محمدنبی سربلوکی

Cancer is a multistep process that develops very rapidly after its onset. Previous studies have confirmed antitumor effects of curcumin (1,7-bis (4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione; diferuloylmethane) that can potentially prevent colon cancer development with low side-effects. Different methods have been performed to increase the efficiency and effectiveness of curcumin among which dendrosome, a nanoparticle created by Sarbolouki et al. was used in this study. The present study was undertaken to evaluate the effects of dendrosomal curcumin on rat colon cancer. In this study which was performed in Cancer Research Center of Tehran University of Medical Sciences in 2010 year, forty rats were equally divided into control, curcumin and curcumin-dendrosome groups. Animals received azoxymethane (15 mg/kg s.c.), a carcinogen, once a week for two weeks. Curcumin (0.2%) and curcumin-dendrosome were administered to the respective animals 2 weeks before the first and 14 weeks after the last azoxymethane injections. Eventually, colorectal specimens from tumoral and adjacent non-tumoral mucosal tissues were fixed in 10% formaldehyde, and passaged and embedded in paraffin. Histopathological and immunohistochemical studies were performed on the specimens. The mean number of lesions, nuclear/cytoplasmic ratio, epithelial stratification, loss of nuclear polarity, goblet depletion, structural abnormality and beta-catenin expression were higher in the control group compared to curcumin and curcumin-dendrosome groups. These parameters had significantly decreased in the dendrosomal curcumin group (P<0.05). The present study shows that dendrosome can be used as a suitable nanoparticle to increase curcumin efficiency in the prevention or treatment of colon cancer.

The scaffolds for bone tissue engineering should consider the functional requirements: porosity, biocompatibility, and biodegradability. In this study, porous Poly (lactic-co-glycolic acid)/Hydroxyapatite composites were prepared with different weight ratios. Porous samples were fabricated by freeze-extraction method, coated with triblock copolymer and sterilized by UV. Then, human mesenchymal stem cells were cultured on scaffolds. Microstructural studies with SEM suggest the formation of about 50 micrometer size porous structure and interconnected porosity so that cells adhesion within the structure is well in depth in coated samples. DAPI fluorescence microscopy showed cells adhesion to the coated scaffolds and cells diffusion into the pores. Also, direct assay of cell proliferation performed with MTT test showed that, cells grew on the scaffold similar to or more than control samples result. Therefore, these findings suggest that the triblock-coated Poly (lactic-coglycolic acid)/ Hydroxyapatite porous composite scaffolds could provide cells adhesion and proliferation and are appropriate matrices for bone tissue engineering.

We considered the motion of DNA molecules through a hexagonal array under uniform electric fields as a Fokker-Planck process which is affected by the entropic barriers; and we have simulated this motion by computer. We solved the Fokker-Planck equation with numerical simulation of the Brownian dynamics by the Euler method. For different DNA molecules, under different physical conditions, the mean value of velocity, variance, and < x2 > have been calculated, and the results have been compared with the Phase Diagram of our previous results. In the light of this comparison we could find the physics of the DNA behavior in different regimes. It is observed that in regime-1 (small DNA molecules under weak Electric force) we have a pure diffusion process, in regime-3 (large DNA molecules under high Electric field) the entropic barrier model is the dominated physics, and in regime-2 (medium DNA molecules under medium and relative high Electric fields), which is a more complicated regime we have a drifted diffusion phenomenon.

The global HIV epidemic continues to expand and exceeding previous predictions. An effective vaccine represents the best hope to curtail the HIV epidemic. DNA vaccines induce humoral and cellular responses and mimic live vaccines without their pathogenic potential. The importance of CD8+ CTL responses in controlling HIV and SIV viremia has led to production of a series of vaccine candidates that effectively induce these responses. It is now widely believed that an HIV vaccine strategy must stimulate both a strong humoral (antibody) as well as cell-mediated (CTL) immune response.The p24 and gp41 play many important roles in host-virus interaction and pathogenesis. These proteins are considered as attractive vaccine candidate in which their immunogenecity and immunomodulatory effects have been confirmed. In this study, a construct, pcDNA3.1Hygro- (p24-gp41), was evaluated as a DNA vaccine candidate in Balb/C mice for generation of effective cellular immune responses. For immunizing, we used dendrosome, a novel family of vehicles for transfection and therapy. IFN-γ cytokine production and total antibody were detected by ELISA. Lymphoprolifration assay was performed by MTT test. ELISA and MTT assays confirmed that the cited p24-gp41 fusion gene is able to enhance immune responses in mice. The construct that was used in this research can be a good candidate for DNA vaccine against HIV-1, if the future complementary tests demonstrate the same trends of immunogenic responses shown in this study.

Eczema is a common inflammatory skin disease. Although history and physical examination are important in diagnosis of allergen, because of extent of environmental allergens, those are not simply recognized. The objective of this study was to determine allergens in patients with contact or atopic dermatitis referred to Razi hospital.

This descriptive, cross sectional study was performed on patients with contact or atopic dermatitis in 2003-2004 with European Standard Series patch test containing 24 allergens.

In this study 223 patients were tested with a mean age of 31 years (SD=12). The most common involved location was hand (59%). The most common allergens were nickel sulphate (23/2%), cobalt (11/4%) and thiuram (8/3%).

Nickel sulphate was the most common contact allergen in this study.