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1.
Immunity ; 54(6): 1304-1319.e9, 2021 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-34048708

RESUMEN

Despite mounting evidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) engagement with immune cells, most express little, if any, of the canonical receptor of SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2). Here, using a myeloid cell receptor-focused ectopic expression screen, we identified several C-type lectins (DC-SIGN, L-SIGN, LSECtin, ASGR1, and CLEC10A) and Tweety family member 2 (TTYH2) as glycan-dependent binding partners of the SARS-CoV-2 spike. Except for TTYH2, these molecules primarily interacted with spike via regions outside of the receptor-binding domain. Single-cell RNA sequencing analysis of pulmonary cells from individuals with coronavirus disease 2019 (COVID-19) indicated predominant expression of these molecules on myeloid cells. Although these receptors do not support active replication of SARS-CoV-2, their engagement with the virus induced robust proinflammatory responses in myeloid cells that correlated with COVID-19 severity. We also generated a bispecific anti-spike nanobody that not only blocked ACE2-mediated infection but also the myeloid receptor-mediated proinflammatory responses. Our findings suggest that SARS-CoV-2-myeloid receptor interactions promote immune hyperactivation, which represents potential targets for COVID-19 therapy.


Asunto(s)
COVID-19/metabolismo , COVID-19/virología , Interacciones Huésped-Patógeno , Lectinas Tipo C/metabolismo , Proteínas de la Membrana/metabolismo , Células Mieloides/inmunología , Células Mieloides/metabolismo , Proteínas de Neoplasias/metabolismo , SARS-CoV-2/fisiología , Enzima Convertidora de Angiotensina 2/metabolismo , Sitios de Unión , COVID-19/genética , Línea Celular , Citocinas , Regulación de la Expresión Génica , Interacciones Huésped-Patógeno/genética , Interacciones Huésped-Patógeno/inmunología , Humanos , Mediadores de Inflamación/metabolismo , Lectinas Tipo C/química , Proteínas de la Membrana/química , Modelos Moleculares , Proteínas de Neoplasias/química , Unión Proteica , Conformación Proteica , Anticuerpos de Dominio Único/inmunología , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/metabolismo , Relación Estructura-Actividad
2.
Nature ; 617(7961): 564-573, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36996872

RESUMEN

Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children.


Asunto(s)
Infecciones por Adenovirus Humanos , Genómica , Hepatitis , Niño , Humanos , Enfermedad Aguda/epidemiología , Infecciones por Adenovirus Humanos/epidemiología , Infecciones por Adenovirus Humanos/inmunología , Infecciones por Adenovirus Humanos/virología , Linfocitos B/inmunología , Perfilación de la Expresión Génica , Hepatitis/epidemiología , Hepatitis/inmunología , Hepatitis/virología , Inmunohistoquímica , Hígado/inmunología , Hígado/virología , Proteómica , Linfocitos T/inmunología
3.
Nature ; 609(7926): 320-326, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-36045291

RESUMEN

The nervous system uses various coding strategies to process sensory inputs. For example, the olfactory system uses large receptor repertoires and is wired to recognize diverse odours, whereas the visual system provides high acuity of object position, form and movement1-5. Compared to external sensory systems, principles that underlie sensory processing by the interoceptive nervous system remain poorly defined. Here we developed a two-photon calcium imaging preparation to understand internal organ representations in the nucleus of the solitary tract (NTS), a sensory gateway in the brainstem that receives vagal and other inputs from the body. Focusing on gut and upper airway stimuli, we observed that individual NTS neurons are tuned to detect signals from particular organs and are topographically organized on the basis of body position. Moreover, some mechanosensory and chemosensory inputs from the same organ converge centrally. Sensory inputs engage specific NTS domains with defined locations, each containing heterogeneous cell types. Spatial representations of different organs are further sharpened in the NTS beyond what is achieved by vagal axon sorting alone, as blockade of brainstem inhibition broadens neural tuning and disorganizes visceral representations. These findings reveal basic organizational features used by the brain to process interoceptive inputs.


Asunto(s)
Tronco Encefálico , Sensación , Tronco Encefálico/anatomía & histología , Tronco Encefálico/citología , Tronco Encefálico/fisiología , Calcio/metabolismo , Postura/fisiología , Sensación/fisiología , Células Receptoras Sensoriales/fisiología , Núcleo Solitario/anatomía & histología , Núcleo Solitario/citología , Núcleo Solitario/fisiología , Nervio Vago/fisiología
4.
Nature ; 609(7927): 517-522, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-36104558

RESUMEN

Arctic sea ice is diminishing with climate warming1 at a rate unmatched for at least 1,000 years2. As the receding ice pack raises commercial interest in the Arctic3, it has become more variable and mobile4, which increases safety risks to maritime users5. Satellite observations of sea-ice thickness are currently unavailable during the crucial melt period from May to September, when they would be most valuable for applications such as seasonal forecasting6, owing to major challenges in the processing of altimetry data7. Here we use deep learning and numerical simulations of the CryoSat-2 radar altimeter response to overcome these challenges and generate a pan-Arctic sea-ice thickness dataset for the Arctic melt period. CryoSat-2 observations capture the spatial and the temporal patterns of ice melting rates recorded by independent sensors and match the time series of sea-ice volume modelled by the Pan-Arctic Ice Ocean Modelling and Assimilation System reanalysis8. Between 2011 and 2020, Arctic sea-ice thickness was 1.87 ± 0.10 m at the start of the melting season in May and 0.82 ± 0.11 m by the end of the melting season in August. Our year-round sea-ice thickness record unlocks opportunities for understanding Arctic climate feedbacks on different timescales. For instance, sea-ice volume observations from the early summer may extend the lead time of skilful August-October sea-ice forecasts by several months, at the peak of the Arctic shipping season.

5.
Nature ; 589(7842): 474-479, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33299186

RESUMEN

The psychedelic alkaloid ibogaine has anti-addictive properties in both humans and animals1. Unlike most medications for the treatment of substance use disorders, anecdotal reports suggest that ibogaine has the potential to treat addiction to various substances, including opiates, alcohol and psychostimulants. The effects of ibogaine-like those of other psychedelic compounds-are long-lasting2, which has been attributed to its ability to modify addiction-related neural circuitry through the activation of neurotrophic factor signalling3,4. However, several safety concerns have hindered the clinical development of ibogaine, including its toxicity, hallucinogenic potential and tendency to induce cardiac arrhythmias. Here we apply the principles of function-oriented synthesis to identify the key structural elements of the potential therapeutic pharmacophore of ibogaine, and we use this information to engineer tabernanthalog-a water-soluble, non-hallucinogenic, non-toxic analogue of ibogaine that can be prepared in a single step. In rodents, tabernanthalog was found to promote structural neural plasticity, reduce alcohol- and heroin-seeking behaviour, and produce antidepressant-like effects. This work demonstrates that, through careful chemical design, it is possible to modify a psychedelic compound to produce a safer, non-hallucinogenic variant that has therapeutic potential.


Asunto(s)
Conducta Adictiva/tratamiento farmacológico , Diseño de Fármacos , Ibogaína/análogos & derivados , Ibogaína/efectos adversos , Alcoholismo/tratamiento farmacológico , Animales , Antidepresivos/farmacología , Arritmias Cardíacas/inducido químicamente , Técnicas de Química Sintética , Depresión/tratamiento farmacológico , Modelos Animales de Enfermedad , Femenino , Alucinógenos/efectos adversos , Dependencia de Heroína/tratamiento farmacológico , Masculino , Ratones , Ratones Endogámicos C57BL , Plasticidad Neuronal/efectos de los fármacos , Seguridad del Paciente , Receptor de Serotonina 5-HT2A/metabolismo , Agonistas del Receptor de Serotonina 5-HT2/farmacología , Trastornos Relacionados con Sustancias/tratamiento farmacológico , Natación , Tabernaemontana/química
6.
PLoS Biol ; 21(2): e3001941, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36757937

