Biomedical subjects

T Miyamoto

Publications and source records attributed to T Miyamoto.

At least 91 records · Page 5Linked to original sources

PubMed2001

Successful surgical management of a tracheopulmonary artery fistula caused by an intratracheal expandable metal stent.

We describe a boy who underwent slide tracheoplasty and relocation of the left pulmonary artery at 3 months of age to treat pulmonary artery sling with congenital tracheal stenosis. Persisting tracheal stenosis required that he have a Palmaz stent inserted on postoperative day 77. He developed massive hemoptysis after the fourth attempt to expand the stent balloon and immediate computed tomography showed a tracheopulmonary artery fistula. Using cardiopulmonary bypass, we conducted emergency surgery to successfully manage the fistula. He currently depends on mechanical ventilation.

Arterio-Arterial Fistula↗

PubMed2001

Usefulness of indium-111-oxine-labeled leukocyte scintigraphy in diagnosis of inflammation associated with chronic aortic dissection.

BACKGROUND: Patients with chronic aortic dissection require monitoring for indications of disease progression. In present study, inflammation adjacent to associated aortic wall was evaluated by indium-111-oxine-labeled leukocyte scintigraphy, scince inflammation of the blood vessel wall often associates with progression of chronic aortic dissection. METHODS AND RESULTS: Fifteen patients with aortic dissection underwent indium-111-oxine-labeled leukocyte scintigraphy. Seven showed positive images at sites corresponding to the actual sites of the dissociated aorta. Four patients with positive images underwent surgery. Histologic examination revealed inflammatory and necrotic changes of the aortic wall. During a mean follow-up period of 2.3 years, progression of aortic dissection was observed in two of the seven patients with positive intimal imaging. CONCLUSION: Indium-111-oxine-labeled leukocyte scintigraphy may be a useful noninvasive technique to assess the persistent inflammation in patients with chronic aortic dissection.

Adult↗

PubMed2001

Guglielmi detachable coil embolization for ruptured lower-midbasilar trunk aneurysms--a report of five cases.

Detachable coil embolization currently plays an essential role for patients with ruptured basilar artery aneurysms, even though it may have an unfavorable outcome and there may be some technical problems of embolization. We describe Guglielmi detachable coil (GDC) embolization for five ruptured lower-mid basilar trunk aneurysms, using a variety of techniques. The patients' ages ranged from 61 to 78 years; Hunt and Kosnik grade was distributed from 2 to 4, and three patients were found to have fenestrations of the lower basilar arteries. All patients underwent aneurysmal embolization at the subacute or chronic stage. The transfemoral route was used in three patients--one of whom, with a wide-necked aneurysm, was treated by the balloon remodeling technique. The transbrachial approach was chosen for the fourth patient, while vertebral artery origin exposure followed by a direct puncture was achieved in the fifth. All patients were assessed with 80-100% aneurysmal obliteration. No patient re-bled after the embolization. Small cerebellar infarction, possibly due to embolism from the obliterated aneurysmal sac, occurred 11 days after the treatment. Of the five patients, four achieved a good recovery, and one became severely disabled. Ruptured basilar trunk aneurysms can be successfully treated with GDC embolization. In addition to the routine transfemoral route, the transbrachial route, direct vertebral artery puncture, and balloon remodeling technique are also useful for the embolization of this location of aneurysm.

Aged↗

PubMed2001

Accumulation of latent transforming growth factor-beta binding protein-1 and TGF beta 1 in extracellular matrix of filtering bleb and of cultured human subconjunctival fibroblasts.

PURPOSE: To examine immunohistochemically whether extracellular matrix (ECM) of the filtering bleb and of cultured human subconjunctival fibroblasts contains latent TGF beta binding protein-1 (LTBP-1) and TGF beta. METHODS: An enucleated human eye that had undergone trabeculectomy and cultured human subconjunctival fibroblasts were processed for light microscopic immunohistochemistry. Antibodies against LTBP-1, collagen types, fibrillin-1 and TGF beta s were used. TGF beta 1 was located by detecting beta 1-latency associated peptide (LAP). RESULTS: LTBP-1, beta 1-LAP and fibrillin-1 were all located in the subepithelial ECM as well as in the basal epithelial cells of the conjunctiva over the filtering bleb. TGF beta 2 and beta 3 were immunolocated to epithelium and/or fibroblasts/keratocytes. ECM deposited in confluent fibroblast cultures was positive for beta 1-LAP, LTBP-1 and fibrillin-1, whereas sparse cells were negative. CONCLUSIONS: LTBP-1, beta 1-LAP and fibrillin-1 are co-localized to the ECM of the filtering bleb and of cultured conjunctival fibroblasts. Both conjunctival epithelium and fibroblasts are considered to be the source of TGF beta in healing bleb. ECM secreted by in vivo and in vitro subconjunctival fibroblasts may works as a scavenger or repository of TGF beta.

