Geospatial analysis of spatiotemporal patterns of pH, total suspended sediment and chlorophyll-a on the Amazon floodplain

We applied spatial data analysis and geostatistical procedures to pH, total suspended sediment and chlorophyll-a concentration data gathered on an Amazon floodplain lake. Variographic analysis and ordinary kriging interpolation were used to identify and describe spatiotemporal patterns of variability in these parameters, which are relevant to understand the dynamics of water circulation on the floodplain lake. In spite of the complexity of the processes underlying the spatiotemporal patterns, this approach demonstrated that the heterogeneity in the seasonal water composition is forced not only by the Amazon River flood pulse, but also by the lake bottom topography and the wind intensity.     

Macroconsumers are more important than specialist macroinvertebrate shredders in leaf processing in urban forest streams of Rio de Janeiro,Brazil

Coarse particulate organic matter is often broken down by specialist shredder invertebrates in temperate streams. In some tropical streams, larger, non-specialist, omnivorous fauna, (macroconsumers), particularly decapod shrimps and crabs, have been found to process coarse particulate matter. Larger shrimps and fish may also prey on or inhibit smaller invertebrates. Depending on the relative importance of larger and smaller fauna in leaf processing and in predatory interactions, we could expect that exclusion of larger fauna could either result in a decrease in leaf processing (if they were important in shredding or bioturbation) or increase in leaf processing if they negatively affected smaller shredders. We tested this by excluding fauna of different sizes from leaf peaks using bags with different sizes of mesh –0.2 mm (exclusion of most fauna), 2 mm (exclusion of larger fauna), and 10 mm (access to most fauna). Bag effect on leaf processing was minimized by constructing the bags of the same, fine, material, and sewing a relatively small window of the required mesh size. The experiment was conducted on two occasions in three streams of the urban forest of Parque Estadual da Pedra Branca, city of Rio de Janeiro. The three streams differed in larger fauna of shrimps (Macrobrachium potiuna), crabs, tadpoles, and fish. Packs were incubated for six time intervals and the rate of leaf processing calculated as the exponential rate of loss of leaf material. Rate of leaf processing was faster in bags with the largest mesh size; the rates in the other two mesh sizes were not statistically different. Rates varied between experiments and among streams. We could not attribute the faster leaf processing to any particular component of the larger fauna; the patterns of differences among streams and between experiments were not associated with particular taxa. There was no general trend of fewer smaller fauna in the presence of macroconsumers; the few smaller taxa that were different between mesh sizes were variously less and more abundant in the 10-mm mesh bags compared to the 2-mm. Known shredders were rare in the smaller fauna; the mining chironomid Stenochironomus was common, but was apparently not affected by larger fauna and apparently did not increase leaf processing. We conclude that macroconsumers and not smaller fauna had a positive effect on leaf processing, and this confirms a pattern observed in some other coastal Neotropical streams.     

Leptin G-2548A and leptin receptor Q223R gene polymorphisms are not associated with obesity in Romanian subjects

We aimed to investigate whether polymorphisms LEP G-2548A and LEPR Q223R in the human leptin (LEP), and leptin receptor (LEPR) genes are associated with obesity and metabolic traits in a sample of Romanian population. Two hundred and two subjects divided in obese (body mass index, BMI ? 30 kg/m²), and non-obese were included in this study. The polymorphisms were genotyped using polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) analysis. The results showed no significant differences in LEP and LEPR genotype and allele frequencies between obese and non-obese subjects. Logistic regression analysis showed that LEP -2548GG genotype presented an increased risk of obesity (p = 0.013, OR = 1.003, 95% CI = 1.000-1.007), after adjusting for age and gender. The association analysis with metabolic syndrome quantitative traits showed that homozygous for LEP -2548G allele had significantly higher leptin levels (17.2 ± 6.6 ng/ml vs. 13.2 ± 4.9 ng/ml, p = 0.011), and carriers of R allele had higher levels of triglycerides (p = 0.017) and glucose (p = 0.040), and enhanced systolic (p = 0.015) and diastolic blood pressure (p = 0.026), after adjustment for age, gender, and BMI. These results indicate that LEP G-2548A and LEPR Q223R SNPs may not be considered as genetic risk factors for obesity in a sample of Romanian population. However, LEP -2548GG genotype appear to be important in regulating leptin levels, whereas the LEPR 223R allele might predispose healthy subjects to develop metabolic disturbances.     

