Seventeen Indian folklore medicinal plants were investigated to evaluate antibacterial activity of aqueous, ethanol and acetone extracts against 66 multidrug resistant isolates of major urinary tract pathogens (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Enterococcus faecalis) by disc diffusion method. Ethanol extract of Zingiber officinale and Punica granatum showed strong antibacterial activity against Escherichia coli. Ethanol extracts of Terminalia chebula and Ocimum sanctum exhibited antibacterial activity against Klebsiella pneumoniae. Ethanol extract of Cinnamomum cassia showed maximum antibacterial activity against Pseudomonas aeruginosa while ethanol extract of Azadirachta indica and Ocimum sanctum exhibited antibacterial activity against Enterococcus faecalis. The results support the folkloric use of these plants in the treatment of urinary tract infections by the tribals of Mahakoshal region of central India.

Asparaginase is an important antileukemic agent extensively used worldwide but the intrinsic glutaminase activity of this enzymatic drug is responsible for serious life threatening side effects. Hence, glutaminase free asparaginase is much needed for upgradation of therapeutic index of asparaginase therapy. In the present study, glutaminase free asparaginase produced from Enterobacter cloacae was purified to apparent homogeneity. The purified enzyme was found to be homodimer of approximately 106 kDa with monomeric size of approximately 52 kDa and pI 4.5. Purified enzyme showed optimum activity between pH 7–8 and temperature 35–40°C, which is close to the internal environment of human body. Monovalent cations such as Na+ and K+ enhanced asparaginase activity whereas divalent and trivalent cations, Ca2+, Mg2+, Zn2+, Mn2+, and Fe3+ inhibited the enzyme activity. Kinetic parameters Km, Vmax and Kcat of purified enzyme were found to be 1.58×10−3 M, 2.22 IU μg-1 and 5.3 × 104 S-1, respectively. Purified enzyme showed prolonged in vitro serum (T1/2 = ~ 39 h) and trypsin (T1/2 = ~ 32 min) half life, which is therapeutically remarkable feature. The cytotoxic activity of enzyme was examined against a panel of human cancer cell lines, HL-60, MOLT-4, MDA-MB-231 and T47D, and highest cytotoxicity observed against HL-60 cells (IC50 ~ 3.1 IU ml-1), which was comparable to commercial asparaginase. Cell and nuclear morphological studies of HL-60 cells showed that on treatment with purified asparaginase symptoms of apoptosis were increased in dose dependent manner. Cell cycle progression analysis indicates that enzyme induces apoptosis by cell cycle arrest in G0/G1 phase. Mitochondrial membrane potential loss showed that enzyme also triggers the mitochondrial pathway of apoptosis. Furthermore, the enzyme was found to be nontoxic for human noncancerous cells FR-2 and nonhemolytic for human erythrocytes.

Calcium signaling, in addition to its numerous physiological roles, is also implicated in several pathological conditions including cancer. An increasing body of evidence suggest critical roles of calcium signaling in the promotion of different aspects of cancer, including cell proliferation, therapy resistance and metastatic-related processes. In many cases, this is associated with altered expression and/or activity of some calcium channels and pumps. Brain cancers have also been the subject of many of these studies. In addition to diverse roles of calcium signals in normal brain function, a number of proteins involved in calcium transport are implicated to have specific roles in some brain cancers including gliomas, medulloblastoma, neuroblastoma and meningioma. This review discusses research that has been conducted so far to understand diverse roles of Ca2+-transporting proteins in the progression of brain cancers, as well as any attempts to target these proteins towards a therapeutic approach for the control of brain cancers. Finally, some knowledge gaps in the field that may need to be further considered are also discussed.

