Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 181
Filtrar
1.
Pituitary ; 27(2): 187-196, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38273189

RESUMEN

PURPOSE: To prospectively evaluate the usefulness of T1-weighted imaging (T1WI) and diffusion-weighted imaging (DWI) sequences in predicting the consistency of macroadenomas. In addition, to determine their values ​​as prognostic factors of surgical outcomes. METHODS: Patients with pituitary macroadenoma and surgical indication were included. All patients underwent pre-surgical magnetic resonance imaging (MRI) that included the sequences T1WI before and after contrast administration and DWI with the apparent diffusion coefficient (ADC) map. Post-surgical MRI was performed at least 3 months after surgery. The consistency of the macroadenomas was evaluated at surgery, and they were grouped into soft and intermediate/hard adenomas. Mean ADC values, signal on T1WI and the ratio of tumor ADC values ​​to pons (ADCR) were compared with tumor consistency and grade of surgical resection. RESULTS: A total of 80 patients were included. A softened consistency was found at surgery in 53 patients and hardened in 27 patients. The median ADC in the soft consistency group was 0.532 × 10-3 mm2/sec (0.306 - 1.096 × 10-3 mm2/sec), and in the intermediate/hard consistency group was 0.509 × 10-3 mm2/sec (0.308 - 0.818 × 10-3 mm2/sec). There was no significant difference between the median values ​​of ADC, ADCR and signal on T1W between the soft and hard tumor groups, or between patients with and without tumor residue. CONCLUSION: Our results did not show usefulness of the DWI and T1WI for assessing the consistency of pituitary macroadenomas, nor as a predictor of the degree of surgical resection.


Asunto(s)
Adenoma , Neoplasias Hipofisarias , Humanos , Neoplasias Hipofisarias/diagnóstico por imagen , Neoplasias Hipofisarias/cirugía , Neoplasias Hipofisarias/patología , Imagen de Difusión por Resonancia Magnética/métodos , Imagen por Resonancia Magnética/métodos , Adenoma/diagnóstico por imagen , Adenoma/cirugía , Adenoma/patología , Estudios Retrospectivos
2.
Microb Pathog ; 180: 106119, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37098385

RESUMEN

Streptococcus pneumoniae is a bacterium that causes serious infections, including pneumonia. The limited range of available vaccines and the rise of antibiotic-resistant bacteria mean that new treatments are needed. This study looked at the potential of quercetin as an antimicrobial agent against S. pneumoniae in both isolation and in biofilms. The researchers used microdilution tests, checkerboard assays, and death curve assays, as well as in silico and in vitro cytotoxicity evaluations. They found that quercetin at a concentration of 125.0 µg/mL had both inhibitory and bactericidal effects against S. pneumoniae, and these effects were increased when quercetin was combined with ampicillin. Quercetin also reduced the growth of pneumococcal biofilms. In addition, quercetin (absence or in combination with ampicillin) reduced the death time of Tenebrio molitor larvae compared to the infection control. The study also demonstrated that quercetin had low toxicity in both in silico and in vivo assays, suggesting that it could be a promising treatment for infections caused by S. pneumoniae.


Asunto(s)
Antiinfecciosos , Infecciones Neumocócicas , Humanos , Streptococcus pneumoniae , Quercetina/farmacología , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Antiinfecciosos/farmacología , Ampicilina/farmacología , Pruebas de Sensibilidad Microbiana , Infecciones Neumocócicas/tratamiento farmacológico , Infecciones Neumocócicas/microbiología
3.
Analyst ; 148(2): 305-315, 2023 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-36541436

