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1.
Bull Math Biol ; 86(5): 58, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38627264

RESUMO

The microtubule cytoskeleton is responsible for sustained, long-range intracellular transport of mRNAs, proteins, and organelles in neurons. Neuronal microtubules must be stable enough to ensure reliable transport, but they also undergo dynamic instability, as their plus and minus ends continuously switch between growth and shrinking. This process allows for continuous rebuilding of the cytoskeleton and for flexibility in injury settings. Motivated by in vivo experimental data on microtubule behavior in Drosophila neurons, we propose a mathematical model of dendritic microtubule dynamics, with a focus on understanding microtubule length, velocity, and state-duration distributions. We find that limitations on microtubule growth phases are needed for realistic dynamics, but the type of limiting mechanism leads to qualitatively different responses to plausible experimental perturbations. We therefore propose and investigate two minimally-complex length-limiting factors: limitation due to resource (tubulin) constraints and limitation due to catastrophe of large-length microtubules. We combine simulations of a detailed stochastic model with steady-state analysis of a mean-field ordinary differential equations model to map out qualitatively distinct parameter regimes. This provides a basis for predicting changes in microtubule dynamics, tubulin allocation, and the turnover rate of tubulin within microtubules in different experimental environments.


Assuntos
Modelos Biológicos , Tubulina (Proteína) , Tubulina (Proteína)/metabolismo , Conceitos Matemáticos , Microtúbulos/metabolismo , Citoesqueleto
3.
J Phys Chem Lett ; 15(12): 3404-3411, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38502942

RESUMO

The process of dissociation for two hydrofluorocarbon molecules in low triplet states excited by electron impact in plasma is investigated by ab initio molecular dynamics (AIMD). The interest in the dissociation of hydrofluorocarbons in plasma is motivated by their role in plasma etching in microelectronic technologies. Dissociation of triplet states is very fast, and the reaction products can be predicted. In this work, it was found that higher triplet states relax into the lowest triplet state within a few femtoseconds due to nonadiabatic dynamics, such that the simplest ab initio MD on the lowest triplet state seems to give a reasonable estimate of the reaction channels branching ratios. We provide evidence of the existence of simple rules for the dissociation of hydrofluorocarbon molecules in triplet states. For molecules with a double bond, the bonds adjacent to the double bond dissociate faster than the other bonds.

4.
Artigo em Inglês | MEDLINE | ID: mdl-38386258

RESUMO

BACKGROUND: The disproportionate effects of the human immunodeficiency virus (HIV) and the Coronavirus 2019 (COVID-19) on Black American communities highlight structural systems rooted in racism and must be addressed with national strategies that improve both biomedicine and social determinants of health. PURPOSE: The purpose of this study was to qualitatively examine the experiences and interpretations of experts in the HIV workforce (local, state, and national HIV-related organizations) regarding the state of HIV and COVID-19 among Black Americans. METHODS: Within key informant interviews and a focus group recorded and transcribed verbatim, fifteen members of the HIV workforce and Black community described their experiences and provided insights to inform ending the negative outcomes resulting from HIV and COVID-19. RESULTS: Data were analyzed using NVivo software, and eight themes emerged to address disease disproportionality through a Black lens. Themes reflected (1) accessing information and care; (2) key potential partners/stakeholders; (3) investing in Black communities; (4) governmental support; (5) increasing engagement and advocacy; (6) HIV-related community conversations; (7) developments since COVID-19; and (8) the Ending the HIV Epidemic (EHE) trajectory. CONCLUSIONS: Themes directly speak to recommendations to adjust education and policy strategies for HIV and COVID-19 prevention and intervention. Such recommendations, (1) amplifying Black voices, (2) investing sustainable dollars into Black communities, and (3) leaning into advocacy, can bolster the foundation for the HIV workforce and Black community to break ineffective response patterns and lead the fight against these systemic issues of inequity.

