Efeitos das faixas de controle do capim-braquiária (Brachiaria decumbens) no desenvolvimento inicial e na produtividade do cafeeiro (Coffea arabica)

Neste trabalho, objetivou-se avaliar os efeitos das diferentes faixas de controle do capim-braquiária (Brachiaria decumbens) no desenvolvimento inicial e na produtividade do cafeeiro (Coffea arabica). O experimento foi conduzido entre março de 2002 e maio de 2004, na Fazenda Cachoeiras de São Pedro, município de Garça-SP. As plantas de café utilizadas foram Mundo Novo (var. 388/17) no espaçamento de 1,40 m na linha de plantio e 4,0 m nas entrelinhas, sendo duas mudas por cova. Os tratamentos foram constituídos pelas seguintes faixas de controle: 0, 25, 50, 75, 100, 125 e 150 cm de largura para cada lado da linha cultivada do cafeeiro. O delineamento experimental utilizado foi de blocos casualizados, com quatro repetições. Foram avaliados a altura e o diâmetro na base do caule das mudas de café, a produção bruta e a produção beneficiada dos grãos. Pelos resultados obtidos, pode-se concluir que a largura mínima da faixa de controle a ser utilizada foi de 100 cm de cada lado da linha, a fim de manter as plantas de café livres da interferência de capim-braquiária.

Eficiência no uso da água e interferência de plantas daninhas no meloeiro cultivado nos sistemas de plantio direto e convencional

Com o objetivo de avaliar o efeito dos sistemas de plantio direto e convencional e estratégias de manejo de plantas daninhas na economia de água de irrigação na cultura do melão (Cucumis melo), conduziu-se um experimento na horta didática do Departamento de Ciências Vegetais da Universidade Federal Rural do Semiárido, em Mossoró-RN, utilizando o delineamento experimental de blocos casualizados, no esquema de parcelas subdivididas. Nas parcelas foram avaliados dois sistemas de plantio (plantio direto e convencional) e, nas subparcelas, três sistemas de manejo de plantas daninhas (cobertura com filme de polietileno, mantido no limpo por meio de capinas e testemunha sem capinas). Avaliaram-se a densidade e a massa seca das plantas daninhas aos 30 dias após o transplante, a produtividade comercial e total e o consumo diário de água. O manejo da água foi realizado mediante a curva característica de água no solo para cada sistema de plantio a 15 e 30 cm de profundidade, e o controle da lâmina de água foi feito com base na leitura diária de um conjunto de tensiômetros instalados nas mesmas profundidades, de modo que se mantivesse a umidade do solo sempre acima de 75% da água disponível total. A partir da produtividade e do consumo de água, determinou-se a eficiência no uso da água (EUA), dada em kg m-3. Verificou-se que o sistema de plantio direto na palha reduziu a densidade populacional e a massa seca acumulada pelas plantas daninhas em 86,7 e 61%, respectivamente, em relação ao plantio convencional, e a interferência destas reduziu a produtividade comercial em 100% no plantio convencional e 36,5% no direto. A cobertura do solo com filme de polietileno no plantio convencional e no plantio direto e a palhada no plantio direto reduziram o consumo de água em 23% (388,8 m³ ha-1), 21% (363,0 m³ ha-1) e 13% (215,0 m³ ha-1), respectivamente, em relação ao tratamento com capinas no plantio convencional. A cobertura do solo com filme de polietileno nos dois sistemas de plantio ou com cobertura morta no plantio direto aumentou a eficiência no uso da água em relação ao solo sem cobertura. No tratamento sem capinas no sistema de plantio convencional, além da perda total na produtividade comercial, a interferência das plantas daninhas aumentou o consumo de água em 9,6%.