Carrier Proteins↗

PubMed2001

Surgical posterior vitreous detachment combined with gas/air tamponade for treating macular edema associated with branch retinal vein occlusion: retinal tomography and visual outcome.

PURPOSE: To assess the effectiveness of surgical posterior vitreous detachment (PVD) together with gas/air tamponade in treating visual impairment from macular edema associated with branch retinal vein occlusion (BRVO-macular edema). METHODS: A cohort study was conducted. To treat visual disturbance caused by BRVO-macular edema in 19 consecutive patients at a University Hospital, phacoemulsification, intraocular lens implantation, and vitrectomy were performed, together with gas/air tamponade. Patients were followed up postoperatively for 3-18 months. Foveal structure was defined using optical coherence tomography (OCT). Preoperative visual acuity, central retinal thickness, and interval between BRVO onset and operation were compared between patients with postoperative visual improvement and those without improvement. RESULTS: Ten patients recovered normal or near-normal foveal configuration, while nine patients did not. Mean postoperative visual acuity in the former group of patients was significantly higher than in the latter. Mean foveal retinal thickness decreased significantly after the operation. The interval from onset of BRVO until operation was significantly shorter in patients with improved postoperative vision than in other patients, and patients operated on within 11 months had significantly increased postoperative visual acuity. CONCLUSIONS: Surgical PVD and gas/air tamponade appears effective in treating BRVO-macular edema, although relatively short duration from disease onset until operation is critical for improvement of vision. When a good postoperative foveal contour is seen, it seems to be associated with better visual outcome.

Adult↗

PubMed2001

Localization and expression of osteopontin in the rotator cuff tendons in patients with calcifying tendinitis.

Calcifying tendinitis of rotator cuff tendons is a common and painful condition caused by ectopic calcification in humans. To examine the involvement of osteopontin (OPN), a potent regulator of calcium deposition on connective tissues, localization and expression of OPN protein and messenger (m)RNA were investigated in human tissue samples of calcified rotator cuff tendons. Immunohistochemistry demonstrated that OPN was localized in cells surrounding the calcified area. OPN was localized in two distinct cell types, i.e., fibroblast-like cells negative for CD68 and tartrate-resistant acid phosphatase (TRAP) and multinucleated macrophages positive for CD68 and TRAP. In situ hybridization revealed that the mRNA expression of OPN in these cells coincided with the immunohistochemistry results, and these results were supported by reverse transcriptase polymerase chain reaction analysis using human OPN-specific oligonucleotides. Cells located away from the calcified area did not express OPN. The present findings indicate the involvement of OPN in the process of calcification of rotator cuff tendons and suggest that OPN plays a role in such painful disorders through the actions of at least two cell types.

Acid Phosphatase↗

PubMed2001

Evaluation of the growth and inhibition strength of hydrocarbon solvents against Escherichia coli and Pseudomonas putida grown in a two-liquid phase culture system consisting of a medium and organic solvent.

The growth of microorganisms is often inhibited in a two-liquid phase culture system consisting of an aqueous medium and a large volume of hydrophobic solvent. Escherichia coli and Pseudomonas putida were cultured in a two-phase system containing a solvent with a log Pow value in a range of 2.1 to 6.0. The increase in the cell mass was monitored by increase in turbidity of the medium phase. We devised a semiquantitative method to evaluate the growth inhibition strength of solvents based on the relative amount of bacterial growth occurring in the two-phase system. Analyses of growth of the bacteria by this method showed that the growth inhibition strength of a given solvent was usually but not always correlated inversely with its polarity. It is clear that growth inhibition strength is not determined simply by polarity of the solvent.

Culture Media↗

PubMed2001

Diagnosis of Japanese patients with HHH syndrome by molecular genetic analysis: a common mutation, R179X.

