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1.
Cell ; 174(6): 1450-1464.e23, 2018 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-30100184

RESUMEN

Synapses are fundamental units of communication in the brain. The prototypical synapse-organizing complex neurexin-neuroligin mediates synapse development and function and is central to a shared genetic risk pathway in autism and schizophrenia. Neurexin's role in synapse development is thought to be mediated purely by its protein domains, but we reveal a requirement for a rare glycan modification. Mice lacking heparan sulfate (HS) on neurexin-1 show reduced survival, as well as structural and functional deficits at central synapses. HS directly binds postsynaptic partners neuroligins and LRRTMs, revealing a dual binding mode involving intrinsic glycan and protein domains for canonical synapse-organizing complexes. Neurexin HS chains also bind novel ligands, potentially expanding the neurexin interactome to hundreds of HS-binding proteins. Because HS structure is heterogeneous, our findings indicate an additional dimension to neurexin diversity, provide a molecular basis for fine-tuning synaptic function, and open therapeutic directions targeting glycan-binding motifs critical for brain development.


Asunto(s)
Heparitina Sulfato/metabolismo , Moléculas de Adhesión de Célula Nerviosa/metabolismo , Sinapsis/metabolismo , Secuencia de Aminoácidos , Animales , Proteínas de Unión al Calcio , Moléculas de Adhesión Celular Neuronal/antagonistas & inhibidores , Moléculas de Adhesión Celular Neuronal/genética , Moléculas de Adhesión Celular Neuronal/metabolismo , Drosophila , Proteínas de Drosophila/antagonistas & inhibidores , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Femenino , Glicopéptidos/análisis , Heparitina Sulfato/química , Humanos , Proteínas de la Membrana , Ratones , Ratones Endogámicos C57BL , Proteínas del Tejido Nervioso , Moléculas de Adhesión de Célula Nerviosa/antagonistas & inhibidores , Moléculas de Adhesión de Célula Nerviosa/genética , Neuronas/citología , Neuronas/metabolismo , Unión Proteica , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Ratas , Alineación de Secuencia
2.
Proc Natl Acad Sci U S A ; 121(3): e2315341121, 2024 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-38190519

RESUMEN

Wing dimorphism of insect vectors is a determining factor for viral long-distance dispersal and large-area epidemics. Although plant viruses affect the wing plasticity of insect vectors, the potential underlying molecular mechanisms have seldom been investigated. Here, we found that a planthopper-vectored rice virus, rice stripe virus (RSV), specifically induces a long-winged morph in male insects. The analysis of field populations demonstrated that the long-winged ratios of male insects are closely associated with RSV infection regardless of viral titers. A planthopper-specific and testis-highly expressed gene, Encounter, was fortuitously found to play a key role in the RSV-induced long-winged morph. Encounter resembles malate dehydrogenase in the sequence, but it does not have corresponding enzymatic activity. Encounter is upregulated to affect male wing dimorphism at early larval stages. Encounter is closely connected with the insulin/insulin-like growth factor signaling pathway as a downstream factor of Akt, of which the transcriptional level is activated in response to RSV infection, resulting in the elevated expression of Encounter. In addition, an RSV-derived small interfering RNA directly targets Encounter to enhance its expression. Our study reveals an unreported mechanism underlying the direct regulation by a plant virus of wing dimorphism in its insect vectors, providing the potential way for interrupting viral dispersal.


Asunto(s)
Epidemias , Virus de Plantas , Infecciones por Virus Sincitial Respiratorio , Tenuivirus , Masculino , Animales , Virus de Plantas/genética , Tenuivirus/genética , Insectos Vectores , Péptidos Similares a la Insulina
3.
N Engl J Med ; 389(18): 1649-1659, 2023 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-37913505

RESUMEN

BACKGROUND: Recurrent bleeding from the small intestine accounts for 5 to 10% of cases of gastrointestinal bleeding and remains a therapeutic challenge. Thalidomide has been evaluated for the treatment of recurrent bleeding due to small-intestinal angiodysplasia (SIA), but confirmatory trials are lacking. METHODS: We conducted a multicenter, double-blind, randomized, placebo-controlled trial to investigate the efficacy and safety of thalidomide for the treatment of recurrent bleeding due to SIA. Eligible patients with recurrent bleeding (at least four episodes of bleeding during the previous year) due to SIA were randomly assigned to receive thalidomide at an oral daily dose of 100 mg or 50 mg or placebo for 4 months. Patients were followed for at least 1 year after the end of the 4-month treatment period. The primary end point was effective response, which was defined as a reduction of at least 50% in the number of bleeding episodes that occurred during the year after the end of thalidomide treatment as compared with the number that occurred during the year before treatment. Key secondary end points were cessation of bleeding without rebleeding, blood transfusion, hospitalization because of bleeding, duration of bleeding, and hemoglobin levels. RESULTS: Overall, 150 patients underwent randomization: 51 to the 100-mg thalidomide group, 49 to the 50-mg thalidomide group, and 50 to the placebo group. The percentages of patients with an effective response in the 100-mg thalidomide group, 50-mg thalidomide group, and placebo group were 68.6%, 51.0%, and 16.0%, respectively (P<0.001 for simultaneous comparison across the three groups). The results of the analyses of the secondary end points supported those of the primary end point. Adverse events were more common in the thalidomide groups than in the placebo group overall; specific events included constipation, somnolence, limb numbness, peripheral edema, dizziness, and elevated liver-enzyme levels. CONCLUSIONS: In this placebo-controlled trial, treatment with thalidomide resulted in a reduction in bleeding in patients with recurrent bleeding due to SIA. (Funded by the National Natural Science Foundation of China and the Shanghai Municipal Education Commission, Gaofeng Clinical Medicine; ClinicalTrials.gov number, NCT02707484.).


Asunto(s)
Angiodisplasia , Hemorragia Gastrointestinal , Fármacos Hematológicos , Enfermedades Intestinales , Intestino Delgado , Talidomida , Humanos , Angiodisplasia/complicaciones , Angiodisplasia/tratamiento farmacológico , China , Método Doble Ciego , Hemorragia Gastrointestinal/tratamiento farmacológico , Hemorragia Gastrointestinal/etiología , Talidomida/administración & dosificación , Talidomida/efectos adversos , Talidomida/uso terapéutico , Resultado del Tratamiento , Enfermedades Intestinales/complicaciones , Enfermedades Intestinales/tratamiento farmacológico , Recurrencia , Intestino Delgado/irrigación sanguínea , Administración Oral , Fármacos Hematológicos/administración & dosificación , Fármacos Hematológicos/efectos adversos , Fármacos Hematológicos/uso terapéutico
4.
Eur J Immunol ; 54(3): e2350662, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38366919

RESUMEN

Helicobacter pylori is one of the main predisposing factors for gastric cancer, causing chronic inflammation and proper glands atrophy in the gastric mucosa. Although H. pylori-induced inflammation is a key inducer of precancerous lesions in the gastric mucosa, it remains unclear which precise immune cell subsets are responsible for the progression of H. pylori-induced gastritis. Here, we observed an abundance of CD4+ IL-17A+ FOXP3+ T cells exhibiting a Th17-like phenotype within the microenvironment of H. pylori-induced gastritis. Mechanistically, H. pylori upregulated the expression of IL-6 in Dendritic cells and macrophages, by activating NF-κB signaling through the virulence factor CagA and thus, induced IL-17A expression in FOXP3+ T cells. Moreover, CD4+ IL-17A+ FOXP3+ T cells were positively associated with advanced precancerous lesions. Therefore, these findings offer essential insights into how FOXP3+ T cells sense inflammatory signals from the environment, such as IL-6, during H. pylori infections, thereby guiding the effector immune response and aggravating the gastritis.


Asunto(s)
Gastritis , Infecciones por Helicobacter , Helicobacter pylori , Lesiones Precancerosas , Humanos , Interleucina-17/metabolismo , Interleucina-6 , Gastritis/metabolismo , Gastritis/patología , Inflamación , Linfocitos T Reguladores , Factores de Transcripción Forkhead/metabolismo , Microambiente Tumoral
5.
Arterioscler Thromb Vasc Biol ; 44(7): 1467-1473, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38924435

RESUMEN

CLINICAL PROBLEM: Most abdominal aortic aneurysms (AAAs) are small with low rupture risk (<1%/y) when diagnosed but slowly expand to ≥55 mm and undergo surgical repair. Patients and clinicians require medications to limit AAA growth and rupture, but drugs effective in animal models have not translated to patients. RECOMMENDATIONS FOR INCREASING TRANSLATION FROM MOUSE MODELS: Use models that simulate human AAA tissue pathology, growth patterns, and rupture; focus on the clinically relevant outcomes of growth and rupture; design studies with the rigor required of human clinical trials; monitor AAA growth using reproducible ultrasound; and perform studies in both males and females. SUMMARY OF STRENGTHS AND WEAKNESSES OF MOUSE MODELS: The aortic adventitial elastase oral ß-aminopropionitrile model has many strengths including simulating human AAA pathology and modeling prolonged aneurysm growth. The Ang II (angiotensin II) model performed less well as it better simulates acute aortic syndrome than AAA. The elastase plus TGFß (transforming growth factor-ß) blocking antibody model displays a high rupture rate, making prolonged monitoring of AAA growth not feasible. The elastase perfusion and calcium chloride models both display limited AAA growth.


