Iranian

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Background: Trichophyton tonsurans is one of the dermatophyte fungi which invades the skin and hair of human. Several properties of this fungus have been investigated so far. However a few studies were carried out in the field of molecular biology of this fungus. In the present study, we tried to identify the Squalene epoxidase gene which is related to synthesis of ergosterol in this fungus. Methods: Pairs of 23 and 24 nucleotides primers were designed from highly conserved regions of the similar genes in other fungi. Mentioned primers were utilized in PCR by using isolated genomic DNA of T. tonsurans whereas the PCR fragments were then sequenced. Results and Conclusion: Nucleotides (n = 558) have been sequenced from this new gene which encodes a polypeptide with 186 amino acids. Sequences comparison in gene data banks (NCBI, NIH) for this part of DNA and its deduced amino acid revealed significant homology with members of the eukaryotic Squalene epoxidase.

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Background: To develop a new green approach for biosynthesis of silver nanoparticles, myconanotechnology has been represented as a novel field of study in nanotechnology. In this study, we have reported the extracellular synthesis of highly stable silver nanoparticles using three species of dermatophytes: Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis. Methods: Clinical strains of these species were grown in a liquid medium containing mineral salt and incubated at 25°C for 5-7 days. The cell-free filtrate of each culture was obtained and subjected to synthesize silver nanoparticles in the presence of 1 mM AgNO3. Results: The reduction of Ag+ ions in metal nanoparticles was investigated virtually by tracing the solution color which was switched into reddish-light brown after 72 h. For T. mentagrophytes, a UV-visible spectra demonstrating a strong, quite narrow peak located between 422 and 425 nm was obtained. For M. canis, a fairly wide peak centering at 441 nm and for T. rubrum, a weak spectrum to decipher were observed. According to transmission electron microscopy (TEM) results, fairly uniform, spherical, and small in size with almost less than 50 nm particles were forms in case of T. mentagrophytes. For the other two species, TEM images showed existence of small spherical nanosilvers but not as small as nanoparticles synthesized by T. mentagrophytes. Conclusion: We observed that species belong to a single genus of the fungi have variable ability to synthesize silver nanoparticles extracellulary with different efficiency. Furthermore, the extracellular synthesis may make the process simpler and easier for following processes.

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Background: The most important virulence factor which plays a central role in Candida albicans pathogenesis is the ability of this yeast to alternate between unicellular yeast and filamentous hyphal forms. Efg1 protein is thought to be the main positive regulating transcription factor, which is responsible for regulating hyphal-specific gene expression under most conditions. ALS3 is one of the Efg1-associated genes encoding a multi-functional adhesive polypeptide, which mediates adherence to diverse host substrates. In this study, the EFG1 gene was knocked down by using synthetic siRNA in C. albicans and the regulation in ALS3 as one of the Efg1-dependent genes was investigated. Method: The 19-nucleotide siRNA was designed based on cDNA sequence of EFG1 gene in C. albicans. Transfection was performed using modified- plyethylen glycol/LiAc method. To quantify the level of EFG1 and the hyphal-specific ALS3 gene expression, the cognate EFG1 and ALS3 mRNA were measured in C. albicans by quantitative real-time RT-PCR. Results: Fluorescent microscopy pictures indicated that transfection was performed successfully. Also, according to relative expression software tool, expression of EFG1 gene was decreased significantly with 500 nM siRNA as well as 1 µM siRNA (P<0.05). However, more significant down-regulations were observed in the expression of ALS3 in both concentrations of 500 nM and 1 µM siRNA (P<0.05). Conclusion: In conclusion, we demonstrated the down-regulation of ALS3 gene as a consequent of applying EFG1-specific siRNA in C. albicans. This may lead us to design anti-fungal-specific agents in order to face with C. albicans-associated infections.

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Background: Introduction of the RNA interference (RNAi) machinery has guided the researchers to discover the function of essential vital or virulence factor genes in the microorganisms such as fungi. In the filamentous fungus Aspergillus nidulans, the gene sidB plays an essential role in septation, conidiation and vegetative hyphal growth. In the present study, we benefited from the RNAi strategy for down-regulating a vital gene, sidB, in the fungus A. nidulans. Methods: The 21-nucleotide small interfering RNA (siRNA) was designed based on the cDNA sequence of the sidB gene in A. nidulans. Transfection was performed through taking up siRNA from medium by 6 hour-germinated spores. To evaluate the morphologic effects of siRNA on the fungus, germ tube elongation was followed. Moreover, total RNA was extracted and quantitative changes in expression of the sidB gene were analyzed by measuring the cognate sidB mRNA level by use of a quantitative real-time RT-PCR assay. Results: Compared to untreated-siRNA samples, a significant inhibition in germ tube elongation was observed in the presence of 25 nM of siRNA (42 VS 21 µM). In addition, at the concentration of 25 nM, a considerable decrease in sidB gene expression was revealed. Conclusion: Usage of RNAi as a kind of post-transcriptional gene silencing methods is a promising approach for designing new antifungal agents and discovering new drug delivery systems.

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Background: Candida parapsilosis is one of the five common strains of yeasts involved in invasive candidiasis. The expression analysis of sterol biosynthesis pathway genes, which are associated with resistance, can assist the better understanding of antifungal resistance mechanisms. Methods: The antifungal susceptibility of 120 clinical C. parapsilosis isolates was examined. The changes in the gene expression related to resistance were analyzed. Results: Eight strains were resistant to fluconazole (FLC), itraconazole (ITC), and amphotericin B (AMB). The regulation variations included increased mRNA levels of ERG3, ERG6, and ERG11 and decreased mRNA levels of ERG3 and ERG6 in response to FLC. ERG11 mRNA level increases in response to ITC and AMB. Conclusion: The mechanism of resistance to azoles in C. parapsilosis is very similar to C. Albicans. This feature may help to design new treatment strategy for candidiasis.

