595 research outputs found
Larval anatomy of monotypic painted ant nest frogs Lithodytes lineatus reveals putative homoplasies with the Leptodactylus pentadactylus group (Anura: Leptodactylidae)
The morphological diversity of anuran larvae made them an important source of information for evolutionary and systematic studies. For the monotypic frog genus Lithodytes, which has an interesting taxonomic history, including its past synonymizing with Adenomera and its placement as a subgenus of Leptodactylus, the information provided from its larvae can help to understand its systematics interrelationships and also provide insights about its evolutionary trajectories. Herein, we provide a detailed description of the larval morphology of Lithodytes lineatus, including novel data of internal morphology (buccopharyngeal cavity and skeleton), and discuss some morphological and evolutionary aspects in relation to other members of the subfamily Leptodactylinae. Despite the overall similar larval morphology with others members of the subfamily, we identified four autapomorphic traits for Lithodytes and seven purported homoplastic traits with a subclade of the Leptodactylus pentadactylus species group that likely evolved convergently. Some of these traits have been previously associated with a carnivorous diet. Putative homoplastic and autapomorphic characters served as additional diagnostic traits for Lithodytes, supporting its recognition as a distinct genus within Leptodactylidae
Tadpole of the Amazonia frog Edalorhina perezi (Anura: Leptodactylidae) with description of oral internal and chondrocranial morphology
The genus Edalorhina consists of two species of small forest-floor frogs inhabiting the Amazon basin. The tadpole of Edalorhina perezi, the most widely distributed species, was previously described based on a single and early stage (Gosner 25) individual. Herein, we provide a description of the tadpole in Gosner stages 35–36 including internal morphology data (i.e., buccopharyngeal cavity and larval skeleton) based on samples from two populations from Ecuador. Edalorhina shares a generalized morphology with most members of its closely related taxa; however, it is distinguished from the other species by having an almost terminal oral disc. The presence of a dextral vent tube is considered a synapomorphy for the clade consisting of Edalorhina, Engystomops, and Physalaemus. Within this clade, the combination of two lingual papillae, a filiform median ridge, and the lack of buccal roof papillae are diagnostic of E. perezi and putative autapomorphies of Edalorhina. Chondrocranial anatomy provides characteristics, that is, presence of and uniquely shaped processus pseudopterygoideus and cartilago suprarostralis with corpora and alae joined by dorsal and ventral connections that readily differentiates the genus from other Leiuperinae
Metabolic fate of glutamine in lymphocytes, macrophages and neutrophils
Eric Newsholmes laboratory was the first to show glutamine utilization by lymphocytes and macrophages. Recently, we have found that neutrophils also utilize glutamine. This amino acid has been shown to play a role in lymphocyte proliferation, cytokine production by lymphocytes and macrophages and phagocytosis and superoxide production by macrophages and neutrophils. Knowledge of the metabolic fate of glutamine in these cells is important for the understanding of the role and function of this amino acid in the maintenance of the proliferative, phagocytic and secretory capacities of these cells. Glutamine and glucose are poorly oxidized by these cells and might produce important precursors for DNA, RNA, protein and lipid synthesis. The high rate of glutamine utilization and its importance in such cells have raised the question as to the source of this glutamine, which, according to current evidence, appears to be muscle
Evaluation of the effect of hypothermia by cold water immersion on blood neutrophils and lymphocytes of rats submitted to acute exercise
O estresse sistêmico induzido pelo exercício libera substâncias bioativas determinantes da mobilização neutrofílica. A crioterapia diminui a reação inflamatória e atenua a elevação da perfusão sanguínea induzida pelo exercício. O objetivo deste trabalho foi analisar a influência da hipotermia decorrente da crioimersão corporal (CIC) imediata ao esforço físico agudo nas concentrações neutrofílicas e linfocíticas no sangue. Os ratos do grupo controle (AI) foram mantidos em repouso enquanto os do grupo AII foram submetidos ao protocolo de CIC a 10ºC por 10 minutos. Enquanto os animais dos grupos BI, BII, BIII e BIV realizaram o esforço físico agudo (EFA) em água a 31ºC durante 100 minutos com sobrecarga corpórea de 5% do peso corporal, os dos grupos CI, CII, CIII e