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1.
Molecules ; 27(7)2022 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-35408563

RESUMEN

Spatially resolved information on corrosion reactions operating at the cut edges of coated metals can be obtained using microelectrochemical scanning techniques using a suitable selection of operation modes and scanning probes. The scanning vibrating electrode technique (SVET) provides current density maps with a spatial resolution of the order of the dimensions of the sample, which allows the temporal evolution of the corrosion reactions to be followed over time. This leads to the identification and localization of cathodic and anodic sites, although the technique lacks chemical specificity for the unequivocal identification of the reactive species. The application of scanning electrochemical microscopy (SECM) was previously limited to image cathodic reaction sites, either due to oxygen consumption in the amperometric operation or by the alkalinisation of the electrolyte in potentiometric operation. However, it is shown that anodic sites can be effectively monitored using an ion-selective microelectrode (ISME) as a probe. The ISME probes detected differences in the local concentrations of Zn2+ and OH- ions from the cut edges of a complete coil coating system compared to the same system after the polymeric layers were removed. In this way, it has been shown that the inhibitor loading in the polymer layers effectively contributes to reducing the corrosion rates at the cut edge, thus helping to extend the useful life of the sacrificial galvanized layer bonded directly to the steel matrix. Additionally, these two probe configurations can be integrated into a multi-electrode tip for potentiometric operation to simultaneously monitor localized changes in pH values and metal ion dissolution in a single scan. Spatial and temporal distributions were further investigated using different rastering procedures, and the potential of constructing pseudomaps for 2D-imaging is described.

2.
Sensors (Basel) ; 21(15)2021 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-34372300

RESUMEN

Diabetes mellitus represents one of the most widespread diseases in civilization nowadays. Since the costs for treating and diagnosing of diabetes represent several billions of dollars per year, a cheap, fast, and simple sensor for diabetes diagnosis is needed. Electrochemical insulin sensors can be considered as a novel approach for diabetes diagnosis. In this study, carbon electrode with electrodeposited NiO nanoparticles was selected as a suitable electrode material for insulin determination. The morphology and surface composition were studied by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, and X-ray photoelectron spectroscopy (XPS). For a better understanding of insulin determination on NiO-modified electrodes, the mechanism of electrochemical reaction and the kinetic parameters were studied. They were calculated from both voltammetric and amperometric measurements. The modified carbon electrode displayed a wide linear range from 600 nM to 10 µM, a low limit of detection of 19.6 nM, and a high sensitivity of 7.06 µA/µM. The electrodes were stable for 30 cycles and were able to detect insulin even in bovine blood serum. Additionally, the temperature stability of this electrode and its storage conditions were studied with appropriate outcomes. The above results show the high promise of this electrode for detecting insulin in clinical samples.


Asunto(s)
Técnicas Electroquímicas , Nanopartículas , Animales , Bovinos , Electrodos , Humanos , Insulina , Límite de Detección , Níquel
3.
Ann Clin Microbiol Antimicrob ; 16(1): 31, 2017 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-28410611

RESUMEN

BACKGROUND: Scedosporium apiospermum is an emerging opportunistic filamentous fungus, which is notorious for its high levels of antifungal-resistance. It is able to cause localized cutaneous or subcutaneous infections in both immunocompromised and immunocompetent persons, pulmonary infections in patients with predisposing pulmonary diseases and invasive mycoses in immunocompromised patients. Subcutaneous infections caused by this fungus frequently show chronic mycetomatous manifestation. CASE REPORT: We report the case of a 70-year-old immunocompromised man, who developed a fungal mycetomatous infection on his right leg. There was no history of trauma; the aetiological agent was identified by microscopic examination and ITS sequencing. This is the second reported case of S. apiospermum subcutaneous infections in Hungary, which was successfully treated by surgical excision and terbinafine treatment. After 7 months, the patient remained asymptomatic. Considering the antifungal susceptibility and increasing incidence of the fungus, Scedosporium related subcutaneous infections reported in the past quarter of century in European countries were also reviewed. CONCLUSIONS: Corticosteroid treatment represents a serious risk factor of S. apiospermum infections, especially if the patient get in touch with manure-enriched or polluted soil or water. Such infections have emerged several times in European countries in the past decades. The presented data suggest that besides the commonly applied voriconazole, terbinafine may be an alternative for the therapy of mycetomatous Scedosporium infections.


