Synthesis,characterization, biological evaluation,and drug release study of polyamidoamine-containing neridronate

Polyamidoamines were synthesized by Michael-type polyaddition reaction and conjugates characterized by ¹H NMR, ³¹ Mosmann, T. Rapid Colorimetric Assay for Cellular Growth and Survival: Application to Proliferation and Cytotoxicity Assays. J. Immunol. Meth. 1983, 65, 55–63.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]P NMR, FTIR, SEM, and EDX. The biological evaluation of the new materials revealed 12–30% inhibition of the human breast cancer cells (MCF7) and 25% of the Plasmodium falciparum malaria parasites by the conjugates. The hemolysis assay revealed that these materials did not have any effect on the host red blood cell membrane. The release mechanism of neridronate followed Korsmeyer–Peppas model at pH 1.2 with a diffusion coefficient of 0.45 indicating a Fickian diffusion mechanism; Higuchi model at pH 6.0 thus indicating a diffusion mechanism.     

Unusual switchable peroxidase-mimicking nanozyme for the determination of proteolytic biomarker

Detection of enzyme biomarkers originating from either bio-fluids or contaminating microorganisms is of utmost importance in clinical diagnostics and food safety. Herein, we present a simple, low-cost and easy-to-use sensing approach based on the switchable peroxidase-mimicking activity of plasmonic gold nanoparticles (AuNPs) that can catalyse for the oxidation of 3,3’,5’5-tetramethylbenzidine (TMB) for the determination of protease enzyme. The AuNP surface is modified with casein, showing dual functionalities. The first function of the coating molecule is to suppress the intrinsic peroxidase-mimicking activity of AuNPs by up to 77.1%, due to surface shielding effects. Secondly, casein also functions as recognition sites for the enzyme biomarker. In the presence of protease, the enzyme binds to and catalyses the degradation of the coating layer on the AuNP surface, resulting in the recovery of peroxidase-mimicking activity. This is shown visually in the development of a blue colored product (oxidised TMB) or spectroscopically as an increase in absorbance at 370 and 650 nm. This mechanism allows for the detection of protease at 44 ng·mL⁻¹ in 90 min. The nanosensor circumvents issues associated with current methods of detection in terms of ease of use, compatibility with point-of-care testing, low-cost production and short analysis time. The sensing approach has also been applied for the detection of protease spiked in ultra-heat treated (UHT) milk and synthetic human urine samples at a limit of detection of 490 and 176 ng·mL⁻¹, respectively, showing great potential in clinical diagnostics, food safety and quality control.

     

Expression and characterisation of recombinant human CD48 and isolation of a human anti‐CD48 monoclonal antibody by phage display

Human CD48, a membrane‐bound, glycosylphosphatidylinositol (GPI)‐linked glycoprotein, is a potential tumour target for the treatment of leukaemias and lymphomas. CD48 is expressed on T‐ and B‐cells, however <5% of CD34⁺ progenitor cells express CD48. A truncated, 45 kDa soluble form of the full length CD48 was expressed in Chinese hamster ovary (CHO) cells, and was shown to consist of a broad range of charge isoforms, with the most abundant isoforms between pI 4.5 and 5.0. The truncated form of CD48 was shown to bind to antibodies raised against native, GPI‐linked CD48 by surface plasmon resonance analysis. A synthetic, human, scFv immunoglobulin gene library was screened against recombinant CD48 by phage display, and an scFv antibody fragment, (designated N2A) was isolated after four rounds of biopanning. N2A was reassembled as a human IgG1 human monoclonal antibody, expressed in CHO cells and the binding of IgG1‐N2A to recombinant CD48 was confirmed by surface plasmon resonance. Flow cytometry studies of IgG1‐N2A binding to Raji cells showed the specificity of N2A for GPI‐linked CD48 was conserved, and presents the potential for IgG1‐N2A as a lead antibody candidate for the treatment of white blood cell malignancies. Copyright © 2005 Society of Chemical Industry     

Rule selection versus rule execution in preschoolers: An error-detection approach.

In 2 experiments, an error-detection approach was used to determine whether 3-year-olds' perseverative errors on the postswitch phase of the Dimensional Change Card Sort (DCCS) are due to lack of response control or representational inflexibility. In Experiment 1, 3-, 4-, and 5-year-olds watched a puppet sort perseveratively on the postswitch phase and evaluated its responses. Most 4- and 5-year-olds detected the puppet's perseverative errors, whereas most 3-year-olds failed to do so despite detecting errors on a simpler card sort. Experiment 2 revealed that 3-year-olds who failed to correctly evaluate the puppet's behavior tended to fail their own DCCS. Results imply that perseveration on the DCCS cannot be attributed to difficulty inhibiting prepotent motor responses. Instead, changes in rule use between 3 and 5 years of age are interpreted in terms of the development of representational flexibility. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reflections on a proposed theory of reservation-dwelling American Indian alcohol use: Comment on Spillane and Smith (2007).