CIV foram submetidos ao EFA seguido imediatamente de CIC. Nos grupos B e C, os animais foram sacrificados nos períodos de 06 (I), 12 (II), 24 (III) e 48 (IV) horas posteriores ao EFA. Através da microscopia óptica realizou-se a contagem dos neutrófilos e linfócitos. Utilizou-se do Teste T Student para análise estatística considerando-se nível de significância p < 0,05. Observou-se uma significativa neutrofilia nos grupos AII, BI, BII, BIII, BIV, CI, CII e CIII em relação a AI, diferentemente do grupo CIV, que apresentou quantidade de neutrófilos igual ao grupo controle. Os valores de linfócitos nos grupos BII, BIII, BIV, CI e CII foram significativamente menores do que AI, e nos grupos AII, BI, CIII e CIV foram iguais a AI. A neutrofilia e a linfopenia posteriores ao intenso exercício agudo são mantidas por 48 horas ou mais, porém, mediante a aplicação da crioimersão corporal imediata ao exercício, são normalizadas em 24 horas.Systemic stress induced by exercise increases bioactive substances in plasma which leads to neutrophilic mobilization. Cryotherapy causes a decrease in the inflammatory reaction and attenuates high blood perfusion after exercise. The objective of this work was to analyze the influence of cold water immersion (CWI) after acute exercise on neutrophil and lymphocyte mobilization. A control group of rats (AI) was kept at rest and a second group (AII) was submitted to CWI at 10º C for 10 minutes. The animals of Groups BI, BII, BIII and BIV were submitted to acute exercise which consisted in swimming in water at 31º C for 100 minutes with a load equivalent to 5% of the body weight. Groups CI, CII, CIII and CIV were submitted to CWI immediately after acute exercise. The animals were sacrificed at 6 (I), 12 (II), 24 (III) and 48 (IV) hours after the exercise and neutrophil and lymphocyte cells were counted for all groups by optic microscopy. The Student t-test was used for statistical analysis with a significance level of p< 0.05. A significant increase in the number of neutrophils was observed in Groups AII, BI, BII, BIII, BIV, CI, CII and CIII compared to AI. The neutrophil count of the CIV Group was similar to the Control Group. There was a significant drop in the number of lymphocytes in Groups BII, BIII, BIV, CI and CII when compared to Group AI. The lymphocyte count of Groups AII, BI, CIII and CIV were similar to the Control Group. The changes in neutrophil and lymphocyte counts caused by acute exercise were reverted to normal at 24 hours by cold water immersion
High-resolution genetic map and QTL analysis of growth-related traits of Hevea brasiliensis cultivated under suboptimal temperature and humidity conditions
Rubber tree (Hevea brasiliensis) cultivation is the main source of natural rubber worldwide and has been extended to areas with suboptimal climates and lengthy drought periods; this transition affects growth and latex production. High-density genetic maps with reliable markers support precise mapping of quantitative trait loci (QTL), which can help reveal the complex genome of the species, provide tools to enhance molecular breeding, and shorten the breeding cycle. In this study, QTL mapping of the stem diameter, tree height, and number of whorls was performed for a full-sibling population derived from a GT1 and RRIM701 cross. A total of 225 simple sequence repeats (SSRs) and 186 single-nucleotide polymorphism (SNP) markers were used to construct a base map with 18 linkage groups and to anchor 671 SNPs from genotyping by sequencing (GBS) to produce a very dense linkage map with small intervals between loci. The final map was composed of 1,079 markers, spanned 3,779.7 cM with an average marker density of 3.5 cM, and showed collinearity between markers from previous studies. Significant variation in phenotypic characteristics was found over a 59-month evaluation period with a total of 38 QTLs being identified through a composite interval mapping method. Linkage group 4 showed the greatest number of QTLs (7), with phenotypic explained values varying from 7.67 to 14.07%. Additionally, we estimated segregation patterns, dominance, and additive effects for each QTL. A total of 53 significant effects for stem diameter were observed, and these effects were mostly related to additivity in the GT1 clone. Associating accurate genome assemblies and genetic maps represents a promising strategy for identifying the genetic basis of phenotypic traits in rubber trees. Then, further research can benefit from the QTLs identified herein, providing a better understanding of the key determinant genes associated with growth of Hevea brasiliensis under limiting water conditions
Linkage disequilibrium and population structure in wild and cultivated populations of rubber tree (Hevea brasiliensis).
