143 research outputs found

    Evaluation of Antioxidant and Antihyperlipidemic Activity of extracts Rich in Polyphenols

    Get PDF
    Polyphenols are phytochemicals present in plants that contribute to their antioxidant and different pharmacological activities. Flavonoids comprise of one class of polyphenols which play a beneficial role in preventing free radical damage and owe its antioxidant property. Lipid peroxidation and lipid-derived oxidized products have been implicated in the pathogenesis of a variety of human diseases. To clarify the role of oxidative stress in prevention of atherosclerosis and hypercholesterolemia, the antioxidant status of plant extracts of Oroxylum indicum, Vitis vinifera and Policosanol isolated from, Saccharum officinarum were selected for the study.The extracts were evaluated by in vitro methods by monitoring the production of malondialdehyde as Thiobarbituric acid Reacting Substances (TBARs). The antihypperlipidemic activity was examined in cholesterol induced hyperlipidemic model using Albino Wistar rats.The result of the study exhibited significant reduction in total cholesterol, triglycerides, LDL-C, VLDL-C levels and remarkable increase in the level of HDL-C when compared to standard lovastatin drug. The artherogenic index and LDL-C: HDL-C risk ratio was also reduced to significant extent in the group treated with extracts. The levels of SGOT and SGPT were estimated and found to be significantly less than that of hyperlipidemic control group.The highest antihyperlipidemic activity was exhibited by total extract of the bark of Oroxylum indicum followed by extracts of fruits of Vitis vinifera and Policosanol isolated from sugarcane wax.Keywords:- Polyphenols, Antihyperlipidemic, Antioxidant, Oroxylum indicum, Vitis vinifera, Policosano

    Is <i>de novo</i> membranous nephropathy suggestive of alloimmunity in renal transplantation? A case report.

    Get PDF
    BackgroundPost-transplant nephrotic syndrome (PTNS) in a renal allograft carries a 48% to 77% risk of graft failure at 5 years if proteinuria persists. PTNS can be due to either recurrence of native renal disease or de novo glomerular disease. Its prognosis depends upon the underlying pathophysiology. We describe a case of post-transplant membranous nephropathy (MN) that developed 3 mo after kidney transplant. The patient was properly evaluated for pathophysiology, which helped in the management of the case.Case summaryThis 22-year-old patient had chronic pyelonephritis. He received a living donor kidney, and human leukocyte antigen-DR (HLA-DR) mismatching was zero. PTNS was discovered at the follow-up visit 3 mo after the transplant. Graft histopathology was suggestive of MN. In the past antibody-mediated rejection (ABMR) might have been misinterpreted as de novo MN due to the lack of technologies available to make an accurate diagnosis. Some researchers have observed that HLA-DR is present on podocytes causing an anti-DR antibody deposition and development of de novo MN. They also reported poor prognosis in their series. Here, we excluded the secondary causes of MN. Immunohistochemistry was suggestive of IgG1 deposits that favoured the diagnosis of de novo MN. The patient responded well to an increase in the dose of tacrolimus and angiotensin converting enzyme inhibitor.ConclusionExposure of hidden antigens on the podocytes in allografts may have led to subepithelial antibody deposition causing de novo MN

    Evaluation of Perceptual Contrast and Sharpness Measures for Meteorological Satellite Images

    Get PDF
    AbstractSharpness and contrast have great impact on perceived quality of an image. This paper focuses on sharpness and contrast measures to evaluate quality of Thermal Infrared (TIR1) channel of Indian National Satellite-3D (INSAT-3D) without using any reference image. Most of the sharpness metrics can scarcely manage to discern image quality degradation against high frequency behavior due to noise. Six Image Quality Measures (IQMs) are employed to study their behavior in terms of blur, noise and intensity changes simultaneously. Results show that (1) change in value of Measure Of Enhancement By Entropy (EMEE) is more discernible with change in contrast of an INSAT-3D image as compared to other measures and (2) Second Derivative Like Measure Of Enhancement (SDME) has a potential to distinguish high frequency content due to sharpness arisen due to un estimated noise up to some remarkable level in case of TIR1 INSAT-3D satellite images. Performance comparison of six measures against blur, noise, contrast and sharpness changes is presented

    Use of a dual reporter plasmid to demonstrate bactofection with an attenuated aroa- derivative of Pasteurella multocida b:2

    Get PDF
    A reporter plasmid pSRG has been developed which expresses red fluorescent protein (RFP) from a constitutive prokaryotic promoter within Pasteurella multocida B:2 and green fluorescent protein (GFP) from a constitutive eukaryotic promoter within mammalian cells. This construct has been used to determine the location and viability of the bacteria when moving from the extracellular environment into the intracellular compartment of mammalian cells. Invasion assays with embryonic bovine lung (EBL) cells and an attenuated AroA- derivative of Pasteurella multocida B:2 (strain JRMT12), harbouring the plasmid pSRG, showed that RFP-expressing bacteria could be detected intracellularly at 3 h post-invasion. At this stage, some EBL cells harbouring RFP-expressing bacteria were observed to express GFP simultaneously, indicating release of the plasmid into the intracellular environment. At 5 h post-invasion, more EBL cells were expressing GFP, while still harbouring RFP-expressing bacteria. Concurrently, some EBL cells were shown to express only GFP, indicating loss of viable bacteria within these cells. These experiments proved the functionality of the pSRG dual reporter system and the potential of P. multocida B:2 JRMT12 for bactofection and delivery of a DNA vaccine

    Evaluation of camel milk for selected processing related parameters and comparisons with cow and buffalo milk

    Get PDF
    Cow and buffalo milk and camel milk were analyzed and compared for processing related parameters. The average heat stability of cow, buffalo and camel milk samples analyzed was 1807.4 seconds, 1574.6 seconds and 133.6 seconds respectively at 140 °C. Thus, the heat stability of camel milk was significantly lower than the cow milk and buffalo milk. The average rennet coagulation time (RCT) of cow, buffalo and camel milk was 310.6 seconds, 257.4 seconds and 604.2 seconds respectively. Thus, RCT of camel milk was significantly higher than the cow milk and buffalo milk. The camel, cow and buffalo milk samples showed negative alcohol stability. The rate of acidity was increased propositionally with time in camel milk with no curd formation and weaker body

    Listeriolysin O Is Strongly Immunogenic Independently of Its Cytotoxic Activity

    Get PDF
    The presentation of microbial protein antigens by Major Histocompatibility Complex (MHC) molecules is essential for the development of acquired immunity to infections. However, most biochemical studies of antigen processing and presentation deal with a few relatively inert non-microbial model antigens. The bacterial pore-forming toxin listeriolysin O (LLO) is paradoxical in that it is cytotoxic at nanomolar concentrations as well as being the source of dominant CD4 and CD8 T cell epitopes following infection with Listeria monocytogenes. Here, we examined the relationship of LLO toxicity to its antigenicity and immunogenicity. LLO offered to antigen presenting cells (APC) as a soluble protein, was presented to CD4 T cells at picomolar to femtomolar concentrations- doses 3000–7000-fold lower than free peptide. This presentation required a dose of LLO below the cytotoxic level. Mutations of two key tryptophan residues reduced LLO toxicity by 10–100-fold but had no effect on its presentation to CD4 T cells. Thus there was a clear dissociation between the cytotoxic properties of LLO and its very high antigenicity. Presentation of LLO to CD8 T cells was not as robust as that seen in CD4 T cells, but still occurred in the nanomolar range. APC rapidly bound and internalized LLO, then disrupted endosomal compartments within 4 hours of treatment, allowing endosomal contents to access the cytosol. LLO was also immunogenic after in vivo administration into mice. Our results demonstrate the strength of LLO as an immunogen to both CD4 and CD8 T cells

    Protective Immunity to Listeria Monocytogenes Infection Mediated by Recombinant Listeria innocua Harboring the VGC Locus

    Get PDF
    In this study we propose a novel bacterial vaccine strategy where non-pathogenic bacteria are complemented with traits desirable for the induction of protective immunity. To illustrate the proof of principle of this novel vaccination strategy, we use the model organism of intracellular immunity Listeria. We introduced a, low copy number BAC-plasmid harbouring the virulence gene cluster (vgc) of L. monocytogenes (Lm) into the non-pathogenic L. innocua (L.inn) strain and examined for its ability to induce protective cellular immunity. The resulting strain (L.inn::vgc) was attenuated for virulence in vivo and showed a strongly reduced host detrimental inflammatory response compared to Lm. Like Lm, L.inn::vgc induced the production of Type I Interferon's and protection was mediated by Listeria-specific CD8+ T cells. Rational vaccine design whereby avirulent strains are equipped with the capabilities to induce protection but lack detrimental inflammatory effects offer great promise towards future studies using non-pathogenic bacteria as vectors for vaccination

    Genetic Control of Resistance to Trypanosoma brucei brucei Infection in Mice

    Get PDF
    Trypanosoma brucei are extracellular protozoa transmitted to mammalian host by the tsetse fly. They developed several mechanisms that subvert host's immune defenses. Therefore analysis of genes affecting host's resistance to infection can reveal critical aspects of host-parasite interactions. Trypanosoma brucei brucei infects many animal species including livestock, with particularly severe effects in horses and dogs. Mouse strains differ greatly in susceptibility to T. b. brucei. However, genes controlling susceptibility to this parasite have not been mapped. We analyzed the genetic control of survival after T. b. brucei infection using CcS/Dem recombinant congenic (RC) strains, each of which contains a different random set of 12.5% genes of their donor parental strain STS/A on the BALB/c genetic background. The RC strain CcS-11 is even more susceptible to parasites than BALB/c or STS/A. In F2 hybrids between BALB/c and CcS-11 we detected and mapped four loci, Tbbr1-4 (Trypanosoma brucei brucei response 1–4), that control survival after T. b. brucei infection. Tbbr1 (chromosome 3) and Tbbr2 (chromosome 12) have independent effects, Tbbr3 (chromosome 7) and Tbbr4 (chromosome 19) were detected by their mutual inter-genic interaction. Tbbr2 was precision mapped to a segment of 2.15 Mb that contains 26 genes

    Potentiation of Epithelial Innate Host Responses by Intercellular Communication

    Get PDF
    The epithelium efficiently attracts immune cells upon infection despite the low number of pathogenic microbes and moderate levels of secreted chemokines per cell. Here we examined whether horizontal intercellular communication between cells may contribute to a coordinated response of the epithelium. Listeria monocytogenes infection, transfection, and microinjection of individual cells within a polarized intestinal epithelial cell layer were performed and activation was determined at the single cell level by fluorescence microscopy and flow cytometry. Surprisingly, chemokine production after L. monocytogenes infection was primarily observed in non-infected epithelial cells despite invasion-dependent cell activation. Whereas horizontal communication was independent of gap junction formation, cytokine secretion, ion fluxes, or nitric oxide synthesis, NADPH oxidase (Nox) 4-dependent oxygen radical formation was required and sufficient to induce indirect epithelial cell activation. This is the first report to describe epithelial cell-cell communication in response to innate immune activation. Epithelial communication facilitates a coordinated infectious host defence at the very early stage of microbial infection

    Increasing the bactofection capacity of a mammalian expression vector by removal of the f1 ori

    Get PDF
    Bacterial-mediated cancer therapy has shown great promise in in vivo tumour models with increased survival rates post-bacterial treatment. Improving efficiency of bacterial-mediated tumour regression has focused on controlling and exacerbating bacterial cytotoxicity towards tumours. One mechanism that has been used to carry this out is the process of bactofection where post-invasion, bacteria deliver plasmid-borne mammalian genes into target cells for expression. Here we utilised the cancer-targeting Salmonella Typhimurium strain, SL7207, to carry out bactofection into triple negative breast cancer MDA-MB-231 cells. However, we noted that post-transformation with the commonly used mammalian expression vector pEGFP, S. Typhimurium became filamentous, attenuated and unable to invade target cells efficiently. Filamentation did not occur in Escherichia coli-transformed with the same plasmid. Further investigation identified the region inducing S. Typhimurium filamentation as being the f1 origin of replication (f1 ori), an artefact of historic use of mammalian plasmids for single stranded DNA production. Other f1 ori-containing plasmids also induced the attenuated phenotype, while removal of the f1 ori from pEGFP restored S. Typhimurium virulence and increased the bactofection capacity. This work has implications for interpretation of prior bactofection studies employing f1 ori-containing plasmids in S. Typhimurium, while also indicating that future use of S. Typhimurium in targeting tumours should avoid the use of these plasmids
    corecore