Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
Opt Express ; 30(23): 41459-41472, 2022 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-36366624

RESUMEN

With the increasing data rate requirements on short-reach links, the recent standardization of unamplified coherent optical systems is paving the way for a cost and power-effective solution, targeting a massive deployment in the near future. However, unamplified systems are introducing new challenges. Particularly, the performance is highly dependent on the peak-to-average power ratio (PAPR) of the transmitted signal, which puts at question the use of the typical constellation formats. In this work, we use an end-to-end deep learning framework to optimize the geometry of different constellation sizes, ranging from 8- to 128-ary constellations. In general, it is shown that the performance of these systems is maximized with constellations whose outer symbols are disposed in a square shape, owing to the minimization of the real-valued PAPR. Following this premise, we experimentally demonstrate that odd-bit constellations can be significantly optimized for unamplified coherent links, achieving power budget gains in the range of 0.5-3 dB through the geometric optimization of 8-, 32- and 128-ary constellations.

2.
Neotrop Entomol ; 48(3): 515-521, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30637578

RESUMEN

Nasutitermes corniger (Motschulsky, 1855) (Termitidae: Nasutitermitinae) is an important pest in urban environments and bioinsecticides can be an alternative to its control. Here, we determined the toxicity and repellence of the essential oil (EO) prepared from stems of Aristolochia trilobata L. (Aristolochiaceae) and its major constituents on N. corniger. We also investigated behavioral changes of individuals exposed to limonene. The lethal dose required to kill 50% of N. corniger population (LD50) of EO of A. trilobata was 2.44 µg mg-1. Limonene was the most toxic compound to N. corniger followed by linalool (LD50 = 1.02 and 1.29 µg mg-1, respectively). In addition, all treatments presented median lethal time (LT50) less than 11 h. A. trilobata EO and its constituents showed irritability activity, but only limonene repelled soldiers more than workers. The negative behaviors of N. corniger groups were higher in individuals treated with limonene. A. trilobata EO and its constituents, especially the limonene, are promising for the control of N. corniger due the high toxicity, repellence, and possible disturbance in the colonies.


Asunto(s)
Aristolochia/química , Insecticidas , Isópteros , Aceites Volátiles , Monoterpenos Acíclicos , Animales , Repelentes de Insectos , Limoneno , Monoterpenos , Aceites de Plantas , Pruebas de Toxicidad Aguda
3.
Neotrop Entomol ; 47(6): 769-779, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29995283

RESUMEN

Leaf-cutting ants belonging to the genus Atta (Formicidae: Myrmicinae) are important pests in agricultural and forest environments. In the present study, we evaluated the formicidal activity of the essential oil of Pogostemon cablin and its nanoformulation on the leaf-cutting ants: Atta opaciceps (Borgmeier, 1939), Atta sexdens (Linnaeus, 1758), and Atta sexdens rubropilosa Forel, 1908. The nanoformulation was developed by magnetic stirring using polyoxyethylene (36%), pure ethanol (36%), essential oil of P. cablin (18%), and water (10%). Bioassays of acute toxicity by fumigation and behavioral bioassays in treated arenas, with and without choice, were performed. The essential oil of P. cablin and its nanoformulation demonstrated efficient insecticidal activity and irritability to ant species. The concentration required to kill 50% of workers varied from 1.06 to 2.10 µL L-1, with a mean time to death of less than or equal to 42 h. The essential oil of P. cablin and its nanoformulation reduced the displacement and velocity speed of the workers of A. opaciceps and A. sexdens rubropilosa in totally treated arenas. In the bioassays with choices, the three species of ants walked less and at a greater speed on the treated side of arena. This work demonstrates the potential of the essential oil of P. cablin and its nanoformulation to the generation of new formicidal products.


Asunto(s)
Hormigas , Insecticidas , Aceites Volátiles , Pogostemon/química , Animales , Conducta Animal , Pruebas de Toxicidad Aguda
4.
J Dairy Sci ; 101(8): 7638-7649, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29885897

