Transfecting pDNA to E. coli DH5α using bovine serum albumin nanoparticles as a delivery vehicle

We describe the formulation of bovine serum albumin nanoparticles (BSA‐NPs) by the coacervation method using surfactants. Plasmids (pUC18, pUC18egfp and pBBR1MCS‐2) isolated from E. coli were incorporated into the BSA matrix by incubating in albumin solution prior to formulation of NPs. Plasmid incorporation was calculated by % yield, entrapment efficiency, DNA loading capacity and release of entrapped DNA by comparing with blank NPs. BSA‐DNA binding studies were carried out by using fluorescence spectroscopy and Fourier Transform Infra Red Spectroscopy (FT‐IR). The surface charge distribution of the NPs loaded with plasmid was calculated using zeta potential. The photoluminescence of BSA‐NPs was quenched when loaded with pDNA, confirming the interaction of DNA with BSA. Altogether, these results provide evidences for the excellent DNA carrying efficiency of BSA‐NPs without loss of plasmid's integrity. The NPs were used to transfect E. coli DH5α strain lacking ampicillin resistance. They, however, showed ampicillin resistance subsequent to transfection with plasmid encoding ampicillin resistance gene. Effect of transfection was confirmed by confocal microscopy and by the isolation of the plasmid by agarose gel electrophoresis from the transfected bacterial culture. This study clearly demonstrates the efficacy of BSA‐NPs as delivery vehicle for pDNA transfection. Copyright © 2014 John Wiley & Sons, Ltd.     

Crystal structure and solution conformation of S,S'-bis(Boc-Cys-Ala-OMe): intramolecular antiparallel beta-sheet conformation of an acyclic cystine peptide

The conformation of the acyclic biscystine peptide S,S'-bis(Boc-Cys-Ala-OMe) has been studied in the solid state by x-ray diffraction, and in solution by 1H- and 13C-nmr, ir, and CD methods. The peptide molecule has a twofold rotation symmetry and adopts an intramolecular antiparallel beta-sheet structure in the solid state. The two antiparallel extended strands are stabilized by two hydrogen bonds between the Boc CO and Ala NH groups [N...O 2.964 (3) A, O...HN 2.11 (3) A, and NH...O angle 162 (3) degrees]. The disulfide bridge has a right-handed conformation with the torsion angle C beta SSC beta = 95.8 (2) degrees. In solution the presence of a twofold rotation symmetry in the molecule is evident from the 1H- and 13C-nmr spectra. 1H-nmr studies, using solvent and temperature dependencies of NH chemical shifts, paramagnetic radical induced line broadening, and rate of deuterium-hydrogen exchange effects on NH resonances, suggest that Ala NH is solvent shielded and intramolecularly hydrogen bonded in CDCl3 and in (CD3)2SO. Nuclear Overhauser effects observed between Cys C alpha H and Ala NH protons and ir studies provide evidence of the occurrence of antiparallel beta-sheet structure in these solvents. The CD spectra of the peptide in organic solvents are characteristic of those observed for cystine peptides that have been shown to adopt antiparallel beta-sheet structures.     

Microtubule inhibitors differentially affect translational movement,cell surface expression,and endocytosis of transferrin receptors in K562 cells

We used quantitative fluorescence microscopy and fluorescence photobleaching recovery techniques to investigate the translational movement, cell surface expression, and endocytosis of transferrin receptors in K562 human erythroleukemia cells. Receptors were labeled with fluorescein-conjugated transferrin (FITC-Tf). Coordinated decreases in surface fluorescence counts, the photobleachig parameter K, and transferrin receptor fractional mobility were observed as FITC-Tf was cleared from the cell surface by receptor-mediated endocytosis. Based on the kinetics of decrease in these parameters, first order rate constants for FITC-Tf uptake at 37°C and 21°C were calculated to be 0.10-0.15 min^?1 and 0.02–0.03 min, respectively. K562 cells were treated with colchicine or vinblastine to investigate the role of microtubules in transferrin receptor movement and endocytosis. Treatment of cells for 1 hr with a microtubule inhibitor prevented transferrin receptor endocytosis but had no effect on the translational mobility of cell surface receptors. In contrast, drug treatment for 3 hr caused translational immobilization of cell surface receptors as well as inhibition of endocytosis. These effects were not produced by β-lumicolchicine, an inactive colchicine analog, or by cytochalasin, a microfilament inhibitor. The effect of microtuble inhibitors on transferrin receptor mobility was reversed by pretreating cells with taxol, a microtubule-stabilizing agent. Microtubule inhibitors had no effect on the translational mobility of cell surface glycophorins or phospholipids, indicating that intact microtubules were not required for translational movement of these molecules. We conclude that the translational movement of cell surface transferrin receptors is directed by a subpopulation of relatively drug-resistant microtubules. In contrast, transferrin receptor endocytosis depends on a subpopulation of microtubules that is relatively sensitive to the action of inhibitors. These results appear to demonstrate at least two functional roles for microtubules in receptor-mediated transferrin uptake in K562 cells. © 1994 Wiley-Liss, Inc.     

