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3.
Ultrasound Obstet Gynecol ; 53(4): 555, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30938480
4.
Ultrasound Obstet Gynecol ; 52(6): 715-721, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29027723

RESUMO

OBJECTIVE: To determine the frequency and nature of copy number variants (CNVs) identified by chromosomal microarray analysis (CMA) in a large cohort of fetuses with isolated increased nuchal translucency thickness (NT) ≥ 3.5 mm. METHODS: This was a retrospective, multicenter study, including 11 French hospitals, of data from the period between April 2012 and December 2015. In total, 720 fetuses were analyzed by rapid aneuploidy test and the fetuses identified as euploid underwent CMA. CNVs detected were evaluated for clinical significance and classified into five groups: pathogenic CNVs; benign CNVs; CNVs predisposing to neurodevelopmental disorders; variants of uncertain significance (VOUS); and CNVs not related to the phenotype (i.e. incidental findings). RESULTS: In 121 (16.8%) fetuses, an aneuploidy involving chromosome 13, 18 or 21 was detected by rapid aneuploidy test and the remaining 599 fetuses were euploid. Among these, 53 (8.8%) had a CNV detected by CMA: 16/599 (2.7%) were considered to be pathogenic, including 11/599 (1.8%) that were cryptic (not visible by karyotyping); 7/599 (1.2%) were CNVs predisposing to neurodevelopmental disorders; and 8/599 (1.3%) were VOUS. Additionally, there was one (0.2%) CNV that was unrelated to the reason for referral diagnosis (i.e. an incidental finding) and the remaining 21 were benign CNVs, without clinical consequence. Interestingly, we identified five genomic imbalances of the 1q21.1 or 15q11.2 regions known to be associated with congenital heart defects. CONCLUSION: Our study demonstrates the benefit of CMA in the etiological diagnosis of fetuses with isolated increased NT. It is worth noting that most (69%) of the detected pathogenic CNVs were cryptic. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Aberrações Cromossômicas , Variações do Número de Cópias de DNA , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Diagnóstico Pré-Natal/métodos , Adolescente , Adulto , Aneuploidia , Cromossomos Humanos/genética , Feminino , Idade Gestacional , Humanos , Idade Materna , Medição da Translucência Nucal , Gravidez , Estudos Retrospectivos , Adulto Jovem
5.
J Thromb Haemost ; 15(1): 47-56, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27790827

RESUMO

Essentials The role of omega-3 fatty acids (n-3 FAs) in recurrent venous thromboembolism (VTE) is unknown. Association of n-3 FAs with recurrent VTE or total mortality was investigated in 826 patients. Whole blood n-3 FAs were inversely correlated with recurrent VTE or total mortality. Major and non-major bleeding was not increased in patients with higher levels of n-3 FAs. SUMMARY: Background The role of omega-3 fatty acids (n-3 FAs) in recurrent venous thromboembolism (VTE) remains unknown. Objectives To investigate the association of n-3 FAs with recurrent VTE or total mortality at 6 months and 3 years. Methods N-3 FAs were assessed in 826 patients aged ≥ 65 years, categorized into low, medium and high based on the 25th and 75th percentile. Mean follow-up was 29 months. Results At 6 months, subjects with medium (adjusted hazard ratio [HR], 0.37; 95% confidence interval [CI], 0.22-0.62) and high n-3 FA levels (adjusted HR, 0.36; 95% CI, 0.20-0.67) were less likely to develop recurrent VTE or total mortality, compared with those with low n-3 FAs. At 3 years, medium levels (adjusted HR, 0.67; 95% CI, 0.47-0.96) were associated with lower risk of recurrent VTE or total mortality. As compared with low n-3 FAs, the adjusted sub-hazard ratio [SHR] of recurrent VTE was 0.39 (95% CI, 0.15-0.99) in patients with medium and 0.17 (95% CI, 0.03-0.82) in patients with high n-3 FAs. The cumulative incidence of recurrent VTE was lower in the medium and high n-3 FA groups as compared with the low n-3 FA groups, but seems to have worn off after 3 years. The incidence of major and non-major bleeding was not greater in the high n-3 FA group. Conclusion Higher levels of n-3 FAs were associated with a lower risk of recurrent VTE or total mortality in elderly patients with VTE, but not with greater bleeding risk.


