Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Life Sci ; 286: 120042, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34678262

RESUMO

At present, little information on the biopharmaceutical behaviour of proton pump inhibitors (PPIs) describing their absorption and biodistribution in vivo has been reported because the extreme instability of PPIs in the gastrointestinal environment makes it difficult to analyze such behaviour. In this work, a modified rat in situ intestinal perfusion model was employed to investigate absorption in the gastrointestinal tract and subsequent biodistribution of several PPIs (ilaprazole, esomeprazole and rabeprazole), which have different physicochemical properties. Our data indicated that PPIs exhibited significantly enhanced absorption rates in the whole intestine, including the duodenum, jejunum, ileum and colon, corresponding to the increase in the oil-water partition coefficient (LogP). PPIs and corresponding salt types showed no obvious differences in absorption, implying that solubility changes in the PPI have little effect on its absorption in the gastrointestinal tract. Among these PPIs, ilaprazole presented a more stable intestinal absorption behaviour, as well as more distribution and longer residence time in the stomach by HPLC-MS/MS analysis and radioactivity counts after 14C radiolabelling. These results may be useful information for PPI optimization and oral formulation design.


Assuntos
Absorção Fisico-Química/efeitos dos fármacos , Absorção Intestinal/efeitos dos fármacos , Inibidores da Bomba de Prótons/farmacologia , 2-Piridinilmetilsulfinilbenzimidazóis/farmacologia , Absorção Fisico-Química/fisiologia , Adsorção , Animais , Produtos Biológicos/farmacocinética , Produtos Biológicos/farmacologia , Fenômenos Químicos/efeitos dos fármacos , China , Esomeprazol/farmacologia , Feminino , Íleo/metabolismo , Absorção Intestinal/fisiologia , Jejuno/metabolismo , Masculino , Inibidores da Bomba de Prótons/metabolismo , Inibidores da Bomba de Prótons/farmacocinética , Rabeprazol/farmacologia , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas em Tandem/métodos , Distribuição Tecidual/efeitos dos fármacos
2.
Artigo em Inglês | MEDLINE | ID: mdl-33865541

RESUMO

The genotoxic and cytotoxic effects of 2,4-dichlorophenoxyacetic acid (2,4-D) on specimens of Astyanax lacustris were evaluated using different biomarkers. Additionally, this study evaluated the efficiency of an activated carbon filter made from the husks green coconut, which was used as a biosorbent to remove 2,4-D dissolved in the water, and the potential effectiveness of this procedure for the reduction of the toxic effects of this compound on A. lacustris. Three sublethal concentrations of 2,4-D (10, 20, and 40 mg L-1) were tested over 24, 48, and 72 h, and their effects on Astyanax lacustris were evaluated using chromosomal aberration test, the mitotic index, the frequency of micronuclei and nuclear alterations, and the comet assay. Exposure to 2,4-D increased the frequency of chromosomal aberrations, reduced the mitotic index, and caused significant levels of nuclear modification in some of the treatments, in comparison with the negative control. The comet assay revealed DNA damage (classes 1-3) at all 2,4-D concentrations, reaching significant levels in the 20 mg L-1 (48 h) and 40 mg L-1 (72 h) treatments. The coconut husk biosorbent was highly effective for the removal of 2,4-D and the fish exposed to the water decontaminated by this filter had low levels of cellular alteration. The findings of the present study demonstrated, for the first time, the genotoxic and cytotoxic effects of 2,4-D in Astyanax lacustris, as well as suggests the potential application of a biosorbent for the effective decontamination of water contaminated with pesticides.


Assuntos
Ácido 2,4-Diclorofenoxiacético/isolamento & purificação , Ácido 2,4-Diclorofenoxiacético/toxicidade , Materiais Biocompatíveis/farmacocinética , Characidae , Recuperação e Remediação Ambiental/métodos , Absorção Fisico-Química/efeitos dos fármacos , Animais , Materiais Biocompatíveis/química , Characidae/genética , Aberrações Cromossômicas/induzido quimicamente , Aberrações Cromossômicas/veterinária , Cocos/química , Ensaio Cometa , Análise Citogenética/veterinária , Dano ao DNA , Monitoramento Ambiental/métodos , Filtração/instrumentação , Filtração/métodos , Herbicidas/isolamento & purificação , Herbicidas/toxicidade , Testes de Mutagenicidade , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/toxicidade , Purificação da Água/métodos
3.
Food Chem ; 356: 129713, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33836360

RESUMO

In this study, we investigated the effects of melatonin application on berry coloration, sugar accumulation, and nutrient absorption in 'Summer Black' grapes. Melatonin spraying at 100 µmol L-1 on grapes during veraison induced skin coloration earlier than that in controls, as well as higher transcript abundance of anthocyanin biosynthesis-related genes and transcription factors MYBA1 and MYBA2. Melatonin treatment increased the soluble sugar content, especially of sucrose, by promoting the activity of sucrose phosphate synthase, and also increased endogenous melatonin content and the concentrations of mineral nutrients N, K, Cu, Fe, and Zn in grape berries. Correlation analysis suggested that high sugar content promoted anthocyanin synthesis. These findings provide a sound theoretical basis for the development of techniques aimed to achieve optimum coloration of grapes in hot and rainy regions.


