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1.
BJU Int ; 131(6): 745-754, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36648168

RESUMO

OBJECTIVES: To evaluate different scenarios for the management of early diagnosis of cancer (PCa) in men at high genetic risk, using recently developed blood and urinary molecular biomarkers in combination with clinical information alongside multiparametric magnetic resonance imaging (mpMRI). PATIENTS AND METHODS: A total of 322 patients with a high genetic risk (familial or personal history of cancers or a predisposing germline variant) were included in this study. The primary outcome was the detection rates of PCa (positive biopsy) or clinically significant PCa (biopsy with International Society of Urological Pathology [ISUP] grade >1). Clinical parameters included age, body mass index, ancestry, and germline mutational status, mpMRI, prostate-specific antigen density (PSAD), Prostate Health Index and urinary markers (Prostate Cancer Associated 3, SelectMdx™ and T2:ERG score) were assessed. Sensitivity (Se) and specificity (Sp) for each marker at their recommended cut-off for clinical practice were calculated. Comparison between diagnoses accuracy of each procedure and scenario was computed using mutual information based and direct effect contribution using a supervised Bayesian network approach. RESULTS: A mpMRI Prostate Imaging-Reporting and Data System (PI-RADS) score ≥3 showed higher Se than mpMRI PI-RADS score ≥4 for detection of PCa (82% vs 61%) and for the detection of ISUP grade >1 lesions (96% vs 80%). mpMRI PI-RADS score ≥3 performed better than a PSA level of ≥3 ng/mL (Se 96%, Sp 53% vs Se 91%, Sp 8%) for detection of clinically significant PCa. In case of negative mpMRI results, the supervised Bayesian network approach showed that urinary markers (with the same accuracy for all) and PSAD of ≥0.10 ng/mL/mL were the most useful indicators of decision to biopsy. CONCLUSIONS: We found that screening men at high genetic risk of PCa must be based on mpMRI without pre-screening based on a PSA level of >3 ng/mL, to avoid missing too many ISUP grade >1 tumours and to significantly reduce the number of unnecessary biopsies. However, urinary markers or a PSAD of ≥0.10 ng/mL/mL when mpMRI was negative increased the detection of ISUP grade >1 cancers. We suggest that a baseline mpMRI be discussed for men at high genetic risk from the age of 40 years.


Assuntos
Neoplasias da Próstata , Masculino , Humanos , Adulto , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/genética , Próstata/diagnóstico por imagem , Próstata/patologia , Imageamento por Ressonância Magnética/métodos , Antígeno Prostático Específico , Teorema de Bayes , Biomarcadores , Biópsia Guiada por Imagem/métodos , Estudos Retrospectivos
2.
Proc Natl Acad Sci U S A ; 116(20): 9859-9864, 2019 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31036638

RESUMO

Nucleation is one of the least understood steps of microtubule dynamics. It is a kinetically unfavorable process that is templated in the cell by the γ-tubulin ring complex or by preexisting microtubules; it also occurs in vitro from pure tubulin. Here we study the nucleation inhibition potency of natural or artificial proteins in connection with their binding mode to the longitudinal surface of α- or ß-tubulin. The structure of tubulin-bound CopN, a Chlamydia protein that delays nucleation, suggests that this protein may interfere with two protofilaments at the (+) end of a nucleus. Designed ankyrin repeat proteins that share a binding mode similar to that of CopN also impede nucleation, whereas those that target only one protofilament do not. In addition, an αRep protein predicted to target two protofilaments at the (-) end does not delay nucleation, pointing to different behaviors at both ends of the nucleus. Our results link the interference with protofilaments at the (+) end and the inhibition of nucleation.


