Evaluation of immunogenicity and protective efficacy of a liposome containing Brucella abortus S19 outer membrane protein in BALB/c mice

The use of liposome as an adjuvant and a vaccine carrier has been cited previously in the literature. It has also been shown to be effective in enhancing the immunogenicity of vaccine candidates. BALB/c mice immunized subcutaneously with outer membrane protein (OMP) of Brucella abortus S19 vaccine strain entrapped in a commercial cationic liposome (S19-OMP-liposome) for vaccine delivery, showed enhanced protection (P<0.05) compared to groups of mice inoculated with S19 OMP alone, S19 live B. abortus vaccine and liposome alone, when challenged intra-peritoneally with virulent B. abortus strain 544 at 30 days post-immunization (DPI). The S19-OMP-liposome preparation was found to be safer compared to the live B. abortus S19 vaccine at 15 days post challenge (DPC), as evidenced by the significant difference in spleen weight between S19-OMP-liposome, S19 OMP and S19 live as well as the liposome control groups (P<0.01). Antibody isotype response profiles of the experimental groups indicated that the immune response was Th1 cell mediated. The protective advantage conferred to mice immunized with S19-OMP entrapped in liposome over those immunized with the live B. abortus S19 version, could probably be related to the significantly different response of IgG2b at 30 DPI (P<0.01), IgG2a (P<0.01), IgG2b (P<0.01) and IgG3 (P<0.05) at the DPC stages, respectively.

Characterization of mechanical properties of materials using ultrasound broadband spectroscopy

This article explores the characterization of homogenous materials (metals, alloys, glass and polymers) by a simple broadband ultrasonic interrogation method. The novelty lies in the use of ultrasound in a continuous way with very low input power (0 dBm or less) and analysis of the transmitted acoustic wave spectrum for material property characterization like speed of sound, density and dimensions of a material. Measurements were conducted on various thicknesses of samples immersed in liquid where continuous-wave, frequency swept ultrasonic energy was incident normal to the sample surface. The electro-acoustic transmission response is analyzed in the frequency domain with respect to a specifically constructed multi-layered analytical model. From the acoustic signature of the sample materials, material properties such as speed of sound and acoustic impedance can be calculated with experimentally derived values found to be in general agreement with the literature and with pulse-echo technique establishing the basis for a non-contact and non-destructive technique for material characterization. Further, by looking at the frequency spacing of the peaks of water when the sample is immersed, the thickness of the sample can be calculated independently from the acoustic response. This technique can prove to be an effective non-contact, non-destructive and fast material characterization technique for a wide variety of materials.

An electron microscopy based method for the detection and quantification of nanomaterial number concentration in environmentally relevant media

Improved detection and characterization of nanomaterials (NMs) in complex environmental media requires the development of novel sampling approaches to improve the detection limit to be close to environmentally realistic concentrations. Transmission electron microscopy (TEM) is an indispensable metrological tool in nanotechnology and environmental nanoscience due to its high spatial resolution and analytical capabilities when coupled to spectroscopic techniques. However, these capabilities are hampered by the conventional sample preparation methods, which suffer from low NM recovery. The current work presents a validated, fully quantitative sampling technique for TEM that overcomes conventional sample preparation shortcomings, and thus enables the use of TEM for measurement of particle number concentration and their detection in complex media at environmentally realistic concentrations. This sampling method is based on ultracentrifugation of NMs from suspension onto a poly-l-lysine (PLL) functionalized TEM grid, using active deposition (by ultracentrifugation) and retention (by PLL interactions with NM surface) of NMs on the substrate, enabling fully quantitative analysis. Similar analysis with AFM was satisfactory in simple media but the lack of chemical-selectivity of AFM limits its applicability for the detection of NMs in complex environmental samples. The sampling approach was validated using both citrate- and PVP-coated AuNMs in pure water, which demonstrated an even distribution of NM on the TEM grid and high NM recovery (80-100%) at environmentally relevant NM concentrations (ca. 0.20-100 μg L(-1)). The applicability of the sampling method to complex environmental samples was demonstrated by the quantification of particle number concentration of AuNMs in EPA soft water (with and without Suwannee River fulvic acid) and lake water. This sample preparation approach is also applicable to other types of NMs with some modifications (e.g. centrifugation force and time) to insure full sample recovery. This TEM sampling method is key to the accurate quantification of NM number concentration, and therefore to improving our understanding of environmental fate, behavior, effects and dose of NMs.

