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1.
Anal Chem ; 94(3): 1678-1685, 2022 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-34928586

RESUMEN

The employment of ethylenediaminetetraacetic acid (EDTA) across several fields in chemistry and biology has required the creation of a high number of quantitative assays. Nonetheless, the determination of trace EDTA, especially in biologics and vaccines, remains challenging. Herein, we introduce an automated high-throughput approach based on EDTA esterification in 96-well plates using boron trifluoride-methanol combined with rapid analysis by ultra-high-performance liquid chromatography-triple quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS). Derivatization of EDTA to its methyl ester (Me-EDTA) serves to significantly improve chromatographic performance (retention, peak shape, and selectivity), while also delivering a tremendous enhancement of sensitivity in the positive ion mode electrospray ionization (ESI+). This procedure, in contrast to previous EDTA methods based on complexation with metal ions, is not affected by high concentration of other metals, buffers, and related salts abundantly present in biopharmaceutical processes (e.g., iron, copper, citrate, etc.). Validation of this assay for the determination of ng·mL-1 level EDTA in monoclonal antibody and vaccine products demonstrated excellent performance (repeatability, precision, and linear range) with high recovery from small sample volumes while also providing an advantageous automation-friendly workflow for high-throughput analysis.


Asunto(s)
Productos Biológicos , Vacunas , Boranos , Cromatografía Líquida de Alta Presión/métodos , Ácido Edético , Metanol , Espectrometría de Masas en Tándem/métodos
3.
Infect Immun ; 83(9): 3675-83, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26150536

RESUMEN

The Lyme disease spirochete, Borrelia burgdorferi, expresses RevA and numerous outer surface lipoproteins during mammalian infection. As an adhesin that promotes bacterial interaction with fibronectin, RevA is poised to interact with the extracellular matrix of the host. To further define the role(s) of RevA during mammalian infection, we created a mutant that is unable to produce RevA. The mutant was still infectious to mice, although it was significantly less well able to infect cardiac tissues. Complementation of the mutant with a wild-type revA gene restored heart infectivity to wild-type levels. Additionally, revA mutants led to increased evidence of arthritis, with increased fibrotic collagen deposition in tibiotarsal joints. The mutants also induced increased levels of the chemokine CCL2, a monocyte chemoattractant, in serum, and this increase was abolished in the complemented strain. Therefore, while revA is not absolutely essential for infection, deletion of revA had distinct effects on dissemination, arthritis severity, and host response.


Asunto(s)
Proteínas de la Membrana Bacteriana Externa/genética , Borrelia burgdorferi/patogenicidad , Enfermedad de Lyme/inmunología , Enfermedad de Lyme/patología , Animales , Proteínas de la Membrana Bacteriana Externa/inmunología , Western Blotting , Modelos Animales de Enfermedad , Femenino , Técnicas de Inactivación de Genes , Enfermedad de Lyme/genética , Ratones
4.
J Biol Chem ; 288(36): 26220-26234, 2013 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-23846702

RESUMEN

The PUR domain is a nucleic acid-binding motif found in critical regulatory proteins of higher eukaryotes and in certain species of bacteria. During investigations into mechanisms by which the Lyme disease spirochete controls synthesis of its Erp surface proteins, it was discovered that the borrelial PUR domain protein, Bpur, binds with high affinity to double-stranded DNA adjacent to the erp transcriptional promoter. Bpur was found to enhance the effects of the erp repressor protein, BpaB. Bpur also bound single-stranded DNA and RNA, with relative affinities RNA > double-stranded DNA > single-stranded DNA. Rational site-directed mutagenesis of Bpur identified amino acid residues and domains critical for interactions with nucleic acids, and it revealed that the PUR domain has a distinct mechanism of interaction with each type of nucleic acid ligand. These data shed light on both gene regulation in the Lyme spirochete and functional mechanisms of the widely distributed PUR domain.


