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1.
Arch Razi Inst ; 76(1): 7-16, 2021 03.
Article in English | MEDLINE | ID: mdl-33818953

ABSTRACT

Clostridium perfringens and Clostridium septicum are gram-positive, anaerobic, spore-forming rods and pathogens for humans and livestock, which are widespread in nature as well as human and animal digestive systems. C. perfringens produces numerous different exoproteins, which are various systems of action. The major C. perfringens toxins include alpha, beta, epsilon, and iota. C. perfringens are classified into five groups (A-E) on the basis of the production of these lethal toxins. Furthermore, toxins secreted from C. septicum include alpha, beta, delta, and gamma. Epsilon and alpha toxins of C. perfringens and C. septicum are the major causes of enterotoxemia and braxy in sheep and goats, respectively. The production of recombinant immunogenic proteins of these bacteria using suitable expression vectors and expression prokaryotic hosts can be a convenient method for the reduction of the costs and production time of clostridial anaerobic vaccines. In the present study, recombinant Escherichia coli strain TOP10 containing pJETεα was used for the evaluation of C. perfringens type D and C. septicum epsilon-alpha fusion protein using different commercial vectors. After the extraction of pJETεα from the recombinant cell, it was digested by NdeI and XhoI restriction enzymes and subcloned into pET22b (+), pET26b (+), and pGEM-B1 expression vectors in E. coli/Rosetta and E. coli/BL21 (DE3). The expression of recombinant fusion toxin was evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blotting in three different temperatures, various isopropyl β-D-1-thiogalactopyranoside (IPTG) gradients, and different times using pGEMεα, pET22εα, and pET26εα vectors in E. coli/Rosetta and E. coli/BL21 (DE3). According to the obtained results, recombinant E. coli/Rosetta/pET22εα showed better expression at a temperature of 37°C after 6 h of induction by IPTG.


Subject(s)
Bacterial Toxins , Escherichia coli , Animals , Clostridium perfringens/genetics , Escherichia coli/genetics , Gene Expression , Recombinant Proteins/genetics , Sheep
2.
Proc Natl Acad Sci U S A ; 118(13)2021 Mar 30.
Article in English | MEDLINE | ID: mdl-33758098

ABSTRACT

Spontaneous condensation of excitons is a long-sought phenomenon analogous to the condensation of Cooper pairs in a superconductor. It is expected to occur in a semiconductor at thermodynamic equilibrium if the binding energy of the excitons-electron (e) and hole (h) pairs interacting by Coulomb force-overcomes the band gap, giving rise to a new phase: the "excitonic insulator" (EI). Transition metal dichalcogenides are excellent candidates for the EI realization because of reduced Coulomb screening, and indeed a structural phase transition was observed in few-layer systems. However, previous work could not disentangle to which extent the origin of the transition was in the formation of bound excitons or in the softening of a phonon. Here we focus on bulk [Formula: see text] and demonstrate theoretically that at high pressure it is prone to the condensation of genuine excitons of finite momentum, whereas the phonon dispersion remains regular. Starting from first-principles many-body perturbation theory, we also predict that the self-consistent electronic charge density of the EI sustains an out-of-plane permanent electric dipole moment with an antiferroelectric texture in the layer plane: At the onset of the EI phase, those optical phonons that share the exciton momentum provide a unique Raman fingerprint for the EI formation. Finally, we identify such fingerprint in a Raman feature that was previously observed experimentally, thus providing direct spectroscopic confirmation of an ideal excitonic insulator phase in bulk [Formula: see text] above 30 GPa.

