Dear Editor, Cyclic guanosine 3’, 5’ monophosphate (cGMP), as a second messenger, plays a key role in cell proliferation, differentiation, and apoptosis. It is formed by guanylyl cyclase (GC) from its precursor, guanosine triphosphate (GTP) (1). GC enzymes can be found in 2 major forms: soluble or cytosol form (sGC) and particulate or transmembrane form (pGC) (1).

Image restoration is an essential preprocessing step for many image analysis applications. In any image restoration techniques, keeping structure of the image unchanged is very important. Such structure in an image often corresponds to the region discontinuities and edges. The techniques based on partial differential equations, such as the heat equations, are receiving considerable attention in image restoration. In this paper, a new algorithm is proposed for image restoration using partial differential equations applied on neighbors longer than one pixel. To better preserve edges in this technique, slant edges are considered in addition to vertical and horizontal edges. A number of experiments have been preformed to evaluate performance of the proposed method and to compare its performance with the existing algorithms, wiener and median filters. The results express the considerable superiority of the proposed methods.

Objective(s): Recently, we showed that some new synthetic compounds structurally related to cilostamide (4-(1, 2-dihydro-2-oxoquinolin-6-hydroxy)-N-cyclohexyl-N-methylbutanamide), a selective phosphodiesterase 3 (PDE3) inhibitor, produce inotropic effect comparable to that of IBMX (3-isobutyl-1-methylxanthine), a non-selective PDE inhibitor, but with differential chronotropic effect. In this investigation, we compared the pharmacological effects of these compounds as potential cardiotonic agents using the spontaneously beating atria model. Materials and Methods: In each experiment, rats were treated with reserpine. The atrium was isolated and mounted in an organ bath. We assessed chronotropic and inotropic effects using cumulative log concentration-response curves of isoprenaline alone or in combination of each test-compound. Results: Majority of test compounds augment atria contraction force (ACF) significantly but with different potencies on atrium contraction rate. Cilostamide, MCPIP ([4-(4-methyl piperazin-1-yl)-4-oxobutoxy)-4-methylquinolin-2(1H)-one]), methyl carbostyril compounds-(mc1), mc2 and mc5 increased the isoprenaline effect on ACF synergistically. But, mc6 failed to potentiate the effect of isoprenalin; mc3 and mc4 did not increase ACF, which may be because of their higher hydrophilic nature. It was interesting that mc2, alone or in combination with isoprenaline, produced the highest inotropic effect while it did not affect the basal contraction rate and almost blocked the isoprenaline chronotropic effect. Conclusion: Combination of mc2 with isoprenaline had synergistic effect on inotropic effect, but this combination reduced isoprenaline chronotropic effect; therefore, these effects cannot be related to reducing B-adrenergic receptors activity. These compounds showed different effects; probably all of them were not mediated via PDE3 inhibition and other mechanisms are involving.