Assuntos
Absorção Fisico-Química/efeitos dos fármacos , Frutas/efeitos dos fármacos , Melatonina/farmacologia , Nutrientes/metabolismo , Pigmentação/efeitos dos fármacos , Sacarose/metabolismo , Vitis/efeitos dos fármacos , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Humanos , Vitis/genética , Vitis/crescimento & desenvolvimento , Vitis/metabolismo
4.
J Oleo Sci ; 70(4): 509-519, 2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33692240

RESUMO

Softening agents, when applied in appropriate amounts, can impart softness to fabrics, particularly cotton towels, such that improved comfort and feel can be achieved when using the fabrics. On the other hand, water absorbency, which is commonly regarded as the mark of high-quality cotton products, significantly decreases when any of the currently existing softeners is used. To date, when a softener is used on cotton fabrics, there is a trade-off between excellent softness and high-water absorbency. In our research, we introduced a new sensory evaluation indicator called the "water wiping-off feeling ratio" which looks primitive but shows high correlation with our actual feel over any other existing indicators. Furthermore, we developed a new method and model to overcome the above-mentioned trade-off, involving the use of small particles with a hydrophilic surface together with the softener. Inspired by the theory of fractal geometry and the combination of models/equations by Cassie, Baxter, and Wenzel, the idea of adding new convex hydrophilic domains onto the surface of cotton fibers along with the softening agent was conceived. Finally, we successfully improved the wiping-off feel without decreasing the softness, i.e., we developed a strategy to overcome the above-mentioned trade-off in softener-treated fabrics that has proven challenging thus far.


Assuntos
Absorção Fisico-Química/efeitos dos fármacos , Fibra de Algodão , Interações Hidrofóbicas e Hidrofílicas , Tensoativos/química , Tensoativos/farmacologia , Água , Compostos Orgânicos/química , Compostos Orgânicos/farmacologia
5.
Carbohydr Polym ; 261: 117883, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33766370

RESUMO

A new biosorbent Ca-crosslinked pectin/lignocellulose nanofibers/chitin nanofibers (PLCN) was synthesized for cholesterol and bile salts adsorption from simulated intestinal fluid during gastric-intestinal passage. The physico-chemical properties of PLCN were studied using SEM, FTIR, XRD, DSC and BET. Before gastrointestinal passage, PLCN had an amorphous single-phase, compact structure formed via hydrogen and van der Waals bonds that revealed an irregular shape with the shriveled surface but watery condition and enzymatic digestion led to create a porous structure without destruction because of the water-insoluble nanofibers, therefore increasing the adsorption capacity. The maximum adsorption capacity reached 37.9 and 5578.4 mg/g for cholesterol and bile salts, respectively. Freundlich isotherm model indicated the reversible heterogeneous adsorption of both cholesterol and bile salts on PLCN. Further, their adsorption followed pseudo-second order kinetic model. These results suggest that PLCN has potential as a gastrointestinal-resistant biosorbent for cholesterol and bile salts adsorption applicable in medicine and food industry.


Assuntos
Ácidos e Sais Biliares/farmacocinética , Quitina/química , Colesterol/farmacocinética , Lignina/química , Nanofibras/química , Pectinas/química , Absorção Fisico-Química/efeitos dos fármacos , Adsorção/efeitos dos fármacos , Quitina/farmacocinética , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/metabolismo , Humanos , Técnicas In Vitro , Cinética , Lignina/farmacocinética , Nanocompostos/análise , Nanocompostos/química , Pectinas/farmacocinética
6.
Dokl Biochem Biophys ; 497(1): 95-98, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33666805

RESUMO

We found an experimental solution to the paradox when the reabsorption of solute-free water increases with a simultaneous increase in diuresis and saluresis in the rat kidney under the oxytocin action. Injection of oxytocin to rats (0.25 nmol/100 g of body weight) increases diuresis from 0.16 ± 0.03 to 0.26 ± 0.02 mL/h, the excretion of solutes from 134 ± 13.7 to 300 ± 16.3 µOsm/h, and the reabsorption of solute-free water, which correlates with the renal excretion of oxytocin (p < 0.001). The mechanism of the effect is that oxytocin decreases the reabsorption of ultrafiltrate in the proximal tubule (the clearance of lithium increases) and increases the fluid flow through the distal segment of the nephron. In vivarium rats, urine osmolality (1010 ± 137 mOsm/kg H2O) and the concentration of vasopressin are high, this causes an increase in the reabsorption of solute-free water. Thus, oxytocin increases saluresis, which, against the background of a high level of endogenous vasopressin, increases the water reabsorption in the collecting ducts.