Asunto(s)
Proteínas Bacterianas/química , Borrelia burgdorferi/química , ADN Bacteriano/química , Proteínas de Unión al ADN/química , ARN Bacteriano/química , Proteínas de Unión al ARN/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Borrelia burgdorferi/genética , Borrelia burgdorferi/metabolismo , ADN Bacteriano/genética , ADN Bacteriano/metabolismo , ADN de Cadena Simple/química , ADN de Cadena Simple/genética , ADN de Cadena Simple/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Humanos , Enfermedad de Lyme/genética , Enfermedad de Lyme/metabolismo , Proteínas de la Membrana/biosíntesis , Proteínas de la Membrana/genética , Estructura Terciaria de Proteína , ARN Bacteriano/genética , ARN Bacteriano/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo
5.
Curr Oncol ; 31(2): 733-746, 2024 01 29.
Artículo en Inglés | MEDLINE | ID: mdl-38392048

RESUMEN

Whilst existing quantitative research identifies outcomes believed to be important by researchers and clinicians, it may neglect outcomes that are meaningful to patients. This study aimed to explore the outcomes of exercise that are important to people with lung cancer and their carers. Data collection involved a qualitative methodology including semi-structured interviews and focus groups. Question guide development was informed by the International Classification of Functioning (ICF) framework. Data were analyzed by two researchers with NVivo (v12) software using a conventional content analysis process, followed by directed content analysis to map outcomes to the ICF. Conduct and reporting adhered to COREQ guidelines. Fifteen participants provided data. Most participants had received their diagnoses 24 months prior to study involvement (n = 9), and one-third had completed treatment (n = 5). Important outcomes were reported by participants across all domains of the ICF: activity and participation (n = 24), body function (n = 19), body structure (n = 5), environmental factors (n = 5), and personal factors (n = 1). Additional code categories pertained to the impacts of non-cancer factors such as age, frailty, and comorbidities; identifying barriers to exercise; and individualizing outcome measures. Clinicians and researchers should consider selecting outcomes from all relevant domains of the ICF, with a focus on the activity and participation domain, in addition to non-cancer factors such as ageing, frailty, and co-morbidities. Feedback should be provided to patients following outcome measures collection and reassessment.


Asunto(s)
Fragilidad , Neoplasias Pulmonares , Humanos , Clasificación Internacional del Funcionamiento, de la Discapacidad y de la Salud , Neoplasias Pulmonares/terapia , Investigación Cualitativa , Grupos Focales
6.
PM R ; 15(1): 31-40, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-35138036

RESUMEN

INTRODUCTION: Exercise testing is essential to determine the safety and efficacy of prescribing exercise. Limited evidence exists to support remotely supervised exercise testing in oncology literature. OBJECTIVE: To determine the feasibility, safety, and convergent validity of the 30-second sit-to-stand test (30STS) delivered via telehealth in an oncology population. Exploratory analyses informed remote test feasibility according to participant and treatment characteristics. DESIGN: Cross-sectional, observational study. SETTING: Telehealth outpatient clinic, tertiary metropolitan oncology hospital. PARTICIPANTS: Thirty-two consecutive outpatients attending telehealth exercise appointments were screened for inclusion. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: A pre-test safety screening questionnaire included the Australia-modified Karnofsky Performance Status (AKPS) and Clinical Frailty Scale (CFS). Following one practice, one 30STS test was completed using a standardized protocol modified for telehealth assessment. Secondary measures: International Physical Activity Questionnaire-Short Form (IPAQ-SF) and pre/post-test Borg Rating of Perceived Exertion (RPE). RESULTS: Thirty participants were deemed as being safe using the screening questionnaire and completed the remote 30STS. Participants were a median (interquartile range [IQR]) 62.5 (51.8 to 66.5) years old, 59% male, 72% undergoing cancer treatment, 34% with metastatic disease, and 56% met current exercise guidelines. Moderate correlation was found between 30STS and IPAQ-SF (rho = 0.49, p = .006), providing evidence of convergent validity. Correlations between 30STS and AKPS (rho = 0.26, p = .161), and CFS (rho = -0.23, p = .214), were fair. Chair-height standardization was poor (range 43 to 60 cm). The clinician could visualize the participant's whole body in 2 of 30 tests. No significant difference in test performance was found for participants with metastatic disease, higher age, or body mass index. No adverse events occurred. CONCLUSION: With screening, the 30STS, performed by telehealth, is a safe and feasible measure of function and lower limb strength. Telehealth exercise testing presents challenges in standardizing the environment and ensuring participant safety. Minimal space and equipment requirements and moderate convergent validity with physical activity provide good clinical utility in this setting.


