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1.
Int J Mol Sci ; 23(11)2022 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-35682592

RESUMO

(1) Background: Systemic infection is associated with increased neuroinflammation and accelerated cognitive decline in AD patients. Activated neutrophils produce neutrophil-derived microvesicles (NMV), which are internalised by human brain microvascular endothelial cells and increase their permeability in vitro, suggesting that NMV play a role in blood-brain barrier (BBB) integrity during infection. The current study investigated whether microRNA content of NMV from AD patients is significantly different compared to healthy controls and could impact cerebrovascular integrity. (2) Methods: Neutrophils isolated from peripheral blood samples of five AD and five healthy control donors without systemic infection were stimulated to produce NMV. MicroRNAs isolated from NMV were analysed by RNA-Seq, and online bioinformatic tools were used to identify significantly differentially expressed microRNAs in the NMV. Target and pathway analyses were performed to predict the impact of the candidate microRNAs on vascular integrity. (3) Results: There was no significant difference in either the number of neutrophils (p = 0.309) or the number of NMV (p = 0.3434) isolated from AD donors compared to control. However, 158 microRNAs were significantly dysregulated in AD NMV compared to controls, some of which were associated with BBB dysfunction, including miR-210, miR-20b-5p and miR-126-5p. Pathway analysis revealed numerous significantly affected pathways involved in regulating vascular integrity, including the TGFß and PDGFB pathways, as well as Hippo, IL-2 and DNA damage signalling. (4) Conclusions: NMV from AD patients contain miRNAs that may alter the integrity of the BBB and represent a novel neutrophil-mediated mechanism for BBB dysfunction in AD and the accelerated cognitive decline seen as a result of a systemic infection.


Assuntos
Doença de Alzheimer , MicroRNAs , Doença de Alzheimer/metabolismo , Barreira Hematoencefálica/metabolismo , Células Endoteliais/metabolismo , Humanos , MicroRNAs/metabolismo , Neutrófilos/metabolismo , RNA-Seq
2.
Epidemiol Infect ; 145(11): 2269-2279, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28629484

RESUMO

Mycobacterium marinum, a bacterium found in freshwater and saltwater, can infect persons with direct exposure to fish or aquariums. During December 2013, the New York City Department of Health and Mental Hygiene learned of four suspected or confirmed M. marinum skin or soft tissue infections (SSTIs) among persons who purchased whole fish from Chinese markets. Ninety-eight case-patients with non-tuberculous mycobacteria (NTM) SSTIs were identified with onset June 2013-March 2014. Of these, 77 (79%) were female. The median age was 62 years (range 30-91). Whole genome sequencing of clinical isolates revealed two main clusters and marked genetic diversity. Environmental samples from distributors yielded NTM though not M. marinum. We compared 56 case-patients with 185 control subjects who shopped in Chinese markets, frequency-matched by age group and sex. Risk factors for infection included skin injury to the finger or hand (odds ratio [OR]: 15·5; 95% confidence interval [CI]: 6·9-37·3), hand injury while preparing fish or seafood (OR 8·3; 95% CI 3·8-19·1), and purchasing tilapia (OR 3·6; 95% CI 1·1-13·9) or whiting (OR 2·7; 95% CI 1·1-6·6). A definitive environmental outbreak source was not identified.


Assuntos
Surtos de Doenças , Infecções por Mycobacterium não Tuberculosas/epidemiologia , Mycobacterium marinum/isolamento & purificação , Dermatopatias Bacterianas/epidemiologia , Infecções dos Tecidos Moles/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Estudos de Casos e Controles , Feminino , Peixes , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Infecções por Mycobacterium não Tuberculosas/microbiologia , Cidade de Nova Iorque/epidemiologia , Dermatopatias Bacterianas/microbiologia , Infecções dos Tecidos Moles/microbiologia
3.
Virol J ; 10: 322, 2013 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-24168271

