Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 857
Filter
1.
Front Psychol ; 15: 1404726, 2024.
Article in English | MEDLINE | ID: mdl-38911965

ABSTRACT

This research investigates how entrepreneurs perceive the hypothetical nature of technologies (based on situations that are often imagined or theoretical) as a foundation for entrepreneurial endeavors and how this perception influences the formation of business Opportunity Beliefs. Drawing on the Construal Level Theory, we explore the relationship between the perceived hypotheticality of technologies and Opportunity Beliefs. Two experimental studies are conducted to examine these relationships, with Study 1 (n = 177 entrepreneurs) focusing on the perception of innovative technologies as more distant or hypothetical, and Study 2 (n = 404 entrepreneurs) delving into how the perceived distance to technology influences Opportunity Beliefs. The results indicate that entrepreneurs view more innovative technologies as more hypothetical and that hypotheticality mediates the relationship between the perceived degree of innovation and Opportunity Beliefs. We find evidence that Entrepreneurs tend to view the feasibility and fit/alignment of business opportunities more favorably when they perceive the psychological distance (hypotheticality) of the opportunity as closer rather than more distant. However, the difference this difference is nonsignificant in how they evaluate the desirability of the opportunity in any psychological distance. These results provide insight into the cognitive processes of entrepreneurs and offer implications for understanding how entrepreneurs perceive and evaluate business opportunities.

2.
Clin Exp Allergy ; 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38938054

ABSTRACT

Persistent and unresolved inflammation is a common underlying factor observed in several and seemingly unrelated human diseases, including cardiovascular and neurodegenerative diseases. Particularly, in atopic conditions, acute inflammatory responses such as those triggered by insect venom, food or drug allergies possess also a life-threatening potential. However, respiratory allergies predominantly exhibit late immune responses associated with chronic inflammation, that can eventually progress into a severe phenotype displaying similar features as those observed in other chronic inflammatory diseases, as is the case of uncontrolled severe asthma. This review aims to explore the different facets and systems involved in chronic allergic inflammation, including processes such as tissue remodelling and immune cell dysregulation, as well as genetic, metabolic and microbiota alterations, which are common to other inflammatory conditions. Our goal here was to deepen on the understanding of an entangled disease as is chronic allergic inflammation and expose potential avenues for the development of better diagnostic and intervention strategies.

3.
Life (Basel) ; 14(6)2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38929711

ABSTRACT

Parkinson's disease (PD) caused by SNCA gene triplication (3XSNCA) leads to early onset, rapid progression, and often dementia. Understanding the impact of 3XSNCA and its absence is crucial. This study investigates the differentiation of human induced pluripotent stem cell (hiPSC)-derived floor-plate progenitors into dopaminergic neurons. Three different genotypes were evaluated in this study: patient-derived hiPSCs with 3XSNCA, a gene-edited isogenic line with a frame-shift mutation on all SNCA alleles (SNCA 4KO), and a normal wild-type control. Our aim was to assess how the substantia nigra pars compacta (SNpc) microenvironment, damaged by 6-hydroxydopamine (6-OHDA), influences tyrosine hydroxylase-positive (Th+) neuron differentiation in these genetic variations. This study confirms successful in vitro differentiation into neuronal lineage in all cell lines. However, the SNCA 4KO line showed unusual LIM homeobox transcription factor 1 alpha (Lmx1a) extranuclear distribution. Crucially, both 3XSNCA and SNCA 4KO lines had reduced Th+ neuron expression, despite initial successful neuronal differentiation after two months post-transplantation. This indicates that while the SNpc environment supports early neuronal survival, SNCA gene alterations-either amplification or knock-out-negatively impact Th+ dopaminergic neuron maturation. These findings highlight SNCA's critical role in PD and underscore the value of hiPSC models in studying neurodegenerative diseases.