Asunto(s)
Aneurisma de la Aorta Abdominal , Rotura de la Aorta , Modelos Animales de Enfermedad , Animales , Aneurisma de la Aorta Abdominal/diagnóstico por imagen , Aneurisma de la Aorta Abdominal/patología , Humanos , Rotura de la Aorta/prevención & control , Rotura de la Aorta/diagnóstico por imagen , Rotura de la Aorta/patología , Elastasa Pancreática , Ratones , Aorta Abdominal/patología , Aorta Abdominal/efectos de los fármacos , Aorta Abdominal/diagnóstico por imagen , Aorta Abdominal/metabolismo , Femenino , Progresión de la Enfermedad , Masculino
6.
Arterioscler Thromb Vasc Biol ; 44(5): 1021-1030, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38572647

RESUMEN

AGT (angiotensinogen) is the unique precursor for the generation of all the peptides of the renin-angiotensin system, but it has received relatively scant attention compared to many other renin-angiotensin system components. Focus on AGT has increased recently, particularly with the evolution of drugs to target the synthesis of the protein. AGT is a noninhibitory serpin that has several conserved domains in addition to the angiotensin II sequences at the N terminus. Increased study is needed on the structure-function relationship to resolve many unknowns regarding AGT metabolism. Constitutive whole-body genetic deletion of Agt in mice leads to multiple developmental defects creating a challenge to use these mice for mechanistic studies. This has been overcome by creating Agt-floxed mice to enable the development of cell-specific deficiencies that have provided considerable insight into a range of cardiovascular and associated diseases. This has been augmented by the recent development of pharmacological approaches targeting hepatocytes in humans to promote protracted inhibition of AGT synthesis. Genetic deletion or pharmacological inhibition of Agt has been demonstrated to be beneficial in a spectrum of diseases experimentally, including hypertension, atherosclerosis, aortic and superior mesenteric artery aneurysms, myocardial dysfunction, and hepatic steatosis. This review summarizes the findings of recent studies utilizing AGT manipulation as a therapeutic approach.


Asunto(s)
Angiotensinógeno , Enfermedades Cardiovasculares , Enfermedades Metabólicas , Animales , Humanos , Enfermedades Cardiovasculares/tratamiento farmacológico , Enfermedades Cardiovasculares/metabolismo , Enfermedades Cardiovasculares/genética , Angiotensinógeno/metabolismo , Angiotensinógeno/genética , Enfermedades Metabólicas/tratamiento farmacológico , Enfermedades Metabólicas/metabolismo , Enfermedades Metabólicas/genética , Sistema Renina-Angiotensina/efectos de los fármacos , Terapia Molecular Dirigida
7.
Arterioscler Thromb Vasc Biol ; 44(7): 1555-1569, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38779856

RESUMEN

BACKGROUND: ß-aminopropionitrile (BAPN) is a pharmacological inhibitor of LOX (lysyl oxidase) and LOXLs (LOX-like proteins). Administration of BAPN promotes aortopathies, although there is a paucity of data on experimental conditions to generate pathology. The objective of this study was to define experimental parameters and determine whether equivalent or variable aortopathies were generated throughout the aortic tree during BAPN administration in mice. METHODS: BAPN was administered in drinking water for a period ranging from 1 to 12 weeks. The impacts of BAPN were first assessed with regard to BAPN dose, and mouse strain, age, and sex. BAPN-induced aortic pathological characterization was conducted using histology and immunostaining. To investigate the mechanistic basis of regional heterogeneity, the ascending and descending thoracic aortas were harvested after 1 week of BAPN administration before the appearance of overt pathology. RESULTS: BAPN-induced aortic rupture predominantly occurred or originated in the descending thoracic aorta in young C57BL/6J or N mice. No apparent differences were found between male and female mice. For mice surviving 12 weeks of BAPN administration, profound dilatation was consistently observed in the ascending region, while there were more heterogeneous changes in the descending thoracic region. Pathological features were distinct between the ascending and descending thoracic regions. Aortic pathology in the ascending region was characterized by luminal dilatation and elastic fiber disruption throughout the media. The descending thoracic region frequently had dissections with false lumen formation, collagen deposition, and remodeling of the wall surrounding the false lumen. Cells surrounding the false lumen were predominantly positive for α-SMA (α-smooth muscle actin). One week of BAPN administration compromised contractile properties in both regions equivalently, and RNA sequencing did not show obvious differences between the 2 aortic regions in smooth muscle cell markers, cell proliferation markers, and extracellular components. CONCLUSIONS: BAPN-induced pathologies show distinct, heterogeneous features within and between ascending and descending aortic regions in mice.