RESUMO

BACKGROUND: Leukotriene B4, a 5-lipoxygenase product of arachidonic acid with potent chemotactic effects on neutrophils, has not been assessed in dengue patients. In this study, plasma leukotriene B4 and serum high-sensitivity C-reactive protein levels were determined in adult patients during the febrile, convalescent and defervescent stages of dengue serotype-2 (DENV-2) infection, and compared with those of age-matched healthy and non-dengue febrile subjects. In vitro studies were performed to examine the effects of live and heat-inactivated DENV-2 on the activities and expression of 5-lipoxygenase in human neutrophils. RESULTS: Plasma leukotriene B4 was elevated during the febrile stages of dengue infection compared to levels during convalescence and in study controls. Plasma leukotriene B4 also correlated with serum high-sensitivity C-reactive protein in dengue patients (febrile, r = 0.91, p < 0.001; defervescence, r = 0.87, p < 0.001; convalescence, r = 0.87, p < 0.001). Exposure of human neutrophils to DENV-2 resulted in a significant rise in leukotriene B4; the extent of increase, however, did not differ between exposure to live and heat-inactivated DENV-2. Pre-incubation of either live or heat-inactivated DENV-2 resulted in reduced leukotriene B4 release by neutrophils, indicating that contact with dengue antigens (and not replication) triggers the neutrophil response. Production of leukotriene B4 was associated with an increase in 5-lipoxygenase expression in human neutrophils; addition of MK886 (a 5-lipoxygenase activating protein inhibitor) attenuated further increase in leukotriene B4 production. CONCLUSION: These findings provide important clinical and mechanistic data on the involvement of 5-lipoxygenase and its metabolites in dengue infection. Further studies are needed to elucidate the therapeutic implications of these findings.


Assuntos
Araquidonato 5-Lipoxigenase/biossíntese , Dengue/fisiopatologia , Adulto , Proteína C-Reativa/análise , Estudos de Casos e Controles , Células Cultivadas , Dengue/classificação , Feminino , Humanos , Leucotrieno B4/sangue , Masculino , Neutrófilos/metabolismo , Neutrófilos/virologia , Sorotipagem
4.
Stroke ; 42(8): 2326-9, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21700941

RESUMO

BACKGROUND AND PURPOSE: We investigated changes in oxidative damage after ischemic stroke using multiple biomarkers. METHODS: Serial blood and urine samples of ischemic stroke subjects and age-matched control subjects were assayed for F2-isoprostanes, hydroxyeicosatetraenoic acid products, F4-neuroprostanes, 24-hydroxycholesterol, allantoin, and urate. RESULTS: Sixty-six stroke subjects (mean age, 65 years; median National Institutes of Health Stroke Scale 17) and 132 control subjects were recruited. A bimodal pattern of change was observed in plasma and urinary F2-isoprostanes and plasma 24-hydroxycholesterol. The rise in plasma hydroxyeicosatetraenoic acid products, F4-neuroprostanes, and allantoin was highest 6 to 12 hours after stroke onset, whereas plasma urate was significantly lower than controls on Days 1 to 3. After adjusting for age and baseline National Institutes of Health Stroke Scale, baseline plasma esterified hydroxyeicosatetraenoic acid products (OR, 1.01; 95% CI, 1.01 to 1.02), plasma urate (1.01; 1.00 to 1.01), and plasma free F4-neuroprostanes (2.73; 1.76 to 3.93) were associated with 90-day good functional recovery (modified Rankin Scale ≤1). CONCLUSIONS: Multiple markers of oxidative damage are increased immediately after stroke and remain elevated for several days. Recognition of these temporal changes may help design better antioxidant treatment trials for acute ischemic stroke.


Assuntos
Isquemia Encefálica/metabolismo , F2-Isoprostanos/metabolismo , Hidroxicolesteróis/metabolismo , Estresse Oxidativo/fisiologia , Acidente Vascular Cerebral/metabolismo , Idoso , Alantoína/metabolismo , Biomarcadores/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neuroprostanos/metabolismo , Oxirredução
5.
JACC Case Rep ; 3(10): 1258-1263, 2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34471874

RESUMO

This paper describes the case of a patient who developed refractory heart failure due to a fistula from the left ventricle to the coronary sinus that was unintentionally created after a surgical myectomy and mitral valve replacement. Advanced image guidance with a pre-procedure 3-dimensional physical model and intraprocedure echocardiography fusion facilitated transcatheter plugging of the shunt with symptom resolution. (Level of Difficulty: Advanced.).