Assuntos
Proteínas de Bactérias/metabolismo , Microtúbulos/metabolismo , Tubulina (Proteína)/metabolismo , Chlamydophila pneumoniae
3.
Med Sci (Paris) ; 29(2): 194-9, 2013 Feb.
Artigo em Francês | MEDLINE | ID: mdl-23452607

RESUMO

Cytoplasm organization greatly depends on the cytoskeleton and especially on microtubules. Their multiple roles comprise for instance long-distance vesicular traffic or the organization of several signalling pathways. A variety of cellular functions require highly dynamic microtubules, which alternate between growing and shrinking phases. Meanwhile, other functions use stable microtubules, in which tubulin often bears multiple post-translational modifications like acetylation. Recent progress has been made in understanding some molecular mechanisms that control microtubule dynamics or tubulin acetylation. These mechanisms reveal the high plasticity of microtubules and point out the importance of their compartmentalization at structural and functional levels.


Assuntos
Compartimento Celular/fisiologia , Microtúbulos/metabolismo , Acetilação , Animais , Microambiente Celular/fisiologia , Humanos , Microtúbulos/fisiologia , Modelos Biológicos , Processamento de Proteína Pós-Traducional/fisiologia , Transporte Proteico/fisiologia , Tubulina (Proteína)/química , Tubulina (Proteína)/metabolismo , Tubulina (Proteína)/fisiologia
4.
Artigo em Inglês | MEDLINE | ID: mdl-37023569

RESUMO

Therapeutic drug monitoring (TDM) of antibiotics is particularly important in populations with high pharmacokinetic variabilities, such as critically ill patients, leading to unpredictable plasma concentrations and clinical outcomes. Here, we i) describe an original method for the simultaneous quantification of ten antibiotics (cefepime, ceftazidime, ampicillin, piperacillin/tazobactam, cefotaxime, amoxicillin, cloxacillin, oxacillin, linezolid) using 5-sulfosalicylic acid dihydrate (SSA) solution for protein precipitation together with 2D-LC-MS/MS, and ii) evaluate its impact in a one-year retrospective study. The method involved simple dilution with an aqueous mix of deuterated internal standards and plasma protein precipitation with SSA. Twenty microliters of the supernatant was injected into a C8 SPE online cartridge (30 × 2.1 mm) without any evaporation step and back-flushed onto a C18 UHPLC (100 × 2.1 mm) analytical column. Mass spectrometry detection (Xevo TQD) was performed in positive electrospray, in scheduled MRM mode. Overall analytical runtime was 7 min. Due to analytical constraints and the physicochemical properties of the antibiotics, protein precipitation using organic solvents could not be applied. As an alternative, SSA used with 2D-LC offered various advantages: i) lack of dilution resulting in better assay sensitivity, and ii) good chromatography of hydrophilic compounds. Ten microliters of 30% SSA in water eliminated>90% of plasma proteins, including the most abundant high molecular weight proteins at 55 and 72 kDa. The assay was successfully validated according to FDA and EMA guidelines for all the antibiotics, and the coefficients of variation of the quality control (QC) run during sample analysis over one year were below 10%, whatever the QC levels or the antibiotics. The use of 2D-LC combined with SSA precipitation allowed development of a robust, sensitive and rapid quantification assay. Feedback to clinicians was reduced to 24 h, thus allowing rapid dosage adjustment. During one year, 3,304 determinations were performed in our laboratory: 41% were not in the therapeutic range, 58% of which were sub-therapeutic, underlining the importance of early TDM of antibiotics to limit therapeutic failures and the emergence of bacterial resistance.


Assuntos
Antibacterianos , Monitoramento de Medicamentos , Humanos , Antibacterianos/química , Cromatografia Líquida/métodos , Monitoramento de Medicamentos/métodos , Estudos Retrospectivos , Espectrometria de Massas em Tandem/métodos , Ceftazidima , Reprodutibilidade dos Testes , Cromatografia Líquida de Alta Pressão/métodos
5.
Ann Biol Clin (Paris) ; 80(1): 91-95, 2022 Feb 01.
Artigo em Francês | MEDLINE | ID: mdl-35107065

RESUMO

The first step to complete in a method validation of a biological analysis is the study of precision intra-assay. In the absence or insufficient quantity of control material, this study may be difficult to perform. This article proposes a methodology for preparing its own control samples for the radioimmunological assay of the amino-terminal peptide of procollagene type III (PIIIP). This methodology is easy to carry out, cost-effective and can be applied to analyses other than PIIIP. Furthermore, it allows the execution of control samples which have similar concentrations of analytes to those described in the precision studies of the datasheets provided by the manufacturers.


