345 research outputs found
Racial and ethnic disparities in cervical cancer screening from three U.S. healthcare settings
INTRODUCTION: This study sought to characterize racial and ethnic disparities in cervical cancer screening and follow-up of abnormal findings across 3 U.S. healthcare settings.
METHODS: Data were from 2016 to 2019 and were analyzed in 2022, reflecting sites within the Multi-level Optimization of the Cervical Cancer Screening Process in Diverse Settings & Populations Research Center, part of the Population-based Research to Optimize the Screening Process consortium, including a safety-net system in the southwestern U.S., a northwestern mixed-model system, and a northeastern integrated healthcare system. Screening uptake was evaluated among average-risk patients (i.e., no previous abnormalities) by race and ethnicity as captured in the electronic health record, using chi-square tests. Among patients with abnormal findings requiring follow-up, the proportion receiving colposcopy or biopsy within 6 months was reported. Multivariable regression was conducted to assess how clinical, socioeconomic, and structural characteristics mediate observed differences.
RESULTS: Among 188,415 eligible patients, 62.8% received cervical cancer screening during the 3-year study period. Screening use was lower among non-Hispanic Black patients (53.2%) and higher among Hispanic (65.4%,) and Asian/Pacific Islander (66.5%) than among non-Hispanic White patients (63.5%, all p\u3c0.001). Most differences were explained by the distribution of patients across sites and differences in insurance. Hispanic patients remained more likely to screen after controlling for a variety of clinical and sociodemographic factors (risk ratio=1.14, CI=1.12, 1.16). Among those receiving any screening test, Black and Hispanic patients were more likely to receive Pap-only testing (versus receiving co-testing). Follow-up from abnormal results was low for all groups (72.5%) but highest among Hispanic participants (78.8%, p\u3c0.001).
CONCLUSIONS: In a large cohort receiving care across 3 diverse healthcare settings, cervical cancer screening and follow-up were below 80% coverage targets. Lower screening for Black patients was attenuated by controlling for insurance and site of care, underscoring the role of systemic inequity. In addition, it is crucial to improve follow-up after abnormalities are identified, which was low for all populations
Free-electron interaction with nonlinear optical states in microresonators
The short de Broglie wavelength and strong interaction empower free electrons
to probe scattering and excitations in materials and resolve the structure of
biomolecules. Recent advances in using nanophotonic structures to mediate
bilinear electron-photon interaction have brought novel optical manipulation
schemes to electron beams, enabling high space-time-energy resolution electron
microscopy, quantum-coherent optical modulation, attosecond metrology and pulse
generation, transverse electron wavefront shaping, dielectric laser
acceleration, and electron-photon pair generation. However, photonic
nanostructures also exhibit nonlinearities, which have to date not been
exploited for electron-photon interactions. Here, we report the interaction of
electrons with spontaneously generated Kerr nonlinear optical states inside a
continuous-wave driven photonic chip-based microresonator. Optical parametric
processes give rise to spatiotemporal pattern formation, or dissipative
structures, corresponding to coherent or incoherent optical frequency combs. By
coupling such microcombs in situ to electron beams, we demonstrate that
different dissipative structures induce distinct fingerprints in the electron
spectra and Ramsey-type interference patterns. In particular, using
spontaneously formed femtosecond temporal solitons, we achieve ultrafast
temporal gating of the electron beam without the necessity of a pulsed laser
source or a pulsed electron source. Our work elucidates the interaction of free
electrons with a variety of nonlinear dissipative states, demonstrates the
ability to access solitons inside an electron microscope, and extends the use
of microcombs to unexplored territories, with ramifications in novel ultrafast
electron microscopy, light-matter interactions driven by on-chip temporal
solitons, and ultra-high spatiotemporal resolution sampling of nonlinear
optical dynamics and devices
Mapping evolutionary process: a multi-taxa approach to conservation prioritization
Human-induced land use changes are causing extensive habitat fragmentation. As a result, many species are not able to shift their ranges in response to climate change and will likely need to adapt in situ to changing climate conditions. Consequently, a prudent strategy to maintain the ability of populations to adapt is to focus conservation efforts on areas where levels of intraspecific variation are high. By doing so, the potential for an evolutionary response to environmental change is maximized. Here, we use modeling approaches in conjunction with environmental variables to model species distributions and patterns of genetic and morphological variation in seven Ecuadorian amphibian, bird, and mammal species. We then used reserve selection software to prioritize areas for conservation based on intraspecific variation or species-level diversity. Reserves selected using species richness and complementarity showed little overlap with those based on genetic and morphological variation. Priority areas for intraspecific variation were mainly located along the slopes of the Andes and were largely concordant among species, but were not well represented in existing reserves. Our results imply that in order to maximize representation of intraspecific variation in reserves, genetic and morphological variation should be included in conservation prioritization
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Multi-ancestry study of blood lipid levels identifies four loci interacting with physical activity.
