RESUMEN
OBJECTIVES: To determine the association between smoking and tooth loss in individuals aged 18 years or more living in Brazil. METHODS: Secondary analysis of the 2019 Brazilian National Health Survey data. The outcome was self-reported tooth loss, and the main independent variable was tobacco smoking. Family income, schooling, sex and age were covariates. Multiple linear regression analysis determined the association between tobacco smoking and the number of missing teeth and then the average number of missing teeth was predicted according to smoking status. RESULTS: The mean number of missing teeth in 88,531 individuals aged 18 or more was 7.7 (95%CI: 7.6-7.8). At least one missing tooth was identified in 72.0% (95%CI: 71.4-72.6) of the population, 21.3% (95%CI: 20.9-21.7) had a non-functional dentition, 14.2% (95%CI: 13.9-14.6) had severe tooth loss and 10.3% (95%CI: 10.0-10.6) were edentulous. The adjusted regression coefficients for number of missing teeth showed that current or former smokers, individuals with low family income and schooling, older age and females exhibited higher tooth loss. Current and former smokers had 1.40 (95%CI: 1.35-1.46) and 1.13 (95%CI: 0.54-0.98) times more lost teeth than never smokers, respectively. CONCLUSIONS: Both tooth loss and smoking are common in Brazilians and are associated. Unfavorable socioeconomic status and demographic factors also predict tooth loss.
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Fumar Tabaco , Pérdida de Diente , Humanos , Brasil/epidemiología , Pérdida de Diente/epidemiología , Estudios Transversales , Femenino , Masculino , Adulto , Persona de Mediana Edad , Anciano , Fumar Tabaco/epidemiología , Fumar Tabaco/efectos adversos , Adulto Joven , AdolescenteRESUMEN
Cashew nut meal (CNM) is widely used in tropical countries due to the high protein and energy levels; therefore, it has potential to be an alternative feed supplementation for livestock. Our objective was to evaluate the use of CNM as feed supplement for lambs. Twenty-four lambs were divided into a randomized block design with four treatments, starting with a diet control of Tifton 85 (Cynodon spp.) hay and CNM as a supplement at three different levels representing 6, 12, and 18% of the total mixed ration (TMR) provided. There were evaluated intake (g/day and g/kgBW0.75); the digestibility of DM and nutrients; nitrogen balance; and ingestive behavior. The CP and ether extract (EE) intake (g/day) as well as DM, and organic matter (OM) intake (g/kgBW0.75) were influenced by supplementation with CNM in a positive linear increase (Pâ¯<â¯0.05). The digestibility of DM, OM and NDF increased according to the levels of CNM up to 12% and markedly decreased at the higher level (Pâ¯<â¯0.05). The EE and CP digestibility raised according to the CNM levels (Pâ¯<â¯0.05) and consequently increased the nitrogen retention resulting in a positive nitrogen balance. The protein and energetic characteristics of CNM show that it can be used as an alternative supplementation to low-quality forages for lambs. However, its use as a single supplement ingredient above 7% on total mixed ration may reduce fiber digestibility.