Assuntos
Ácidos Graxos Ômega-3/sangue , Tromboembolia Venosa/epidemiologia , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Hemorragia , Humanos , Estimativa de Kaplan-Meier , Masculino , Mortalidade , Neoplasias/complicações , Modelos de Riscos Proporcionais , Estudos Prospectivos , Embolia Pulmonar/tratamento farmacológico , Recidiva , Fatores de Risco
6.
J Thromb Haemost ; 14(4): 685-94, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26816339

RESUMO

BACKGROUND: Venous thromboembolism (VTE) and subclinical thyroid dysfunction (SCTD) are both common in elderly patients. SCTD has been related to a hypercoagulable state and an increased thromboembolic risk. However, prospective data on the relationship between SCTD and VTE are lacking. OBJECTIVES: To investigate the relationship between SCTD and recurrent VTE (rVTE), all-cause mortality, and thrombophilic biomarkers. Patients Elderly patients with VTE were studied. METHODS: In a prospective multicenter cohort, thyroid hormones and thrombophilic biomarkers were measured 1 year after acute VTE, as both may be influenced by acute thrombosis. We defined subclinical hypothyroidism (SHypo) as elevated thyroid-stimulating hormone (TSH) levels (4.50-19.99 mIU L(-1) ), and subclinical hyperthyroidism (SHyper) as TSH levels of < 0.45 mIU L(-1) , both with normal free thyroxine levels. Outcomes were incidence of rVTE and overall mortality during follow-up starting after the 1-year blood sampling. RESULTS: Of 561 participants (58% with anticoagulation), 6% had SHypo and 5% had SHyper. After 20.8 months of mean follow-up, 9% developed rVTE and 10% died. The rVTE incidence rate was 7.2 (95% confidence interval [CI] 2.7-19.2) per 100 patient-years in SHypo participants, 0.0 (95% CI 0.0-7.6) in SHyper participants, and 5.9 (95% CI 4.4-7.8) in euthyroid participants. In multivariate analyses, the sub-hazard ratio for rVTE was 0.00 (95% CI 0.00-0.58) in SHyper participants and 1.50 (95% CI 0.52-4.34) in SHypo participants as compared with euthyroid participants, without increased levels of thrombophilic biomarkers. SHyper (hazard ratio [HR] 0.80, 95% CI 0.23-2.81) and SHypo (HR 0.99, 95% CI 0.30-3.29) were not associated with mortality. CONCLUSION: In elderly patients, SHyper may be associated with lower rVTE risks. SHypo showed a non-statistically significant pattern of an association with rVTE, without increased mortality or differences in thrombophilic biomarkers.


Assuntos
Doenças da Glândula Tireoide/complicações , Doenças da Glândula Tireoide/fisiopatologia , Tromboembolia Venosa/complicações , Tromboembolia Venosa/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Coagulação Sanguínea , Feminino , Humanos , Hipertireoidismo/fisiopatologia , Hipotireoidismo/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Tromboembolia , Trombofilia/sangue , Trombose/fisiopatologia , Doenças da Glândula Tireoide/mortalidade , Glândula Tireoide/fisiopatologia , Tireotropina/sangue , Tiroxina/sangue , Resultado do Tratamento , Tromboembolia Venosa/mortalidade
7.
Eur J Pain ; 19(8): 1129-38, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25565607

RESUMO

BACKGROUND: Pain drawings (PDs) are an important component of the assessment of a patient with pain. The aim of this work is to present the test-retest reliability of a novel method of quantifying the extent and location of pain. Additionally, the association between PD variables and clinical features in patients with chronic neck pain (CNP) and chronic low back pain (CLBP) was explored. METHODS: Fifty-one patients with CLBP and 56 patients with CNP participated. Each patient shaded two consecutive PDs using a digital tablet. Software was developed to quantify the pain extent, to analyse the pain overlap between PDs and to produce pain frequency maps. Correlations were obtained between pain extent and clinical features including the level of pain intensity, disability, and psychological distress and cognitive function. RESULTS: The intraclass correlation coefficients for pain extent in CLBP and CNP were very high: 0.97 (95% CI: 0.95-0.98) and 0.92 (95% CI: 0.87-0.98), respectively. The Bland Altman showed a mean difference close to zero: 5.4% pixels in CNP group and 3% pixels in the CLBP group. Significant correlations were observed between pain extent and pain intensity in CLBP and CNP and pain extent and disability in CNP. There was no relation between pain extent and the level of distress or cognitive function. CONCLUSIONS: A novel method for the acquisition of PD was presented. Test-retest reliability of reporting pain extent and pain location was supported in people with CNP and CLBP. Future research is needed to establish psychometric properties of PD.


