736 research outputs found
Late Pleistocene echimyid rodents (Rodentia, Hystricognathi) from northern Brazil
Echimyidae (spiny rats, tree rats and the coypu) is the most diverse family of extant South American hystricognath rodents (caviomorphs). Today, they live in tropical forests (Amazonian, coastal and Andean forests), occasionally in more open xeric habitats in the Cerrado and Caatinga of northern South America, and open areas across the southern portion of the continent (Myocastor). The Quaternary fossil record of this family remains poorly studied. Here, we describe the fossil echimyids found in karst deposits from southern Tocantins, northern Brazil. The analyzed specimens are assigned to Thrichomys sp., Makalata cf. didelphoides and Proechimys sp. This is the first time that a fossil of Makalata is reported. The Pleistocene record of echimyids from this area is represented by fragmentary remains, which hinders their determination at specific levels. The data reported here contributes to the understanding of the ancient diversity of rodents of this region, evidenced until now in other groups, such as the artiodactyls, cingulates, carnivores, marsupials, and squamate reptiles.Facultad de Ciencias Naturales y Muse
Drought tolerance conferred to sugarcane by association with Gluconacetobacter diazotrophicus: a transcriptomic view of hormone pathways
Sugarcane interacts with particular types of beneficial nitrogen-fixing bacteria that provide fixed-nitrogen and plant growth hormones to host plants, promoting an increase in plant biomass. Other benefits, as enhanced tolerance to abiotic stresses have been reported to some diazotrophs. Here we aim to study the effects of the association between the diazotroph Gluconacetobacter diazotrophicus PAL5 and sugarcane cv. SP70-1143 during water depletion by characterizing differential transcriptome profiles of sugarcane. RNA-seq libraries were generated from roots and shoots of sugarcane plants free of endophytes that were inoculated with G. diazotrophicus and subjected to water depletion for 3 days. A sugarcane reference transcriptome was constructed and used for the identification of differentially expressed transcripts. The differential profile of non-inoculated SP70-1143 suggests that it responds to water deficit stress by the activation of drought-responsive markers and hormone pathways, as ABA and Ethylene. qRT-PCR revealed that root samples had higher levels of G. diazotrophicus 3 days after water deficit, compared to roots of inoculated plants watered normally. With prolonged drought only inoculated plants survived, indicating that SP70-1143 plants colonized with G. diazotrophicus become more tolerant to drought stress than non-inoculated plants. Strengthening this hypothesis, several gene expression responses to drought were inactivated or regulated in an opposite manner, especially in roots, when plants were colonized by the bacteria. The data suggests that colonized roots would not be suffering from stress in the same way as non-inoculated plants. On the other hand, shoots specifically activate ABA-dependent signaling genes, which could act as key elements in the drought resistance conferred by G. diazotrophicus to SP70-1143. This work reports for the first time the involvement of G. diazotrophicus in the promotion of drought-tolerance to sugarcane cv. SP70-1143, and it describes the initial molecular events that may trigger the increased drought tolerance in the host plant
Efficacy of single-dose cholecalciferol in the blood pressure of patients with type 2 diabetes, hypertension and hypovitaminoses D
Observational and experimental data reinforce the concept that vitamin D is associated with the pathogenesis of arterial hypertension. We investigated the efect of a single dose of 100,000 IU of cholecalciferol, in ofce blood pressure (BP), and 24-h ambulatory blood pressure monitoring (ABPM) in patients with type 2 diabetes mellitus (DM), hypertension, and hypovitaminosis D. Fortythree patients were randomized to a placebo or cholecalciferol group. BP was assessed by ofce measurements and 24-h ABPM, before and after intervention. At week 8, a greater decrease in median ABPM values was observed in cholecalciferol supplementation than in the placebo group for systolic 24-h (− 7.5 vs. − 1; P= 0.02), systolic daytime (− 7 vs. − 1; P= 0.007), systolic nighttime (− 7.0 vs. 3; P= 0.009), diastolic 24-h (− 3.5 vs. − 1; P= 0.037), and daytime DBP (− 5 vs. 0; P= 0.01). Ofce DBP was also reduced after vitamin D supplementation. A single dose of vitamin D3 improves BP in patients with type 2 diabetes, hypertension, and vitamin D insufciency, regardless of vitamin D normalization. Vitamin D supplementation could be a valuable tool to treat patients with type 2 DM, hypertension, and hypovitaminosis D