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Anacardium , Digestión , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Dieta/veterinaria , Suplementos Dietéticos , Nitrógeno , Nueces , OvinosRESUMEN
The emergence of livestock-associated methicillin-resistant Staphylococcus aureus strains (LA-MRSA) and the potential role of pigs in the evolution of these strains has led to increased interest in research of these microorganisms. However, this has contributed to a lack of research in the isolation and characterization of methicillin-susceptible S. aureus strains (MSSA). In this study, the prevalence of S. aureus in pigs in the nursery and finishing stages were analyzed. The susceptibility profiles to antibiotics, tolerance to heavy metals, and biofilm production of the isolates were evaluated using phenotypic and genotypic techniques. A total of 1,250 colonies suggestive of Staphylococcus spp. were isolated from 128 pigs, of which 63.6% (n = 795) belonged to this microbial genus. Sixty-seven colonies isolated from 34 animals (26.5%) were confirmed as S. aureus (8.4%). No strains resistant to copper, zinc, or methicillin were detected; however, all strains presented a resistance profile to at least three different classes of antimicrobials and 21 produced biofilms. These data are of concern, as they indicate the need for increased surveillance in the use of antimicrobials as well as reinforce the importance of studies on MSSA strains.(AU)
A emergência de cepas de Staphylococcus aureus resistentes à meticilina associadas à pecuária (LA-MRSA) e o papel potencial dos suínos na evolução dessas cepas têm levado ao aumento do interesse na pesquisa desses microrganismos. No entanto, isso tem contribuído para a falta de estudos sobre o isolamento e a caracterização de cepas de S. aureus sensíveis à meticilina (MSSA). Neste estudo, foi analisada a prevalência de S. aureus em suínos nas fases de creche e terminação. Os perfis de suscetibilidade aos antibióticos, a tolerância a metais pesados e a produção de biofilme dos isolados foram avaliados por meio de técnicas fenotípicas e genotípicas. Um total de 1.250 colônias sugestivas de Staphylococcus spp. foi isolado de 128 suínos, das quais 63,6% (n = 795) pertenciam a esse gênero microbiano. Sessenta e sete colônias isoladas de 34 animais (26,5%) foram confirmadas como S. aureus (8,4%). Nenhuma cepa resistente ao cobre, ao zinco ou à meticilina foi detectada; entretanto, todas as cepas apresentaram perfil de resistência a pelo menos três classes diferentes de antimicrobianos e 21 produziam biofilme. Esses dados são preocupantes, pois indicam a necessidade de maior vigilância no uso de antimicrobianos, bem como reforçam a importância de estudos com cepas de MSSA.(AU)
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Animales , Staphylococcus aureus/aislamiento & purificación , Porcinos , Factores de Virulencia/análisis , Staphylococcus aureus Resistente a Meticilina , Farmacorresistencia Microbiana , BiopelículasRESUMEN
Intragenic antimicrobial peptides (IAPs) are internal sequences of proteins with physicochemical similarities to Antimicrobial Peptides (AMPs) that, once identified and synthesized as individual entities, present antimicrobial activity. Many mature proteins encoded by the genomes of virtually any organism may be regarded as inner reservoirs of IAPs, conferring them ample biotechnological potential. However, IAPs may also share shortcomings with AMPs, such as low half-life in biological media and non-specific adsorption in eukaryotic cells. The present manuscript reports a translational approach that encompasses the uncovering of two novel IAPs from human proteins as well as the first results concerning the incorporation and sustained release of one of these peptides from ureasil-polyether hybrid polymeric films. For such, the software Kamal was used to scan putative IAPs in the human proteome, and two peptides, named Hs05 and Hs06, were identified, synthesized, and tested as antimicrobials. Biophysical assays were conducted using model phospholipid vesicles and 1H NMR solution structures in phospholipid micelles were obtained for the IAP Hs05. This peptide was incorporated in a polymeric matrix composed of the ureasil/PPO-PEO-PPO triblock copolymer, and the resulting films were evaluated by atomic force microscopy and imaging mass spectrometry. The release rate of Hs05 from the polymeric matrix was assessed and the antimicrobial activity of Hs05-loaded hybrid polymeric films was evaluated against the bacterium Escherichia coli. This study represents the first steps towards the development of polymeric films enriched with IAPs obtained from the human proteome as sustained release devices for topical application.
