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1.
Proc Natl Acad Sci U S A ; 121(29): e2320962121, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-38980904

RESUMEN

Turbulent flows have been used for millennia to mix solutes; a familiar example is stirring cream into coffee. However, many energy, environmental, and industrial processes rely on the mixing of solutes in porous media where confinement suppresses inertial turbulence. As a result, mixing is drastically hindered, requiring fluid to permeate long distances for appreciable mixing and introducing additional steps to drive mixing that can be expensive and environmentally harmful. Here, we demonstrate that this limitation can be overcome just by adding dilute amounts of flexible polymers to the fluid. Flow-driven stretching of the polymers generates an elastic instability, driving turbulent-like chaotic flow fluctuations, despite the pore-scale confinement that prohibits typical inertial turbulence. Using in situ imaging, we show that these fluctuations stretch and fold the fluid within the pores along thin layers ("lamellae") characterized by sharp solute concentration gradients, driving mixing by diffusion in the pores. This process results in a [Formula: see text] reduction in the required mixing length, a [Formula: see text] increase in solute transverse dispersivity, and can be harnessed to increase the rate at which chemical compounds react by [Formula: see text]-enhancements that we rationalize using turbulence-inspired modeling of the underlying transport processes. Our work thereby establishes a simple, robust, versatile, and predictive way to mix solutes in porous media, with potential applications ranging from large-scale chemical production to environmental remediation.

2.
Artículo en Inglés | MEDLINE | ID: mdl-38902476

RESUMEN

Prostate cancer (PCa) incidence, morbidity, and mortality rates are significantly impacted by racial disparities. Despite innovative therapeutic approaches and advancements in prevention, men of African American (AA) ancestry are at a higher risk of developing PCa and have a more aggressive and metastatic form of the disease at the time of initial PCa diagnosis than other races. Research on PCa has underlined the biological and molecular basis of racial disparity and emphasized the genetic aspect as the fundamental component of racial inequality. Furthermore, the lower enrollment rate, limited access to national-level cancer facilities, and deferred treatment of AA men and other minorities are hurdles in improving the outcomes of PCa patients. This review provides the most up-to-date information on various biological and molecular contributing factors, such as the single nucleotide polymorphisms (SNPs), mutational spectrum, altered chromosomal loci, differential gene expression, transcriptome analysis, epigenetic factors, tumor microenvironment (TME), and immune modulation of PCa racial disparities. This review also highlights future research avenues to explore the underlying biological factors contributing to PCa disparities, particularly in men of African ancestry.

3.
Proc Natl Acad Sci U S A ; 119(43): e2208019119, 2022 10 25.
Artículo en Inglés | MEDLINE | ID: mdl-36256809

RESUMEN

How do growing bacterial colonies get their shapes? While colony morphogenesis is well studied in two dimensions, many bacteria grow as large colonies in three-dimensional (3D) environments, such as gels and tissues in the body or subsurface soils and sediments. Here, we describe the morphodynamics of large colonies of bacteria growing in three dimensions. Using experiments in transparent 3D granular hydrogel matrices, we show that dense colonies of four different species of bacteria generically become morphologically unstable and roughen as they consume nutrients and grow beyond a critical size-eventually adopting a characteristic branched, broccoli-like morphology independent of variations in the cell type and environmental conditions. This behavior reflects a key difference between two-dimensional (2D) and 3D colonies; while a 2D colony may access the nutrients needed for growth from the third dimension, a 3D colony inevitably becomes nutrient limited in its interior, driving a transition to unstable growth at its surface. We elucidate the onset of the instability using linear stability analysis and numerical simulations of a continuum model that treats the colony as an "active fluid" whose dynamics are driven by nutrient-dependent cellular growth. We find that when all dimensions of the colony substantially exceed the nutrient penetration length, nutrient-limited growth drives a 3D morphological instability that recapitulates essential features of the experimental observations. Our work thus provides a framework to predict and control the organization of growing colonies-as well as other forms of growing active matter, such as tumors and engineered living materials-in 3D environments.


