Effect of immunosuppression on dengue virus infection in mice

Mean survival time following intracerebral inoculation of dengue virus was reduced and the titre of the virus in the brain of immunosuppressed mice was markedly increased. A single dose of cyclophosphamide given 24 h after dengue virus i.c. or i.p. substantially reduced the number of antibody forming cells in the spleen. Three doses of dengue virus, each followed by cyclophosphamide 24 h later, produced specific hyporesponsiveness to the dengue virus but not to a heterologous virus (Coxsackie B4), with a reduction in antibody forming cells in the spleen of such animals against dengue virus but not against Coxsackie B4 virus. Adoptive immunity by antiserum was abolished along with increased titres of the virus in the brain of immunosuppressed mice but the protection could be restored by a second dose of antiserum. Pre-treatment of mice with immune or normal spleen cells i.v. or reconstitution of immunosuppressed mice by such cells had no effect. Thus, humoral antibodies play a crucially important role in host defence mechanism in recovery of mice from primary dengue virus infection

Laser pulse annealing of ion-implanted GaAs

GaAs single-crystals wafers are implanted at room temperature with 400-keV Te + ions to a dose of 1×10^15 cm^–2 to form an amorphous surface layer. The recrystallization of this layer is investigated by backscattering spectrometry and transmission electron microscopy after transient annealing by Q-switched ruby laser irradiation. An energy density threshold of about 1.0 J/cm^2 exists above which the layer regrows epitaxially. Below the threshold the layer is polycrystalline; the grain size increases as the energy density approaches threshold. The results are analogous to those reported for the elemental semiconductors, Si and Ge. The threshold value observed is in good agreement with that predicted by the simple model successfully applied previously to Si and Ge

Host defence mechanisms against dengue virus infection of mice

Serum obtained from mice 3 to 5 weeks after the third i.p. dose of dengue type 2 virus (DV) protected recipient mice against intracerebral challenge with DV, whereas the serum obtained after 1 and 2 weeks provided minimum protection. Adoptive intravenous transfer of immune spleen cells obtained from mice 1 to 5 weeks after immunization did not protect recipient mice against even a small dose (10 LD50) of DV. Depletion of T-cells by treatment of mice with anti-thymocyte serum did not potentiate DV infection. Development of a cell-mediated immune response (CMI) against DV was noted only at two periods by the leucocyte migration inhibition test (LMI), with borderline values of 20 and 21%. Dengue virus did not cause illness or death in mice when given by i.p. or i.v. routes and this was not affected by pre-treatment of mice with silica to damage local macrophages. It is concluded that humoral antibody plays a critical role in recovery from primary dengue virus infection of mice whereas CMI and macrophages appear to have no protective role

Biochemical study of certain enzymes and metabolites of the carbohydrate metabolism in the skeletal muscle of the dengue virus-infected mice

Changes in enzymes and metabolites of the carbohydrate metabolism in skeletal muscles were studied in mice after intracerebral inoculation of dengue type 2 virus. It was noted that lactic dehydrogenase, aldolase, phosphogluco-isomerase, phosphoglucomutase, GO-T and GP-T activity were enhanced initially by two- to three-fold, reaching a peak on day 5. As the illness appeared in mice, all the enzyme activities were lowered and were about three times less in the paralytic stage on the 8th day as compared to controls. Fructose-1,6-diphosphatase activity was increased on the 4th and 5th days but decreased later. Acid phosphatase increased abruptly from the 6th day while alkaline phosphatase activity was irregular. Creatine increased on the 4th and 5th days but diminished later. Glycogen decreased from the beginning and was lowest on the 5th day, but the levels increased later and were maximum in paralysed muscles. On the other hand, lactic acid began accumulating in the muscles and was maximum on the 5th day, then declined. Dengue virus was detected in the muscles from the 2nd day but higher titres were seen from the 6th day. Changes similar to the preparalytic stage of mice may occur in human beings, causing myalgia

An Eulerian–Eulerian formulation for erosion modelling: an alternate approach.

