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1.
Artículo en Inglés | MEDLINE | ID: mdl-38780469

RESUMEN

Treatments of colitis, inflammation of the intestine, is today relying on induction of immune suppression associated with systemic adverse events including recurrent infections. This treatment strategy is specifically problematic in the increasing population of cancer patients with immune checkpoint inhibitor (ICI)-induced colitis, as immune suppression also interferes with the ICI-treatment response. Thus, there is a need for local-acting treatments which reduce inflammation and enhance intestinal healing. Here, we investigated the effect and safety of bacterial delivery of short-lived immunomodulating chemokines to the inflamed intestine in mice with colitis. Colitis was induced by DSS alone or in combination with ICI (anti-PD1, anti-CTLA-4) and L. reuteri R2LC genetically modified to express the chemokine CXCL12-1α (R2LC_CXCL12, emilimogene sigulactibac) was given perorally. In addition, pharmacology and safety of the formulated drug candidate, ILP100-Oral, was evaluated in rabbits. Peroral CXCL12-producing L. reuteri R2LC significantly improved colitis symptoms already after 2 days in mice with overt DSS and ICI-induced colitis, which in benchmarking experiments was demonstrated to be superior to treatments with anti-TNF-α, anti-α4ꞵ7 and corticosteroids. The mechanism of action involved chemokine delivery to Peyer´s Patches (PPs), confirmed by local CXCR4 signaling, and increased numbers of colonic, regulatory immune cells expressing IL-10 and TGF-ß1. No systemic exposure or engraftment could be detected in mice, and product feasibility, pharmacology and safety were confirmed in rabbits. In conclusion, peroral CXCL12-producing L. reuteri R2LC efficiently ameliorates colitis and enhances mucosal healing, and has a favorable safety profile.

2.
Protein Expr Purif ; 218: 106446, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38395209

RESUMEN

The small GTPase Rat sarcoma virus proteins (RAS) are key regulators of cell growth and involved in 20-30% of cancers. RAS switches between its active state and inactive state via exchange of GTP (active) and GDP (inactive). Therefore, to study active protein, it needs to undergo nucleotide exchange to a non-hydrolysable GTP analog. Calf intestine alkaline phosphatase bound to agarose beads (CIP-agarose) is regularly used in a nucleotide exchange protocol to replace GDP with a non-hydrolysable analog. Due to pandemic supply problems and product shortages, we found the need for an alternative to this commercially available product. Here we describe how we generated a bacterial alkaline phosphatase (BAP) with an affinity tag bound to an agarose bead. This BAP completely exchanges the nucleotide in our samples, thereby demonstrating an alternative to the commercially available product using generally available laboratory equipment.


Asunto(s)
Proteínas de Unión al GTP Monoméricas , Proteínas de Unión al GTP Monoméricas/metabolismo , Nucleótidos , Fosfatasa Alcalina/genética , Fosfatasa Alcalina/metabolismo , Sefarosa , Guanosina Trifosfato/metabolismo , Guanosina Difosfato/metabolismo
3.
Cell ; 135(3): 462-74, 2008 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-18984158

RESUMEN

tRNAs are synthesized as immature precursors, and on their way to functional maturity, extra nucleotides at their 5' ends are removed by an endonuclease called RNase P. All RNase P enzymes characterized so far are composed of an RNA plus one or more proteins, and tRNA 5' end maturation is considered a universal ribozyme-catalyzed process. Using a combinatorial purification/proteomics approach, we identified the components of human mitochondrial RNase P and reconstituted the enzymatic activity from three recombinant proteins. We thereby demonstrate that human mitochondrial RNase P is a protein enzyme that does not require a trans-acting RNA component for catalysis. Moreover, the mitochondrial enzyme turns out to be an unexpected type of patchwork enzyme, composed of a tRNA methyltransferase, a short-chain dehydrogenase/reductase-family member, and a protein of hitherto unknown functional and evolutionary origin, possibly representing the enzyme's metallonuclease moiety. Apparently, animal mitochondria lost the seemingly ubiquitous RNA world remnant after reinventing RNase P from preexisting components.


Asunto(s)
Mitocondrias/enzimología , ARN Catalítico/análisis , Ribonucleasa P/química , Animales , Línea Celular , Escherichia coli/genética , Escherichia coli/metabolismo , Evolución Molecular , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , ARN de Transferencia/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Ribonucleasa P/genética , Ribonucleasa P/aislamiento & purificación , Ribonucleasa P/metabolismo
4.
Proc Natl Acad Sci U S A ; 117(39): 24258-24268, 2020 09 29.
Artículo en Inglés | MEDLINE | ID: mdl-32913056