Asunto(s)
Aminopropionitrilo , Aorta Torácica , Rotura de la Aorta , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Animales , Aminopropionitrilo/toxicidad , Aminopropionitrilo/farmacología , Aorta Torácica/patología , Aorta Torácica/efectos de los fármacos , Aorta Torácica/metabolismo , Femenino , Masculino , Rotura de la Aorta/inducido químicamente , Rotura de la Aorta/patología , Rotura de la Aorta/metabolismo , Rotura de la Aorta/prevención & control , Ratones , Remodelación Vascular/efectos de los fármacos , Dilatación Patológica , Músculo Liso Vascular/patología , Músculo Liso Vascular/efectos de los fármacos , Músculo Liso Vascular/metabolismo , Factores de Edad , Factores de Tiempo , Factores Sexuales , Proliferación Celular/efectos de los fármacos , Proteína-Lisina 6-Oxidasa/metabolismo
8.
Artículo en Inglés | MEDLINE | ID: mdl-38957985

RESUMEN

Institutional support is crucial for the successful career advancement of all faculty but in particular those who are women. Evolving from the past, in which gender disparities were prevalent in many institutions, recent decades have witnessed significant progress in supporting the career advancement of women faculty in science and academic medicine. However, continued advancement is necessary as previously unrecognized needs and new opportunities for improvement emerge. To identify the needs, opportunities, and potential challenges encountered by women faculty, the Women's Leadership Committee of the Arteriosclerosis, Thrombosis, and Vascular Biology Council developed an initiative termed GROWTH (Generating Resources and Opportunities for Women in Technology and Health). The committee designed a survey questionnaire and interviewed 19 leaders with roles and responsibilities in faculty development from a total of 12 institutions across various regions of the United States. The results were compiled, analyzed, and discussed. Based on our interviews and analyses, we present the current status of these representative institutions in supporting faculty development, highlighting efforts specific to women faculty. Through the experiences, insights, and vision of these leaders, we identified success stories, challenges, and future priorities. Our article provides a primer and a snapshot of institutional efforts to support the advancement of women faculty. Importantly, this article can serve as a reference and resource for academic entities seeking ideas to gauge their commitment level to women faculty and to implement new initiatives. Additionally, this article can provide guidance and strategies for women faculty as they seek support and resources from their current or prospective institutions when pursuing new career opportunities.

9.
Exp Cell Res ; 439(1): 114088, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38744409

RESUMEN

Neuroinflammation mediated by microglia plays an important role in the etiology of Parkinson's disease (PD). Rho family GTPase 3 (RND3) exerts anti-inflammatory effects and may act as a potential new inducer of neuroprotective phenotypes in microglia. However, whether RND3 can be used to regulate microglia activation or reduce neuroinflammation in PD remains elusive. The study investigated the microglia modulating effects and potential anti-inflammatory effects of RND3 in vivo and in vitro, using animal models of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD and cell models of BV-2 cells stimulated by LPS plus IFN-γ with or without RND3-overexpression. The results showed that RND3 was highly expressed in the MPTP-induced PD mouse model and BV-2 cells treated with LPS and IFN-γ. In vivo experiments confirmed that RND3 overexpression could modulate microglia phenotype and ameliorate MPTP-induced neuroinflammation through inhibiting activation of the NLRP3 inflammasome in substantia nigra pars compacta (SNpc). In vitro study showed that RND3 overexpression could attenuate the production of pro-inflammatory factors in BV2 cells stimulated by LPS and IFN-γ. Mechanistically, RND3 reduced the activation of the NLRP3 inflammasome upon LPS and IFN-γ stimulation. Taken together, these findings suggest that RND3 modulates microglial polarization and alleviates neuroinflammation in Parkinson's disease by suppressing NLRP3 inflammasome activation.


