507 research outputs found
Foraging Activity of Xylocopa cearensis (Ducke) in Sand Dune Landscape
Bees foraging strategy is affected by the distribution and abundance of flower resources, mainly nectar and pollen. Homing-time of female Xylocopa cearensis (Ducke) bees to their nests was assessed through a simple translocation method. The hypothesis addressed was that resource distribution in the landscape level influences bee homing time. The study area comprises about 300ha in a sand dune field with patchy shrubs in Salvador, Bahia, Brazil. The mean homing time after translocation was 60 min (sd = 4.36 min; n= 03), except for one bee that did not returned. The translocation technique was successfully applied to large solitary bees, since they do return to their own nest and can be easily recognized when arriving. Also, bees returned carrying pollen, what suggests foraging activity after translocations. Results evidence landscape functional connectivity since bees were able to move through local habitats. Further studies should address movement cost tradeoffs and its consequences on bee diversity conservation
Histopathological and parasitological study of the gastrointestinal tract of dogs naturally infected with Leishmania infantum
<p>Abstract</p> <p>Background</p> <p>The aim of this study was to provide a systematic pathological and parasitological overview of the gastrointestinal tract (GIT), including the stomach, duodenum, jejunum, ileum, caecum and colon, of dogs naturally infected with <it>Leishmania</it>.</p> <p>Methods</p> <p>Twenty mongrel dogs naturally infected with <it>Leishmania (Leishmania) infantum </it>and obtained from the Control Zoonosis Center of the Municipality of Ribeirão das Neves, Belo Horizonte Metropolitan area, Minas Gerais (MG) state, Brazil, were analyzed. The dogs were divided into two groups: Group 1 comprised nine clinically normal dogs and group 2 comprised 11 clinically affected dogs. After necropsy, one sample was collected from each GIT segment, namely the stomach, duodenum, jejunum, ileum, caecum and colon. Furthermore, paraffin-embedded samples were used for histological and parasitological (immunohistochemistry) evaluation and a morphometrical study were carried out to determine the parasite load (immunolabeled amastigote forms of <it>Leishmania</it>). The Friedman and the Mann Whitney tests were used for statistical analysis. The Friedman test was used to analyze each segment of the GIT within each group of dogs and the Mann Whitney test was used to compare the GIT segments between clinically unaffected and affected dogs.</p> <p>Results</p> <p>The infected dogs had an increased number of macrophages, plasma cells and lymphocytes, but lesions were generally mild. Parasite distribution in the GIT was evident in all intestinal segments and layers of the intestinal wall (mucosal, muscular and submucosal) irrespective of the clinical status of the dogs. However, the parasite load was statistically higher in the caecum and colon than in other segments of the GIT.</p> <p>Conclusion</p> <p>The high parasite burden evident throughout the GIT mucosa with only mild pathological alterations led us to consider whether <it>Leishmania </it>gains an advantage from the intestinal immunoregulatory response (immunological tolerance).</p
Chemical constituents of Cardiospermum corindum L. and their distribution in Sapindaceae
AbstractPhytochemical investigation on the aerial parts of Cardiospermum corindum L. led to the isolation of two triterpenes [friedelin (1) and friedelinol (2)], two coumarins, [umbelliferone (4) and scopoletin (5)], three methoxylated flavones [umuhengerin (3), luteolin 3’,4’-dimethyl ether (6) and chrysoeriol (7)], one non-cyanogenic glucoside [epidermin (8)] and one cyclitol [(L)-quebrachitol (9)]. To our knowledge, 2, 3, 6 and 8 were isolated for the first time within Sapindaceae. Of these classes of metabolites, the distribution of methoxylated flavonoids in Cardiospermum is reviewed, including the new records, indicating that polymethoxylated flavonoid (3) may be value as chemotaxonomic markers for this genus
Integrated process production and extraction of the fibrinolytic protease from Bacillus sp. UFPEDA 485
