RESUMO
Wolff-Chaikoff effect is characterized by the blockade of thyroid hormone synthesis and secretion due to iodine overload. However, the regulation of monocarboxylate transporter 8 during Wolff-Chaikoff effect and its possible role in the rapid reduction of T4 secretion by the thyroid gland remains unclear. Patients with monocarboxylate transporter 8 gene loss-of-function mutations and monocarboxylate transporter 8 knockout mice were shown to have decreased serum T4 levels, indicating that monocarboxylate transporter 8 could be involved in the secretion of thyroid hormones from the thyroid gland. Herein, we aimed to evaluate the regulation of monocarboxylate transporter 8 during the Wolff-Chaikoff effect and the escape from iodine overload, besides the importance of iodine organification for this regulation. Monocarboxylate transporter 8 mRNA and protein levels significantly decreased after 1 day of NaI administration to rats, together with decreased serum T4; while no alteration was observed in LAT2 expression. Moreover, both monocarboxylate transporter 8 expression and serum T4 was restored after 6 days of NaI. The inhibition of thyroperoxidase activity by methimazole prevented the inhibitory effect of NaI on thyroid monocarboxylate transporter 8 expression, suggesting that an active thyroperoxidase is necessary for MCT8 downregulation by iodine overload, similarly to other thyroid markers, such as sodium iodide symporter. Therefore, we conclude that thyroid monocarboxylate transporter 8 expression is downregulated during iodine overload and that the normalization of its expression parallels the escape phenomenon. These data suggest a possible role for monocarboxylate transporter 8 in the changes of thyroid hormones secretion during the Wolff-Chaikoff effect and escape.
Assuntos
Iodo/metabolismo , Transportadores de Ácidos Monocarboxílicos/fisiologia , Glândula Tireoide/metabolismo , Sistema y+ de Transporte de Aminoácidos/análise , Animais , Regulação para Baixo , Cadeias Leves da Proteína-1 Reguladora de Fusão/análise , Masculino , Transportadores de Ácidos Monocarboxílicos/análise , Transportadores de Ácidos Monocarboxílicos/genética , Ratos , Ratos Wistar , Hormônios Tireóideos/metabolismoRESUMO
Objectives: To evaluate the association of physical and functional measures with sarcopenia in moderate chronic obstructive pulmonary disease (COPD) and to establish cutoff points for sarcopenia screening.Methods: The study included COPD with and without sarcopenia, of both sexes who were over 50 years old. Participants were assessed for lung function, body composition, grip strength, Short Physical Performance Battery (SPPB), 5-repetition, 10-repetition and 30-s sit-to-stand tests (5STS, 10STS, and 30STS, respectively). In addition, 6-min walking test, respiratory muscular strength, and physical activity level were tested.Results: The study had 35 participants, 24 men (68.6%) and moderate COPD (51.4%). COPD-sarcopenia showed lower values in lean mass, body fat and body mass alongside lower performance in 10 and 30 STS tests, SPPB and gait speed compared to non-sarcopenic group. The cutoff points with better sensitivity and specificity to identify sarcopenia were 10.88 and 34.14 s, 15 repetitions, and 10 points in the 5STS, 10STS, 30STS, and SPPB, respectively. The comparison of the receiver operating curves evidenced no differences between the functional tests. Only 30STS and SPPB showed acceptable discriminatory power.Conclusion: Functional tests, especially 30STS and SPPB, are simple and affordable tools for screening sarcopenia in COPD with moderate obstruction.
Assuntos
Doença Pulmonar Obstrutiva Crônica , Sarcopenia , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Força Muscular , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Sarcopenia/diagnóstico , Sarcopenia/epidemiologia , Teste de CaminhadaRESUMO
Studies suggest that brain-derived neurotrophic factor (BDNF) and the hypothalamic-pituitary-adrenal (HPA) axis modulate dopaminergic activity in response to nicotine and that the concentrations of BDNF and cortisol seem to be dependent on the amount and duration of smoking. Therefore, we investigated BDNF and cortisol levels in smokers ranked by daily cigarette consumption. Twenty-seven adult males (13 non-smokers and 14 smokers) participated in the study. The smokers were divided in two groups: light (n=7) and heavy smokers (n=7). Anthropometric parameters and age were paired between the groups, and plasma BDNF and salivary cortisol levels were measured. Saliva samples were collected on awakening, 30 min after awakening, at 10:00 and 12:00 am, 5:00 and 10:00 pm. Additionally, cotinine serum levels were measured in smokers. Heavy smokers had higher mean values of BDNF compared to the control group (P=0.01), whereas no difference was observed in light smokers. Moreover, heavy smokers presented lower cortisol levels in the last collection (10:00 pm) than the control group (P=0.02) and presented statically higher values of cotinine than the light smokers (P=0.002). In conclusion, changes in BDNF and cortisol levels (10:00 pm) appear to be dependent on heavy cigarette smoking and can be involved in activation and in the relationship between the mesolimbic system and the HPA axis.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/sangue , Hidrocortisona/análise , Fumar/metabolismo , Adulto , Análise de Variância , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Humanos , Técnicas Imunoenzimáticas , Masculino , Nicotina/efeitos adversos , Nicotina/metabolismo , Valores de Referência , Saliva/química , Fumar/efeitos adversos , Estatísticas não Paramétricas , Fatores de Tempo , Produtos do Tabaco/efeitos adversosRESUMO
Chronic exposure to cigarette smoke seems to be related to an increase of pro-inflammatory cytokines, oxidative stress and changes in muscular and physical performances of healthy smokers. However, these parameters have not yet been evaluated simultaneously in previous studies. The participants of this study were healthy males divided into two groups: smokers (n=20) and non-smokers (n=20). Inflammation was evaluated by measuring plasma levels of the cytokines IL-10, IL-6 e TNF-α, and of the soluble receptors sTNFR1 and sTNFR2. Oxidative stress was evaluated by determination of thiobarbituric acid reactive substances (TBARS) plasma levels, total antioxidant capacity of plasma and erythrocytes activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase. Muscular performance was evaluated by measuring the peak torque of knee flexors and extensors, and by determining the total work of the knee extensors. Physical performance was assessed by measuring the peak oxygen uptake (VO2 peak), the maximum heart rate (HRmax) and the walking distance in the shuttle walking test. Smokers showed an increase in the levels of the sTNFR1 and TBARS and a decrease in the total antioxidant capacity of plasma, in the catalase activity and in the total work (P<0.05). IL-6, IL-10, sTNFR2, SOD, peak torque, VO2 peak, HRmax and walking distance were similar between groups. Smokers presented increased oxidative stress and skeletal muscle dysfunction, demonstrating that the changes in molecular and muscular parameters occur simultaneously in healthy smokers.
Assuntos
Músculo Esquelético/fisiopatologia , Estresse Oxidativo/fisiologia , Fumar/fisiopatologia , Adulto , Estudos de Casos e Controles , Humanos , Inflamação/sangue , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/sangue , Receptores Tipo II do Fator de Necrose Tumoral/sangue , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Fator de Necrose Tumoral alfa/sangueRESUMO
Some dietary flavonoids inhibit thyroperoxidase and hepatic deiodinase activity, indicating that these compounds could be classified as anti-thyroid agents. In this study, we evaluated the in vitro effect of various flavonoids on thyroid type 1 iodothyronine deiodinase activity (D1). D1 activity was measured in murine thyroid microsome fractions by the release of 125I from 125I-reverse T3. D1 activity was significantly inhibited by all the flavonoids tested; however, the inhibitory potencies on thyroid D1 activity differed greatly among them. A 50% inhibition of D1 activity (IC(50)) was obtained at 11 microM baicalein, 13 microM quercetin, 17 microM catechin, 55 microM morin, 68 microM rutin, 70 microM fisetin, 72 microM kaempferol and 77 microM biochanin A. Our data reinforce the concept that dietary flavonoids might behave as antithyroid agents, and possibly their chronic consumption could alter thyroid function.
Assuntos
Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Iodeto Peroxidase/antagonistas & inibidores , Animais , Cinética , CamundongosRESUMO
Most natural forests have been converted for human use, restricting biological life to small forest fragments. Many animals, including some species of bats are disappearing and the list of these species grows every day. It seems that the destruction of the habitat is one of its major causes. This study aimed to analyze how this community of bats was made up in environments with different sizes and quality of habitat. Data from studies conducted in the region of Londrina, Parana, Brazil, from 1982 to 2000 were used. Originally, this area was covered by a semi deciduous forest, especially Aspidosperma polyneuron (Apocynaceae), Ficus insipida (Moraceae), Euterpe edulis (Arecaceae), Croton floribundus (Euforbiaceae), and currently, only small remnants of the original vegetation still exist. The results showed a decline in the number of species caught in smaller areas compared to the largest remnant. In about 18 years of sampling, 42 species of bats were found in the region, representing 67% of the species that occur in Paraná and 24.4% in Brazil. There were two species of Noctilionidae; 21 of Phyllostoma; 11 Vespertilionidae and eight Molossidae. Eight of these were captured only in the largest fragment, Mata dos Godoy State Park (680 ha). Ten species had a low capture rate in the smaller areas with less than three individuals. Of the total sampled, 14 species were found in human buildings, and were able to tolerate modified environments, foraging and even using them as shelter. As the size of the forest area increases, there is a greater variety of ecological opportunities and their physical conditions become more stable, i.e., conditions favorable for growth and survival of a greater number of species. Forest fragmentation limits and creates subpopulations, preserving only long-lived K-strategist animals for some time, where the supporting capacity of the environment is a limiting factor. The reduction of habitats, species and genetic diversity resulting from human activities are endangering the future adaptability in natural ecosystems, which promotes the disappearance of low adaptive potential species.
Assuntos
Quirópteros/fisiologia , Ecossistema , Atividades Humanas , Animais , Biodiversidade , Brasil , Quirópteros/classificação , Humanos , Densidade Demográfica , Dinâmica Populacional , ÁrvoresRESUMO
OBJECTIVE: The purpose of this study was to analyse the use of digital tools for image enhancement of mandibular radiolucent lesions and the effects of this manipulation on the percentage of correct radiographic diagnoses. METHODS: 24 panoramic radiographs exhibiting radiolucent lesions were selected, digitized and evaluated by non-experts (undergraduate and newly graduated practitioners) and by professional experts in oral diagnosis. The percentages of correct and incorrect diagnoses, according to the use of brightness/contrast, sharpness, inversion, highlight and zoom tools, were compared. All dental professionals made their evaluations without (T1) and with (T2) a list of radiographic diagnostic parameters. RESULTS: Digital tools were used with low frequency mainly in T2. The most preferred tool was sharpness (45.2%). In the expert group, the percentage of correct diagnoses did not change when any of the digital tools were used. For the non-expert group, there was an increase in the frequency of correct diagnoses when brightness/contrast was used in T2 (p=0.008) and when brightness/contrast and sharpness were not used in T1 (p=0.027). The use or non-use of brightness/contrast, zoom and sharpness showed moderate agreement in the group of experts [kappa agreement coefficient (κ) = 0.514, 0.425 and 0.335, respectively]. For the non-expert group there was slight agreement for all the tools used (κ ≤ 0.237). CONCLUSIONS: Consulting the list of radiographic parameters before image manipulation reduced the frequency of tool use in both groups of examiners. Consulting the radiographic parameters with the use of some digital tools was important for improving correct diagnosis only in the group of non-expert examiners.
Assuntos
Doenças Mandibulares/diagnóstico por imagem , Intensificação de Imagem Radiográfica/métodos , Radiografia Panorâmica/métodos , Ameloblastoma/diagnóstico por imagem , Cisto Dentígero/diagnóstico por imagem , Odontólogos , Diagnóstico Bucal , Humanos , Cistos Maxilomandibulares/diagnóstico por imagem , Neoplasias Mandibulares/diagnóstico por imagem , Tumores Odontogênicos/diagnóstico por imagem , Radiografia Dentária Digital/métodos , Radiologia , Estudantes de OdontologiaRESUMO
O presente trabalho visou avaliar a influência de diferentes tempos de extração no teor e composição química do óleo essencial da espécie Pothomorphe umbellata. Folhas de pariparoba foram coletadas em Cajamar - SP, no mês de junho de 2006. O delineamento experimental adotado foi inteiramente casualizado, com seis tempos de extração (90, 120, 150, 180, 210 e 240 minutos) e 4 repetições. A extração do óleo essencial foi realizada por hidrodestilação e a análise química em CG-EM. O tempo de 180 minutos proporcionou maior rendimento do óleo essencial (0,42%), enquanto a composição química não foi influenciada pelos diferentes tempos de destilação. As principais substâncias identificadas foram: D-germacreno (65,5%), alfa-selineno (9,7%), trans-cariofileno (7,5%), e espatulenol (6,58%). Conclui-se que o tempo de extração afeta diretamente o rendimento e a proporção das substâncias químicas, recomendando-se a extração em até 180 minutos. .