3.
Arch Razi Inst ; 74(1): 7-20, 2019 03.
Article in English | MEDLINE | ID: mdl-31013003

ABSTRACT

The haemolytic biovar of Gallibacterium anatis (G. anatis) is responsible for urogenital, gastrointestinal, and respiratory diseases in chickens. There are numerous reports on the resistance of G. anatis to antibiotics and recurrence of the disease, which raise concerns about antimicrobial treatment efficiency. Vaccination has been considered as the most feasible procedure of prevention in high risk farms. Subunit vaccines containing immunogenic components can have practical protective value in preventive measures regarding the infection. The present study aimed to introduce a polytopic vaccine candidate based on epitope detection. All registered sequences of four immunogenic proteins, includig Flfa, GTxA, Gab_1309, and Gab_2348 were retrieved and directed for variational analysis. A vaccine isolate was selected for each protein and tested for B-cell epitope mapping using different tools. Furthermore, consensus selected immunogenic regions with special patterns fused together by flexible linkers were integrated into two constructs and checked for the best status of proteasomal cleavage sites, as well as hydropathy plot. Moreover, back translations, along with codon optimization were performed, and then some tags were added to the constructs. The selected consensus B-cell immunogenic epitopes were for 12656: AA114-181, 7990: AA114-181, Avicor: AA42-77, 134-197, and IPDH: 61-155 for Flfa protein, AA185-235, AA372-457, and AA807-941 for GtxA-N, AA260-305, AA340-400, and AA110-146 for Gab-1309, and AA125-AA175 for Gab-2348. Two suitable patterns of attachment were selected from the different fusion patterns of epitopes in B-cell polytopic vaccinal constructs. Finally, the examination of these constructs showed their effect and efficacy for immune system stimulation. Based on bioinformatics results, these immunogens could be utilized as potential candidates to develop polytopic protective vaccines and design diagnostic kits.


Subject(s)
Bacterial Vaccines/immunology , Chickens , Epitopes/immunology , Pasteurellaceae Infections/veterinary , Pasteurellaceae/immunology , Poultry Diseases/prevention & control , Animals , Computer Simulation , Pasteurellaceae Infections/prevention & control
4.
Pharmaceutics ; 10(2)2018 May 18.
Article in English | MEDLINE | ID: mdl-29783687

ABSTRACT

Lipid-based drug delivery systems, or lipidic carriers, are being extensively employed to enhance the bioavailability of poorly-soluble drugs. They have the ability to incorporate both lipophilic and hydrophilic molecules and protecting them against degradation in vitro and in vivo. There is a number of physical attributes of lipid-based nanocarriers that determine their safety, stability, efficacy, as well as their in vitro and in vivo behaviour. These include average particle size/diameter and the polydispersity index (PDI), which is an indication of their quality with respect to the size distribution. The suitability of nanocarrier formulations for a particular route of drug administration depends on their average diameter, PDI and size stability, among other parameters. Controlling and validating these parameters are of key importance for the effective clinical applications of nanocarrier formulations. This review highlights the significance of size and PDI in the successful design, formulation and development of nanosystems for pharmaceutical, nutraceutical and other applications. Liposomes, nanoliposomes, vesicular phospholipid gels, solid lipid nanoparticles, transfersomes and tocosomes are presented as frequently-used lipidic drug carriers. The advantages and limitations of a range of available analytical techniques used to characterize lipidic nanocarrier formulations are also covered.

5.
Arch Razi Inst ; 72(3): 147-157, 2017 09.
Article in English | MEDLINE | ID: mdl-30341935

ABSTRACT

Bovine leukocyte antigen (BoLA) DRB3 is a highly polymorphic gene in major histocompatibility complex (MHC) class II that plays a central role in immune responses and production factors. As of yet, molecular and evolutionary characteristics of BoLA-DRB3.2* have not been as fully understood as human and mouse. Therefore, we attempted to analyze variability and phylogeny of BoLA-DRB3.2* and illustrate some novel practical evidence on interspecies diversity, the resistance /susceptibility points in cattle breeding, and vaccine design. Initially, BoLA-DRB3.2* alleles and orthologous exons in the selected livestock were retrieved and checked. In the next step, the secondary/tertiary structure of BoLA-DRB3.2*24 gene product was modeled and validated. Then, hypervariable regions (HVRs) of alleles were identified by hybrid approaches. In the last step, interspecies relationship, allele’s phylogeny/grouping, and estimate of average evolutionary divergence were explored. Shannon entropy variation analysis showed eight HVRs and three semi-variable regions in BoLADRB3.2* alleles. These HVRs were present in all the three sub-structures and dominantly existed in alpha helix. In addition, strong relationships and little diversity were noted in phylogenetic trees of cattle, buffaloes, sheep, and goats. Furthermore, there was some evidence on divergence of DRB3 before speciation among the mentioned species and possibility of cross prediction resistance/susceptibility alleles. Finally, DRB3 alleles were grouped into seven clusters, and older and newer alleles were identified. The results show that similar studies should be done in other animals to better understand the nature of the DRB3 attributes.