RESUMEN

Microcystins (MCs) are highly toxic peptides produced by cyanobacteria during algal blooms. Microcystin-leucine-arginine (MC-LR) is the most toxic and common MC variant with major effects on human and animal health upon exposure. MC-LR detection has become critical to ensure water safety, therefore robust and reliable analytical methods are needed. This work reports the development of a simple and optimized Molecularly Imprinted Nanoparticle-Based Assay (MINA) for MC-LR detection in water. Molecularly Imprinted Nanoparticles (MINs) were prepared by solid-phase polymerization on glass beads conjugated to MC-LR through (3-aminopropyl) triethoxysilane (APTES) via amide bonding. APTES-modified glass beads were obtained under optimized conditions to maximize the density of surface amino groups available for MC-LR conjugation. Two quinary mixtures of acrylic monomers differing in charge, polarity, and functionality were selected from molecular docking calculations and used to obtain MINs for MC-LR recognition using N,N'-methylene-bis-acrylamide (BIS) as the crosslinking agent. MINs were immobilized by physical adsorption onto 96-well polystyrene microplate and evaluated as per their rebinding capacity toward the analyte by using a covalent conjugate between MC-LR and the enzyme horseradish peroxidase (HRP). Experimental conditions for the MINs immobilization protocol, HRP-MC-LR concentration, and composition of the blocking solution were set to maximize the colorimetric response of the MINs compared to non-treated wells. Optimized conditions were then applied to conduct competitive MINAs with the HRP-MC-LR conjugate and the free analyte, which confirmed the preferential binding of MC-LR to the immobilized MINs for analyte concentrations ranging from 1 × 10-5 nmol L-1 to 100 nmol L-1. The best competitive MINA showed a limit of detection of 2.49 × 10-4 nmol L-1 and coefficients of variation less than 10% (n = 6), which are auspicious for the use of MINs as analytical tools for MC-LR detection below the permissible limits issued by WHO for safe water consumption (1.00 nmol L-1). This assay also proved to be selective to the analyte in cross-reactivity studies with two analogous microcystins (MC-RR and MC-YR). Analyses of lagoon and drinking water samples enriched with MC-LR revealed strong matrix effects that reduce the MINA response to the analyte, thus suggesting the need for sample pretreatment methods in future development in this subject.


Asunto(s)
Agua Potable , Microcistinas , Agua Potable/análisis , Toxinas Marinas , Microcistinas/análisis , Simulación del Acoplamiento Molecular
4.
An Acad Bras Cienc ; 95(3): e20220856, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37909564

RESUMEN

The properties of adhesive mortars can change due to heating, compromising the durability of the coating systems. The aim of this article was to evaluate the influence of cement and polymer contents on the tensile bond strength of adhesive mortars after thermal storage. Ceramic tiling system specimens were prepared with seventeen formulations of adhesive mortars. These specimens were stored under dry (reference) at temperature of 23 ± 2 °C and 60 ± 5% of relative humidity and thermal (temperature of 70 ± 2 °C) conditions. The results showed that the cement content was the major factor concerning tensile bond strength. The vinyl acetate-ethylene (VAE) polymer improved the tensile bond strength of mortars under thermal storage. However, the hydroxypropyl methyl cellulose (HPMC) content contributed to the tensile bond strength only when higher cement contents were used. Besides, microstructure analysis showed that ettringite was degraded during thermal storage.


Asunto(s)
Adhesivos , Polietilenos , Cementos de Resina/química , Resistencia a la Tracción , Polímeros , Metilcelulosa , Propiedades de Superficie
5.
J Fish Biol ; 2023 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-37812457

RESUMEN

An opportunistic rescue of a stranded 6 m giant manta ray off Ilha Comprida, in São Paulo, southeastern Brazil, revealed a new technique for returning large bodied mobulid rays to the water once beached. The technique, adapted from protocols to move stranded cetaceans, was modified to suit the dorso-ventrally compressed shape of mobulid rays and reduce damage to the animal while being pulled back into deeper water. The method and suggestions for its improvement have been described with the intention of assisting in the rescue of other stranded large mobulids.

6.
J Environ Manage ; 326(Pt A): 116655, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36368206

RESUMEN

The iron ore mining activity results in considerable waste production and impacts on surrounding ecosystems. Natural recovery of impacted areas is absent or occurs slowly, especially when associated with prolonged dry seasons in tropical regions. The objective of this work was to unveil the mechanisms of Paspalum densum (Poir.) grass to overcome the periods of seasonal drought and its metal accumulation in areas impacted by iron mining, a tailings storage facilities and surrounding ferruginous grassland in Brazil. Lower mortality was observed among individuals in the tailings storage facilities, with a 74.3% survival rate. In contrast, after the beginning of the dry season, all individuals died in the ferruginous grassland. The plants in the tailings deposits showed better nutrition, with a higher concentration of P, Cu, Fe, Zn, Mn and greater capacity to accumulate Pb and Cd over time. Pb was the element with highest bioconcetration factor (BCF) and bioaccumulation coefficient (BAC), while Mn was the one with the highest translocation factor (TF). The dry season resulted in reduced chlorophyll a, b and total and effective quantum yield of photosystem II (PSII) of P. densum individuals. However, the plants in the tailings storage facilities showed adjustments to overcome the effects of drought, with an increase in the concentration of proline in leaves and reduction of oxidative damage (MDA and H2O2) at the end of the dry season. The grass P. densum showed rapid acclimatization in the tailings storage facilities and resistance to drought through antioxidant and photosynthetic adjustments and was still able to bioaccumulate and translocate in plant tissues some metals present in the iron ore impacted sites.