RESUMEN

The small GTPase KRAS is localized at the plasma membrane where it functions as a molecular switch, coupling extracellular growth factor stimulation to intracellular signaling networks. In this process, KRAS recruits effectors, such as RAF kinase, to the plasma membrane where they are activated by a series of complex molecular steps. Defining the membrane-bound state of KRAS is fundamental to understanding the activation of RAF kinase and in evaluating novel therapeutic opportunities for the inhibition of oncogenic KRAS-mediated signaling. We combined multiple biophysical measurements and computational methodologies to generate a consensus model for authentically processed, membrane-anchored KRAS. In contrast to the two membrane-proximal conformations previously reported, we identify a third significantly populated state using a combination of neutron reflectivity, fast photochemical oxidation of proteins (FPOP), and NMR. In this highly populated state, which we refer to as "membrane-distal" and estimate to comprise ∼90% of the ensemble, the G-domain does not directly contact the membrane but is tethered via its C-terminal hypervariable region and carboxymethylated farnesyl moiety, as shown by FPOP. Subsequent interaction of the RAF1 RAS binding domain with KRAS does not significantly change G-domain configurations on the membrane but affects their relative populations. Overall, our results are consistent with a directional fly-casting mechanism for KRAS, in which the membrane-distal state of the G-domain can effectively recruit RAF kinase from the cytoplasm for activation at the membrane.


Asunto(s)
Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Quinasas raf/metabolismo , Membrana Celular/metabolismo , Simulación de Dinámica Molecular
5.
Eur Heart J ; 43(22): 2127-2135, 2022 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-35171989

RESUMEN

AIMS: We aimed to investigate the association of clinically overt and silent brain lesions with cognitive function in atrial fibrillation (AF) patients. METHODS AND RESULTS: We enrolled 1227 AF patients in a prospective, multicentre cohort study (Swiss-AF). Patients underwent standardized brain magnetic resonance imaging (MRI) at baseline and after 2 years. We quantified new small non-cortical infarcts (SNCIs) and large non-cortical or cortical infarcts (LNCCIs), white matter lesions (WML), and microbleeds (Mb). Clinically, silent infarcts were defined as new SNCI/LNCCI on follow-up MRI in patients without a clinical stroke or transient ischaemic attack (TIA) during follow-up. Cognition was assessed using validated tests. The mean age was 71 years, 26.1% were females, and 89.9% were anticoagulated. Twenty-eight patients (2.3%) experienced a stroke/TIA during 2 years of follow-up. Of the 68 (5.5%) patients with ≥1 SNCI/LNCCI, 60 (88.2%) were anticoagulated at baseline and 58 (85.3%) had a silent infarct. Patients with brain infarcts had a larger decline in cognition [median (interquartile range)] changes in Cognitive Construct score [-0.12 (-0.22; -0.07)] than patients without new brain infarcts [0.07 (-0.09; 0.25)]. New WML or Mb were not associated with cognitive decline. CONCLUSION: In a contemporary cohort of AF patients, 5.5% had a new brain infarct on MRI after 2 years. The majority of these infarcts was clinically silent and occurred in anticoagulated patients. Clinically, overt and silent brain infarcts had a similar impact on cognitive decline. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02105844, https://clinicaltrials.gov/ct2/show/NCT02105844.


Asunto(s)
Fibrilación Atrial , Ataque Isquémico Transitorio , Accidente Cerebrovascular , Anciano , Fibrilación Atrial/complicaciones , Fibrilación Atrial/patología , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Infarto Encefálico , Cognición , Estudios de Cohortes , Femenino , Humanos , Ataque Isquémico Transitorio/complicaciones , Imagen por Resonancia Magnética , Masculino , Estudios Prospectivos , Accidente Cerebrovascular/patología
6.
Crim Law Forum ; : 1-34, 2023 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-36811023

RESUMEN

Dilemma scenarios have always been among the most common problems of moral philosophy and criminal law theory. One only has to contemplate the Plank of Carneades, the classic thought experiment whereby two shipwrecked people's only hope of rescue is a floating board that can only be occupied by one person. Other scenarios are Welzel's switchman case and the well-known Trolley Problem. In most of the debated cases the death of one or more people is absolutely unavoidable. The protagonists do not cause the situation but are fated to come into conflict. The focus of this article is on one recent and one future variant. First, the prioritization of medical aid (also known as "triage") is the subject of intense debate, because the COVID-19 pandemic posed a permanent risk of a temporary collapse in the health system in several countries. Situations had arisen whereby some patients can no longer be treated owing to lack of capacity. It can be asked whether a decision to treat may be based on which patients have a better chance of survival, whether reckless previous behaviour may play a role, and whether a treatment, once started, may be discontinued in favour of another. Second, dilemma scenarios are also one of the last remaining (largely unresolved) legal difficulties of autonomous vehicles. Never before has a machine been given the power to determine the life or death of human beings. Even though the automotive industry promises that such situations will hardly ever occur, the problem could prove to be a tangible obstacle to acceptance and innovation. The article offers solutions for those distinct scenarios, but it is also intended to demonstrate the underlying legal concepts of German law: namely, the tripartite analysis of criminal law and the idea of human dignity as a fundamental principle of the German constitution.

