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Botulinum toxin use in patients with post-stroke spasticity: a nationwide retrospective study from France. Front Neurol 2023; 14:1245228. [PMID: 37681005 PMCID: PMC10482253 DOI: 10.3389/fneur.2023.1245228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 08/11/2023] [Indexed: 09/09/2023] Open
Abstract
Background Current guidelines recommend intramuscular botulinum toxin type A (BoNT-A) injection as first-line treatment for spasticity, a frequent and impairing feature of various central nervous system (CNS) lesions such as stroke. Patients with spasticity commonly require BoNT-A injections once every 3 to 4 months. We conducted a nationwide, population-based, retrospective cohort study, using the French National Hospital Discharge Database (PMSI), to describe BoNT-A use for spasticity in clinical practice in France between 2014 and 2020. The PMSI database covers the whole French population, corresponding to over 66 million persons. Methods We first searched the PMSI database for healthcare facility discharge of patients who received BoNT-A injections between 2014 and 2020, corresponding to the first set. For each BoNT-A-treated patient, we identified the medical condition for which BoNT-A may have been indicated. Another search of the PMSI database focused on patients admitted for acute stroke between 2014 and 2016 and their spasticity-related care pathway (second set). Overall, two subpopulations were analysed: 138,481 patients who received BoNT-A injections between 2014 and 2020, and 318,025 patients who survived a stroke event between 2014 and 2016 and were followed up until 2020. Results Among the 138,481 BoNT-A-treated patients, 53.5% received only one or two BoNT-A injections. Most of these patients (N = 85,900; 62.0%) received BoNT-A because they had CNS lesions. The number of patients with CNS lesions who received ≥1 BoNT-A injection increased by a mean of 7.5% per year from 2014 to 2019, but decreased by 0.2% between 2019 and 2020, corresponding to the COVID-19 outbreak. In stroke survivors (N = 318,025), 10.7% were coded with post-stroke spasticity, 2.3% received ≥1 BoNT-A injection between 2014 and 2020, and only 0.8% received ≥3 injections within the 12 months following BoNT-A treatment initiation, i.e., once every 3 to 4 months. Conclusion Our analysis of the exhaustive PMSI database showed a suboptimal implementation of BoNT-A treatment recommendations in France. BoNT-A treatment initiation and re-administration are low, particularly in patients with post-stroke spasticity. Further investigations may help explain this observation, and may target specific actions to improve spasticity-related care pathway.
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Electrospun Metal-Organic Framework-Fabric Nanocomposites as Efficient Bactericides. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023. [PMID: 37384737 DOI: 10.1021/acs.langmuir.3c01039] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/01/2023]
Abstract
In this work, we utilized electrospinning to develop advanced composite membranes of polyvinyl chloride (PVC) loaded with postmetalated metal-organic frameworks (MOFs), specifically UiO-66(COOH)2-Ag and ZIF-8-Ag. This innovative technique led to the creation of highly stable PVC/MOFs-Ag membrane composites, which were thoroughly characterized using various analytical techniques, including scanning electron microscopy, powder X-ray diffraction, thermogravimetric analysis, X-ray photoelectron spectroscopy, porosity analysis, and water contact angle measurement. The results verified the successful integration of MOF crystals within the nanofibrous PVC membranes. The obtained composites exhibited larger fiber diameters for 5 and 10% MOF loadings and a smaller diameter for 20% loading. Additionally, they displayed greater average pore sizes than traditional PVC membranes across most MOF loading percentages. Furthermore, we examined the antibacterial properties of the fabricated membranes at different MOFs-Ag loadings. The findings revealed that the membranes demonstrated significant antibacterial activity up to 95% against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria as the MOFs-Ag loading increased, even when maintaining a constant silver concentration. This indicates a contact-based inhibition mechanism. The outcomes of this study have crucial implications for the development of novel, stable, and highly effective antibacterial materials, which could serve as superior alternatives for face masks and be integrated into materials requiring regular decontamination, as well as potential water filtration systems.
