Parenchymal fibrosis

Aberle DR, Gamsu G, Ray CS, et al. 1988a. Asbestos-related pleural and parenchymal fibrosis Detection with high-resolution CT. Radiology 166 729-734. 

Asbestos-related pleural abnormalities have been commonly associated with asbestos-related lung parenchyma lesions, but the American Thoracic Society (1986) noted that they should be diagnosed separately because there are difierences between pleural and parenchymal fibrosis in epidemiology, clinical features, and prognosis. Asbestos-related pleural plaques have been described as fibrohyaline nodular lesions, most often on the parietal pleura, but also on the diaphragmatic pleura and less frequently on the pericardium (Mossman and Gee 1989). 

Asbestosis must be defined as pulmonary parenchymal fibrosis resulting from inhalation of considerable amounts of, and usually after prolonged ex-... 

Terminology As shown in Table 2.1.6, asbestos induces several different types of benign lesions of the pleura some authors have referred to the benign pleural lesions as pleural asbestosis, an incorrect and confusing usage, since asbestosis by definition refers only to asbestos-induced parenchymal fibrosis. 

Chest radiographs are limited with respect to sensitivity and specificity in the detection of mild or early asbestosis (Fig. 3.1.4.). Among individuals with asbestosis confirmed by histopathological findings, 15-20% had no radiographic evidence of parenchymal fibrosis (Kipen et al. 1987), similar to the proportion of other interstitial lung diseases that present with normal chest films (Epler et al. 1978). More recent studies have shown that between 5% (Paris et al. 2004) and 30% (Lee et al. 2003) of subjects with documented asbestos exposure and pulmonary... 

Hillerdal G (1990) Pleural and parenchymal fibrosis mainly affecting the upper lobes in persons exposed to asbestos. Respir Med 84 129-134... 

Figure 4.2. Diagram outlining the pathogenesis of liver fibrosis. Injury to parenchymal cells (PC) results in the activation of Kupffer cells (KC) and sinusoidal endothelial cells (SEC) and the recruitment of inflammatory cells (IC). These cells release cytokines, growth factors and reactive oxygen species that induce activation and proliferation of hepatic stellate cells (HSC). HSCs gradually transform into myofibroblasts (MF), the major producers of extracellular matrix (ECM) proteins.

Late adverse effects include hepatic dysfunction, with altered liver function tests and hyperbilirubinemia. After prolonged use of nicotinic acid and nicotinyl alcohol, histological changes, for example parenchymal cell injury, portal fibrosis, cholangitis, cholestasis, biliary casts, and lymphocytic infiltrations around the bile ducts, have occasionally been seen. 

Gn pig (NS) 35 wk 2 or 4x/wk (GO) Hepatic 0.75 (moderate to marked fibrosis, parenchymal fatty metamorphosis, slight bile duct proliferation, hypertrophy, atrophy) Ashburn et al. 1948... 

Lilis R, Miller A, Godbold J, et al. 1991. Radiographic abnormalities in asbestos insulators Effects of duration from onset of exposure and smoking. Relationships of dyspnea with parenchymal and pleural fibrosis. Am J Ind Med 20 1-15. 

Oksa P, Koskinen H, Rinne JP, et al. 1992. Parenchymal and pleural fibrosis in constmction workers. 

Parenchyma The functional cells or tissue of a gland or organ for example, the lung parenchyma. The major lung parenchymal abnormality associated with exposure to asbestos is the development of scar-like tissue referred to as pulmonary interstitial fibrosis or asbestosis. 

Pulmonary interstitial fibrosis Scar-like tissue that develops in the lung parenchymal tissue in response to inhalation of dusts of certain types of substances such as asbestos. 

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