4.
Microbiol Spectr ; 12(6): e0421323, 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38700324

ABSTRACT

A US collection of invasive Escherichia coli serotype O1 bloodstream infection (BSI) isolates were assessed for genotypic and phenotypic diversity as the basis for designing a broadly protective O-antigen vaccine. Eighty percent of the BSI isolate serotype O1 strains were genotypically ST95 O1:K1:H7. The carbohydrate repeat unit structure of the O1a subtype was conserved in the three strains tested representing core genome multi-locus sequence types (MLST) sequence types ST95, ST38, and ST59. A long-chain O1a CRM197 lattice glycoconjugate antigen was generated using oxidized polysaccharide and reductive amination chemistry. Two ST95 strains were investigated for use in opsonophagocytic assays (OPA) with immune sera from vaccinated animals and in murine lethal challenge models. Both strains were susceptible to OPA killing with O1a glycoconjugate post-immune sera. One of these, a neonatal sepsis strain, was found to be highly lethal in the murine challenge model for which virulence was shown to be dependent on the presence of the K1 capsule. Mice immunized with the O1a glycoconjugate were protected from challenges with this strain or a second, genotypically related, and similarly virulent neonatal isolate. This long-chain O1a CRM197 lattice glycoconjugate shows promise as a component of a multi-valent vaccine to prevent invasive E. coli infections. IMPORTANCE: The Escherichia coli serotype O1 O-antigen serogroup is a common cause of invasive bloodstream infections (BSI) in populations at risk such as newborns and the elderly. Sequencing of US BSI isolates and structural analysis of O polysaccharide antigens purified from strains that are representative of genotypic sub-groups confirmed the relevance of the O1a subtype as a vaccine antigen. O polysaccharide was purified from a strain engineered to produce long-chain O1a O-antigen and was chemically conjugated to CRM197 carrier protein. The resulting glycoconjugate elicited functional antibodies and was protective in mice against lethal challenges with virulent K1-encapsulated O1a isolates.


Subject(s)
Escherichia coli Infections , Escherichia coli , Glycoconjugates , O Antigens , Animals , O Antigens/immunology , O Antigens/genetics , Mice , Escherichia coli Infections/prevention & control , Escherichia coli Infections/microbiology , Escherichia coli Infections/immunology , Escherichia coli/genetics , Escherichia coli/immunology , Glycoconjugates/immunology , Humans , Serogroup , Escherichia coli Vaccines/immunology , Antibodies, Bacterial/blood , Antibodies, Bacterial/immunology , Female , Virulence , Vaccines, Conjugate/immunology , Multilocus Sequence Typing , Disease Models, Animal , Bacteremia/prevention & control , Bacteremia/microbiology , Bacteremia/immunology , Bacterial Proteins
5.
Nanotechnology ; 35(17)2024 Feb 09.
Article in English | MEDLINE | ID: mdl-38266307

ABSTRACT

In this work, we have studied the multi-photon excited photoluminescence from metal nanoclusters (NCs) of Au, Ag and Pt embedded in Al2O3matrix by ion implantation. The thermal annealing process allows to obtain a system composed of larger plasmonic metal nanoparticles (NPs) surrounded by photoluminescent ultra-small metal NCs. By exciting at 1064 nm, visible emission, ranging from 450 to 800 nm, was detected. The second and fourth-order nature of the multiphoton process was verified in a power-dependent study measured for each sample below the damage threshold. Experiments show that Au and Ag NCs exhibit a four-fold enhanced multiphoton excited photoluminescence with respect to that observed for Pt NCs, which can be explained as a result of a plasmon-mediated near-field process that is of less intensity for Pt NPs. These findings provide new opportunities to combine plasmonic nanoparticles and photoluminescent nanoclusters inside a robust inorganic matrix to improve their optical properties. Plasmon-enhanced multiphoton excited photoluminescence from metal nanoclusters may find potential application as ultrasmall fluorophores in multiphoton sensing, and in the development of solar cells with highly efficient energy conversion modules.

6.
Purinergic Signal ; 20(1): 73-82, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37055675

ABSTRACT

Plasmacytoid dendritic cells (pDCs) are a specialized DC subset mainly associated with sensing viral pathogens and high-type I interferon (IFN-I) release in response to toll-like receptor (TLR)-7 and TLR-9 signaling. Currently, pDC contribution to inflammatory responses is extensively described; nevertheless, their regulatory mechanisms require further investigation. CD39 and CD73 are ectoenzymes driving a shift from an ATP-proinflammatory milieu to an anti-inflammatory environment by converting ATP to adenosine. Although the regulatory function of the purinergic halo CD39/CD73 has been reported in some immune cells like regulatory T cells and conventional DCs, its presence in pDCs has not been examined. In this study, we uncover for the first time the expression and functionality of the purinergic halo in human blood pDCs. In healthy donors, CD39 was expressed in the cell surface of 14.0 ± 12.5% pDCs under steady-state conditions, while CD73 showed an intracellular location and was only expressed in 8.0 ± 2.2% of pDCs. Nevertheless, pDCs stimulation with a TLR-7 agonist (R848) induced increased surface expression of both molecules (43.3 ± 23.7% and 18.6 ± 9.3%, respectively), as well as high IFN-α secretion. Furthermore, exogenous ATP addition to R848-activated pDCs significantly increased adenosine generation. This effect was attributable to the superior CD73 expression and activity because blocking CD73 reduced adenosine production and improved pDC allostimulatory capabilities on CD4 + T cells. The functional expression of the purinergic halo in human pDCs described in this work opens new areas to investigate its participation in the regulatory pDC mechanisms in health and disease.


