A π-π Bonding-Assisted Molecular-Wiring of Folded-Cytochrome c and Naphthoquinone and Its Electron-Relay-Based Bioelectrocatalytic H2O2 Reduction Reaction Visualized by Redox-Competitive Scanning Electrochemical Microscopy

The electron-transfer (ET) reaction of cytochrome c (Cytc) protein with biomolecules is a cutting-edge research area of interest in understanding the functionalities of natural systems. Several electrochemical biomimicking studies based on Cytc-protein-modified electrodes prepared via electrostatic interaction and covalent bonding approaches have been reported. Indeed, natural enzymes involve multiple types of bonding, such as hydrogen, ionic, covalent, and π-π, etc. In this work, we explore a Cytc-protein chemically modified glassy carbon electrode (GCE/CB@NQ/Cytc) prepared via π-π bonding using graphitic carbon as an underlying surface and an aromatic organic molecule, naphthoquinone (NQ), as a cofactor for an effective ET reaction. A simple drop-casting technique-based preparation of GCE/CB@NQ showed a distinct surface-confined redox peak at a standard electrode potential (E°) = -0.2 V vs Ag/AgCl (surface excess = 21.3 nmol cm-2) in pH 7 phosphate buffer solution. A control experiment of modification of NQ on an unmodified GCE failed to show any such unique feature. For the preparation of GCE/CB@NQ/Cytc, a dilute solution of Cytc-pH 7 phosphate buffer was drop-cast on the GCE/CB@NQ surface, wherein the protein folding and denaturalization-based complication and its associated ET functionalities were avoided. Molecular dynamics simulation studies show the complexation of NQ with Cytc at the protein binding sites. The protein-bound surface shows an efficient and selective bioelectrocatalytic reduction performance of H2O2, as demonstrated using cyclic voltammetry and amperometric i-t techniques. Finally, the redox-competition scanning electrochemical microscopy (RC-SECM) technique was adopted for in situ visualization of the electroactive adsorbed surface. The RC-SECM images clearly show the regions of highly bioelectrocatalytic active sites of Cytc-proteins bound to NQ molecules on a graphitic carbon surface. The binding of Cytc with NQ has significant implications for studying the biological electron transport mechanism, and the proposed method provides the requisite framework for such a study.

Immunomodulatory Effects of Jacalin, a Dietary Plant Lectin on the Peripheral Blood Mononuclear Cells (PBMCs)

The tumor microenvironment that refers to the tumor's surroundings is a key modulator of tumor growth and invasion. The tumor-derived signals are known to downregulate the anti-tumor effects of the effector cells present in the TME. Thus, the cross-talk between the tumor cells with the surrounding immune cells helps in evading the tumor surveillance as well as aiding in tumor growth and proliferation. Hence, knowledge regarding the effects of drugs/compound on the tumor-stromal interactions is gaining importance. In the present study, the effects of jacalin, a dietary lectin on the proliferation and cytokine production of peripheral blood mononuclear cells (PBMCs), are investigated. Jacalin was shown to act as a mitogen of PBMCs, the key cytokine secreting immune cells. Also, jacalin initially induced increased mRNA expression of pro-inflammatory cytokine IFN-γ; however, prolonged stimulation of PBMCs resulted in increased expression of anti-inflammatory cytokine, mainly TGF-β. Furthermore, 6 h jacalin prestimulated PBMCs (Jac-PBMCs) were shown to inhibit HeLa cell proliferation while 24 h Jac-PBMCs were found to favor tumor growth. Thus, it may be postulated that while jacalin initially polarizes the PBMCs to hinder the tumor growth, after a stipulated time point, interaction of jacalin with PBMCs can lead to an immunosuppressive TME that may probably assist in tumor growth and progression.

