Effect of landscape attributes on the occurrence of the endangered golden-headed lion tamarin in southern Bahia, Brazil

The golden-headed lion tamarin (Leontopithecus chrysomelas) is an endangered primate that occurs exclusively in the Atlantic Forest of southern Bahia, Brazil. Its geographic range has been severely reduced by deforestation and its populations are restricted to a human-modified landscape consisting primarily of Atlantic forest fragments and shade cacao (Theobroma cacao) agroforestry, locally known as cabrucas. In the last 30 years, there has been a 42% reduction in the geographic range and a 60% reduction in the population size of L. chrysomelas, with only 8% of its habitat represented by protected areas. Thus, we investigated the occurrence of L. chrysomelas in forest fragments and cabrucas based on interviews and using playback census, and evaluated the influence of landscape attributes on its occurrence. The occurrence was measured using a Generalized Linear Model using a set of 12 predictor variables, including fragment size and elevation. L. chrysomelas inhabited 186 (38%) of the 495 forest fragments and cabrucas. Most inhabited habitat patches (n = 169, 91%) are in the eastern portion (ca. 70 km wide region from the Atlantic coast to inland) of its geographic range. The remaining (n = 17, 9%) are in the western portion of the distribution, between 70 and 150 km from the Atlantic coast. Our models indicate a higher occurrence of L. chrysomelas in the eastern portion of its geographic range, where the landscape exhibits lower land cover diversity, greater functional connectivity, lower altitudes (<400 m), and is primarily composed of forest fragments and cabrucas with a higher core percentage. In contrast, we observed a lower occurrence of L. chrysomelas in the western portion, where the landscape is more diverse and heterogeneous due to anthropogenic activities, such as agriculture and livestock. We urge the establishment of ecological corridors via reforestation of degraded areas in the western portion of the range. This increase in habitat availability and suitability in the west together with the protection of the forests and cabrucas in the east would increase our chances of saving L. chrysomelas from extinction.

Effects of Prebiotic Therapy on Gastrointestinal Microbiome of Individuals with Different Inflammatory Conditions: A Systematic Review of Randomized Controlled Trials

Prebiotics are substrates selectively utilized by host microorganisms conferring a health benefit. The effects of prebiotics on the gut microbiome of individuals with inflammatory processes need further investigations. The purpose of this study was to evaluate the effects of prebiotics on the gastrointestinal microbiome of individuals with some types of inflammatory conditions. Randomized controlled clinical trials (RCTs) evaluating the effects of different prebiotics on the gut microbiome were included. A systematic review of the literature including searches in PubMed/MEDLINE, EMBASE, Cochrane Library, Web of Science, and Scopus databases was performed until 23 March 2023. The risk of bias was assessed using the Cochrane Collaboration's criteria. Qualitative data was tabulated to facilitate comparisons and represented in the form of descriptive statistics and summary tables. Thirty trials, ranging from 12 to 135 patients, were included. The most commonly used prebiotic type was inulin-type fructans, and the treatment duration ranged from 1 to 36 weeks. The majority of the trials investigated the gut microbiome using 16 s rRNA gene sequencing on the Illumina Miseq platform. In general, prebiotic therapy exerted positive effects on inflammatory conditions. An increase in Bifidobacterium genus was the most common shift in bacterial composition observed. Within the limits of this systematic review, it can be suggested that prebiotic therapy presents the potential to favorably modulate the gastrointestinal microbiome of individuals with different types of inflammatory conditions.

Data on vegetation across forest edges from the FERN (Forest Edge Research Network)

Many studies have focused on vegetation across forest edges to study impacts of edges created by human activities on forest structure and composition, or patterns of vegetation at inherent natural edges. Our objective was to create a database of plant-related variables across different types of edges from various studies (mainly from across Canada, but also in Brazil and Belize) to facilitate edge research. We compiled data on vegetation along more than 300 transects perpendicular to forest edges adjacent to clear-cuts, burned areas, bogs, lakes, barrens, insect disturbances, and riparian areas from 24 studies conducted over the past three decades. Data were compiled for more than 400 plant species and forest structure variables (e.g., trees, logs, canopy cover). All data were collected with a similar sampling design of quadrats along transects perpendicular to forest edges, but with varying numbers of transects and quadrats, and distances from the edge. The purpose for most of the studies was either to determine the distance of edge influence (edge width) or to explore the pattern of vegetation along the edge to interior gradient. We provide data tables for the cover of plant species and functional groups, the species and size of live and dead trees, the density of saplings, maximum height of functional groups and shrub species, and the cover of functional groups at different heights (vertical distribution of vegetation). The Forest Edge Research Network (FERN) database provides extensive data on many variables that can be used for further study including meta-analyses and can assist in answering questions important to conservation efforts (e.g., how is distance of edge influence from created edges affected by different factors?). We plan to expand this database with subsequent studies from the authors and we invite others to contribute to make this a more global database. The data are released under a CC0 license. When using these data, we ask that you cite this data paper and any relevant publications listed in our metadata file. We also encourage you to contact the first author if you are planning to use or contribute to this database.

Global urban environmental change drives adaptation in white clover

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale.

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data.