RESUMEN

The aim of this work was to investigate associations between individual cow Mycobacterium avium ssp. paratuberculosis (MAP) seropositivity, 305-d corrected milk production, and somatic cell count during 5 lactations lifespan in Portuguese dairy herds using multilevel mixed models. We used MAP serum ELISA (Idexx MAP Ac, Idexx Laboratories Inc., Westbrook, ME) results (n = 23,960) from all the 20,221 adult cows present in 329 farms and corresponding 47,586 lactation records from the National Dairy Improvement Association. Cows and farms were classified as positive or negative. Multilevel mixed models were used to investigate the association of cow MAP status with variation in milk production and somatic cell count. Cow MAP status, farm status, and lactation number were considered as independent variables. A quadratic function of lactation number was used to mimic the effect of lactation order on milk production. The models considered 3 levels: measurement occasion (level 1) within cow (level 2) and cow within farm (level 3). Four final models were produced, including all herds and cows, to address the effect of farm status (models 1 and 2) or the effect of cow status (models 3 and 4) on the outcome variables. Our results show that MAP status affects milk production. Losses are detectable from third lactation onward. During the first 5 lactations, positive cows accumulated an average loss of 1,284.8 kg of milk when compared with the negative cows. We also observed that somatic cell counts were higher in positive cows and a positive interaction occurs between cow status and lactation number, suggesting a positive association between MAP infection and increased somatic cell counts. Our results are in line with previous studies, suggesting a possible positive relation between cow milk production and susceptibility to MAP infection.


Asunto(s)
Enfermedades de los Bovinos/fisiopatología , Bovinos , Recuento de Células/veterinaria , Lactancia/fisiología , Paratuberculosis/fisiopatología , Animales , Enfermedades de los Bovinos/microbiología , Femenino , Leche , Paratuberculosis/epidemiología
5.
J Nutr Health Aging ; 18(5): 471-8, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24886733

RESUMEN

OBJECTIVE: To analyze the simultaneous effects of sociodemographic variables and time on each food group contribution to total Portuguese elderly household food availability. DESIGN: Four cross sectional Portuguese Household Budget Surveys were used. A multivariate analysis of variance (MANOVA), using a general linear model (GLM), was applied to analyze the simultaneous effects of sociodemographic variables and time. SETTING: Portuguese population. SUBJECTS: Nationally representative samples of households with members aged ≥ 65 years were selected and categorized as solitary elderly female, solitary elderly male, or couple (one elderly female and one elderly male). Samples included 1,967 households in 1989-1990, 2,219 households in 1994-1995, 2,533 households in 2000-2001 and 2,441 households in 2005-2006. RESULTS: The simultaneous effects of sociodemographic variables and time were significant for all food groups (P<0.001). The highest contribution for the total household food availability was found for cereals, potatoes, alcoholic beverages, non-alcoholic beverages and fruits. The effects were large for "household food availability" and medium for "elderly household type", "urbanization degree", "income", "food expenses" and "eating out expenses". Solitary elderly male households had the highest proportion of cereals and alcoholic beverages, whilst solitary elderly female households had higher availability of milk/milk products and fruits. Households located in urban areas had higher contribution of milk/milk products while rural, had higher contribution of potatoes. CONCLUSIONS: The simultaneous effect of the studied variables on food group contribution to total household food availability can be considered when addressing dietary recommendation for providing an insight into the motivations associated with food purchases.


Asunto(s)
Dieta/economía , Dieta/estadística & datos numéricos , Composición Familiar , Alimentos/economía , Encuestas Nutricionales , Anciano , Bebidas , Presupuestos , Estudios Transversales , Productos Lácteos , Grano Comestible , Femenino , Abastecimiento de Alimentos/economía , Frutas , Humanos , Masculino , Portugal , Población Rural , Factores Socioeconómicos , Solanum tuberosum , Población Urbana
6.
J Nutr Health Aging ; 18(3): 243-50, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24626750

RESUMEN

OBJECTIVE: To identify diet quality time trends in Portuguese elderly households and the association of diet quality with sociodemographic characteristics. DESIGN: Set of four cross-sectional studies. SETTING: Portuguese population. SUBJECTS: Nationally representative samples from Household Budget Surveys (1989-1990, 1994-1995, 2000-2001 and 2005-2006 versions). Households with members aged ≥ 65 years were categorized as solitary elderly female, solitary elderly male, or elderly couple (composed of one elderly female and one elderly male) and compared with adult households with the same composition. METHODS: Diet quality was assessed through a revised version of the Healthy Diet Indicator (HDIr). Univariate and multiple backward linear regression models were used to study the association with sociodemographic characteristics. RESULTS: Mean values of dietary index were low and the proportion of elderly households with low diet quality (HDIr≤4) was high (between 47.4% and 68.4%). However, the frequency of HDIr inadequacy for adult household was even higher (P<0.05). In general, adjusted coefficients for survey year, educational level of the household head, and eating out expenses were inversely associated with HDIr; whilst semi-urban and rural location of the households predicted higher HDIr values. Exceptions were found in elderly male households where the educational level of the household head was positively associated with HDIr values. CONCLUSIONS: Overall, diet quality was low and decreased over time but lonely elderly female and elderly couple households had higher values of HDIr. Adherence to a healthier diet was associated with lower educational level of the household head and location of the household in less urbanized areas.