Asunto(s)
Neoplasias , Telemedicina , Humanos , Masculino , Persona de Mediana Edad , Anciano , Femenino , Estudios de Factibilidad , Estudios Transversales , Modalidades de Fisioterapia , Neoplasias/diagnóstico , Neoplasias/terapia
7.
J Clin Med ; 12(5)2023 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-36902659

RESUMEN

BACKGROUND: Growing evidence supports exercise for people with lung cancer. This overview aimed to summarise exercise intervention efficacy and safety across the care continuum. METHODS: Eight databases (including Cochrane and Medline) were searched (inception-February 2022) for systematic reviews of RCTs/quasi-RCTs. Eligibility: population-adults with lung cancer; intervention: exercise (e.g., aerobic, resistance) +/- non-exercise (e.g., nutrition); comparator: usual care/non-exercise; primary outcomes: exercise capacity, physical function, health-related quality of life (HRQoL) and post-operative complications. Duplicate, independent title/abstract and full-text screening, data extraction and quality ratings (AMSTAR-2) were completed. RESULTS: Thirty systematic reviews involving between 157 and 2109 participants (n = 6440 total) were included. Most reviews (n = 28) involved surgical participants. Twenty-five reviews performed meta-analyses. The review quality was commonly rated critically low (n = 22) or low (n = 7). Reviews commonly included combinations of aerobic, resistance and/or respiratory exercise interventions. Pre-operative meta-analyses demonstrated that exercise reduces post-operative complications (n = 4/7) and improves exercise capacity (n = 6/6), whilst HRQoL findings were non-significant (n = 3/3). Post-operative meta-analyses reported significant improvements in exercise capacity (n = 2/3) and muscle strength (n = 1/1) and non-significant HRQoL changes (n = 8/10). Interventions delivered to mixed surgical and non-surgical populations improved exercise capacity (n = 3/4), muscle strength (n = 2/2) and HRQoL (n = 3). Meta-analyses of interventions in non-surgical populations demonstrated inconsistent findings. Adverse event rates were low, however, few reviews reported on safety. CONCLUSIONS: A large body of evidence supports lung cancer exercise interventions to reduce complications and improve exercise capacity in pre- and post-operative populations. Additional higher-quality research is needed, particularly in the non-surgical population, including subgroup analyses of exercise type and setting.