Investigating biomechanical noise in neuroblastoma cells using the quartz crystal microbalance

Quantifying cellular behaviour by motility and morphology changes is increasingly important in formulating an understanding of fundamental physiological phenomena and cellular mechanisms of disease. However, cells are complex biological units, which often respond to external environmental factors by manifesting subtle responses that may be difficult to interpret using conventional biophysical measurements. This paper describes the adaptation of the quartz crystal microbalance (QCM) to monitor neuroblastoma cells undergoing environmental stress wherein the frequency stability of the device can be correlated to changes in cellular state. By employing time domain analysis of the resulting frequency fluctuations, it is possible to study the variations in cellular motility and distinguish between different cell states induced by applied external heat stress. The changes in the frequency fluctuation data are correlated to phenotypical physical response recorded using optical microscopy under identical conditions of environmental stress. This technique, by probing the associated biomechanical noise, paves the way for its use in monitoring cell activity, and intrinsic motility and morphology changes, as well as the modulation resulting from the action of drugs, toxins and environmental stress.

Monitoring sessile droplet evaporation on a micromechanical device

A bulk acoustic mode micro-electro-mechanical dual resonator platform is utilised to study the evaporation of sub-microliter water droplets from the surface of the resonator. An analytical formulation for the observed frequency shift and the measure dependence of resonant frequency on the modes of evaporation which is consistent with the optically derived data. The resonators access only a thin layer of the liquid through shear contact and, hence, the response is not affected by the bulk mass of the droplet to first order. A relationship between the droplet contact area and the elapsed time was established for the evaporation process and is used to derive a value of the diffusion coefficient of water in air that is found to be in reasonable agreement with literature values. This work introduces a new tool for the electro-mechanical monitoring of droplet evaporation with relevance to applications such as biosensing in liquid samples of sub-microliter volumes.

Cysteine proteinase genes in Indian strain of Haemonchus contortus

The genes of microvillar cysteine proteinases such as hmcp1, hmcp6 and gcp7 of phenotypically distinct morphotypes of female H. contortus having knobbed and linguiform vulvar flaps were cloned and characterized. Complementary DNA (cDNA) was synthesized from total RNA of both the morphotypes. The hmcp1, hmcp6 and gcp7 genes were amplified from cDNA. The amplicons were cloned in pDRIVE T/A cloning vector and sequenced by Sanger's dideoxy method. The nucleotide and deduced amino acid sequences were compared with the USA/UK strain H. contortus cysteine proteinase sequences. The cysteine proteinase genes of Indian strain show considerable variations with USA/UK strains. Our results revealed that Indian strain of H. contortus expresses both UK strain (hmcp1 and 6) and USA strain (gcp7) cysteine proteinases.

Quantitative measurement of the nanoparticle size and number concentration from liquid suspensions by atomic force microscopy