Assuntos
Dor Crônica/diagnóstico , Medição da Dor/métodos , Adulto , Idoso , Dor Crônica/psicologia , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/psicologia , Avaliação da Deficiência , Feminino , Humanos , Dor Lombar/diagnóstico , Dor Lombar/psicologia , Masculino , Pessoa de Meia-Idade , Cervicalgia/diagnóstico , Cervicalgia/psicologia , Psicometria , Reprodutibilidade dos Testes , Estresse Psicológico/etiologia , Estresse Psicológico/psicologia
8.
J Thromb Haemost ; 13(2): 197-205, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25403550

RESUMO

BACKGROUND: Although the possibility of bleeding during anticoagulant treatment may limit patients from taking part in physical activity, the association between physical activity and anticoagulation-related bleeding is uncertain. OBJECTIVES: To determine whether physical activity is associated with bleeding in elderly patients taking anticoagulants. PATIENTS/METHODS: In a prospective multicenter cohort study of 988 patients aged ≥ 65 years receiving anticoagulants for venous thromboembolism, we assessed patients' self-reported physical activity level. The primary outcome was the time to a first major bleeding, defined as fatal bleeding, symptomatic bleeding in a critical site, or bleeding causing a fall in hemoglobin or leading to transfusions. The secondary outcome was the time to a first clinically relevant non-major bleeding. We examined the association between physical activity level and time to a first bleeding by using competing risk regression, accounting for death as a competing event. We adjusted for known bleeding risk factors and anticoagulation as a time-varying covariate. RESULTS: During a mean follow-up of 22 months, patients with a low, moderate, and high physical activity level had an incidence of major bleeding of 11.6, 6.3, and 3.1 events per 100 patient-years and an incidence of clinically relevant non-major bleeding of 14.0, 10.3, and 7.7 events per 100 patient-years, respectively. A high physical activity level was significantly associated with a lower risk of major bleeding (adjusted sub-hazard ratio 0.40, 95% confidence interval 0.22-0.72). There was no association between physical activity and non-major bleeding. CONCLUSIONS: A high level of physical activity is associated with a decreased risk of major bleeding in elderly patients receiving anticoagulant therapy.


Assuntos
Anticoagulantes/efeitos adversos , Hemorragia/induzido quimicamente , Hemorragia/prevenção & controle , Atividade Motora , Tromboembolia Venosa/tratamento farmacológico , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Hemorragia/sangue , Hemorragia/diagnóstico , Hemorragia/mortalidade , Humanos , Incidência , Masculino , Estudos Prospectivos , Fatores de Proteção , Medição de Risco , Fatores de Risco , Suíça/epidemiologia , Fatores de Tempo , Resultado do Tratamento , Tromboembolia Venosa/sangue , Tromboembolia Venosa/diagnóstico
9.
J Intern Med ; 276(4): 378-86, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24645727