Asunto(s)
Dieta/estadística & datos numéricos , Composición Familiar , Conducta Alimentaria , Adulto , Anciano , Anciano de 80 o más Años , Presupuestos , Estudios Transversales , Recolección de Datos , Dieta/economía , Escolaridad , Femenino , Evaluación Geriátrica , Humanos , Modelos Lineales , Masculino , Portugal/epidemiología , Población Rural/estadística & datos numéricos , Factores Sexuales , Factores Socioeconómicos , Población Urbana/estadística & datos numéricos
7.
Ann Hum Biol ; 39(6): 526-9, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23101434

RESUMEN

BACKGROUND: Growth trends have never been studied in adolescents of the Autonomous Region of Madeira, Portugal. AIMS: To analyse growth trends in weight, height, body mass index (BMI), waist circumference (WC), mid-upper arm circumference (MUAC) and triceps skin-fold thickness (TST) of adolescents (10-17 years old) of the Autonomous Region of Madeira between 1996-1998 and 2007-2009. SUBJECTS AND METHODS: A cross-sectional study was carried out between 2007-2009, including 4314 adolescents, 2237 girls and 2077 boys (10-17 years old). To study secular growth trends, data were compared with a sample from 1996-1998, comparing the means for each anthropometric variable by age and sex using the independent-sample t-test. RESULTS: An average increase was found in weight of 5.8 kg in boys and 6.3 kg in girls; in height of 3.0 cm in boys and 3.7 cm in girls; in BMI of 1.5 kg/m(2) in boys and 1.7 kg/m(2) in girls; in WC a difference of 5.6 cm and 4.9 cm for boys and girls, respectively, and for MUAC a difference of 2.7 cm in boys and 2.0 cm in girls. No differences were found in TST in boys, but in girls an increase of 1.2 mm was observed. CONCLUSIONS: A general increase in anthropometric measurements, more marked in weight, BMI, WC and MUAC and at younger ages, was observed.


Asunto(s)
Desarrollo Infantil/fisiología , Crecimiento , Adolescente , Antropometría , Composición Corporal , Estatura , Índice de Masa Corporal , Peso Corporal , Niño , Estudios Transversales , Recolección de Datos , Femenino , Humanos , Masculino , Portugal
8.
Arq. bras. med. vet. zootec ; Arq. bras. med. vet. zootec. (Online);63(4): 805-813, ago. 2011. graf, tab
Artículo en Portugués | LILACS | ID: lil-599597

RESUMEN

Avaliou-se o efeito da suplementação de uma combinação homeopática sobre a contagem de células somáticas do leite (CCS), o teor sanguíneo de cortisol e a resposta de anticorpos neutralizantes antivírus da raiva de vacas leiteiras. Trinta e duas vacas Holandesas em lactação foram blocadas em pares e aleatoriamente alocadas a um de dois tratamentos por 63 dias, posterior a um período de padronização de 14 dias. A CCS mensurada no final da padronização ajustou os valores semanais de CCS no modelo de análise estatística. Os tratamentos foram: 150 gramas de uma combinação homeopática (Hypothalamus, 10-30; Colibacilinum, 10-30; Streptococus Beta Hemolyticum, 10-60; Streptococus Uberis, 10-60; Phytolacca, 10-60; Calcium Phosphoricum, 10-30; Natrum Muriaticum, 10-60; Urtica Urens, 10-30; Silicea Terra, 10-400) em veículo mineral, ou 150 gramas do mesmo veículo mineral (controle). A homeopatia tendeu a aumentar a CCS de 124 para 222 x1.000 células mL-1 (P=0,09) e a CCS linearizada (P=0,08). Não foram detectados efeitos de tratamento sobre a concentração sérica de cortisol após estresse induzido por aspiração percutânea do saco ventral do rúmen (P=0,59) ou sobre o título de anticorpos neutralizantes em resposta à vacinação antivírus da raiva (P=0,40). A suplementação com homeopatia tendeu a aumentar a CCS de vacas com baixa CCS.


The effect of supplementing a homeopathic combination on milk somatic cell count (SCC), blood cortisol content and the antibody response to rabies vaccination of dairy cows was evaluated. Thirty-two lactating Holstein cows were paired blocked and randomly assigned to one of two treatments for 63 days, following a 14-day standardization period. The SCC measured at the end of standardization period adjusted weekly SCC values in the statistical analysis model. Treatments were: 150 grams of a homeopathic combination (Hypothalamus, 10-30; Colibacilinum, 10-30; Streptococcus Beta Hemolyticum, 10-60, Streptococcus Uberis, 10-60; Phytolacca, 10-60; Calcium Phosphoricum, 10-30; Natrum Muriaticum, 10-60; Urtica Urens, 10-30, Silicea Terra, 10-400) in mineral vehicle, or 150 grams of the same mineral vehicle (Control). Homeopathy tended to increase SCC from 124 to 222 x1,000 cells mL-1 (P=0.09) and linear SCC (P=0.08). There were no detectable treatment effects upon serum cortisol concentration following stress induced by percutaneous aspiration of the ventral rumen (P=0.59) and upon serum antibody title in response to rabies vaccination (P=0.40). The supplementation with homeopathy tented to increase the SCC of low SCC cows.