Partial purification of tightly bound mitochondrial hexokinase from maize (Zea mays L.) root membranes

In mammals, hexokinase (HK) is strategically located at the outer membrane of mitochondria bound to the porin protein. The mitochondrial HK is a crucial modulator of apoptosis and reactive oxygen species generation. In plants, these properties related to HK are unknown. In order to better understand the physiological role of non-cytosolic hexokinase (NC-HK) in plants, we developed a purification strategy here described. Crude extract of 400 g of maize roots (230 mg protein) contained a specific activity of 0.042 µmol G6P min-1 mg PTN-1. After solubilization with detergent two fractions were obtained by DEAE column chromatography, NC-HK 1 (specific activity = 3.6 µmol G6P min-1 mg PTN-1 and protein recovered = 0.7 mg) and NC-HK 2. A major purification (yield = 500-fold) was obtained after passage of NC-HK 1 through the hydrophobic phenyl-Sepharose column. The total amount of protein and activity recovered were 0.04 and 18%, respectively. The NC-HK 1 binds to the hydrophobic phenyl-Sepharose matrix, as observed for rat brain HK. Mild chymotrypsin digestion did not affect adsorption of NC-HK 1 to the hydrophobic column as it does for rat HK I. In contrast to mammal mitochondrial HK, glucose-6-phosphate, clotrimazole or thiopental did not dissociate NC-HK from maize (Zea mays) or rice (Oryza sativa) mitochondrial membranes. These data show that the interaction between maize or rice NC-HK to mitochondria differs from that reported in mammals, where the mitochondrial enzyme can be displaced by modulators or pharmacological agents known to interfere with the enzyme binding properties with the mitochondrial porin protein.

Association between the -174 G/C promoter polymorphism of the interleukin-6 gene and cardiovascular disease risk factors in Brazilian older women

In worldwide studies, interleukin-6 (IL-6) is implicated in age-related disturbances. The aim of the present report was to determine the possible association of IL-6 -174 C/G promoter polymorphism with the cytokine profile as well as with the presence of selected cardiovascular risk features. This was a cross-sectional study on Brazilian women aged 60 years or older. A sample of 193 subjects was investigated for impaired glucose regulation, diabetes, hypertension, and dyslipidemia. Genotyping was done by direct sequencing of PCR products. IL-6 and C-reactive protein were quantified by high-sensitivity assays. General linear regression models or the Student t-test were used to compare continuous variables among genotypes, followed by adjustments for confounding variables. The chi-square test was used to compare categorical variables. The genotypes were consistent with Hardy-Weinberg equilibrium proportions. In a recessive model, mean waist-to-hip ratio, serum glycated hemoglobin and serum glucose were markedly lower in C homozygotes (P = 0.001, 0.028, and 0.047, respectively). In a dominant hypothesis, G homozygotes displayed a trend towards higher levels of circulating IL-6 (P = 0.092). Non-parametric analysis revealed that impaired fasting glucose and hypertension were findings approximately 2-fold more frequent among G homozygous subjects (P = 0.042 and 0.043, respectively). Taken together, our results show that the IL-6 -174 G-allele is implicated in a greater cardiovascular risk. To our knowledge, this is the first investigation of IL-6 promoter variants and age-related disturbances in the Brazilian elderly population.

Women with primary ovarian insufficiency have lower bone mineral density

The aim of the present study was to assess the prevalence of osteoporosis in a sample of 32 patients with spontaneous primary ovarian insufficiency (POI) in comparison to reference groups of 25 pre- and 55 postmenopausal women. Hip (lumbar) and spinal bone mineral density (BMD) measurements were performed by dual-energy X-ray absorptiometry in the three groups. The median age of POI patients at the time of diagnosis was 35 years (interquartile range: 27-37 years). The mean ± SD age of postmenopausal reference women (52.16 ± 3.65 years) was higher than that of POI (46.28 ± 10.38 years) and premenopausal women (43.96 ± 7.08; P = 0.001) at the time of BMD measurement. Twenty-seven (84.4%) POI women were receiving hormone replacement therapy (HRT) at the time of the study. In the postmenopausal reference group, 30.4% were current users of HRT. Lumbar BMD was significantly lower in the POI group (1.050 ± 0.17 g/cm²) compared to the age-matched premenopausal reference group (1.136 ± 0.12 g/cm²; P = 0.040). Moreover, 22 (68.7%) POI women had low bone density (osteopenia/osteoporosis by World Health Organization criteria) versus 47.3% of the postmenopausal reference group (P = 0.042). In conclusion, the present data indicate that BMD is significantly lower in patients with POI than in age-matched premenopausal women. Also, the prevalence of osteopenia/osteoporosis is higher in POI women than in women after natural menopause. Early medical interventions are necessary to ensure that women with POI will maintain their bonemass.