Patients with mitochondrial ornithine transporter deficiency (or HHH syndrome) present with various neurological symptoms, including mental retardation, spastic paraparesis with pyramidal signs, cerebellar ataxia, and episodic disturbance of consciousness or coma due to hyperammonemia. We previously described three novel mutations in the ORNT1 gene in Japanese patients with HHH syndrome. In this article, we report a new patient with HHH syndrome, a 52-year-old woman, who had the typical clinical features, except for an absence of mental retardation. When we screened this patient, as well as a previously described Japanese patient, for mutations in the ORNT1 gene, we found that both were homozygous for a nonsense mutation (R179X). Furthermore, reverse transcription (RT)-polymerase chain reaction (PCR) of fibroblast RNA from one patient showed exon 4 skipping, as had been observed in a previously reported patient with R179X. These results, together with the findings in our previous report, show that, in three of our five reported Japanese HHH patients (six of ten alleles), R179X is present, suggesting that this is a common mutation in Japanese patients with HHH syndrome.

Amino Acid Metabolism, Inborn Errors↗

PubMed2001

Prevention and detection of spinal cord injury during thoracic and thoracoabdominal aortic repairs.

BACKGROUND: Spinal cord injury is a most dreaded and unpredictable complication. In this study, based on our experimental results in dogs and early clinical results, we reviewed the incidence of paraplegia and the detection of spinal cord injury. METHODS: Eighty-two patients who underwent elective surgical repair of the descending thoracic and thoracoabdominal aorta over 17 years were subjects for this study. Sixty-two patients were male and 20 were female. Their mean age was 61.6 years (range, 17 to 81 years). Monitoring somatosensory evoked potentials (SEP) and measurement of mean distal aortic pressure and cerebrospinal fluid pressure were performed perioperatively. RESULTS: Sixty patients had no ischemic change in SEP. In 17 patients with significant ischemic changes of SEP, SEP recovered by increasing spinal cord perfusion pressure to more than 40 mm Hg. Two patients with complete loss of SEP experienced paraplegia. One patient had delayed paraplegia. CONCLUSIONS: These results strongly suggest that SEP, mean distal aortic pressure, cerebrospinal fluid pressure should be monitored during aortic cross-clamping. Maintaining spinal cord perfusion pressure at more than 40 mm Hg by increasing mean distal aortic pressure or withdrawal of cerebrospinal fluid is valuable for preventing paraplegia.

Adolescent↗

PubMed2001

Direct closure of ostium primum defect in the repair of atrioventricular septal defect.

BACKGROUND: Patch closure is generally performed for atrial septation of an atrioventricular septal defect. We recently developed a new surgical technique for repairing atrioventricular septal defects that avoids the use of any patch material for closing the atrial septal defect. We report our experience with this procedure. METHODS: Seven patients (complete type: 5, partial type: 2) underwent this new operation. The diameters of the atrial septal defects were measured by transesophageal echocardiography. The preoperative electrocardiograms were compared with those taken after the operations. RESULTS: Diameters of the atrial defects ranged from 3 to 10 mm. Electrocardiograms before and after the operations did not change. No significant atrioventricular valve regurgitation and no residual shunts were detected by postoperative echocardiography. CONCLUSIONS: This method simplifies the repair of atrioventricular septal defects. In the short-term results, no arrhythmia and no valve regurgitation was seen.

Blood Vessel Prosthesis Implantation↗

PubMed2001

Biomimetic apatite formation on polyethylene photografted with vinyltrimethoxysilane and hydrolyzed.

A photografting technique to produce functional groups of silanol able to induce apatite nucleation was attempted on polyethylene substrate for biomimetic formation of bone-mineral-like apatite layer on its surface. The polyethylene surface was subjected to vapor-phase photografting of vinyltrimethoxysilane and subsequently to hydrolysis. The photografting formed methoxysilyl groups on the polyethylene substrate, which was changed into silanol groups successively by the hydrolysis in a hydrochloric solution. The polyethylene modified in this way formed a dense and homogeneous bone-mineral-like apatite layer in a solution with ion concentrations 1.5 times that of human blood plasma. This result indicates that the biomimetic process in combination with a polymeric grafting technique might provide a homogeneous bone-mineral-like apatite coating even on polymer fibers to be woven into an apatite-polymer composite with three-dimensional structure analogous to that of natural bone.

Apatites↗

PubMed2001

Molecular, cellular, and functional characterization of chicken cytokines homologous to mammalian IL-15 and IL-2.

