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1.
Artículo en Inglés | MEDLINE | ID: mdl-38588764

RESUMEN

Colorectal cancer (CRC) is the third most common cancer in the United States.1 Although CRC incidence has declined in individuals >50 years, incidence is rising in adults <50 years (early onset).1 By 2027, CRC is projected to become the leading cause of cancer mortality in US adults <50 years.2 To combat the rising incidence of early onset CRC (EOCRC), national guidelines recently lowered the screening age from 50 to 45 years for average-risk individuals.3 Understanding the risk profile of EOCRC can help combat the rising burden in young adults, especially in those ineligible for screening.

2.
Neuroendocrinology ; 114(2): 120-133, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37690447

RESUMEN

Practice of neuroendocrine neoplasms (NENs) of the digestive tract, which comprise of a highly diverse group of tumors with a rising incidence, faces multiple biological, diagnostic, and therapeutic issues. Part of these issues is due to misuse and misinterpretation of the classification and terminology of NENs of the digestive tract, which make it increasingly challenging to evaluate and compare the literature. For instance, grade 3 neuroendocrine tumors (NETs) are frequently referred to as neuroendocrine carcinomas (NECs) and vice versa, while NECs are, by definition, high grade and therefore constitute a separate entity from NETs. Moreover, the term NET is regularly misused to describe NENs in general, and NETs are frequently referred to as benign, while they should always be considered malignancies as they do have metastatic potential. To prevent misconceptions in future NEN-related research, we reviewed the most recent terminology used to classify NENs of the digestive tract and created an overview that combines the classification of these NENs according to the World Health Organization (WHO) with location- and functionality-based classifications. This overview may help clinicians and researchers in understanding the current literature and could serve as a guide in the clinic as well as for writing future studies on NENs of the digestive tract. In this way, we aim for the universal use of terminology, thereby providing an efficient foundation for future NEN-related research.


Asunto(s)
Carcinoma Neuroendocrino , Tumores Neuroendocrinos , Neoplasias Pancreáticas , Humanos , Tumores Neuroendocrinos/patología , Carcinoma Neuroendocrino/patología , Organización Mundial de la Salud , Tracto Gastrointestinal/patología , Neoplasias Pancreáticas/patología
3.
J Surg Oncol ; 129(4): 820-826, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38151827

RESUMEN

BACKGROUND: Lynch syndrome (LS) is an autosomal dominant genetic predisposition to multiple malignancies and is characterized by deficient DNA mismatch repair. Increased incidence of sarcomas is not formally ascribed to LS; however, increasing evidence suggests a preponderance of these malignancies in affected families. Sarcomas typically possess a low tumor mutational burden and incite a poor immune infiltrate, thereby rendering them poorly responsive to immunotherapy. METHODS: We searched the University of California, Los Angeles (UCLA) sarcoma program database for patients with a diagnosis of sarcoma and LS from 2016 to 2023. Three such patients were identified and all three were treated with PD1 blockade. RESULTS: We present three cases of LS-associated sarcomas (two soft tissue sarcoma and one osteosarcoma) with increased tumor mutational burdens. These patients were each treated with an anti-PD1 antibody and experienced a response far superior to that reported for non-LS-associated sarcomas. CONCLUSIONS: Increased mutational burden and immune infiltrate are observed for sarcomas associated with LS. Although unselected patients with sarcoma have demonstrated poor response rates to immunotherapy, our findings suggest that patients with Lynch-associated sarcomas are more likely to respond to treatment with anti-PD1. These patients should be given consideration for immunotherapy.


Asunto(s)
Neoplasias Colorrectales Hereditarias sin Poliposis , Sarcoma , Neoplasias de los Tejidos Blandos , Humanos , Neoplasias Colorrectales Hereditarias sin Poliposis/genética , Neoplasias Colorrectales Hereditarias sin Poliposis/terapia , Neoplasias Colorrectales Hereditarias sin Poliposis/diagnóstico , Sarcoma/genética , Sarcoma/terapia , Sarcoma/patología , Biomarcadores de Tumor/genética , Inmunoterapia , Reparación de la Incompatibilidad de ADN
4.
Proc Natl Acad Sci U S A ; 118(7)2021 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-33574061