Assuntos
Fragmentos de Peptídeos , Pró-Colágeno , Humanos , Radioimunoensaio
6.
Innate Immun ; 28(1): 3-10, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35089113

RESUMO

Little is known about the immuno-inflammatory response to Tocilizumab and its association with outcome in critically-ill SARS-CoV2 pneumonia. In this multicenter retrospective cohort of SARS-CoV-2 patients admitted to three intensive care units between March and April 2020, we matched on gender and SAPS II 21 Tocilizumab-treated patients to 42 non-treated patients. Need for mechanical ventilation was 76% versus 79%. IL-6, C-reactive protein, and fibrinogen had been collected within the first days of admission (T1), 3 d (T2) and 7 d (T3) later. Tocilizumab-treated patients had persistently higher IL-6 plasma levels and persistently lower C-Reactive protein and fibrinogen levels. Among Tocilizumab-treated patients, baseline levels of inflammatory biomarkers were not different according to outcome. Conversely, C-reactive protein and fibrinogen decrease was delayed in non-survivors. C-Reactive protein decreased at T1 in survivors (45 [30-98] vs 170 [69-204] mg/l, P < 0.001) but only at T2 in non-survivors (37 [13-74] vs 277 [235-288], P = 0.03). Fibrinogen decreased at T2 in survivors (4.11 [3.58-4.69] vs 614 [5.61-7.85] g/l, P = 0.005) but not in non-survivors (4.79 [4.12-7.58] vs 7.24 [6.22-9.24] g/l, P = 0.125). Tocilizumab treatment was thus associated with a persistent both increase in plasma IL-6, and decrease in C-reactive protein and fibrinogen. Among Tocilizumab-treated patients, the decrease in inflammatory biomarkers was delayed in non-survivors.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Antivirais/uso terapêutico , Tratamento Farmacológico da COVID-19 , COVID-19/mortalidade , Inflamação/tratamento farmacológico , Idoso , Biomarcadores/sangue , Proteína C-Reativa/análise , Estudos de Coortes , Estado Terminal , Feminino , Fibrinogênio/análise , Humanos , Interleucina-6/sangue , Masculino , Pessoa de Meia-Idade , Respiração Artificial , Estudos Retrospectivos , Resultado do Tratamento
7.
Ann Intensive Care ; 11(1): 9, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33439360

RESUMO

BACKGROUND: SARS coronavirus 2 (SARS-CoV-2) is responsible for high morbidity and mortality worldwide, mostly due to the exacerbated inflammatory response observed in critically ill patients. However, little is known about the kinetics of the systemic immune response and its association with survival in SARS-CoV-2+ patients admitted in ICU. We aimed to compare the immuno-inflammatory features according to organ failure severity and in-ICU mortality. METHODS: Six-week multicentre study (N = 3) including SARS-CoV-2+ patients admitted in ICU. Analysis of plasma biomarkers at days 0 and 3-4 according to organ failure worsening (increase in SOFA score) and 60-day mortality. RESULTS: 101 patients were included. Patients had severe respiratory diseases with PaO2/FiO2 of 155 [111-251] mmHg), SAPS II of 37 [31-45] and SOFA score of 4 [3-7]. Eighty-three patients (83%) required endotracheal intubation/mechanical ventilation and among them, 64% were treated with prone position. IL-1ß was barely detectable. Baseline IL-6 levels positively correlated with organ failure severity. Baseline IL-6 and CRP levels were significantly higher in patients in the worsening group than in the non-worsening group (278 [70-622] vs. 71 [29-153] pg/mL, P < 0.01; and 178 [100-295] vs. 100 [37-213] mg/L, P < 0.05, respectively). Baseline IL-6 and CRP levels were significantly higher in non-survivors compared to survivors but fibrinogen levels and lymphocyte counts were not different between groups. After adjustment on SOFA score and time from symptom onset to first dosage, IL-6 and CRP remained significantly associated with mortality. IL-6 changes between Day 0 and Day 3-4 were not different according to the outcome. A contrario, kinetics of CRP and lymphocyte count were different between survivors and non-survivors. CONCLUSIONS: In SARS-CoV-2+ patients admitted in ICU, a systemic pro-inflammatory signature was associated with clinical worsening and 60-day mortality.