Asunto(s)
Bacterias , Modelos Biológicos , Morfogénesis , Hidrogeles , Suelo
4.
Biophys J ; 123(8): 957-967, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38454600

RESUMEN

Many bacterial habitats-ranging from gels and tissues in the body to cell-secreted exopolysaccharides in biofilms-are rheologically complex, undergo dynamic external forcing, and have unevenly distributed nutrients. How do these features jointly influence how the resident cells grow and proliferate? Here, we address this question by studying the growth of Escherichia coli dispersed in granular hydrogel matrices with defined and highly tunable structural and rheological properties, under different amounts of external forcing imposed by mechanical shaking, and in both aerobic and anaerobic conditions. Our experiments establish a general principle: that the balance between the yield stress of the environment that the cells inhabit, σy, and the external stress imposed on the environment, σ, modulates bacterial growth by altering transport of essential nutrients to the cells. In particular, when σy<σ, the environment is easily fluidized and mixed over large scales, providing nutrients to the cells and sustaining complete cellular growth. By contrast, when σy>σ, the elasticity of the environment suppresses large-scale fluid mixing, limiting nutrient availability and arresting cellular growth. Our work thus reveals a new mechanism, beyond effects that change cellular behavior via local forcing, by which the rheology of the environment may modulate microbial physiology in diverse natural and industrial settings.


Asunto(s)
Escherichia coli , Escherichia coli/fisiología
5.
Ann Oncol ; 35(2): 183-189, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37992871

RESUMEN

BACKGROUND: Predicting relapse and overall survival (OS) in early-stage non-small-cell lung cancer (NSCLC) patients remains challenging. Therefore, we hypothesized that detection of circulating tumor DNA (ctDNA) can identify patients with increased risk of relapse and that integrating radiological tumor volume measurement along with ctDNA detectability improves prediction of outcome. PATIENTS AND METHODS: We analyzed 366 serial plasma samples from 85 patients who underwent surgical resections and assessed ctDNA using a next-generation sequencing liquid biopsy assay, and measured tumor volume using a computed tomography-based three-dimensional annotation. RESULTS: Our results showed that patients with detectable ctDNA at baseline or after treatment and patients who did not clear ctDNA after treatment had a significantly worse clinical outcome. Integrating radiological analysis allowed the stratification in risk groups prognostic of clinical outcome as confirmed in an independent cohort of 32 patients. CONCLUSIONS: Our findings suggest ctDNA and radiological monitoring could be valuable tools for guiding follow-up care and treatment decisions for early-stage NSCLC patients.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , ADN Tumoral Circulante , Neoplasias Pulmonares , Carcinoma Pulmonar de Células Pequeñas , Humanos , ADN Tumoral Circulante/genética , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/cirugía , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/cirugía , Carga Tumoral , Mutación , Recurrencia , Biomarcadores de Tumor/genética
6.
Soft Matter ; 20(24): 4795-4805, 2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38847805

RESUMEN

Bacteriophages ("phages") are viruses that infect bacteria. Since they do not actively self-propel, phages rely on thermal diffusion to find target cells-but can also be advected by fluid flows, such as those generated by motile bacteria themselves in bulk fluids. How does the flow field generated by a swimming bacterium influence how it encounters phages? Here, we address this question using coupled molecular dynamics and lattice Boltzmann simulations of flagellated bacteria swimming through a bulk fluid containing uniformly-dispersed phages. We find that while swimming increases the rate at which phages attach to both the cell body and flagellar propeller, hydrodynamic interactions strongly suppress this increase at the cell body, but conversely enhance this increase at the flagellar bundle. Our results highlight the pivotal influence of hydrodynamics on the interactions between bacteria and phages, as well as other diffusible species, in microbial environments.