Assuntos
Absorção Fisico-Química/efeitos dos fármacos , Ocitocina/farmacologia , Sódio/urina , Água/metabolismo , Animais , Diurese/efeitos dos fármacos , Concentração Osmolar , Ratos
7.
Ars pharm ; 60(4): 205-211, oct.-dic. 2019. tab
Artigo em Inglês | IBECS | ID: ibc-188483

RESUMO

Objectives: The physicochemical characteristics of bran of cassava starch flour and bran of cassava flour (viz. organoleptic characteristics, pH value, moisture content, total ashes, lipid, protein, starch and fiber contents) and biopharmacotechnical parameters (viz. granulometry, flow capacity, angle at rest, outflow time and apparent density) were evaluated aiming at assessing their potential use as tablet excipients. Methodos: Three tablet formulations of venlafaxine hydrochloride were proposed, having as excipients bran of cassava flour, bran of cassava starch flour and Starch 1500(R). The tablets were produced using two different pressures (98 ± 5 MPa and 32 ± 6 Mpa) and their mechanical (hardness and friability) and dissol-ubility characteristics were evaluated. Results and Conclusions: The tablets produced with both cassava flours, using higher pressures, presented similar physicochemical characteristics to those obtained with the excipient Starch1500(R), thus indicating that cassava flours possess the potential to be used as disintegrating agents in tablets


Objetivos: Se evaluaron características físico-químicas del salvado de harina y del salvado de la fécula de mandioca (características organolépticas, pH, humedad, cenizas totales y contenido de lípidos, proteínas, almidones y fibras) y biofarmacotécnicas (granulometría, capacidad de flujo, ángulo en reposo, tiempo de salida y densidad aparente) con el objetivo de evaluar el uso de estos residuos como excipientes para comprimidos. Métodos: Se propusieron tres formulaciones en comprimidos de venlafaxina teniendo como excipientes salvado de harina de mandioca, salvado de fécula de mandioca y Starch 1500 (R). Las pastillas se produjeron utilizando dos presiones diferentes (98 ± 5 MPa y 32 ± 6 Mpa). Las características mecánicas (dureza y friabilidad) y de disolución de los comprimidos se evaluaron. Resultados y Conclusiones: Los comprimidos producidos con ambos salvados de mandioca, utilizando las presiones más elevadas, presentaron características físico-químicas similares a las obtenidas con el excipiente Starch1500(R), indicando que las harinas de mandioca poseen potencial para ser utilizadas como agentes desintegrantes en comprimidos


Assuntos
Excipientes Farmacêuticos , Comprimidos/farmacologia , Manihot/química , Comprimidos/normas , Físico-Química/métodos , Absorção Fisico-Química/efeitos dos fármacos
8.
Farm. hosp ; 43(5): 163-165, sept.-oct. 2019. tab
Artigo em Espanhol | IBECS | ID: ibc-183929

RESUMO

Objetivo: Determinar experimentalmente si micafungina y anidulafungina poseen propiedades fisicoquímicas adecuadas para su nebulización. Método: Se determinó el pH, la osmolalidad, la viscosidad, la densidad y el contenido en cloruros mediante pH-metría, osmometría, viscosimetría, densitometría y potenciometría, respectivamente, en dos muestras de diferente concentración, 5 y 10 mg/ml, de cada equinocandina. Resultados: Para la solución de micafungina 5 mg/ml los resultados obtenidos fueron: pH 5,80 (0,14), osmolalidad 293,33 (1,53) mOsm/kg, contenido en cloruros 134,67 (0,58) mmol/l y densidad 1.009,4 (0,1) kg/m3; y para la solución de 10 mg/ml: osmolalidad 342,00 (1,00) mOsm/kg, contenido en cloruros 139,67 (0,58) mmol/l y densidad 1.014,5 (0,2) kg/m3. Para la solución de anidulafungina 5 mg/ml los resultados obtenidos fueron: pH 4,22 (0,01), osmolalidad 464,67 (2,52) mOsm/kg, contenido en cloruros 137,00 (0,00) mmol/l y densidad 1.016,5 (0,2) kg/m3; y para la solución de 10 mg/ml: osmolalidad 656,33 (1,15) mOsm/kg, contenido en cloruros 132,00 (0,00) mmol/l y densidad 1.029,8 (0,4) kg/m3. Conclusiones: Los valores de pH, osmolalidad, contenido en cloruros y densidad resultaron adecuados para una correcta tolerabilidad mediante nebulización


Objective: To determine by experimentation whether micafungin and anidulafungin possess physicochemical properties suitable for nebulization. Method: PH, osmolality, viscosity, density and chloride content were determined by pH monitoring, osmometry, viscometry, densitometry and potentiometry in two samples of different concentrations, 5 and 10 mg/mL each echinocandin. Results: The results obtained for micafungin solution were: pH 5.80 (0.14), osmolality 293.33 (1.53) mOsm/kg, chloride content 134.67 (0.58) mmol/L and density 1,009.4 (0,1) kg/m3; while for 10 mg/mL solution: osmolality 342.00 (1.00) mOsm/kg, chloride content 139.67 (0.58) mmol/L and density 1,014.5 (0.2) kg/m3. The results obtained for 5 mg/mL anidulafungin were: pH 4.22 (0.01), osmolality 464.67 (2.52) mOsm/kg, chloride content 137.00 (0.00) mmol/L and density 1,016.5 (0,2) kg/m3; while for 10 mg/mL solution: osmolality 656.33 (1.15) mOsm/kg, chloride content 132.00 (0.00) mmol/L and density 1,029.8 (0.4) kg/m3. Conclusions: PH, osmolality, chloride content and density values proved to be suitable for proper tolerability by nebulization


