49 research outputs found

    Colorimetric Identification of Proteins Using Gold Nanoparticles

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    Proteins are the principal executive biomolecules of life. Their existence is required to drive and regulate countless physiological and biochemical activities within the cell. The study of biochemistry and biology are therefore frequently concerned with monitoring the presence, distribution, and function of proteins. Conventional protein identification assays are often labour-intensive and rely on the use of expensive antibodies. The development of new protein biosensors that incorporate nanotechnology, specifically gold nanoparticles (AuNPs), may allow for facile detection, identification, and quantification of proteins due to their colorimetric output. Unlike other strategies that use antibody-functionalized gold nanoparticles, the pairing of non-functionalized nanoparticles with spectroscopic analysis may further reduce the cost of analysis and make this technology viable for consumer-level applications. This thesis focuses on the development of a gold nanoparticle biosensor for the detection, identification, and quantification of proteins. The underlying principle is based on the aggregation of non-functionalized gold nanoparticles in the presence of proteins. The physicochemical characteristics of these gold nanoparticles can be manipulated to alter their response to different proteins. In order to achieve identification based on non-specific interactions, a “chemical nose” strategy is followed, whereby different gold-nanoparticles produce different individual responses, and their collective response defines a unique signature for a given protein. A review of current literature presents the variety of biological, chemical, and physical factors that can affect protein-nanoparticle interactions, and their resultant effect on colloidal stability. This review also highlights the complexity with which these factors can interact and identifies key considerations for maintaining or controlling colloidal stability in various applications. The experiments herein address the role of shape and surfactant-type on aggregation of gold nanoparticles. Shape has previously been shown to affect protein-nanoparticle interactions, but to our knowledge has not been exploited for protein sensing applications. The role of surfactant on protein-gold nanoparticle interactions is not well studied and provides a novel avenue for investigation. This work demonstrates that both these parameters can be used to alter protein-nanoparticle interactions, thereby permitting “chemical nose”-type detection of proteins. Overall, these studies highlight how modifying protein-nanoparticle interactions can be used for the benefit of biosensing in research and clinical settings. In addition to biosensing, this manner of investigation can serve as a powerful tool to study protein-nanoparticle interactions, with widespread implications in medicine, environmental protection, and water treatment

    CEP128 Localizes to the Subdistal Appendages of the Mother Centriole and Regulates TGF-β/BMP Signaling at the Primary Cilium

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    Summary: The centrosome is the main microtubule-organizing center in animal cells and comprises a mother and daughter centriole surrounded by pericentriolar material. During formation of primary cilia, the mother centriole transforms into a basal body that templates the ciliary axoneme. Ciliogenesis depends on mother centriole-specific distal appendages, whereas the role of subdistal appendages in ciliary function is unclear. Here, we identify CEP128 as a centriole subdistal appendage protein required for regulating ciliary signaling. Loss of CEP128 did not grossly affect centrosomal or ciliary structure but caused impaired transforming growth factor-β/bone morphogenetic protein (TGF-β/BMP) signaling in zebrafish and at the primary cilium in cultured mammalian cells. This phenotype is likely the result of defective vesicle trafficking at the cilium as ciliary localization of RAB11 was impaired upon loss of CEP128, and quantitative phosphoproteomics revealed that CEP128 loss affects TGF-β1-induced phosphorylation of multiple proteins that regulate cilium-associated vesicle trafficking. : Mönnich et al. show that CEP128 localizes to the subdistal appendages of the mother centriole and basal body of the primary cilium. CEP128 regulates vesicular trafficking and targeting of RAB11 to the primary cilium. CEP128 loss leads to impaired TGF-β/BMP signaling, which, in zebrafish, is associated with defective organ development. Keywords: primary cilium, basal body, centriole, subdistal appendage, centrosome, transforming growth factor β, TGF-β, bone morphogenetic protein, BMP, zebrafish, phosphoproteomics, CEP12

    Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

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    BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

    Internal Thoracic Impedance - A Useful Method for Expedient Detection and Convenient Monitoring of Pleural Effusion

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    <div><p>Measurement of internal thoracic impedance (ITI) is sensitive and accurate in detecting acute pulmonary edema even at its preclinical stage. We evaluated the suitability of the highly sensitive and noninvasive RS-207 monitor for detecting pleural effusion and for demonstrating increased ITI during its resolution. This prospective controlled study was performed in a single department of internal medicine of a university-affiliated hospital between 2012-2013. One-hundred patients aged 25–96 years were included, of whom 50 had bilateral or right pleural effusion of any etiology (study group) and 50 had no pleural effusion (controls). ITI, the main component of which is lung impedance, was continuously measured by the RS-207 monitor. The predictive value of ITI monitoring was determined by 8 measurements taken every 8 hours. Pleural effusion was diagnosed according to well-accepted clinical and roentgenological criteria. During treatment, the ITI of the study group increased from 32.9±4.2 ohm to 42.8±3.8 ohm (<i>p</i><0.0001) compared to non-significant changes in the control group (59.6±6.6 ohm, <i>p</i> = 0.24). Prominent changes were observed in the respiratory rate of the study group: there was a decrease from 31.2±4.0 to 19.5±2.4 ohm (35.2%) compared to no change for the controls, and a mean increase from 83.6±5.3%-92.5±1.6% (13.2%) in O2 saturation compared to 94.2±1.7% for the controls. Determination of ITI for the detection and monitoring of treatment of patients with pleural effusion enables earlier diagnosis and more effective therapy, and can prevent hospitalization and serious complications, such as respiratory distress, and the need for mechanical ventilation.</p><p>Trial Registration</p><p>The study is registered at ClinicalTrials.gov <a href="https://clinicaltrials.gov/ct2/results?term=NCT01601444" target="_blank">NCT01601444</a></p></div

    Mechanical Contact Characteristics of PC3 Human Prostate Cancer Cells on Complex-Shaped Silicon Micropillars

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    In this study we investigated the contact characteristics of human prostate cancer cells (PC3) on silicon micropillar arrays with complex shapes by using high-resolution confocal fluorescence microscopy techniques. These arrays consist of micropillars that are of various cross-sectional geometries which produce different deformation profiles in adherent cells. Fluorescence micrographs reveal that some DAPI (4′,6-diamidino-2-phenylindole)-stained nuclei from cells attached to the pillars develop nanometer scale slits and contain low concentrations of DNA. The lengths of these slits, and their frequency of occurrence, were characterized for various cross-sectional geometries. These DNA-depleted features are only observed in locations below the pillar’s top surfaces. Results produced in this study indicate that surface topography can induce unique nanometer scale features in the PC3 cell

    Methylation of <i>CLEC11A</i> across cytogenetic risk factor classification.

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    Average methylation of the CLEC11A gene was analyzed based on favorable, intermediate, or poor risk prognosis. Total methylation (A; p = 0.00005354), as well as methylation at the CpG island (B; p = 0.03174), North Shore (C; p = 0.00001247), and South Shore (D; p = 0.1991) are shown. Statistical significance was determined utilizing a Kruskal-Willis test with Dunn’s multiple comparisons and Bonferroni correction. Statistical significance between individual risk factor groups is indicated on graphs as appropriate.</p
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