Asunto(s)
Animales , Femenino , Anticuerpos Neutralizantes/metabolismo , Bovinos/crecimiento & desarrollo , Recuento de Células , Células Híbridas/metabolismo , Hidrocortisona/sangre , Homeopatía/veterinaria , Rabia/veterinaria , Fenómenos Fisiológicos Nutricionales del Lactante , Mastitis Bovina
9.
Arq. bras. med. vet. zootec ; Arq. bras. med. vet. zootec. (Online);63(4): 922-930, ago. 2011. ilus, graf, tab
Artículo en Portugués | LILACS | ID: lil-599612

RESUMEN

Avaliou-se o efeito da suplementação de uma combinação homeopática sobre o desempenho e a digestibilidade de nutrientes em vacas leiteiras. Trinta e duas vacas Holandesas foram blocadas em pares e aleatoriamente alocadas a um de dois tratamentos por 63 dias, posterior a um período de padronização de 14 dias. Variáveis mensuradas no final da padronização ajustaram medidas semanais da mesma variável no modelo de análise estatística. Os tratamentos foram: Suplementação diária com 150 gramas de uma combinação homeopática (Hypothalamus, 10-30; Colibacilinum, 10-30; Streptococus Beta Hemolyticum, 10-60; Streptococus Uberis, 10-60; Phytolacca, 10-60; Calcium Phosphoricum, 10-30; Natrum Muriaticum, 10-60; Urtica Urens, 10-30; Silicea Terra, 10-400) em veículo mineral, ou 150 gramas do mesmo veículo mineral (controle). A suplementação com homeopatia aumentou o teor de proteína no leite de 3,09 para 3,19 por cento (P=0,01) e tendeu a aumentar a secreção diária de proteína de 0,737 para 0,776kg (P=0,10). A queda na digestibilidade da fibra e da matéria orgânica (P=0,10), e a similaridade na relação entre alantoína e creatinina na urina (P=0,32), sugerem que houve aumento na eficiência de síntese de proteína microbiana no rúmen. Apesar de o mecanismo não ter sido elucidado, a combinação homeopática aumentou o teor de proteína do leite.


The effect of supplementing a homeopathic combination on dairy cow performance and nutrient digestibility was evaluated. Thirty-two Holstein cows were paired blocked and randomly assigned to one of two treatments for 63 days, following a 14-day standardization period. Variables measured at the end of the standardization period adjusted weekly measurements of the same variable in the statistical analysis model. Treatments were: Daily supplementation of 150 grams of a homeopathic combination (Hypothalamus, 10-30; Colibacilinum, 10-30; Streptococcus Beta Hemolyticum, 10-60, Streptococcus Uberis, 10-60; Phytolacca, 10-60; Calcium Phosphoricum, 10-30; Natrum Muriaticum, 10-60; Urtica Urens, 10-30, Silicea Terra, 10-400) in mineral vehicle, or 150 grams of the same mineral vehicle (Control). Supplementation with homeopathy increased milk protein content from 3.09 to 3.19 percent (P=0.01) and tended to increase the daily secretion of protein from 0.737 to 0.776kg (P=0.10). The trend for decreased fiber and organic matter digestibilities (P=0.10), and the similar allantoin to creatinine ratio in urine (P=0.32), suggests that there was an increase in the efficiency of microbial protein synthesis in the rumen. Although the mechanism could not be elucidated, the homeopathic combination increased milk protein content.


Asunto(s)
Animales , Femenino , Bovinos/crecimiento & desarrollo , Digestión , Homeopatía/veterinaria , Fenómenos Fisiológicos Nutricionales del Lactante , Motilidad Gastrointestinal , Silicea Terra/administración & dosificación , Sólidos Totales
10.
Eur J Nutr ; 50(6): 391-400, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21107585