Assuntos
Micafungina/química , Anidulafungina/química , Nebulizadores e Vaporizadores , Físico-Química/métodos , Absorção Fisico-Química/efeitos dos fármacos , Administração por Inalação , Concentração de Íons de Hidrogênio , Concentração Osmolar , Viscosidade , Equinocandinas/análise
9.
Nutrients ; 11(12)2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31888255

RESUMO

Polyphenols are widely acknowledged for their health benefits, especially for the prevention of inflammatory and age-related diseases. We previously demonstrated that hydroxytyrosol (HT) and procyanidins (PCy), alone or in combination, drive preventive anti-osteoathritic effects in vivo. However, the lack of sufficient clinical evidences on the relationship between dietary phytochemicals and osteoarthritis remains. In this light, we investigated in humans the potential osteoarticular benefit of a grapeseed and olive extract (OPCO) characterized for its hydroxytyrosol (HT) and procyanidins (PCy) content. We first validated, in vitro, the anti-inflammatory and chondroprotective properties of the extract on primary cultured human articular chondrocytes stimulated by interleukin-1 beta (IL-1 ß). The sparing effect involved a molecular mechanism dependent on the nuclear transcription factor-kappa B (NF-κB) pathway. To confirm the clinical relevance of such a nutritional strategy, we designed an innovative clinical approach taking into account the metabolites that are formed during the digestion process and that appear in circulation after the ingestion of the OPCO extract. Blood samples from volunteers were collected following ingestion, absorption, and metabolization of the extract and then were processed and applied on human primary chondrocyte cultures. This original ex vivo methodology confirmed at a clinical level the chondroprotective properties previously observed in vitro and in vivo.


Assuntos
Absorção Fisico-Química/efeitos dos fármacos , Anti-Inflamatórios/farmacologia , Condrócitos/efeitos dos fármacos , Extrato de Sementes de Uva/farmacologia , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Adulto , Células Cultivadas , Voluntários Saudáveis , Humanos , Interleucina-1beta/sangue , Masculino , NF-kappa B/sangue , Álcool Feniletílico/análogos & derivados , Álcool Feniletílico/farmacologia , Proantocianidinas/farmacologia , Adulto Jovem
10.
J Tradit Chin Med ; 39(5): 609-623, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-32186110

RESUMO

OBJECTIVE: To examine changes in the morphology and physiological functions of human proximal tubular epithelial cells (HK-2 cells) caused by total Dahuang (Radix Et Rhizoma Rhei Palmati) anthraquinones (TDA) and emodin. METHODS: HK-2 cells were cultured on polycarbonate (PCF) membranes to form a complete monolayer of cells. A fluorescein isothiocyanate-dextran (FITC) permeability assay was conducted and secretion of γ-glutamyltranspeptidase (GGT), lactate dehydrogenase (LDH), N-acetyl-ß-D-glucosaminidase (NAG) and kidney injury molecule 1 (KIM-1) was examined. The reabsorption of glucose and the excretion of para-aminohippuric acid (PAH) by HK-2 cells were also examined. The morphology of HK-2 cells was observed using optical microscopy and scanning electron microscopy. The cytoskeleton of HK-2 cells was observed under a fluorescence microscope. RESULTS: Compared with the results for the dimethyl sulfoxide group, treatment of cells with TDA and emodin showed statistically significant differences in the FITC leakage rate, the apical / basolateral ratio of LDH and GGT, and the secretion of GGT, LDH, NAG and KIM-1. At 64 µg/mL, TDA markedly inhibited blood glucose reabsorption and remarkably suppressed PAH excretion by HK-2 cells. Both TDA and emodin caused various degrees of damage to the morphology and cytoskeleton of HK-2 cells with the degree of damage correlating positively with the dosage of the tested substances. CONCLUSION: Both TDA and emodin caused damage to human renal proximal tubular epithelial cells at certain dosages. At the same dosage, TDA caused more severe damage than emodin to the HK-2 cells.


Assuntos
Antraquinonas/efeitos adversos , Emodina/efeitos adversos , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Túbulos Renais Proximais/citologia , Rheum/química , Absorção Fisico-Química/efeitos dos fármacos , Actinas/metabolismo , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Células Epiteliais/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Receptor Celular 1 do Vírus da Hepatite A/metabolismo , Humanos , L-Lactato Desidrogenase/metabolismo , Proteínas de Neoplasias/metabolismo , gama-Glutamiltransferase/metabolismo
11.
J Lipid Res ; 60(1): 161-167, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30323110