ATLANTIC-CAMTRAPS: a dataset of medium and large terrestrial mammal communities in the Atlantic Forest of South America

Our understanding of mammal ecology has always been hindered by the difficulties of observing species in closed tropical forests. Camera trapping has become a major advance for monitoring terrestrial mammals in biodiversity rich ecosystems. Here we compiled one of the largest datasets of inventories of terrestrial mammal communities for the Neotropical region based on camera trapping studies. The dataset comprises 170 surveys of medium to large terrestrial mammals using camera traps conducted in 144 areas by 74 studies, covering six vegetation types of tropical and subtropical Atlantic Forest of South America (Brazil and Argentina), and present data on species composition and richness. The complete dataset comprises 53,438 independent records of 83 species of mammals, includes 10 species of marsupials, 15 rodents, 20 carnivores, eight ungulates and six armadillos. Species richness averaged 13 species (±6.07 SD) per site. Only six species occurred in more than 50% of the sites: the domestic dog Canis familiaris, crab-eating fox Cerdocyon thous, tayra Eira barbara, south American coati Nasua nasua, crab-eating raccoon Procyon cancrivorus and the nine-banded armadillo Dasypus novemcinctus. The information contained in this dataset can be used to understand macroecological patterns of biodiversity, community, and population structure, but also to evaluate the ecological consequences of fragmentation, defaunation, and trophic interactions.

ATLANTIC BATS: a data set of bat communities from the Atlantic Forests of South America

Bats are the second most diverse mammal order and they provide vital ecosystem functions (e.g., pollination, seed dispersal, and nutrient flux in caves) and services (e.g., crop pest suppression). Bats are also important vectors of infectious diseases, harboring more than 100 different virus types. In the present study, we compiled information on bat communities from the Atlantic Forests of South America, a species-rich biome that is highly threatened by habitat loss and fragmentation. The ATLANTIC BATS data set comprises 135 quantitative studies carried out in 205 sites, which cover most vegetation types of the tropical and subtropical Atlantic Forest: dense ombrophilous forest, mixed ombrophilous forest, semideciduous forest, deciduous forest, savanna, steppe, and open ombrophilous forest. The data set includes information on more than 90,000 captures of 98 bat species of eight families. Species richness averaged 12.1 per site, with a median value of 10 species (ranging from 1 to 53 species). Six species occurred in more than 50% of the communities: Artibeus lituratus, Carollia perspicillata, Sturnira lilium, Artibeus fimbriatus, Glossophaga soricina, and Platyrrhinus lineatus. The number of captures divided by sampling effort, a proxy for abundance, varied from 0.000001 to 0.77 individuals·h^-1 ·m^-2 (0.04 ± 0.007 individuals·h^-1 ·m^-2 ). Our data set reveals a hyper-dominance of eight species that together that comprise 80% of all captures: Platyrrhinus lineatus (2.3%), Molossus molossus (2.8%), Artibeus obscurus (3.4%), Artibeus planirostris (5.2%), Artibeus fimbriatus (7%), Sturnira lilium (14.5%), Carollia perspicillata (15.6%), and Artibeus lituratus (29.2%).

Ventilation-induced changes correlate to pulmonary vascular response and VEGF, VEGFR-1/2, and eNOS expression in the rat model of postnatal hypoxia

Neonatal asphyxia occurs due to reduction in oxygen supply to vital organs in the newborn. Rapid restoration of oxygen to the lungs after a long period of asphyxia can cause lung injury and decline of respiratory function, which result from the activity of molecules that induce vascular changes in the lung such as nitric oxide (NO) and vascular endothelial growth factors (VEGF). In this study, we evaluated the pulmonary and vascular morphometry of rats submitted to the model of neonatal asphyxia and mechanical ventilation, their expression of pulmonary VEGF, VEGF receptors (VEGFR-1/VEGFR-2), and endothelial NO synthase (eNOS). Neonate Sprague-Dawley rats (CEUA #043/2011) were divided into four groups (n=8 each): control (C), control submitted to ventilation (CV), hypoxia (H), and hypoxia submitted to ventilation (HV). The fetuses were harvested at 21.5 days of gestation. The morphometric variables measured were body weight (BW), total lung weight (TLW), left lung weight (LLW), and TLW/BW ratio. Pulmonary vascular measurements, VEGFR-1, VEGFR-2, VEGF, and eNOS immunohistochemistry were performed. The morphometric analysis showed decreased TLW and TLW/BW ratio in HV compared to C and H (P<0.005). Immunohistochemistry showed increased VEGFR-2/VEGF and decreased VEGFR-1 expression in H (P<0.05) and lower eNOS expression in H and HV. Median wall thickness was increased in H, and the expression of VEGFR-1, VEGFR-2, VEGF, and eNOS was altered, especially in neonates undergoing H and HV. These data suggested the occurrence of arteriolar wall changes mediated by NO and VEGF signaling in neonatal hypoxia.