DNA sequence analysis of a chicken interleukin (IL)-15 cDNA identified a 187 amino acid open reading frame encoding a protein with a predicted molecular weight of 21,964Da, two potential N-linked glycosylation sites, four highly conserved Cys residues, two out-of-frame AUG initiation codons in the 5' untranslated region, and an unusually long (66 amino acid) signal peptide such that the expected size of the mature protein is 14,462Da. Chicken IL-15 and IL-2 were compared with regard to their molecular, cellular, and functional characteristics. The predicted amino acid sequences of both chicken cytokines showed greater homologies with mammalian IL-15s compared with mammalian IL-2s. Northern hybridization and RT-PCR demonstrated chicken IL-15 gene transcripts in a wide variety of tissues and cell types while the chicken IL-2 gene was expressed only in concanavalin A (con A)-activated spleen cells. Both recombinant cytokines stimulated the growth of spleen T-cells and enhanced the activity of natural killer (NK) cells in vitro. Subcutaneous injection with an expression plasmid encoding IL-15 increased the percentage of CD3+ spleen T-lymphocytes whereas injection of an IL-2 cDNA augmented CD3+, CD4+, CD8+, T-cell receptor (TCR)1+, and TCR2+ T-cells. Collectively, these results indicate that chicken IL-15 and IL-2 are T-cell growth factors potentially capable of enhancing cell-mediated immunity in vivo.

Amino Acid Sequence↗

PubMed2001

Therapeutic effects of FTY720, a new immunosuppressive agent, in a murine model of acute viral myocarditis.

OBJECTIVES: This study examines the efficacy of FTY720 (FTY), a new immunosuppressor, in the treatment of acute viral myocarditis in a murine model. BACKGROUND: Immunosuppressive agents have no proven therapeutic efficacy in experimental or clinical myocarditis. METHODS: Encephalomyocarditis virus was inoculated i.p. in DBA/2 mice on day 0. Postinoculation treatment consisted of FTY 10 mg/kg/day p.o. (FTY group), or cyclosporine A (CsA) 40 mg/kg/day p.o. (CsA group) or distilled water p.o. only (control group). Survival until day 14, as well as cardiac histopathology, virus concentrations, cytokines (interleukin [IL]-2, IL-12, interferon [IFN]-gamma and tumor necrosis factor [TNF]-alpha) and nitric oxide (NO) on day 5 were examined. RESULTS: In the control and CsA groups, all mice died within 10 and 7 days, respectively. However, in the FTY group, 27% of the animals survived up to day 14. Compared with the control group, 1) histological scores were significantly lower in the FTY group but unchanged in the CsA group; 2) virus concentration was significantly higher in the CsA group but not in the FTY group; 3) expressions of IL-2, IL-12 and IFN-gamma in the heart were suppressed in both the FTY and CsA groups, though suppression was weaker in the FTY group; 4) TNF-alpha and NO were significantly increased in the CsA group but not in the FTY group. CONCLUSIONS: FTY720 had a significant therapeutic effect in acute experimental myocarditis without inducing excessive virus replication. This report is the first to describe a beneficial effect by an immunosuppressive agent in the treatment of acute viral myocarditis.

Acute Disease↗

PubMed2001

Alcohol consumption and blood pressure in Japanese men.

In a study of Japanese men, a nonlinear association of alcohol consumption and blood pressure was not observed. This cross-sectional study was conducted to clarify the effect of infrequent or light alcohol consumption on blood pressure in normotensive Japanese men. The subjects were 2,179 male workers ranging in age from 40 to 54 years. Drinking habits were represented by three indices: episodic alcohol consumption, frequency of drinking, and monthly alcohol consumption. Seven items were analyzed as covariates: age, body mass index, salt intake, physical activity, and levels of gamma-glutamyl transpeptidase, uric acid, and plasma glucose. The association between drinking habits and blood pressure was evaluated by using analysis of covariance. Both episodic alcohol consumption and frequency of drinking were significantly associated with blood pressure in subjects aged 45 to 54 years. In those aged 40 to 44 years, there was a significant association between frequency of drinking and diastolic blood pressure. Significant associations of monthly alcohol consumption with blood pressure in every age group also were found. In subjects aged 45 to 54 years, linear associations between episodic alcohol consumption, frequency of drinking, monthly alcohol consumption, and adjusted blood pressure were observed. In those aged 40 to 44 years, nonlinear associations of monthly alcohol consumption and frequency of drinking with adjusted blood pressure were observed, and threshold effects of 540 ml of alcohol per month and a frequency of 1 to 12 days per month were found. In conclusion, habitual alcohol consumption increases blood pressure linearly in normotensive workers aged 45 to 54 years, although light consumption does not affect blood pressure in those aged 40 to 44 years.

Adult↗

PubMed2001

Lens epithelial cell regeneration of a capsule-like structure during postoperative healing in rabbits.

