Environmental carcinogens, such as polycyclic aromatic hydrocarbons (PAHs), require metabolic activation to DNA-reactive metabolites in order to exert their tumorigenic effects. Benzo[a]pyrene (B[a]P), a prototypic PAH, is metabolized by cytochrome P450 (P450) 1A1/1B1 and epoxide hydrolase to (-)-B[a]P-7,8-dihydro-7,8-diol (B[a]P-7,8-dihydrodiol). B[a]P-7,8-dihydrodiol then undergoes further P4...

Excessive mesangial cell (MC) proliferation is a hallmark of many glomerulopathies. In our recent study on cultured rat MC (Matousovic, K., J.P. Grande, C.C.S. Chini, E.N. Chini, and T.P. Dousa. 1995. J. Clin. Invest. 96:401-410) we found that inhibition of isozyme cyclic-3',5'-nucleotide phosphodiesterase (PDE) type III (PDE-III) suppressed MC mitogenesis by activating cAMP-dependent protein k...

یکی از انواع ترک های مشاهده شده در شرایط خستگی تماس غلتشی، ترک های زیرسطحی بیضوی هستند. بروز پدیده کوپلینگ مودهای شکست و بسته شدن سطوح ترک، این ترک ها را از سایر انواع آن متمایز می سازد. بسته شدن سطوح ترک که ناشی از اعمال تنش فشاری است، باعث می شود این ترک ها عمدتاً تحت مودهای برشی رشد نمایند. در این مطالعه، قابلیت استفاده از ماتریس تابع وزن دوبعدی ارائه شده در مراجع، برای ترک زیرسطحی بیضوی کامل...

Counterfeit phosphodiesterase-5 inhibitors (PDE-5i) are an increasing problem. Already in widespread use, the market for PDE-5i is steadily growing as the population ages. Counterfeiters are taking advantage of this growing market by developing illicit and counterfeit PDE-5i products. Many factors are contributing to the rapid growth of the illicit market, such as the low risk of prosecution, p...

OBJECTIVES With the introduction of sildenafil citrate (Viagra), the concept of phosphodiesterase (PDE) inhibition has gained tremendous interest in the field of urology. Cyclic nucleotide second messengers cGMP and cAMP have been assumed to be involved in the control of the normal function of the prostate. The aim of the present study was to evaluate by means of immunohistochemistry the expres...

سابقه و هدف: جنگل­ های زاگرس به ­عنوان یکی از بوم ­سازگان­ جنگلی مهم ایران پوشش­ گیاهی (درختان، درختچه ­ها گونه­ علفی) متنوعی برخوردار می­ باشد. شناسایی آگاهی دقیق نقش ­شناختی آنها در این ­سازگان تواند حفاظت منابع طبیعی توسعه پایدار کمک شایانی نماید. به‌منظور مطالعه تنوع گونه‌ای گیاهان چوبی ذخیره کربن خاک رابطه با عوامل فیزیوگرافیک (جهت، شیب ارتفاع سطح دریا)، رویشگاه کیکم (var. cinerascens Acer...

The amino acid sequences of all known cGMP-binding phosphodiesterases (PDEs) contain internally homologous repeats (a and b) that are 80-90 residues in length and are arranged in tandem within the putative cGMP-binding domains. In the bovine lung cGMP-binding, cGMP-specific PDE (cGB-PDE or PDE5A), these repeats span residues 228-311 (a) and 410-500 (b). An aspartic acid (residue 289 or 478) tha...

Ebstein's anomaly (EA) is a rare congenital heart disease. Paradoxical embolism (PDE) may occur in EA due to associated atrial septal defect (ASD). An 18 year old male with EA presented with left lower limb ischemia due to PDE to the limb. No features of cerebral embolism was present. PDE is a potential complication of EA. High level of awareness is needed for early diagnosis of PDE in EA to sa...