RESUMEN

PURPOSE: Excess weight may be related to the development of adverse cardiometabolic risk factors in children. The aim of this study was to evaluate the effect of a lifestyle intervention program (nutrition and exercise counseling) on anthropometric parameters and metabolic syndrome (MS) components in Portuguese overweight/obese children. METHODS: A total of 83 overweight/obese children aged 7-9 years were assigned to a 1-year individual or group-based treatment (GT); 61 children (z-score BMI (zBMI): 1.93 ± 0.28; 27 boys and 34 girls) completed the program. Anthropometric and biochemical parameters were assessed at baseline, at 6 months and at 1 year. RESULTS: The overweight/obese children, compared to normal-weight ones, presented significantly higher blood pressure, total-cholesterol, total-cholesterol/high density lipoprotein cholesterol (HDL) ratio, triglycerides, Apolipoprotein B and C-reactive protein levels, while HDL and Apolipoprotein A-I were significantly lower. At baseline, the prevalence of MS was 16.4% in overweight/obese and 0% in normal-weight children. The number of components of MS was significantly higher in children with higher zBMI. Lifestyle intervention led to a significant improvement in zBMI, waist circumference/height ratio, HDL, triglycerides, Apolipoprotein A-I, and Apolipoprotein B levels. The prevalence of MS decreased to 14.8%. The GT intervention seems to be more successful, with a significant decrease in zBMI and an increase in HDL and a lower drop-out rate. CONCLUSIONS: Overweight/obese children have multiple risk factors associated with the MS. Lifestyle intervention, both individual and group-based treatment, led to an improvement in the degree of overweight/obesity and in MS components.


Asunto(s)
Estilo de Vida , Síndrome Metabólico/prevención & control , Obesidad/terapia , Terapia Conductista , Biomarcadores/sangre , Estatura , Niño , Conducta Infantil , Dieta Reductora , Dislipidemias/epidemiología , Dislipidemias/etiología , Dislipidemias/prevención & control , Ejercicio Físico , Salud de la Familia , Femenino , Humanos , Hipertensión/epidemiología , Hipertensión/etiología , Hipertensión/prevención & control , Masculino , Síndrome Metabólico/epidemiología , Síndrome Metabólico/etiología , Síndrome Metabólico/fisiopatología , Obesidad/sangre , Obesidad/dietoterapia , Obesidad/fisiopatología , Sobrepeso/dietoterapia , Sobrepeso/terapia , Pacientes Desistentes del Tratamiento , Portugal/epidemiología , Prevalencia , Factores de Riesgo , Circunferencia de la Cintura
11.
Arq. bras. med. vet. zootec ; Arq. bras. med. vet. zootec. (Online);62(5): 1174-1182, out. 2010. tab
Artículo en Portugués | LILACS | ID: lil-570477

RESUMEN

Avaliaram-se o desempenho e a eficiência digestiva de vacas leiteiras suplementadas com levedura viva, cepa KA500. Vinte vacas da raça Holandesa formaram 10 blocos de dois animais com base na produção diária de leite e foram aleatoriamente alocadas em uma sequência de dois tratamentos, em delineamento de reversão simples, com períodos de 28 dias e mensurações na quarta semana. Os tratamentos foram: 10g de levedura (2x10(10)ufc/g) ou controle. A composição das dietas foi ( por cento da MS): silagem de milho (45,0), feno de tifton (4,1) e concentrado à base de milho, polpa cítrica e farelo de soja (50,9). O consumo de matéria seca foi de 21,3kg com levedura e de 21,8kg no controle (P=0,01), e a produção de leite de 29,6 e 29,3kg, respectivamente (P=0,45). A produção de leite por unidade de consumo foi de 1,37 com levedura e de 1,32 no controle (P=0,05). A suplementação de levedura reduziu a contagem de células somáticas do leite (P=0,02). Não houve efeito da suplementação sobre as variáveis que descreveram a função ruminal ou a digestibilidade dos nutrientes no trato digestivo total. A suplementação com levedura aumentou a eficiência alimentar e reduziu a contagem de células somáticas do leite.


Performance and digestive efficiency of dairy cows supplemented with live yeast strain KA500 were evaluated. Twenty Holstein cows formed ten blocks of two animals based on daily milk production and were randomly assigned to a sequence of two treatments, in a cross-over design, with 28-day periods, and measurements on the fourth week. Treatments were: 10g of yeast (2x10(10)/cfu/g) or control. The composition of the diets were ( percent of DM): corn silage (45.0), tifton hay (4.1), and a corn, citrus pulp, soybean meal-based concentrate (50.9). The dry matter intake was 21.3kg with yeast and 21.8kg for the control (P=0.01), and milk yield was 29.6 and 29.3kg, respectively (P=0.45). Milk yield per unit of intake was 1.37 with yeast and 1.32 for the control (P=0.05). The supplementation of yeast reduced (P=0.02) the somatic cell count in milk. There was no effect of the supplementation upon variables related to the rumen function or the total tract digestibility of nutrients. Yeast supplementation increased feed efficiency and reduced milk somatic cell count.


