PubMed Health⌕ Search

Biomedical subjects

Koichi Honma

Publications and source records attributed to Koichi Honma.

9 recordsLinked to original sources
PubMed2006

Heme oxygenase-1, a potential biomarker of chronic silicosis, attenuates silica-induced lung injury.

RATIONALE: Heme oxygenase-1 (HO-1), a rate-limiting enzyme in heme catabolism, has antioxidative, antiapoptotic, and antiinflammatory activities. We examined whether HO-1 might be involved in silicosis. OBJECTIVES: To investigate whether HO-1 can reduce silicosis in mice and humans. METHODS AND MEASUREMENTS: Silicosis was studied using a murine model, and in 46 male patients. Serum HO-1 and 8-hydroxydeoxyguanosine (a marker of oxidative stress) were measured by enzyme-linked immunosorbent assay. Levels of HO-1 were measured by immunohistochemistry and immunoblotting. MAIN RESULTS: Serum HO-1 levels were significantly elevated in patients with silicosis compared with age-matched control subjects or patients with chronic obstructive pulmonary disease. Serum HO-1 levels also correlated inversely with serum 8-hydroxydeoxyguanosine levels and positively with vital capacity and forced expiratory volume in one second in patients with silicosis. HO-1 was present in the lungs of humans and mice with silicosis, especially at sites of silica particle deposition. In mice, silica exposure was associated with acute leukocyte infiltration, leading to development of silicotic lung lesions. The inflammation was suppressed by treatment with hemin, an inducer of HO-1, and enhanced by zinc protoporphyrin, an inhibitor of HO-1. CONCLUSIONS: Pulmonary HO-1 expression is increased in silicosis. HO-1 suppresses reactive oxygen species activity, and subsequent pathologic changes, thereby attenuating disease progression.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2006

Cardiovascular autonomic nervous response to postural change in 610 healthy Japanese subjects in relation to age.

To determine the effect of aging on the cardiovascular response to postural change, we examined the cardiovascular sympathetic and parasympathetic response to active standing in 610 healthy Japanese subject (6-83 years) measuring the initial heart rate (HR) response for 3 min in the supine and standing position, we also measured the coefficient of variation of R-R interval (CV(R-R)). As a result, the cardiovascular response to active standing demonstrated a different change with aging between sympathetic and parasympathetic. Sympathetic function was in a sthenia state in young subjects, and that this function declined with age increasing. Whereas, parasympathetic function was immature enough to inhibit the sympathetic tone in young subjects and matured at 20 years of age, and had an ability to inhibit sympathetic tone. CV(R-R) show a linear change that decline with age increasing. These results indicated that the cardiovascular parasympathetic response to active standing shows a characteristic change with aging that differs from cardiovascular parasympathetic at rest represented by CV(R-R). The present study is the first report to demonstrate the cardiovascular response to standing in relation to aging in large population. These results suggested that the cardiovascular response to postural change is dependent on subject's age.

Adolescent↗
PubMed2005

Pleural disease in silicosis: pleural thickening, effusion, and invagination.

PURPOSE: To retrospectively evaluate pleural disease on images from patients with autopsy-proved silicosis. MATERIALS AND METHODS: The study had institutional review board approval, and informed consent from relatives of diseased subjects was waived. Lung specimens were obtained at autopsy in 110 men (mean age, 72 years) who had been followed up radiologically for a mean of 14.8 years. Computed tomographic (CT) scans obtained within 2 years before death were examined for presence of pleural thickening; shape, composition, size, and subpleural location of progressive massive fibrosis (PMF); and pleural invagination (bandlike structure between lesion and pleura). Lung specimens were reviewed and compared with CT findings. Serial chest radiographs and CT scans were reviewed for presence of pleural effusion. Association between radiographic findings and pleural invagination was analyzed with chi2 and Student t tests. Multiple logistic regression analysis was used to find predictive variables for pleural invagination. RESULTS: Pleural effusion was found in 12 (11%) patients at chest radiography and CT, and thickening was found in 64 (58%) patients at CT; the latter finding was significantly more frequent with complicated silicosis (P < .001). At CT, 128 PMF lesions were seen, 39 (30%) of which showed pleural invagination; CT scans showed pleural thickening in 36 (92%) of these 39 lesions. In 17 (44%) PMF lesions, CT scans depicted a bandlike structure that was pathologically confirmed to represent invaginated pleura in all cases. Pathologic presence of invagination was significantly associated with pleural thickening (P < .001), ipsilateral pleural effusion (P < .01), interstitial fibrosis (P < .05), and the nearness of PMF to the pleura (P < .005). Multiple logistic regression analysis showed that pleural thickening (odds ratio, 62.51; 95% confidence interval [CI]: 5.564, 70.2) and pleural effusion (odds ratio, 25.865; 95% CI: 1.992, 335.8) were significant CT variables associated with presence of pathologic pleural invagination (P = .001 and .013, respectively). Five PMF lesions had radiographic features of rounded atelectasis. CONCLUSION: Various pleural abnormalities can occur in silicosis, especially in advanced disease.