6.
Compr Rev Food Sci Food Saf ; 9(5): 530-551, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33467832

RESUMO

Functional foods may be regarded as foods that have nutritional value, but in particular, they also have beneficial effects on one or more body functions. Thus, functional foods may improve health and/or reduce the risk of developing certain diseases when taken in amounts that can be consumed in a normal diet. Based on nearly 2 decades of research since the term "French paradox" was first coined in 1992, wine would appear to fit this definition. Yet there seems to be reluctance to consider wine as a functional food. In this review, we present an overview of the accumulated evidence for the health benefits of wine-and its key phenolic components such as resveratrol, quercetin, catechin-and show that these alone are not enough to firmly establish wine as a functional food. What is required is to create clearly defined products based on wine that are targeted to consumers' needs and expectations when it comes to purchasing functional foods. Moreover, the crucial question of alcohol and health also needs to be addressed by the functional food industry. Suggestions are presented for working through this issue, but in many regards, wine is like any other food-it should be consumed sensibly and in amounts that are beneficial to health. Overindulgence of any kind does not promote good health.

7.
Free Radic Biol Med ; 44(7): 1314-22, 2008 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-18226605

RESUMO

Oxidized lipids such as F2-isoprostanes (F2-IsoPs), hydroxyeicosatetraenoic acid products (HETEs), and cholesterol oxidation products (COPs) are widely believed to be involved in multiple diseases. Usually, each product is measured individually in separate blood samples. In this study we describe a method allowing us to measure F2-IsoPs, HETEs, COPs, and arachidonate using a single sample. Plasma (1 ml) samples from healthy volunteers were diluted with heavy isotopic standards, hydrolyzed in alkali with organic solvent, and then subjected to anionic-exchange solid-phase extraction (SPE). After the SPE column was washed, hexane and hexane/ethyl acetate portions were collected and combined for COPs measurement. Thereafter the column was loaded with hexane/ethanol/acetic acid and fractions were collected for total F2-IsoPs, total HETEs, and arachidonate measurement. All compounds in the eluates were measured by gas chromatography-mass spectrometry. The efficiency of SPE and reproducibility for all compounds measured were high. Levels of total F2-IsoPs (0.45+/-0.26 ng/ml (n=157)), total HETEs (34.06+/-16.35 ng/ml (n=21)), total arachidonate (68.36+/-24.45 microg/ml (n=33)), and COPs (7-ketocholesterol, 12.25+/-6.56 ng/ml; 7beta-hydroxycholesterol, 6.32+/-3.46 ng/ml; 7alpha-hydroxycholesterol, 15.06+/-7.06 ng/ml; 24-hydroxycholesterol, 41.39+/-18.22 ng/ml; and 27-hydroxycholesterol, 29.08+/-16.79 ng/ml (n=26)) were recorded in healthy subjects (age range 20 to 66 years; average male to female ratio 1:1).


Assuntos
F2-Isoprostanos/metabolismo , Ácidos Hidroxieicosatetraenoicos/química , Esteróis/metabolismo , Acetatos/química , Adulto , Idoso , Ácido Araquidônico/química , F2-Isoprostanos/análise , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Ácidos Hidroxieicosatetraenoicos/análise , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Reprodutibilidade dos Testes , Solventes/química , Esteróis/análise
8.
Nat Genet ; 14(1): 10-2, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8782811
9.
Free Radic Biol Med ; 43(12): 1649-55, 2007 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-18037130

RESUMO

This study was aimed at investigating oxidative stress in thalassemic patients by measurement of the oxidative damage biomarker, F(2)-isoprostanes (F(2)-IsoPs), using gas chromatography-mass spectrometry. The results showed that the mean value of urinary F(2)-IsoPs, normalized with creatinine, in the thalassemic group was significantly higher than that from healthy subjects (3.38+/-2.15 ng/mg creatinine vs 0.86+/-0.55 ng/mg creatinine, respectively), and the mean value of plasma total F(2)-IsoPs in the thalassemic group was also significantly higher than that from healthy subjects (0.39+/-0.15 ng/ml vs 0.18+/-0.03 ng/ml, respectively). Serum ferritin, erythrocyte superoxide dismutase (SOD), glutathione peroxidase, glutathione, and TBARS levels after treatment of erythrocytes with H(2)O(2) were also investigated, and serum ferritin and erythrocyte SOD levels were significantly higher in thalassemic patients. Our findings are consistent with oxidative stress in thalassemia patients.