Self - Adaptive Load Balancing Using Live Migration of Virtual Machines in Cloud Environment

In this paper, a self-adaptive load balancing technique is proposed using live migration of heterogeneous virtual machines (VM) in a Hyper-V based cloud environment. A cloud supported plugin as a management activity within the infrastructure as a service strategy. It is proposed to assist the load balancing process in such a way so that all hypervisors are almost equally loaded once the overload status gets triggered. In the cloud computing environment, load balancing plays a major role if the large number of events triggered has a high impact on the performance of the system. The efficiency of cloud computing is based on the efficient load balancing having a self-adjustable technique using live migration of VMs across clusters of nodes. The proposed load balancing model is efficient in performance improvement by efficient resource utilization and also it helps to avoid the situation occurrence of server hanging by the cause of server overload within the infrastructure of multiple Microsoft Hyper-V hypervisors environment.

Preparation of Atorvastatin Loaded Chitosan Nanoparticles: In Vitro and In Vivo Evaluations

This study is aimed at the preparation and evaluation of atorvastatin (AN)-loaded chitosan (CS) nanoparticles to achieve improved bioavailability of atorvastatin as its bioavailability is very poor. Chitosan is a popular choice in the application as a drug delivery carrier due to its biocompatibility, chemical versatility, aqueous solubility and low cost. Hence, a total of nine formulations (AN1–AN9) were prepared to study the effects of CS:tripolyphosphate (TPP) ratio and the amount of drug. The best formulation was selected by calculating the overall desirability (OD) factor. Among all, AN9 was found to possess the maximum percentage yield, loading efficiency and percentage (%) drug release compared to other formulations due to the incorporation of more amount of polymer compared to other formulations. SEM microphotographs and zeta-sizer reports indicated that atorvastatin-loaded chitosan nanoparticles were in the nanometric range and were spherical, discrete and uniform in size. The selected polymer chitosan was found to possess good compatibility with atorvastatin, without any mutual interaction, based on the results of DSC and FTIR analyses. The nanoparticles were found to have good flow properties. The in vivo results proved that the best formulation has shown significant difference in the reduction of triglycerides (TG), total cholesterol (TC) and no significant change in high density lipids (HDL) cholesterol levels in blood when compared with the marketed formulation. Better regenerative changes were observed during histopathological evaluation of liver in a group treated with atorvastatin nanoparticles than those of other groups, that confirmed the improved hypolipidemic action. Thus, from all the above observations, it was concluded that AN9 formulation has shown the highest in vitro drug release and loading efficiency than other formulations, which might be due to increased entrapment of drug and the surface area through decreased particle size which further confirmed the improved in vitro bioavailability and in vivo performance than those of marketed atorvastatin tablet. This study strongly suggests the use of chitosan nanoparticles as drug delivery system to improve the bioavailability of atorvastatin.

Sub-Micellar Concentration of Sodium Dodecyl Sulphate Prevents Thermal Denaturation Induced Aggregation of Plant Lectin, Jacalin

The irreversible thermal unfolding of jacalin, the lectin purified from jackfruit seeds was accompanied by aggregation, where intermolecular interactions among the subunits are favoured over intramolecular interactions. The extent of aggregation increased as a function of temperature, time and protein concentration. The anionic surfactant, sodium dodecyl sulphate (SDS) significantly suppressed the formation of aggregates as observed by turbidity measurements and Rayleigh scattering assay. Moreover, far UV-CD spectra indicate that the protein β sheet transforms into α helical structure, when denatured in the presence of 3 mM SDS. Further, jacalin when heated in the presence of SDS partially retained the hemagglutination activity when jacalin-SDS mixture was diluted to 1:8 factor since 3 mM SDS was found to lyse the red blood cells. Thus, SDS only altered the aggregation behaviour of jacalin by preventing intermolecular hydrogen bonding among the exposed residues but did not completely stabilize the native conformation.

An unusual case of Corynebacterium striatum endocarditis in a patient with congenital lymphedema and rheumatic heart disease

Corynebacterium striatum (C. striatum) is a ubiquitous saprophyte with a potential to cause bacteremia. We report the first case of C. striatum endocarditis in a patient with congenital lymphedema and rheumatic heart disease.

