Search PubMed⌕ Search

Biomedical subjects

H Miyamoto

Publications and source records attributed to H Miyamoto.

At least 55 records · Page 3Linked to original sources

Sampling and detection of Legionella pneumophila aerosols generated from an industrial cooling tower.

Cooling tower water has frequently been cited as a source of infection in outbreaks of Legionnaires' disease. However, there have been few reports on the presence of legionellae in aerosols from cooling towers. This paper describes our use of an impinger or a six-stage microbial impactor for detecting legionellae in air around a cooling tower contaminated with L. pneumophila (1.2+/-0.3x10(5) CFU/100 ml). Phosphate-buffered saline, Page's saline, 2% yeast extract solution and buffered yeast extract (BYE) broth were tested to evaluate their collection efficiency. These solutions were compared in laboratory experiments using an aerosol of L. pneumophila serogroup (SG) 1. Because BYE broth was the most efficient and storable collecting fluid among them, it was used for outdoor air sampling. In the outdoor air sampling, aerosolized L. pneumophila SG 6 was detected in the air around the cooling tower by the impinger (0.09 CFU/l. air). No legionellae were detected by the impactor with Legionella-selective agar plates (WYOalpha) because the plates were overgrown with fungi. Repetitive element PCR (rep-PCR) and arbitrarily primed PCR (AP-PCR) were employed to assess the epidemiological relationship among Legionella isolates from the air sample and the cooling tower water samples. L. pneumophila SG 6 isolated from the aerosols produced rep-PCR and AP-PCR fingerprints identical to those of L. pneumophila SG 6 strains from the cooling tower water, suggesting that the bacterium was aerosolized from the cooling tower.

Aerosols↗

[A case of mediastinal esophago-bronchogenic cyst associated with high serum level of CA 19-9].

We report a case of mediastinal esophago-bronchogenic cyst in a patient with a high serum level of CA 19-9. A 49-year-old man presented with a complaint of dysphagia. Chest X-ray, CT, and MRI showed posterior mediastinal cystic shadow which was diagnosed preoperatively. The serum level of CA 19-9 was 158 U/ml. We underwent extirpation of the cyst through video-assisted thoracoscopic surgery (VATS) and confirmed to be a bronchogenic cyst histologically. The serum level of CA 19-9 returned to normal after the operation.

Bronchogenic Cyst↗

[A case of congenital esophagobronchial fistula discovered incidentally on esophagography].

A 50-year-old man was admitted to our hospital because of an abnormal shadow, detected during an upper gastrointestinal examination. A chest radiograph showed an infiltrating shadow in the right middle lung field. A chest CT showed a fistula communicating between a bronchus (rt. B6) and the middle of the esophagus. Resection of the fistula was performed by video-assisted thoracoscopic surgery (VATS). Isolation of the fistula was straightforward, and there was no evidence of inflammation or adherent lymph nodes around it. Histologic examination of the resected specimen revealed that the fistula lumen was covered with squamous epithelium and muscularis mucosa. These findings suggested that this case could be categorized as Braimbridge type II. In this case, the chest CT showed the esophagobronchial fistula clearly, and was useful for the diagnosis.

Bronchial Fistula↗

A unique and common restriction fragment pattern of the nucleotide sequences homologous to the genome of vf33, a filamentous bacteriophage, in pandemic strains of Vibrio parahaemolyticus O3:K6 O4:K68, and O1:K untypeable.

Vf33 is a filamentous bacteriophage isolated from Vibrio parahaemolyticus. We performed Southern blot hybridization analysis to examine the distribution of Vf33-related genetic elements in the pandemic strains (O3:K6 strains isolated between 1995 and 1997, O4:K68 and O1:K untypeable strains isolated between 1997 and 1999) of V. parahaemolyticus. Nucleotide sequences homologous to the Vf33 DNA were detected in all 57 test strains including pandemic and non-pandemic strains. However, the profiles of hybridization, including the restriction fragment length polymorphism, with nine Vf33-derived DNA probes exhibited by the pandemic strains were identical and were different from those by the non-pandemic strains. The results support the hypothesis that the pandemic strains are clonal, and suggest a possibility that they have acquired (a) new gene(s) via a Vf33-like filamentous phage.

Bacteriophages↗

Long-term sustained release of ganciclovir from biodegradable scleral implant for the treatment of cytomegalovirus retinitis.