Assuntos
F2-Isoprostanos/metabolismo , Talassemia/metabolismo , Adulto , Antioxidantes/metabolismo , Bilirrubina/sangue , Biomarcadores/metabolismo , Estudos de Casos e Controles , Índices de Eritrócitos , Eritrócitos/metabolismo , F2-Isoprostanos/sangue , F2-Isoprostanos/urina , Feminino , Ferritinas/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo , Talassemia/sangue , Talassemia/urina , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
10.
Free Radic Res ; 41(4): 479-88, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17454130

RESUMO

Soy sauce is a traditional fermented seasoning in Asian countries, that has high antioxidant activity in vitro and some antioxidant activity in vivo. We attempted to identify the major antioxidants present, using the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay as a guide. 3-Hydroxy-2-methyl-4H-pyran-4-one (maltol) was one of several active compounds found in an ethyl acetate extract of dark soy sauce (DSS) and was present at millimolar concentrations in DSS. However, most of the antioxidant activity was present in colored fractions, two of which (CP1 and CP2) were obtained by gel filtration chromatography. Their structural characteristics based on nuclear magnetic resonance (NMR) and electrospray-ionization time-of-flight mass spectrometry (ESI-TOF-MS) analysis suggest that carbohydrate-containing pigments such as melanoidins are the major contributors to the high antioxidant capacity of DSS.


Assuntos
Antioxidantes/análise , Análise de Alimentos/métodos , Alimentos de Soja/análise , Acetatos/química , Antioxidantes/química , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Sequestradores de Radicais Livres , Espectroscopia de Ressonância Magnética , Peptídeos/química , Polímeros/química , Pironas/química , Espectrometria de Massas por Ionização por Electrospray
11.
Anaesth Intensive Care ; 43(6): 757-63, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26603801

RESUMO

Acute kidney injury (AKI) is a common complication following orthotopic liver transplantation. It is associated with increased morbidity and mortality, as well as increased healthcare costs. The aetiology of AKI post liver transplantation is multifactorial and understanding these factors is pivotal in developing risk stratification and prevention strategies. This study aims to investigate the preoperative and intraoperative factors that may be associated with AKI in patients undergoing liver transplantation at the Princess Alexandra Hospital, Brisbane, Queensland. In our study, retrospective data of 97 consecutive orthotopic liver transplantations performed between January 2009 and August 2012 were recorded. Univariate and multivariate analyses were performed to investigate the preoperative and intraoperative risk factors for the development of AKI in this cohort. In the cohort of 97 patients who underwent orthotopic liver transplantation, 24 patients (25%) developed postoperative AKI. Univariate analysis demonstrated that high preoperative body mass index and intraoperative noradrenaline use were both associated with AKI. Multivariate analysis demonstrated that high body mass index, high Model for End-stage Liver Disease score and intraoperative noradrenaline use were associated with AKI. Overall mortaility was 4.1% during the study period and was not significantly different between the two groups. The high incidence of AKI following liver transplantation in this study cohort highlights the importance of this issue. This study has identified several potential pre- and intraoperative risk factors, providing a focus for patient surveillance and future research.


Assuntos
Injúria Renal Aguda/etiologia , Transplante de Fígado/efeitos adversos , Adulto , Idoso , Índice de Massa Corporal , Doença Hepática Terminal/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Período Perioperatório , Estudos Retrospectivos
12.
J Neurol ; 262(5): 1344-53, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25845763

RESUMO

Friedreich ataxia (FRDA) is due to a triplet repeat expansion in FXN, resulting in deficiency of the mitochondrial protein frataxin. Resveratrol is a naturally occurring polyphenol, identified to increase frataxin expression in cellular and mouse models of FRDA and has anti-oxidant properties. This open-label, non-randomized trial evaluated the effect of two different doses of resveratrol on peripheral blood mononuclear cell (PBMC) frataxin levels over a 12-week period in individuals with FRDA. Secondary outcome measures included PMBC FXN mRNA, oxidative stress markers, and clinical measures of disease severity. Safety and tolerability were studied. Twenty-four participants completed the study; 12 received low-dose resveratrol (1 g daily) and 12 high-dose resveratrol (5 g daily). PBMC frataxin levels did not change in either dosage group [low-dose group change: 0.08 pg/µg protein (95% CI -0.05, 0.21, p = 0.21); high-dose group change: 0.03 pg/µg protein (95% CI -0.10, 0.15, p = 0.62)]. Improvement in neurologic function was evident in the high-dose group [change in Friedreich Ataxia Rating Scale -3.4 points, 95% CI (-6.6, -0.3), p = 0.036], but not the low-dose group. Significant improvements in audiologic and speech measures, and in the oxidative stress marker plasma F2-isoprostane were demonstrated in the high-dose group only. There were no improvements in cardiac measures or patient-reported outcome measures. No serious adverse events were recorded. Gastrointestinal side-effects were a common, dose-related adverse event. This open-label study shows no effect of resveratrol on frataxin levels in FRDA, but suggests that independent positive clinical and biologic effects of high-dose resveratrol may exist. Further assessment of efficacy is warranted in a randomized placebo-controlled trial.