Effect of pea and lentil lectins on in vitro absorption of nutrients

In vitro absorption of nutrients like glucose, leucine, protein hydrolysate and Ca2+ by ligated loops of small intestine was significantly affected in presence of lectins from peas and lentils. Except for sucrose, all other nutrients showed significant decrease in their absorption in presence of lectins. Lentil lectins had a greater inhibitory effect than pea lectins.     

Self-Administered Tuberculosis Treatment Outcomes in a Tribal Population on the Indo-Myanmar Border,Nagaland, India

Background

Multiple strategies are being adopted by national tuberculosis (TB) programmes to achieve universal coverage of tuberculosis treatment. However, populations living in ‘hard-to-reach’ areas of north-east India have poor access to health services. Our study aimed to detail treatment outcomes in TB program supported by Médecins Sans Frontières (MSF) and using an alternative model of TB treatment delivery in Mon district, Nagaland, India.

Methods

This was a retrospective cohort study of TB patients, initiated on self-administered therapy (SAT) through Mon District Hospital, Nagaland, India between April 2012 and March 2013.

Results

A total of 238 tuberculosis patients had final TB treatment outcomes during the study period, including 82 and 156 from semi-urban and rural areas respectively. The majority of patients (62%, 147/238) were suffering from pulmonary, smear-positive tuberculosis. Overall, 74% of patients (175/238) had successful outcomes, being cured or having completed their treatment. Females (81%), pulmonary TB patients (75%) and those on a Category I regimen (79%) had better treatment success rates than males (67%), extra-pulmonary TB patients (62%) and patients on a Category II regimen (61%). The univariate and bivariate analyses found age, sex and TB treatment regimen significantly associated with unsuccessful TB treatment outcomes (defined as death, loss-to-follow-up and failure). However, only older age showed significance in a multivariate binary logistic regression model.

Conclusion

Our study suggests that self-administered TB treatment is feasible for patients living in areas with limited or no access to health services. The relatively low number of patients with adverse outcomes suggests that SAT models are safe; other advantages include the need for fewer resources and less frequent movements by patients. National TB programmes should consider allowing SAT strategies for delivery of TB treatment to ‘hard-to-reach’ populations, which could in turn help to achieve universal coverage and contribute to global TB elimination by 2050.     

Immune Derangements in Patients with Myelofibrosis: The Role of Treg,Th17, and sIL2Rα

Myelofibrosis (MF), including primary myelofibrosis, post-essential thrombocythemia MF, and post-polycythemia vera MF, has been reported to be associated with autoimmune phenomena. IMiDs have been reported to be effective in some patients with MF, presumably for their immune-modulator effects. We therefore sought to elucidate the immune derangements in patients with MF. We found no differences in T regulatory cells (Treg) and T helper 17 (Th17) cells in MF patients and normal healthy controls. However, we found significantly elevated soluble interleukin 2 alpha (sIL2Rα) in MF patients compared to those with other myeloproliferative neoplasm diseases and normal healthy controls. Our studies with MF patients further revealed that Treg cells were the predominant cells producing sIL2Rα. sIL2Rα and IL2 complex induced the formation of Treg cells but not the formation of Th1 or Th17 cells. sIL2Rα induced CD8⁺ T cell proliferation in the presence of Treg cells. Monocytes or neutrophils had no effect on the production of sIL2Rα by Treg cells. Furthermore, we found plasma sIL2Rα levels were correlated to the auto-immune serology in MPN patients and ruxolitinib significantly inhibits the sIL2Rα production by the Treg cells in MF patients which may explain the effects of ruxolitinib on the relief of constitutional symptoms. All these findings suggest that sIL2Rα likely plays a significant role in autoimmune phenomena seen in patients with MF. Further studies of immune derangement may elucidate the mechanism of IMiD, and exploration of immune modulators may prove to be important for treating myelofibrosis.     

Long-term Survival From Muscleinvasive Bladder Cancer With Initial Presentation of Symptomatic Cerebellar Lesion: The Role of Selective Surgical Extirpation of the Primary and Metastatic Lesion

A 59-year-old man was diagnosed with urothelial carcinoma involving an isolated cerebellar metastasis after presenting to the emergency department for headache complaints. After selective surgical excision of the symptomatic brain lesion and delayed cystectomy due to intractable hematuria, he survived 11 years without evidence of recurrence or subsequent systemic chemotherapy. He eventually expired after delayed recurrence in the lung, supraclavicular lymph node, and brain. To our knowledge, this is the only case of prolonged survival from urothelial carcinoma after selective surgical extirpation of the primary and metastatic lesion without subsequent systemic chemotherapy.Key words: Bladder cancer, Cystectomy, Metastasis, Urothelial carcinomaUsually, brain metastasis of bladder urothelial carcinoma is associated with widespread systemic disease and/or multiple brain lesions. It is exceedingly rare to have bladder cancer metastasize to the brain without evidence of additional systemic manifestations.¹ As with other forms of distant urothelial carcinoma metastasis, brain metastasis is associated with poor prognosis, with survival often less than 14 months in those with solitary brain lesions.² We report an isolated bladder urothelial carcinoma metastasis to the cerebellum with an 11-year survival fol-lowing extirpative therapy of both the primary lesion and brain metastasis.     

