Biomedical subjects

Takeshi Oyaizu

Publications and source records attributed to Takeshi Oyaizu.

4 recordsLinked to original sources

PubMed2004

Anti-allergic agent tranilast decreases development of obliterative airway disease in rat model of heterotopic tracheal transplantation.

BACKGROUND: Tranilast is an anti-allergic agent known to inhibit the release of histamine, interleukin-1beta, transforming growth factor beta1, and platelet-derived growth factor from various cells and currently is used to treat allergic diseases, keloids, and hypertrophic scars. We evaluated the ability of tranilast to inhibit the development of obliterative airway disease (OAD) in a rat model of heterotopic tracheal transplantation. METHODS: We transplanted tracheal segments from donor rats (Brown Norway) into subcutaneous pouches in major histocompatibility complex-incompatible recipient rats (Lewis). At Days 21 and 28 after transplantation, we histologically assessed the harvested allografts scored the degree of OAD, on a scale from zero to 4 as previously described, caused by fibroproliferative tissue. RESULTS: Recipient animals treated orally with 400 mg/kg/day tranilast throughout the experiment showed significantly decreased OAD compared with control animals, with a histologic score of 1.1 +/- 0.4 vs 3.0 +/- 1.3, respectively (mean +/- SD, p=0.007), at Day 21 after transplantation and 2.0 +/- 1.4 vs 3.9 +/- 0.4, respectively (mean +/- SD, p=0.017), at Day 28 after transplantation. CONCLUSION: These results showed that treatment with tranilast significantly decreased fibroproliferative airway changes associated with allograft rejection in a rat model of tracheal transplantation, suggesting that tranilast may be useful in preventing bronchiolitis obliterans after lung transplantation.

Administration, Oral↗

PubMed2003

Reduction of recipient macrophages by gadolinium chloride prevents development of obliterative airway disease in a rat model of heterotopic tracheal transplantation.

BACKGROUND: Recent studies have shown the possible role of growth factors and the involvement of macrophages as a source of them in the pathogenesis of bronchiolitis obliterans (BO) after lung transplantation. OBJECTIVE: The authors intended to determine whether depletion of recipient macrophages by gadolinium chloride (GdCl3) resulted in decreased obliterative airway disease (OAD) in a rat model of heterotopic tracheal transplantation. METHODS: A tracheal segment of donor rats (Brown Norway) was transplanted into a subcutaneous pouch of fully major histocompatibility complex-incompatible recipient rats (Lewis). Recipients were injected intravenously with 80 mg/kg of GdCl3.6H2O or saline on days 0, 7, and 14 posttransplant. Allografts were harvested on days 7, 14, 17, and 21 and the degree of OAD resulting from fibroproliferative tissue was pathologically scored on a scale of 0 to 4. A portion of allografts was submitted to reverse-transcriptase polymerase chain reaction analysis to examine mRNA expression for platelet-derived growth factor (PDGF), basic fibroblast growth factor, and transforming growth factor-beta1. RESULTS: Immunohistochemical studies confirmed reduction in the number of ED2+ macrophages in tracheal allografts by GdCl3 injection. GdCl3 treatment significantly decreased OAD of allografts, with the histologic score of 1.4+/-0.3 in the treated animals compared with 3.0+/-0.5 in the controls (mean+/-SE, P=0.02) at day 21 posttransplant, and this was accompanied by decreased PDGF-A and PDGF-B gene expression in the GdCl3 group at day 17 posttransplant. CONCLUSIONS: Macrophage reduction by GdCl3 resulted in significantly decreased OAD development and reduced PDGF mRNA expression in allografts. This suggests a potential effectiveness of therapies targeting recipient macrophages in preventing BO after lung transplantation.

Animals↗

PubMed2003

A prospective evaluation of transbronchial ultrasonography for assessment of depth of invasion in early bronchogenic squamous cell carcinoma.

In order to determine the appropriate treatment modality for roentgenographically occult bronchogenic squamous cell carcinoma (ROSCC), it is essential to evaluate the depth of invasion, because ROSCC invading beyond the cartilaginous layer cannot be effectively treated by photodynamic therapy (PDT) due to spread of disease. Transtracheal endoscopic ultrasonography (TUS) was useful for predicting the depth of invasion in some ROSCCs. In order to assess the actual significance of TUS as a diagnostic tool for predicting the depth of carcinoma invasion, we have conducted a prospective trial with 22 lesions of ROSCCs. We ultrasonographically classified the degree of the depth of invasion into two groups; A: "invasion does not reach cartilaginous layer" and B: "invasion involves cartilaginous layer". Then the patients were treated by irradiation, PDT, or surgical resection. Pathological findings were also classified into A or B. In order to calculate the sensitivity for evaluating the depth of invasion by TUS, the cases without any tumor and/or malignant cells after PDT were regarded as pathological A. In the evaluation of the depth of carcinoma invasion staying inside the cartilaginous layer, the sensitivity and the positive predictive value were 85.7%, the specificity was 66.7%, and the accuracy was 80.0%. With TUS, preoperative evaluation of the depth of invasion would be more accurate, and the decision of treatment modality would be more appropriate, compared with the conventional bronchoscopic observation alone.

Aged↗

PubMed2002

Computed tomographic image comparison between mediastinal and lung windows provides possible prognostic information in patients with small peripheral lung adenocarcinoma.

OBJECTIVES: The purpose of this study was to determine whether the ratio of the area of the mediastinal computed tomographic image to that of the lung computed tomographic image can be a prognostic factor of small peripheral lung adenocarcinoma. METHODS: We studied the computed tomographic images of 143 patients with primary peripheral lung adenocarcinoma of 30 mm or less in maximum diameter. Two groups were categorized according to the tumor's ratio of the area of the mediastinal computed tomographic image to that of the lung computed tomographic image (tumor's area in the mediastinal computed tomographic image/tumor's area in lung computed tomographic image x 100%), both faint density-type (<50%) and solid-type images (>/=50%). Clinical factors and prognoses of the 2 groups were analyzed. RESULTS: There were 58 patients with the solid-type tumor image and 85 patients with the faint density-type tumor image. The number of patients with tumor size of less than 20 mm in the faint density-type tumor group (n = 30) was significantly higher than that in the solid-type tumor group (n = 8, P =.008). The 5-year survival of patients with faint density-type tumors was 74.1%, whereas that in patients with solid-type tumors was 54.2% (P =.013). Furthermore, the survival curve of patients with the solid-type computed tomographic image combined with ground-glass opacity was similar to that of patients with the faint density-type image. Multivariate analysis revealed the prognostic influence of the ratio of the area of the mediastinal computed tomographic image to that of the lung computed tomographic image on survival (P =.029, relative risk = 0.48) and showed to be of second highest influence after the N factor. CONCLUSIONS: It is suggested that the ratio of the area of the mediastinal computed tomographic image to that of the lung computed tomographic image can be a prognostic factor in patients with small peripheral lung adenocarcinoma.

Adenocarcinoma↗