Predicting the future of threatened birds from a Neotropical ecotone area

Climate change affects ecosystems in different ways. These effects are particularly worrying in the Neotropical region, where species are most vulnerable to these changes because they live closer to their thermal safety limits. Thus, establishing conservation priorities, particularly for the definition of protected areas (PAs), is a priority. However, some PA systems within the Neotropics are ineffective even under the present environmental conditions. Here, we test the effectiveness of a PA system, within an ecotone in northern Brazil, in protecting 24 endangered bird species under current and future (RCP8.5) climatic scenarios. We used species distribution modeling and dispersal corridor modeling to describe the priority areas for conservation of these species. Our results indicate that several threatened bird taxa are and will potentially be protected (i.e., occur within PAs). Nonetheless, the amount of protected area is insufficient to maintain the species in the ecotone. Moreover, most taxa will probably present drastic declines in their range sizes; some are even predicted to go globally extinct soon. Thus, we highlight the location of a potentially effective system of dispersal corridors that connects PAs in the ecotone. We reinforce the need to implement public policies and raise public awareness to maintain PAs and mitigate anthropogenic effects within them, corridors, and adjacent areas, aiming to conserve the richness and diversity of these already threatened species.

Transcriptomic response of the intertidal limpet Patella vulgata to temperature extremes

Global warming is challenging wild species in land and water. In the intertidal zone, species are already living at their thermal limits, being vulnerable even to small increases in maximum habitat temperatures. Knowledge of the mechanisms by which many intertidal zone species cope with elevated temperatures is limited. We analysed the molecular thermal stress response of the limpet Patella vulgata under slight and frequent (one-day), and extreme and rare (three-day) warming events. Using RNA-seq to assess differential gene expression among treatments, differing molecular responses were obtained in the two treatments, with more changes in gene expression after the three-day event; with one-third of the differentially expressed transcripts being down-regulated. However, across treatments we observed shifts in gene expression for common aspects of the heat stress response including intra-cellular communication, protein chaperoning, proteolysis and cell cycle arrest. Of the 71,675 transcripts obtained, only 259 were differentially expressed after both heating events. From these, 218 defined the core group (i.e. genes induced by thermal stress with similar expression patterns irrespective of the magnitude of the warming event). The core group was composed of already well-studied genes in heat stress responses in intertidal organisms (e.g. heat shock proteins), but also genes from less explored metabolic pathways, e.g. the ubiquitin system, which were also fundamental regardless of the magnitude of the imposed warming. Moreover, we have also identified 41 signaling genes (i.e. a set of genes responding to both events and with expression patterns specific to the intensity of thermal stress), principally including genes involved in the maintenance of extracellular structure that have previously not been identified as part of the response to thermal stress in intertidal zone organisms. These signaling genes will be useful heat stress molecular biomarkers for monitoring heat stress in natural populations.

Recent population differentiation in the habitat specialist Glossy Antshrike (Aves: Thamnophilidae) across Amazonian seasonally flooded forests

We assessed population structure and the spatio-temporal pattern of diversification in the Glossy Antshrike Sakesphorus luctuosus (Aves, Thamnophilidae) to understand the processes shaping the evolutionary history of Amazonian floodplains and address unresolved taxonomic controversies surrounding its species limits. By targeting ultraconserved elements (UCEs) from 32 specimens of S. luctuosus, we identified independent lineages and estimated their differentiation, divergence times, and migration rates. We also estimated current and past demographic histories for each recovered lineage. We found evidence confirming that S. luctuosus consists of a single species, comprising at least four populations, with some highly admixed individuals and overall similar levels of migration between populations. We confirmed the differentiation of the Araguaia River basin population (S. l. araguayae) and gathered circumstantial evidence indicating that the taxon S. hagmanni may represent a highly introgressed population between three distinct phylogroups of S. luctuosus. Divergences between populations occurred during the last 1.2 mya. Signs of population expansions were detected for populations attributed to subspecies S. l. luctuosus, but not for the S. l. araguayae population. Our results support that S. luctuosus has had a complex population history, resulting from a high dependence on southeastern "clear water" seasonally flooded habitats and their availability through time. Spatial and demographic expansions toward the western "white water" flooded forests might be related to recent changes in connectivity and availability of these habitats. Our study reinforces the view that isolation due to absence of suitable habitat has been an important driver of population differentiation within Amazonian flooded forests, but also that differences between várzeas ("white water" floodplains, mostly in southwestern Amazonia) and igapós ("clear water" floodplains, especially located in the east) should be further explored as drivers of micro-evolution for terrestrial species.