Abstract: Among rubber tree species, which belong to the Hevea genus of the Euphorbiaceae family, Hevea brasiliensis (Willd. ex Adr.de Juss.) Muell. Arg. is the main commercial source of natural rubber production worldwide. Knowledge of the population structure and linkage disequilibrium (LD) of this species is essential for the efficient organization and exploitation of genetic resources. Here, we obtained single-nucleotide polymorphisms (SNPs) using a genotyping-by-sequencing (GBS) approach and then employed the SNPs for the following objectives: (i) to identify the positions of SNPs on a genetic map of a segregating mapping population, (ii) to evaluate the population structure of a germplasm collection, and (iii) to detect patterns of LD decay among chromosomes for future genetic association studies in rubber tree. A total of 626 genotypes, including both germplasm accessions (368) and individuals from a genetic mapping population (254), were genotyped. A total of 77,660 and 21,283 SNPs were detected by GBS in the germplasm and mapping populations, respectively. The mapping population, which was previously mapped, was constructed with 1,062 markers, among which only 576 SNPs came from GBS, reducing the average interval between two adjacent markers to 4.4 cM. SNPs from GBS genotyping were used for the analysis of genetic structure and LD estimation in the germplasm accessions. Two groups, which largely corresponded to the cultivated and wild populations, were detected using STRUCTURE and via principal coordinate analysis. LD analysis, also using the mapped SNPs, revealed that non-random associations varied along chromosomes, with regions of high LD interspersed with regions of low LD. Considering the length of the genetic map (4,693 cM) and the mean LD (0.49 for cultivated and 0.02 for wild populations), a large number of evenly spaced SNPs would be needed to perform genome-wide association studies in rubber tree, and the wilder the genotypes used, the more difficult the mapping saturation
Antifungal activity of amphotericin B conjugated to nanosized magnetite in the treatment of paracoccidioidomycosis
This study reports on in vitro and in vivo tests that sought to assess the antifungal activity of a newly developed magnetic carrier system comprising amphotericin B loaded onto the surface of pre-coated (with a double-layer of lauric acid) magnetite nanoparticles. The in vitro tests compared two drugs; i.e., this newly developed form and free amphotericin B. We found that this nanocomplex exhibited antifungal activity without cytotoxicity to human urinary cells and with low cytotoxicity to peritoneal macrophages. We also evaluated the efficacy of the nanocomplex in experimental paracoccidioidomycosis. BALB/c mice were intratracheally infected with Paracoccidioides brasiliensis and treated with the compound for 30 or 60 days beginning the day after infection. The newly developed amphotericin B coupled with magnetic nanoparticles was effective against experimental paracoccidioidomycosis,
and it did not induce clinical, biochemical or histopathological alterations. The
nanocomplex also did not induce genotoxic effects in bone marrow cells. Therefore, it is reasonable to believe that amphotericin B coupled to magnetic nanoparticles and stabilized with bilayer lauric acid is a promising nanotool for the treatment of the experimental paracoccidioidomycosis because it exhibited antifungal activity that was similar to that of free amphotericin B, did not induce adverse effects in therapeutic doses and allowed for a reduction in the number of applications
Direct enzymatic esterification of cotton and Avicel with wild-type and engineered cutinases
In this work, the surface of cellulose, either Avicel or cotton fabric, was modified using cutinases without any previous treatment to swell or to solubilise the polymer. Aiming further improvement of cutinase ester synthase activity on cellulose, an engineered cutinase was investigated. Wild-type cutinase from Fusarium solani and its fusion with the carbohydrate-binding module N1 from Cellulomonas fimi were able to esterify the hydroxyl groups of cellulose with distinct efficiencies depending on the acid substrate/solvent system used, as shown by titration and by ATR-FTIR. The carbonyl stretching peak area increased significantly after enzymatic treatment during 72 h at 30 °C. Cutinase treatment resulted in relative increases of 31 and 9 % when octanoic acid and vegetable oil were used as substrates, respectively. Cutinase-N1 treatment resulted in relative increases of 11 and 29 % in the peak area when octanoic acid and vegetable oil were used as substrates, respectively. The production and application of cutinase fused with the domain N1 as a cellulose ester synthase, here reported for the first time, is therefore an interesting strategy to pursuit.This work was co-funded by the European Social Fund through the management authority POPH and FCT, Postdoctoral fellowship reference: SFRH/BPD/47555/2008. The authors also want to thank Doctor Raul Machado for his valuable help on FTIR spectral data treatment
Twelve-Month Follow-Up of Dexamethasone Implants for Macular Edema from Various Diseases in Vitrectomized and Nonvitrectomized Eyes
Purpose. To evaluate the best-corrected visual acuity (BCVA), central retinal thickness (CRT), and the number of dexamethasone implants needed to treat cystoid macular edema (CME) from various etiologies over 12 months in vitrectomized and nonvitrectomized eyes. Methods. This multicenter retrospective cohort study included 112 patients with CME secondary to retinal diseases treated pro re nata (PRN) with a 0.7 mg intravitreal dexamethasone implant for 12 months. The BCVA, CRT, adverse events, safety data, and number of implants were recorded. Results. Vitrectomized and nonvitrectomized eyes received means of three implants and one implant, respectively, over 12 months (P<0.001). The mean BCVA of all patients improved from 0.13 at baseline to 0.33 (P<0.001) 12 months after one (P=0.001), two (P=0.041), and three (P<0.001) implants but not four implants (P=0.068). The mean baseline CRT decreased significantly (P<0.001) from 463 to 254 microns after 12 months with one (P<0.001), two (P=0.002), and three (P=0.001) implants but not with four implants (P=0.114). The anatomic and functional outcomes were not significantly different between vitrectomized and nonvitrectomized eyes. Increased IOP was the most common adverse event (23.2%). Conclusions. Dexamethasone implant administered PRN improved VA and decreased CRT in CME, with possible long-term clinically relevant benefits for treating CME from various etiologies. Vitrectomized eyes needed more implants compared with nonvitrectomized eyes
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