60 research outputs found

    Implication in Paediatrics of the First International Consensus Statement for the Diagnosis and management of pseudohypoparathyroidism and related disorders

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    Desde que en 1942 Albright y colaboradores describieran por primera vez el pseudohipoparatiroidismo como la existencia de hipocalcemia e hiperfosfatemia asociadas a resistencia tisular a la hormona paratiroidea (PTH) en presencia de una función renal normal, se han realizado grandes avances en la caracterización clínica y genética de los pacientes afectos de esta enfermedad. De hecho, no solo se han identificado las alteraciones moleculares responsables, sino que se ha podido establecer que variantes en otros genes de la misma vía de señalización, PTH/PTHrP a través de la proteína Gsα, son la causa de enfermedades que comparten determinadas manifestaciones clínicas con el pseudohipoparatiroidismo. En el ámbito pediátrico, los primeros síntomas o signos que deben hacernos pensar en alteraciones en esta vía son la presencia de osificaciones subcutáneas, la braquidactilia y/o la obesidad de inicio precoz, seguidas en el tiempo por la posible aparición de resistencia a la PTH. Esta sospecha clínica deberá ser confirmada mediante un diagnóstico molecular que permita el correcto seguimiento clínico coordinado y multidisciplinar. Entre los aspectos a tener en cuenta en la atención de estos pacientes se incluye la evaluación al diagnóstico y seguimiento de la eventual presencia de resistencia a la PTH y a la hormona tirotropa (TSH), deficiencia de hormona de crecimiento (GH), hipogonadismo, alteraciones esqueléticas, alteraciones de la salud dental, obesidad, resistencia a la acción de la insulina, intolerancia a la glucosa o diabetes mellitus tipo 2 e hipertensión, así como osificaciones ectópicas (subcutáneas o con afectación de tejidos más profundos) y alteración del desarrollo neurocognitivoSince Albright and co-workers described pseudohypoparathyroidism in 1942 as the combined presence of hypocalcaemia and hyperphosphataemia associated with the existence of tissue resistance to parathyroid hormone (PTH) action upon normal renal function, great advances have been made in the clinical and genetic profile of patients affected by this condition. Furthermore, not only have genetic bases of pseudohypoparathyroidism been unravelled, but also variants in other genes involved in the PTH/PTHrP signalling pathway through Gsα, have been identified as the cause of diseases that share clinical features with pseudohypoparathyroidism. In the paediatric setting, the first symptoms suggesting the impairment of this signalling pathway are the presence of subcutaneous ossifications, brachydactyly and/or early onset obesity, followed by the possible development of PTH resistance. This clinical suspicion should be confirmed by an accurate molecular diagnosis to allow for coordinated multidisciplinary clinical management. Among the features of this group of disorders, physicians should pay attention to evaluation of PTH and/or thyrotropin (TSH) resistance at diagnosis and throughout follow-up, as well as growth hormone deficiency, hypogonadism, skeletal deformities, dental impairment, obesity, insulin resistance, impaired glucose tolerance or type 2 diabetes mellitus and hypertension, as well as ectopic ossifications (either subcutaneous or affecting deeper tissues) and impairment of neurocognitive developmen

    Antiparasitic activity of bromotyrosine alkaloids and new analogues isolated from the Fijian marine Sponge Aplysinella rhax

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    Ten bromotyrosine alkaloids( 1 ‐ 10 ) were isolated and characterised from the marine sponge Aplysinella rhax ( de Laubenfels 1954) collected from the Fiji Islands, which included one new bromotyrosine analogue, psammaplin P ( 6 ) and two other analogues, psammaplins O ( 5 ) and 4‐bromo‐6‐carbomethoxy salicylic acid ( 7 ), which have not been previously reported from natural sources. HRESIMS, 1D and 2D NMR spectroscopic methods were used in the elucidation of the compounds. Bisaprasin, a biphenylic dimer of psammaplin A, showed moderate activity with IC 50 at 19+/‐ 5 and 29+/‐ 6 μM against Trypanzoma cruzi Tulahuen C4, and the lethal human malaria species Plasmodium falciparum clone 3D7, respectively, while psammaplins A ( 1 ) and D ( 4 ) exhibited low activity against both parasites. This is the first report of the antimalarial and antitrypanosomal activity of the psammaplin‐type compounds. Additionally, the biosynthesis hypotheses of the three natural products ( 5 , 6 and 7 ) were proposed