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Antiinfecciosos , Micelas , Antiinfecciosos/farmacología , Humanos , Péptidos , Polímeros , Proteínas Citotóxicas Formadoras de PorosRESUMEN
Ketamine (KET) is an N-methyl-D-aspartate (NMDA) antagonist with rapid and long-lasting antidepressant effects, but how the drug shows its sustained effects is still a matter of controversy. The objectives were to evaluate the mechanisms for KET rapid (30 min) and long-lasting (15 and 30 days after) antidepressant effects in mice. A single dose of KET (2, 5, or 10 mg/kg, po) was administered to male Swiss mice and the forced swim test (FST) was performed 30 min, 15, or 30 days later. Imipramine (IMI, 30 mg/kg, ip), a tricyclic antidepressant drug, was used as reference. The mice were euthanized, separated into two time-point groups (D1, first day after KET injection; D30, 30 days later), and brain sections were processed for glycogen synthase kinase-3 (GSK-3), histone deacetylase (HDAC), brain-derived neurotrophic factor (BDNF), and glial fibrillary acidic protein (GFAP) immunohistochemical assays. KET (5 and 10 mg/kg) presented rapid and long-lasting antidepressant-like effects. As expected, the immunoreactivities for brain GSK-3 and HDAC decreased compared to control groups in all areas (striatum, DG, CA1, CA3, and mainly pre-frontal cortex, PFC) after KET injection. Increases in BDNF immunostaining were demonstrated in the PFC, DG, CA1, and CA3 areas at D1 and D30 time-points. GFAP immunoreactivity was also increased in the PFC and striatum at both time-points. In conclusion, KET changed brain BDNF and GFAP expressions 30 days after a single administration. Although neuroplasticity could be involved in the observed effects of KET, more studies are needed to explain the mechanisms for the drug's sustained antidepressant-like effects.
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Animales , Masculino , Conejos , Encéfalo/efectos de los fármacos , Encéfalo/enzimología , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Ketamina/farmacología , Antidepresivos/farmacología , Astrocitos , Glucógeno Sintasa Quinasa 3 , Modelos Animales de Enfermedad , Proteína Ácida Fibrilar de la Glía , Histona DesacetilasasRESUMEN
Ketamine (KET) is an N-methyl-D-aspartate (NMDA) antagonist with rapid and long-lasting antidepressant effects, but how the drug shows its sustained effects is still a matter of controversy. The objectives were to evaluate the mechanisms for KET rapid (30 min) and long-lasting (15 and 30 days after) antidepressant effects in mice. A single dose of KET (2, 5, or 10 mg/kg, po) was administered to male Swiss mice and the forced swim test (FST) was performed 30 min, 15, or 30 days later. Imipramine (IMI, 30 mg/kg, ip), a tricyclic antidepressant drug, was used as reference. The mice were euthanized, separated into two time-point groups (D1, first day after KET injection; D30, 30 days later), and brain sections were processed for glycogen synthase kinase-3 (GSK-3), histone deacetylase (HDAC), brain-derived neurotrophic factor (BDNF), and glial fibrillary acidic protein (GFAP) immunohistochemical assays. KET (5 and 10 mg/kg) presented rapid and long-lasting antidepressant-like effects. As expected, the immunoreactivities for brain GSK-3 and HDAC decreased compared to control groups in all areas (striatum, DG, CA1, CA3, and mainly pre-frontal cortex, PFC) after KET injection. Increases in BDNF immunostaining were demonstrated in the PFC, DG, CA1, and CA3 areas at D1 and D30 time-points. GFAP immunoreactivity was also increased in the PFC and striatum at both time-points. In conclusion, KET changed brain BDNF and GFAP expressions 30 days after a single administration. Although neuroplasticity could be involved in the observed effects of KET, more studies are needed to explain the mechanisms for the drug's sustained antidepressant-like effects.