7.
Biophys J ; 121(19): 3630-3650, 2022 10 04.
Artículo en Inglés | MEDLINE | ID: mdl-35778842

RESUMEN

During the activation of mitogen-activated protein kinase (MAPK) signaling, the RAS-binding domain (RBD) and cysteine-rich domain (CRD) of RAF bind to active RAS at the plasma membrane. The orientation of RAS at the membrane may be critical for formation of the RAS-RBDCRD complex and subsequent signaling. To explore how RAS membrane orientation relates to the protein dynamics within the RAS-RBDCRD complex, we perform multiscale coarse-grained and all-atom molecular dynamics (MD) simulations of KRAS4b bound to the RBD and CRD domains of RAF-1, both in solution and anchored to a model plasma membrane. Solution MD simulations describe dynamic KRAS4b-CRD conformations, suggesting that the CRD has sufficient flexibility in this environment to substantially change its binding interface with KRAS4b. In contrast, when the ternary complex is anchored to the membrane, the mobility of the CRD relative to KRAS4b is restricted, resulting in fewer distinct KRAS4b-CRD conformations. These simulations implicate membrane orientations of the ternary complex that are consistent with NMR measurements. While a crystal structure-like conformation is observed in both solution and membrane simulations, a particular intermolecular rearrangement of the ternary complex is observed only when it is anchored to the membrane. This configuration emerges when the CRD hydrophobic loops are inserted into the membrane and helices α3-5 of KRAS4b are solvent exposed. This membrane-specific configuration is stabilized by KRAS4b-CRD contacts that are not observed in the crystal structure. These results suggest modulatory interplay between the CRD and plasma membrane that correlate with RAS/RAF complex structure and dynamics, and potentially influence subsequent steps in the activation of MAPK signaling.


Asunto(s)
Cisteína , Proteínas Proto-Oncogénicas c-raf , Sitios de Unión , Membrana Celular/metabolismo , Cisteína/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Unión Proteica , Proteínas Proto-Oncogénicas c-raf/química , Proteínas Proto-Oncogénicas c-raf/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Solventes/metabolismo
8.
Protein Expr Purif ; 174: 105686, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32504802

RESUMEN

The SARS-CoV-2 spike trimer is the primary antigen for several serology assays critical to determining the extent of SARS-CoV-2 exposure in the population. Until stable cell lines are developed to increase the titer of this secreted protein in mammalian cell culture, the low yield of spike protein produced from transient transfection of HEK293 cells will be a limiting factor for these assays. To improve the yield of spike protein and support the high demand for antigens in serology assays, we investigated several recombinant protein expression variables by altering the incubation temperature, harvest time, chromatography strategy, and final protein manipulation. Through this investigation, we developed a simplified and robust purification strategy that consistently yields 5 mg of protein per liter of expression culture for two commonly used forms of the SARS-CoV-2 spike protein. We show that these proteins form well-behaved stable trimers and are consistently functional in serology assays across multiple protein production lots.


Asunto(s)
Betacoronavirus/metabolismo , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/aislamiento & purificación , Betacoronavirus/genética , COVID-19 , Prueba de COVID-19 , Técnicas de Laboratorio Clínico , Infecciones por Coronavirus/sangre , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/virología , Expresión Génica , Células HEK293 , Humanos , Pandemias , Neumonía Viral/sangre , Neumonía Viral/diagnóstico , Neumonía Viral/virología , Estabilidad Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/metabolismo , Transfección
9.
Int J Mol Sci ; 21(15)2020 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-32751838

RESUMEN

Bladder dysfunction is characterized by urgency, frequency (pollakisuria, nocturia), and dysuria and may lead to urinary incontinence. Most of these symptoms can be attributed to disturbed bladder sensitivity. There is growing evidence that, besides the urothelium, suburothelial interstitial cells (suICs) are involved in bladder afferent signal processing. The massive expansion of the bladder during the filling phase implicates mechanical stress delivered to the whole bladder wall. Little is known about the reaction of suICs upon mechanical stress. Therefore, we investigated the effects of mechanical stimulation in cultured human suICs. We used fura-2 calcium imaging as a major physiological readout. We found spontaneous intracellular calcium activity in 75 % of the cultured suICs. Defined local pressure application via a glass micropipette led to local increased calcium activity in all stimulated suICs, spreading over the whole cell. A total of 51% of the neighboring cells in a radius of up to 100 µm from the stimulated cell showed an increased activity. Hypotonic ringer and shear stress also induced calcium transients. We found an 18-times increase in syncytial activity compared to unstimulated controls, resulting in an amplification of the primary calcium signal elicited in single cells by 50%. Our results speak in favor of a high sensitivity of suICs for mechanical stress and support the view of a functional syncytium between suICs, which can amplify and distribute local stimuli. Previous studies of connexin expression in the human bladder suggest that this mechanism could also be relevant in normal and pathological function of the bladder in vivo.