Seven years of evaluation of ectoparasites and vector-borne pathogens among ring-tailed coatis in an urban park in southeastern Brazil

Wild animals have been recognized as potential reservoirs of vector-borne pathogens. Proximity between these animals and urban areas increases the need to know which pathogens these are and whether they can infect domestic animals and humans. In Mangabeiras Municipal Park in Belo Horizonte, Brazil, coatis live near the urban area, which is mainly occupied by human residents and their domestic animals. Therefore, the objective of this study was to detect, through molecular and direct methods, the presence of ectoparasites and hemoparasites in coatis. A total of 216 samples were collected, of which 209 samples were from first-captures and seven were from recaptures. The following parasites were found: ticks of the genus Amblyomma, lice of the species Neotrichodectes pallidus and fleas of the species Rhopalopsyllus lutzi lutzi and Ctenocephalides felis felis. All the samples were negative for the family Anaplasmataceae and the species Leishmania sp. and Trypanosoma cruzi. The hemoparasites Trypanosoma evansi, Hepatozoon procyonis, Babesia sp. and Sarcocystis neurona were found. The area of the present study is not endemic for T. evansi, which therefore suggests that these coatis may be acting as reservoirs or sentinels of this parasite. This finding is of great epidemiological importance and should be investigated more closely. Thus, this study showed that there is a great variety of pathogens in the park that transit among coatis and, probably, among other animals that inhabit or live close to the park.

Taxonomy of the Sylvilagus brasiliensis complex in Central and South America (Lagomorpha: Leporidae)

A taxonomic framework for South American cottontail rabbits (Lagomorpha: Leporidae: Sylvilagus) was recently published by Diersing and Wilson (2017). Although we agree with some of its taxonomic conclusions (e.g., species status for S. apollinaris and S. fulvescens), we disagree with others. We provide herein evidence supporting S. andinus as a valid species based on morphological characters and novel molecular data. We also provide details of the morphological characters of S. apollinaris and S. fulvescens that support separating these from S. brasiliensis. We adduce data suggestive to the effect that—absent any type material—S. defilippi is at best a nomen dubium. Finally, we provide evidence in support of recognizing additional Neotropical species of Sylvilagus.

Un esquema taxonómico para los conejos sudamericanos (Lagomorpha: Leporidae: Sylvilagus) fue recientemente publicado por Diersing y Wilson (2017). Aunque estamos de acuerdo con algunas de sus conclusiones (por ejemplo: estatus de especie válida para S. apollinaris y S. fulvescens), no estamos de acuerdo con las restantes conclusiones taxonómicas. Aportamos aquí pruebas convincentes sobre la característica naturaleza de los caracteres morfológicos y moleculares de S. andinus, pruebas que esgrimimos en apoyo de la hipótesis que esta última es una especie válida, así confirmando su escisión de S. brasiliensis. Proporcionamos detalles de los caracteres morfológicos de S. apollinaris y S. fulvescens que confirman la decisión taxonómica de asimismo separarlos de S. brasiliensis. Proporcionamos datos en aditamento que indican que a falta de cualquier material tipo para S. defilippi, este nombre es en el mejor de los casos un nomen dubium. Finalmente, ofrecemos datos y evidencia apoyando nuestras decisiones de reconocer un mayor número de especies Neotropicales de Sylvilagus que previamente se conocían.

