Fluxo difusivo de ferro em solos sob influência de doses de fósforo e de níveis de acidez e umidade

A deficiência de Fe em plantas de café cultivadas em Latossolos ricos em Fe pode ser causada por condições que afetam o transporte deste nutriente no solo, como teores de P, valores de pH elevados e déficit hídrico no solo. O fluxo difusivo do Fe (FFe) em solos foi avaliado como variável de doses de P e de níveis de acidez e umidade. Para isso, amostras superficiais de dois solos, um Latossolo Vermelho distroférrico típico A moderado textura muito argilosa e um Latossolo Vermelho-Amarelo distroférrico A moderado textura média, receberam 20 mg dm-3 de Fe na forma de FeSO4 e, posteriormente, foram submetidas aos tratamentos: sem ou com calagem (para V = 60 %), sem ou com P (500 mg dm-3, na forma de NH4H2PO4) e três níveis de umidade correspondentes aos potenciais: -0,01, -0,04 e -0,1 MPa, constituindo um fatorial 2 × 2 × 2 × 3, com três repetições distribuídas em blocos inteiramente casualizados. Para a determinação do FFe foram montadas câmaras de difusão que receberam uma lâmina de resina de troca catiônica como dreno de Fe. O Fe total adsorvido às lâminas foi extraído após 10 dias de contato com os solos, estimando-se o FFe. Os resultados mostraram que, em ambos os solos, o FFe mostrou-se altamente dependente da umidade e da acidez do solo (calagem) e que, no Latossolo Vermelho distroférrico, foi muito influenciado pela adição de P. O FFe aumentou com a umidade e com a acidez do solo, mas diminuiu com a adição de P no solo mais argiloso, possivelmente pela formação de compostos Fe-P insolúveis neste solo.

Brain Tissue Hypoxia is a Strong Predictor of Outcome after Severe Traumatic Brain Injury Independent from Elevated Intracranial Pressure

Introduction: Low brain tissue oxygen pressure (PbtO2) is associated with worse outcome in patients with severe traumatic brain injury (TBI). However, it is unclear whether brain tissue hypoxia is merely a marker of injury severity or a predictor of prognosis, independent from intracranial pressure (ICP) and injury severity. Hypothesis: We hypothesized that brain tissue hypoxia was an independent predictor of outcome in patients wih severe TBI, irrespective of elevated ICP and of the severity of cerebral and systemic injury. Methods: This observational study was conducted at the Neurological ICU, Hospital of the University of Pennsylvania, an academic level I trauma center. Patients admitted with severe TBI who had PbtO2 and ICP monitoring were included in the study. PbtO2, ICP, mean arterial pressure (MAP) and cerebral perfusion pressure (CPP = MAP-ICP) were monitored continuously and recorded prospectively every 30 min. Using linear interpolation, duration and cumulative dose (area under the curve, AUC) of brain tissue hypoxia (PbtO2 < 15 mm Hg), elevated ICP >20 mm Hg and low CPP <60 mm Hg were calculated, and the association with outcome at hospital discharge, dichotomized as good (Glasgow Outcome Score [GOS] 4-5) vs. poor (GOS 1-3), was analyzed. Results: A total of 103 consecutive patients, monitored for an average of 5 days, was studied. Brain tissue hypoxia was observed in 66 (64%) patients despite ICP was < 20 mm Hg and CPP > 60 mm Hg (72 +/- 39% and 49 +/- 41% of brain hypoxic time, respectively). Compared with patients with good outcome, those with poor outcome had a longer duration of brain hypoxia (1.7 +/- 3.7 vs. 8.3 +/- 15.9 hrs, P<0.01), as well as a longer duration (11.5 +/- 16.5 vs. 21.6 +/- 29.6 hrs, P=0.03) and a greater cumulative dose (56 +/- 93 vs. 143 +/- 218 mm Hg*hrs, P<0.01) of elevated ICP. By multivariable logistic regression, admission Glasgow Coma Scale (OR, 0.83, 95% CI: 0.70-0.99, P=0.04), Marshall CT score (OR 2.42, 95% CI: 1.42-4.11, P<0.01), APACHE II (OR 1.20, 95% CI: 1.03-1.43, P=0.03), and the duration of brain tissue hypoxia (OR 1.13; 95% CI: 1.01-1.27; P=0.04) were all significantly associated with poor outcome. No independent association was found between the AUC for elevated ICP and outcome (OR 1.01, 95% CI 0.97-1.02, P=0.11) in our prospective cohort. Conclusions: In patients with severe TBI, brain tissue hypoxia is frequent, despite normal ICP and CPP, and is associated with poor outcome, independent of intracranial hypertension and the severity of cerebral and systemic injury. Our findings indicate that PbtO2 is a strong physiologic prognostic marker after TBI. Further study is warranted to examine whether PbtO2-directed therapy improves outcome in severely head-injured patients .

