Effect of fibrin packing on managing hepatic hemorrhage and liver wound healing in a model of liver stab wound in rat

To evaluate the effect of fibrin perihepatic packing on controlling liver hemorrhage and liver wound healing

Methods: In this animal experimental study, 20 adult male Sprague Dawley rats, weighing 200-220 g, were included. Stab wound injury was created by number 15 scalpel, so that bilateral liver capsules and liver tissue were cut, and acute bleeding was accrued. The animals were divided into 2 study groups: control [with a primary gauze packing treatment] and test group [with fibrin packing treatment]. Serum alanine aminotransferase [ALT], aspartate aminotransferase [AST], and total serum bilirubin [TSB] levels were measured as a liver function test during the treatment period. Blood loss was calculated for estimation of hepatic hemorrhage during surgery. After four weeks, the liver wound repair was evaluated by sampling and Hematoxylin and Eosin staining [Hand E]

Results: In the test group, all of animals were alive [mortality rate=0%]. Significantly, ALT and AST levels were raised after surgery, followed by a decrease ALT [p=0.783] and AST [p=0.947] to the normal level during 4 days. Estimated blood loss was 2.89 +/- 0.73 mL [about 19.65% of estimated blood volume]. Hematocrit levels returned to the normal level [p=0.109] after 48 hours. In the control group, the mortality rate was 50% during 12h after surgery. ALT [p=0.773] and AST [p=0.853] were decreased to normal level during 6 days, and estimated blood loss was 4.98+/-0.77 mL [about 32.98% of estimated blood volume] in the remaining animals. Moreover, hematocrit levels returned to the normal level [p=0.432] after 72 hours. Estimated blood loss in the test group was significantly less than control group [p<0.001]. Total serum bilirubin levels were not significantly different from the normal level, before and after surgery in both groups. Histopathology sections from the post-hepatectomy specimens showed that the site of the previous incision was completely repaired, and a dense fibrous septum was observed in both groups

Conclusion: The fibrin dressing was effective in preventing blood loss and saving lives after a liver stab injury and major internal bleeding in the animal model of rat

Evaluation of recombinant human growth hormone secretion in E. coli using the L-asparaginase II signal peptide

Background: In the recent years, there has been an increasing interest in secretory production of recombinant proteins, due to its various advantages compared with intracellular expression. Signal peptides play a critical role in prosperous secretion of recombinant proteins. Accordingly, different signal peptides have been assessed for their ability to produce secretory proteins by trial-and-error experiments. The aim of this study was to evaluate the effect of L-asparaginase II signal peptide on the recombinant human Growth Hormone [hGH] protein secretion in the Escherichia coli [E. coli] host

Methods: Cloning and expression of a synthetic hGH gene, containing L-asparaginase II signal sequence was performed in E. coli BL21 [DE3] using 0.1mM IPTG as an inducer at 23[degree]C overnight. Periplasmic protein extraction was performed using three methods, including osmotic shock, osmotic shock in the presence of glycine and combined Lysozyme/ EDTA osmotic shock. Afterwards, the hGH expression was determined by SDSPAGE

Results: Based on experimentally obtained results, hGH protein is expressed as inclusion body even in the presence of L-asparaginase II signal peptide

Conclusion: Therefore, this signal peptide is not effective for secretory production of the recombinant hGH

Production of a novel multi-epitope vaccine based on outer membrane proteins of Klebsiella pneumoniae

Klebsiella pneumoniae is a hospital-acquired pathogen that leads to various infections. Hence, efforts to develop an effective vaccine against that pathogen are well documented. Our interest is the production of the previously designed multi-epitope vaccine construct against the K. pneumoniae in a prokaryotic host. Therefore, a new construct containing the nucleotide sequence of the novel vaccine was successfully expressed in Escherichia coli and then purified by Ni-NTA spin column. The purified recombinant protein can be considered as potential vaccine candidate for wet-laboratory analysis aiming to fight K pneumoniae

Computational analysis of collagenase from different Vibrio, Clostridium and Bacillus strains to find new enzyme sources

Collagenase is one the important enzyme, which is applied in varied fields ranging from tannery, food and cosmetic industries to clinical therapies. Currently, the commercially available collagenase enzyme has been produced by Clostridium histolyticum bacteria. In our study, in order to find new sources of collagenase producer, 30 collagenases from different species of Clostridium, Vibrio and Bacillus were evaluated from the view of phylogenetic relation, domain architecture and physiochemical features. Totally our results indicate that the non-pathogenic C. novyi [NT] with the aliphatic index [80.68], instability index [27], pI [6.54], Mw [112.838 kDa] and two PPC domain could be suggested as a potent bacteria for industrial production of collagenase