RESUMO

OBJECTIVE: Whether or not a high risk of falls increases the risk of bleeding in patients receiving anticoagulants remains a matter of debate. METHODS: We conducted a prospective cohort study involving 991 patients ≥ 65 years of age who received anticoagulants for acute venous thromboembolism (VTE) at nine Swiss hospitals between September 2009 and September 2012. The study outcomes were as follows: the time to a first major episode of bleeding; and clinically relevant nonmajor bleeding. We determined the associations between the risk of falls and the time to a first episode of bleeding using competing risk regression, accounting for death as a competing event. We adjusted for known bleeding risk factors and anticoagulation as a time-varying covariate. RESULTS: Four hundred fifty-eight of 991 patients (46%) were at high risk of falls. The mean duration of follow-up was 16.7 months. Patients at high risk of falls had a higher incidence of major bleeding (9.6 vs. 6.6 events/100 patient-years; P = 0.05) and a significantly higher incidence of clinically relevant nonmajor bleeding (16.7 vs. 8.3 events/100 patient-years; P < 0.001) than patients at low risk of falls. After adjustment, a high risk of falls was associated with clinically relevant nonmajor bleeding [subhazard ratio (SHR) = 1.74, 95% confidence interval (CI) = 1.23-2.46], but not with major bleeding (SHR = 1.24, 95% CI = 0.83-1.86). CONCLUSION: In elderly patients who receive anticoagulants because of VTE, a high risk of falls is significantly associated with clinically relevant nonmajor bleeding, but not with major bleeding. Whether or not a high risk of falls is a reason against providing anticoagulation beyond 3 months should be based on patient preferences and the risk of VTE recurrence.


Assuntos
Acidentes por Quedas , Anticoagulantes/efeitos adversos , Hemorragia/epidemiologia , Tromboembolia Venosa/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/uso terapêutico , Feminino , Hemorragia/etiologia , Humanos , Masculino , Estudos Prospectivos , Fatores de Risco
10.
J Thromb Haemost ; 11(3): 435-43, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23279158

RESUMO

BACKGROUND: The Outpatient Bleeding Risk Index (OBRI) and the Kuijer, RIETE and Kearon scores are clinical prognostic scores for bleeding in patients receiving oral anticoagulants for venous thromboembolism (VTE). We prospectively compared the performance of these scores in elderly patients with VTE. METHODS: In a prospective multicenter Swiss cohort study, we studied 663 patients aged ≥ 65 years with acute VTE. The outcome was a first major bleeding at 90 days. We classified patients into three categories of bleeding risk (low, intermediate and high) according to each score and dichotomized patients as high vs. low or intermediate risk. We calculated the area under the receiver-operating characteristic (ROC) curve, positive predictive values and likelihood ratios for each score. RESULTS: Overall, 28 out of 663 patients (4.2%, 95% confidence interval [CI] 2.8-6.0%) had a first major bleeding within 90 days. According to different scores, the rate of major bleeding varied from 1.9% to 2.1% in low-risk, from 4.2% to 5.0% in intermediate-risk and from 3.1% to 6.6% in high-risk patients. The discriminative power of the scores was poor to moderate, with areas under the ROC curve ranging from 0.49 to 0.60 (P = 0.21). The positive predictive values and positive likelihood ratios were low and varied from 3.1% to 6.6% and from 0.72 to 1.59, respectively. CONCLUSION: In elderly patients with VTE, existing bleeding risk scores do not have sufficient accuracy and power to discriminate between patients with VTE who are at a high risk of short-term major bleeding and those who are not.


Assuntos
Anticoagulantes/efeitos adversos , Técnicas de Apoio para a Decisão , Hemorragia/induzido quimicamente , Tromboembolia Venosa/tratamento farmacológico , Doença Aguda , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Distribuição de Qui-Quadrado , Análise Discriminante , Monitoramento de Medicamentos/métodos , Feminino , Humanos , Coeficiente Internacional Normatizado , Estimativa de Kaplan-Meier , Funções Verossimilhança , Modelos Logísticos , Masculino , Valor Preditivo dos Testes , Estudos Prospectivos , Curva ROC , Reprodutibilidade dos Testes , Medição de Risco , Fatores de Risco , Suíça , Fatores de Tempo , Resultado do Tratamento
11.
J Thromb Haemost ; 10(11): 2270-6, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22985129