8.
J Cell Biol ; 219(7)2020 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-32491151

RESUMO

The stress-induced c-Jun N-terminal kinase (JNK) controls microtubule dynamics by enhancing both microtubule growth and rescues. Here, we show that upon cell stress, JNK directly phosphorylates the microtubule rescue factor CLIP-170 in its microtubule-binding domain to increase its rescue-promoting activity. Phosphomimetic versions of CLIP-170 enhance its ability to promote rescue events in vitro and in cells. Furthermore, while phosphomimetic mutations do not alter CLIP-170's capability to form comets at growing microtubule ends, both phosphomimetic mutations and JNK activation increase the occurrence of CLIP-170 remnants on the microtubule lattice at the rear of comets. As the CLIP-170 remnants, which are potential sites of microtubule rescue, display a shorter lifetime when CLIP-170 is phosphorylated, we propose that instead of acting at the time of rescue occurrence, CLIP-170 would rather contribute in preparing the microtubule lattice for future rescues at these predetermined sites.


Assuntos
MAP Quinase Quinase 4/genética , Proteínas Associadas aos Microtúbulos/genética , Microtúbulos/metabolismo , Proteínas de Neoplasias/genética , Estresse Fisiológico/genética , Animais , Anisomicina/farmacologia , Linhagem Celular , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/efeitos da radiação , Fibroblastos/ultraestrutura , Regulação da Expressão Gênica , Células HeLa , Humanos , MAP Quinase Quinase 4/metabolismo , Camundongos , Proteínas Associadas aos Microtúbulos/antagonistas & inibidores , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos/efeitos dos fármacos , Microtúbulos/efeitos da radiação , Microtúbulos/ultraestrutura , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/metabolismo , Fosforilação/efeitos dos fármacos , Fosforilação/efeitos da radiação , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais , Cloreto de Sódio/farmacologia , Raios Ultravioleta
9.
Curr Biol ; 26(24): 3399-3406, 2016 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-27916523

RESUMO

Microtubule dynamics rely on the properties of tubulin and are regulated by microtubule-associated proteins. GTP-tubulin assembles into hollow polymers, which can depolymerize upon GTP hydrolysis. Depolymerizing microtubules may stop shrinking and resume growth. Such rescues are regulated by microtubule-associated proteins like CLIP-170 and the CLASPs [1, 2]. Microtubule domains prone to rescues contain discrete regions (previously termed "GTP islands") that retain a GTP-tubulin-like conformation in the main body of the microtubule [3]. However, the exact nature of these domains and the mechanisms controlling their occurrence and distribution are largely unknown. Here we show that collisions between growing microtubules and mechanical obstacles (including other microtubules) in vitro result in the higher abundance of GTP-like islands in stressed microtubule regions. Furthermore, these islands were found to be efficiently generated by both lateral contacts and mechanical constraints applied to the main body of the microtubules. They were also particularly prominent where shifts in the number of protofilaments occur in the microtubule lattice. GTP-like islands and rescues frequently co-occurred at microtubule intersections in vitro and in living cells, both in crossing and in crossed microtubules. We also observed that CLIP-170 recognizes GTP-like islands in vivo and is retained at microtubule crossings. Therefore, we propose that rescues occur via a two-stage mechanism: (1) lattice defects determine potential rescue-promoting islands in the microtubule structure, and (2) CLIP-170 detects these islands to stimulate microtubule rescue. Our results reveal the interplay between rescue-promoting factors and microtubule architecture and organization to control microtubule dynamics.