Fat oxidation kinetics during exercise in obese individuals

Introduction An impaired ability to oxidize fat may be a factor in the obesity's aetiology (3). Moreover, the exercise intensity (Fatmax) eliciting the maximal fat oxidation rate (MFO) was lower in obese (O) compared with lean (L) individuals (4). However, difference in fat oxidation rate (FOR) during exercise between O and L remains equivocal and little is known about FORs during high intensities (>60% ) in O compared with L. This study aimed to characterize fat oxidation kinetics over a large range of intensities in L and O. Methods 12 healthy L [body mass index (BMI): 22.8±0.4] and 16 healthy O men (BMI: 38.9±1.4) performed submaximal incremental test (Incr) to determine whole-body fat oxidation kinetics using indirect calorimetry. After a 15-min resting period (Rest) and 10-min warm-up at 20% of maximal power output (MPO, determined by a maximal incremental test), the power output was increased by 7.5% MPO every 6-min until respiratory exchange ratio reached 1.0. Venous lactate and glucose and plasma concentration of epinephrine (E), norepinephrine (NE), insulin and non-esterified fatty acid (NEFA) were assessed at each step. A mathematical model (SIN) (1), including three variables (dilatation, symmetry, translation), was used to characterize fat oxidation (normalized by fat-free mass) kinetics and to determine Fatmax and MFO. Results FOR at Rest and MFO were not significantly different between groups (p≥0.1). FORs were similar from 20-60% (p≥0.1) and significantly lower from 65-85% in O than in L (p≤0.04). Fatmax was significantly lower in O than in L (46.5±2.5 vs 56.7±1.9 % respectively; p=0.005). Fat oxidation kinetics was characterized by similar translation (p=0.2), significantly lower dilatation (p=0.001) and tended to a left-shift symmetry in O compared with L (p=0.09). Plasma E, insulin and NEFA were significantly higher in L compared to O (p≤0.04). There were no significant differences in glucose, lactate and plasma NE between groups (p≥0.2). Conclusion The study showed that O presented a lower Fatmax and a lower reliance on fat oxidation at high, but not at moderate, intensities. This may be linked to a: i) higher levels of insulin and lower E concentrations in O, which may induce blunted lipolysis; ii) higher percentage of type II and a lower percentage of type I fibres (5), and iii) decreased mitochondrial content (2), which may reduce FORs at high intensities and Fatmax. These findings may have implications for an appropriate exercise intensity prescription for optimize fat oxidation in O. References 1. Cheneviere et al. Med Sci Sports Exerc. 2009 2. Holloway et al. Am J Clin Nutr. 2009 3. Kelley et al. Am J Physiol. 1999 4. Perez-Martin et al. Diabetes Metab. 2001 5. Tanner et al. Am J Physiol Endocrinol Metab. 2002