RESUMEN

In mammals with frontal eyes, optic-nerve fibers from nasal retina project to the contralateral hemisphere of the brain, and fibers from temporal retina project ipsilaterally. The division between crossed and uncrossed projections occurs at or near the vertical meridian. If the division was precise, a problem would arise. Small objects near midline, but nearer or farther than current fixation, would produce signals that travel to opposite hemispheres, making the binocular disparity of those objects difficult to compute. However, in species that have been studied, the division is not precise. Rather, there are overlapping crossed and uncrossed projections such that some fibers from nasal retina project ipsilaterally as well as contralaterally and some from temporal retina project contralaterally as well as ipsilaterally. This increases the probability that signals from an object near vertical midline travel to the same hemisphere, thereby aiding disparity estimation. We investigated whether there is a deficit in binocular vision near the vertical meridian in humans and found no evidence for one. We also investigated the effectiveness of the observed decussation pattern, quantified from anatomical data in monkeys and humans. We used measurements of naturally occurring disparities in humans to determine disparity distributions across the visual field. We then used those distributions to calculate the probability of natural disparities transmitting to the same hemisphere, thereby aiding disparity computation. We found that the pattern of overlapping projections is quite effective. Thus, crossed and uncrossed projections from the retinas are well designed for aiding disparity estimation and stereopsis.


Asunto(s)
Adaptación Fisiológica , Percepción de Profundidad , Retina/fisiología , Percepción Visual , Adulto , Animales , Encéfalo/fisiología , Ambiente , Humanos , Macaca mulatta , Masculino , Vías Visuales/fisiología
5.
Int J Paediatr Dent ; 2024 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-38736091

RESUMEN

BACKGROUND: Referrals of paediatric patients to a university clinic have been increasing over the last several years. AIM: To evaluate characteristics of referred and non-referred patients at the University of Iowa's Pediatric Dental Clinic (UIPDC). DESIGN: A retrospective chart review included dental records of 340 referred and 383 non-referred patients from July 1, 2015, to May 31, 2016 (n = 723). Age, distance to the clinic, size of the patient's community, insurance, number of teeth with decay, treatment needs, educational level of the provider, and presence of patient special health care needs were obtained. Descriptive statistics, bivariate analysis, and multivariable logistic regression were performed to analyze the outcomes (alpha = .05). RESULTS: Referred patients were more likely to live >60 miles away, live in a community of >75 000 people, have special health care needs, have caries/greater number of teeth with decay, need endodontic treatment, and were less likely to remain patients at the clinic (p < .0001). Referred patients were also more likely to need extractions (p = .0104), but less likely to need space maintenance/comprehensive orthodontic treatment (p = .0002). CONCLUSION: There was a difference in the complexity of patient treatment needs between referred and non-referred patients.

6.
J Neurosci ; 2022 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-35853720

RESUMEN

Individual differences among human brains exist at many scales, spanning gene expression, white matter tissue properties, and the size and shape of cortical areas. One notable example is an approximately 3-fold range in the size of human primary visual cortex (V1), a much larger range than is found in overall brain size. A previous study (Andrews et al., 1997) reported a correlation between optic tract cross-section area and V1 size in post-mortem human brains, suggesting that there may be a common developmental mechanism for multiple components of the visual pathways. We evaluated the relationship between properties of the optic tract and V1 in a much larger sample of living human brains by analyzing the Human Connectome Project 7 Tesla Retinotopy Dataset (including 107 females and 71 males). This dataset includes retinotopic maps measured with functional MRI (fMRI) and fiber tract data measured with diffusion MRI (dMRI). We found a negative correlation between optic tract fractional anisotropy and V1 surface area (r = -0.19). This correlation, though small, was consistent across multiple dMRI datasets differing in acquisition parameters. Further, we found that both V1 size and optic tract properties were correlated among twins, with higher correlations for monozygotic than dizygotic twins, indicating a high degree of heritability for both properties. Together, these results demonstrate covariation across individuals in properties of the retina (optic tract) and cortex (V1) and show that each is influenced by genetic factors.SIGNIFICANCE STATEMENT:The size of human primary visual cortex (V1) has large inter-individual differences. These differences do not scale with overall brain size. A previous post-mortem study reported a correlation between the size of the human optic tract and V1. In this study, we evaluated the relationship between the optic tract and V1 in living humans by analyzing a neuroimaging dataset that included functional and diffusion MRI data. We found a small, but robust correlation between optic tract tissue properties and V1 size, supporting the existence of structural covariance between the optic tract and V1 in living humans. The results suggest that characteristics of retinal ganglion cells, reflected in optic tract measurements, are related to individual differences in human V1.

