6,452 research outputs found

    Murine infection with bioluminescent Leishmania infantum axenic amastigotes applied to drug discovery

    Get PDF
    Leishmaniasis is an important vector-borne neglected tropical disease caused by Leishmania parasites. Current anti-Leishmania chemotherapy is unsatisfactory, justifying the continued search for alternative treatment options. Herein, we demonstrate that luciferase-expressing Leishmania infantum axenic amastigotes, unlike promastigotes, are highly infectious to BALB/c mice and thus generate a robust bioluminescent signal in target organs, such as the liver and the spleen, as early as two weeks after infection. Treatment with the reference drugs amphotericin B and miltefosine was effective at reducing parasite burdens. This model allows the assessment of treatment efficacy using whole-mouse bioluminescence imaging without the need to wait several weeks for spleen infections to be detectable by this non-invasive method. In conclusion, we propose the use of this model in an initial approach to evaluate the treatment efficacy of promising chemical entities without having to sacrifice large numbers of animals or to wait several days for a readout.We thank Carla Oliveira from i3S for the support with the statistical analysis. Part of the content of this manuscript has been released as a pre-print in BioRxiv (https://doi.org/10.1101/326355). This work was financed by FEDER - Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 - Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT - Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project POCI-01-0145-FEDER-031013 (PTDC/SAU-PAR/31013/2017). This work also received funds from: Norte-01-0145-FEDER-000012 “Structured program on bioengineered therapies for infectious diseases and tissue regeneration” of Norte Portugal Regional Operational Programme (NORTE 2020) under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (FEDER) and through the Research Unit No. 4293; Individual funding from FCT through SFRH/BD/123734/2016 (to DC), SFRH/BD/121252/2016 (to PC) and CEECIND/02362/2017 (to JT)

    Peripheral Blood Leukocytes And Serum Nested Polymerase Chain Reaction Are Complementary Methods For Monitoring Active Cytomegalovirus Infection In Transplant Patients.

    Get PDF
    Human cytomegalovirus is an important cause of morbidity and mortality in immunocompromised patients. Qualitative polymerase chain reaction (PCR) has proven to be a sensitive and effective technique in defining active cytomegalovirus infection, in addition to having low cost and being a useful test for situations in which there is no need for quantification. Real-time PCR has the advantage of quantification; however, the high cost of this methodology makes it impractical for routine use. To apply a nested PCR assay to serum (sPCR) and to evaluate its efficiency to diagnose active cytomegalovirus infection compared with PCR of peripheral blood leukocytes (L-PCR). Samples of 37 patients were prospectively evaluated. An internal control was created and applied to sPCR to exclude false-negative results. In total, 21 patients (57%) developed active cytomegalovirus infection. After analyzing the two methods for the diagnosis of active infection, higher sensitivity and negative predictive value of the L-PCR versus sPCR (100% versus 62%), and higher specificity and positive predictive value of sPCR versus L-PCR (81% versus 50% and 72%, respectively) were observed. Discordant results were observed in 11 patients who were L-PCR-positive but sPCR-negative for active cytomegalovirus infection, five of whom developed clinical symptoms of cytomegalovirus. Clinical symptoms were observed in 14 patients, 12 of whom were diagnosed with active infection by nested L-PCR (P=0.007) and seven by nested sPCR (P=0.02). Higher specificity and a positive predictive value for sPCR were observed. Nested L-PCR and sPCR were considered to be complementary methods for the diagnosis and management of symptomatic cytomegalovirus infection.24e69-7

    A genetic contribution from the Far East into Ashkenazi Jews via the ancient Silk Road

    Get PDF
    Contemporary Jews retain a genetic imprint from their Near Eastern ancestry, but obtained substantial genetic components from their neighboring populations during their history. Whether they received any genetic contribution from the Far East remains unknown, but frequent communication with the Chinese has been observed since the Silk Road period. To address this issue, mitochondrial DNA (mtDNA) variation from 55,595 Eurasians are analyzed. The existence of some eastern Eurasian haplotypes in eastern Ashkenazi Jews supports an East Asian genetic contribution, likely from Chinese. Further evidence indicates that this connection can be attributed to a gene flow event that occurred less than 1.4 kilo-years ago (kya), which falls within the time frame of the Silk Road scenario and fits well with historical records and archaeological discoveries. This observed genetic contribution from Chinese to Ashkenazi Jews demonstrates that the historical exchange between Ashkenazim and the Far East was not confined to the cultural sphere but also extended to an exchange of genes

    TRSP is dispensable for the Plasmodium pre-erythrocytic phase

    Get PDF
    Plasmodium sporozoites deposited in the skin following a mosquito bite must migrate and invade blood vessels to complete their development in the liver. Once in the bloodstream, sporozoites arrest in the liver sinusoids, but the molecular determinants that mediate this specific homing are not yet genetically defined. Here we investigate the involvement of the thrombospondin-related sporozoite protein (TRSP) in this process using knockout Plasmodium berghei parasites and in vivo bioluminescence imaging in mice. Resorting to a homing assay, trsp knockout sporozoites were found to arrest in the liver similar to control parasites. Moreover, we found no defects in the establishment of infection in mice following inoculation of trsp knockout sporozoites via intravenous and cutaneous injection or mosquito bite. Accordingly, mutant sporozoites were also able to successfully invade hepatocytes in vitro. Altogether, these results suggest TRSP may have a redundant role in the completion of the pre-erythrocytic phase of the malaria parasite. Nonetheless, identifying molecules with paramount roles in this phase could aid in the search for new antigens needed for the design of a protective vaccine against malaria.We would like to thank: Prof. Anabela Cordeiro da Silva from the IBMC/i3S for the exceptional hosting conditions; Dr. Ana Xavier Carvalho from the IBMC/i3S for the critical reading of the manuscript; the team of the CEPIA from Institut Pasteur, Paris, for providing the Anopheles stephensi female mosquitos. The following reagents were obtained through BEI Resources, NIAID, NIH: (a) Plasmid pL0001, for Transfection in Plasmodium berghei, MRA-770, contributed by Andrew P. Waters; (b) Hybridoma 3D11 Anti-Plasmodium berghei 44-Kilodalton Sporozoite Surface Protein (Pb44), MRA-100, contributed by Victor Nussenzweig. This work was supported by funds from project Norte-01-0145-FEDER-000012 - Structured program on bioengineered therapies for infectious diseases and tissue regeneration, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through FEDER. This work also received funds from the Fundação para a Ciência e Tecnologia (FCT)/Ministério da Educação e Ciência (MEC) co-funded by FEDER (EXPL/JTAVARES-IF/00881/2012/CP0158/CT0005,EXPL/IMI-MIC/1331/ 2013) under the Partnership agreement PT2020, through the Research Unit No. 4293. J.T. is an Investigator FCT funded by National funds through FCT and co-funded through European Social Fund within the Human Potential Operating Programme. D.M.C., M.S. and A.R.T. are funded by FCT individual fellowships SFRH/ BD/123734/2016, SFRH/BD/133485/2017 and SFRH/BD/133276/2017 respectively). The authors acknowledge the support of the BioSciences Screening i3S Scientific Platform, member of the PPBI (PPBI-POCI-01-0145-FEDER-022122)

    Increased sympathetic tone and hypothalamic–pituitary–adrenal (HPA) axis activation impact in metabolic parameters from hypertensive rats

    Get PDF
    Increased activity of the sympathetic nervous system (SNS) may play an important role in the development of hypertension and in adiposity disorders. We aimed to investigate the influence of increased sympathetic tone and hypothalamic–pituitary–adrenal (HPA) axis activation in metabolic parameters by evaluating the morphometry of isolated adipocytes from different fat pads and energy consumption. Serum levels of catecholamines, HPA hormones, T3 and adipokines were measured in 15-weeks-old Wistar (WIS), Wistar-Kyoto (WKY), Spontaneously Hypertensive Rats (SHR) and WIS treated with NG-nitro-L-arginine methyl ester (L-NAME). L-NAME and SHR showed a reduced adiposity when compared to their controls, which may be related to higher concentrations of T3. However, SHR presented the most evident lipodystrophy, presenting significant changes in the morphometry from isolated adipocytes and the production of adipokines. Thus, our study suggests that endocrine changes in hypertension models may highlight possible therapeutic targets in the treatment of metabolic changes associated with hypertension

    Simvastatin improves the sexual health-related quality of life in men aged 40 years and over with erectile dysfunction : Additional data from the Erectile Dysfunction and Statin trial

    Get PDF
    © 2014 Trivedi et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.Background: Erectile dysfunction is prevalent in men over 40 years, affecting their quality of life and that of their partners. The aims of this study were:a)To evaluate the internal reliability of the male erectile dysfunction specific quality of life (MED-QoL) scale and explore its factor structure.b)To evaluate the effect of simvastatin on subscales of the MED-QoL in men over forty years with erectile dysfunction. Methods: This is a double blind randomised controlled trial of 40 mg simvastatin or placebo given once daily for six months to men over forty years with untreated erectile dysfunction, who were not at high cardiovascular risk and were not on anti-hypertensive or lipid-lowering medication. 173 eligible men were recruited from 10 general practices in East of England. Data were collected at two points over 30 weeks. We report on the factor structure of MED-QoL, the internal reliability of the scale and the derived subscales, and the effect of simvastatin on MED-QoL subscales. Results: An initial analysis of the MED-QoL items suggested that a number of items should be removed (MED-QoL-R). Exploratory factor analysis identified three subscales within the MED-QoL-R which accounted for 96% of the variance, related to feelings of Control, initiating Intimacy, and Emotional response to erectile dysfunction. The alpha value for the revised scale (MED-Qol-R) was >0.95 and exceeded .82 for each subscale. Regression analysis showed that patients in the placebo group experienced a significantly reduced feeling of Control over erectile dysfunction than those in the statin group. Those in the placebo group had significantly lower Emotional response than those in the statin group at the close of trial, but there was no significant treatment effect on Intimacy. Conclusions: Our revised MED-QoL-R identified three subscales. Secondary analysis showed a significant improvement in sexual health related quality of life, specifically in relation to perception of control and emotional health in men with untreated erectile dysfunction given 40 mg simvastatin for six months. Trial registration: Current Controlled Trials ISRCTN66772971.Peer reviewe

    Correlators of Vertex Operators for Circular Strings with Winding Numbers in AdS5xS5

    Full text link
    We compute semiclassically the two-point correlator of the marginal vertex operators describing the rigid circular spinning string state with one large spin and one windining number in AdS_5 and three large spins and three winding numbers in S^5. The marginality condition and the conformal invariant expression for the two-point correlator obtained by using an appropriate vertex operator are shown to be associated with the diagonal and off-diagonal Virasoro constraints respectively. We evaluate semiclassically the three-point correlator of two heavy circular string vertex operators and one zero-momentum dilaton vertex operator and discuss its relation with the derivative of the dimension of the heavy circular string state with respect to the string tension.Comment: 16 pages, LaTeX, no figure

    Decision Making for Inconsistent Expert Judgments Using Negative Probabilities

    Full text link
    In this paper we provide a simple random-variable example of inconsistent information, and analyze it using three different approaches: Bayesian, quantum-like, and negative probabilities. We then show that, at least for this particular example, both the Bayesian and the quantum-like approaches have less normative power than the negative probabilities one.Comment: 14 pages, revised version to appear in the Proceedings of the QI2013 (Quantum Interactions) conferenc
    corecore