A dynamic continental moisture gradient drove Amazonian bird diversification

The Amazon is the primary source of Neotropical diversity and a nexus for discussions on processes that drive biotic diversification. Biogeographers have focused on the roles of rivers and Pleistocene climate change in explaining high rates of speciation. We combine phylogeographic and niche-based paleodistributional projections for 23 upland terra firme forest bird lineages from across the Amazon to derive a new model of regional biological diversification. We found that climate-driven refugial dynamics interact with dynamic riverine barriers to produce a dominant pattern: Older lineages in the wetter western and northern parts of the Amazon gave rise to lineages in the drier southern and eastern parts. This climate/drainage basin evolution interaction links landscape dynamics with biotic diversification and explains the east-west diversity gradients across the Amazon.

NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

Xenarthrans-anteaters, sloths, and armadillos-have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, 10 anteaters, and 6 sloths. Our data set includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the southern United States, Mexico, and Caribbean countries at the northern portion of the Neotropics, to the austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n = 5,941), and Cyclopes sp. have the fewest (n = 240). The armadillo species with the most data is Dasypus novemcinctus (n = 11,588), and the fewest data are recorded for Calyptophractus retusus (n = 33). With regard to sloth species, Bradypus variegatus has the most records (n = 962), and Bradypus pygmaeus has the fewest (n = 12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other data sets of Neotropical Series that will become available very soon (i.e., Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans data set. Please cite this data paper when using its data in publications. We also request that researchers and teachers inform us of how they are using these data.

Implicações da Adição de Própolis nas Propriedades Físico-Mecânicas do Cimento de Ionômero de Vidro

O objetivo do presente trabalho foi realizar uma revisão da literatura sobre as propriedades físico-mecânicas do cimento de ionômero de vidro (CIV) adicionado de própolis. Para essa finalidade, foi efetuada busca no banco de dados Medline/Pubmed, utilizando os descritores “propolis”, “glass ionomer cements” e “dental materials”, na língua inglesa, no período de 2009 a 2017. Foi encontrado um total de 7 artigos, dos quais foram selecionados 6 após leitura de títulos e resumos, considerando o idioma, o período e o grau de envolvimento do artigo com o tema em questão como critérios de inclusão/exclusão. Como resultados, verificou-se que, embora os estudos apontem melhora dos efeitos antimicrobianos a partir da associação entre a própolis e o CIV, seus efeitos sobre as propriedades físico-mecânicas do cimento ainda não são totalmente conhecidos. Nos artigos selecionados foram avaliadas propriedades como resistência à compressão, solubilidade e sorção de água, com alguns resultados controversos. Tendo em vista que o cimento de ionômero de vidro é um material muito útil e versátil na Odontologia e que a própolis tem sido cada vez mais adicionada a ele    em situações como no tratamento restaurador atraumático e na cimentação de bandas ortodônticas a fim de potencializar a ação antimicrobiana dos CIVs, ainda são necessárias pesquisas adicionais para melhor compreensão dessas peculiaridades.Palavras-chave: Propolis. Glass Ionomer Cements. Dental Materials.

Delimiting priority areas for the conservation of endemic and threatened Neotropical birds using a niche-based gap analysis

Knowledge of spatiotemporal distribution of biodiversity is still very incomplete in the tropics. This is one of the major problems preventing the assessment and effectiveness of conservation actions. Mega-diverse tropical regions are being exposed to fast and profound environmental changes, and the amount of resources available to describe the distribution of species is generally limited. Thus, the tropics is losing species at unprecedented rates, without a proper assessment of its biodiversity. Species distribution models (SDMs) can be used to fill such biogeographic gaps within a species' range and, when allied with systematic conservation planning (e.g. analyses of representativeness, gap analysis), help transcend such data shortage and support practical conservation actions. Within the Neotropics, eastern Amazon and northern Cerrado present a high variety of environments and are some of the most interesting ecotonal areas within South America, but are also among the most threatened biogeographic provinces in the world. Here, we test the effectiveness of the current system of Protected Areas (PAs), in protecting 24 threatened and endemic bird species using SDMs. We found that taxa with wider distributions are potentially as protected as taxa with smaller ranges, and larger PAs were more efficient than smaller PAs, while protecting these bird species. Nonetheless, Cerrado PAs are mostly misallocated. We suggest six priority areas for conservation of Neotropical birds. Finally, we highlight the importance of indigenous lands in the conservation of Neotropical biodiversity, and recommend the development of community management plans to conserve the biological resources of the region.