Asunto(s)
Inflamasomas , Ratones Endogámicos C57BL , Microglía , Proteína con Dominio Pirina 3 de la Familia NLR , Enfermedad de Parkinson , Proteínas de Unión al GTP rho , Animales , Microglía/metabolismo , Microglía/patología , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Ratones , Inflamasomas/metabolismo , Masculino , Proteínas de Unión al GTP rho/metabolismo , Proteínas de Unión al GTP rho/genética , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/patología , Enfermedad de Parkinson/genética , Enfermedades Neuroinflamatorias/metabolismo , Enfermedades Neuroinflamatorias/patología , Lipopolisacáridos/farmacología , Modelos Animales de Enfermedad , Polaridad Celular , 1-Metil-4-fenil-1,2,3,6-Tetrahidropiridina , Inflamación/metabolismo , Inflamación/patología , Inflamación/genética , Interferón gamma/metabolismo
10.
Proc Natl Acad Sci U S A ; 119(36): e2207848119, 2022 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-36037368

RESUMEN

Exosomes play a key role in virus exocytosis and transmission. The exportin family is usually responsible for cargo nucleocytoplasmic trafficking, and they are frequently found in exosomes. However, the function of exportins sorted in exosomes remains unknown. Here, we successfully isolated "cup holder"-like exosomes from the saliva of ∼30,000 small brown planthoppers, which are vectors of rice stripe virus (RSV). RSV virions were packed in comparatively large exosomes. Four viral genomic RNAs at a certain ratio were identified in the saliva exosomes. The virions contained in the saliva exosomes were capable of replicating and causing disease in rice plants. Interference with each phase of the insect exosome system affected the transmission of RSV from the insect vectors to rice plants. Fragmented exportin 6 was coimmunoprecipitated with viral nucleocapsid protein in saliva and sorted to exosomes via interactions with the cargo sorting protein VPS37a. When the expression of exportin 6 was knocked down, the amounts of RSV secreted in saliva and rice plants were reduced by 60% and 74%, respectively. These results showed that exportin 6 acted as a vehicle for transporting RSV into exosomes to overcome the barrier of insect salivary glands for horizontal transmission. Exportin 6 would represent an ideal target that could be manipulated to control the outbreak of insect-borne viruses in the future.


Asunto(s)
Exosomas , Hemípteros , Carioferinas , Oryza , Tenuivirus , Animales , Exosomas/virología , Hemípteros/virología , Insectos Vectores/virología , Carioferinas/metabolismo , Oryza/virología , Enfermedades de las Plantas/virología , Tenuivirus/patogenicidad
11.
Nano Lett ; 24(22): 6585-6591, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38785400

RESUMEN

The gallium-doped hafnium oxide (Ga-HfO2) films with different Ga doping concentrations were prepared by adjusting the HfO2/Ga2O3 atomic layer deposition cycle ratio for high-speed and low-voltage operation in HfO2-based ferroelectric memory. The Ga-HfO2 ferroelectric films reveal a finely modulated coercive field (Ec) from 1.1 (HfO2/Ga2O3 = 32:1) to an exceptionally low 0.6 MV/cm (HfO2/Ga2O3 = 11:1). This modulation arises from the competition between domain nucleation and propagation speed during polarization switching, influenced by the intrinsic domain density and phase dispersion in the film with specific Ga doping concentrations. Higher Ec samples exhibit a nucleation-dominant switching mechanism, while lower Ec samples undergo a transition from a nucleation-dominant to a propagation-dominant reversal mechanism as the electric field increases. This work introduces Ga as a viable dopant for low Ec and offers insights into material design strategies for HfO2-based ferroelectric memory applications.

12.
Nano Lett ; 24(22): 6617-6624, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38717095

RESUMEN

The mapping of long-wavelength phonons is important to understand and manipulate the thermal transport in multilayered structures, but it remains a long-standing challenge due to the collective behaviors of phonons. In this study, an experimental demonstration of mapping the long-wavelength phonons in an alloyed Al0.1Ga0.9As/Al0.9Ga0.1As superlattice system is reported. Multiple strategies to filter out the short- to mid-wavelength phonons are used. The phonon mean-free-path-dependent thermal transport properties directly demonstrate both the suppression effect of the ErAs nanoislands and the contribution of long-wavelength phonons. The contribution from phonons with mean free path longer than 1 µm is clearly demonstrated. A model based on the Boltzmann transport equation is proposed to calculate and describe the thermal transport properties, which depicts a clear physical picture of the transport mechanisms. This method can be extended to map different wavelength phonons and become a universal strategy to explore their thermal transport in various application scenarios.