Asunto(s)
Metales Pesados , Contaminantes del Suelo , Oligoelementos , Humanos , Poaceae , Contaminantes del Suelo/análisis , Clorofila A , Ecosistema , Peróxido de Hidrógeno , Plomo , Hierro/análisis , Plantas
7.
Neurogenetics ; 23(3): 167-177, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35397036

RESUMEN

The syndromic group of hereditary spastic paraplegias has a heterogeneous clinical profile and a broad differential diagnosis, including neurometabolic disorders that are potentially treatable. This group includes 5,10-methylenetetrahydrofolate reductase deficiency, cobalamin C deficiency disease, dopamine responsive dystonia, cerebrotendinous xanthomatosis, biotinidase deficiency, GLUT1 deficiency syndrome, delta-e-pyrroline-carboxylase-synthetase deficiency, hyperonithinemia-hyperammonemia-homocitrullinuria syndrome, arginase deficiency, multiple carboxylase deficiency, and X-linked adrenoleukodystrophy. This review describes these diseases in detail, highlighting the importance of early diagnosis and effective treatment aiming at preserving functionality and quality of life in these patients. For the purpose of this study, we carried a non-systematic review on PUBMED, finding an initial sample of 122 papers; upon refining, 41 articles were found relevant to this review. Subsequently, we added review articles and works with historical relevance, totalizing 76 references. An adequate diagnostic workup in patients presenting with spastic paraplegia phenotype should include screening for these rare conditions, followed by parsimonious ancillary investigation.


Asunto(s)
Homocistinuria , Paraplejía Espástica Hereditaria , Humanos , Espasticidad Muscular , Calidad de Vida , Paraplejía Espástica Hereditaria/diagnóstico , Paraplejía Espástica Hereditaria/genética , Paraplejía Espástica Hereditaria/metabolismo , Deficiencia de Vitamina B 12/congénito
8.
Photosynth Res ; 154(3): 259-276, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36181569

RESUMEN

Nitrogen (N) deficiency represents an important limiting factor affecting photosynthetic productivity and the yields of crop plants. Significant reported differences in N use efficiency between the crop species and genotypes provide a good background for the studies of diversity of photosynthetic and photoprotective responses associated with nitrogen deficiency. Using distinct wheat (Triticum aestivum L.) genotypes with previously observed contrasting responses to nitrogen nutrition (cv. Enola and cv. Slomer), we performed advanced analyses of CO2 assimilation, PSII, and PSI photochemistry, also focusing on the heterogeneity of the stress responses in the different leaf levels. Our results confirmed the loss of photosynthetic capacity and enhanced more in lower positions. Non-stomatal limitation of photosynthesis was well reflected by the changes in PSII and PSI photochemistry, including the parameters derived from the fast-fluorescence kinetics. Low photosynthesis in N-deprived leaves, especially in lower positions, was associated with a significant decrease in the activity of alternative electron flows. The exception was the cyclic electron flow around PSI that was enhanced in most of the samples with a low photosynthetic rate. We observed significant genotype-specific responses. An old genotype Slomer with a lower CO2 assimilation rate demonstrated enhanced alternative electron flow and photorespiration capacity. In contrast, a modern, highly productive genotype Enola responded to decreased photosynthesis by a significant increase in nonphotochemical dissipation and cyclic electron flow. Our results illustrate the importance of alternative electron flows for eliminating the excitation pressure at the PSII acceptor side. The decrease in capacity of electron acceptors was balanced by the structural and functional changes of the components of the electron transport chain, leading to a decline of linear electron transport to prevent the overreduction of the PSI acceptor side and related photooxidative damage of photosynthetic structures in leaves exposed to nitrogen deficiency.