Aged↗
PubMed2004

Proposed criteria for mixed-dust pneumoconiosis: definition, descriptions, and guidelines for pathologic diagnosis and clinical correlation.

We defined mixed-dust pneumoconiosis (MDP) pathologically as a pneumoconiosis showing dust macules or mixed-dust fibrotic nodules (MDF), with or without silicotic nodules (SN), in an individual with a history of exposure to mixed dust. We defined the latter arbitrarily as a mixture of crystalline silica and nonfibrous silicates. According to our definition of MDP, therefore, MDF should outnumber SN in the lung to make a pathologic diagnosis of MDP. In the absence of confirmation of exposure, mineralogic analyses can be used to support the pathologic diagnosis. The clinical diagnosis of MDP requires the exclusion of other well-defined pneumoconioses, including asbestosis, coal workers' pneumoconiosis, silicosis, hematite miners' pneumoconiosis, welders' pneumoconiosis, berylliosis, hard metal disease, silicate pneumoconiosis, diatomaceous earth pneumoconiosis, carborundum pneumoconiosis, and corundum pneumoconiosis. Typical occupations associated with the diagnosis of MDP include metal miners, quarry workers, foundry workers, pottery and ceramics workers, and stonemasons. Irregular opacities are the major radiographic findings in MDP (ILO 1980), in contrast to silicosis, in which small rounded opacities predominate. Clinical symptoms of MDP are nonspecific. MDP must be distinguished from a variety of nonoccupational interstitial pulmonary disorders.

Dust↗
PubMed2002

Adenocarcinoma with extensive neuroendocrine differentiation arising in an ileal diverticulum: report of a case.

A 62-year-old man presented with right-sided abdominal pain. Radiologic examinations disclosed a solid tumor in the ileocecal mesentery that obstructed the right ureter, thus resulting in urinary extravasation. An en bloc tumor resection with the ascending colon, the terminal ileum, and a portion of the right ureter was performed. Histopathologically, the tumor was adenocarcinoma with extensive neuroendocrine differentiation which had arisen in an ileal diverticulum. The patient developed metastases to the lymph nodes, liver, and brain, and died 18 months after surgery.

Adenocarcinoma↗
PubMedDate not supplied

Computed tomography findings of Caplan syndrome.

We report a case of Caplan syndrome complicated with tuberculosis, which was clinically followed up for 18 years and underwent autopsy. Initial chest radiograph showed 2 large nodules against the background of smaller pneumoconiotic nodules. One of the large nodules showed cavitation during follow-up. Computed tomography (CT) was helpful in identifying calcification in another large nodule. Autopsy confirmed the 2 large nodules as burned-out rheumatoid nodules and revealed additional rheumatoid nodules that were indistinguishable from silicotic nodules by CT.

Caplan Syndrome↗
PubMedDate not supplied

Total intraoperative enteroscopy using a colonoscope for detecting the bleeding point.

We report a case of bleeding in the small intestine of a 59-year-old man that was successfully diagnosed and treated by total intraoperative enteroscopy. The patient was admitted to our hospital because of gastrointestinal bleeding. Gastroscopy, colonoscopy and mesenteric arteriography could not identify the bleeding point. Technetium-99m-labeled red blood cell scintigraphy suggested bleeding from the small intestine but could not reveal the precise lesion. As the patient presented melena and went into a state of shock, we performed emergency laparotomy with total intraoperative enteroscopy using a colonoscope. A small ulceration was found at the jejunum, and subsequently partial resection of the jejunum was performed. The lesion was diagnosed histopathologically as angiodysplasia. The patient recovered uneventfully and was discharged on the 24th postoperative day. Bleeding in the small intestine is rare and difficult to diagnose but it sometimes induces a severe condition. Total intraoperative enteroscopy using a colonoscope is effective for detecting the bleeding point in the small intestine and can be performed at most centers without special fiberscopes and techniques.

Angiodysplasia↗