Asunto(s)
Antifúngicos/administración & dosificación , Desbridamiento , Pierna/patología , Micetoma/diagnóstico , Micetoma/terapia , Naftalenos/administración & dosificación , Scedosporium/aislamiento & purificación , Anciano , Análisis por Conglomerados , ADN de Hongos/química , ADN de Hongos/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Dermatomicosis/diagnóstico , Dermatomicosis/microbiología , Dermatomicosis/patología , Dermatomicosis/terapia , Humanos , Hungría , Huésped Inmunocomprometido , Masculino , Microscopía , Micetoma/microbiología , Micetoma/patología , Filogenia , Recurrencia , Scedosporium/clasificación , Scedosporium/citología , Scedosporium/genética , Análisis de Secuencia de ADN , Terbinafina , Resultado del Tratamiento
4.
Orv Hetil ; 153(9): 323-9, 2012 Mar 04.
Artículo en Húngaro | MEDLINE | ID: mdl-22348847

RESUMEN

Patients with diabetes are approximately 1.5 times more likely to experience cognitive decline than individuals without diabetes mellitus. Most of the data suggest that patients with diabetes have reduced performance in numerous domains of cognitive function. In patients with type 1 diabetes, specific and global deficits involving speed of psychomotor efficiency, information processing, mental flexibility, attention, and visual perception seem to be present, while in patients with type 2 diabetes an increase in memory deficits, a reduction in psychomotor speed, and reduced frontal lobe (executive) functions have been found. The complex pathophysiology of changes in the central nervous system in diabetes has not yet been fully elucidated. It is important to consider the patient's age at the onset of diabetes, the glycemic control status, and the presence of diabetic complications. Neurological consequences of diabetes appear parallel to those observed in the aging brain. Neuroimaging studies highlight several structural cerebral changes, cortical and subcortical atrophy, beside increased leukoaraiosis that occurs in association with diabetes. There is supporting evidence from many hypotheses to explain the pathophysiology of cognitive decline associated with diabetes. The main hypotheses pointing to the potential, implied mechanisms involve hyperglycemia, hypoglycemia, microvascular disease, insulin resistance, hyperinsulinism, hyperphosphorylation of tau protein, and amyloid-ß deposition.


Asunto(s)
Encéfalo/patología , Trastornos del Conocimiento/etiología , Cognición , Diabetes Mellitus/patología , Diabetes Mellitus/psicología , Actividad Nerviosa Superior , Desempeño Psicomotor , Edad de Inicio , Animales , Atención , Encéfalo/fisiopatología , Trastornos del Conocimiento/patología , Trastornos del Conocimiento/fisiopatología , Complicaciones de la Diabetes/patología , Complicaciones de la Diabetes/psicología , Diabetes Mellitus/metabolismo , Diabetes Mellitus/fisiopatología , Diabetes Mellitus Tipo 1/psicología , Diabetes Mellitus Tipo 2/psicología , Lóbulo Frontal/patología , Hipocampo , Humanos , Leucoaraiosis , Trastornos de la Memoria/etiología , Pensamiento
5.
Orv Hetil ; 153(27): 1068-76, 2012 Jul 08.
Artículo en Húngaro | MEDLINE | ID: mdl-22759747

RESUMEN

UNLABELLED: The objective of the research was to assess the health related quality of life and productivity of women with overactive bladder. METHODS: A cross-sectional survey was performed in 5 outpatient centers. General health status (EQ-5D), disease-specific quality of life (King's Health Questionnaire) and productivity (Work Productivity and Activity Impairment) were assessed. RESULTS: Sixty-one women with mean age of 57.7 (SD = 11.6) years have had symptoms for 6.6 (SD = 6.2) years and 57 (93%) had incontinence. The EQ-5D (mean 0.668, SD = 0.314) was not significantly lower than that of the average population (p>0.05). The impact of incontinence and physical limitation (mean 70.5 and 68.9, respectively) were significant, the King's Health Questionnaire-utility was 0.932 (SD = 0.029). Productivity scores of involved patients were: absenteeism 0.04% (SD = 0.11), presenteeism 43.64% (SD = 28.54), overall work impairment 40.97% (SD = 26.91), and other activities 47.72% (SD = 27.24). CONCLUSIONS: Applicability of the EQ-5D and King's Health Questionnaire as utility measures in overactive bladder deserve further research. Presenteeism should be considered in the evaluation of the therapy.


Asunto(s)
Eficiencia , Calidad de Vida , Vejiga Urinaria Hiperactiva/epidemiología , Vejiga Urinaria Hiperactiva/psicología , Absentismo , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Emociones , Femenino , Estado de Salud , Humanos , Hungría/epidemiología , Relaciones Interpersonales , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Sueño , Encuestas y Cuestionarios , Incontinencia Urinaria/epidemiología , Incontinencia Urinaria/psicología
6.
World J Diabetes ; 13(10): 835-850, 2022 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-36312000

