Fibrotic reactions

The main target tissues incorporated in the oculomucocutaneous syndrome are skin, conjunctiva, serosal surfaces, and peritoneum, but there are reports of fibrotic reactions affecting the lungs and liver which appear to be the result of practolol therapy. Brown et al. (1978) reported two patients who developed biliary cirrhosis after long-term practolol administration. One of the patients also had an eczematous rash and complained of dry eyes, and the second had the typical psoriasiform rash. 

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Mineral dust-induced ROMs contributes to pulmonary fibrosis, malignancy, hypersensitivity and emphysema (Doelman etctl., 1990 Kamp etui., 1992). The involvement of ROMs in pulmonary fibrotic reactions is indicated by the participation of PMN oxidants in the autoactivation of latent coUagenase (Weiss et al., 1985). Prolyl hydroxylase, a key enzyme in collagen fibril formation, has been shown to be dependent on the reaction of superoxide with prolyl residues (Myllyla et al., 1979). 

A combination of phentolamine with the nonspecific smooth muscle relaxant papaverine, when injected directly into the penis, may cause erections in men with sexual dysfunction. Long-term administration may result in fibrotic reactions. Systemic absorption may lead to orthostatic hypotension priapism may require direct treatment with an -adrenoceptor agonist such as phenylephrine. Alternative therapies for erectile dysfunction include prostaglandins (see Chapter 18), sildenafil and other cGMP phosphodiesterase inhibitors (see Chapter 12), and apomorphine. 

For subcutaneous injections a large skin surface area is available for daily applications. It is recommended to change the site of injections continuously because repeated injection to the same site can cause fibrotic reactions and, in case of treatments for a period of 1 year and longer, induce subcutaneous tumors especially in small rodents. The risk of inducing local skin tumors is high if the pH value of the administration solution is below 5. 

However, it has at the same time been shown that dry powder carbon nanotubes can persist in the lungs and have the potential to induce inflammatory and fibrotic reactions, evident in the form of collagen-rich granulomas in the bronchi and inter-stitium [265], This emphasizes the need for caution and further work to establish the exact cause of these effects given the propensity of nanotubes to agglomerate. 

It is difficult to be sure how far venlafaxine contributed to this presentation, but no other cause could be established and the patient improved quickly when venlafaxine was withdrawn. Venlafaxine is a potent 5HT re-uptake inhibitor and 5HT has been implicated in fibrotic reactions in a variety of tissues. 

Adamson lY, Bowden DH. 1987a. Response of mouse lung to crocidolite asbestos. 1. Minimal fibrotic reaction to short fibres. J Pathol 152 99-107. 

Other fibrotic reactions have been reported in patients taking ergot derivatives. 

HCV has been associated with many extrahepatic manifestations [35, 36, 67], including myocarditis and cardiomyopathy [68, 69]. Histological and functional observations have led to the hypothesis that mast cells play an important role in many fibrotic reactions [70-72], Potential mast cell-derived mediators of the fibrotic response include histamine, tryptase and TGF-fl, which stimulate fibroblast proliferation and collagen synthesis [73-75]. By producing these factors, chronic activation of cardiac mast cells by protein Fv may contribute to the heart fibrosis found in some patients with HCV infection [68, 69]. 

Soon-Shiong, P., Otterlie, M., Skjak-Braek, G., Smidsrod, O., Heintz, R., Lanza, R. P, and Espevik, T. An immunologic basis for the fibrotic reaction to implanted microcapsules. Transplant. Proc. 23 (1991) 758-759. 

Fibrotic reactions The literature on dopamine agonists and fibrotic heart valve disease continues to grow. 

Intrinsic moiety 5HT2b receptors Distribution Serosae, cardiac valves Outcome Hyperplasia (fibrosis) Sequela Fibrotic reactions due to some ergot-derived dopamine receptor agonists... 

Ergot-derived dopamine receptor agonists fibrotic reactions... 

Pneumoconiotic micronodules detected using CT correspond to dust deposits with more or less fibrotic reaction at the level of respiratory bronchioles, where particle deposition is maximal (Parkes 1994). This kind of small airways lesion can exist without airflow limitation detected by classical manoeuvres (FEVi and FEVi/VC), which are more likely to reflect preacinar airway alterations. Morphological changes at the level of respiratory bronchioles can, however, be associated with abnormalities of other indices, such as inert gas washout tests when the FEVi/VC ratio is within normal range (Churg et al. 1985 Van Muylem et al. 1992). 

Majd,H., Scherer, S., Boo, S., Ramondetti, S., Cambridge, E., Raffoul, W., Friedrich, M., Pittet, B., Pioletti, D., Hinz, B., Pietramaggiori, G., 2015. Novel micropattems mechanically control fibrotic reactions at the surface of silicone implants. Biomaterials 54, 136-147. 

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