Correlation between total nitrite/nitrate concentrations and monoamine oxidase (types A and B) and semicarbazide-sensitive amine oxidase enzymatic activities in human mesenteric arteries from non-diabetic and type 2 diabetic patients

The aim of this study was to determine the correlation between total nitrite/nitrate concentrations (NOx) and the kinetic parameters of monoamine oxidase enzymes (MAO-A and MAO-B) and semicarbazide-sensitive amine oxidase (SSAO) in human mesenteric arteries. Arteries were from non-diabetic and type 2 diabetic patients with sigmoid or rectum carcinoma for whom surgery was the first option and who were not exposed to neo-adjuvant therapy. Segments of human inferior mesenteric arteries from non-diabetic (61.1 ± 8.9 years old, 7 males and 5 females, N = 12) and type 2 diabetic patients (65.8 ± 6.2 years old, 8 males and 4 females, N = 12) were used to determine NOx concentrations and the kinetic parameters of MAO-A, MAO-B and SSAO by the Griess reaction and by radiochemical assay, respectively. The NOx concentrations in arteries from diabetic patients did not differ significantly from those of the non-diabetic group (10.28 ± 4.61 vs 10.71 ± 4.32 nmol/mg protein, respectively). In the non-diabetic group, there was a positive correlation between NOx concentrations and MAO-B parameters: Km (r = 0.612, P = 0.034) and Vmax (r = 0.593, P = 0.042), and a negative correlation with the SSAO parameters: Km (r = -0.625, P = 0.029) and Vmax (r = -0.754, P = 0.005). However, in the diabetic group no correlation was found between NOx concentrations and the three kinetic parameters of the enzymes. These results suggest an important function of sympathetic nerves and vascular NOx concentrations in arteries of non-diabetic patients. Thus, these results confirm the importance of a balance between oxidants and antioxidants in the maintenance of vascular homeostasis to prevent oxidative stress.

Relationship between deep venous thrombosis and inflammatory cytokines in postoperative patients with malignant abdominal tumors

Deep venous thrombosis (DVT) is a common surgical complication in cancer patients and evidence that inflammation plays a role in the occurrence of DVT is increasing. We studied a population of cancer patients with abdominal malignancies with the aim of investigating whether the levels of circulating inflammatory cytokines were associated with postoperative DVT, and to determine the levels in DVT diagnoses. The serum levels of C-reactive protein (CRP), interleukins (IL)-6 and IL-10, nuclear transcription factor-κB (NF-κB) and E-selectin (E-Sel) were determined in 120 individuals, who were divided into 3 groups: healthy controls, patients with and patients without DVT after surgery for an abdominal malignancy. Data were analyzed by ANOVA, Dunnet's T3 test, chi-square test, and univariate and multivariate logistic regression as needed. The CRP, IL-6, NF-κB, and E-Sel levels in patients with DVT were significantly higher than those in the other groups (P<0.05). The IL-10 level was higher in patients with DVT than in controls but lower than in patients without DVT. Univariate analysis revealed that CRP, IL-6, NF-κB, and E-Sel were statistically associated with the risk of DVT (OR=1.98, P=0.002; OR=1.17, P=0.000; OR=1.03, P=0.042; and OR=1.38, P=0.003; respectively), whereas IL-10 had a protective effect (OR=0.94, P=0.011). Multivariate analysis showed that E-Sel was an independent risk factor (OR=1.41, P=0.000). Thus, this study indicated that an increased serum level of E-Sel was associated with increased DVT risk in postoperative patients with abdominal malignancy, indicating that E-Sel may be a useful predictor of diagnosis of DVT.

