Increased sink strength offsets the inhibitory effect of sucrose on sugarcane photosynthesis.

Spraying sucrose inhibits photosynthesis by impairing Rubisco activity and stomatal conductance (gs), whereas increasing sink demand by partially darkening the plant stimulates sugarcane photosynthesis. We hypothesized that the stimulatory effect of darkness can offset the inhibitory effect of exogenous sucrose on photosynthesis. Source-sink relationship was perturbed in two sugarcane cultivars by imposing partial darkness, spraying a sucrose solution (50mM) and their combination. Five days after the onset of the treatments, the maximum Rubisco carboxylation rate (Vcmax) and the initial slope of A-Ci curve (k) were estimated by measuring leaf gas exchange and chlorophyll fluorescence. Photosynthesis was inhibited by sucrose spraying in both genotypes, through decreases in Vcmax, k, gs and ATP production driven by electron transport (Jatp). Photosynthesis of plants subjected to the combination of partial darkness and sucrose spraying was similar to photosynthesis of reference plants for both genotypes. Significant increases in Vcmax, gs and Jatp and marginal increases in k were noticed when combining partial darkness and sucrose spraying compared with sucrose spraying alone. Our data also revealed that increases in sink strength due to partial darkness offset the inhibition of sugarcane photosynthesis caused by sucrose spraying, enhancing the knowledge on endogenous regulation of sugarcane photosynthesis through the source-sink relationship.

Physiological Plasticity Is Important for Maintaining Sugarcane Growth under Water Deficit.

The water availability at early phenological stages is critical for crop establishment and sugarcane varieties show differential performance under drought. Herein, we evaluated the relative importance of morphological and physiological plasticity of young sugarcane plants grown under water deficit, testing the hypothesis that high phenotypic plasticity is associated with drought tolerance. IACSP95-5000 is a high yielding genotype and IACSP94-2094 has good performance under water limiting environments. Plants were grown in rhizotrons for 35 days under three water availabilities: high (soil water matric potential [Ψm] higher than -20 kPa); intermediate (Ψm reached -65 and -90 kPa at the end of experimental period) and low (Ψm reached values lower than -150 kPa). Our data revealed that morphological and physiological responses of sugarcane to drought are dependent on genotype and intensity of water deficit. In general, IACSP95-5000 showed higher physiological plasticity given by leaf gas exchange and photochemical traits, whereas IACSP94-2094 showed higher morphological plasticity determined by changes in leaf area (LA) and specific LA. As IACSP94-2094 accumulated less biomass than IACSP95-5000 under varying water availability, it is suggested that high morphological plasticity does not always represent an effective advantage to maintain plant growth under water deficit. In addition, our results revealed that sugarcane varieties face water deficit using distinct strategies based on physiological or morphological changes. When the effectiveness of those changes in maintaining plant growth under low water availability is taken into account, our results indicate that the physiological plasticity is more important than the morphological one in young sugarcane plants.

Comportamento da lactacemia pós-exercício contínuo e intervalado em indivíduos com cardiomiopatia chagásica sintomáticos e assintomáticos / Lactate behavior post-exercise in individuals with Chagas' heart

Avaliar o comportamento do lactato sanguíneo pós-exercício aeróbico contínuo (EAC) e pós-exercício resistido intervalado (ERI). Estudo analítico tipo cross-over, do qual participaram voluntários com doença de Chagas crônica divididos em dois grupos, grupo sintomático (GS), com seis voluntários, e grupo assintomático (GA) com oito voluntários. Os sujeitos foram submetidos a um teste cardiopulmonar em esteira ergométrica para determinar o limiar de anaerobiose (LA) e o VO² pico, e 24 horas depois a um teste de carga máxima (CM). Decorridos sete dias, os voluntários participaram de uma sessão de EAC e, sete dias posteriormente, a uma sessão de ERI. O EAC foi realizado em esteira ergométrica durante 20 minutos (min), sendo 10 min a 40% de VO² pico, 7 min no LA e a mais 3 min em intensidade decrescente. O ERI teve duração aproximada de 20 min e foi realizado com pesos livres a 30% da CM em duas séries de quatro movimentos. Foram coletados amostras sanguíneas para dosagem da lactacemia nos tempos 0 (repouso), 5 e 10 min após as sessões de EAC e ERI. O GA apresentou maior variação do lactato em relação ao repouso (p=0,05) no ERI ao final dos 10 min de atividade quando comparado ao GS, tendo esse último apresentado maior variação do lactato no EAC, sem diferença significativa. O ERI parece ser mais confortável e seguro que o EAC quando aplicado em indivíduos chagásicos sintomáticos. Já para indivíduos assintomáticos, parece ser indiferente o emprego do EAC ou do ERI.