RESUMO

BACKGROUND: The Geneva Prognostic Score (GPS), the Pulmonary Embolism Severity Index (PESI) and its simplified version (sPESI) are well-known clinical prognostic scores for a pulmonary embolism (PE). OBJECTIVES: To compare the prognostic performance of these scores in elderly patients with a PE. PATIENTS AND METHODS: In a multicenter Swiss cohort of elderly patients with venous thromboembolism, we prospectively studied 449 patients aged ≥ 65 years with a symptomatic PE. The outcome was 30-day overall mortality. We dichotomized patients as low vs. higher risk in all three scores using the following thresholds: GPS scores ≤ 2 vs. > 2, PESI risk classes I-II vs. III-V and sPESI scores 0 vs. ≥ 1. We compared 30-day mortality in low- vs. higher-risk patients and the areas under the receiver-operating characteristic curve (ROC). RESULTS: Overall, 3.8% of patients (17/449) died within 30 days. The GPS classified a greater proportion of patients as low risk (92% [413/449]) than the PESI (36.3% [163/449]) and the sPESI (39.6% [178/449]) (P < 0.001 for each comparison). Low-risk patients based on the sPESI had a mortality of 0% (95% confidence interval [CI] 0-2.1%) compared with 0.6% (95% CI 0-3.4%) for low-risk patients based on the PESI and 3.4% (95% CI 1.9-5.6%) for low-risk patients based on the GPS. The areas under the ROC curves were 0.77 (95% CI 0.72-0.81), 0.76 (95% CI 0.72-0.80) and 0.71 (95% CI 0.66-0.75), respectively (P = 0.47). CONCLUSIONS: In this cohort of elderly patients with PE, the GPS identified a higher proportion of patients as low risk but the PESI and sPESI were more accurate in predicting mortality.


Assuntos
Embolia Pulmonar/diagnóstico , Embolia Pulmonar/mortalidade , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Estudos de Coortes , Feminino , Hemodinâmica , Humanos , Masculino , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Embolia Pulmonar/patologia , Curva ROC , Risco , Índice de Gravidade de Doença , Suíça , Resultado do Tratamento
12.
Virologie (Montrouge) ; 11(2): 121-133, 2007 Apr 01.
Artigo em Francês | MEDLINE | ID: mdl-37012833

RESUMO

This work reviews the opportunities and scientific bases in the development of anti-dengue drugs. The timeliness of anti-dengue drug development is addressed in the context of the growing impact of dengueworldwide and existing strategies to fight the virus. The antiviral approach in therapy or prophylaxis during an epidemic as well as the impact of recent technological advances in drug-discovery and antiviral chemotherapy on the development of anti-dengue drugs are discussed. An analysis of current sources of synthetic or natural drugs is provided. Finally, we summarize the current knowledge on dengue virus proteins, which are currently considered the most viable as drug targets, as the envelop protein E and non-structural proteins NS3 and NS5 carrying protease, helicase, RNA triphosphatase, methyltransferase and RNA-dependent RNA polymerase activities. Other viral proteins proposed to be part of the replication complex and the complex itself are considered as potential targets of anti-dengue drugs. State-of-the-art methods are listed, that are expected to allow the discovery, design, and characterisation of anti-dengue drugs effective against the four serotypes.

13.
Acta Crystallogr D Biol Crystallogr ; 62(Pt 10): 1125-36, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17001090

RESUMO

Protein characterization plays a role in two key aspects of structural proteomics. The first is the quality assessment of the produced protein preparations. Obtaining well diffracting crystals is one of the major bottlenecks in the structure-determination pipeline. Often, this is caused by the poor quality of the protein preparation used for crystallization trials. Hence, it is essential to perform an extensive quality assessment of the protein preparations prior to crystallization and to use the results in the evaluation of the process. Here, a protein-production and crystallization strategy is proposed with threshold values for protein purity (95%) and monodispersity (85%) below which a further optimization of the protein-production process is strongly recommended. The second aspect is the determination of protein characteristics such as domains, oligomeric state, post-translational modifications and protein-protein and protein-ligand interactions. In this paper, applications and new developments of protein-characterization methods using MS, fluorescence spectroscopy, static light scattering, analytical ultracentrifugation and small-angle X-ray scattering within the EC Structural Proteomics in Europe contract are described. Examples of the application of the various methods are given.


Assuntos
Proteínas/metabolismo , Proteômica/métodos , Cristalização , Hidrólise , Luz , Espectrometria de Massas , Microscopia de Fluorescência , Modelos Moleculares , Conformação Proteica , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Espalhamento de Radiação , Tripsina , Ultracentrifugação , Raios X
14.
Acta Crystallogr D Biol Crystallogr ; 62(Pt 10): 1196-207, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17001096

RESUMO

The Structural Proteomics In Europe (SPINE) programme is aimed at the development and implementation of high-throughput technologies for the efficient structure determination of proteins of biomedical importance, such as those of bacterial and viral pathogens linked to human health. Despite the challenging nature of some of these targets, 175 novel pathogen protein structures (approximately 220 including complexes) have been determined to date. Here the impact of several technologies on the structural determination of proteins from human pathogens is illustrated with selected examples, including the parallel expression of multiple constructs, the use of standardized refolding protocols and optimized crystallization screens.


