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1.
Cereb Cortex Commun ; 4(4): tgad021, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38074408

RESUMEN

Introduction: Mind wandering (MW) has been associated with reduced responsiveness to external stimuli ("perceptual decoupling"). Conversely, increased perceptual demands of a task result in reduced MW. Here we propose a neurobiological account attributing the mutually-limiting relationship of MW and perception to brain-wide limits on cerebral metabolism. Since overall cerebral metabolism is known to remain constant, despite increased mental task demands, we tested whether increased perceptual processing load in a visual task will result in reduced oxygen metabolism in MW-related medial prefrontal cortex (mPFC) regions. Methods: We used broadband near-infrared spectroscopy to measure oxidation states of the cytochrome-c-oxidase enzyme (oxCCO), an intracellular marker of metabolism, in mPFC while sampling participants' MW experiences during their performance of a visual task of either low (feature search) or high(conjunction search) perceptual load. Results: Increased perceptual load in the task resulted in reduced oxCCO signal in mPFC regions related to MW reports. High perceptual load was also found to specifically suppress detailed (and hence more metabolism-demanding) rather than vague MW. Discussion: Overall, the results support a shared metabolism account of the relationship between MW and perception and demonstrate that attentional-regulation of metabolism only supports ongoing detailed MW when perceptual processing demands are low.

2.
Skin Res Technol ; 25(1): 68-78, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29923636

RESUMEN

BACKGROUND: Diagnostics of healing, infection, and inflammation in chronic wounds in comparison with physiological wound healing in acute wounds may help for therapy decisions toward individualized therapy management. With emerging new optical techniques the coupling of optical diagnostic devices with tissue provides a great challenge. Traditional coupling with cover slips is used since the early days of microscopy. In modern health care, hygienic covering of surfaces is necessary to avoid infections and cross-contaminations. METHODS: Measurements in chronic wounds were performed at three different areas including the center of the wound, the border of the wound and healthy skin as comparison area. For each measurement area, three vertical stacks were taken by MPT. Additionally, three different optical measuring procedures (MPT, OCT, CLSM) were used for the examination of BNC foil. Examinations of BNC foil were carried out at two different areas of healthy skin compared to a standard setup as control. RESULTS: The MPT evaluation revealed a distinct difference in the second harmonic generation-to-autofluorescence aging index of dermis (SAAID) behavior between the vertical stacks taken at central wound areas and wound margins as well as unaffected skin. Through BNC foil covers, MPT CLSM and OCT images were captured with good quantitative and qualitative results. CONCLUSIONS: Phases in chronic wounds could be matched with physiologically healing in acute wounds according to SAAID and MPT imaging. BNC provided an alternative covering for MPT, OCT, and CLSM with clear morphological images.


Asunto(s)
Bacterias/metabolismo , Celulosa/farmacología , Piel/lesiones , Cicatrización de Heridas/efectos de los fármacos , Vendajes , Humanos , Microscopía de Fluorescencia por Excitación Multifotónica , Nanoestructuras/química , Piel/efectos de los fármacos , Tomografía de Coherencia Óptica/métodos
3.
Dent Mater ; 34(10): 1542-1554, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29970234

RESUMEN

OBJECTIVE: Biomaterials for periodontal regeneration may have insufficient mechanical and antimicrobial properties or are difficult to apply under clinical conditions. The aim of the present study was to develop a polymeric bone grafting material of suitable physical appearance and antimicrobial photodynamic activity. METHODS: Two light curable biomaterials based on urethane dimethacrylate (BioM1) and a tri-armed oligoester-urethane methacrylate (BioM2) that additionally contained a mixture of ß-tricalcium phosphate microparticles and 20wt% photosensitizer mTHPC (PS) were fabricated and analyzed by their compressive strength, flexural strength and modulus of elasticity. Cytotoxicity was observed by incubating eluates and in direct-contact to MC3T3-E1 cells. Antimicrobial activity was ascertained on Porphyromonas gingivalis and Enterococcus faecalis upon illumination with laser light (652nm, 1×100J/cm2, 2×100J/cm2). RESULTS: The compressive strength, flexural strength and elastic modulus were, respectively, 311.73MPa, 22.81MPa and 318.85MPa for BioM1+PS and 742.37MPa, 7.58MPa and 406.23MPa for BioM2+PS. Both materials did not show any cytotoxic behavior. Single laser-illumination (652nm) caused total suppression of P. gingivalis (BioM2+PS), while repeated irradiation reduced E. faecalis by 3.7 (BioM1+PS) and 3.1 (BioM2+PS) log-counts. SIGNIFICANCE: Both materials show excellent mechanical and cytocompatible properties. In addition, irradiation with 652nm induced significant bacterial suppression. The manufactured biomaterials might enable a more efficient cure of periodontal bone lesions. Due to the mechanical properties functional stability might be increased. Further, the materials are antimicrobial upon illumination with light that enables a trans-mucosal eradication of residual pathogens.