Asunto(s)
Antidepresivos/farmacología , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/enzimología , Ketamina , Animales , Astrocitos , Modelos Animales de Enfermedad , Proteína Ácida Fibrilar de la Glía , Glucógeno Sintasa Quinasa 3 , Histona Desacetilasas , Ketamina/farmacología , Masculino , RatonesRESUMEN
Sheep production systems in Brazilian caatinga rangelands require supplementation adapted to changes in floristic and chemical composition as dry seasons progress. Meeting sheep nutritional needs in extensive semiarid systems is challenging because of sheep dietary preferences and habits. The objective of this trial was to evaluate the substitutive effect of concentrate supplementation on grazing sheep in the Brazilian caatinga rangeland and its consequences on performance in different seasons. The trial was conducted from March to August 2013 at Embrapa Goat and Sheep in Sobral, Ceará State, Brazil. Thirty-two Brazilian Somali multiparous ewes were submitted to estrus synchronization and controlled breeding. At the start of the trial, ewes averaged 30.45 + 2.60 kg body weight (BW). Ewes were divided into four groups and individually offered 0, 200, 350, or 500 g supplement head-1 day-1. Intake prediction and digestibility trials were evaluated at three periods: rainy season (April), transition rainy-dry (June), and dry season (August). Sheep weights were taken every 14 days to measure their performance from late gestation until weaning. Ewe BW and body condition score changes were determined too. Lamb BW changes were also measured every 14 days from birth through weaning. A completely randomized design with split plot arrangement using eight replications was used for intake and digestibility measurements. The differences between supplement offered (0, 200, 350, and 500 g sheep-1) and season (rainy, transition rainy-dry, and dry) were submitted to analyses of variance and multiple means were separated, where differences were detected, using the Tukey's test. During lactation up through weaning, ewes supplemented at 500 g day-1 had greater BW than ewes without supplement. Ewes supplemented with 200 g concentrate head-1 day-1 had 9.1% greater (P ≤ 0.05) BW at weaning and their lambs had 19.7% greater birth and 16.6% heavier wean BW despite lower dry matter intake compared to unsupplemented animals. Supplementation with 200 g concentrate increased carrying capacity by 28.8% during the dry season and by 20.5% during the rainy season. This study confirmed that in the dry season, when quality of rangeland forages decreases, supplementation contributes to greater DMI, improves postpartum and lactation BW recovery of ewes, and contributes to greater lamb birth and wean weights. Moreover, supplementation leads to feed substitution effects that may increase rangeland resilience by mitigating overgrazing. Supplementation with 200 g concentrate can also prevent negative energy balance for grazing animals, improving longer postnatal recovery, longer intervals between parturitions, fewer double and is necessary to ensure a better BW at birth to lambs.
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Digestión , Ingestión de Alimentos , Preñez , Oveja Doméstica/fisiología , Alimentación Animal/análisis , Crianza de Animales Domésticos , Fenómenos Fisiológicos Nutricionales de los Animales/efectos de los fármacos , Animales , Brasil , Dieta/veterinaria , Suplementos Dietéticos/análisis , Digestión/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ingestión de Alimentos/efectos de los fármacos , Ecosistema , Femenino , Embarazo , Preñez/efectos de los fármacos , Distribución Aleatoria , Estaciones del Año , DesteteAsunto(s)
Donantes de Sangre , Deficiencia de Glucosafosfato Deshidrogenasa/epidemiología , Deficiencia de Glucosafosfato Deshidrogenasa/genética , Glucosafosfato Deshidrogenasa/genética , Recuento de Células Sanguíneas , Brasil/epidemiología , Índices de Eritrocitos , Deficiencia de Glucosafosfato Deshidrogenasa/diagnóstico , Humanos , Mutación , PrevalenciaRESUMEN
The objective of this study was to explore the influence of the renin-angiotensin system on cardiac prooxidants and antioxidants levels and its association to autonomic imbalance induced by hyperthyroidism. Male Wistar rats were divided into four groups: control, losartan (10mg/kg/day by gavage, 28 day), thyroxine (T4) (12 mg/L in drinking water for 28 days), and T4+losartan. Spectral analysis (autonomic balance), angiotensin II receptor (AT1R), NADPH oxidase, Nrf2 and heme-oxygenase-1 (HO-1) myocardial protein expression, and hydrogen peroxide (H2O2) concentration were quantified. Autonomic imbalance induced by hyperthyroidism (~770%) was attenuated in the T4+losartan group (~32%) (P<0.05). AT1R, NADPH oxidase, H2O2, as well as concentration, Nrf2 and HO-1 protein expression were elevated (~172%, 43%, 40%, 133%, and 154%, respectively) in T4 group (P<0.05). H2O2 and HO-1 levels were returned to control values in the T4+losartan group (P<0.05). The overall results demonstrate a positive impact of RAS blockade in the autonomic control of heart rate, which was associated with an attenuation of H2O2 levels, as well as with a reduced counter-regulatory response of HO-1 in experimental hyperthyroidism.