Assuntos
Infecções Bacterianas/metabolismo , Proteínas de Bactérias/química , Proteômica/métodos , Proteínas Virais/química , Viroses/metabolismo , Animais , Infecções Bacterianas/microbiologia , Humanos , Dobramento de Proteína , Viroses/virologia
15.
Ann Biol Clin (Paris) ; 63(1): 27-41, 2005.
Artigo em Francês | MEDLINE | ID: mdl-15689310

RESUMO

International guidelines emphasize the importance of LDL cholesterol (LDL-C) assay in the care and follow-up of patients with cardiovascular risk. Most studies and common practice use Friedewald's formula for LDL-C calculation. The accuracy of the result depends closely on the precision of the input parameters (total cholesterol, triglycerides (TG) and HDL cholesterol), and discrepancies between calculated LDL-C and measurement by reference methods appear when TG exceed 4.5 mmol/L, or in the presence of abnormal lipoproteins. These restrictions and uncertainties in calculations have prompted the recent development of direct and homogeneous methods that fit all analyzers. A multicenter evaluation of four direct assays of LDL-C (Daiichi, Denka Seiken, Kyowa, Wako) was carried out on 45 serum samples (TG below 3.1 mmol/L) in eight laboratories using different analyzers. For three methods (Daiichi, Kyowa, Wako), the interlaboratory reproducibility was markedly improved relative to that of calculation. A strong correlation was found for all new methods when compared with a beta-quantification assay. Average bias in Denka Seiken assays was greater than Kyowa's and Daiichi's (although less dispersed for the latter) and for Wako all bias were positive. The relationship between bias variations and the lipid parameters of the samples was studied. Three methods, Daiichi, Kyowa and Wako, revealed a significant positive correlation between bias and serum VLDL-C/TG ratio, clearly indicating that cholesterol enrichment of VLDL was a source of variability in these assays. Specificity of the four methods was tested in situation of dyslipidemia by spiking isolated lipoproteins (chylomicrons, VLDL and HDL). This experiment revealed differences in behavior, most evidently upon addition of VLDL. No method was truly specific, but up to 8 mmol/L of TG the variations were acceptable. In the presence of type III hyperlipoproteinemia, however, only the Denka Seiken method was reliable. Linearity up to 20 mmol/L (Daiichi, Denka Seiken) or 14 mmol/L (Kyowa, Wako) of LDL-C allows these tests to be used in main routine cases. New direct assays are an obvious technological advance in terms of analytical performance and conveniency. Their use for the diagnosis and follow-up of hyperlipidemic patients offers an alternative that overcomes the limitations of the Friedewald calculation.


Assuntos
LDL-Colesterol/sangue , Análise Química do Sangue/métodos , Colesterol/sangue , Humanos , Hiperlipoproteinemias/sangue , Laboratórios , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Triglicerídeos/sangue
16.
Structure ; 9(8): 689-97, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11587643

RESUMO

BACKGROUND: Maltose phosphorylase (MP) is a dimeric enzyme that catalyzes the conversion of maltose and inorganic phosphate into beta-D-glucose-1-phosphate and glucose without requiring any cofactors, such as pyridoxal phosphate. The enzyme is part of operons that are involved in maltose/malto-oligosaccharide metabolism. Maltose phosphorylases have been classified in family 65 of the glycoside hydrolases. No structure is available for any member of this family. RESULTS: We report here the 2.15 A resolution crystal structure of the MP from Lactobacillus brevis in complex with the cosubstrate phosphate. This represents the first structure of a disaccharide phosphorylase. The structure consists of an N-terminal complex beta sandwich domain, a helical linker, an (alpha/alpha)6 barrel catalytic domain, and a C-terminal beta sheet domain. The (alpha/alpha)6 barrel has an unexpected strong structural and functional analogy with the catalytic domain of glucoamylase from Aspergillus awamori. The only conserved glutamate of MP (Glu487) superposes onto the catalytic residue Glu179 of glucoamylase and likely represents the general acid catalyst. The phosphate ion is bound in a pocket facing the carboxylate of Glu487 and is ideally positioned for nucleophilic attack of the anomeric carbon atom. This site is occupied by the catalytic base carboxylate in glucoamylase. CONCLUSIONS: These observations strongly suggest that maltose phosphorylase has evolved from glucoamylase. MP has probably conserved one carboxylate group for acid catalysis and has exchanged the catalytic base for a phosphate binding pocket. The relative positions of the acid catalytic group and the bound phosphate are compatible with a direct-attack mechanism of a glycosidic bond by phosphate, in accordance with inversion of configuration at the anomeric carbon as observed for this enzyme.


