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1.
Adv Sci (Weinh) ; : e2401625, 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38582518

RESUMO

Thin-films patterned with complex motifs are of fundamental interest because of their advanced optical, mechanical and electronic properties, but fabrication of these materials remains challenging. Self-organization strategies, such as immersion controlled reaction-diffusion patterning, have shown great potential for production of patterned thin-films. However, the autonomous nature of such processes limits controllable pattern customizability and complexity. Here, it is demonstrated that photography inspired manipulation processes can overcome this limitation to create highly-complex tapestries of micropatterned films (MPF's). Inspired by classical photographic processes, MPF's are developed, bleached, exposed, fixed, and contoured into user-defined shapes and photographic toning reactions are used to convert the chemical composition MPF's, while preserving the original stripe patterns. By applying principles of composite photography, highly complex tapestries composed of multiple MPF layers are designed, where each layer can be individually manipulated into a specific shape and composition. By overcoming fundamental limitations, this synergistic approach broadens the design possibilities of reaction-diffusion processes, furthering the potential of self-organization strategies for the development of complex materials.

2.
Clin Biochem ; 48(9): 617-21, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25818475

RESUMO

BACKGROUND: Lithium remains a mainstay in the management of mood disorders. As with many psychotropic drugs, lithium treatment requires continuous observation for adverse effects and strict monitoring of serum concentrations. The present study aimed to assess the appropriateness of lithium assays used by Belgian laboratories, and to evaluate acceptability of their clinical interpretations. METHODS: Nine in-house serum samples spiked with predetermined concentrations of lithium were distributed to 114 participants in the Belgian external quality assessment scheme. Laboratories were requested to report the assay technique, lithium measurements and interpretations with regard to measured concentrations. Inter/intramethod imprecision and bias were reported and acceptability of clinical interpretations was assessed. The intramethod variability was evaluated by selecting methods used by 6 laboratories or more. Flame photometry (IL 943) was considered as the reference method. RESULTS: Laboratories returned assay results using colorimetry (69.3%), ion selective electrode (15.8%), flame photometry (8.8%), atomic absorption spectroscopy (5.2%) or mass spectrometry (0.9%). Lithium concentrations were systematically higher when measured with the Vitros assay (median bias: 4.0%), and were associated with consecutive biased interpretations. In contrast, the Thermo Scientific Infinity assay showed a significant negative bias (median bias: 9.4%). 36.0% of laboratories reported numerical values below their manufacturer cut-off for the blank sample; 16.6% of these laboratories detected residual lithium concentrations. CONCLUSIONS: The present study revealed assay-related differences in lithium measurements and their interpretations. Overall, there appeared to be a need to continue EQA of therapeutic drug monitoring for lithium in Belgium.


Assuntos
Antipsicóticos/sangue , Monitoramento de Medicamentos/normas , Lítio/sangue , Bélgica , Técnicas de Laboratório Clínico , Colorimetria/normas , Humanos , Laboratórios , Espectrometria de Massas/normas , Fotometria/normas , Reprodutibilidade dos Testes
3.
Acta Clin Belg ; 69(2): 83-6, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24724745

RESUMO

Autoantibodies to nuclear antigens, i.e. antinuclear antibodies (ANA), antibodies to double-stranded DNA (dsDNA) and extractable nuclear antigens (ENA), are useful as diagnostic markers for a variety of autoimmune diseases. In March 2010, the Belgian national External Quality Assessment Scheme sent a questionnaire on ANA, anti-dsDNA and anti-ENA antibody testing designed by the Dutch EASI (European Autoimmunity Standardization Initiative) team, to all clinical laboratories performing ANA testing. Virtually all laboratories completed the questionnaire (97·7%, 127/130). This paper discusses the results of this questionnaire and provides valuable information on the state-of-the-art of ANA, anti-dsDNA and anti-ENA antibody testing as practiced in the Belgian laboratories. In addition, this work presents practical recommendations developed by the members of the advisory board of the scheme as a result of the outcome of this study.