Asunto(s)
Antiinfecciosos/farmacología , Materiales Biocompatibles/farmacología , Regeneración Tisular Guiada Periodontal/métodos , Metacrilatos/farmacología , Fotoquimioterapia/métodos , Poliuretanos/farmacología , Fosfatos de Calcio/farmacología , Fuerza Compresiva , Módulo de Elasticidad , Enterococcus faecalis/efectos de los fármacos , Resistencia Flexional , Ensayo de Materiales , Tamaño de la Partícula , Fármacos Fotosensibilizantes/farmacología , Porphyromonas gingivalis/efectos de los fármacos
4.
mSphere ; 3(3)2018.
Artículo en Inglés | MEDLINE | ID: mdl-29720528

RESUMEN

USA500 isolates are clonal complex 8 (CC8) Staphylococcus aureus strains closely related to the prominent community- and hospital-associated USA300 group. Despite being relatively understudied, USA500 strains cause a significant burden of disease and are the third most common methicillin-resistant S. aureus (MRSA) strains identified in the U.S. Emerging Infections Program (EIP) invasive S. aureus surveillance. To better understand the genetic relationships of the strains, we sequenced the genomes of 539 USA500 MRSA isolates from sterile site infections collected through the EIP between 2005 and 2013 in the United States. USA500 isolates fell into three major clades principally separated by their distribution across different U.S. regions. Clade C1 strains, found principally in the Northeast, were associated with multiple IS256 insertion elements in their genomes and higher levels of antibiotic resistance. C2 was associated with Southern states, and E1 was associated with Western states. C1 and C2 strains all shared a frameshift in the gene encoding AdsA surface-attached surface protein. We propose that the term "USA500" should be used for CC8 strains sharing a recent common ancestor with the C1, C2, and E1 strains but not in the USA300 group.IMPORTANCE In this work, we have removed some of the confusion surrounding the use of the name "USA500," placed USA500 strains in the context of the CC8 group, and developed a strategy for assignment to subclades based on genome sequence. Our new phylogeny of USA300/USA500 will be a reference point for understanding the genetic adaptations that have allowed multiple highly virulent clonal strains to emerge from within CC8 over the past 50 years.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina/clasificación , Staphylococcus aureus Resistente a Meticilina/genética , Tipificación Molecular , Filogeografía , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología , Monitoreo Epidemiológico , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Epidemiología Molecular , Estados Unidos/epidemiología , Secuenciación Completa del Genoma
5.
HLA ; 90(1): 25-31, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28503844

RESUMEN

Recent years have seen a rapid increase in the discovery of novel allelic variants of the human leukocyte antigen (HLA) genes. Commonly, only the exons encoding the peptide binding domains of novel HLA alleles are submitted. As a result, the IPD-IMGT/HLA Database lacks sequence information outside those regions for the majority of known alleles. This has implications for the application of the new sequencing technologies, which deliver sequence data often covering the complete gene. As these technologies simplify the characterization of the complete gene regions, it is desirable for novel alleles to be submitted as full-length sequences to the database. However, the manual annotation of full-length alleles and the generation of specific formats required by the sequence repositories is prone to error and time consuming. We have developed TypeLoader to address both these facets. With only the full-length sequence as a starting point, Typeloader performs automatic sequence annotation and subsequently handles all steps involved in preparing the specific formats for submission with very little manual intervention. TypeLoader is routinely used at the DKMS Life Science Lab and has aided in the successful submission of more than 900 novel HLA alleles as full-length sequences to the European Nucleotide Archive repository and the IPD-IMGT/HLA Database with a 95% reduction in the time spent on annotation and submission when compared with handling these processes manually. TypeLoader is implemented as a web application and can be easily installed and used on a standalone Linux desktop system or within a Linux client/server architecture. TypeLoader is downloadable from http://www.github.com/DKMS-LSL/typeloader.