Assuntos
Glucana 1,4-alfa-Glucosidase/química , Glucosiltransferases/química , Lactobacillus/enzimologia , Sítios de Ligação , Catálise , Cristalografia por Raios X , Dimerização , Evolução Molecular , Glucose/química , Glucofosfatos/química , Modelos Moleculares , Fosfatos/química
17.
BJU Int ; 85(1): 48-53, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10619945

RESUMO

OBJECTIVE: To assess the reliability of the histological diagnosis of bladder cancer by assessing the interobserver variability of staging and grading in pTa/pT1 tumours and evaluating the clinical significance of discrepancies. MATERIALS AND METHODS: All sections from 301 superficial bladder carcinomas were reviewed by one pathologist. The prognostic relevance of grade and stage from both the initial and review diagnosis were determined in 128 patients for whom there was long-term follow-up information. RESULTS: There were significant interobserver differences in both the grading and staging of tumours. From a total of 235 tumours that were initially considered pT1, the reviewer classified 35% as pTa, 56% as pT1, 6% as pT1- (at least pT1), and 3% as pT2-4. In 39% of all biopsies there were interobserver differences in tumour grade. The prognostic significance of grade and stage differed between the initial pathology report and the reviewer's diagnosis. The reviewer's staging allowed a better estimate of the risk of subsequent tumour progression than the initial staging. Progression was significantly more common in 49 tumours in which the reviewer agreed with stage pT1 than in 29 tumours that were down-staged from pT1 to pTa (P = 0.0116). However, the initial tumour grade (P = 0.0386) but not the reviewer's grade (P = 0.2645) was significantly linked to progression. CONCLUSIONS: These results show that grading and staging by different pathologists have varying prognostic implications. If possible, biopsies from bladder tumours should be independently evaluated by two different pathologists before radical therapy is administered.


Assuntos
Estadiamento de Neoplasias/métodos , Neoplasias da Bexiga Urinária/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias/normas , Variações Dependentes do Observador , Prognóstico , Sensibilidade e Especificidade
18.
Ann Biol Clin (Paris) ; 57(5): 561-72, 1999.
Artigo em Francês | MEDLINE | ID: mdl-10518058

RESUMO

Most frequently, in routine laboratories, C-HDL is measured in the supernatant after precipitation of apolipoprotein B-containing lipoproteins by the sodium phosphotungstate/magnesium chloride reagent (PTA). This method involves precipitation, centrifugation and decantation steps which prevent full automation of the measurement and decrease the accuracy of the results. Recently, three direct assays for C-HDL including alpha-cyclodextrin sulphate (alpha-CD), polyanions/detergents (PA-D) or antibodies anti-beta-lipoproteins (AC) have been commercialized, in which all steps are fully managed by automated analyzers. These new methods have been compared to the conventional procedure (PTA), in multicenter studies among six laboratories using different analyzers. The C-HDL values measured by the alpha-CD and PA-D assays correlated well with those of the PTA method (r > 0.98), on most of the analyzers. With the AC assay, only the results obtained with the Hitachi 717 analyzer were correlated with C-HDL values of the PTA method. The linearity and specificity studies were evaluated in the laboratory A on a Kone Specific analyzer. The alpha-CD and PA-D assays were linear for C-HDL values from 0 to 5.56 mmol/l, as observed by increasing amounts of HDL2 + HDL3 or serum without lipoprotein isolated by ultracentrifugation. The specificity of these two methods was evaluated simultaneously, by adding various amounts of lipoproteins isolated by sequential ultracentrifugation. No interference was observed when adding chylomicrons up to 13.4 mmol/l of triglycerides for both methods. Inversely, increased C-HDL values were observed with added VLDL from 6 mmol/l of triglycerides for the PA-D assay and from 8 mmol/l for the alpha-CD assay. No interference was observed with added LDL up to 11.5 mmol/l of C-LDL for the alpha-CD assay and up to 6.7 mmol/l for the PA-D assay. In conclusion, the present multicenter evaluation demonstrates that the new procedures for the direct automation of C-HDL are easy and accurate and most of them correlated well with the classical precipitation method. In addition the study provides arguments for a choice between the different direct C-HDL methods.