Coccidiosis in European rabbit (Oryctolagus cuniculus algirus) populations in the Iberian Peninsula

The European rabbit Oryctolagus cuniculus is a keystone species from the Iberian Peninsula where viral diseases have played a prominent role in regulating their populations. Coccidiosis, a parasitic disease caused primarily by Eimeria spp., is also thought to have important negative effects. However, few studies have investigated the impact of coccidia on wild European rabbit populations on the Iberian Peninsula. Here we estimate coccidian prevalence in rabbit faecal samples collected along transects established in two ecological regions. Six Eimeria species, with different pathogenicity, were identified (E. coecicola, E. perforans, E media, E. magna, E. irresidua and E. flavescens). Species diversity varied significantly between regions although mean oocyst excretion levels were generally low in both areas (57.61 s.d.±78.07 and 17.03 s.d.±27.72, oocyst per gram of rabbit faeces). This study is the first to describe the composition of the Eimeria spp. assemblage for wild rabbit populations on the Iberian Peninsula and provides fundamental information for future studies on the potential interaction of viral and parasitic diseases.

Effects of bromopride on expression of metalloproteinases and interleukins in left colonic anastomoses: an experimental study

Anastomotic dehiscence is the most severe complication of colorectal surgery. Metalloproteinases (MMPs) and interleukins (ILs) can be used to analyze the healing process of anastomosis. To evaluate the effects of bromopride on MMP and cytokine gene expression in left colonic anastomoses in rats with or without induced abdominal sepsis, 80 rats were divided into two groups for euthanasia on the third or seventh postoperative day (POD). They were then divided into subgroups of 20 rats for sepsis induction or not, and then into subgroups of 10 rats for administration of bromopride or saline. Left colonic anastomosis was performed and abdominal sepsis was induced by cecal ligation and puncture. A colonic segment containing the anastomosis was removed for analysis of gene expression of MMP-1α, MMP-8, MMP-13, IL-β, IL-6, IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ). On the third POD, bromopride was associated with increased MMP-1α, MMP-13, IL-6, IFN-γ, and IL-10 gene expression. On the seventh POD, all MMP transcripts became negatively modulated and all IL transcripts became positively modulated. In the presence of sepsis, bromopride administration increased MMP-8 and IFN-γ gene expression and decreased MMP-1, TNF-α, IL-6, and IL-10 gene expression on the third POD. On the seventh POD, we observed increased expression of MMP-13 and all cytokines, except for TNF-α. In conclusion, bromopride interferes with MMP and IL gene expression during anastomotic healing. Further studies are needed to correlate these changes with the healing process.

Cardiac effect of ischemic preconditioning and heparin following intestinal ischemia and reperfusion in rats

To study the role of heparin and ischemic preconditioning (IPC) in cardiac injury after intestinal ischemia (I) and reperfusion (R), 54 rats underwent 60 minutes of I, which was produced by occlusion of the superior mesenteric artery, and/or 120 minutes of R. The IPC group had the I procedure stimulation for 5 minutes and R for 10 minutes. The control group was subjected to sham surgery only, and the other groups were injected with saline solution (SS; 0.1 mL) or heparin (100 IU/kg) via the inferior cava vein 5 minutes before I and 5 minutes before R and 55 minutes after the R begins in I-R groups. In all animals, cardiac samples were stained with hematoxylin and eosin for optical microscopy analysis, and other sample was processed for lipid peroxidation determination. In I-R groups, both heparin and IPC showed significant protection compared to the SS group; conversely, in animals subjected only to I, no protection was observed. Moreover, when heparin was associated with IPC, I-R protection was compromised and the ischemic injury increased. Data showed that IPC and heparin attenuated cardiac dysfunction caused by intestinal I and I-R, but when used in association did not show beneficial effects.