Assuntos
Antioxidantes/uso terapêutico , Ataxia de Friedreich/tratamento farmacológico , Ataxia de Friedreich/metabolismo , Proteínas de Ligação ao Ferro/metabolismo , Estilbenos/uso terapêutico , 8-Hidroxi-2'-Desoxiguanosina , Adulto , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , F2-Isoprostanos/sangue , Feminino , Análise de Fourier , Humanos , Proteínas de Ligação ao Ferro/genética , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Resveratrol , Resultado do Tratamento , Adulto Jovem , Frataxina
13.
Biochem Pharmacol ; 48(3): 595-608, 1994 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-7520698

RESUMO

The inhibition of HIV-1 integrase by flavones and related compounds was investigated biochemically and by means of structure-activity relationships. Purified enzyme and synthetic oligonucleotides were used to assay for three reactions catalysed by integrase: (1) processing of 3' termini by cleavage of the terminal dinucleotide; (2) strand transfer, which models the integration step; and (3) "disintegration," which models the reversal of the strand transfer reaction. Inhibitions of all three reactions by flavones generally occurred in parallel, but caffeic acid phenethyl ester (CAPE) appeared to inhibit reaction 2 selectively. CAPE, however, inhibited reactions 1 and 3 effectively when preincubated with the enzyme, suggesting that this compound differs from the flavones primarily in requiring more time to block the enzyme. The core integrase fragment consisting of amino acids 50-212 retained the ability to catalyse reaction 3, and flavones and CAPE retained the ability to inhibit. Hence, the putative zinc-finger region that is deleted in this fragment is probably not the target of inhibition. Inhibition by flavones usually required the presence of at least one ortho pair of phenolic hydroxyl groups and at least one or two additional hydroxyl groups. Potency was enhanced by the presence of additional hydroxyl groups, especially when present in ortho pairs or in adjacent groups of three. Inhibitory activity was reduced or eliminated by methoxy or glycosidic substitutions or by saturation of the 2,3 double bond. These structure-activity findings for flavones were generally concordant with those previously reported for reverse transcriptase and topoisomerase II. These findings are discussed in the context of a review of the effects of flavones on various enzymes, the possible mechanisms of inhibition, and the potential for building upon a general pharmacophore to generate target specificity.


Assuntos
Ácidos Cafeicos/farmacologia , DNA Nucleotidiltransferases/antagonistas & inibidores , Flavonoides/farmacologia , HIV-1/enzimologia , Álcool Feniletílico/análogos & derivados , Sequência de Bases , Cátions Bivalentes , DNA/efeitos dos fármacos , DNA Nucleotidiltransferases/genética , Relação Dose-Resposta a Droga , Integrases , Cinética , Dados de Sequência Molecular , Oligonucleotídeos/metabolismo , Álcool Feniletílico/farmacologia , Relação Estrutura-Atividade
14.
Am J Med Genet ; 36(4): 391-3, 1990 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2389794

RESUMO

We report on a case of 46,XY/46,XY,r(19) mosaicism. The patient shows minimal clinical abnormality and the terminal deletions prerequisite for the ring formation are not microscopically discernible. The origin of the mosaicism is discussed. Firstly, the mosaicism may represent chimerism with a prezygotic origin of the ring chromosome; secondly, the ring chromosome could have arisen postzygotically; and thirdly, the ring could have been of a prezygotic origin with the apparently normal cells actually containing reopened rings. The consequences of these hypothesis on genetic counselling are discussed.