RESUMEN

It has been 100 years since the first successful clinical use of insulin, yet it remains the only treatment option for type 1 diabetes mellitus (T1DM) patients. Advances in diabetes care, such as insulin analogue therapies and new devices, including continuous glucose monitoring with continuous subcutaneous insulin infusion have improved the quality of life of patients but have no impact on the pathogenesis of the disease. They do not eliminate long-term complications and require several lifestyle sacrifices. A more ideal future therapy for T1DM, instead of supplementing the insufficient hormone production (a consequence of ß-cell destruction), would also aim to stop or slow down the destructive autoimmune process. The discovery of the autoimmune nature of type 1 diabetes mellitus has presented several targets by which disease progression may be altered. The goal of disease-modifying therapies is to target autoimmune mechanisms and prevent ß-cell destruction. T1DM patients with better ß-cell function have better glycemic control, reduced incidence of long-term complications and hypoglycemic episodes. Unfortunately, at the time symptomatic T1DM is diagnosed, most of the insulin secreting ß cells are usually lost. Therefore, to maximize the salvageable ß-cell mass by disease-modifying therapies, detecting autoimmune markers in an early, optimally presymptomatic phase of T1DM is of great importance. Disease-modifying therapies, such as immuno- and regenerative therapies are expected to take a relevant place in diabetology. The aim of this article was to provide a brief insight into the pathogenesis and course of T1DM and present the current state of disease-modifying therapeutic interventions that may impact future diabetes treatment.

7.
Blood Press ; 20(3): 134-9, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21133825

RESUMEN

BACKGROUND: The aim of this study was to obtain epidemiological data and to determine the prevalence of adolescent hypertension implementing a blood pressure (BP) screening. METHODS: We performed a cross-sectional, population-based survey in a major Hungarian city (Debrecen, population 230,000). After a 10-min resting period, three consecutive BP measurements were taken. RESULTS: Complete records were obtained for 10,194 subjects (5163 boys and 5031 girls). The mean age was 16.6±1.0 years. BP for boys was higher than for girls (ΔBP(syst)=11 mmHg; ΔBP(diast)=2 mmHg, p<0.001). A significant decrease was observed in BP during the three consecutive measurements (time 1-3: ΔBP(syst)=4 mmHg; ΔBP(diast)=2.5 mmHg; p<0.001). Systolic and/or diastolic BP exceeded the age-, gender- and height-adjusted 90th percentile in 1614 (15.84%) adolescents. Following two lots of three extra measurements on 1461 subjects of this sub-sample, hypertension (systolic and/or diastolic BP exceeded the 95th percentile) was confirmed in 2.12% of the subjects (male: 2.27%, female: 1.97%). Considering there were individuals either already diagnosed with hypertension (n=19) or refusing further participation, the prevalence of hypertension was 2.53% in adolescents in the age range 15-18 years. CONCLUSION: Our population-based study was the first to determine the point-prevalence of adolescent hypertension in Central-Eastern Europe. Identifying and following-up cases of confirmed hypertension is inevitable to prevent or delay the manifestations of target organ damage and reduce hypertension-related mortality.


Asunto(s)
Adolescente , Presión Sanguínea/fisiología , Hipertensión/diagnóstico , Hipertensión/fisiopatología , Estudios Transversales , Diástole , Femenino , Humanos , Hungría/epidemiología , Hipertensión/epidemiología , Masculino , Prevalencia , Vigilancia de Guardia , Sístole
8.
Orv Hetil ; 152(13): 498-504, 2011 Mar 27.
Artículo en Húngaro | MEDLINE | ID: mdl-21398210

RESUMEN

Diabetes mellitus and depression are public health concerns of the present and, as predicted, also the future. The observation that depression is seen more frequently in diabetic patients compared to the non-diabetic population has been proven by several recent studies. The co-occurrence carries further risks for the affected patients, as depression in diabetics may affect sufficient treatment of diabetes and enhance the development of diabetic complications. These may further worsen depressive symptoms causing a vicious cycle in these patients. In the present paper authors discuss in detail the theoretic and practical issues of the complex two directional relationships between diabetes and depression. Their goal is to draw attention to depression as co-morbidity of diabetes that may interfere with the optimization of diabetic patient's carbohydrate metabolism. If sufficient glycaemic control is not achieved using routine clinical methods depression should be evaluated as a probable cause. If needed, depression should be treated to improve the medical outcomes and quality of life of diabetic patients.


