Nurbuanto Tradjutrisno, Nurbuanto
Unknown Affiliation

Published : 2 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 2 Documents
Search

Pterygium: degeneration, exuberant wound healing or benign neoplasm? Tradjutrisno, Nurbuanto
Universa Medicina Vol 28, No 3 (2009)
Publisher : Faculty of Medicine, Trisakti University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18051/UnivMed.2009.v28.179-187

Abstract

Pterygium is a condition characterized by the encroachment of a fleshy triangle of conjunctival tissue into the cornea. Despite various studies, the pathogenesis of pterygium remains unclear. Chronic exposure to sun is the only factor of which the role has been clearly documented by epidemiologic and in vitro studies. Recent studies have provided data such as loss of heterozygosity and microsatellite instability, decreased apoptosis, increased growth factors, increased p53 expression, telomerase activity, and presence of oncogenic viruses, which support the concept that pterygia can be considered a neoplastic condition. Some of results are contradictory and some features were only found in a proportion of pterygia; this may be due to differences in methodology and study population, but may also be indicative of multiple causative factors. This implies that the pterygium should be viewed as a final common outcome of various etiological factors, such as geography and ethnicity, with ultraviolet radiation-induced damage as the main factor. Thus the pterygium remains an enigma, having the features of an exuberant growth but also those of a benign neoplasm. In this connection there is a need for a unifying theory capable of explaining all of the characteristics of the pterygium.
Cancer-associated retinopathy: an autoimmune retinopathy Tradjutrisno, Nurbuanto
Universa Medicina Vol 29, No 1 (2010)
Publisher : Faculty of Medicine, Trisakti University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18051/UnivMed.2010.v29.56-64

Abstract

Cancer-associated retinopathy (CAR) is a paraneoplastic syndrome most commonly associated with small-cell carcinoma of the lung, but also less frequently reported in patients with breast, endometrial, and other cancers. A paraneoplastic syndrome (PNS) is a secondary organ dysfunction occurring in a cancer patient at a site that is anatomically remote from the tumor. PNS is not due to a direct effect of the tumor itself or its metastases but caused by other mechanisms, commonly autoimmune mechanisms develop when malignant tumors express proteins, paraneoplastic antigens (PNA), which are normally present only in neurons. One retinal antigen implicated in the autoimmune mechanism of CAR is recoverin, a 23 kDa photoreceptor-specific calcium-binding protein modulating the activity of photoreceptor guanylyl cyclase. The anti-recoverin antibodies induced by the primary tumor may on contact with intraretinal recoverin initiate a photoreceptor degeneration and trigger photoreceptor death by apoptosis, thus causing blindness. Other circulating antibodies directed against a 46 kDa protein identified as retinol enolase and a 60 kDa retinal protein have been demonstrated in patients with clinically diagnosed CAR syndrome. In certain patients no specific antibody has been identified. This suggests that the CAR syndrome includes an heterogenous group of autoimmune conditions directed against various retinal proteins.