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Gen Yamada

Publications and source records attributed to Gen Yamada.

51 records · Page 3Linked to original sources
PubMed2003

Increased airway vascularity in newly diagnosed asthma using a high-magnification bronchovideoscope.

Hypervascularity in the bronchial wall is part of airway remodeling, but has remained an ill-defined process in asthma pathogenesis. Previous morphologic assessment has been limited to biopsy specimens, and therefore a high-magnification bronchovideoscope (side-viewing type) was developed for less invasive examination of subepithelial vessels. We evaluated vascularity in the lower trachea, using this novel scope in 12 normal control subjects, 13 patients with chronic obstructive pulmonary disease, and 24 subjects with stable asthma; 8 were steroid naive with newly diagnosed asthma (Group A) and 16 had been treated with inhaled corticosteroids for more than 5 years (Group B). The redness of bronchial mucosa in patients with asthma observed by conventional fiberoptic bronchoscopy proved to be due to a fine vascular network. Morphometric measurements of subepithelial vessels showed that both vessel area density and vessel length density were significantly (p<0.0001) increased in subjects with asthma as compared with control subjects and patients with chronic obstructive pulmonary disease. The degree of increase in vessels did not differ between Group A and Group B. The increase in subepithelial vessels of the airway is present even in newly diagnosed asthma. This novel bronchovideoscope is useful for assessment of vessel network in the surface of the airway lumen in vivo.

Adult↗
PubMed2003

Microbubble-enhanced sonoporation: efficient gene transduction technique for chick embryos.

The gene transduction technique is a useful method to study gene functions that underlie vertebrate embryogenesis. In this study, a new gene transduction technique is reported using microbubble-enhanced sonoporation (hereafter referred to as sonoporation) to achieve ectopic and transient gene expression for several embryonic organs including embryonic chick limb bud mesenchymes. The technique proposed in this study has the advantages of 1) relatively simple gene transduction procedures, and 2) efficient exogenous gene transduction and expression with lower damages to embryos. Green fluorescent protein (GFP) or LacZ was misexpressed in limb bud mesenchymes by sonoporation, with the introduced expression transiently detected in the injected sites. Most of the transduced chick embryos survived without showing significant embryonic abnormalities or cell death after sonoporation. To demonstrate its efficacy for assessing the effect of transient gene transduction, the Shh (sonic hedgehog) was transduced into the developing chick limb bud. The transduced limb bud displayed limb malformations including partial digit duplication. Advantages and possible future applications in relation to this method are discussed.

Animals↗
PubMed2003

Invasive thymoma with paraneoplastic retinopathy.

A 60-year-old man was admitted for progressive visual loss in both eyes. He was diagnosed with retinopathy and chest computed tomography revealed an invasive thymoma. In western blot analysis, serum autoantibodies against recoverin, photoreceptor-specific calcium-binding protein, and heat shock cognate protein 70 which were identified as the cause of cancer-associated retinopathy (CAR). Immunofluorescence staining showed that thymoma cells also expressed recoverin. These observations strongly suggested that similar pathogenesis of CAR was involved in the presented case.

Biomarkers, Tumor↗
PubMed2003

Cellular and molecular mechanisms of development of the external genitalia.

The limb and external genitalia are appendages of the body wall. Development of these structures differs fundamentally in that masculine development of the external genitalia is androgen dependent, whereas development of the limb is not. Despite this fundamental difference in developmental regulation, epithelial-mesenchymal interactions play key roles in the development of both structures, and similar regulatory molecules are utilized as mediators of morphogenetic cell-cell interactions during development of both the limb and external genitalia. Given the relatively high incidence of hypospadias, a malformation of penile development, it is appropriate and timely to review the morphological, endocrine, and molecular mechanisms of development of the genital tubercle (GT), the precursor of the penis in males and the clitoris in females. Morphological observations comparing development of the GT in humans and mouse emphasize the validity of the mouse as an animal model of GT development and validate the results of experimental studies. Accordingly, the use of mutant mice provides important insights into the roles of specific regulatory molecules in development of the external genitalia. While our current understanding of the morphological and molecular mechanisms of mammalian external genitalia development is still rudimentary, this review summarizes the current state of our knowledge and whenever possible draws from the rich experimental embryology literature on other relevant organs such as the developing limb. Future research on the hormonal and molecular mechanisms of GT development may yield strategies to prevent or reduce the incidence of hypospadias and to elucidate the molecular genetic mechanisms of GT morphogenesis, especially in relation to common organogenetic pathways utilized in other organ systems.

Animals↗
PubMed2003

Silicon compatible with the height of human vertebral column.