Asunto(s)
Bacteriófagos , Hidrodinámica , Bacteriófagos/fisiología , Flagelos/fisiología , Bacterias/virología , Simulación de Dinámica Molecular , Acoplamiento Viral , Movimiento
7.
Soft Matter ; 20(7): 1425-1437, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38252539

RESUMEN

Obstructions influence the growth and expansion of bodies in a wide range of settings-but isolating and understanding their impact can be difficult in complex environments. Here, we study obstructed growth/expansion in a model system accessible to experiments, simulations, and theory: hydrogels swelling around fixed cylindrical obstacles with varying geometries. When the obstacles are large and widely-spaced, hydrogels swell around them and remain intact. In contrast, our experiments reveal that when the obstacles are narrow and closely-spaced, hydrogels fracture as they swell. We use finite element simulations to map the magnitude and spatial distribution of stresses that build up during swelling at equilibrium in a 2D model, providing a route toward predicting when this phenomenon of self-fracturing is likely to arise. Applying lessons from indentation theory, poroelasticity, and nonlinear continuum mechanics, we also develop a theoretical framework for understanding how the maximum principal tensile and compressive stresses that develop during swelling are controlled by obstacle geometry and material parameters. These results thus help to shed light on the mechanical principles underlying growth/expansion in environments with obstructions.

8.
Phys Rev Lett ; 131(11): 118301, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37774273

RESUMEN

Collectives of actively moving particles can spontaneously separate into dilute and dense phases-a fascinating phenomenon known as motility-induced phase separation (MIPS). MIPS is well-studied for randomly moving particles with no directional bias. However, many forms of active matter exhibit collective chemotaxis, directed motion along a chemical gradient that the constituent particles can generate themselves. Here, using theory and simulations, we demonstrate that collective chemotaxis strongly competes with MIPS-in some cases, arresting or completely suppressing phase separation, or in other cases, generating fundamentally new dynamic instabilities. We establish principles describing this competition, thereby helping to reveal and clarify the rich physics underlying active matter systems that perform chemotaxis, ranging from cells to robots.

9.
Phys Rev Lett ; 130(12): 128204, 2023 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-37027860

RESUMEN

We use a theoretical model to explore how fluid dynamics, in particular, the pressure gradient and wall shear stress in a channel, affect the deposition of particles flowing in a microfluidic network. Experiments on transport of colloidal particles in pressure-driven systems of packed beads have shown that at lower pressure drop, particles deposit locally at the inlet, while at higher pressure drop, they deposit uniformly along the direction of flow. We develop a mathematical model and use agent-based simulations to capture these essential qualitative features observed in experiments. We explore the deposition profile over a two-dimensional phase diagram defined in terms of the pressure and shear stress threshold, and show that two distinct phases exist. We explain this apparent phase transition by drawing an analogy to simple one-dimensional mass-aggregation models in which the phase transition is calculated analytically.

10.
PLoS Comput Biol ; 18(5): e1010063, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35533196

RESUMEN

The spreading of bacterial populations is central to processes in agriculture, the environment, and medicine. However, existing models of spreading typically focus on cells in unconfined settings-despite the fact that many bacteria inhabit complex and crowded environments, such as soils, sediments, and biological tissues/gels, in which solid obstacles confine the cells and thereby strongly regulate population spreading. Here, we develop an extended version of the classic Keller-Segel model of bacterial spreading via motility that also incorporates cellular growth and division, and explicitly considers the influence of confinement in promoting both cell-solid and cell-cell collisions. Numerical simulations of this extended model demonstrate how confinement fundamentally alters the dynamics and morphology of spreading bacterial populations, in good agreement with recent experimental results. In particular, with increasing confinement, we find that cell-cell collisions increasingly hinder the initial formation and the long-time propagation speed of chemotactic pulses. Moreover, also with increasing confinement, we find that cellular growth and division plays an increasingly dominant role in driving population spreading-eventually leading to a transition from chemotactic spreading to growth-driven spreading via a slower, jammed front. This work thus provides a theoretical foundation for further investigations of the influence of confinement on bacterial spreading. More broadly, these results help to provide a framework to predict and control the dynamics of bacterial populations in complex and crowded environments.


Asunto(s)
Bacterias , Fenómenos Biológicos , Modelos Biológicos
11.
Soft Matter ; 19(37): 7184-7191, 2023 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-37705404

RESUMEN

We recast the problem of hydrogel swelling under physical constraints as an energy optimization problem. We apply this approach to compute equilibrium shapes of hydrogel spheres confined within a jammed matrix of rigid beads and interpret the results to determine how confinement modifies the mechanics of swollen hydrogels. In contrast to the unconfined case, we find a spatial separation of strains within the bulk of the hydrogel as the strain becomes localized to an outer region. We also explore the contact mechanics of the gel, finding a transition from Hertzian behavior to non-Hertzian behavior as a function of swelling. Our model, implemented in the Morpho shape optimization environment and validated against an experimentally demonstrated prototypical scenario, can be applied in any dimension, readily adapted to diverse swelling scenarios and extended to use other energies in conjunction.