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Trends in Botulinum Toxin Use among Patients with Multiple Sclerosis: A Population-Based Study. Toxins (Basel) 2023; 15:toxins15040280. [PMID: 37104218 PMCID: PMC10142089 DOI: 10.3390/toxins15040280] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/03/2023] [Accepted: 04/07/2023] [Indexed: 04/28/2023] Open
Abstract
There are limited real-world data on the use of botulinum toxin type A (BoNT-A) in patients with multiple sclerosis (MS). Accordingly, this nationwide, population-based, retrospective cohort study aimed to describe BoNT-A treatment trends in patients with MS between 2014 and 2020 in France. This study extracted data from the French National Hospital Discharge Database (Programme de Médicalisation des Systèmes d'Information, PMSI) covering the entire French population. Among 105,206 patients coded with MS, we identified those who received ≥1 BoNT-A injection, administered within striated muscle for MS-related spasticity and/or within the detrusor smooth muscle for neurogenic detrusor overactivity (NDO). A total of 8427 patients (8.0%) received BoNT-A injections for spasticity, 52.9% of whom received ≥3 BoNT-A injections with 61.9% of the repeated injections administered every 3 to 6 months. A total of 2912 patients (2.8%) received BoNT-A injections for NDO, with a mean of 4.7 injections per patient. Most repeated BoNT-A injections within the detrusor smooth muscle (60.0%) were administered every 5 to 8 months. There were 585 patients (0.6%) who received both BoNT-A injections within striated muscle and the detrusor smooth muscle. Overall, our study highlights a broad range of BoNT-A treatment practices between 2014 and 2020 in patients with MS.
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French health insurance data for chronic rhinosinusitis with nasal polyps between 2011 and 2018: A STROBE-compliant analysis. Eur Ann Otorhinolaryngol Head Neck Dis 2023; 140:65-69. [PMID: 36028425 DOI: 10.1016/j.anorl.2022.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
AIMS The main aim of the present study was to report the annual volume of surgeries performed for chronic rhinosinusitis with nasal polyps (CRSwNP) in France, based on health insurance data. The secondary objectives were to describe the different characteristics of the surgeries and their complications, and to estimate the number of patients eligible for biotherapy. MATERIAL AND METHODS This was a descriptive observational retrospective study using data from French national health insurance databases for the period 2011-2018. Inclusion criteria comprised all hospital stays with procedures related to CRSwNP according to the French Common Classification of Medical Acts and consistent with French practices. RESULTS Ninety-two thousand one hundred and fourty one patients (92,141) for 92,884 admissions for CRSwNP surgery were analyzed, providing an accurate representation of CRSwNP surgery in France between 2011 and 2018. The revision surgery rate for patients operated on in 2011 was 13.0% (1,457/11,212), corresponding to an average annual rate of 1.86% over 7 years. In the 11,750 sinus surgery admissions in 2018, the complications rate was only 0.65% (77/11,750). CONCLUSION Sinus surgery is safe (0.65% complications) and reliable (estimated revision rate, 5.5%: 5,078/92,884). This study provides the first evaluation of the target population for biotherapy in France.
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The contribution of real-world evidence to cost-effectiveness analysis: case study of Dabigatran etexilate in France. THE EUROPEAN JOURNAL OF HEALTH ECONOMICS : HEPAC : HEALTH ECONOMICS IN PREVENTION AND CARE 2020; 21:235-249. [PMID: 31650440 DOI: 10.1007/s10198-019-01123-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Accepted: 10/02/2019] [Indexed: 06/10/2023]
Abstract
OBJECTIVE The goal of this study was to assess the differences between an ex ante and an ex post cost-effectiveness analysis of Dabigatran etexilate vs VKAs for the prevention of thromboembolic events in non-valvular atrial fibrillation patients and to draw lessons on the design and use of real-world data for decision making. METHODS The same model was used to calculate the cost-effectiveness ratio using two sets of parameters. One set included the efficacy and safety outcomes data from RE-LY, the pivotal trial comparing Dabigatran to warfarin; cost data came from an ex ante publication. Outcomes data for the second set came from real-world data studies. Cost data were a mix of real-world data and other sources. Two treatment strategies were compared: treatment initiation by either Dabigatran or VKAs, followed by either VKAs or Dabigatran. A crude comparison of results was performed; the impact of data differences was then assessed. Probabilistic sensitivity results of the two analyses were compared. RESULTS With real-world evidence, Dabigatran at both dosages was more effective for the prevention of ischemic strokes, intra-cranial haemorrhages, with less major extra-cranial haemorrhages and a similar risk of myocardial infarction. Using clinical trial data, Dabigatran150 mg (resp. Dabigatran110 mg) as a first-line treatment vs VKAs yielded an ICER of € 8077/QALY (resp. € 13,116/QALY). Real-world evidence scenarios were cost-saving and more effective for both dosages. CONCLUSION The reassessment of outcomes and cost data had an impact on results, improving the efficiency of Dabigatran. We identify methodological issues which should be discussed if post-launch RWE based cost-effectiveness data become a standard in HTA decision making.