In the study on human vertebral composites, silicon was found to be related to the height of the vertebral column. The element ratio of silicon to calcium in the lumbar vertebra was twice that of the lowest one in the cervical vertebra. The element ratio gradually increased from approx 0.5 at the cervical vertebra to approx 1.0 at the lumbar one. Silicon is preserved catastropically much more in the lower height of the backbone in contrast with the calcium amount, and the ratio to sulfur appears to be unchanged. This suggests that silicon is compatible with the biokinetics of the vertebral bone structure of calcium.

Aged↗
PubMed2003

A special comment on trace metals in the viscera of turbo marmoratus, a toxic snail, on Ryukyu Island.

Trace metals in the viscera of Turbo marmoratus, a huge conical spire, in the coral reef of Ryukyu Island were analyzed. The highest amount of Zn and Fe was detectable in the midgut gland known to be polluted by saxitoxin. This intestine maintained a considerable amount of Si (higher than Ca) which fluctuated in parallel with the taurine amount. These data suggest that the viscera of the alimentary tract accumulate some metals, especially Zn and Fe.

Animals↗
PubMed2003

Secondary pulmonary alveolar proteinosis associated with myelodysplastic syndrome.

A 47-year-old man, who had been diagnosed as myelodysplastic syndrome (MDS), complained of a severe cough and a high-grade fever. Chest CT disclosed scattered small nodules and ground-glass opacities with interlobular septal thickening in both lung fields and a mass lesion in the right lower lobe. Pathological findings of the ground-glass opacities and the mass lesion obtained by video-assisted thoracoscopic surgery revealed the accumulation of eosinophilic amorphous material in the alveoli and confirmed the diagnosis of pulmonary alveolar proteinosis (PAP). Autoantibodies against granulocyte-macrophage colony-stimulating factor (GM-CSF) in sera were below sensitivity, while the GM-CSF level was elevated in bronchoalveolar lavage fluid. He was diagnosed as secondary PAP associated with MDS.

Biopsy, Needle↗
PubMed2002

Elevated levels of serum macrophage migration inhibitory factor in patients with pulmonary tuberculosis.

Macrophage migration inhibitory factor (MIF) was originally described as a T-cell-derived cytokine that inhibits the random migration of macrophages and promotes the delayed-type hypersensitivity reaction. MIF plays an important role in the regulation of the Th1/Th2 balance in inflammatory response. This study investigated serum levels of circulating MIF in patients with pulmonary tuberculosis. The levels of MIF in sera were measured by enzyme-linked immunosorbent assay in 34 patients with pulmonary tuberculosis (16 males and 18 females) and 30 healthy controls (15 males and 15 females). The mean levels of circulating MIF values were significantly higher in those with pulmonary tuberculosis (19.84 +/- 11.27 ng/ml; P < 0.0001) than in the healthy controls (4.38 +/- 1.34 ng/ml). Circulating MIF values significantly correlated with circulating interferon-gamma values (r = 0.537, P < 0.0001). Thus, MIF may play an important role in immune responses to human infection with Mycobacterium tuberculosis.

Adult↗
PubMed2002

Targeted disruption of the Tab1 gene causes embryonic lethality and defects in cardiovascular and lung morphogenesis.

The transforming growth factor-beta (TGF-beta) superfamily consists of a group of secreted signaling molecules that perform important roles in the regulation of cell growth and differentiation. TGF-beta activated kinase-1 binding protein-1 (TAB1) was identified as a molecule that activates TGF-beta activated kinase-1 (TAK1). Recent studies have revealed that the TAB1-TAK1 interaction plays an important role in signal transduction in vitro, but little is known about the role of these molecules in vivo. To investigate the role of TAB1 during development, we cloned the murine Tab1 gene and disrupted it by homologous recombination. Homozygous Tab1 mutant mice died, exhibiting a bloated appearance with extensive edema and hemorrhage at the late stages of gestation. By histological examinations, it was revealed that mutant embryos exhibited cardiovascular and lung dysmorphogenesis. Tab1 mutant embryonic fibroblast cells displayed drastically reduced TAK1 kinase activities and decreased sensitivity to TGF-beta stimulation. These results indicate a possibility that TAB1 plays an important role in mammalian embryogenesis and is required for TAK1 activation in TGF-beta signaling.

Adaptor Proteins, Signal Transducing↗
PubMed2002

Pulmonary MALT lymphoma with amyloid production in a patient with primary Sjögren's syndrome.

A 53-year-old woman was admitted to our hospital complaining of cough, low grade fever, chest pain and sicca symptoms. A chest radiograph showed an abnormal shadow and chest computed tomography revealed a tumor in left S6. She was diagnosed as Sjögren's syndrome by sialography and histological findings of labial biopsy. The surgically resected tumor specimen showed proliferation of lymphoid cells with lymphoepithelial lesions, which were positive for CD20 and kappa light chain. Kappa light chain-positive amyloid was found within the tumor. The tumor showed rearranged kappa light chain genes. The diagnosis was pulmonary mucosa associated lymphoid tissue lymphoma with amyloid production.

