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1.
Homeopathy ; 110(1): 42-51, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32615611

RESUMO

BACKGROUND: Nuclear magnetic resonance (NMR) proton relaxation is sensitive to the dynamics of the water molecule, H2O, through the interaction of the spin of the proton (1H) with external magnetic and electromagnetic fields. NMR relaxation times describe how quickly the spin of 1H, forced in a direction by an external electromagnetic field, returns to a normal resting position. As a result, such measurements allow us potentially to describe higher structuring of water in homeopathic medicines. OBJECTIVE: The purpose of the present study was to verify whether specific NMR relaxation times could be measured in full lines of cH dynamizations of a metal (copper) and of a plant substance (Gelsemium sempervirens), compared with a solvent control, a potentized lactose control and a control prepared by simple dilution, in three production lines. It is aimed at verification of a previous publication (2017) on two new manufacturing lines of the same starting material and controls. MATERIALS AND METHODS: To monitor dilution and potentization processes, measurements of 1H spin-lattice T1 and spin-spin T2 relaxation times were used. T1 and T2 relaxation times were measured at 25°C with a spin analyser working at a frequency of 20 MHz. To account for its possible role as a confounding factor, free oxygen was also measured in all samples, using a MicroOptode meter. RESULTS: When the values of the three production lines were pooled, a statistically significant discrimination of NMR relaxation times between the medicines and their controls was confirmed. We found for copper cH and Gelsemium sempervirens cH a highly significant influence of the starting material (p = 0.008), a highly significant influence of level of dilution (p < 0.001), and a significant influence of the O2 concentration (p = 0.04). CONCLUSIONS: We have evidence of an obvious retention of a specific magnetic resonance signal when a substance (lactose, copper, Gelsemium) is diluted/potentized in pure water. This means that homeopathic solutions cannot be considered to be pure water. O2 is a covariant and not an explanatory variable: this factor itself is too weak to explain the NMR signal specificities in potentized samples. Homeopathic dilutions may thus have a specific material configuration governed not only by the potentized substance but also by the chemical nature of the containers, the chemical nature of dissolved gases and even by the electromagnetic environment. This sensitivity of homeopathically prepared medicines to electromagnetic fields may be amplified by the processes routinely applied during their preparation; because it occurs only when a dynamization has been performed, we may call this phenomenon "dynamic pharmacy".


Assuntos
Cobre/fisiologia , Gelsemium/fisiologia , Espectroscopia de Ressonância Magnética/métodos , Humanos , Materia Medica , Água/química
2.
Clin Lab ; 58(7-8): 725-36, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22997973

RESUMO

BACKGROUND: Free T4 (FT4) and free T3 (FT3) immunoassays exhibit wide inter-assay variations. We therefore established control values with three different immunoassays and compared their clinical performances in thyroidal diseases and severe/acute non-thyroidal illnesses (NTI). METHODS: The UniCel DxI 800, Architect i2000, and Elecsys 2010 assays were used. FT4 and FT3 reference ranges were established in 68 controls, without conditions interfering with thyroid function, with normal TSH (0.35-3.02 mU/L) and negative anti-thyroid peroxidase antibodies. Free hormones were determined in 60 patients with thyroid diseases (TSH: < 0.001-31.5 mU/L) and 45 NTI patients (TSH: 0.10-4.72 mU/L). Control values were normalized as Z-scores; patients' results were expressed as Z-scores, using the control values of each assay. Pairwise comparisons of the Z-scores were performed by Deming's regression. Classification of patients' results based on 95% control values were evaluated by kappa agreement statistics. RESULTS: Control values for FT4 (pmol/L; geometrical means; 95% confidence intervals) were: 11.1 (7.6-16.1), 12.3 (9.1-16.6), 15.6 (11.4-21.4) and for FT3: 4.8 (4.0-5.7), 4.0 (3.0-5.3), 4.3 (3.1-5.09), with DxI 800, Architect, and Elecsys, respectively. Pairs of control Z-scores correlated significantly, but with different strengths (FT4: r = 0.915, 0.740, 0.770; FT3: r = 0.615; 0.589; 0.790, for DxI 800 vs. Elecsys; DxI 800 vs. Architect; Elecsys vs. Architect; p < 0.001); slopes and intercepts of paired controls were 1.00 and zero. In thyroid diseases, slopes of FT4 Z-scores among assays differed slightly from 1.00 (1.11, 0.88, 0.87 for DxI versus Elecsys, DxI 800 versus Architect, Elecsys versus Architect, respectively; p < 0.05); slopes of FT3 Z-scores were consistent with unity, except for DxI 800 versus Elecsys (0.88; p < 0.05). In NTI patients, regression slopes were consistent with unity (p < 0.05). The agreement statistics showed moderate to very good inter-assay concordances for thyroid and NTI patients' results. CONCLUSIONS: FT4 and FT3 assays show moderate to very good agreement, in patients with thyroid diseases or NTI when compared pairwise to their control values. Slight quantitative differences between some pairs of assays are observed in thyroid diseases, after normalization as Z-scores.


Assuntos
Imunoensaio/métodos , Doenças da Glândula Tireoide/sangue , Tiroxina/sangue , Tri-Iodotironina/sangue , Estudos de Casos e Controles , Humanos
3.
Peptides ; 37(2): 258-62, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22902597

RESUMO

Fibroblast growth factor 23 (FGF23) is a bone-derived hormone involved in the regulation of phosphate and calcium metabolism. We have evaluated the levels of C-terminal FGF23 (Ct-FGF23) in 73 patients presenting heart failure with reduced ejection fraction (HF-REF) and assess their potential predictive value for long-term survival through a 6 years follow-up. Ct-FGF23 levels were markedly increased in HF-REF. In univariate proportional hazard model, survival was related to glomerular filtration rate (eGFR), intact parathyroid hormone (PTH), B-type natriuretic peptides (BNP) and Ct-FGF23. In a multivariate analysis including age, EF, PTH, BNP, Ct-FGF23, calcium, phosphorus and eGFR levels, Ct-FGF23 is the strongest predictor of long term CV death.


Assuntos
Fatores de Crescimento de Fibroblastos/sangue , Fatores de Crescimento de Fibroblastos/química , Insuficiência Cardíaca Sistólica/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Fator de Crescimento de Fibroblastos 23 , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Taxa de Sobrevida
4.
Scand J Clin Lab Invest ; 72(5): 387-94, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22794032

RESUMO

Severe adult growth hormone deficiency (AGHD) is associated with increased cardiovascular risk. We have therefore investigated levels of amino terminal pro-brain natriuretic peptide (Nt-proBNP), a well established biomarker for cardiac failure, in adult GHD patients before and after GH replacement therapy, and potential parallel variations in cardiac function. Nt-proBNP concentrations were determined at baseline and after GH treatment in two studies including 28 and 12 patients with severe AGHD, respectively. In the second study, a maximal exercise test and a doppler echocardiography were performed to assess cardiac functional parameters. At baseline, Nt-proBNP levels were higher in AGHD patients than in controls (median: 7.8 vs. 3.7 pmol/L; p < 0.01 in study 1; 8.4 vs. 4.1 pmol/L; p < 0.01 in study 2). Following GH treatment, Nt-proBNP levels decreased significantly in both studies. None of the AGHD patients had signs of cardiac dysfunction at baseline and no significant effect of GH replacement therapy was observed on cardiac functional parameters, independent of changes in Nt-proBNP. In conclusion, GH treatment markedly reduces Nt-proBNP concentrations in adult GHD patients without obvious parallel changes in cardiac functional parameters. These results suggest that Nt-proBNP may appear as a biomarker of GH status and GH treatment efficiency.


Assuntos
Terapia de Reposição Hormonal , Hormônio do Crescimento Humano/uso terapêutico , Hipopituitarismo/tratamento farmacológico , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Adulto , Análise de Variância , Fator Natriurético Atrial/sangue , Pressão Sanguínea , Estudos de Casos e Controles , Creatinina/sangue , Teste de Esforço , Feminino , Testes de Função Cardíaca , Frequência Cardíaca , Humanos , Hipopituitarismo/sangue , Hipopituitarismo/diagnóstico por imagem , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Pessoa de Meia-Idade , Ultrassonografia
5.
Clin Biochem ; 43(6): 589-98, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20036226

RESUMO

OBJECTIVES: The study aims to develop empirical models able to predict the pharmacokinetics (PK) of four beta-lactams using the amikacin (AMK) therapeutic drug monitoring (TDM), in order to optimize their dosage regimens. DESIGN AND METHODS: 69 critically ill septic patients were included. All received a first dose of AMK combined with piperacillin/tazobactam, ceftazidime, cefepime or meropenem. A multivariate analysis was performed to predict the beta-lactam PK using AMK PK parameters estimated from TDM and using pathophysiological variables. RESULTS: An optimal prediction model was identified for each PK parameter of each beta-lactam. The best predictor of each model was one of the AMK PK parameters estimated from TDM. Other variables included colloid solution, renal and hepatic biomarkers, age and body weight. CONCLUSION: PK of the four beta-lactams could be easily and rapidly predicted in critically ill septic patients using the AMK TDM. These predictions could improve the beta-lactam dosages in clinical practice.


Assuntos
Amicacina/administração & dosagem , Estado Terminal/terapia , Cálculos da Dosagem de Medicamento , Monitoramento de Medicamentos , Modelos Teóricos , Sepse/tratamento farmacológico , beta-Lactamas/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Amicacina/farmacocinética , Antibacterianos/administração & dosagem , Antibacterianos/farmacocinética , Calibragem , Monitoramento de Medicamentos/métodos , Sinergismo Farmacológico , Quimioterapia Combinada , Pesquisa Empírica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sepse/sangue , Adulto Jovem
6.
Clin Pharmacokinet ; 48(11): 745-58, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19817503

RESUMO

BACKGROUND AND OBJECTIVE: Mycophenolate mofetil is a prodrug of mycophenolic acid (MPA), an immunosuppressive agent used in combination with corticosteroids and calcineurin inhibitors or sirolimus for the prevention of acute rejection after solid organ transplantation. Although MPA has a rather narrow therapeutic window and its pharmacokinetics show considerable intra- and interindividual variability, dosing guidelines recommend a standard dosage regimen of 0.5-1.0 g twice daily in adult renal, liver and cardiac transplant recipients. The main objective of the present study was to develop a method to predict the MPA area under the plasma concentration-time curve during one 12-hour dosing interval (AUC(12)) by using multiple linear regression models and maximum a posteriori (MAP) Bayesian estimation methods in patients co-medicated with ciclosporin or sirolimus, aiming to individualize the dosage regimen of mycophenolate mofetil. PATIENTS AND METHODS: Pharmacokinetic profiles of MPA and mycophenolic acid glucuronide (MPAG), the main metabolite of MPA, were obtained from 40 stable adult renal allograft recipients on three different occasions: the day before switching from ciclosporin to sirolimus co-medication (+/-7.4 months post-transplantation; period I) and at 60 days and 270 days after the switch (periods II and III). Blood samples for determination of MPA and MPAG concentrations in plasma were taken at 0 hours (pre-dose) and at 0.33, 0.66, 1.25, 2, 4, 6, 8 and 12 hours after oral intake of mycophenolate mofetil. The MPA AUC(12) was calculated by the trapezoidal method (the observed AUC(12)). Patients were randomly divided into (i) a model-building test group (n = 27); and (ii) a model-validation group (n = 13). Multiple linear regression models were developed, based on three sampling times after drug administration. Subsequently, a population pharmacokinetic model describing MPA and MPAG plasma concentrations was developed using nonlinear mixed-effects modelling and a Bayesian estimator based on the population pharmacokinetic model was used to predict the MPA AUC(12) based on three sampling times taken within 2 hours following dosing. RESULTS: Fifty-two percent of the observed AUC(12) values (three periods) in the 40 patients receiving a fixed dose of mycophenolate mofetil 750 mg twice daily were outside the recommended therapeutic range (30-60 microg x h/mL). The failure of the standard dose to yield an AUC(12) value within the therapeutic range was especially pronounced during the first study period. Of the multiple linear regression models that were tested, the equation based on the 0-hour (pre-dose), 0.66- and 2-hour sampling times showed the best predictive performance in the validation group: r2 = 0.79, relative root mean square error (rRMSE) = 14% and mean relative prediction error (MRPE) = 0.9%. The pharmacokinetics of MPA and MPAG were best described by a two-compartment model with first-order absorption and elimination for MPA, plus a compartment for MPAG, also including a gastrointestinal compartment and enterohepatic cycling in the case of sirolimus co-medication. The ratio of aminotransferase liver enzymes (AST and ALT) and the glomerular filtration rate significantly influenced MPA glucuronidation and MPAG renal excretion, respectively. Bayesian estimation of the MPA AUC(12) based on 0-, 1.25- and 2-hour sampling times predicted the observed AUC(12) values of the patients in the validation group, with the following predictive performance characteristics: r2 = 0.93, rRMSE = 12.4% and MRPE = -0.4%. CONCLUSION: Use of the developed multiple linear regression equation and Bayesian estimator, both based on only three blood sampling times within 2 hours following a dose of mycophenolate mofetil, allowed an accurate prediction of a patient's MPA AUC(12) for therapeutic drug monitoring and dose individualization. These findings should be validated in a randomized prospective trial.


Assuntos
Ciclosporina/uso terapêutico , Monitoramento de Medicamentos/métodos , Imunossupressores/farmacocinética , Transplante de Rim , Ácido Micofenólico/análogos & derivados , Sirolimo/uso terapêutico , Adulto , Idoso , Área Sob a Curva , Teorema de Bayes , Disponibilidade Biológica , Cálculos da Dosagem de Medicamento , Quimioterapia Combinada , Feminino , Taxa de Filtração Glomerular , Glucuronídeos/sangue , Humanos , Imunossupressores/administração & dosagem , Imunossupressores/uso terapêutico , Modelos Lineares , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Ácido Micofenólico/administração & dosagem , Ácido Micofenólico/sangue , Ácido Micofenólico/farmacocinética , Ácido Micofenólico/uso terapêutico , Dinâmica não Linear , Valor Preditivo dos Testes , Pró-Fármacos , Adulto Jovem
7.
Clin Biochem ; 41(10-11): 764-72, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18424267

RESUMO

OBJECTIVES: Abnormal airway ion transport is a feature of cystic fibrosis. The aim of this study was to investigate whether distinct components of ion transport are associated with the clinical expression and severity of the disease. DESIGN AND METHODS: Univariate and multivariate analyses were used to study interaction effects between nasal potential difference parameters and clinical status, recorded at stable conditions, in 75 F508del homozygous young adults. RESULTS: All patients demonstrated increased sodium and reduced chloride conductances. Less sodium transport abnormalities were related to better respiratory function and nutrition. Presentation with digestive symptoms at diagnosis was associated with lower chloride conductance. With an accuracy of 85% good nutritional status was linked to more preserved lung function, increasing age and more preserved chloride conductance. CONCLUSIONS: Ion transport abnormalities have distinct clinical outcomes. Sodium conductance relates to respiratory function and nutrition; chloride conductance to nutrition and presentation with digestive symptoms at diagnosis.


Assuntos
Fibrose Cística/fisiopatologia , Transporte de Íons/fisiologia , Adolescente , Adulto , Fatores Etários , Transporte Biológico , Criança , Pré-Escolar , Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística/fisiologia , Doenças em Gêmeos , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Mucosa Nasal/fisiopatologia , Perfusão , Potenciometria , Índice de Gravidade de Doença , Irmãos , Sódio/metabolismo
8.
Biotechniques ; 38(2): 287-93, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15727135

RESUMO

Quantification of mRNA expression levels using real-time reverse transcription PCR (RT-PCR) is increasingly used to validate results of DNA microarrays or GeneChips. It requires an improved method that is more robust and more suitable for high-throughput measurements. In this report, we compare a user non-influent, second derivative method with that of a user influent, fit point method that is widely used in the literature. We also describe the advantage of using a double correction: one correction using the expression levels of a housekeeping gene of an experiment as an internal standard and a second using reference expression levels of the same housekeeping gene in the tissue or cells. The first correction permits one to decrease errors due to sample preparation and handling, while the second correction permits one to avoid the variation of the results with the variability of housekeeping in each tissue, especially in experiments using various treatments. The data indicate that the real-time PCR method is highly efficient with an efficiency coefficient close to the theoretical value of two. The results also show that the second derivative method is more accurate than the fit point method in quantifying low gene expression levels. Using triplicate experiments, we show that measurement variations using our method are low with a mean of variation coefficients of <1%.


Assuntos
Algoritmos , Perfilação da Expressão Gênica/métodos , Análise Numérica Assistida por Computador , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Sistemas Computacionais , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
9.
Clin Chem Lab Med ; 41(1): 61-7, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12636051

RESUMO

Nasal potential difference (NPD) measurements have been proposed to assess defective ion transport in cystic fibrosis (CF). Implementing it routinely is, however, difficult. Therefore, a modified method based on nasal instillation in supine position at reduced flow rate was tested to evaluate its ability to discriminate CF from non-CF subjects. Classical and modified methods were compared in nine healthy subjects and there were no statistical differences. Following the new method, 97 tests were performed on 74 subjects divided in three cohorts: 21 CF patients and two control groups consisting of 19 patients with other pulmonary diseases and 34 healthy subjects. Twenty five children were enrolled in this study. Maximal NPD in CF patients (-44.9 +/- 2.5 mV) was significantly different from that obtained in control groups (-18.1 +/- 1.6 and -17.2 +/- 1.1 mV). Depolarization after amiloride also discriminated CF patients (25.9 +/- 1.4 mV) from control groups (10.5 +/- 0.9 and 8.1 +/- 0.7 mV). Marked repolarization following isoprenaline plus amiloride in low chloride solution was seen in control groups (-15.7 +/- 1.1 and -15.3 +/- 1.1 mV). We conclude that the modified method represents a simplified and equally effective approach to discriminate CF patients from non-CF subjects. Moreover, this method presents practical advantages for the patients related to hygiene and convenience, favoring its application in small children.


Assuntos
Cloretos/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/fisiologia , Fibrose Cística/diagnóstico , Mucosa Nasal/fisiologia , Sódio/metabolismo , Adolescente , Adulto , Amilorida , Transporte Biológico Ativo/fisiologia , Estudos de Casos e Controles , Criança , Estudos de Coortes , Fibrose Cística/fisiopatologia , Potenciais Evocados , Feminino , Humanos , Transporte de Íons/fisiologia , Isoproterenol , Masculino , Pessoa de Meia-Idade , Suor/metabolismo
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