Asunto(s)
Antidepresivos/uso terapéutico , Glucemia/metabolismo , Depresión/diagnóstico , Depresión/terapia , Complicaciones de la Diabetes/psicología , Complicaciones de la Diabetes/terapia , Diabetes Mellitus/psicología , Afecto , Comorbilidad , Depresión/sangre , Depresión/complicaciones , Depresión/tratamiento farmacológico , Depresión/epidemiología , Trastorno Depresivo Mayor/diagnóstico , Trastorno Depresivo Mayor/terapia , Complicaciones de la Diabetes/sangre , Complicaciones de la Diabetes/diagnóstico , Complicaciones de la Diabetes/epidemiología , Diabetes Mellitus/sangre , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/tratamiento farmacológico , Humanos
9.
ACS Appl Mater Interfaces ; 13(36): 43587-43596, 2021 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-34473486

RESUMEN

Recently, the cytotoxic properties of galvanically coupled Ti-Mg particles have been shown in different cells. This cytotoxic effect has been attributed mainly to Mg due to its tendency to undergo activation when coupled with Ti, forming a galvanic cell consisting of an anode (Mg) and a cathode (Ti). However, the role of the Ti cathode has been ignored in explaining the cytotoxic effect of Ti-Mg particles due to its high resistance to corrosion. In this work, the role of titanium (Ti) in the cytotoxic mechanism of galvanically coupled Ti-Mg particles was examined. A model galvanic cell (MGC) was prepared to simulate the Mg-Ti particles. The electrochemical reactivity of the Ti sample and the pH change in it due to galvanic coupling with Mg were investigated using scanning electrochemical microscopy (SECM). It was observed that the Ti surface changed from passive to electrochemically active when coupled with Mg. Furthermore, after only 15 min of galvanic coupling with Mg, the pH in the electrolyte volume adjacent to the Ti surface increased to an alkaline pH value. The effects of the galvanic coupling of Ti and Mg, as well as those of the alkaline pH environment, on the viability of Hs27 fibroblast cells were investigated. It was shown that the viability of Hs27 cells significantly diminished when Mg and Ti were galvanically coupled compared to when the two metals were electrically disconnected. Thus, although Ti usually exhibited high corrosion resistance when exposed to physiological environments, an electrochemically active surface was observed when galvanically coupled with Mg, and this surface may participate in electron transfer reactions with chemical species in the neighboring environment; this participation resulted in the increased pH values above its surface and enhanced generation of reactive oxygen species. These features contributed to the development of cytotoxic effects by galvanically coupled Ti-Mg particles.


Asunto(s)
Magnesio/toxicidad , Titanio/toxicidad , Línea Celular , Supervivencia Celular/efectos de los fármacos , Humanos , Concentración de Iones de Hidrógeno , Microscopía Electroquímica de Rastreo , Especies Reactivas de Oxígeno/metabolismo
10.
Diabetes Metab Res Rev ; 26(8): 646-55, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20922819

RESUMEN

BACKGROUND: Diabetes mellitus results in accelerated atherosclerosis. We evaluated preclinical, morphological and functional vascular changes in type 1 diabetes mellitus. METHODS: Diameter, intima-media thickness, intima-media cross-section area, and elasticity features (compliance, distensibility coefficient, circumferential strain, stiffness index, incremental elastic modulus) of the common carotid arteries and carotid-femoral pulse wave velocity were studied in 42 patients with type 1 diabetes mellitus without macroangiopathy, and 41 control subjects matched for sex, age and body mass index using an ultrasonographic vessel wall-movement tracking system and applanation tonometry. RESULTS: Significantly larger intima-media thickness (523 ± 55 versus 567 ± 89 µm, p < 0.01), intima-media cross-section area (11.60 ± 1.81 versus 13.08 ± 3.02 mm(2) , p < 0.01), SI (5.58 ± 1.24 versus 7.08 ± 2.69, p < 0.01) and pulse wave velocity (6.00 ± 0.82 versus 6.61 ± 1.56 m/s, p < 0.05) were found in type 1 diabetes mellitus patients compared to controls. When type 1 diabetes mellitus patients with short and long disease duration (≤ or > 10 years) were compared, diameter (6450 ± 433 versus 6847 ± 750 µm, p < 0.05), intima-media cross-section area (11.97 ± 1.98 versus 14.01 ± 3.43 mm, p < 0.05) and pulse wave velocity (5.90 ± 0.92 versus 7.20 ± 1.74 m/s, p < 0.01) differed significantly. When multivariate analyses were restricted to type 1 diabetes mellitus patients, age was an independent predictor of stiffness index and pulse wave velocity, the duration of diabetes mellitus of intima-media cross-section area and pulse wave velocity, systolic blood pressure of diameter and pulse wave velocity, and low-density lipoprotein-cholesterol of intima-media thickness, intima-media cross-section area and stiffness index. CONCLUSIONS: There are differences in the time course of evolution and in predictors of morphological and functional changes in arteries in type 1 diabetes mellitus.


