NaHS induces relaxation response in prostaglandin F-2 alpha precontracted bovine retinal arteries partially via K-v and K-ir channels

Hydrogen sulphide (H2S) is known to be produced endogenously in ocular tissues with the highest levels in the retina and cornea. However, it is yet unclear whether it can modulate retinal arterial tone. Herein, we aimed to investigate the effectiveness and the mechanism of the action of H2S in the isolated bovine retinal arteries. For this purpose, the probable vasorelaxant and inhibitory effects of H2S on vascular reactivity were tested comparatively in the retinal arteries by using the donor, sodium hydrosulphide (NaHS). Thereafter, in relation to the mechanism of action of H2S, the role of nitric oxide (NO) and endothelial vasodilators of cyclooxygenase pathway as well as ATP-sensitive potassium channel (K-ATP), voltage-dependent potassium channel (K-v), calcium-activated potassium channel (K-Ca(++)), inwardly rectifying potassium channel (K-ir), L-type voltage-dependent calcium channel and adenylate cyclase pathway were evaluated. NaHS (1 mu M-3 mM) displayed prominent relaxations over the concentrations of 300 mu M in both PGF(2 alpha) and K+ precontracted retinal arteries. Comparatively, in the presence of NaHS (3 mM) pretreatment, the maximum contractile responses and pEC(50) values to PGF(2 alpha) and K+ were significantly reduced as well. Neither the presence of the known inhibitors of NO synthase, guanylate cyclase, cyclooxygenase, adenylate cyclase, KA(ATP) and K-Ca(++) type K+ channels, and L-type voltage-dependent calcium channels nor the removal of endothelium, modified the relaxation response to NaHS in retinal arteries. However, a remarkable decrease was observed in the presence of the inhibitors of K-v or K-ir type K+ channels. In addition, administration of L-cysteine (1 mu M-3 mM), the precursor of H2S, induced a modest relaxation response in PGF(2 alpha) precontracted retinal arteries, which was significantly decreased in the presence of cystathionine-beta-synthase (CBS) inhibitor, aminooxyacetic acid, but was unmodified in the presence of the cystathionine-gamma-Iyase (CSE) inhibitor, DL-propargylglycine or the deendothelization of retinal arteries. Our findings suggested that H2S might play a substantial role in the regulation of retinal arterial tone possibly by acting on K-v and K-ir channels. (C) 2015 Elsevier Ltd. All rights reserved

Pattern of lung cancer in Turkey, 1994-1998

WOS: 000176736600005PubMed ID: 12097762Background: Lung cancer is the most common neoplasm in Turkey, but there is not enough data on the characteristics of this mortal illness in our country. Objectives and Methods: The Turkish Thoracic Society, Lung and Pleural Malignancies Study Group (TTS-LPMSG) conducted a national retrospective hospital-based study to determine the pattern of lung cancer in Turkey. Results: A total of 11,849 lung cancer patients were studied between 1994 and 1998, 90.4% were male and 9.6% were female. The majority of patients were smokers (77.9%) or ex-smokers (10.8%). The mean age at the time of diagnosis was 58.4 years (20-84) and 56.7% of the patients were aged between 46 and 65 years. The most common histological types were squamous cell (45.4%), small cell (SCLC; 20.5%) and adenocarcinoma (20.2%). The majority of patients with non-small-cell lung cancer were diagnosed with metastatic disease (40.4%). Of the patients with SCLC patients, 37.9% had limited stage disease and 62.7% extensive stage disease at diagnosis. Conclusion: The results of the largest data so far collected in Turkey show that the vast majority of patients with lung cancer are male, squamous cell is the most common histological type, and only a small proportion of patients are diagnosed at an early stage. Copyright (C) 2002 S. Karger AG, Basel

cell lung cancer in Turkey

Aim: The early diagnosis and treatment of lung cancer are important for the prognosis of patients with lung cancer. This study was undertaken to investigate patient and doctor delays in the diagnosis and treatment of NSCLC and the factors affecting these delays.Materials and methods: A total of 1016 patients, including 926 (91.1%) males and 90 (8.9%) females with a mean age of 61.5 +/- 10.1 years, were enrolled prospectively in this study between May 2010 and May 2011 from 17 sites in various Turkish provinces.Results: The patient delay was found to be 49.9 +/- 96.9 days, doctor delay was found to be 87.7 +/- 99.6 days, and total delay was found to be 131.3 +/- 135.2 days. The referral delay was found to be 61.6 +/- 127.2 days, diagnostic delay was found to be 20.4 +/- 44.5 days, and treatment delay was found to be 24.4 +/- 54.9 days. When the major factors responsible for these delays were examined, patient delay was found to be more frequent in workers, while referral delay was found to be more frequent in patients living in villages (p < 0.05). We determined that referral delay, doctor delay, and total delay increased as the number of doctors who were consulted by patients increased (p < 0.05). Additionally, we determined that diagnostic and treatment delays were more frequent at the early tumour stages in NSCLC patients (p < 0.05).Discussion: The extended length of patient delay underscores the necessity of educating people about lung cancer. To decrease doctor delay, education is a crucial first step. Additionally, to further reduce the diagnostic and treatment delays of chest specialists, multidisciplinary management and algorithms must be used regularly. (C) 2015 Elsevier Ltd. All rights reserved