The previous scleral implant composed of poly(D, L-lactide-co-glycolide) with ganciclovir (GCV) had some disadvantages such as the second burst in the late phase of release. In this study, the GCV release rate from scleral implants was modified by blending poly(D,L-lactide) (PLA) of two different molecular weights. The scleral implants were prepared by blending PLA-70000 (molecular weight: 70000) and PLA-5000 (molecular weight: 5000) or PLA-130000 (molecular weight: 130000) and PLA-5000 at weight ratios of 100/0, 95/5, 90/10, 80/20, and 0/100. In vitro release tests were performed in 0.1 M phosphate-buffered solution (pH 7.4) at 37 degrees C. An increase in the blended amount of PLA-5000 clearly accelerated the GCV release and the onset of the second burst in the late phase of release tended to delay. The two implants both prepared at a blend ratio of 80/20 successfully prevented the second burst and the GCV release profiles followed the pseudozero-order kinetics after the initial burst as resulting from a diffusional mechanism following Higuchi's equation. Duration of the sustained GCV release could be controlled by changing the blending ratio of high and low molecular weight PLA. The 25% GCV-loaded scleral implants composed of PLA-70000 and PLA-5000 with a blending ratio of 80/20 were implanted in pigmented rabbit eyes. The GCV concentrations in the vitreous after implantation of PLA-70000/PLA-5000 scleral implant with a blending ratio of 80/20 were maintained in the range of effective level for 6 months without a significant burst. Our results suggest that the blended implants are promising for the intraocular controlled drug delivery over a period of several months to one year to treat cytomegalovirus retinitis.

Animals↗

[Contamination of a bronchial fiberscope by mycobacteria linked to an automated bronchoscope disinfection machine].

Mycobacteria are being isolated with increasing frequency from automated bronchoscope disinfection machines. This has led to misdiagnosis and nosocomial infections. In this study, we isolated Mycobacterium chelonae from a bronchoscope disinfection machine and found one strain to be resistant to 2% glutaraldehyde and sensitive to 70% ethanol. Since we began cleaning the sink of the machine with 70% ethanol, no mycobacteria has been seen throughout the machine.

Bronchoscopy↗

Enantioselective photocyclization of amides to beta-lactam derivatives in inclusion crystals with an optically active host

Irradiation of inclusion crystals of 2-(N-acyl-N-alkylamino)cyclohex-2-enones and N,N-dimethylphenylglyoxylamide with chiral host molecules gave the optically active N-alkyl-1-azaspiro[3.5]-nonane-2,5-diones and 3-hydroxy-1-methyl-3-phenylazetidin-2-one, respectively. The crystal structure of the 1:1 inclusion complex of N,N-dimethylphenylglyoxylamide with (-)-trans-1,4-bis[3-(o-chlorophenyl)-3-hydroxy-3-phenylprop-1-ynyl]-2,3,5,6- tetrachloro-2,5-cyclohexadiene-1,4-diol was analyzed by X-ray diffraction.

Journal Article↗

Development of infantile rat ovaries autotransplanted after cryopreservation by vitrification.

We cryopreserved infantile rat ovaries by vitrification and assessed their viability by autotransplantation. Hemilateral ovarian transplantation was performed on rats on postnatal Days 10 to 12. The left ovary of each rat was dissected out, cryopreserved by vitrification using a modified vitrification solution (VS1), and then autotransplanted under the capsule of the right kidney. The right ovary of each rat was removed. For the control, the left ovary was dissected out from each rat and was immediately transplanted by the same procedure, without cryopreservation. Rats were nursed until weaning, and then the day of vaginal opening, estrous cyclicity from the day of vaginal opening until postnatal Day 84, and histology of ovarian grafts at postnatal Day 84 were examined. The time course of development of endocrine function of cryopreserved grafts was similar to that of fresh grafts. In ovarian transplants recovered on postnatal Day 84, antral follicles and corpora lutea (CL) were observed in addition to small follicles, although the number of antral follicles in cryopreserved grafts was smaller than in the fresh grafts. These results indicate that cryopreservation of ovarian tissue by vitrification can be used for the preservation of fertility and endocrine function of ovaries.

Animals↗

Cloning and expression of the mouse Pse gene encoding a novel Ets family member.

Human prostate-specific Ets (hPSE) is a novel Ets transcription factor and is exclusively expressed in human prostate glandular epithelium. To explore the role of PSE, we cloned the mouse Pse (mPse) and examined its pattern of expression. A sequence analysis indicated that mPse contains a conserved carboxy-terminal ETS DNA-binding domain and central Pointed domain, and the overall amino acid sequence shares 86% identity with that of hPSE. The ETS DNA-binding domain is highly conserved between human and mouse (98.8% sequence identity) and is similar to Drosophila dets4 (76.7% identity), but not similar to other Ets factors. A Northern blotting analysis revealed that mPse shows organ-specific expression. An in situ hybridization analysis of the prostate and intestine showed that mPse transcripts were present in their epithelial cells. mPse transactivates the promoter of the MASPIN gene in transient transfection assay. These results suggest that mPse encodes a novel Ets family member and is expressed in epithelial cells of restricted organs.