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Fluorescent-Based Thermal Sensing in Lipid Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:1221-1226. [PMID: 31941281 DOI: 10.1021/acs.langmuir.9b03128] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Thermal mapping in biological membranes could unlock and help us understand many chemical and physical processes that do not only pertain to localized membrane phenomena but also extend to many other intra- and extracellular pathways. In this manuscript, we report the development of a ratiometric thermal fluorescent probe based on the Förster resonance energy transfer between a lipid-embedded conjugated polyelectrolyte and a lyophilic acceptor dye. We showed that the Förster resonance energy transfer (FRET) pair is sensitive within the relevant physiological temperature window (20.0-50.0 °C). The signal was also shielded from an external pH and stable when cycled multiple times. The probe was also sensitive to the membrane composition and could, therefore, be further developed to probe the membrane composition and viscosity.
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Abstract
Heat generated from magnetic nanoparticles when placed in an alternating magnetic field is used to drive a catalytic chemical reaction.
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Fluorescent thermal sensing using conjugated polyelectrolytes in thin polymer films. Anal Chim Acta 2019; 1077:249-254. [PMID: 31307716 DOI: 10.1016/j.aca.2019.05.046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Revised: 04/20/2019] [Accepted: 05/20/2019] [Indexed: 01/23/2023]
Abstract
Thermal sensing in thin films polymers has been a significant limitation towards optimizing the heat dissipation in micro- and nano-electronic devices as well as many other thin film-based technologies. In this work, we report on poly (phenylene ethynylene) fluorescent-based conjugated polyelectrolyte capable of detecting thermal fluctuations in polymer films prepared from polyvinylpyrrolidone-co-vinyl acetate. The sensor was first optimized in solution by testing two polyvinylpyrrolidone (PVP) copolymers (co-vinyl acetate (VA) and co-polystyrene (PS)) before it was spun cast onto quartz slides and imaged using a DSLR camera at different temperatures. The images were analyzed and showed a change in color with the increase in temperature. When not illuminated, the polymer thin film is clear and transparent.
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Silver-Modified Cross-Linked Polyvinylpyrrolidone and Its Antibacterial Activity. ACS APPLIED BIO MATERIALS 2018; 1:1864-1870. [DOI: 10.1021/acsabm.8b00377] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
Porphyrins have been widely used in many optical devices given their unique photochemical properties. Their poor photostability has, however, limited their wide applications in bioimaging and biosensing schemes. Herein, we report the remarkable photostability enhancement of the porphyrin, carboxyphenyl porphyrin (TCPP-H2) when locked in a zirconium based metal-organic framework (MOF-525). Steady-state ensemble fluorescence spectroscopy experiments showed minimal changes (2%) in the recorded signal when MOF-525 was continuously illuminated as compared to a 16% decrease for free porphyrins. Single particle fluorescence imaging revealed bright microparticles with exceptional photostability and no-blinking within the experiment window. This study highlights the use of metal-organic frameworks for preparing photostable microstructures by leveraging on their unique self-assembly properties.
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The Role of Hydrophobicity in the Cellular Uptake of Negatively Charged Macromolecules. Macromol Biosci 2017; 18. [DOI: 10.1002/mabi.201700309] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 11/09/2017] [Indexed: 12/18/2022]
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Medical management of spasticity using botulinum toxin in France: Etiologies and evolution of practices. Ann Phys Rehabil Med 2017. [DOI: 10.1016/j.rehab.2017.07.163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Abstract
We report a self-referencing ratiometric nanothermometer based on short conjugated polyelectrolytes (CPEs).
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Turning the heat on conjugated polyelectrolytes: an off–on ratiometric nanothermometer. Chem Commun (Camb) 2016; 52:823-6. [DOI: 10.1039/c5cc08541a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A ratiometric single component nanothermometer fluorescent probe.
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Nanohybrid conjugated polyelectrolytes: highly photostable and ultrabright nanoparticles. NANOSCALE 2015; 7:15149-15158. [PMID: 26255590 DOI: 10.1039/c5nr03299g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present a general and straightforward one-step approach to enhance the photophysical properties of conjugated polyelectrolytes. Upon complexation with an amphiphilic polymer (polyvinylpyrrolidone), an anionic conjugated polyelectrolyte (poly[5-methoxy-2-(3-sulfopropoxy)-1,4-phenylenevinylene]) was prepared into small nanoparticles with exceptional photostability and brightness. The polymer fluorescence intensity was enhanced by 23 -fold and could be easily tuned by changing the order of addition. Single molecule experiments revealed a complete suppression of blinking. In addition, after only losing 18% of the original intensity, a remarkable amount of photons were emitted per particle (∼10(9), on average). This number is many folds greater than popular organic fluorescent dyes. We believe that an intimate contact between the two polymers is shielding the conjugated polyelectrolyte from the destructive photooxidation. The prepared nanohybrid particles will prove instrumental in single particle based fluorescent assays and can serve as a probe for the current state-of-the-art bioimaging fluorescence techniques.