Assuntos
HDL-Colesterol/sangue , alfa-Ciclodextrinas , Anticorpos , Apolipoproteínas B/sangue , Análise Química do Sangue/instrumentação , Análise Química do Sangue/métodos , Centrifugação , Precipitação Química , LDL-Colesterol/sangue , Quilomícrons/sangue , Ciclodextrinas , Detergentes , Humanos , Indicadores e Reagentes , Lipoproteínas LDL/imunologia , Lipoproteínas VLDL/sangue , Cloreto de Magnésio , Ácido Fosfotúngstico , Sensibilidade e Especificidade , Triglicerídeos/sangue , Ultracentrifugação
19.
J Biol Chem ; 274(24): 16995-7002, 1999 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-10358049

RESUMO

Fat digestion in humans requires not only the classical pancreatic lipase but also gastric lipase, which is stable and active despite the highly acidic stomach environment. We report here the structure of recombinant human gastric lipase at 3.0-A resolution, the first structure to be described within the mammalian acid lipase family. This globular enzyme (379 residues) consists of a core domain belonging to the alpha/beta hydrolase-fold family and a "cap" domain, which is analogous to that present in serine carboxypeptidases. It possesses a classical catalytic triad (Ser-153, His-353, Asp-324) and an oxyanion hole (NH groups of Gln-154 and Leu-67). Four N-glycosylation sites were identified on the electron density maps. The catalytic serine is deeply buried under a segment consisting of 30 residues, which can be defined as a lid and belonging to the cap domain. The displacement of the lid is necessary for the substrates to have access to Ser-153. A phosphonate inhibitor was positioned in the active site that clearly suggests the location of the hydrophobic substrate binding site. The lysosomal acid lipase was modeled by homology, and possible explanations for some previously reported mutations leading to the cholesterol ester storage disease are given based on the present model.


Assuntos
Lipase/química , Lisossomos/enzimologia , Estômago/enzimologia , Sequência de Aminoácidos , Carboxipeptidases/química , Domínio Catalítico , Catepsina A , Simulação por Computador , Cristalografia por Raios X , Humanos , Lipase/antagonistas & inibidores , Lipase/genética , Lipólise , Modelos Moleculares , Dados de Sequência Molecular , Organofosfonatos/farmacologia , Proteínas Recombinantes/química , Homologia de Sequência de Aminoácidos
20.
Acta Crystallogr D Biol Crystallogr ; 55(Pt 1): 360-2, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10089450

RESUMO

The alpha-amylase from Tenebrio molitor larvae (TMA) has been crystallized in complex with the alpha-amylase inhibitor (alpha-AI) from the bean Phaseolus vulgaris. A molecular-replacement solution of the structure was obtained using the refined pig pancreatic alpha-amylase (PPA) and alpha-AI atomic coordinates as starting models. The structural analysis showed that although TMA has the typical structure common to alpha-amylases, large deviations from the mammalian alpha-amylase models occur in the loops. Despite these differences in the interacting loops, the bean inhibitor is still able to inhibit both the insect and mammalian alpha-amylase.


Assuntos
Inibidores Enzimáticos/química , Fabaceae/química , Plantas Medicinais , Tenebrio/enzimologia , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/química , Animais , Cristalização , Cristalografia por Raios X , Substâncias Macromoleculares , Modelos Moleculares , Conformação Proteica , Sementes/química , alfa-Amilases/classificação
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