To evaluate blood lactate post continuous aerobic exercise (CAE) and post resistance exercise interval (REI). Analytical study crossover which involved volunteers with chronic Chagas disease divided into two groups, the symptomatic group (SG) with six volunteers and asymptomatic group (AG) with eight volunteers. First, the subjects underwent cardiopulmonar exercise testing on a treadmill to determine the anaerobic threshold (AT) and VO² peak, and 24 hours after a maximum load test (ML). After seven days, the volunteers underwent a session of CAE and seven days later at a session of REI. The CAE was performed on a treadmill for 20 min, 10 min and 40% of VO² peak, 7 min in LA and decreasing in intensity over 3 min. The REI lasted approximately 20 minutes and was carried out with free weights to 30% of ML in two series of four movements. Blood samples were collected to determine lacticemia at 0 (rest), 5 and 10 min after the sessions of CAE and REI. The AG varied more lactate in relation to rest (p=0.05) in the REI at the end of 10 minutes of activity compared to SG, the later presented a greater variation of lactate in the CAE, without significant difference. The REI appears to be more comfortable and secure than CAE when applied to symptomatic chagasic individuals. Whereas asymptomatic individuals seem to be indiferent to the use of the CAE or the REI.

Autoimmune endocrine disorders and coeliac disease in children and adolescents with juvenile idiopathic arthritis and rheumatic fever.

OBJECTIVES: There have been few studies on the association between childhood autoimmune and rheumatic diseases. Therefore, this study aims to assess the frequency of autoimmune thyroiditis (AT), coeliac disease (CD) and type 1 diabetes mellitus (T1DM) in children and adolescents with juvenile idiopathic arthritis (JIA) and rheumatic fever (RF). METHODS: This cross-sectional study includes 53 patients with JIA, 66 patients with RF and 40 healthy subjects controls. All subjects were evaluated for thyrotropin (TSH), triiodothyronine (T3), free thyroxine (FT4), antithyroglobulin (Tg) and antiperoxidase antibodies, fasting glucose, C-peptide, anti-glutamic acid decarboxylase (GAD), anti-islet cell (IA) and antitransglutaminase IgA (tTG) antibodies. Patients with thyroid dysfunction, positive anti-thyroid antibodies or tTG underwent thyroid ultrasonography and jejunal biopsy, respectively. RESULTS: In group 1 (n=53), 21 patients presented thyroid disorders (40%; 42% oligoarticular), either subclinical hypothyroidism (13%) or positive anti-thyroid antibodies (26%, 50% oligoarticular), significantly higher than in control group (p<0.009, OR=10.5, CI 1.29-85.2). In group 2 (n=66), thyroid disorders were identified in 11 patients, four (6%) with subclinical hypothyroidism and seven (11%) with positive anti-thyroid antibodies (p=0.06, compared with the control group). There were no cases of clinical overt hypothyroidism, positive anti-GAD or anti-IA, nor changes in serum C-peptide and glycemia. CD was confirmed in one patient from each group. CONCLUSIONS: Patients with JIA (especially the oligoarticular form) and RF should be investigated for thyroid dysfunction. Longitudinal studies could establish screening protocols for CD in patients with JIA and RF. The cost-effectiveness of T1DM screening is not justified in this population.

Adultos com cardiopatia congênita submetidos à primeira cirurgia: prevalência e resultados em um hospital terciário / Adults with congenital heart disease undergoing first surgery: prevalence and outcomes at a tertiary hospital

