alternative bacterial expression system using bacillus pumilus SG2 chitinase promoter

Background: Chitin is an abundant natural polysaccharide found in fungi, algae, and exoskeleton of insects. Several bacterial species are capable of utilizing chitin as their carbon source. These bacteria produce chitinases for degradation of chitin into N-acetyl-D-glucosamine. So far, regulation of the chitinase encoding genes has been studied in different bacterial species. Among Bacillus species, B. pumilus strain SG2 encodes two chitinases, ChiS and ChiL. The promoter region of chiSL genes [PchiS] is mainly regulated by the general carbon catabolite repression [CCR] system in B. subtilis due to the presence of a catabolite responsive element [cre]

Objectives: Use of P[chiS] in constructing an inducible expression system in B. subtilis was investigated

Materials and Methods: In the first step, complete and shortened versions of P[chiS] were inserted upstream of the lacZ on a pBS72/pUC18 shuttle plasmid. The beta-galactosidase activity of B. subtilis carrying one of the relevant plasmids was measured in the presence of different carbon sources

Results: An expression system based on the chitinase promoter of B. pumilus SG2 was established. Modification of PchiS and the culture medium resulted in production of beta-galactosidase in B. subtilis up to 1,800 Miller unit [MU] activity

Conclusions: The chitinase promoter developed in this study, has potential to be used in an expression vector that could be induced by chitin. In addition, compared to the other inducers like IPTG and lactose, chitin is definitely cheaper and more available as an inducer

[Effect of chloroformic extract of Cichorium intybus on liver function tests and serum level of TNF- alpha in obstructive cholestasis in rat]

Liver plays important roles in the production of bile, detoxification, and elimination of foreign material and synthesis of plasma proteins. Obstructive cholestasis is one of the liver disorders that can result in increased concentration of oxidants and inflammatory agents in the liver. In traditional medicine, Cichorium intybus has been used as a liver protectant, anti inflamatory and detoxifying agent. The aim of this study was to evaluate the effect of chloroformic extract of Cichorium intybus on liver functional tests and serum level of TNF- alpha in cholestatic rat model. In this experimental study, male Wistar rats were randomly divided into 5 groups [n= 6] including sham operated, control [Bile Duct Ligation [BDL] + vehicle], and 3 groups with BDL + extract treatments [100, 200, 400 mg/kg/day ip]. These groups were treated for seven days and on the eighth day, prothrombin time [PT], serum albumin, alanine amino transferase [ALT], aspartate amino transferase [AST], total bilirubin, direct bilirubin, alkaline phosphatase [ALP] and lactate dehydrogenase [LDH], were measured by calorimetric and TNF- alpha was measured by ELISA methods. The results were analyzed by one way ANOVA. The results of the present study showed that the Cichorium extract [100 mg/kg/day] decreased the serum level of direct bilirubin, AST, ALT, and TNF- alpha significantly compared to the control group [p <0.05]. Furthermore, at the higher dose [200 mg/kg/day] PT, ALP, LDH and AST decreased significantly in comparison to the control group [p <0.05], while the serum albumin level increased significantly in the treated animals [p <0.05]. In conclusion, we found that, low doses of chloroformic extract of Cichorium intybus protected the liver against obstructive cholestasis induced -injury

Drug comparison and categorizing regarded with human serum albumin from years 2006 to 2012

Human serum albumin [HSA] is the most abundant protein constituent of blood plasma. This protein consists of a single polypeptide chain of 585 amino acid residues, which has many important physiological functions. HSA can bind and carry many drugs, including anticoagulants, tranquilizers, and general Anesthetics. Some technique such as: fluorescence spectroscopy, three-dimensional fluorescence, UV-visible, FT-IR, circular dichroism [CD], X-ray scattering [SAXS] technique and molecular modeling was utilized to investigate the effects of acceptor on conformation of the donor [HSA]. The binding site number n and apparent binding constant K[A] drugs corresponding thermodynamic parameters, the free energy change [DELTA G], enthalpy change [DELTA H], and entropy change [DELTA S] were calculated. The hydrophobic effect, van der Waals forces, hydrogen bond and electrostatic interactions play a major role in stabilizing the complex. More investigation also revealed that these drugs bind to the amino acids on the hydrophobic pocket of HSA and induce changes to the secondary structure of the HSA. In this study for better understanding of HSA-drug interactions, we categorized drugs into ten groups from years 2006 to 2012 and are suggested that two important parameters such as Delta G[0][H20] and [D] [½] can be calculated for each groups and refer to ten categories to finally indicate that fine structural change in human serum albumin

Designing and manufacturing of the extremely low frequency electromagnetic field generator and detector

Electromagnetic fields [EMFs] are inevitable consequences of modern civilizations and the era of technology. Many investigations have been carried out in order to determine the effects of EMFs on biological organisms specially on human being. In one hand, most of the generators used in these kinds of experiment are not able to expose a large number of animals simultaneously and on the other hand, many environmental electromagnetic fields could be hazardous for exposing people while a portable, low cost and reliable electromagnetic detector is not commercially available. In this study, we introduced an ELF/EMFs generator capable of exposing a large experimental space and a detector of environmental ELF/EMFs which can define their spatial parameters and relevant biological effects

Study of apoptosis inducing activity of calprotectin on fibroblast cell

One of the prominent types of connective tissue cells is fibroblast that synthesizes and maintains the extracellular matrix of many animal tissues. Previous studies illustrated that calprotectin protein has different cytotoxicity effects on fibroblast cells. Calprotectin is abundant in the mneutrophil cytosol; it has growth-inhibitory and apoptosis-inducing activities against various mcell types such mas tumor cells. The present study tries to introduce mechanism of growth inhibitory effect of calprotectin on human foreskin fibroblast cells [HFFF] and compare to etoposide [chemotherapy agent as control]. Calprotectin was purified from human neutrophil by chromatography methods. HFFF cell lines were used, maintained in RPMI 1640 medium supplemented with 10% FCS in a humidified incubator [37 degreeC and 5% CO2]. The HFFF cells were exposed to the different concentrations of calprotectin and etoposide for 24, 48 and 72 hours. Cell proliferation was assessed by using dimethylthiazol diphenyl tetrazolium bromide assay. Flow cytometric analysis was performed to evaluate the cytotoxic mechanism of calprotectin on HFFF cells. Our results revealed that calprotectin and etoposide induce growth inhibition of HFFF in dose- and time-dependent manners. Sensitivity of HFFF cells to cytotoxic effect of human calprotectin was highly remarkable. In addition, growth inhibitory effect of this cytotoxic agent mostly was governed through induction of apoptosis in the HFFF cells. Taken together, calprotectin not only has more potent anticancer activity in comparison with the etoposide, but it also is an apoptosis inducer that acts on the proliferation of normal cells like fibroblasts

Mathematical modeling of schizophrenia

Abnormal brain function in schizophrenia involves an extended network of brain structures. In schizophrenia, an abnormal dopamine activity in accordance with altered GABA and glutamate transmission appears to interfere with this process. In this study, we have examined the effect of dopamine hyperactivity on CA3 pyramidal cells using a mathematical model. Our simulation results show that while normal activity of dopamine system causes the membrane potential of pyramidal cell to display a periodic bursting behavior, hyperactivity of this system brings about irregular and aperiodic patterns of activity. In addition, it is suggested that hypo-glutamatergic conditions result in reduced activation of the striatal complex and may induce psychotic symptoms. Thus, we also investigated the role of glutamate level in postsynaptic cell activity. Simulation results indicate that hypo-glutamatergic condition has the same effect on the membrane potential of pyramidal cells, i.e. aperiodic and irregular firing patterns. Based on these results, we hypothesize that glutamate receptor activation may have good therapeutic results in schizophrenia