Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
Neurol Neurochir Pol ; 57(6): 477-483, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37955596

RESUMEN

INTRODUCTION: Many recent studies have suggested that generalised epilepsy is associated with cortical epileptogenic focus, and therefore distinguishing between focal and generalised often becomes difficult. AIM OF STUDY: We aimed to detect differences between default mode function in patients with idiopathic generalised epilepsy who have discharges on EEG, and healthy persons. MATERIAL AND METHODS: This was a case-control study; we performed EEG analysis with LORETA in 17 patients with a type of generalised epilepsy and a control group represented by 17 healthy age-matched persons. We performed statistical non- -parametric tests for current density electrical distribution for our two groups ('t-statistic on Log transformed data') and we defined regions of interest (ROIs) from the default mode network. In the second part, we compared the average activation for each ROI for each timeframe in the epoch for the group with epilepsy, and for controls (we performed a Wilcoxon rank-sum test for two means). RESULTS: In the first part, we obtained that in the medial frontal gyrus (BA 9) delta oscillations significantly differed in patients with epilepsy who had electrical discharges on EEG in resting state conditions compared to healthy controls (medial frontal gyrus in this group had a greater number of synchronously oscillating neurons than did the controls). In the second part, we ran statistics on our localised activity from the default mode network (defined ROIs) and we obtained statistically significant differences in the left medial frontal gyrus (the values were higher for the group with epilepsy, p-value = 0.0066). CONCLUSIONS AND CLINICAL IMPLICATIONS: It may be possible to move from a 'generalised theory' about epilepsy to a 'focused theory' by understanding how various areas of interest are activated within default mode networks. Insights into the pathophysiology of generalised epilepsy may lead to new treatment options.


Asunto(s)
Electroencefalografía , Epilepsia Generalizada , Humanos , Estudios de Casos y Controles , Epilepsia Generalizada/diagnóstico por imagen , Mapeo Encefálico , Imagen por Resonancia Magnética , Encéfalo/diagnóstico por imagen
3.
Front Physiol ; 14: 1213075, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38260099

RESUMEN

This study examined the determinants of sustained physical activity. Eighty-four participants undertook a 7-weeks walking regime (i.e., a 1-h biometrically-monitored walk, at least 5 days/week), with bioelectrical impedance (BIA) and total cholesterol capillary blood measurements performed before and after programme. To investigate behavioural habit formation, 7 weeks after walking termination, all participants were interviewed and (health) re-tested. Data were modelled with an artificial neural network (ANN) cascading algorithm. Our results highlight the successful prediction of continued physical activity by considering one's physical fitness state, the environmental living context, and risk for cardiovascular disease. Importantly, those artificial neural network models also taking body mass index (BMI) and blood cholesterol as predictors excel at predicting walking continuation (i.e., predictions with 93% predictability). These results are first to highlight the type and importance of available physiological drivers in maintaining a sustained physical activity regime such as walking. They are discussed within the framework of habit formation and the nowadays health and/or wellbeing focus.

4.
Pharmaceutics ; 14(6)2022 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-35745760

RESUMEN

The current studies entail quality by design (QbD)-enabled development of a simple, rapid, precise, accurate, and cost-effective high-performance liquid chromatographic method for estimation of metformin hydrochloride (M-HCl). Design of experiments (DoE) was applied for multivariate optimization of the experimental conditions of the HPLC method. Risk assessment was performed to identify the critical method parameters (CMPs) using Ishikawa diagram. The factor screening studies were performed using a two-factor three-levels design. Two independent factors, buffer pH and mobile phase composition, were used to design mathematical models. Central composite design (CCD) was used to study the response surface methodology and to study in depth the effects of these independent factors, thus evaluating the critical analytical attributes (CAAs), namely, retention time, peak area, and symmetry factor as the parameters of method robustness. Desirability function was used to simultaneously optimize the CAAs. The optimized and predicted data from contour diagram consisted of 0.02 M acetate buffer pH = 3/methanol in a ratio of 70/30 (v/v) as the mobile phase with a flow rate 1 mL/min. The separation was made on a Thermoscientific ODS HypersylTM chromatographic column (250 × 4.6 mm, 5 µm) with oven temperature 35 °C and UV detection at 235 nm. The optimized assay conditions were validated according to ICH guidelines. Hence, the results clearly showed that QbD approach could be successfully applied to optimize HPLC method for estimation of M-HCl. The method was applied both for the evaluation of M-HCl content in tablets, and for in vitro dissolution studies of M-HCl from conventional and prolonged-release tablets.