Subject(s)
Adenosine , CD4-Positive T-Lymphocytes , Humans , Adenosine/metabolism , Signal Transduction , Adenosine Triphosphate/metabolism , Dendritic Cells/metabolism
7.
Sci Rep ; 13(1): 17796, 2023 10 18.
Article in English | MEDLINE | ID: mdl-37853101

ABSTRACT

Parkinson's disease (PD) is one of the most common neurodegenerative diseases, but no disease modifying therapies have been successful in clinical translation presenting a major unmet medical need. A promising target is alpha-synuclein or its aggregated form, which accumulates in the brain of PD patients as Lewy bodies. While it is not entirely clear which alpha-synuclein protein species is disease relevant, mere overexpression of alpha-synuclein in hereditary forms leads to neurodegeneration. To specifically address gene regulation of alpha-synuclein, we developed a CRISPR interference (CRISPRi) system based on the nuclease dead S. aureus Cas9 (SadCas9) fused with the transcriptional repressor domain Krueppel-associated box to controllably repress alpha-synuclein expression at the transcriptional level. We screened single guide (sg)RNAs across the SNCA promoter and identified several sgRNAs that mediate downregulation of alpha-synuclein at varying levels. CRISPRi downregulation of alpha-synuclein in iPSC-derived neuronal cultures from a patient with an SNCA genomic triplication showed functional recovery by reduction of oxidative stress and mitochondrial DNA damage. Our results are proof-of-concept in vitro for precision medicine by targeting the SNCA gene promoter. The SNCA CRISPRi approach presents a new model to understand safe levels of alpha-synuclein downregulation and a novel therapeutic strategy for PD and related alpha-synucleinopathies.


Subject(s)
Methicillin-Resistant Staphylococcus aureus , Parkinson Disease , Humans , alpha-Synuclein/genetics , alpha-Synuclein/metabolism , Methicillin-Resistant Staphylococcus aureus/genetics , Staphylococcus aureus/genetics , DNA, Mitochondrial/metabolism , CRISPR-Cas Systems , RNA, Guide, CRISPR-Cas Systems , Stem Cells/metabolism , Oxidative Stress/genetics
8.
Nat Prod Res ; : 1-6, 2023 Jun 27.
Article in English | MEDLINE | ID: mdl-37367484

ABSTRACT

In the present study, we have evaluated the cytotoxic activity of 282 extracts from 72 native plant species of the Brazilian Atlantic Forest biome. As a result, Casearia arborea and Sorocea hilarii leaves extracts showed cytotoxic activity against three tumour cell lines tested (B16F10, SW480 and Jurkat). After bioassay-guided fractionation, the bioactive fractions were submitted to the dereplication study via High-performance Liquid Chromatography, connected to High-resolution Mass Spectrometry (HPLC-ESI-QTOF/MS) analysis, combined with a Global Natural Products Social Molecular Networking (GNPS) tool. A combination of bioactivity-guided and dereplication approaches resulted in the putative annotation of 27 clerodane diterpenes and 9 flavonoids as main compounds present in the cytotoxic fractions of C. arborea. Regarding the active fraction of S. hilarii, 10 megastigmans, 17 spirostane steroids derivatives and 2 lignans were putatively identified. In conclusion, Casearia arborea and Sorocea hilarii are potential sources of antitumor compounds.