Asunto(s)
Clorofila , Triticum , Triticum/genética , Clorofila/genética , Nitrógeno , Electrones , Dióxido de Carbono , Genotipo
9.
Rev Esp Enferm Dig ; 113(8): 563-569, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33267594

RESUMEN

INTRODUCTION: hepatic osteodystrophy, including osteoporosis, is an abnormal bone metabolism related with chronic liver diseases. Osteoporosis is associated with an increased risk of bone fractures, with a significant impact on morbidity, mortality and healthcare costs. Nevertheless, bone disorders tend to be undervalued in cirrhosis due to alcohol-related liver disease (ALD cirrhosis). This study aimed to assess the prevalence of hepatic osteodystrophy and osteoporosis in ALD cirrhosis. METHODS: a prospective observational study was performed that included patients with ALD cirrhosis, between September 2017 and December 2018. Bone mineral density was determined by dual energy X-ray absorptiometry at the lumbar spine and the femoral neck. Hepatic osteodystrophy was defined as a T-score below -1 SD and osteoporosis as a T-score below -2.5 SD. RESULTS: ninety-four patients were included; 24.5 % (n = 23) had prior fragility fractures and ten patients suffered new osteoporotic fractures during the study period. Hepatic osteodystrophy was diagnosed in 79.8 % (n = 75) and osteoporosis in 21.3 % (n = 20) of cases. Patients with hepatic osteodystrophy presented significantly worse Child-Turcotte-Pugh (p < 0.05) and Model for End-Stage Liver Disease (MELD-sodium) scores (p = 0.01). According to the multivariate analysis, lower body mass index (BMI) (OR = 0.787, 95 % CI: 0.688-0.901, p = 0.001) and vitamin D deficiency (OR = 6.798, 95 % CI: 1.775-26.038, p = 0.005) were significantly and independently associated with hepatic osteodystrophy. Patients with osteoporosis also had a lower BMI (p = 0.01). Female patients and those with prior fragility fractures were more likely to suffer from osteoporosis (p < 0.05). CONCLUSION: our study revealed a high prevalence of hepatic osteodystrophy and osteoporosis in patients with ALD cirrhosis (particularly in those with a lower BMI) and a concerning high rate of fragility fractures. Bone mineral density should be assessed in order to allow for an early diagnosis and the implementation of preventive measures.


Asunto(s)
Enfermedad Hepática en Estado Terminal , Hepatopatías , Absorciometría de Fotón , Densidad Ósea , Femenino , Humanos , Cirrosis Hepática/complicaciones , Cirrosis Hepática/epidemiología , Factores de Riesgo , Índice de Severidad de la Enfermedad
10.
Int J Colorectal Dis ; 35(4): 769-773, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32006136

RESUMEN

BACKGROUND: Eosinophilic enterocolitis is a rare condition included in the spectrum of the eosinophilic gastrointestinal disorders. Diagnosis is based on clinical presentation combined with an increase infiltration of eosinophils in the gastrointestinal tract, in the absence of other secondary causes of eosinophilic infiltration. CASE PRESENTATION: We report a case of a 22-year-old male with eosinophilic enterocolitis presenting with malabsorption syndrome (diarrhea, vomiting, weight loss), bowel wall thickening, and ascites. Secondary causes of intestinal eosinophilia were excluded, and diagnosis was established in a timely manner. Treatment plan included a 6-food elimination diet and corticosteroid therapy, with clinical remission after 2 weeks of therapy. The patient remains asymptomatic after 12 months of follow-up, with no relapse.


Asunto(s)
Ascitis/complicaciones , Diarrea/complicaciones , Abdomen/diagnóstico por imagen , Ascitis/sangre , Ascitis/diagnóstico por imagen , Ascitis/patología , Líquido Ascítico/patología , Diarrea/sangre , Diarrea/diagnóstico por imagen , Diarrea/patología , Endoscopía , Humanos , Masculino , Ultrasonografía , Adulto Joven
11.
Appl Opt ; 59(31): 9710-9714, 2020 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-33175807

RESUMEN

The testing of astigmatism and field curvature of an optical system with light-field imaging is proposed. The method consists in measuring the depth map, obtained with a plenoptic camera, of the image of a test pattern formed by the optical system. To demonstrate the accuracy of the method, the virtual image formed by a plano-convex lens was tested. The resulting depth map was compared with the sagittal and tangential foci distances calculated with the Coddington theory. The proposed method could be applied to the quality testing of ocular optics, including eyeglasses, eyepieces, virtual reality goggles, and augmented reality devices.