Asunto(s)
Alelos , Automatización de Laboratorios , Antígenos HLA/clasificación , Antígenos HLA/genética , Anotación de Secuencia Molecular/métodos , Programas Informáticos , Secuencia de Bases , Bases de Datos Factuales , Expresión Génica , Genotipo , Antígenos HLA/inmunología , Humanos , Internet , Flujo de Trabajo
6.
HLA ; 90(2): 79-87, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28547825

RESUMEN

The high-throughput department of DKMS Life Science Lab encounters novel human leukocyte antigen (HLA) alleles on a daily basis. To characterise these alleles, we have developed a system to sequence the whole gene from 5'- to 3'-UTR for the HLA loci A, B, C, DQB1 and DPB1 for submission to the European Molecular Biology Laboratory - European Nucleotide Archive (EMBL-ENA) and the IPD-IMGT/HLA Database. Our workflow is based on a dual redundant sequencing strategy. Using shotgun sequencing on an Illumina MiSeq instrument and single molecule real-time (SMRT) sequencing on a PacBio RS II instrument, we are able to achieve highly accurate HLA full-length consensus sequences. Remaining conflicts are resolved using the R package DR2S (Dual Redundant Reference Sequencing). Given the relatively high throughput of this strategy, we have developed the semi-automated web service TypeLoader, to aid in the submission of sequences to the EMBL-ENA and the IPD-IMGT/HLA Database. In the IPD-IMGT/HLA Database release 3.24.0 (April 2016; prior to the submission of the sequences described here), only 5.2% of all known HLA alleles have been fully characterised together with intronic and UTR sequences. So far, we have applied our strategy to characterise and submit 1056 HLA alleles, thereby more than doubling the number of fully characterised alleles. Given the increasing application of next generation sequencing (NGS) for full gene characterisation in clinical practice, extending the HLA database concomitantly is highly desirable. Therefore, we propose this dual redundant sequencing strategy as a workflow for submission of novel full-length alleles and characterisation of sequences that are as yet incomplete. This would help to mitigate the predominance of partially known alleles in the database.


Asunto(s)
Alelos , Bases de Datos de Ácidos Nucleicos , Sitios Genéticos , Antígenos HLA/genética , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos
7.
Eur J Trauma Emerg Surg ; 43(2): 201-214, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26619853

RESUMEN

PURPOSE: Early detection and management of trauma haemorrhage and coagulopathy have been associated with improved outcomes. We assessed infrastructure, logistics and management practice of trauma-associated haemorrhage and coagulopathy across German trauma centres. METHODS: A web-based survey of 20 questions was developed using the open source survey application LimeSurvey®. It was disseminated among surgeons and anaesthetists in Germany. RESULTS: 145 Questionnaires were returned of which 106 were completed and analysed. Two-thirds of the respondents declared they worked in level I trauma centres. Only 61 % followed a treatment algorithm. Over 90 % used standard laboratory and coagulation tests for decision-making. 56.6 % declared they additionally used extended coagulation assays (TEG/ROTEM). Packed red blood cells, fresh frozen plasma, platelet concentrates, prothrombin complex concentrates, tranexamic acid, calcium, fibrinogen and vitamin K were used by more than 85 % of the respondents for the initial treatment. In all hospitals, irrespective of care level, the first blood product was administered in less than 30 min upon patient arrival (49 % <15 min, 48.1 % <30 min). New oral anticoagulants (NOACs) were identified as an increasing problem in today`s trauma care (>95 %) and 65 % of the respondents necessitated reliable tests for early risk stratification. 57.6 % necessitated interdisciplinary training programs to improve clinical skills. CONCLUSIONS: There is variation in the local infrastructure, logistics and management of trauma haemorrhage and coagulopathy across German trauma centres. More than one-third of the respondents declare they do not consistently follow a treatment algorithm. NOACs are considered as an increasing problem in acute trauma care.


