent wet condition including recurrent otorrhea. RESULTS: First, the outcome of all the four ears of which ETs were considered mechanically obstructed was poor. Next, among the remaining 74 ears, none of the three individual parameters, including positive and negative middle-ear pressure-equalizing functions and mastoid aeration, showed significantly positive correlation with the outcome of the surgery, but significantly higher incidence of poor outcome was seen only when all the three parameters were poor. CONCLUSIONS: These results indicated that impairment of all the middle-ear pressure-regulation functions was likely to cause poor outcome of tympanoplasty, and also allowed us reconfirm that ears with mechanically obstructed ETs were contraindicated for tympanoplasty. Therefore, assessment of mastoid condition is important as well as the ET function before tympanoplasty.

Adolescent↗

The influence of Er. YAG laser application in fenestration to the inner ear.

OBJECTIVE: Erbium (Er.) YAG laser may be usable for middle ear surgery because of its ability to ablate bony tissue. We investigated the inner ear damage caused by the fenestration to the inner ear with Er. YAG laser. DESIGN: We investigated the influence of Er. YAG laser on the inner ear using electrophysiological technique. RESULTS: Several cases had a decrease in endocochlear potential (EP) and cochlear microphonics (CM) after the fenestration to the inner ear. CONCLUSIONS: Er. YAG laser is safe if it is used for the small and superficial fenestration to the stapes footplate. However, a few extra pulses after fenestration are dangerous.

Acoustic Stimulation↗

A case with sinonasal teratocarcinosarcoma in the nasal cavity and ethmoid sinus.

Sinonasal teratocarcinosarcoma (SNTCS) is a rare and aggressive malignant neoplasm histologically characterized by the combination of one or more epithelial elements and mesenchymal components. We report a 61-year-old man with SNTCS involving left nasal cavity and ethmoid sinus. He complained of left epistaxis for 1 week. Computed tomography and magnetic resonance imaging revealed a soft tissue filling the left middle meatus and ethmoid sinus, and effusion in the left sphenoid sinus but no invasion to the orbit or skull base. Tumor was completely removed with lateral rhinotomy, and post-operative radiation therapy (Liniac 60 Gy) was performed. Follow-up examination for 3 years and 5 months after the radiation therapy has shown no evidence of recurrence or metastasis. This report describes his clinical course, etiology, diagnosis and management of SNTCS with a review of literature.

Carcinosarcoma↗

Molecular-shape imprinting and immobilization of biomolecules on a polymer containing azo dye.

We demonstrate a novel technique for molecular imprinting and immobilization on a surface of a polymer containing azo dyes (azopolymer). The azopolymer was found to be capable of immobilizing micrometer- and nanometer-scale macromolecules (e.g., lambda-DNA, immunoglobulin G (IgG), bacterial protease, and 1-mum polystyrene particles) through photoirradiation with blue-wavelength light. Fluorescence and atomic force microscopy studies revealed that the azopolymer surface deformed along with the shape of the macromolecules, holding them in place after photoirradiation. The desorption of the immobilized macromolecules from the azopolymer surface in an aqueous medium was observed to be very slow, on the time scale of 10 min to weeks, depending on the photoirradiation time. Immunological and enzymatic studies showed that IgG and bacterial protease immobilized on the azopolymer surface retained their original functionality. These results suggest that the azopolymer physically, not chemically, binds the macromolecules because of the increase in contact area between the macromolecules and the azopolymer surface after photoirradiation.

Azo Compounds↗

A SNP in the ABCC11 gene is the determinant of human earwax type.

Human earwax consists of wet and dry types. Dry earwax is frequent in East Asians, whereas wet earwax is common in other populations. Here we show that a SNP, 538G --> A (rs17822931), in the ABCC11 gene is responsible for determination of earwax type. The AA genotype corresponds to dry earwax, and GA and GG to wet type. A 27-bp deletion in ABCC11 exon 29 was also found in a few individuals of Asian ancestry. A functional assay demonstrated that cells with allele A show a lower excretory activity for cGMP than those with allele G. The allele A frequency shows a north-south and east-west downward geographical gradient; worldwide, it is highest in Chinese and Koreans, and a common dry-type haplotype is retained among various ethnic populations. These suggest that the allele A arose in northeast Asia and thereafter spread through the world. The 538G --> A SNP is the first example of DNA polymorphism determining a visible genetic trait.

ATP-Binding Cassette Transporters↗

Does topical application of 5-fluorouracil ointment influence inner ear function?

OBJECTIVE: To investigate the effect of 5-fluorouracil (5-FU) ointment on the inner ear of guinea pigs. STUDY DESIGN AND SETTING: In group A (n = 7), 5-FU ointment was applied into the left external auditory canal. In group B (n = 10), 5-FU ointment was applied to the left middle ear through myringotomy. In both groups, the right ear served as a control. One week later the endocochlear DC potential (EP) was measured and morphology of the cochleae was examined using scanning electron microscopy (SEM) and light microscopy. RESULTS: In group A, there was no significant difference between the EP values of the experimental side and the control side. In group B, there was a statistically significant difference between them (P < 0.05). Morphologic findings showed no damage. CONCLUSION: 5-FU ointment application to the external ear seems to be safe but its application to the middle ear may pose some risk of ototoxicity.