5.
J Med Ethics ; 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38383151

RESUMO

Those giving birth within modern maternity systems are recognised as facing a number of barriers to person-centred care. In this paper, I argue that in order to best facilitate the conditions for positive change, work needs to be done to provide a more granular articulation of the specific barriers. I then offer a nuanced and contextually aware articulation of one key component of the overall failure to ensure person-centred care: medical authority and the expectation of conformity. Articulating these barriers with increased specificity is valuable, as it creates a stronger foundation from which to challenge existing problems which serve to constrain the autonomy of birthing individuals. The analysis offered in this paper also underscores the need for change at an institutional, rather than individual, level.

6.
ArXiv ; 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-37904745

RESUMO

The microtubule cytoskeleton is responsible for sustained, long-range intracellular transport of mRNAs, proteins, and organelles in neurons. Neuronal microtubules must be stable enough to ensure reliable transport, but they also undergo dynamic instability, as their plus and minus ends continuously switch between growth and shrinking. This process allows for continuous rebuilding of the cytoskeleton and for flexibility in injury settings. Motivated by \textit{in vivo} experimental data on microtubule behavior in \textit{Drosophila} neurons, we propose a mathematical model of dendritic microtubule dynamics, with a focus on understanding microtubule length, velocity, and state-duration distributions. We find that limitations on microtubule growth phases are needed for realistic dynamics, but the type of limiting mechanism leads to qualitatively different responses to plausible experimental perturbations. We therefore propose and investigate two minimally-complex length-limiting factors: limitation due to resource (tubulin) constraints and limitation due to catastrophe of large-length microtubules. We combine simulations of a detailed stochastic model with steady-state analysis of a mean-field ordinary differential equations model to map out qualitatively distinct parameter regimes. This provides a basis for predicting changes in microtubule dynamics, tubulin allocation, and the turnover rate of tubulin within microtubules in different experimental environments.

7.
Intern Med J ; 54(2): 290-294, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37449655

RESUMO

BACKGROUND: In the last few decades, the life expectancy of patients with transfusion-dependent thalassaemia (TDT) and sickle cell disease (SCD) has improved significantly, in part because of improved iron chelation. Fertility challenges and pregnancy complications have historically limited reproductive options in this group; however, improved multi-disciplinary care has made infertility a chronic disease complication requiring attention. Despite this, there are very few reports and no Australian data describing fertility and pregnancy outcomes in this population. AIMS: To identify the rate of assisted reproductive technologies (ART) utilisation in our female transfusion-dependent haemoglobinopathy patients and to establish the nature of maternal and neonatal complications in this cohort. METHODS: A 20-year retrospective analysis (1997-2017) at an Australian centre captured data on conception rates, use of assisted reproductive techniques (ART), and pregnancy and neonatal outcomes in female transfusion-dependent haemoglobinopathy patients. RESULTS: Conception was attempted in 14 women (11 TDT and three SCD) during the study period. A total of 28 pregnancies resulting in 25 live births were recorded. ART supported 13 conceptions. A positive association was not identified between elevated mean serum ferritin and ART use; however, all patients with an established diagnosis of hypogonadotropic hypogonadism (HH) required ART. Maternal complications included gestational diabetes mellitus and post-partum haemorrhage. There were no cardiac complications. Two-thirds of women underwent lower segment caesarean section, with prematurity complicating 20% of births. There were no neonatal or maternal deaths. CONCLUSION: Pregnancy is an achievable goal for women with transfusion-dependent haemoglobinopathies, although the support of ART may be required in a subset of patients.