5.
Antibiotics (Basel) ; 11(6)2022 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-35740230

RESUMEN

The empirical administration of antibiotics for suspected bacterial meningitis denotes a poor bacterial stewardship. In this context, the use of biomarkers can distinguish between bacterial and viral infections before deciding treatment. Our study assesses how levels of heparin-binding protein (HBP), neutrophil gelatinase-associated lipocalin (NGAL), S100 calcium-binding protein B (S100B), and neuron-specific enolase (NSE) in cerebrospinal fluid (CSF) and in blood can promptly confirm bacterial etiology and the need for antibiotic treatment. The CSF and blood levels of HBP, NGAL, S100B, and NSE of 81 patients with meningitis were measured and analyzed comparatively. Statistical sensitivity, specificity, and positive and negative predictive values were evaluated. CSF levels of HBP and NGAL and the blood level of S100B in the bacterial meningitis group were significantly higher (p < 0.05). The area under curve (AUC) for predicting bacterial meningitis was excellent for the CSF level of HBP (0.808 with 93.54% sensitivity and 80.64% specificity), good for the CSF level of NGAL (0.685 with 75.00% sensitivity and 65.62% specificity), and good for the blood level of S100B (0.652 with 65.90% sensitivity and 57.14% specificity). CSF levels of HBP and NGAL, as well as the blood level of S100B, could help discriminate between bacterial and viral meningitis before considering antibiotic treatment.

6.
Mater Sci Eng C Mater Biol Appl ; 118: 111436, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33255029

RESUMEN

In vitro electrochemical characterization and in vivo implantation in an animal model were employed to evaluate the degradation behaviour and the biological activity of FeMnSi and FeMnSiCa alloys obtained using UltraCast (Ar atmosphere) melting. Electrochemical characterization was based on open circuit potential measurement, electrochemical impedance spectroscopy and potentiodynamic polarization techniques while the alloys were immersed in Ringer's solution at 37 °C for 7 days. Higher corrosion rates were measured for the Ca-containing material, resulting from inefficient passivation of the metal surface by oxy-hydroxide products. In vivo osseointegration was investigated on a tibia implant model in rabbits by referring to a standard control (AISI 316 L) stainless steel using standard biochemical, histological and radiological methods of investigation. Changes in the biochemical parameters were related to the main stages of the bone defect repair, whereas implantation of the alloys in rabbit's tibia provided the necessary mechanical support to the injured bone area and facilitated the growth of the newly connective tissue, as well as osteoid formation and mineralization, as revealed by either histological sections or computed tomography reconstructed images and validated by the bone morphometric indices. The present study highlighted that the FeMnSiCa alloy promotes better osteoinduction and osseconduction processes when compared to the base FeMnSi alloy or with AISI 316 L, and in vivo degradation rates correlate well with corrosion resistance measurements in Ringer's solution.


Asunto(s)
Aleaciones , Materiales Biocompatibles , Aleaciones/farmacología , Animales , Materiales Biocompatibles/farmacología , Corrosión , Ensayo de Materiales , Oseointegración , Prótesis e Implantes , Conejos
7.
Acta Chim Slov ; 65(1): 97-107, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29562115

RESUMEN

The present study reports the first time use of MCM-41 mesoporous silica as highly efficient carrier for bexarotene - an antineoplastic agent specific for cutaneous T-cell lymphoma treatment. Bexarotene is highly toxic and poor-water soluble, having low bioavailability in the conventional pharmaceutical forms. Comparative uptake of bexarotene on amino-functionalized silica host at various functionalization degrees is discussed in details taking into account all structural features, of matrix as well as properties of the drug molecules. The obtained results proved a successful bexarotene loading on amino-functionalized MCM-41 silica. The bexarotene molecules are adsorbed on the active centers in non-crystalline state proving the major role of the silica amino-functionalization for the drug solubility and bioavailability enhancing. In vitro dissolution tests showed a prolonged release of bexarotene during 12 h, reaching 50% release of loaded active molecules. The prolonged release has been demonstrated to be a result of the presence of aminopropyl groups on the silica pore walls.


Asunto(s)
Antineoplásicos/química , Bexaroteno/química , Preparaciones de Acción Retardada/química , Portadores de Fármacos/química , Dióxido de Silicio/química , Adsorción , Antineoplásicos/farmacología , Bexaroteno/farmacología , Disponibilidad Biológica , Composición de Medicamentos/métodos , Liberación de Fármacos , Nanopartículas/química , Tamaño de la Partícula , Porosidad , Solubilidad , Propiedades de Superficie , Agua
8.
Molecules ; 22(11)2017 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-29156646