Fibrinolytic proteases are enzymes that degrade fibrin; these enzymes are a promising alternative for thrombolytic therapy, and microorganisms produce them. The aim of this study was to evaluate the optimum conditions for the integrated production and purification of fibrinolytic protease from Bacillus sp. UFPEDA 485. Extractive fermentation was carried out in a culture medium containing soybean flour and by adding polyethylene glycol (PEG) and Na2SO4 according to a 23 experimental design. In all assays, the enzyme preferentially partitioned to the bottom phase (K < 1), with an optimum activity of 835 U ml−1 in the bottom phase (salt-rich phase). The best conditions for extractive fermentation were obtained with 18 % PEG 8000 and 13 % Na2SO4. Characterization showed that it is a metalloprotease, as a strong inhibition—residual activity of 3.13 %—occurred in the presence of ethylenediaminetetraacetic acid. It was also observed that enzymatic activity was stimulated in the presence of ions: CaCl2 (440 %), MgCl2 (440 %), FeSO4 (268 %), and KCl (268 %). The obtained results indicate that the use of a low-cost substrate and the integration of fermentation with an aqueous two-phase system extraction may be an interesting alternative for the production of fibrinolytic protease.The authors thank CAPES (National Council for the Improvement of Higher Education) for the scholarship and CNPq (National Counsel of Technological and Scientific Development) and RENORBIO for the financial support
Myosteatosis in a systemic inflammation-dependent manner predicts favorable survival outcomes in locally advanced esophageal cancer
Increased adiposity and its attendant metabolic features as well as systemic inflammation have been associated with prognosis in locally advanced esophageal cancer (LAEC). However, whether myosteatosis and its combination with systemic inflammatory markers are associated with prognosis of esophageal cancer is unknown. Our study aimed to investigate the influence of myosteatosis and its association with systemic inflammation on progression-free survival (PFS) and overall survival (OS) in LAEC patients treated with definitive chemoradiotherapy (dCRT). We retrospectively gathered information on 123 patients with LAEC submitted to dCRT at the University of Campinas Hospital. Computed tomography (CT) images at the level of L3 were analyzed to assess muscularity and adiposity. Systemic inflammation was mainly measured by calculating the neutrophil-to-lymphocyte ratio (NLR). Median PFS for patients with myosteatosis (n = 72) was 11.0 months vs 4.0 months for patients without myosteatosis (n = 51) (hazard ratio [HR]: 0.53; 95% confidence interval [CI], 0.34-0.83; P = .005). Myosteatosis was also independently associated with a favorable OS. Systemic inflammation (NLR > 2.8) was associated with a worse prognosis. The combination of myosteatosis with systemic inflammation revealed that the subgroup of patients with myosteatosis and without inflammation presented less than half the risk of disease progression (HR: 0.47; 95% CI: 0.26-0.85; P = .013) and death (HR: 0.39; 95% CI, 0.21-0.72; P = .003) compared with patients with inflammation. This study demonstrated that myosteatosis without systemic inflammation was independently associated with favorable PFS and OS in LAEC patients treated with dCRT81669676976FAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulo2018/23428-
Pregnancy outcomes in women with repeated implantation failures after intracytoplasmic morphologically selected sperm injection (IMSI)
<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to compare laboratory and clinical outcomes of intracytoplasmic morphologically selected sperm injection (IMSI) and conventional intracytoplasmic sperm injection (ICSI) in couples with repeated implantation failures.</p> <p>Methods</p> <p>A total of 200 couples with at least two prior unsuccessful ICSI cycles were enrolled: 100 couples were submitted to IMSI and 100 were submitted to routine ICSI. For IMSI, spermatozoa were selected at 8400× magnification using an inverted microscope equipped with Nomarski (differential interference contrast) optics. For conventional ICSI, spermatozoa were selected at 400× magnification. Clinical outcomes were evaluated between the two groups.</p> <p>Results</p> <p>Study patients were comparable in age, number of treatment failures, aetiology of infertility, percentage of normal form assessed by MSOME (motile sperm organelle morphology examination), semen parameters, total number of oocytes collected, number of mature oocytes collected, total number of embryos transferred and number of high-quality embryos transferred. No statistically significant differences between the two groups were observed with regard to rates of fertilisation, implantation and pregnancy/cycle. Although not statistically significant, rates of miscarriage (IMSI:15.3% vs ICSI:31.7%), ongoing pregnancy (IMSI:22% vs ICSI:13%) and live births (IMSI:21% vs ICSI:12%) showed a trend towards better outcomes in the IMSI group. In addition, analysis of subpopulations with or without male factor showed similar results.</p> <p>Conclusions</p> <p>Our results suggest that IMSI does not provide a significant improvement in clinical outcome compared to ICSI, at least in couples with repeated implantation failures after conventional ICSI. However, it should be noted that there were clear trends for lower miscarriage rates (≈50% reduced) and higher rates of ongoing pregnancy and live births (both nearly doubled) within the IMSI group. Further confirmation as well as randomized large-scale trials are needed to confirm the beneficial effects of IMSI in couples with poor reproductive prognoses.</p
IVF/ICSI outcomes after culture of human embryos at low oxygen tension: a meta-analysis
<p>Abstract</p> <p>Background</p> <p>Improved pregnancy, implantation, and birth rates have been reported after the use of reduced O2 concentration during embryo culture, mainly due to a reduction of the cumulative detrimental effects of reactive oxygen species. However, some studies have failed to report any positive effects. The objective of this meta-analysis was to evaluate the effect of a low-O2 environment on IVF/intracytoplasmic sperm injection (ICSI) outcomes.</p> <p>Methods</p> <p>All available published and ongoing randomised trials that compared the effects of low (~5%; OC~5) and atmospheric (~20%; OC~20) oxygen concentrations on IVF/ICSI outcomes were included. Search strategies included online surveys of databases from 1980 to 2011. The outcomes measured were fertilisation rate, implantation rate and ongoing pregnancy rates. The fixed effects model was used to calculate the odds ratio.</p> <p>Results</p> <p>Seven studies were included in this analysis. The pooled fertilisation rate did not differ significantly (<it>P </it>= 0.54) between the group of oocytes cultured at low O2 tension and the group at atmospheric O2 tension. Concerning all cycles, the implantation (<it>P </it>= 0.06) and ongoing pregnancy (<it>P </it>= 0.051) rates were not significantly different between the group receiving transferred sets containing only OC~5 embryos and the group receiving transferred sets with only OC~20 embryos. In a meta-analysis performed for only those trials in which embryos were transferred on day 2/3, implantation (<it>P </it>= 0.63) and ongoing pregnancy (<it>P </it>= 0.19) rates were not significantly different between the groups. In contrast, when a meta-analysis was performed using only trials in which embryos were transferred on days 5 and 6 (at the blastocyst stage), the group with transferred sets of only OC~5 embryos showed a statistically significantly higher implantation rate (<it>P </it>= 0.006) than the group receiving transferred sets with only OC~20 embryos, although the ongoing pregnancy (<it>P </it>= 0.19) rates were not significantly different between the groups.</p> <p>Conclusions</p> <p>Despite some promising results, it seems too early to conclude that low O2 culture has an effect on IVF outcome. Additional randomised controlled trials are necessary before evidence-based recommendations can be provided. It should be emphasised that the present meta-analysis does not provide any evidence that low oxygen concentration is unnecessary.</p
Regulation of Amyloid Oligomer Binding to Neurons and Neurotoxicity by the Prion Protein-mGluR5 Complex
The prion protein (PrPC) has been suggested to operate as a scaffold/receptor protein in neurons, participating in both physiological and pathological associated events. PrPC, laminin, and metabotropic glutamate receptor 5 (mGluR5) form a protein complex on the plasma membrane that can trigger signaling pathways involved in neuronal differentiation. PrPC and mGluR5 are co-receptors also for -amyloid oligomers (AOs) and have been shown to modulate toxicity and neuronal death in Alzheimer\u27s disease. In the present work, we addressed the potential crosstalk between these two signaling pathways, laminin-PrPC-mGluR5 or AO-PrPC-mGluR5, as well as their interplay. Herein, we demonstrated that an existing complex containing PrPC-mGluR5 has an important role in AO binding and activity in neurons. A peptide mimicking the binding site of laminin onto PrPC (Ln-1) binds to PrPC and induces intracellular Ca2+ increase in neurons via the complex PrPC-mGluR5. Ln-1 promotes internalization of PrPC and mGluR5 and transiently decreases AO biding to neurons; however, the peptide does not impact AO toxicity. Given that mGluR5 is critical for toxic signaling by AOs and in prion diseases, we tested whether mGlur5 knock-out mice would be susceptible to prion infection. Our results show mild, but significant, effects on disease progression, without affecting survival of mice after infection. These results suggest that PrPC-mGluR5 form a functional response unit by which multiple ligands can trigger signaling. We propose that trafficking of PrPC-mGluR5 may modulate signaling intensity by different PrPC ligands