Many genetic loci affect circulating lipid levels, but it remains unknown whether lifestyle factors, such as physical activity, modify these genetic effects. To identify lipid loci interacting with physical activity, we performed genome-wide analyses of circulating HDL cholesterol, LDL cholesterol, and triglyceride levels in up to 120,979 individuals of European, African, Asian, Hispanic, and Brazilian ancestry, with follow-up of suggestive associations in an additional 131,012 individuals. We find four loci, in/near CLASP1, LHX1, SNTA1, and CNTNAP2, that are associated with circulating lipid levels through interaction with physical activity; higher levels of physical activity enhance the HDL cholesterol-increasing effects of the CLASP1, LHX1, and SNTA1 loci and attenuate the LDL cholesterol-increasing effect of the CNTNAP2 locus. The CLASP1, LHX1, and SNTA1 regions harbor genes linked to muscle function and lipid metabolism. Our results elucidate the role of physical activity interactions in the genetic contribution to blood lipid levels
Cooperation of Sumoylated Chromosomal Proteins in rDNA Maintenance
SUMO is a posttranslational modifier that can modulate protein activities, interactions, and localizations. As the GFP-Smt3p fusion protein has a preference for subnucleolar localization, especially when deconjugation is impaired, the nucleolar role of SUMO can be the key to its biological functions. Using conditional triple SUMO E3 mutants, we show that defects in sumoylation impair rDNA maintenance, i.e., the rDNA segregation is defective and the rDNA copy number decreases in these mutants. Upon characterization of sumoylated proteins involved in rDNA maintenance, we established that Top1p and Top2p, which are sumoylated by Siz1p/Siz2p, most likely collaborate with substrates of Mms21p to maintain rDNA integrity. Cohesin and condensin subunits, which both play important roles in rDNA stability and structures, are potential substrates of Mms21, as their sumoylation depends on Mms21p, but not Siz1p and Siz2p. In addition, binding of cohesin and condensin to rDNA is altered in the mms21-CH E3-deficient mutant
Early cellular signaling responses to axonal injury
<p>Abstract</p> <p>Background</p> <p>We have used optic nerve injury as a model to study early signaling events in neuronal tissue following axonal injury. Optic nerve injury results in the selective death of retinal ganglion cells (RGCs). The time course of cell death takes place over a period of days with the earliest detection of RGC death at about 48 hr post injury. We hypothesized that in the period immediately following axonal injury, there are changes in the soma that signal surrounding glia and neurons and that start programmed cell death. In the current study, we investigated early changes in cellular signaling and gene expression that occur within the first 6 hrs post optic nerve injury.</p> <p>Results</p> <p>We found evidence of cell to cell signaling within 30 min of axonal injury. We detected differences in phosphoproteins and gene expression within the 6 hrs time period. Activation of TNFα and glutamate receptors, two pathways that can initiate cell death, begins in RGCs within 6 hrs following axonal injury. Differential gene expression at 6 hrs post injury included genes involved in cytokine, neurotrophic factor signaling (Socs3) and apoptosis (Bax).</p> <p>Conclusion</p> <p>We interpret our studies to indicate that both neurons and glia in the retina have been signaled within 30 min after optic nerve injury. The signals are probably initiated by the RGC soma. In addition, signals activating cellular death pathways occur within 6 hrs of injury, which likely lead to RGC degeneration.</p
Caveolin-1 Plays a Crucial Role in Inhibiting Neuronal Differentiation of Neural Stem/Progenitor Cells via VEGF Signaling-Dependent Pathway
In the present study, we aim to elucidate the roles of caveolin-1(Cav-1), a 22 kDa protein in plasma membrane invaginations, in modulating neuronal differentiation of neural progenitor cells (NPCs). In the hippocampal dentate gyrus, we found that Cav-1 knockout mice revealed remarkably higher levels of vascular endothelial growth factor (VEGF) and the more abundant formation of newborn neurons than wild type mice. We then studied the potential mechanisms of Cav-1 in modulating VEGF signaling and neuronal differentiation in isolated cultured NPCs under normoxic and hypoxic conditions. Hypoxic embryonic rat NPCs were exposed to 1% O2 for 24 h and then switched to 21% O2 for 1, 3, 7 and 14 days whereas normoxic NPCs were continuously cultured with 21% O2. Compared with normoxic NPCs, hypoxic NPCs had down-regulated expression of Cav-1 and up-regulated VEGF expression and p44/42MAPK phosphorylation, and enhanced neuronal differentiation. We further studied the roles of Cav-1 in inhibiting neuronal differentiation by using Cav-1 scaffolding domain peptide and Cav-1-specific small interfering RNA. In both normoxic and hypoxic NPCs, Cav-1 peptide markedly down-regulated the expressions of VEGF and flk1, decreased the phosphorylations of p44/42MAPK, Akt and Stat3, and inhibited neuronal differentiation, whereas the knockdown of Cav-1 promoted the expression of VEGF, phosphorylations of p44/42MAPK, Akt and Stat3, and stimulated neuronal differentiation. Moreover, the enhanced phosphorylations of p44/42MAPK, Akt and Stat3, and neuronal differentiation were abolished by co-treatment of VEGF inhibitor V1. These results provide strong evidence to prove that Cav-1 can inhibit neuronal differentiation via down-regulations of VEGF, p44/42MAPK, Akt and Stat3 signaling pathways, and that VEGF signaling is a crucial target of Cav-1. The hypoxia-induced down-regulation of Cav-1 contributes to enhanced neuronal differentiation in NPCs