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Cost-benefit analysis: newborn screening for inborn errors of metabolism in Lebanon. J Med Screen 2015; 22:182-6. [PMID: 26062758 DOI: 10.1177/0969141315590675] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Accepted: 05/12/2015] [Indexed: 11/16/2022]
Abstract
OBJECTIVES Few countries in the Middle East-North Africa region have adopted national newborn screening for inborn errors of metabolism by tandem mass spectrometry (MS/MS). We aimed to evaluate the cost-benefit of newborn screening for such disorders in Lebanon, as a model for other developing countries in the region. METHODS Average costs of expected care for inborn errors of metabolism cases as a group, between ages 0 and 18, early and late diagnosed, were calculated from 2007 to 2013. The monetary value of early detection using MS/MS was compared with that of clinical "late detection", including cost of diagnosis and hospitalizations. RESULTS During this period, 126000 newborns were screened. Incidence of detected cases was 1/1482, which can be explained by high consanguinity rates in Lebanon. A reduction by half of direct cost of care, reaching on average 31,631 USD per detected case was shown. This difference more than covers the expense of starting a newborn screening programme. CONCLUSION Although this model does not take into consideration the indirect benefits of the better quality of life of those screened early, it can be argued that direct and indirect costs saved through early detection of these disorders are important enough to justify universal publicly-funded screening, especially in developing countries with high consanguinity rates, as shown through this data from Lebanon.
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Interaction of anionic phenylene ethynylene polymers with lipids: from membrane embedding to liposome fusion. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:10704-10711. [PMID: 25115171 DOI: 10.1021/la502572u] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Here we report spectroscopic studies on the interaction of negatively charged, amphiphilic polyphenylene ethynylene (PPE) polymers with liposomes prepared either from negative, positive or zwitterionic lipids. Emission spectra of PPEs of 7 and 49 average repeat units bearing carboxylate terminated side chains showed that the polymer embeds within positively charged lipids where it exists as free chains. No interaction was observed between PPEs and negatively charged lipids. Here the polymer remained aggregated giving rise to broad emission spectra characteristic of the aggregate species. In zwitterionic lipids, we observed that the majority of the polymer remained aggregated yet a small fraction readily embedded within the membrane. Titration experiments revealed that saturation of zwitterionic lipids with polymer typically occurred at a polymer repeat unit to lipid mole ratio close to 0.05. No further membrane embedding was observed above that point. For liposomes prepared from positively charged lipids, saturation was observed at a PPE repeat unit to lipid mole ratio of ∼0.1 and liposome precipitation was observed above this point. FRET studies showed that precipitation was preceded by lipid mixing and liposome fusion induced by the PPEs. This behavior was prominent for the longer polymer and negligible for the shorter polymer at a repeat unit to lipid mole ratio of 0.05. We postulate that fusion is the consequence of membrane destabilization whereby the longer polymer gives rise to more extensive membrane deformation than the shorter polymer.
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Dynamics of hepatitis C virus (HCV) RNA-dependent RNA polymerase NS5B in complex with RNA. J Biol Chem 2014; 289:14399-411. [PMID: 24692556 DOI: 10.1074/jbc.m113.529743] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The hepatitis C virus (HCV) non-structural protein 5B (NS5B) is an RNA-dependent RNA polymerase that is essentially required for viral replication. Although previous studies revealed important properties of static NS5B-RNA complexes, the nature and relevance of dynamic interactions have yet to be elucidated. Here, we devised a single molecule Förster Resonance Energy Transfer (SM-FRET) assay to monitor temporal changes upon binding of NS5B to surface immobilized RNA templates. The data show enzyme association-dissociation events that occur within the time resolution of our setup as well as FRET-fluctuations in association with stable binary complexes that extend over prolonged periods of time. Fluctuations are shown to be dependent on the length of the RNA substrate, and enzyme concentration. Mutations in close proximity to the template entrance (K98E, K100E), and in the center of the RNA binding channel (R394E), reduce both the population of RNA-bound enzyme and the fluctuations associated to the binary complex. Similar observations are reported with an allosteric nonnucleoside NS5B inhibitor. Our assay enables for the first time the visualization of association-dissociation events of HCV-NS5B with RNA, and also the direct monitoring of the interaction between HCV NS5B, its RNA template, and finger loop inhibitors. We observe both a remarkably low dissociation rate for wild type HCV NS5B, and a highly dynamic enzyme-RNA binary complex. These results provide a plausible mechanism for formation of a productive binary NS5B-RNA complex, here NS5B slides along the RNA template facilitating positioning of its 3' terminus at the enzyme active site.