Amino Acid Sequence↗

Effects on Rb(+)(K+) uptake of HeLa cells in a high K(+) medium of exposure to a switched 1.7 Tesla magnetic field.

Effects of a switched, time-varying 1.7 T magnetic field on Rb(+)(K+) uptake by HeLa S3 cells incubated in an isosmotic high K(+) medium were examined. The magnetic flux density was varied intermittently from 0.07-1.7 T at an interval of 3 s. K(+) uptake was activated by replacement of normal medium by high K(+) medium. A membrane-permeable Ca(2+) chelating agent (BAPTA-AM) and Ca(2+)-dependent K(+) channel inhibitors (quinine, charibdotoxin, and iberiotoxin) were found to reduce the Rb(+)(K+) uptake by about 30-40%. Uptake of K(+) that is sensitive to these drugs is possibly mediated by Ca(2+)-dependent K(+) channels. The intermittent magnetic field partly suppress ed the drug-sensitive K(+) uptake by about 30-40% (P < 0.05). To test the mechanism of inhibition by the magnetic fields, intracellular Ca(2+) concentration ([Ca(2+)]c) was measured using Fura 2-AM. When cells were placed in the high K(&plus;) medium, [Ca(2+)]c increased to about 1.4 times the original level, but exposure to the magnetic fields completely suppressed the increase (P < 0.01). Addition of a Ca(2+) ionophore (ionomycin) to the high K(+) medium increased [Ca(2+)]c to the level of control cells, regardless of exposure to the magnetic field. But the inhibition of K(+) uptake by the magnetic fields was not restored by addition of ionomycin. Based on our previous results on magnetic field-induced changes in properties of the cell membrane, these results indicate that exposure to the magnetic fields partly suppresses K(+) influx, which may be mediated by Ca(2+)-dependent K(+) channels. The suppress ion of K(+) fluxes could relate to a change in electric properties of cell surface and an inhibition of Ca(2+) influx mediated by Ca(2+) channels of either the cell plasma membrane or the inner vesicular membrane of intracellular Ca(2+) stores.

Calcium↗

Complementary DNA Cloning and Characterization of Pearlin, a New Class of Matrix Protein in the Nacreous Layer of Oyster Pearls.

Calcified shell layer is composed of two polymorphs of CaCO(3), aragonite or calcite, and an organic matrix. The organic matrix consists of EDTA-soluble and insoluble fractions. These fractions are thought to regulate the formation of the elaborate shell structure. After decalcification of powdered pearl with 0.3 M EDTA, an EDTA-insoluble fraction was extracted with 0.3 M EDTA/8 M urea. This extraction step enabled us to purify a new class of EDTA-insoluble protein, Pearlin, almost homogeneously. Pearlin has a molecular weight of about 15 kDa and contains a sulfated mucopolysaccharide. We cloned the complementary DNA coding for Pearlin and deduced its complete amino acid sequence. Sequence analysis reveals that Pearlin is composed of 129 amino acids with a high proportion of Gly (10.8%), Tyr (10.0%), Cys (8.5%), Asn (7.7%), Asp (7.7%), and Arg (7.7%). Northern blot analysis showed that Pearlin messenger RNA was expressed specifically in mantle epithelium. From the sequencing data, Pearlin was shown to be quite different from the fibrous protein rich in Ala and Gly. The function of this protein in biomineralization is discussed.

Journal Article↗

Combination of nedaplatin and vindesine for treatment of relapsed or refractory non-small-cell lung cancer.

PURPOSE: A phase II study of nedaplatin and vindesine was conducted to evaluate their efficacy and safety for treatment of relapsed or refractory non-small-cell lung cancer (NSCLC). METHODS: Between August 1996 and September 1998, 48 patients who had previously received chemotherapy, thoracic radiotherapy, and/or surgery were enrolled in the study. Patients were required to have an Eastern Cooperative Oncology Group performance status of 0 to 2 and an age between 20 and 79 years. Treatment consisted of nedaplatin (80 mg/m2, day 1) and vindesine (3 mg/m2, days 1 and 8) every 3 to 4 weeks. RESULTS: Of 48 patients, 7 (14.6%) exhibited an objective response. Four (50%) of eight chemotherapy-naive patients had a partial response. However, of the 40 patients who had received prior chemotherapy, a partial response was observed in only 3 (7.5%). At a median follow-up time of 85.1 weeks, the median survival time was 43.6 weeks (95% confidence interval 34.4-52.7) for patients who had received chemotherapy, with a survival rate of 40% at 1 year. Grade 3 or 4 neutropenia occurred in 43 of 48 patients (90%), and neutropenic fever was observed in 3 of the 43 patients, one of whom died of sepsis. Pharmacokinetic and pharmacodynamic analyses of platinum were performed in 43 patients during the first cycle of chemotherapy. Percent reduction in absolute neutrophil count was correlated not only with the area under the plasma ultrafilterable platinum concentration versus time curve (r = 0.41, P = 0.007) but also with the duration of ultrafilterable platinum concentration above 1 microg/ml (r = 0.41, P = 0.007). Patients with progressive disease exhibited a shorter duration of ultrafilterable platinum concentration over 1 microg/ml (P = 0.046) than those with other responses. CONCLUSION: A combination of nedaplatin and vindesine was unsatisfactory as second-line chemotherapy for NSCLC, although the combination was well tolerated. The duration of ultrafilterable platinum concentration above 1 microg/ml was an important pharmacokinetic parameter for predicting both chemotherapy-induced neutropenia and treatment outcome.

