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1.
Cell ; 186(17): 3674-3685.e14, 2023 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-37494934

RESUMEN

Epigenetic lesions that disrupt regulatory elements represent potential cancer drivers. However, we lack experimental models for validating their tumorigenic impact. Here, we model aberrations arising in isocitrate dehydrogenase-mutant gliomas, which exhibit DNA hypermethylation. We focus on a CTCF insulator near the PDGFRA oncogene that is recurrently disrupted by methylation in these tumors. We demonstrate that disruption of the syntenic insulator in mouse oligodendrocyte progenitor cells (OPCs) allows an OPC-specific enhancer to contact and induce Pdgfra, thereby increasing proliferation. We show that a second lesion, methylation-dependent silencing of the Cdkn2a tumor suppressor, cooperates with insulator loss in OPCs. Coordinate inactivation of the Pdgfra insulator and Cdkn2a drives gliomagenesis in vivo. Despite locus synteny, the insulator is CpG-rich only in humans, a feature that may confer human glioma risk but complicates mouse modeling. Our study demonstrates the capacity of recurrent epigenetic lesions to drive OPC proliferation in vitro and gliomagenesis in vivo.


Asunto(s)
Neoplasias Encefálicas , Epigénesis Genética , Glioma , Animales , Humanos , Ratones , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patología , Metilación de ADN , Glioma/genética , Glioma/patología , Isocitrato Deshidrogenasa/genética , Mutación , Oncogenes , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/genética
2.
Cell ; 178(4): 835-849.e21, 2019 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-31327527

RESUMEN

Diverse genetic, epigenetic, and developmental programs drive glioblastoma, an incurable and poorly understood tumor, but their precise characterization remains challenging. Here, we use an integrative approach spanning single-cell RNA-sequencing of 28 tumors, bulk genetic and expression analysis of 401 specimens from the The Cancer Genome Atlas (TCGA), functional approaches, and single-cell lineage tracing to derive a unified model of cellular states and genetic diversity in glioblastoma. We find that malignant cells in glioblastoma exist in four main cellular states that recapitulate distinct neural cell types, are influenced by the tumor microenvironment, and exhibit plasticity. The relative frequency of cells in each state varies between glioblastoma samples and is influenced by copy number amplifications of the CDK4, EGFR, and PDGFRA loci and by mutations in the NF1 locus, which each favor a defined state. Our work provides a blueprint for glioblastoma, integrating the malignant cell programs, their plasticity, and their modulation by genetic drivers.


Asunto(s)
Neoplasias Encefálicas/genética , Plasticidad de la Célula/genética , Glioblastoma/genética , Adolescente , Anciano , Animales , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Linaje de la Célula/genética , Niño , Estudios de Cohortes , Modelos Animales de Enfermedad , Femenino , Heterogeneidad Genética , Glioblastoma/patología , Xenoinjertos , Humanos , Lactante , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Persona de Mediana Edad , Mutación , RNA-Seq , Análisis de la Célula Individual/métodos , Microambiente Tumoral/genética
3.
Mol Cell ; 84(7): 1365-1376.e7, 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38452764

RESUMEN

Enhancer-gene communication is dependent on topologically associating domains (TADs) and boundaries enforced by the CCCTC-binding factor (CTCF) insulator, but the underlying structures and mechanisms remain controversial. Here, we investigate a boundary that typically insulates fibroblast growth factor (FGF) oncogenes but is disrupted by DNA hypermethylation in gastrointestinal stromal tumors (GISTs). The boundary contains an array of CTCF sites that enforce adjacent TADs, one containing FGF genes and the other containing ANO1 and its putative enhancers, which are specifically active in GIST and its likely cell of origin. We show that coordinate disruption of four CTCF motifs in the boundary fuses the adjacent TADs, allows the ANO1 enhancer to contact FGF3, and causes its robust induction. High-resolution micro-C maps reveal specific contact between transcription initiation sites in the ANO1 enhancer and FGF3 promoter that quantitatively scales with FGF3 induction such that modest changes in contact frequency result in strong changes in expression, consistent with a causal relationship.


Asunto(s)
Cromatina , Elementos de Facilitación Genéticos , Factor de Unión a CCCTC/genética , Factor de Unión a CCCTC/metabolismo , Cromatina/genética , Oncogenes , ADN/química
4.
Nature ; 604(7906): 457-462, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35444321

RESUMEN

Gate-model quantum computers promise to solve currently intractable computational problems if they can be operated at scale with long coherence times and high-fidelity logic. Neutral-atom hyperfine qubits provide inherent scalability owing to their identical characteristics, long coherence times and ability to be trapped in dense, multidimensional arrays1. Combined with the strong entangling interactions provided by Rydberg states2-4, all the necessary characteristics for quantum computation are available. Here we demonstrate several quantum algorithms on a programmable gate-model neutral-atom quantum computer in an architecture based on individual addressing of single atoms with tightly focused optical beams scanned across a two-dimensional array of qubits. Preparation of entangled Greenberger-Horne-Zeilinger (GHZ) states5 with up to six qubits, quantum phase estimation for a chemistry problem6 and the quantum approximate optimization algorithm (QAOA)7 for the maximum cut (MaxCut) graph problem are demonstrated. These results highlight the emergent capability of neutral-atom qubit arrays for universal, programmable quantum computation, as well as preparation of non-classical states of use for quantum-enhanced sensing.

