RESUMO
Deoxynivalenol (DON) is a toxic secondary metabolite produced by several species of Fusarium fungi, which can be predominantly found in agricultural crops such as wheat. In livestock, deoxynivalenol-contaminated grain can produce vomiting, feed refusal, weight loss, and diarrhea. This paper reports an electrochemical immunosensor for the detection of residual DON mycotoxin in food samples. The device uses electrochemical nanoprobes (CdSNP-AbDON) and antigen biofunctionalized magnetic µ-particles (DON-BSAMP) to detect the mycotoxin. CdSNP-AbDON are prepared by labelling the DON-specific antibodies with CdS nanoparticles (CdSNPs). Nanoparticle size and CdSNP-AbDON conjugation ratio are characterized using TEM images. The metal ions released by the CdSNP are reduced at the working electrode and read by anodic stripping voltammetry. DON can be detected in PBST buffer with an IC50 of 6.74 ± 0.19 µg L-1. The high detectability of the immunosensor developed allows detection of DON residues in 50-fold diluted wheat extracts. The limit of detection (LOD, IC90) accomplished in wheat is of 342.4 µg kg-1, which is below the maximum residue limit (MRL, 1750 µg kg-1 for unprocessed durum wheat, 750 µg kg-1 for cereals intended for direct human consumption) established by the EU for this mycotoxin. The working range is in the interval between 610 and 6210 µg kg-1. The performance of the immunosensor was compared with the ELISA assay. DON naturally contaminated wheat samples were analyzed with the immunosensor, showing acceptable recoveries. Graphical abstract.
Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Contaminação de Alimentos/análise , Sondas Moleculares , Micotoxinas/análise , Nanopartículas , Tricotecenos/análise , Triticum/química , Limite de Detecção , Microscopia Eletrônica de Transmissão , Reprodutibilidade dos TestesRESUMO
A new electrochemical magnetoimmunosensor (EMIS) has been developed for the screening of residues of sulfonamide antimicrobials in honey samples. The immunosensor is able to detect up to ten different sulfonamide congeners at levels below the action points established in some European countries (25 µg kg(-1)) after a hydrolysis step in which the sulfonamides are released from the corresponding conjugates formed in samples of this type. In spite of the complexity of the sample after the hydrolysis procedure, the EMIS could perform quantitative measurements, directly in these samples, without any additional sample cleanup or extraction step. For example, sulfapyridine, used as a reference, can be detected in hydrolyzed honey with a limit of detection (IC90) of 0.1 ± 0.03 µg kg(-1). Considering that the use of antibiotics for bee treatment is prohibited in the European Union, the immunosensor presented here could be an excellent screening tool. Moreover, several samples can be processed in parallel, which facilitates the analysis, reducing the necessity to use more costly confirmatory methods for just screening. As a proof of concept, a set of blind honey samples (spiked and incurred) were analyzed and the results were compared with those obtained by high-performance liquid chromatography-tandem mass spectrometry, demonstrating the potential of the EMIS as a screening tool.
Assuntos
Resíduos de Drogas/análise , Eletroquímica/instrumentação , Tecnologia de Alimentos/instrumentação , Tecnologia de Alimentos/métodos , Mel/análise , Magnetismo , Sulfonamidas/análise , Animais , Abelhas , Equipamentos e ProvisõesRESUMO
BACKGROUND/AIMS: This study aims to evaluate the pelvic floor (PF) tension response during simulated increased intra-abdominal pressure (IAP) and the vaginal biomechanical properties. METHODS: A 3-dimensional computational finite element model for PF was developed based on magnetic resonance imaging from a nulliparous healthy volunteer. The model was used to simulate an IAP of 90 cm H(2)O and to evaluate the PF stresses in the longitudinal and transversal axes. The vaginal samples were obtained from 15 non-prolapsed female cadavers. A uniaxial tensile test to obtain stiffness and maximum stress of vaginal tissue in the longitudinal and transversal axes was performed. RESULTS: The simulated IAP was associated with a similar PF stress state in the longitudinal and transversal axes. The stiffness and maximum stress in vaginal tissues presented a great variability between subjects. There was no difference in the vaginal tissue elasticity (6.2 ± 1.5 vs. 5.4 ± 1.1 MPa; p = 0.592) and maximum stress (2.3 ± 0.5 vs. 2.6 ± 0.9 MPa; p = 0.692) regarding the measurements in the longitudinal and transversal axes. CONCLUSION: The isotropic biomechanical behavior of vagina is in agreement with the PF stress state response during increased IAP.