8.
Eur J Drug Metab Pharmacokinet ; 48(3): 311-327, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37086340

RESUMEN

BACKGROUND AND OBJECTIVE: N,N-dimethyltryptamine (DMT) is a psychedelic compound under development for the treatment of major depressive disorder (MDD). This study evaluated the preclinical and clinical pharmacokinetics and metabolism of DMT in healthy subjects. METHODS: The physiochemical properties of DMT were determined using a series of in vitro experiments and its metabolic profile was assessed using monoamine oxidase (MAO) and cytochrome P450 (CYP) inhibitors in hepatocyte and mitochondrial fractions. Clinical pharmacokinetics results are from the phase I component of a phase I/IIa randomised, double-blind, placebo-controlled, parallel-group, dose-escalation trial (NCT04673383). Healthy adults received single escalating doses of DMT fumarate (SPL026) via a two-phase intravenous (IV) infusion. Dosing regimens were calculated based on pharmacokinetic modelling and predictions with progression to each subsequent dose level contingent upon safety and tolerability. RESULTS: In vitro clearance of DMT was reduced through the inhibition of MAO-A, CYP2D6 and to a lesser extent CYP2C19. Determination of lipophilicity and plasma protein binding was low, indicating that a high proportion of DMT is available for distribution and metabolism, consistent with the very rapid clinical pharmacokinetics. Twenty-four healthy subjects received escalating doses of DMT administered as a 10-min infusion over the dose range of 9-21.5 mg (DMT freebase). DMT was rapidly cleared for all doses: mean elimination half-life was 9-12 min. All doses were safe and well tolerated and there was no relationship between peak DMT plasma concentrations and body mass index (BMI) or weight. CONCLUSION: This is the first study to determine, in detail, the full pharmacokinetics profile of DMT following a slow IV infusion in humans, confirming rapid attainment of peak plasma concentrations followed by rapid clearance. These findings provide evidence which supports the development of novel DMT infusion regimens for the treatment of MDD. CLINICAL TRIAL REGISTRATION: Registered on ClinicalTrials.gov (NCT04673383).


Asunto(s)
Trastorno Depresivo Mayor , N,N-Dimetiltriptamina , Adulto , Humanos , Trastorno Depresivo Mayor/tratamiento farmacológico , Citocromo P-450 CYP2D6/metabolismo , Monoaminooxidasa/metabolismo , Cinética , Método Doble Ciego , Relación Dosis-Respuesta a Droga
9.
SLAS Technol ; 28(5): 375-379, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37327946

RESUMEN

Laboratory automation uses large amounts of plastic consumables, generating substantial single-use plastic waste. Automated ELISAs are an indispensable analytical tool in vaccine formulation and process development. Current workflows, however, rely on disposable liquid handling tips. In progress toward sustainability, we developed workflows for washing 384-well format liquid handling tips, using nontoxic reagents, for re-use during ELISA testing. We estimate that this workflow reduces plastic and cardboard waste in our facility by 989 kg/year and 202 kg/year, respectively, without introducing new chemicals into our waste steam.

11.
J Bacteriol ; 194(13): 3395-406, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22544270

RESUMEN

Nearly every known species of Eubacteria encodes a homolog of the Borrelia burgdorferi EbfC DNA-binding protein. We now demonstrate that fluorescently tagged EbfC associates with B. burgdorferi nucleoids in vivo and that chromatin immunoprecipitation (ChIP) of wild-type EbfC showed it to bind in vivo to sites throughout the genome, two hallmarks of nucleoid-associated proteins. Comparative RNA sequencing (RNA-Seq) of a mutant B. burgdorferi strain that overexpresses EbfC indicated that approximately 4.5% of borrelial genes are significantly impacted by EbfC. The ebfC gene was highly expressed in rapidly growing bacteria, but ebfC mRNA was undetectable in stationary phase. Combined with previous data showing that EbfC induces bends in DNA, these results demonstrate that EbfC is a nucleoid-associated protein and lead to the hypothesis that B. burgdorferi utilizes cellular fluctuations in EbfC levels to globally control transcription of numerous genes. The ubiquity of EbfC proteins in Eubacteria suggests that these results apply to a wide range of pathogens and other bacteria.


Asunto(s)
Proteínas Bacterianas/metabolismo , Borrelia burgdorferi/metabolismo , Proteínas de Unión al ADN/metabolismo , Regulación Bacteriana de la Expresión Génica , Proteínas Bacterianas/genética , Secuencia de Bases , Borrelia burgdorferi/genética , Borrelia burgdorferi/crecimiento & desarrollo , Nucléolo Celular , Inmunoprecipitación de Cromatina , ADN Bacteriano/genética , ADN Bacteriano/metabolismo , Proteínas de Unión al ADN/genética , Enfermedad de Lyme/microbiología , Datos de Secuencia Molecular , Análisis de Secuencia de ARN
12.
J Bacteriol ; 194(17): 4570-8, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22730122

