Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
1.
Int J Hematol ; 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38634996

RESUMO

Gamma heavy chain disease (gHCD) is a rare B-cell lymphoproliferative disorder that mostly occurs after childbearing age. Here we report the first case of gHCD in a pregnant patient that was diagnosed in the second trimester, and another pregnancy in the same patient after initial treatment for gHCD. The former pregnancy ended in intrauterine fetal death, believed to be caused by insufficient maternal blood flow due to multiple placental infarcts. The latter pregnancy course was uneventful. Although we cannot rule out the possibility that the poor outcome of the former pregnancy was due to an unfortunate complication independent of gHCD, the courses of these pregnancies suggest that non-lymphomatous gamma heavy chain may have a significant impact on pregnancy and that its removal by treatment may improve outcomes.

2.
Sci Rep ; 13(1): 10015, 2023 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-37340079

RESUMO

Early detection of cervical myelopathy (CM) is important for a favorable outcome, as its prognosis is poor when left untreated. We developed a screening method for CM using machine learning-based analysis of the drawing behavior of 38 patients with CM and 66 healthy volunteers. Using a stylus pen, the participants traced three different shapes displayed on a tablet device. During the tasks, writing behaviors, such as the coordinates, velocity, and pressure of the stylus tip, along with the drawing time, were recorded. From these data, features related to the drawing pressure, and time to trace each shape and combination of shapes were used as training data for the support vector machine, a machine learning algorithm. To evaluate the accuracy, a receiver operating characteristic curve was generated, and the area under the curve (AUC) was calculated. Models with triangular waveforms tended to be the most accurate. The best triangular wave model identified patients with and without CM with 76% sensitivity and 76% specificity, yielding an AUC of 0.80. Our model was able to classify CM with high accuracy and could be applied to the development of disease screening systems useful outside the hospital setting.


Assuntos
Doenças da Medula Espinal , Humanos , Doenças da Medula Espinal/diagnóstico , Prognóstico , Programas de Rastreamento , Algoritmos , Aprendizado de Máquina
3.
J Clin Med ; 10(19)2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34640454

RESUMO

When carpal tunnel syndrome (CTS), an entrapment neuropathy, becomes severe, thumb motion is reduced, which affects manual dexterity, such as causing difficulties in writing; therefore, early detection of CTS by screening is desirable. To develop a screening method for CTS, we developed a tablet app to measure the stylus trajectory and pressure of the stylus tip when drawing a spiral on a tablet screen using a stylus and, subsequently, used these data as training data to predict the classification of participants as non-CTS or CTS patients using a support vector machine. We recruited 33 patients with CTS and 31 healthy volunteers for this study. From our results, non-CTS and CTS were classified by our screening method with 82% sensitivity and 71% specificity. Our CTS screening method can facilitate the screening for potential patients with CTS and provide a quantitative assessment of CTS.

4.
Intern Med ; 60(9): 1433-1442, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33952814

RESUMO

The gastrointestinal tract is considered an important endocrine organ for controlling glucose homeostasis via the production of incretins. A 21-year-old man emergently underwent total colectomy due to severe ulcerative colitis, and overt diabetes became evident. Weekly administration of a glucagon-like peptide (GLP)-1 receptor agonist (RA) dramatically improved his glucose control. Levels of GLP-1 or gastric inhibitory polypeptide (GIP) were low at the baseline in the duodenum and serum of the patient. After 11 months of GLP-1RA treatment, his HbA1c worsened again, and intensive insulin therapy was necessary to control his glucose levels. Our report may explain the significance of residual incretin for maintaining the pancreatic ß-cell function.