Sand is commonly produced besides petroleum fluids and it presents a major erosional hazard leading to pipe failures. Particle erosion is a complex process in which material is removed due to the repeated particle impacts. Conventionally, a CFD flow solver and computationally intensive lagrangian particle tracking sub–routines, known as Eulerian–Lagrangian (E–L) model, along with empirical erosion equations are used to predict the erosion rates. The present work introduces an Eulerian–Eulerian (E–E) approach in which the multiphase granular model resolves the solid phase and obviates the need of particles tracking. Particle–laden turbulent flow across a flow restrictor, based on an experimental study, is chosen for validation. Numerical experiments are done in Simcenter STAR–CCM+. Comparison with the experimental data demonstrate a good agreement and in particular, the E–E model yields reliable predictions of impact wear locations, erosion rates as those of E–L model. A 90° square bend is also simulated and comparison of erosion rates on the concave wall demonstrate that E–E model can be used as an alternate to computationally expensive approaches

Simulation of rectangular fluidised bed with Geldart D particles.

In this study, simulations are carried out using the Euler-Euler granular model in STAR-CCM+ for a gas-solid flow in a rectangular bubbling fluidized bed. The problem studied was announced as Small Scale Challenge Problem (SSCP-I) in 2013. Experiments for this problem were conducted by The Department of Energy's (DOE) National Energy Technology Laboratory (NETL). The objective of this numerical study is to evaluate the reliability of the kinetic theory based granular model (KTGF) in predicting the hydrodynamics of gas-solid flows. The experimental measurements of the bubbling fluidized bed investigated in this numerical study are 3"x9"x48". The bed material for the experiment is Geldart group D particles of uniform size and high sphericity. Simulations were performed for all the three gas superficial velocities (U = 2.19, 3.28 and 4.38 m/s) for which experiments were conducted. Results from numerical simulations are validated for vertical component of particle velocity, horizontal component of particle velocity, granular temperature and the mean axial pressure gradient. The effect of the treatment at wall boundaries and coefficient of restitution (particle-particle interactions) is studied on the results

Pathological studies of Pestalotia mangiferae

Pestalotia mangiferæ has been observed on leaves of Mangiferœ indica at Allahabad and Madras. The pathogenicity of this organism has been established on leaves, stem and fruits of mango and symptoms have been described. Cross-inoculations on Psidium gujava, Mimusops hexandra, Butea frondosa, Eucalyptus sp. and Citrus sp. were unsuccessful. Storage of fruits at temperatures below 8°C. prevented fruit rot. Dusting the leaves with zinc sulphate controlled the disease but similar dustings on fruits failed to control the rot

Cost-effectiveness of interventions to control cardiovascular diseases and type 2 diabetes mellitus in South Asia: protocol for a systematic review.

INTRODUCTION: While a number of strategies are being implemented to control cardiovascular diseases (CVDs) and type 2 diabetes mellitus (T2DM), the cost-effectiveness of these in the South Asian context has not been systematically evaluated. We aim to systematically review the economic (cost-effectiveness) evidence available on the individual-, group- and population-level interventions for control of CVD and T2DM in South Asia. METHODS AND ANALYSIS: This review will consider all relevant economic evaluations, either conducted alongside randomised controlled trials or based on decision modelling estimates. These studies must include participants at risk of developing CVD/T2DM or with established disease in one or more of the South Asian countries (India, Bangladesh, Pakistan, Sri Lanka, Nepal, Maldives, Bhutan and Afghanistan). We will identify relevant papers by systematically searching all major databases and registries. Selected articles will be screened by two independent researchers. Methodological quality of the studies will be assessed using a modified Drummond and a Phillips checklist. Cochrane guidelines will be followed for bias assessment in the effectiveness studies. RESULTS: Results will be presented in line with the PRISMA (Preferred Reporting Items for Systematic review and Meta-analysis) checklist, and overall quality of evidence will be presented as per the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach. ETHICS AND DISSEMINATION: The study has received ethics approval from the All India Institute of Medical Sciences, New Delhi, India. The results of this review will provide policy-relevant recommendations for the uptake of cost-effectiveness evidence in prioritising decisions on essential chronic disease care packages for South Asia. STUDY REGISTRATION NUMBER: PROSPERO CRD42013006479