Assuntos
Abdome/fisiologia , Pressão , Vagina/fisiologia , Adolescente , Adulto , Fenômenos Biomecânicos/fisiologia , Simulação por Computador , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Modelos Biológicos , Diafragma da Pelve/fisiologia , Estresse Mecânico , Resistência à Tração , Adulto JovemRESUMO
OBJECTIVE: Adenomyosis is the consequence of the myometrial invasion by endometrial glands and stroma. Transvaginal ultrasonography plays a decisive role in the diagnosis and monitoring of this pathology. Our study aims to evaluate the efficacy of LNG-IUS (Levonorgestrel Releasing Intrauterine System) as medical therapy. We analyzed both clinical symptoms and ultrasonographic aspects of menometrorrhagia and dysmenorrhea in patients with adenomyosis and the control group. PATIENTS AND METHODS: A prospective cohort study was carried out on 28 patients suffering from symptomatic adenomyosis treated with LNG-IUS. Adenomyosis was diagnosed through transvaginal ultrasonography by an expert sonographer. A control group of 27 symptomatic patients (menorrhagia and dysmenorrhea) without a transvaginal ultrasonographic diagnosis of adenomyosis was treated in the same way. The two cohorts were compared to the efficacy of LNG-IUS on menorrhagia and dysmenorrhea. Patients are evaluated at the time of LNG-IUS insertion and six months after for: increased uterine volume, globulous uterine morphology, uterine symmetry, alterations in the junctional zone, heterogeneous myometrial texture, presence of myometrial cysts, hyperechogenic lines crossing the myometrium, adenomyomas, menstrual blood loss and dysmenorrhea. RESULTS: After six months, the uterine volume decreased significantly in both cohorts (p=0.005; p=0.005). Furthermore, uterine symmetry, visibility of the junctional zone, heterogeneity of myometrial texture, presence of myometrial cysts, hyperechogenic lines and adenomyomas improved in patients affected by adenomyosis (p>0.001; p>0.001; p>0.001; p=0.014; p=0.025; p=0.014). The blood loss decreased significantly in both the cohorts (p<0.001) and particularly in adenomyotic patients. Pain relief was observed in all the patients (p<0.001). CONCLUSIONS: LNG-IUS can be considered an effective treatment for managing symptoms and improving uterine morphology.
Assuntos
Adenomiose/tratamento farmacológico , Dismenorreia/tratamento farmacológico , Dispositivos Intrauterinos Medicados , Levanogestrel/uso terapêutico , Menorragia/tratamento farmacológico , Adenomiose/diagnóstico por imagem , Adulto , Estudos de Coortes , Dismenorreia/diagnóstico por imagem , Feminino , Humanos , Menorragia/diagnóstico por imagem , Pessoa de Meia-Idade , Estudos Prospectivos , UltrassonografiaRESUMO
BACKGROUND: Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in patients with chronic kidney disease (CKD). Cardiovascular risk assessment in this population is hampered by the failure of traditional risk factors to fully account for the elevated CVD risk, mainly due to the reverse epidemiology effect, and the presence of risk factors specifically related to uremia. Hereby, we present the protocol of a prospective study aimed to assess the predictive value of imaging techniques and biomarkers for CVD in patients with CKD. METHODS: From November 2009, 2.661 asymptomatic adult patients with stages 3-5D CKD will be recruited from nephrology services and dialysis units throughout Spain. Eight hundred forty-three participants without CKD (control group) will be also recruited. During the follow-up, CVD events and mortality will be recorded from all CKD patients. One trained itinerant team will carry out a carotid ultrasound to assess intima-media thickness and presence of plaques. A composite atherosclerosis score will be constructed based on carotid ultrasound data and ankle-brachial index. Presence and type of calcifications will be assessed in carotid, femoral and brachial arteries, and in cardiac valves, by ultrasound. Finally, blood samples will be collected from all participants to study biomarkers. DISCUSSION: The NEFRONA study will allow us to examine the usefulness of imaging techniques and biomarkers to assess atherosclerosis development and their predictive value in a Spanish population with CKD.
Assuntos
Doenças Cardiovasculares/diagnóstico por imagem , Doenças Cardiovasculares/etiologia , Nefropatias/complicações , Adolescente , Adulto , Idoso , Biomarcadores/sangue , Doenças Cardiovasculares/sangue , Doença Crônica , Feminino , Humanos , Nefropatias/sangue , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Valor Preditivo dos Testes , Fatores de Risco , Espanha , Ultrassonografia , Adulto JovemRESUMO
BACKGROUND: Chronic kidney disease is a widely recognized cardiovascular risk factor. Its detection within large populations depends upon the method used to estimate glomerular filtration. The Cockcroft and MDRD equations are widely used, although their accuracy is limited in certain cases. METHODS: The present study analyzes glomerular filtration values in 674 young, healthy subjects using five methods: Cockcroft, Cockcroft corrected for body surface, MDRD-4 Lund-Malmö and Sawyer formulas. Glomerular filtration values obtained with the first three methods were compared using ANOVA. The Spearman coefficient was calculated to estimate the correlation between MDRD-4 and Cockcroft values, and between Cockcroft values and body mass index. RESULTS: There was a slight glomerular filtration rate decrease (< 90 ml/min) seen in 394 subjects using the Cockcroft equation, and in 344 subjects using the MDRD-4 formula. The prevalence of chronic kidney disease (glomerular filtration < 60 ml/min) was seen in 3 subjects using the MDRD-4 equation and 161 subjects using the Cockcroft formula. There was significant discordance, by method, between values obtained, with 40% of the population being classified into different stages (> 90 or < 90 ml/min) depending on the formula used. In 8% of the population there was even greater discordance, because they had strictly normal renal function according to MDRD-4 (> 90 ml/min) but fell into chronic kidney disease Stage 3 (< 60 ml/min) according to the Cockcroft formula. There was poor correlation between glomerular filtration rates obtained using the Cockcroft and MDRD-4 equations, suggesting that the subjects with a glomerular filtration rate decrease detected by the two methods were not the same ones. There was correlation between body mass index and glomerular filtration rates obtained with Cockcroft, Cockcroft corrected for body surface and Sawyer formulas and not with MDRD and Lund-Malmö equations. CONCLUSIONS: There are important discrepancies between the methods used to assess renal function in healthy populations. These limitations must be taken into account when deciding on strategies for diagnosis and control of occult chronic kidney disease in the general population.
Assuntos
Taxa de Filtração Glomerular/fisiologia , Falência Renal Crônica/diagnóstico , Adulto , Feminino , Humanos , Falência Renal Crônica/epidemiologia , Falência Renal Crônica/fisiopatologia , Masculino , Prevalência , Valores de Referência , Espanha/epidemiologiaRESUMO
OBJECTIVE: This is a pilot study to evaluate the effectiveness of the treatment with Vaginal Soft gels technology in the improvement of common signs and symptoms in postmenopausal, postpartum and with recurrent vulvovaginitis patients. These conditions may cause the onset of Vulvovaginal Atrophy (VVA) with effects on sexual activity, self-confidence and daily activities. The main symptoms are itching, irritation and dryness. Many therapies have been evaluated and almost all those without hormonal component have shown poor results. PATIENTS AND METHODS: Women diagnosed with severe VVA from January to September 2018 were recruited. The study groups were composed of 25 postmenopausal women, 30 post-partum women and 30 women with recurrent vulvovaginitis. For each group, patients were randomized 1:1 among those who carried out the experimental treatment and those that did not perform it. The efficacy of treatment was evaluated with a clinical visit in which Vaginal Health Index (VHI) was estimated. The symptomatology was determined through the questionnaire Female Sexual Function Index (FSFI). RESULTS: A significant improvement has been shown with regard to the sexual function (orgasm, lubrification, pain) in patients who performed the treatment. A significant increase in VHI has been evaluated in postmenopausal patients (4 months p=0.054, 6 months p=0.005) and in recurrent vulvovaginitis but not in post-partum patients (4 months p=0.681, 6 months p=0.109). An improvement of lubrication, satisfaction, orgasm, pain, as well as dyspareunia, was observed in the three study groups. CONCLUSIONS: In this pilot study the treatment with soft gels seems to be effective in improving sexual health and atrophy being a treatment available for all types of patients thanks to the absence of systemic and local side effects. It is an excellent alternative especially for patients who cannot use hormones. These findings must be confirmed by larger and randomized further studies.