Assuntos
Diabetes Mellitus Tipo 2 , Incretinas , Adulto , Glicemia , Polipeptídeo Inibidor Gástrico , Glucose , Homeostase , Humanos , Insulina , Masculino , Adulto Jovem
5.
Endocr Connect ; 10(5): 521-533, 2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-33883285

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is often accompanied by metabolic disorders such as metabolic syndrome and type 2 diabetes (T2DM). Heat shock response (HSR) is one of the most important homeostatic abilities but is deteriorated by chronic metabolic insults. Heat shock (HS) with an appropriate mild electrical stimulation (MES) activates HSR and improves metabolic abnormalities including insulin resistance, hyperglycemia and inflammation in metabolic disorders. To analyze the effects of HS + MES treatment on NAFLD biomarkers, three cohorts including healthy men (two times/week, n = 10), patients with metabolic syndrome (four times/week, n = 40), and patients with T2DM (n = 100; four times/week (n = 40) and two, four, seven times/week (n = 20 each)) treated with HS + MES were retrospectively analyzed. The healthy subjects showed no significant alterations in NAFLD biomarkers after the treatment. In patients with metabolic syndrome, many of the NAFLD steatosis markers, including fatty liver index, NAFLD-liver fat score, liver/spleen ratio and hepatic steatosis index and NAFLD fibrosis marker, aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio, were improved upon the treatment. In patients with T2DM, all investigated NAFLD steatosis markers were improved and NAFLD fibrosis markers such as the AST/ALT ratio, fibrosis-4 index and NAFLD-fibrosis score were improved upon the treatment. Thus, HS + MES, a physical intervention, may become a novel treatment strategy for NAFLD as well as metabolic disorders.

6.
JMIR Mhealth Uhealth ; 9(3): e26320, 2021 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-33714936

RESUMO

BACKGROUND: Carpal tunnel syndrome (CTS) is a medical condition caused by compression of the median nerve in the carpal tunnel due to aging or overuse of the hand. The symptoms include numbness of the fingers and atrophy of the thenar muscle. Thenar atrophy recovers slowly postoperatively; therefore, early diagnosis and surgery are important. While physical examinations and nerve conduction studies are used to diagnose CTS, problems with the diagnostic ability and equipment, respectively, exist. Despite research on a CTS-screening app that uses a tablet and machine learning, problems with the usage rate of tablets and data collection for machine learning remain. OBJECTIVE: To make data collection for machine learning easier and more available, we developed a screening app for CTS using a smartphone and an anomaly detection algorithm, aiming to examine our system as a useful screening tool for CTS. METHODS: In total, 36 participants were recruited, comprising 36 hands with CTS and 27 hands without CTS. Participants controlled the character in our app using their thumbs. We recorded the position of the thumbs and time; generated screening models that classified CTS and non-CTS using anomaly detection and an autoencoder; and calculated the sensitivity, specificity, and area under the curve (AUC). RESULTS: Participants with and without CTS were classified with 94% sensitivity, 67% specificity, and an AUC of 0.86. When dividing the data by direction, the model with data in the same direction as the thumb opposition had the highest AUC of 0.99, 92% sensitivity, and 100% specificity. CONCLUSIONS: Our app could reveal the difficulty of thumb opposition for patients with CTS and screen for CTS with high sensitivity and specificity. The app is highly accessible because of the use of smartphones and can be easily enhanced by anomaly detection.


Assuntos
Síndrome do Túnel Carpal , Smartphone , Síndrome do Túnel Carpal/diagnóstico , Estudos de Casos e Controles , Mãos , Humanos , Nervo Mediano
7.
JMIR Mhealth Uhealth ; 7(9): e14172, 2019 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-31586365