RESUMEN

The Borrelia burgdorferi BpaB proteins of the spirochete's ubiquitous cp32 prophages are DNA-binding proteins, required both for maintenance of the bacteriophage episomes and for transcriptional regulation of the cp32 erp operons. Through use of DNase I footprinting, we demonstrate that BpaB binds the erp operator initially at the sequence 5'-TTATA-3'. Electrophoretic mobility shift assays indicated that BpaB also binds with high affinity to sites located in the 5' noncoding regions of two additional cp32 genes. Characterization of the proteins encoded by those genes indicated that they are a single-stranded DNA-binding protein and a nuclease, which we named SsbP and NucP, respectively. Chromatin immunoprecipitation indicated that BpaB binds erp, ssbP, and nucP in live B. burgdorferi. A mutant bacterium that overexpressed BpaB produced significantly higher levels of ssbP and nucP transcript than did the wild-type parent.


Asunto(s)
Proteínas Bacterianas/genética , Borrelia burgdorferi/genética , Borrelia burgdorferi/virología , Proteínas de Unión al ADN/genética , Desoxirribonucleasas/genética , Profagos/genética , Proteínas Bacterianas/metabolismo , Secuencia de Bases , Sitios de Unión , Borrelia burgdorferi/metabolismo , Inmunoprecipitación de Cromatina , Huella de ADN , Proteínas de Unión al ADN/metabolismo , Desoxirribonucleasas/metabolismo , Datos de Secuencia Molecular , Regiones Operadoras Genéticas , Profagos/metabolismo , Unión Proteica , Replicón , Transcripción Genética
13.
J Bacteriol ; 194(4): 778-86, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22155777

RESUMEN

Vector-borne pathogens regulate their protein expression profiles, producing factors during host infection that differ from those produced during vector colonization. The Lyme disease agent, Borrelia burgdorferi, produces Erp surface proteins throughout mammalian infection and represses their synthesis during colonization of vector ticks. Known functions of Erp proteins include binding of host laminin, plasmin(ogen), and regulators of complement activation. A DNA region immediately 5' of erp operons, the erp operator, is required for transcriptional regulation. The B. burgdorferi BpaB and EbfC proteins exhibit high in vitro affinities for erp operator DNA. In the present studies, chromatin immunoprecipitation (ChIP) demonstrated that both proteins bind erp operator DNA in vivo. Additionally, a combination of in vivo and in vitro methods demonstrated that BpaB functions as a repressor of erp transcription, while EbfC functions as an antirepressor.


Asunto(s)
Antígenos Bacterianos/metabolismo , Proteínas de la Membrana Bacteriana Externa/metabolismo , Proteínas Bacterianas/metabolismo , Borrelia burgdorferi/genética , Borrelia burgdorferi/metabolismo , Proteínas de Unión al ADN/metabolismo , Lipoproteínas/metabolismo , Antígenos Bacterianos/biosíntesis , Proteínas de la Membrana Bacteriana Externa/biosíntesis , Proteínas Bacterianas/biosíntesis , Proteínas Bacterianas/genética , Secuencia de Bases , Inmunoprecipitación de Cromatina , Activación de Complemento , ADN Bacteriano/genética , ADN Bacteriano/metabolismo , Proteínas de Unión al ADN/biosíntesis , Proteínas de Unión al ADN/genética , Fibrinolisina/metabolismo , Laminina/metabolismo , Lipoproteínas/biosíntesis , Enfermedad de Lyme/patología , Datos de Secuencia Molecular , Regiones Operadoras Genéticas , Transcripción Genética
14.
Nucleic Acids Res ; 38(16): 5443-55, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20421207