RESUMO

Very few studies have investigated the interrelations between proprotein convertase subtilisin/kexin type 9 (PCSK9) metabolism, cholesterol synthesis, and cholesterol absorption. We aimed to address this issue in a large clinical trial of 245 patients with hypercholesterolemia. Serum lipids, PCSK9, lathosterol (cholesterol synthesis marker), campesterol, and sitosterol (cholesterol absorption markers) were measured before and 4-8 weeks after the start of treatment with PCSK9-antibodies (alirocumab or evolocumab). The patients had mean (standard error) LDL-cholesterol and PCSK9 concentrations of 3.87 (0.10) mmol/l and 356 (17) ng/ml, respectively. Eighty-four patients received no lipid-lowering pretreatment, 26 ezetimibe, 38 statins, and 97 ezetimibe + statins. Circulating PCSK9 increased in parallel with the potency of lipid-lowering pretreatment with circulating PCSK9 being highest in the ezetimibe + statin group (P < 0.001). Treatment with PCSK9-antibodies strongly decreased LDL-cholesterol, lathosterol, campesterol, and sitosterol (all P < 0.001) but hardly affected noncholesterol sterol to cholesterol ratios. Lipid-lowering pretreatment was not associated with the effects of PCSK9-antibodies on noncholesterol sterols (all P > 0.05). Summing up, circulating PCSK9 is increased by cholesterol synthesis and absorption inhibitors. Increased PCSK9 expression may partly explain the strong reductions of LDL-cholesterol achieved with PCSK9-antibodies after such pretreatment. On the other hand, treatment with PCSK9-antibodies does not significantly change the balance between cholesterol synthesis and absorption.


Assuntos
Absorção Fisico-Química , Colesterol/biossíntese , Colesterol/metabolismo , Pró-Proteína Convertase 9/metabolismo , Absorção Fisico-Química/efeitos dos fármacos , Feminino , Humanos , Hipolipemiantes/farmacologia , Masculino , Pessoa de Meia-Idade , Pró-Proteína Convertase 9/sangue
12.
J Lipid Res ; 60(2): 333-340, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30552287

RESUMO

Various functions of dietary sphingolipids have been reported; however, little is known about marine sphingolipids. Ceramide 2-aminoethylphosphonate (CAEP), an abundant sphingolipid in marine mollusks, frequently has a unique triene type of sphingoid base [2-amino-9-methyl-4,8,10-octadecatriene-1,3-diol (d19:3)]. We previously reported that dietary CAEP prepared from the skin of squid was digested in the intestinal mucosa of mice via ceramides to yield free sphingoid bases. How dietary CAEP is then used in the body remains unclear. Here, we investigated the absorption of dietary CAEP using a lipid absorption assay on the lymph collected from rats with thoracic duct cannulation. Our results reveal that sphingoid bases derived from CAEP, including d16:1, d18:1, and d19:3, were detected in the lymph after administration of CAEP. Lymphatic recovery of d19:3 was lower than that of other sphingoid bases. A large fraction of the absorbed sphingoid bases was present as complex sphingolipids, whereas a smaller portion was present in the free form. Fatty acids in ceramide moieties found in the lymph were partially different from dietary CAEP, which indicates that sphingoid bases derived from CAEP could be, at least in part, resynthesized into complex sphingolipids. Future studies should elucidate the metabolism of sphingoid bases derived from CAEP.


Assuntos
Absorção Fisico-Química , Ácido Aminoetilfosfônico/análogos & derivados , Ceramidas/química , Carboidratos da Dieta , Linfa/metabolismo , Esfingolipídeos/metabolismo , Absorção Fisico-Química/efeitos dos fármacos , Ácido Aminoetilfosfônico/química , Ácido Aminoetilfosfônico/farmacologia , Animais , Ceramidas/farmacologia , Carboidratos da Dieta/farmacologia , Linfa/efeitos dos fármacos , Ratos
13.
Epilepsia ; 59 Suppl 2: 207-215, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30159892

RESUMO

A subgroup of patients with drug-resistant epilepsy have seizure clusters, which are a part of the continuum of seizure emergencies that includes prolonged episodes and status epilepticus. When the patient or caregiver can identify the beginning of a cluster, the condition is amenable to certain treatments, an approach known as rescue therapy. Intravenous drug administration offers the fastest onset of action, but this route is usually not an option because most seizure clusters occur outside of a medical facility. Alternate routes of administration have been used or are proposed including rectal, buccal, intrapulmonary, subcutaneous, intramuscular, and intranasal. The objective of this narrative review is to describe the (1) anatomical, physiologic, and drug physicochemical properties that need to be considered when developing therapies for seizure emergencies and (2) products currently in development. New therapies must consider parameters of Fick's law such as absorptive surface area, blood flow, membrane thickness, and lipid solubility, because these factors affect both rate and extend of absorption. For example, the lung has a 50 000-fold greater absorptive surface area than that associated with a subcutaneous injection. Lipid solubility is a physicochemical property that influences the absorption rate of small molecule drugs. Among drugs currently used or under development for rescue therapy, allopregnanolone has the greatest lipid solubility at physiologic pH, followed by propofol, midazolam, diazepam, lorazepam, alprazolam, and brivaracetam. However, greater lipid solubility correlates with lower water solubility, complicating formulation of rescue therapies. One approach to overcoming poor aqueous solubility involves the use of a water-soluble prodrug coadministered with a converting enzyme, which is being explored for the intranasal delivery of diazepam. With advances in seizure prediction technology and the development of drug delivery systems that provide rapid onset of effect, rescue therapies may prevent the occurrence of seizures, thus greatly improving the management of epilepsy.


