Veysel Tahan

Prof. Dr. Veysel Tahan

Gastroenterology and Hepatology, Northeast Ohio Medical University, Ravenna, Ohio, USA
+1
orcid

Research Focus & Metrics

Academic Career Length

28Years (1999-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 October 2011 in Canadian Journal Of Surgery
Verified
Journal Article
Closed access
GTGulgun Tahan
Gulgun Tahan
EAErman Aytac
Erman Aytac
HAHuseyin Aytekin
Huseyin Aytekin
FGFeyza Gunduz
Feyza Gunduz
GDGulen Dogusoy
Gulen Dogusoy
HUHafize Uzun
Hafize Uzun
Increased free radical production, decreased antioxidant capacity and excessive inflammation are well-known features in the pathogenesis of inflammatory bowel disease. Vitamin E is a powerful antioxidant and a scavenger of hydroxyl radicals, and it has been shown to have anti-inflammatory activities in tissues. We investigated the effects of vitamin E on inflammatory activities using an acetic acid (AA)-induced ulcerative colitis model in rats. Wistar rats were divided into 4 groups. Acetic acid was given to 2 groups of animals to induce colitis while the other 2 groups received saline intrarectally. One AA-induced colitis group and 1 control group received vitamin E (30 U/kg/d) intraperitoneally and the pair groups received saline. After 4 days, we evaluated colonic changes biochemically by measuring proinflammatory cytokine levels in tissue homogenates and by histopathologic examination. Acetic acid caused colonic mucosal injury, whereas vitamin E administration suppressed these changes in the AA-induced colitis group (p < 0.001). Administration of AA resulted in increased levels of tumour necrosis factor-α, interleukin-1β, interleukin-6, myeloperoxidase and malondialdehyde, and decreased levels of glutathione and superoxide dismutase; vitamin E reversed these effects (all p < 0.001). Our study proposes that vitamin E is an effective anti-inflammatory and antioxidant and may be a promising therapeutic option for ulcerative colitis.

3 March 2011 in Hepatology
Verified
Journal Article
Open access
PDF file
FMFabio Marongiu
Fabio Marongiu
Roberto GramignoliRoberto Gramignoli
Roberto Gramignoli
KDKenneth Dorko
Kenneth Dorko
TMToshio Miki
Toshio Miki
ARAarati R. Ranade
Aarati R. Ranade
SSStephen C. Strom
Stephen C. Strom
Hepatocyte transplantation to treat liver disease is largely limited by the availability of useful cells. Human amniotic epithelial cells (hAECs) from term placenta express surface markers and gene characteristics of embryonic stem cells and have the ability to differentiate into all three germ layers, including tissues of endodermal origin (i.e., liver). Thus, hAECs could provide a source of stem cell–derived hepatocytes for transplantation. We investigated the differentiation of hAECs in vitro and after transplantation into the livers of severe combined immunodeficient (SCID)/beige mice. Moreover, we tested the ability of rat amniotic epithelial cells (rAECs) to replicate and differentiate upon transplantation into a syngenic model of liver repopulation. In vitro results indicate that the presence of extracellular matrix proteins together with a mixture of growth factors, cytokines, and hormones are required for differentiation of hAECs into hepatocyte-like cells. Differentiated hAECs expressed hepatocyte markers at levels comparable to those of fetal hepatocytes. They were able to metabolize ammonia, testosterone, and 17α-hydroxyprogesterone caproate, and expressed inducible fetal cytochromes. After transplantation into the liver of retrorsine (RS)-treated SCID/beige mice, naïve hAECs differentiated into hepatocyte-like cells that expressed mature liver genes such as cytochromes, plasma proteins, transporters, and other hepatic enzymes at levels equal to adult liver tissue. When transplanted in a syngenic animal pretreated with RS, rAECs were able to engraft and generate a progeny of cells with morphology and protein expression typical of mature hepatocytes. Conclusion: Amniotic epithelial cells possess the ability to differentiate into cells with characteristics of functional hepatocytes both in vitro and in vivo , thus representing a useful and noncontroversial source of cells for transplantation. (Hepatology 2011;)

1 December 2019 in Current Opinion in Pharmacology
Verified
Journal Article
Closed access
FDFrancis E Dailey
Francis E Dailey
ETErica P Turse
Erica P Turse
Ebubekir DaglilarEbubekir Daglilar
Ebubekir Daglilar
Veysel TahanVeysel Tahan
Veysel Tahan

1 May 2017 in Journal of Hepatology
Verified
Journal Article
Closed access
KSKyle A. Soltys
Kyle A. Soltys
KSKentaro Setoyama
Kentaro Setoyama
ETEdgar N. Tafaleng
Edgar N. Tafaleng
AGAlejandro Soto Gutiérrez
Alejandro Soto Gutiérrez
JFJason Fong
Jason Fong
IFIra J. Fox
Ira J. Fox

13 October 2007 in Digestive Diseases and Sciences
Verified
Journal Article
Closed access
PDF file
SUSuleyman Uraz
Suleyman Uraz
Veysel TahanVeysel Tahan
Veysel Tahan
CACem Aygun
Cem Aygun
FEFatih Eren
Fatih Eren
GUGoksenin Unluguzel
Goksenin Unluguzel
NTNurdan Tozun
Nurdan Tozun

1 April 2005 in American Journal of Gastroenterology
Verified
Journal Article
Closed access
Veysel TahanVeysel Tahan
Veysel Tahan
CKCetin Karaca
Cetin Karaca
BYBeytullah Yildirim
Beytullah Yildirim
ABAysun Bozbas
Aysun Bozbas
ROResat Ozaras
Resat Ozaras
NTNurdan Tozun
Nurdan Tozun
The sexual transmission of hepatitis C virus (HCV) is debated. By excluding other risk factors, the role of sexual intercourse in the transmission could be detected more accurately. We screened HCV prevalence and risk factors in the spouses of chronic hepatitis C (CHC) patients and followed the seroconversion rate of anti-HCV negative spouses. Six hundred spouses of CHC patients were recruited. The spouses' HCV risk factors were questioned and the spouses were tested for anti-HCV. The 216 spouses who were anti-HCV negative were checked annually for anti-HCV. Anti-HCV was positive in 12 of 600 (2%) of the spouses. Of the 12 anti-HCV positive spouses, 11 were HCV-RNA positive. Of anti-HCV positive and negative spouse groups, mean age was 52.3 +/- 9.8 and 49.8 +/- 12.4 yr; duration of marriage was 1521 +/- 506.7 and 1532.4 +/- 670.2 wk (p > 0.05); and the number of total sexual intercourse was 434 +/- 295 and 307 +/- 333 (p= 0.055), respectively. In our prospective study, none of the spouses developed anti-HCV seroconversion in mean 35.7 +/- 6.3 months and 257.9 +/- 72.2 sexual intercourse. Anti-HCV was found positive in 2% of the spouses. None of the seronegative spouses developed seroconversion in the 3-yr follow-up period. This is the first study that stresses the importance of the total number of sexual intercourse in sexual transmission (p= 0.055). Our results of special monogamous group with very limited risk factors support the role of number of total sexual intercourse in HCV transmission. However, the seroprevalence rate of the spouses was still within the upper limit of our country population.