Peri-implant soft tissue management: A case report (2 years follow-up) (Patrick Palacci technique revisited)

Peri-implant plastic surgery aims at improving the esthetic aspects of smile and masticatory function. Over the years, several techniques such as tissue punch technique, full thickness flaps, and scalloping adjustment of flaps around implants have been employed; it was very difficult to achieve a papilla like formation around implants. These added time and expense of the final results and led to undesirable complications. In order to overcome these difficulties, this case report describes a surgical technique where in papilla like formation and increase in width of attached gingiva around implants can be achieved with a single surgical procedure.

Vegetables' juice influences polyol pathway by multiple mechanisms in favour of reducing development of oxidative stress and resultant diabetic complications

OBJECTIVE

Hyperglycemia induced generation of free radicals and consequent development of oxidative stress by polyol pathway is one of the crucial mechanisms stirring up development of diabetic complications. We evaluated influence of ten vegetables' juice on polyol pathway along with their antioxidant and antioxidative stress potentials.

MATERIALS AND METHODS

Aldose reductase activity was determined utilising goat lens and human erythrocytes. In goat lens, utilization of nicotinamine adenine dinucleotide phosphate (NADPH) and aldose reductase inhibition was assayed. In human erythrocytes, sorbitol formation was measured as an index of aldose reductase activity under normoglycemic and hyperglycemic conditions. Ability of juices in inhibiting oxidative damage to deoxyribose sugar and calf thymus DNA and inhibitory activity against hydrogen peroxide induced hemolysis of erythrocytes was also analysed. Phytochemical contents like total polyphenol, total flavonoid and total protein were measured to find their influence on biological activities.

RESULTS

Vegetables' juice displayed varying degrees of inhibitory potentials in mitigating NADPH dependent catalytic activity of aldose reductase in goat lens, accumulation of sorbitol in human erythrocytes under different glucose concentrations; Fenton-reaction induced oxidative damage to deoxyribose sugar, and calf thymus DNA. Substantial variations in vegetables phytochemicals content were also noticed in this study.

CONCLUSIONS

Vegetables' juice possesses potent activities in influencing polyol pathway by various mechanisms in favour of reducing development of oxidative stress independent of their inherent antioxidative properties. Juice of ivy gourd followed by green cucumber and ridge gourd were among the most potent for they displayed strong activities on various parameters analysed in this study. These vegetables' juice may become part of mechanism-based complementary antioxidant therapy to prevent development of diabetic complications.

Expression profile of toll-like receptor 2 mRNA in selected tissues of shark (Chiloscyllium sp.)

Sharks are a species of delight for immunologists from the evolutionary perspective since it is considered as the first species to have evolved the adaptive immune responses in addition to the innate immune system. One of the components of the highly conserved innate immune system is the toll-like receptors (TLR) which has a conserved overall protein structure throughout deuterostome evolution. There is no report that demonstrates the expression of these receptors in sharks. In this study we successfully amplified a 270 bp amplicon using a degenerate primer design strategy that corresponded to the Toll/IL-1 receptor (TIR) domain of TLR2 (GenBank ID: JF792813). BLAST analysis revealed a maximum nucleotide identity of 87% and 76% with the TLR2 of higher mammals and teleost fishes respectively. Domain prediction revealed a TIR structure between 1 and 87 amino acids that had a maximum identity of 58% and 76% with TLR2 - TIR protein of teleost fishes and higher mammals respectively. Phylogenetic analysis revealed a closer clustering of the shark TIR sequence with those from human, cattle, goat, sheep and chicken than with other fish species. Basal expression levels of the TLR2-TIR mRNA were found to be significantly higher in kidneys followed by fins, spleen and intestinal spiral valve (ISV). In tissues such as spleen and kidney the expression of the TLR2-TIR mRNA could be localized to lymphoid and macrophages like cells and tubular epithelial cells respectively. In-vivo exposure of sharks to peptidoglycan (TLR 2 ligand) resulted in 9 folds higher expression of TLR2-TIR mRNA in gills followed by 5 folds in the fins. However, when inoculated with a TLR ligand pool, the expression levels significantly increased to 12 fold in skin followed by epigonal, kidneys and ISV. These findings not only support the presence of the TLRs in sharks but also their induction upon exposure to specific ligands. Further studies are needed to identify their numbers, their ligand specificity and downstream cytokine responses.