Assuntos
Cesárea , Hemoglobinopatias , Recém-Nascido , Gravidez , Humanos , Feminino , Estudos Retrospectivos , Austrália/epidemiologia , Técnicas de Reprodução Assistida , Resultado da Gravidez/epidemiologia , Hemoglobinopatias/complicações , Hemoglobinopatias/epidemiologia , Hemoglobinopatias/terapia
8.
J Palliat Med ; 27(2): 216-223, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37738323

RESUMO

Background: Digital health interventions are becoming increasingly important for adults, children, and young people with cancer and palliative care needs, but there is little research to guide policy and practice. Objectives: To identify recommendations for policy development of digital health interventions in cancer and palliative care. Design: Expert elicitation workshop. Setting: European clinical (cancer and palliative care, adult and pediatric), policy, technical, and research experts attended a one-day workshop in London, England, in October 2022, along with MyPal research consortium members. Methods: As part of the European Commission-funded MyPal project, we elicited experts' views on global, national, and institutional policies within structured facilitated groups, and conducted qualitative analysis on these discussions. Results/Implementation: Thirty-two experts from eight countries attended. Key policy drivers and levers in digital health were highlighted. Global level: global technology regulation, definitions, access to information technology, standardizing citizens' rights and data safety, digital infrastructure and implementation guidance, and incorporation of technology into existing health systems. National level: country-specific policy, compatibility of health apps, access to digital infrastructure including vulnerable groups and settings, development of guidelines, and promoting digital literacy. Institutional level: undertaking a needs assessment of service users and clinicians, identifying best practice guidelines, providing education and training for clinicians on digital health and safe digital data sharing, implementing plans to minimize barriers to accessing digital health care, minimizing bureaucracy, and providing technical support. Conclusions: Developers and regulators of digital health interventions may find the identified recommendations useful in guiding policy making and future research initiatives. MyPal child study Clinical Trial Registration NCT04381221; MyPal adult study Clinical Trial Registration NCT04370457.


Assuntos
Neoplasias , Cuidados Paliativos , Adulto , Humanos , Criança , Adolescente , Políticas , Europa (Continente) , Neoplasias/terapia
9.
Intern Med J ; 2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-38064543

RESUMO

BACKGROUND: Sickle cell disease (SCD) is the most common monogenic disorder worldwide. In deoxygenated conditions, the altered beta chain (haemoglobin S [HbS]) polymerises and distorts the erythrocyte, resulting in pain crises, vasculopathy and end-organ damage. Clinical complications of SCD cause substantial morbidity, and therapy demands expertise and resources. Optimising care for patients and planning resource allocation for the future requires an understanding of the disease in the Australian population. The Australian Haemoglobinopathy Registry (HbR) is a collaborative initiative of specialist centres collating and analysing data on patients with haemoglobin disorders. AIMS: To provide a snapshot of SCD in Australia over a 12-month period based on data from the HbR. METHODS: Patients with a clinically significant sickling disorder across 12 clinical sites were included for analysis. Data include demographic and diagnostic details, as well as details of the clinical management of the condition over a 12-month period. RESULTS: Data on 359 SCD patients demonstrate a shift in the demographic of patients in Australia, with a growing proportion of sub-Saharan African ethnicities associated with the HbSS genotype. Acute and chronic complications are common, and patients require significant outpatient and inpatient support. Prevalence of disease complications and therapeutic trends are in keeping with other high-income countries. CONCLUSIONS: This study provides the first national picture of SCD in Australia, describing the characteristics and needs of SCD patients, elucidating demand for current and novel therapy and facilitating the planning of services for this vulnerable population.

10.
Heliyon ; 9(9): e19725, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37809987

RESUMO

Type 2 diabetes (T2D) is a public health issue that needs to be addressed. In the U.S., 11.3% of the population have diabetes. It is estimated that 90-95% of all diabetes cases are T2D cases. One of the best methods to address T2D is self-management. Prior research found a relationship between religiosity and T2D self-management. The purpose of this study was to examine religiosity and T2D self-management. This was a cross-sectional and qualitative study, which included Muslim adults, who have T2D and live in California. We utilized snowballing to recruit participants and the saturation concept to determine the number of participants. Additionally, we used semi-structured design for the interviews and focus groups. We had 30 participants for the interviews (however, only 25 provided demographic data) and 28 for the combined focus groups. Zoom was used to conduct the interviews and two focus groups. The grounded theory was used to deduce themes from the interviews and focus groups. The main themes for religiosity and self-management are Allah sustains life, everything will be ok/hope, faith gives strength, and the role of self within the fate concept. The themes for self-efficacy are diabetes requires new life approach, stress, and Islamic religious practices promote self-management. The main theme for perceived seriousness is taking action and making changes. Our findings provide significant insight about the relationship between religiosity, perceived seriousness, fatalism, and self-efficacy and self-management of T2D. A recommendation based on this study is that providers and health educators should be aware of the different experiences Muslims with T2D face, and tailor recommendations and programs based on that.