Asunto(s)
Calcio/metabolismo , Presión Osmótica , Estrés Mecánico , Vejiga Urinaria Hiperactiva , Vejiga Urinaria de Baja Actividad , Urotelio , Anciano , Células Cultivadas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vejiga Urinaria/citología , Vejiga Urinaria Hiperactiva/metabolismo , Vejiga Urinaria Hiperactiva/patología , Vejiga Urinaria de Baja Actividad/metabolismo , Vejiga Urinaria de Baja Actividad/patología , Urotelio/metabolismo , Urotelio/patología
10.
Int J Comput Dent ; 23(1): 73-82, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32207463

RESUMEN

BACKGROUND: Accurate implant placement in the bone is key to successful implant treatment. Once inserted, it can be difficult to correct the orientation of the implant axis, especially of a one-piece implant. Prosthetic-driven digital implant planning in combination with fully guided implant surgery can offer additional safety in such cases. CASE PRESENTATION: The patient presented with a wide, edentulous interdental space extending from sites 13 to 16, which was to be restored with three one-piece zirconia implants supporting a zirconia fixed partial denture comprizing a cantilever to the mesial aspect. Digital planning based on DICOM (Digital Imaging and Communications in Medicine) and intraoral surface data was performed to ensure optimal positioning. Guided implant placement was executed using a contra-angle handpiece with special attachments and a compatible, sleeveless drill guide. Impressions of the implants for the final restoration were acquired using an intraoral scanner. Reflection-related errors were compensated for by using the given digital abutment geometry. The DICOM and STL datasets were superimposed and used as the basis for fabricating a monolithic zirconia restoration through a subtractive milling process. The final restoration was adhesively cemented. CONCLUSIONS: By using a prosthetic-driven implant planning strategy, it was possible to place the one-piece ceramic implants without an available implant manufacturer's guide-based solution. This was accomplished using a contra-angle surgical handpiece with special attachments and a compatible drill guide. This approach is particularly recommended for the placement of one-piece implants, which otherwise require irreversible abutment grinding for the adjustment of the implant axis orientation after placement. To increase the precision of the digital impressions of the implants, the ideal abutment geometry was imported and superimposed onto the scan data. The results demonstrate that the proposed method can dispense with the need for gingival retraction when acquiring impressions for implants of this type in the future.


Asunto(s)
Implantes Dentales , Flujo de Trabajo , Cerámica , Diseño Asistido por Computadora , Dentadura Parcial Fija , Humanos
11.
Zentralbl Chir ; 145(5): 456-466, 2020 Oct.
Artículo en Alemán | MEDLINE | ID: mdl-31931546

RESUMEN

Aneurysms of arteries in the extremities have a low incidence and are often manifest through complications. The most serious complications are rupture and extremity-threatening ischemia. Both usually lead to the diagnosis. Absolute indications for therapy are symptomatic aneurysms and asymptomatic aneurysms of 2 cm diameter or more. The extrailiacal gold standard is interponat or bypass with venous graft material. Endovascular methods are reserved for inoperable patients and clinical decisions on special cases. In contrast, complex endovascular techniques have been established in isolated iliac aneurysms and have significantly improved treatment options. Their implementation is bound to the existence of a suitable landing zone. This is the basis for a new classification of isolated iliac artery aneurysm. With the help of morphological subtypes, this classification permits standardised procedure planning for perfusion preservation of the internal iliac artery. The present article gives an overview of the current treatment strategy for aneurysms of extremities arteries. Similarities and regional differences in therapy are discussed.


Asunto(s)
Aneurisma de la Aorta Abdominal , Implantación de Prótesis Vascular , Procedimientos Endovasculares , Aneurisma Ilíaco , Aneurisma de la Aorta Abdominal/cirugía , Prótesis Vascular , Humanos , Aneurisma Ilíaco/diagnóstico por imagen , Aneurisma Ilíaco/cirugía , Arteria Ilíaca/diagnóstico por imagen , Arteria Ilíaca/cirugía , Stents , Resultado del Tratamiento
12.
Lancet ; 392(10150): 849-856, 2018 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-30170854