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Post-genomics nanotechnology is gaining momentum: nanoproteomics and applications in life sciences. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2014; 18:111-31. [PMID: 24410486 DOI: 10.1089/omi.2013.0074] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The post-genomics era has brought about new Omics biotechnologies, such as proteomics and metabolomics, as well as their novel applications to personal genomics and the quantified self. These advances are now also catalyzing other and newer post-genomics innovations, leading to convergences between Omics and nanotechnology. In this work, we systematically contextualize and exemplify an emerging strand of post-genomics life sciences, namely, nanoproteomics and its applications in health and integrative biological systems. Nanotechnology has been utilized as a complementary component to revolutionize proteomics through different kinds of nanotechnology applications, including nanoporous structures, functionalized nanoparticles, quantum dots, and polymeric nanostructures. Those applications, though still in their infancy, have led to several highly sensitive diagnostics and new methods of drug delivery and targeted therapy for clinical use. The present article differs from previous analyses of nanoproteomics in that it offers an in-depth and comparative evaluation of the attendant biotechnology portfolio and their applications as seen through the lens of post-genomics life sciences and biomedicine. These include: (1) immunosensors for inflammatory, pathogenic, and autoimmune markers for infectious and autoimmune diseases, (2) amplified immunoassays for detection of cancer biomarkers, and (3) methods for targeted therapy and automatically adjusted drug delivery such as in experimental stroke and brain injury studies. As nanoproteomics becomes available both to the clinician at the bedside and the citizens who are increasingly interested in access to novel post-genomics diagnostics through initiatives such as the quantified self, we anticipate further breakthroughs in personalized and targeted medicine.
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Abstract
Understanding how living cells interact with nanostructures is integral to a better understanding of the fundamental principles of biology and the development of next-generation biomedical/bioenergy devices. Recent studies have demonstrated that mammalian cells can recognize nanoscale topographies and respond to these structures. From this perspective, there is a growing recognition that nanostructures, along with their specific physicochemical properties, can also be used to regulate the responses and motions of bacterial cells. Here, by utilizing a well-defined silicon nanowire array platform and single-cell imaging, we present direct evidence that Shewanella oneidensis MR-1 can recognize nanoscale structures and that their swimming patterns and initial attachment locations are strongly influenced by the presence of nanowires on a surface. Analyses of bacterial trajectories revealed that MR-1 cells exhibited a confined diffusion mode in the presence of nanowires and showed preferential attachment to the nanowires, whereas a superdiffusion mode was observed in the absence of nanowires. These results demonstrate that nanoscale topography can affect bacterial movement and attachment and play an important role during the early stages of biofilm formation.
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Site-specific fluorescent labeling and oriented immobilization of a triple mutant of CYP3A4 via C64. Bioconjug Chem 2012; 23:826-36. [PMID: 22433037 DOI: 10.1021/bc200672s] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The generation of site-specific bioconjugates of proteins is highly desired for a number of biophysical and nanotechnological applications. To this end, many strategies have been developed that allow the specific modification of certain canonical amino acids and, more recently, noncanonical functional groups. P450 enzymes are heme-dependent monooxygenases involved in xenobiotic metabolism and in the biosynthesis of a variety of secondary metabolites. We became interested in the site-specific modification of these enzymes, CYP3A4 in particular, through our studies of their in vitro biocatalytic properties and our desire to exploit their remarkable ability to oxidize unactivated C-H bonds in a regio- and stereospecific manner. Obtained via a partial cysteine-depletion approach, a functional triple mutant of CYP3A4 (C98S/C239S/C468G) is reported here which is singly modified at C64 by maleimide-containing groups. While cysteine-labeling of the wild-type enzyme abolished >90% of its enzymatic activity, this mutant retained ≥75% of the activity of the unmodified wild-type enzyme with 9 of the 18 maleimides that were tested. These included both fluorescent and solid-supported maleimides. The loss of activity observed after labeling with some maleimides is attributed to direct enzyme inhibition rather than to steric effects. We also demonstrate the functional immobilization of this mutant on maleimide-functionalized agarose resin and silica microspheres.
