66 research outputs found

    Synthesis and biological activity of a new class of antitumor cyclopeptides based on the solomonamides

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    Solomonamides A (1) and B (2) are novel natural products recently isolated from the marine sponge Theonella swinhoei [1]. Preliminary structural studies revealed an unprecedented cyclic peptide type structure. Interestingly, solomonamide A exhibits anti-inflammatory activity, showing potent reduction (60%) of inflammation at a very low concentration of 100 µg/kg in animal models. However, the scarcity of these compounds from their natural sources has been a drawback for further pharmacological assays. In fact, the anti-inflammatory activity of solomonamide B was not evaluated due to the limited amounts. This difficulty to access large amounts of these compounds makes quite difficult to gain insight into their biological profiles and mechanism of action and justifies the chemical synthesis of this new class of cyclic peptides. As a consequence, the solomonamides have been the subject of several synthetic efforts [2] notably by the Reddy group who has recently reported the first total synthesis of solomonamide B based on a intramolecular Heck reaction, which led to a revision of the initially proposed structure for 2 [3].Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Exploring the ring-closing metathesis for the construction of the solomonamide macrocyclic core: identification of bioactive precursors

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    New synthetic strategies directed toward the novel cyclopeptides solomonamides have been explored utilizing an olefin metathesis as the key reaction. In the various strategies investigated, we worked on minimally oxidized systems, and the olefin metathesis reaction demonstrated efficiency and validity for the construction of the macrocyclic core. The described synthetic strategies toward the solomonamides are well suited for the subsequent access to the natural products and represent flexible and diversityoriented routes that allow for the generation of a variety of analogues via oxidative transformations. In addition, preliminary biological evaluations of the generated solomonamide precursors revealed antitumor activity against various tumor cell lines.This work was financially supported by the Ministerio de Economía y Competitividad (MINECO) (ref BIO2014-56092-R, CTQ2014-60223-R and CTQ2016-76311-R) and Junta de Andalucía and “Fondo Europeo de Desarrollo Regional-FEDER” (P12 CTS-1507). I.C.-S. thanks Ministerio de Educación, Cultura y Deporte for a predoctoral fellowship (FPU programme)

    Dog bites as a zoonotic risk in Ecuador : Need for the implementation of a One Health approach

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    Rabies is a viral zoonotic disease that can infect all mammals and the main route of transmission to human is attributed to dog bites. Due to the limited information available about the rabies vaccination coverage, although Ecuador is supposed to be free of rabies, we conducted a retrospective study of the epidemiological surveillance records on the notification of dog attacks to humans in Guayaquil, the most populated city in Ecuador. The results showed an annual incidence rate of 105.6 dog bites per 100,000 inhabitants, where the most affected anatomical parts are the lower extremities; individuals from 1 to 14 years of age were the most affected age group (IC95% 1.42-1.92; p < 0.001). As for the severity of the wounds, most of them (65%) were mild. Moreover, 25% of the dogs were free roaming ones, and only 43% of the dogs with owner had a complete vaccination scheme against rabies virus. We found a important dog attack rate in Guayaquil city and more than half of the dogs involved were not vaccinated against rabies. Under a potential scenario of rabies circulation in canine population, there would be a serious risk for rabies transmission to humans. Hence, it is important to reinforce rabies surveillance and vaccination programs aligned to the One Health concept to manage this public health issue

    Synthesis and Biological Evaluation of Depudecin Analogues

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    (-)-Depudecin (1) (Figure 1), isolated from the culture broths of the fungus Alternaria brassicicola,1 and later, from the weed pathogen Nimbya scirpicola,2 has been identified as a selective inhibitor of histone deacetylases (HDAC) with an IC50 in the low M range.3 In contrast to representative HDAC inhibitors, depudecin represents a unique inhibitor of these enzymes by virtue of its molecular structure, featuring the presence of two oxirane rings separated by a trans double bond. Originally discovered as part of a biological screening directed towards the identification of antitumour agents with detransforming activity,4 depudecin was identified as a bioactive metabolite capable of reverting the transformed morphology of tumor cells. This biological activity elicited a great biomedical and biological interest by virtue of its potential as an antitumor agent as well as for further understanding the biological roles of HDACs. Depudecin induced not only morphological changes but also cell cycle arrest and cellular differentiation,5 and also exhibited remarkable anti-angiogenesis activity.6 Prompted by its striking biological properties and enticing structure, we decided to initiate a research program directed towards the synthesis of natural depudecin. Our synthetic plan has recently culminated with linear and convergent total syntheses.7Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Genotypic tropism testing in proviral DNA to guide maraviroc initiation in aviremic subjects: 48‐week analysis of the PROTEST study