Microscopy techniques are indispensable to the nanoanalytical toolbox and can provide accurate information on the number size distribution and number concentration of nanoparticles (NPs) at low concentrations (ca. ppt to ppb range) and small sizes (ca. <20 nm). However, the high capabilities of microscopy techniques are limited by the traditional sample preparation based on drying a small volume of suspension of NPs on a microscopy substrate. This method is limited by low recovery of NPs (ca. <10%), formation of aggregates during the drying process, and thus, the complete misrepresentation of the NP suspensions under consideration. This paper presents a validated quantitative sampling technique for atomic force microscopy (AFM) that overcomes the above-mentioned shortcomings and allows full recovery and representativeness of the NPs under consideration by forcing the NPs into the substrate via ultracentrifugation and strongly attaches the NPs to the substrate by surface functionalization of the substrate or by adding cations to the NP suspension. The high efficiency of the analysis is demonstrated by the uniformity of the NP distribution on the substrate (that is low variability between the number of NPs counted on different images on different areas of the substrate), the high recovery of the NPs up to 71%) and the good correlation (R > 0.95) between the mass and number concentrations. Therefore, for the first time, we developed a validated quantitative sampling technique that enables the use of the full capabilities of microscopy tools to quantitatively and accurately determine the number size distribution and number concentration of NPs at environmentally relevant low concentrations (i.e. 0.34-100 ppb). This approach is of high environmental relevance and can be applied widely in environmental nanoscience and nanotoxicology for (i) measuring the number concentration dose in nanotoxicological studies and (ii) accurately measuring the number size distribution of NPs; both are key requirements for the implementation of the European Commission recommendation for definition of nanomaterials.

Haemostatic effect of ecliptaalba on albino rabbits

Ecliptaalba (Bhringraj) is an important traditional Indian medicinal plant reported to have antipyretic, anti-inflammatory, antihistaminic, hepatoprotective and anthelmintic effect well documented in literature. In the present study ethanolic leaf extract of eclipta alba (EEEA) was evaluated for its haemostatic activity by their ability to affect the screening test or modify the experimentally induced prolongation of test time on the basis of its folklore claim in normal, aspirin and heparin treated rabbits. The parameters recorded were BT, CT, PT and APTT & platelet count in all the three groups. The study was carried out in 3 parts in different doses 200,400,600 & 800mg/kg. Part-A-study of the haemostatic effect of Ethanolic extract of E. alba (EEEA) in graded doses on normal rabbits. Part-B-study of EEEA in aspirin treated rabbits. Part-C-study of EEEA in heparin treated rabbits. Tranexamic acid was used as the standard drug. Statistical analysis was performed using one way ANOVA & student t test. In normal rabbits EEEA high doses 800mg/k & 600mg/kg exhibited significant reduction in BT & CT (p<0.01). The same doses were found to decrease the aspirin induced increase in BT & heparin induced increase in CT in a significant manner (p<0.01). As decrease in CT might be due to liberation of some active principles from leaves of Ecliptaalba which demonstrated to have anti-haemorrhagic activity against snake bite not affecting any coagulation factor. No significant effect on PT, APPT and platelet count was observed. EEEA exhibited definite haemostatic effect in the above 3 sets of study. Phytochemical analysis and isolation of active principle is essential to carry on beneficial effects from laboratory bench to bedside of patients.

Perception of medical students about pharmacology and scope of improvement

Pharmacology is a subject taught in the medical curriculum in India over a period of one and half years along with pathology, microbiology and forensic medicine. The present study was planned to know the opinion of medical students regarding pharmacology and to assess the proposed teaching schedule and methods of teaching pharmacology. The study was conducted in a private medical college in eastern India among the medical undergraduate students in 5th semester. Total 74 students participated in the study. A pre-designed, pre-tested, semi-structured questionnaire was given to the students and data was collected after one hour. Collected data was compiled, tabulated and analyzed in SPSS (version 16.0). The subject was perceived as interesting and useful by majority of students and most of them were in opinion to integrate pharmacology with the clinical subjects. Lecture in whole class was the most preferred teaching method according to the students and teaching with chalk and board they preferred most. Rational use of medicine, clinical trial, pediatric and geriatric pharmacology are the important topics the students felt to be included in the curriculum. Regular assessment of teaching methods by the students and taking suggestions from the students about improving the teaching method and redesigning the curriculum can help a lot in improving the learning capacity of the medical students and that will give benefit for the society as a whole.