Asunto(s)
Arterias/patología , Arteria Carótida Común/fisiopatología , Diabetes Mellitus Tipo 1/fisiopatología , Adulto , Velocidad del Flujo Sanguíneo , Presión Sanguínea , Arteria Carótida Común/diagnóstico por imagen , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/patología , Femenino , Humanos , Masculino , Flujo Pulsátil/fisiología , Túnica Íntima/patología , Túnica Media/patología , Ultrasonografía , Resistencia Vascular
11.
Orv Hetil ; 151(22): 899-902, 2010 May 30.
Artículo en Húngaro | MEDLINE | ID: mdl-20478811

RESUMEN

UNLABELLED: Dipeptidyl peptidase-4 (DPP-4) has an important role in the carbohydrate metabolism with the degradation of incretin hormones. AIM: We assessed the serum DPP-4 activity both in fasting and postprandial condition in patients with type 1-, type 2 diabetes and healthy controls. METHODS: Serum DPP-4 activities were determined at fasting sate and at 60 and 180 minutes after test meal. DPP-4 activity was measured by microplate-based kinetic assay in 41 type 1-, and in 87 type 2 diabetic patients and in 25 healthy volunteers. RESULTS: Serum DPP-4 activities were found significantly higher both in fasting and postprandial state in patients with type 1 diabetes than in type 2 and control subjects. No change in the enzyme activities was found after test meal. Correlation was neither detected between the fasting plasma glucose nor between the HbA(1C) and the DPP-4 values in any of the groups studied. CONCLUSIONS: RESULTS suggest that it is not the hyperglycemia, rather the type of diabetes which determinates the serum DPP-4 enzymatic activity. The exact background of this phenomenon is not yet clear, however, increased serum DPP-4 enzyme activity in type 1 diabetes mellitus may refer to pancreatic autoimmune process, concomitant autoimmune diseases, hormonal feed back mechanism, or even target organ damage.


Asunto(s)
Diabetes Mellitus Tipo 1/enzimología , Dipeptidil Peptidasa 4/sangre , Adulto , Anciano , Biomarcadores/sangre , Glucemia/metabolismo , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 2/enzimología , Dipeptidil Peptidasa 4/metabolismo , Femenino , Péptido 1 Similar al Glucagón/sangre , Hemoglobina Glucada/metabolismo , Humanos , Masculino , Persona de Mediana Edad
12.
BMC Med Genet ; 10: 79, 2009 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-19691832

RESUMEN

BACKGROUND: Hypoxia inducible factor-1 alpha (HIF-1alpha) is a transcription factor that plays an important role in neo-vascularisation, embryonic pancreas beta-cell mass development, and beta cell protection. Recently a non synonymous single nucleotide polymorphism (g.C45035T SNP, rs11549465) of HIF-1alpha gene, resulting in the p.P582S amino acid change has been shown to be associated with type 2 diabetes (T2DM) in a Japanese population. Our aim was to replicate these findings on a Caucasian (Hungarian) population, as well as to study whether this genetic effect is restricted to T2DM or can be expanded to diabetes in general. METHODS: A large Caucasian sample (N = 890) was recruited including 370 T2DM, 166 T1DM and 354 healthy subjects. Genotyping was validated by two independent methods: a restriction fragment analysis (RFLP) and a real time PCR using TaqMan probes. An overestimation of heterozygotes by RFLP was observed as a consequence of a nearby SNP (rs34005929). Therefore genotyping results of the justified TaqMan system were accepted. The measured genotype distribution corresponded to Hardy-Weinberg equilibrium (P = 0.740) RESULTS: As the TT genotype was extremely rare in the population (0.6% in clinical sample and 2.5% in controls), the genotypes were grouped as T absent (CC) and T present (CT and TT). Genotype-wise analysis showed a significant increase of T present group in controls (24.0%) as compared to patients (16.8%, P = 0.008). This genetic effect was demonstrated in the separated samples of type 1 (15.1%, P = 0.020), and also in type 2 (17.6%, P = 0.032) diabetes. Allele-wise analysis gave identical results showing a higher frequency of the T allele in the control sample (13.3%) than in the clinical sample (8.7%, P = 0.002) with similar results in type 1 (7.8%, P = 0.010) and type 2 (9.1%, P = 0.011) diabetes. The odds ratio for diabetes (either type 1 or 2) was 1.56 in the presence of the C allele. CONCLUSION: We confirmed the protective effect of a rare genetic variant of HIF-1alpha gene against type 2 diabetes in a Caucasian sample. Moreover we demonstrated a genetic contribution of the same polymorphism in type 1 diabetes as well, supporting a possible overlap in pathomechanism for T2DM and a T1DM.