RESUMO

BACKGROUND: Carpal tunnel syndrome (CTS), the most common neuropathy, is caused by a compression of the median nerve in the carpal tunnel and is related to aging. The initial symptom is numbness and pain of the median nerve distributed in the hand area, while thenar muscle atrophy occurs in advanced stages. This atrophy causes failure of thumb motion and results in clumsiness; even after surgery, thenar atrophy does not recover for an extended period. Medical examination and electrophysiological testing are useful to diagnose CTS; however, visits to the doctor tend to be delayed because patients neglect the symptom of numbness in the hand. To avoid thenar atrophy-related clumsiness, early detection of CTS is important. OBJECTIVE: To establish a CTS screening system without medical examination, we have developed a tablet-based CTS detection system, focusing on movement of the thumb in CTS patients; we examined the accuracy of this screening system. METHODS: A total of 22 female CTS patients, involving 29 hands, and 11 female non-CTS participants were recruited. The diagnosis of CTS was made by hand surgeons based on electrophysiological testing. We developed an iPad-based app that recorded the speed and timing of thumb movements while playing a short game. A support vector machine (SVM) learning algorithm was then used by comparing the thumb movements in each direction among CTS and non-CTS groups with leave-one-out cross-validation; with this, we conducted screening for CTS in real time. RESULTS: The maximum speed of thumb movements between CTS and non-CTS groups in each direction did not show any statistically significant difference. The CTS group showed significantly slower average thumb movement speed in the 3 and 6 o'clock directions (P=.03 and P=.005, respectively). The CTS group also took a significantly longer time to reach the points in the 2, 3, 4, 5, 6, 8, 9, and 11 o'clock directions (P<.05). Cross-validation revealed that 27 of 29 CTS hands (93%) were classified as having CTS, while 2 of 29 CTS hands (7%) did not have CTS. CTS and non-CTS were classified with 93% sensitivity and 73% specificity. CONCLUSIONS: Our newly developed app could classify disturbance of thumb opposition movement and could be useful as a screening test for CTS patients. Outside of the clinic, this app might be able to detect middle-to-severe-stage CTS and prompt these patients to visit a hand surgery specialist; this may also lead to medical cost-savings.


Assuntos
Síndrome do Túnel Carpal/diagnóstico , Programas de Rastreamento/instrumentação , Aplicativos Móveis/tendências , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Computadores de Mão/tendências , Feminino , Voluntários Saudáveis , Humanos , Programas de Rastreamento/métodos , Pessoa de Meia-Idade
8.
J Clin Med ; 8(5)2019 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-31091693

RESUMO

Because the renin-angiotensin-aldosterone system influences glucose homeostasis, the mineralocorticoid receptor (MR) signal in pancreatic islets may regulate insulin response upon glucose load. Glucagon-like peptide-1 (GLP-1) production is stimulated by interleukin-6 (IL-6) in pancreatic α-cells. To determine how glucose homeostasis is regulated by interactions of MR, IL-6 and GLP-1 in islets, we performed glucose tolerance and histological analysis of islets in primary aldosteronism (PA) model rodents and conducted in vitro experiments using α-cell lines. We measured active GLP-1 concentration in primary aldosteronism (PA) patients before and after the administration of MR antagonist eplerenone. In PA model rodents, aldosterone decreased insulin-secretion and the islet/pancreas area ratio and eplerenone added on aldosterone (E+A) restored those with induction of IL-6 in α-cells. In α-cells treated with E+A, IL-6 and GLP-1 concentrations were increased, and anti-apoptotic signals were enhanced. The E+A-treatment also significantly increased MR and IL-6 mRNA and these upregulations were blunted by MR silencing using small interfering RNA (siRNA). Transcriptional activation of the IL-6 gene promoter by E+A-treatment required an intact MR binding element in the promoter. Active GLP-1 concentration was significantly increased in PA patients after eplerenone treatment. MR signal in α-cells may stimulate IL-6 production and increase GLP-1 secretion, thus protecting pancreatic ß-cells and improving glucose homeostasis.

9.
Anal Sci ; 34(7): 853-857, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29998971

RESUMO

In this work, we applied post-column reaction gas chromatography (GC) using a flame ionization detector (FID) system to study nitrogen-containing organic compounds (NOCs). The results were subsequently validated. After separation by column, the target components were converted to carbon dioxide using an oxidizing catalyst and then reduced to methane, followed by detection using an FID. SI-traceable testing mixtures containing NOCs (isoprocarb, napropamide, and pendimethalin) were prepared by the gravimetric blending method. These mixtures were analyzed using a post-column reaction GC-FID system; standard materials of hydrocarbons were used as calibrants in this analysis. The determined values were compared with the values obtained for samples prepared at the corresponding concentrations, and statistical analyses were performed in all cases. It was shown that the determined and prepared values agreed well with each other within the uncertainty limits.