Subject(s)
Cattle/genetics , Gene Frequency , Genetic Variation , Histocompatibility Antigens Class II/genetics , Amino Acid Sequence , Animals , Base Sequence , Cattle/metabolism , Histocompatibility Antigens Class II/chemistry , Histocompatibility Antigens Class II/metabolism , Phylogeny
6.
SAR QSAR Environ Res ; 25(8): 637-49, 2014.
Article in English | MEDLINE | ID: mdl-25027467

ABSTRACT

There has been considerable interest in DNA topoisomerases over the last decade, as they have been shown to be one of the major cellular targets in anticancer drug development. Previously we synthesized some benzothiazole derivatives and corresponding benzothiazolium forms, and tested their DNA inhibitory activity to develop novel antitumor agents. Among the 12 prepared compounds, compound BM3 (3-aminobenzothiazole-3-ium 4-methylbenzene sulfonate) exhibited extreme topoisomerase II inhibitory activity compared with the reference drug etoposide. We also tried to determine the DNA and enzyme binding abilities of BM3 and found that BM3 acted on topoisomerase II first at low doses, while it had also showed DNA minor groove binding properties at higher doses. In this study the interactions between DNA topoisomerase II and the compounds were examined in detail by molecular modelling studies such as molecular docking and pharmacophore analysis performed using Discovery Studio 3.5. As a result, it was found that benzothiazolium compounds exhibited a totally different mechanism than benzothiazoles by binding to the different amino acids at the active site of the protein molecule. 3-Aminobenzothiazoliums are worthy of carrying onto anticancer studies; BM3 especially would be a good anticancer candidate for preclinical studies.


Subject(s)
Benzothiazoles/pharmacology , Models, Molecular , Quantitative Structure-Activity Relationship , Topoisomerase II Inhibitors , Antineoplastic Agents/chemistry , Benzothiazoles/chemistry , DNA Topoisomerases, Type II/metabolism , Drug Design , Molecular Docking Simulation , Neoplasms/drug therapy
7.
J Clin Lab Anal ; 25(3): 185-90, 2011.
Article in English | MEDLINE | ID: mdl-21567466

ABSTRACT

BACKGROUND: Venipuncture sampling in test tubes for detecting malaria parasites using PCR assays possesses a number of limitations such as reluctance of patients, some difficulties in transportation of blood samples and freezing them for long time. To overcome the mentioned limitations, some approaches have been employed by a number of authors. This study was proposed to compare between DNA Banking Card (DBC) filter papers containing dried finger-prick blood and venipunctured frozen liquid blood. METHODS: A total of 75 specimens was prepared from the equal enrolled individuals using three blood storage approaches; making Geimsa-stained thin and thick smears from each individual to determine the malaria-positive or -negative specimens, spotting two to three drops of finger-prick blood onto the DBC filter paper, and collecting a 2-ml venous blood sample into EDTA-contained test tube from each individual. A semi-nested Multiplex PCR technique with DNA extracted from the two latter sets of specimens was used for plasmodia diagnosis. RESULTS: DNA samples isolated from dried blood spotted on the DBC filter papers resulted in 32 (42.7%) positive and 43 (57.3%) negative cases comparable with the results outcome of frozen liquid blood with 35 (46.7%) positive and 40 (53.3%) negative cases. Statistical analysis revealed higher sensitivity for SnM-PCR using DNA from liquid blood with 100% vs. dried blood spotted on DBC with 97% but higher specificity for the DBC with 100% vs. liquid blood with 95.2%. CONCLUSIONS: Based on the results obtained from this study to overcome the problems of venipuncture frozen liquid blood sampling, replacement of a reliable filter paper for preserving finger-prick blood samples is a trustable and useful facilitator particularly in remote malaria-endemic areas.


Subject(s)
Blood Specimen Collection/methods , DNA, Protozoan/blood , Freezing , Plasmodium falciparum/isolation & purification , Plasmodium vivax/isolation & purification , Polymerase Chain Reaction/methods , Electrophoresis, Agar Gel , Humans , Molecular Sequence Data , Sensitivity and Specificity
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