9.
Odontol. sanmarquina (Impr.) ; 26(2): e25050, Marzo 2023.
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1437080

ABSTRACT

Objetivo: Determinar la frecuencia de calcificación del complejo estilohioideo en radio-grafías panorámicas digitales de un centro radiológico. Métodos. El tipo de estudio fue cualitativo, diseño descriptivo, transversal y retrospectivo; se estudiaron 400 radiografías panorámicas digitales entre edades de 25 a 70 años. Se realizó una evaluación visual de las radiografías panorámicas digitales donde se observó el tipo y patrón de calcificación del ligamento estilohioideo. Resultados. El 56,8% presentó calcificación del complejo estilohioideo en radiografías panorámicas digitales; según sexo en el grupo femenino se presentó en un 64,6%; respecto al grupo etario el 65.8% presentó calcificación en adultos de 30 a 59 años; según el lado afectado el 71,4% fue bilateral, según la apariencia radiográfica el tipo I presentó una mayor frecuencia con un 50,1% en el lado derecho y el 62,5% en el lado izquierdo; finalmente el patrón de calcificación más frecuente fue el completamente calcificado con un 23,8% en el lado derecho y un 48,5% en el lado izquierdo. Conclusión. La frecuencia de calcificación del complejo estilohioideo en ra-diografías panorámicas digitales en la muestra estudiada fue alta por lo que es importante el uso de la radiografía panorámica como medio de diagnóstico para poder detectar este tipo de hallazgos que junto a una evaluación clínica nos permitan hacer un correcto diagnóstico en fin de un tratamiento adecuado.


Objective: To determine the frequency of the stylohyoid complex calcification in digital panoramic radiographs of a radiological center. Methods.The type of study was quali-tative, descriptive, cross-sectional and retrospective design; 400 digital panoramic radio-graphs between the ages of 25 and 70 were analyzed. A visual evaluation of the digital panoramic radiographs was performed to assess the type and pattern of the stylohyoid ligament calcification. Results. The 56.8% presented calcification of the stylohyoid com-plex in digital panoramic radiographs; according to sex in the female group it was present in 64.6%; Regarding the age group, 65.8% presented calcification in adults aged 30-59 years-old; According to the affected side, 71.4% were bilateral, according to the radio-graphic appearance, type I presented a higher frequency with 50.1% on the right side and 62.5% on the left side. Finally, the most frequent calcification was the completely calcified pattern, with 23.8% on the right side and 48.5% on the left side. Conclusion.The frequency of calcification of the stylohyoid complex in digital panoramic radio-graphs in the sample studied was high, so it is important to use panoramic radiography as a means of diagnosis to be able to detect this type of findings that, together with a clinical evaluation, allow us to make a correct diagnosis and perform an adequate treatment.

10.
bioRxiv ; 2023 Jan 24.
Article in English | MEDLINE | ID: mdl-36747875

ABSTRACT

Parkinson's disease (PD) is one of the most common neurodegenerative diseases, but no disease modifying therapies have been successful in clinical translation presenting a major unmet medical need. A promising target is alpha-synuclein or its aggregated form, which accumulates in the brain of PD patients as Lewy bodies. While it is not entirely clear which alpha-synuclein protein species is disease relevant, mere overexpression of alpha-synuclein in hereditary forms leads to neurodegeneration. To specifically address gene regulation of alpha-synuclein, we developed a CRISPR interference (CRISPRi) system based on the nuclease dead S. aureus Cas9 (SadCas9) fused with the transcriptional repressor domain Krueppel-associated box to controllably repress alpha-synuclein expression at the transcriptional level. We screened single guide (sg)RNAs across the SNCA promoter and identified several sgRNAs that mediate downregulation of alpha-synuclein at varying levels. CRISPRi downregulation of alpha-synuclein in iPSC-derived neuronal cultures from a patient with an SNCA genomic triplication showed functional recovery by reduction of oxidative stress and mitochondrial DNA damage. Our results are proof-of-concept in vitro for precision medicine by targeting the SNCA gene promoter. The SNCA CRISPRi approach presents a new model to understand safe levels of alpha-synuclein downregulation and a novel therapeutic strategy for PD and related alpha-synucleinopathies.

11.
Clin Oral Investig ; 27(6): 3105-3116, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36809355

ABSTRACT

OBJECTIVE: To investigate the effect of fluoride-containing whitening products on sound enamel and on artificial caries lesions during a cariogenic challenge. MATERIALS AND METHODS: Bovine enamel specimens (n = 120) with three areas [non-treated sound enamel (NSE), treated sound enamel (TSE), and treated artificial caries lesion (TACL)] were randomly assigned to the four groups: whitening mouthrinse (WM: 2.5% hydrogen peroxide-100 ppm F-), placebo mouthrinse (PM: 0% hydrogen peroxide-100 ppm F-), whitening gel (WG: 10% carbamide peroxide-1130 ppm F-), and deionized water (negative control; NC). The treatments (2 min for WM, PM, and NC, and 2 h for WG) were carried out during a 28-day pH-cycling model (6 × 60 min demineralization/day). Relative surface reflection intensity (rSRI) and transversal microradiography (TMR) analyses were performed. Fluoride uptake (surface and subsurface) was measured in additional enamel specimens. RESULTS: For TSE, a higher value of rSRI was observed in WM (89.99% ± 6.94), and a greater decrease in rSRI was observed for WG and NC, and no sign of mineral loss was verified for all groups (p > 0.05). For TACL, rSRI significantly decreased after pH-cycling for all experimental groups with no difference between them (p < 0.05). Higher amounts of fluoride were found in WG. WG and WM exhibited intermediate values of mineral loss, similar to PM. CONCLUSIONS: The whitening products did not potentialize the enamel demineralization under a severe cariogenic challenge, and they did not exacerbate mineral loss of the artificial caries lesions. CLINICAL RELEVANCE: Low concentrated hydrogen peroxide whitening gel and mouthrinse containing fluoride do not intensify the progression of caries lesions.


Subject(s)
Dental Caries , Tooth Demineralization , Animals , Cattle , Cariostatic Agents/pharmacology , Cariostatic Agents/therapeutic use , Dental Caries/pathology , Dental Caries Susceptibility , Dental Enamel , Fluorides/pharmacology , Hydrogen Peroxide/pharmacology , Hydrogen-Ion Concentration , Minerals/pharmacology , Mouthwashes/pharmacology , Tooth Demineralization/pathology , Tooth Remineralization
12.
Phys Rev Lett ; 130(4): 043802, 2023 Jan 27.
Article in English | MEDLINE | ID: mdl-36763436

ABSTRACT

Confining photons in cavities enhances the interaction between light and matter. In cavity optomechanics, this enables a wealth of phenomena ranging from optomechanically induced transparency to macroscopic objects cooled to their motional ground state. Previous work in cavity optomechanics employed devices where ubiquitous structural disorder played no role beyond perturbing resonance frequencies and quality factors. More generally, the interplay between disorder, which must be described by statistical physics, and optomechanical effects has thus far been unexplored. Here, we demonstrate how sidewall roughness in air-slot photonic-crystal waveguides can induce sufficiently strong backscattering of slot-guided light to create Anderson-localized modes with quality factors as high as half a million and mode volumes estimated to be below the diffraction limit. We observe how the interaction between these disorder-induced optical modes and in-plane mechanical modes of the slotted membrane is governed by a distribution of coupling rates, which can exceed g_{o}/2π∼200 kHz, leading to mechanical amplification up to self sustained oscillations via optomechanical backaction. Our Letter constitutes the first steps towards understanding optomechanics in the multiple-scattering regime and opens new perspectives for exploring complex systems with a multitude of mutually coupled degrees of freedom.

13.
J Asthma ; 60(6): 1210-1220, 2023 06.
Article in English | MEDLINE | ID: mdl-36322679

ABSTRACT

OBJECTIVE: To assess the cost-effectiveness of benralizumab (benra) vs. mepolizumab (mepo) and dupilumab (dupi) for the treatment of patients with severe uncontrolled asthma from the Spanish Health System perspective. METHODS: Exacerbations avoided, quality-adjusted life years (QALYs) gained and costs in a 5-year period were estimated with a Markov model for a cohort of 1,000 patients in which, based on published evidence, 31% of the patients received biologics + oral corticosteroids (OCS) and 69% received only biologics. Efficacy data (exacerbation reduction and OCS elimination) were derived from a matching-adjusted indirect comparison. Published EQ-5D utilities per health state (biologic alone, biologic + OCS, standard of care + OCS, exacerbations, and post-exacerbations) were used for QALY estimation. Utility decrements associated with exacerbation management [-0.1 (OCS or emergency visits), -0.2 (hospitalization)] derived from the literature were applied. Costs (€, 2022) included drug acquisition (ex-factory price), administration and disease management. An expert panel (2 pneumologists and 1 pharmacist) validated all inputs. RESULTS: Benra was more effective (52.21 QALYs) than mepo (51.39 QALYs) and dupi (51.30 QALYs). Benra avoided more exacerbations (2.87 exacerbations) compared to mepo (4.70 exacerbations) and dupi (5.11 exacerbations) for the 5-year horizon. Total costs/patient were €56,093.77 (benra), €59,280.45 (mepo) and €62,991.76 (dupi), resulting in benra dominating (more QALYs with lower costs) vs. mepo and dupi. CONCLUSIONS: Benralizumab can be considered as a dominant treatment alternative vs. other biologic drugs for the treatment of uncontrolled severe eosinophilic asthma patients in Spain.