Amyloid↗
PubMed2002

Experience with oseltamivir in the control of nursing home influenza A outbreak.

OBJECTIVE: Influenza outbreaks have revealed that elderly persons are a great risk of death and serious complications after infection. The administration of oseltamivir, a neuramidase inhibitor, is effective for prophylaxis of influenza and to reduce disease duration and severity in healthy adults with naturally acquired febrile influenza. To clarify the usefulness of oseltamivir in the elderly we administered oseltamivir to all residents when an influenza A outbreak occurred in a nursing home. PATIENTS: Sixty-eight residents in the nursing home were investigated in which the influenza A outbreak occurred; 32 residents had fever and 28 residents were positive for influenza A with direct enzyme immunoassay. METHODS: Oseltamivir was administered at 75 mg twice daily for 5 days to all residents. RESULTS: Oseltamivir almost inhibited symptom onset in the influenza A-positive afebrile group. Initiation at 0 hour (22 cases), 1-12 hours (4 cases), 13-24 hours (5 cases) or 72 hours (1 case) from onset of symptoms was associated with mean fever durations of 26+/-18 hours, 38+/-21 hours, 54+/-12 hours and 120 hours, respectively, indicating that earlier initiation of therapy was associated with faster resolution of fever in elderly patients. Oseltamivir may be effective for household prophylaxis in the elderly persons. Oseltamivir administration was well tolerated in elderly persons. CONCLUSION: Oseltamivir is effective for the reduction or prophylaxis of influenza A infection in elderly persons.

Acetamides↗
PubMed2002

Pulmonary lymphangioleiomyomatosis; unusual radiological manifestation of multiple large nodules.

A 44-year-old woman was admitted to our hospital in August 1999 for multiple large nodules detected on chest roentgenogram in an annual health check. Chest CT scans showed bilateral large nodules (>10 mm in diameter) with irregular margins and multiple thin walled cystic lesions. From these radiologic examinations, we suspected pulmonary Langerhans cell histiocytosis. Histological examination of the biopsy specimen by video-assisted thoracoscopy revealed a marked proliferation of the spindle cells, which were immunologically positive for alpha-smooth muscle actin and HMB-45, in the cyst walls and lung parenchyma. The large nodules consisted of proliferation of the smooth muscle cells surrounded by a dense layer of hemosiderinladen macrophages. During the two years subsequent to these 1999 examinations, the opacities have gradually diminished and the patient was found to have pulmonary lymphangioleiomyomatosis. This case exhibited rare radiologic manifestations of multiple large nodules mimicking Langerhans cell histiocytosis.

Actins↗
PubMed2002

[A case of chronic hypersensitivity pneumonia with elevation of serum SP-D and KL-6].

A 73-year-old woman suffering from dyspnea on effort and chronic cough was admitted to our hospital. Chest computed tomography disclosed ground-glass opacities, irregular linear opacities and honeycombing distributed predominantly in the subpleural area. The serum levels of SP-D and KL-6 rose to 889 ng/ml, 1,755 U/ml, respectively. These findings indicated idiopathic pulmonary fibrosis. However, the number of lymphocytes and the CD4/CD8 ratio in the BAL fluid were elevated. Transbronchial lung biopsy specimens demonstrated alveolitis with granuloma formation. The evidence that she had lived in a house with a heavy fungal growth and that tests of precipitation in response to Penicillium corylophilum were positive confirmations of a diagnosis of chronic hypersensitivity pneumonia.

Aged↗
PubMedDate not supplied

Embryonic development of mouse external genitalia: insights into a unique mode of organogenesis.

The mammalian external genitalia are specialized appendages for efficient copulation, internal fertilization and display marked morphological variation among species. In this paper, we described the embryonic development of mouse genital tubercle (GT), an anlage of the external genitalia utilizing the scanning electron microscope (SEM) analysis. It has been shown that the Distal Urethral Epithelium (DUE) may fulfill an essential role in the outgrowth control of the GT. Our present SEM analysis revealed a small distal protrusion at the tip of the GT of normal embryos as well as some morphological differences between male and female embryonic external genitalia. Previous analysis shows that the teratogenic dose of Retinoic Acid (RA) induces a drastic marformation of the urethral plate, but not gross abnormalities for GT outgrowth. Interestingly, a small distal protrusion at the tip of GT was clearly observed also after RA treatement. Furthermore, we showed that treatment with anti-androgen flutamide resulted in the demasculinization of the GT in males. The unique character of GT development and the sexual dimorphism are discussed.

Animals↗