Adenoid Cystic Carcinoma of the Breast: A Rare Cancer Network Study

Purpose/Objective(s): Mammary adenoid cystic carcinoma (ACC) is a rare breast cancer variant. It accounts for less than 0.1% of all invasive breast malignancies. Typically, it presents as a small breast lump with a low propensity to metastasize to regional lymph nodes or distant sites. The aim of this retrospective multicenter Rare Cancer Network study is to assess prognostic factors and patterns of failure in ACC, as well as the role of radiation therapy (RT) in this rare disease. Materials/Methods: Between January 1980 and December 2007, 61 women with breast ACC were included in this study. Median age was 59 years (range, 28-94 years). The majority of the patients had good performance status (49 patients with WHO 0, 12 patients with WHO 1), and 70% of the patients (n = 42) were premenopausal. Surgery consisted of tumorectomy in 35 patients, mastectomy in 20, or quadrantectomy in 6. Median tumor size was 20 mm (range, 6-170 mm). Surgical margins were clear in 50 (82%) patients. Axillary dissection (n = 41) or sentinel node assessment (n = 10) was realized in the majority of the patients. There were 53 (87%) pN0 and 8 pNx (13%) patients. Estrogen (ER) and progesterone receptor (PR) was negative in 43 (71%) and 42 (69%) patients, respectively. In 16 patients (26%), the receptor status was unknown. Adjuvant chemotherapy or hormonotherapy was administered in 8 (13%) and 7 (12%) patients, respectively. Postoperative RT with a median total dose of 50 Gy (1.8-2.0 Gy/fraction; range, 44-70 Gy) was given in 40 patients. Results: With a median follow-up of 79 months (range, 6-285 months), 5-year overall and disease-free survival (DFS) rates were 94% (95% confidence interval [CI]: 88-100%) and 82% (95% CI: 71-93%), respectively. Five-year locoregional control rate was 95% (95% CI: 89-100%). There were only 4 patients with local relapse who were all salvaged successfully, and 4 other patients developed distant metastases. According to the Common Terminology Criteria for Adverse Events v3.0, late toxicity consisted of grade 2-3 cutaneous fibrosis in 4 (10%) patients, grade 1-2 edema in 2 (5%), and grade 3 lung fibrosis in 2 (5%). In univariate analyses, the outcome was influenced neither by the type of surgery nor the use of postoperative RT. However, positive receptor status had a negative influence on the outcome. Multivariate analysis (Cox model) revealed that negative ER (p = 0.006) or PR (p = 0.04) status was associated with improved DFS. Conclusions: ACC of the breast is a relatively indolent disease with excellent local control and survival. The prognosis of patients with ACC is much better than that for patients with other breast cancers, especially those who are ER and PR negative. The role of postoperative RT is not clear. More aggressive treatments may be warranted for patients with positive receptor status.

IL28B polymorphisms, IP-10 and viral load predict virological response to therapy in chronic hepatitis C.

Aliment Pharmacol Ther 2011; 33: 1162-1172 SUMMARY: Background  Hepatitis C virus (HCV) is a major cause of chronic liver disease, cirrhosis and hepatocellular carcinoma and the identification of the predictors of response to antiviral therapy is an important clinical issue. Aim  To determine the independent contribution of factors including IL28B polymorphisms, IFN-gamma inducible protein-10 (IP-10) levels and the homeostasis model assessment of insulin resistance (HOMA-IR) score in predicting response to therapy in chronic hepatitis C (CHC). Methods  Multivariate analysis of factors predicting rapid (RVR) and sustained (SVR) virological response in 280 consecutive, treatment-naive CHC patients treated with peginterferon alpha and ribavirin in a prospective multicentre study. Results  Independent predictors of RVR were HCV RNA <400 000 IU/mL (OR 11.37; 95% CI 3.03-42.6), rs12980275 AA (OR 7.09; 1.97-25.56) and IP-10 (OR 0.04; 0.003-0.56) in HCV genotype 1 patients and lower baseline γ-glutamyl-transferase levels (OR = 0.02; 0.0009-0.31) in HCV genotype 3 patients. Independent predictors of SVR were rs12980275 AA (OR 9.68; 3.44-27.18), age <40 years (OR = 4.79; 1.50-15.34) and HCV RNA <400 000 IU/mL (OR 2.74; 1.03-7.27) in HCV genotype 1 patients and rs12980275 AA (OR = 6.26; 1.98-19.74) and age <40 years (OR 5.37; 1.54-18.75) in the 88 HCV genotype 1 patients without a RVR. RVR was by itself predictive of SVR in HCV genotype 1 patients (OR 33.0; 4.06-268.32) and the only independent predictor of SVR in HCV genotype 2 (OR 9.0, 1.72-46.99) or genotype 3 patients (OR 7.8, 1.43-42.67). Conclusions  In HCV genotype 1 patients, IL28B polymorphisms, HCV RNA load and IP-10 independently predict RVR. The combination of IL28B polymorphisms, HCV RNA level and age may yield more accurate pre-treatment prediction of SVR. HOMA-IR score is not associated with viral response.