The present work aimed to evaluate the influence of different times of extraction in the yield and chemical composition of the essential oil of "pariparoba" (Pothomorphe umbellate). Leaves of "pariparoba" were collected in the municipal district of Cajamar - state of São Paulo, Brazil, in June 2006. The adopted experimental design was completely randomized, with six times of extraction (90, 120, 150, 180, 210, and 240 minutes) and 4 repetitions. The extraction of the essential oil was accomplished by hydrodistillation, and the chemical analysis was performed in GC-MS. The time of extraction of 180 minutes provided greater yield of the essential oil (0.42%), and its chemical composition was not influenced by the different times of hydrodistillation. The main substances showed are D-germacrene (65.5%), alpha-selinene (9.7%), trans-caryophyllene (7.5%) and spathulenol (6.58%). The results of this work showed that the time of extraction affects the yield and the proportion of the chemical substances and it is recommended the extraction in up to 180 minutes.
Assuntos
Óleos Voláteis/síntese química , Química , Piperaceae/anatomia & histologia , /análise , Destilação/instrumentaçãoRESUMO
Rubella infection is an exanthematic disease, with high prevalence in the adult population. The only modality of disease that causes serious consequences is congenital rubella syndrome (CRS), which happens when a pregnant woman seronegative to rubella virus acquires the infection during early pregnancy. Due to the lack of signals and characteristic symptoms of disease, diagnosis of rubella is based essentially on laboratory tests: antibodies detection and/or virus isolation. Results of serologic tests should always be interpreted with caution, because they can be affected by the quality of blood samples, processing and storage of sera, the equipment and reagents used to perform tests, and finally by the technical expertise and training of biologists. The collection tubes with gel seem to facilitate serum separation, but on the other hand gels can retain and consequently decrease antibody titers. Therefore, we decided to investigate whether the use of collection tubes containing gel separator might interfere with rubella virus antibody detection in blood samples from children. We did not observe statistically significant differences with respect to rubella virus antibody detection (immunoglobulin M [IgM] and immunoglobulin G [IgG]) for samples collected in tubes with or without gel separator, from the two evaluated manufacturers.
Assuntos
Anticorpos Antivirais/sangue , Coleta de Amostras Sanguíneas/instrumentação , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Criança , Géis , HumanosRESUMO
The only threatening modality of rubella is the Congenital Rubella Syndrome that affects fetuses of women who acquire infection during early pregnancy. Laboratory diagnosis is based on serological parameters. We compared anti-rubella IgM and IgG detection of two commercial immunoassay kits (Abbott and Roche). Although we observed an agreement of 97.8% for IgM and 95.7% for IgG when the categories positive, negative and indeterminate were considered, mean titers of IgG and the absorbance/cut off of IgM were statistically different for both kits, thus corroborating the idea that serological results depend very much on the methodology and must be carefully interpreted.
Assuntos
Anticorpos Antivirais/sangue , Imunoensaio/métodos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Kit de Reagentes para Diagnóstico , Rubéola (Sarampo Alemão)/diagnóstico , Adolescente , Anticorpos Antivirais/análise , Criança , Pré-Escolar , Humanos , Imunoglobulina G/análise , Imunoglobulina M/análise , Rubéola (Sarampo Alemão)/sangue , Rubéola (Sarampo Alemão)/imunologiaRESUMO
A Pothomorphe umbellata (Piperaceae), é uma espécie medicinal nativa do Brasil, utilizada na indústria de cosméticos e protetores de pele contra raios UVA e UVB. Com o intuito de gerar informações aplicadas à propagação da espécie, o presente trabalho relacionou a coloração e a massa de sementes de P. umbellata a seu comportamento germinativo. A coloração e a massa de sementes de P. umbellata foram características adequadas para avaliar a homogeneidade fisiológica, o vigor, o potencial e o comportamento germinativo. Assim, conclui-se que, embora de germinação lenta, as sementes de coloração preta e mais densa devem ser as escolhidas quando de coleta ou de processo seletivo.
Pothomorphe umbellata (Piperaceae) is a medicinal species native to Brazil, which has been used in the cosmetic industry and in products that protect the skin against UVA and UVB rays. To generate information applied to the species propagation, the present work related the coloration and the mass of P. umbellata seeds to their germinative behavior. The coloration and the mass of seeds of P. umbellata were characteristic appropriate to evaluate physiologic homogeneity, vigor, potential and germinative behavior. Thus, although of slow germination, seeds of black and denser coloration should be chosen during collection or selective process.
Assuntos
Pigmentação/genética , Piperaceae/embriologia , Sementes/anatomia & histologia , Plantas Medicinais/embriologiaRESUMO
New evidence is presented in support of the hypothesis put forth by CAMBA et al. [1] that streptomycin enters bacterial cells by a process of active transport. In this paper a general inhibitor of transport, uranyl nitrate, when added to the bacterial suspension prior to the addition of streptomycin, was shown to significantly increase the resistance to the drug. Furthermore, in suspensions of cells with a progressively exhausted endogenous metabolism and consequently with less available energy, a corresponding increase in the amount of streptomycin remaining in the supernatant was observed.
Assuntos
Pseudomonas aeruginosa/metabolismo , Estreptomicina/metabolismo , Transporte Biológico Ativo/efeitos dos fármacos , Parede Celular/metabolismo , Estreptomicina/administração & dosagem , Nitrato de Uranil/farmacologiaRESUMO
Avaliou-se o efeito da inclusão de diferentes níveis (0, 5, 10 e 15 por cento) de bagaço de mandioca à dieta de 12 vacas mestiças leiteiras Holandês x Zebu (composição racial com variação de » a ¾ de sangue H x Z) com 478,5kg de peso corporal médio e com 100 a 150 dias de lactação, distribuídas em três Quadrados Latinos 4 x 4. Foi avaliado o consumo de matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), extrato etéreo (EE), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), carboidratos totais (CHT), carboidratos não-fibrosos (CNF) e nutrientes digestíveis totais (NDT). Forneceu-se silagem de capim-elefante como fonte de volumoso. As relações volumoso:concentrado utilizadas foram de 65,19:34,81; 61,59:38,41; 59,08:40,92 e 54,76:45,24. Formularam-se as dietas isoprotéicas e isoenergéticas. Houve aumento linear do consumo de MS, MO, PB, CHT, CNF e NDT, efeito quadrático do consumo de EE e redução do consumo de FDA com o aumento do BM, enquanto o consumo de FDN não diferiu entre os tratamentos.O bagaço de mandioca pode ser utilizado até o nível de 15 por cento de inclusão na dieta total de vacas mestiças leiteiras sem trazer transtornos fisiológicos ou nutricionais aos animais.
The effect of different inclusion levels (0, 5, 10, and 15 percent) of cassava bagasse to the diet of 12 Holstein x Zebu crossbred dairy cows (breed composition varying from » to ¾ H x Z blood), averaging 478.5kg body weight and 100 to 150 days in milk was evaluated. Cows were distributed in three 4 x 4 latin squares. The intake of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), total carbohydrates (TC), non fiber carbohydrates (NFC), and total digestible nutrients (TDN) were evaluated. Elephant grass silage was provided as roughage source. The roughage:concentrate ratios were 65.19:34.81; 61.59:38.41; 59.08:40.92; and 54.76:45.24. Isonitogen and isoenergetic diets were formulated. There was a linear increase in DM, OM, CP, TC, NFC, and TDN intakes, quadratic effect of EE intake, and a reduction of ADF intake with the increase of the BM; while no diference among treatments was observed for NDF intake. The cassava bagasse can be used until 15 percent inclusion level in the total diet of crossbred dairy cows without physiological or nutritional damage.