PURPOSE: To determine whether lens epithelial cells (LECs) can regenerate the lens capsule during healing after lens extraction and intraocular lens (IOL) implantation. SETTING: Department of Ophthalmology, Wakayama Medical College, Japan. METHODS: Extracapsular lens extraction and IOL implantation were performed in 5 adult albino rabbits. Lens capsules were examined histologically and immunohistochemically 3 and 5 months later. RESULTS: Lens epithelial cells proliferated and regenerated lens fibers within the capsular bag. A multilayered homogenous capsule-like structure was present in the equatorial region. The structures contained type IV collagen but not type I collagen. CONCLUSION: Lens epithelial cells can regenerate lens capsule-like structures during healing after lens extraction. Postoperative LECs without phenotypic conversion to a fibroblastic type may produce this structure.

Animals↗

PubMed2001

Comparison of Scheimpflug images of posterior capsule opacification and histological findings in rabbits and humans.

PURPOSE: To compare the posterior capsule opacification in Scheimpflug photographic images produced by an electronic anterior eye segment analysis system with the histopathological findings in rabbits and humans. SETTING: Department of Ophthalmology, Wakayama Medical College, Japan. METHODS: Opacified posterior capsules were photographed using the EAS-1000 system (Nidek) and were then extracted during vitreous surgery for proliferative diabetic retinopathy or proliferative vitreoretinopathy in 2 patients. In rabbits, phacoemulsification and aspiration (PEA) with intraocular lens (IOL) implantation was performed. The IOL was implanted in the bag or in the sulcus. After intervals of healing, the posterior capsule was photographed with the EAS-1000 and the animals were then killed. In both clinical and experimental specimens, the posterior capsule was processed for light microscopic histology and immunohistochemistry. RESULTS: Opacified human capsules were well imaged by the EAS-1000. Histology showed that lens epithelial cells proliferated with and without an accumulation of extracellular matrix. Details such as rolling of the capsulotomy edge were seen well. Regenerated lens fibers of Soemmering's ring were seen as a mass within the capsule. In the rabbit model, Scheimpflug images accurately represented the capsules as they appeared histologically. CONCLUSION: The EAS-1000 system provided faithful, relatively high-resolution images that corresponded to the histologic findings in the posterior capsules after PEA-IOL surgery in humans and rabbits.

Aged↗

PubMed2001

Effects of antiinflammatory drugs on migration of the rabbit corneal epithelium.

PURPOSE: To evaluate and compare the effects of diclofenac sodium 0.1% and betamethasone phosphate 0.1% on corneal wound healing. SETTING: Department of Ophthalmology, Wakayama Medical College, Wakayama, Japan. METHODS: Using the method described by Nishida et al., corneal epithelial spreading was measured in vitro in a rabbit corneal block in the presence or absence of 2 antiinflammatory agents at various doses. RESULTS: At clinical doses (1 microg/mL and 10 microg/mL), the drugs did not suppress migration of the corneal epithelium. At high doses (20 microg/mL, 50 microg/mL, and 100 microg/mL), they did inhibit the migration. There was no between-group difference in corneal epithelial migration at clinical doses. At high doses, corneal epithelial migration was inhibited in the diclofenac sodium group compared with the betamethasone group. CONCLUSIONS: At clinical doses, diclofenac sodium and betamethasone did not inhibit corneal epithelial migration. However, these drugs should be prescribed cautiously in patient with high-risk diseases such as diabetes mellitus and glaucoma.

Animals↗

PubMed2001

Characterization of itch-associated responses of NC mice with mite-induced chronic dermatitis.

To clarify the behavioral and pathological features of spontaneous scratching of NC mice with mite-induced chronic dermatitis, we investigated the spontaneous and pruritogen-evoked scratching of NC mice. Although the frequency of scratching of NC mouse did not increase under specific pathogen-free environment, it gradually and markedly increased from 3 to 6 weeks after transfer to conventional environment. The onset of increase in spontaneous scratching was similar to that of dermatitis development and the elevation of plasma concentration of immunoglobulin E. At chronic stage (16 weeks after environment change), the frequency of spontaneous scratching was roughly parallel to the degree of dermatitis, but not to the plasma concentration of immunoglobulin E. The spontaneous scratching of NC mice with dermatitis was inhibited by distraction and the opioid antagonist naltrexone, suggesting that the scratching is itch-associated response. An intradermal injection of serotonin, but not histamine and substance P, elicited scratching of the injected site. Methysergide and cyproheptadine inhibited the serotonin-induced scratching but not spontaneous scratching. The results suggest that marked elevation of plasma immunoglobulin E is not always the cause of spontaneous itch-associated response of NC mice with dermatitis. Serotonin, histamine and substance P may not play an important role in spontaneous itch-scratch response at a chronic stage.

Animals↗