    Discovery of New Compounds Active against Plasmodium falciparum by High Throughput Screening of Microbial Natural Products

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    Due to the low structural diversity within the set of antimalarial drugs currently available in the clinic and the increasing number of cases of resistance, there is an urgent need to find new compounds with novel modes of action to treat the disease. Microbial natural products are characterized by their large diversity provided in terms of the chemical complexity of the compounds and the novelty of structures. Microbial natural products extracts have been underexplored in the search for new antiparasitic drugs and even more so in the discovery of new antimalarials. Our objective was to find new druggable natural products with antimalarial properties from the MEDINA natural products collection, one of the largest natural product libraries harboring more than 130,000 microbial extracts. In this work, we describe the optimization process and the results of a phenotypic high throughput screen (HTS) based on measurements of Plasmodium lactate dehydrogenase. A subset of more than 20,000 extracts from the MEDINA microbial products collection has been explored, leading to the discovery of 3 new compounds with antimalarial activity. In addition, we report on the novel antiplasmodial activity of 4 previously described natural productsThis work was supported by the Junta de Andalucía [BIO-199, P09-CVI- 5367], the VI Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica 2008-2011, Instituto de Salud Carlos III-Subdirección General de Redes y Centros de Investigación Cooperativa-Red de Investigación Cooperativa en Enfermedades Tropicales (RICET FIS Network: RD12/0018/0017),the Plan Nacional (SAF2013-48999-R), the FEDER funds from the EU and the PARAMET network (FP7-PEOPLE-2011-ITN. GA290080) to DG-P. Research of FV and OG was supported by the Instituto de Salud Carlos III-Subdirección General de Redes y Centros de Investigación Cooperativa-Red de Investigación Cooperativa en Enfermedades Tropicales (RICET FIS Network: RD12/0018/0005) and the FEDER funds from the EU and the PARAMET network (FP7-PEOPLE-2011-ITN. GA290080). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe

    Antiparasitic Activities of Compounds Isolated from Aspergillus fumigatus Strain Discovered in Northcentral Nigeria

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    This article belongs to the Special Issue Antimicrobial and Anti-infective Activity of Natural Products. The authors are grateful to the Schlumberger Foundation Faculty for the Future board for their financial support in conducting the present study.Peer reviewedPublisher PD

    New Compounds with Bioisosteric Replacement of Classic Choline Kinase Inhibitors Show Potent Antiplasmodial Activity

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    In the fight against Malaria, new strategies need to be developed to avoid resistance of the parasite to pharmaceutics and other prevention barriers. Recently, a Host Directed Therapy approach based on the suppression of the starting materials uptake from the host by the parasite has provided excellent results. In this article, we propose the synthesis of bioisosteric compounds that are capable of inhibiting Plasmodium falciparum Choline Kinase and therefore to reduce choline uptake, which is essential for the development of the parasite. Of the 41 bioisosteric compounds reported herein, none showed any influence of the linker on the antimalarial and enzyme inhibitory activity, whereas an effect of the type of cationic heads used could be observed. SARs determined that the thienopyrimidine substituted in 4 by a pyrrolidine is the best scaffold, independently of the chosen linker. The decrease in lipophilicity seems to improve the antimalarial activity but to cause an opposite effect on the inhibition of the enzyme. While potent compounds with similar good inhibitory values have been related to the proposed mechanism of action, some of them still show discrepancies and further studies are needed to determine their specific molecular target

    Determinants of Progression and Regression of Subclinical Atherosclerosis Over 6 Years.

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    BACKGROUND Atherosclerosis is a systemic disease that frequently begins early in life. However, knowledge about the temporal disease dynamics (ie, progression or regression) of human subclinical atherosclerosis and their determinants is scarce. OBJECTIVES This study sought to investigate early subclinical atherosclerosis disease dynamics within a cohort of middle-aged, asymptomatic individuals by using multiterritorial 3-dimensional vascular ultrasound (3DVUS) imaging. METHODS A total of 3,471 participants from the PESA (Progression of Early Subclinical Atherosclerosis) cohort study (baseline age 40-55 years; 36% female) underwent 3 serial 3DVUS imaging assessments of peripheral arteries at 3-year intervals. Subclinical atherosclerosis was quantified as global plaque volume (mm3) (bilateral carotid and femoral plaque burden). Multivariable logistic regression models for progression and regression were developed using stepwise forward variable selection. RESULTS Baseline to 6-year subclinical atherosclerosis progression occurred in 32.7% of the cohort (17.5% presenting with incident disease and 15.2% progressing from prevalent disease at enrollment). Regression was observed in 8.0% of those patients with baseline disease. The effects of higher low-density lipoprotein cholesterol (LDL-C) and elevated systolic blood pressure (SBP) on 6-year subclinical atherosclerosis progression risk were more pronounced among participants in the youngest age stratum (Pinteraction = 0.04 and 0.02, respectively). CONCLUSIONS Over 6 years, subclinical atherosclerosis progressed in one-third of middle-age asymptomatic subjects. Atherosclerosis regression is possible in early stages of the disease. The impact of LDL-C and SBP on subclinical atherosclerosis progression was more pronounced in younger participants, a finding suggesting that the prevention of atherosclerosis and its progression could be enhanced by tighter risk factor control at younger ages, with a likely long-term impact on reducing the risk of clinical events. (Progression of Early Subclinical Atherosclerosis [PESA; also PESA-CNIC-Santander]; NCT01410318).S

    Establishment of a screening platform based on human coronavirus OC43 for the identification of microbial natural products with antiviral activity

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    Human coronaviruses (HCoVs) cause respiratory tract infections and are of great importance due to the recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Human betacoronavirus OC43 (HCoV-OC43) is an adequate surrogate for SARS-CoV-2 because it infects the human respiratory system, presents a comparable biology, and is transmitted in a similar way. Its use is advantageous since it only requires biosafety level (BSL)-2 infrastructure which minimizes costs and biosafety associated limitations. In this report, we describe a high-throughput screening (HTS) platform to identify compounds that inhibit the propagation of HCoV-OC43. Optimization of assays based on inhibition of the cytopathic effect and virus immunodetection with a specific antibody, has provided a robust methodology for the screening of a selection of microbial natural product extracts from the Fundación MEDINA collection. Using this approach, a subset of 1280 extracts has been explored. Of these, upon hit confirmation and early LC-MS dereplication, 10 extracts were identified that contain potential new compounds. In addition, we report on the novel antiviral activity of some previously described natural products whose presence in bioactive extracts was confirmed by LC/MS analysis.This work was funded by the the European Commission—Next Generation EU (regulation EU 2020/2094), through CSIC's Global Health Platform (PTI Salud Global), the Instituto de Salud Carlos III Subdirección General de Redes y Centros de Investigación Cooperativa-Red de Investigación Cooperativa en Enfermedades Tropicales (RICET: RD16/0027/0014), the MCIN/AEI/10.13039/501100011033 (PID2019-109623RB-I00), the MCIN/AEI/10.13039/501100011033 and FEDER Una manera de hacer Europa (2016-79957-R) and by the Junta de Andalucía (BIO-199)N

    Strong Cellular Immune Response, but Not Humoral, against SARS-CoV-2 in Oncohematological Patients with Autologous Stem Cell Transplantation after Natural Infection