Assuntos
Anticonvulsivantes/uso terapêutico , Convulsões/tratamento farmacológico , Resultado do Tratamento , Absorção Fisico-Química/efeitos dos fármacos , Anticonvulsivantes/sangue , Anticonvulsivantes/farmacocinética , Vias de Administração de Medicamentos , Sistemas de Liberação de Medicamentos , Feminino , Humanos , Masculino
14.
Artigo em Inglês | MEDLINE | ID: mdl-26930688

RESUMO

The human colorectal carcinoma cell line (Caco-2) is a commonly used in-vitro test that predicts the absorption potential of orally administered drugs. In-silico prediction methods, based on the Caco-2 assay data, may increase the effectiveness of the high-throughput screening of new drug candidates. However, previously developed in-silico models that predict the Caco-2 cellular permeability of chemical compounds use handcrafted features that may be dataset-specific and induce over-fitting problems. Deep Neural Network (DNN) generates high-level features based on non-linear transformations for raw features, which provides high discriminant power and, therefore, creates a good generalized model. We present a DNN-based binary Caco-2 permeability classifier. Our model was constructed based on 663 chemical compounds with in-vitro Caco-2 apparent permeability data. Two hundred nine molecular descriptors are used for generating the high-level features during DNN model generation. Dropout regularization is applied to solve the over-fitting problem and the non-linear activation. The Rectified Linear Unit (ReLU) is adopted to reduce the vanishing gradient problem. The results demonstrate that the high-level features generated by the DNN are more robust than handcrafted features for predicting the cellular permeability of structurally diverse chemical compounds in Caco-2 cell lines.


Assuntos
Absorção Fisico-Química/efeitos dos fármacos , Aprendizado Profundo , Modelos Estatísticos , Preparações Farmacêuticas/metabolismo , Células CACO-2 , Permeabilidade da Membrana Celular/efeitos dos fármacos , Biologia Computacional , Simulação por Computador , Avaliação Pré-Clínica de Medicamentos , Humanos
15.
J Inorg Biochem ; 181: 139-144, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28967474

RESUMO

The aim of this study was to determine the content, distribution and behaviour of Al in soils under beech forest with different parent rock, and to assess the role of herbaceous vegetation on soil Al behaviour. We hypothesize that the contents of elements in the soil sorption complex (Al etc.) are strongly influenced by vegetation cover. Also, low molecular mass organic acids (LMMOA) can be considered as an indicator of soil organic matter (SOM) decomposition and vegetation litter turnover. Speciation of LMMOA, nutrition content (PO43-, Ca2+, K+) and element composition in aqueous extracts were determined by means of ion chromatography and inductively coupled plasma - optical emission spectrometry (ICP-OES) respectively. Active and exchangeable pH, sorption characteristics and exchangeable Al (Alex) were determined in BaCl2 extracts by ICP-OES. Elemental composition of parent rocks was assessed by means of X-ray fluorescence spectroscopy. Herb-poor localities showed lower pH, less nutrients (PO43-, Ca2+, K+), less LMMOA, a larger stock of SOM and greater cation exchange capacity. There was also lower mobilisation of Al in organic horizons, which explains the larger pools of Al. Generally, we can conclude that LMMOA, and thus soil vegetation cover, play an important role in the Al soil cycle.


Assuntos
Alumínio/toxicidade , Quelantes/química , Sedimentos Geológicos/química , Desenvolvimento Vegetal/efeitos dos fármacos , Plantas Medicinais/efeitos dos fármacos , Poluentes do Solo/toxicidade , Solo/química , Absorção Fisico-Química/efeitos dos fármacos , Absorção Fisiológica/efeitos dos fármacos , Alumínio/análise , Alumínio/química , Alumínio/metabolismo , Quelantes/análise , República Tcheca , Fagus/química , Fagus/efeitos dos fármacos , Fagus/crescimento & desenvolvimento , Fagus/metabolismo , Florestas , Substâncias Húmicas/análise , Concentração de Íons de Hidrogênio , Peso Molecular , Plantas/efeitos dos fármacos , Plantas/metabolismo , Plantas Medicinais/crescimento & desenvolvimento , Plantas Medicinais/metabolismo , Poluentes do Solo/análise , Poluentes do Solo/química , Poluentes do Solo/metabolismo , Solubilidade
16.
Lancet Haematol ; 4(11): e524-e533, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29032957

