IgG Receptors on Eosinophils: - Using Immune Scanning Electron Microscopy

Using carboxylate modified latex particles covalently conjugated with anti-IgG, IgG receptors on eosinophils were examined with scanning electron microscopy (SEM). After block and inhibition tests, significant number of latex particles were confirmed to bound on the surface of eosinophils. Earlier reports described that density of eosinophils decreased in hypereosinophilic patients and the heterogeneity of eosinophils came into focus. Our experiment revealed that eosinophils of hypereosinophilic patients had more IgG receptors than those of normal volunteers. This difference might be due to the heterogeneity of eosinophils

Advances in the Molecular Biology of Malignant Mesothelioma

Malignant mesothelioma (MM) is a highly aggressive tumor with a dismal prognosis. The incidence of MM is increasing as a result of widespread exposure to asbestos. As for the molecular alterations that occur in MM, chromosome alterations including homo-deletion of the P16 and P14 genes located in the 9p21 are well known. Mutations are rare in the P53 and Ras genes, which are frequently present in epithelial solid tumors. However, mutations are frequently present in the neurofi bromatosis type 2 gene. Epigenetic alterations including DNA methylation have been found in the MM, the profi le of which is diff erent from that of lung cancer, although differential diagnosis is sometimes clinically difficult. As in other malignant tumors, genes that are related to immortalization, proliferation, metastasis, angiogenesis, and anti-apoptosis are also overexpressed in MM, contributing to its malignant phenotype. It is of interest that simian virus 40 has been implicated to be one of the causative factors of MM in western countries. Although the causative role of asbestos is well-known in MM, much less information is available for MM than for other malignant tumors regarding the molecular alterations that occur in the disease. In terms of future tasks, it will be necessary to apply the knowledge that is learned about molecular alterations to clinical practice and to further elucidate the pathogenesis of MM with extensive research.</p

Pilot Analysis of Asbestos-induced Diffuse Pleural Thickening with Respiratory Compromise

We investigated the clinical features of asbestos-induced diffuse pleural thickening (DPT) with severe respiratory compromise. We conducted a retrospective study of consecutive subjects with asbestos-induced DPT. Medical data such as initial symptoms, radiological findings, respiratory function test results, and clinical course were collected and analyzed. There were 24 patients between 2003 and 2012. All were men, and the median age at the development of DPT was 74 years. The top occupational category associated with asbestos exposure was dockyard workers. The median duration of asbestos exposure was 35.0 years, and the median latency from first exposure to the onset of DPT was 49.0 years. There were no significant differences in respiratory function test results between the higher and lower Brinkman index groups or between unilateral and bilateral DPT. Thirteen patients had a history of benign asbestos pleural effusion (BAPE), and the median duration from pleural fluid accumulation to DPT with severe respiratory compromise was 28.4 months. DPT with severe respiratory compromise can develop after a long latency following occupational asbestos exposure and a history of BAPE

Effects of mask fitness and worker education on the prevention of occupational dust exposure

To decrease the incidence of pneumoconiosis, we examined dust protective mask performance and its relation to pulmonary function as well as the effects of worker education on the proper wearing of masks. One hundred and seventy-eight workers from 15 factories subject to dust exposure participated in this study. All participants were interviewed to obtain relevant personal information and underwent both a mask leakage and a pulmonary function test. The mask leakage was expressed as a percentage, with under 10% leakage indicating that the dust protective mask worked efficiently. In addition, 23 workers from 2 factories were educated on how to wear masks properly. The average mask leakage was 24.3%, and 58% of workers wore ineffective masks. Though pulmonary function was almost normal, the percent vital capacity (%VC) tended to be lower depending on the mask leakage. Mask education, which was very easy and took only a short time, dramatically decreased average mask leakage from 32.1% to 10.5% (p0.001). Educating workers to wear masks properly might prevent the worsening of pulmonary function in response to dust exposure. Appropriate mask fitness by education could be useful in preventing the development of pneumoconiosis.</p

Computer aided diagnosis for severity assessment of pneumoconiosis using CT images

240,000 participants have a screening for diagnosis of pneumoconiosis every year in Japan. Radiograph is used for staging of severity in pneumoconiosis worldwide. This paper presents a method for quantitative assessment of severity in pneumoconiosis using both size and frequency of lung nodules that detected by thin-section CT images. This method consists of three steps. First, thoracic organs (body, ribs, spine, trachea, bronchi, lungs, heart, and pulmonary blood vessels) are segmented. Second, lung nodules that have radius over 1.5mm are detected. These steps used functions of our developed computer aided detection system of chest CT images. Third, severity in pneumoconiosis is quantified using size and frequency of lung nodules. This method was applied to nine pneumoconiosis patients. The initial results showed that proposed method can assess severity in pneumoconiosis quantitatively. This paper demonstrates effectiveness of our method in diagnosis and prognosis of pneumoconiosis in CT screening

Studies on Rat Peritoneal Mast Cells 1. Purification of Mast Cells From Rat Peritoneal Cavity

To get a high recovery rate of mast cells from the rat peritoneal cavity, a new modified method was discussed using BSA density gradient. Three procedures, peritoneal lavage, washing of peritoneal cells and purification by BSA, were tested in this study, and the numbers of total cells and mast cells in each procedure were calculated. The recovery rate was the highest in BSA density gradient purification of the cells washed once with low speed centrifugation. The recovery rate was 73.7% and the number of mast cells taken from one rat was approximately 1.5×10(6). The purity of the cells with this procedure was 95.0% (range from 93.0 to 96.0%)

Clinical, Radiological, and Pathological Investigation of Asbestosis

By the radiological examination, differential diagnosis of asbestosis from chronic interstitial pneumonia such as IPF/UIP is difficult. The pathological features of asbestosis show the peribronchiolar fibrosis which suggest that asbestos fibers cause the inflammation of bronchioli. Therefore, the criteria for pathological diagnosis of asbestosis in 2010, contain the finding of peribronchiolar fibrosis again. Chest CT scanning including HRCT for total of 38 cases clinically diagnosed asbestosis were reviewed by 3 radiologists and one pulmonologist. On the other hand, the histology of lung tissues obtained by surgery or autopsy were examined by 4 pulmonological pathologists. Furthermore, the content of asbestos bodies in the lung was counted by phase-contrast microscopy. Thirteen cases were definitely diagnosed of asbestosis in the image including HRCT and 17 cases were diagnosed by the histopathological examination showing lung fibrosis with peribronchiolar fibrosis. Only 10 cases were indicated asbestosis by both the radiological and histopathological examinations. The mean value of asbestos bodies for these cases, was 2,133,255 per gram of dry lung tissue

The current state of workers' pneumoconiosis in relationship to dusty working environments in Okayama Prefecture, Japan.

This study involved the examination of 1,006 chest x-ray films of workers from the industries devoted to shipyard welding, stone grinding, and refractory crushing in southern Okayama prefecture. Of the reviewed films, analysis was focused on subjects with a profusion rate of 0/1 as well as pneumoconiotic subjects (exhibiting profusion rates of 1/0 or greater) in order to discover cases in the beginning stages. One-hundred-and-seventy-four films illustrated a profusion rate of 0/1 or greater, and the proportion of this profusion rate was revealed to be highest in shipyard welders. Even some workers under 40 years of age were found to have already developed pneumoconiosis. Of these 1,006 subjects, 30 volunteers permitted us to measure their personal dust exposure concentrations. The measured concentration of the shipyard welders' dust exposure (respirable dust; 3.3 86.3 mg/m3, total dust; 7.5-117.0 mg/m3) was higher than those of the other 2 industries. Statistical differences among the industries were observed in the respirable dust concentrations. A statistically significant positive correlation was demonstrated between the working duration in dusty environments and the rate of profusion. The present findings suggest the need for taking adequate measures in Okayama in order to prevent workers from developing, or to help retard the progression of, pneumoconiosis.</p

Studies on Rat Peritoneal Mast Cells 2. Effect of BSA on Ca(2+) Uptake of Mast Cells

To examine the effect of BSA on the cell surface of mast cells, the (45)Ca influx was observed in mast cells from actively sensitized rats and also in cells passively sensitized with IgE-containing serum before or after purification by BSA. The mast cells from actively sensitized rats showed a marked increase in the (45)Ca uptake with stimulation by ovalbumin. The value of (45)Ca uptake by the cells was 1495 ± 104 cpm / 10(5) cells. The uptake of (45)Ca by mast cells passively sensitized before or after separation through BSA was also increased in response to ovalbumin, although the degree of 45Ca uptake by the latter showed marked variation. These results may suggest that BSA affects mast cell surface when the cells are sensitized after separation by BSA