Vibrio cholerae is indigenous to the aquatic environment, and serotype non-O1 strains are readily isolated from coastal waters. However, in comparison with intensive studies of the O1 group, relatively little effort has been made to analyze the population structure and molecular evolution of non-O1 V. cholerae. In this study, high-resolution genomic DNA fingerprinting, amplified fragment length polymorphism (AFLP), was used to characterize the temporal and spatial genetic diversity of 67 V. cholerae strains isolated from Chesapeake Bay during April through July 1998, at four different sampling sites. Isolation of V. cholerae during the winter months (January through March) was unsuccessful, as observed in earlier studies (J. H. L. Kaper, R. R. Colwell, and S. W. Joseph, Appl. Environ. Microbiol. 37:91-103, 1979). AFLP fingerprints subjected to similarity analysis yielded a grouping of isolates into three large clusters, reflecting time of the year when the strains were isolated. April and May isolates were closely related, while July isolates were genetically diverse and did not cluster with the isolates obtained earlier in the year. The results suggest that the population structure of V. cholerae undergoes a shift in genotype that is linked to changes in environmental conditions. From January to July, the water temperature increased from 3°C to 27.5°C, bacterial direct counts increased nearly an order of magnitude, and the chlorophyll a concentration tripled (or even quadrupled at some sites). No correlation was observed between genetic similarity among isolates and geographical source of isolation, since isolates found at a single sampling site were genetically diverse and genetically identical isolates were found at several of the sampling sites. Thus, V. cholerae populations may be transported by surface currents throughout the entire Bay, or, more likely, similar environmental conditions may be selected for a specific genotype. The dynamic nature of the population structure of this bacterial species in Chesapeake Bay provides new insight into the ecology and molecular evolution of V. cholerae in the natural environment.

Conductive hydrogels are attracting considerable interest in view of their potential in a wide range of applications that include healthcare and electronics. Such hydrogels are generally incorporated with conductive materials/polymers....

Repair of critical size bone defects is a clinical challenge that usually necessitates the use of bone substitutes. For successful bone repair, the substitute should possess osteoconductive, osteoinductive, and vascularization potential, with the ability to control post-implantation infection serving as an additional advantage. With an aim to develop one such substitute, we optimized a zinc-doped hydroxyapatite (HapZ) nanocomposite decorated on reduced graphene oxide (rGO), termed as G3HapZ, and demonstrated its potential to augment the bone repair. The biocompatible composite displayed its osteoconductive potential in biomineralization studies, and its osteoinductive property was confirmed by its ability to induce mesenchymal stem cell (MSC) differentiation to osteogenic lineage assessed by in vitro mineralization (Alizarin red staining) and expression of osteogenic markers including runt-related transcription factor 2 (RUNX-2), alkaline phosphatase (ALP), type 1 collagen (COL1), bone morphogenic protein-2 (BMP-2), osteocalcin (OCN), and osteopontin (OPN). While the potential of G3HapZ to support vascularization was displayed by its ability to induce endothelial cell migration, attachment, and proliferation, its antimicrobial activity was confirmed using S. aureus. Biocompatibility of G3HapZ was demonstrated by its ability to induce bone regeneration and neovascularization in vivo. These results suggest that G3HapZ nanocomposites can be exploited for a range of strategies in developing orthopedic bone grafts to accelerate bone regeneration.

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The aim of stem cell therapy is to repair damaged tissues. Some of the challenges facing its success include cell retention and survival at the wound site. While the retention of cells has been addressed by employing scaffolds, the survival of transplanted cells in the repair tissue is however low. It is hypothesized that the observed regeneration is more a result of migration of tissue repairing cells from adjoining tissues in response to paracrine factors secreted by implanted cells than by the implanted cells per se. In this study, we report the synthesis of a self-healing hybrid hydrogel that is injectable. The hybrid hydrogel was developed using the dynamic equilibrium of Schiff base linkage between the aldehyde groups on carboxymethyl cellulose dialdehyde (CMC-D) and amino groups on carboxymethyl chitosan (CMCh). The hydrogel stiffness and kinetics of gelation were observed to be modulated with different molecular weights of chitosan. In vitro studies demonstrated the cytocompatibility, hemocompatibility, and biodegradability of the hydrogel. The chemotactic, proliferative, and wound-healing response of cells to the paracrine factors secreted from the mesenchymal stem cell (MSC)−hydrogel composite confirmed the ability of the hydrogel to support the paracrine response of stem cells. Our results suggest that the synthesized hydrogel−MSC composite could serve as a potential scaffold for studying the in vitro response of cells to the paracrine factors released by the encapsulated cells as well as a cell delivery vehicle for in vivo applications.