The last frontier: Coupling technological developments with scientific challenges to improve hazard assessment of deep-sea mining

The growing economic interest in the exploitation of mineral resources on deep-ocean beds, including those in the vicinity of sensitive-rich habitats such as hydrothermal vents, raise a mounting concern about the damage that such actions might originate to these poorly-know ecosystems, which represent millions of years of evolution and adaptations to extreme environmental conditions. It has been suggested that mining may cause a major impact on vent ecosystems and other deep-sea areas. Yet, the scale and the nature of such impacts are unknown at present. Hence, building upon currently available scientific information it is crucial to develop new cost-effective technologies embedded into rigorous operating frameworks. The forward-thinking provided here will assist in the development of new technologies and tools to address the major challenges associated with deep sea-mining; technologies for in situ and ex situ observation and data acquisition, biogeochemical processes, hazard assessment of deep-sea mining to marine organisms and development of modeling tools in support of risk assessment scenarios. These technological developments are vital to validate a responsible and sustainable exploitation of the deep-sea mineral resources, based on the precautionary principle.

ATLANTIC BIRDS: a data set of bird species from the Brazilian Atlantic Forest

South America holds 30% of the world's avifauna, with the Atlantic Forest representing one of the richest regions of the Neotropics. Here we have compiled a data set on Brazilian Atlantic Forest bird occurrence (150,423) and abundance samples (N = 832 bird species; 33,119 bird individuals) using multiple methods, including qualitative surveys, mist nets, point counts, and line transects). We used four main sources of data: museum collections, on-line databases, literature sources, and unpublished reports. The data set comprises 4,122 localities and data from 1815 to 2017. Most studies were conducted in the Florestas de Interior (1,510 localities) and Serra do Mar (1,280 localities) biogeographic sub-regions. Considering the three main quantitative methods (mist net, point count, and line transect), we compiled abundance data for 745 species in 576 communities. In the data set, the most frequent species were Basileuterus culicivorus, Cyclaris gujanensis, and Conophaga lineata. There were 71 singletons, such as Lipaugus conditus and Calyptura cristata. We suggest that this small number of records reinforces the critical situation of these taxa in the Atlantic Forest. The information provided in this data set can be used for macroecological studies and to foster conservation strategies in this biodiversity hotspot. No copyright restrictions are associated with the data set. Please cite this Data Paper if data are used in publications and teaching events.

Effectiveness and safety of foam sclerotherapy with 5% ethanolamine oleate in the treatment of low-flow venous malformations in the head and neck region: a case series

The aim of this study was to evaluate the effectiveness and safety of 5% ethanolamine oleate (EO) foam in the treatment of low-flow venous malformations in the head and neck region. Seventeen consecutive patients (six male, 11 female) and 34 low-flow venous malformations were enrolled. The vascular anomalies ranged between 20mm and 80mm in size. The typical clinical indication was a swelling (88.2%) with a purple colour (85.3%); the most frequent location was the tongue (23.5%). Ethanolamine oleate foam was produced via the Tessari method and applied at 10mg per 1cm to the vascular anomalies. This process resulted in the highest clinical healing score in 64.7% of cases, and half of the patients reported a high level of satisfaction (score >9). In the majority of cases (88.2%), the patients reported that the pain immediately postoperative was mild or moderate. There were direct relationships between vascular anomaly size and the volume of EO applied, the number of sessions, and healing (P<0.05). No recurrence was observed during 6 months of follow-up. This case series showed the effectiveness and safety of 5% EO foam for the treatment of venous malformations in the head and neck region.

Space Use and Movement of a Neotropical Top Predator: The Endangered Jaguar

Accurately estimating home range and understanding movement behavior can provide important information on ecological processes. Advances in data collection and analysis have improved our ability to estimate home range and movement parameters, both of which have the potential to impact species conservation. Fitting continuous-time movement model to data and incorporating the autocorrelated kernel density estimator (AKDE), we investigated range residency of forty-four jaguars fit with GPS collars across five biomes in Brazil and Argentina. We assessed home range and movement parameters of range resident animals and compared AKDE estimates with kernel density estimates (KDE). We accounted for differential space use and movement among individuals, sex, region, and habitat quality. Thirty-three (80%) of collared jaguars were range resident. Home range estimates using AKDE were 1.02 to 4.80 times larger than KDE estimates that did not consider autocorrelation. Males exhibited larger home ranges, more directional movement paths, and a trend towards larger distances traveled per day. Jaguars with the largest home ranges occupied the Atlantic Forest, a biome with high levels of deforestation and high human population density. Our results fill a gap in the knowledge of the species' ecology with an aim towards better conservation of this endangered/critically endangered carnivore-the top predator in the Neotropics.

Threshold effect of habitat loss on bat richness in cerrado-forest landscapes

Understanding how animal groups respond to contemporary habitat loss and fragmentation is essential for development of strategies for species conservation. Until now, there has been no consensus about how landscape degradation affects the diversity and distribution of Neotropical bats. Some studies demonstrate population declines and species loss in impacted areas, although the magnitude and generality of these effects on bat community structure are unclear. Empirical fragmentation thresholds predict an accentuated drop in biodiversity, and species richness in particular, when less than 30% of the original amount of habitat in the landscape remains. In this study, we tested whether bat species richness demonstrates this threshold response, based on 48 sites distributed across 12 landscapes with 9-88% remaining forest in Brazilian cerrado-forest formations. We also examined the degree to which abundance was similarly affected within four different feeding guilds. The threshold value for richness, below which bat diversity declines precipitously, was estimated at 47% of remaining forest. To verify if the response of bat abundance to habitat loss differed among feeding guilds, we used a model selection approach based on Akaike's information criterion. Models accounted for the amount of riparian forest, semideciduous forest, cerrado, tree plantations, secondary forest, and the total amount of forest in the landscape. We demonstrate a nonlinear effect of the contribution of tree plantations to frugivores, and a positive effect of the amount of cerrado to nectarivores and animalivores, the groups that responded most to decreases in amount of forest. We suggest that bat assemblages in interior Atlantic Forest and cerrado regions of southeastern Brazil are impoverished, since we found lower richness and abundance of different groups in landscapes with lower amounts of forest. The relatively higher threshold value of 47% suggests that bat communities have a relatively lower resistance to habitat degradation than other animal groups. Accordingly, conservation and restoration strategies should focus on increasing the amount of native vegetation of landscapes so as to enhance species richness of bats.