Influence of segmental chromosome abnormalities on survival in children over the age of 12 months with unresectable localised peripheral neuroblastic tumours without MYCN amplification.

BACKGROUND: The prognostic impact of segmental chromosome alterations (SCAs) in children older than 1 year, diagnosed with localised unresectable neuroblastoma (NB) without MYCN amplification enrolled in the European Unresectable Neuroblastoma (EUNB) protocol is still to be clarified, while, for other group of patients, the presence of SCAs is associated with poor prognosis. METHODS: To understand the role of SCAs we performed multilocus/pangenomic analysis of 98 tumour samples from patients enrolled in the EUNB protocol. RESULTS: Age at diagnosis was categorised into two groups using 18 months as the age cutoff. Significant difference in the presence of SCAs was seen in tumours of patients between 12 and 18 months and over 18 months of age at diagnosis, respectively (P=0.04). A significant correlation (P=0.03) was observed between number of SCAs per tumour and age. Event-free (EFS) and overall survival (OS) were calculated in both age groups, according to both the presence and number of SCAs. In older patients, a poorer survival was associated with the presence of SCAs (EFS=46% vs 75%, P=0.023; OS=66.8% vs 100%, P=0.003). Moreover, OS of older patients inversely correlated with number of SCAs (P=0.002). Finally, SCAs provided additional prognostic information beyond histoprognosis, as their presence was associated with poorer OS in patients over 18 months with unfavourable International Neuroblastoma Pathology Classification (INPC) histopathology (P=0.018). CONCLUSIONS: The presence of SCAs is a negative prognostic marker that impairs outcome of patients over the age of 18 months with localised unresectable NB without MYCN amplification, especially when more than one SCA is present. Moreover, in older patients with unfavourable INPC tumour histoprognosis, the presence of SCAs significantly affects OS.

Exaggerated exercise-induced pulmonary hypertension causes lung water accumulation and right ventricular dysfunction in patients with chronic mountain sickness

Background: Chronic mountain sickness (CMS) is characterized by exaggerated exercise-induced pulmonary hypertension. Evidences suggests that exercise may cause lung fluid accumulation at high altitude. We hypothesized that, in patients with CMS, exercise causes lung fluid accumulation.Methods: In 21 male CMS patients and 20 matched healthy controls born and permanently living in La Paz (Bolivia, 3600m) we assessed with echocardiogram, pulmonary artery pressure (PASP), right and left ventricular function and ultrasoundlung comets (ULCs, a marker of lung fluid accumulation) at rest and during mild bicycle exercise (10 min at 50W).Results: CMS patients presented a more than 2-fold greater exercise-induced increase in pulmonary artery pressure than controls (17.1±8.3 vs 7.2±7.9 mmHg, P=0.003). This exaggerated PASP response to exercise was associated with a roughly 3-fold greater increase in UCLs in patients with CMS than in controls (6.3±5.1 vs. 2.1±5.3, p<0.05), and there existed a significant relationship between PASP and UCLs (r=0.44, p<0.001). Finally, TDI on lateral tricuspid annulus decreased during exercise in patients with CMS (from 13.2±3.2 to 11.5±2.1 cm s-1, p=0.03), but increased in controls (from 13.1±2.9 to 14.9±2.6 cm s-1 , p=0.04). Left ventricular function remained unaltered in the 2 groups.Conclusions: we provide the first direct evidence in CMS patients that exaggerated exercise-induced pulmonary hypertension causes rapid lung fluid accumulation and right ventricular dysfunction. We speculate that in patients with CMS these two phenomena contribute to reduced exercise performances and Figure 1 increased cardiovascular morbidity and mortality that characterise these subjects.