Asunto(s)
Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 2/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Adolescente , Adulto , Anciano , Alelos , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Hipoxia de la Célula , Línea Celular Tumoral , Femenino , Genotipo , Humanos , Hungría , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Transfección , Población Blanca/genética , Adulto Joven
13.
Anal Biochem ; 393(1): 8-22, 2009 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-19524544

RESUMEN

Amadori peptides were enriched using boronate affinity tips and measured by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS). As demonstrated by electrochemical measurements, the tips show the highest binding efficiency for glucose at pH 8.2 employing ammonium chloride/ammonia buffer with ionic strength of 150 mM, exceeding taurine buffer at the same concentration. The bound constituents were released by sorbitol and formic acid. It was also demonstrated that elution with sorbitol at 1.2 M is superior to acidic media. Comparison of results was based on the numbers of detected peptides and their glycated sites. Using sorbitol for elution requires desalting prior to analysis. Therefore, three different sorbents were tested: fullerene-derivatized silica, ZipTip (C18), and C18 silica. Fullerene-derivatized silica and ZipTip showed the same performance regarding the numbers of glycated peptides, and sites were better than C18 silica. The elaborated off-line method was compared with liquid chromatography-tandem mass spectrometry (LC-MS/MS) measurements, by which considerable less modified peptides were detected. Affinity tips used under optimized conditions were tested for the analysis of human serum albumin (HSA) from sera of healthy and diabetic individuals. A peptide with a mass of 1783.9 Da could be detected only in samples of diabetic patients and, therefore, could be a very interesting biomarker candidate.


Asunto(s)
Cromatografía de Afinidad/métodos , Glicopéptidos/química , Glicopéptidos/aislamiento & purificación , Glicoproteínas/química , Péptidos/aislamiento & purificación , Ácidos Borónicos/química , Cromatografía de Afinidad/instrumentación , Humanos , Estructura Molecular , Péptidos/química , Ribonucleasa Pancreática/análisis , Albúmina Sérica/análisis
14.
Anal Bioanal Chem ; 394(7): 1955-63, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19517100

RESUMEN

The diffusion coefficient of glucose in different media is an important parameter in life sciences, as well as in biotechnology and microbiology. In this work a simple, fast method is proposed that is based on the electrochemical time of flight principle. In most of the earlier time of flight experiments performed, a constant flight distance was applied. In the present work a scanning electrochemical microscope (SECM) was applied as a measuring tool. With use of the SECM, the flying distance could be changed with high precision, making measurements with several flight distances more accurate and reliable values could be obtained for solutions as well as for gels. The conventional voltammetric methods are not applicable for glucose detection. In our work electrocatalytic copper oxide coated copper microelectrodes and micro-sized amperometric enzyme sensors were used as detectors, while microdroplet-ejecting pneumatically driven micropipettes were used as a source.


Asunto(s)
Geles/química , Glucosa/análisis , Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Catálisis , Cobre/química , Difusión , Electroquímica , Análisis de Inyección de Flujo/instrumentación , Análisis de Inyección de Flujo/métodos , Microelectrodos , Tamaño de la Partícula , Sensibilidad y Especificidad , Soluciones , Propiedades de Superficie , Factores de Tiempo
15.
Orv Hetil ; 160(39): 1554-1562, 2019 Sep.
Artículo en Húngaro | MEDLINE | ID: mdl-31544495

RESUMEN

Introduction and aim: Earlier results in the literature suggest that overweight subjects show weaker performance in executive function tasks as compared to normal weight people. Dopaminergic system is strongly linked to executive functions, body mass regulation and ingestion. The aim of the present study was to examine the possible relationship between DRD4 VNTR 7-repeat allele, body mass index and Stroop performance in a healthy adult population, and to draw psychogenetic conclusions. Method: 152 subjects without diabetic or psychiatric history participated in the study. Along with non-invasive DNA sampling, demographic, weight and height data were collected. The participants also solved the computerized Stroop task. 11 subjects belonged to the underweight (mean body mass index = 17.9 kg/m2), 98 subjects to the normal (mean body mass index = 21.8 kg/m2), and 43 subjects to the overweight (mean body mass index = 28.9 kg/m2) category. After grouping participants according to their body mass index and DRD4 VNTR genotype, we compared their mean performance to investigate the possible psychogenetic associations. Results: Body mass index and stimuli type showed significant interaction on error number (p = 0.045): subjects with normal body mass index made significantly less error as compared to under- and overweight subjects in incongruent trials. The 7-repeat allele carriers made tendentiously more errors than non-carriers. Normal weight people made less error - independently from their genotype -, while subjects with either low or high BMI carrying the 7-repeat allele made more errors compared to non-carriers. Conclusion: Under- and overweight subjects perform weaker where inhibition is necessary in the task. This may reflect their reactions to food-related situations. Orv Hetil. 2019; 160(39): 1554-1562.