7.
J Neurosci ; 42(46): 8629-8646, 2022 11 16.
Artículo en Inglés | MEDLINE | ID: mdl-36180226

RESUMEN

How variable is the functionally defined structure of early visual areas in human cortex and how much variability is shared between twins? Here we quantify individual differences in the best understood functionally defined regions of cortex: V1, V2, V3. The Human Connectome Project 7T Retinotopy Dataset includes retinotopic measurements from 181 subjects (109 female, 72 male), including many twins. We trained four "anatomists" to manually define V1-V3 using retinotopic features. These definitions were more accurate than automated anatomical templates and showed that surface areas for these maps varied more than threefold across individuals. This threefold variation was little changed when normalizing visual area size by the surface area of the entire cerebral cortex. In addition to varying in size, we find that visual areas vary in how they sample the visual field. Specifically, the cortical magnification function differed substantially among individuals, with the relative amount of cortex devoted to central vision varying by more than a factor of 2. To complement the variability analysis, we examined the similarity of visual area size and structure across twins. Whereas the twin sample sizes are too small to make precise heritability estimates (50 monozygotic pairs, 34 dizygotic pairs), they nonetheless reveal high correlations, consistent with strong effects of the combination of shared genes and environment on visual area size. Collectively, these results provide the most comprehensive account of individual variability in visual area structure to date, and provide a robust population benchmark against which new individuals and developmental and clinical populations can be compared.SIGNIFICANCE STATEMENT Areas V1, V2, and V3 are among the best studied functionally defined regions in human cortex. Using the largest retinotopy dataset to date, we characterized the variability of these regions across individuals and the similarity between twin pairs. We find that the size of visual areas varies dramatically (up to 3.5×) across healthy young adults, far more than the variability of the cerebral cortex size as a whole. Much of this variability appears to arise from inherited factors, as we find very high correlations in visual area size between monozygotic twin pairs, and lower but still substantial correlations between dizygotic twin pairs. These results provide the most comprehensive assessment of how functionally defined visual cortex varies across the population to date.


Asunto(s)
Corteza Visual , Vías Visuales , Femenino , Humanos , Masculino , Adulto Joven , Mapeo Encefálico/métodos , Imagen por Resonancia Magnética , Corteza Visual Primaria , Campos Visuales
8.
Hum Brain Mapp ; 44(8): 3123-3135, 2023 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-36896869

RESUMEN

The neural pathways that carry information from the foveal, macular, and peripheral visual fields have distinct biological properties. The optic radiations (OR) carry foveal and peripheral information from the thalamus to the primary visual cortex (V1) through adjacent but separate pathways in the white matter. Here, we perform white matter tractometry using pyAFQ on a large sample of diffusion MRI (dMRI) data from subjects with healthy vision in the U.K. Biobank dataset (UKBB; N = 5382; age 45-81). We use pyAFQ to characterize white matter tissue properties in parts of the OR that transmit information about the foveal, macular, and peripheral visual fields, and to characterize the changes in these tissue properties with age. We find that (1) independent of age there is higher fractional anisotropy, lower mean diffusivity, and higher mean kurtosis in the foveal and macular OR than in peripheral OR, consistent with denser, more organized nerve fiber populations in foveal/parafoveal pathways, and (2) age is associated with increased diffusivity and decreased anisotropy and kurtosis, consistent with decreased density and tissue organization with aging. However, anisotropy in foveal OR decreases faster with age than in peripheral OR, while diffusivity increases faster in peripheral OR, suggesting foveal/peri-foveal OR and peripheral OR differ in how they age.