RESUMEN

BACKGROUND: Drug-coated balloons (DCB) are a novel therapeutic strategy for small native coronary artery disease. However, their safety and efficacy is poorly defined in comparison with drug-eluting stents (DES). METHODS: BASKET-SMALL 2 was a multicentre, open-label, randomised non-inferiority trial. 758 patients with de-novo lesions (<3 mm in diameter) in coronary vessels and an indication for percutaneous coronary intervention were randomly allocated (1:1) to receive angioplasty with DCB versus implantation of a second-generation DES after successful predilatation via an interactive internet-based response system. Dual antiplatelet therapy was given according to current guidelines. The primary objective was to show non-inferiority of DCB versus DES regarding major adverse cardiac events (MACE; ie, cardiac death, non-fatal myocardial infarction, and target-vessel revascularisation) after 12 months. The non-inferiority margin was an absolute difference of 4% in MACE. This trial is registered with ClinicalTrials.gov, number NCT01574534. FINDINGS: Between April 10, 2012, and February 1, 2017, 382 patients were randomly assigned to the DCB group and 376 to DES group. Non-inferiority of DCB versus DES was shown because the 95% CI of the absolute difference in MACE in the per-protocol population was below the predefined margin (-3·83 to 3·93%, p=0·0217). After 12 months, the proportions of MACE were similar in both groups of the full-analysis population (MACE was 7·5% for the DCB group vs 7·3% for the DES group; hazard ratio [HR] 0·97 [95% CI 0·58-1·64], p=0·9180). There were five (1·3%) cardiac-related deaths in the DES group and 12 (3·1%) in the DCB group (full analysis population). Probable or definite stent thrombosis (three [0·8%] in the DCB group vs four [1·1%] in the DES group; HR 0·73 [0·16-3·26]) and major bleeding (four [1·1%] in the DCB group vs nine [2·4%] in the DES group; HR 0·45 [0·14-1·46]) were the most common adverse events. INTERPRETATION: In small native coronary artery disease, DCB was non-inferior to DES regarding MACE up to 12 months, with similar event rates for both treatment groups. FUNDING: Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Basel Cardiovascular Research Foundation, and B Braun Medical AG.


Asunto(s)
Angioplastia Coronaria con Balón/métodos , Materiales Biocompatibles Revestidos/uso terapéutico , Enfermedad de la Arteria Coronaria/terapia , Stents Liberadores de Fármacos , Intervención Coronaria Percutánea/métodos , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios Prospectivos
13.
Proc Natl Acad Sci U S A ; 113(44): E6766-E6775, 2016 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-27791178

RESUMEN

Farnesylation and carboxymethylation of KRAS4b (Kirsten rat sarcoma isoform 4b) are essential for its interaction with the plasma membrane where KRAS-mediated signaling events occur. Phosphodiesterase-δ (PDEδ) binds to KRAS4b and plays an important role in targeting it to cellular membranes. We solved structures of human farnesylated-methylated KRAS4b in complex with PDEδ in two different crystal forms. In these structures, the interaction is driven by the C-terminal amino acids together with the farnesylated and methylated C185 of KRAS4b that binds tightly in the central hydrophobic pocket present in PDEδ. In crystal form II, we see the full-length structure of farnesylated-methylated KRAS4b, including the hypervariable region. Crystal form I reveals structural details of farnesylated-methylated KRAS4b binding to PDEδ, and crystal form II suggests the potential binding mode of geranylgeranylated-methylated KRAS4b to PDEδ. We identified a 5-aa-long sequence motif (Lys-Ser-Lys-Thr-Lys) in KRAS4b that may enable PDEδ to bind both forms of prenylated KRAS4b. Structure and sequence analysis of various prenylated proteins that have been previously tested for binding to PDEδ provides a rationale for why some prenylated proteins, such as KRAS4a, RalA, RalB, and Rac1, do not bind to PDEδ. Comparison of all four available structures of PDEδ complexed with various prenylated proteins/peptides shows the presence of additional interactions due to a larger protein-protein interaction interface in KRAS4b-PDEδ complex. This interface might be exploited for designing an inhibitor with minimal off-target effects.


Asunto(s)
3',5'-GMP Cíclico Fosfodiesterasas/química , 3',5'-GMP Cíclico Fosfodiesterasas/metabolismo , Dominios y Motivos de Interacción de Proteínas , Prenilación de Proteína/fisiología , Proteínas Proto-Oncogénicas p21(ras)/química , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , 3',5'-GMP Cíclico Fosfodiesterasas/genética , Secuencia de Aminoácidos , Sitios de Unión , Membrana Celular/metabolismo , Cristalografía por Rayos X , Genes ras , Humanos , Metilación , Modelos Moleculares , Conformación Molecular , Mutación , Unión Proteica/fisiología , Proteínas Proto-Oncogénicas p21(ras)/genética , Análisis de Secuencia , Proteína de Unión al GTP rac1/metabolismo , Proteínas de Unión al GTP ral/metabolismo
14.
Eur J Clin Microbiol Infect Dis ; 37(4): 735-743, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29307004

