Prospective study of HDR brachytherapy (BT), external beam radiotherapy (EBRT) and androgen deprivation therapy (ADT): 10-years experience of an MRI-guided approach.

OBJECTIVES: To evaluate the predictive factors for biochemical failure and distant metastases in a prospective cohort of patients with localized prostate cancer treated with the combination of HDR BT and EBRT. METHODS AND MATERIALS: Patients with intermediate (IR) or high-risk (HR) prostate adenocarcinoma received a single fraction of HDR of 15 Gy combined with RT of 37.5 Gy in 15 fractions. ADT duration was used depending on risk-group. Descriptive analyses were performed. Univariate and multivariate Hazard Ratios were obtained. Finally, the Kaplan-Meier model was used to describe the survival of the events of interest. RESULTS: 309 patients were treated prospectively (199 were IR and 110 HR). Median age was 72 years; 58.3 % were MRI stage ≤ T2c, 34.1 % T3a and 7.6 % T3b; ISUP-grade 1-3 in 78.9 % and ISUP 4-5 in 21.1 %. 71.8 % of patients had ≤ 50 % positive-cores in biopsy and 28.2 % had > 50 %. Median pre-treatment PSA was 9.9 ng/mL. After a median follow-up of 88 months, 41 patients presented biochemical failure and 18 developed distant metastases. Multivariate cox-regression analyses found that MR-T3b Stage (HR 3.88, p = 0.001) and ADT use (HR 3.99, p = 0.03) were the only predictive factors for biochemical failure and the number of positive cores (>50 %) the only independent predictive factor of distant metastases (HR 4.36, p = 0.002). CONCLUSIONS: Patients with mpMRI evidence of invasion of the SV and involvement of more than 50% of the cores in the prostate biopsy are patients with a higher risk of presenting a biochemical recurrence or developing metastasis due to their prostate cancer, respectively.

Human mesenchymal stem cells as a two-edged sword in hepatic regenerative medicine: engraftment and hepatocyte differentiation versus profibrogenic potential.

BACKGROUND AND AIMS: Mesenchymal stem cells from bone marrow (MSCs) may have the potential to differentiate in vitro and in vivo into hepatocytes. We investigated whether transplanted human MSCs (hMSCs) may engraft the liver of non-obese diabetic severe combined immuno-deficient (NOD/SCID) mice and differentiate into cells of hepatic lineage. METHODS: Ex vivo expanded, highly purified and functionally active hMSCs from bone marrow were transplanted (caudal vein) in sublethally irradiated NOD/SCID mice that were either exposed or not to acute liver injury or submitted to a protocol of chronic injury (single or chronic intraperitoneal injection of CCl(4), respectively). Chimeric livers were analysed for expression of human transcripts and antigens. RESULTS: Liver engraftment of cells of human origin was very low in normal and acutely injured NOD/SCID mice with significantly higher numbers found in chronically injured livers. However, hepatocellular differentiation was relatively rare, limited to a low number of cells (ranging from less than 0.1% to 0.23%) as confirmed by very low or not detectable levels of human transcripts for alpha-fetoprotein, CK18, CK19 and albumin in either normal or injured livers. Finally, a significant number of cells of human origin exhibited a myofibroblast-like morphology. CONCLUSIONS: Transplanted hMSCs have the potential to migrate into normal and injured liver parenchyma, particularly under conditions of chronic injury, but differentiation into hepatocyte-like cells is a rare event and pro-fibrogenic potential of hMSC transplant should be not under-evaluated.

Water residence time affecting phytoplankton blooms: study case in Ibitinga Reservoir (São Paulo, Brazil) using Landsat/TM images.