Diet Overlap and Foraging Activity between Feral Pigs and Native Peccaries in the Pantanal

Inter-specific competition is considered one of the main selective pressures affecting species distribution and coexistence. Different species vary in the way they forage in order to minimize encounters with their competitors and with their predators. However, it is still poorly known whether and how native species change their foraging behavior in the presence of exotic species, particularly in South America. Here we compare diet overlap of fruits and foraging activity period of two sympatric native ungulates (the white-lipped peccary, Tayassu pecari, and the collared peccary, Pecari tajacu) with the invasive feral pig (Sus scrofa) in the Brazilian Pantanal. We found high diet overlap between white-lipped peccaries and feral pigs, but low overlap between collared peccaries and feral pigs. Furthermore, we found that feral pigs may influence the foraging period of both native peccaries, but in different ways. In the absence of feral pigs, collared peccary activity peaks in the early evening, possibly allowing them to avoid white-lipped peccary activity peaks, which occur in the morning. In the presence of feral pigs, collared peccaries forage mostly in early morning, while white-lipped peccaries forage throughout the day. Our results indicate that collared peccaries may avoid foraging at the same time as white-lipped peccaries. However, they forage during the same periods as feral pigs, with whom they have lower diet overlap. Our study highlights how an exotic species may alter interactions between native species by interfering in their foraging periods.

The taxonomic distinctness of macroinvertebrate communities of Atlantic Forest streams cannot be predicted by landscape and climate variables, but traditional biodiversity indices can

Predicting how anthropogenic activities may influence the various components of biodiversity is essential for finding ways to reduce diversity loss. This challenge involves: a) understanding how environmental factors influence diversity across different spatial scales, and b) developing ways to measure these relationships in a way that is fast, economical, and easy to communicate. In this study, we investigate whether landscape and bioclimatic variables could explain variation in biodiversity indices in macroinvertebrate communities from 39 Atlantic Forest streams. In addition to traditional diversity measures, i.e., species richness, abundance and Shannon index, we used a taxonomic distinctness index that measures the degree of phylogenetic relationship among taxa. The amount of variation in the diversity measures that was explained by environmental and spatial variables was estimated using variation partitioning based on multiple regression. Our study demonstrates that taxonomic distinctness does not respond in the same way as the traditional used in biodiversity studies. We found no evidence that taxonomic distinctness responds predictably to variation in landscape metrics, indicating the need for the incorporation of predictors at multiple scales in this type of study. The lack of congruence between taxonomic distinctness and other indices and its low predictability may be related to the fact that this measure expresses long-term evolutionary adaptation to ecosystem conditions, while the other traditional biodiversity metrics respond to short-term environmental changes.

Tools for determining critical levels of atmospheric ammonia under the influence of multiple disturbances

Critical levels (CLEs) of atmospheric ammonia based on biodiversity changes have been mostly calculated using small-scale single-source approaches, to avoid interference by other factors, which also influence biodiversity. Thus, it is questionable whether these CLEs are valid at larger spatial scales, in a multi- disturbances context. To test so, we sampled lichen diversity and ammonia at 80 sites across a region with a complex land-cover including industrial and urban areas. At a regional scale, confounding factors such as industrial pollutants prevailed, masking the CLEs. We propose and use a new tool to calculate CLEs by stratifying ammonia concentrations into classes, and focusing on the highest diversity values. Based on the significant correlations between ammonia and biodiversity, we found the CLE of ammonia for Mediterranean evergreen woodlands to be 0.69 μg m(-3), below the previously accepted value of 1.9 μg m(-3), and below the currently accepted pan-European CLE of 1.0 μg m(-3).

Protein kinase C-mediated ATP stimulation of Na(+)-ATPase activity in LLC-PK1 cells involves a P2Y2 and/or P2Y4 receptor

ATP-activated P2Y receptors play an important role in renal sodium excretion. The aim of this study was to evaluate the modulation of ATPase-driven sodium reabsorption in the proximal tubule by ATP or adenosine (Ado). LLC-PK1 cells, a model of porcine proximal tubule cells, were used. ATP (10(-6)M) or Ado (10(-6)M) specifically stimulated Na(+)-ATPase activity without any changes in (Na(+)+K(+))-ATPase activity. Our results show that the Ado effect is mediated by its conversion to ATP. Furthermore, it was observed that the effect of ATP was mimicked by UTP, ATPγS and 2-thio-UTP, an agonist of P2Y2 and P2Y4 receptors. In addition, ATP-stimulated Na(+)-ATPase activity involves protein kinase C (PKC). Our results indicate that ATP-induced stimulation of proximal tubule Na(+)-ATPase activity is mediated by a PKC-dependent P2Y2 and/or P2Y4 pathway. These findings provide new perspectives on the role of the effect of P2Y-mediated extracellular ATP on renal sodium handling.