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Bloqueadores del Receptor Tipo 1 de Angiotensina II/farmacología , Hipertiroidismo/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Receptor de Angiotensina Tipo 1/fisiología , Bloqueadores del Receptor Tipo 1 de Angiotensina II/uso terapéutico , Animales , Frecuencia Cardíaca/efectos de los fármacos , Frecuencia Cardíaca/fisiología , Hipertiroidismo/tratamiento farmacológico , Masculino , Ratas , Ratas WistarRESUMEN
BACKGROUND AND OBJECTIVES: Transfusion-related acute lung injury (TRALI) is characterized by leukocyte transmigration and alveolar capillary leakage shortly after transfusion. TRALI pathogenesis has not been fully elucidated. In some cases, the infusion of alloantibodies (immune model), whereas in others the combination of neutrophil priming by proinflammatory molecules with the subsequent infusion of biological response modifiers (BRMs) in the hemocomponent (non-immune model) have been implicated. Our aim was to compare the pathological events involved in TRALI induced by antibodies or BRMs using murine models. MATERIALS AND METHODS: In the immune model, human HNA-2(+) neutrophils were incubated in vitro with a monoclonal antibody (anti-CD177, clone 7D8) directed against the HNA-2 antigen and injected i.v. in NOD/SCID mice. In the non-immune model, BALB/c mice were treated with low doses of lipopolysaccharide (LPS) followed by platelet-activating factor (PAF) infusion 2 h later. Forty minutes after PAF administration, or 6 h after neutrophil injection, lungs were isolated and histological analysis, determination of a variety of cytokines and chemokines including keratinocyte-derived chemokine (KC), MIP-2, the interleukins IL-1ß, IL-6, IL-8 as well as TNFα, cell influx and alveolar capillary leakage were performed. RESULTS: In both models, characteristic histological findings of TRALI and an increase in KC and MIP-2 levels were detected. In contrast to the immune model, in the non-immune model, there was a dramatic increase in IL-1ß and TNFα. However, capillary leakage was only detected if PAF was administrated. CONCLUSIONS: Regardless of the triggering event(s), KC, MIP-2 and integrins participate in TRALI pathogenesis, whereas PAF is essential for capillary leakage when two events are involved.
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Lesión Pulmonar Aguda/inmunología , Lesión Pulmonar Aguda/patología , Reacción a la Transfusión , Lesión Pulmonar Aguda/etiología , Animales , Quimiocinas/inmunología , Modelos Animales de Enfermedad , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos NOD , Ratones SCID , Neutrófilos/inmunología , Neutrófilos/patologíaRESUMEN
The vitamin E derivative (+)α-tocopheryl succinate (α-TOS) exerts pro-apoptotic effects in a wide range of tumors and is well tolerated by normal tissues. Previous studies point to a mitochondrial involvement in the action mechanism; however, the early steps have not been fully elucidated. In a model of acute promyelocytic leukemia (APL) derived from hCG-PML-RARα transgenic mice, we demonstrated that α-TOS is as effective as arsenic trioxide or all-trans retinoic acid, the current gold standards of therapy. We also demonstrated that α-TOS induces an early dissipation of the mitochondrial membrane potential in APL cells and studies with isolated mitochondria revealed that this action may result from the inhibition of mitochondrial respiratory chain complex I. Moreover, α-TOS promoted accumulation of reactive oxygen species hours before mitochondrial cytochrome c release and caspases activation. Therefore, an in vivo antileukemic action and a novel mitochondrial target were revealed for α-TOS, as well as mitochondrial respiratory complex I was highlighted as potential target for anticancer therapy.
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Arsenicales/uso terapéutico , Complejo I de Transporte de Electrón/antagonistas & inhibidores , Leucemia Promielocítica Aguda/tratamiento farmacológico , Mitocondrias/efectos de los fármacos , Óxidos/uso terapéutico , Tretinoina/uso terapéutico , alfa-Tocoferol/farmacología , alfa-Tocoferol/uso terapéutico , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Antioxidantes/farmacología , Antioxidantes/uso terapéutico , Apoptosis/efectos de los fármacos , Trióxido de Arsénico , Caspasas/metabolismo , Línea Celular Tumoral , Citocromos c/metabolismo , Modelos Animales de Enfermedad , Complejo II de Transporte de Electrones/antagonistas & inhibidores , Humanos , Leucemia Promielocítica Aguda/mortalidad , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratones , Ratones Transgénicos , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/metabolismo , Proteínas de Fusión Oncogénica/metabolismo , Estabilidad Proteica/efectos de los fármacos , Ratas , Especies Reactivas de Oxígeno/metabolismo , Trasplante IsogénicoRESUMEN
Leandra lacunosa, popularly known as "erva-do-jabuti", is used in Brazilian folkloric medicine for the treatment of diabetes mellitus. Based on this traditional indication, the aim of this work was to evaluate the hypoglycemic activity of the hydroalcoholic extract of L. lacunosa aerial parts (LLH) in normal and alloxan-induced diabetic rats. Chromatographic fractionation of LLH was also carried out by several techniques, affording isolation of the following major compounds: ursolic acid (1), kaempferol (2), luteolin (3), and quercetin (4). The oral administration of LLH (500 mg/kg) in normal rats caused a significant reduction of 24.7% (P<0.05) in the blood glucose levels after 2 h of treatment, while the administration of chlorpropamide (20 mg/kg, p.o.) led to a reduction of 40.2% (P<0.01). After oral administration of glucose (10 g/kg, p.o.), LLH (500 mg/kg, p.o.) significantly inhibited the increase in blood glucose levels compared with the negative control group. The oral treatment with LLH (500 mg/kg) in alloxan-induced diabetic rats significantly reduced the blood glucose levels in 47.8% after 4 h of treatment, while chlorpropamide resulted in a significant reduction of 71.7% in the 4th hour. Our results showed that LLH, displays hypoglycemic activity, which may be related to the effect of the major compounds identified in the crude extract. This study seems to provide biological evidence for the folkloric use of L. lacunosa in the treatment of diabetes mellitus.
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Diabetes Mellitus Experimental/tratamiento farmacológico , Hipoglucemiantes/farmacología , Melastomataceae/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Aloxano , Animales , Glucemia/efectos de los fármacos , Prueba de Tolerancia a la Glucosa , Hipoglucemiantes/química , Masculino , Estructura Molecular , Ratas , Ratas WistarRESUMEN
A região lombar desempenha um papel fundamental na acomodação de cargas decorrentes do peso corporal, da ação muscular e das forças aplicadas externamente. A funcionalidade dessa região é mantida através do sinergismo entre os mecanismos ativo, passivo e neural da estabilização lombar. O desequilíbrio proporcionará a instabilidade que terá como principal conseqüência à dor. O objetivo do estudo foi mostrar a íntima relação existente entre a Fáscia Tóraco Lombar e mecanismo ativo de estabilização lombar. A metodologia utilizada foi baseada na revisão bibliografia de estudos realizados no período de 1984 a 2004, sendo 43 artigos científicos e 10 livros. Destes, foram utilizados no trabalho, 20 artigos e 8 livros. Os bancos de dados pesquisados foram Lilás, Medline e Pedro. O estudo pôde confirmar que a Fáscia Tóraco Lombar é uma estrutura passiva que apresenta conecção com diversos músculos, comporta a função de suporte mecânico e participa dinamicamente, complementando a ação das outras estruturas estabilizadoras. Logo, a reabilitação de pacientes lombálgicos deve se basear em atividades que aprimorem a função de cada um dos componentes deste complexo mecanismo de estabilização.
