comparative study of MTA solubility in various media

Solubility of root filling materials is heavily influenced by the environment they are in contact with. This study compared the solubility of ProRoot MTA in deionized water and synthetic tissue fluid. Forty specimens of prepared MTA were immersed in deionized water and synthetic tissue fluid [20 samples each]. The solubility was assessed after 7 and 28 days. Scanning electron microscope observation was also performed. The mean weight loss was evaluated using a digital scale. Data were analyzed using one-way ANOVA. Tukey test was performed for multiple comparisons. MTA solubility in synthetic tissue fluid was significantly lower than deionized water after 7 and 28 days [P<0.05]. Secondary electron detectors revealed the presence of lumps and platelets on the surfaces of both specimens. Also, more voids were observed in specimen stored in deionized water. MTA dissolved faster in deionized water than synthetic tissue fluid. Despite this, the solubility of this material in both media was acceptable

[Serratia marcescens B4A chitinase product optimization using Taguchi approach]

Chitinase production by newly isolated Serratia marcescens B4A was optimized following Taguchi's array methods. Twenty-three bacterial isolates were screened from shrimp culture ponds in the South of Iran. A chitinase-producing bacterium was isolated based on it's ability to utilize chitin as the sole carbon source. The isolate designated as B4A, was identified as Serratia marcescens based on its 16S rRNA sequence and key morphological, physiological and biochemical characteristics. The cultivation of Serratia marcescens B4A in the appropriate liquid medium resulted in production of high levels of chitinase. The malt extract and colloidal chitin represented the best nitrogen and carbon sources, respectively. Chitinase production by Serratia marcescens B4A was optimized following the Taguchi orthogonal array [OA] for the design of experiments [DOE]. Statistical experimental design via the Taguchi method was applied to determine the optimal levels of physical parameters and key media components in the medium, such as temperature, pH, NaCl and chitin concentrations. The results of this study showed that temperature of 30§C, pH 7.9, NaCl 0.1% [w/v] and chitin 1% [w/v] are optimal conditions for this protocol

Sequence and phylogenetic analysis of the non-structural 3A and 3B protein-coding regions of foot-and-mouth disease virus subtype A Iran 05

The A Iran 05 foot-and-mouth disease virus (FMDV) subtype was detected in Iran during 2005 and has proven to be highly virulent. This study was undertaken to focus on molecular and phylogenetic analysis of 3A and 3B coding-regions in the A Iran 05 field isolate. To assess the genetic relatedness of A Iran 05 isolate the nucleotide and predicted amino acid sequences of the 3AB region of type A FMDV isolates were compared with twenty previously described type A FMDV isolates. The phylogenetic tree based on the 672 bp 3AB gene sequences of type A FMDV from thirteen different locations clustered them into five distinct lineages. The A Iran 05 isolate clustered in lineage A along with four type A variants and was closely matched with viruses isolated in Turkey and Pakistan during 2005~2006. The number of protein sequence differences exhibited by each of the isolates revealed that A Iran 05 isolate contains three amino acid substitutions at positions 47 and 119 of 3A and 27 of the 3B coding region. The nucleotide identity between A Iran 05 and the other four isolates of lineage A was estimated to be 98%.

Detection of bovine viral diarrhea virus in bovine semen using nested-PCR

A rapid and sensitive reverse transcription polymerase chain reaction [RT-PCR] and nested-PCR were used to detect bovine viral diarrhea virus 1 [BVDV-1] in bull semen. Selected primers could amplify a part of the 5'UTR of the BVDV genome. A 294 bp DNA fragment was amplified and specificity of the results was confirmed by direct sequencing of the PCR product. Prior to RNA extraction, the seminal inhibitors were eliminated using a simple dilution method. Therefore, a sensitivity of 3x102 50% tissue culture infective dose [TCID50] was achieved when experimentally infected semen was used for RNA extraction. In nested-PCR a 160 bp fragment was amplified and sensitivity of the test was increased to 3 TCID50. This technique can be used as a rapid and sensitive method of BVDV-1 detection in bovine semen

Bacterial expression and purification of C1C2 domain of human factor VIII

The cDNA from the mycoparasitic fungus Trichoderma atroviride PTCC5220 encoding a 42 kDa chitinase [Chit42] was isolated. The nucleotide sequence of the cDNA fragment as having a 1263 bp open reading frame that encodes a 421 amino acid polypeptide, and a high homology was found with other reported Chit42 belonging to the Trichoderma sp. The 22 amino acid N-terminal sequence is a putative signal pep-tide for the possible secretion of the protein. The protein has been expressed and secreted as a mature form in Escherichia coll BL21[DE3] using the pelB leader sequence. The E. coll strain expressed Chit42 in an active form and secreted the protein into the medium. This recombinant chitinase has been shown to have inhibitory activity on mycelial growth and also, lytic activity on the cell wall of Rhizoctonia solani [AG2-2], causal agent of root rot in sugar beet in vitro. Expressed chitinase was optimally active at pH 5 and at 40°C. It is thermally stable at 60°C for more than 120 min at pH5