Ageing with HIV: medication use and risk for potential drug-drug interactions.

OBJECTIVES: To compare the use of co-medication, the potential drug-drug interactions (PDDIs) and the effect on antiretroviral therapy (ART) tolerability and efficacy in HIV-infected individuals according to age, ≥ 50 years or <50 years. METHODS: All ART-treated participants were prospectively included once during a follow-up visit of the Swiss HIV Cohort Study. Information on any current medication was obtained by participant self-report and medical prescription history. The complete treatment was subsequently screened for PDDIs using a customized version of the Liverpool drug interaction database. RESULTS: Drug prescriptions were analysed for 1497 HIV-infected individuals: 477 age ≥ 50 and 1020 age <50. Older patients were more likely to receive one or more co-medications compared with younger patients (82% versus 61%; P < 0.001) and thus had more frequent PDDIs (51% versus 35%; P < 0.001). Furthermore, older patients tended to use a higher number of co-medications and certain therapeutic drug classes more often, such as cardiovascular drugs (53% versus 19%; P < 0.001), gastrointestinal medications (10% versus 6%; P = 0.004) and hormonal agents (6% versus 3%; P = 0.04). PDDIs with ART occurred mainly with cardiovascular drugs (27%), CNS agents (22%) and methadone (6%) in older patients and with CNS agents (27%), methadone (15%) and cardiovascular drugs (11%) in younger patients. The response to ART did not differ between the two groups. CONCLUSIONS: The risk for PDDIs with ART increased in older patients who take more drugs than their younger HIV-infected counterparts. However, medication use in older and younger patients did not differ in terms of effect on antiretroviral tolerability and response.

Prognostic significance of deep vein thrombosis in patients presenting with acute symptomatic pulmonary embolism.

RATIONALE: Concomitant deep vein thrombosis (DVT) in patients with acute pulmonary embolism (PE) has an uncertain prognostic significance. OBJECTIVES: In a cohort of patients with PE, this study compared the risk of death in those with and those without concomitant DVT. METHODS: We conducted a prospective cohort study of outpatients diagnosed with a first episode of acute symptomatic PE. Patients underwent bilateral lower extremity venous compression ultrasonography to assess for concomitant DVT. MEASUREMENTS AND MAIN RESULTS: The primary study outcome, all-cause mortality, and the secondary outcome of PE-specific mortality were assessed during the 3 months of follow-up after PE diagnosis. Multivariate Cox proportional hazards regression was done to adjust for significant covariates. Of 707 patients diagnosed with PE, 51.2% (362 of 707) had concomitant DVT and 10.9% (77 of 707) died during follow-up. Patients with concomitant DVT had an increased all-cause mortality (adjusted hazard ratio [HR], 2.05; 95% confidence interval [CI], 1.24 to 3.38; P = 0.005) and PE-specific mortality (adjusted HR, 4.25; 95% CI, 1.61 to 11.25; P = 0.04) compared with those without concomitant DVT. In an external validation cohort of 4,476 patients with acute PE enrolled in the international multicenter RIETE Registry, concomitant DVT remained a significant predictor of all-cause (adjusted HR, 1.66; 95% CI, 1.28 to 2.15; P < 0.001) and PE-specific mortality (adjusted HR, 2.01; 95% CI, 1.18 to 3.44; P = 0.01). CONCLUSIONS: In patients with a first episode of acute symptomatic PE, the presence of concomitant DVT is an independent predictor of death in the ensuing 3 months after diagnosis. Assessment of the thrombotic burden should assist with risk stratification of patients with acute PE.

Factors influencing emergency delays in acute stroke management.

Early admission to hospital with minimum delay is a prerequisite for successful management of acute stroke. We sought to determine our local pre- and in-hospital factors influencing this delay. Time from onset of symptoms to admission (admission time) was prospectively documented during a 6-month period (December 2004 to May 2005) in patients consecutively admitted for an acute focal neurological deficit presented at arrival and of presumed vascular origin. Mode of transportation, patient's knowledge and correct recognition of stroke symptoms were assessed. Physicians contacted by the patients or their relatives were interviewed. The influence of referral patterns on in-hospital delays was further evaluated. Overall, 331 patients were included, 249 had an ischaemic and 37 a haemorrhagic stroke. Forty-five patients had a TIA with neurological symptoms subsiding within the first hours after admission. Median admission time was 3 hours 20 minutes. Transportation by ambulance significantly shortened admission delays in comparison with the patient's own means (HR 2.4, 95% CI 1.6-3.7). The only other factor associated with reduced delays was awareness of stroke (HR 1.9, 95% CI 1.3-2.9). Early in-hospital delays, specifically time to request CT-scan and time to call the neurologist, were shorter when the patient was referred by his family or to a lesser extent by an emergency physician than by the family physician (p < 0.04 and p < 0.01, respectively) and were shorter when he was transported by ambulance than by his own means (p < 0.01). Transportation by ambulance and referral by the patient or family significantly improved admission delays and early in-hospital management. Correct recognition of stroke symptoms further contributed to significant shortening of admission time. Educational programmes should take these findings into account.

Diagnostic performance of CT-arthrography and 1.5T MR-arthrography for the assessment of glenohumeral joint cartilage: a comparative study with arthroscopic correlation.

PURPOSE: To compare the diagnostic performance of multi-detector CT arthrography (CTA) and 1.5-T MR arthrography (MRA) in detecting hyaline cartilage lesions of the shoulder, with arthroscopic correlation. PATIENTS AND METHODS: CTA and MRA prospectively obtained in 56 consecutive patients following the same arthrographic procedure were independently evaluated for glenohumeral cartilage lesions (modified Outerbridge grade ≥2 and grade 4) by two musculoskeletal radiologists. The cartilage surface was divided in 18 anatomical areas. Arthroscopy was taken as the reference standard. Diagnostic performance of CTA and MRA was compared using ROC analysis. Interobserver and intraobserver agreement was determined by κ statistics. RESULTS: Sensitivity and specificity of CTA varied from 46.4 to 82.4 % and from 89.0 to 95.9 % respectively; sensitivity and specificity of MRA varied from 31.9 to 66.2 % and from 91.1 to 97.5 % respectively. Diagnostic performance of CTA was statistically significantly better than MRA for both readers (all p ≤ 0.04). Interobserver agreement for the evaluation of cartilage lesions was substantial with CTA (κ = 0.63) and moderate with MRA (κ = 0.54). Intraobserver agreement was almost perfect with both CTA (κ = 0.94-0.95) and MRA (κ = 0.83-0.87). CONCLUSION: The diagnostic performance of CTA and MRA for the detection of glenohumeral cartilage lesions is moderate, although statistically significantly better with CTA. KEY POINTS: ? CTA has moderate diagnostic performance for detecting glenohumeral cartilage substance loss. ? MRA has moderate diagnostic performance for detecting glenohumeral cartilage substance loss. ? CTA is more accurate than MRA for detecting cartilage substance loss.

IL28B polymorphisms leading to poor response to treatment are associated with low necroinflammatory activity and slow fibrosis progression in HCV genotype non-1-infected patients