Functional redundancy and complementarities of seed dispersal by the last neotropical megafrugivores

BACKGROUND

Functional redundancy has been debated largely in ecology and conservation, yet we lack detailed empirical studies on the roles of functionally similar species in ecosystem function. Large bodied frugivores may disperse similar plant species and have strong impact on plant recruitment in tropical forests. The two largest frugivores in the neotropics, tapirs (Tapirus terrestris) and muriquis (Brachyteles arachnoides) are potential candidates for functional redundancy on seed dispersal effectiveness. Here we provide a comparison of the quantitative, qualitative and spatial effects on seed dispersal by these megafrugivores in a continuous Brazilian Atlantic forest.

METHODOLOGY/PRINCIPAL FINDINGS

We found a low overlap of plant species dispersed by both muriquis and tapirs. A group of 35 muriquis occupied an area of 850 ha and dispersed 5 times more plant species, and 13 times more seeds than 22 tapirs living in the same area. Muriquis dispersed 2.4 times more seeds in any random position than tapirs. This can be explained mainly because seed deposition by muriquis leaves less empty space than tapirs. However, tapirs are able to disperse larger seeds than muriquis and move them into sites not reached by primates, such as large forest gaps, open areas and fragments nearby. Based on published information we found 302 plant species that are dispersed by at least one of these megafrugivores in the Brazilian Atlantic forest.

CONCLUSIONS/SIGNIFICANCE

Our study showed that both megafrugivores play complementary rather than redundant roles as seed dispersers. Although tapirs disperse fewer seeds and species than muriquis, they disperse larger-seeded species and in places not used by primates. The selective extinction of these megafrugivores will change the spatial seed rain they generate and may have negative effects on the recruitment of several plant species, particularly those with large seeds that have muriquis and tapirs as the last living seed dispersers.

Characterization of ecto-ATPase activity in the surface of LLC-PK1 cells and its modulation by ischemic conditions

BACKGROUND

The concentration of extracellular nucleotides is regulated by enzymes that have their catalytic site facing the extracellular space, the so-called ecto-enzymes.

METHODS

We used LLC-PK1 cells, a well-characterized porcine renal proximal tubule cell line, to biochemically characterize ecto-ATPase activity in the luminal surface. The [γ-(32)P]Pi released after reaction was measured in aliquots of the supernatant by liquid scintillation.

RESULTS

This activity was linear with time up to 20min of reaction and stimulated by divalent metals. The ecto-ATPase activity measured in the presence of 5mM MgCl(2) was (1) optimum at pH 8, (2) insensitive to different inhibitors of intracellular ATPases, (3) inhibited by 1mM suramin, an inhibitor of ecto-ATPases, (4) sensitive to high concentrations of sodium azide (NaN(3)) and (5) also able to hydrolyze ADP in the extracellular medium. The ATP:ADP hydrolysis ratio calculated was 4:1. The ecto-ADPase activity was also inhibited by suramin and NaN(3). The dose-response of ATP revealed a hyperbolic profile with maximal velocity of 25.2±1.2nmol Pixmg(-1)xmin(-1) and K(0.5) of 0.07±0.01mM. When cells were submitted to ischemia, the E-NTPDase activity was reduced with time, achieving 71% inhibition at 60min of ischemia.

CONCLUSION

Our results suggest that the ecto-ATPase activity of LLC-PK1 cells has the characteristics of a type 3 E-NTPDase which is inhibited by ischemia.

GENERAL SIGNIFICANCE

This could represent an important pathophysiologic mechanism that explains the increase in ATP concentration in the extracellular milieu in the proximal tubule during ischemia.

Effect of intermittent convection movements on voltammogram and current transients

The influence of intermittent convection movements on electrochemical voltammograms is investigated. When the bath temperature rises to 315 K, the voltammograms exhibit irregular plateaus that differ for independent voltammetry scans, even when the setup is maintained under exactly the same conditions. In this paper, we show that such behavior can be caused by convection movements that develop in the electrolytic cell as a consequence of velocity fluctuations, since no bubbles or regular convective patterns are observed at this temperature. Theoretical current-potential curves for the heterogeneous deposition of metals on silicon electrodes is derived from a model consisting of a one-dimensional balance equation that includes diffusion, convection, and reaction through a time-dependent boundary condition. We obtain the current density associated with the adsorption of particles on the surface and, through this expression, we consider the effect of constant convective velocities on voltammograms. Finally, we examine the effect of random convective movements, described by a Monte Carlo algorithm that takes into account the random temporal fluctuations around a null convective current. The model predicts accentuated fluctuations on the current profiles, especially on the current plateaus that correspond to a stationary current regime. The validity of the theoretical model is checked against experimental data.

Atopic disease and body mass index

BACKGROUND

Obesity and atopy are two increasingly important population health issues. Excess weight and obesity are potential risk factors for atopy (specifically asthma).

OBJECTIVE AND METHODS

To determine the body mass index (BMI) in children with atopic disease compared with nonatopic children, and to determine whether obesity is associated to more severe disease. Children aged 5 to 16 years with diagnosed atopic disease that attended the Ambulatory Hospital Center where eligible as cases. Children aged 5 to 16 years without atopic disease from a school in the same geographic area were used as controls.

