561 research outputs found

    Contribution of midgut bacteria to blood digestion and egg production in aedes aegypti (diptera: culicidae) (L.)

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    <p>Abstract</p> <p>Background</p> <p>The insect gut harbors a variety of microorganisms that probably exceed the number of cells in insects themselves. These microorganisms can live and multiply in the insect, contributing to digestion, nutrition, and development of their host.</p> <p>Recent studies have shown that midgut bacteria appear to strengthen the mosquito's immune system and indirectly enhance protection from invading pathogens. Nevertheless, the physiological significance of these bacteria for mosquitoes has not been established to date. In this study, oral administration of antibiotics was employed in order to examine the contribution of gut bacteria to blood digestion and fecundity in <it>Aedes aegypti</it>.</p> <p>Results</p> <p>The antibiotics carbenicillin, tetracycline, spectinomycin, gentamycin and kanamycin, were individually offered to female mosquitoes. Treatment of female mosquitoes with antibiotics affected the lysis of red blood cells (RBCs), retarded the digestion of blood proteins and reduced egg production. In addition, antibiotics did not affect the survival of mosquitoes. Mosquito fertility was restored in the second gonotrophic cycle after suspension of the antibiotic treatment, showing that the negative effects of antibiotics in blood digestion and egg production in the first gonotrophic cycle were reversible.</p> <p>Conclusions</p> <p>The reduction of bacteria affected RBC lysis, subsequently retarded protein digestion, deprived mosquito from essential nutrients and, finally, oocyte maturation was affected, resulting in the production of fewer viable eggs. These results indicate that <it>Ae. aegypti </it>and its midgut bacteria work in synergism to digest a blood meal.</p> <p>Our findings open new possibilities to investigate <it>Ae. aegypti</it>-associated bacteria as targets for mosquito control strategies.</p

    Use of the checkerboard DNA-DNA hybridization technique for bacteria detection in Aedes aegypti (Diptera:Culicidae) (L.)

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    <p>Abstract</p> <p>Background</p> <p>Bacteria associated with insects can have a substantial impact on the biology and life cycle of their host. The checkerboard DNA-DNA hybridization technique is a semi-quantitative technique that has been previously employed in odontology to detect and quantify a variety of bacterial species in dental samples. Here we tested the applicability of the checkerboard DNA-DNA hybridization technique to detect the presence of <it>Aedes aegypti</it>-associated bacterial species in larvae, pupae and adults of <it>A. aegypti</it>.</p> <p>Findings</p> <p>Using the checkerboard DNA-DNA hybridization technique we could detect and estimate the number of four bacterial species in total DNA samples extracted from <it>A. aegypti </it>single whole individuals and midguts. <it>A. aegypti </it>associated bacterial species were also detected in the midgut of four other insect species, <it>Lutzomyia longipalpis, Drosophila melanogaster</it>, <it>Bradysia hygida </it>and <it>Apis mellifera</it>.</p> <p>Conclusions</p> <p>Our results demonstrate that the checkerboard DNA-DNA hybridization technique can be employed to study the microbiota composition of mosquitoes. The method has the sensitivity to detect bacteria in single individuals, as well as in a single organ, and therefore can be employed to evaluate the differences in bacterial counts amongst individuals in a given mosquito population. We suggest that the checkerboard DNA-DNA hybridization technique is a straightforward technique that can be widely used for the characterization of the microbiota in mosquito populations.</p

    Anatomical alterations in plants of Chorisia speciosa A. St.-Hil submitted to flooding

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    An experiment was carried out in order to study the morpho-anatomical responses of plants of Chorisia speciosa to flooding. Plants were maintained in well-drained and flooded soils for 45 days. The flooded plants grew less than the control and formed a great number of hypertrophied lenticels. Flooding caused death of part of the original roots and the remaining roots exhibited low regeneration capacity. The stem base of flooded plants showed a thicker cortex, narrower vessel members and a lower number of sclerenchyma bundles than the control. In the transition region of flooded plants hypertrophied lenticels, hair and root primordia were observed. Although vegetative growth was reduced in flooded plants, the species presented morpho-anatomical plasticity, which could contribute to its tolerance to flooding.25943644

    Testing for sexually transmitted infections in general practice: cross-sectional study

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    Background: Primary care is an important provider of sexual health care in England. We sought to explore the extent of testing for chlamydia and HIV in general practice and its relation to associated measures of sexual health in two contrasting geographical settings.Methods: We analysed chlamydia and HIV testing data from 64 general practices and one genitourinary medicine (GUM) clinic in Brent (from mid-2003 to mid-2006) and 143 general practices and two GUM clinics in Avon (2004). We examined associations between practice testing status, practice characteristics and hypothesised markers of population need (area level teenage conception rates and Index of Multiple Deprivation, IMD scores).Results: No HIV or chlamydia testing was done in 19% (12/64) of general practices in Brent, compared to 2.1% (3/143) in Avon. In Brent, the mean age of general practitioners (GPs) in Brent practices that tested for chlamydia or HIV was lower than in those that had not conducted testing. Practices where no HIV testing was done had slightly higher local teenage conception rates (median 23.5 vs. 17.4/1000 women aged 15-44, p = 0.07) and served more deprived areas (median IMD score 27.1 vs. 21.8, p = 0.05). Mean yearly chlamydia and HIV testing rates, in practices that did test were 33.2 and 0.6 (per 1000 patients aged 15-44 years) in Brent, and 34.1 and 10.3 in Avon, respectively. In Brent practices only 20% of chlamydia tests were conducted in patients aged under 25 years, compared with 39% in Avon.Conclusions: There are substantial geographical differences in the intensity of chlamydia and HIV testing in general practice. Interventions to facilitate sexually transmitted infection and HIV testing in general practice are needed to improve access to effective sexual health care. The use of routinely-collected laboratory, practice-level and demographic data for monitoring sexual health service provision and informing service planning should be more widely evaluated

    Contribution of microscopy for understanding the mechanism of action against trypanosomatids

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    Transmission electron microscopy (TEM) has proved to be a useful tool to study the ultrastructural alterations and the target organelles of new antitrypanosomatid drugs. Thus, it has been observed that sesquiterpene lactones induce diverse ultrastructural alterations in both T. cruzi and Leishmania spp., such as cytoplasmic vacuolization, appearance of multilamellar structures, condensation of nuclear DNA, and, in some cases, an important accumulation of lipid vacuoles. This accumulation could be related to apoptotic events. Some of the sesquiterpene lactones (e.g., psilostachyin) have also been demonstrated to cause an intense mitochondrial swelling accompanied by a visible kinetoplast deformation as well as the appearance of multivesicular bodies. This mitochondrial swelling could be related to the generation of oxidative stress and associated to alterations in the ergosterol metabolism. The appearance of multilamellar structures and multiple kinetoplasts and flagella induced by the sesquiterpene lactone psilostachyin C indicates that this compound would act at the parasite cell cycle level, in an intermediate stage between kinetoplast segregation and nuclear division. In turn, the diterpene lactone icetexane has proved to induce the external membrane budding on T. cruzi together with an apparent disorganization of the pericellar cytoskeleton. Thus, ultrastructural TEM studies allow elucidating the possible mechanisms and the subsequent identification of molecular targets for the action of natural compounds on trypanosomatids.Fil: Lozano, Esteban Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Spina Zapata, Renata María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Barrera, Patricia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Tonn, Carlos Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Sosa Escudero, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentin

    The Portuguese Society of Rheumatology position paper on the use of biosimilars

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    Biotechnological drugs have become a fundamental resource for the treatment of rheumatic patients. Patent expiry of some of these drugs created the opportunity for biopharmaceutical manufacturers to develop biosimilar drugs intended to be as efficacious as the originator product but with a lower cost to healthcare systems. Due to the complex manufacturing process and highly intricate structure of biologicals, a biosimilar can never be an exact copy of its reference product. Consequently, regulatory authorities issued strict preclinical and clinical guidelines to ensure safety and efficacy equivalence and, in September 2013, the biosimilar of infliximab was the first biosimilar monoclonal antibody to be authorized for use in the European Union. The current document is a position statement of the "Sociedade Portuguesa de Reumatologia" (Portuguese Society of Rheumatology) on the use of biosimilar drugs in rheumatic diseases. Two systematic literature reviews were performed, one concerning clinical trials and the other one concerning international position papers on biosimilars. The results were presented and discussed in a national meeting and a final position document was discussed, written and approved by Portuguese rheumatologists. Briefly, this position statement is contrary to automatic substitution of the originator by the biosimilar, defends either a different INN or the prescription by brand name, supports that switching between biosimilars and the originator molecule should be done after at least 6 months of treatment and based on the attending physician decision and after adequate patient information, recommends the registration of all biosimilar treated patients in Reuma.pt for efficacy, safety and immunogenicity surveillance, following the strategy already ongoing for originators, and opposes to extrapolation of indications approved to the originator to completely different diseases and/or age groups without adequate pre-clinical, safety or efficacy data.info:eu-repo/semantics/publishedVersio