Asunto(s)
Alelos , Índice de Masa Corporal , Función Ejecutiva/fisiología , Polimorfismo Genético , Receptores de Dopamina D4/genética , Adulto , Genética Conductual , Genotipo , Humanos , Repeticiones de Minisatélite , Receptores de Dopamina D4/efectos de los fármacos , Receptores de Dopamina D4/metabolismo
16.
Artículo en Inglés | MEDLINE | ID: mdl-30664971

RESUMEN

INTRODUCTION: The activation of the ATP-gated P2RX7 (purinergic receptor P2X, ligand-gated ion channel, 7) produces microglial activation, a process which has been demonstrated in depression, bipolar disorder, and schizophrenia. Emerging data over the last years highlighted the importance of P2X7 cation channel as a potential drug target for these central nervous system disorders. The Gln460Arg (rs2230912) polymorphism of the P2RX7 gene has been widely studied in mood disorders, however the results are still controversial. Therefore, we aimed to investigate the C-terminal region of this gene in major depressive and bipolar disorders (MDD and BD) by studying possibly functional, non-synonymous polymorphisms within a 7 kb long region around the Gln460Arg, including Ala348Thr (rs1718119), Thr357Ser (rs2230911), and Glu496Ala (rs3751143) variants. Since Gln460Arg is located at the 3' end of the P2RX7 gene, we included additional, potentially functional single nucleotide polymorphisms (SNPs) from the 3' untranslated region (UTR), which can be in linkage with Gln460Arg. Based on in silico search, we chose two SNPs in putative microRNA target sites which are located in consecutive positions: rs1653625 and rs1718106. METHODS: P2RX7 SNPs from the C-terminal region were selected based on previous functional assays, 3' UTR variants were chosen using PolymiRTS and Patrocles databases. The genotyping of the non-synonymous SNPs was carried out by pre-designed TaqMan® kits, while the 3' UTR variants were analyzed by PCR-RFLP method. Case-control analyses were carried out between 315 inpatients with acute major depressive episode (195 MDD, 120 BD) and 406 healthy control subjects. The two subscales of the Hospital Anxiety and Depression Scale (HADS) self-report questionnaire were used for quantitative analyses, including an additional, "at-risk" population of 218 patients with diabetes mellitus. The in vitro reporter gene assays were carried out on HEK and SK-N-FI cells transiently transfected with pMIR vector constructs containing the P2RX7 3' UTR downstream of the luciferase gene. RESULTS: Haplotype analysis indicated a relatively high linkage between the analyzed P2RX7 SNPs. Our case-control study did not yield any association between P2RX7 gene variants and depression. However, dimensional analyses showed significant associations of the HADS depression severity scores with Gln460Arg (rs2230912) and Ala348Thr (rs1718119) in the depressed and diabetic patient groups. In the in vitro experiments, the P2RX7 3' UTR constructs with the lowest predicted binding efficiency to their miRNAs showed the highest expression of the gene. The combination of the depression-associated P2RX7 C-terminal and 3' UTR SNPs contributed to the highest depression severity score in the haplotype analysis. CONCLUSION: Based on our findings, we propose that a P2RX7 haplotype combination of the Gln460Arg and neighboring SNPs contribute to the observed genetic association with depressive symptoms.


Asunto(s)
Trastorno Bipolar/genética , Trastorno Depresivo Mayor/genética , Predisposición Genética a la Enfermedad , Polimorfismo de Nucleótido Simple , Receptores Purinérgicos P2X7/genética , Adulto , Trastorno Bipolar/metabolismo , Estudios de Casos y Controles , Línea Celular , Simulación por Computador , Trastorno Depresivo Mayor/metabolismo , Diabetes Mellitus/genética , Diabetes Mellitus/metabolismo , Femenino , Frecuencia de los Genes , Estudios de Asociación Genética , Haplotipos , Humanos , Desequilibrio de Ligamiento , Masculino , MicroARNs/metabolismo , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , Receptores Purinérgicos P2X7/metabolismo
17.
Prog Neuropsychopharmacol Biol Psychiatry ; 32(8): 1884-8, 2008 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-18801407

RESUMEN

AIMS: Both diabetes mellitus and major depression are public health concerns, and the co-occurrence of these illnesses is highly frequent. Acting as a potential risk factor, hyperglycemia might facilitate the manifestation of depression in patients genetically predisposed to affective disorders. In the present study, candidate polymorphisms of the serotonin transporter, the tryptophan hydroxylase 2 (TPH2) genes, as well as of the brain-derived neurotrophic factor BDNF, and the P2RX7 purinergic receptor genes were analyzed in Hungarian diabetic population. We assumed that genetic influence would be stronger on depressive symptoms in the "poor glycemic control" group (PC: HbA1C>7%) compared to the "good glycemic control" group (GC: HbA1C