12.
J Fluoresc ; 2023 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-37542589

RESUMEN

In this work, we introduced a simple aggregation-induced emission enhancement (AIEE) sensor (PHCS) which can selectively detect and discriminate three environmentally and biologically imperative heavy metal ions (Cu2+, Co2+ and Hg2+) and a hazard class 1 categorized nitro-explosive picric acid (PA) in differential media. By virtue of its weak fluorescence attributes in pure organic medium owing to the synergistic operation of multiple photophysical quenching mechanisms, the molecular probe showcased highly selective 'TURN ON' fluorogenic response towards hazardous Hg2+ with a limit of detection (LOD) as low as 97 nM. Comprehensive investigation of binding mechanism throws light on the cumulative effect of probe-metal complexation induced chelation enhanced fluorescence (CHEF) effect and subsequent AIEE activation within the formed probe-metal adducts. Noteworthily, the probe (PHCS) can be readily used in real water samples for the quantitative determination of Hg2+ in a wide concentration range. In addition, the probe displayed modest colorimetric recognition performances to selectively detect and discriminate two essential heavy metal ions (Cu2+ and Co2+) with a LOD of 96 nM and 65 nM for Cu2+ and Co2+ respectively, in semi-aqueous medium. Intriguingly, based on high photoluminescence efficiency, the AIEE active nano-aggregated PHCS displayed a remarkable propensity to be used as a selective and ultra-sensitive 'TURN-OFF' fluorogenic chemosensor towards PA with LOD of 34.4 ppb in aqueous medium. Finally, we specifically shed light on the interaction of PHCS hydrosol towards PA using some unprecedented techniques, which helped uncover new photophysical insights of probe-explosive molecule interaction. We shed light on novel photophysical insights toward unique multifunctional sensory aptitude of a simple aggregation-induced emission enhancement active organic functional molecule in differential media, enabling ultra-sensitive discriminative detection of toxic heavy metal ions and explosive molecule simultaneously.

13.
J Ind Microbiol Biotechnol ; 50(1)2023 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-37989723

RESUMEN

Rhodotorula toruloides is being developed for the use in industrial biotechnology processes because of its favorable physiology. This includes its ability to produce and store large amounts of lipids in the form of intracellular lipid bodies. Nineteen strains were characterized for mating type, ploidy, robustness for growth, and accumulation of lipids on inhibitory switchgrass hydrolysate (SGH). Mating type was determined using a novel polymerase chain reaction (PCR)-based assay, which was validated using the classical microscopic test. Three of the strains were heterozygous for mating type (A1/A2). Ploidy analysis revealed a complex pattern. Two strains were triploid, eight haploid, and eight either diploid or aneuploid. Two of the A1/A2 strains were compared to their parents for growth on 75%v/v concentrated SGH. The A1/A2 strains were much more robust than the parental strains, which either did not grow or had extended lag times. The entire set was evaluated in 60%v/v SGH batch cultures for growth kinetics and biomass and lipid production. Lipid titers were 2.33-9.40 g/L with a median of 6.12 g/L, excluding the two strains that did not grow. Lipid yields were 0.032-0.131 (g/g) and lipid contents were 13.5-53.7% (g/g). Four strains had significantly higher lipid yields and contents. One of these strains, which had among the highest lipid yield in this study (0.131 ± 0.007 g/g), has not been previously described in the literature. SUMMARY: The yeast Rhodotorula toruloides was used to produce oil using sugars extracted from a bioenergy grass.