Association between NOx exposure and deaths caused by respiratory diseases in a medium-sized Brazilian city

Exposure to nitrogen oxides (NOx) emitted by burning fossil fuels has been associated with respiratory diseases. We aimed to estimate the effects of NOx exposure on mortality owing to respiratory diseases in residents of Taubaté, São Paulo, Brazil, of all ages and both sexes. This time-series ecological study from August 1, 2011 to July 31, 2012 used information on deaths caused by respiratory diseases obtained from the Health Department of Taubaté. Estimated daily levels of pollutants (NOx, particulate matter, ozone, carbon monoxide) were obtained from the Centro de Previsão de Tempo e Estudos Climáticos Coupled Aerosol and Tracer Transport model to the Brazilian developments on the Regional Atmospheric Modeling System. These environmental variables were used to adjust the multipollutant model for apparent temperature. To estimate association between hospitalizations owing to asthma and air pollutants, generalized additive Poisson regression models were developed, with lags as much as 5 days. There were 385 deaths with a daily mean (±SD) of 1.05±1.03 (range: 0-5). Exposure to NOx was significantly associated with mortality owing to respiratory diseases: relative risk (RR)=1.035 (95% confidence interval [CI]: 1.008-1.063) for lag 2, RR=1.064 (95%CI: 1.017-1.112) lag 3, RR=1.055 (95%CI: 1.025-1.085) lag 4, and RR=1.042 (95%CI: 1.010-1.076) lag 5. A 3 µg/m3 reduction in NOx concentration resulted in a decrease of 10-18 percentage points in risk of death caused by respiratory diseases. Even at NOx concentrations below the acceptable standard, there is association with deaths caused by respiratory diseases.

Produção de protoplastos e lise da parede celular de leveduras utilizando β-1,3 glucanase

O presente trabalho visou a aplicação da β-1,3 glucanase lítica, obtida do microrganismo Cellulosimicrobium cellulans 191, na produção de protoplastos e na lise da parede celular de leveduras. A preparação bruta da enzima foi capaz de lisar as leveduras Kluyveromyces lodderi, Saccharomyces cerevisiae (Fleischmann e Itaiquara), S. cerevisiae KL-88, S. diastaticus NCYC 713, S. cerevisiae NCYC 1001, Candida glabrata NCYC 388, Kluyveromyces marxianus NCYC 587 e Hansenula mrakii NCYC 500. A β-1,3 glucanase purificada foi capaz de lisar as leveduras Saccharomyces cerevisiae KL-88, Saccharomyces capensis, Debaromyces vanriji, Pachysolen tannophillus, Kluyveromyces drosophilarum, Candida glabrata, Hansenula mrakii e Pichia membranaefaciens e formar protoplastos de Saccharomyces cerevisiae KL-88.

Effect of pectinolitic enzymes on the physical properties of caja-manga (Spondias cytherea Sonn.) pulp

Cajá-manga, also known as golden apple and hog-plum, is an exotic fruit native from Îles de la Société (French Polynesia), which was first introduced in Brazil in 1985. The pulp of ripe fruit was treated with the commercial enzymatic pool and its effect was evaluated in terms of yield, as well as the physical properties viscosity, turbidity and color (L* values). Response surface methodology was used and three levels were adopted for the independent variables temperature (30, 40, and 50 ºC), incubation time (30, 60 and 90 minutes) and enzyme concentration (0.01, 0.05, 0.09 v/v%). A central composite statistical design was used to guide the experimental work. The enzyme treatment highly increased both juice yield (up to 56%) and color (up to 8.6%) and strongly decreased viscosity (up to 57.4%), clarity (up to 77%) and turbidity (up to 85.5%). Incubation time was the most interacting facto, whereas temperature was the least one. Optimization analysis was carried out to reduce enzyme concentration to a minimum by superposing the contour plots of the tested properties, and the recommended ranges of the variables enzyme concentration, process temperature and incubation time were, respectively, 0.042-0.068%, 47.0-49.0 ºC and 82-90 minutes.