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Single Molecule Studies Reveal Sliding Dynamics of Hcv NS5B in Complex with RNA. Biophys J 2011. [DOI: 10.1016/j.bpj.2010.12.1267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Unravelling Electronic Energy Transfer in Single Conjugated Polyelectrolytes Encapsulated in Lipid Vesicles. Biophys J 2011. [DOI: 10.1016/j.bpj.2010.12.958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Unraveling electronic energy transfer in single conjugated polyelectrolytes encapsulated in lipid vesicles. Proc Natl Acad Sci U S A 2010; 107:17480-5. [PMID: 20876146 PMCID: PMC2955115 DOI: 10.1073/pnas.1008068107] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A method for the study of conjugated polyelectrolyte (CPE) photophysics in solution at the single-molecule level is described. Extended observation times of single polymer molecules are enabled by the encapsulation of the CPEs within 200-nm lipid vesicles, which are in turn immobilized on a surface. When combined with a molecular-level visualization of vesicles and CPE via cryo-transmission electron microscopy, these single-molecule spectroscopy studies on CPEs enable us to directly correlate the polymer conformation with its spectroscopic features. These studies are conducted with poly[5-methoxy-2-(3-sulfopropoxy)-1,4-phenylene-vinylene] (MPS-PPV, a negatively charged CPE), when encapsulated in neutral and in negatively charged lipid vesicles. MPS-PPV exists as a freely diffusing polymer when confined in negatively charged vesicles. Individual MPS-PPV molecules adopt a collapsed-chain conformation leading to efficient energy migration over multiple chromophores. Both the presence of stepwise photobleaching in fluorescence intensity-time trajectories and emission from low-energy chromophores along the chain are observed. These results correlate with the amplified sensing potential reported for MPS-PPV in aqueous solution. When confined within neutral vesicles, single MPS-PPV molecules adopt an extended conformation upon insertion in the lipid bilayer. In this case emission arises from multiple chromophores within the isolated polymer chains, leading to an exponential decay of the intensity over time and a broad blue-shifted emission spectrum.
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Loading and selective release of cargo in DNA nanotubes with longitudinal variation. Nat Chem 2010; 2:319-28. [DOI: 10.1038/nchem.575] [Citation(s) in RCA: 267] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Accepted: 01/15/2010] [Indexed: 11/09/2022]
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Mechanistic Studies at the Single Molecule Level Reveal the Dynamics of HCV Polymerase Protein in Complex with RNA. Biophys J 2010. [DOI: 10.1016/j.bpj.2009.12.1460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Single Molecule Studies on Hcv RNA Polymerase Activity. Biophys J 2010. [DOI: 10.1016/j.bpj.2009.12.416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Modular construction of DNA nanotubes of tunable geometry and single- or double-stranded character. NATURE NANOTECHNOLOGY 2009; 4:349-352. [PMID: 19498394 DOI: 10.1038/nnano.2009.72] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Accepted: 03/05/2009] [Indexed: 05/27/2023]
Abstract
DNA nanotubes can template the growth of nanowires, orient transmembrane proteins for nuclear magnetic resonance determination, and can potentially act as stiff interconnects, tracks for molecular motors and nanoscale drug carriers. Current methods for the construction of DNA nanotubes result in symmetrical and cylindrical assemblies that are entirely double-stranded. Here, we report a modular approach to DNA nanotube synthesis that provides access to geometrically well-defined triangular and square-shaped DNA nanotubes. We also construct the first nanotube assemblies that can exist in double- and single-stranded forms with significantly different stiffness. This approach allows for parameters such as geometry, stiffness, and single- or double-stranded character to be fine-tuned, and could enable the creation of designer nanotubes for a range of applications, including the growth of nanowires of controlled shape, the loading and release of cargo, and the real-time modulation of stiffness and persistence length within DNA interconnects.
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Phenol-Based Lipophilic Fluorescent Antioxidant Indicators: A Rational Approach. J Org Chem 2009; 74:3641-51. [PMID: 19364120 DOI: 10.1021/jo900335z] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Development of a virtual reality haptic Veress needle insertion simulator for surgical skills training. Stud Health Technol Inform 2009; 142:233-238. [PMID: 19377157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The Veress needle is the most commonly used technique for creating the pneumoperitoneum at the start of a laparoscopic surgical procedure. Inserting the Veress needle correctly is crucial since errors can cause significant harm to patients. Unfortunately, this technique can be difficult to teach since surgeons rely heavily on tactile feedback while advancing the needle through the various layers of the abdominal wall. This critical step in laparoscopy, therefore, can be challenging for novice trainees to learn without adequate opportunities to practice in a safe environment with no risk of injury to patients. To address this issue, we have successfully developed a prototype of a virtual reality haptic needle insertion simulator using the tactile feedback of 22 surgeons to set realistic haptic parameters. A survey of these surgeons concluded that our device appeared and felt realistic, and could potentially be a useful tool for teaching the proper technique of Veress needle insertion.