Asunto(s)
Rhodotorula , Azúcares , Lípidos , Biomasa , Rhodotorula/genética , Ploidias
14.
Altern Ther Health Med ; 29(4): 102-109, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-34653025

RESUMEN

Context: Acceptance of chiropractic services as an effective therapy for neck or back pain has been well established with randomized controlled trials (RCTs); however, there have been limited observations made on the treatment frequency patterns seen in the real world. Objective: The purpose of this study is to identify chiropractic users with neck or back pain who did not meet recommended treatment frequency guidelines and examine their demographics and chiropractic costs. Design: In this cross-sectional retrospective study, the nationally representative 2017 Medical Expenditure Panel Survey database was used. Setting: This study used nationally representative US survey data. Participants: Inclusion criteria were adults aged 18 years and older with a diagnosis of neck or back pain with one or more chiropractic visits in 2017. Outcomes Measures: Chiropractic utilization was categorized as concordant or discordant with treatment frequency guidelines; concordant was defined as 5 or more visits to a chiropractor within any 2-month time frame or at least 12 total visits during the year. Discordant was defined as circumstances not meeting concordant criteria. The groups were compared by demographics including age, sex, race, region, years of education, health insurance coverage, employment status, family income, presence of headache diagnosis, Charlson Comorbidity Index score and the presence of any limitation of physical function. Comparisons were made between the two groups using Chi-squared tests. Logistic regression was used to adjust for covariates. Results: There were 159 and 310 adults classified as concordant and discordant, respectively (weighted total: 1 849 108 [31.44%] and 4 032 541 [68.56%], with significantly different mean chiropractic costs of $2555 and $434, respectively. Significant independent predictors of discordant chiropractic utilization were race, years of education, family income and the presence of any limitation of physical function. Conclusions: Most chiropractic users with diagnosed neck or back pain were considered discordant with treatment frequency guidelines, which may indicate inefficiencies in treatment and inefficient use of healthcare resources.


Asunto(s)
Quiropráctica , Manipulación Quiropráctica , Adulto , Humanos , Estados Unidos , Dolor de Cuello/epidemiología , Dolor de Cuello/terapia , Dolor de Espalda/epidemiología , Dolor de Espalda/terapia , Demografía
15.
J Am Pharm Assoc (2003) ; 63(2): 511-517.e8, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36376213

RESUMEN

BACKGROUND: During the coronavirus disease 2019 pandemic, pediatric vaccination rates for routine childhood vaccines have been declining. To boost pediatric immunizations, pharmacists in the United States may order and administer age-appropriate vaccines to children of 3 years of age and older without a prescription. OBJECTIVE: The objective of this study was to examine parents' intention to have their young children between 3 and 10 years of age vaccinated in a community pharmacy setting. METHODS: A survey instrument was designed based on the health belief model (HBM). The cross-sectional survey was administered online via Qualtrics Panels to parents in the United States with at least 1 child between the ages of 3 and 10 years. Confirmatory factor analysis was used to estimate the correlation between each of the HBM constructs and a 3-item scale measuring parents' intention to have their children between the ages of 3 and 10 vaccinated in a community pharmacy. RESULTS: There were 416 usable responses collected for an effective response rate of 25.95%. Most participants were white (79.09%) and female (51.44%), and many had a graduate degree (48.32%). More than half of parents (69.7%) indicated they would be willing to have their child vaccinated in a community pharmacy. Intention to have their child vaccinated in a pharmacy was most strongly corrected with health benefit beliefs (ψ 0.79 [95% CI 0.75-0.83]), (ψ 0.86 [95% CI 0.83-0.89])cues to action, and perceived convenience.(ψ 0.71 [95% CI 0.66-0.76]). CONCLUSION: Many parents have high intention to vaccinate their young children in community pharmacies. Parents should be educated and informed about services that community pharmacies offer. Stakeholders need to engage in interventions targeted at promoting health benefits of getting vaccinations at a pharmacy and strong recommendations from health care providers.