Mutação G20210A no gene da protrombina, fator V de Leiden e anticorpos anticardiolipina não influenciam a sobrevida do enxerto renal após o transplante

INTRODUÇÃO: Complicações tromboembólicas são importantes fatores de risco para perda do enxerto e pior evolução após o transplante renal. Pacientes com defeito trombofílico apresentam maior risco de complicações tromboembólicas. Foram analisados, entre receptores de transplante renal, a prevalência de defeito trombofílico e o risco atribuído a esta condição para a perda do enxerto e para o desenvolvimento de tromboses intravasculares. MÉTODOS: Estudo do tipo coorte incluindo 388 receptores adultos analisados quanto à presença de trombofilia de acordo com a pesquisa de anticorpos anticardiolipina (aCL) por ELISA e das mutações G1691A no gene do fator V (FV) e G20210A no gene da protrombina (PT) por PCR multiplex. RESULTADOS: Defeito trombofílico foi identificado em 25,8% dos pacientes. As taxas de sobrevida de 2 anos do enxerto foram semelhantes entre os pacientes com e sem defeito trombofílico (94% versus 94%, p = 0,53), bem como a sobrevida dos enxertos livres de tromboses intravasculares (97% versus 97%, p = 0,83). Pacientes com defeito trombofílico apresentaram prevalência de tromboses intravasculares semelhante à do grupo-controle (3% versus 3,5%, p = 0,82). O transplante renal anterior foi associado a maior risco de perda de enxerto (OR 20,8, p < 0,001) e de ocorrência de tromboses intravasculares (OR 6,8, p = 0,008). CONCLUSÕES: As prevalências das mutações FV G1691A e PT G20210A na população estudada foram semelhantes às da população geral não transplantada, e a prevalência de anticorpos aCL superou a observada entre os indivíduos sadios. Não houve associação entre os marcadores de trombofilia estudados e a sobrevida em médio prazo do transplante renal.

Terapia de indução com alentuzumabe em receptores de transplante renal

INTRODUÇÃO: Terapias de indução são usualmente utilizadas em receptores sensibilizados contra antígenos HLA, retransplantes e pacientes com risco de apresentar função tardia do enxerto (FTE). MÉTODO: Estudo retrospectivo com objetivo de avaliar os desfechos do transplante renal com doador falecido em pacientes que receberam indução com alentuzumabe (n = 9). Os pacientes do grupo controle, pareados conforme idade do receptor, tempo em diálise e tempo de isquemia fria, receberam timoglobulina (n = 18). RESULTADOS: Não houve diferença nas características demográficas entre os grupos. A idade média dos receptores foi de 47 anos e dos doadores, de 59 anos. Entre os doadores, 67% apresentavam critério expandido. A incidência de FTE foi de 55% e 56%, respectivamente. Ao final do primeiro ano, não houve diferença nas sobrevidas livre de rejeição aguda comprovada por biópsia (67,0% e 84,6%, p = 0,26), do paciente (83,3% e 81,2%; p = 0,63), do enxerto (62,5% e 66,7%; p = 0,82), do enxerto com óbito censorado (62,5% e 76,6%; p = 0,73) e na função renal (depuração de creatinina: 61,6 ± 18,2 versus 52,7 ± 26,1 mL/min, p = 0,503). Houve maior redução na contagem de linfócitos no sangue periférico no grupo alentuzumabe (dia 14:172 ± 129 versus 390 ± 195 N/mm³, p < 0,05; dia 30: 135 ± 78 versus 263±112 N/mm³, p < 0,05), porém com retorno mais rápido a valores normais após o transplante (dia 90: 683 ± 367 versus 282 ± 72 N/mm³, p < 0,05; dia 360: 1269 ± 806 versus 690±444 N/mm³, p < 0,05). O custo do tratamento com alentuzumabe foi de R$ 1.388,00, enquanto que o custo médio com timoglobulina foi de R$ 7.398,00. CONCLUSÃO: Essa experiência com alentuzumabe não demonstrou eficácia e/ou segurança superiores aos regimes com timoglobulina, apesar do custo ser em média cinco vezes menor.