11.
Matern Child Health J ; 27(11): 2038-2047, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37589829

RESUMO

INTRODUCTION: Smoking during pregnancy adversely affects perinatal outcomes for both women and infants. We conducted a retrospective cohort study of the state-funded Comprehensive Tobacco Treatment Program (CTTP) - the largest maternal tobacco cessation program in San Bernardino County, California - to determine the real-world program effectiveness and to identify variables that can potentially improve effectiveness. METHODS: During 2012-2019, women who smoked during pregnancy were enrolled in CTTP's multicomponent behavioral smoking cessation program that implemented components of known efficacy (i.e., incentives, biomarker testing, feedback, and motivational interviewing). RESULTS: We found that 40.1% achieved prolonged abstinence by achieving weekly, cotinine-verified, 7-day abstinence during 6 to 8 weeks of enrollment. Using intention-to-treat analyses, we computed that the self-reported point prevalence abstinence rate (PPA) at the six-month telephone follow-up was 36.7%. Cohort members achieving prolonged abstinence during the CTTP were five times more likely to achieve PPA six months after CTTP. Several non-Hispanic ethnicities (Black, Native American, White, or More than one ethnicity) in the cohort were two-fold less likely (relative to Hispanics) to achieve prolonged abstinence during CTTP or PPA at six months after CTTP. This disparity was further investigated in mediation analysis. Variables such as quitting during the first trimester and smoking fewer cigarettes at enrollment were also associated with achieving PPA at six months. DISCUSSION: Racial/ethnic health disparities that have long been linked to a higher rate of maternal smoking persist even when the pregnant smoker enrolls in a smoking cessation program.


Assuntos
Abandono do Hábito de Fumar , Gravidez , Lactente , Humanos , Feminino , Estudos Retrospectivos , Fumar/efeitos adversos , Fumar/epidemiologia , Comportamentos Relacionados com a Saúde
12.
Chem Sci ; 14(29): 7867-7874, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37502328

RESUMO

We report unprecedented photochemistry for the diamidocarbene 1. Described within are the double cyclopropanation of 1-bromonaphthalene, the double addition to pyridine, and remarkably, the insertion into the unactivated sp3 C-H bonds of cyclohexane, tetramethylsilane, and n-pentane to give compounds 2-6, respectively. All compounds have been fully characterized, and the solid state structure of 4 was obtained using single crystal electron diffraction.

13.
Ageing Res Rev ; 90: 101989, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37442369

RESUMO

BACKGROUND: Quercetin, a natural flavonoid, has shown promise as a senolytic agent for various degenerative diseases. Recently, its protective effect against osteoarthritis (OA), a representative age-related disease of the musculoskeletal system, has attracted much attention. The aim of this study is to summarize and analyze the current literature on the effects of quercetin on OA cartilage in in vivo preclinical studies. METHODS: The Medline (via/using PubMed), Embase, and Web of Science databases were searched up to March 10th, 2023. Risk of bias and the qualitative assessment including mechanisms of all eligible studies and a meta-analysis of cartilage histological scores among the applicable studies was performed. RESULTS: A total of 12 in vivo animal studies were included in this systematic review. A random-effects meta-analysis was performed on six studies using the Osteoarthritis Research Society International (OARSI) scoring system, revealing that quercetin significantly improved OA cartilage OARSI scores (SMD, -6.30 [95% CI, -9.59 to -3.01]; P = 0.0002; heterogeneity: I2 = 86%). The remaining six studies all supported quercetin's protective effects against OA during disease and aging. CONCLUSIONS: Quercetin has shown beneficial effects on cartilage during OA across animal species. Future double-blind randomized controlled clinical trials are needed to verify the efficacy of quercetin in the treatment of OA in humans.