Assuntos
Microtúbulos/fisiologia , Animais , Linhagem Celular , Guanosina Trifosfato , Simulação de Dinâmica Molecular , Polímeros , Conformação Proteica
11.
Biochim Biophys Acta ; 1631(1): 42-50, 2003 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-12573448

RESUMO

Class B type I scavenger receptor (SR-BI) mediates the selective uptake of high-density lipoprotein (HDL)-derived cholesteryl esters (HDL-CE) in steroidogenic cells and hepatocytes. SR-BI is enriched in the caveolae of some cell types, genetically modified or not, and these domains have already been shown to constitute primary acceptors for HDL-CE. Nevertheless, the fate of caveola-free cell types has not yet been discussed.NCI-H295R, a human adrenal cell line, highly active in HDL-CE uptake via SR-BI, does not display any morphologically defined caveolae and expresses caveolin at a very low level. Using two different fractionation protocols, we have shown, in this cell type, that SR-BI is homogeneously distributed along the plasma membrane and consists principally of a non-raft membrane-associated pool. Raft destabilisation and caveolin-1 displacement from plasma membrane did not modify the SR-BI-mediated HDL-CE selective uptake. Moreover, the induction of SR-BI expression that is associated with increased CE selective uptake was not associated with any modification in caveolin-1 expression or any raft-targeting mechanism of SR-BI in NCI-H295R. In conclusion, we provide evidence that SR-BI does not require raft/caveola localisation to be implicated in CE selective uptake either in basal or in induced conditions.


Assuntos
Glândulas Suprarrenais/metabolismo , Antígenos CD36/metabolismo , Ésteres do Colesterol/metabolismo , Proteínas de Membrana , Receptores Imunológicos , Receptores de Lipoproteínas , Glândulas Suprarrenais/ultraestrutura , Antígenos CD36/biossíntese , Cavéolas/metabolismo , Cavéolas/ultraestrutura , Linhagem Celular , Colforsina , Humanos , Microdomínios da Membrana/metabolismo , Microdomínios da Membrana/ultraestrutura , Octoxinol , Receptores Depuradores , Receptores Depuradores Classe B
12.
Biochim Biophys Acta ; 1631(3): 218-28, 2003 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-12668173

RESUMO

In human adrenal cells, cholesterol for steroidogenesis is derived from both high-density lipoproteins (HDL) via the Scavenger Receptor Class B Type I (SR-BI) and low-density lipoproteins (LDL) via the LDL receptor pathway. We have previously shown that, in the human adrenocortical carcinoma cell line, NCI-H295R, SR-BI and LDL receptor expression and steroidogenesis are coordinately regulated by activators of protein kinase A (PKA) leading to glucocorticoid synthesis. In the present study, we studied whether SR-BI and LDL receptor expression are regulated by activators of the protein kinase C (PKC) signaling pathway, such as angiotensin II, which stimulate mineralocorticoid synthesis. First, it is shown that, in NCI-H295R cells, aldosterone synthesis is stimulated by a phorbol ester (phorbol-12-myristate-13 acetate, PMA), a potent PKC activator. Northern blot analysis indicated that both angiotensin II and PMA stimulated SR-BI expression in a time-dependent manner. LDL receptor expression is slightly stimulated by PMA. The induction of SR-BI gene expression occurs at the transcriptional level, via an activation of the human SR-BI promoter, as shown by transient transfection experiments. Finally, SR-BI protein level was increased in angiotensin II- and PMA-stimulated cells, resulting in higher lipoprotein binding and specific cholesteryl ester (CE) uptake from HDL, as well from LDL after angiotensin II and PMA stimulation.


Assuntos
Córtex Suprarrenal/efeitos dos fármacos , Aldosterona/biossíntese , Angiotensina II/farmacologia , Proteínas de Membrana , Receptores Imunológicos/metabolismo , Receptores de LDL/metabolismo , Receptores de Lipoproteínas , Acetato de Tetradecanoilforbol/farmacologia , Córtex Suprarrenal/metabolismo , Aldosterona/metabolismo , Antígenos CD36 , Ésteres do Colesterol/metabolismo , HDL-Colesterol/metabolismo , LDL-Colesterol/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , RNA Mensageiro/biossíntese , Receptores Imunológicos/biossíntese , Receptores de LDL/biossíntese , Receptores Depuradores , Receptores Depuradores Classe B , Células Tumorais Cultivadas
13.
Proteomics Clin Appl ; 9(7-8): 787-93, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25641685