Effect of standard and neutral-pH peritoneal dialysis solutions upon fibroblasts proliferation

Introduction: Continuous exposition of the peritoneal membrane to conventional dialysis solutions is an important risk factor for inducing structural and functional alterations. Objective: To compare in vitro mouse fibroblast NIH-3T3 cell viability after exposition to a neutral pH dialysis solution in comparison to cells exposed to a standard solution. Methods: Experimental study to compare the effects of a conventional standard or a neutral-pH, low-glucose degradation products peritoneal dialysis solution on the viability of exposed fibroblasts in cell culture. Both solutions were tested in all the commercially available glucose concentrations. Cell viability was evaluated with tetrazolium salt colorimetric assay. Results: Fibroblast viability was significantly superior in the neutral pH solution in comparison to control, in all three glucose concentrations (Optical density in nm-means ± SD: 1.5% 0.295 ± 0.047 vs. 0.372 ± 0.042, p < 0.001; 2.3% 0.270 ± 0.036 vs. 0.337 ± 0.051, p < 0.001; 4.25% 0.284 ± 0.037 vs. 0.332 ± 0.032, p < 0.001; control vs. neutral pH respectively, Student t Test). There was no significant difference in cell viability between the three concentrations of glucose when standard solution was used (ANOVA p = 0.218), although cell viability was higher after exposition to neutral pH peritoneal dialysis fluid at 1.5% in comparison to 2.3 and 4.25% glucose concentrations (ANOVA p = 0.008: Bonferroni 1.5% vs. 2.3% p = 0.033, 1.5% vs. 4.25% p = 0.014, 2.3% vs. 4.25% p = 1.00). Conclusion: Cell viability was better in neutral pH dialysis solution, especially in the lower glucose concentration. A more physiological pH and lower glucose degradation products may be responsible for such results.

Desesperança, ideação suicida e depressão em pacientes renais crônicos em tratamento por hemodiálise ou transplante

Introdução: Sintomas de desesperança, ideação suicida e depressão influenciam na qualidade e expectativa de vida de doentes renais crônicos. Objetivo: Avaliar se existe diferença nos sintomas de desesperança, ideação suicida e depressão entre pacientes renais crônicos em hemodiálise ou transplantados. Analisamos também se variáveis sociodemográficas como atividade laboral, ter dependentes, sexo e estado civil interferem nesses sintomas. Métodos: Estudo comparativo, de corte transversal, em que 50 pacientes em hemodiálise crônica e 50 transplantados renais, clinicamente estáveis, sem psicopatologias, pareados por sexo e idade, foram selecionados aleatoriamente. Instrumentos -Beck Hopelessness Scale (BHS), Beck Scale for Suicide Ideation (BSI) e Beck Depression Inventory (BDI). Resultados: BHS: 2% de cada grupo tiveram escore > 8 (p = 1,00). BSI: 4% em hemodiálise e 6% dos transplantados tinham escore > 1 (p = 1,00). BDI: 20% em hemodiálise e 12% dos transplantados apresentaram escore > 14 (p = 0,275). Não houve relação entre as variáveis testadas e os sintomas de desesperança e ideação suicida. Não exercer atividade laboral implicou mais sintomas depressivos (escore médio BDI: 10,5 vs. 7,3, p = 0,027). Transplantados de doadores falecidos apresentaram mais sintomas depressivos comparados aos receptores de doadores vivos (escore médio BDI: 11,0 vs. 6,7, p = 0,042). Conclusão: Não houve diferença na intensidade dos sintomas de desesperança, ideação suicida e depressão entre pacientes estáveis em hemodiálise e transplantados. Não exercer atividade laboral e receber transplante de doador falecido levou a mais sintomas depressivos. A prevalência de ideação suicida e sintomas depressivos, nas duas modalidades, merece atenção e indica a necessidade de monitorização e cuidados nesses pacientes.