New S19 Mutant to Improve Distinction Between Infected and Vaccinated Animals.

Background: Using Strain 19 (S19) to control bovine brucellosis is restricted due to induce antibodies to the O-side chain of the smooth lipopolysaccharide (LPS) which may be difficult to differentiate vaccinated and infected animals. Furthermore, it is virulent for humans and can induce abortion to cattle.

Objectives: The aim of this study was to employ gene knockout S19 for the first time to eliminate diagnostic defects and obtain the attenuated mutant strain.

Optimization and One-Step Purification of Recombinant V Antigen Production from Yersinia pestis.

The purpose of this study was to develop an efficient and inexpensive method for the useful production of recombinant protein V antigen, an important virulence factor for Yersinia pestis. To this end, the synthetic gene encoding the V antigen was subcloned into the downstream of the intein (INT) and chitin-binding domain (CBD) from the pTXB1 vector using specific primers. In the following, the produced new plasmid, pTX-V, was transformed into E.

Evaluation of a single amino acid substitution at position 79 of human IFN-α2b in interferon-receptor assembly and activity.

Type I interferons (IFNs) are homologous cytokines that bind to a cell surface receptor and establish signaling pathways that motivate immune responses. The purpose of the current study is to assess the activity of a novel-engineered IFN-α2b. The crystallographic structure of IFN-α2b and its receptors was acquired from Protein Data Bank.

Design of a recombinant immunotoxin against the human granulocyte-colony stimulating factor receptor.

Immunotoxin is a new strategy for protein therapy of cancer. This engineered protein contains two parts, the immune part which is an antibody or cytokine, directed against the cancer cell receptor, and the toxin part consisting of a plant or bacterial toxin leading to apoptosis by protein synthesis inhibition. The knowledge of cell-surface receptor overexpression in cancer cells can help scientists to construct new anti-cancer agents.

A new method for simultaneous gene deletion and down-regulation in Brucella melitensis Rev.1.

In this study, our aim was to integrate an antisense expression cassette in bacterial chromosome for providing a long-term expression down-regulation in a bid to develop a new approach for simultaneous deletion and down-regulation of target genes in bacterial system. Therefore, we were used this approach for simultaneous deletion of the perosamine synthetase (per) gene and down-regulation of the virB1 expression in Brucella melitensis Rev.1.

Stabilisation of recombinant aequorin by polyols: activity, thermostability and limited proteolysis.

The photoprotein aequorin is a calcium-dependent bioluminescent enzyme which is most widely used in biotechnology processes, but this protein is susceptible to aggregation and proteolysis degradation. Various additives such as polyols are known to enhance the stability of proteins and protect them in native folded and functional state. In this work, for study of aequorin stability, the histidine-tagged apoaequorin was expressed in Escherichia coli and purified by nickel chelate affinity chromatography.

Design and characterization of an aequorin-based bacterial biosensor for detection of toluene and related compounds.

An aequorin-based Escherichia coli strain JM109 biosensor was constructed and characterized for its potential to detect toluene and related compounds in aqueous solutions. The biosensor was constructed based on a PGL2 plasmid carrying the lower pathway promoter (Pu) of the xyl operon of Pseudomonas putida mt-2, which was incorporated with transcriptional activator xylR and fused to aequorin cDNA named pGL2-aequorin. Binding of xylR protein to a subset of toluene-like compounds activates transcription at the Pu promoter, thus expression of aequorin is controlled by xylR and Pu.

Trifluoperazine-induced cholestatic jaundice.

Liver injury occurs with many drugs; therefore, a thorough work up is important for establishing the diagnosis. We report a case of trifluoperazine-induced cholestatic jaundice. A 44-year old male with schizoaffective disorder developed an increase in liver enzymes and jaundice after starting treatment with trifluoperazine.

Kidney retransplantation in comparison with first kidney transplantation.

Introduction: The aim of this study was to depict the outcome of second and third kidney allografts in comparison with first kidney allografts.

Methods: Among 2150 kidney transplantations are 103 second and 5 third transplantations. Demographic characteristics and survivals of retransplanted patients were compared with a randomly selected group of first kidney recipients, consisting of two cases matched with each retransplanted patient for age, gender, and date of transplantation.