Administration, Topical↗

A case of actinomycosis causing unilateral tonsillar hypertrophy.

We report a case of unusual presentation of actinomycosis in the tonsil causing massive unilateral enlargement in a 78-year-old female. To our knowledge, only three cases of actinomycosis causing unilateral tonsillar enlargement have been published previously. Since this anaerobic organism is difficult to culture, the diagnosis is made by observing its associated sulfur granules in the biopsy specimen. In the present case, treatment consisting of tonsillectomy and antibiotic therapy (penicillin) for several days produced a good prognosis.

Actinomycosis↗

D-lactic acid production by metabolically engineered Saccharomyces cerevisiae.

Poly D-lactic acid is an important polymer because it improves the thermostability of poly L-lactic acid by the stereo complex formation. We constructed a metabolically engineered Saccharomyces cerevisiae that produces D-lactic acid efficiently. In this recombinant, the coding region of pyruvate decarboxylase 1 (PDC1) was completely deleted, and two copies of the D-lactate dehydrogenase (D-LDH) gene from Leuconostoc mesenteroides subsp. mesenteroides strain NBRC3426 were introduced into the genome. The D-lactate production reached 61.5 g/l, the amount of glucose being transformed into D-lactic acid being 61.2% under neutralizing conditions. Additionally, the yield of free D-lactic acid was also shown to be 53.0% under non-neutralizing conditions. It was confirmed that D-lactic acid of extremely high optical purity of 99.9% or higher. Our finding obtained the possibility of a new approach for pure d-lactic acid production without a neutralizing process compared with other techniques involving lactic acid bacteria and transgenic Escherichia coli.

Amino Acid Sequence↗

The effect of pyruvate decarboxylase gene knockout in Saccharomyces cerevisiae on L-lactic acid production.

A plant- and crop-based renewable plastic, poly-lactic acid (PLA), is receiving attention as a new material for a sustainable society in place of petroleum-based plastics. We constructed a metabolically engineered Saccharomyces cerevisiae that has both pyruvate decarboxylase genes (PDC1 and PDC5) disrupted in the genetic background to express two copies of the bovine L-lactate dehydrogenase (LDH) gene. With this recombinant, the yield of lactate was 82.3 g/liter, up to 81.5% of the glucose being transformed into lactic acid on neutralizing cultivation, although pdc1 pdc5 double disruption led to ineffective decreases in cell growth and fermentation speed. This strain showed lactate productivity improvement as much as 1.5 times higher than the previous strain. This production yield is the highest value for a lactic acid-producing yeast yet reported.

Bioreactors↗

Metabolic engineering of Saccharomyces cerevisiae for efficient production of pure L-(+)-lactic acid.

We developed a metabolically engineered Saccharomyces cerevisiae, which produces optically pure L-lactic acid efficiently using cane juice-based medium. In this recombinant, the coding region of pyruvate decarboxylase (PDC)1 was completely deleted, and six copies of the bovine L-lactate dehydrogenase (L-LDH) genes were introduced on the genome under the control of the PDC1 promoter. To confirm optically pure lactate production in low-cost medium, cane juice-based medium was used in fermentation with neutralizing conditions. L-lactate production reached 122 g/L, with 61% of sugar being transformed into L-lactate finally. The optical purity of this L-lactate, that affects the physical characteristics of poly-L-lactic acid, was extremely high, 99.9% or over.

Animals↗

Clinical efficacy of 5-fluorouracil (5-FU) topical cream for treatment of cholesteatoma.

OBJECTIVE: In order to clarify clinical efficacy of commercially available 5-fluorouracil (5-FU) topical cream, a clinical study was conducted. METHODS: Two to three cubic millimetres of 5-FU topical cream (Kyowa, Roche) was applied on 50 cases of various types of cholesteatoma (50 patients) two to five times with the interval of 2 weeks, and its clinical efficacy was evaluated by the criteria we developed. RESULTS: In total, 59% of the cholesteatomas showed good effect, 29% of them showed fair effect, and the effect was poor in the remaining 12%. It was particularly effective in cholesteatomas in the EAC, attic cholesteatomas with an aerated mastoid, and in recurrent-type cholesteatomas. CONCLUSION: 5-FU topical cream appeared effective for the treatment of cholesteatomas.

Administration, Topical↗

Investigation about the homogeneity of nasopharyngeal microflora at the different location of nasopharynx of children with acute otitis media.