In their recent article, N. Spillane and G. Smith (see record 2007-06095-002) suggested that reservation-dwelling American Indians have higher rates of problem drinking than do either non–American Indians or those American Indians living in nonreservation settings. These authors further argued that problematic alcohol use patterns in reservation communities are due to the lack of contingencies between drinking and “standard life reinforcers” (SLRs), such as employment, housing, education, and health care. This comment presents evidence that these arguments were based on a partial review of the literature. Weaknesses in the application of SLR constructs to American Indian reservation communities are identified as is the need for culturally contextualized empirical evidence supporting this theory and its application. Cautionary notes are offered about the development of literature reviews, theoretical frameworks, and policy recommendations for American Indian communities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Job stress in the Australian and international health and community services sector: A review of the literature.

We reviewed 25 international and 10 Australian studies published between 1999 and 2004 for evidence of individual and organizational impacts of stress in the health and community services (HCS) sector. Several HCS occupations showed high levels of distress compared to Australian population data. Results were consistent with the Job Demands-Resources model: High demands (e.g., workload, emotional) combined with low resources (e.g., control, rewards, support) were associated with adverse health (e.g., psychological, physical) and organizational impacts (e.g., reduced job satisfaction, sickness absence). Australian-specific issues included rural and remote work and the complex role of Aboriginal Health Workers. Strong associations between modifiable work factors and adverse outcomes provide a rationale for primary preventive policy development by occupational health and safety regulators and workers' compensation authorities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Review of Occupational Stress Interventions in Australia.

The authors investigated empirical research into occupational stress interventions conducted in Australia within the past 10 years. They focused on evidence published and the quality of the evidence base. All intervention studies were conducted in the public sector. Only 1 study reached the gold standard in evidence-based research. Most interventions were individually focused, despite the preponderance of research identifying risky work environment stressors. Results suggest a paucity of published information regarding what works with occupational stress interventions in Australia and an urgent need for further research in the area, particularly focusing on the private sector, rural workers, and scientific evaluation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spectral characterization of electroluminescent devices containing functionalized dipyrido[3,2-a:2′,3′-c]phenazine complexes

A series of functionalized dipyrido[3,2-a:2′,3′-c]phenazine complexes with copper(I), rhenium(I), ruthenium(II) and iridium(III) have been synthesized and used as dopants in OLEDs. The ruthenium-based complexes are the most efficient appearing blue in colour, the copper complexes give devices that appear white in emission. In most cases the emission colour is a mixture of emission from the metal complex and from the matrix (PVK).     

Synthesis of new phosphate derivative of benzothiazole and its inhibiting effect on two series of human neuroblastoma cell growth

The sodium salt of di ((1-hydroxy-2-benzothiazolium-1-yl) ethyliden-1,1-H-bisphosphonic acid) orthophosphate was synthesized and its toxicity and viability effects screened on two different human neuroblastoma cell lines. This novel derivative of benzothiazole provides a new compound in connection with research and therapeutic application for tumor cell growth inhibition. Benzothiazole was alkylated in reaction with bromoacetic acid and then converted to its H-bisphosphonic acid derivative in presence of H₃PO₃/POCl₃. The procedure led to formation of two molecules of corresponding H-bisphosphonic acid which attached together via a phosphate bridge. The investigated compound exhibits activities (IC₅₀ value) ranging from 14–23 μM (corresponding to human neuroblastoma SK-BE (2) and SK-NM-C cells).     

Polymerised high internal phase emulsion cement hybrids: Macroporous polymer scaffolds for setting cements

We polymerised the continuous styrene/divinylbenzene monomer phase of high internal phase emulsions (HIPEs) containing 70 vol.% cement slurry as internal phase to synthesise polymer cement hybrid materials. These novel cement containing poly(merised)HIPEs have an interconnected bi-phasic structure consisting of an interpenetrating network of set cement and polymer. Incorporating 14 wt.% of polymer into the cement resulted in an increased compressive strain to failure as compared to pure set cement but both elastic modulus and crush strength decreased. These novel polymer cement hybrid materials have a better chemical resistance against acetic acid then pure cement and showed also no shrinkage when exposed to xylene and dodecane.