Asunto(s)
COVID-19 , Farmacias , Vacunas , Humanos , Niño , Femenino , Estados Unidos , Preescolar , Estudios Transversales , Intención , COVID-19/prevención & control , Padres , Vacunación , Conocimientos, Actitudes y Práctica en Salud
16.
Phys Rev Lett ; 128(14): 148101, 2022 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-35476484

RESUMEN

In contexts ranging from embryonic development to bacterial ecology, cell populations migrate chemotactically along self-generated chemical gradients, often forming a propagating front. Here, we theoretically show that the stability of such chemotactic fronts to morphological perturbations is determined by limitations in the ability of individual cells to sense and thereby respond to the chemical gradient. Specifically, cells at bulging parts of a front are exposed to a smaller gradient, which slows them down and promotes stability, but they also respond more strongly to the gradient, which speeds them up and promotes instability. We predict that this competition leads to chemotactic fingering when sensing is limited at too low chemical concentrations. Guided by this finding and by experimental data on E. coli chemotaxis, we suggest that the cells' sensory machinery might have evolved to avoid these limitations and ensure stable front propagation. Finally, as sensing of any stimuli is necessarily limited in living and active matter in general, the principle of sensing-induced stability may operate in other types of directed migration such as durotaxis, electrotaxis, and phototaxis.


Asunto(s)
Escherichia coli , Modelos Biológicos , Bacterias , Quimiotaxis
17.
J Magn Reson Imaging ; 56(6): 1863-1871, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35396789

RESUMEN

BACKGROUND: Recently, a data-driven regression analysis method was developed to utilize the resting-state (rs) blood oxygenation level-dependent signal for cerebrovascular reactivity (CVR) mapping (rs-CVR), which was previously optimized by comparing with the CO2 inhalation-based method in health subjects and patients with neurovascular diseases. PURPOSE: To investigate the agreement of rs-CVR and the CVR mapping with breath-hold MRI (bh-CVR) in patients with gliomas. STUDY TYPE: Retrospective. POPULATION: Twenty-five patients (12 males, 13 females; mean age ± SD, 48 ± 13 years) with gliomas. FIELD STRENGTH/SEQUENCE: Dynamic T2*-weighted gradient-echo echo-planar imaging during a breath-hold paradigm and during the rs on a 3-T scanner. ASSESSMENT: rs-CVR with various frequency ranges and resting-state fluctuation amplitude (RSFA) were assessed. The agreement between each rs-based CVR measurement and bh-CVR was determined by voxel-wise correlation and Dice coefficient in the whole brain, gray matter, and the lesion region of interest (ROI). STATISTICAL TESTS: Voxel-wise Pearson correlation, Dice coefficient, Fisher Z-transformation, repeated-measure analysis of variance and post hoc test with Bonferroni correction, and nonparametric repeated-measure Friedman test and post hoc test with Bonferroni correction were used. Significance was set at P < 0.05. RESULTS: Compared with bh-CVR, the highest correlations were found at the frequency bands of 0.04-0.08 Hz and 0.02-0.04 Hz for rs-CVR in both whole brain and the lesion ROI. RSFA had significantly lower correlations than did rs-CVR of 0.02-0.04 Hz and a wider frequency range (0-0.1164 Hz). Significantly higher correlations and Dice coefficient were found in normal tissues than in the lesion ROI for all three methods. DATA CONCLUSION: The optimal frequency ranges for rs-CVR are determined by comparing with bh-CVR in patients with gliomas. The rs-CVR method outperformed the RSFA. Significantly higher correlation and Dice coefficient between rs- and bh-CVR were found in normal tissue than in the lesion. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2.


Asunto(s)
Mapeo Encefálico , Glioma , Masculino , Femenino , Humanos , Mapeo Encefálico/métodos , Circulación Cerebrovascular , Estudios Retrospectivos , Imagen por Resonancia Magnética/métodos , Encéfalo/diagnóstico por imagen , Encéfalo/irrigación sanguínea , Glioma/diagnóstico por imagen
18.
J Neurooncol ; 156(3): 491-498, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35083579