Asunto(s)
Trastornos de la Coagulación Sanguínea/terapia , Adhesión a Directriz/estadística & datos numéricos , Encuestas de Atención de la Salud , Hemorragia/terapia , Pautas de la Práctica en Medicina/estadística & datos numéricos , Centros Traumatológicos , Heridas y Lesiones/terapia , Anticoagulantes/uso terapéutico , Trastornos de la Coagulación Sanguínea/diagnóstico , Transfusión Sanguínea , Alemania/epidemiología , Hemorragia/diagnóstico , Hemostáticos/uso terapéutico , Humanos , Guías de Práctica Clínica como Asunto , Encuestas y Cuestionarios , Resultado del Tratamiento , Heridas y Lesiones/complicaciones , Heridas y Lesiones/diagnóstico
8.
J Clin Microbiol ; 54(3): 745-8, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26677248

RESUMEN

The performance of a rapid penicillin-binding protein 2a (PBP2a) detection assay, the Alere PBP2a culture colony test, was evaluated for identification of PBP2a-mediated beta-lactam resistance in human and animal clinical isolates of Staphylococcus intermedius group, Staphylococcus lugdunensis, and Staphylococcus schleiferi. The assay was sensitive and specific, with all PBP2a-negative and PBP2a-positive strains testing negative and positive, respectively.


Asunto(s)
Cromatografía de Afinidad , Proteínas de Unión a las Penicilinas/metabolismo , Péptido Sintasas/metabolismo , Staphylococcus intermedius/metabolismo , Staphylococcus lugdunensis/metabolismo , Animales , Cromatografía de Afinidad/métodos , Cromatografía de Afinidad/normas , Humanos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Infecciones Estafilocócicas/microbiología , Staphylococcus intermedius/aislamiento & purificación , Staphylococcus lugdunensis/aislamiento & purificación
9.
Eur J Trauma Emerg Surg ; 41(4): 413-20, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26037989

RESUMEN

PURPOSE: Early detection and management of post-traumatic haemorrhage and coagulopathy have been associated with improved outcomes, but local infrastructures, logistics and clinical strategies may differ. METHODS: To assess local differences in infrastructure, logistics and clinical management of trauma-associated haemorrhage and coagulopathy, we have conducted a web-based survey amongst the delegates to the 15th European Congress of Trauma and Emergency Surgery (ECTES) and the 2nd World Trauma (WT) Congress held in Frankfurt, Germany, 25-27 May 2014. RESULTS: 446/1,540 delegates completed the questionnaire yielding a response rate of 29%. The majority specified to work as consultants/senior physicians (47.3%) in general (36.1%) or trauma/orthopaedic surgery (44.5%) of level I (70%) or level II (19%) trauma centres. Clinical assessment (>80%) and standard coagulation assays (74.6%) are the most frequently used strategies for early detection and monitoring of bleeding trauma patients with coagulopathy. Only 30% of the respondents declared to use extended coagulation assays to better characterise the bleeding and coagulopathy prompted by more individualised treatment concepts. Most trauma centres (69%) have implemented local protocols based on international and national guidelines using conventional blood products, e.g. packed red blood cell concentrates (93.3%), fresh frozen plasma concentrates (93.3%) and platelet concentrates (83%), and antifibrinolytics (100%). 89% considered the continuous intake of anticoagulants including "new oral anticoagulants" and platelet inhibitors as an increasing threat to bleeding trauma patients. CONCLUSIONS: This study confirms differences in infrastructure, logistics and clinical practice for the detection and management of trauma-haemorrhage and trauma-associated coagulopathy amongst international centres. Ongoing work will focus on geographical differences.


Asunto(s)
Trastornos de la Coagulación Sanguínea/diagnóstico , Trastornos de la Coagulación Sanguínea/terapia , Hemorragia/diagnóstico , Hemorragia/terapia , Heridas y Lesiones/complicaciones , Adulto , Anticoagulantes/uso terapéutico , Actitud del Personal de Salud , Trastornos de la Coagulación Sanguínea/etiología , Transfusión de Componentes Sanguíneos/métodos , Manejo de la Enfermedad , Urgencias Médicas , Femenino , Alemania , Encuestas de Atención de la Salud , Hemorragia/etiología , Hemostáticos/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Grupo de Atención al Paciente/organización & administración , Encuestas y Cuestionarios , Centros Traumatológicos , Resultado del Tratamiento , Heridas y Lesiones/diagnóstico , Heridas y Lesiones/terapia
10.
J Clin Microbiol ; 49(12): 4126-30, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21998435