Asunto(s)
Arginina/genética , Depresión/genética , Complicaciones de la Diabetes , Glutamina/genética , Polimorfismo Genético/genética , Receptores Purinérgicos P2/genética , Factor Neurotrófico Derivado del Encéfalo/genética , Depresión/etiología , Diabetes Mellitus/fisiopatología , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Análisis Multivariante , Receptores Purinérgicos P2X7 , Proteínas de Transporte de Serotonina en la Membrana Plasmática/genética , Triptófano Hidroxilasa/genética
18.
J Biochem Biophys Methods ; 70(5): 713-20, 2007 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-17509692

RESUMEN

Distribution of serotonin (5-HT) content of nervous fibers in both the somatic and the visceral muscle of Eisenia fetida have been investigated using immunocytochemical staining and voltammetric measurements. The somatic muscles in the body wall are richer innervated with serotoninergic fibers than the visceral ones in the pharynx and gizzard. The relative density of immunopositive fibers in the circular muscle layer of the body wall was found to be 2.73% while in the prostomium it was 1.02%. In the case of the muscle in pharynx 1.12% and in gizzard 1.28% density values were found. Differential Pulse Voltammetric (DPV) measurements with carbon fiber electrodes in the above mentioned muscle layers gave 272.5 nA, 135.0 nA, 122.5 nA, 137.5 nA peak heights, respectively. In the statistical analysis T-test was used at a confidence level of 95% (p<0.05). DPV current peak (i(p)) values reflect clearly the 5-HT concentration differences. Significant correlation was found between the innervation density and the i(p) values recorded in different areas. The i(p) values recorded at different times in different locations are determined by instantaneous serotonin concentration of the living tissue. As far as we know this is the first report using in vivo voltammetry investigating serotonin content in earthworm, E. fetida.


Asunto(s)
Músculos/metabolismo , Oligoquetos/anatomía & histología , Oligoquetos/metabolismo , Serotonina/metabolismo , Animales , Electroquímica , Molleja No Aviar/inervación , Molleja No Aviar/metabolismo , Inmunohistoquímica , Técnicas In Vitro , Músculos/anatomía & histología , Músculos/inervación , Fibras Nerviosas/metabolismo , Faringe/inervación , Faringe/metabolismo , Distribución Tisular
19.
Physiol Meas ; 28(4): R41-55, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17395989

RESUMEN

Chemical reactions, including oxidation and reduction of molecules, occur in every cell. These reactions can lead to the production of free radicals. Free radicals react with organic substrates such as lipids, proteins, and DNA. Through oxidation free radicals cause damage to these molecules, disturbing their normal function, and may therefore contribute to a variety of diseases. The anti-oxidation system, which consists of enzymatic antioxidants and non-enzymatic antioxidants, defends against oxidative stress. The aim of this review is to summarize general aspects of methods to measure the antioxidant defence system all in one (total antioxidant capacity) and discuss a number of methods which are currently used for detection of antioxidant properties.


Asunto(s)
Antioxidantes/análisis , Bioensayo/métodos , Técnicas Biosensibles/métodos , Análisis por Micromatrices/métodos , Estrés Oxidativo/fisiología , Especies Reactivas de Oxígeno/análisis , Oxidación-Reducción
20.
Physiol Meas ; 28(12): 1533-42, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18057517

RESUMEN

The reactive oxygen species are thought to play major roles in developing different physiological disorders. A commercial, needle-type amperometric glucose enzyme sensor manufactured for human patients was investigated. This sensor measures glucose by detecting hydrogen peroxide evolved in the enzymatic reaction of glucose. In the experiments, the immobilized enzyme layer of the sensor was inactivated. The applicability of this 'inhibited' glucose sensor for detecting hydrogen peroxide was tested. The simple battery powered, single purpose electronic unit was replaced by an advanced electrochemical workstation. The sensitivity, selectivity and lower limit of detection of the hydrogen peroxide measurements were investigated. Voltammetric measurements were carried out in intensively stirred buffered aqueous media, in plasma samples as well as in subcutan areas of anesthetized Wistar rats. Preliminary measurements carried out with the amperometric and periodically interrupted amperometric technique predicted that the human clinical sensor, after our enzyme inhibition step, can be used for checking the elevation of the hydrogen peroxide level in different subcutan areas of human subjects.


Asunto(s)
Técnicas Biosensibles/instrumentación , Peróxido de Hidrógeno/análisis , Animales , Técnicas Biosensibles/métodos , Glucemia/análisis , Conductometría/instrumentación , Electrodos Implantados , Glucosa/metabolismo , Glucosa Oxidasa/antagonistas & inhibidores , Glucosa Oxidasa/metabolismo , Masculino , Microelectrodos , Ratas , Ratas Wistar , Sensibilidad y Especificidad
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