Satellite images are an effective tool for the detection of phytoplankton blooms, since they cause striking changes in water color. Bloom intensity can be expressed in terms of chlorophyll-a concentration. Previous studies suggest the use of Landsat TM4/TM3 reflectance ratio to retrieve surface chlorophyll-a concentration from aquatic systems. In this study we assumed that a remote sensing trophic state index can be applied to investigate how changes in HRT along the hydrologic year affect the spatial distribution of the phytoplankton blooms at Ibitinga's reservoir surface. For that, we formulated two objectives: (1) apply a semi-empirical model which uses this reflectance ratio to map chlorophyll-a concentration at Ibitinga reservoir along the 2005 hydrologic year and (2) assess how changes in hydraulic residence time (HRT) affect the spatial distribution of phytoplankton blooms at Ibitinga Reservoir. The study site was chosen because previous studies reported seasonal changes in the reservoir limnology which might be related to the reservoir seasonality and hydrodynamics. Six Landsat/TM images were acquired over Ibitinga reservoir during 2005 and water flow measurements provided by the Brazilian Electric System National Operator - ONS were used to compute the reservoir´s residence time, which varied from 5.37 to 52.39 days during 2005. The HRT in the date of image acquisition was then compared to the distribution of chlorophyll-a in the reservoir. The results showed that the HRT increasing implies the increasing of the reservoir surface occupied by phytoplankton blooms.

Modeling pollution potential input from the drainage basin into Barra Bonita reservoir, São Paulo - Brazil.

In this study multi-criteria modeling tools are applied to map the spatial distribution of drainage basin potential to pollute Barra Bonita Reservoir, São Paulo State, Brasil. Barra Bonita Reservoir Basin had undergone intense land use/land cover changes in the last decades, including the fast conversion from pasture into sugarcane. In this respect, this study answers to the lack of information about the variables (criteria) which affect the pollution potential of the drainage basin by building a Geographic Information System which provides their spatial distribution at sub-basin level. The GIS was fed by several data (geomorphology, pedology, geology, drainage network and rainfall) provided by public agencies. Landsat satellite images provided land use/land cover map for 2002. Ratings and weights of each criterion defined by specialists supported the modeling process. The results showed a wide variability in the pollution potential of different sub-basins according to the application of different criterion. If only land use is analyzed, for instance, less than 50% of the basin is classified as highly threatening to water quality and include sub basins located near the reservoir, indicating the importance of protection areas at the margins. Despite the subjectivity involved in the weighing processes, the multi-criteria analysis model allowed the simulation of scenarios which support rational land use polices at sub-basin level regarding the protection of water resources.

Abiotic variability among different aquatic systems of the central Amazon floodplain during drought and flood events.

This paper examines water properties from lakes, (depression lakes, sensu Junk et al., 2012), channels (scroll lakes with high connectivity, sensu Junk et al., 2012) and paleo-channels (scroll lakes with low connectivity-sensu Junk et al., 2012, locally called ressacas) located in Mamirauá Sustainable Development Reserve, in Central Amazon floodplain, Amazonas, Brazil. We analysed surface temperature, conductivity, pH, dissolved oxygen, turbidity, transparency, suspended inorganic and organic matter, chlorophyll-a, pheophytin, total nitrogen, total phosphorus, organic and inorganic carbon in 2009 high water phase, 2009 and 2010 low water phases. Multivariate statistical analyses of 24 aquatic systems (6 ressacas, 12 lakes and 6 channels, 142 samples) were applied to the variables in order to: 1) quantify differences among aquatic system types; 2) assess how those differences are affected in the different phases of the hydrological year. First, we analysed the entire set of variables to test for differences among phases of the hydrological year and types of aquatic systems using a PERMANOVA two-way crossed design. The results showed that the all measured limnological variables are distinct regarding both factors: types of aquatic systems and hydrological phases. In general, the magnitude and amplitude of all variables were higher in the low water phase than in the high water phase, except for water transparency in all aquatic system's types. PERMANOVA showed that the differences between aquatic system's types and hydrological phases of all variables were highly significant for both main factors (type and phase) and for the type x phase interaction. Limnological patterns of Amazon floodplain aquatic systems are highly dynamic, dependent on the surrounding environment, flood pulse, main river input and system type. These patterns show how undisturbed systems respond to natural variability in such a diverse environment, and how distinct are those aquatic systems, especially during the low water phase. Aquatic systems in Mamirauá floodplain represent limnological patterns of almost undisturbed areas and can be used as future reference for comparison with disturbed areas, such as those of the Lower Amazon, and as a baseline for studies on the effects of anthropogenic influences and climate change and on Amazon aquatic ecosystem.

Insulin resistance in patients with a recent diagnosis of coronary artery disease.