Mental health problems and smoking among adolescents from Southern Brazil
OBJECTIVE: To analyze the association between mental health problems and smoking in adolescents. METHODS: A total of 4,325 adolescents aged 15 from the 1993 birth cohort of the city of Pelotas, Southern Brazil, was studied. Smoking was defined as having smoked one or more cigarettes in the previous 30 days. Mental health was assessed according to the total score of the Strengths and Difficulties Questionnaire. Score >; 20 points was considered positive. Data were analyzed using Poisson regression with adjustment for robust variance. RESULTS: Smoking prevalence was 6.0% and about 30% of the adolescents presented some mental health problem. In the crude analysis, the prevalence ratio for smoking was 3.3 (95%CI 2.5; 4.2). After the adjusted analysis (for sex, age, skin color, family income, mother's level of schooling, group of friends who smoke, employment in the previous year, school failure, physical activity during leisure time and experimental use of alcohol), it decreased to 1.7 (95%CI 1.2; 2.3) among those with mental health problem. CONCLUSIONS: Mental health problems in adolescence may be related to tobacco consumption.OBJETIVO: Analisar a associação entre problemas de saúde mental e uso de tabaco em adolescentes. MÉTODOS: Foram analisados 4.325 adolescentes de 15 anos da coorte de nascimentos de 1993 da cidade de Pelotas, RS. Tabagismo foi definido como fumar um ou mais cigarros nos últimos 30 dias. Saúde mental foi avaliada de acordo com o escore total do questionário Strengths and Difficulties Questionnaire e escore maior ou igual a 20 pontos foi considerado como positivo. Os dados foram analisados por regressão de Poisson, com ajuste robusto para variância. RESULTADOS: A prevalência de tabagismo foi 6,0% e cerca de 30% dos adolescentes apresentaram algum tipo de problema de saúde mental. Na análise bruta, a razão de prevalências para tabagismo foi de 3,3 (IC95% 2,5; 4,2). Após ajuste (para sexo, idade, cor da pele, renda familiar, escolaridade da mãe, grupo de amigos fumantes, trabalho no último ano, repetência escolar, atividade física de lazer e uso experimental de bebida alcoólica), diminuiu para 1,7 (IC95% 1,2; 2,3) entre aqueles com problemas de saúde mental. CONCLUSÕES: Problemas de saúde mental na adolescência podem ter relação com o consumo de tabaco.OBJETIVO: Analizar la asociación entre problemas de salud mental y uso de cigarro en adolescentes. MÉTODOS: Se analizaron 4.325 adolescentes de 15 años de la cohorte de nacimientos de 1993 de la ciudad de Pelotas, Sur de Brasil. Tabaquismo fue definido como fumar uno o más cigarros en los últimos 30 días. Salud mental fue evaluada de acuerdo con el escore total del cuestionario Strengths and Difficulties Questionnaire y escore mayor o igual a 20 puntos fue considerado como positivo. Los datos fueron analizados por regresión de Poisson, con ajuste robusto para varianza. RESULTADOS: La prevalencia de tabaquismo fue 6,0% y cerca de 30% de los adolescentes presentaron algún tipo de problema de salud mental. En el análisis bruto, la tasa de prevalencias de problema de tabaquismo de 3,3 (IC95% 2,5;4,2). Posterior al ajuste para sexo, edad, color de la piel, renta familiar, escolaridad de la madre, grupo de amigos fumadores, trabajo en el último año, repitencia escolar, actividad física de ocio y uso experimental de bebida alcohólica, disminuyó a 1,7 (IC95% 1,2;2,3) entre aquellos con problemas de salud mental. CONCLUSIONES: Problemas de salud mental en la adolescencia pueden tener relación con el consumo de tabaco
Sustainable intensification using irrigation and N fertilization for pasture production in Tocantins, Brazil.
To verify the influence of irrigation in a pasture of Panicum maximum cv. Massai was carried out a field research testing rainfed and two irrigation depths (SO and 100% of evapotranspiration) and 300 kg ha-1 year-1 of N-urea, during one year at the periods Jun-Sep, Oct-Nov, Dec-Mar and Apr-May, in Tocantins state, Brazil
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