[Neurophysiological and functional assessment of patients with difficult-to-control asthma]

INTRODUCTION

Due to the inadequate response to inhaled corticoids, patients with difficult-to-control asthma (DCA) are submitted to oral corticoids or use of Omalizumab. Although it is necessary to treat these patients, a significant relationship between steroid usage and both peripheral and respiratory weakness muscle, results in implications such as loss of quality of life and compromised lung function. Nonetheless, it is not known whether these patients suffer neurophysiological changes due to drug effect.

OBJECTIVE

To investigate the neurophysiological and functional characteristics of patients with DCA in order to gain a better understanding of the condition.

METHOD

A cross-sectional study was carried out involving three groups of patients: DCA-C (use of oral corticosteroids), DCA-O (use of omalizumab) and CG (healthy controls matched for age). The assessment involved the six-minute walk test, sit-to-stand test, static balance on a pressure platform, patellar and Achilles reflexes and quadriceps strength in the dominant leg.

RESULTS

The results revealed no statistically significant differences between the control group and DCA groups in relation to neurophysiological aspects. However, the DCA groups exhibited a significant reduction in functional capacity [decreased muscle strength (p < 0.05), shorter distance covered on walk test (p < 0.05) and lesser number of repetitions on sit-to-stand test (p < 0.05)] in comparison to the control group.

CONCLUSION

Individuals with DCA exhibited a reduction in functional capacity. The DCA-C group also demonstrated a reduction in muscle strength when compared with control group, likely caused by the continual use of corticoids. However, no neurophysiological alterations were found in the studied population.

Use of a new dual-antigen enzyme-linked immunosorbent assay to detect and characterize the human antibody response to the human immunodeficiency virus type 2 envelope gp125 and gp36 glycoproteins

A dual-antigen enzyme-linked immunosorbent assay specific for human immunodeficiency virus type 2 (HIV-2) envelope proteins, ELISA-HIV2, was developed with two new recombinant polypeptides, rpC2-C3 and rgp36, derived from the HIV-2 envelope. The diagnostic performance was determined with HIV-2, HIV-1, and HIV-1/2 samples. Both polypeptides showed 100% specificity. Clinical sensitivity was 100% for rgp36 and 93.4% for rpC2-C3. ELISA-HIV2 may be used for the specific diagnosis and confirmation of HIV-2 infection.

Basal forebrain neurons modulate the synthesis and expression of neuropeptides in the rat suprachiasmatic nucleus

We tested the hypothesis that efferents from the nucleus basalis magnocellularis (NBM) play a direct role in the regulation of neuropeptide synthesis and expression by neurons of the rat suprachiasmatic nucleus (SCN). Adult male rats in which the NBM was destroyed with quinolinic acid, either unilaterally or bilaterally, were compared with rats injected with physiological saline and with control rats. The estimators used to assess the effects of cholinergic deafferentation on the neuroanatomy and neurochemistry of the SCN were the total number of SCN neurons, the total number and somatic size of SCN neurons producing vasopressin (VP) and vasoactive intestinal polypeptide (VIP), and the respective mRNA levels. Bilateral destruction of the NBM did not produce cell death in the SCN, but caused a marked reduction in the number and somatic size of SCN neurons expressing VP and VIP, and in the mRNA levels of these peptides. The decrease in the number of VP- and VIP-producing neurons provoked by unilateral lesions was less striking than that resulting from bilateral lesions. It was, however, statistically significant in the ipsilateral hemisphere, but not in the contralateral hemisphere. The results show that the reduction of cholinergic inputs to the SCN impairs the synthesis, and thereby decreases the expression of neuropeptides by SCN neurons, and that the extent of the decline correlates with the amount of cholinergic afferents destroyed. This supports the notion that acetylcholine plays an important, and direct role in the regulation of the metabolic activity of SCN neurons.