RESUMO

BACKGROUND: Current guidelines to treat iron deficiency recommend daily provision of ferrous iron divided through the day to increase absorption. However, daily dosing and split dosing might increase serum hepcidin and decrease iron absorption from subsequent doses. Our study aim was to compare iron absorption from oral iron supplements given on consecutive versus alternate days and given as single morning doses versus twice-daily split dosing. METHODS: We did two prospective, open-label, randomised controlled trials assessing iron absorption using (54Fe)-labelled, (57Fe)-labelled, or (58Fe)-labelled ferrous sulfate in iron-depleted (serum ferritin ≤25 µg/L) women aged 18-40 years recruited from ETH Zurich and the University of Zurich, Switzerland. In study 1, women were randomly assigned (1:1) to two groups. One group was given 60 mg iron at 0800 h (±1 h) on consecutive days for 14 days, and the other group was given the same doses on alternate days for 28 days. In study 2, women were assigned to two groups, stratified by serum ferritin so that two groups with similar iron statuses could be formed. One group was given 120 mg iron at 0800 h (±1 h) and the other was given the dose split into two divided doses of 60 mg at 0800 h (±1 h) and 1700 h (±1 h) for three consecutive days. 14 days after the final dose, the groups were each crossed over to the other regimen. Within-individual comparisons were done. The co-primary outcomes in both studies were iron bioavailability (total and fractional iron absorption), assessed by measuring the isotopic label abundance in erythrocytes 14 days after administration, and serum hepcidin. Group allocations in both studies were not masked and primary and safety analyses were done on an intention-to-treat basis. The studies were registered at ClinicalTrials.gov, numbers NCT02175888 (study 1) and NCT02177851 (study 2) and are complete. FINDINGS: For study 1, 40 women were enrolled on Oct 15-29, 2015. 21 women were assigned to the consecutive-day group and 19 to the alternate-day group. At the end of treatment (14 days for the consecutive-day group and 28 days for the alternate-day group), geometric mean (-SD, +SD) cumulative fractional iron absorptions were 16·3% (9·3, 28·8) in the consecutive-day group versus 21·8% (13·7, 34·6) in the alternate-day group (p=0·0013), and cumulative total iron absorption was 131·0 mg (71·4, 240·5) versus 175·3 mg (110·3, 278·5; p=0·0010). During the first 14 days of supplementation in both groups, serum hepcidin was higher in the consecutive-day group than the alternate-day group (p=0·0031). In study 2, 20 women were enrolled between Aug 13 and 18, 2015. Ten women were assigned to receive once-daily dosing and ten were assigned to receive twice-daily divided dosing. No significant differences were seen in fractional (day 1-3 geometric mean: 11·8% [7·1, 19·4] once daily vs 13·1% [8·2, 20·7] twice daily; p=0·33) or total iron absorption (day 1-3: 44·3 mg [29·4, 66·7] once daily vs 49·4 [35·2, 69·4] twice daily; p=0·33) between the two dosing regimens. Twice-daily divided doses resulted in a higher serum hepcidin concentration than once-daily dosing (p=0·013). No grade 3 or 4 adverse events were reported in either study. INTERPRETATION: In iron-depleted women, providing iron supplements daily as divided doses increases serum hepcidin and reduces iron absorption. Providing iron supplements on alternate days and in single doses optimises iron absorption and might be a preferable dosing regimen. These findings should be confirmed in iron-deficient anaemic patients. FUNDING: Swiss National Science Foundation, Bern, Switzerland.


Assuntos
Absorção Fisico-Química/efeitos dos fármacos , Ferro/administração & dosagem , Ferro/metabolismo , Administração Oral , Adolescente , Adulto , Esquema de Medicação , Feminino , Hepcidinas/sangue , Humanos , Ferro/farmacologia , Deficiências de Ferro , Masculino , Adulto Jovem
17.
J Clin Lipidol ; 11(4): 1032-1042, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28826566

RESUMO

BACKGROUND: Growth hormone (GH) replacement therapy improves hypercholesterolemia in patients with GH deficiency, suggesting that GH modulates cholesterol metabolism. OBJECTIVES: We examined GH effects on lipid profiles and cholesterol-related markers reflecting hepatic and cerebral cholesterol metabolism in small-for-gestational age (SGA) children without catch-up growth. METHODS: This study examined SGA children without catch-up growth (n = 22) and healthy children (controls, n = 11). Based on parents' choice, 11 SGA children received GH at 0.23 to 0.25 mg/kg/d for 6 months, and at 0.34 to 0.36 mg/kg/d for the subsequent 6 months (GH (+) group). The other SGA children received no GH (GH (-) group, n = 11). We ascertained baseline and posttreatment lipid profiles and cholesterol-related markers reflecting hepatic and cerebral cholesterol metabolism. RESULTS: Baseline lipid profiles of SGA children and controls were similar. Serum 24S-hydroxycholesterol (marker for cerebral cholesterol metabolism) concentration was 19% lower in SGA children than in controls (P < .05). Compared with baseline, the GH (+) group low-density lipoprotein-cholesterol concentration had decreased by 6.6% during 6 months and 8.8% during 12 months (P < .01), whereas the high-density lipoprotein-cholesterol concentration had increased by 1.7% (P = .07) and 3.3% (P < .01). Serum 7α-hydroxycholesterol (marker for hepatic cholesterol elimination) concentration had increased by 34% at 6 months and 35% at 12 months (P < .01). In addition, 24S-hydroxycholesterol increased by 25% and 26% (P < .001). No marker for cholesterol synthesis or absorption changed. The GH (-) group lipid profiles and oxysterols remained unchanged during the observation period. CONCLUSION: GH activates hepatic and cerebral cholesterol metabolism in SGA children without catch-up growth.