OBJECTIVE: To elucidate whether insulin resistance is present in coronary artery disease (CAD) at diagnosis and to study its relationship with other known cardiovascular risk factors. METHODS: We evaluated the incidence of insulin resistance in 40 newly diagnosed CAD patients. Fifteen healthy subjects were used as a control group. The patients and controls had no previous history of metabolic disorders, and were not being administered any medication that might have affected their insulin sensitivity. Immediately after diagnosis of CAD, a standard 75 g oral glucose-tolerance test (OGTT) and an insulin suppression test (IST) were performed on separate days. The IST consisted of a constant infusion of glucose, insulin and somatostatin for 150 min; insulin resistance was estimated by determining the steady-state plasma glucose (SSPG) concentrations during the last 60 min of the test. The insulin sensitivity index (ISI) was calculated by the formula ISI = (glucose infusion rate/SSPG]x10(3). RESULTS: Insulin resistance, defined by an ISI below the normal range derived from the control group, was present in 82.5% of the CAD patients. As a group, the patients with CAD displayed lower ISI (means +/- SD:29.23 +/- 11.23 versus 50.33 +/- 9.37 dl/kg per min, P < 0.001) than did controls. Serum triglycerides and uric acid were higher and high-density lipoprotein cholesterol levels were lower in patients than they were in controls. No differences were observed in fasting plasma insulin, glucose, total and low-density lipoprotein cholesterol concentration. An abnormal OGTT result was observed in 27 patients. The ISI was low in 88.8% of the patients with an abnormal OGTT result and in 69% of the 13 patients with a normal OGTT result. CONCLUSIONS: Insulin resistance and even impaired glucose tolerance are common findings in CAD at diagnosis. The changes in the lipid profile and in uric acid levels paralleled the changes in insulin sensitivity. These results suggest that insulin resistance might play a role in the development of coronary atherosclerosis and that its early diagnosis might be important in the prophylaxis of CAD.

Nonspecific immunity in Down syndrome: a study of chemotaxis, phagocytosis, oxidative metabolism, and cell surface marker expression of polymorphonuclear cells.

We have investigated several aspects of nonspecific immunity in Down syndrome (DS), utilizing peripheral polymorphonuclear leukocytes (PMNL), obtained from 12 children aged 8-16, diagnosed as trisomy 21, and their healthy matched controls. We used the under agarose method for chemotaxis assays, and flow cytometry for the determination of phagocytosis of monodispersed fluorescent beads, metabolic burst activity, and neutrophil surface marker expression on these cells. Our results indicate that a chemotactic defect exists in PMNL of DS children. However, no statistically significant differences were found between PMNL from DS children and those from controls in phagocytosis, oxidative burst, and expression of the markers CD11a, CD11b, CD16, and CD 18. Furthermore, no overexpression of CD11a and CD18 was present as a consequence of gene overdosage in PMNL from DS children. On the other hand, 3 different neutrophil subpopulations could be observed according to the CD16 staining pattern in DS children and controls; this might be a consequence of genetic variation or may represent different states of activation of these cells. Other factors such as T-cell involvement, and the role of cytokines, cyclic nucleotides, and zinc serum levels in DS patients should be further investigated in order to define the causes of the immunological derangement present in this condition.

Periodontitis and anti-neutrophil cytoplasmic antibodies in systemic lupus erythematosus and rheumatoid arthritis: a comparative study.

BACKGROUND: This investigation was designed to determine and compare the distribution pattern of anti-neutrophil cytoplasmic antibodies (ANCA) in patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) in the presence or absence of periodontal disease. METHODS: Sera of 30 patients with SLE and 30 with RA were tested for ANCA utilizing an indirect enzyme immunosorbent assay (ELISA) directed to a neutrophil granular extract and 6 neutrophil granule proteins. A control group of 20 healthy individuals showing neither evidence of periodontal disease nor systemic compromise was also included in this study. RESULTS: For RA, the number of ANCA-positive sera was very low but was evenly distributed among patients with and without periodontitis. Conversely, a high number of ANCA-positive sera in SLE was found mostly in individuals presenting periodontal compromise. A statistically significant association between ANCA and periodontitis in SLE patients was found (P <0.005, chi square test). CONCLUSIONS: A marked difference in the number and distribution of ANCA with respect to periodontitis between RA and SLE was found. Hyperresponsiveness of B cells and polyclonal B activation to periodontopathic bacteria in SLE might be accountable for the high numbers of ANCA and the close association observed between those autoantibodies and periodontitis in SLE.

A possible defective estimation of antineutrophil cytoplasmic antibodies in systemic lupus erythematosus due to the coexistence of periodontitis: preliminary observations.

The objectives of this study is to determine if periodontitis-related ANCA hinder the accurate estimation of this kind of autoantibodies in systemic lupus erythematosus (SLE), due to the frequent coexistence of SLE and periodontitis, and the high incidence of antineutrophil cytoplasmic antibodies (ANCA) in this periodontal condition. Thirty SLE, thirty periodontitis lacking systemic involvement patients, and twenty healthy controls were utilized in this study. The periodontal condition and the presence of ANCA in sera of all individuals was carefully evaluated. For ANCA determination an EIA assay was utilized, directed to a neutrophil granular extract and six neutrophil granule proteins. Sixty percent of SLE patients had periodontitis, and sixty-five percent were ANCA positive. Eighty three percent of all ANCA cases were coexisting with periodontitis. A significant association (p > 0.005) between periodontitis and ANCA was found (Chi Square Test). Fifty percent of the patients with periodontitis lacking systemic involvement were ANCA positive. The results obtained in this study suggest that the figures of ANCA previously reported for SLE, might be overestimated due to the inadvertent presence of periodontitis.

White blood cell count and insulin resistance in patients with coronary artery disease.

White blood cell (WBC) count has been shown as a risk factor for cardiovascular disease. Decreased insulin sensitivity has been suggested as the link between these two entities. Our aim was to study the potential relation between insulin sensitivity and WBC count in patients with coronary artery disease. In order to assess insulin sensitivity, we performed 83 insulin suppression tests before and after therapy in 50 patients with coronary artery disease. Patients with glucose intolerance, arterial hypertension or obesity were excluded. Steady-state plasma glucose (SSPG) and insulin sensitivity index (ISI=1 000 x glucose infusion rate/SSPG) were considered as a measure of insulin sensitivity. WBC count, blood platelets, fibrinogen, microalbuminuria, creatinine, urea and HbA1c were also assessed. Simple and multiple correlation analysis were carried out between insulin sensitivity parameters and the other variables measured. There were significant correlation between SSPG and WBC count (r=0,32: p=0,003) and microalbuminuria (r=0,28: p=0,012). We also found statistically significant correlation between ISI and WBC count (r=0,27: p=0,015) and microalbuminuria (r=0,24: p=0,029). No correlation could be detected between either SSPG or ISI and the other variables measured. In multiple regression analysis, WBC count was found to be an independent predictor of both SSPG (p<0.01) and ISI (p<0.05). Our data show the existence of a significant relationship between decreased insulin sensitivity and WBC count in patients with coronary artery disease. The results of this study suggest that an elevated WBC count could be postulated as part of the insulin resistant syndrome.

[Antineutrophil cytoplasmic antibodies (ANCA): study of their presence in diseases not associated with arteritis]. / Anticuerpos anticitoplasmáticos de neutrófilos (ANCA): un estudio sobre su presencia en patologías no asociadas con arteritis.

Our study describes the presence of antineutrophil cytoplasmic antibodies (ANCA) in a group of different pathologies comprising 101 patients. Rheumatoid arthritis, systemic lupus erithematosus, idiopatic neutropenia, acute post-streptoccocal glomerulonephritis, minimal change nephrotic syndrome, Downs syndrome, adult periodontitis, tumoral calcinosis, monoartheritis and lipodystrophy were investigated for ANCA, through indirect immunofluorescence and an indirect solid-phase immunoassay (ELISA). Our results show the pattern of distribution of ANCA in the diseases investigated, and allowed us to make the first description of ANCA in diseases such as Downs syndrome, acute post-streptococcal glomerulonephritis and adult periodontitis. The high percentage of reactivity for ANCA detected in adult periodontitis, raise important questions about the possibility of reporting inaccurate percentages of positivity for some diseases, due to the presence of a concurrent disease such as adult periodontitis.

Structure and style in the Hippocratic treatise Prorrheticon 2.

Bearing in mind both the capacity of man and his limits, the author of Prorrheticon 2 states his opposition to irrational prognoses and brings forward the sêmeia as the only basis for a correct prognostic. He does so by enhancing his statements by means of structure (ring-composition, psychological structure of recurrence) and style: in this field he uses several devices aimed to attract the reader's attention, putting together colloquial and high-level expressions. In this paper a similar stylistic technique is intended in order to illustrate the points of the Greek author.

Marshall's vein persistence: a rare and occasional finding during pacemaker implantation.

In adults the oblique vein of Marshall is usually absent or very thin, and it is hard to be found. In this case report we describe a case of persistence observed during pacemaker implantation.

Water quality changes in floodplain lakes due to the Amazon River flood pulse: Lago Grande de Curuaí (Pará).

Assurance of water quality for human consumption is essential for public health policies. In the Amazon floodplain, the seasonal water level variation causes periodic flooding of marginal areas that are usually used for settlements, agriculture and livestock. Therefore, the exchange of materials between the terrestrial and aquatic ecosystem affects the proportion of suspended and dissolved components in water and its physical-chemical characteristics, and consequently the quality of the water used by local people. Following this approach, the aim of this study is to evaluate changes in water quality in Lago Grande de Curuaí floodplain, Óbidos, Pará in response to the flood pulse, during one hydrological year from 2003 to 2004, based on water use classes (according to National Water Agency 357/2005 resolution) using chlorophyll-a and dissolved oxygen concentration as parameters and the eutrophication index. Ordinary kriging was applied to interpolate chlorophyll-a and dissolved oxygen and to predict values at non sampled locations. Each location was then classified according to water use acceptable parameters and to Carlson Trophic State Index modified by Toledo to map lake water classes and trophic status. The result showed that Lago Grande de Curuaí floodplain is a supereutrophic system, with levels of dissolved oxygen and chlorophyll-a not suitable for human supply during the receding water phase. These areas are located near the riverine communities, which can cause health problems due to the presence of potentially toxic algae. Therefore, monitoring water quality in Amazon lakes is essential to ensure the availability has appropriate quality for human and animal supplies.

Water residence time affecting phytoplankton blooms: study case in Ibitinga Reservoir (São Paulo, Brazil) using Landsat/TM images / Efeito de variações no tempo de residência hidráulica sobre a ocorrência de florações de fitoplâncton: estudo de caso no Reservatório de Ibitinga (SP) com o uso de imagens Landsat/TM

Abstract Satellite images are an effective tool for the detection of phytoplankton blooms, since they cause striking changes in water color. Bloom intensity can be expressed in terms of chlorophyll-a concentration. Previous studies suggest the use of Landsat TM4/TM3 reflectance ratio to retrieve surface chlorophyll-a concentration from aquatic systems. In this study we assumed that a remote sensing trophic state index can be applied to investigate how changes in HRT along the hydrologic year affect the spatial distribution of the phytoplankton blooms at Ibitinga’s reservoir surface. For that, we formulated two objectives: (1) apply a semi-empirical model which uses this reflectance ratio to map chlorophyll-a concentration at Ibitinga reservoir along the 2005 hydrologic year and (2) assess how changes in hydraulic residence time (HRT) affect the spatial distribution of phytoplankton blooms at Ibitinga Reservoir. The study site was chosen because previous studies reported seasonal changes in the reservoir limnology which might be related to the reservoir seasonality and hydrodynamics. Six Landsat/TM images were acquired over Ibitinga reservoir during 2005 and water flow measurements provided by the Brazilian Electric System National Operator - ONS were used to compute the reservoir´s residence time, which varied from 5.37 to 52.39 days during 2005. The HRT in the date of image acquisition was then compared to the distribution of chlorophyll-a in the reservoir. The results showed that the HRT increasing implies the increasing of the reservoir surface occupied by phytoplankton blooms.