OBJECTIVE: Nasopharynx is thought to be a very important site as becterial reservoir for acute otitis media (AOM). In this study, we investigated on the homogeneity of nasopharyngeal microflora at the different location of nasopharynx of children with AOM. METHODS: Thirty nasopharyngeal samples of 15 children with AOM, two samples harvested from both nostrils of each child, were cultured and analyzed by patterns of antibiotic susceptibility and pulsed-field gel electrophoresis analysis (PFGE). RESULTS: A total of 30 nasopharyngeal samples were cultured and 19 isolates of Streptococcus pneumoniae from 10 children (66.7%), 8 isolates of Haemophilus influenzae from 4 children (26.7%), and 12 isolates of Moraxella catarrhalis from 7 children (46.7%) were obtained. In all children except three, the nasopharyngeal microflora at right and left orifice of the eustachian tubes showed no obvious differences in the bacterial species and quantities. Furthermore, in children with the same species of were cultured from right and left orifice of the eustachian tubes at the same time, all nine couples of S. pneumoniae isolates, four couples of H. influenzae isolates, and five couples of M. catarrhalis isolates showed about the same susceptibility and PFGE patterns. CONCLUSION: These results suggest that the microflora at the different location of nasopharynx of children with AOM is almost homogeneous, irrespective of the clinical signs.

Acute Disease↗

A case with tracheo-innominate artery fistula. Successful management of endovascular embolization of innominate artery.

Tracheo-innominate artery fistula (TIF) is known as a fatal complication after tracheostomy. We report a 9-year-old girl with early hypoxic encephalopathy who had a tracheo-innominate artery fistula with exsanguinating hemorrhage from her tracheostoma 10 months after tracheostomy. After temporary control of bleeding, embolization of the innominate artery was performed. The patient has remained well 1 year after the procedure. We reviewed the aetiology, diagnosis and management of the tracheo-innominate fistula, and findings suggest that endovascular embolization of the innominate artery may be an appropriate treatment for patients with tracheo-innominate artery fistula.

Brachiocephalic Trunk↗

In vitro investigation of the indirect pathogenicity of beta-lactamase-producing microorganisms in the nasopharyngeal microflora.

OBJECTIVE: Nasopharyngeal microflora contains some beta-lactamase-producing microorganisms. In this study, we investigated in vitro on the indirect pathogenicities of Haemophilus parainfluenzae (H. parainfluenzae) and Moraxella catarrhalis (M. catarrhalis) against the antipneumococcul activities of some beta-lactams. METHODS: We compared the antimicrobial and bactericidal activities of beta-lactams against penicillin-susceptible Streptococcus pneumoniae (PSSP) with or without presence of the enzymes of two species of beta-lactamase-producing microorganisms, H. parainfluenzae and M. catarrhalis. RESULTS: When adding the enzymes extracted from these two beta-lactamase-producing microorganisms in equivalent amounts of 10(7) CFU/spot, the minimum inhibitory concentrations of amoxicillin (AMPC) and cefaclor (CCL) increased to >64 microg/mL. Even third-generation cephalosporins, such as cefditren (CDTR) and ceftriaxone (CTRX) showed marked increases with the enzyme of M. catarrhalis. In time-kill kinetics, same phenomenon was observed in mixed culture indicating the indirect pathogenicities of distinct bacteria, not extracted enzymes, on the cidal activities of beta-lactams against PSSP. Clavulanic acid (CVA)/AMPC, faropenem (FRPM), and imipenem (IPM) were not affected by these beta-lactamase-producing strains with respect to their activities against PSSP. However, these two beta-lactamase-producing strains and their enzymes did not show any significant influence on the antipneumococcul activities of beta-lactams, until the number of bacterial cells reached >10(8) CFU/mL. CONCLUSION: Our results suggest that these two species of beta-lactamase-producing microorganisms in the nasopharyngeal microflora may act as indirect pathogens on the antipneumococcul activities of beta-lactams with reflecting their substrate profiles, but this is dependent on sufficient amounts of enzyme for their influence as indirect pathogens.

Amoxicillin↗

Efficient production of L-Lactic acid by metabolically engineered Saccharomyces cerevisiae with a genome-integrated L-lactate dehydrogenase gene.

We developed a metabolically engineered yeast which produces lactic acid efficiently. In this recombinant strain, the coding region for pyruvate decarboxylase 1 (PDC1) on chromosome XII is substituted for that of the l-lactate dehydrogenase gene (LDH) through homologous recombination. The expression of mRNA for the genome-integrated LDH is regulated under the control of the native PDC1 promoter, while PDC1 is completely disrupted. Using this method, we constructed a diploid yeast transformant, with each haploid genome having a single insertion of bovine LDH. Yeast cells expressing LDH were observed to convert glucose to both lactate (55.6 g/liter) and ethanol (16.9 g/liter), with up to 62.2% of the glucose being transformed into lactic acid under neutralizing conditions. This transgenic strain, which expresses bovine LDH under the control of the PDC1 promoter, also showed high lactic acid production (50.2 g/liter) under nonneutralizing conditions. The differences in lactic acid production were compared among four different recombinants expressing a heterologous LDH gene (i.e., either the bovine LDH gene or the Bifidobacterium longum LDH gene): two transgenic strains with 2microm plasmid-based vectors and two genome-integrated strains.

Animals↗