Asunto(s)
Imagen de Difusión por Resonancia Magnética , Sustancia Blanca , Humanos , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Sustancia Blanca/diagnóstico por imagen , Fibras Nerviosas , Visión Ocular , Tálamo , Anisotropía , Vías Visuales/diagnóstico por imagen
9.
Cancer Causes Control ; 34(6): 495-503, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36995554

RESUMEN

PURPOSE: Cancer burden is rising rapidly in Nigeria, the most populous country in sub-Saharan Africa; this trend may in part be attributable to diet. We developed and validated a semi-quantitative food frequency questionnaire (FFQ) to assess regional diet in Nigeria. METHODS: We recruited 68 adult participants from rural and urban settings in South West Nigeria. We developed an FFQ administered at baseline and assessed its validity using 3 dietary recalls (baseline, 7 days post baseline, 3 months post baseline). We calculated Spearman's rank correlation coefficients and energy-adjusted de-attenuated correlation coefficients for food items and macronutrients. We evaluated cross-classification using quartiles of macronutrient intake. RESULTS: Energy-adjusted de-attenuated food item correlations between the FFQ and dietary recalls ranged from -0.08 (smoked beef/goat) to 0.73 (fried snacks) for the average intake from the first 2 recalls (2DR) and from -0.05 (smoked beef/goat) to 0.75 (smoked fish) for the average of all 3 recalls (3DR). Macronutrient correlations ranged from 0.15 (fat) to 0.37 (fiber) for the 2DR and from 0.08 (fat) to 0.41 (carbohydrates) for the 3DR. The percent of participants classified in the same quartile ranged from 16.4% (fat) to 32.8% (fiber, protein) for the 2DR and from 25.6% (fat) to 34.9% (carbohydrates) for the 3DR. Agreement improved when including adjacent quartiles, from 65.5% (carbohydrates) to 70.5% (fat, fiber) for the 2DR and from 62.8% (protein) to 76.8% (carbohydrate) for the 3DR. CONCLUSION: Our semi-quantitative FFQ was reasonably valid for ranking intake of certain foods and macronutrients in adults in South West Nigeria.


Asunto(s)
Ingestión de Energía , Neoplasias , Humanos , Nigeria/epidemiología , Encuestas y Cuestionarios , Encuestas sobre Dietas , Reproducibilidad de los Resultados , Dieta , Carbohidratos , Neoplasias/epidemiología , Registros de Dieta
10.
PLoS Comput Biol ; 18(1): e1009771, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-35007281

RESUMEN

Visual performance varies around the visual field. It is best near the fovea compared to the periphery, and at iso-eccentric locations it is best on the horizontal, intermediate on the lower, and poorest on the upper meridian. The fovea-to-periphery performance decline is linked to the decreases in cone density, retinal ganglion cell (RGC) density, and V1 cortical magnification factor (CMF) as eccentricity increases. The origins of polar angle asymmetries are not well understood. Optical quality and cone density vary across the retina, but recent computational modeling has shown that these factors can only account for a small percentage of behavior. Here, we investigate how visual processing beyond the cone photon absorptions contributes to polar angle asymmetries in performance. First, we quantify the extent of asymmetries in cone density, midget RGC density, and V1 CMF. We find that both polar angle asymmetries and eccentricity gradients increase from cones to mRGCs, and from mRGCs to cortex. Second, we extend our previously published computational observer model to quantify the contribution of phototransduction by the cones and spatial filtering by mRGCs to behavioral asymmetries. Starting with photons emitted by a visual display, the model simulates the effect of human optics, cone isomerizations, phototransduction, and mRGC spatial filtering. The model performs a forced choice orientation discrimination task on mRGC responses using a linear support vector machine classifier. The model shows that asymmetries in a decision maker's performance across polar angle are greater when assessing the photocurrents than when assessing isomerizations and are greater still when assessing mRGC signals. Nonetheless, the polar angle asymmetries of the mRGC outputs are still considerably smaller than those observed from human performance. We conclude that cone isomerizations, phototransduction, and the spatial filtering properties of mRGCs contribute to polar angle performance differences, but that a full account of these differences will entail additional contribution from cortical representations.


Asunto(s)
Retina/fisiología , Visión Ocular/fisiología , Corteza Visual/fisiología , Campos Visuales/fisiología , Adulto , Biología Computacional , Humanos , Células Fotorreceptoras Retinianas Conos/fisiología , Células Ganglionares de la Retina/fisiología , Máquina de Vectores de Soporte , Adulto Joven
11.
Environ Res ; 220: 115176, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36584844

RESUMEN

BACKGROUND: Ambient temperatures are projected to increase in the future due to climate change. Alzheimer's disease (AD) and Alzheimer's disease-related dementia (ADRD) affect millions of individuals and represent substantial health burdens in the US. High temperature may be a risk factor for AD/ADRD outcomes with several recent studies reporting associations between temperature and AD mortality. However, the link between heat and AD morbidity is poorly understood. METHODS: We examined short-term associations between warm-season daily ambient temperature and AD/ADRD emergency department (ED) visits for individuals aged 45 years or above during the warm season (May to October) for up to 14 years (2005-2018) in five US states: California, Missouri, North Carolina, New Jersey, and New York. Daily ZIP code-level maximum, average and minimum temperature exposures were derived from 1 km gridded Daymet products. Associations are assessed using a time-stratified case-crossover design using conditional logistic regression. RESULTS: We found consistent positive short-term effects of ambient temperature among 3.4 million AD/ADRD ED visits across five states. An increase of the 3-day cumulative temperature exposure of daily average temperature from the 50th to the 95th percentile was associated with a pooled odds ratio of 1.042 (95% CI: 1.034, 1.051) for AD/ADRD ED visits. We observed evidence of the association being stronger for patients 65-74 years of age and for ED visits that led to hospital admissions. Temperature associations were also stronger among AD/ADRD ED visits compared to ED visits for other reasons, particularly among patients aged 65-74 years. CONCLUSION: People with AD/ADRD may represent a vulnerable population affected by short-term exposure to high temperature. Our results support the development of targeted strategies to reduce heat-related AD/ADRD morbidity in the context of global warming.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Anciano , Estaciones del Año , Temperatura , Enfermedad de Alzheimer/epidemiología , Servicio de Urgencia en Hospital , Calor
12.
Br J Neurosurg ; : 1-4, 2023 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-37287223

RESUMEN

PURPOSE: We studied 571 patients with intracranial meningioma for clinical characteristics and tumor location associated with high grade meningioma (WHO II/III). MATERIALS AND METHODS: Patients were participants in a multicentre epidemiologic study of risk factors for primary brain tumors including meningioma recruited from September 2005 to November 2019. We included patients 18 or older with a recent diagnosis of a primary intracranial meningioma of any subtype (ICD9/10: 9530-0, 9531-0, 9532-0, 9537-0, 9533-0, 9534-0, 9530-0, 9538-1, 9538-3) who were enrolled at neuro-oncology and neuro-surgery clinics in the southeastern U.S. RESULTS: The median patient age was 58 years (IQR: 48-68) and the majority of patients were female (n = 415; 72.7%) and Caucasian (n = 516; 90.4%). Most patients were symptomatic (n = 460; 80.6%) and their tumours more commonly occurred in a non-skull base location (n = 298; 52.2%). A total of 86 patients (15.0%) had a WHO grade II/III meningioma. Compared to patients with WHO grade I tumours, patients with WHO II/III meningiomas were over 3-times more likely to be male (odds ratio (OR): 3.25; 95% confidence interval (CI): 1.98, 5.35) adjusting for age, race, symptomatic presentation, and skull-based location. Moreover, a WHO grade II/III meningioma was substantially less likely to be observed in asymptomatic patients (OR: 0.15, 95% CI: 0.04, 0.42), and in patients with a skull-based tumour (OR: 0.40, 95% CI: 0.24, 0.66), adjusting for other factors. Male gender, symptomatic tumour, and a non-skull base location were independently associated with WHO grade II/III meningioma. CONCLUSION: These findings may shed additional light on the underlying pathogenesis of meningioma.