RESUMEN

PURPOSE: Pineal region tumors are surgically demanding tumors to resect. Long term neuro-oncologic outcomes following surgical excision of tumors from this region have been underreported. We sought to define the long term outcomes of patients undergoing resection of pineal region tumors. METHODS: A retrospective analysis of a prospectively maintained database was performed on patients who underwent intended surgical excision of pineal region tumors. Overall survival (OS) and progression free survival (PFS) were the primary endpoints of this study. Factors associated with OS, PFS and the degree of resection were analyzed, along with 30-day complication rates and dependence on CSF diversion. RESULTS: Sixty-eight patients with a mean age of 30.9 ± 15.3 years were analyzed. The median clinical and radiographic follow-up was 95.7 and 48.2 months, respectively. The supracerebellar infratentorial and the occipital transtentorial corridors were utilized in the majority of cases (80.9%). The gross total resection (GTR) rate was 52.9% (n=36). The 5-year OS and PFS rates were 70.2% and 58.5%, respectively. Achieving GTR was associated with improved OS (HR 0.39, p = 0.03) and PFS (HR 0.4, p = 0.006). The 30-day mortality rate was 5.9%. The need for CSF diversion was high with 77.9% of patients requiring a shunt or ETV by last follow-up. CONCLUSIONS: This is the first modern surgical series providing long term follow-up for patients undergoing surgical resection of pineal region tumors. Obtaining a GTR of these challenging tumors is beneficial with regards to PFS/OS. Higher grade tumors have diminished PFS/OS and are treated with adjuvant chemotherapy and/or radiotherapy.


Asunto(s)
Pinealoma , Adolescente , Adulto , Humanos , Persona de Mediana Edad , Pinealoma/cirugía , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
19.
Curr Opin Urol ; 32(1): 96-101, 2022 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-34798639

RESUMEN

PURPOSE OF REVIEW: African-American men in the USA have a higher incidence of and mortality from prostate cancer (PCa), with a longstanding debate about the cause for these worse outcomes. This review examines differences in tumour biology and socioeconomics for African-American and Non-Hispanic White (NHW) men to answer the question 'why AA men face higher risks for lethal PCa' and draw a management consensus to redress the imbalance. RECENT FINDINGS: Recent evidence from over the past 2 years suggests the reasons why African-American men face a higher risk of lethal PCa are multifactorial, with contributions from differences in tumour biology as well as socioeconomic and healthcare access factors. Regarding tumour biology, genomic and transcriptome profiling suggests African-American men have upregulated expression of genes related to inflammatory pathways with downregulation of DNA repair genes. In contrast, NHW men have higher DNA repair pathways and metabolic pathways involving glycolysis and cell cycle activity. In addition, epidemiological evidence suggests equal healthcare access ensures equal PCa specific outcomes, implying African-American men's disease is not inherently more lethal. However, differences in tumour biology remain, which may explain specific differences in PCa incidence and the clinical findings of African-American men's increased response to immunotherapy and radiotherapy in recent trials. SUMMARY: Regardless of racial differences in disease outcomes and the factors causing them, African-American and NHW men seem to have diseases unique to their ancestry. This supports the exploration of personalized PCa treatment approaches, leveraging translational basic science research to uncover these differences and devise specific individualized methods therapeutic regimes to address them.


Asunto(s)
Negro o Afroamericano , Neoplasias de la Próstata , Negro o Afroamericano/genética , Accesibilidad a los Servicios de Salud , Humanos , Inmunoterapia , Masculino , Neoplasias de la Próstata/epidemiología , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/terapia , Población Blanca/genética
20.
Soft Matter ; 18(33): 6254-6263, 2022 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-35946517

RESUMEN

Functionalized cellulosics have shown promise as naturally derived thermoresponsive gelling agents. However, the dynamics of thermally induced phase transitions of these polymers at the lower critical solution temperature (LCST) are not fully understood. Here, with experiments and theoretical considerations, we address how molecular architecture dictates the mechanisms and dynamics of phase transitions for cellulose ethers. Above the LCST, we show that hydroxypropyl substituents favor the spontaneous formation of liquid droplets, whereas methyl substituents induce fibril formation through diffusive growth. In celluloses which contain both methyl and hydroxypropyl substituents, fibrillation initiates after liquid droplet formation, suppressing the fibril growth to a sub-diffusive rate. Unlike for liquid droplets, the dissolution of fibrils back into the solvated state occurs with significant thermal hysteresis. We tune this hysteresis by altering the content of substituted hydroxypropyl moieties. This work provides a systematic study to decouple competing mechanisms during the phase transition of multi-functionalized macromolecules.


Asunto(s)
Celulosa , Éteres , Transición de Fase , Polímeros , Temperatura
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