RESUMEN

Interactions between viruses during coinfections can influence viral fitness and population diversity, as seen in the generation of reassortant pandemic influenza A virus (IAV) strains. However, opportunities for interactions between closely related viruses are limited by a process known as superinfection exclusion (SIE), which blocks coinfection shortly after primary infection. Using IAVs, we asked whether SIE, an effect which occurs at the level of individual cells, could limit interactions between populations of viruses as they spread across multiple cells within a host. To address this, we first measured the kinetics of SIE in individual cells by infecting them sequentially with 2 isogenic IAVs, each encoding a different fluorophore. By varying the interval between addition of the 2 IAVs, we showed that early in infection SIE does not prevent coinfection, but that after this initial lag phase the potential for coinfection decreases exponentially. We then asked how the kinetics of SIE onset controlled coinfections as IAVs spread asynchronously across monolayers of cells. We observed that viruses at individual coinfected foci continued to coinfect cells as they spread, because all new infections were of cells that had not yet established SIE. In contrast, viruses spreading towards each other from separately infected foci could only establish minimal regions of coinfection before reaching cells where coinfection was blocked. This created a pattern of separate foci of infection, which was recapitulated in the lungs of infected mice, and which is likely to be applicable to many other viruses that induce SIE. We conclude that the kinetics of SIE onset segregate spreading viral infections into discrete regions, within which interactions between virus populations can occur freely, and between which they are blocked.


Asunto(s)
Coinfección , Gripe Humana , Orthomyxoviridae , Sobreinfección , Ratones , Animales , Humanos , Virus Reordenados
7.
Nat Mater ; 23(1): 79-87, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37957266

RESUMEN

Reservoir computing is a neuromorphic architecture that may offer viable solutions to the growing energy costs of machine learning. In software-based machine learning, computing performance can be readily reconfigured to suit different computational tasks by tuning hyperparameters. This critical functionality is missing in 'physical' reservoir computing schemes that exploit nonlinear and history-dependent responses of physical systems for data processing. Here we overcome this issue with a 'task-adaptive' approach to physical reservoir computing. By leveraging a thermodynamical phase space to reconfigure key reservoir properties, we optimize computational performance across a diverse task set. We use the spin-wave spectra of the chiral magnet Cu2OSeO3 that hosts skyrmion, conical and helical magnetic phases, providing on-demand access to different computational reservoir responses. The task-adaptive approach is applicable to a wide variety of physical systems, which we show in other chiral magnets via above (and near) room-temperature demonstrations in Co8.5Zn8.5Mn3 (and FeGe).

8.
Mol Pharmacol ; 106(1): 33-46, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38719474

RESUMEN

DNA topoisomerase IIα (TOP2α; 170 kDa, TOP2α/170) is an essential enzyme for proper chromosome dysjunction by producing transient DNA double-stranded breaks and is an important target for DNA damage-stabilizing anticancer agents, such as etoposide. Therapeutic effects of TOP2α poisons can be limited due to acquired drug resistance. We previously demonstrated decreased TOP2α/170 levels in an etoposide-resistant human leukemia K562 subline, designated K/VP.5, accompanied by increased expression of a C-terminal truncated TOP2α isoform (90 kDa; TOP2α/90), which heterodimerized with TOP2α/170 and was a determinant of resistance by exhibiting dominant-negative effects against etoposide activity. Based on 3'-rapid amplification of cDNA ends, we confirmed TOP2α/90 as the translation product of a TOP2α mRNA in which a cryptic polyadenylation site (PAS) harbored in intron 19 (I19) was used. In this report, we investigated whether the resultant intronic polyadenylation (IPA) would be attenuated by blocking or mutating the I19 PAS, thereby circumventing acquired drug resistance. An antisense morpholino oligonucleotide was used to hybridize/block the PAS in TOP2α pre-mRNA in K/VP.5 cells, resulting in decreased TOP2α/90 mRNA/protein levels in K/VP.5 cells and partially circumventing drug resistance. Subsequently, CRISPR/CRISPR-associated protein 9 with homology-directed repair was used to mutate the cryptic I19 PAS (AATAAA→ACCCAA) to prevent IPA. Gene-edited clones exhibited increased TOP2α/170 and decreased TOP2α/90 mRNA/protein and demonstrated restored sensitivity to etoposide and other TOP2α-targeted drugs. Together, results indicated that blocking/mutating a cryptic I19 PAS in K/VP.5 cells reduced IPA and restored sensitivity to TOP2α-targeting drugs. SIGNIFICANCE STATEMENT: The results presented in this study indicate that CRISPR/CRISPR-associated protein 9 gene editing of a cryptic polyadenylation site (PAS) within I19 of the TOP2α gene results in the reversal of acquired resistance to etoposide and other TOP2-targeted drugs. An antisense morpholino oligonucleotide targeting the PAS also partially circumvented resistance.


Asunto(s)
ADN-Topoisomerasas de Tipo II , Resistencia a Antineoplásicos , Etopósido , Intrones , Poliadenilación , Humanos , Etopósido/farmacología , ADN-Topoisomerasas de Tipo II/genética , ADN-Topoisomerasas de Tipo II/metabolismo , Resistencia a Antineoplásicos/genética , Resistencia a Antineoplásicos/efectos de los fármacos , Células K562 , Poliadenilación/efectos de los fármacos , Poliadenilación/genética , Intrones/genética , Sistemas CRISPR-Cas
9.
J Cell Biochem ; : e30612, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38923575

RESUMEN

Glioblastoma (GBM) is the most common form of malignant primary brain tumor with a high mortality rate. The aim of the present study was to investigate the clinical significance of Family with Sequence Similarity 3, Member C, FAM3C, in GBM using bioinformatic-integrated analysis. First, we performed the transcriptomic integration analysis to assess the expression profile of FAM3C in GBM using several data sets (RNA-sequencing and scRNA-sequencing), which were obtained from TCGA and GEO databases. By using the STRING platform, we investigated FAM3C-coregulated genes to construct the protein-protein interaction network. Next, Metascape, Enrichr, and CIBERSORT databases were used. We found FAM3C high expression in GBM with poor survival rates. Further, we observed, via FAM3C coexpression network analysis, that FAM3C plays key roles in several hallmarks of cancer. Surprisingly, we also highlighted five FAM3C­coregulated genes overexpressed in GBM. Specifically, we demonstrated the association between the high expression of FAM3C and the abundance of the different immune cells, which may markedly worsen GBM prognosis. For the first time, our findings suggest that FAM3C not only can be a new emerging biomarker with promising therapeutic values to GBM patients but also gave a new insight into a potential resource for future GBM studies.

10.
Am J Physiol Gastrointest Liver Physiol ; 326(3): G291-G309, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38252699

RESUMEN

Hepatocellular carcinoma (HCC) is the fastest-growing cause of cancer-related deaths worldwide. Chronic inflammation and fibrosis are the greatest risk factors for the development of HCC. Although the cell of origin for HCC is uncertain, many theories believe this cancer may arise from liver progenitor cells or stem cells. Here, we describe the activation of hepatic stem cells that overexpress the cholecystokinin-B receptor (CCK-BR) after liver injury with either a DDC diet (0.1% 3, 5-diethoxy-carbonyl 1,4-dihydrocollidine) or a NASH-inducing CDE diet (choline-deficient ethionine) in murine models. Pharmacologic blockade of the CCK-BR with a receptor antagonist proglumide or knockout of the CCK-BR in genetically engineered mice during the injury diet reduces the expression of hepatic stem cells and prevents the formation of three-dimensional tumorspheres in culture. RNA sequencing of livers from DDC-fed mice treated with proglumide or DDC-fed CCK-BR knockout mice showed downregulation of differentially expressed genes involved in cell proliferation and oncogenesis and upregulation of tumor suppressor genes compared with controls. Inhibition of the CCK-BR decreases hepatic transaminases, fibrosis, cytokine expression, and alters the hepatic immune cell signature rendering the liver microenvironment less oncogenic. Furthermore, proglumide hastened recovery after liver injury by reversing fibrosis and improving markers of synthetic function. Proglumide is an older drug that is orally bioavailable and being repurposed for liver conditions. These findings support a promising therapeutic intervention applicable to patients to prevent the development of HCC and decrease hepatic fibrosis.NEW & NOTEWORTHY This investigation identified a novel pathway involving the activation of hepatic stem cells and liver oncogenesis. Receptor blockade or genetic disruption of the cholecystokinin-B receptor (CCK-BR) signaling pathway decreased the activation and proliferation of hepatic stem cells after liver injury without eliminating the regenerative capacity of healthy hepatocytes.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Ratones , Animales , Receptor de Colecistoquinina B/genética , Receptor de Colecistoquinina B/metabolismo , Carcinoma Hepatocelular/patología , Proglumida/farmacología , Neoplasias Hepáticas/metabolismo , Hígado/metabolismo , Fibrosis , Células Madre/metabolismo , Carcinogénesis/metabolismo , Transformación Celular Neoplásica/metabolismo , Colecistoquinina/metabolismo , Microambiente Tumoral
11.
J Cell Sci ; 135(2)2022 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-34982109

RESUMEN

The human apolipoprotein E4 isoform (APOE4) is the strongest genetic risk factor for late-onset Alzheimer's disease (AD), and lysosomal dysfunction has been implicated in AD pathogenesis. We found, by examining cells stably expressing each APOE isoform, that APOE4 increases lysosomal trafficking, accumulates in enlarged lysosomes and late endosomes, alters autophagic flux and the abundance of autophagy proteins and lipid droplets, and alters the proteomic contents of lysosomes following internalization. We investigated APOE-related lysosomal trafficking further in cell culture, and found that APOE from the post-Golgi compartment is degraded through autophagy. We found that this autophagic process requires the lysosomal membrane protein LAMP2 in immortalized neuron-like and hepatic cells, and in mouse brain tissue. Several macroautophagy-associated proteins were also required for autophagic degradation and internalization of APOE in hepatic cells. The dysregulated autophagic flux and lysosomal trafficking of APOE4 that we observed suggest a possible novel mechanism that might contribute to AD pathogenesis. This article has an associated First Person interview with the first author of the paper.


Asunto(s)
Enfermedad de Alzheimer , Proteómica , Enfermedad de Alzheimer/genética , Animales , Apolipoproteína E4/genética , Apolipoproteínas E/genética , Autofagia , Lisosomas , Ratones , Isoformas de Proteínas/genética
12.
J Pharmacol Exp Ther ; 389(2): 186-196, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38508753

RESUMEN

DNA topoisomerase IIß (TOP2ß/180; 180 kDa) is a nuclear enzyme that regulates DNA topology by generation of short-lived DNA double-strand breaks, primarily during transcription. TOP2ß/180 can be a target for DNA damage-stabilizing anticancer drugs, whose efficacy is often limited by chemoresistance. Our laboratory previously demonstrated reduced levels of TOP2ß/180 (and the paralog TOP2α/170) in an acquired etoposide-resistant human leukemia (K562) clonal cell line, K/VP.5, in part due to overexpression of microRNA-9-3p/5p impacting post-transcriptional events. To evaluate the effect on drug sensitivity upon reduction/elimination of TOP2ß/180, a premature stop codon was generated at the TOP2ß/180 gene exon 19/intron 19 boundary (AGAA//GTAA→ATAG//GTAA) in parental K562 cells (which contain four TOP2ß/180 alleles) by CRISPR/Cas9 editing with homology-directed repair to disrupt production of full-length TOP2ß/180. Gene-edited clones were identified and verified by quantitative polymerase chain reaction and Sanger sequencing, respectively. Characterization of TOP2ß/180 gene-edited clones, with one or all four TOP2ß/180 alleles mutated, revealed partial or complete loss of TOP2ß mRNA/protein, respectively. The loss of TOP2ß/180 protein correlated with decreased (2-{4-[(7-chloro-2-quinoxalinyl)oxy]phenoxy}propionic acid)-induced DNA damage and partial resistance in growth inhibition assays. Partial resistance to mitoxantrone was also noted in the gene-edited clone with all four TOP2ß/180 alleles modified. No cross-resistance to etoposide or mAMSA was noted in the gene-edited clones. Results demonstrated the role of TOP2ß/180 in drug sensitivity/resistance in K562 cells and revealed differential paralog activity of TOP2-targeted agents. SIGNIFICANCE STATEMENT: Data indicated that CRISPR/Cas9 editing of the exon 19/intron 19 boundary in the TOP2ß/180 gene to introduce a premature stop codon resulted in partial to complete disruption of TOP2ß/180 expression in human leukemia (K562) cells depending on the number of edited alleles. Edited clones were partially resistant to mitoxantrone and XK469, while lacking resistance to etoposide and mAMSA. Results demonstrated the import of TOP2ß/180 in drug sensitivity/resistance in K562 cells and revealed differential paralog activity of TOP2-targeted agents.