13.
J Vasc Interv Radiol ; 33(6): 695-701, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35311666

RESUMEN

PURPOSE: To assess the utility of the radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, and location relative to polar lines (RENAL) nephrometry scoring system at predicting adverse events and outcomes in percutaneous microwave ablation (MWA) of renal tumors. MATERIALS AND METHODS: A retrospective review of 116 patients who underwent MWA from 2004 to 2018 at 2 large university hospitals was conducted. Patient demographics and tumor characteristics were collected. The RENAL nephrometry scores were calculated, and procedure-related adverse events were stratified into minor and major (the Society of Interventional Radiology classification of class C or higher). Technical and oncologic outcomes were based on follow-up magnetic resonance imaging and computed tomography scans after ablation. RESULTS: The mean RENAL score was 6.6 (range, 4-11), and the mean tumor size was 24 mm. Follow-up ranged between 16 and 161 weeks (median, 50 weeks; mean, 65 weeks). Oncologic control was achieved in 96% (n = 111) of patients. The major and minor adverse event rates were 8.6% (n = 10) and 17% (n = 19), respectively. The mean RENAL score for patients with recurrent and/or residual tumor (8.2 ± 2.7) was higher than that for patients without disease recurrence (6.5 ± 3.5, P = .05). However, in a multivariate analysis, the RENAL score was not found to be an independent predictor of oncologic outcomes (odds ratio, 1.548; P = .092). CONCLUSIONS: The RENAL nephrometry score has minimal utility for predicting outcomes and adverse events in MWA of renal tumors. The inconsistent nature of RENAL nephrometry scoring in percutaneous ablation procedures underscores the need for an ablation-specific risk stratification system.


Asunto(s)
Carcinoma de Células Renales , Neoplasias Renales , Carcinoma de Células Renales/cirugía , Humanos , Neoplasias Renales/diagnóstico por imagen , Neoplasias Renales/etiología , Neoplasias Renales/cirugía , Microondas/efectos adversos , Recurrencia Local de Neoplasia/cirugía , Nefrectomía/efectos adversos , Estudios Retrospectivos
14.
Inorg Chem ; 61(28): 10986-10998, 2022 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-35786924

RESUMEN

Transition-metal complexes that undergo ligand-to-metal charge transfer (LMCT) to d0 metals are of interest as possible photocatalysts due to the lack of deactivating d-d states. Herein, the synthesis and characterization of nine titanocene complexes of the formula Cp2Ti(C2Ar)2·MX (where Ar = phenyl, dimethylaniline, or triphenylamine; and MX = CuCl, CuBr, or AgCl) are presented. Solid-state structural characterization demonstrates that MX coordinates to the alkyne tweezers and CuX coordination has a greater structural impact than AgCl. All complexes, including the parent complexes without coordinated MX, are brightly emissive at 77 K (emission max between 575 and 767 nm), with the coordination of MX redshifting the emission in all cases except for the coordination of AgCl into Cp2Ti(C2Ph)2. TDDFT investigations suggest that emission is dominated by arylalkynyl-to-titanium 3LMCT in all cases except Cp2Ti(C2Ph)2·CuBr, which is dominated by CuBr-to-Ti charge transfer. In room-temperature fluid solution, only Cp2Ti(C2Ph)2 and Cp2Ti(C2Ph)2·AgCl are emissive, albeit with photoluminescent quantum yields ≤2 × 10-4. The parent complexes photodecompose in room-temperature solution with quantum yields, Φrxn, between 0.25 and 0.99. The coordination of MX decreases Φrxn by two to three orders of magnitude. There is a clear trend that Φrxn increases as the emission energy increases. This trend is consistent with a competition between energy-gap-law controlled nonradiative decay and thermally activated intersystem crossing between the 3LMCT state and the singlet transition state for decomposition.

15.
Oecologia ; 200(3-4): 385-396, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36224498

RESUMEN

Seed and soil microbiomes strongly affect plant performance, and these effects can scale-up to influence plant community structure. However, seed and soil microbial community composition are variable across landscapes, and different microbial communities can differentially influence multiple plant metrics (biomass, germination rate), and community stabilizing mechanisms. We determined how microbiomes inside seeds and in soils varied among alpine plant species and communities that differed in plant species richness and density. Across 10 common alpine plant species, we found a total of 318 bacterial and 128 fungal operational taxonomic units (OTUs) associated with seeds, with fungal richness affected by plant species identity more than sampling location. However, seed microbes had only marginally significant effects on plant germination success and timing. In contrast, soil microbes associated with two different plant species had significant effects on plant biomass, and their effect depended both on the plant species and the location the soils were sampled from. This led to significant changes in plant-soil feedback at different locations that varied in plant density and richness, such that plant-soil feedback favored plant species coexistence in some locations and opposed coexistence at other locations. Importantly, we found that coexistence-facilitating feedback was associated with low plant species richness, suggesting that soil microbes may promote the diversity of colonizing plants during the course of climate change and glacial recession.