RESUMEN

We compared recovery of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) from nasal and groin swab specimens of 600 HIV-infected outpatients by selective and nonselective direct plating and broth enrichment. Swabs were collected at baseline, 6-month, and 12-month visits and cultured by direct plating to mannitol salt agar (MSA) and CHROMagar MRSA (CM) and overnight broth enrichment with subculture to MSA (broth). MRSA isolates were characterized by pulsed-field gel electrophoresis (PFGE), staphylococcal cassette chromosome mec (SCCmec) typing, and PCR for the Panton-Valentine leukocidin. At each visit, 13 to 15% of patients were colonized with MRSA and 30 to 33% were colonized with methicillin-susceptible S. aureus (MSSA). Broth, CM, and MSA detected 95%, 82%, and 76% of MRSA-positive specimens, respectively. MRSA recovery was significantly higher from broth than CM (P ≤ 0.001) or MSA (P ≤ 0.001); there was no significant difference in recovery between MSA and CM. MSSA recovery also increased significantly when using broth than when using MSA (P ≤ 0.001). Among specimens collected from the groin, broth, CM, and MSA detected 88%, 54%, and 49% of the MRSA-positive isolates, respectively. Broth enrichment had a greater impact on recovery of MRSA from the groin than from the nose compared to both CM (P ≤ 0.001) and MSA (P ≤ 0.001). Overall, 19% of MRSA-colonized patients would have been missed with nasal swab specimen culture only. USA500/Iberian and USA300 were the most common MRSA strains recovered, and USA300 was more likely than other strain types to be recovered from the groin than from the nose (P = 0.05).


Asunto(s)
Técnicas Bacteriológicas/métodos , Infecciones por VIH/complicaciones , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/microbiología , Toxinas Bacterianas/genética , ADN Bacteriano/genética , Electroforesis en Gel de Campo Pulsado , Exotoxinas/genética , Genotipo , Ingle/microbiología , Humanos , Leucocidinas/genética , Staphylococcus aureus Resistente a Meticilina/clasificación , Staphylococcus aureus Resistente a Meticilina/genética , Tipificación Molecular , Nariz/microbiología , Pacientes Ambulatorios , Reacción en Cadena de la Polimerasa , Sensibilidad y Especificidad
12.
Eur J Pharm Sci ; 28(1-2): 134-40, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16504490

RESUMEN

The objective of this study was to evaluate the ability of meso-tetra(hydroxyphenyl)chlorin (m-THPC) encapsulated into liposomal formulations to occlude neovascularization. Two m-THPC formulations including conventional or plain liposomes (Foslip) based on dipalmitoylphosphatidylcholine (DPPC) and the corresponding long-circulating poly(ethylene glycol) (PEG)-modified liposomes (PEGylated liposomes: Fospeg) were evaluated as delivery systems. Using the chick chorioallantoic membrane (CAM) as in vivo model, the fluorescence pharmacokinetic behaviour of encapsulated m-THPC reflecting the rate of the extravasation of the dye from the CAM vasculature and its photothrombic effectiveness were determined. This study was focused on the influence of the drug and/or light doses on the mean retention time of m-THPC within the CAM blood vessels after intravenous injection, and its photothrombic efficacy. Irrespective of the formulations tested and the drug doses injected, similar fluorescence pharmacokinetic profiles were obtained. The fluorescence contrast reached a steady state 30 s after injection. Constant positive values of the fluorescence contrast suggest that m-THPC is confined into the intravascular compartment during the experimental time (500 s). However, the photodynamic therapy assays showed that Foslip appears to be less potent than Fospeg in terms of photothrombic activities on the CAM model. For instance, the light dose necessary to induce the desired vascular damage with Foslip was twice (100 J/cm2) higher than with Fospeg (50 J/cm2). It can be inferred that this pre-clinical study showed that the formulation based on PEGylated liposomes technology offers a suitable delivery system for the treatment of choroidal neovascularization associated with age-related macular degeneration.