Asunto(s)
Antineoplásicos , Leucemia , Humanos , Etopósido/farmacología , Células K562 , ADN-Topoisomerasas de Tipo II/genética , ADN-Topoisomerasas de Tipo II/metabolismo , Mitoxantrona , Sistemas CRISPR-Cas/genética , Codón sin Sentido , Antineoplásicos/farmacología , ADN , Fenotipo
13.
J Exp Zool B Mol Dev Evol ; 342(3): 278-290, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38185943

RESUMEN

Development of reliable germplasm repositories is critical for preservation of genetic resources of aquatic species, which are widely utilized to support biomedical innovation by providing a foundational source for naturally occurring variation and development of new variants through genetic manipulations. A significant barrier in repository development is the lack of cryopreservation capability and reproducibility across the research community, posing great risks of losing advances developed from billions of dollars of research investment. The emergence of open scientific hardware has fueled a new movement across biomedical research communities. With the increasing accessibility of consumer-level fabrication technologies, such as three-dimensional printers, open hardware devices can be custom designed, and design files distributed to community members for enhancing rigor, reproducibility, and standardization. The overall goal of this review is to explore pathways to create open-hardware ecosystems among the communities using aquatic model resources for biomedical research. To gain feedback and insights from community members, an interactive workshop focusing on open-hardware applications in germplasm repository development was held at the 2022 Aquatic Models for Human Disease Conference, Woods Hole, Massachusetts. This work integrates conceptual strategies with practical insights derived from workshop interactions using examples of germplasm repository development. These insights can be generalized for establishment of open-hardware ecosystems for a broad biomedical research community. The specific objectives were to: (1) introduce an open-hardware ecosystem concept to support biomedical research; (2) explore pathways toward open-hardware ecosystems through four major areas, and (3) identify opportunities and future directions.


Asunto(s)
Investigación Biomédica , Animales , Ecosistema , Organismos Acuáticos , Modelos Animales
14.
Opt Express ; 32(10): 17189-17196, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38858908

RESUMEN

High-finesse microcavities offer a platform for compact, high-precision sensing by employing high-reflectivity, low-loss mirrors to create effective optical path lengths that are orders of magnitude larger than the device geometry. Here, we investigate the radiation hardness of Fabry-Pérot microcavities formed from dielectric mirrors deposited on the tips of optical fibers. The microcavities are irradiated under both conventional (∼ 0.1 Gy/s) and ultrahigh (FLASH, ∼ 20 Gy/s) radiotherapy dose rates. Within our measurement sensitivity of ∼ 40 ppm loss, we observe no degradation in the mirror absorption after irradiation with over 300 Gy accumulated dose. This result highlights the excellent radiation hardness of the dielectric mirrors forming the cavities, enabling new optics-based, real-time, in-vivo, tissue-equivalent radiation dosimeters with ∼ 10 micron spatial resolution (our motivation), as well as other applications in high-radiation environments.

15.
Chemistry ; 30(27): e202400501, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38433109

RESUMEN

The ability of an octanuclear cubic coordination cage to catalyse a nucleophilic aromatic substitution reaction on a cavity-bound guest was studied with 2,4-dinitrofluorobenzene (DNFB) as the guest/substrate. It was found that DNFB undergoes a catalysed reaction with hydroxide ions within the cavity of the cubic cage (in aqueous buffer solution, pH 8.6). The rate enhancement of kcat/kuncat was determined to be 22, with cavity binding of the guest being required for catalysis to occur. The product, 2,4-dinitrophenolate (DNP), remained bound within the cavity due to electrostatic stabilisation and exerts two apparently contradictory effects: it initially auto-catalyses the reaction when present at low concentrations, but at higher concentrations inhibits catalysis when a pair of DNP guests block the cavity. When encapsulated, the UV/Vis absorption spectrum of DNP is red-shifted when compared to the spectrum of free DNP in aqueous solution. Further investigations using other aromatic guests determined that a similar red-shift on cavity binding also occurred for 4-nitrophenolate (4NP) at pH 8.6. The red-shift was used to determine the stoichiometry of guest binding of DNP and 4NP within the cage cavity, which was confirmed by structural analysis with X-ray crystallography; and was also used to perform catalytic kinetic studies in the solution-state.

16.
Brain Behav Immun ; 115: 3-12, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37769980

RESUMEN

Oxidative stress may contribute to declining course and poor outcomes in psychosis. However, in vivo Magnetic Resonance Spectroscopy studies yield disparate results due to clinical stage, sample demographics, neuroanatomical focus, sample size, and acquisition method variations. We investigated glutathione in brain regions from participants with psychosis, and the relation of glutathione to clinical features and spectroscopy protocols. Meta-analysis comprised 21 studies. Glutathione levels did not differ between total psychosis patients (N = 639) and controls (N = 704) in the Medial Prefrontal region (k = 21, d = -0.09, CI = -0.28 to 0.10, p = 0.37). Patients with stable schizophrenia exhibited a small but significant glutathione reduction compared to controls (k = 14, d = -0.20, CI = -0.40 to -0.00, p = 0.05). Meta-regression showed older studies had greater glutathione reductions, possibly reflecting greater accuracy related to spectroscopy advancements in more recent studies. No significant effects of methodological variables, such as voxel size or echo time were found. Reduced glutathione in patients with stable established schizophrenia may provide novel targets for precision medicine. Standardizing MRS acquisition methods in future studies may help address discrepancies in glutathione levels.


Asunto(s)
Trastornos Psicóticos , Esquizofrenia , Humanos , Esquizofrenia/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Espectroscopía de Resonancia Magnética/métodos , Glutatión
17.
Phys Chem Chem Phys ; 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39046422

RESUMEN

While two-dimensional (2D) MoS2 has recently shown promise as a material for resistive random-access memory (RRAM) devices due to its demonstrated resistive switching (RS) characteristics, its practical application faces a significant challenge in industry regarding its limited yield and endurance. Our earlier work introduced an effective switching layer model to understand RS behavior in both mono- and multi-layered MoS2. However, functioning as a phenomenological percolation modeling tool, it lacks the capability to accurately simulate the intricate current-voltage (I-V) characteristics of the device, thereby hindering its practical applicability in 2D RRAM research. In contrast to the established conductive filament model for oxide-based RRAM, the RS mechanism in 2D RRAM remains elusive. This paper presents a novel simulator aimed at providing an intuitive, visual representation of the stochastic behaviors involved in the RS process of multi-layer 2D MoS2 RRAM devices. Building upon the previously proposed phenomenological simulator for 2D RRAM, users can now simulate both the I-V characteristics and the resistive switching behaviors of the RRAM devices. Through comparison with experimental data, it was observed that yield and endurance characteristics are linked to defect distributions in MoS2.

18.
Mol Ther ; 31(12): 3545-3563, 2023 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-37807512

RESUMEN

Huntington's disease (HD), a genetic neurodegenerative disorder, primarily affects the striatum and cortex with progressive loss of medium-sized spiny neurons (MSNs) and pyramidal neurons, disrupting cortico-striatal circuitry. A promising regenerative therapeutic strategy of transplanting human neural stem cells (hNSCs) is challenged by the need for long-term functional integration. We previously described that, with short-term hNSC transplantation into the striatum of HD R6/2 mice, human cells differentiated into electrophysiologically active immature neurons, improving behavior and biochemical deficits. Here, we show that long-term (8 months) implantation of hNSCs into the striatum of HD zQ175 mice ameliorates behavioral deficits, increases brain-derived neurotrophic factor (BDNF) levels, and reduces mutant huntingtin (mHTT) accumulation. Patch clamp recordings, immunohistochemistry, single-nucleus RNA sequencing (RNA-seq), and electron microscopy demonstrate that hNSCs differentiate into diverse neuronal populations, including MSN- and interneuron-like cells, and form connections. Single-nucleus RNA-seq analysis also shows restoration of several mHTT-mediated transcriptional changes of endogenous striatal HD mouse cells. Remarkably, engrafted cells receive synaptic inputs, innervate host neurons, and improve membrane and synaptic properties. Overall, the findings support hNSC transplantation for further evaluation and clinical development for HD.


Asunto(s)
Enfermedad de Huntington , Células-Madre Neurales , Humanos , Ratones , Animales , Enfermedad de Huntington/genética , Enfermedad de Huntington/terapia , Cuerpo Estriado , Neuronas , Fenotipo , Modelos Animales de Enfermedad , Ratones Transgénicos , Proteína Huntingtina/genética
19.
Int J Qual Health Care ; 36(1)2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-38381655

RESUMEN

Goal planning is an important element in brief health interventions provided in primary healthcare settings, with specific, measurable, achievable, realistic/relevant, and timed (SMART) goals recommended as best practice. This study examined the use of SMART goals by Australian community pharmacists providing a brief goal-oriented wellbeing intervention with service-users experiencing severe and persistent mental illnesses (SPMIs), in particular, which aspects of SMART goal planning were incorporated into the documented goals. Goal data from the PharMIbridge Randomized Controlled Trial (RCT) were used to investigate how community pharmacists operationalized SMART goals, goal quality, and which SMART goal planning format aspects were most utilized. Goals were evaluated using the SMART Goal Evaluation Method (SMART-GEM) tool to determine how closely each documented goal met the SMART criteria. Goals were also categorized into five domains describing their content or purpose. Descriptive analysis was used to describe the SMART-GEM evaluation results, and the Kruskal-Wallis H test was used to compare the evaluation results across the goal domains. All goals (n = 512) co-designed with service-users (n = 156) were classified as poor quality when assessed against the SMART guidelines for goal statements, although most goals contained information regarding a specific behaviour and/or action (71.3% and 86.3%, respectively). Less than 25% of goals identified how goal achievement would be measured, with those related to lifestyle and wellbeing behaviours most likely to include measurement information. Additionally, the majority (93.5%) of goals lacked details regarding monitoring goal progress. Study findings raise questions regarding the applicability of the SMART goal format in brief health interventions provided in primary healthcare settings, particularly for service-users experiencing SPMIs. Further research is recommended to identify which elements of SMART goals are most relevant for brief interventions. Additionally, further investigation is needed regarding the impact of SMART goal training or support tools on goal quality.


Asunto(s)
Servicios de Salud Mental , Farmacias , Humanos , Australia , Enfermedad Crónica , Objetivos , Farmacéuticos , Ensayos Clínicos Controlados Aleatorios como Asunto
20.
Proc Natl Acad Sci U S A ; 118(21)2021 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-33972412

RESUMEN

We analyze data from the fall 2020 pandemic response efforts at the University of Colorado Boulder, where more than 72,500 saliva samples were tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using qRT-PCR. All samples were collected from individuals who reported no symptoms associated with COVID-19 on the day of collection. From these, 1,405 positive cases were identified. The distribution of viral loads within these asymptomatic individuals was indistinguishable from what has been previously observed in symptomatic individuals. Regardless of symptomatic status, ∼50% of individuals who test positive for SARS-CoV-2 seem to be in noninfectious phases of the disease, based on having low viral loads in a range from which live virus has rarely been isolated. We find that, at any given time, just 2% of individuals carry 90% of the virions circulating within communities, serving as viral "supercarriers" and possibly also superspreaders.


Asunto(s)
COVID-19/virología , Portador Sano/virología , SARS-CoV-2 , Infecciones Asintomáticas/epidemiología , COVID-19/diagnóstico , COVID-19/epidemiología , COVID-19/transmisión , Portador Sano/diagnóstico , Portador Sano/epidemiología , Portador Sano/transmisión , Colorado/epidemiología , Hospitalización/estadística & datos numéricos , Humanos , Tamizaje Masivo/estadística & datos numéricos , SARS-CoV-2/genética , SARS-CoV-2/aislamiento & purificación , Saliva/virología , Universidades , Carga Viral , Virión
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