10.
J Diabetes Investig ; 9(6): 1370-1377, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29624902

RESUMO

AIMS/INTRODUCTION: Gestational diabetes mellitus (GDM) is a risk for adverse perinatal outcomes, and patients with a history of GDM have an increased risk of impaired glucose tolerance (IGT). Here, we carried out two non-interventional and retrospective studies of GDM patients in Japan. MATERIALS AND METHODS: In the first study, we enrolled 529 GDM patients and assessed predictors of the need for insulin therapy. In the second study, we enrolled 185 patients from the first study, and assessed predictors of postpartum IGT. RESULTS: In the first study, gestational weeks at GDM diagnosis and history of pregnancy were significantly lower, and pregestational body mass index, family history of diabetes mellitus, 1- and 2-h glucose levels in a 75-g oral glucose tolerance test (OGTT), the number of abnormal values in a 75-g OGTT, and glycated hemoglobin were significantly higher in participants receiving insulin therapy. In the second study, 1- and 2-h glucose levels in a 75-g OGTT, the number of abnormal values in a 75-g OGTT, glycated hemoglobin, and ketone bodies in a urine test were significantly higher in participants with OGT. Logistic regression analysis showed that gestational weeks at GDM diagnosis, 1-h glucose levels in a 75-g OGTT and glycated hemoglobin were significant predictors of the need for insulin therapy, and 1-h glucose levels in a 75-g OGTT at diagnosis and ketone bodies in a urine test were significant predictors for postpartum IGT. CONCLUSIONS: Antepartum 1-h glucose levels in a 75-g OGTT was a predictor of the need for insulin therapy in pregnancy and postpartum IGT.


Assuntos
Diabetes Gestacional/diagnóstico , Diabetes Gestacional/tratamento farmacológico , Intolerância à Glucose/diagnóstico , Intolerância à Glucose/tratamento farmacológico , Teste de Tolerância a Glucose/métodos , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Adulto , Glicemia/análise , Feminino , Idade Gestacional , Intolerância à Glucose/complicações , Humanos , Japão , Período Pós-Parto , Gravidez , Estudos Retrospectivos , Fatores de Risco
11.
Anal Sci ; 31(6): 463-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26063006

RESUMO

Acetaldehyde is regulated as a toxic substance in various fields, and the method for monitoring or analysis of acetaldehyde is important. However, handling is difficult because of the high reactivity and low boiling point of acetaldehyde. Therefore, a reference material for high purity acetaldehyde with high accuracy was not available. Although the measuring method of acetaldehyde as a reagent is published in the Japanese Industrial Standard (JIS) where the specification of acetaldehyde purity is more than 80%, the analytical method described in JIS is not enough for an accuracy purity determination method. In this research, the high precision purity determination method for development of a certified reference material (CRM) of acetaldehyde was examined. By controlling the volatility and reactivity of acetaldehyde, we established the purity determination method of acetaldehyde with a relative standard uncertainty of less than 0.3%. Furthermore, this method was applied to develop a high purity acetaldehyde CRM with an expanded uncertainty of 0.005 kg kg(-1) (k = 2).

12.
Can Urol Assoc J ; 8(1-2): E86-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24554980

RESUMO

Primary renal lymphoma is rare, and most are intermediate- and high-grade lymphomas of B-cell lineage, such as diffuse large B-cell or Burkitt lymphoma. We report a case of low-grade B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) arising from the kidney. Only a few cases of primary renal MALT lymphoma have been published.

13.
J Chromatogr A ; 1282: 190-3, 2013 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-23415447

RESUMO

High-purity carbon monoxide (CO) gas as a certified reference material (CRM) was analyzed using a micro gas chromatograph (micro-GC) with a micro thermal conductivity detector. The main reason to select the micro-GC was its compact size to provide a safe experimental environment. Thus, both the CO gas cylinder and the micro-GC were placed inside a draft shield with a limited small space. Peaks of several impurities were found in chromatograms of the micro-GC. The main impurities in the CO gas were helium, hydrogen, oxygen, nitrogen and carbon dioxide. It was found that helium was the impurity of the highest concentration. High-accuracy calibration gas mixtures were used to construct calibration lines for the micro-GC. The mixtures were precisely prepared by the gravimetric blending method. Calibration lines had enough linearity and accuracy for quantitative analyses of the impurities. The values of detection limit of the impurities were 0.7-4µmol/mol. The purity of the high-purity CO gas was around 99.996%, which was the value estimated from the sum of the concentrations of the impurities.