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    Oncohematological patients show a low immune response against SARS-CoV-2, both to natural infection and after vaccination. Most studies are focused on the analysis of the humoral response; therefore, the information available about the cellular immune response is limited. In this study, we analyzed the humoral and cellular immune responses in nine individuals who received chemotherapy for their oncohematological diseases, as well as consolidation with autologous stem cell transplantation (ASCT), after being naturally infected with SARS-CoV-2. All individuals had asymptomatic or mild COVID-19 and were not vaccinated against SARS-CoV-2. These results were compared with matched healthy individuals who also had mild COVID-19. The humoral response against SARS-CoV-2 was not detected in 6 of 9 oncohematological individuals prior to ASCT. The levels of antibodies and their neutralization capacity decreased after ASCT. Conversely, an enhanced cytotoxic activity against SARS-CoV-2-infected cells was observed after chemotherapy plus ASCT, mostly based on high levels of NK, NKT, and CD8+TCRγδ+ cell populations that were able to produce IFNγ and TNFα. These results highlight the importance of performing analyses not only to evaluate the levels of IgGs against SARS-CoV-2, but also to determine the quality of the cellular immune response developed during the immune reconstitution after ASCT.This work was supported by the Coordinated Research Activities at the Centro Nacional de Microbiología (CNM, Instituto de Salud Carlos III) (COV20_00679) to promote an integrated response against SARS-CoV-2 in Spain (Spanish Ministry of Science and Innovation) that is coordinated by Dr Inmaculada Casas (WHO National Influenza Center of the CNM), the Spanish Ministry of Science and Innovation (PID2019-110275RB-I00), and AES 2021 grant from Instituto de Salud Carlos III (PI21/00877). The work of Sara Rodríguez-Mora is financed by NIH grant R01AI143567. The work of Montserrat Torres is supported by Instituto de Salud Carlos III (COV20_00679). The work of Lorena Vigón is supported by a pre-doctoral grant from Instituto de Salud Carlos III (FIS PI16CIII/00034-ISCIII-FEDER).S

    Validation of Plasmodium falciparum dUTPase as the target of 5'-tritylated deoxyuridine analogues with anti-malarial activity

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    BACKGROUND: Malaria remains as a major global problem, being one of the infectious diseases that engender highest mortality across the world. Due to the appearance of resistance and the lack of an effective vaccine, the search of novel anti-malarials is required. Deoxyuridine 5'-triphosphate nucleotido-hydrolase (dUTPase) is responsible for the hydrolysis of dUTP to dUMP within the parasite and has been proposed as an essential step in pyrimidine metabolism by providing dUMP for thymidylate biosynthesis. In this work, efforts to validate dUTPase as a drug target in Plasmodium falciparum are reported. METHODS: To investigate the role of PfdUTPase in cell survival different strategies to generate knockout mutants were used. For validation of PfdUTPase as the intracellular target of four inhibitors of the enzyme, mutants overexpressing PfdUTPase and HsdUTPase were created and the IC50 for each cell line with each compound was determined. The effect of these compounds on dUTP and dTTP levels from P. falciparum was measured using a DNA polymerase assay. Detailed localization studies by indirect immunofluorescence microscopy and live cell imaging were also performed using a cell line overexpressing a Pfdut-GFP fusion protein. RESULTS:Different attempts of disruption of the dut gene of P. falciparum were unsuccessful while a 3' replacement construct could recombine correctly in the locus suggesting that the enzyme is essential. The four 5'-tritylated deoxyuridine analogues described are potent inhibitors of the P. falciparum dUTPase and exhibit antiplasmodial activity. Overexpression of the Plasmodium and human enzymes conferred resistance against selective compounds, providing chemical validation of the target and confirming that indeed dUTPase inhibition is involved in anti-malarial activity. In addition, incubation with these inhibitors was associated with a depletion of the dTTP pool corroborating the central role of dUTPase in dTTP synthesis. PfdUTPase is mainly localized in the cytosol. CONCLUSION: These results strongly confirm the pivotal and essential role of dUTPase in pyrimidine biosynthesis of P. falciparum intraerythrocytic stages
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