Assuntos
Cromossomos Humanos Par 19 , Mosaicismo/genética , Humanos , Recém-Nascido , Cariotipagem , Masculino
15.
Am J Med Genet ; 65(3): 190-6, 1996 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-9240742

RESUMO

Although fluorescent in situ hybridization (FISH) is rapidly becoming a part of clinical cytogenetics, no organization sponsors multicenter determinations of the efficacy of probes. We report on 23 laboratories that volunteered to provide slides and to use a probe for small nuclear ribonucleoprotein polypeptide N (SNRPN) and a control locus. Experiences with FISH for these laboratories during 1994 ranged from 0 to 645 utilizations (median = 84) involving blood, amniotic fluid, and bone marrow. In an initial study of hybridization efficiency, the median percentage of metaphases from normal individuals showing two SNRPN and two control signals for slides prepared at each site was 97.0 (range = 74-100); for slides prepared by a central laboratory, it was 97.8 (range = 81.6-100). In a subsequent blind study, each laboratory attempted to score 5 metaphases from each of 23 specimens [8 with del(15)(q11.2-->q12) and 15 with normal #15 chromosomes]. Of 529 challenges, the correct SNRPN pattern was found in 5 of 5 metaphases in 457 (86%) and in 4 of 5 in 33 (6%). Ambiguous, incomplete, or no results were reported for 32 (6%) challenges. Seven (1%) diagnostic errors were made, including 6 false positives and 1 false negative: 1 laboratory made 3 errors, 1 made 2, and 2 made 1 each. Most errors and inconsistencies seemed due to inexperience with FISH. The working time to process and analyze slides singly averaged 49.5 min; slides processed in batches of 4 and analyzed singly required 36.9 min. We conclude that proficiency testing for FISH by using an extensive array of challenges is possible and that multiple centers can collaborate to test probes and to evaluate costs.


Assuntos
Autoantígenos/genética , Cromossomos Humanos Par 15 , Hibridização in Situ Fluorescente/normas , Ribonucleoproteínas Nucleares Pequenas , Humanos , Metáfase , Controle de Qualidade , Padrões de Referência , Sensibilidade e Especificidade , Proteínas Centrais de snRNP
16.
Am J Med Genet ; 64(4): 539-45, 1996 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-8870919

RESUMO

Although fluorescent in situ hybridization (FISH) is rapidly becoming a part of clinical cytogenetics, no organization sponsors multi-center determinations of the efficacy of probes. We report on 23 laboratories that volunteered to provide slides and to use a probe for SNRPN and a control locus. Experiences with FISH for these laboratories during 1994 ranged from 0 to 645 utilizations (median = 84) involving blood, amniotic fluid and bone marrow. In an initial study of hybridization efficiency, the median percentage of metaphases from normal individuals showing two SNRPN and 2 control signals for slides prepared at each site was 97.0 (range = 74-100); for slides prepared by a central laboratory, it was 97.8 (range = 81.6-100). In a subsequent blind study, each laboratory attempted to score 5 metaphases from each of 23 specimens [8 with del(15) (q11.2-->q12) and 15 with normal 15 chromosomes]. Of 529 challenges, the correct SNRPN pattern was found in 5 of 5 metaphases in 457 (86%) and in 4 of 5 in 33 (6%). Ambiguous, incomplete or no results were reported for 32 (6%) challenges. Seven (1%) diagnostic errors were made including 6 false positives and 1 false negative: 1 laboratory made 3 errors, 1 made 2, and 2 made 1 each. Most errors and inconsistencies seemed due to inexperience with FISH. The working time to process and analyze slides singly averaged 49.5 minutes; slides processed in batches of 4 and analyzed singly required 36.9 minutes. We conclude that proficiency testing for FISH using an extensive array of challenges is possible and that multiple centers can collaborate to test probes and to evaluate costs.


Assuntos
Hibridização in Situ Fluorescente , Padrões de Referência , Humanos , Controle de Qualidade
17.
Cancer Genet Cytogenet ; 116(2): 97-104, 2000 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-10640140

RESUMO

Twenty-eight laboratories evaluated a new fluorescence in situ hybridization (FISH) strategy for chronic myeloid leukemia. In a three-part study, bcr/abl1 D-FISH probes were used to study bone marrow specimens. First, laboratories familiarized themselves with the strategy by applying it to known normal and abnormal specimens. Then, collectively the laboratories studied 20 normal and 20 abnormal specimens blindly and measured workload. Finally, each laboratory and two experts studied six serial dilutions with 98-0% abnormal nuclei. Using the reported normal cutoff of < 1% abnormal nuclei, participants reported no false-negative cases and 15 false-positive cases (1-6.6% abnormal nuclei). Results provided by participants for serial dilutions approximated the expected percentages of abnormal nuclei, but those from the experts exhibited greater precision. The clinical sensitivity, precision, nomenclature, workload, recommendations for training, and quality assurance in methods using D-FISH in clinical practice are discussed.


Assuntos
Técnicas de Laboratório Clínico/normas , Proteínas de Fusão bcr-abl/genética , Hibridização in Situ Fluorescente , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Medula Óssea/patologia , Corantes Fluorescentes , Humanos , Hibridização in Situ Fluorescente/instrumentação , Hibridização in Situ Fluorescente/métodos , Hibridização in Situ Fluorescente/normas , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Controle de Qualidade , Sensibilidade e Especificidade , Carga de Trabalho
18.
Biophys Chem ; 104(1): 121-30, 2003 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-12834832

RESUMO

The water self-diffusion behavior in yeast cell water suspension was investigated by pulsed field gradient NMR techniques. Three types of water were detected, which differ according to the self-diffusion coefficients: bulk water, extracellular and intracellular water. Intracellular and extracellular water self-diffusion was restricted; the sizes of restriction regions were approximately 3 and 15-20 microm, respectively. The smallest restriction size was determined as inner cell size. This size and also cell permeability varied with the growth phase of yeast cell. Cell size increased, but permeability decreased with increasing growth time. The values of cell permeabilities P(1)(d) obtained from time dependence of water self-diffusion coefficient were in good agreement with the permeabilities obtained from the exchange rate constants P(1)(eff). The values of P(1)(eff) were 7 x 10(-6), 1.2 x 10(-6) and 1.6 x 10(-6) m/s, and P(1)(d) were 6.3 x 10(-6), 8.4 x 10(-7), 1.5 x 10(-6) m/s for yeast cells incubated for 9 h (exponential growth phase), 24 h (end of exponential growth phase), and 48 h (stationary growth phase), respectively.


Assuntos
Permeabilidade da Membrana Celular/fisiologia , Leveduras/fisiologia , Transporte Biológico Ativo , Difusão , Espectroscopia de Ressonância Magnética/métodos , Água/metabolismo , Leveduras/crescimento & desenvolvimento
19.
Magn Reson Imaging ; 21(9): 1009-17, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14684204

RESUMO

The water self-diffusion behavior in chlorella water suspension was investigated by pulsed field gradient NMR technique. Three types of water was determined, which differs according to the self-diffusion coefficients; bulk water, extracellular and intracellular water. Intracellular and extracellular water self-diffusion were restricted, and the sizes of restriction regions were 3.4 microm and 17 microm, respectively. The water molecular exchange process between these three diffusion regions was investigated. The residence time and exchange rate constant for chlorella cells were obtained. The cell wall permeability determined from the rate constant as 3 x 10(-6) m/s agreed with the permeability 10(-6) m/s obtained from time dependence of intracellular water self-diffusion coefficient. The structural cluster model of chlorella cell is estimated to describe the extracellular water self-diffusion in chlorella water suspension.


Assuntos
Chlorella/citologia , Chlorella/metabolismo , Água/metabolismo , Permeabilidade da Membrana Celular/fisiologia , Tamanho Celular , Difusão , Modelos Estruturais , Ressonância Magnética Nuclear Biomolecular
20.
Acad Radiol ; 10(12): 1433-41, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14697011

RESUMO

RATIONALE AND OBJECTIVES: The purpose of this study was to develop a method to assist the cardiologist in planning an interventional procedure while the patient is on the catheterization table. MATERIALS AND METHODS: A rotational single plane x-ray system is used to acquire images while rapidly rotating the C-arm around the patient. Based on electrocardiogram-selected projections, both a volumetric cone-beam reconstruction of the coronary tree as well as a three-dimensional model of the vessel segment of interest is generated. This information is used to compute the appropriateness of a range of different viewing angles with respect to the overlap and foreshortening of the vessel segment of interest during the cardiac cycle which results in an interactive optimal view map. RESULTS: The proposed method has been tested on patient data and several phantom objects. The results show that both an accurate 3D model of a vessel segment of interest and its associated optimal view map can be generated to predict an appropriate gantry angle for subsequent image acquisition. CONCLUSION: The method provides an appropriate and feasible tool to assist interventional cardiologists in planning a coronary intervention while the patient is still on the catheterization table following diagnostic coronary angiography.


Assuntos
Cateterismo Cardíaco , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Radiografia Intervencionista , Doença das Coronárias/diagnóstico por imagem , Humanos , Planejamento de Assistência ao Paciente , Imagens de Fantasmas
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