RESUMO

PURPOSE: The O-glycan abnormalities accompanying some congenital disorders of glycosylation, namely conserved oligomeric Golgi-congenital disorders of glycosylation (COG-CDGs) and ATP6V0A2-CDGs, are mainly detected using electrophoresis methods applied to circulating apolipoprotein C-III. The objective of this study was to evaluate the reliability of MALDI-TOF MS of apoC-III for the detection and characterization of CDG-associated O-glycan defects. EXPERIMENTAL DESIGN: plasmas from CDG-negative, COG-CDG, and ATP6V0A2-CDG patients were analyzed and results were compared to those obtained using 2DE followed by Western blot. RESULTS: MALDI-TOF of apoC-III allowed to detect various significant O-glycan abnormalities in CDG-patients with emphasis to COG-CDG. Furthermore, in CDG samples, comparison study between 2DE and MALDI-TOF showed a particular behavior of monosialylated apoC-III in the mass spectrometer that could be related to an abnormal O-glycan structure. CONCLUSIONS AND CLINICAL RELEVANCE: MALDI-TOF MS appears as a powerful technique for the analysis of apoC-III glycoforms for potential routine screening of COG- and ATP6V0A2-CDGs.


Assuntos
Apolipoproteína C-III/metabolismo , Defeitos Congênitos da Glicosilação/metabolismo , Eletroforese em Gel Bidimensional/métodos , Glicoproteínas/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Western Blotting , Humanos , Mucinas/química , Mucinas/metabolismo , Polissacarídeos/química , Polissacarídeos/metabolismo
14.
Methods Cell Biol ; 115: 139-53, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23973071

RESUMO

Microtubules display a very dynamic behavior, and the presence of the guanosine-triphosphate (GTP) cap at the plus ends of microtubules is essential to regulate microtubule dynamics. Dimitrov et al. (2008) showed that GTP-tubulin is present not only at the plus ends but also in discrete locations along the microtubule lattice. These GTP islands were proposed to contribute to rescue events. Studying the localization of GTP-tubulin in microtubules is essential to better comprehend some core aspects in the regulation of microtubule dynamics. In this chapter, we recapitulate essential tools to study the GTP-tubulin using the recombinant antibody MB11 from permeabilized cells to in vitro assays.


Assuntos
Guanosina Trifosfato/metabolismo , Microtúbulos/metabolismo , Tubulina (Proteína)/metabolismo , Anticorpos Monoclonais/imunologia , Linhagem Celular Tumoral , Proliferação de Células , Células HeLa , Humanos , Microtúbulos/imunologia , Ligação Proteica , Conformação Proteica , Epitélio Pigmentado da Retina/citologia , Coloração e Rotulagem/métodos
16.
Ann Biol Clin (Paris) ; 70(4): 451-5, 2012.
Artigo em Francês | MEDLINE | ID: mdl-22796616

RESUMO

Result of renewed interest due to the large amount of literature that reported numerous epidemiological data demonstrating the high prevalence of vitamin D deficiency, the number of prescriptions of serum vitamin D assays has grown exponentially in recent years with a cost for health insurance that increased almost fivefold in four years. The quantitative and qualitative analysis of assays carried out from 2007 to 2011 in a French university adult short-stay hospital shows changes in practices not only quantitatively but also qualitatively resulting in an overtime increase in the frequency of prescriptions in patients younger, less vitamin D deficient and more frequently male. In the absence of French guidelines, this development cannot be qualified as deviant but justifies the urgent need to establish evidence-based recommendations for good prescriptions and adequate assays of blood vitamin D.