RESULTS

A total of 228 children where included in the analysis: 112 children with atopy (75.9% asthma, 21.4% rhinitis and 2.7% eczema) and 116 children without atopy. The median age was 10.5 and 10.3 years for the atopic and non-atopic children, respectively. The prevalence of overweight or obese subjects was significantly greater in the atopic group (44.6% vs 31.9%, p 0.05). The obese asthmatic children had a significantly higher prevalence of sleep disturbances due to wheezing in the last 12 months (45.5% vs 15.9%, p 0.05). They also reported dry cough at night more often (50% vs 28.6%, p = 0.07), and a higher number of wheezing attacks in the past 12 months (72.7% vs 50.8%, p = 0.074), than the non-obese asthmatic children. Most of the obese atopic children were already overweight or obese at the time of the diagnosis (66.6%). None of the associations were significantly different for boys or girls.

DISCUSSION

There is some evidence of an association between excess body weight or obesity and atopy--particularly asthma.

Nocturnal plasma levels of melatonin in quails (Coturnix japonica) injected with l-5-hydroxy-tryptophan

This study aimed to demonstrate the influence of the systemic administration of l-5-hydroxy-tryptophan (L-HTP) on the plasma levels of melatonin during the dark period in quails. Throughout daylight, the plasma levels of melatonin did not differ significantly, oscillating between 110.2 ± 15.8 pg.mL-1 and 157.4 ± 34.8 pg.mL-1, from 8 to 16 hours. L-HTP (25 mg.kg-1, through the intracelomic route) administered at 18 hours lessened significantly the nocturnal increase of the plasma levels of melatonin (controls, 327.3 ± 20.1 and 315.8 ± 20.9 pg.mL-1 vs. 242.1 ± 24.8 and 217.5 ± 21 pg.mL-1, respectively, at 20 and 24 hours, P < 0.05). The results obtained showed that the administration of LHTP reduced the nocturnal melatonin release, possibly by bringing about an increase in serotonin synthesis and synaptic release in the pineal. Therefore, the serotoninergic transmission from the raphe towards the pineal would constitute a mechanism of modulation of the synthesis and melatonin release in quails.

Hepatitis B and C virus markers among patients with hepatosplenic mansonic schistosomiasis

PURPOSE

To evaluate the frequency and the consequences of the co-infection of hepatitis B and C viruses in patients with hepatosplenic schistosomiasis (HSS).

METHODS

B and C serologic markers, exposure to risk factors, biochemical assays, upper gastrointestinal endoscopies, and abdominal ultrasonograms were evaluated in 101 patients with HSS from 1994 to 1997. Whenever possible, PCR was tested and histopathological studies were reviewed.

RESULTS

At least one HBV virus marker was found in 15.8%, and anti-HCV was detected in 12.9% of the subjects. The seropositive subjects tended to be older than the seronegative ones. A history of blood transfusion was significantly related to the presence of anti-HCV. Three (18.75%) out of 16 subjects exposed to B virus were HBsAg positive. Eleven (84.6%) out of thirteen patients who were anti-HCV positive demonstrated viral activity. Patients with ongoing viral infection presented a higher average level of liver aminotransferases, a higher frequency of cell decompensation and a higher rate of chronic hepatitis. Portal hypertension parameters were not influenced by viral exposure.

CONCLUSIONS

The rate of hepatitis B and C viruses serologic markers observed in the patients with HSS was higher than the control group. The co-infection was responsible for a higher frequency of cell decompensation.

[Vaccination coverage in the first year of life in 4 cities of the state of São Paulo, Brazil]

Immunization is an important disease prevention measure, and evaluating the effectiveness of immunization programs is crucial to ensuring their success. This study describes the results of a household survey in four cities in the state of São Paulo, Brazil: Francisco Morato, Guarulhos, Osasco, and São Paulo. The survey was done in order to estimate immunization coverage for the cohort of children born in 1996. The city of São Paulo was divided into five strata, according to socioeconomic and living conditions. The survey followed the methodology that the Pan American Health Organization recommends for immunization coverage surveys. The proportion of children who had received a complete set of the recommended vaccinations at the time of the interview, taking into account both oral reports and information recorded on the children's immunization cards, was above 90% for all the cities except Francisco Morato, which had the worst living conditions. In the city of São Paulo, the worst coverage was found in the lowest and highest strata. When only the doses received during the first year of life were considered, the coverage was not adequate to produce herd immunity. The use of private vaccination services was higher in the areas with better living conditions. The difference between the coverage calculated based on data from health services and the coverage calculated based on the survey was inversely proportional to living conditions. Our results suggest that surveys similar to the one described here should be carried out in other cities. Employees who provide vaccination services should be trained to correctly record vaccination data. In addition, it is important to make health professionals aware of the official immunization calendar, and to facilitate the public's access to health services.