Background and Aims: Genetic polymorphisms near IL28Bhave been associated with spontaneous and treatment-inducedclearance of hepatitis C virus (HCV). This is believed to proceed viathe appropriate activation of innate and adaptive immune responsestargeting infected hepatocytes. Intrahepatic inflammation is thereflection of the host cell immune response, but its relationshipwith IL28B polymorphisms has yet to be fully appreciated.Methods: We analyzed the association of IL28B polymorphismswith Metavir activity (≥1) and fibrosis scores (≥2) in 1114 HCVinfectedCaucasian patients enrolled in the Swiss Hepatitis C CohortStudy (629, 127, 268 and 110 infected with HCV genotype 1, 2, 3and 4, respectively). In a subgroup of 915 patients with an estimateddate of infection, the association between IL28B polymorphismsand fibrosis progression rate (FPR > median) was assessed. Singlenucleotide polymorphisms (SNPs) of interest were extracted froma dataset generated in a genome-wide association study and/orgenotyped by TaqMan assay. Associations of alleles with differentdegrees of activity and fibrosis were evaluated using an additivemodel of inheritance by multivariate logistic regression, accountingfor all relevant covariates.Results: The rare G allele at marker rs8099917 was associated withlower activity (P = 0.008) and fibrosis (P = 0.01), as well as slower FPR(P = 0.02). Most striking associations were observed among patientsinfected with non-1 genotypes (P = 0.002 for activity, P = 0.002 forfibrosis and P = 0.005 for FPR). In genotype 1-infected patients, theassociation with activity was observed only in the recessive model(P = 0.04), whereas other associations were not significant (P = 0.7for fibrosis and P = 0.4 for FPR).Conclusions: In chronic hepatitis C, IL28B polymorphisms linkedwith a poor virological response to therapy are also associated withreduced intrahepatic necroinflammation and slower liver diseaseprogression. These observations underscore the role played by thehost immune response in clearing HCV, especially in patients withHCV genotypes non-1.

Balanço do carbono orgânico no solo sob integração lavoura-pecuária no sul do Brasil

A integração lavoura-pecuária tem apresentado um avanço recente em áreas historicamente utilizadas com pecuária de corte extensiva no sul do Brasil. O inadequado manejo das pastagens de inverno associado ao uso da monocultura da soja no verão podem limitar o aporte de resíduos vegetais ao solo e reduzir os estoques de C orgânico do solo. O objetivo deste trabalho foi avaliar o impacto do aumento da freqüência de pastejo no inverno e de sistemas de culturas de verão no estoque de C orgânico total do solo (COT). O experimento, realizado por quatro anos sob sistema plantio direto, seguiu um delineamento de blocos ao acaso, em arranjo bifatorial 3x3, com quatro repetições. O fator A foi constituído por três intervalos de pastejos durante o inverno: sem pastejo (SP), pastejo a cada 28 dias (P28) e pastejo a cada 14 dias (P14). O fator B constou de três sistemas de culturas de verão: monocultura de soja (Mon-S), monocultura de milho (Mon-M) e rotação anual de soja e milho (Rot-S/M). Foram quantificadas as adições de C ao solo via resíduos vegetais e os estoques de COT do solo segundo os métodos de camada e massa equivalentes de solo. O aumento da freqüência de pastejo diminuiu o aporte de C oriundo das pastagens de inverno de 5,3 Mg ha-1 no tratamento SP, para 1,7 e 1,3 Mg ha-1 nos tratamentos P28 e P14, respectivamente. O milho foi a cultura que proporcionou o maior aporte de C ao solo, com uma média de 6,0 Mg ha-1, enquanto a soja adicionou apenas 2,2 Mg ha-1. Os estoques de C orgânico calculados com base em camadas equivalentes de solo foram superestimados nos tratamentos P14 e P28 e subestimados no tratamento SP em comparação aos resultados obtidos com base nas massas equivalentes de solo, que foram utilizados para comparação dos sistemas de manejo. Os estoques de C orgânico nas camadas de 0-0,025, 0,025-0,05 e 0,05-0,10 m foram linearmente relacionados à adição anual de C pelas culturas (pastagem + culturas anuais), sendo necessária a adição de 4,48 Mg ha-1 ano-1 para a manutenção do estoque original de C orgânico da camada de 0-0,10 m. A baixa adição de C ao solo pelos resíduos vegetais no tratamento P14 resultou numa emissão líquida estimada de C para a atmosfera (0,05 a 0,27 Mg ha-1 ano-1 ), enquanto o solo no tratamento SP atuou como um dreno de C atmosférico (0,19 a 0,30 Mg ha-1 ano-1). No tratamento P28, o comportamento do solo como fonte ou dreno de C dependeu do sistema de cultura de verão, tendo sido estimada uma emissão líquida de C do solo sob Mon-S (0,04 Mg ha-1 ano-1 ) e uma retenção líquida de C sob Mon-M (0,15 Mg ha-1 ano-1 ) e Rot-S/M (0,11 Mg ha-1 ano-1 ). O maior intervalo entre pastejos, durante o inverno, associado à utilização do milho no verão contribuiu para maiores adições de resíduos vegetais e acúmulo de C orgânico no solo.

Sequential or concomitant chemotherapy in limited stage small-cell lung cancer.

PURPOSE: Chemotherapy (CT) combined with radiation therapy (RT) is the standard treatment for limited disease small-cell lung cancer (LDSCLC). Many questions including RT dose, fractionation, and sequence of RT/CT administration remain controversial. In this paper, we retrospectively assessed the outcome of patients with LDSCLC treated with radiation of at least 50 Gy.METHODS AND MATERIALS: From December 1997 to January 2006, 69 consecutive patients with LDSCLC were treated at our institutions. Treatment consisted of at least 4 cycles of CT, and 3D conformal thoracic RT. The median age was 61 years (range, 37-78 years). Sequential or concomitant CT/RT was given in 47 (68%) and 22 (32%) of the patients, respectively. The median RT dose was 60 Gy. Prophylactic cranial irradiation (PCI) was administered in 47 (68%) patients.RESULTS: With a median follow-up of 36 months (range, 6-107), 16 patients were alive without disease. The median overall survival time was 24 months, with a 3-year survival rate of 29%. The 3-year disease-free survival (DFS) and loco-regional control (LRC) rates were 23% and 60%, respectively. A better DFS was significantly associated with performance status (PS) 0 (p = 0.004), complete response to treatment (p = 0.03), and PCI group (p = 0.03). A trend towards improved overall survival (OS) was observed for patients who underwent PCI (p = 0.07). Patients treated with sequential CT/RT had a better outcome than those treated with concomitant treatment (3-year DFS rate 27% vs. 13%; p = 0.04). However, PCI was delivered more frequently for the sequential group. No significant dose-response relationship was found in terms of LRC. The multivariate analysis showed that complete response to treatment was the only significant factor for OS.CONCLUSION: Complete response to treatment was the most important factor for OS. A better DFS was significantly associated with the PCI group. We did not find a significant difference in outcome between patients receiving doses of 60 Gy or more and patients receiving 60 Gy or less.

Numerical analysis of the impact of charcoal production on soil hydrological behavior, runoff response and erosion susceptibility

The impact of charcoal production on soil hydraulic properties, runoff response and erosion susceptibility were studied in both field and simulation experiments. Core and composite samples, from 12 randomly selected sites within the catchment of Kotokosu were taken from the 0-10 cm layer of a charcoal site soil (CSS) and adjacent field soils (AFS). These samples were used to determine saturated hydraulic conductivity (Ksat), bulk density, total porosity, soil texture and color. Infiltration, surface albedo and soil surface temperature were also measured in both CSS and AFS. Measured properties were used as entries in a rainfall runoff simulation experiment on a smooth (5 % slope) plot of 25 x 25 m grids with 10 cm resolutions. Typical rainfall intensities of the study watershed (high, moderate and low) were applied to five different combinations of Ks distributions that could be expected in this landscape. The results showed significantly (p < 0.01) higher flow characteristics of the soil under charcoal kilns (increase of 88 %). Infiltration was enhanced and runoff volume reduced significantly. The results showed runoff reduction of about 37 and 18 %, and runoff coefficient ranging from 0.47-0.75 and 0.04-0.39 or simulation based on high (200 mm h-1) and moderate (100 mm h-1) rainfall events over the CSS and AFS areas, respectively. Other potential impacts of charcoal production on watershed hydrology were described. The results presented, together with watershed measurements, when available, are expected to enhance understanding of the hydrological responses of ecosystems to indiscriminate charcoal production and related activities in this region.