Relative Effect of Food Supplementation and Natural Resources on Female Red Deer Distribution in a Mediterranean Ecosystem

ABSTRACT Supplementary feeding is a widespread game management practice in several red deer (Cervus elaphus) populations, with important potential consequences on the biology of this species. In Mediterranean ecosystems food supplementation occurs in the rutting period, when it may change mating system characteristics. We studied the role of food supplementation relative to natural resources in the spatial distribution, aggregation, and mean harem size of females in Iberian red deer (Cervus elaphus hispanicus) during the rut. We studied 30 red deer populations of southwestern Spain, 63% of which experienced supplementary feeding. Using multivariate spatial analyses we found that food supplementation affected distribution of females in 95% of the populations in which it occurred. Green meadows present during the mating season acted as an important natural resource influencing female distribution. Additionally, the level of female aggregation and mean harem size were significantly higher in those populations in which food supplementation determined female distribution than in populations in which female distribution did not depend on supplementary feeding. Because female aggregation and mean harem size are key elements in sexual selection, supplementary feeding may constitute an important anthropogenic element with potential evolutionary implications for populations of Iberian red deer.     

B cell depletion in diffuse progressive systemic sclerosis: safety,skin score modification and IL-6 modulation in an up to thirty-six months follow-up open-label trial

Introduction  

An over-expression of CD19 has been shown in B cells of systemic sclerosis (SSc) and B cells are thought to contribute to the induction of skin fibrosis in the tight skin mouse model. The aim was to define the outcome on safety and the change in skin score after rituximab therapy in SSc patients and to correlate the clinical characteristics with the levels of interleukin (IL)-6 and with the immune cell infiltrate detected by immunohistochemistry.     

Early renal structure alteration in rat offspring from dams fed low protein diet

To investigate the early renal alterations due to severe maternal protein restriction (MPR) Wistar dams received 23% (normal protein, NP) or 5% (low protein, LP) chow during gestation and lactation periods. In NP offspring at birth, the cortex-to-medulla (C/M) ratio was 35% greater in female than in male offspring and the mature/immature glomeruli ratio was lower in both sexes of LP offspring than in the matched NP ones (by 20%). At birth and at weaning the kidney of the LP offspring showed fewer glomeruli (40% less) than the age-matched NP offspring. The NP female offspring had almost 20% fewer glomeruli than the matched male offspring. At weaning, the number of glomeruli was positively correlated with BM at birth (R=0.86; P<0.001). The effects of gender and maternal protein restriction, both individually and overall, based on biometrical and stereological parameters were: day 1, MPR largely responsible for the majority of alterations observed in LP groups, however gender influenced C/M ratio; day 21, MPR and gender interacted and modified the number of glomeruli per kidney. The early adverse of MPR effect on renal development is disproportionate between mature and immature glomeruli at birth leading to fewer glomeruli at weaning. This supports epidemiological data in humans underlying why fetuses with low birth weight carry an increased risk of mortality from chronic diseases in adulthood, including hypertension.     

