Mineralized Human Amniotic Membrane as a Biomimetic Scaffold for Hard Tissue Engineering Applications.

The human amniotic membrane (HAM) has been viewed as a potential regenerative material for a wide variety of injured tissues because of its collagen-rich content. High degradability of HAM limits its wide practical application in bone tissue engineering. In this study, the natural matrix of the decellularized amniotic membrane was developed by the double diffusion method. The results confirmed a reduction of the amniotic membrane's degradability because of the deposition of calcium and phosphate ions during the double diffusion process. Real-time PCR results showed a high expression of osteogenesis-related genes from adipose-derived mesenchymal stem cells (ADMSCs) cultured on the surface of the developed mineralized amniotic membrane (MAM). Further in vivo experiments were conducted using an MAM preseeded with ADMSCs and a critical-size rat calvarial defect model. Histopathological results confirmed that the MAM + cell sample has excellent potential in bone regeneration.

Molecular characterization and Functional Analysis of the PilQ380-706: a Novel Secretin Domain in Pseudomonas aeruginosa.

BACKGROUND: Type 4 pili (T4P) is an important virulence factor of Pseudomonas aeruginosa (P. aeruginosa). T4P pass the outer membrane through a large oligomeric channel made of a single PilQ protein that is most highly conserved at their C-termini. To develop a functional vaccine that can be used in clinical application, the secretin domain of the PilQ (PilQ380-706) was produced as a recombinant protein. METHODS: A 981 bp fragment of C-terminal of the pilQ secretin (pilQ1138-2118) from was designed into the prokaryotic expression vector pET28a. The presence of the pilQ1138-2118 gene in the recombinant construct (pET28a/pilQ) was assessed by double digestion and PCR. After transformation, expression of the recombinant PilQ was induced by addition of IPTG. The expressed recombinant protein was purified by a modified method using a HisTrap affinity column and finally confirmed by SDS-PAGE. The functional activities of the produced PilQ380-706 confirmed by Western blot analysis and twitching inhibition assay. RESULTS: The PCR and enzymatic digestion results showed the presence of the pilQ1138-2118 gene in the construct. The protein electrophoresis showed that the molecular weight of the recombinant PilQ380-706 is approximately 37 kDa. The Western blot analysis confirmed the specificity of specific IgG against the PilQ380-706 protein. The PilQ380-706 protein showed high biological activity in all of these standard assays. CONCLUSION: Since, the PilQ380-706 protein plays an important role in the biogenesis of pili; and thus, the primary establishment of P. aeruginosa; it seems that it can be used as a candidate vaccine or an adjuvant in the future studies.

Seroepidemiology of leptospirosis in Guilan province, northern Iran: comparison between MAT and IgM-ELISA techniques.

INTRODUCTION: Leptospirosis is a widespread zoonotic disease which is endemic in Guilan province, Iran. Besides economic losses in the dairy industry, leptospirosis is also considered an important public health problem. This study aimed to evaluate two serological techniques, MAT and IgM-ELISA for detection of leptospiral antibodies. METHODOLOGY: A total of 185 samples were collected from individuals in Guilan province suspected of having leptospirosis from April 2016 to December 2016. Sera from participants were analyzed for Leptospira IgM antibodies using an available ELISA test and the MAT method. The specificity and sensitivity of the tests were calculated and compared. RESULTS: Of the 185 serum samples examined 114 (61.6%) and 94 (50.8%) samples were determined to be positive by MAT and IgM-ELISA, respectively. The results also showed that 17.5% of the sera that reacted positive in MAT were negative by IgM-ELISA, and 20.2% of IgM-ELISA positive sera were negative by MAT. We also showed that the MAT had specificity and sensitivity of 100%, when compared to leptospirosis-positive and negative serum samples. The specificity and sensitivity of IgM-ELISA was calculated as 78.8% and 82.4% respectively when compared with MAT. Bivariate analysis showed high correlation between the season, community of residence, possible reasons of pollution and leptospirosis (P < 0.1). CONCLUSION: Rural areas of Guilan, especially rice farming areas, are endemic for leptospirosis. Rice farmers have a high risk of infection with leptospirosis; infection is associated with direct exposure to rodent urine, gender (male) and season (spring).

Antibiotic Resistance Pattern and Distribution of pslA Gene Among Biofilm Producing Pseudomonas aeruginosa Isolated From Waste Water of a Burn Center.

BACKGROUND: Pseudomonas aeruginosa is considered as a major cause of hospital-acquired infections due to its high antibacterial resistance. Biofilm formation is a well-known pathogenic mechanism in P. aeruginosa infections, since sessile bacteria are protected in an extracellular matrix of exopolysaccharide. The expression of polysaccharide synthesis locus (pslA gene) can be important for biofilm formation by P. aeruginosa. OBJECTIVES: The purpose of this research was to evaluate the antibiotic resistance pattern and distribution of the pslA gene among biofilm-producing P. aeruginosa isolates obtained from waste water of Burn Centre in Guilan, Iran. MATERIALS AND METHODS: Fifty isolates of P. aeruginosa were obtained from waste water of a burn center. The P. aeruginosa isolates were identified using standard bacteriological procedures. Drug susceptibility test was performed by disk diffusion method for all the isolates against nine antimicrobial agents. Biofilm formation was measured by microtiter plate assay. Polymerase chain reaction (PCR) was used to identify the presence of the pslA gene among the isolates. RESULTS: Biofilm formation was observed in 70% of the P. aeruginosa isolates. The potential formation of biofilm was significantly associated with resistance to gentamicin, imipenem, tobramycin and piperacillin. In addition, the pslA gene only existed in biofilm-producing isolates with a frequency of 42.9% (n = 15). CONCLUSIONS: The findings of the present study well demonstrated that the P. aeruginosa biofilm-producing isolates were more resistant to the tested antibiotics. Furthermore, because of wide distribution, it seems that the pslA gene is associated with biofilm formation.