Determination of lamotrigine simultaneously with carbamazepine, carbamazepine epoxide, phenytoin, phenobarbital, and primidone in human plasma by SPME-GC-TSD

A simple and rapid analytical method is presented for the determination of lamotrigine simultaneously with primidone, carbamazepine, carbamazepine epoxide, phenobarbital, and phenytoin in human plasma using solid-phase microextraction (SPME) and gas chromatography with thermionic specific detection. The best conditions for the SPME procedure is established as following: direct extraction on a 65-microm Carbowax-divinylbenzene fiber; 1.0 mL of a sample plasma matrix modified with 15% NaCl and 3 mL of a potassium phosphate buffer (pH 7.0); extraction temperature at 30 degrees C; and stirring at a rate of 2500 rpm for 15 min. The method shows good linearity between 0.05 and 40.0 microg/mL with regression coefficients ranging between 0.9965 and 0.9995 and a coefficient of variation of the points of the calibration curve lower than 10%. The lowest limit of quantitation for the plasma-investigated drugs varies from 0.05 to 0.20 microg/mL, according to the drug. The proposed method is sensitive enough to work into subtherapeutic and therapeutic concentrations, being that it is applied in pharmacokinetic studies and patient routine therapeutic drug monitoring.

Comparison between solid-phase extraction methods for the chromatographic determination of organophosphorus pesticides in water

A solid-phase microextraction (SPME) procedure has been developed to extract eight organophosphorus pesticides (OPs) in water and the method was compared with a conventional solid phase extraction (SPE) technique. The extracted OPs were analyzed by gas chromatography using thermionic specific detection. Both extraction methods presented linear calibration at least over the concentration range investigated (100 to 1000 ng x mL(-1) for SPE and 1 to 100 ng x mL(-1) for SPME). SPME method presented higher sensitivity than SPE. The quantitation limits were between 0.1 to 1.0 ng x mL(-1) for SPME depending upon the analyte, and 100 ng x mL(-1) for SPE. The precision, as measured by the standard deviations (RSD), were in the range 3.6% to 5.8% for SPME and 2.4% to 9.2% for SPE. Along with the feature of being a solvent - free sampling technique, SPME offers additional benefits due to its high sensitivity, simplicity, and small size sample required (typically: SPE - 500 mL, SPME - 5 mL).

Nerve growth factor restores mRNA levels and the expression of neuropeptides in the suprachiasmatic nucleus of rats submitted to chronic ethanol treatment and withdrawal

Chronic ethanol treatment and withdrawal from alcohol decrease the synthesis and expression of neuropeptides in the hypothalamic suprachiasmatic nucleus. Given the existing evidence that neurotrophins modulate the synthesis and expression of neurotransmitters/neuromodulators in the mature brain, we have hypothesized that such alterations might result from the reduced biological activity or brain content of neurotrophic factors. To test this possibility, nerve growth factor (NGF) was delivered intraventricularly, over a 4-week period, to rats submitted to ethanol treatment for 6 months and to withdrawn rats. Vasopressin (AVP) and vasoactive intestinal polypeptide (VIP), and the respective mRNAs were detected by immunocytochemistry and in situ hybridization histochemistry, and their levels estimated using stereological methods and densitometry. In ethanol-treated and withdrawn rats, NGF produced increases in the number of AVP- and VIP-immunostained neurons to values identical to those of controls. Corresponding variations were detected in AVP and VIP mRNA levels, which indicates that NGF restored the expression of AVP and VIP by enhancing neuropeptide synthesis. These findings show that NGF can correct the changes induced by chronic ethanol treatment and withdrawal in the gene expression and protein content of the neuropeptides synthesized by suprachiasmatic neurons. They also reveal that NGF plays an important role in the maintenance of the neurochemical phenotype of the suprachiasmatic nucleus in the adult rat. Because suprachiasmatic neurons do not express trkA, NGF might have exerted its effects either through direct signalling of suprachiasmatic neurons via p75(NTR) activation or, indirectly, by enhancing the activity of the cholinergic and/or glutamatergic afferents to the suprachiasmatic nucleus, or both.