RESUMEN

Pseudomonas aeruginosa status influences cystic fibrosis (CF) clinical management but no 'gold standard' definition exists. The Leeds criteria are commonly used but may lack sensitivity for chronic P. aeruginosa. We compared clinicians' decision with the Leeds criteria in three adult CF centres. Two independent prospective datasets (Sheffield dataset, n = 185 adults; ACtiF pilot dataset, n = 62 adults from two different centres) were analysed. Clinicians involved in deciding P. aeruginosa status were blinded to the study objectives. Clinicians considered more adults with CF to have chronic P. aeruginosa infection compared to the Leeds criteria. This was more so for the Sheffield dataset (106/185, 57.3% with clinicians' decision vs. 80/185, 43.2% with the Leeds criteria; kappa coefficient between these two methods 0.72) compared to the ACtiF pilot dataset (34/62, 54.8% with clinicians' decision vs. 30/62, 48.4% with the Leeds criteria; kappa coefficient between these two methods 0.82). However, clinicians across different centres were relatively consistent once age and severity of lung disease, as indicated by the type of respiratory samples provided, were taken into account. Agreement in P. aeruginosa status was similar for both datasets among adults who predominantly provided sputum samples (kappa coefficient 0.78) or adults > 25 years old (kappa coefficient 0.82). Across three different centres, clinicians did not always agree with the Leeds criteria and tended to consider the Leeds criteria to lack sensitivity. Where disagreement occurred, clinicians tended to diagnose chronic P. aeruginosa infection because other relevant information was considered. These results suggest that a better definition for chronic P. aeruginosa might be developed by using consensus methods to move beyond a definition wholly dependent on standard microbiological results.


Asunto(s)
Fibrosis Quística/complicaciones , Fibrosis Quística/epidemiología , Infecciones por Pseudomonas/complicaciones , Infecciones por Pseudomonas/epidemiología , Adulto , Estudios Transversales , Femenino , Humanos , Masculino , Afecciones Crónicas Múltiples/epidemiología , Pseudomonas , Infecciones por Pseudomonas/diagnóstico , Infecciones por Pseudomonas/microbiología , Esputo/microbiología , Reino Unido/epidemiología , Adulto Joven
15.
Clin Exp Nephrol ; 22(2): 474-480, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28856476

RESUMEN

BACKGROUND: The aim of this study was to evaluate the effect of ibandronate administration on long-term graft function and graft survival after successful renal transplantation. METHODS: Seventy-two renal transplant recipients (36 patients each in the treatment and control group) were included and followed over a 15-year period. Data on graft function and death-censored transplant outcome were recorded at 1, 5, 10, and 15 years. RESULTS: Death-censored Kaplan-Meier analysis showed significantly improved graft survival of the treatment group (p = 0.026), whereas Cox regression analysis showed that ibandronate was positively associated with improved transplant survival (p = 0.028, hazard ratio 0.24, 95% confidence interval 0.07-0.86). Although general linear modelling did not indicate that ibandronate had a significant effect on transplant function (calculated using the estimated glomerular filtration rate according to Chronic Kidney Disease Epidemiology Collaboration equation) over the entire 15-year period (p = 0.650), there was a tendency towards improved graft function 1-year post-transplantion (p = 0.056). CONCLUSIONS: Ibandronate treatment within the first year of transplantation resulted in a trend towards better graft function within the first few year post-transplant, and was associated with increased transplant survival at long-term follow-up.


Asunto(s)
Difosfonatos/uso terapéutico , Rechazo de Injerto/prevención & control , Supervivencia de Injerto/efectos de los fármacos , Factores Inmunológicos/uso terapéutico , Riñón/efectos de los fármacos , Macrófagos/efectos de los fármacos , Monocitos/efectos de los fármacos , Adulto , Difosfonatos/efectos adversos , Femenino , Estudios de Seguimiento , Alemania , Tasa de Filtración Glomerular/efectos de los fármacos , Rechazo de Injerto/inmunología , Rechazo de Injerto/fisiopatología , Humanos , Ácido Ibandrónico , Factores Inmunológicos/efectos adversos , Estimación de Kaplan-Meier , Riñón/inmunología , Riñón/fisiopatología , Trasplante de Riñón/efectos adversos , Modelos Lineales , Macrófagos/inmunología , Masculino , Persona de Mediana Edad , Monocitos/inmunología , Modelos de Riesgos Proporcionales , Ensayos Clínicos Controlados Aleatorios como Asunto , Estudios Retrospectivos , Factores de Riesgo , Linfocitos T Colaboradores-Inductores/efectos de los fármacos , Linfocitos T Colaboradores-Inductores/inmunología , Factores de Tiempo , Resultado del Tratamiento
16.
J Cardiovasc Electrophysiol ; 28(6): 651-658, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28301685