Assuntos
Osteoartrite do Joelho , Osteoartrite , Animais , Humanos , Quercetina/uso terapêutico , Senoterapia , Osteoartrite/patologia , Envelhecimento , Osteoartrite do Joelho/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto
14.
Stem Cells ; 41(7): 698-710, 2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37279940

RESUMO

Mesenchymal stem cells (MSCs) have long been viewed as a promising therapeutic for musculoskeletal repair. However, regulatory concerns including tumorgenicity, inconsistencies in preparation techniques, donor-to-donor variability, and the accumulation of senescence during culture expansion have hindered the clinical application of MSCs. Senescence is a driving mechanism for MSC dysfunction with advancing age. Often characterized by increased reactive oxygen species, senescence-associated heterochromatin foci, inflammatory cytokine secretion, and reduced proliferative capacity, senescence directly inhibits MSCs efficacy as a therapeutic for musculoskeletal regeneration. Furthermore, autologous delivery of senescent MSCs can further induce disease and aging progression through the secretion of the senescence-associated secretory phenotype (SASP) and mitigate the regenerative potential of MSCs. To alleviate these issues, the use of senolytic agents to selectively clear senescent cell populations has become popular. However, their benefits to attenuating senescence accumulation in human MSCs during the culture expansion process have not yet been elucidated. To address this, we analyzed markers of senescence during the expansion of human primary adipose-derived stem cells (ADSCs), a population of fat-resident MSCs commonly used in regenerative medicine applications. Next, we used the senolytic agent fisetin to determine if we can reduce these markers of senescence within our culture-expanded ADSC populations. Our results indicate that ADSCs acquire common markers of cellular senescence including increased reactive oxygen species, senescence-associated ß-galactosidase, and senescence-associated heterochromatin foci. Furthermore, we found that the senolytic agent fisetin works in a dose-dependent manner and selectively attenuates these markers of senescence while maintaining the differentiation potential of the expanded ADSCs.


Assuntos
Heterocromatina , Células-Tronco Mesenquimais , Humanos , Espécies Reativas de Oxigênio , Senoterapia , Células Cultivadas , Senescência Celular/genética , Diferenciação Celular , Proliferação de Células
16.
JMIR Form Res ; 7: e39891, 2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-37040161

RESUMO

BACKGROUND: Confidence in health information access is a measure of the perceived ability to obtain health information. One's beliefs or perceived ability to access health information is particularly important in understanding trends in health care access. Previous literature has found that access to health information is lowest among society's most vulnerable population groups. These groups include older, less educated, and low-income populations. While health confidence has previously been used as a scale to measure health outcomes, additional research is needed describing the demographic factors associated with users' confidence in health information access. This may be a key component of health information seeking that affects beneficial health outcomes such as prevention and treatment. OBJECTIVE: This study examines the demographic factors associated with the levels of confidence in using the internet to access health information for adults 18 years and older in the United States. METHODS: Using a cross-sectional design, secondary data from the Health Information National Trends Survey (HINTS) 5, Cycle 3 (2019) were analyzed (N=5374). An ordinal regression stratified by internet use was used to determine the association between demographic characteristics and level of confidence in health information access. RESULTS: When the internet is the primary source for health information, high school graduates (adjusted odds ratio [AOR] 0.58, 95% CI 0.37-0.89) compared to those with a college degree or more had significantly lower odds of being confident in obtaining health information. In addition, non-Hispanic Asian participants (AOR 0.44, 95% CI 0.24-0.82) compared to non-Hispanic White participants, male participants (AOR 0.72, 95% CI 0.54-0.97) compared to female participants, and those who made between US $20,000-$35,000 annually (AOR 0.55, 95% CI 0.31-0.98) compared to those who made US $75,000 or more annually had significantly lower odds of being confident in obtaining health information via the internet. Moreover, when the internet is the primary source for health information, those with health insurance had significantly higher odds of being confident in obtaining health information (AOR 2.91, 95% CI 1.58-5.34) compared to those who do not have health insurance. Lastly, a significant association was observed between confidence in health information access and primary health information source and frequency of visiting a health care provider. CONCLUSIONS: Confidence in accessing health information can differ by individual demographics. Accessing health-related information from the internet has become increasingly more common and can provide insight into health information-seeking behaviors. Further exploration of these factors can inform the science of health education by providing deeper insight into improving access to health information for vulnerable populations.

17.
Phys Rev E ; 107(2-1): 024413, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36932478

RESUMO

Fibrin gelation involves the enzymatic conversion of the plasma protein fibrinogen to fibrin monomers which then polymerize to form the gel that is a major structural component of a blood clot. Because fibrinogen provides the material from which fibrin is made, it is generally regarded as promoting the gelation process. However, fibrinogen can bind to a site on a fibrin oligomer, preventing another fibrin oligomer from binding there, thus slowing the polymerization process. "Soluble fibrin oligomers," which are mixtures of fibrin and fibrinogen, are found in the blood plasma and serve as biomarkers for various clotting disorders, so understanding the interplay between fibrin and fibrinogen during fibrin polymerization may have medical importance. We present a kinetic gelation model of fibrin polymerization which accounts for the dual and antagonistic roles of fibrinogen. It builds on our earlier model of fibrin polymerization that proposed a novel mechanism for branch formation, which is a necessary component of gelation. This previous model captured salient experimental observations regarding the determinants of the structure of the gel, but did not include fibrinogen binding. Here, we add to that model reactions between fibrinogen and fibrin, so oligomers are now mixtures of fibrin and fibrinogen, and characterizing their dynamics leads to equations of substantially greater complexity than previously. Using a moment generating function approach, we derive a closed system of moment equations and we track their dynamics until the finite time blow-up of specific second moments indicates that a gel has formed. In simulations begun with an initial mixture of fibrin and fibrinogen monomers, a sufficiently high relative concentration of fibrinogen prevents gelation; the critical concentration increases with the branch formation rate. In simulations begun with only fibrinogen monomers that are converted to fibrin at a specified rate, the rates of conversion, fibrinogen binding to oligomers, and branch formation together determine whether a gel forms, how long it takes to form, and the structural properties of the gel that results.


Assuntos
Fibrina , Fibrinogênio , Fibrina/química , Fibrina/metabolismo , Fibrinogênio/química , Fibrinogênio/metabolismo , Trombina/metabolismo , Polimerização
18.
J Osteoporos ; 2023: 5572754, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36875869

RESUMO

Aging leads to several geriatric conditions including osteoporosis (OP) and associated frailty syndrome. Treatments for these conditions are limited and none target fundamental drivers of pathology, and thus identifying strategies to delay progressive loss of tissue homeostasis and functional reserve will significantly improve quality of life in elderly individuals. A fundamental property of aging is the accumulation of senescent cells. Senescence is a cell state defined by loss of proliferative capacity, resistance to apoptosis, and the release of a proinflammatory and anti-regenerative senescence-associated secretory phenotype (SASP). The accumulation of senescent cells and SASP factors is thought to significantly contribute to systemic aging. Senolytics-compounds which selectively target and kill senescent cells-have been characterized to target and inhibit anti-apoptotic pathways that are upregulated during senescence, which can elicit apoptosis in senescent cells and relieve SASP production. Senescent cells have been linked to several age-related pathologies including bone density loss and osteoarthritis in mice. Previous studies in murine models of OP have demonstrated that targeting senescent cells pharmacologically with senolytic drugs can reduce symptomology of the disease. Here, we demonstrate the efficacy of senolytic drugs (dasatinib, quercetin, and fisetin) to improve age-associated degeneration in bone using the Zmpste24-/- (Z24-/-) progeria murine system for Hutchinson-Gilford progeria syndrome (HGPS). We found that the combination of dasatinib plus quercetin could not significantly mitigate trabecular bone loss although fisetin administration could reduce bone density loss in the accelerated aging Z24-/- model. Furthermore, the overt bone density loss observed in the Z24-/- model reported herein highlights the Z24 model as a translational model to recapitulate alterations in bone density associated with advanced age. Consistent with the "geroscience hypothesis," these data demonstrate the utility of targeting a fundamental driver of systemic aging (senescent cell accumulation) to alleviate a common condition with age, bone deterioration.