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    Introduction: In a previous interim 24‐week virological safety analysis of the PROTEST study [1], initiation of Maraviroc (MVC) plus 2 nucleoside reverse‐transcriptase inhibitors (NRTIs) in aviremic subjects based on genotypic tropism testing of proviral HIV‐1 DNA was associated with low rates of virological failure. Here we present the final 48‐week analysis of the study. Methods PROTEST was a phase 4, prospective, single‐arm clinical trial (ID: NCT01378910) carried on in 24 HIV care centres in Spain. Maraviroc‐naïve HIV‐1‐positive adults with HIV‐1 RNA (VL) 10% in a singleton), initiated MVC with 2 NRTIs and were followed for 48 weeks. Virological failure was defined as two consecutive VL>50 c/mL. Recent adherence was calculated as: (# pills taken/# pills prescribed during the previous week)*100. Results Tropism results were available from 141/175 (80.6%) subjects screened: 87/141 (60%) were R5 and 74/87 (85%) were finally included in the study. Their median age was 48 years, 16% were women, 31% were MSM, 36% had CDC category C at study entry, 62% were HCV+ and 10% were HBV+. Median CD4+ counts were 616 cells/mm3 at screening, and median nadir CD4+ counts were 143 cells/mm3. Previous ART included PIs in 46 (62%) subjects, NNRTIs in 27 (36%) and integrase inhibitors (INIs) in 1 (2%). The main reasons for treatment change were dyslipidemia (42%), gastrointestinal symptoms (22%), and liver toxicity (15%). MVC was given alongside TDF/FTC in 40 (54%) subjects, ABC/3TC in 30 (40%), AZT/3TC in 2 (3%) and ABC/TDF in 2 (3%). Sixty‐two (84%) subjects maintained VL<50 c/mL through week 48, whereas 12 (16%) discontinued treatment: two (3%) withdrew informed consent, one (1%) had a R5→X4 shift in HIV tropism between the screening and baseline visits, one (1%) was lost to follow‐up, one (1%) developed an ART‐related adverse event (rash), two (3%) died due to non‐study‐related causes (1 myocardial infarction at week 0 and 1 lung cancer at week 36), and five (7%) developed protocol‐defined virological failure, although two of them regained VL<50 c/mL with the same MVC regimen (Table 1). Conclusions Initiation of MVC plus 2 NRTIs in aviremic subjects based on genotypic tropism testing of proviral HIV‐1 DNA is associated with low rates of virological failure up to one year

    A multiple stakeholder multicriteria decision analysis in diabetic macular edema management: the MULTIDEX‑EMD study

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    Background The clinical and economic management of retinal diseases has become more complex following the introduction of new intravitreal treatments. Multicriteria decision analysis (MCDA) ofers the potential to overcome the challenges associated with traditional decision-making tools. Objectives A MCDA to determine the most relevant criteria to decision-making in the management of diabetic macular edema (DME) based on the perspectives of multiple stakeholders in Spain was developed. This MCDA was termed the MULTIDEX-EMD study. Methods Nineteen stakeholders (7 physicians, 4 pharmacists, 5 health authorities and health management experts, 1 psychologist, and 2 patient representatives) participated in this three-phase project. In phase A, an advisory board defned all of the criteria that could infuence DME treatment decision-making. These criteria were then screened using a discrete choice experiment (DCE) (phase B). Next, a multinomial logit model was ftted by applying the backward elimination algorithm (relevant criteria: p value<0.05). Finally, the results were discussed in a deliberative process (phase C). Results Thirty-one criteria were initially defned (phase A) and grouped into 5 categories: efcacy/efectiveness, safety, organizational and economic impact, patient-reported outcomes, and other therapeutic features. The DCE results (phase B) showed that 10 criteria were relevant to the decision-making process for a 50- to 65-year-old DME patient: mean change in best corrected visual acuity (p value<0.001), percentage of patients with an improvement of ≥15 letters (p value<0.001), efect duration per administration (p value=0.008), retinal detachment (p value<0.001), endophthalmitis (p value=0.012), myocardial infarction (p value<0.001), intravitreal hemorrhage (p value=0.021), annual treatment cost per patient (p value=0.001), health-related quality of life (HRQoL) (p value=0.004), and disability level (p value=0.021). Conclusions From a multi-stakeholder perspective, the selection of an appropriate treatment for DME patients should guarantee patient safety and maximize the visual acuity improvement and treatment efect duration. It should also contribute to system sustainability by being afordable, it should have a positive impact on HRQoL, and it should prevent disability

    HTLV-1 infection in solid organ transplant donors and recipients in Spain

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    Background: HTLV-1 infection is a neglected disease, despite infecting 10–15 million people worldwide and severe illnesses develop in 10% of carriers lifelong. Acknowledging a greater risk for developing HTLV-1 associated illnesses due to immunosuppression, screening is being widely considered in the transplantation setting. Herein, we report the experience with universal HTLV testing of donors and recipients of solid organ transplants in a survey conducted in Spain. Methods: All hospitals belonging to the Spanish HTLV network were invited to participate in the study. Briefly, HTLV antibody screening was performed retrospectively in all specimens collected from solid organ donors and recipients attended since the year 2008. Results: A total of 5751 individuals were tested for HTLV antibodies at 8 sites. Donors represented 2312 (42.2%), of whom 17 (0.3%) were living kidney donors. The remaining 3439 (59.8%) were recipients. Spaniards represented nearly 80%. Overall, 9 individuals (0.16%) were initially reactive for HTLV antibodies. Six were donors and 3 were recipients. Using confirmatory tests, HTLV-1 could be confirmed in only two donors, one Spaniard and another from Colombia. Both kidneys of the Spaniard were inadvertently transplanted. Subacute myelopathy developed within 1 year in one recipient. The second recipient seroconverted for HTLV-1 but the kidney had to be removed soon due to rejection. Immunosuppression was stopped and 3 years later the patient remains in dialysis but otherwise asymptomatic. Conclusion: The rate of HTLV-1 is low but not negligible in donors/recipients of solid organ transplants in Spain. Universal HTLV screening should be recommended in all donor and recipients of solid organ transplantation in Spain. Evidence is overwhelming for very high virus transmission and increased risk along with the rapid development of subacute myelopath

    Rapid subacute myelopathy following kidney transplantation from HTLV-1 donors: role of immunosuppresors and failure of antiretrovirals

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    Two kidney transplant recipients from a single donor became infected with HTLV-1 (human T-lymphotropic virus type 1) in Spain. One developed myelopathy 8 months following surgery despite early prescription of antiretroviral therapy. The allograft was removed from the second recipient at month 8 due to rejection and immunosuppressors discontinued. To date, 3 years later, this patient remains infected but asymptomatic. HTLV-1 infection was recognized retrospectively in the donor, a native Spaniard who had sex partners from endemic regions. Our findings call for a reappraisal of screening policies on donor-recipient organ transplantation. Based on the high risk of disease development and the large flux of persons from HTLV-1 endemic regions, pre-transplant HTLV-1 testing should be mandatory in Spain

    Overview of recent TJ-II stellarator results

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    The main results obtained in the TJ-II stellarator in the last two years are reported. The most important topics investigated have been modelling and validation of impurity transport, validation of gyrokinetic simulations, turbulence characterisation, effect of magnetic configuration on transport, fuelling with pellet injection, fast particles and liquid metal plasma facing components. As regards impurity transport research, a number of working lines exploring several recently discovered effects have been developed: the effect of tangential drifts on stellarator neoclassical transport, the impurity flux driven by electric fields tangent to magnetic surfaces and attempts of experimental validation with Doppler reflectometry of the variation of the radial electric field on the flux surface. Concerning gyrokinetic simulations, two validation activities have been performed, the comparison with measurements of zonal flow relaxation in pellet-induced fast transients and the comparison with experimental poloidal variation of fluctuations amplitude. The impact of radial electric fields on turbulence spreading in the edge and scrape-off layer has been also experimentally characterized using a 2D Langmuir probe array. Another remarkable piece of work has been the investigation of the radial propagation of small temperature perturbations using transfer entropy. Research on the physics and modelling of plasma core fuelling with pellet and tracer-encapsulated solid-pellet injection has produced also relevant results. Neutral beam injection driven Alfvénic activity and its possible control by electron cyclotron current drive has been examined as well in TJ-II. Finally, recent results on alternative plasma facing components based on liquid metals are also presentedThis work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 under Grant Agreement No. 633053. It has been partially funded by the Ministerio de Ciencia, Inovación y Universidades of Spain under projects ENE2013-48109-P, ENE2015-70142-P and FIS2017-88892-P. It has also received funds from the Spanish Government via mobility grant PRX17/00425. The authors thankfully acknowledge the computer resources at MareNostrum and the technical support provided by the Barcelona S.C. It has been supported as well by The Science and Technology Center in Ukraine (STCU), Project P-507F

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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