313 research outputs found

    Optimizing Sequence Coverage for a Moderate Mass Protein in Nano-Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry

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    Sample pretreatment was optimized to obtain high sequence coverage for human serum albumin (HSA, 66.5 kDa) when using nano-electrospray ionization quadrupole time-of-flight mass spectrometry (nESI-Q-TOF-MS). Use of the final method with trypsin, Lys-C and Glu-C digests gave a combined coverage of 98.8%. The addition of peptide fractionation resulted in 99.7% coverage. These results were comparable to those obtained previously with matrixassisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The sample pretreatment/nESI-Q-TOF-MS method was also used with collision-induced dissociation to analyze HSA digests and to identify peptides that could be employed as internal mass calibrants in future studies of modifications to HSA

    Optimizing Sequence Coverage for a Moderate Mass Protein in Nano-Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry

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    Sample pretreatment was optimized to obtain high sequence coverage for human serum albumin (HSA, 66.5 kDa) when using nano-electrospray ionization quadrupole time-of-flight mass spectrometry (nESI-Q-TOF-MS). Use of the final method with trypsin, Lys-C and Glu-C digests gave a combined coverage of 98.8%. The addition of peptide fractionation resulted in 99.7% coverage. These results were comparable to those obtained previously with matrixassisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The sample pretreatment/nESI-Q-TOF-MS method was also used with collision-induced dissociation to analyze HSA digests and to identify peptides that could be employed as internal mass calibrants in future studies of modifications to HSA

    Intratracheal Instillation of Cerium Oxide Nanoparticles Induces Hepatic Toxicity in Male Sprague-Dawley Rats

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    Background: Cerium oxide (CeO2) nanoparticles have been posited to have both beneficial and toxic effects on biological systems. Herein, we examine if a single intratracheal instillation of CeO2 nanoparticles is associated with systemic toxicity in male Sprague-Dawley rats. Methods and results: Compared with control animals, CeO2 nanoparticle exposure was associated with increased liver ceria levels, elevations in serum alanine transaminase levels, reduced albumin levels, a diminished sodium-potassium ratio, and decreased serum triglyceride levels (P \u3c 0.05). Consistent with these data, rats exposed to CeO2nanoparticles also exhibited reductions in liver weight (P \u3c 0.05) and dose-dependent hydropic degeneration, hepatocyte enlargement, sinusoidal dilatation, and accumulation of granular material. No histopathological alterations were observed in the kidney, spleen, and heart. Analysis of serum biomarkers suggested an elevation of acute phase reactants and markers of hepatocyte injury in the rats exposed to CeO2 nanoparticles. Conclusion: Taken together, these data suggest that intratracheal instillation of CeO2nanoparticles can result in liver damage

    Priprava i in vitro vrednovanje bukoadhezivnih tableta karvedilola

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    Buccoadhesive tablets of carvedilol were prepared using HPMC K4M, HPMC K15M and Carbopol 934 as mucoadhesive polymers. Fifteen formulations were developed with varying concentrations of polymers. Formulations of the BC or BD series were composed of HPMC K4M or HPMC K15M in ratios of 1:1 to 1:5 whereas in the BE series Carbopol 934 was used (1:0.25 to 1:1.50). The formulations were tested for in vitro drug release, in vitro bioadhesion, moisture absorption and in vitro drug permeation through porcine buccal mucosa. Formulation BC3 showed maximum release of the drug (88.7 ± 0.4%) with the Higuchi model release profile and permeated 21.5 ± 2.9% of the drug (flux 8.35 ± 0.291 µg h1cm2) permeation coefficient 1.34 ± 0.05 cm h1) through porcine buccal membrane. BC3 formulation showed 1.62 ± 0.15 N of peak detachment force and 0.24 ± 0.11 mJ of work of adhesion. FTIR results showed no evidence of interaction between the drug and polymers. XRD study revealed that the drug is in crystalline form in the polymer matrix. The results indicate that suitable bioadhesive buccal tablets with desired permeability could be prepared.Varirajući koncentracije bukoadhezivnih polimera HPMC K4M, HPMC K15M i Carbopol 934 pripravljeno je 15 tableta karvedilola. Pripravci iz serije BC ili BD izrađeni su iz karvedilola i HPMC K4 M ili HPMC K 15M u omjerima 1:1, 1:2, 1:3, 1:4 i 1:5, a pripravci iz BE serije iz karvedilola i Carbopol 934 u omjerima 1:0.25, 1:0.50, 1:0.75, 1:1.00 i 1:1.50. In vitro je ispitivana brzina oslobađanja ljekovite tvari, bioadhezija, apsorpcija vlage i permeacija kroz bukalnu membranu svinje. Iz pripravka BC3 postignuto je maksimalno oslobađanje (88,7 + 0,4 %) koje je slijedilo Higuchijev model i maksimalna permeacija 21,5 + 2,9 % (fluks 8,35 ± 0,291 µg h-1 cm-2; permeacijski koeficijent 1,34 ± 0,05 cm h-1). Sila odvajanja za taj pripravak bila je 1,62 ± 0,15 N, a adhezija 0,24 ± 0,11 mJ. FTIR ispitivanja su pokazala da nije bilo interakcija između ljekovite tvari i polimera, a XRD ispitivanja da je ljekovita tvar u kristaliničnoj formi u polimernom matriksu. Pripravljene bukalne tablete su dovoljno bioadhezivne, a permeacija iz njih je zadovoljavajuća

    A Proposal for Expansion of the Medical Specialty of Rehabilitation Medicine

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    The workforce of the medical specialty of Rehabilitation Medicine (RM) in the UK is 10 times less than the European average for the specialty of Physical and Rehabilitation Medicine (PRM). This can be explained partly by the difference in the scope of practice within the specialty between the UK and other European countries and USA. This opinion paper aims to compare the rehabilitation needs in chronic medical conditions and compare the scope of practice between countries within Europe and other regions of the world. The potential advantages of a broader remit specialty to improve rehabilitation care for patients by involving rehabilitation physicians in various medical conditions is explored. Recommendations have been put forward in the Rehabilitation Medicine Expansion Proposal (RMEP), which is likely to make the medical specialty of RM/ PRM more satisfying for the doctors working in the specialty and a more attractive career choice for those entering training in the specialty. There is a need for an international universal framework for the scope of the specialty to have a greater impact on improving the lives of those with chronic medical conditions

    Statistical Derivation of Basic Equations of Diffusional Kinetics in Alloys with Application to the Description of Diffusion of Carbon in Austenite

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    Basic equations of diffusional kinetics in alloys are statistically derived using the master equation approach. To describe diffusional transformations in substitution alloys, we derive the "quasi-equilibrium" kinetic equation which generalizes its earlier versions by taking into account possible "interaction renormalization" effects. For the interstitial alloys Me-X, we derive the explicit expression for the diffusivity D of an interstitial atom X which notably differs from those used in previous phenomenological treatments. This microscopic expression for D is applied to describe the diffusion of carbon in austenite basing on some simple models of carbon-carbon interaction. The results obtained enable us to make certain conclusions about the real form of these interactions, and about the scale of the "transition state entropy" for diffusion of carbon in austenite.Comment: 26 pages, 5 postscript figures, LaTe

    Inhibition of interferon response by cystatin B: implication in HIV replication of macrophage reservoirs

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    Cystatin B and signal transducer and activator of transcription-1 (STAT-1) phosphorylation have recently been shown to increase human immunodeficiency virus-1 (HIV-1) replication in monocyte-derived macrophages (MDM), but the molecular pathways by which they do are unknown. We hypothesized that cystatin B inhibits the interferon (IFN) response and regulates STAT-1 phosphorylation by interacting with additional proteins. To test if cystatin B inhibits the IFN-β response, we performed luciferase reporter gene assays in Vero cells, which are IFN deficient. Interferon-stimulated response element (ISRE)-driven expression of firefly luciferase was significantly inhibited in Vero cells transfected with a cystatin B expression vector compared to cells transfected with an empty vector. To determine whether cystatin B interacts with other key players regulating STAT-1 phosphorylation and HIV-1 replication, cystatin B was immunoprecipitated from HIV-1-infected MDM. The protein complex was analyzed by liquid chromatography tandem mass spectrometry. Protein interactions with cystatin B were verified by Western blots and immunofluorescence with confocal imaging. Our findings confirmed that cystatin B interacts with pyruvate kinase M2 isoform, a protein previously associated cocaine enhancement of HIV-1 replication, and major vault protein (MVP), an IFN-responsive protein that interferes with JAK/STAT signals. Western blot studies confirmed the interaction with pyruvate kinase M2 isoform and MVP. Immunofluorescence studies of HIV-1-infected MDM showed that upregulated MVP colocalized with STAT-1. To our knowledge, the current study is the first to demonstrate the coexpression of cystatin B, STAT-1, MVP, and pyruvate kinase M2 isoform with HIV-1 replication in MDM and thus suggests novel targets for HIV-1 restriction in macrophages, the principal reservoirs for HIV-1 in the central nervous system

    Screening of viral-vectored P. falciparum pre-erythrocytic candidate vaccine antigens using chimeric rodent parasites

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    To screen for additional vaccine candidate antigens of Plasmodium pre-erythrocytic stages, fourteen P. falciparum proteins were selected based on expression in sporozoites or their role in establishment of hepatocyte infection. For preclinical evaluation of immunogenicity of these proteins in mice, chimeric P. berghei sporozoites were created that express the P. falciparum proteins in sporozoites as an additional copy gene under control of the uis4 gene promoter. All fourteen chimeric parasites produced sporozoites but sporozoites of eight lines failed to establish a liver infection, indicating a negative impact of these P. falciparum proteins on sporozoite infectivity. Immunogenicity of the other six proteins (SPELD, ETRAMP10.3, SIAP2, SPATR, HT, RPL3) was analyzed by immunization of inbred BALB/c and outbred CD-1 mice with viral-vectored (ChAd63 or ChAdOx1, MVA) vaccines, followed by challenge with chimeric sporozoites. Protective immunogenicity was determined by analyzing parasite liver load and prepatent period of blood stage infection after challenge. Of the six proteins only SPELD immunized mice showed partial protection. We discuss both the low protective immunogenicity of these proteins in the chimeric rodent malaria challenge model and the negative effect on P. berghei sporozoite infectivity of several P. falciparum proteins expressed in the chimeric sporozoites.Host-parasite interactio

    Machine Learning Framework to Identify Individuals at Risk of Rapid Progression of Coronary Atherosclerosis : From the PARADIGM Registry

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    Background Rapid coronary plaque progression (RPP) is associated with incident cardiovascular events. To date, no method exists for the identification of individuals at risk of RPP at a single point in time. This study integrated coronary computed tomography angiography-determined qualitative and quantitative plaque features within a machine learning (ML) framework to determine its performance for predicting RPP. Methods and Results Qualitative and quantitative coronary computed tomography angiography plaque characterization was performed in 1083 patients who underwent serial coronary computed tomography angiography from the PARADIGM (Progression of Atherosclerotic Plaque Determined by Computed Tomographic Angiography Imaging) registry. RPP was defined as an annual progression of percentage atheroma volume 651.0%. We employed the following ML models: model 1, clinical variables; model 2, model 1 plus qualitative plaque features; model 3, model 2 plus quantitative plaque features. ML models were compared with the atherosclerotic cardiovascular disease risk score, Duke coronary artery disease score, and a logistic regression statistical model. 224 patients (21%) were identified as RPP. Feature selection in ML identifies that quantitative computed tomography variables were higher-ranking features, followed by qualitative computed tomography variables and clinical/laboratory variables. ML model 3 exhibited the highest discriminatory performance to identify individuals who would experience RPP when compared with atherosclerotic cardiovascular disease risk score, the other ML models, and the statistical model (area under the receiver operating characteristic curve in ML model 3, 0.83 [95% CI 0.78-0.89], versus atherosclerotic cardiovascular disease risk score, 0.60 [0.52-0.67]; Duke coronary artery disease score, 0.74 [0.68-0.79]; ML model 1, 0.62 [0.55-0.69]; ML model 2, 0.73 [0.67-0.80]; all P<0.001; statistical model, 0.81 [0.75-0.87], P=0.128). Conclusions Based on a ML framework, quantitative atherosclerosis characterization has been shown to be the most important feature when compared with clinical, laboratory, and qualitative measures in identifying patients at risk of RPP
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