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Aim: Certain Mycoplasma species, the smallest and simplest free-living bacteria which lack a rigid cell wall, are considered as important pathogenic organisms in human and recognized to have a role in rheumatoid arthritis. The aim of this study was to use molecular methods to detect Mycoplasma spp. in synovial fluid of patients with reactive arthritis in comparison with patients suffering from non-inflammatory arthritis as a control group.
Materials & Methods: Synovial fluid samples were collected from 99 patients with arthritis, all of which fulfilled the standard criteria of American College of Rheumatology for the diagnosis of inflammatory arthritis (59 patients) or non-inflammatory arthritis (40 patients). The DNA of all synovial fluid samples was extracted, and PCR was performed with a specific set of general primers for 16S rRNA of Mycoplasma genus. The PCR products were confirmed via restriction enzyme digestion using BamH1 and sequencing.
Finding: A total of 11 out of 99 (11.1%) samples of patients with reactive arthritis revealed a 270bp amplification band. Digesting the PCR product of 16S rRNA by BamH1 confirmed the PCR assay. The sequencing also confirmed the amplified products.
Conclusion: The pathophysiology of inflammatory arthritis could be attributed, at least in part, to the persistence of bacterial DNA in the joint of patients with reactive arthritis.

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Hyper-glycosylation is an approach to introduce new N-glycosylation consensus sequence(s) (َAsn-Xxx-Ser/Thr three-peptide) into a protein primary amino acid sequences by site-directed mutagenesis which is followed by the attachment of a new glycan to the Asn residue located within the three-peptide sequence. Hyper-glycosylation has attracted lots of interest especially in the protein therapeutics industry. The attached glycan may improve the pharmacokinetic properties of the hyper-glycosylated priteins and increase their half-life in the bloodstream. In the current study, a new N-glycosylation site was introduced into N-terminal Gla domain of hFIX. Arg³⁷ position of mature hFIX was targeted to be converted into Asn residue by site-directed mutagenesis using overlap extension PCR. Recombinant expression plasmids for native and mutant hFIX were constructed. The expression of the recombinant wild-type and mutant hFIX was analyzed in mammalian HEK293 cells using gradient SDS-PAGE and western blotting analysis. The results indicated in higher molecular weight for R37N mutant in compared with the native protein. The glycan attachment to R37N mutant was further confirmed by PNGase digestion and western blotting.