Reliability of current estimates of schistosomiasis prevalence in the Rainforest Zone of the state of Pernambuco, Northeastern Brazil

The Program for Schistosomiasis Control within the Unified Health System (PCE-SUS) was implemented by 1999 in the Rainforest Zone or "Zona da Mata" of Pernambuco (ZMP) aiming to carry out biennial stool surveys of whole populations through municipal health organs followed by treatment of the positives through the local units of the Family Health Program (PSF). Yearly reports from the Health Department of Pernambuco State (SES/PE) from 2002 to 2004 on the PCE-SUS surveys were assessed to evaluate whether the current estimates of prevalence in the municipalities of the ZMP are based on reliable samples so as to allow considerations on the real situation of schistosomiasis in that area. The surveys carried out in that period did not follow the major principles underlying sampling design, thus posing problems in both precision and validity of the estimates. Only 12 out of 43 municipalities had minimally reliable estimates: five with moderate prevalence (10-50%) and seven with low prevalence (< 10%). Surveys with appropriate sampling procedures aimed either at representative target groups (school-aged children) or communities are recommended for the ZMP and other endemic areas not only to provide reliable information on the current situation of schistosomiasis but also to plan adequate control strategies.     

Neuronal differentiation of human mesenchymal stem cells: changes in the expression of the Alzheimer's disease-related gene seladin-1

Seladin-1 (SELective Alzheimer's Disease INdicator-1) is an anti-apoptotic gene, which is down-regulated in brain regions affected by Alzheimer's disease (AD). In addition, seladin-1 catalyzes the conversion of desmosterol into cholesterol. Disruption of cholesterol homeostasis in neurons may increase cell susceptibility to toxic agents. Because the hippocampus and the subventricular zone, which are affected in AD, are the unique regions containing stem cells with neurogenic potential in the adult brain, it might be hypothesized that this multipotent cell compartment is the predominant source of seladin-1 in normal brain. In the present study, we isolated and characterized human mesenchymal stem cells (hMSC) as a model of cells with the ability to differentiate into neurons. hMSC were then differentiated toward a neuronal phenotype (hMSC-n). These cells were thoroughly characterized and proved to be neurons, as assessed by molecular and electrophysiological evaluation. Seladin-1 expression was determined and found to be significantly reduced in hMSC-n compared to undifferentiated cells. Accordingly, the total content of cholesterol was decreased after differentiation. These original results demonstrate for the first time that seladin-1 is abundantly expressed by stem cells and appear to suggest that reduced expression in AD might be due to an altered pool of multipotent cells.     

ErbB-receptors expression and survival in breast carcinoma: a 15-year follow-up study

Aberrant expression of the epidermal growth factor receptor family has been implicated in the pathogenesis and progression of breast cancer and associated with poor prognosis. To evaluate the prognostic impact of the ErbB receptors expression profile, we analyzed a well-characterized series of 145 primary breast carcinomas for the simultaneous expression of epidermal growth factor receptor (EGFR/HER-1), ErbB-2 (HER-2), ErbB-3 (HER-3), and ErbB-4 (HER-4), using immunohistochemistry. Tumors were considered negative or positive for each marker when less than or more than 25% of the cancer cells were immunopositive. Expression of EGFR, ErbB-2, ErbB-3, and ErbB-4 was observed in 31 (21.4%), 65 (44.8%), 72 (49.7%), and 81 (55.9%) of the cases, respectively. There were significant associations between EGFR expression and pT status (P = 0.01), and between ErbB-3 expression and pN (P = 0.003), menopausal (P = 0.01) and PR (P < 0.001) status. The majority of the cases co-expressed two or more receptors. ErbB-3 resulted positive in 51/81 (63.0%) of the ErbB-4 positive cases and ErbB-3/ErbB-4 co-expression was statistically significant (P = 0.0003). As expected, ErbB-2 expression was associated with reduced overall survival at 15 years of follow-up (P = 0.04), even after adjusting for a series of other prognostic factors (P = 0.05). Moreover, cumulative analysis of ErbB-2/3/4 expression showed a strong positive association between higher total ErbB-2/3/4 expression score and worse prognosis (P = 0.002). The simultaneous expression in cancer cells of more than one ErbB receptor identifies a subset of breast cancer patients at high risk for poor survival.