CD4(+) T cells participate in the nephropathy of canine visceral leishmaniasis

Renal involvement in visceral leishmaniasis (VL) is very frequent. The renal lesions of humans and dogs are similar but their pathogenesis has not been clearly elucidated. There is growing evidence that the cellular immune response is involved in the pathogenesis of immunologically mediated glomerulonephritis. Since T cells could participate in the pathogenesis of nephropathy, in the present study we investigated the possible involvement of CD4(+) and CD8(+) T cells in the nephropathy of canine VL. Six dogs naturally infected with Leishmania (Leishmania) chagasi from the endemic area in the Northeast of Brazil, the town of Teresina in the State of Piauí, were studied. An expressive inflammatory infiltrate of CD4(+) T cells both in glomeruli and in interstitium was present in 4 animals and absent in 2. CD8(+) T cells were detected only in one animal. CD4(+) T cells alone were observed in 3 animals; when CD8+ T cells were present CD4(+) T cells were also present. CD4(+) T cells were observed in cases of focal segmental glomerulosclerosis, diffuse membranoproliferative glomerulonephritis, diffuse mesangial proliferative glomerulonephritis and crescentic glomerulonephritis. CD8(+) T cells were present only in a case of crescentic glomerulonephritis. Leishmania antigen was detected in glomeruli and in interstitial inflammatory infiltrate in 4 animals and immunoglobulins were observed in 4 dogs. In this study we observed that T cells, in addition to immunoglobulins, are present in the renal lesion of canine VL. Further studies are in progress addressing the immunopathogenic mechanisms involving the participation of immunoglobulins and T cells in canine VL nephropathy.

[Captopril use in pregnancy and its effects on the fetus and the newborn: case report]

Angiotensin-converting enzyme (ACE) inhibitors have been widely used to control hypertension, but their use during gestation may result in fetal death, intra-uterine growth retardation, oligoamnium sequence, hypotension, acute renal failure and ductus arteriosus patency in the newborn. The aim of this case report is to highlight the risks of using this drug during gestation. The authors present a case of captopril use during pregnancy, whose newborn developed acute renal failure and ductus arteriosus patency early in the newborn period. This presentation strengthens the importance of not only monitoring amniotic fluid volume and fetal growth, but also, during the newborn period, control the weight gain, diuresis, systemic arterial pressure and renal function, mainly in the first 72 hours of life.

Dietary deficiency or enrichment of essential fatty acids modulates tumorigenesis in the whole body of cobalt-60-irradiated mice

The effect of dietary polyunsaturated fatty acids (PUFAs) on whole body-induced tumorigenesis was assayed in mice fed on essential fatty acid sufficient (EFAS) or essential fatty acid deficient (EFAD) diets following cobalt-60 irradiation. Four groups of mice were maintained, one on a control stock diet and three on experimental diets: a) without added fat (fat free, FF); b) containing 5% olein (O), rich in n-9; and c) containing 5% corn oil, rich in n-6 EFA (CO). Only mice fed on FF or O diets showed clinical and biochemical signs of EFAD. Total incidence of tumors showed an increase in FF (P < 0.02) and O (P < 0.03) mice. Tumors developed mostly in the liver in each of the EFAD groups (P < 0.001). Slight promoting activity on lung tumorigenesis was recorded in the CO group when this parameter was compared in EFAD and EFA sufficient mice. It may be concluded that, when a tumor initiator injures the body as a whole, EFAD, achieved either through a fat-free or an oleic-supplemented diet, behaves as a general promoting condition for tumorigenesis. The borderline tumorigenic effect of n-6 corn oil on the lungs suggests that this effect, when present, is target specific.