RESUMEN

Borrelia burgdorferi produces Erp outer surface proteins throughout mammalian infection, but represses their synthesis during colonization of vector ticks. A DNA region 5' of the start of erp transcription, Operator 2, was previously shown to be essential for regulation of expression. We now report identification and characterization of a novel erp Operator 2-binding protein, which we named BpaB. erp operons are located on episomal cp32 prophages, and a single bacterium may contain as many as 10 different cp32s. Each cp32 family member encodes a unique BpaB protein, yet the three tested cp32-encoded BpaB alleles all bound to the same DNA sequence. A 20-bp region of erp Operator 2 was determined to be essential for BpaB binding, and initial protein binding to that site was required for binding of additional BpaB molecules. A 36-residue region near the BpaB carboxy terminus was found to be essential for high-affinity DNA-binding. BpaB competed for binding to erp Operator 2 with a second B. burgdorferi DNA-binding protein, EbfC. Thus, cellular levels of free BpaB and EbfC could potentially control erp transcription levels.


Asunto(s)
Proteínas de la Membrana Bacteriana Externa/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Borrelia burgdorferi/genética , Proteínas de Unión al ADN/metabolismo , Regiones Operadoras Genéticas , Secuencia de Aminoácidos , Proteínas Bacterianas/química , Secuencia de Bases , Sitios de Unión , Unión Competitiva , Borrelia burgdorferi/virología , ADN Bacteriano/química , ADN Bacteriano/metabolismo , Proteínas de Unión al ADN/química , Datos de Secuencia Molecular , Profagos/genética , Estructura Terciaria de Proteína , Homología de Secuencia de Aminoácido
15.
AAPS J ; 25(1): 10, 2022 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-36482268

RESUMEN

The rapid development of biologics and vaccines in response to the current pandemic has highlighted the need for robust platform assays to characterize diverse biopharmaceuticals. A critical aspect of biopharmaceutical development is achieving a highly pure product, especially with respect to residual host cell material. Specifically, two important host cell impurities of focus within biopharmaceuticals are residual DNA and protein. In this work, a novel high-throughput host cell DNA quantitation assay was developed for rapid screening of complex vaccine drug substance samples. The developed assay utilizes the commercially available, fluorescent-sensitive Picogreen dye within a 96-well plate configuration to allow for a cost effective and rapid analysis. The assay was applied to in-process biopharmaceutical samples with known interferences to the dye, including RNA and protein. An enzymatic digestion pre-treatment was found to overcome these interferences and thus allow this method to be applied to wide-ranging, diverse analyses. In addition, the use of deoxycholate in the digestion treatment allowed for disruption of interactions in a given sample matrix in order to more accurately and selectively quantitate DNA. Critical analytical figures of merit for assay performance, such as precision and spike recovery, were evaluated and successfully demonstrated. This new analytical method can thus be successfully applied to both upstream and downstream process analysis for biologics and vaccines using an innovative and automated high-throughput approach.


Asunto(s)
Productos Biológicos , Vacunas , Proyectos de Investigación , ADN
16.
Nucleic Acids Res ; 37(6): 1973-83, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19208644

RESUMEN

The Lyme disease spirochete, Borrelia burgdorferi, encodes a novel type of DNA-binding protein named EbfC. Orthologs of EbfC are encoded by a wide range of bacterial species, so characterization of the borrelial protein has implications that span the eubacterial kingdom. The present work defines the DNA sequence required for high-affinity binding by EbfC to be the 4 bp broken palindrome GTnAC, where 'n' can be any nucleotide. Two high-affinity EbfC-binding sites are located immediately 5' of B. burgdorferi erp transcriptional promoters, and binding of EbfC was found to alter the conformation of erp promoter DNA. Consensus EbfC-binding sites are abundantly distributed throughout the B. burgdorferi genome, occurring approximately once every 1 kb. These and other features of EbfC suggest that this small protein and its orthologs may represent a distinctive type of bacterial nucleoid-associated protein. EbfC was shown to bind DNA as a homodimer, and site-directed mutagenesis studies indicated that EbfC and its orthologs appear to bind DNA via a novel alpha-helical 'tweezer'-like structure.