INTRODUÇÃO: O tratamento cirúrgico da cardiopatia congênita em adultos apresentou importante crescimento nos últimos anos. Contudo, ainda assim, o número de pacientes que atingem a idade adulta sem tratamento cirúrgico adequado permanece elevado. OBJETIVO: Avaliar os resultados hospitalares e diagnósticos dos pacientes adultos com cardiopatia congênita submetidos à primeira operação. MÉTODOS: Estudo retrospectivo, que analisou prontuários de pacientes operados para correção de cardiopatia congênita com idade maior ou igual a 18 anos. O critério de exclusão foi cirurgia para reoperação. Foi analisado o período entre dezembro de 2007 e dezembro de 2010, com inclusão de 79 pacientes. RESULTADOS: Os defeitos do septo atrial foram os mais prevalentes (53,1%), seguidos de comunicação interventricular (15,2%), coarctação da aorta (6,3%) e canal atrioventricular parcial (6,3%). Treze (16,4%) pacientes apresentavam doença associada adquirida e 14 pacientes (17,7%), congênita. Trinta e três (41,8%) pacientes apresentavam hipertensão pulmonar. O tempo médio de internamento em UTI e hospitalar foi de 3,9 e 14,5 dias, respectivamente. Complicações ocorreram em 18 (22,8%) pacientes, sendo as infecciosas as mais comuns. A mortalidade hospitalar foi de dois (2,5%) pacientes. CONCLUSÃO: O tratamento da cardiopatia congênita em adultos como primeira cirurgia apresentou resultado bastante favorável. Contudo, em nossa série, houve maior tempo de internamento em UTI e hospitalar.

INTRODUCTION: Surgical treatment of congenital heart disease in adults showed a significant growth in recent years. But even so, the number of patients who reach adulthood without adequate surgical treatment remains high. OBJECTIVE: To demonstrate the results and hospital diagnoses of adult patients with congenital heart disease underwent the first surgery. METHODS: A retrospective analysis of records of patients operated for correction of congenital heart disease and age greater than or equal to 18 years. The exclusion criterium was surgery for reoperation. Period analyzed was from December 2007 to December 2010 with inclusion of 79 patients. RESULTS: The atrial septal defects were the most prevalent (53.1%), followed by VSD (15.2%), the coarctation (6.3%) and partial atrioventricular canal (6.3%). Thirteen (16.4%) patients had associated disease acquired and 14 (17.7%) congenital disease. Complications occurred in 18 (22.8%) patients, with infections being the most common. The average hospital stay in ICU and hospital were 3.9 and 14.5 days, respectively. Thirty-three (41.8%) patients had pulmonary hypertension. The hospital mortality was two (2.5%) patients. CONCLUSION: The treatment of congenital heart disease in adults as first surgery has very favorable results. However, in our series, there was an increased length of stay in ICU and hospital.

Adults with congenital heart disease undergoing first surgery: prevalence and outcomes at a tertiary hospital.

INTRODUCTION: Surgical treatment of congenital heart disease in adults showed a significant growth in recent years. But even so, the number of patients who reach adulthood without adequate surgical treatment remains high. OBJECTIVE: To demonstrate the results and hospital diagnoses of adult patients with congenital heart disease underwent the first surgery. METHODS: A retrospective analysis of records of patients operated for correction of congenital heart disease and age greater than or equal to 18 years. The exclusion criterium was surgery for reoperation. Period analyzed was from December 2007 to December 2010 with inclusion of 79 patients. RESULTS: The atrial septal defects were the most prevalent (53.1%), followed by VSD (15.2%), the coarctation (6.3%) and partial atrioventricular canal (6.3%). Thirteen (16.4%) patients had associated disease acquired and 14 (17.7%) congenital disease. Complications occurred in 18 (22.8%) patients, with infections being the most common. The average hospital stay in ICU and hospital were 3.9 and 14.5 days, respectively. Thirty-three (41.8%) patients had pulmonary hypertension. The hospital mortality was two (2.5%) patients. CONCLUSION: The treatment of congenital heart disease in adults as first surgery has very favorable results. However, in our series, there was an increased length of stay in ICU and hospital.

Saneamento básico e problemas ambientais no município de Manaus / Basic sanitation and environmental problems in the "município" of Manaus

Examina a questäo Saneamento Básico e suas inter-relaçöes com o meio ambiente, avaliando a repercussäo dessas relaçöes na saúde da populaçäo. Mostra que os vazios demográficos observados na área urbana do município de Manaus, seja em razäo de entraves físicos ou decorrentes de uma ocupaçäo mal planejada, prejudicam e encarecem a implantaçäo de equipamentos urbanos e de serviços como os dos sistemas de abastecimento de água, esgotos sanitários, limpeza pública e coleta de lixo e da rede de drenagem pluvial, trazendo dificuldades para o controle ambiental. Em seguida, trata dos usos da água para o abastecimento público e para diluiçäo de esgotos sanitários produzidos e lançados nos igarapés e demais recursos hídricos. Finalmente, identifica, a nível de Distritos Sanitários, a proporçäo da ocorrência das doenças preveníveis por serviços de saneamento básico, procurando correlacionar a qualidade da oferta desses serviços com o nível geral de saúde da populaçäo.(AU)