Adult↗

Biodegradable scleral implant for intravitreal controlled release of ganciclovir.

BACKGROUND: The aims of this study were to develop biodegradable scleral implants that could overcome previously reported disadvantages such as an adverse burst in the late phase of release and to investigate the release profile of modified scleral implants in vitro and in vivo. METHODS: The modified scleral implants (weight 8.5 mg, length 5 mm) were made of mixtures of poly(DL-lactide) (PLA) with different molecular weights and contained 25 weight % of ganciclovir (GCV). The release of GCV was evaluated in vitro by spectrophotometry. Intravitreal GCV concentrations in vivo were measured by high-performance liquid chromatography following plug implantation in pigmented rabbits. The biocompatibility of the device was determined by indirect ophthalmoscopy and light microscopy. RESULTS: The in vitro release studies showed stable, long-term sustained and slow release. The in vivo release studies showed that the implants had long-term release in the diffusional phase of the triphasic release pattern and only a minor adverse burst of GCV in the late phase. No significant retinal toxicity was observed by histologic examination. CONCLUSION: Our findings showed that this newly modified scleral implant may provide suitable intravitreal drug delivery for treatment of cytomegalovirus retinitis.

Absorbable Implants↗

C-ERBB-2 gene amplification as a prognostic marker in human bladder cancer.

OBJECTIVES: To evaluate c-erbB-2 gene amplification and its prognostic significance in transitional cell carcinoma of the bladder. METHODS: Alterations in the gene copy number of c-erbB-2 were detected in 57 bladder tumor samples using a method based on the polymerase chain reaction. RESULTS: Eighteen tumors (32%) showed gene amplification of c-erbB-2, which correlated with tumor grade and stage. A strong association of c-erbB-2 amplification with patient survival was also found. The amplification resulted in a significantly poorer prognosis among the patients with high-grade and/or invasive tumors. Multivariate analysis revealed that c-erbB-2 amplification and tumor grade were independent prognostic factors. CONCLUSIONS: Our data indicate a possible role of the c-erbB-2 gene in the development of aggressive behavior in bladder tumors. Moreover, the use of c-erbB-2 gene amplification, together with tumor grade and stage, could provide an accurate basis for determining the prognosis of bladder cancer.

Adult↗

Effects of the mycelial extract of cultured Cordyceps sinensis on in vivo hepatic energy metabolism and blood flow in dietary hypoferric anaemic mice.

The beneficial effects of a traditional Chinese medicine, Cordyceps sinensis (Cs), on mice with hypoferric anaemia were evaluated by NMR spectroscopy. Experimental hypoferric anaemia was induced in mice by feeding with an Fe-free diet for 6 weeks. They were then given extract from cultured Cs (200 mg/kg body weight daily, orally) and were placed on an Fe-containing recovery diet (35 mg Fe/kg diet) for 4 weeks. In vivo 31P and 2H NMR spectra acquired noninvasively and quantitatively at weekly intervals were used to evaluate hepatic energy metabolism and blood flow in the mice. During the 4-week Cs-extract treatment, consistent increases were observed in liver beta-ATP: inorganic phosphate value by liver 31P NMR spectroscopy, representing the high energy state, and in blood-flow rate as determined by 2H NMR spectroscopy of deuterated water (D2O) uptake after intravenous injection of D2O. The haematological variables (the packed cell volume and the haemoglobin level) and the hepatic intracellular pH, which was determined from the NMR chemical shift difference between the inorganic phosphate peak and the alpha-phosphate peak of ATP, were not significantly different between Cs-extract-treated and control mice. As blood flow and energy metabolism are thought to be linked, the Cs-extract-increased hepatic energy metabolism in the dietary hypoferric anaemic mice was concluded to be due to increased hepatic blood flow.

Adenosine Triphosphate↗