Assuntos
Anticorpos Antinucleares/sangue , Técnica Indireta de Fluorescência para Anticorpo/normas , Laboratórios/normas , Bélgica , Linhagem Celular , DNA/imunologia , Humanos , Laboratórios/estatística & dados numéricos , Guias de Prática Clínica como Assunto , Valores de Referência , Inquéritos e Questionários
4.
Eur J Clin Nutr ; 62(3): 401-10, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17426748

RESUMO

OBJECTIVE: The two- to fourfold higher risk of cardiovascular disease in diabetes mellitus is more strongly predicted by the postprandial than by the fasting blood glucose and lipids. We aimed to investigate the impact of postprandial changes in serum lipoprotein fractions on lipid peroxidation in type I diabetes mellitus (T1DM). DESIGN: This was a prospective observational study. SETTING: The study was performed at Antwerp University Hospital, Belgium. SUBJECTS: Twenty-three well-controlled T1DM patients were included. INTERVENTION: Patients received a standard breakfast and lunch (>50% energy as fat). Blood was sampled at fasting (F), after the post-breakfast hyperglycemic peak (BP), just before lunch (B), after the post-lunch hyperglycemic peak (LP), after the post-lunch dale (LD) and 5 h after lunch (L) for the measurement of serum lipids, lipoprotein subfraction composition, alpha-tocopherol and lipid peroxidation in vivo and in vitro. RESULTS: Serum triacylglycerols (Tgs) increased (from 1.03+/-0.40 at F to 1.60+/-0.87 mmol/l at LP, P=0.001), but cholesterol decreased by 12% in parallel with alpha-tocopherol (from 4.43+/-0.76 at F to 4.12+/-0.82 micromol/mmol total lipid at B, P=0.006). Although plasma malondialdehyde increased from 1.02+/-0.36 at F to 1.14+/-0.40 micromol/L at LP, P=0.03, copper-induced in vitro peroxidation decreased in the low-density lipoprotein and high-density lipoprotein fractions. CONCLUSIONS: In well-controlled T1DM patients moderate postprandial increases in serum Tgs are accompanied by a relative deficiency in alpha-tocopherol. Lipid peroxidation in vivo increases but cannot be ascribed to changes in the susceptibility of lipoproteins to copper-induced in vitro peroxidation.


Assuntos
Diabetes Mellitus Tipo 1/metabolismo , Peroxidação de Lipídeos , Lipídeos/sangue , Adulto , Área Sob a Curva , Colesterol/sangue , Diabetes Mellitus Tipo 1/sangue , Jejum/sangue , Feminino , Humanos , Masculino , Malondialdeído/sangue , Pessoa de Meia-Idade , Estresse Oxidativo , Período Pós-Prandial , Estudos Prospectivos , Triglicerídeos/sangue , alfa-Tocoferol/sangue
5.
Scand J Clin Lab Invest ; 67(8): 859-67, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17852824

RESUMO

OBJECTIVE: To evaluate the performing technical and clinical characteristics of an automated system for routine measurement of anticyclic citrullinated peptide antibodies (aCCP), a new marker for rheumatoid arthritis (RA). MATERIAL AND METHODS: Reproducibility, repeatability and linearity of aCCP, as measured by an automated fluorescent enzyme immunoassay (FEIA/Phadia), were evaluated and compared with the performance of a manual ELISA technique (Axis Shield Diagnostics). Clinical verification of both methods included estimation of sensitivity in RA patients (n = 42) and specificity in well-characterized non-RA autoimmune disease controls (n = 49) and healthy subjects (n = 39). RESULTS: Precision studies showed a coefficient of variation between 4.9 % and 10 % for the FEIA technique and between 6.35% and 19% for the ELISA technique. Both systems showed good linear response. Sensitivity of aCCP for RA was 74% for FEIA and 79% for ELISA. Specificity was 100% for both methods, as calculated for healthy subjects. For non-RA-diseased controls, specificities of 98% and 94% were obtained for FEIA and ELISA, respectively. Both methods were concordant in 97% of cases. Increasing the cut-off for the ELISA system from >5 U/mL to >11 U/mL resulted in lower sensitivity (71.4%) but higher specificity (98.0%), i.e. improved discriminating power between RA and non-RA and 100% agreement between both methods. CONCLUSION: Automated FEIA measurement of aCCP in the routine clinical laboratory improves imprecision compared to the manual ELISA. Our preliminary results suggest that an increase in cut-off for the ELISA can improve specificity to RA from 94% to 98 %.


Assuntos
Anticorpos/análise , Técnicas Imunoenzimáticas/métodos , Técnicas Imunoenzimáticas/normas , Laboratórios , Peptídeos Cíclicos/imunologia , Adulto , Idoso , Automação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Reprodutibilidade dos Testes , Fator Reumatoide
6.
Clin Exp Immunol ; 126(2): 236-41, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11703366

RESUMO

The autoimmune attack in type 1 diabetes is not only targeted to beta cells. We assessed the prevalence of thyroid peroxidase (aTPO), parietal cell (PCA), antiadrenal (AAA) and endomysial antibodies (EmA-IgA), and of overt autoimmune disease in type 1 diabetes, in relation to gender, age, duration of disease, age at onset, beta-cell antibody status (ICA, GADA, IA2A) and HLA-DQ type. Sera from 399 type 1 diabetic patients (M/F: 188/211; mean age: 26 +/- 16 years; duration: 9 +/- 8 years) were tested for ICA, PCA, AAA and EmA-IgA by indirect immunofluorescence, and for IA2A (tyrosine phosphatase antibodies), GADA (glutamic acid decarboxylase-65 antibodies) and aTPO by radiobinding assays. The prevalence rates were: GADA 70%; IA2A, 44%; ICA, 39%; aTPO, 22%; PCA, 18%; EmA-IgA, 2%; and AAA, 1%. aTPO status was determined by female gender (beta = - 1.15, P = 0.002), age (beta = 0.02, P = 0.01) and GADA + (beta = 1.06, P = 0.02), but not by HLA-DQ type or IA2A status. Dysthyroidism (P < 0.0001) was more frequent in aTPO + subjects. PCA status was determined by age (beta = 0.03, P = 0.002). We also observed an association between PCA + and GADA + (OR = 1.9, P = 0.049), aTPO + (OR = 1.9, P = 0.04) and HLA DQA1*0501-DQB1*0301 status (OR = 2.4, P = 0.045). Iron deficiency anaemia (OR = 3.0, P = 0.003) and pernicious anaemia (OR = 40, P < 0.0001) were more frequent in PCA + subjects. EmA-IgA + was linked to HLA DQA1*0501-DQB1*0201 + (OR = 7.5, P = 0.039), and coeliac disease was found in three patients. No patient had Addison's disease. In conclusion, GADA but not IA2A indicate the presence of thyrogastric autoimmunity in type 1 diabetes. aTPO have a female preponderance, PCA are weakly associated with HLA DQA1*0501-DQB1*0301 and EmA-IgA + with HLA DQA1*0501-DQB1*0201.


Assuntos
Autoimunidade , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Antígenos HLA-DQ/genética , Adolescente , Glândulas Suprarrenais/imunologia , Adulto , Autoanticorpos/sangue , Doença Celíaca/imunologia , Criança , Feminino , Ligação Genética , Glutamato Descarboxilase/imunologia , Humanos , Iodeto Peroxidase/imunologia , Masculino , Especificidade de Órgãos , Células Parietais Gástricas/imunologia
7.
J Clin Endocrinol Metab ; 86(9): 4358-63, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11549675

RESUMO

A quarter of type 1 diabetic patients have thyrogastric autoantibodies (thyroid peroxidase and gastric parietal cell antibodies). Clinical, immune, and genetic risk factors help predict antibody status. First degree relatives of these patients may also frequently exhibit these antibodies. We assessed the prevalence of thyrogastric antibodies and dysfunction in first degree relatives in relation to age, gender, human leukocyte antigen-DQ type, beta-cell antibody (islet cell, glutamic acid decarboxylase-65, and tyrosine phosphatase antibodies), and proband thyrogastric antibody status. Sera from 272 type 1 diabetic patients (116 men and 156 women; mean age, 27 +/- 18 yr; duration, 10 +/- 9 y), 397 first degree relatives (192 men and 205 women; parents/siblings/offspring, 48/222/127; age, 22 +/- 10 yr), and 100 healthy controls were tested for islet cell antibodies and gastric parietal cell antibodies by indirect immunofluorescence and for tyrosine phosphatase, glutamic acid decarboxylase-65, and thyroid peroxidase antibodies by radiobinding assays. Glutamic acid decarboxylase-65 antibodies were present in 68% and 5%, islet cell antibodies were present in 36% and 2.5%, tyrosine phosphatase antibodies were present in 45% and 0.5%, thyroid peroxidase antibodies were present in 21% and 4.5%, and gastric parietal cell antibodies were present in 18% and 11% of diabetic patients and relatives, respectively. The presence of thyroid peroxidase antibodies in relatives was determined by age (beta = 0.22; P = 0.0001) and proband thyroid peroxidase antibodies status (beta = -2.6; P = 0.002; odds ratio = 11.1). Gastric parietal cell antibody positivity in relatives was associated with age (beta = 0.04; P = 0.026). Gastric parietal cell antibody-positive compared with gastric parietal cell antibody-negative relatives were more likely to have gastric parietal cell antibody-positive probands (P = 0.01; odds ratio = 3.0). beta-Cell antibody status and human leukocyte antigen-DQ type did not influence thyrogastric antibody status in relatives. (Sub)clinical dysthyroidism was found in 3%, iron deficiency anemia was present in 12% (26% gastric parietal cell antibody-positive and 9% gastric parietal cell antibody-negative subjects; P = 0.009), and pernicious anemia was found in 0.5% (5% gastric parietal cell antibody-positive and 0% gastric parietal cell antibody-negative subjects; P = 0.012) of relatives. They had less thyroid dysfunction (P < 0.0001) and pernicious anemia (P = 0.018) than diabetic probands. In conclusion, thyrogastric antibodies and dysfunction are more prevalent in type 1 diabetic patients than in first degree relatives. The presence of these antibodies in relatives is associated with age and proband antibody status, but not with beta-cell antibodies or human leukocyte antigen-DQ type.


Assuntos
Autoanticorpos/sangue , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Estômago/imunologia , Glândula Tireoide/imunologia , Adulto , Envelhecimento/metabolismo , Feminino , Imunofluorescência , Glutamato Descarboxilase/imunologia , Antígenos HLA-DQ/metabolismo , Humanos , Iodeto Peroxidase/imunologia , Masculino , Células Parietais Gástricas/imunologia , Caracteres Sexuais
8.
Diabetes Care ; 23(9): 1384-8, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10977038

RESUMO

OBJECTIVE: A total of 15-20% of type 1 diabetic patients have parietal cell antibodies (PCAs). PCA+ subjects are at increased risk for iron deficiency anemia and atrophic gastritis. Recently, soluble transferrin receptor (sTfR) levels have proven to be a sensitive indicator for iron deficiency They are, in contrast with ferritin levels, independent of inflammation, liver and hormonal status, and sex. We are the first to evaluate sTfR levels in type 1 diabetes and tested the hypothesis of higher sTfR levels in patients with PCAs and/or autoimmune gastritis. RESEARCH DESIGN AND METHODS: We examined 148 type 1 diabetic patients (85 men and 63 women; 50 were PCA+) and 59 sex- and age-matched control subjects (30 men and 29 women). The main outcome measures were sTfR levels, iron deficiency anemia, and atrophic gastritis. Logistical regression analysis tested risk factors for iron deficiency RESULTS: Iron deficiency was present in 38 subjects. Iron (P<0.0001) and ferritin (P<0.0001) levels but not sTfR levels were lower in women. sTfR levels were similar in diabetic and control subjects but were higher in PCA+ subjects (P = 0.015). In diabetic subjects, iron deficiency anemia was more prevalent in PCA+ than in PCA- patients (odds ratio 3.07, P = 0.013) and was associated with sex (P = 0.0001), age (P = 0.046), and sTfR (P = 0.0008) levels. Atrophic gastritis was present in 15 of 28 PCA+ and in 1 of 11 PCA diabetic subjects (P = 0.014). sTfR levels tended to be higher in patients with atrophic gastritis (P = 0.062). CONCLUSIONS: In type 1 diabetes, sTfR levels can be used to diagnose iron deficiency anemia, which is more prevalent in PCA+ subjects. sTfR levels are higher in PCA+ individuals who are at risk for developing atrophic gastritis.


Assuntos
Anemia Ferropriva/diagnóstico , Anemia Ferropriva/etiologia , Autoanticorpos/sangue , Diabetes Mellitus Tipo 1/imunologia , Células Parietais Gástricas/imunologia , Receptores da Transferrina/sangue , Adulto , Anemia Ferropriva/sangue , Biomarcadores/sangue , Diabetes Mellitus Tipo 1/complicações , Feminino , Gastrite Atrófica/complicações , Gastrite Atrófica/imunologia , Hemoglobinas Glicadas/análise , Humanos , Masculino , Curva ROC , Sensibilidade e Especificidade
11.
Int J Obes ; 13(3): 255-63, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2767878

RESUMO

In order to assess the relationship between obesity and serum lipids, a homogenous group of adult men and premenopausal women is assessed for body mass index, body fat distribution reflected by the waist/hip ratio (WHR), serum lipid parameters and apolipoproteins. Body fat distribution is distinguished in an abdominal and gluteal-femoral type using a cut-off point of 1.00 for the ratio of waist-to-hips girth for men. In women the cut-off value is considered as 0.80 but was also evaluated when considered as 0.85. In the next step tertiles for WHR are created to show a graded relationship between WHR and lipoprotein fraction. The results indicate that WHR is an important determinant for most atherosclerosis-related lipids and apoproteins: in both men (P less than 0.05) and women (P less than 0.005) WHR is significantly correlated with apolipoprotein B. Using multiple regression analysis, in women WHR seems to be the most important dependent variable, where body mass index is not significantly contributing to the explained variance. In men, however, besides WHR age is the most significant variable, although age distribution is similar in men and women. Using tertiles of WHR, we show a clear graded relationship with most lipids and lipoproteins; this gives additionally an argument to confirm that in women WHR = 0.80 is the most accurate cut-off value for abdominal obesity. This study demonstrates that both obese men and women with an abdominal fat mass distribution show a lipid and apoprotein profile that is less favorable than that seen in gluteal-femoral obese subjects insofar as the risk of coronary artery disease is concerned.


Assuntos
Tecido Adiposo/anatomia & histologia , Apolipoproteínas/sangue , Obesidade/sangue , Abdome , Adulto , Nádegas , Doença da Artéria Coronariana/etiologia , Feminino , Humanos , Lipídeos/sangue , Masculino , Obesidade/complicações , Fatores de Risco , Fatores Sexuais
12.
Intensive Care Med ; 14(3): 221-6, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3132492

RESUMO

Propylene glycol, an alcohol frequently used as a solvent in medical preparations, is considered non-toxic. We found that this solvent, used in a commercially available IV nitroglycerin solution, may cause hyperosmolality, hemolysis and lactic acidosis. The influence of kidney function as the main determinant in causing accumulation of this solvent and consequently hyperosmolality is emphasized. A review of the literature dealing with propylene glycol is given. The possible mechanisms of neurological disturbances occurring during IV nitroglycerin therapy are discussed.


Assuntos
Acidose Láctica/induzido quimicamente , Nitroglicerina/uso terapêutico , Propilenoglicóis/efeitos adversos , Solventes/efeitos adversos , Desequilíbrio Hidroeletrolítico/induzido quimicamente , Adulto , Idoso , Doença das Coronárias/tratamento farmacológico , Feminino , Hemólise/efeitos dos fármacos , Humanos , Rim/fisiopatologia , Masculino , Pessoa de Meia-Idade , Nitroglicerina/administração & dosagem , Concentração Osmolar , Propilenoglicol
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