13.
Plant Biotechnol J ; 22(5): 1387-1401, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38130080

RESUMEN

Viral diseases seriously threaten rice production. Plasmodesmata (PD)-associated proteins are deemed to play a key role in viral infection in host plants. However, few PD-associated proteins have been discovered in rice to afford viral infection. Here, inspired by the infection mechanism in insect vectors, we identified a member of the Flotillin family taking part in the cell-to-cell transport of rice stripe virus (RSV) in rice. Flotillin1 interacted with RSV nucleocapsid protein (NP) and was localized on PD. In flotillin1 knockout mutant rice, which displayed normal growth, RSV intercellular movement was retarded, leading to significantly decreased disease incidence. The PD pore sizes of the mutant rice were smaller than those of the wild type due to more callose deposits, which was closely related to the upregulation of two callose synthase genes. RSV infection stimulated flotillin1 expression and enlarged the PD aperture via RSV NP. In addition, flotillin1 knockout decreased disease incidences of southern rice black-streaked dwarf virus (SRBSDV) and rice dwarf virus (RDV) in rice. Overall, our study reveals a new PD-associated protein facilitating virus cell-to-cell trafficking and presents the potential of flotillin1 as a target to produce broad-spectrum antiviral rice resources in the future.


Asunto(s)
Hemípteros , Proteínas de la Membrana , Oryza , Virosis , Animales , Plasmodesmos/metabolismo , Proteínas Virales/metabolismo , Oryza/metabolismo , Enfermedades de las Plantas , Hemípteros/metabolismo
14.
Opt Express ; 32(5): 8447-8458, 2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38439500

RESUMEN

Field-effect transistors are capable of detecting electromagnetic radiation from less than 100 GHz up to very high frequencies reaching well into the infrared spectral range. Here, we report on frequency coverage of up to 30THz, thus reaching the technologically important frequency regime of CO2 lasers, using GaAs/AlGaAs high-electron-mobility transistors. A detailed study of the speed and polarization dependence of the responsivity allows us to identify a cross over of the dominant detection mechanism from ultrafast non-quasistatic rectification at low Terahertz frequencies to slow rectification based on a combination of the Seebeck and bolometric effects at high frequencies, occurring at about the boundary between the Terahertz frequency range and the infrared at 10THz.

15.
Clin Sci (Lond) ; 138(7): 435-487, 2024 04 10.
Artículo en Inglés | MEDLINE | ID: mdl-38571396

RESUMEN

Patients with inflammatory liver diseases, particularly alcohol-associated liver disease and metabolic dysfunction-associated fatty liver disease (MAFLD), have higher incidence of infections and mortality rate due to sepsis. The current focus in the development of drugs for MAFLD is the resolution of non-alcoholic steatohepatitis and prevention of progression to cirrhosis. In patients with cirrhosis or alcoholic hepatitis, sepsis is a major cause of death. As the metabolic center and a key immune tissue, liver is the guardian, modifier, and target of sepsis. Septic patients with liver dysfunction have the highest mortality rate compared with other organ dysfunctions. In addition to maintaining metabolic homeostasis, the liver produces and secretes hepatokines and acute phase proteins (APPs) essential in tissue protection, immunomodulation, and coagulation. Inflammatory liver diseases cause profound metabolic disorder and impairment of energy metabolism, liver regeneration, and production/secretion of APPs and hepatokines. Herein, the author reviews the roles of (1) disorders in the metabolism of glucose, fatty acids, ketone bodies, and amino acids as well as the clearance of ammonia and lactate in the pathogenesis of inflammatory liver diseases and sepsis; (2) cytokines/chemokines in inflammatory liver diseases and sepsis; (3) APPs and hepatokines in the protection against tissue injury and infections; and (4) major nuclear receptors/signaling pathways underlying the metabolic disorders and tissue injuries as well as the major drug targets for inflammatory liver diseases and sepsis. Approaches that focus on the liver dysfunction and regeneration will not only treat inflammatory liver diseases but also prevent the development of severe infections and sepsis.


Asunto(s)
Hepatopatías Alcohólicas , Enfermedad del Hígado Graso no Alcohólico , Sepsis , Humanos , Hígado/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Cirrosis Hepática/metabolismo , Hepatopatías Alcohólicas/metabolismo , Sepsis/complicaciones
16.
J Magn Reson Imaging ; 59(3): 987-995, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37318377

