Publications by authors named "Alicia Castro"

12 Publications

  • Page 1 of 1

endocarditis with multiple cerebral emboli in a pregnant woman with coronavirus.

IDCases 2019 10;18:e00593. Epub 2019 Jul 10.

Department of Internal Medicine, Division of Pulmonary and Critical Care, Westchester Medical Center, New York Medical College, Valhalla, NY, United States.

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http://dx.doi.org/10.1016/j.idcr.2019.e00593DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6676006PMC
July 2019

Clinical aspects of visceral leishmaniasis caused by L. infantum in adults. Ten years of experience of the largest outbreak in Europe: what have we learned?

Parasit Vectors 2019 Jul 24;12(1):359. Epub 2019 Jul 24.

Área de Infecciosas, Servicio de Medicina Interna, Hospital Universitario de Fuenlabrada, Camino del Molino 2, 28942, Fuenlabrada, Madrid, Spain.

Background: An outbreak of leishmaniasis caused by Leishmania infantum was declared in the southwest of the Madrid region (Spain) in June 2009. This provided a unique opportunity to compare the management of visceral leishmaniasis (VL) in immunocompetent adults (IC-VL), patients with HIV (HIV-VL) and patients receiving immunosuppressants (IS-VL).

Methods: A cohort of adults with VL, all admitted to the Hospital Universitario de Fuenlabrada between June 2009 and June 2018, were monitored in this observational study, recording their personal, epidemiological, analytical, diagnostic, treatment and outcome variables.

Results: The study population was made up of 111 patients with VL (10% HIV-VL, 14% IS-VL, 76% IC-VL). Seventy-one percent of the patients were male; the mean age was 45 years (55 years for the IS-VL patients, P = 0.017). Fifty-four percent of the IC-VL patients were of sub-Saharan origin (P = 0.001). Fever was experienced by 98% of the IC-VL patients vs 73% of the LV-HIV patients (P = 0.003). Plasma ferritin was > 1000 ng/ml in 77% of the IC-VL patients vs 17% of the LV-HIV patients (P = 0.007). Forty-two percent of patients fulfilled the criteria for haemophagocytic lymphohistiocytosis. RDT (rK39-ICT) serological analysis returned sensitivity and specificity values of 45% and 99%, respectively, and ELISA/iIFAT returned 96% and 89%, respectively, with no differences in this respect between patient groups. Fourteen (13.0%) patients with VL experienced treatment failure, eight of whom were in the IC-VL group. Treatment with < 21 mg/kg (total) liposomal amphotericin B (LAB) was associated with treatment failure in the IC-VL patients [P = 0.002 (OR: 14.7; 95% CI: 2.6-83.3)].

Conclusions: IS-VL was more common than HIV-VL; the lack of experience in dealing with IS-VL is a challenge that needs to be met. The clinical features of the patients in all groups were similar, although the HIV-VL patients experienced less fever and had lower plasma ferritin concentrations. RDT (rK39-ICT) analysis returned a good specificity value but a much poorer sensitivity value than reported in other scenarios. The patients with HIV-VL, IS-VL and IC-VL returned similar serological results. Current guidelines for treatment seem appropriate, but the doses of LAB required to treat patients with HIV-VL and IS-VL are poorly defined.
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http://dx.doi.org/10.1186/s13071-019-3628-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6657057PMC
July 2019

Asymptomatic immune responders to Leishmania among HIV positive patients.

PLoS Negl Trop Dis 2019 06 3;13(6):e0007461. Epub 2019 Jun 3.

WHO Collaborating Centre for Leishmaniasis, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda (Madrid), Spain.

Concomitant infection with human immunodeficiency virus (HIV) and the Leishmania parasite is a growing public health problem, the result of the former spreading to areas where the latter is endemic. Leishmania infection is usually asymptomatic in immunocompetent individuals, but the proportion of HIV+ individuals in contact with the parasite who remain asymptomatic is not known. The aim of the present work was to examine the use of cytokine release assays in the detection of asymptomatic immune responders to Leishmania among HIV+ patients with no previous leishmaniasis or current symptomatology. Eighty two HIV+ patients (all from Fuenlabrada, Madrid, Spain, where a leishmaniasis outbreak occurred in 2009) were examined for Leishmania infantum infection using molecular and humoral response-based methods. None returned a positive molecular or serological result for the parasite. Thirteen subjects showed a positive lymphoproliferative response to soluble Leishmania antigen (SLA), although the mean CD4+ T lymphocyte counts of these patients was below the normal range. Stimulation of peripheral blood mononuclear cells (PBMC) or whole blood with SLA (the lymphoproliferative assay and whole blood assay respectively), led to the production of specific cytokines and chemokines. Thus, despite being immunocompromised, HIV+ patients can maintain a Th1-type cellular response to Leishmania. In addition, cytokine release assays would appear to be useful tools for detecting these individuals via the identification of IFN-γ in the supernatants of SLA-stimulated PBMC, and of IFN-γ, MIG and IL-2 in SLA-stimulated whole blood. These biomarkers appear to be 100% reliable for detecting asymptomatic immune responders to Leishmania among HIV+ patients.
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http://dx.doi.org/10.1371/journal.pntd.0007461DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6564048PMC
June 2019

Mechanosynthesis of the Whole YBiMnFeO Perovskite System: Structural Characterization and Study of Phase Transitions.

Materials (Basel) 2019 May 9;12(9). Epub 2019 May 9.

Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain.

Perovskite BiFeO and YMnO are both multiferroic materials with distinctive magnetoelectric coupling phenomena. Owing to this, the YBi MnFeO solid solution seems to be a promising system, though poorly studied. This is due to the metastable nature of the orthorhombic perovskite phase of YMnO at ambient pressure, and to the complexity of obtaining pure rhombohedral phases for BiFeO-rich compositions. In this work, nanocrystalline powders across the whole perovskite system were prepared for the first time by mechanosynthesis in a high-energy planetary mill, avoiding high pressure and temperature routes. Thermal decomposition temperatures were determined, and structural characterization was carried out by X-ray powder diffraction and Raman spectroscopy on thermally treated samples of enhanced crystallinity. Two polymorphic phases with orthorhombic Pnma and rhombohedral R3c h symmetries, and their coexistence over a wide compositional range were found. A gradual evolution of the lattice parameters with the composition was revealed for both phases, which suggests the existence of two continuous solid solutions. Following bibliographic data for BiFeO, first order ferroic phase transitions were located by differential thermal analysis in compositions with x ≥ 0.9. Furthermore, an orthorhombic-rhombohedral structural evolution across the ferroelectric transition was characterized with temperature-dependent X-ray diffraction.
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http://dx.doi.org/10.3390/ma12091515DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6539740PMC
May 2019

Cellular Markers of Active Disease and Cure in Different Forms of -Induced Disease.

Front Cell Infect Microbiol 2018 13;8:381. Epub 2018 Nov 13.

WHO Collaborating Centre for Leishmaniasis, National Centre for Microbiology, Instituto de Salud Carlos III, Madrid, Spain.

Increased numbers of peripheral blood mononucleocytes (PBMC) and increased IFN-γ secretion following challenge of blood samples with soluble antigen (SLA), have been proposed as biomarkers of specific cell-mediated immunity, indicating that treatment of visceral leishmaniasis (VL) has been successful. However, infection may manifest as cutaneous leishmaniasis (CL), and less commonly as localized leishmanial lymphadenopathy (LLL) or mucosal leishmaniasis (ML). The present work examines the value of these biomarkers as indicators of cured leishmaniasis presenting in these different forms. Blood samples were collected before and after treatment from patients living in Fuenlabrada (Madrid, Spain), an endemic area recently the center of a leishmaniasis outbreak. All samples were subjected to -specific PCR, serological tests (IFAT and rK39-ICT), and the SLA-cell proliferation assay (SLA-CPA), recording PBMC proliferation and the associated changes in IFN-γ production. Differences in the results recorded for the active and cured conditions were only significant for VL. PCR returned positive results in 67% of patients with active VL and in 3% of those with cured leishmaniasis. Similarly, rK39-ICT returned a positive result in 77% of active VL samples . 52% in cured VL samples, and IFAT in 90% . 56%; in the SLA-CPA, PBMC proliferation was seen in 16% . 90%, and an associated increase in IFN-γ production of 14 and 84%, respectively. The present findings reinforce the idea that PBMC proliferation and increased IFN-γ production in SLA-stimulated PBMC provide biomarkers of clinical cure in VL. Other tests are urgently needed to distinguish between the cured and active forms of the other types of clinical leishmaniasis caused by .
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http://dx.doi.org/10.3389/fcimb.2018.00381DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6243388PMC
September 2019

Multilayer Ceramic Magnetoelectric Composites with Tailored Interfaces for Enhanced Response.

ACS Appl Mater Interfaces 2017 Nov 25;9(44):39094-39104. Epub 2017 Oct 25.

Instituto de Ciencia de Materiales de Madrid, CSIC , Cantoblanco, 28049 Madrid, Spain.

Composite materials consisting of two dissimilar ferroic phases are an excellent alternative to single-phase multiferroics for a wide range of magnetoelectric technologies. In composites with strain-mediated magnetoelectric coupling the response is strongly dependent on the characteristics of the interface between the two mechanically coupled phases. Among the different material approaches considered, cofired ceramic composites offer improved reliability in applications and are more adequate for free-forming and miniaturization. However, their magnetoelectric response often suffers from poor reproducibility, which has been reiteratively associated with the quality of the interfaces with little experimental support. Here, we report an in-depth study of the local material properties across the interfaces of 0.36BiScO-0.64PbTiO/NiFeO multilayer ceramic composites, processed by spark plasma sintering of nanocrystalline powders. Tailored microstructures and low residual stress levels were obtained by adjusting the sintering mismatch between the two ferroic phases, which also resulted in fully functional interfaces and enhanced magnetoelectric responses.
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http://dx.doi.org/10.1021/acsami.7b14775DOI Listing
November 2017

Lymphoproliferative response after stimulation with soluble leishmania antigen (SLA) as a predictor of visceral leishmaniasis (VL) relapse in HIV+ patients.

Acta Trop 2016 Dec 28;164:345-351. Epub 2016 Sep 28.

WHO Collaborating Centre for Leishmaniasis, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain.

The introduction of HAART resulted in the decrease of Leishmania/HIV co-infection cases; nevertheless, the number of relapses remains high and secondary prophylaxis is recommended. However, secondary prophylaxis is not necessary in all patients, and presents a high risk of toxicity and an elevated cost. Our aim was to study whether specific cellular response to Leishmania infantum (measured by cell proliferation response after stimulation with soluble Leishmania antigen (SLA)), could be a useful tool to attempt a secondary prophylaxis withdrawal. In June 2009 an outbreak of leishmaniasis by Leishmania infantum was declared in the southeast of Madrid, and since January 2013, we recruited 10 HIV+ patients that had been treated for visceral leishmaniasis. 6 patients had positive SLA-cell proliferation test. The mean CD4 cell counts of those patients with positive SLA were 140 cel/mm3 and 40 cel/mm3 in those with negative SLA test. 3 patients with positive SLA-cell proliferation test (CD4 count: 336, 307, 625) were not on prophylaxis, and the other 3 patients (CD4 count: 152, 189, 359) were on secondary prophylaxis that was withdrawn after the positive SLA-cell proliferation test with no posterior relapses (mean follow up 60 weeks). From the 4 patients, which had negative SLA-cell proliferation test and continued on prophylaxis, 3 had positive PCR for Leishmania at the end of the follow-up and 2 presented clinical relapses. The performance of SLA-cell proliferation test can be a useful tool that can permit us to try withdrawal of the prophylaxis in Leishmania/HIV co-infected patients with low CD4 counts under clinical supervision, diminishing risk of toxicity and cost.
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http://dx.doi.org/10.1016/j.actatropica.2016.09.026DOI Listing
December 2016

A novel perovskite oxide chemically designed to show multiferroic phase boundary with room-temperature magnetoelectricity.

Nat Commun 2016 Sep 28;7:12772. Epub 2016 Sep 28.

Instituto de Ciencia de Materiales de Madrid, CSIC. Cantoblanco, 28049 Madrid, Spain.

There is a growing activity in the search of novel single-phase multiferroics that could finally provide distinctive magnetoelectric responses at room temperature, for they would enable a range of potentially disruptive technologies, making use of the ability of controlling polarization with a magnetic field or magnetism with an electric one (for example, voltage-tunable spintronic devices, uncooled magnetic sensors and the long-searched magnetoelectric memory). A very promising novel material concept could be to make use of phase-change phenomena at structural instabilities of a multiferroic state. Indeed, large phase-change magnetoelectric response has been anticipated by a first-principles investigation of the perovskite BiFeO-BiCoO solid solution, specifically at its morphotropic phase boundary between multiferroic polymorphs of rhombohedral and tetragonal symmetries. Here, we report a novel perovskite oxide that belongs to the BiFeO-BiMnO-PbTiO ternary system, chemically designed to present such multiferroic phase boundary with enhanced ferroelectricity and canted ferromagnetism, which shows distinctive room-temperature magnetoelectric responses.
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http://dx.doi.org/10.1038/ncomms12772DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5052705PMC
September 2016

High-sensitivity piezoelectric perovskites for magnetoelectric composites.

Sci Technol Adv Mater 2015 Feb 18;16(1):016001. Epub 2015 Feb 18.

Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain.

A highly topical set of perovskite oxides are high-sensitivity piezoelectric ones, among which Pb(Zr,Ti)O at the morphotropic phase boundary (MPB) between ferroelectric rhombohedral and tetragonal polymorphic phases is reckoned a case study. Piezoelectric ceramics are used in a wide range of mature, electromechanical transduction technologies like piezoelectric sensors, actuators and ultrasound generation, to name only a few examples, and more recently for demonstrating novel applications like magnetoelectric composites. In this case, piezoelectric perovskites are combined with magnetostrictive materials to provide magnetoelectricity as a product property of the piezoelectricity and piezomagnetism of the component phases. Interfaces play a key issue, for they control the mechanical coupling between the piezoresponsive phases. We present here main results of our investigation on the suitability of the high sensitivity MPB piezoelectric perovskite BiScO-PbTiO in combination with ferrimagnetic spinel oxides for magnetoelectric composites. Emphasis has been put on the processing at low temperature to control reactions and interdiffusion between the two oxides. The role of the grain size effects is extensively addressed.
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http://dx.doi.org/10.1088/1468-6996/16/1/016001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5036485PMC
February 2015

Study of nanocrystalline BiMnO3-PbTiO3: synthesis, structural elucidation, and magnetic characterization of the whole solid solution.

Chemistry 2012 Jul 1;18(29):9075-82. Epub 2012 Jun 1.

Electroceramics for the Information Technologies, Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain.

In the last ten years, the study and the search for new multiferroic materials have been a major challenge due to their potential applications in electronic technology. In this way, bismuth-containing perovskites (BiMO(3)), and particularly those in which the metal M position is occupied by a magnetically active cation, have been extensively investigated as possible multiferroic materials. From the point of view of synthesis, only a few of the possible bismuth-containing perovskites can be prepared by conventional methods but at high pressures. Herein, the preparation of one of these potential multiferroic systems, the solid solution xBiMnO(3)-(1-x)PbTiO(3) by mechanosynthesis is reported. Note that this synthetic method allows the oxides with high x values, and more particularly the BiMnO(3) phase, to be obtained as nanocrystalline phases, in a single step and at room temperature without the application of external pressure. These results confirm that, in the case of Bi perovskites, mechanosynthesis is a good alternative to high-pressure synthesis. These materials have been studied from the point of view of their structural characteristics by precession electron diffraction and magnetic property measurements.
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http://dx.doi.org/10.1002/chem.201200148DOI Listing
July 2012

Structural elucidation of the Bi(2(n + 2))Mo(n)O(6(n + 1)) (n = 3, 4, 5 and 6) family of fluorite superstructures by transmission electron microscopy.

Acta Crystallogr B 2009 Aug 16;65(Pt 4):458-66. Epub 2009 Jul 16.

Instituto de Ciencia de Materiales de Madrid, ICMM, CSIC, Sor Juana Inés de la Cruz 3, Cantoblanco, 28049 Madrid, Spain.

The cationic framework structure of a whole new family of compounds with the general formula Bi(2(n + 2))Mo(n)O(6(n + 1)) (n = 3, 4, 5 and 6) has been elucidated by transmission electron microscopy (TEM) methods. High-resolution transmission electron microscopy (HRTEM) has been used to postulate heavy-atom models based on the known structure of the n = 3 phase, Bi(10)Mo(3)O(24). These models were tested by HRTEM image simulation, electron diffraction and powder X-ray diffraction simulation methods which agreed with the experimental results. The four known phases of this family correspond to n = 3, 4, 5 and 6 members and all show fluorite superstructures. They consist of a common delta-Bi(2)O(3) fluorite-type framework, inside of which are distributed ribbons of {MoO(4)} tetrahedra which are infinite along b, one tetrahedron thick along c, and of variable widths of 3, 4, 5 or 6 {MoO(4)} tetrahedra along a depending on the family member (n value). These {MoO(4)} tetrahedra are isolated, i.e. without sharing any corner as in the [Bi(12)O(14)] columnar structural-type phase Bi[Bi(12)O(14)][MoO(4)](4)[VO(4)]. The structure of all these family members can be described as crystallographic shear derivatives from Aurivillius-type phases such as Bi(2)MoO(6), the n = infinity end member. All these compounds are good oxygen-ion conductors.
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http://dx.doi.org/10.1107/S0108768109023908DOI Listing
August 2009

Relaxor behavior, polarization buildup, and switching in nanostructured 0.92 PbZn1/3Nb2/3O3-0.08 PbTiO3 ceramics.

Small 2007 Nov;3(11):1906-11

Instituto de Ciencia de Materiales de Madrid (ICMM), Cantoblanco, 28049 Madrid, Spain.

The relaxor-type behavior, electrical polarization buildup, and switching in 0.92Pb(Zn(1/3)Nb(2/3))O(3)-0.08PbTiO(3) nanostructured ceramics with a grain size of approximately 20 nm is reported for the first time. This composition presents the highest-known piezoelectric coefficients, yet phase stability is an issue. Ceramics can only be obtained by the combination of mechanosynthesis and spark-plasma sintering. The results raise the possibility of using nanoscale, perovskite-relaxor-based morphotropic-phase-boundary materials for sensing and actuation in nanoelectromechanical systems.
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http://dx.doi.org/10.1002/smll.200700284DOI Listing
November 2007
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