RESUMEN

Our research has focused on in vitro and in vivo evaluations of a new Carmustine (BCNU)-loaded clinoptilolite-based delivery system. Two clinoptilolite ionic forms-hydrogen form (HCLI) and sodium form (NaCLI)-were prepared, allowing a loading degree of about 5-6 mg BCNU/g of zeolite matrix due to the dual porous feature of clinoptilolite. Clinoptilolite-based delivery systems released 35.23% of the load in 12 h for the BCNU@HCLI system and only 10.82% for the BCNU@NaCLI system. The BCNU@HCLI system was chosen to develop gel and cream semisolid dosage forms. The cream (C_BCNU@HCLI) released 29.6% of the loaded BCNU after 12 h in the Nylon synthetic membrane test and 31.6% in the collagen membrane test, higher by comparison to the gel. The new cream was evaluated in vivo in a chemically induced model of skin cancer in mice. Quantitative immunohistochemistry analysis showed stronger inhibition of B-cell lymphoma-2 (bcl-2) and cyclooxygenase 2 (cox-2) protein expression, known markers for cancer survival and aggressiveness, after the treatment with C_BCNU@HCLI by comparison to all the control treatment types, including an off-label magistral formula commercially available Carmustine cream as reference, bringing evidence that a clinoptilolite-based delivery systems could be used as a cancer drug carriers and controlled release systems (skin-targeted topical delivery systems).


Asunto(s)
Antineoplásicos/química , Antineoplásicos/uso terapéutico , Carmustina/química , Carmustina/uso terapéutico , Ciclooxigenasa 2/metabolismo , Portadores de Fármacos/química , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Neoplasias Cutáneas/tratamiento farmacológico , Zeolitas/química , Animales , Ratones
9.
Molecules ; 21(7)2016 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-27367664

RESUMEN

The present paper focuses on solid lipid particles (SLPs), described in the literature as the most effective lipid drug delivery systems that have been introduced in the last decades, as they actually combine the advantages of polymeric particles, hydrophilic/lipophilic emulsions and liposomes. In the current study, we present our most recent advances in the preparation of alendronate (AL)-loaded SLPs prepared by hot homogenization and ultrasonication using various ratios of a self-emulsifying lipidic mixture of Compritol 888, Gelucire 44/14, and Cremophor A 25. The prepared AL-loaded SLPs were investigated for their physicochemical, morphological and structural characteristics by dynamic light scattering, differential scanning calorimetry, thermogravimetric and powder X-ray diffraction analysis, infrared spectroscopy, optical and scanning electron microscopy. Entrapment efficacy and actual drug content were assessed by a validated HPLC method. In vitro dissolution tests performed in simulated gastro-intestinal fluids and phosphate buffer solution pH 7.4 revealed a prolonged release of AL of 70 h. Additionally, release kinetics analysis showed that both in simulated gastrointestinal fluids and in phosphate buffer solution, AL is released from SLPs based on equal ratios of lipid excipients following zero-order kinetics, which characterizes prolonged-release drug systems.


Asunto(s)
Alendronato/administración & dosificación , Conservadores de la Densidad Ósea/administración & dosificación , Sistemas de Liberación de Medicamentos , Liposomas , Administración Oral , Administración Tópica , Rastreo Diferencial de Calorimetría , Portadores de Fármacos , Liberación de Fármacos , Lípidos/química , Liposomas/química , Liposomas/ultraestructura , Análisis Espectral , Difracción de Rayos X
10.
Pharmacology ; 93(5-6): 253-9, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25059844

RESUMEN

BACKGROUND/AIMS: The present study investigates the effects of pregabalin (PGB), acetaminophen (ACET) and tenoxicam (TNX) administration in somatic and visceral nociception, using the tail flick test and the writhing test in mice. METHODS: In the tail flick test, the substances were administered orally and the latency time response was recorded 15, 30, 60, 90 and 120 min after administration. In the writhing test, pain responses were scored every 5 min during a 30-min period after intraperitoneal injection of diluted acetic acid. RESULTS: Our study demonstrated that oral administration of the combination PGB-ACET resulted in a stronger increase of latency reaction - statistically significant after 15 min compared to TNX and after 30 min compared to PGB in tail flick test. In the writhing test, the combination PGB-ACET, but also PGB-TNX, resulted in a stronger decrease of writhe numbers - statistically significant compared to the effects of the separate administration of each substance. This decrease was more intense in animals treated with the combination PGB-ACET than with PGB-TNX. CONCLUSION: These results suggest an antinociceptive activity which may be a consequence of the synergic action of the substances.


Asunto(s)
Acetaminofén/uso terapéutico , Analgésicos/uso terapéutico , Dolor/tratamiento farmacológico , Ácido gamma-Aminobutírico/análogos & derivados , Acetaminofén/administración & dosificación , Ácido Acético , Analgésicos/administración & dosificación , Animales , Combinación de Medicamentos , Sinergismo Farmacológico , Calor , Masculino , Ratones , Dolor/inducido químicamente , Dolor/etiología , Piroxicam/administración & dosificación , Piroxicam/análogos & derivados , Piroxicam/uso terapéutico , Pregabalina , Ácido gamma-Aminobutírico/administración & dosificación , Ácido gamma-Aminobutírico/uso terapéutico
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA