TRARESA: a tissue microarray-based hospital system for biomarker validation and discovery

Formalin fixed and paraffin embedded tissue (FFPE) collections in pathology departments are the largest resource for retrospective biomedical research studies. Based on the literature analysis of FFPE related research, as well as our own technical validation, we present the Translational Research Arrays (TRARESA), a tissue microarray centred, hospital based, translational research conceptual framework for both validation and/or discovery of novel biomarkers. TRARESA incorporates the analysis of protein, DNA and RNA in the same samples, correlating with clinical and pathological parameters from each case, and allowing (a) the confirmation of new biomarkers, disease hypotheses and drug targets, and (b) the postulation of novel hypotheses on disease mechanisms and drug targets based on known biomarkers. While presenting TRARESA, we illustrate the use of such a comprehensive approach. The conceptualisation of the role of FFPE-based studies in translational research allows the utilisation of this commodity, and adds to the hypothesis-generating armamentarium of existing high-throughput technologies.     

Preparation and evaluation of immunogenic conjugates of Salmonella enterica serovar Typhi O-specific polysaccharides with diphtheria toxoid

Typhoid fever, caused by Salmonella enterica serovar Typhi (S. Typhi), is a major health problem particularly in developing countries. The available vaccines have certain limitations regarding their efficacy, and inability to induce an immune response especially in individuals under 2 years of age. Conjugate vaccines which consist of a bacteria-specific polysaccharide chemically bound to a carrier protein overcome these problems by inducing a T-cell dependent immune response characterized by enhanced immunogenicity in all ages. In this study, O-specific polysaccharides (OSP) of S. Typhi were conjugated to diphtheria toxoid (DT) using adipic acid dihydrazide (ADH) as a linker. These conjugates (OSP-AH-DT) were then evaluated for their immunogenicity using mice as a model and showed significantly higher levels of IgG ELISA titers (P = 0.0241 and 0.0245) than lipopolysaccharides alone. Different immunization schedules were compared and it was found that schedule-B (three injections with 4-weeks interval) induced higher immune responses than schedule-A (three injections with 2-weeks interval). We showed that diphtheria toxoid can be successfully employed as a carrier protein for conjugation with Salmonella OSP and play an important role in facilitating adequate immune response.     

Feasibility of fiber optic displacement sensor scanning system for imaging of dental cavity

The purpose of this study is to investigate the potential of intensity modulated fiber optic displacement sensor scanning system for the imaging of dental cavity. Here, we discuss our preliminary results in the imaging of cavities on various teeth surfaces, as well as measurement of the diameter of the cavities which are represented by drilled holes on the teeth surfaces. Based on the analysis of displacement measurement, the sensitivities and linear range for the molar, canine, hybrid composite resin, and acrylic surfaces are obtained at 0.09667 mV/mm and 0.45 mm; 0.775 mV/mm and 0.4 mm; 0.5109 mV/mm and 0.5 mm; and 0.25 mV/mm and 0.5 mm, respectively, with a good linearity of more than 99%. The results also show a clear distinction between the cavity and surrounding tooth region. The stability, simplicity of design, and low cost of fabrication make it suitable for restorative dentistry.     

Comparing the efficacy of team based learning strategies in a problem based learning curriculum

We introduced two variants of team based learning (TBL) strategies in pathology course to seek their efficacy in a problem based learning (PBL) curriculum. The TBL strategy was adopted in two different sessions. One during regular resource session (RS‐TBL) and other during a weekly review session (RVS‐TBL) of the PBL curriculum. The study involved 104 second year students during their 8 weeks of cardiovascular‐respiratory units and 3 weeks of hematology units. RS‐TBL was adopted for cardiovascular‐respiratory unit and RVS‐TBL for hematology unit. The first 8 weeks of the course were implemented as RS‐TBL and the last 3 weeks as RVS‐TBL. The results showed that the group performance was markedly improved than individual performance in both RS‐TBL and RVS‐TBL (p < 0.001). Comparison between the RS‐TBL and RVS‐TBL revealed that individual student and group performance was better in the RVS‐BL (p < 0.001). The result of the student attitudinal survey indicated an 88% agreement that TBL enhanced their understanding of pathology concepts and critical analysis. Most of the participants (85%) found RVS‐TBL to be more useful. Post‐TBL, end of semester examination results proved beneficial for the students in risk. The study demonstrated that RVS‐TBL may be preferably adopted to enhance the philosophy of TBL in a PBL curriculum.     