Assuntos
Encéfalo/efeitos dos fármacos , Colesterol/metabolismo , Hormônio do Crescimento Humano/farmacologia , Recém-Nascido Pequeno para a Idade Gestacional/crescimento & desenvolvimento , Recém-Nascido Pequeno para a Idade Gestacional/metabolismo , Fígado/efeitos dos fármacos , Absorção Fisico-Química/efeitos dos fármacos , Apolipoproteínas/metabolismo , Estatura/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Encéfalo/metabolismo , Criança , Pré-Escolar , Colesterol/biossíntese , Feminino , Glucose/metabolismo , Humanos , Fígado/metabolismo , Masculino
18.
Chem Biodivers ; 13(6): 755-61, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27138247

RESUMO

In continuation of our research program on Mediterranean dietary plants, a bioassay-guided fractionation of extracts from several accessions of Capparis sicula subsp. sicula and Capparis orientalis aerial parts was carried out. Antilipidemic activity of samples was assayed using inhibition of pancreatic lipase. To study the metabolic variability in Capparis species, HPTLC analyses were performed in order to characterize the species through the detection, isolation, and quantitative evaluation of rutin taken as significant chemical marker. The best activity was exerted by C. orientalis accession no. C10 and C. sicula subsp. sicula accession no. C6. The bioactivity evaluation of specific chemical markers, rutin and glucocapparin, led to the identification of a potent antilipidemic compound rutin. The HPTLC analysis showed large variation among the different analyzed samples with respect to rutin concentration. The chemical investigation showed a different composition between the species and between the collection zones. The variations showed by the studied accessions of caper could be attributed to exogenous factors. Capparis species contained predominantly quercetin rutinoside (rutin), accompanied by other constituents such as the glucosinolate glucocapparin. These rutin-rich extracts exhibited pronounced dose-dependent enzyme inhibitory activities toward pancreatic lipase.


Assuntos
Absorção Fisico-Química/efeitos dos fármacos , Capparis/química , Capparis/metabolismo , Inibidores Enzimáticos/farmacologia , Hipolipemiantes/farmacologia , Lipase/antagonistas & inibidores , Metabolismo dos Lipídeos/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Glucosinolatos/química , Glucosinolatos/isolamento & purificação , Glucosinolatos/farmacologia , Humanos , Hipolipemiantes/química , Hipolipemiantes/metabolismo , Lipase/metabolismo , Conformação Molecular , Rutina/isolamento & purificação , Rutina/farmacologia , Relação Estrutura-Atividade
19.
BMJ Case Rep ; 20162016 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-26746838

RESUMO

A 53-year-old woman attended for a routine outpatient appointment for follow-up of antineutrophil cytoplasmic antibody-positive vasculitis. Her disease had relapsed despite appropriate medical management with mycophenolate mofetil (MMF), as evidenced by rising acute phase response and antimyeloperoxidase titre with ongoing symptoms. On further questioning, she had been taking oral charcoal as part of a detoxification diet, which we postulate was causing significantly impaired MMF absorption. This case report summarises the presentation and highlights the importance of a thorough drug history, and should prompt the reader to keep an open mind with regard to drug interactions and treatment regimen adherence when treatment is, unexpectedly, seemingly failing.


Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/tratamento farmacológico , Imunossupressores/farmacocinética , Ácido Micofenólico/análogos & derivados , Absorção Fisico-Química/efeitos dos fármacos , Anticorpos Anticitoplasma de Neutrófilos/sangue , Antídotos/efeitos adversos , Carvão Vegetal/efeitos adversos , Interações Medicamentosas , Feminino , Humanos , Imunossupressores/uso terapêutico , Pessoa de Meia-Idade , Ácido Micofenólico/farmacocinética , Ácido Micofenólico/uso terapêutico , Prednisolona/uso terapêutico , Recidiva
20.
Environ Res ; 138: 298-305, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25749125

RESUMO

OBJECTIVE: To evaluate the association between mercury exposure and thyroid-stimulating hormone (TSH), total triiodothyronine (TT3) and free thyroxine (FT4) levels during pregnancy as well as to explore if there is any synergic action between mercury and intake of iodine from different sources. METHODS: The study population was 1407 pregnant women participating in the Spanish INMA birth cohort study. Total mercury concentrations were analyzed in cord blood. Thyroid hormones (THs) were measured in serum samples collected at 13.2±1.5 weeks of gestation. The association between mercury and TH levels was evaluated with multivariate linear regression models. Effect modification caused by iodine intake from supplements and diet was also evaluated. RESULTS: The geometric means of TSH, TT3, FT4 and mercury were 1.1µU/L, 2.4nmol/L, 10.5pmol/L and 7.7µg/L, respectively. Mercury levels were marginally significantly associated with TT3 (ß: -0.05; 95%CI: -0.10, 0.01), but were neither associated with TSH nor FT4. The inverse association between mercury and TT3 levels was stronger among the iodine supplement consumers (-0.08; 95%CI: -0.15, -0.02, interaction p-value=0.07). The association with FT4 followed the same pattern, albeit not significant. CONCLUSION: Prenatal mercury exposure was inversely associated with TT3 levels among women who took iodine supplements during pregnancy. These results could be of public health concern, although further research is needed.


Assuntos
Suplementos Nutricionais , Exposição Ambiental , Iodo/farmacologia , Mercúrio/sangue , Tireotropina/sangue , Tiroxina/sangue , Tri-Iodotironina/sangue , Absorção Fisico-Química/efeitos dos fármacos , Adulto , Estudos de Coortes , Monitoramento Ambiental , Feminino , Sangue Fetal/química , Fluorimunoensaio , Humanos , Gravidez , Espanha , Espectrofotometria Atômica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...