[Postural tremor and dystonia. Clinical aspects and physiopathological considerations]

The coexistence of tremor and dystonia is usually seen but there is not a satisfactory explanation for it. Some consider that essential tremor (ET) and idiopathic dystonia (ID) may be genetically linked. To clarify this relationship we evaluated the frequency of postural hand tremor in ID and symptomatic dystonia (SD) patients. We studied the records of patients with dystonia seen in our Movement Disorders Unit. ID was considered when there was no other neurological abnormality in the examination aside from dystonia, normal laboratorial tests and neuroimaging related to dystonia, and a negative past history for any known cause for it, except for genetic predisposition. We analyzed the clinical characteristics of dystonia and the occurrence of postural tremor. We collected 185 patients, being 120 with ID and 65 with SD. Tremor was seen in 27 (22.5%) of ID and 14 (21.5%) of SD. Tremor was present in either focal, segmental or generalized dystonia in both ID and SD. Family history for ET was absent in all patients. The similar frequency of tremor in ID and SD patients suggests that the pathophysiologic derangement resulting in dystonia can favor the development of tremor.

Poisoning by chemical non-medicinal products in Brazil: clinical and laboratory findings in 132 patients

One hundred and thirty-two patients with suspected exogenous intoxication were analysed according to clinical manifestation and toxicological results. Detection of toxic substances was performed in blood, urine and cerebrospinal fluid. The greatest occurrence of chronic exogenous intoxication was in males aged 21 to 50 years old. Peasants and industrial workers were the most affected. 70% of all patients showed neurological manifestations. There was clear predominance of central nervous system impairment associated with poisoning with herbicides and organophosphates.

[Variations in peripheral blood cells levels found in Holochilus brasiliensis nanus Thomas, 1897, infected with Trypanosoma cruzi Sambon, 1907, from pre-Amazonia]

Foram constituídos quatro grupos de roedores silvestres para a contagem de células sangüíneas periféricas, da seguinte forma: Grupo I - formado de animais normais, nascidos em biotério, com 30 dias de vida; Grupo II - formado de animais que foram capturados no campo e considerados não infectados com S. mansoni, após ovohelmintoscopia das fezes, realizada durante 30 dias de observação; Grupo III - animáis capturados no campo, nautralmente infectados com o esquistossomo, e o Grupo IV - de animais nascidos em biotério, com 30 dias de vida, e infectados com 150 cercárias de S. mansoni, oriundas da Região da Baixada Maranhense. Semanalmente, a partir da data da infecção, estes animais foram sangrados e tiveram suas células sangüíneas periféricas contadas global e especificamente. Os resultados mostraram que o número de hemácias e leucócitos por mm³ não variou nos animais normais, tanto de campo como de biotério. No grupo de animais experimentalmente infectados, foi observado decréscimo do número de hemácias à proporção que a infecção evoluia. Comportamento oposto foi verificado com os leucócitos. Elevados níveis de eosinófilos só foram observados nos animais com infecção natural. Estes resultados foram discutidos com dados da literatura e considerados importantes para complementar as informações sobre este hospedeiro natural do trematódeo, oferecido como modelo experimental do verme, e para sua própria história natural.

Isolation and characterization of collagen-synthesizing polysomes from chick embryos

Collagen-synthesizing polysomes were isolated by low-speed centrifugation of the post-mitochondrial supernatant of chick homogenates. Electron microscopy of the fraction thus isolated shows it to be exclusively composed of ribosomes. Amino acid incorporation in vitro showed that these particles were efficient in the incorporation of proline, but not tryptophan, as opposed to ribosomes obtained from the supernatant of the low-speed centrifugation. The incorporation process was highly dependent on GTP, and exibited an optimal Mg2+concentration of 5.6mM. The reaction was inhibited by RNase, elongation inhibitors as anysomycin, sparsomycin, fusidic acid and GDPCP. It was also moderately inhibited by initiation inhibitors such as aurintricarboxilic acid and pyrocatechol violet. The product of the incorporation was characterized as collagen by its sensitivity towards purified collagenase, lack of tryptophan, chromatography in CM-cellulose and molecular sieve chromatography in Sephadex G-200.