Asunto(s)
Animales , Femenino , Lactante , Bovinos , Producción de Alimentos , Probióticos , Bovinos , Saccharomyces cerevisiae
12.
Acta Biotheor ; 58(4): 391-404, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20683639

RESUMEN

We analyse the effect of the regulatory T cells (Tregs) in the local control of the immune responses by T cells. We obtain an explicit formula for the level of antigenic stimulation of T cells as a function of the concentration of T cells and the parameters of the model. The relation between the concentration of the T cells and the antigenic stimulation of T cells is an hysteresis, that is unfold for some parameter values. We study the appearance of autoimmunity from cross-reactivity between a pathogen and a self antigen or from bystander proliferation. We also study an asymmetry in the death rates. With this asymmetry we show that the antigenic stimulation of the Tregs is able to control locally the population size of Tregs. Other effects of this asymmetry are a faster immune response and an improvement in the simulations of the bystander proliferation. The rate of variation of the levels of antigenic stimulation determines if the outcome is an immune response or if Tregs are able to maintain control due to the presence of a transcritical bifurcation for some tuning between the antigenic stimuli of T cells and Tregs. This behavior is explained by the presence of a transcritical bifurcation.


Asunto(s)
Modelos Inmunológicos , Linfocitos T Reguladores/citología , Linfocitos T Reguladores/inmunología , Linfocitos T/citología , Linfocitos T/inmunología , Antígenos/inmunología , Muerte Celular , Proliferación Celular , Humanos
13.
Arch Dis Child ; 89(8): 785-8, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15269085

RESUMEN

AIM: To evaluate compliance in children with acute lymphoblastic leukaemia (ALL). METHODS: Compliance was assessed through specific interviews, annotations from medical charts, and erythrocytic determination of 6-mercaptopurine metabolites. RESULTS: A total of 39 patients who had concluded maintenance phase of chemotherapy were included in the study. Mothers were responsible for delivering 6-MP in 87% of cases. Thirty five interviewees said that medical prescription was well understood and that the main reason for non-compliance was forgetfulness. Non-compliance was detected through interviews (33.3% of the cases), reports from medical charts (30.7%), and drug determination (16.6%); 53.8% of children were found to be non-compliant. Non-compliance was significantly associated with chronic undernourishment. Although not statistically significant, there was a trend for the group of non-compliant children to be associated with low per capita family income. No significant associations of non-compliance with age at diagnosis, gender, parents' schooling level, number of family members, power consumption, and medians of absolute leucocyte or neutrophil blood counts were detected. A short follow up period precluded valid analysis on outcome. In the non-compliant group (n = 21), seven children relapsed, contrasting with three relapses in the compliant group (n = 18). CONCLUSIONS: Results suggest that non-compliance is one of the mechanisms which underlies the adverse influence of socioeconomic factors on the outcome of children with ALL. Additional studies are necessary to confirm this hypothesis. Comprehensive approaches to the problem of non-compliance are urgently needed.


Asunto(s)
Cooperación del Paciente , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Adolescente , Antimetabolitos Antineoplásicos/uso terapéutico , Biomarcadores de Tumor/sangre , Recuento de Células Sanguíneas , Niño , Preescolar , Enfermedad Crónica , Femenino , Humanos , Lactante , Entrevistas como Asunto , Masculino , Mercaptopurina/uso terapéutico , Madres , Trastornos Nutricionales/complicaciones , Pobreza , Leucemia-Linfoma Linfoblástico de Células Precursoras/sangre , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicaciones , Recurrencia
14.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;37(5): 649-658, May 2004. ilus, tab, graf
Artículo en Inglés | LILACS | ID: lil-357554

RESUMEN

A procedure is described for the rapid determination of the intra-erythrocyte concentration of 6-mercaptopurine (6-MP) and its metabolites, 6-thioguanine nucleotides (6-TGN) and 6-methylmercaptopurine (6-MMP). Erythrocytes (8 x 10(8) cells) in 350 æl Hanks solution containing 7.5 mg dithiothreitol were treated with 50 æl 70 percent perchloric acid. The precipitate was removed by centrifugation (13,000 g) and the supernatant hydrolyzed at 100§C for 45 min. After cooling, 100 æl was analyzed directly by HPLC using a Radialpack Resolve C18 column eluted with methanol-water (7.5:92.5, v/v) containing 100 mM triethylamine. 6-TG, 6-MP and the hydrolysis product of 6-MMP, 4-amino-5-(methylthio)carbonyl imidazole, were monitored at 342, 322 and 303 nm using a Shimadzu SPD-M10A diode array UV detector. The analytes eluted at 5.3, 6.0 and 10.2 min, respectively. The calibration curves were linear (rý > 0.998), and the analytical recoveries were 73.2 percent for 6-TG, 119.1 percent for 6-MP and 97.4 percent for 6-MMP. The intra- and inter-assay variations were highest for 6-MP (9.6 and 14.3 percent, respectively). The lowest detectable concentrations were 3, 3 and 25 pmol/8 x 10(8) erythrocytes for 6-TG, 6-MP and 6-MMP, respectively. The quantification limits (coefficients of variation <15 percent) were 8, 10 and 70 pmol/8 x 10(8) erythrocytes for 6-TG, 6-MP and 6-MMP, respectively. The method was applied to the analysis of 183 samples from 36 children under chemotherapy for acute lymphoblastic leukemia. The concentrations of the metabolites in the red cells of the patients ranged from 0 to 1934 pmol/8 x 10(8) erythrocytes for 6-TGN, and from 0 to 105.8 and 0 to 45.9 nmol/8 x 10(8) erythrocytes for 6-MP and 6-MMP, respectively. The procedure gave results that were in agreement with those obtained with other methods designed to detect cases of non-compliance with treatment, including patient interviews and medical evaluation, among others, demonstrating its applicability to monitoring the treatment of leukemic children.


Asunto(s)
Humanos , Niño , Mercaptopurina , Cromatografía Líquida de Alta Presión , Eritrocitos , Leucemia-Linfoma Linfoblástico de Células Precursoras , Biomarcadores , Ditiotreitol , Tioguanina
15.
Braz J Med Biol Res ; 37(5): 649-58, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15107925

RESUMEN

A procedure is described for the rapid determination of the intra-erythrocyte concentration of 6-mercaptopurine (6-MP) and its metabolites, 6-thioguanine nucleotides (6-TGN) and 6-methylmercaptopurine (6-MMP). Erythrocytes (8 x 10(8) cells) in 350 microl Hanks solution containing 7.5 mg dithiothreitol were treated with 50 microl 70% perchloric acid. The precipitate was removed by centrifugation (13,000 g) and the supernatant hydrolyzed at 100 degrees C for 45 min. After cooling, 100 microl was analyzed directly by HPLC using a Radialpack Resolve C18 column eluted with methanol-water (7.5:92.5, v/v) containing 100 mM triethylamine. 6-TG, 6-MP and the hydrolysis product of 6-MMP, 4-amino-5-(methylthio)carbonyl imidazole, were monitored at 342, 322 and 303 nm using a Shimadzu SPD-M10A diode array UV detector. The analytes eluted at 5.3, 6.0 and 10.2 min, respectively. The calibration curves were linear (r(2) > 0.998), and the analytical recoveries were 73.2% for 6-TG, 119.1% for 6-MP and 97.4% for 6-MMP. The intra- and inter-assay variations were highest for 6-MP (9.6 and 14.3%, respectively). The lowest detectable concentrations were 3, 3 and 25 pmol/8 x 10(8) erythrocytes for 6-TG, 6-MP and 6-MMP, respectively. The quantification limits (coefficients of variation <15%) were 8, 10 and 70 pmol/8 x 10(8) erythrocytes for 6-TG, 6-MP and 6-MMP, respectively. The method was applied to the analysis of 183 samples from 36 children under chemotherapy for acute lymphoblastic leukemia. The concentrations of the metabolites in the red cells of the patients ranged from 0 to 1934 pmol/8 x 10(8) erythrocytes for 6-TGN, and from 0 to 105.8 and 0 to 45.9 nmol/8 x 10(8) erythrocytes for 6-MP and 6-MMP, respectively. The procedure gave results that were in agreement with those obtained with other methods designed to detect cases of non-compliance with treatment, including patient interviews and medical evaluation, among others, demonstrating its applicability to monitoring the treatment of leukemic children.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Eritrocitos/química , Mercaptopurina/sangre , Leucemia-Linfoma Linfoblástico de Células Precursoras/sangre , Biomarcadores/sangre , Niño , Ditiotreitol/sangre , Ditiotreitol/uso terapéutico , Humanos , Mercaptopurina/uso terapéutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Tioguanina/sangre , Tioguanina/uso terapéutico
16.
Electrophoresis ; 22(8): 1568-72, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11386671

RESUMEN

The concentration of different phenolic compounds was measured in Spanish Albariño and Portuguese Alvarinho and Loureiro white wines by capillary zone electrophoresis (CZE), in order to characterize them. Although all samples presented the same qualitative pattern (characterized by tyrosol; (-)-epicatechin; syringic acid; ferulic acid; p-coumaric acid; caffeic acid, gallic acid; 3,4-dihydroxybenzoic acid; cis-coumaroyl tartaric acid (COUTA); trans-COUTA; trans-caffeoyl tartaric acid (CAFTA), and hydroxycinnamic esters), some quantitative differences were observed. When samples were analyzed by high-performance liquid chromatography (HPLC), in order to compare the results obtained by both techniques, no significant qualitative or quantitative differences were obtained. Nevertheless, CZE proved to be a more convenient technique for the routinary analyses of these wines, due to better separation of the different compounds, better peak shapes, and higher speed than HPLC.