19.
Biosensors (Basel) ; 13(3)2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36979543

RESUMO

Urinary chloride concentration is a valuable health metric that can aid in the early detection of serious conditions, such as acid base disorders, acute heart failure, and incidences of acute renal failure in the intensive care unit. Physiologically, urinary chloride levels frequently change and are difficult to measure, involving time-consuming and inconvenient lab testing. Thus, near real-time simple sensors are needed to quickly provide actionable data to inform diagnostic and treatment decisions that affect health outcomes. Here, we introduce a chronopotentiometric sensor that utilizes commercially available screen-printed electrodes to accurately quantify clinically relevant chloride concentrations (5-250 mM) in seconds, with no added reagents or electrode surface modification. Initially, the sensor's performance was optimized through the proper selection of current density at a specific chloride concentration, using electrical response data in conjunction with scanning electron microscopy. We developed a unique swept current density algorithm to resolve the entire clinically relevant chloride concentration range, and the chloride sensors can be reliably reused for chloride concentrations less than 50 mM. Lastly, we explored the impact of pH, temperature, conductivity, and additional ions (i.e., artificial urine) on the sensor signal, in order to determine sensor feasibility in complex biological samples. This study provides a path for further development of a portable, near real-time sensor for the quantification of urinary chloride.


Assuntos
Cloretos , Técnicas Eletroquímicas , Eletrodos , Microscopia Eletrônica de Varredura
20.
Front Bioeng Biotechnol ; 11: 1295313, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38264578

RESUMO

Introduction: Impaired fracture healing, specifically non-union, has been found to occur up to 14% in tibial shaft fractures. The current standard of care to treat non-union often requires additional surgeries which can result in long recovery times. Injectable-based therapies to accelerate fracture healing have the potential to mitigate the need for additional surgeries. Gene therapies have recently undergone significant advancements due to developments in nanotechnology, which improve mRNA stability while reducing immunogenicity. Methods: In this study, we tested the efficacy of mineral coated microparticles (MCM) and fluoride-doped MCM (FMCM) to effectively deliver firefly luciferase (FLuc) mRNA lipoplexes (LPX) to the fracture site. Here, adult mice underwent a tibia fracture and stabilization method and all treatments were locally injected into the fracture. Level of osteogenesis and amount of bone formation were assessed using gene expression and histomorphometry respectively. Localized and systemic inflammation were measured through gene expression, histopathology scoring and measuring C-reactive protein (CRP) in the serum. Lastly, daily IVIS images were taken to track and measure transfection over time. Results: MCM-LPX-FLuc and FMCM-LPX-FLuc were not found to cause any cytotoxic effects when tested in vitro. When measuring the osteogenic potential of each mineral composition, FMCM-LPX-FLuc trended higher in osteogenic markers through qRT-PCR than the other groups tested in a murine fracture and stabilization model. Despite FMCM-LPX-FLuc showing slightly elevated il-1ß and il-4 levels in the fracture callus, inflammation scoring of the fracture callus did not result in any differences. Additionally, an acute systemic inflammatory response was not observed in any of the samples tested. The concentration of MCM-LPX-FLuc and FMCM-LPX-FLuc that was used in the murine fracture model did not stimulate bone when analyzed through stereological principles. Transfection efficacy and kinetics of delivery platforms revealed that FMCM-LPX-FLuc prolongs the luciferase signal both in vitro and in vivo. Discussion: These data together reveal that FMCM-LPX-FLuc could serve as a promising mRNA delivery platform for fracture healing applications.

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