12.
Artif Organs ; 43(7): 688-693, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30589443

RESUMEN

This article presents experimental and computational results of electroporation in rat liver. The experiments were performed using different forms of electrodes and waveforms of applied electric pulses. For the numerical simulation, the electroporation model proposed by Ramos and Weinert in a previous publication was used. Dynamic adjustments were used for obtaining a good modeling of the electric current. A single set of model parameters was obtained to fit the simulated current response for different waveforms and electrodes. These parameters were obtained with the use of a genetic algorithm that minimized the error between the simulated and experimental currents. The electroporation model with dynamic adjustment proved to be an appropriate simulation tool to predict the tissue conductivity during stimulation by intense electrical fields.


Asunto(s)
Simulación por Computador , Electroporación/métodos , Hígado/fisiología , Modelos Biológicos , Algoritmos , Animales , Conductividad Eléctrica , Electricidad , Electrodos , Electroporación/instrumentación , Diseño de Equipo , Ratas Wistar
14.
J Environ Sci (China) ; 78: 257-266, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30665644

RESUMEN

The revegetation of mined areas poses a great challenge to the iron ore mining industry. The initial recovery process in degraded areas might rely on the use of Fe-resistant grasses. Tropical grasses, such as Paspalum densum and Echinochloa crus-galli, show different resistance strategies to iron toxicity; however, these mechanisms are poorly understood. The Fe-resistance mechanisms and direct iron toxicity as a function of root apex removal were investigated. To achieve this purpose, both grass species were grown for up to 480 hr in a nutrient solution containing 0.019 or 7 mmol/L Fe-EDTA after the root apices had been removed or maintained. Cultivation in the presence of excess iron-induced leaf bronzing and the formation of iron plaque on the root surfaces of both grass species, but was more significant on those plants whose root apex had been removed. Iron accumulation was higher in the roots, but reached phytotoxic levels in the aerial parts as well. It did not hinder the biosynthesis of chloroplastidic pigments. No significant changes in gas exchange and chlorophyll a fluorescence occurred in either grass when their roots were kept intact; the contrary was true for plants with excised root apices. In both studied grasses, the root apoplastic barriers had an important function in the restriction of iron translocation from the root to the aerial plant parts, especially in E. crus-galli. Root apex removal negatively influenced the iron toxicity resistance mechanisms (tolerance in P. densum and avoidance in E. crus-galli).


Asunto(s)
Adaptación Fisiológica/fisiología , Biodegradación Ambiental , Hierro/toxicidad , Poaceae/metabolismo , Contaminantes del Suelo/toxicidad , Clorofila A/metabolismo , Hojas de la Planta/metabolismo , Raíces de Plantas/metabolismo , Brotes de la Planta/metabolismo , Clima Tropical
15.
Eye Contact Lens ; 44 Suppl 2: S233-S240, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29077584

RESUMEN

OBJECTIVES: The objective of this investigation was to evaluate the level of comfort and ocular dryness during wear with six daily disposable contact lenses (DDCL) and also determine the changes in contact lens equilibrium water content (EWC) resulting from their wear. METHODS: In this contralateral open trial, 27 subjects were randomly fitted with six DDCL (stenfilcon A, delefilcon A, nelfilcon A, narafilcon A, nesofilcon A, and omafilcon A). The evaluation of comfort and ocular dryness sensation was recorded by the participants at two moments of the day (11 AM and 5 PM) over a period of 10 days of contact lens wear. The assessment was made with the aid of visual analogue scales (0-10). The refractive index of 54 contact lenses was accessed by a single operator using a digital automated refractometer (CLR 12-70; Index Instruments). The EWC of the lenses was estimated based on its refractive index values. RESULTS: Comfort ratings were slightly higher for delefilcon A (9.56±0.67, P=0.01) and narafilcon A (9.40±0.93, P=0.01) and these lenses wearers also reported less ocular dryness. The results revealed a pronounced water content reduction for omafilcon A (P=0.002), narafilcon A (P=0.008), and nesofilcon A (P=0.003). CONCLUSION: Although changes in subjective responses and EWC were distinct among the materials analyzed, all the contact lenses performed well during the 10 days of wear.