Subject(s)
Anti-Asthmatic Agents , Asthma , Biological Products , Pulmonary Eosinophilia , Humans , Cost-Benefit Analysis , Spain , Pulmonary Eosinophilia/drug therapy , Adrenal Cortex Hormones/therapeutic use , Biological Products/therapeutic use
14.
Rev. neurol. (Ed. impr.) ; 75(12): 369-376, Dic 12, 2022. tab, ilus, graf
Article in Spanish | IBECS | ID: ibc-213694

ABSTRACT

Introducción: El registro con microelectrodos en la estimulación cerebral profunda (ECP) ha demostrado una gran utilidad. Es posible mejorar su eficiencia caracterizando las propiedades de los potenciales de acción extracelulares (PAE). Pacientes y métodos: Hemos analizado registros de nueve pacientes operados por epilepsia o agresividad bajo anestesia general. Se han determinado las propiedades de los PAE de los núcleos talámicos centromediano, ventral intermedio, ventrocaudal e hipotalámico posteromedial. Resultados: Hemos analizado 706 células talámicas y 142 hipotalámicas. La proporción de tipos celulares resultó específica de cada núcleo celular. El tipo celular más frecuente fue P1P2N1 (59,5%), seguido por N1P1N2 (23,1%). La primera fase del PAE es altamente variable. Las propiedades de las fases del PAE de la misma morfología difieren altamente entre núcleos. Conclusiones: Hemos demostrado que diversos núcleos cerebrales profundos tienen propiedades específicas de la morfología de los PAE. Esto permitirá una mejora en la localización de estos núcleos durante la ECP.(AU)


Introduction: Using microelectrodes for recording purposes in deep brain stimulation (DBS) has proven to be very useful. Their efficiency can be improved by characterising the properties of extracellular action potentials (EAPs). Patients and methods: We analysed the records of nine patients who underwent surgery for epilepsy or aggressiveness under general anaesthesia. The properties of the EAPs of the centromedian, ventral intermediate, ventrocaudal and posteromedial hypothalamic nuclei of the thalamus have been determined. Results: We have analysed 706 thalamic and 142 hypothalamic cells. The proportion of cell types was found to be specific to each cell nucleus. The most frequent cell type was P1P2N1 (59.5%), followed by N1P1N2 (23.1%). The first phase of the EAP is highly variable. The properties of the EAP phases of the same morphology differ greatly from one nucleus to another. Conclusions: We have shown that several deep brain nuclei have properties that are specific to the morphology of the EAPs. This will allow for improved localisation of these nuclei during DBS.(AU)


Subject(s)
Humans , Male , Female , Thalamic Diseases , Deep Brain Stimulation , Thalamic Nuclei , Microelectrodes , Hypothalamic Diseases , Neurology , Nervous System Diseases
15.
Rev Neurol ; 75(12): 369-376, 2022 12 16.
Article in Spanish | MEDLINE | ID: mdl-36514203

ABSTRACT

INTRODUCTION: Using microelectrodes for recording purposes in deep brain stimulation (DBS) has proven to be very useful. Their efficiency can be improved by characterising the properties of extracellular action potentials (EAPs). PATIENTS AND METHODS: We analysed the records of nine patients who underwent surgery for epilepsy or aggressiveness under general anaesthesia. The properties of the EAPs of the centromedian, ventral intermediate, ventrocaudal and posteromedial hypothalamic nuclei of the thalamus have been determined. RESULTS: We have analysed 706 thalamic and 142 hypothalamic cells. The proportion of cell types was found to be specific to each cell nucleus. The most frequent cell type was P1P2N1 (59.5%), followed by N1P1N2 (23.1%). The first phase of the EAP is highly variable. The properties of the EAP phases of the same morphology differ greatly from one nucleus to another. CONCLUSIONS: We have shown that several deep brain nuclei have properties that are specific to the morphology of the EAPs. This will allow for improved localisation of these nuclei during DBS.


TITLE: Hacia una definición fisiológica positiva de los núcleos cerebrales profundos en humanos.Introducción. El registro con microelectrodos en la estimulación cerebral profunda (ECP) ha demostrado una gran utilidad. Es posible mejorar su eficiencia caracterizando las propiedades de los potenciales de acción extracelulares (PAE). Pacientes y métodos. Hemos analizado registros de nueve pacientes operados por epilepsia o agresividad bajo anestesia general. Se han determinado las propiedades de los PAE de los núcleos talámicos centromediano, ventral intermedio, ventrocaudal e hipotalámico posteromedial. Resultados. Hemos analizado 706 células talámicas y 142 hipotalámicas. La proporción de tipos celulares resultó específica de cada núcleo celular. El tipo celular más frecuente fue P1P2N1 (59,5%), seguido por N1P1N2 (23,1%). La primera fase del PAE es altamente variable. Las propiedades de las fases del PAE de la misma morfología difieren altamente entre núcleos. Conclusiones. Hemos demostrado que diversos núcleos cerebrales profundos tienen propiedades específicas de la morfología de los PAE. Esto permitirá una mejora en la localización de estos núcleos durante la ECP.


Subject(s)
Deep Brain Stimulation , Epilepsy , Humans , Thalamus , Microelectrodes , Epilepsy/therapy , Action Potentials
16.
Anal Chem ; 94(43): 14974-14984, 2022 11 01.
Article in English | MEDLINE | ID: mdl-36260070

ABSTRACT

Accurate quantification of metabolites by nuclear magnetic resonance (NMR) is of prime importance in the field of health sciences for understanding the metabolic pathways of the investigated system, to address the mechanisms of action of diseases, and improving their diagnosis, treatment, and prognosis. Unfortunately, the absolute quantitative analysis of complex samples is still limited by sensitivity and resolution issues that are intrinsic to this technique. Ultrahigh-resolution pure shift methods have especially shown to be suitable for interpreting mixtures of metabolites in biological samples. Here, we introduce a robust analytical protocol based on the use of a pure shift library of calibration reference spectra to fit the fingerprint of each metabolite of interest and determine its concentration. The approach based on the SAPPHIRE pulse sequence enhanced with a block for solvent suppression has been validated through the results of a series of model mixtures, exhibiting excellent trueness (slope values in the range of 0.93-1.02) and linearity (R2 > 0.996) in a total time (a few hours) that is fully compatible with metabolomics studies. Furthermore, we have successfully applied our method to determine the absolute metabolite concentrations in a lymphoma extracellular medium, which improves metabolomic protocols reported to date by providing a quantitative and highly resolved vision of metabolic processes at play.


Subject(s)
Magnetic Resonance Imaging , Metabolomics , Metabolomics/methods , Magnetic Resonance Spectroscopy/methods , Calibration
17.
Orphanet J Rare Dis ; 17(1): 386, 2022 10 24.
Article in English | MEDLINE | ID: mdl-36280881

ABSTRACT

BACKGROUND: Variants in the mitochondrial complex I assembly factor, NUBPL are associated with a rare cause of complex I deficiency mitochondrial disease. Patients affected by complex I deficiency harboring homozygous NUBPL variants typically have neurological problems including seizures, intellectual disability, and ataxia associated with cerebellar hypoplasia. Thus far only 19 cases have been reported worldwide, and no treatment is available for this rare disease. METHODS: To investigate the pathogenesis of NUBPL-associated complex I deficiency, and for translational studies, we generated a knock-in mouse harboring a patient-specific variant Nubpl c.311T>C; p. L104P reported in three families. RESULTS: Similar to Nubpl global knockout mice, the Nubpl p. L104P homozygous mice are lethal at embryonic day E10.5, suggesting that the Nubpl p. L104P variant is likely a hypomorph allele. Given the recent link between Parkinson's disease and loss-of-function NUBPL variants, we also explored aging-related behaviors and immunocytochemical changes in Nubpl hemizygous mice and did not find significant behavioral and pathological changes for alpha-synuclein and oxidative stress markers . CONCLUSION: Our data suggest that homozygotes with Nubpl variants, similar to the null mice, are lethal, and heterozygotes are phenotypically and neuropathologically normal. We propose that a tissue-specific knockout strategy is required to establish a mouse model of Nubpl-associated complex I deficiency disorder for future mechanistic and translational studies.