5.
Nature ; 597(7876): 376-380, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34471286

RESUMEN

Pleistocene hominin dispersals out of, and back into, Africa necessarily involved traversing the diverse and often challenging environments of Southwest Asia1-4. Archaeological and palaeontological records from the Levantine woodland zone document major biological and cultural shifts, such as alternating occupations by Homo sapiens and Neanderthals. However, Late Quaternary cultural, biological and environmental records from the vast arid zone that constitutes most of Southwest Asia remain scarce, limiting regional-scale insights into changes in hominin demography and behaviour1,2,5. Here we report a series of dated palaeolake sequences, associated with stone tool assemblages and vertebrate fossils, from the Khall Amayshan 4 and Jubbah basins in the Nefud Desert. These findings, including the oldest dated hominin occupations in Arabia, reveal at least five hominin expansions into the Arabian interior, coinciding with brief 'green' windows of reduced aridity approximately 400, 300, 200, 130-75 and 55 thousand years ago. Each occupation phase is characterized by a distinct form of material culture, indicating colonization by diverse hominin groups, and a lack of long-term Southwest Asian population continuity. Within a general pattern of African and Eurasian hominin groups being separated by Pleistocene Saharo-Arabian aridity, our findings reveal the tempo and character of climatically modulated windows for dispersal and admixture.


Asunto(s)
Hominidae , Migración Humana/historia , Animales , Antropología , Arabia , Asia , Historia Antigua , Paleontología , Comportamiento del Uso de la Herramienta
6.
J Gen Intern Med ; 39(8): 1414-1422, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38148474

RESUMEN

BACKGROUND: The FDA issued a "black box" warning regarding risks of fluoroquinolones in 2008 with updates in 2011, 2013, and 2016. OBJECTIVE: To examine antimicrobial use in hospital-treated UTIs from 2000 to 2020. DESIGN: Cross-sectional study with interrupted time series analysis. PARTICIPANTS: Patient encounters with a diagnosis of UTI from January 2000 to March 2020, excluding diagnoses of renal abscess, chronic cystitis, and infection of the gastrointestinal tract, lungs, or prostate. MAIN MEASURES: Monthly use of fluoroquinolone and non-fluoroquinolone antibiotics were assessed. Fluoroquinolone resistance was assessed in available cultures. Interrupted time series analysis examined level and trend changes of antimicrobial use with each FDA label change. KEY RESULTS: A total of 9,950,790 patient encounters were included. From July 2008 to March 2020, fluoroquinolone use declined from 61.7% to 11.7%, with similar negative trends observed in inpatients and outpatients, age ≥ 60 and < 60 years, males and females, patients with and without pyelonephritis, and across physician specialties. Ceftriaxone use increased from 26.4% encounters in July 2008 to 63.6% of encounters in March 2020. Among encounters with available culture data, fluoroquinolone resistance declined by 28.9% from 2009 to 2020. On interrupted time series analysis, the July 2008 FDA warning was associated with a trend change (-0.32%, < 0.001) and level change (-5.02%, p < 0.001) in monthly fluoroquinolone use. CONCLUSIONS: During this era of "black box" warnings, there was a decline in fluoroquinolone use for hospital-treated UTI with a concomitant decline in fluoroquinolone resistance and rise in ceftriaxone use. Efforts to restrict use of a medication class may lead to compensatory increases in use of a single alternative agent with changes in antimicrobial resistance profiles.


Asunto(s)
Antibacterianos , United States Food and Drug Administration , Infecciones Urinarias , Humanos , Infecciones Urinarias/tratamiento farmacológico , Masculino , Femenino , Estados Unidos/epidemiología , Estudios Transversales , Antibacterianos/uso terapéutico , Antibacterianos/efectos adversos , Persona de Mediana Edad , Anciano , Adulto , Fluoroquinolonas/uso terapéutico , Análisis de Series de Tiempo Interrumpido , Infección Hospitalaria/tratamiento farmacológico , Infección Hospitalaria/epidemiología
7.
Cerebellum ; 2024 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-38217689

RESUMEN

SCA6 patients with the same size CAG repeat allele can vary significantly in age at onset (AAO) and clinical progression. The specific external factors affecting SCA6 have yet to be investigated. We assessed the effect of early life events on AAO, severity, and progression in SCA6 patients using a social determinant of health approach. We performed a survey of biological and social factors in SCA6 patients enrolled in the SCA6 Network at the University of Chicago. AAO of ataxia symptoms and patient-reported outcome measure (PROM) of ataxia were used as primary outcome measures. Least absolute shrinkage and selection operation (LASSO) regressions were used to identify which early life factors are predictive of SCA6 AAO, severity, and progression. Multiple linear regression models were then used to assess the degree to which these determinants influence SCA6 health outcomes. A total of 105 participants with genetically confirmed SCA6 completed the assessments. SCA6 participants with maternal difficulty during pregnancy, active participation in school sports, and/or longer CAG repeats were determined to have earlier AAO. We found a 13.44-year earlier AAO for those with maternal difficulty in pregnancy than those without (p = 0.008) and a 12.31-year earlier AAO for those active in school sports than those who were not (p < 0.001). Higher education attainment was associated with decreased SCA6 severity and slower progression. Early life biological and social factors can have a strong influence on the SCA6 disease course, indicating that non-genetic factors can contribute significantly to SCA6 health outcomes.

8.
Trop Med Int Health ; 29(5): 365-376, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38480005

RESUMEN

BACKGROUND: In northern Tanzania, Q fever, spotted fever group (SFG) rickettsioses, and typhus group (TG) rickettsioses are common causes of febrile illness. We sought to describe the prevalence and risk factors for these zoonoses in a pastoralist community. METHODS: Febrile patients ≥2 years old presenting to Endulen Hospital in the Ngorongoro Conservation Area were enrolled from August 2016 through October 2017. Acute and convalescent blood samples were collected, and a questionnaire was administered. Sera were tested by immunofluorescent antibody (IFA) IgG assays using Coxiella burnetii (Phase II), Rickettsia africae, and Rickettsia typhi antigens. Serologic evidence of exposure was defined by an IFA titre ≥1:64; probable cases by an acute IFA titre ≥1:128; and confirmed cases by a ≥4-fold rise in titre between samples. Risk factors for exposure and acute case status were evaluated. RESULTS: Of 228 participants, 99 (43.4%) were male and the median (interquartile range) age was 27 (16-41) years. Among these, 117 (51.3%) had C. burnetii exposure, 74 (32.5%) had probable Q fever, 176 (77.2%) had SFG Rickettsia exposure, 134 (58.8%) had probable SFG rickettsioses, 11 (4.8%) had TG Rickettsia exposure, and 4 (1.8%) had probable TG rickettsioses. Of 146 participants with paired sera, 1 (0.5%) had confirmed Q fever, 8 (5.5%) had confirmed SFG rickettsioses, and none had confirmed TG rickettsioses. Livestock slaughter was associated with acute Q fever (adjusted odds ratio [OR] 2.54, 95% confidence interval [CI] 1.38-4.76) and sheep slaughter with SFG rickettsioses case (OR 4.63, 95% CI 1.08-23.50). DISCUSSION: Acute Q fever and SFG rickettsioses were detected in participants with febrile illness. Exposures to C. burnetii and to SFG Rickettsia were highly prevalent, and interactions with livestock were associated with increased odds of illness with both pathogens. Further characterisation of the burden and risks for these diseases is warranted.


Asunto(s)
Fiebre Q , Infecciones por Rickettsia , Rickettsiosis Exantemáticas , Humanos , Tanzanía/epidemiología , Fiebre Q/epidemiología , Masculino , Factores de Riesgo , Femenino , Adulto , Adolescente , Prevalencia , Rickettsiosis Exantemáticas/epidemiología , Rickettsiosis Exantemáticas/microbiología , Adulto Joven , Persona de Mediana Edad , Niño , Infecciones por Rickettsia/epidemiología , Infecciones por Rickettsia/microbiología , Animales , Rickettsia/inmunología , Rickettsia/aislamiento & purificación , Preescolar , Coxiella burnetii/inmunología , Anciano , Zoonosis/microbiología
9.
Ann Allergy Asthma Immunol ; 132(6): 759-764.e2, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38341029

RESUMEN

BACKGROUND: Alpha-gal syndrome (AGS) is an allergy to galactose-α-1,3-galactose (alpha-gal), a carbohydrate found in most mammals. Evidence indicates that AGS develops after a tick bite, and in the United States, AGS is most associated with bites from Amblyomma americanum (lone star tick); however, not all persons bitten by ticks develop clinical AGS. OBJECTIVE: To investigate intrinsic risk factors associated with the development of AGS. METHODS: We performed a case-control study among adults presenting for diagnosis or management of AGS at an allergy clinic in North Carolina during 2019 to 2020 and compared them with controls enrolled from 2 nearby internal medicine clinics. A questionnaire gathered epidemiologic and tick exposure data, and blood was obtained for alpha-gal-specific IgE and other testing. RESULTS: The 82 enrolled case patients and 191 controls did not differ significantly by age or sex. Case patients were more likely than controls to have A or O blood types (non B-antigen), have experienced childhood allergies, and have a family history of AGS and other food allergies. Case patients were also more likely to report experiencing long healing times for insect bites or stings and a family history of allergy to stinging or biting insects. CONCLUSION: This study suggested that intrinsic factors contribute to risk of developing AGS. Some traits are genetic, but common behaviors among households and family units likely also contribute. Identification of these risk factors can inform personal risk, aid health care providers in understanding susceptible populations, and contribute to ongoing understanding of AGS epidemiology.


Asunto(s)
Hipersensibilidad a los Alimentos , Mordeduras de Garrapatas , Humanos , Estudios de Casos y Controles , Femenino , Masculino , Factores de Riesgo , Persona de Mediana Edad , Adulto , Hipersensibilidad a los Alimentos/epidemiología , Mordeduras de Garrapatas/epidemiología , Mordeduras de Garrapatas/inmunología , Animales , Anciano , Inmunoglobulina E/sangre , Inmunoglobulina E/inmunología , North Carolina/epidemiología , Amblyomma/inmunología , Adulto Joven , Adolescente
10.
Allergy ; 78(2): 477-487, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36178236

RESUMEN

BACKGROUND: Alpha-gal syndrome (AGS) is an IgE-mediated allergy to galactose-alpha-1,3-galactose. Clinical presentation ranges from hives to anaphylaxis; episodes typically occur 2-6 h after exposure to alpha-gal-containing products. In the United States, lone star tick bites are associated with the development of AGS. To characterize features of AGS, we evaluated a cohort of patients presenting for care at the University of North Carolina, focusing on symptoms, severity, and identifying features unique to specific alpha-gal-containing product exposures. METHODS: We performed a chart review and descriptive analysis of 100 randomly selected patients with AGS during 2010-2019. RESULTS: Median age at onset was 53 years, 56% were female, 95% reported White race, 86% reported a history of tick bite, and 75% met the criteria for anaphylaxis based on the involvement of ≥2 organ systems. Those reporting dairy reactions were significantly less likely to report isolated mucocutaneous symptoms (3% vs. 24%; ratio [95% CI]: 0.1 [0.1, 0.3]) than those who tolerated dairy, and were more likely to report gastrointestinal symptoms (79% vs. 59%; ratio [95% CI]: 1.3 [0.7, 2.6]), although this difference was not statistically significant. Dairy-tolerant patients demonstrated higher alpha-gal sIgE titers (as a percentage of total IgE) than dairy-reactive patients (GM 4.1 [95% CI: 2.7, 6.1] vs. GM 2.5 [95% CI: 1.3, 4.8], respectively; ratio -1.6 [95% CI: -1.0, 3.9]). CONCLUSION: While tick exposure is common in the southern United States, nearly all AGS patients reported a tick bite. Gastrointestinal symptoms were prominent among those reporting reactions to dairy. Anaphylaxis was common, underscoring the severity and need to raise awareness of AGS among patients and providers.


Asunto(s)
Anafilaxia , Hipersensibilidad a los Alimentos , Mordeduras de Garrapatas , Humanos , Femenino , Masculino , Anafilaxia/diagnóstico , Anafilaxia/epidemiología , Anafilaxia/etiología , Mordeduras de Garrapatas/complicaciones , Galactosa , Alérgenos , Inmunoglobulina E , Hipersensibilidad a los Alimentos/diagnóstico , Hipersensibilidad a los Alimentos/epidemiología , Hipersensibilidad a los Alimentos/complicaciones
11.
MMWR Morb Mortal Wkly Rep ; 72(30): 815-820, 2023 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-37498787

RESUMEN

Alpha-gal syndrome (AGS) is an emerging, tick bite-associated allergic condition characterized by a potentially life-threatening immunoglobulin E (IgE)-mediated hypersensitivity to galactose-alpha-1,3-galactose (alpha-gal), an oligosaccharide found in most nonprimate mammalian meat and products derived from these mammals. Specific symptoms and severity of AGS vary among persons, and no treatment or cure is currently available. During 2010-2018, more than 34,000 suspected cases of AGS were identified in the United States, but current knowledge of where cases occur is limited. This study examined alpha-gal-specific IgE (sIgE) antibody testing results submitted to the commercial laboratory responsible for nearly all testing in the United States before 2022 to assess the geographic distribution and magnitude of this emerging condition. During January 1, 2017-December 31, 2022, a total of 357,119 tests were submitted from residences in the United States, corresponding to 295,400 persons. Overall, 90,018 (30.5%) persons received a positive test result in the study period, and the number of persons with positive test results increased from 13,371 in 2017 to 18,885 in 2021. Among 233,521 persons for whom geographic data were available, suspected cases predominantly occurred in counties within the southern, midwestern, and mid-Atlantic U.S. Census Bureau regions. These data highlight the evolving emergence of AGS and can be used to help state and local health agencies initiate surveillance and target public health outreach and health care provider education to high-risk localities.


Asunto(s)
Hipersensibilidad a los Alimentos , Mordeduras de Garrapatas , Animales , Humanos , Estados Unidos/epidemiología , Galactosa , Mordeduras de Garrapatas/epidemiología , Inmunoglobulina E , Mamíferos
12.
Ann Allergy Asthma Immunol ; 130(4): 472-478, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36574585

RESUMEN

BACKGROUND: The disaccharide galactose-α-1,3-galactose (alpha-gal) is expressed in mammals other than humans, apes, and old-world monkeys. In humans, elevated immunoglobulin E (IgE) antibodies specific for alpha-gal can result in allergic hypersensitivity known as alpha-gal syndrome (AGS). Case reports and series suggest that tick bites can induce alpha-gal-specific IgE (sIgE) antibodies. OBJECTIVE: To evaluate tick exposure as a risk factor for AGS and elevated alpha-gal sIgE level. METHODS: We conducted a case-control study comparing patients with AGS from a North Carolina allergy clinic with controls who were patients at a nearby internal medicine clinic. Cases and controls were administered a questionnaire to obtain information about demographics, home environment, outdoor activities, and recollection of tick bite. Serum samples taken at the time of enrollment were tested for total IgE, alpha-gal sIgE, and antibodies to other tick-borne pathogens. RESULTS: The patients with AGS were more likely to recall finding a tick on themselves (odds ratio [OR], 11.20; 95% confidence interval [CI], 4.97-25.15), live near wooded forest (OR, 2.27; 95% CI, 0.92-5.55), and spend 17 or more hours per week outdoors in wooded areas (OR, 5.58; 95% CI, 2.56-12.19). The patients with AGS were also more likely to report 4 or more tick bites (OR, 33.05; 95% CI, 9.92-155.12) and reactions at the site of tick bites (OR, 7.93; 95% CI, 3.74-16.80). Furthermore, elevated alpha-gal sIgE level was observed in 33% of the controls and was associated with tick exposure in the controls (OR, 4.25; 95% CI, 2.21-8.18). CONCLUSION: The results define tick bite as a risk factor for AGS and elevated alpha-gal sIgE level.


Asunto(s)
Hipersensibilidad a los Alimentos , Mordeduras de Garrapatas , Garrapatas , Animales , Humanos , Alérgenos , Estudios de Casos y Controles , Galactosa , Inmunoglobulina E , Factores de Riesgo
14.
Climacteric ; 26(3): 182-192, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37051868

RESUMEN

The sex steroid hormone estrogen plays a number of regulatory roles in female development. During menopause, estrogen synthesis in the ovaries decreases, which results in adverse physiological remodeling and increased risk of disease. Reduced bone density, changes in the community composition profiles of the gut and vaginal microbiome, mood swings and changes in the vaginal environment are to be expected during this time. To alleviate these changes, postmenopausal women can be prescribed hormone replacement therapy (HRT) through the use of exogenous estradiol, often in conjunction with progestin treatment, which re-induces estrogenic action throughout the body. The microbiome and estrogen have a bidirectional, regulatory relationship in the gut, while in the vaginal environment estrogen works indirectly on the microbiome through restoring the vaginal tissue environment that leads to microbial homeostasis. This review discusses what is known about how the gut and vaginal microbiomes of postmenopausal women are responding to HRT, and the potential future of microbe-based therapeutics for symptoms of menopause.


Asunto(s)
Microbiota , Posmenopausia , Femenino , Humanos , Posmenopausia/fisiología , Terapia de Reemplazo de Hormonas , Menopausia , Estrógenos/farmacología , Terapia de Reemplazo de Estrógeno
15.
Environ Monit Assess ; 195(8): 939, 2023 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-37436485

RESUMEN

Eelgrass cover extent is among the most reliable indicators for measuring changes in coastal ecosystems. Eelgrass has colonized the mouth of the Romaine River and has become a part of environmental monitoring there since 2013. The presence of eelgrass in this area is an essential factor for the early detection of changes in the Romaine coastal ecosystem. This will act as a trigger for an appropriate environmental response to preserve ecosystem health. In this paper, a cost- and time-efficient workflow for such spatial monitoring is proposed using a pixel-oriented k-NN algorithm. It can then be applied to multiple modellers to efficiently map the eelgrass cover. Training data were collected to define key variables for segmentation and k-NN classification, providing greater edge detection for the presence of eelgrass. The study highlights that remote sensing and training data must be acquired under similar conditions, replicating methodologies for collecting data on the ground. Similar approaches must be used for the zonal statistic requirements of the monitoring area. This will allow a more accurate and reliable assessment of eelgrass beds over time. An overall accuracy of over 90% was achieved for eelgrass detection for each year of monitoring.


Asunto(s)
Ecosistema , Zosteraceae , Monitoreo del Ambiente , Tecnología de Sensores Remotos , Aprendizaje Automático
16.
Radiology ; 303(1): 141-150, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34981978

RESUMEN

Background MR spectroscopic imaging (MRSI) allows in vivo assessment of brain metabolism and is of special interest in multiple sclerosis (MS), where morphologic MRI cannot depict major parts of disease activity. Purpose To evaluate the ability of 7.0-T MRSI to depict and visualize pathologic alterations in the normal-appearing white matter (NAWM) and cortical gray matter (CGM) in participants with MS and to investigate their relation to disability. Materials and Methods Free-induction decay MRSI was performed at 7.0 T. Participants with MS and age- and sex-matched healthy controls were recruited prospectively between January 2016 and December 2017. Metabolic ratios were obtained in white matter lesions, NAWM, and CGM regions. Subgroup analysis for MS-related disability based on Expanded Disability Status Scale (EDSS) scores was performed using analysis of covariance. Partial correlations were applied to explore associations between metabolic ratios and disability. Results Sixty-five participants with MS (mean age ± standard deviation, 34 years ± 9; 34 women) and 20 age- and sex-matched healthy controls (mean age, 32 years ± 7; 11 women) were evaluated. Higher signal intensity of myo-inositol (mI) with and without reduced signal intensity of N-acetylaspartate (NAA) was visible on metabolic images in the NAWM of participants with MS. A higher ratio of mI to total creatine (tCr) was observed in the NAWM of the centrum semiovale of all MS subgroups, including participants without disability (marginal mean ± standard error, healthy controls: 0.78 ± 0.04; EDSS 0-1: 0.86 ± 0.03 [P = .02]; EDSS 1.5-3: 0.95 ± 0.04 [P < .001]; EDSS ≥3.5: 0.94 ± 0.04 [P = .001]). A lower ratio of NAA to tCr was found in MS subgroups with disabilities, both in their NAWM (marginal mean ± standard error, healthy controls: 1.46 ± 0.04; EDSS 1.5-3: 1.33 ± 0.03 [P = .03]; EDSS ≥3.5: 1.30 ± 0.04 [P = .01]) and CGM (marginal mean ± standard error, healthy controls: 1.42 ± 0.05; EDSS ≥3.5: 1.23 ± 0.05 [P = .006]). mI/NAA correlated with EDSS (NAWM of centrum semiovale: r = 0.47, P < .001; parietal NAWM: r = 0.43, P = .002; frontal NAWM: r = 0.34, P = .01; frontal CGM: r = 0.37, P = .004). Conclusion MR spectroscopic imaging at 7.0 T allowed in vivo visualization of multiple sclerosis pathologic findings not visible at T1- or T2-weighted MRI. Metabolic abnormalities in the normal-appearing white matter and cortical gray matter were associated with disability. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Barker in this issue.


Asunto(s)
Personas con Discapacidad , Esclerosis Múltiple , Sustancia Blanca , Adulto , Encéfalo/patología , Creatina/metabolismo , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Esclerosis Múltiple/patología , Receptores de Antígenos de Linfocitos T/metabolismo , Sustancia Blanca/patología
17.
Mol Psychiatry ; 26(11): 6912-6925, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-33981006

RESUMEN

Reduced activity of the mediodorsal thalamus (MD) and abnormal functional connectivity of the MD with the prefrontal cortex (PFC) cause cognitive deficits in schizophrenia. However, the molecular basis of MD hypofunction in schizophrenia is not known. Here, we identified leucine-rich-repeat transmembrane neuronal protein 1 (LRRTM1), a postsynaptic cell-adhesion molecule, as a key regulator of excitatory synaptic function and excitation-inhibition balance in the MD. LRRTM1 is strongly associated with schizophrenia and is highly expressed in the thalamus. Conditional deletion of Lrrtm1 in the MD in adult mice reduced excitatory synaptic function and caused a parallel reduction in the afferent synaptic activity of the PFC, which was reversed by the reintroduction of LRRTM1 in the MD. Our results indicate that chronic reduction of synaptic strength in the MD by targeted deletion of Lrrtm1 functionally disengages the MD from the PFC and may account for cognitive, social, and sensorimotor gating deficits, reminiscent of schizophrenia.


Asunto(s)
Esquizofrenia , Animales , Cognición/fisiología , Proteínas de la Membrana , Ratones , Proteínas del Tejido Nervioso/genética , Corteza Prefrontal , Esquizofrenia/genética , Filtrado Sensorial , Tálamo
18.
Nature ; 539(7628): 268-271, 2016 11 10.
Artículo en Inglés | MEDLINE | ID: mdl-27732585

RESUMEN

Despite advances in hydrogen atom transfer (HAT) catalysis, there are currently no molecular HAT catalysts that are capable of homolysing the strong nitrogen-hydrogen (N-H) bonds of N-alkyl amides. The motivation to develop amide homolysis protocols stems from the utility of the resultant amidyl radicals, which are involved in various synthetically useful transformations, including olefin amination and directed carbon-hydrogen (C-H) bond functionalization. In the latter process-a subset of the classical Hofmann-Löffler-Freytag reaction-amidyl radicals remove hydrogen atoms from unactivated aliphatic C-H bonds. Although powerful, these transformations typically require oxidative N-prefunctionalization of the amide starting materials to achieve efficient amidyl generation. Moreover, because these N-activating groups are often incorporated into the final products, these methods are generally not amenable to the direct construction of carbon-carbon (C-C) bonds. Here we report an approach that overcomes these limitations by homolysing the N-H bonds of N-alkyl amides via proton-coupled electron transfer. In this protocol, an excited-state iridium photocatalyst and a weak phosphate base cooperatively serve to remove both a proton and an electron from an amide substrate in a concerted elementary step. The resultant amidyl radical intermediates are shown to promote subsequent C-H abstraction and radical alkylation steps. This C-H alkylation represents a catalytic variant of the Hofmann-Löffler-Freytag reaction, using simple, unfunctionalized amides to direct the formation of new C-C bonds. Given the prevalence of amides in pharmaceuticals and natural products, we anticipate that this method will simplify the synthesis and structural elaboration of amine-containing targets. Moreover, this study demonstrates that concerted proton-coupled electron transfer can enable homolytic activation of common organic functional groups that are energetically inaccessible using traditional HAT-based approaches.


Asunto(s)
Carbono/química , Transporte de Electrón , Hidrógeno/química , Protones , Alquenos/química , Alquilación/efectos de la radiación , Amidas/química , Aminación , Catálisis/efectos de la radiación , Iridio/química , Nitrógeno/química , Oxidación-Reducción
19.
J Prosthet Dent ; 128(4): 784-792, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33741142

RESUMEN

STATEMENT OF PROBLEM: The light source stability of digital cameras and smartphones is important in shade matching in restorative and prosthetic dentistry to communicate objectively with the dental laboratory. Techniques that standardize the light source of such devices are lacking, and this limitation can lead to color mismatches, difficulties in color communication, and treatment documentation. PURPOSE: The purpose of this clinical study was to compare the magnitude of color difference (ΔE) among 3 shade selection methods during the fabrication of ceramic crowns: visual shade selection with a shade guide, digital shade selection with a digital camera and cross-polarizing filter, and digital shade selection with a smartphone and a light-correcting device. MATERIAL AND METHODS: Forty-five patients in need of ceramic crowns were enrolled, and shade selection was evaluated according to different protocols: visual shade selection (A-D shade guide and IPS Natural Die Material Shade Guide, sent to the dental laboratory technician via a laboratory prescription); digital shade selection with a digital camera (D7000; Nikon Corp) with an 85-mm lens and wireless close-up flash, with and without a cross-polarizing filter (Polar eyes); and digital shade selection with a smartphone and a light-correcting device (iPhone XS attached to Smile Lite MDP, with and without its cross-polarizing filter accessory). Information from the smartphone was imported to an app (IPS e.max Shade Navigation App; Ivoclar AG) that converted the reading to a shade and level of translucency for the ceramic restoration. For all photographs, a gray reference card with known color values was positioned by the mandibular teeth and was used for white balancing of the digital photographs with a software program. All photographs were edited and sent to the dental laboratory: white-balanced with the shade guide; white-balanced with the substrate shade guide; black and white; saturated; and cross-polarized. Ceramic crowns were made with the same lithium disilicate material (IPS e.max CAD; Ivoclar AG) and cemented with the same resin cement (RelyX Ultimate Clicker, A3 shade; 3M). The ΔE values between the crown and the adjacent tooth were determined. The data were analyzed by using a 1-way analysis of variance (ANOVA) and Tukey post hoc tests (α=.05). RESULTS: The mean ΔE between a cemented ceramic crown and the adjacent tooth in the visual shade selection group was 5.32, significantly different than both digital camera (ΔE=2.75; P=.002) and smartphone (ΔE=2.34; P=.001), which were not different from each other (P=.857). CONCLUSIONS: The digital shade selection with photographs acquired with both a digital camera and a smartphone with a light-correcting device showed a threshold within the acceptable values (ΔE<3.7), whereas the visual shade selection showed an average ΔE above the threshold for acceptable values (ΔE>3.7). The use of a gray reference card helped standardize the white balance from the digital images.


Asunto(s)
Porcelana Dental , Teléfono Inteligente , Humanos , Color , Coronas , Cementos de Resina , Cerámica
20.
J Vasc Surg ; 74(4): 1301-1308.e1, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-33887424

RESUMEN

OBJECTIVE: Significant physiologic perturbations can occur in patients with chronic mesenteric ischemia (CMI) undergoing open mesenteric bypass (OMB). These events have frequently been attributed to ischemia-reperfusion events and have been directly implicated in the occurrence of multiple organ dysfunction (MOD). Scoring systems (MOD score [MODS] and sequential organ failure assessment [SOFA]) have been derived within the critical care field to provide a composite metric for these pathophysiologic changes. The purpose of the present study was to describe the early pathophysiologic changes that occur after OMB for CMI and determine whether these are predictive of the outcomes. METHODS: Patients with CMI who had undergone elective OMB from 2002 to 2018 at a single institution were reviewed. Changes in the hemodynamic, pulmonary, hepatic, renal, and hematologic parameters in the first 96 hours postoperatively were analyzed. The MODSs and SOFA scores were calculated. Cox regression was used to determine the association of the MODSs and SOFA scores with the outcomes. RESULTS: The use of OMB was analyzed for 72 patients (age, 66 ± 11 years; 68% women; body mass index, 23.8 ± 6 kg/m2; 48 ± 34-lb weight loss in 59%). Previous mesenteric stent placement or bypass had been performed in 39% [stenting in 21; bypass in 8; (one patient had both)]. An antegrade configuration (93%) was most common (retrograde configuration, 7%), with revascularization of the superior mesenteric artery/celiac vessels in 85% (superior mesenteric artery only in 15%). Postoperative pathophysiologic and metabolic changes were common, and the mean MODSs and SOFA scores were 3.6 ± 2.4 (range, 1-10) and 4.0 ± 2.7 (range, 1-13), respectively. The median length of stay was 14 days (interquartile range, 9-21). The 30-day mortality was 4% (n = 3) and in-hospital morbidity was 53% (n = 38; gastrointestinal, 25%; infectious, 22%; cardiac, 18%; pulmonary, 18%; renal, 11%). The clinical follow-up period was 16 ± 20 months. The MODSs and SOFA scores correlated linearly with overall mortality (MODS: odds ratio [OR], 1.4; 95% confidence interval [CI], 1.2-1.7; P < .01; SOFA score: OR, 1.4; 95% CI, 1.2-1.7; P < .01 per unit), with a score of ≥5 the inflection point most predictive of mortality (MODS: OR, 3.9; 95% CI, 1.6-9.9; P ≤ .01; SOFA score: OR, 2.8; 95% CI, 1.2-6.6; P = .02). The 1- and 3-year primary bypass patency and freedom from reintervention was 91% ± 5% and 83% ± 7%, respectively, with no association with the MODSs or SOFA scores. The 1- and 3-year survival was 86% ± 4% and 71% ± 6% with significantly worse outcomes for patients with higher MODSs and/or SOFA scores. CONCLUSIONS: Most CMI patients undergoing OMB will experience significant metabolic derangements resulting from sequelae of the ischemia-reperfusion phenomenon postoperatively. These can be objectively assessed in the early postoperative period using simply applied scoring systems to reliably predict the early and long-term outcomes. A derivation of the MODS and/or SOFA score after OMB for CMI can identify the most vulnerable patients at the greatest risk of mortality.


Asunto(s)
Hemodinámica , Isquemia Mesentérica/cirugía , Daño por Reperfusión/etiología , Circulación Esplácnica , Procedimientos Quirúrgicos Vasculares/efectos adversos , Anciano , Enfermedad Crónica , Bases de Datos Factuales , Metabolismo Energético , Femenino , Humanos , Masculino , Isquemia Mesentérica/diagnóstico por imagen , Isquemia Mesentérica/mortalidad , Isquemia Mesentérica/fisiopatología , Persona de Mediana Edad , Insuficiencia Multiorgánica/etiología , Puntuaciones en la Disfunción de Órganos , Daño por Reperfusión/diagnóstico , Daño por Reperfusión/mortalidad , Daño por Reperfusión/fisiopatología , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Grado de Desobstrucción Vascular , Procedimientos Quirúrgicos Vasculares/mortalidad
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