[Correlation between homicide rates and economic indicators in São Paulo, Brazil, 1996]

Around 30% of the deaths due to violent causes in Brazil result from homicides. Violence has traditionally been related to larger social problems, such as poverty. Recently, however, a positive correlation has been observed between higher incomes and an increase in the homicide rate, so that some researchers have begun to consider inequality, rather than poverty, as an explanation for the epidemic of violence. The objective of this study was to investigate the correlation between urbanization, poverty, and economic inequality and homicide rates in the state of São Paulo, Brazil, in 1996. Information regarding population size, average monthly income of household heads, income distribution, and Gini index was obtained for each municipality, based on the demographic census. Homicide rates were calculated based on official data. Data were analyzed in terms of correlation and relative risk with 95% confidence intervals. Homicide rates rose in direct proportion to city population and ranged from 6.96 (per 100,000 inhabitants) in municipalities with a population smaller than 10,000 inhabitants, to 55.54 in municipalities with more than 1 million inhabitants. Relative risk ranged from 1.35 to 7.98. A significant correlation with population size was found only for incomes above 3.11 times the minimum wage and a Gini index greater than 0.50. There was a strong, direct, and significant correlation between homicide rates and the income ratio between the ninetieth and the twentieth percentiles of the population. It is necessary to probe more deeply into the macrosocial determinants of homicide rates in order to identify indicators of inequality that can generate meaningful data for developing public health strategies.

[Time trends in death rates from homicides in the city of Sao Paulo, Brazil, 1979-1994]

To study homicide trends by gender and age, 1979-1994, São Paulo, Brazil, cubic polynomials were used to determine the best model for adjusting to time trends in homicide mortality rates by age and gender in the city of São Paulo, Brazil, 1979-1994. The model best adjusted to each group was selected considering the regression coefficient (Beta) , R2 value, residual analysis, and model's simplicity. The results show linear growth for total rates and rates by gender due to behavior of rates in the 20-29 and 30-39 year age groups. The reciprocal model adjusted best to rates for the 40-49 and 50-59 year age groups, while rates for adolescents followed the multiplicative model. There was no significant relationship between homicide rates and time for the remaining groups (under 10 and over 59 years). Rates for males were considerably higher in all age groups. The remarkably steady growth in homicide rates among adolescents and young adults is consistent with trends observed in other urban areas in developing and developed countries and denotes deteriorating living conditions and increased poverty.

[Nursing and the environmental question: proposal of a theoretical model for the professional practice]

Considering the side effects of environmental changes over the population's health, a theoretical model is proposed in this study in order to incorporate ecologic matters into the nursing practices. The reference for this work is the eco-socialist-marxist theory. The model is based on the analysis of the capitalist economic process, its production technologies and consumption. It is known that this economic model generates ecoinequalities and anthropogenic impacts that rebound on the health-disease profile of the population. The nursing action, permeated by ecological awareness, can prevent and also combat ecoinequalities and destructive human actions on the environment.

Prenatal diagnosis of mosaicism for tetrasomy 18p: cytogenetic, fish and morphological findings

A case of mosaicism for tetrasomy 18p detected prenatally is reported. We believe this is the second case where fetal anomalies were found at autopsy.

Pharmacological evidence for GABAergic and glutamatergic involvement in the convulsant and behavioral effects of glutaric acid

The effect of intrastriatal administration of glutaric acid (GTR), a metabolite that accumulates in glutaric acidemia type I (GA-I), on the behavior of adult male rats was investigated. After cannula placing, rats received unilateral intrastriatal injections of GTR buffered to pH 7.4 with NaOH or NaCl. GTR induced rotational behavior toward the contralateral side of injection and clonic convulsions in a dose-dependent manner. Rotational behavior was prevented by intrastriatal preadministration of DNQX and muscimol, but not by the preadministration of MK-801. Convulsions were prevented by intrastriatal preinjection of muscimol. This study provides evidence for a participation of glutamatergic non-NMDA and GABAergic mechanisms in the GTR-induced behavioral alterations. These findings may be of value in understanding the physiopathology of the neurological dysfunction in glutaric acidemia.

[Perceptions of the nursing staff after a death: the ritual of post mortem preparation of the body]

This paper intends verificated the significance of the patients' death in nursing professionals and the emotions during the prepare of his bodies. The dispositions were collected with 23 professionals at UTI service in a hospital of São Paulo city. The results shows some sad during the prepare of the body and the comprehension that the time of the experience and the type of relationship make the different in this procedure.

Intra-urban differentials in death rates from homicide in the city of São Paulo, Brazil, 1988-1994

The objective of this research was to analyze the relationship between socioeconomic statistics and homicide mortality rates in the city of São Paulo between 1988 and 1994. City districts were grouped into five geographic areas. A socioeconomic indicator (ISE) was constructed with census information combining average income of the family head, illiteracy rate for the population over 5 yr of age, average number of rooms and number of persons per household. The higher the score, the better the socioeconomic situation (possible values: 4 to 384). Deaths from homicide were grouped by residential areas, and the rates for these areas were calculated. The association between homicide rates and the socioeconomic situation was analyzed with Spearman correlation coefficients. Average ISE scores varied from 291 in the Central area (homicide rate = 27.96 deaths per 100000) to 119.9 in the East area (homicide rate = 40.38). The Spearman coefficient between ISEs and homicide rates was -0.98 (p < 0.05). Due to the heterogeneity inside the areas, the median ISE is a better indicator of the socioeconomic conditions yielding an rs = -1.0. Almost half the population resides in areas with the highest risk of homicide mortality (East and South). Taking the Central area as a reference, we found risks of 1.36 in the Western, 1.37 in the Northern, 1.44 in the Eastern and 2.67 in the Southern areas.