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Background: Typically, non-cellulytic glucanase, including fungi and yeast cell wall hydrolyzing enzymes, are released by some symbiotic fungi and plants during the mycoparasitic fungi attack on plants. These enzymes are known as the defense mechanisms of plants. This study intends to investigate the biochemical properties of β-1,6-glucanase (bg16M) from native thermophilic bacteria, Cohnella A01. Methods: bg16M gene was cloned and expressed in E. coli BL21 (DE3). The enzyme was purified utilizing Ni-NTA nikcle sepharose column. Pustulan and laminarin were selected as substrates in enzyme assay. The purified bg16M enzyme was treated with different pH, temperature, metal ions, and detergents. Results: The expressed protein, including 639 amino acids, showed a high similarity with the hydrolytic glycosylated family 30. The molecular weight of enzyme was 64 kDa, and purification yield was 46%. The bg16M demonstrated activity as 4.83 U/ml on laminarin and 2.88 U/ml on pustulan. The optimum pH and temperature of the enzyme were 8 and 50 °C, respectively. The enzyme had an appropriate stability at high temperatures and in the pH range of 7 to 9, showing acceptable stability, while it did not lose enzymatic activity completely at acidic or basic pH. None of the studied metal ions and chemical compounds was the activator of bg16M, and urea, SDS, and copper acted as enzyme inhibitors. Conclusion: Biochemical characterization of this enzyme revealed that bg16M can be applied in beverage industries and medical sectors because of its high activity, as well as thermal and alkaline stability.

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Background: Mesenchymal stem cells (MSCs) can be used to treat premature ovarian failure (POF). Different methods have already been applied to detect MSCs in tissues. This study aimed to investigate the quantitative distribution of CM-DiI-labeled human umbilical cord vein MSCs (hUCV-MSCs) in different regions of the ovarian tissue of the cyclophosphamide ( CTX )-induced POF in mice. Methods: Adult female C57BL/6 mice (n = 40) were divided into four groups: (1) Mice receiving PBS as control (Ctrl) group; (2) mice receiving hUCV-MSCs intravenously as Ctrl + hUCV-MSCs group; (3) mice receiving CTX intraperitoneally (i.p.) as CTX group; (4) mice receiving CM-DiI-labeled hUCV-MSCs after CTX injection as CTX + hUCV-MSCs group. Histological changes and CM-DiI-labeled hUCV-MSCs distribution were analyzed in the ovarian tissues. Quantitative real-time PCR was performed to detect human mitochondrial cytochrome b (MTCYB) gene in the ovarian tissues of the mice. Results: The mean number of the fluorescent hUCV-MSCs was 20 ± 2.5 (57.1%) in the medulla, 11.3 ± 2.8 (32.2%) in the cortex, and 5.5 ± 1 (15%) in the germinal epithelium of the ovarian tissue (p < 0.05). Moreover, MTCYB gene was detected in the mice ovaries of the CTX + hUCV-MSCs group, but not in other groups. Conclusion: Our findings suggest that the distribution of the transplanted hUCV-MSCs in different regions of the ovarian tissue is not equal, and it is greater in the medulla than the cortex and germinal epithelium. This is the first report of quantitative distribution of MSCs in different regions of ovarian tissue in the POF model.

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Crohn's disease (CD) is an inflammatory disease of the gastrointestinal tract (GIT) and can affect several parts of the digestive system. There is a relationship between impaired mucosal barrier in the GIT of inflammatory bowel disease patients and the role of bacteria such as Mycobacterium avium in CD. Apart from different therapeutic approaches for treating CD, development of a vaccine is a novel modality. In the present article, most available therapeutic opportunities in the last decade, especially the possibility of vaccines against CD, are reviewed. According to the search, availability of a new generation of vaccines against CD is expected specially tolerogenic ex vivo-derived DC-based vaccines. Regarding different locations of the challenge and the variety of clinical manifests of CD and also the type of resident antigen-presenting cells and their traffic in different parts of GIT, the results of immunotherapy with DC-based vaccines may vary case by case. 

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Background: Numerous studies confirmed that significant decrease in tissue decorin (DCN) expression is associated to tumor progression and metastasis in certain types of cancer including prostate cancer (PC). However, the potential prognostic value of tissue DCN in PC has not yet been investigated. Methods: A total number of 40 PC and 42 patients with benign prostatic hyperplasia (BPH) were investigated for the expression levels of DCN in their prostatic tissues using real-time quantitative polymerase chain reaction and immunohistochemical analyses. Urinary and plasma DCN levels were also measured by ELISA. Results: Despite no significant changes in the mean of urine and plasma DCN concentrations between the two study groups, tissue DCN mRNA was found to be 5.5fold lower in cancer than BPH (p = 0.0001). Similarly, the stained DCN levels appeared significantly lower in cancer patients with higher Gleason Scores (8 and 9, n = 6) than those with lower Gleason Scores (6 and 7, n = 26), with a p value of 0.049. Conclusion: Here, we report, for the first time, that urine and plasma DCN does not seem to have a diagnostic value in PC, while tissue DCN could potentially be used as a prognostic marker in PC.