Molecular structure,vibrational spectroscopic,NBO and HOMO–LUMO studies of 2-amino 6-bromo 3-formylchromone

A systematic quantum mechanical study of the possible conformations and vibrational spectra of 2-amino 6-bromo 3-formylchromone has been reported. The equilibrium geometry, harmonic vibrational frequencies, infrared intensities and activities of Raman scattering were calculated by Hartree–Fock and density functional theory employing Becke's three-parameter (local, non-local and HF) hybrid exchange functionals with Lee–Yang–Parr co-relational (B3LYP) functionals using 6-311++G(d,p) basis set with complete relaxation in the potential energy surface. The calculated wavenumbers after proper scaling show a very good agreement with the observed values. The electrostatic potential mapped onto isodensity surface has been obtained. The natural bond orbital analysis has been carried out in order to study the intra-molecular bonding, interactions among bonds and delocalisation of unpaired electrons. The highest occupied molecular orbital–lowest unoccupied molecular orbital studies have been conducted in order to determine the way the molecule interacts with other species.     

Localized Surface Plasmon Resonance and Refractive Index Sensitivity of Metal–Dielectric–Metal Multilayered Nanostructures

The localized surface plasmon resonances of multilayered nanostructures are studied using finite difference time domain simulations and plasmon hybridization method. Concentric metal–dielectric–metal (MDM) structure with metal core and nanoshell separated by a thin dielectric layer exhibits a strong coupling between the core and nanoshell plasmon resonance modes. The coupled resonance mode wavelengths show dependence on the dielectric layer thickness and composition of core and outer layer metal. The aluminum-based MDM structures show lower plasmon wavelength compared with Ag- and Au-based MDM nanostructures. The calculated refractive index sensitivity (RIS) factor is in the order Ag–Air–Ag>Au–Air–Au>Al–Air–Al for monometallic multilayered nanostructures. Bimetallic multilayered nanostructures support strong and tunable plasmon resonance wavelengths as well as high RIS factor of 510 nm/refractive index unit (RIU) and 470 nm/RIU for Al–Air–Au and Ag-Air-Au, respectively. The MDM structures not only exhibit higher index sensitivity but also cover a wide ultraviolet–near-infrared wavelengths, making these structures very promising for index sensing, biomolecule sensing, and surface-enhanced Raman spectroscopy.     

1-Benzyl-3-cetyl-2-methylimidazolium iodide (NH125) induces phosphorylation of eukaryotic elongation factor-2 (eEF2): a cautionary note on the anticancer mechanism of an eEF2 kinase inhibitor

Eukaryotic elongation factor-2 kinase (eEF2K) relays growth and stress signals to protein synthesis through phosphorylation and inactivation of eukaryotic elongation factor 2 (eEF2). 1-Benzyl-3-cetyl-2-methylimidazolium iodide (NH125) is a widely accepted inhibitor of mammalian eEF2K and an efficacious anti-proliferation agent against different cancer cells. It implied that eEF2K could be an efficacious anticancer target. However, eEF2K siRNA was ineffective against cancer cells including those sensitive to NH125. To test if pharmacological intervention differs from siRNA interference, we identified a highly selective small molecule eEF2K inhibitor A-484954. Like siRNA, A-484954 had little effect on cancer cell growth. We carefully examined the effect of NH125 and A-484954 on phosphorylation of eEF2, the known cellular substrate of eEF2K. Surprisingly, NH125 increased eEF2 phosphorylation, whereas A-484954 inhibited the phosphorylation as expected for an eEF2K inhibitor. Both A-484954 and eEF2K siRNA inhibited eEF2K and reduced eEF2 phosphorylation with little effect on cancer cell growth. These data demonstrated clearly that the anticancer activity of NH125 was more correlated with induction of eEF2 phosphorylation than inhibition of eEF2K. Actually, induction of eEF2 phosphorylation was reported to correlate with inhibition of cancer cell growth. We compared several known inducers of eEF2 phosphorylation including AMPK activators and an mTOR inhibitor. Interestingly, stronger induction of eEF2 phosphorylation correlated with more effective growth inhibition. We also explored signal transduction pathways leading to NH125-induced eEF2 phosphorylation. Preliminary data suggested that NH125-induced eEF2 phosphorylation was likely mediated through multiple pathways. These observations identified an opportunity for a new multipathway approach to anticancer therapies.