A Comparative Study on Morphochemical Properties and Osteogenic Cell Differentiation within Bone Graft and Coral Graft Culture Systems

The objective of this study was to compare the morphological and chemical composition of bone graft (BG) and coral graft (CG) as well as their osteogenic differentiation potential using rabbit mesenchymal stem cells (rMSCs) in vitro. SEM analysis of BG and CG revealed that the pores in these grafts were interconnected, and their micro-CT confirmed pore sizes in the range of 107-315 µm and 103-514 µm with a total porosity of 92% and 94%, respectively. EDS analysis indicated that the level of calcium in CG was relatively higher than that in BG. FTIR of BG and CG confirmed the presence of functional groups corresponding to carbonyl, aromatic, alkyl, and alkane groups. XRD results revealed that the phase content of the inorganic layer comprised highly crystalline form of calcium carbonate and carbon. Atomic force microscopy analysis showed CG had better surface roughness compared to BG. In addition, significantly higher levels of osteogenic differentiation markers, namely, alkaline phosphatase (ALP), Osteocalcin (OC) levels, and Osteonectin and Runx2, Integrin gene expression were detected in the CG cultures, when compared with those in the BG cultures. In conclusion, our results demonstrate that the osteogenic differentiation of rMSCs is relatively superior in coral graft than in bone graft culture system.     

Identification of potential inhibitors of Zika virus NS5 RNA-dependent RNA polymerase through virtual screening and molecular dynamic simulations

Zika virus (ZIKV) is one of the mosquito borne flavivirus with several outbreaks in past few years in tropical and subtropical regions. The non-structural proteins of flaviviruses are suitable active targets for inhibitory drugs due to their role in pathogenicity. In ZIKV, the non-structural protein 5 (NS5) RNA-Dependent RNA polymerase replicates its genome. Here we have performed virtual screening to identify suitable ligands that can potentially halt the ZIKV NS5 RNA dependent RNA polymerase (RdRp). During this process, we searched and screened a library of ligands against ZIKV NS5 RdRp. The selected ligands with significant binding energy and ligand-receptor interactions were further processed. Among the selected docked conformations, top five was further optimized at atomic level using molecular dynamic simulations followed by binding free energy calculations. The interactions of ligands with the target structure of ZIKV RdRp revealed that they form strong bonds within the active sites of the receptor molecule. The efficacy of these drugs against ZIKV can be further analyzed through in-vitro and in-vivo studies.     

Association of FcγRIIa Polymorphism with Clinical Outcome of Dengue Infection: First Insight from Pakistan

Dengue illness has been a major health concern in Pakistan during the last decade. Dengue infection can result in a spectrum of clinically distinct outcomes, ranging from asymptomatic infection to potentially life-threatening forms of dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). A single-nucleotide polymorphism in FcγRIIa (rs1801274) results in altered affinity of the receptor for different subclasses of immunoglobulin G, and is a key player in determining the susceptibility to or protection from severe clinical infection of dengue. In this study, we analyzed the allelic and genotypic distribution of rs1801274 in subjects of Pakistani origin with subclinical dengue infection (n = 40), dengue fever (DF) (n = 40), and DHF/DSS (n = 30). We found that HH homozygotes and heterozygotes were significantly more likely to develop clinical dengue (odds ratio [OR] = 3.21, 95% confidence interval [CI] = 1.29–7.97, P = 0.009), either DF (OR = 2.82, 95% CI = 1.00–7.97, P = 0.045) or DHF/DSS (OR = 3.90, 95% CI = 1.13–13.07, P = 0.024) than the asymptomatic dengue infection. Results of allelic distribution comparisons and logistic regression analysis also supported the same relationship. The results suggest complex nature of interacting factors in determining the course for severe dengue illness.     

A rare case of multiple bronchial artery aneurysms associated with a double aortic arch

Bronchial artery aneurysm is uncommon, and the occurrence of multiple aneurysms arising from a bronchial artery is even rarer. To date, there has been only one published case report describing double bronchial artery aneurysms. We herein describe a case of three aneurysms arising from a left bronchial artery, accompanied by multiple bilateral hypertrophied bronchial and intercostobronchial arteries, as well as a double aortic arch. Bronchial artery aneurysm is potentially life-threatening, and immediate treatment is recommended to minimise the potential risk of rupture. The aneurysms in our case were successfully treated via transcatheter arterial embolisation using coils.     

The immune response in two populations of wild badgers naturally infected with bovine tubercle bacilli

This study describes the immune responses of two defined badger populations; one from East Sussex and another from Staffordshire. The mean in vitro lymphoproliferative response, of all infected badgers from both areas, to Glaxo BCG, was significantly greater than that of healthy animals. The infected badgers had significantly higher antibody levels against mycobacterial antigens, especially New Tuberculin, than did the healthy animals. All the healthy and tuberculous badgers from the Staffordshire area were invariably unreactive to the various preparations used for skin-testing. However, in the East Sussex area, positive reactions were obtained in 10 out of 37 healthy and 7 out of 10 infected animals. This is the first account of positive skin tests in free living badgers. These results support the concept that badgers infected with bovine tubercle bacilli pass through an immunological spectrum throughout much of which they are unlikely to be important sources of infection. In the early stages, tubercle bacilli are excreted from infected wounds, whereas in the later stages, failure of cell-mediated immunity results in excretion of tubercle bacilli from other sites and the badger becomes a potent source of infection.     

The effect of mycobacterial virulence and viability on MAP kinase signalling and TNF alpha production by human monocytes

SETTING: The success of Mycobacterium tuberculosis as a human pathogen depends on its ability to tolerate and perhaps manipulate host defense mechanisms. OBJECTIVE: To determine the induction of tumour necrosis factor-alpha (TNF alpha), a central mediator of immunity, by human monocytes infected with virulent M. tuberculosis, M. leprae and attenuated M. bovis BCG. DESIGN: Mycobacteria-induced cellular activation pathways of TNF alpha production was investigated using an inhibitor of protein tyrosine kinase (PTKs) and an inhibitor of mitogen-activated protein (MAP) kinases. RESULTS: TNF alpha production was significantly lower during infection with virulent M. tuberculosis than with BCG and this differential response was independent of mycobacterial viability. TNF alpha production involved the PTK and MAP kinase pathways. Reduced TNF alpha induction by M. tuberculosis was associated with a reduction in the extent and duration of phosphorylation of extracellular-signal regulated kinases (ERK 1/2). Infection with M. leprae triggered low and transient ERK 1/2 activation as well as low TNF alpha production. CONCLUSION: Maintenance of the differential response in both live and heat-killed preparations suggests that the reduced TNF alpha response associated with virulent mycobacteria is due to differences in the presence of components capable of triggering host pattern recognition receptors, rather than events associated with phagosome trafficking or the active release of intracellular modulators.