Asunto(s)
Corion/efectos de los fármacos , Mesoporfirinas/administración & dosificación , Mesoporfirinas/farmacología , Fármacos Fotosensibilizantes/administración & dosificación , Fármacos Fotosensibilizantes/farmacología , 1,2-Dipalmitoilfosfatidilcolina , Algoritmos , Animales , Vasos Sanguíneos/efectos de los fármacos , Química Farmacéutica , Embrión de Pollo , Corion/irrigación sanguínea , Excipientes , Inyecciones Intravenosas , Liposomas , Membranas/química , Flujo Sanguíneo Regional/efectos de los fármacos , Espectrometría de Fluorescencia
13.
Photochem Photobiol ; 81(6): 1505-10, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15960590

RESUMEN

In the present study, photodynamic activity of a novel photosensitizer (PS), Chlorin e(6)-2.5 N-methyl-d-glucamine (BLC 1010), was evaluated using the chorioallantoic membrane (CAM) as an in vivo model. After intravenous (i.v.) injection of BLC 1010 into the CAM vasculature, the applicability of this drug for photodynamic therapy (PDT) was assessed in terms of fluorescence pharmacokinetics, i.e. leakage from the CAM vessels, and photothrombic activity. The influence of different PDT parameters including drug and light doses on the photodynamic activity of BLC 1010 has been investigated. It was found that, irrespective of drug dose, an identical continuous decrease in fluorescence contrast between the drug inside and outside the blood vessels was observed. The optimal treatment conditions leading to desired vascular damage were obtained by varying drug and light doses. Indeed, observable damage was achieved when irradiation was performed at light doses up to 5 J/cm(2) 1 min after i.v. injection of drug doses up to 0.5 mg/kg body weight(b.w.). However, when irradiation with light doses of more than 10 J/cm(2) was performed 1 min after injection of drug doses up to 2 mg/kg body weight, this led to occlusion of large blood vessels. It has been demonstrated that it is possible to obtain the desired vascular occlusion and stasis with BLC 1010 for different combinations of drug and/or light doses.


Asunto(s)
Capilares/efectos de los fármacos , Membrana Corioalantoides/efectos de los fármacos , Fármacos Fotosensibilizantes/farmacología , Porfirinas/química , Porfirinas/farmacología , Animales , Capilares/patología , Capilares/efectos de la radiación , Embrión de Pollo , Clorofilidas , Membrana Corioalantoides/irrigación sanguínea , Membrana Corioalantoides/efectos de la radiación , Relación Dosis-Respuesta a Droga , Relación Dosis-Respuesta en la Radiación , Evaluación Preclínica de Medicamentos , Luz , Estructura Molecular , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/farmacocinética , Porfirinas/farmacocinética , Solubilidad , Agua/química
14.
Mol Genet Genomics ; 272(4): 379-96, 2004 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15517392

RESUMEN

In Arabidopsis thaliana, the Toc34 receptor component of the chloroplast import machinery is encoded by two independent but highly homologous genes, atToc33 and atToc34. We have isolated a T-DNA insertion mutant of atToc33 which is characterized by a pale phenotype, due to reductions in the levels of photosynthetic pigments, and alterations in protein composition. The latter involve not only chloroplast proteins but also some cytosolic polypeptides, including 14-3-3 proteins which, among other functions, have been proposed to be cytosolic targeting factors for nucleus-encoded chloroplast proteins. Within the chloroplast, many, though not all, proteins of the photosynthetic apparatus, as well as proteins not directly involved in photosynthesis, are found in significantly reduced amounts in the mutant. However, the accumulation of other chloroplast proteins is unaffected. This suggests that the atToc33 receptor is responsible for the import of a specific subset of nucleus-encoded chloroplast proteins. Supporting evidence for this conclusion was obtained by antisense repression of the atToc34 gene in the atToc33 mutant, which results in an exacerbation of the phenotype.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Cloroplastos/genética , ADN Bacteriano/genética , Proteínas de la Membrana/genética , Mutación/genética , Northern Blotting , Southern Blotting , Western Blotting , Carotenoides/metabolismo , Clorofila/metabolismo , Cloroplastos/ultraestructura , Clonación Molecular , Cartilla de ADN , Fluorescencia , Componentes del Gen , Vectores Genéticos , Espectrometría de Masas , Microscopía Electrónica de Transmisión , Fenotipo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
15.
EMBO J ; 20(5): 1051-63, 2001 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-11230129