Asunto(s)
Lentes de Contacto Hidrofílicos , Síndromes de Ojo Seco/prevención & control , Dolor Ocular/diagnóstico , Adulto , Lentes de Contacto Hidrofílicos/efectos adversos , Lentes de Contacto Hidrofílicos/normas , Equipos Desechables , Femenino , Humanos , Masculino , Satisfacción del Paciente , Refractometría , Agua/análisis
16.
Rev Esp Enferm Dig ; 110(2): 123, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29278001

RESUMEN

An 84-years old woman, medicated with acenocumarol, was admitted to the Emergency Room with lower abdominal pain and nauseas and no history of trauma. She was medicated with acenocumarol and had a non-measurable international normalized ratio. The findings of the bowel ultrasound, ileocolonoscopy and biopsies specimens were suggestive of intramural bleeding of the ileum, ileocecal valve and cecum. Spontaneous intramural bleeding of the gastrointestinal wall associated with oral anticoagulation is rare.


Asunto(s)
Anticoagulantes/efectos adversos , Hemorragia Gastrointestinal/inducido químicamente , Anciano de 80 o más Años , Anticoagulantes/uso terapéutico , Ciego/patología , Femenino , Hemorragia Gastrointestinal/diagnóstico por imagen , Hemorragia Gastrointestinal/patología , Humanos , Íleon/patología , Mucosa Intestinal/patología
18.
Metab Brain Dis ; 32(2): 359-368, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-27714582

RESUMEN

We evaluated the in vitro effects of galactose at 0.1, 3.0, 5.0 and 10.0 mM on thiobarbituric acid-reactive substances (TBA-RS), total sulfhydryl content, protein carbonyl content, on the activities of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and on acetylcholinesterase (AChE) activity in the cerebral cortex, cerebellum and hippocampus of rats. We also investigated the influence of the antioxidants (each at 1 mM), α-tocopherol, ascorbic acid and glutathione, on the effects elicited by galactose on the parameters tested. Results showed that galactose, at a concentration of 3.0 mM, enhanced TBA-RS levels in the hippocampus, cerebral cortex and cerebellum of rats. In the cerebral cortex, galactose at concentrations of 5.0 and 10.0 mM increased TBA-RS and protein carbonyl content, and at 10.0 mM increased CAT activity and decreased AChE activity. In the cerebellum, galactose at concentrations of 5.0 and 10.0 mM increased TBA-RS, SOD and GSH-Px activities. In the hippocampus, galactose at concentrations of 5.0 and 10.0 mM increased TBA-RS and CAT activity and at 10.0 mM decreased GSH-Px. Data showed that at the pathologically high concentration (greater than 5.0 mM), galactose induces lipid peroxidation, protein carbonylation, alters antioxidant defenses in the cerebrum, and also alters cholinesterase activity. Trolox, ascorbic acid and glutathione addition prevented the majority of alterations in oxidative stress parameters and the decrease in AChE activity that were caused by galactose. Our findings lend support to a potential therapeutic strategy for this condition, which may include the use of appropriate antioxidants for ameliorating the damage caused by galactose.


Asunto(s)
Acetilcolinesterasa/metabolismo , Antioxidantes/farmacología , Cerebro/metabolismo , Galactosa/farmacología , Fármacos Neuroprotectores/farmacología , Estrés Oxidativo/efectos de los fármacos , Animales , Ácido Ascórbico/farmacología , Catalasa/metabolismo , Cerebro/efectos de los fármacos , Cerebro/enzimología , Glutatión/farmacología , Glutatión Peroxidasa/metabolismo , Técnicas In Vitro , Masculino , Carbonilación Proteica/efectos de los fármacos , Ratas , Ratas Wistar , Superóxido Dismutasa/metabolismo , alfa-Tocoferol/farmacología
19.
Ecotoxicol Environ Saf ; 144: 307-314, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28645032