Subject(s)
Mitochondrial Proteins , alpha-Synuclein , Animals , Mice , Mitochondrial Proteins/genetics , Mutation , Electron Transport Complex I/metabolism , Mice, Knockout
18.
HGG Adv ; 3(4): 100137, 2022 Oct 13.
Article in English | MEDLINE | ID: mdl-36092952

ABSTRACT

Spinocerebellar ataxia type 10 (SCA10) is an autosomal-dominant disorder caused by an expanded pentanucleotide repeat in the ATXN10 gene. This repeat expansion, when fully penetrant, has a size of 850-4,500 repeats. It has been shown that the repeat composition can be a modifier of disease, e.g., seizures. Here, we describe a Mexican kindred in which we identified both pure (ATTCT)n and mixed (ATTCT)n-(ATTCC)n expansions in the same family. We used amplification-free targeted sequencing and optical genome mapping to decipher the composition of these repeat expansions. We found a considerable degree of mosaicism of the repeat expansion. This mosaicism was confirmed in skin fibroblasts from individuals with ATXN10 expansions with RNAScope in situ hybridization. All affected family members with the mixed ATXN10 repeat expansion showed typical clinical signs of spinocerebellar ataxia and epilepsy. In contrast, individuals with the pure ATXN10 expansion present with Parkinson's disease or are unaffected, even in individuals more than 20 years older than the average age at onset for SCA10. Our findings suggest that the pure (ATTCT)n expansion is non-pathogenic, while repeat interruptions, e.g., (ATTCC)n, are necessary to cause SCA10. This mechanism has been recently described for several other repeat expansions including SCA31 (BEAN1), SCA37 (DAB1), and three loci for benign adult familial myoclonic epilepsy BAFME (SAMD12, TNRC6A, RAPGEF2). Therefore, long-read sequencing and optical genome mapping of the entire genomic structure of repeat expansions are critical for clinical practice and genetic counseling, as variations in the repeat can affect disease penetrance, symptoms, and disease trajectory.

19.
Parasitol Int ; 91: 102640, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35933034

ABSTRACT

We performed a study of congenital toxoplasmosis of the first and third gestation periods in mice, and determined its effects on the embryos/fetuses, the placentae and the maternal organs. We infected pregnant BALB/c mice by i.v. injection of 2.5--10.0 × 106 tachyzoites of the ME49 T. gondii strain and euthanized them 72 h later. The tissues were analyzed by histopathology, immunohistochemistry and parasite-specific qPCR. Infections with the lowest dose induced remarkably different changes in the two thirds: a) all doses diminished the number of products/litter, the lowest dose only by 14%; but most embryos still visible were degenerated in the case of the first period, while the fetuses of the last third were perfectly preserved; b) the transmission rate in the first third was relatively high, but with a very low parasite burden; c) with the lowest dose, strong vascular changes (congestion, thrombosis and hemorrhage) predominated in the placentas of the first period, while they were absent in the last third; d) necrosis caused by T. gondii to maternal organs was much stronger during the last gestation period than in the first. Our results suggest that the vascular alterations at the placenta of the first third of pregnancy prevent embryo from large parasite burden, but provoke its death by starvation. In the last gestation period, there was poor control of parasite dissemination to the placenta and the fetus, but there was greater capacity of the product to defend itself from T. gondii.


Subject(s)
Toxoplasma , Toxoplasmosis, Congenital , Animals , Disease Models, Animal , Female , Humans , Mice , Mice, Inbred BALB C , Mothers , Placenta/parasitology , Pregnancy , Toxoplasmosis, Congenital/parasitology
20.
Nat Nanotechnol ; 17(9): 947-951, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35941289

ABSTRACT

Controlling vibrations in solids is crucial to tailor their elastic properties and interaction with light. Thermal vibrations represent a source of noise and dephasing for many physical processes at the quantum level. One strategy to avoid these vibrations is to structure a solid such that it possesses a phononic stop band, that is, a frequency range over which there are no available elastic waves. Here we demonstrate the complete absence of thermal vibrations in a nanostructured silicon membrane at room temperature over a broad spectral window, with a 5.3-GHz-wide bandgap centred at 8.4 GHz. By constructing a line-defect waveguide, we directly measure gigahertz guided modes without any external excitation using Brillouin light scattering spectroscopy. Our experimental results show that the shamrock crystal geometry can be used as an efficient platform for phonon manipulation with possible applications in optomechanics and signal processing transduction.

SELECTION OF CITATIONS
SEARCH DETAIL
...