RESUMEN

The Arabidopsis calcineurin B-like calcium sensor proteins (AtCBLs) interact with a group of serine-threonine protein kinases (AtCIPKs) in a calcium-dependent manner. Here we identify a 24 amino acid domain (NAF domain) unique to these kinases as being required and sufficient for interaction with all known AtCBLs. Mutation of conserved residues either abolished or significantly diminished the affinity of AtCIPK1 for AtCBL2. Comprehensive two-hybrid screens with various AtCBLs identified 15 CIPKs as potential targets of CBL proteins. Database analyses revealed additional kinases from Arabidopsis and other plant species harbouring the NAF interaction module. Several of these kinases have been implicated in various signalling pathways mediating responses to stress, hormones and environmental cues. Full-length CIPKs show preferential interaction with distinct CBLs in yeast and in vitro assays. Our findings suggest differential interaction affinity as one of the mechanisms generating the temporal and spatial specificity of calcium signals within plant cells and that different combinations of CBL-CIPK proteins contribute to the complex network that connects various extracellular signals to defined cellular responses.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Señalización del Calcio , Proteínas de Unión al Calcio/química , Proteínas de Unión al Calcio/metabolismo , Secuencia Conservada , Proteínas Serina-Treonina Quinasas/química , Proteínas Serina-Treonina Quinasas/metabolismo , Secuencia de Aminoácidos , Arabidopsis/química , Arabidopsis/enzimología , Arabidopsis/genética , Arabidopsis/metabolismo , Sitios de Unión , Proteínas de Unión al Calcio/genética , Sustancias Macromoleculares , Datos de Secuencia Molecular , Mutación/genética , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Unión Proteica , Proteínas Serina-Treonina Quinasas/genética , Estructura Terciaria de Proteína , Alineación de Secuencia , Análisis de Secuencia de ADN , Transducción de Señal , Especificidad por Sustrato , Técnicas del Sistema de Dos Híbridos
16.
Plant Cell ; 11(12): 2393-405, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10590166

RESUMEN

Members of the Arabidopsis calcineurin B-like Ca(2)+ binding protein (AtCBL) family are differentially regulated by stress conditions. One AtCBL plays a role in salt stress; another is implicated in response to other stress signals, including drought, cold, and wounding. In this study, we identified a group of novel protein kinases specifically associated with AtCBL-type Ca(2)+ sensors. In addition to a typical protein kinase domain, they all contain a unique C-terminal region that is both required and sufficient for interaction with the AtCBL-type but not calmodulin-type Ca(2)+ binding proteins from plants. Interactions between the kinases and AtCBLs require micromolar concentrations of Ca(2)+, suggesting that increases in cellular Ca(2)+ concentrations may trigger the formation of AtCBL-kinase complexes in vivo. Unlike most serine/threonine kinases, the AtCBL-interacting kinase efficiently uses Mn(2)+ to Mg(2)+ as a cofactor and may function as a Mn(2)+ binding protein in the cell. These findings link a new type of Ca(2)+ sensors to a group of novel protein kinases, providing the molecular basis for a unique Ca(2)+ signaling machinery in plant cells.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis/metabolismo , Calcineurina/metabolismo , Señalización del Calcio/fisiología , Proteínas de Unión al Calcio/química , Proteínas de Unión al Calcio/metabolismo , Calcio/fisiología , Proteínas Quinasas/química , Proteínas Quinasas/metabolismo , Secuencia de Aminoácidos , Sitios de Unión , Datos de Secuencia Molecular , Fosforilación , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido
17.
Anticancer Res ; 18(1B): 583-6, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9568181

RESUMEN

A prospectively randomized clinical study was performed with breast carcinoma patients to determine the correlation of defined parameters of the cellular immunity and beta-endorphin plasma levels after mistletoe lectin (ML-1) standardized therapy. The subcutaneous administration of optimal ML-1 dosages (0.5-1.0 ng ML-1/kg body weight; twice a week) induced an increased beta-endorphin plasma level, enhanced activity of peripheral blood natural killer (NK-)cells and T-lymphocytes (expression of CD-25/interleukin-2 receptors and HLA/DR-antigens). Statistical analysis of the data (Spearman correlation) revealed a significant correlation between NK- and T-cell activity and beta-endorphin plasma level. Thus, an obvious correlation between immune system and the neuroendocrine system may be anticipated which might gain therapeutical relevance.