Assuntos
Deficiência de Vitamina D/epidemiologia , Vitamina D/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radioimunoensaio/estatística & dados numéricos , Radioimunoensaio/tendências , Deficiência de Vitamina D/diagnóstico
17.
Clin Chem Lab Med ; 46(2): 271-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18076351

RESUMO

BACKGROUND: GEM Premier 4000 (Instrumentation Laboratory), a new blood gas/CO-Oximeter/hematocrit/electrolyte/glucose/lactate analyzer was evaluated. The only reagents required were disposable cartridges (GEM Premier 4000 PAK comprise all components necessary for analysis, including quality controls). METHODS: The evaluation was performed in two laboratories according to the Valtec protocol guidelines. Analytical performances (imprecision at three levels, linearity, inaccuracy by method comparison using patient samples, interferences) and instrument practicability were compared with three routinely used laboratory blood gas analyzers (ABL 835 and 725, Radiometer; OMNI S, Roche Diagnostics) and the centrifuged microhematocrit method. RESULTS: Within-run and between-run imprecision yielded good coefficients of variation values for all parameters. Linearity was satisfactory and within the expected ranges provided by the manufacturer. Method comparisons demonstrated close agreement (Deming's regression correlation coefficients 0.92-1.00). No interferences of lipemia, hyperbilirubinemia and hemolysis were found on CO-Oximetry parameters. Fetal hemoglobin >35% overestimated carboxyhemoglobin measurements, but the magnitude of error was reduced with the fetal hemoglobin correction analysis mode. CONCLUSION: The GEM Premier 4000 analytical performance was validated for all parameters with the accuracy and the reliability of traditional systems. This blood gas analyzer fulfills most of the requirements for both point-of-care and laboratory use.


Assuntos
Monóxido de Carbono/sangue , Eletrólitos/sangue , Sistemas Automatizados de Assistência Junto ao Leito , Humanos , Reprodutibilidade dos Testes
18.
Diabetes ; 56(11): 2797-808, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17704298

RESUMO

OBJECTIVE: Rosiglitazone displays powerful antidiabetes benefits but is associated with increased body weight and adipogenesis. Keeping in mind the concept of selective peroxisome proliferator-activated receptor (PPAR)gamma modulator, the aim of this study was to characterize the properties of a new PPARgamma ligand, S 26948, with special attention in body-weight gain. RESEARCH DESIGN AND METHODS: We used transient transfection and binding assays to characterized the binding characteristics of S 26948 and GST pull-down experiments to investigate its pattern of coactivator recruitment compared with rosiglitazone. We also assessed its adipogenic capacity in vitro using the 3T3-F442A cell line and its in vivo effects in ob/ob mice (for antidiabetes and antiobesity properties), as well as the homozygous human apolipoprotein E2 knocking mice (E2-KI) (for antiatherogenic capacity). RESULTS: S 26948 displayed pharmacological features of a high selective ligand for PPARgamma with low potency in promoting adipocyte differentiation. It also displayed a different coactivator recruitment profile compared with rosiglitazone, being unable to recruit DRIP205 or PPARgamma coactivator-1 alpha. In vivo experiments showed that S 26948 was as efficient in ameliorating glucose and lipid homeostasis as rosiglitazone, but it did not increase body and white adipose tissue weights and improved lipid oxidation in liver. In addition, S 26948 represented one of the few molecules of the PPARgamma ligand class able to decrease atherosclerotic lesions. CONCLUSIONS: These findings establish S 26948 as a selective PPARgamma ligand with distinctive coactivator recruitment and gene expression profile, reduced adipogenic effect, and improved biological responses in vivo.


Assuntos
Aterosclerose/prevenção & controle , Angiopatias Diabéticas/prevenção & controle , Hipoglicemiantes/farmacologia , PPAR gama/fisiologia , Animais , Células COS , Membrana Celular/fisiologia , Chlorocebus aethiops , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Haplorrinos , Humanos , Ligantes , PPAR gama/efeitos dos fármacos , PPAR gama/genética , Receptor X Retinoide alfa/efeitos dos fármacos , Receptor X Retinoide alfa/fisiologia , Transfecção
19.
J Biol Chem ; 280(2): 1123-31, 2005 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-15528207