RESUMEN

BACKGROUND: Arrhythmia recurrence after atrial fibrillation (AF) ablation remains high and requires repeat interventions in a substantial number of patients. We assessed the value of conventional and 3-D echocardiography to predict AF recurrence. METHODS AND RESULTS: Consecutive patients undergoing AF ablation by means of pulmonary vein isolation were included in a prospective registry. Echocardiograms were obtained prior to the ablation procedure, and analyzed offline in a standardized manner, including 3-D left atrial (LA) volumetry and determination of LA function and sphericity. The primary endpoint, AF recurrence (>30 seconds) between 3 to 12 months after AF ablation, was independently adjudicated. We included 276 patients (73% male, mean age 59.9 ± 9.9 years). Paroxysmal and persistent AF were present in 178 (64%) and 98 (36%) patients, respectively. Mean left ventricular ejection fraction and indexed LA volume in 3-D (LAVI) were 52 ± 12% and 42 ± 13 mL/m2 , respectively. AF recurrence was observed in 110 (40%) patients after a single procedure. Median (interquartile range) time to AF recurrence was 123 (92; 236) days. In multivariable Cox regression models, the only predictors for AF recurrence were the minimal, maximal, and indexed 3-D LA volumes, P = 0.024, P = 0.016, and P = 0.014, respectively. Quartile specific analysis of 3-D LAVI showed an HR of 1.885 (95%CI 1.066-3.334; P for trend = 0.015) for the highest compared to the lowest quartile. CONCLUSION: Our results show the important role of LA volume for the long-term freedom from arrhythmia after AF ablation. These data also highlight the potential of 3-D echocardiography in this context and may facilitate patient selection for AF ablation.


Asunto(s)
Fibrilación Atrial/diagnóstico por imagen , Fibrilación Atrial/cirugía , Función del Atrio Izquierdo , Ablación por Catéter/efectos adversos , Ecocardiografía Tridimensional , Atrios Cardíacos/diagnóstico por imagen , Atrios Cardíacos/cirugía , Venas Pulmonares/cirugía , Potenciales de Acción , Anciano , Fibrilación Atrial/fisiopatología , Supervivencia sin Enfermedad , Femenino , Atrios Cardíacos/fisiopatología , Frecuencia Cardíaca , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Venas Pulmonares/fisiopatología , Recurrencia , Sistema de Registros , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
17.
Clin Oral Investig ; 21(6): 2109-2122, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27838845

RESUMEN

OBJECTIVES: The objectives of this study were to identify risk factors associated with the premature cover screw exposure (pCSE) at dental implants and to evaluate the influence of a pCSE on peri-implant marginal bone level (MBL) change compared to non-exposed implants. MATERIALS AND METHODS: Retrospective data assessment from 165 patients (mean age = 54.0 ± 14.4 years) who received 395 submerged implants included demographic, health-related, and therapeutic variables which were analyzed for their respective impact. MBL change was detected at digital radiographs obtained from first- and second-stage surgeries. RESULTS: pCSE were detected in 43 patients (26.1%) and 53 implants (13.4%). An increased frequency of exposure was significantly associated with (I) male gender (p = 0.012) at patient level and (II) the posterior region of the jaws (p = 0.005), implant systems with platform-matching cover screws, and a vertical distance of ≥0.5 mm between bone crest and the implant platform (both p < 0.001) at implant level. The decrease in mesial, distal, and total MBL differed significantly (mean total = 0.8 ± 0.7 vs. 0.3 ± 0.5; mean mesial = 0.8 ± 0.8 vs. 0.3 ± 0.6; mean distal = 0.8 ± 0.8 vs. 0.3 ± 0.6 mm; p < 0.001) between non-exposed and pCSE implants. CONCLUSIONS: Male patients, implants with platform-matched cover screws, or when placed supracrestally or in posterior sites revealed significantly more pCSE, resulting in significantly decreased peri-implant MBL compared with non-exposed implants. CLINICAL RELEVANCE: Patients with an enhanced risk of pCSE should follow frequent regular recalls during the healing period to enable for early diagnosis and intervention.


Asunto(s)
Pérdida de Hueso Alveolar/etiología , Implantes Dentales/efectos adversos , Diseño de Implante Dental-Pilar , Diseño de Prótesis Dental , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiografía Dental Digital , Estudios Retrospectivos , Factores de Riesgo , Factores Sexuales
18.
Eur J Appl Physiol ; 116(10): 2025-34, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27562067