The lumbar region has a major role concerning load accommodation due to body weight, muscle action and externally applied forces. The workability of this region is kept through the synergism among lumbar stabilization active, passive and neural mechanisms. Unbalance will result in instability, and pain will be its main consequence. This study aims to show the close relation between thoracolumbar fascia and the active system of lumbar stabilization. The applied methodology was based on the bibliographical review of 43 scientific articles and 10 books published between 1984 and 2004. From this whole, 8 books and 20 articles have been used in this work. The data research were Lilás, Medline and Pedro. The describers were thoracolumbar fascia, stabilization and active system. This study show that thoracolumbar fascia is a passive structure which is connected to several muscles, thus providing mechanical support, as well as dynamic cooperation to complement the action of other stabilizing structures. Lumbago patients rehabilitation must be based on activities which improve the function of each component in this complex stabilizing mechanism.
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Humanos , Ejercicio Físico , Fascia , Región LumbosacraRESUMEN
In this paper, we introduce a general modeling technique, called vector-quantized temporal associative memory (VQTAM), which uses Kohonen's self-organizing map (SOM) as an alternative to multilayer perceptron (MLP) and radial basis function (RBF) neural models for dynamical system identification and control. We demonstrate that the estimation errors decrease as the SOM training proceeds, allowing the VQTAM scheme to be understood as a self-supervised gradient-based error reduction method. The performance of the proposed approach is evaluated on a variety of complex tasks, namely: i) time series prediction; ii) identification of SISO/MIMO systems; and iii) nonlinear predictive control. For all tasks, the simulation results produced by the SOM are as accurate as those produced by the MLP network, and better than those produced by the RBF network. The SOM has also shown to be less sensitive to weight initialization than MLP networks. We conclude the paper by discussing the main properties of the VQTAM and their relationships to other well established methods for dynamical system identification. We also suggest directions for further work.
RESUMEN
Chemical examination of the leaves of Styrax ferrugineus yielded 5-[3''-(beta-D-glucopyranosyloxy)propyl]-7-methoxy-2-(3',4'-dimethoxyphenyl) benzofuran, along with the known nor-lignans 5-(3''-hydroxypropyl)-7-methoxy-2-(3',4'-methylenedioxyphenyl) benzofuran, 5-(3''-hydroxypropyl)-7-methoxy-2-(3',4'-dimethoxyphenyl)benzofuran, 5-[3''-(beta-D-glucopyranosyloxy)propyl]-7-methoxy-2-(3',4'-methylenedioxyphenyl)benzofuran and the lignan, dihydrodehydrodiconiferyl alcohol. All arylpropanoids isolated showed antibacterial and antifungal activities. The structures of the isolates were established by spectroscopic analysis.
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Antiinfecciosos/farmacología , Antifúngicos/farmacología , Lignanos/farmacología , Magnoliopsida/química , Antibacterianos , Antiinfecciosos/química , Antiinfecciosos/aislamiento & purificación , Antifúngicos/química , Antifúngicos/aislamiento & purificación , Candida albicans/efectos de los fármacos , Lignanos/química , Lignanos/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Pruebas de Sensibilidad Microbiana , Conformación Molecular , Hojas de la Planta/química , Staphylococcus aureus/efectos de los fármacosRESUMEN
Maytenus aquifolium (Celastraceae) and Salacia campestris (Hippocrateaceae) species accumulate friedelane and quinonemethide triterpenoids in their leaves and root bark, respectively. Enzymatic extracts obtained from leaves displayed cyclase activity with conversion of the substrate oxidosqualene to the triterpenes, 3beta-friedelanol and friedelin. In addition, administration of (+/-)5-(3)H mevalonolactone in leaves of M. aquifolium seedlings produced radio labelled friedelin in the leaves, twigs and stems, while the root bark accumulated labelled maytenin and pristimerin. These experiments indicated that the triterpenes once biosynthesized in the leaves are translocated to the root bark and further transformed to the antitumoral quinonemethide triterpenoids.