RESUMO

In the last decade, the notion that microtubules are critical to the spatial organization of signal transduction and contribute to the transmission of signals to downstream targets has been proposed. Because the STAT5B transduction and transcription factor is the major STAT protein activated by growth hormone stimulation in hepatocytes and is a crossroads between many signaling pathways, we studied the involvement of microtubules in STAT5B-mediated growth hormone signaling pathway in the highly differentiated and polarized WIF-B hepatic cell line. We showed that depolymerization of the microtubule network impaired STAT5B translocation to the nucleus upon growth hormone treatment. A significant amount of STAT5B binds to microtubules, while STAT5A and STAT3 are exclusively compartmentalized in the cytosol. Moreover, taxol-induced stabilization of microtubules released STAT5B from its binding, and we show that STAT5B binds specifically to the highly dynamic microtubules and is absent of the stable microtubule subpopulation. The specific involvement of dynamic microtubule subpopulation in growth hormone signaling pathway was confirmed by the inhibition of growth hormone-induced STAT5B nuclear translocation after stabilization of microtubules or specific disruption of highly dynamic microtubules. Upon growth hormone treatment, MT-bound STAT5B was rapidly released from microtubules by a dynein-dependent transport to the nucleus. Altogether, our findings indicate that the labile microtubule subpopulation specifically and dynamically organizes STAT5B-mediated growth hormone signaling in hepatic cells.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Hormônio do Crescimento/farmacologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Microtúbulos/metabolismo , Proteínas do Leite/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transativadores/metabolismo , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Biopolímeros/metabolismo , Linhagem Celular , Meios de Cultura Livres de Soro/farmacologia , Citosol/metabolismo , Complexo Dinactina , Dineínas/metabolismo , Hepatócitos/citologia , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos/efeitos dos fármacos , Nocodazol/farmacologia , Ligação Proteica , Fator de Transcrição STAT3 , Fator de Transcrição STAT5 , Especificidade por Substrato
20.
J Biol Chem ; 279(16): 16154-60, 2004 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-14764586

RESUMO

The peroxisome proliferator-activated receptor alpha (PPARalpha), which is highly expressed in liver, plays key roles in lipid metabolism and inflammation. Interleukin-6 (IL-6) is the principal inducer of acute phase response (APR) gene expression. In the present study, we demonstrate that chronic treatment with the PPARalpha agonist fenofibrate fully prevents the IL-6-induced APR gene expression in wild-type but not in PPARalpha-deficient mice. PPARalpha prevents the IL-6-induced expression of the positive APR genes fibrinogen-alpha, -beta, -gamma, haptoglobulin, and serum amyloid A and the IL-6-induced suppression of the negative APR gene, major urinary protein. Furthermore, the effect of PPARalpha on the APR gene expression does not simply consist in a delayed systemic response to IL-6 but occurs directly at the transcriptional level. This global suppression of acute phase gene transcription may be explained by two PPARalpha-dependent in vivo effects: 1) PPARalpha activation results in the down-regulation of the IL-6 receptor components gp80 and gp130 in the liver, thereby reducing the phosphorylation and activation of the downstream transcription factors STAT3 and c-Jun that transduce the IL-6 signal; and 2) PPARalpha reduces the basal expression of the transcription factors CCAAT enhancer-binding protein-alpha, -beta, -delta, which are responsible for immediate and maintained transcription of APR genes. A similar global effect of fenofibrate on acute phase protein expression is observed in hyperlipidemic patients chronically treated with fenofibrate, which displayed decreased plasma concentrations of the positive APR proteins fibrinogen, C-reactive protein, serum amyloid A, plasminogen, and alpha2-macroglobulin and increased plasma concentrations of the negative APR albumin, underlining the clinical significance of our findings.


Assuntos
Fenofibrato/administração & dosagem , Hipolipemiantes/administração & dosagem , Interleucina-6/genética , Receptores Citoplasmáticos e Nucleares/genética , Fatores de Transcrição/genética , Reação de Fase Aguda/genética , Animais , Apolipoproteínas/antagonistas & inibidores , Regulação para Baixo/efeitos dos fármacos , Fibrinogênio/antagonistas & inibidores , Haptoglobinas/antagonistas & inibidores , Humanos , Interleucina-6/metabolismo , Camundongos , Receptores Citoplasmáticos e Nucleares/agonistas , Receptores Citoplasmáticos e Nucleares/deficiência , Proteína Amiloide A Sérica/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/agonistas , Fatores de Transcrição/deficiência
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