Asunto(s)
Microbiota , Suelo , Suelo/química , Microbiología del Suelo , Plantas , Semillas
16.
Conscious Cogn ; 105: 103411, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36156359

RESUMEN

Understanding the neural basis of consciousness is a fundamental goal of neuroscience, and sensory perception is often used as a proxy for consciousness in empirical studies. However, most studies rely on reported perception of visual stimuli. Here we present behavior, high density scalp EEG and eye metric recordings collected simultaneously during a novel tactile threshold perception task. We found significant N80, N140 and P300 event related potentials in perceived trials and in perceived versus not perceived trials. Significance was limited to a P100 and P300 in not perceived trials. We also found an increase in pupil diameter and blink rate and a decrease in microsaccade rate following perceived relative to not perceived tactile stimuli. These findings support the use of eye metrics as a measure of physiological arousal associated with conscious perception. Eye metrics may also represent a novel path toward the creation of tactile no-report tasks in the future.


Asunto(s)
Estado de Conciencia , Percepción del Tacto , Estado de Conciencia/fisiología , Electroencefalografía , Humanos , Cuero Cabelludo , Tacto/fisiología , Percepción Visual/fisiología
17.
Am J Respir Crit Care Med ; 203(1): 14-23, 2021 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-33385220

RESUMEN

Rationale: Decisions in medicine are made on the basis of knowledge and reasoning, often in shared conversations with patients and families in consideration of clinical practice guideline recommendations, individual preferences, and individual goals. Observational studies can provide valuable knowledge to inform guidelines, decisions, and policy.Objectives: The American Thoracic Society (ATS) created a multidisciplinary ad hoc committee to develop a research statement to clarify the role of observational studies-alongside randomized controlled trials (RCTs)-in informing clinical decisions in pulmonary, critical care, and sleep medicine.Methods: The committee examined the strengths of observational studies assessing causal effects, how they complement RCTs, factors that impact observational study quality, perceptions of observational research, and, finally, the practicalities of incorporating observational research into ATS clinical practice guidelines.Measurements and Main Results: There are strengths and weakness of observational studies as well as RCTs. Observational studies can provide evidence in representative and diverse patient populations. Quality observational studies should be sought in the development of ATS clinical practice guidelines, and medical decision-making in general, when 1) no RCTs are identified or RCTs are appraised as being of low- or very low-quality (replacement); 2) RCTs are of moderate quality because of indirectness, imprecision, or inconsistency, and observational studies mitigate the reason that RCT evidence was downgraded (complementary); or 3) RCTs do not provide evidence for outcomes that a guideline committee considers essential for decision-making (e.g., rare or long-term outcomes; "sequential").Conclusions: Observational studies should be considered in developing clinical practice guidelines and in making clinical decisions.


Asunto(s)
Investigación Biomédica/normas , Toma de Decisiones Clínicas , Cuidados Críticos/normas , Atención a la Salud/normas , Medicina Basada en la Evidencia/normas , Estudios Observacionales como Asunto/normas , Enfermedades Torácicas/terapia , Humanos , Guías de Práctica Clínica como Asunto , Sociedades Médicas , Estados Unidos
18.
Clin Infect Dis ; 73(7): e1467-e1475, 2021 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-32964218

RESUMEN

BACKGROUND: The American Thoracic Society (ATS)/Infectious Diseases Society of America (IDSA) Community-acquired Pneumonia (CAP) guidelines were developed using systematic reviews to inform every recommendation, as suggested by the Institute of Medicine Standards for Trustworthy Guidelines. Recent studies suggest that an expert consensus-based approach, called the Convergence of Opinion on Recommendations and Evidence (CORE) process, can produce recommendations that are concordant with recommendations informed by systematic reviews. PURPOSE: The goal of the study was to evaluate the efficacy of the CORE process had it been used to develop the ATS/IDSA CAP guidelines. METHODS: Experts in CAP who were not on the guideline panel and had no knowledge of the guideline's systematic reviews or recommendations were recruited to participate in the CORE process, addressing the same questions asked by the guideline panel. Recommendations derived from the CORE process were compared to the guideline recommendations. Concordance of the course of action, strength of recommendation, and quality of evidence were determined. RESULTS: Using a threshold of 70% of experts selecting the same course of action to make a recommendation, the CORE process yielded a recommendation for 20 of 31 (65%) questions. Among the 20 CORE-derived recommendations, 19 (95%) were concordant with the guideline recommendations (kappa agreement 0.88, 95% CI .64-1.00). There was less agreement among the strength of recommendations (58%) and quality of evidence (42%). CONCLUSIONS: If the CORE process had been used, 11 systematic reviews would have been necessary rather than 31, with minimal impact on the recommended courses of action.