Asunto(s)
Proteínas Bacterianas/química , Borrelia burgdorferi/genética , ADN Bacteriano/química , Proteínas de Unión al ADN/química , Secuencia de Aminoácidos , Proteínas Bacterianas/clasificación , Proteínas Bacterianas/metabolismo , Secuencia de Bases , Sitios de Unión , Secuencia Conservada , ADN Bacteriano/metabolismo , Proteínas de Unión al ADN/clasificación , Proteínas de Unión al ADN/metabolismo , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , Regiones Operadoras Genéticas , Unión Proteica , Multimerización de Proteína , Estructura Terciaria de Proteína
17.
Methods Mol Biol ; 2277: 345-356, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34080161

RESUMEN

Mitochondrial DNA (mtDNA) has been demonstrated to be a reliable biomarker of UV-induced genetic damage in both animal and human skin. Properties of the mitochondrial genome which allow for its use as a biomarker of damage include its presence in multiple copies within a cell, its limited repair mechanisms, and its lack of protective histones. To measure UV-induced mtDNA damage (particularly in the form of strand breaks), real-time quantitative PCR (qPCR) is used, based on the observation that PCR amplification efficiency is decreased in the presence of high levels of damage. Here, we describe the measurement of UV-induced mtDNA damage which includes the extraction of cellular DNA, qPCR to determine the relative amount of mtDNA, qPCR to determine UV-induced damage within a long strand of mtDNA, and the verification of the amplification process using gel electrophoresis.


Asunto(s)
ADN Mitocondrial/análisis , ADN Mitocondrial/efectos de la radiación , Electroforesis en Gel de Agar/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Piel/efectos de la radiación , Biomarcadores/análisis , Daño del ADN , ADN Mitocondrial/aislamiento & purificación , Marcadores Genéticos , Humanos , Rayos Ultravioleta/efectos adversos
18.
FASEB Bioadv ; 3(10): 855-865, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34632319

RESUMEN

The damaging effects of air pollution on the skin are becoming increasingly researched and the outcomes of this research are now a major influence in the selection and development of protective ingredients for skincare formulations. However, extensive research has not yet been conducted into the specific cellular defense systems that are being affected after exposure to such pollutants. Research investigating the affected systems is integral to the development of suitable interventions that are capable of augmenting the systems most impacted by air pollutant exposure. The following studies involved exposing primary human dermal fibroblasts to different concentrations of particulate matter and analyzing its effects on mitochondrial complex activity, nuclear factor erythroid 2-related factor 2 localization using immunocytochemistry and protein expression of electron transport chain complex proteins, sirtuin-1 (SIRT1), and peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) using western blotting. Particulate matter-induced alterations in both mitochondrial complex protein and activity, indicating oxidative stress, which was also complimented by increased expression of antioxidant proteins GSTP1/2 and SOD2. Particulate matter also seemed to modify expression of the proteins SIRT1 and PGC-1α which are heavily involved in the regulation of mitochondrial biogenesis and energy metabolism. Given the reported results indicating that particulate matter induces damage through oxidative stress and has a profound effect on mitochondrial homeostasis, interventions involving targeted mitochondrial antioxidants may help to minimize the damaging downstream effects of pollutant-induced oxidative stress originating from the mitochondria.

19.
Infect Immun ; 78(5): 2053-9, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20160016

RESUMEN

The spirochete Leptospira interrogans is a highly invasive pathogen of worldwide public health importance. Studies from our laboratories and another have demonstrated that L. interrogans can acquire host plasminogen on its surface. Exogenous plasminogen activators can then convert bound plasminogen into the functionally active protease plasmin. In this study, we extend upon those observations and report that leptospiral endostatin-like protein A (LenA) binds human plasminogen in a dose-dependent manner. LenA-plasminogen interactions were significantly inhibited by the lysine analog xi-aminocaproic acid, suggesting that the lysine-binding sites on the amino-terminal kringle portion of the plasminogen molecule play a role in the binding. Previous studies have shown that LenA also binds complement regulator factor H and the extracellular matrix component laminin. Plasminogen competed with both factor H and laminin for binding to LenA, which suggests overlapping ligand-binding sites on the bacterial receptor. Finally, LenA-bound plasminogen could be converted to plasmin, which in turn degraded fibrinogen, suggesting that acquisition of host-derived plasmin by LenA may aid bacterial dissemination throughout host tissues.