RESUMEN

Tropical woody species occurring in limestone outcrops are frequently exposed to particulate material from cement factories. The effects of 60-day cement dust exposure on physiological traits and enzymatic antioxidant system of young plant leaves of Guazuma ulmifolia Lam., Myracrodruon urundeuva Allemão and Trichilia hirta L. were investigated. Cement dust (2.5 or 5mgcm-2) was applied to the leaf surface or soil or both (leaf plus soil) and plants were maintained at greenhouse. Cement dust barely affected the mineral nutrient levels, except for iron whose content was decreased in leaves/leaflets of all species studied. The incident light was partly blocked in cement dust-treated leaves, regardless of the plant species, causing a decrease in the photosynthetic pigments in M. urundeuva. The chlorophyll b content, however, increased in G. ulmifolia and T. hirta leaves upon cement dust treatment. The potential quantum yield of photosystem II in challenged leaves of G. ulmifolia was 3.8% lower than that of control plants, while such trait remained unaffected in the leaves of the other species. No changes in leaf stomatal conductance and antioxidant enzymes activities were observed, except for M. urundeuva, which experienced a 31% increment in the superoxide dismutase activity upon 5mgcm-2 cement dust (leaf plus soil treatment), when compared with control plants. Overall, the mild changes caused by cement dust in the in physiological and biochemical traits of the species studied indicate that such species might be eligible for further studies of revegetation in fields impacted by cement factories.


Asunto(s)
Contaminantes Atmosféricos/toxicidad , Antioxidantes/metabolismo , Materiales de Construcción/toxicidad , Polvo/análisis , Magnoliopsida/fisiología , Hojas de la Planta/metabolismo , Contaminantes Atmosféricos/análisis , Materiales de Construcción/análisis , Hierro/metabolismo , Fotosíntesis/efectos de los fármacos , Complejo de Proteína del Fotosistema II/metabolismo , Hojas de la Planta/efectos de los fármacos , Suelo/química , Especificidad de la Especie , Clima Tropical
20.
Amino Acids ; 47(9): 1931-9, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25894889

RESUMEN

In the present study, we evaluated the in vitro effects of homoarginine (hArg) at 1, 10 and 20 µM on thiobarbituric acid-reactive substances (TBA-RS), total sulfhydryl content and on the activity of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in plasma, erythrocytes, kidney and liver of rats (60 days old). We also investigated the influence of the antioxidants (each at 1 mM) α-tocopherol and ascorbic acid, as well as of the nitric oxide synthase inhibitor N (G)-nitro-L-arginine methyl ester (L-NAME) at 1 mM, on the effects elicited by hArg on the parameters tested. In plasma, hArg at concentrations of 10 and 20 µM decreased moderately the total sulfhydryl content. At 20 µM, hArg enhanced moderately TBA-RS in the plasma. In plasma, the effects of hArg (20 µM) on TBA-RS and total thiol content were abolished by α-tocopherol, ascorbic acid and L-NAME. At all concentrations tested, hArg did not exert any effect on CAT, SOD or GSH-Px activity in the erythrocytes. In the kidney, hArg exerted effects only at 20 µM and in a different manner: TBA-RS levels increased and total thiol content and CAT activity decreased, while SOD and GSH-Px activity increased. In the renal medulla, α-tocopherol and ascorbic acid but not L-NAME abolished the effects of hArg (20 µM) on TBA-RS, while all agents inhibited the hArg-induced increase in SOD activity. In the renal cortex, α-tocopherol, ascorbic acid and L-NAME abolished the effects of hArg (20 µM) on the total sulfhydryl content and GSH-Px activity, but L-NAME did not reverse the inhibitory effects of hArg on CAT activity. In the liver, no effects of hArg were observed of all biomarkers measured. At the pathologically high concentration of 20 µM, as it may occur in plasma in hyperargininemia, hArg may enhance lipid peroxidation and thiol oxidation and inhibit CAT activity, but may increase SOD and GSH-Px activity predominantly in the kidney.


Asunto(s)
Ácido Ascórbico/farmacología , Eritrocitos/metabolismo , Homoarginina/farmacología , Riñón/metabolismo , Hígado/metabolismo , NG-Nitroarginina Metil Éster/farmacología , Estrés Oxidativo/efectos de los fármacos , alfa-Tocoferol/farmacología , Animales , Masculino , Ratas , Ratas Wistar
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda