Preparation of decellularized three dimentional scaffolds as the model for tissue engineering and their functional assessments in vitro application of blastema tissue

Tissue engineering is based on three main factors including scaffolds, cells and growth factors. Natural scaffolds derived from decellularized tissues and organs have been successfully used in tissue engineering. Decellularization studies have shown that natural scaffolds which maintain their main structure and properties could be a suitable tool for studying cellular behaviors and preparation of such scaffolds is an important part of future research in biology that may have extensive applications in regenerative medicine and tissue engineering. Blastema tissue which is produced after injuries in some organisms has embryonic cell characteristics, and can be a suitable model for evaluation of cell behaviors in various tissues. In this review, the process of decellularization, process involved in preparation of 3D scaffolds derived from extracellular matrix of various tissues including cartilage, bone, gingiva, aorta and bladder, and assessment of their interactions with blastema tissue under in vitro conditions are discussed

[Cloning, gene expression analysis, and phylogenic relationship of dbat gene from Iranian endemic yew [Taxus baccata L.]]

Taxol is one of the most important anticancer agents that its supply mainly depends on biological processes. 10 - deacetyl baccatin III- 0- acetyl transferase [dbat] gene is one of the key genes in Taxol biosynthetic pathway and it is expected that overexpression of this gene would result in an increased production of taxol in biological systems. Investigation of dbat gene characteristics from Iranian endemic yew, Gene expression analysis and Construction of overexpression vector for this gene. First, sequence of the gene was cloned and then, sequence characteristics identified with Bioinformatics analysis. Gene expression analysis was performed under methyl jasmonate elicitation in several time-courses. Finally in order to construct overexpression vector, the sequence was cloned under the control of the CaMV35S promoter in to pCAMBIAI304. Comparison of sequence similarities indicated that this sequence is most similar to Taxus x hunnewelliana. There was one unique amino acid substitution and investigating substituted amino acid revealed that, this replacement can not change overall characteristics of the enzyme and thus it would result in a functional enzyme. Analysis of gene expression showed that in response to methyl jasmonate, gene expression levels increased to maximum rate up to 24 times at 12 hours after elicitation. Finally gene insertion in suitable site of overexpression vector, confirmed by digest with restriction enzymes. Elicitation of shoot cuttings of Taxus would be a suitable alternative for Taxiis cell cultures in gene expression analysis. Simplicity, feasibility, and deletion of time-consuming processes of cell culture are its main advantages

Exposure of sweepers to volatile organic compounds using urinary biological exposure index

Evaluation of exposition to Volatile Organic Compounds [VOC] and compare urinary level of urinary biological exposure index in sweepers in West of Iran. This study was carried out on 40 street sweepers and 40 non-exposed as control group living in Hamadan City, west of Iran. VOC was analyzed using gas chromatography equipped with a Flame Ionization Detector [FID]. The urinary biological exposure index [BEI] was analyzed with High performance Liquid Chromatography [HPLC] equipped with an ultraviolet [UV] detector. The concentration of benzene toluene, m and p-xylene o-xylene and ethyl benzene was 39.01, 121.60, 27.12, 12.30, and 10.21 [micro g/m[3]], respectively. No-difference in the levels of hippuric acid in urine was found in sweepers compared with the control group. Significance differences in the level of o-cresol in urine were found in sweepers compared to control group [P< 0.005]. The poor correlation coefficient was seen between xylenes concentration and urinary MHA for drivers. High VOC are emitted inside of cities at Iran. O-cresol could separate the exposed to toluene from the non-exposed in sweepers. Hippuric acid, methyl hippuric acid and muconic acid arenot suitable biomarkers for occupations such as sweepers exposure to VOC in low concentration

Evaluation of benzene exposure in adults and urinary s-phenylmercapturic acid in children living in Adelaide, South Australia

Benzene Exposure was evaluated in adults and children living in Adelaide, South Australia by measuring benzene and urinary s-phenylmercapturic acid [SPMA]. To determine of benzene exposure in each subject the personal passive samplers was used and samples were analyzed by gas chromatography system equipped to flame ionization detector. The level of SPMA was determined by competitive enzymelinked immunosorbent assay [ELISA] in children. The mean concentration of benzene in Summer and Winter were 1.62 +/- 1.43 and 1.36 +/- 0.87 ppb respectively. There was a significant difference between exposure to benzene for subjects with less and more than 6 hours activity over days of week [p<0.05]. The mean urinary concentrations levels of SPMA adjusted to creatinene for children that living less and more than 200 meters mol/mol creatinene, respectively and distance from main road were 1.56 and 4.67 the significant difference was seen in two groups [p<0.005]. Data shows, that SPMA can be utilized as a biomarker for exposure to benzene in children. Exposure to benzene is more for children that living near to main road compare to other children. Adults have more activity in out side of home has more exposure to benzene than other people

Development of a thermal desorption method for the analysis of particle associated polycyclic aromatic hydrocarbons in ambient air

An investigation for the analysis of polycyclic aromatic hydrocarbons in airborne particulates using thermal desorption and gas chromatography-mass spectrometry is described. Samples are obtained from ambient air using fibreglass filters and the volatile material from the filter is thermally desorbed to gas chromatograph. A 30 meter capillary column is used to separate the hydrocarbons and eight polyaromatic hydrocarbons are used to test the method and recovery is >95%. The eight polycyclic aromatic hydrocarbons anthracene, phenanthrene, fluoranthrene, pyrene, benzo [a] anthracene, chrysene, benzo [a] pyrene and benzo [e] pyrene were the most abundant PAHs found in the samples of ambient air with current method at Uxbridge-London. Application of the measurement of polycyclic aromatic hydrocarbons in ambient air samples shows that the hydrocarbons trapped in the particle phase to a lesser degree at higher ambient temperature. In conclusion a method has been developed to transfer the PAHs in particle phase from a filter to GC-MS by thermal desorption. A standard mixture of PAHs, when absorbed onto the filter, did lead to strong analyte absorbent interactions by the high percent recovery of the sample

Comparative study of lung function in Iranian factory workers exposed to silica dust

The study compared lung function among 322 workers in pottery, ceramic, stone-cutter and stone-grinder factories in the west of the Islamic Republic of Iran. Concentrations of silica particles <2 microm were measured in the ambient air of factories. Forced expiratory volume in 1 second [FEV1] and forced vital capacity [FVC] were significantly lower in stone-grinders compared with pottery, ceramic or stone-cutter workers and a control group. No difference in lung function was found in pottery and stone-cutter workers with less than 20 years occupation compared with controls. The prevalence of respiratory symptoms in stone-grinders was higher than other workers. The concentration of silica particles of stone-grinder factories was 40-110 times higher than in ceramic and potteries factories. More attention is needed to ventilation systems and health care of stone-grinders