Effect of Fibrin Packing on Managing Hepatic Hemorrhage and Liver Wound Healing in a Model of Liver Stab Wound in Rat.

OBJECTIVE: 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 (H&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.

Antimicrobial Efficacy and Cytocompatibility of Calcium Hypochlorite Solution as a Root Canal Irrigant: An in Vitro Investigation.

INTRODUCTION: The purpose of this study was to compare the antimicrobial efficacy of sodium hypochlorite (SH) and calcium hypochlorite (CH) against Enterococcus faecalis (E. faecalis) using quantitative real-time polymerase chain reaction (qPCR) analysis and also to compare their cytocompatibility on L929 murine fibroblasts using Mossman's tetrazolium toxicity (MTT) assay. METHODS AND MATERIALS: A broth micro-dilution susceptibility test was used to determine the minimum inhibitory concentration (MIC) of each irrigant against E. faecalis. Then, the root canals of 50 mature extracted human mandibular premolars were contaminated with E. faecalis and were randomly divided into three groups according to the irrigant used (n=20). Canals were irrigated with SH in group I (n=20) and CH in group II (n=20) at their obtained MIC. In group III (n=10), sterile saline was used. Microbial sampling was performed before and after biomechanical preparation. Quantitative PCR was used to quantify E. faecalis in the root canal samples. For cytocompatibility assessment, L929 murine fibroblasts were exposed to various concentrations of the irrigants. RESULTS: Irrigation with test materials resulted in significant reduction in colony forming units (CFU) in post-instrumentation samples (with the MIC values of SH and CH against E. faecalis being 0.5% and 5%, respectively). However, the reduction in the normal saline group was not significant (P=0.203). In addition, 5% CH was more effective than 0.5% SH (P=0.006) in eliminating E. faecalis. Among the different concentrations of tested irrigants, 0.5% CH and 5% SH showed the least and the most cytotoxicity, respectively (P<0.001). The cytotoxicity of 5% CH and 0.5% SH was similar (P=0.99), and lower than 2.5% SH (P<0.001). CONCLUSION: CH at an MIC of 5% was effective in eliminating E. faecalis in planktonic state and also its biofilm and exhibited comparable cytocompatibility to that of 0.5% SH.

Optimization of Three Dimensional Culturing of the HepG2 Cell Line in Fibrin Scaffold.

BACKGROUND: A potential treatment for healing hepatic tissue is delivering isolated hepatic cells to the site of injury to promote hepatic cells formation. In this technology, providing an appropriate injectable system for delivery of hepatic cells is an important issue. In this regard, fibrin scaffolds were designed with many advantages over other scaffolds like cell delivery vehicles for biodegradation, biocompatibility and hemostasis. OBJECTIVES: The aim of this study was to determine suitable cell culture circumstances for HepG2 cell proliferation and differentiation in 3D fibrin scaffolds by evaluating Ca(2+) concentrations, cell numbers, various ratios of plasma/RPMI 1640 and thickness of fibrin scaffold. MATERIALS AND METHODS: In a one-stage experimental design, Box-Behnken design strategy was performed by Minitab 15 software (version 15, Minitab. State College, PA) with three factors at three levels (low, medium and high) and 27 runs for identification of the effects of ratio of plasma/RPMI 1640, Ca(2+) concentration and thickness on the formation of fibrin gel scaffold and 3D HepG2 culture. RESULTS: The optimal concentrations for fibrin scaffold fabrication were achieved by adding 0.15 mol CaCl2 (50 µL) and 1 × 10(5) cells to 1:4 of plasma/RPMI 1640 ratio (500 µL with 2.3 mm thickness per well). CONCLUSIONS: Our approach provided easy handle method using inexpensive materials like human plasma instead of purified fibrinogen to fabricate fibrin scaffold.

Isolation, identification, and media optimization of high-level cellulase production by Bacillus sp. BCCS A3, in a fermentation system using response surface methodology.

Cellulases are important glycosyl hydrolase enzymes, which break down cellulose to ß-glucose. They have been used widely in biotechnological processing such as bioethanol production. In this work we studied maximizing cellulase production by Bacillus sp. BCCS A3 using response surface methodology (RSM). A good result was attained with these conditions (% w/v): tryptone 0.1, Na2PO4 0.25, (NH4)2SO4 0.2, MgSO4 · 7H2O 0.005, CaCl2 0.005, KH2PO4 0.1, NaCl 0.1, sodium carboxymethylcellulose (CMC) 0.75, and pH 9. The cellulase activity in optimized medium was 49.80 U/ml. Moreover, high level of enzyme production was obtained by using fermentor system (50.30 U/ml). Thus, according to the obtained results, this statistical method provided quick identification and integration of key medium details for Bacillus sp. BCCS A3, leading to more cellulase production.