Isolation of Clostridium perfringens from swine carcasses and feces
Bacterial hazards are the major concern in the production of food of animal origin. Clostridium perfringens is a common cause of food-borne illness. The illness is characterized by profuse diarrhea and acute abdominal pain. At this study 30 carcass swabs from dorsal area and 30 fecal samples from a swine abattoir were analyzed over C. perfringens presence
Late Pleistocene echimyid rodents (Rodentia, Hystricognathi) from northern Brazil
Echimyidae (spiny rats, tree rats and the coypu) is the most diverse family of extant South American hystricognath rodents (caviomorphs). Today, they live in tropical forests (Amazonian, coastal and Andean forests), occasionally in more open xeric habitats in the Cerrado and Caatinga of northern South America, and open areas across the southern portion of the continent (Myocastor). The Quaternary fossil record of this family remains poorly studied. Here, we describe the fossil echimyids found in karst deposits from southern Tocantins, northern Brazil. The analyzed specimens are assigned to Thrichomys sp., Makalata cf. didelphoides and Proechimys sp. This is the first time that a fossil of Makalata is reported. The Pleistocene record of echimyids from this area is represented by fragmentary remains, which hinders their determination at specific levels. The data reported here contributes to the understanding of the ancient diversity of rodents of this region, evidenced until now in other groups, such as the artiodactyls, cingulates, carnivores, marsupials, and squamate reptiles.Facultad de Ciencias Naturales y Muse
Foraminifera as health bioindicators in nearshore and offshore Brazilian coral reef sediments
Abstrac
Discovery of sustainable drugs for neglected tropical diseases: cashew nutshell liquid (CNSL)-based hybrids target mitochondrial function and ATP production in Trypanosoma brucei.
In a search for effective and sustainable treatments for trypanosomiasis, we developed a library of hybrid compounds by merging the structural features of a previously synthesized quinone hit (4) with those of long‐chain phenolic constituents from cashew nut shell liquid (CNSL). CNSL is an agro‐waste product from cashew nut processing factories with great potential as a precursor for the production of drugs. The synthesized compounds were tested against Trypanosoma brucei brucei, including three multi‐drug resistant strains (B48, ISMR1, and aqp2/aqp3‐KO), T. congolense, and a human cell line (HFF). The most potent activity was found against T. b. brucei, the causative agent of African trypanosomiasis. Shorter‐chain derivatives were more active than the starting hit in parasite growth inhibition, displaying rapid trypanocidal activity with low micromolar EC50 values, but no discernable toxicity on human cell lines. Preliminary studies probing their mode of action on trypanosomes showed depletion of cellular ATP, followed by the depolarization of the mitochondrial membrane and ultrastructural damage to the mitochondrion. This was accompanied by the production of high levels of reactive oxygen species. We envisage that such hybrid compounds, obtained from renewable and inexpensive material, might be promising bio‐based, sustainable hits for anti‐trypanosomatid drug discovery
Determination of fipronil in bovine plasma by solid-phase extraction and liquid chromatography with ultraviolet detection
A fast and efficient method has been developed and validated for the determination of fipronil in bovine plasma. Samples were subjected to solid-phase extraction (SPE) followed by reversed phase liquid chromatography (LC) separation, using acetonitrile/water (60:40 v/v) as the mobile phase with a flow rate of 1.0 mL/min and ultraviolet (UV) detection at 210 nm. Ethiprole was used as the internal standard (IS). The method was found to be linear over the range 5-500 ng/mL (r = 0.999). The limit of quantitation (LOQ) was validated at 5 ng/mL. The method was successfully applied to monitor plasma concentrations following subcutaneous administration of fipronil in cattle
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