    Homemade oral supplement: a proposal for the nutritional recovery of children and adolescents with cancer

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    Objective The aim of this study was to evaluate the impact of homemade oral supplements on the nutritional recovery of patients with mild or severe malnutrition or at nutritional risk. Methods Eight recipes of homemade oral supplements containing 30% to 35% of the total energy expenditure were proposed. The patients with severe malnutrition (group B) received the oral supplement for 2 weeks and the others for 4 weeks (group A). Oral supplementation with homemade supplements was compared with oral supplementation with store-bought supplements, investigated earlier with a protocol with the same design. Results Homemade oral supplements contain much lower amounts of certain micronutrients but are five times cheaper than store-bought supplements. In group A, 88% of the patients taking homemade oral supplements and 84% of the patients taking store-bought supplements responded positively to supplementation. In group B, 22% of the patients taking homemade oral supplements and 25% of the patients taking store-bought supplements recovered. The difference was not significant. The impact of store-bought supplementation on the triceps skinfold thicknesses and arm circumferences of the patients in group A was greater than that obtained with homemade supplements. In group B, the effect on triceps skinfold thickness was not significant (p=0.16). Patients taking homemade or store-bought oral supplements presented similar protein and energy intakes and improvements in nutritional status. Only the body composition of patients in group A taking store-bought oral supplements was better. Conclusion The results obtained by this study suggest that the therapeutic use of homemade oral supplements is an alternative capable of promoting the nutritional recovery of cancer patients, especially those who cannot afford store-bought supplements.Objetivo Avaliar o impacto do suplemento oral artesanal na recuperação do estado nutricional de pacientes com desnutrição leve, grave e com risco nutricional. Métodos Propuseram-se oito receitas de suplementos visando ofertar entre 30,0% e 35,0% do gasto energético total. Os pacientes com desnutrição grave (grupo B) receberam o suplemento oral por duas semanas, e os demais pacientes (grupo A), por quatro semanas. Para a comparação dos resultados obtidos com o emprego do suplemento oral artesanal, foram utilizados dados referentes a um protocolo anterior, com o mesmo desenho, entretanto, com a utilização de suplemento oral industrializado. Resultados O suplemento oral artesanal fica muito aquém no que diz respeito a alguns micronutrientes, entretanto é cinco vezes mais barato do que a preparação com o suplemento oral industrializado. Os pacientes do grupo A com suplemento oral artesanal apresentaram 88,0% de resposta positiva na semana de avaliação, enquanto os com suplemento oral industrializado tiveram 84,0%. No grupo B, foram recuperados 22,0% dos pacientes com suplemento oral artesanal e 25,0% do grupo com suplemento oral industrializado, não apresentando, portanto, diferença significante. Comparando o impacto do industrializado com o do artesanal na prega cutânea tricipital e circunferência do braço, verificou-se que o suplemento oral industrializado no grupo A apresentou melhores resultados que o suplemento oral artesanal, e no grupo B, esse efeito observado na prega cutânea não foi significante (p=0,16). Os consumos de energia e de proteína, assim como a evolução nutricional, foram semelhantes entre suplemento oral industrializado e suplemento oral artesanal. Apenas a composição corpórea no grupo A com suplemento oral industrializado apresentou melhores resultados. Conclusão Os resultados apresentados neste estudo sugerem que o emprego da terapia com suplemento artesanal seja uma opção capaz de auxiliar na recuperação nutricional de pacientes oncológicos e uma opção para populações financeiramente desfavorecidas.Hospital Samaritano de São PauloInstituto Adriana GarófoloUniversidade Federal de São Paulo (UNIFESP) Departamento de Pediatria Instituto de Oncologia PediátricaUniversidade Federal de São Paulo (UNIFESP) Departamento de PediatriaUNIFESP, Depto. de Pediatria Instituto de Oncologia PediátricaUNIFESP, Depto. de PediatriaSciEL
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