RESUMEN

BACKGROUND: Numerous studies have indicated altered temporal features of the brain function in Parkinson's disease (PD), and the autocorrelation magnitude of intrinsic neural signals, called intrinsic neural timescales, were often applied to estimate how long neural information stored in local brain areas. However, it is unclear whether PD patients at different disease stages exhibit abnormal timescales accompanied with abnormal gray matter volume (GMV). PURPOSE: To assess the intrinsic timescale and GMV in PD. STUDY TYPE: Prospective. POPULATION: 74 idiopathic PD patients (44 early stage (PD-ES) and 30 late stage (PD-LS), as determined by the Hoehn and Yahr (HY) severity classification scale), and 73 healthy controls (HC). FIELD STRENGTH/SEQUENCE: 3.0 T MRI scanner; magnetization prepared rapid acquisition gradient echo and echo planar imaging sequences. ASSESSMENT: The timescales were estimated by using the autocorrelation magnitude of neural signals. Voxel-based morphometry was performed to calculate GMV in the whole brain. Severity of motor symptoms and cognitive impairments were assessed using the unified PD rating scale, the HY scale, the Montreal cognitive assessment, and the mini-mental state examination. STATISTICAL TEST: Analysis of variance; two-sample t-test; Spearman rank correlation analysis; Mann-Whitney U test; Kruskal-Wallis' H test. A P value <0.05 was considered statistically significant. RESULTS: The PD group had significantly abnormal intrinsic timescales in the sensorimotor, visual, and cognitive-related areas, which correlated with the symptom severity (ρ = -0.265, P = 0.022) and GMV (ρ = 0.254, P = 0.029). Compared to the HC group, the PD-ES group had significantly longer timescales in anterior cortical regions, whereas the PD-LS group had significantly shorter timescales in posterior cortical regions. CONCLUSION: This study suggested that PD patients have abnormal timescales in multisystem and distinct patterns of timescales and GMV in cerebral cortex at different disease stages. This may provide new insights for the neural substrate of PD. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 1.


Asunto(s)
Sustancia Gris , Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/complicaciones , Estudios Prospectivos , Corteza Cerebral , Imagen por Resonancia Magnética/métodos
17.
J Magn Reson Imaging ; 2024 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-38205712

RESUMEN

BACKGROUND: Accurate evaluation of the axillary lymph node (ALN) status is needed for determining the treatment protocol for breast cancer (BC). The value of magnetic resonance imaging (MRI)-based tumor heterogeneity in assessing ALN metastasis in BC is unclear. PURPOSE: To assess the value of deep learning (DL)-derived kinetic heterogeneity parameters based on BC dynamic contrast-enhanced (DCE)-MRI to infer the ALN status. STUDY TYPE: Retrospective. SUBJECTS: 1256/539/153/115 patients in the training cohort, internal validation cohort, and external validation cohorts I and II, respectively. FIELD STRENGTH/SEQUENCE: 1.5 T/3.0 T, non-contrast T1-weighted spin-echo sequence imaging (T1WI), DCE-T1WI, and diffusion-weighted imaging. ASSESSMENT: Clinical pathological and MRI semantic features were obtained by reviewing histopathology and MRI reports. The segmentation of the tumor lesion on the first phase of T1WI DCE-MRI images was applied to other phases after registration. A DL architecture termed convolutional recurrent neural network (ConvRNN) was developed to generate the KHimage (kinetic heterogeneity of DCE-MRI image) score that indicated the ALN status in patients with BC. The model was trained and optimized on training and internal validation cohorts, tested on two external validation cohorts. We compared ConvRNN model with other 10 models and the subgroup analyses of tumor size, magnetic field strength, and molecular subtype were also evaluated. STATISTICAL TESTS: Chi-squared, Fisher's exact, Student's t, Mann-Whitney U tests, and receiver operating characteristics (ROC) analysis were performed. P < 0.05 was considered significant. RESULTS: The ConvRNN model achieved area under the curve (AUC) of 0.802 in the internal validation cohort and 0.785-0.806 in the external validation cohorts. The ConvRNN model could well evaluate the ALN status of the four molecular subtypes (AUC = 0.685-0.868). The patients with larger tumor sizes (>5 cm) were more susceptible to ALN metastasis with KHimage scores of 0.527-0.827. DATA CONCLUSION: A ConvRNN model outperformed traditional models for determining the ALN status in patients with BC. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.

18.
Mol Cell Biochem ; 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38884847

RESUMEN

Mitochondria are pivotal in the modulation of macrophage activation, differentiation, and survival. Furthermore, macrophages are instrumental in the onset and progression of cardiovascular diseases. Hence, it is imperative to investigate the role of mitochondria within macrophages in the context of cardiovascular disease. In this review, we provide an updated description of the origin and classification of cardiac macrophages and also focused on the relationship between macrophages and mitochondria in cardiovascular diseases with respect to (1) proinflammatory or anti-inflammatory macrophages, (2) macrophage apoptosis, (3) macrophage pyroptosis, and (4) macrophage efferocytosis. Clarifying the relationship between mitochondria and macrophages can aid the exploration of novel therapeutic strategies for cardiovascular disease.

19.
Pediatr Res ; 2024 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-38431664

RESUMEN

BACKGROUND: Benign epilepsy with centrotemporal spikes (BECTS) is a common childhood epilepsy syndrome, accompanied by behavioral problems and cognitive impairments. Previous studies of BECTS-related brain structures applied univariate analysis and showed inconsistent results. And neurotransmitter patterns associated with brain structural alterations were still unclear. METHODS: Structural images of twenty-one drug-naïve children with BECTS and thirty-five healthy controls (HCs) were scanned. Segmented gray matter volume (GMV) images were decomposed into independent components (ICs) using the source-based morphometry method. Then spatial correlation analyses were applied to examine possible relationships between GMV changes and neurotransmitter systems. RESULTS: Compared with HCs, drug-naïve children with BECTS showed increased volume in one GMV component (IC7), including bilateral precentral gyrus, bilateral supplementary motor area, left superior frontal cortex, bilateral middle/ inferior frontal cortex and bilateral anterior/ middle cingulate cortex. A positive correlation was observed between one GMV component (IC6) and seizure frequency. There were significantly positive correlations between abnormal GMV in IC7 and serotonergic, GABAergic and glutamatergic systems. CONCLUSION: These findings provided further evidence of changed GMV in drug-naïve children with BECTS related to their behavioral problems and cognitive impairments, and associated neurotransmitters which could help to better understand neurobiological mechanisms and underlying molecular mechanisms of BECTS. IMPACT: The article provides further evidence of changed gray matter volume in drug-naïve children with BECTS related to their behavioral problems and cognitive impairments as well as associated neurotransmitters. Most literature to date has applied univariate analysis and showed inconsistent results, and neurotransmitter patterns associated with brain structural alterations were still unclear. Therefore, this article uses multivariate method and JuSpace toolbox to fill the gap. Significantly increased gray matter volume was found in drug-naïve children with BECTS compared with healthy controls. Abnormal gray matter volume was significantly correlated with clinical data and specific neurotransmitters.

20.
Malar J ; 23(1): 171, 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38816783

RESUMEN

BACKGROUND: Nigeria is facing a severe malaria crisis, accounting for a significant proportion of global cases and deaths of malaria. This study aimed to investigate the differences between female-headed households (FHHs) and male-headed households (MHHs) and their impact on malaria risk among children under five (U5) in Nigeria. METHODS: Data from the 2021 Nigeria Malaria Indicator Survey (NMIS) were used for this cross-sectional study. A representative sample of 10,988 households was analysed, with key variables subjected to frequency calculations, descriptive statistics, and bivariate analyses using t-tests and chi-square analyses to compare the differences between FHHs and MHHs. RESULTS: Among all participants, 92.1% (N = 10,126) reported residing in male-headed households, while 7.8% (N = 862) reported living in female-headed households. MHHs were significantly more likely to own insecticide-treated bed nets (ITNs) than FHHs (64.7% vs. 53.6%, P < 0.001). U5 children in MHHs had a greater likelihood of sleeping under a bed net the night before the survey than U5 children in FHHs (35.3% vs. 30.0%, P < 0.05). The prevalence of fever in the previous two weeks among U5 children was similar in MHHs and FHHs (35.4% vs. 31.4%), and the testing rates for malaria among U5 children who experienced febrile episodes were higher in MHHs than FHHs (22.4% vs. 15.4%, P < 0.05). Although not statistically significant, FHHs exhibited a higher percentage of U5 children testing positive for malaria compared to MHHs (87.8% vs. 78.9%). On the other hand, FHHs had higher education levels, overall wealth index scores, and a larger presence in urban areas compared to MHHs (P < 0.001). Moreover, FHHs reported higher adherence to malaria prevention awareness (P < 0.001). CONCLUSION: In Nigeria, FHHs enjoy relatively better socioeconomic conditions and stronger awareness of malaria prevention compared to their male-headed counterparts. Contrary to expectations, FHHs are at an increased risk of malaria in children under 5 years old. This phenomenon is associated with entrenched gender inequality and the challenges women face in accessing critical assets. As women in FHHs bear the responsibility of income generation while caring for their children, it is crucial to prioritize interventions that address malaria management in FHHs to reduce both malaria incidence and mortality rates.


Asunto(s)
Composición Familiar , Malaria , Humanos , Nigeria/epidemiología , Femenino , Malaria/epidemiología , Malaria/prevención & control , Masculino , Preescolar , Estudios Transversales , Lactante , Adulto , Recién Nacido , Factores de Riesgo , Mosquiteros Tratados con Insecticida/estadística & datos numéricos
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