Resumo As imagens de satélite são frequentemente usadas para a identificação de florações de fitoplâncton porque sua presença causa mudanças significativas na cor da água. A abundância das florações pode ser quantificada por medidas de concentração de clorofila-a. Diversos estudos sugerem o uso da razão de reflectância das bandas TM4/TM3 Landsat, para determinar as concentrações de clorofila-a em sistemas aquáticos. Este trabalho tem como objetivos: (1) aplicar um modelo semi-empírico que usa essa razão para mapear a concentração de clorofila-a no reservatório de Ibitinga ao longo do ano hidrológico de 2005; (2) avaliar como as mudanças no tempo de residência hidráulica afetaram a distribuição de florações na superfície do reservatório. O reservatório de Ibitinga foi selecionado porque estudos prévios indicavam mudanças sazonais nas propriedades limnológicas do reservatório, as quais poderiam estar relacionadas à sazonalidade e à hidrodinâmica. Seis imagens TM/Landsat foram adquiridas sobre o reservatório de Ibitinga durante o ano de 2005. Foi então usada uma tabela associando intervalos de razão de banda a intervalos de concentração de clorofila-a. Medidas de vazão fornecidas pelo Operador Nacional do Sistema Elétrico – ONS foram utilizadas para calcular o tempo de residência hidráulica do reservatório, que variou entre 5,37 e 52,39 dias durante 2005. O tempo de residência hidráulica em cada data de aquisição da imagem foi então comparado com a área ocupada pelas florações de fitoplancton. Os resultados indicaram uma forte relação entre o tempo de residência hidráulica e a área ocupada por florações. Em junho de 2005, quando o reservatório atingiu seu menor tempo de residência hidráulica, apenas 20% de sua área estiveram ocupadas por florações. Em setembro e outubro, quando a residência hidráulica atinge o seu máximo, mais que 80% da superfície do reservatório foram ocupadas por florações de fitoplancton.

Abiotic variability among different aquatic systems of the central Amazon floodplain during drought and flood events / Variabilidade abiótica entre os diferentes sistemas aquáticos da planície de inundação da Amazônia central durante eventos de seca e cheia

Abstract This paper examines water properties from lakes, (depression lakes, sensu Junk et al., 2012), channels (scroll lakes with high connectivity, sensu Junk et al., 2012) and paleo-channels (scroll lakes with low connectivity-sensu Junk et al., 2012, locally called ressacas) located in Mamirauá Sustainable Development Reserve, in Central Amazon floodplain, Amazonas, Brazil. We analysed surface temperature, conductivity, pH, dissolved oxygen, turbidity, transparency, suspended inorganic and organic matter, chlorophyll-a, pheophytin, total nitrogen, total phosphorus, organic and inorganic carbon in 2009 high water phase, 2009 and 2010 low water phases. Multivariate statistical analyses of 24 aquatic systems (6 ressacas, 12 lakes and 6 channels, 142 samples) were applied to the variables in order to: 1) quantify differences among aquatic system types; 2) assess how those differences are affected in the different phases of the hydrological year. First, we analysed the entire set of variables to test for differences among phases of the hydrological year and types of aquatic systems using a PERMANOVA two-way crossed design. The results showed that the all measured limnological variables are distinct regarding both factors: types of aquatic systems and hydrological phases. In general, the magnitude and amplitude of all variables were higher in the low water phase than in the high water phase, except for water transparency in all aquatic system’s types. PERMANOVA showed that the differences between aquatic system’s types and hydrological phases of all variables were highly significant for both main factors (type and phase) and for the type x phase interaction. Limnological patterns of Amazon floodplain aquatic systems are highly dynamic, dependent on the surrounding environment, flood pulse, main river input and system type. These patterns show how undisturbed systems respond to natural variability in such a diverse environment, and how distinct are those aquatic systems, especially during the low water phase. Aquatic systems in Mamirauá floodplain represent limnological patterns of almost undisturbed areas and can be used as future reference for comparison with disturbed areas, such as those of the Lower Amazon, and as a baseline for studies on the effects of anthropogenic influences and climate change and on Amazon aquatic ecosystem.

