silicon and Lung-Diseases--Interstitial

Interstitial pneumonia (IP) is a collective term for diseases whose main lesion is fibrosis of the pulmonary interstitium, and the prognosis associated with acute exacerbation of these conditions is often poor. Therapeutic agents are limited to steroids, immunosuppressants, and antifibrotic drugs, which and have many side effects; therefore, the development of new therapeutic agents is required. Because oxidative stress contributes to lung fibrosis in IP, optimal antioxidants may be effective for the treatment of IP. Silicon (Si)-based agents, when administered orally, can continuously generate a large amount of antioxidant hydrogen in the intestinal tract. In this study, we investigated the effect of our Si-based agent on methotrexate-induced IP, using the IP mouse models. Pathological analysis revealed that interstitial hypertrophy was more significantly alleviated in the Si-based agent-treated group than in the untreated group (decreased by about 22%; P < 0.01). Moreover, additional morphological analysis demonstrated that infiltration of immune cells and fibrosis in the lungs were significantly inhibited by treatment with the Si-based agent. Furthermore, Si-based agent reduced oxidative stress associated with IP by increasing blood antioxidant activity. (increased by about 43%; P < 0.001). Taken together, these results suggest that Si-based agents can be effective therapeutic agents for IP.

Topics: Animals; Lung; Lung Diseases, Interstitial; Mice; Prognosis; Pulmonary Fibrosis; Silicon

Idiopathic interstitial pneumonia (IIP) is a progressive fibrosing interstitial pneumonia of unknown etiology with a poor prognosis. The aim of this study is to prove the occurrence of particle deposition and particle-induced tissue damage in IIP by examining proapoptotic Fas expression with in-air microparticle induced X-ray emission (in-air micro-PIXE) analysis. A total of 21 patients were enrolled. Lung tissues from 12 IIP patients and nontumorous lung tissues from 9 lung cancer patients (as a control) were subjected to in-air micro-PIXE analysis. The distribution of particles in lung tissue was compared with the localization of Fas expression by immunohistochemistry. Silicon (Si) was identified in 58.3% of IIP samples and 44.4% of control samples. Iron (Fe) was identified 25% in IIP samples and 11.1% in control samples. The mean lung tissue content of Si and Fe relative to S did not differ between IIP and control patients. Only two IIP patients showed the co-localization of Si and Fe deposition with Fas expression. Adaptation of this method would contribute to assess the influence of particles on IIP.

Topics: fas Receptor; Humans; Immunohistochemistry; Iron; Lung; Lung Diseases, Interstitial; Silicon; Spectrometry, X-Ray Emission

A 43-year-old man who had been engaged in the precious-metal processing industry for 18 years was admitted to our hospital because of shortness of breath on exertion. Chest roentgenograms disclosed ground glass opacities and annular-nodular shadows in the basal area of the right lung field and almost all of the left lung field. A video-assisted thoracoscopic lung biopsy was performed, and histologic examination disclosed usual interstitial pneumonia (UIP). Mineral analysis revealed high modes of silicon and aluminum, two elements consistent with the materials used in the patient's factory. The histopathological findings indicated interstitial pneumonia caused by the inhalation of dust particles. After corticosteroid therapy, computed tomographic scans disclosed that the ground glass opacities had subsided, but that honeycomb shadows remained. A chest roentgenogram taken 2 years earlier demonstrated only minute granular lesions in the basal area of right lung field. The interstitial shadows had progressed significantly over the intervening 2-year span. The findings in this case should be of value to the etiologic study of UIP.

Topics: Adult; Air Pollutants, Occupational; Aluminum; Disease Progression; Humans; Lung Diseases, Interstitial; Male; Metals; Occupational Diseases; Silicon

A 70-year-old man with a 10-year history of seal engraving presented with exertional dyspnea and dry coughing. Chest roentgenograms showed an interstitial shadow and bilateral progressively enlarging bullae. Open lung biopsy led to the diagnosis of idiopathic interstitial pneumonia (Type B). The size of bullae usually does not change, so cases such as this are rare because the bullae continued to expand subacutely. Persistent stimulation by the inhaled A1 and Si may have played a role in the pathogenesis of this condition.

Topics: Aged; Aluminum; Cysts; Humans; Lung Diseases; Lung Diseases, Interstitial; Male; Occupational Diseases; Occupational Exposure; Pneumothorax; Silicon