p-Glycoprotein ABCB5 and YB-1 expression plays a role in increased heterogeneity of breast cancer cells: correlations with cell fusion and doxorubicin resistance
<p>Abstract</p> <p>Background</p> <p>Cancer cells recurrently develop into acquired resistance to the administered drugs. The iatrogenic mechanisms of induced chemotherapy-resistance remain elusive and the degree of drug resistance did not exclusively correlate with reductions of drug accumulation, suggesting that drug resistance may involve additional mechanisms. Our aim is to define the potential targets, that makes drug-sensitive MCF-7 breast cancer cells turn to drug-resistant, for the anti-cancer drug development against drug resistant breast cancer cells.</p> <p>Methods</p> <p>Doxorubicin resistant human breast MCF-7 clones were generated. The doxorubicin-induced cell fusion events were examined. Heterokaryons were identified and sorted by FACS. In the development of doxorubicin resistance, cell-fusion associated genes, from the previous results of microarray, were verified using dot blot array and quantitative RT-PCR. The doxorubicin-induced expression patterns of pro-survival and pro-apoptotic genes were validated.</p> <p>Results</p> <p>YB-1 and ABCB5 were up regulated in the doxorubicin treated MCF-7 cells that resulted in certain degree of genomic instability that accompanied by the drug resistance phenotype. Cell fusion increased diversity within the cell population and doxorubicin resistant MCF-7 cells emerged probably through clonal selection. Most of the drug resistant hybrid cells were anchorage independent. But some of the anchorage dependent MCF-7 cells exhibited several unique morphological appearances suggesting minor population of the fused cells maybe de-differentiated and have progenitor cell like characteristics.</p> <p>Conclusion</p> <p>Our work provides valuable insight into the drug induced cell fusion event and outcome, and suggests YB-1, GST, ABCB5 and ERK3 could be potential targets for the anti-cancer drug development against drug resistant breast cancer cells. Especially, the ERK-3 serine/threonine kinase is specifically up-regulated in the resistant cells and known to be susceptible to synthetic antagonists.</p
Cerebral Palsy:Early Markers of Clinical Phenotype and Functional Outcome
The Prechtl General Movement Assessment (GMA) has become a cornerstone assessment in early identification of cerebral palsy (CP), particularly during the fidgety movement period at 3-5 months of age. Additionally, assessment of motor repertoire, such as antigravity movements and postural patterns, which form the Motor Optimality Score (MOS), may provide insight into an infant's later motor function. This study aimed to identify early specific markers for ambulation, gross motor function (using the Gross Motor Function Classification System, GMFCS), topography (unilateral, bilateral), and type (spastic, dyskinetic, ataxic, and hypotonic) of CP in a large worldwide cohort of 468 infants. We found that 95% of children with CP did not have fidgety movements, with 100% having non-optimal MOS. GMFCS level was strongly correlated to MOS. An MOS > 14 was most likely associated with GMFCS outcomes I or II, whereas GMFCS outcomes IV or V were hardly ever associated with an MOS > 8. A number of different movement patterns were associated with more severe functional impairment (GMFCS III-V), including atypical arching and persistent cramped-synchronized movements. Asymmetrical segmental movements were strongly associated with unilateral CP. Circular arm movements were associated with dyskinetic CP. This study demonstrated that use of the MOS contributes to understanding later CP prognosis, including early markers for type and severity
Population Structure of Hispanics in the United States: The Multi-Ethnic Study of Atherosclerosis
Using ∼60,000 SNPs selected for minimal linkage disequilibrium, we perform population structure analysis of 1,374 unrelated Hispanic individuals from the Multi-Ethnic Study of Atherosclerosis (MESA), with self-identification corresponding to Central America (n = 93), Cuba (n = 50), the Dominican Republic (n = 203), Mexico (n = 708), Puerto Rico (n = 192), and South America (n = 111). By projection of principal components (PCs) of ancestry to samples from the HapMap phase III and the Human Genome Diversity Panel (HGDP), we show the first two PCs quantify the Caucasian, African, and Native American origins, while the third and fourth PCs bring out an axis that aligns with known South-to-North geographic location of HGDP Native American samples and further separates MESA Mexican versus Central/South American samples along the same axis. Using k-means clustering computed from the first four PCs, we define four subgroups of the MESA Hispanic cohort that show close agreement with self-identification, labeling the clusters as primarily Dominican/Cuban, Mexican, Central/South American, and Puerto Rican. To demonstrate our recommendations for genetic analysis in the MESA Hispanic cohort, we present pooled and stratified association analysis of triglycerides for selected SNPs in the LPL and TRIB1 gene regions, previously reported in GWAS of triglycerides in Caucasians but as yet unconfirmed in Hispanic populations. We report statistically significant evidence for genetic association in both genes, and we further demonstrate the importance of considering population substructure and genetic heterogeneity in genetic association studies performed in the United States Hispanic population
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