Asunto(s)
Proteínas Bacterianas/metabolismo , Leptospira interrogans/patogenicidad , Plasminógeno/metabolismo , Aminocaproatos/farmacología , Factor H de Complemento/metabolismo , Inhibidores Enzimáticos/farmacología , Humanos , Laminina/metabolismo , Unión Proteica , Mapeo de Interacción de Proteínas
20.
Lancet ; 373(9678): 1874-82, 2009 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-19446324

RESUMEN

BACKGROUND: Long-term complications of critical illness include intensive care unit (ICU)-acquired weakness and neuropsychiatric disease. Immobilisation secondary to sedation might potentiate these problems. We assessed the efficacy of combining daily interruption of sedation with physical and occupational therapy on functional outcomes in patients receiving mechanical ventilation in intensive care. METHODS: Sedated adults (>/=18 years of age) in the ICU who had been on mechanical ventilation for less than 72 h, were expected to continue for at least 24 h, and who met criteria for baseline functional independence were eligible for enrolment in this randomised controlled trial at two university hospitals. We randomly assigned 104 patients by computer-generated, permuted block randomisation to early exercise and mobilisation (physical and occupational therapy) during periods of daily interruption of sedation (intervention; n=49) or to daily interruption of sedation with therapy as ordered by the primary care team (control; n=55). The primary endpoint-the number of patients returning to independent functional status at hospital discharge-was defined as the ability to perform six activities of daily living and the ability to walk independently. Therapists who undertook patient assessments were blinded to treatment assignment. Secondary endpoints included duration of delirium and ventilator-free days during the first 28 days of hospital stay. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00322010. FINDINGS: All 104 patients were included in the analysis. Return to independent functional status at hospital discharge occurred in 29 (59%) patients in the intervention group compared with 19 (35%) patients in the control group (p=0.02; odds ratio 2.7 [95% CI 1.2-6.1]). Patients in the intervention group had shorter duration of delirium (median 2.0 days, IQR 0.0-6.0 vs 4.0 days, 2.0-8.0; p=0.02), and more ventilator-free days (23.5 days, 7.4-25.6 vs 21.1 days, 0.0-23.8; p=0.05) during the 28-day follow-up period than did controls. There was one serious adverse event in 498 therapy sessions (desaturation less than 80%). Discontinuation of therapy as a result of patient instability occurred in 19 (4%) of all sessions, most commonly for perceived patient-ventilator asynchrony. INTERPRETATION: A strategy for whole-body rehabilitation-consisting of interruption of sedation and physical and occupational therapy in the earliest days of critical illness-was safe and well tolerated, and resulted in better functional outcomes at hospital discharge, a shorter duration of delirium, and more ventilator-free days compared with standard care. FUNDING: None.


Asunto(s)
Cuidados Críticos/métodos , Enfermedad Crítica/rehabilitación , Ambulación Precoz/métodos , Terapia por Ejercicio/métodos , Terapia Ocupacional/métodos , Respiración Artificial , Actividades Cotidianas , Adulto , Anciano , Reposo en Cama/efectos adversos , Chicago , Sedación Consciente/efectos adversos , Sedación Consciente/métodos , Delirio/etiología , Delirio/prevención & control , Femenino , Humanos , Iowa , Estimación de Kaplan-Meier , Modelos Logísticos , Masculino , Persona de Mediana Edad , Limitación de la Movilidad , Modelos de Riesgos Proporcionales , Respiración Artificial/efectos adversos , Respiración Artificial/métodos , Método Simple Ciego , Estadísticas no Paramétricas , Factores de Tiempo , Resultado del Tratamiento
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