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Sensing of H2O2 at Low Surface Density Assemblies of Pt Nanoparticles in Polyelectrolyte. Anal Chem 2008; 80:5441-8. [DOI: 10.1021/ac702358d] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Liposome Encapsulation of Conjugated Polyelectrolytes: Toward a Liposome Beacon. J Am Chem Soc 2007; 130:457-9. [PMID: 18095683 DOI: 10.1021/ja076217b] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Exclusive cardiac dysfunction in familial primary carnitine deficiency cases: a genotype-phenotype correlation. Clin Genet 2007; 72:59-62. [PMID: 17594400 DOI: 10.1111/j.1399-0004.2007.00814.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
MESH Headings
- Base Sequence
- Cardiomyopathy, Dilated/genetics
- Cardiomyopathy, Dilated/physiopathology
- Carnitine/deficiency
- Child
- Child, Preschool
- Codon, Nonsense
- DNA, Complementary/genetics
- Exons
- Female
- Genes, Recessive
- Genotype
- Humans
- Infant
- Lebanon
- Lipid Metabolism, Inborn Errors/genetics
- Lipid Metabolism, Inborn Errors/physiopathology
- Male
- Organic Cation Transport Proteins/genetics
- Pedigree
- Phenotype
- Solute Carrier Family 22 Member 5
- Ventricular Dysfunction, Left/genetics
- Ventricular Dysfunction, Left/physiopathology
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[Arteriovenous fistula following femoral angioplasty]. JOURNAL DE RADIOLOGIE 1999; 80:945-7. [PMID: 11048550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
We describe a case of arteriovenous fistula developing at the site of balloon dilatation immediately after percutaneous transluminal angioplasty of the superficial femoral artery. This occurred during an otherwise uncomplicated angioplasty. The fistula was treated by inflating a slightly larger balloon with a good clinical result as confirmed by color Doppler ultrasound. This uncommon complication of angioplasty is not widely recognized.
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Henoch-Schoenlein purpura and acute interstitial nephritis after intravenous vancomycin administration in a patient with a staphylococcal infection. Scand J Rheumatol 1998; 27:233-5. [PMID: 9645421 DOI: 10.1080/030097498440886] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We describe a case of Henoch-Schoenlein purpura, associated with oliguric acute renal failure due to acute interstitial nephritis histologically proven, in a patient with a staphylococcal chest infection. The clinical syndrome appeared twice after vancomycin administration and yielded on the withdrawal of the drug. As pathogenetic mechanism we propose an anaphylactoid reaction either to vancomycin or to a staphylococcal glycoprotein released after breakdown of the microbial cells caused by vancomycin.
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Abstract
BACKGROUND Syringomas are common, benign adnexal tumors. In the periorbital area, they pose a cosmetic dilemma for both patients and physicians alike. Many different therapeutic modalities potentially can cause scarring, and recurrences are common. OBJECTIVE To develop a treatment method that minimizes scarring and subsequent recurrences. METHOD Each syringoma is treated with short bursts of high frequency low voltage electrodesiccation delivered with a fine needle electrode that is inserted into the center of the syringoma, as deeply as the reticular dermis. RESULTS Twelve patients treated over a 4-year period showed no permanent adverse effects postoperatively and no recurrences. CONCLUSIONS Intralesional electrodesiccation is a safe, nonscarring and, reliable method that can be used to eradicate periorbital syringomas.
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Abstract
To elucidate the role of GABA in the control of sexual behavior, the effects of the GABA(A) agonist 4,5,6,7-tetrahydroisoxazolo[5,4c]-pyridin-3-ol (THIP), the GABA transaminase inhibitors sodium valproate and gamma-acetylen-GABA (GAG), and the GABA synthesis inhibitors isoniazide and deoxypyridoxine were evaluated in sexual behavior, exploration, and sociosexual interactions with a receptive female or a castrated male. Furthermore, to discriminate possible general inhibitory effects from those specific to sexual behavior, the doses of the drugs that produced a significant inhibition of copulation were tested in a free drinking procedure. THIP (16 mg/kg), sodium valproate (400 mg/kg), GAG (100 mg/kg), and deoxypyridoxine (400 mg/kg) produced a strong inhibition of sexual behavior. The percentage of animals displaying mounts and intromissions as well as the mean number of mounts and intromissions were significantly reduced. Sociosexual interactions with a receptive female or a castrated male and exploratory behaviors were also reduced. The most consistent effects observed were reductions in sniffing, self-grooming, and rearing. Drinking behavior was significantly reduced in doses that inhibited sexual behavior. These results further support the hypothesis that altered GABAergic neurotransmission produces reduced sensitivity to environmental stimuli and thereby inhibits sexual and drinking behavior in a nonspecific way.
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Abstract
BACKGROUND Syringomas are common, benign periorbital adnexal tumors that pose a cosmetic dilemma for both patients and physicians alike. Many therapeutic modalities can potentially cause scarring and recurrences are common. The objective was to develop a treatment method that minimizes scarring and subsequent recurrences. METHODS Each syringoma is treated with short bursts of low voltage electrodesiccation, delivered with an epilating needle that is inserted deeply into the skin at the level of the reticular dermis. RESULTS A patient treated by intralesional electrodesiccation of her long-standing periorbital syringomas remains lesion-free for over 24 months after therapy. CONCLUSIONS Intralesional electrodesiccation is a safe, nonscarring and reliable method that can be used to eradicate periorbital syringomas.
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Abstract
BACKGROUND A 48-week open label trial was conducted in five Middle-Eastern countries (Lebanon, Egypt, Saudi Arabia, Jordan, and the United Arab Emirates) to determine the safety and efficacy of 2% minoxidil in the treatment of early androgenic alopecia and to compare the response with Western countries. METHODS One hundred and ninety-five men aged between 19 and 47 years were enrolled. The duration of their baldness varied from 6 months to 10 years, and they all showed a type III vertex or type IV of the modified Hamilton scale. Baldness pattern, diameter of the balding area, hair counting within a 2.5 cm bald patch as well as investigator's and patient's evaluation were regularly noted. RESULTS No significant changes were observed in vital signs or laboratory parameters. Of the 161 patients considered evaluable at 48 weeks, 80% showed moderate to dense growth. The mean increase in nonvellus hair at 12 months was 234. CONCLUSIONS The age of the patient and the type of baldness rather than its duration affected the final outcome.
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Socio-sexual behavior in male rats after lesions of the medial preoptic area: evidence for reduced sexual motivation. Brain Res 1993; 618:271-6. [PMID: 8374757 DOI: 10.1016/0006-8993(93)91275-w] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Different hypotheses have been put forward trying to explain the mechanisms associated with the disruption of male sexual behavior after lesions of the medial preoptic area (MPOA). It has been suggested that sexual motivation, motor execution or both are affected by MPOA lesions. In the present experiment, the socio-sexual behavior of male rats bearing extensive MPOA lesions, that abolished sexual behavior, was compared with that of sham-lesioned animals and to prelesion levels. The socio-sexual interactions were recorded for 10 min in one prelesion and two postlesion tests. The frequency and duration of the following behaviors were recorded: rearing, sniffing, self-grooming, grooming partner, genital exploration, pursuit and resting. The analysis of the socio-sexual interactions showed that the frequency and duration of pursuit was reduced in the first and second tests after the lesion in comparison to both prelesion levels and to a sham-lesioned group. There is strong evidence that pursuit is the only precopulatory behavior that can consistently predict the appearance of sexual behavior. When pursuit is reduced the transition from the precopulatory to the copulatory phase is made more difficult. Therefore, it appears that the MPOA lesions reduce the subject's motivation to engage in sexual behavior.
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The role of descending venography in the management of patients with chronic venous disease of the lower extremity. Can J Surg 1992; 35:257-60. [PMID: 1617537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The purpose of this paper is to evaluate the efficacy and clinical information obtained from the authors' first 17 consecutive descending venograms. All 17 patients had chronic venous disease refractory to standard conservative and surgical measures. The standard classification of valvular insufficiency was used in evaluating these venograms. There were no deaths, slight morbidity and minimal patient discomfort. In 16 patients meaningful clinical information was derived from the venograms, with 7 patients having deep venous valvular surgery. Descending venography will demonstrate the site of incompetent valves and estimate the degree of reflux. This test is necessary before anticipated reconstruction of deep vein valves.
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Eosinophilic fasciitis terminating as progressive systemic sclerosis in a child. DERMATOLOGICA 1985; 171:291-4. [PMID: 4076501 DOI: 10.1159/000249439] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A child with clinicopathological features of eosinophilic fasciitis terminated in progressive systemic sclerosis. The clinical and laboratory similarities and disparities between these two conditions are presented.
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