RESUMEN

PURPOSE: Acute exercise improves selective aspects of cognition such as executive functioning. Animal studies suggest that some effects are based on exercise-induced alterations in serotonin (5-HT) secretion. This study evaluates the impact of different aerobic exercise intensities on 5-HT serum levels as well as on executive functioning considering 5-HT as a potential mediator. METHODS: 121 young adults (23.8 ± 3.6 years) were examined in a randomized controlled trial including three exercise intervention (35 min) groups (low intensity, 45 % of the maximal heart rate (HRmax); moderate intensity, 65 % HRmax; high intensity, 85 % HRmax) and one control group. 5-HT levels and response inhibition (measured by a computerized Stroop test) were assessed pre- and post-intervention. RESULTS: There was a significant (p = 0.022) difference between groups regarding serum Δ5-HT levels. Post hoc tests indicated significant (p = 0.013) higher 5-HT serum levels for the high-intensity group compared to the control group while other groups did not differ significantly from each other. Serum Δ5-HT levels and exercise intensity were shown to be linearly associated through polynomial contrast analysis (p = 0.003). Furthermore, ANOVA revealed a significant difference for Stroop parameter reading (p = 0.030) and a tendency for reverse Stroop effect (p = 0.061). Correlation analysis showed that augmented 5-HT levels were associated with improved results in response inhibition. CONCLUSIONS: This study indicates that intensive acute exercise increases serum 5-HT levels compared to a control group. These findings might be relevant for many other related research fields in exercise science, since 5-HT receptors are expressed on many different cell types including endothelia and immune cells.


Asunto(s)
Función Ejecutiva/fisiología , Ejercicio Físico/fisiología , Resistencia Física/fisiología , Esfuerzo Físico/fisiología , Serotonina/sangre , Test de Stroop , Adulto , Cognición/fisiología , Femenino , Humanos , Masculino
19.
Biopharm Drug Dispos ; 37(2): 75-92, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26461173

RESUMEN

The mechanisms of absorption, distribution, metabolism and elimination of small and large molecule therapeutics differ significantly from one another and can be explored within the framework of a physiologically based pharmacokinetic (PBPK) model. This paper briefly reviews fundamental approaches to PBPK modeling, in which drug kinetics within tissues and organs are explicitly represented using physiologically meaningful parameters. The differences in PBPK models applied to small/large molecule drugs are highlighted, thus elucidating differences in absorption, distribution and elimination properties between these two classes of drugs in a systematic manner. The absorption of small and large molecules differs with respect to their common extravascular routes of delivery (oral versus subcutaneous). The role of the lymphatic system in drug distribution, and the involvement of tissues as sites of elimination (through catabolism and target mediated drug disposition) are unique features of antibody distribution and elimination that differ from small molecules, which are commonly distributed into the tissues but are eliminated primarily by liver metabolism. Fundamental differences exist in the ability to predict human pharmacokinetics based upon preclinical data due to differing mechanisms governing small and large molecule disposition. These differences have influence on the evolving utilization of PBPK modeling in the discovery and development of small and large molecule therapeutics.


Asunto(s)
Anticuerpos Monoclonales/farmacocinética , Modelos Biológicos , Animales , Humanos
20.
Clin Oral Investig ; 20(7): 1477-86, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26481235

RESUMEN

OBJECTIVES: In order to identify oral candidiasis patients being at risk of carrying potentially drug-resistant Candida, the aim of the study was to detect local, systemic, demographic, and health-related factors influencing (I) yeast spectrum composition and (II) antifungal administration frequency. Additionally, the aim was to investigate (III) species shift occurrence. MATERIALS AND METHODS: Data from 798 patients (496 females, 302 males; mean age 59.7) with oral candidiasis diagnosed based on positive clinical and microbial findings (species identification and CFU count) between 2006 and 2011 were retrospectively analyzed using Pearson's chi(2) test and regression analysis. RESULTS: Among 958 isolates, Candida albicans was the most frequently detected (76.8 %). Also, species intrinsically resistant to azoles were frequently isolated (15.8 and 17.7 % of isolates and patients). (I) Infections only caused by C. albicans were significantly associated with the use of inhalation steroids (p = 0.001) and antibiotics (p = 0.04), super-infection of lichen planus (p = 0.002), and the absence of removable dentures (p < 0.001). (II) Anti-mycotics were significantly more frequently administered in patients using inhalation steroids (p = 0.001), suffering from asthma/COPD, or smoking heavily (p = 0.003) and if C. albicans and non-albicans species were detected together (p = 0.001). (III) Pathogen composition did not change over time within the examined period (p = 0.239). CONCLUSIONS: Different variables enhance the presence of certain Candida and the antifungal prescription frequency. No species shift was evident. CLINICAL RELEVANCE: The major pathogen in oral candidiasis remains C. albicans. Nevertheless, therapeutic problems may be caused by the frequent presence of species intrinsically resistant to azoles, especially in patients wearing dentures.


Asunto(s)
Candidiasis Bucal/etiología , Candidiasis Bucal/microbiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antifúngicos/uso terapéutico , Candida albicans/aislamiento & purificación , Candidiasis Bucal/tratamiento farmacológico , Niño , Recuento de Colonia Microbiana , Dentaduras/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Fumar/efectos adversos , Xerostomía/complicaciones
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