Assuntos
Monóxido de Carbono/análise , Cromatografia Gasosa/métodos , Gases/análise , Calibragem , Monóxido de Carbono/química , Contaminação de Medicamentos , Gases/química , Limite de Detecção
14.
Chem Asian J ; 6(9): 2491-9, 2011 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-21661115

RESUMO

H64D myoglobin mutant was reconstituted with two different types of synthetic hemes that have aromatic rings and a carboxylate-based cluster attached to the terminus of one or both of the heme-propionate moieties, thereby forming a "single-winged cofactor" and "double-winged cofactor," respectively. The reconstituted mutant myoglobins have smaller K(m) values with respect to 2-methoxyphenol oxidation activity relative to the parent mutant with native heme. This suggests that the attached moiety functions as a substrate-binding domain. However, the k(cat) value of the mutant myoglobin with the double-winged cofactor is much lower than that of the mutant with the native heme. In contrast, the mutant reconstituted with the single-winged cofactor has a larger k(cat) value, thereby resulting in overall catalytic activity that is essentially equivalent to that of the native horseradish peroxidase. Enhanced peroxygenase activity was also observed for the mutant myoglobin with the single-winged cofactor, thus indicating that introduction of an artificial substrate-binding domain at only one of the heme propionates in the H64D mutant is the optimal engineering strategy for improving the peroxidase activity of myoglobin.


Assuntos
Coenzimas/química , Peroxidase do Rábano Silvestre/metabolismo , Mioglobina/genética , Mioglobina/metabolismo , Substituição de Aminoácidos , Biocatálise , Guaiacol/química , Heme/química , Oxirredução , Ligação Proteica
16.
Int J Hematol ; 89(2): 244-248, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19132457

RESUMO

Acute eosinophilic pneumonia (AEP) is an acute febrile illness with respiratory impairment, diffuse pulmonary infiltrates, and eosinophilia in bronchoalveolar lavage (BAL) fluid. We report an adult male who developed severe cough and dyspnea with slight fever on day 78 after allogeneic hematopoietic stem transplantation. The symptoms coexisted with skin and gut GVHD. The imaging test demonstrated interstitial infiltrates and BAL analysis revealed marked increase of eosinophils and no sign of infection. We made a diagnosis of AEP and steroid was started. AEP remitted with other GVHD symptoms but exacerbated partially when steroid was decreased. This case suggests a potential link between AEP and GVHD.


Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Eosinofilia Pulmonar/etiologia , Doença Enxerto-Hospedeiro/patologia , Humanos , Leucemia/complicações , Leucemia/terapia , Masculino , Pessoa de Meia-Idade , Pneumonia , Transplante Homólogo
18.
J Med Virol ; 80(10): 1769-75, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18712833

RESUMO

Addition of in vivo alemtuzumab to the conditioning regimen enabled 2- or 3-locus-mismatched hematopoietic stem cell transplantation with an acceptable incidence of graft-versus-host-disease. However, the procedure was associated with a high incidence of cytomegalovirus (CMV) reactivation. Although preemptive therapy with ganciclovir prevented successfully severe CMV diseases and CMV-related mortality, a patient developed persistent positive CMV antigenemia for more than 1 year after transplantation and CMV disease, despite the use of ganciclovir and foscarnet. The in vitro susceptibility assay showed that the clinical isolate was resistant to foscarnet, moderately resistant to ganciclovir, but sensitive to cidofovir. Therefore, cidofovir was administered. CMV antigenemia became negative within 2 weeks and never developed again. Nucleotide sequence of the UL54 and UL97 of the clinical isolate showed 4 amino acid substitutions (V11L, Q578H, S655L, and G874R) in UL54 and 2 mutations (A140V and A594V) in UL97 compared with the Towne and AD169 strains. Ganciclovir resistance was suspected to be caused by both A594V of UL97 and Q578H of UL54, whereas foscarnet resistance was due mainly to Q578H of UL54. In conclusion, the in vitro susceptibility assay as well as nucleotide sequence of clinical isolate is important to choose appropriate antiviral agents for patients who have persistent CMV reactivation after stem cell transplantation.


Assuntos
Anemia Refratária com Excesso de Blastos/cirurgia , Anticorpos Monoclonais/efeitos adversos , Anticorpos Antineoplásicos/efeitos adversos , Retinite por Citomegalovirus/etiologia , Retinite por Citomegalovirus/virologia , Citomegalovirus/genética , Farmacorresistência Viral/genética , Transplante de Células-Tronco Hematopoéticas , Imunossupressores/efeitos adversos , Alemtuzumab , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais Humanizados , Anticorpos Antineoplásicos/administração & dosagem , Antivirais/farmacologia , Antivirais/uso terapêutico , Sequência de Bases , Cidofovir , Citomegalovirus/efeitos dos fármacos , Citomegalovirus/isolamento & purificação , Retinite por Citomegalovirus/tratamento farmacológico , Retinite por Citomegalovirus/prevenção & controle , Citosina/análogos & derivados , Citosina/farmacologia , Citosina/uso terapêutico , DNA Polimerase Dirigida por DNA/genética , Foscarnet/farmacologia , Foscarnet/uso terapêutico , Ganciclovir/farmacologia , Ganciclovir/uso terapêutico , Humanos , Imunossupressores/administração & dosagem , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Dados de Sequência Molecular , Organofosfonatos/farmacologia , Organofosfonatos/uso terapêutico , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Mutação Puntual/efeitos dos fármacos , Proteínas Virais/genética , Ativação Viral/efeitos dos fármacos
19.
Br J Haematol ; 143(1): 60-70, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18710386

RESUMO

Autotaxin (ATX) is a tumour cell motility-stimulating factor originally isolated from melanoma cell supernatants. ATX is identical to lysophospholipase D, which produces a bioactive lipid mediator, lysophosphatidic acid (LPA), from lysophosphatidylcholine. ATX is overexpressed in various malignancies, including Hodgkin lymphoma, and ATX may stimulate tumour progression via LPA production. The present study measured the serum ATX antigen levels in patients with haematological malignancies using a recently developed automated enzyme immunoassay. The serum ATX antigen levels in patients with B-cell neoplasms, especially follicular lymphoma (FL), were higher than those in healthy subjects. Serum ATX antigen levels in FL patients were associated with tumour burden and changed in parallel with the patients' clinical courses. The serum ATX antigen levels were little affected by inflammation, unlike the soluble interleukin-2 receptor and beta2-microglobulin levels. As expected, the plasma LPA levels in FL patients were correlated with the serum ATX antigen levels. Given that leukaemic tumour cells from FL patients expressed ATX, the shedding of ATX from lymphoma cells probably leads to the elevation of serum ATX antigen levels. Our results suggest that the serum ATX antigen level may be a promising and novel marker for FL.


Assuntos
Biomarcadores Tumorais/sangue , Linfoma Folicular/sangue , Complexos Multienzimáticos/sangue , Fosfodiesterase I/sangue , Pirofosfatases/sangue , Adulto , Idoso , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Citometria de Fluxo/métodos , Humanos , Linfócitos/química , Lisofosfolipase/sangue , Masculino , Pessoa de Meia-Idade , Complexos Multienzimáticos/análise , Fosfodiesterase I/análise , Diester Fosfórico Hidrolases , Pirofosfatases/análise , Estatísticas não Paramétricas
20.
Anal Chim Acta ; 619(1): 26-9, 2008 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-18539169

RESUMO

The metrological effectiveness of an analytical method using the post-column reaction GC/FID system was evaluated. The SI-traceable certified reference material (CRM), the eight ester phthalates mixture standard solution, was used as a sample. We assigned specific value to n-eicosane and it was used as an internal standard. A known quantity of n-eicosane was added to the CRM, and the mixture was measured with the post-column reaction GC/FID system. Six phthalate esters were chromatographically separated and determined. The assigned values by our system are in good agreement with the certified values of the CRM, and the combined uncertainties of the measurements by the present system were better than those of the CRM. Our method is classified as a primary ratio method and the specific values of many organic compounds can be assigned very precisely by using a small number of reference materials. Also, the method can make it possible to avoid the purity determination of raw materials and directly to assign their specific values after the preparation of the standard mixture. Conclusively, this post-column reaction GC/FID system is very effective for the chemical metrology.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...