Resumo Esse trabalho investiga as propriedades da água de lagos (lagos de depressão, sensu Junk et al., 2012), canais (scroll lakes com alta conectividade, sensu Junk et al., 2012) e paleo canais (scroll lakes com baixa conectividade - sensu Junk et al., 2012, localmente chamados de ressaca) localizados na Reserva de Desenvolvimento Sustentável Mamirauá (RDSM), na planície de inundação da Amazônia Central, Amazonas, Brasil. Analisaram-se temperatura, condutividade, pH, oxigênio dissolvido, turbidez, e transparência da água na superfície e coletaram-se amostras de água na superfície para a determinação de material orgânico e inorgânico em suspensão, clorofila-a, feofitina, nitrogênio e fósforo total, carbono orgânico e inorgânico dissolvido, em duas fases da hidrógrafa, água alta em 2009, e água baixa em 2009 e 2010. Análises de estatística multivariada de 24 sistemas aquáticos (6 ressacas, 12 lagos e 6 canais, 142 amostras) foram realizadas para: 1) quantificar as diferenças entre os tipos de sistemas aquáticos; 2) determinar como essas diferenças são afetadas nas diferentes fases do ano hidrológico. Primeiramente foram analisadas todas as variáveis para testar as diferenças entre as fases do ano hidrológico e dos tipos de sistemas aquáticos utilizando o teste pareado cruzado PERMANOVA. Os resultados mostraram que todas as variáveis limnológicas medidas são distintas em relação a ambos os fatores: tipos de sistemas aquáticos e fases da hidrógrafa. Em geral, a magnitude e amplitude de todas as variáveis foram maiores na fase seca do que na cheia, com exceção da transparência da água em todos os tipos de sistemas aquáticos. Os resultados da PERMANOVA mostraram que as diferenças entre os tipos de sistemas aquáticos e as fases da hidrógrafa para todas as variáveis foram altamente significativas para ambos os fatores (tipo e fase) e ainda para a interação tipo x fase. Os padrões limnológicos dos sistemas aquáticos da planície de inundação Amazônica são altamente dinâmicos, dependente do ambiente ao redor, do pulso de inundação, do rio principal e do tipo de sistema. Os sistemas aquáticos da planície de inundação de Mamirauá representam os padrões limnológicos de áreas não perturbadas e podem servir como futura referência para comparação com as propriedades dos sistemas aquáticos de áreas perturbadas, como as do Baixo Amazonas. Podem ser também utilizados como linha de base para estudos dos impactos antropogênicos e das mudanças climáticas sobre os ecossistemas aquáticos Amazônicos.

Abiotic variability among different aquatic systems of the central Amazon floodplain during drought and flood events

Abstract This paper examines water properties from lakes, (depression lakes, sensu Junk et al., 2012), channels (scroll lakes with high connectivity, sensu Junk et al., 2012) and paleo-channels (scroll lakes with low connectivity-sensu Junk et al., 2012, locally called ressacas) located in Mamirauá Sustainable Development Reserve, in Central Amazon floodplain, Amazonas, Brazil. We analysed surface temperature, conductivity, pH, dissolved oxygen, turbidity, transparency, suspended inorganic and organic matter, chlorophyll-a, pheophytin, total nitrogen, total phosphorus, organic and inorganic carbon in 2009 high water phase, 2009 and 2010 low water phases. Multivariate statistical analyses of 24 aquatic systems (6 ressacas, 12 lakes and 6 channels, 142 samples) were applied to the variables in order to: 1) quantify differences among aquatic system types; 2) assess how those differences are affected in the different phases of the hydrological year. First, we analysed the entire set of variables to test for differences among phases of the hydrological year and types of aquatic systems using a PERMANOVA two-way crossed design. The results showed that the all measured limnological variables are distinct regarding both factors: types of aquatic systems and hydrological phases. In general, the magnitude and amplitude of all variables were higher in the low water phase than in the high water phase, except for water transparency in all aquatic systems types. PERMANOVA showed that the differences between aquatic systems types and hydrological phases of all variables were highly significant for both main factors (type and phase) and for the type x phase interaction. Limnological patterns of Amazon floodplain aquatic systems are highly dynamic, dependent on the surrounding environment, flood pulse, main river input and system type. These patterns show how undisturbed systems respond to natural variability in such a diverse environment, and how distinct are those aquatic systems, especially during the low water phase. Aquatic systems in Mamirauá floodplain represent limnological patterns of almost undisturbed areas and can be used as future reference for comparison with disturbed areas, such as those of the Lower Amazon, and as a baseline for studies on the effects of anthropogenic influences and climate change and on Amazon aquatic ecosystem.

Resumo Esse trabalho investiga as propriedades da água de lagos (lagos de depressão, sensu Junk et al., 2012), canais (scroll lakes com alta conectividade, sensu Junk et al., 2012) e paleo canais (scroll lakes com baixa conectividade - sensu Junk et al., 2012, localmente chamados de ressaca) localizados na Reserva de Desenvolvimento Sustentável Mamirauá (RDSM), na planície de inundação da Amazônia Central, Amazonas, Brasil. Analisaram-se temperatura, condutividade, pH, oxigênio dissolvido, turbidez, e transparência da água na superfície e coletaram-se amostras de água na superfície para a determinação de material orgânico e inorgânico em suspensão, clorofila-a, feofitina, nitrogênio e fósforo total, carbono orgânico e inorgânico dissolvido, em duas fases da hidrógrafa, água alta em 2009, e água baixa em 2009 e 2010. Análises de estatística multivariada de 24 sistemas aquáticos (6 ressacas, 12 lagos e 6 canais, 142 amostras) foram realizadas para: 1) quantificar as diferenças entre os tipos de sistemas aquáticos; 2) determinar como essas diferenças são afetadas nas diferentes fases do ano hidrológico. Primeiramente foram analisadas todas as variáveis para testar as diferenças entre as fases do ano hidrológico e dos tipos de sistemas aquáticos utilizando o teste pareado cruzado PERMANOVA. Os resultados mostraram que todas as variáveis limnológicas medidas são distintas em relação a ambos os fatores: tipos de sistemas aquáticos e fases da hidrógrafa. Em geral, a magnitude e amplitude de todas as variáveis foram maiores na fase seca do que na cheia, com exceção da transparência da água em todos os tipos de sistemas aquáticos. Os resultados da PERMANOVA mostraram que as diferenças entre os tipos de sistemas aquáticos e as fases da hidrógrafa para todas as variáveis foram altamente significativas para ambos os fatores (tipo e fase) e ainda para a interação tipo x fase. Os padrões limnológicos dos sistemas aquáticos da planície de inundação Amazônica são altamente dinâmicos, dependente do ambiente ao redor, do pulso de inundação, do rio principal e do tipo de sistema. Os sistemas aquáticos da planície de inundação de Mamirauá representam os padrões limnológicos de áreas não perturbadas e podem servir como futura referência para comparação com as propriedades dos sistemas aquáticos de áreas perturbadas, como as do Baixo Amazonas. Podem ser também utilizados como linha de base para estudos dos impactos antropogênicos e das mudanças climáticas sobre os ecossistemas aquáticos Amazônicos.

Dose dependent and divergent effects of superoxide anion on cell death, proliferation, and migration of activated human hepatic stellate cells.

BACKGROUND AND AIMS: Activated myofibroblast-like cells, originating from hepatic stellate cells (HSC/MFs) or other cellular sources, play a key profibrogenic role in chronic liver diseases (CLDs) that, as suggested by studies in animal models or rat HSC/MFs, may be modulated by reactive oxygen intermediates (ROI). In this study, human HSC/MFs, exposed to different levels of superoxide anion (O(2)(.-)) and, for comparison, hydrogen peroxide (H(2)O(2)), were analysed in terms of cytotoxicity, proliferative response, and migration. METHODS: Cultured human HSC/MFs were exposed to controlled O(2)(.-) generation by hypoxanthine/xanthine oxidase systems or to a range of H(2)O(2) concentrations. Induction of cell death, proliferation, and migration were investigated using morphology, molecular biology, and biochemical techniques. RESULTS: Human HSC/MFs were shown to be extremely resistant to induction of cell death by O(2)(.-) and only high rates of O(2)(.-) generation induced either necrotic or apoptotic cell death. Non-cytotoxic low levels of O(2)(.-), able to upregulate procollagen type I expression (but not tissue inhibitor of metalloproteinase 1 and 2), stimulated migration of human HSC/MFs in a Ras/extracellular regulated kinase (ERK) dependent, antioxidant sensitive way, without affecting basal or platelet derived growth factor (PDGF) stimulated cell proliferation. Non-cytotoxic levels of H(2)O(2) did not affect Ras/ERK or proliferative response. A high rate of O(2)(.-) generation or elevated levels of H(2)O(2 )induced cytoskeletal alterations, block in motility, and inhibition of PDGF dependent DNA synthesis. CONCLUSIONS: Low non-cytotoxic levels of extracellularly generated O(2)(.-) may stimulate selected profibrogenic responses in human HSC/MFs without affecting proliferation.