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Biomedical subjects

M Akira

Publications and source records attributed to M Akira.

At least 19 recordsLinked to original sources
PubMed1992

Summer-type hypersensitivity pneumonitis: comparison of high-resolution CT and plain radiographic findings.

Summer-type hypersensitivity pneumonitis is an immunologic disease that occurs only in Japan. It is a form of hypersensitivity pneumonitis in which the clinical symptoms appear in the summer and subside spontaneously in mid autumn. The purpose of our study was to determine the CT findings in this condition, to compare the CT findings with those on chest radiographs, and to assess the variations in the CT findings over time. Accordingly, high-resolution CT scans and chest radiographs of 15 patients with summer-type hypersensitivity pneumonitis were retrospectively studied. Seven patients had sequential CT examinations 18-37 days apart. The CT scans and chest radiographs were reviewed by two observers independently. CT findings included diffuse micronodules (n = 15), slightly elevated lung density (n = 13), and patchy air-space consolidation (n = 13). In one patient, the findings on a chest radiograph were normal, while CT showed parenchymal abnormalities. In two cases, follow-up CT showed micronodular abnormalities after findings on the chest radiograph had returned to normal. Our results show that high-resolution CT findings of summer-type hypersensitivity pneumonitis include pulmonary micronodules, increased lung density, and air-space consolidation. High-resolution CT appears to be more useful than plain chest radiographs in the evaluation of pulmonary parenchymal abnormalities in this condition.

Adult↗
PubMed1991

Early asbestosis: evaluation with high-resolution CT.

To determine the earliest stage at which lesions in asbestosis can be diagnosed and to assess their progression, 23 asbestos-exposed patients with minimal or no abnormalities at plain radiography were examined with high-resolution computed tomography (HRCT) twice, with an interval of 12-37 months between examinations. In 21 of the patients, parenchymal abnormalities were found. Major parenchymal features seen at CT included thickened intralobular and interlobular lines, subpleural curvilinear lines, pleural-based nodular irregularities, hazy patches of increased attenuation, small cystic spaces, and small areas of low attenuation. At paired serial CT, subpleural isolated dots or branching structures connected with the most peripheral branch of the pulmonary artery started to appear in lower subpleural zones and then became confluent to create pleural-based nodular irregularities. CT-pathologic correlation led to the conclusion that the confluence of subpleural peribronchiolar fibrosis creates subpleural fibrosis.

Adult↗
PubMed1990

Asbestosis: high-resolution CT-pathologic correlation.

High-resolution computed tomography (HRCT) was performed in seven inflated and fixed postmortem lungs from seven asbestos-exposed patients with pathologically proved asbestosis. The parenchymal abnormalities seen at in vitro HRCT included thickened intralobular lines (n = 7), thickened interlobular lines (n = 7), pleural-based opacities (n = 7), parenchymal fibrous bands (n = 5), subpleural curvilinear shadows (n = 4), ground-glass appearance (n = 4), traction bronchiectasis (n = 4), and honeycombing (n = 2). The thickened intralobular lines were shown histologically to be due to peribronchiolar fibrosis. Thickened interlobular lines were due mainly to interlobular fibrotic thickening in four lungs and edema in three. The peribronchiolar fibrosis was most severe in the subpleural lung regions, creating curvilinear line shadows and pleural-based areas of opacity. Some subpleural fibrosis extended proximally along the bronchovascular sheath to create bandlike lesions. Areas of ground-glass appearance on HRCT scans were shown to be the result of mild alveolar wall and interlobular septal thickening due to fibrosis or edema. Postmortem HRCT findings were similar to premortem HRCT findings and correlated well with the pathologic findings of asbestosis.

Aged↗
PubMed1989

Radiographic type p pneumoconiosis: high-resolution CT.

High-resolution computed tomography (CT) was performed in 90 patients with pneumoconiosis who had small rounded opacities on radiographs. The CT appearances of radiographic type p small rounded opacities in 55 patients were compared with the appearances of type q and r opacities. Radiographic type p pneumoconiosis on high-resolution CT scans was characterized by tiny binary branching structures or a gathering of a few dots. In 21 of the 55 patients, nonperipheral, small areas of low attenuation with a central dot were found. On the basis of CT-pathologic correlation in two postmortem specimens, these tiny opacities and areas of low attenuation corresponded to irregular fibrosis around and along the respiratory bronchioles and to focal-dust emphysema, respectively. Focal emphysema was most commonly found in pneumoconiosis with p-type changes and can be identified with high-resolution CT scanning. The addition of high-resolution CT to chest radiography is useful in achieving more accurate categorization of the lesions.

Humans↗
PubMed1988

Diffuse panbronchiolitis: evaluation with high-resolution CT.

High-resolution computed tomography (CT) was performed in 20 patients with diffuse panbronchiolitis. Images of abnormal peripheral lung were classified into four types: small nodules around the end of bronchovascular branchings (CT type I), small nodules in the centrilobular area connected with small branching linear opacities (CT type II), nodules accompanied by ring-shaped or small ductal opacities connected to proximal bronchovascular bundles (CT type III), large cystic opacities accompanied by dilated proximal bronchi (CT type IV). CT classifications were compared with radiographic classifications and clinical stages of the disease. The comparison revealed that the classification based on CT findings reflected the clinical stages and pathologic process of diffuse panbronchiolitis. The authors conclude that high-resolution CT is useful in the evaluation of both the location and severity of the lesions.

Adult↗
PubMed1987

Characterization of a cDNA for human protein C inhibitor. A new member of the plasma serine protease inhibitor superfamily.

A cDNA library in lambda-phage lambda gt11 containing DNA inserts prepared from human liver mRNA was screened with monoclonal antibodies to human protein C inhibitor. Six positive clones were isolated from 6 X 10(6) phages and plaque purified. The cDNA in the phage containing the largest insert, which hybridized to a DNA probe prepared on the basis of the amino-terminal amino acid sequence of the mature inhibitor, was sequenced. This cDNA insert contained 2106 base pairs coding for a 5'-noncoding region, a 19-amino acid signal peptide, a 387-amino acid mature protein, a stop codon, and a long 3'-noncoding region of 839 base pairs. Based on the amino acid sequence of the carboxyl-terminal peptide released by cleavage of protein C inhibitor by activated protein C as well as by thrombin, the reactive site peptide bond of protein C inhibitor is Arg354-Ser355. Five potential carbohydrate-binding sites were found in the mature protein. The high homology of the amino acid sequence of protein C inhibitor to the other known inhibitors clearly demonstrates that protein C inhibitor is a member of the superfamily of serine protease inhibitors including alpha 1-antichymotrypsin, alpha 1-antitrypsin, antithrombin III, ovalbumin, and angiotensinogen. Based on the difference matrices for these proteins, we present possible phylogenetic trees for these proteins.

Amino Acid Sequence↗
PubMed1986

Ultrasonography of mediastinal teratoma.

We have studied real-time sonograms of 11 surgically proven benign mediastinal teratomas. Eight cystic teratomas were sonographically visualized as various kinds of masses: four complex, two solid, and two cystic. The echo patterns of cystic teratomas were determined by the serous or nonserous nature of the cysts. In the presence of serous fluid, the tumor was visualized as a cystic mass. If, on the other hand, the cyst of the tumor was nonserous or was sebaceous, it appeared as a solid or complex tumor. The remaining three solid teratomas, which had some small cysts, appeared as complex tumors.

Adult↗
PubMed1986

Molecular cloning of the gene encoding rabbit tumor necrosis factor.

A rabbit genomic DNA library was screened using a cloned cDNA encoding rabbit tumor necrosis factor (TNF) as a probe. The entire gene sequence appears to be contained within a 3.2-kb Eco RI fragment. Comparison of the nucleotide sequence of the gene with that of the cDNA showed that the gene consists of four exons. The nucleotide sequence of the rabbit TNF gene is very homologous to that of the human TNF gene. Southern hybridization of the genomic DNAs showed that there is likely only a single TNF gene in each of the rabbit and human genomes.

Animals↗
PubMed1986

Functioning parathyroid cyst extending from neck to anterior mediastinum. Diagnosis by sonography and computed tomography.

A parathyroid cyst was evaluated by sonography and computed tomography (CT) in a patient with hyperparathyroidism. Sonography demonstrated a cystic lesion near the left lower pole of the thyroid, extending into the anterior mediastinum. On CT, the parathyroid cyst had a slightly high attenuation (30 H), with a smooth wall demonstrated after intravenous administration of contrast material. Fine-needle aspiration biopsy of the cyst showed elevated parathyroid hormone (PTH) level. The lesion probably represents cystic degeneration of an adenoma.

Aged↗
PubMedDate not supplied

CT findings in "pseudoalveolar" sarcoidosis.

To determine the specific high resolution CT (HRCT) features for "pseudoalveolar" sarcoidosis, we reviewed HRCT of 10 patients with pathologically proven sarcoidosis. On HRCT the lesions of pseudoalveolar sarcoidosis were shown as homogeneous or inhomogeneous opacities 1-4 cm in diameter located either along the bronchovascular bundles or in the lung periphery adjacent to the pleural surface. The margin was irregular, and numerous nodules 1-2 mm in diameter were observed in the surrounding lung. Air bronchograms were observed in 6 patients. In addition to these lesions, other CT abnormalities such as nodules, groundglass opacities, thickened bronchovascular bundles, and interlobular septa were found in all 10 cases. Good response of pseudoalveolar sarcoid lesions to administration of corticosteroid was observed in all three cases in which follow-up CT was available.

Adult↗