Asunto(s)
Neoplasias de la Mama/sangre , Neoplasias de la Mama/inmunología , Neoplasias de la Mama/terapia , Inmunidad Celular , Muérdago , Preparaciones de Plantas , Proteínas de Plantas , Plantas Medicinales , Toxinas Biológicas/uso terapéutico , betaendorfina/sangre , Adulto , Humanos , Células Asesinas Naturales/inmunología , Proteínas Inactivadoras de Ribosomas Tipo 2 , Linfocitos T/inmunología
19.
Neuropsychobiology ; 31(1): 47-52, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-7708180

RESUMEN

In contrast to the single-channel dimensional complexity, the global dimensional complexity is calculated from a multichannel EEG. The intention with the method is to measure the spatial distribution of information processing in the brain. The method seems to be of interest in psychopharmacological research, but the interpretation of the results in physiological terms is rather difficult. To get a more detailed information on the physiological significance of the EEG complexity measures, the influence of well-known physiological factors was studied in a group of 14 healthy subjects aged from 1.5 to 61 years. It was found that the correlation dimension was somewhat higher in older individuals, but the correlation with age was not statistically significant. However, the global correlation dimension was significantly lower during full alertness than during drowsiness. These results might reflect the changes in spatial structure of information processing, a high complexity suggesting a 'disorganisation' during drowsiness. As regards the age-dependent changes of the correlation dimension, the spatial 'flexibility' of information processing was also studied, using the differences between the 'alert' and 'drowsy' parts of the same EEG as indicator. It was found that the differences 'drowsy minus alert' were significantly related to age. A plausible interpretation seems to be that the spatial distribution of information processing is more changeable, or more flexible, in adults than in children.


Asunto(s)
Atención/fisiología , Encéfalo/fisiología , Electroencefalografía/estadística & datos numéricos , Adolescente , Adulto , Factores de Edad , Niño , Preescolar , Interpretación Estadística de Datos , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Psiquiatría , Psicofarmacología , Fases del Sueño/fisiología
20.
Cesk Psychiatr ; 89(3): 123-9, 1993 Jun.
Artículo en Checo | MEDLINE | ID: mdl-8353827

RESUMEN

The presented study compares the effect of the well-tested antidepressant maprotiline and a new antidepressant with an atypical pharmacological profile, levoprotiline, on EEG during repeated assessment after single dose administration. From the original number of 34 patients fulfilling the criteria of a major depressive episode (DSM-III-R) on account of a low-voltage record or pathological findings 11 were eliminated. To 12 of the remaining patients levoprotiline was administered and to 11 maprotiline, after a one-week placebo period, in doses of 150 mg. The EEG was recorded after an accommodation session immediately before, 1.5, 3, 4.5, 6 and 24 hours after a single dose administration. The record was taken on a 16-channel average reference montage at rest with closed eyes. Two-minute intervals were divided into 30 four-second periods at a sampling frequency of 128 Hz. From the signal by means of FFT the spectra were estimated and the mean spectrum for the entire recording was calculated. This was then divided into 10 frequency bands. The new method of frequency analysis of alpha-entropy was also used which is a global measure of the difference between two spectra. Three hours after administration of a single dose levoprotiline had an EEG profile corresponding to the profile of tricyclic antidepressants, i.e. it increased the values of the power spectra density in the region of 5-8.5 Hz and in the entire beta band; the decline of power in the alpha band was, however, absent. As regards maprotiline, 3 hours after administration a profile typical for antidepressants was not found; obviously because of the great variance of values of power spectra density as a result of great interindividual differences in the ingestion phase. Changes of the EEG spectrum expressed as values of alpha-entropy during different periods of apparently assessment are not incidental. After the initial rise of values a decline occurs.


Asunto(s)
Antidepresivos/farmacología , Trastorno Depresivo/fisiopatología , Electroencefalografía/efectos de los fármacos , Maprotilina/análogos & derivados , Maprotilina/farmacología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad
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