Properties of chicken lens MIP channels reconstituted into planar lipid bilayers

Membrane fractions highly enriched in chicken lens MIP (MIP28) were found to form ion channels when incorporated into planar lipid bilayers. The channels displayed prominent unitary conductances of about 60 and 290 pS in symmetric 150 mm KCl solution and were slightly anion selective. For both depolarizing and hyperpolarizing voltages, voltage sensitivity of the MIP28-induced conductance could be fit by a Boltzmann relation, symmetric around zero mV, with V0 = 18.5 mV, n = 4.5 and gmin/gmax = 0.17. Channel properties were not appreciably altered by pH in the range of 5.8 to 7, although channel incorporation was observed to occur more frequently at lower pH values. Calcium, at millimolar concentrations, decreased the channel mean open time. Partial proteolysis of MIP28 to yield MIP21 did not appreciably affect single-channel conductance or voltage sensitivity of the reconstituted channels. MIP28 was not phosphorylated by cAMP dependent protein kinase (PKA). Although unitary conductance and selectivity of the chicken MIP channel are similar to those reported for the bovine MIP (MIP26), the voltage sensitivity of MIP28 was higher than that of the bovine homologue, and voltage sensitivity of MIP28 was not modulated by treatments previously shown to affect MIP26 voltage gating (partial proteolysis and protein phosphorylation by PKA: (Ehring et al., 1990). The existence of such strikingly different functional properties in highly homologous channel isoforms may provide a useful system for exploration of the structure-function relations of MIP channels.

Comparative characterization of a human large cell lung carcinoma cell line and the xenograft derived cell line

The HK-1 cell line established from a human large cell lung carcinoma shows a high transformed phenotype and undifferentiated characteristics. This cell line grows as an adherent monolayer in fetal calf serum-supplemented medium, shows a high proliferation index, is able to grow in semi-solid agar and is tumorigenic in athymic nude rats. The cell line HK-2 derived from the HK-1 xenograft in athymic nude rats shows basically the same features found in the original HK-1 cell line, which include aneuploid nuclear DNA content, abnormal chromosomal number. rearranged marker chromosomes and abnormally localised nucleolar organizer regions. Cytokeratin and vimentin intermediary-sized filaments were found in both cell lines as well as in the original and induced tumour, while neither oncofetal antigens (alphafeto-protein, carcinoembryonic antigen, chorionic gonatropin and human placental lactogen) nor neural differentiation markers (neurofilament and neural specific enolase) were expressed. Analysis of sulphated glycosaminoglycans in the cell cultures and in the nude rat induced tumour showed high expression of chondroitin sulphate.

Bilateral retinoblastoma associated with 13q-mosaicism. Possible manifestation of a germinal mutation

Fifteen retinoblastoma patients were studied cytogenetically using G- and R-banding techniques. One patient showed 13q-mosaicism. It is suggested that a postzygotic deficiency in mosaic cases and in tumoral cells may be secondary to germinal mutation.

Sister chromatid exchange frequency in a retinoblastoma mosaic patient with del(13)

The frequencies of sister chromatid exchange (SCE) were investigated in different cell populations derived from a patient with retinoblastoma and 46,XY/46,XY,del(13) (q12.3q21.2) mosaicism. No differences in spontaneous or mitomycin C-induced SCE were detected between cell populations.

Duchenne muscular dystrophy in a girl with an (X;15) translocation

This is a report of a girl with Duchenne muscular dystrophy (DMD) associated with an 46,X,t (X;15) (p21; q 26) chromosome constitution. Although in the eight published cases of girls with DMD and a t(X;aut) different autosomes were involved in the translocation, the breakpoint was always at Xp21. The present case supports the hypothesis that the DMD gene must be located at Xp21. In this study, involvement of the father's chromosomes in the translocation was detected.

Length dependence of activation studied in the isovolumic blood-perfused dog heart

In studies utilizing the isolated isovolumic blood-perfused canine heart, left ventricular pressure was measured following a sudden expansion of ventricular volume. An increase in performance occurred in two phases: first, there was an instantaneous rise of developed pressure simultaneous with ventricular distension; in the second phase, developed pressure continued to increase for several minutes until a final steady state was reached. The immediate increase in developed pressure occurred with a prolongation of the time-to-peak pressure, and there was no further change of time-to-peak pressure during the time-dependent increase of developed pressure. In another series of experiments, systolic pressure was elevated without changing resting volume, and mechanical performance changed in a different manner: after an increase in systolic load, there was a modest and transient decrease of developed pressure; thereafter, ventricular pressure recovered only to original values. The influence of different degrees of ventricular expansion, calcium, and verapamil were studied. Under higher ventricular dilations the immediate as well as the slow increase of contraction were heightened and the time to reach half of the slow increase was shortened. When ventricular dilation was induced during an infusion of calcium chloride, higher values for the immediate pressure increase were observed, whereas the time-dependent increase and the time to reach half of the slow increase did not change in comparison with control studies. Verapamil decreased the immediate and the time-dependent enhancement of contraction. The time-dependent increase in developed pressure occurs more slowly with verapamil.(ABSTRACT TRUNCATED AT 250 WORDS)