Asunto(s)
Fenoles/análisis , Rosales/química , Vino/análisis , Cromatografía Líquida de Alta Presión/métodos , Electroforesis Capilar/métodos , Portugal , España
18.
J Pediatr (Rio J) ; 76(4): 281-6, 2000.
Artículo en Portugués | MEDLINE | ID: mdl-14647656

RESUMEN

OBJECTIVES: To report the experience in the treatment of Hodgkins lymphoma in children at Hospital das Clínicas, UFMG, Brazil.METHODS: 31 children with Hodgkins lymphoma were retrospectively followed up from 1983 to 1999. Fifteen children were treated according to HD-85, a protocol based on German-Austrian studies; the 16 remaining children were treated otherwise.RESULTS: The age at diagnosis varied from 3 to 15 years (median 9 years). There were 28 male patients. The follow-up period ranged from 2 months to 16 years (median 3 years and 7 months). Mixed cellularity was the predominant (61%) histological subtype; 58% had advanced disease (stages III or IV) at diagnosis. Staging abdominal surgery was necessary in 61%. No reduction in the frequency of staging surgeries was observed after starting standardized HD-85 protocol in 1994. Herpes simplex and zoster infections were the most common complications. The estimated probability of disease-free survival (DFS) was 55.6%-/+11.7% at 5 years. Overall survival probability was 96.5%-/+3.5%. No difference in DFS was apparent between children treated with HD-85 and those treated otherwise.CONCLUSIONS: The overall results in DFS are worse than those reported in the literature. The predominance of mixed cellularity subtype, and early age and advanced disease at diagnosis are commonly reported in developing countries and do not fully explain the observed results. A longer follow-up is necessary to evaluate the influence of treatment standardization on the outcome of these children.

19.
Med Pediatr Oncol ; 28(5): 370-2, 1997 May.
Artículo en Inglés | MEDLINE | ID: mdl-9121404

RESUMEN

Non-Hodgkin's lymphomas presenting exclusively in the liver are rather uncommon in adults and extremely rare in children. We describe a six-year-old white boy with jaundice, abdominal pain, and weight loss of two weeks duration. Physical examination disclosed asthenia, jaundice, abdominal swelling, large hepatomegaly, and ascitis. Aminotransferases bilirubin, and alkaline phosphatase were significantly elevated. Bone marrow aspiration, cerebrospinal fluid, chest x-ray, renal function tests, and uric acid were normal. Abdominal ultrasound showed liver enlargement with irregular regular borders, many parenchymal nodules in both liver lobes, a large hypoechogenic mass in the inferior segment of the liver, normal biliary ducts and two pancreatic nodules resembling those in the liver. Liver needle biopsy disclosed diffuse lymphomatous infiltration. Blast cells were positive for leukocyte common antigen (CD 45). Immunohistochemistry study for T or B cell lineage differentiation was not done. The child showed an excellent response to chemotherapy based on the BFM-83 protocol for B cell non-Hodgkin's lymphomas. The patient had his therapy discontinued in June 1995 and remains in first complete remission as of May 20th, 1996.


Asunto(s)
Neoplasias Hepáticas , Linfoma no Hodgkin , Niño , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/terapia , Linfoma no Hodgkin/diagnóstico , Linfoma no Hodgkin/terapia , Masculino
20.
Cell Biochem Funct ; 13(4): 267-71, 1995 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8565147

RESUMEN

The effects of citrinin on energy production along the respiratory chain and on glycolytic lactate production were examined in BHK-21 cultured cells. Citrinin inhibited the oxygen consumption rate by about 45 per cent. The respiratory rate of digitonin-treated cells energized with succinate, in the presence of ADP, was reduced by about 39 per cent. The mycotoxin inhibited the glucose utilization of BHK-21 cells by about 86 per cent. Cells treated with citrinin produced a small quantity of pyruvate, but were unable to produce lactate. It is concluded that BHK-21 cells cannot generate lactate when oxidative metabolism is inhibited by citrinin. The perturbations in BHK-21 cells caused by citrinin are due to alterations in mitochondrial function and in the glycolytic anaerobic pathway.


Asunto(s)
Citrinina/farmacología , Metabolismo Energético/fisiología , Animales , Línea Celular/enzimología , Respiración de la Célula/fisiología , Cricetinae , Glucosa/metabolismo , Glucólisis/fisiología , Riñón/citología , Mitocondrias/enzimología , Fosforilación Oxidativa
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...