Asunto(s)
Infecciones Comunitarias Adquiridas , Neumonía , Infecciones Comunitarias Adquiridas/tratamiento farmacológico , Consenso , Humanos , Neumonía/tratamiento farmacológico
19.
Neuroimage ; 245: 118655, 2021 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-34687857

RESUMEN

Synchronization of neuronal responses over large distances is hypothesized to be important for many cortical functions. However, no straightforward methods exist to estimate synchrony non-invasively in the living human brain. MEG and EEG measure the whole brain, but the sensors pool over large, overlapping cortical regions, obscuring the underlying neural synchrony. Here, we developed a model from stimulus to cortex to MEG sensors to disentangle neural synchrony from spatial pooling of the instrument. We find that synchrony across cortex has a surprisingly large and systematic effect on predicted MEG spatial topography. We then conducted visual MEG experiments and separated responses into stimulus-locked and broadband components. The stimulus-locked topography was similar to model predictions assuming synchronous neural sources, whereas the broadband topography was similar to model predictions assuming asynchronous sources. We infer that visual stimulation elicits two distinct types of neural responses, one highly synchronous and one largely asynchronous across cortex.


Asunto(s)
Electroencefalografía/métodos , Magnetoencefalografía/métodos , Corteza Visual/fisiología , Adulto , Mapeo Encefálico/métodos , Simulación por Computador , Potenciales Evocados , Femenino , Humanos , Masculino , Estimulación Luminosa , Adulto Joven
20.
Neuroimage ; 244: 118609, 2021 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-34582948

RESUMEN

Population receptive field (pRF) models fit to fMRI data are used to non-invasively measure retinotopic maps in human visual cortex, and these maps are a fundamental component of visual neuroscience experiments. Here, we examined the reproducibility of retinotopic maps across two datasets: a newly acquired retinotopy dataset from New York University (NYU) (n = 44) and a public dataset from the Human Connectome Project (HCP) (n = 181). Our goal was to assess the degree to which pRF properties are similar across datasets, despite substantial differences in their experimental protocols. The two datasets simultaneously differ in their stimulus apertures, participant pool, fMRI protocol, MRI field strength, and preprocessing pipeline. We assessed the cross-dataset reproducibility of the two datasets in terms of the similarity of vertex-wise pRF estimates and in terms of large-scale polar angle asymmetries in cortical magnification. Within V1, V2, V3, and hV4, the group-median NYU and HCP vertex-wise polar angle estimates were nearly identical. Both eccentricity and pRF size estimates were also strongly correlated between the two datasets, but with a slope different from 1; the eccentricity and pRF size estimates were systematically greater in the NYU data. Next, to compare large-scale map properties, we quantified two polar angle asymmetries in V1 cortical magnification previously identified in the HCP data. The NYU dataset confirms earlier reports that more cortical surface area represents horizontal than vertical visual field meridian, and lower than upper vertical visual field meridian. Together, our findings show that the retinotopic properties of V1, V2, V3, and hV4 can be reliably measured across two datasets, despite numerous differences in their experimental design. fMRI-derived retinotopic maps are reproducible because they rely on an explicit computational model of the fMRI response. In the case of pRF mapping, the model is grounded in physiological evidence of how visual receptive fields are organized, allowing one to quantitatively characterize the BOLD signal in terms of stimulus properties (i.e., location and size). The new NYU Retinotopy Dataset will serve as a useful benchmark for testing hypotheses about the organization of visual areas and for comparison to the HCP 7T Retinotopy Dataset.


Asunto(s)
Corteza Visual/diagnóstico por imagen , Adulto , Simulación por Computador , Conectoma , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Motivación , New York , Reproducibilidad de los Resultados , Campos Visuales/fisiología
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