Evaluation of Catharanthus roseus leaf extract-mediated biosynthesis of titanium dioxide nanoparticles against Hippobosca maculata and Bovicola ovis

The purpose of the present study was based on assessments of the antiparasitic activities of synthesized titanium dioxide nanoparticles (TiO₂ NPs) utilizing leaf aqueous extract of Catharanthus roseus against the adults of hematophagous fly, Hippobosca maculata Leach (Diptera: Hippoboscidae), and sheep-biting louse, Bovicola ovis Schrank (Phthiraptera: Trichodectidae). The synthesized TiO₂ NPs were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The formation of the TiO₂ NPs synthesized from the XRD spectrum compared with the standard confirmed spectrum of titanium particles formed in the present experiments were in the form of nanocrystals, as evidenced by the peaks at 2?? values of 27.43°, 36.03°, and 54.32°. The FTIR spectra of TiO₂ NPs exhibited prominent peaks at 714 (Ti?CO?CO bond), 1,076 (C?CN stretch aliphatic amines), 1,172 (C?CO stretching vibrations in alcoholic groups), 1,642 (N?CH bend bond), and 3,426 (O?CH stretching due to alcoholic group). SEM analysis of the synthesized TiO₂ NPs clearly showed the clustered and irregular shapes, mostly aggregated and having the size of 25?C110?nm. By Bragg??s law and Scherrer??s constant, it is proved that the mean size of synthesized TiO₂ NPs was 65?nm. The AFM obviously depicts the formation of the rutile and anatase forms in the TiO₂ NPs and also, the surface morphology of the particles is uneven due to the presence of some of the aggregates and individual particles. Adulticidal parasitic activity was observed in varying concentrations of aqueous leaf extract of C. roseus, TiO₂ solution, and synthesized TiO₂ NPs for 24?h. The maximum parasitic activity was observed in aqueous crude leaf extracts of C. roseus against the adults of H. maculata and B. ovis with LD₅₀ values of 36.17 and 30.35?mg/L, and r ² values of 0.948 and 0.908, respectively. The highest efficacy was reported in 5?mM TiO₂ solution against H. maculata and B. ovis (LD₅₀?=?33.40 and 34.74?mg/L; r ²?=?0.786 and 0.873), respectively, and the maximum activity was observed in the synthesized TiO₂ NPs against H. maculata and B. ovis with LD₅₀ values of LD₅₀?=?7.09 and 6.56?mg/L, and r ² values of 0.880 and 0.913, respectively. This method is considered as an innovative alternative approach to control the hematophagous fly and sheep-biting louse.     

Feeding deterrent activity of synthesized silver nanoparticles using Manilkara zapota leaf extract against the house fly, Musca domestica (Diptera: Muscidae)

With a greater awareness of the hazards associated with the use of synthetic organic insecticides, there has been an urgent need to explore suitable alternative products for pest control. Musca domestica is ubiquitous insect that has the potential to spread a variety of pathogens to humans and livestock. They are mechanical carriers of more than hundred human and animal intestinal diseases and are responsible for protozoan, bacterial, helminthic, and viral infections. The present work aimed to investigate the feeding deterrent activity of synthesized silver nanoparticles (Ag NPs) using leaf aqueous extract of Manilkara zapota against M. domestica. The synthesized Ag NPs were recorded from UV–vis spectrum at 421 nm and scanning electron microscopy confirm the biosynthesis and characterization of Ag NPs with spherical and oval in shape and size of 70–140 nm. The FTIR analysis of the purified nanoparticles showed the presence of bands 1,079, 1,383, 1,627, 2,353, and 2,648 cm^?1, which were complete synthesis of AgNPs; the XRD pattern of AgNPs showed diffraction peaks at 2θ values of 38.06°, 44.37°, 64.51°, and 77.31° sets of lattice planes were observed (111), (200), (220), and (311) facts of silver, respectively. Adult flies were exposed to different concentrations of the aqueous extract of synthesized Ag NPs, 1 mM silver nitrate (AgNO₃) solution and aqueous extract of M. zapota for 1, 2, and 3 h; however, AgNPs showed 72% mortality in 1 h, 89% mortality was found in 2 h, and 100% mortality was found in 3 h exposure at the concentration of 10 mg/mL and the leaf aqueous extract showed 32% mortality in 1 h, 48% mortality was found in 2 h, and 83% mortality was found in 3 h exposure at concentration of 50 mg/mL. The most efficient activity was observed in synthesized Ag NPs against M. domestica (LD₅₀?=?3.64 mg/mL; LD₉₀?=?7.74 mg/mL), the moderate activity reported in the aqueous extract of M. zapota (LD₅₀?=?28.35 mg/mL; LD₉₀?=?89.19 mg/mL) and nil activity were observed in AgNO₃ solution at 3 h exposure time at 10 mg/mL. Dimethyl 2, 2-dichlorovinyl phosphate (DDVP) was used as a positive control and showed the LD₅₀ value of 3.38 mL/L. These results suggest that the synthesized Ag NPs have the potential to be used as an ideal eco-friendly approach for the control of the adult of M. domestica. This method is considered as a new approach to control sanitary pest. Therefore, this study provides first report on the feeding deterrent activity of synthesized Ag NPs against housefly.