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Rosales/metabolismo , Triterpenos/aislamiento & purificación , Cromatografía Líquida de Alta Presión , Espectroscopía de Resonancia Magnética , Estructura Molecular , Triterpenos/químicaRESUMEN
Bioactivity-guided fractionation of several bioactive extracts obtained from Cerrado and Atlantic Forest plant species led to the isolation of potent DNA-damaging piperidine 1-5 and guanidine alkaloids 6-9 from Cassia leptophylla and Pterogyne nitens respectively, two common Leguminosae from Atlantic Forest. By means of biotechnological approach on Maytenus aquifolium, a species from Cerrado, moderate DNA-damaging sesquiterpene pyridine alkaloid 10-11 was isolated. Bioassay-guided fractionation on Casearia sylvestris, a medicinal plant species found in Cerrado and Atlantic Forest, led to the isolation of clerodane diterpenes 12-13 which showed effect on DNA. In addition, we have reported several interesting potent antifungal iridoids: 1 beta-hydroxy-dihydrocornin (14), 1 alpha-hydroxy-dihydrocornin (15), alpha-gardiol (16), beta-gardiol (17), plumericin (18), isoplumericin (19), 11-O-trans-caffeoylteucrein (20); ester derivative: 2-methyl-4-hydroxy-butyl-caffeoate (21), amide N-[7-(3',4'-methylenedioxyphenyl)-2Z, 4Z-heptadienoyl] pyrrolidine (22) and triterpene viburgenin (23).
Asunto(s)
Antifúngicos/aislamiento & purificación , Antineoplásicos/aislamiento & purificación , Plantas Medicinales , Brasil , Daño del ADN , Extractos Vegetales/uso terapéuticoRESUMEN
A novel triterpene, viburgenin (1), has been isolated from an extract of the ripe fruit rinds of Rudgea viburnioides, together with the known saponins, arjunglucoside I and trachelosperosides B-1 and E-1, and the triterpenes trachelosperogenin B (2) and arjungenin. Compound 2 was previously obtained as a product from enzymatic hydrolysis, and it is reported for the first time as a natural product. The structure of compound 1 was determined as 2alpha,3beta, 19alpha,23,24-pentahydroxyurs-12-ene by extensive use of 1D and 2D NMR spectroscopic methods. Compound 1 exhibited moderate antifungal activity against Cladosporium cladosporioides.
Asunto(s)
Antifúngicos/aislamiento & purificación , Plantas Medicinales/química , Saponinas/aislamiento & purificación , Triterpenos/aislamiento & purificación , Antifúngicos/farmacología , Brasil , Cromatografía en Capa Delgada , Cladosporium/efectos de los fármacos , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Pruebas de Sensibilidad Microbiana , Saponinas/farmacología , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta , Triterpenos/farmacologíaRESUMEN
PURPOSE: To comprove the efficiency of acetyl salicylic acid (ASA) as platelet antiaggregant drug, a 100 mg/day dose base. METHODS: Two hundred and fifty-eight patients were studied between 1988 and 1990. Platelet functions were measured using an aggregometer plus ADP 5 as platelet aggregation inductor. RESULTS: Two groups were studied: 1st group, using ASA (111 patients), 91 hypoaggregants; 2nd group, not using ASA (147 patients), 120 normals, 12 hypoaggregants and 15 hyperaggregants. From the 2nd group, 91 had another evaluation under the use of ASA and showed a clear effect of the drug. CONCLUSION: The use of aspirin, 100 mg/day dose, is enough to reduce platelet antiaggregation.