Assuntos
Vaginite Atrófica/prevenção & controle , Cremes, Espumas e Géis Vaginais/administração & dosagem , Vulvovaginite/tratamento farmacológico , Vulvovaginite/psicologia , Adulto , Vaginite Atrófica/psicologia , Desenho de Equipamento , Feminino , Humanos , Pessoa de Meia-Idade , Projetos Piloto , Pós-Menopausa , Período Pós-Parto , Distribuição Aleatória , Resultado do Tratamento , Cremes, Espumas e Géis Vaginais/química , Vulvovaginite/complicações , Adulto JovemRESUMO
A novel and very sensitive electrochemical immunosensing strategy for the detection of atrazine based on affinity biocomposite transducers is presented. Firstly, the graphite-epoxy composite transducer was bulk-modified with different universal affinity biomolecules, such as avidin and Protein A. Two strategies for the immobilization of the anti-atrazine antibodies on both biocomposite transducers were evaluated: 'wet-affinity' and 'dry-assisted affinity' immobilization. Finally, the performance of a novel anti-atrazine immunocomposite bulk-modified with anti-atrazine antibodies was also evaluated. The better immobilization performance of the anti-atrazine antibodies was achieved by 'dry-assisted affinity' immobilization on Protein A (2%) graphite-epoxy biocomposite (ProtA(2%)-GEB) as a transducer. The immunological reaction for the detection of atrazine performed on the ProtA(2%)-GEB biosensors is based on a direct competitive assay using atrazine-HRP tracer as the enzymatic label. The electrochemical detection is thus achieved through a suitable substrate and a mediator for the enzyme HRP. This novel strategy was successfully evaluated using spiked orange juice samples. The detection limit for atrazine in orange juices using the competitive electrochemical immunosensing assay was found to be 6 x 10(-3) microgL-1 (0.03 nmolL-1) thus this biosensing method accomplishes by far the LODs required for the European Community directives for potable water and food samples (0.1 microgL-1). This strategy offers great promise for rapid, simple, cost effective, and on-site biosensing of biological, food, and environmental samples.
Assuntos
Atrazina/análise , Técnicas Biossensoriais/métodos , Imunoensaio/métodos , Resíduos de Praguicidas/análise , Atrazina/imunologia , EletroquímicaRESUMO
A novel electrochemical immunosensing strategy for the detection of sulfonamide antibiotics in milk based on magnetic beads is presented. Among the different strategies for immobilizing the class-specific anti-sulfonamide antibody to the magnetic beads--such as those based on the use of Protein A or carboxylate modified magnetic beads - ,the best strategy was found to be the covalent bonding on tosyl-activated magnetic beads. The immunological reaction for the detection of sulfonamide antibiotics performed on the magnetic bead is based on a direct competitive assay using a tracer with HRP peroxidase for the enzymatic labelling. After the immunochemical reactions, the modified magnetic beads can be easily captured by a magneto sensor made of graphite-epoxy composite (m-GEC), which is also used as the transducer for the electrochemical immunosensing. The electrochemical detection is thus achieved through a suitable substrate for the enzyme HRP and an electrochemical mediator. The electrochemical approach is also compared with a novel magneto-ELISA with optical detection. The performance of the electrochemical immunosensing strategy based on magnetic beads was successfully evaluated using spiked milk samples, and the detection limit was found to be 1.44 microg L(-1) (5.92 nmol L(-1)) for raw full cream milk. This strategy offers great promise for rapid, simple, cost-effective and on-site analysis of biological, food and environmental samples.
Assuntos
Antibacterianos/análise , Eletroquímica , Magnetismo , Leite/química , Sulfonamidas/análise , Animais , Antibacterianos/imunologia , Imunoensaio , Sulfonamidas/imunologiaRESUMO
BACKGROUND: The role of mineral metabolism in cardiovascular pathologies has been studied almost exclusively in chronic kidney disease patients. There are no studies that relate mineral metabolism to pulse pressure in healthy populations. METHODS: 692 subjects were initially selected. After applying clinical exclusion criteria, 659 subjects were recruited. Creatinine clearance was then calculated to detect subjects with occult chronic kidney disease. Statistical analysis was applied to the remaining population after excluding subjects with occult chronic kidney disease (n = 466). Pulse pressure, creatinine clearance, calcium, phosphorus, intact parathormone, 25-hydroxivitamin D3 and Bsm I genotype of the vitamin D receptor were determined. Means and frequencies were compared by ANOVA and Chi-square, respectively. Multivariate analysis was applied to the whole population and then to Caucasians, Sub-Saharans, Caucasian men and Caucasian women separately. Pulse pressure (PP) was the dependent variable, and adjustments were made for clinical and laboratory data. RESULTS: The prevalence of occult chronic kidney disease was 32%. In subjects without kidney disease, phosphorus and vitamin D were independent predictors of elevated PP in Caucasian males whereas Bsm I genotype of the vitamin D was an independent predictor of elevated PP in the Caucasian population in both genders. No covariable showed relationship with PP in Sub-Saharan subjects. CONCLUSION: Mineral metabolism influences pulse pressure in Caucasian men.
Assuntos
Pressão Sanguínea/fisiologia , Cálcio/metabolismo , Fósforo/metabolismo , Adulto , Calcifediol/metabolismo , Creatinina/sangue , Creatinina/urina , DNA/análise , Feminino , Genótipo , Humanos , Nefropatias/metabolismo , Nefropatias/fisiopatologia , Masculino , Hormônio Paratireóideo/metabolismo , Reação em Cadeia da Polimerase , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Valores de Referência , Fatores de RiscoRESUMO
Cytosol fraction(s) from McFiFi2(s) fibrosarcoma cells (Fcc), isolated from either cultured cells or solid tumors induced in F344 rats, produced a dose-related inhibition of lymphoproliferative responses to several mitogens, whatever the lymphoid organ or the animal species used as the source of lymphocytes. Only stimulated human lymphocytes were not Fcc inhibited; instead, Fcc was a potent stimulator of their spontaneous proliferation. Fcc cytostatic activity was not effective in various cycling cell lines and was restricted to mitogen-stimulated lymphocytes. Fcc, a primary tumor product, did not induce suppressive cells and was unable to prevent mitogen cell surface binding. However, expression of its modulating effect was accelerated by the simultaneous presence of the mitogen. Moreover, Fcc produced its suppression by interrupting lymphocyte activation at some point within the G0-G1-phase transition. Molecular sieving showed that Fcc contains at least two factors with suppressive (mol wt, approximately 3,000) and stimulatory (mol wt, greater than 5,000) activities, respectively.
Assuntos
Adjuvantes Imunológicos/isolamento & purificação , Citosol/imunologia , Fibrossarcoma/imunologia , Imunossupressores/isolamento & purificação , Animais , Divisão Celular/efeitos dos fármacos , DNA de Neoplasias/biossíntese , Fibrossarcoma/análise , Fibrossarcoma/induzido quimicamente , Cinética , Ativação Linfocitária/efeitos dos fármacos , Metilcolantreno , Ratos , Ratos Endogâmicos F344 , Linfócitos T ReguladoresRESUMO
Several authors have documented beneficial effects of interferon (IFN) in chronic hepatitis C virus (HCV) infection among the dialysis population. Reports about mineral metabolism disturbances during IFN treatment are scarce, especially in dialysis patients. We report the case of a 49-year-old woman on hemodialysis with chronic HCV infection who developed significant decrease in serum calcium (Ca) and phosphorus (P) levels accompanied by relative hypoparathyroidism while being under treatment with alpha-IFN. These changes were closely related to IFN treatment, because they disappeared after INF was discontinued, reaching Ca and P levels which were similar to those of the pre-IFN period. Because IFN may induce immune disorders, several autoimmune markers were analyzed. All of them were negative or within the normal range. To further explore these mineral metabolism disturbances, a number ofparathyroid hormone (PTH) secretion-inhibiting factors, such as aluminum, magnesium, 25-hydroxyvitamin D, and calcitriol were excluded as a cause for these changes. We suggest that mineral metabolism should be carefully observed during interferon treatment in dialysis patients.
Assuntos
Hiperparatireoidismo/induzido quimicamente , Interferons/efeitos adversos , Falência Renal Crônica/terapia , Diálise Renal , Cálcio/sangue , Feminino , Rejeição de Enxerto , Hepatite C Crônica/complicações , Humanos , Interferons/uso terapêutico , Transplante de Rim , Pessoa de Meia-Idade , Hormônio Paratireóideo/sangue , Fósforo/sangueRESUMO
A rapid high-throughput immunochemical screening (HtiS) procedure for the analysis of the sulfonamide (SA)-sugar conjugated fraction of antibiotic contaminated honey samples has been developed. Studies performed with this matrix have indicated that sulfonamide antibiotics are conjugated to sugars rapidly and quantitatively, providing samples with very low SA immunoreactivity. Therefore, sulfonamides must be first released before the analysis, and for this purpose, a simple and fast sample preparation procedure has been established consisting of hydrolyzing the sample for 5 min, adjusting the pH and buffering the sample prior to the immunochemical analysis. Under these conditions, honey samples could be directly analyzed without any additional sample treatment, other than dilution. Recovery values of the whole analytical procedure were greater than 85%. The analysis of the same samples without the hydrolysis provided recovery values below 5%. Selectivity studies performed in hydrolyzed honey samples revealed that nine relevant sulfonamide antibiotics can be detected with limit of detection (LOD) values below the action limits established by some EU countries (Belgium, 20 µg kg(-1), United Kingdom or Switzerland, 50 µg kg(-1)).
Assuntos
Antibacterianos/análise , Carboidratos/análise , Contaminação de Alimentos/análise , Mel/análise , Sulfonamidas/análise , Carboidratos/química , Ensaio de Imunoadsorção Enzimática , Hidrólise , Sulfonamidas/químicaRESUMO
The BsmI polymorphism of the vitamin D receptor (VDR) gene influences mineral metabolism and the course of cancers and infections. The poly-A polymorphism is in linkage disequilibrium with BsmI and could be responsible for clinical associations attributed to BsmI. The objective of this work is to study the influence of VDR polymorphisms on survival of 143 prevalent hemodialysis (HD) patients followed up for 4 years. Chi-square test was used to study the association between survival and these polymorphisms. Cox analysis was performed, adjusting for comorbid conditions in the entire HD population, groups of patients on HD therapy for less than 5 and 3 years before entering 4 years of observation, patients without diabetes, and patients treated with calcitriol. Survival was analyzed by means of Kaplan-Meier according to BsmI genotypes. Results showed a strong influence of the BsmI polymorphism on survival. The bb genotype was overrepresented among survivors (45.7%) compared with nonsurvivors (21.6%), and Cox analysis showed a significant influence of age, diabetes, calcitriol treatment, and BsmI polymorphism in all groups (in the entire population, Exp(B): BB, 3.9; and Bb, 3 with respect to bb), and also of phosphorus in patients without diabetes and calcitriol-treated patients. Survival means by Kaplan-Meier were as follows: BB, 983 days; Bb, 1,152 days; and bb, 1,290 days (log-rank P = 0.01). The BsmI polymorphism influences survival in HD patients, whereas the poly-A and FokI polymorphisms do not.
Assuntos
Nefropatias/genética , Receptores de Calcitriol/genética , Diálise Renal , Alelos , DNA/genética , DNA/metabolismo , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Feminino , Seguimentos , Frequência do Gene , Genótipo , Haplótipos , Humanos , Nefropatias/mortalidade , Nefropatias/terapia , Masculino , Pessoa de Meia-Idade , Poli A/genética , Polimorfismo Genético , Estudos Prospectivos , Análise de Sobrevida , Taxa de SobrevidaRESUMO
The development of an immunoaffinity chromatography (IAC) procedure for the selective extraction of the anti-fouling agent Irgarol 1051 [2-(tert.-butylamino)-4-(cyclopropylamino)-6-(methylthio)-1,3,5-triazine] from seawater is described. The anti-Irgarol 1051 antibodies were covalently bound to agarose-based beads support. IAC column capacities were higher than 400 ng and ethanol-water (70:30) was selected as eluting mixture. After percolation of 250 ml of water sample containing Irgarol 1051 at environmental levels (ng l(-1) ), the breakthrough volume was still not achieved. Other triazine herbicides percolated through the IAC column showed good recoveries. Thus, this IAC procedure may be useful to extract related compounds. The developed IAC column was applied to real seawater samples and compared with RP-C18 cartridges. The limit of detection (LOD) reached by using the IAC procedure was twenty times lower than the LOD achieved by the RP-C 18 cartridges using the same detection system. Irgarol 1051 was detected at ng l(-1) levels in the Barcelona marina (northwestern Mediterranean Sea). An acceptable correlation between enzyme-linked immunosorbent assay and gas chromatography with nitrogen-phosphorus detection was observed, thus analysis of Irgarol 1051 can be performed by either one of the methods. In this work, further confirmation of the analyte identity for real samples was accomplished by gas chromatography-electron impact mass spectrometry.
Assuntos
Cromatografia de Afinidade/métodos , Herbicidas/análise , Imunoensaio/métodos , Água do Mar/análise , Triazinas/análiseRESUMO
A competitive enzyme-linked immunosorbent assay (ELISA) method for carbaryl quantitation in crop extracts was validated by liquid chromatography (LC) with diode array detection (DAD). For this purpose, six crops (banana, carrot, green bean, orange, peach and potato) were chosen for recovery and reproducibility studies. The general sample preparation included extraction with methanol followed by liquid-liquid partitioning and clean-up on Celite-charcoal adsorbent column of the vegetable extracts. ELISA samples consisted of a diluted LC extract in assay phosphate buffer (pH 7.5). The potential effect of methanol in these samples was evaluated. It was observed that a maximum content of 10% methanol present in the assay buffer could be tolerated without expressive losses in the ELISA performance. Under these conditions, a IC50 approximately 1.48 micrograms l-1 was obtained. A minimum matrix effect with a 1:50 dilution of the methanolic extracts in assay buffer was noticed, except for green bean samples that inhibited completely the assay. For the vegetable extracts, the ELISA sensitivities varied from 3.9 to 5.7 micrograms l-1, and good recoveries (82-96%) with R.S.D.s ranging from 5.7 to 12.1% were found. An excellent correlation between the LC-DAD and ELISA techniques was obtained. The confirmation of the carbaryl in less concentrated samples was achieved by LC-mass spectrometry interfaced with atmospheric pressure chemical ionisation. The [M + H]+ = 202 and [M + H-57]+ = 145 ions, equivalent to the protonated molecular and 1-naphthol ions, respectively, were used to carbaryl identification in these samples.
Assuntos
Carbaril/análise , Ensaio de Imunoadsorção Enzimática/métodos , Frutas/química , Inseticidas/análise , Espectrometria de Massas , Verduras/química , Brasil , Cromatografia Líquida , Extratos Vegetais/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , SolventesRESUMO
AIMS: BsmI polymorphism of the vitamin D receptor gene has been linked to hyperparathyroidism severity and calcitriol levels. The aim of this study was to analyze the response to a single bolus of calcitriol in hemodialysis patients with the BB and bb genotype. PATIENTS: Twenty homozygous BsmI hemodialysis patients (9 BB and 11 bb). METHODS: Hyperparathyroidism was assessed comparing basal PTH levels, and in 17 patients, also measuring the inhibition with hypercalcemia. Patients were given a bolus of calcitriol and PTH in absolute terms and in percentages relative to the baseline values at 24, 48 and 72 hours after the bolus were measured. All biochemical parameters were compared between genotypes with univariant ANOVA and additionally, PTH relative values were compared with general factorial analysis of variance, adjusting for calcium and phosphorus. Means were also compared within each genotype between consecutive determinations with non-parametric Wilcoxon analysis, using each patient as his/her own control. The response to calcitriol was also assessed by the area under the curve for each patient and was subsequently compared between genotypes. RESULTS: There were no differences on hyperparathyroidism severity between the groups. The BB genotype showed a better response than bb to calcitriol 72 hours after the bolus (percentage relative to basal PTH value: BB: 63%, bb: 88.6%, p = 0.03; BB vs bb with univariant ANOVA). When general factorial analysis of variance was applied, adjusting for serum calcium and phosphorus, genotype showed a significant influence on the response to calcitriol at 72 hours (p = 0.04). When each patient was used as his/her own control, the BB genotype showed a significant decrease in PTH levels at 48 and 72 hours (p = 0.00 baseline vs 48 h, and p = 0.01 baseline vs 72h) whereas the bb did not. CONCLUSIONS: BsmI polymorphism of the VDR gene induces differences on the response to a single bolus of calcitriol independently of calcium and phosphorus.
Assuntos
Calcitriol/farmacologia , Agonistas dos Canais de Cálcio/farmacologia , Hiperparatireoidismo/genética , Glândulas Paratireoides/efeitos dos fármacos , Hormônio Paratireóideo/sangue , Receptores de Calcitriol/genética , Área Sob a Curva , Cálcio/sangue , Desoxirribonucleases de Sítio Específico do Tipo II , Genótipo , Humanos , Hiperparatireoidismo/sangue , Fósforo/sangue , Polimorfismo Genético , Diálise Renal , Fatores de TempoRESUMO
Porphyria cutanea tarda is treated with phlebotomies in the absence of renal failure. However, in patients on maintenance hemodialysis, this will lead to the need for high doses of erythropoietin. We describe the case of a 63-year-old hemodialysis patient who had chronic hepatitis C virus and developed porphyria cutanea tarda after iron overload due to repeated transfusions. She was treated with erythropoietin and phlebotomies reaching clinical remission 4 months after beginning treatment.
Assuntos
Hepatite C Crônica/complicações , Sobrecarga de Ferro/complicações , Falência Renal Crônica/complicações , Porfiria Cutânea Tardia/etiologia , Eritropoetina/uso terapêutico , Feminino , Hepacivirus/isolamento & purificação , Humanos , Sobrecarga de Ferro/terapia , Falência Renal Crônica/terapia , Pessoa de Meia-Idade , Porfiria Cutânea Tardia/terapia , Diálise RenalRESUMO
UNLABELLED: The role of vitamin D in the regulation of blood pressure is unclear. There are no studies that relate Bsm I polymorphism with blood pressure. OBJECTIVE: To analyze if Bsm I polymorphism and 25-hydroxyvitamin D (25OHD3) influence blood pressure in healthy individuals with normal blood pressure. METHODS: Systolic (SBP) and diastolic (DBP) blood pressure, Body Mass Index (BMI), plasma creatinine, serum calcium, serum phosphorus, serum iPTH, serum 25OHD3 and Bsm I genotype were determined in 590 healthy individuals (260 men and 330 women). Data were analysed using a multiple linear regression model. SBP and DBP were defined as dependent variables and the rest of variables as independent. RESULTS: Gender was strongly associated with both SBP (beta: -12.01, p: 0.000) and DBP (beta: -4.78, p: 0.000). Therefore, a separate analysis was performed according to gender. In males, SBP was associated with BMI (beta: 0.83, p: 0.001), 25OHD3, (beta: 0.36, p: 0.000) and genotype (beta: -3.90, p: 0.002); and DBP with 25OHD 3 (beta: 0.16, p: 0.018) and age (beta: 0.28, p: 0.000). Differences of blood pressure among the three genotypes were explored by analysis of variance. SBP was higher in men with bb genotype than in the other genotypes (p: 0.007). In females, 25OHD3 and genotype were not associated with blood pressure. CONCLUSIONS: Healthy men with higher levels of vitamin D have higher levels of SBP and DBP. Moreover, men with bb genotype have the highest levels of SBP. Blood pressure levels in women are not influenced by vitamin D nor by Bsml genotype. Our data suggest a possible pathophysiological interaction between vitamin D and sex hormones in blood pressure control.
Assuntos
Pressão Sanguínea/efeitos dos fármacos , Calcifediol/farmacologia , Polimorfismo de Fragmento de Restrição , Polimorfismo Conformacional de Fita Simples , Receptores de Calcitriol/genética , Adulto , Pressão Sanguínea/genética , Índice de Massa Corporal , Cálcio/sangue , Creatinina/sangue , Desoxirribonucleases de Sítio Específico do Tipo II , Diástole/efeitos dos fármacos , Diástole/genética , Feminino , Genótipo , Humanos , Modelos Lineares , Masculino , Hormônio Paratireóideo/sangue , Fósforo/sangue , Valores de Referência , Caracteres Sexuais , Espanha , Sístole/efeitos dos fármacos , Sístole/genéticaRESUMO
Atherosclerosis is the principal cause of myocardial infarction, stroke, and peripheral vascular disease, accounting for nearly half of all mortality in developed countries. The excessive growth of vascular smooth muscle cells is an important component in the development of atherosclerotic lesion. The direct effect of calcitriol and vitamin D analogs on the VSMCs proliferation is not clear. In this study we have analysed if calcitriol, Paricalcitol (19-nor-1,25-dihydroxy-vitamin D2) and EB1089 (experimental analog used as anticancerous) modify proliferation and the expression of vitamin D receptor (VDR) gene that is regulated at the transcriptional level by itself in the VSMCs. VSMCs proliferation was analysed by BrdU incorporation and VDR gene expression using RT-PCR. VSMCs proliferation was stimulated when calcitriol was added to the culture. VSMCs proliferation was significantly lower with analogs at the same dose. With regard to the functional study, the expression of VDR gene was upregulated by calcitriol at a concentration of 100 nM. There were no changes in this expression with the analogs. In conclusion, calcitriol, do not modify VSMCs proliferation. Therefore, Paricalcitol could have a minor proliferating effect on the wall of vessels that vitamin D.