166 research outputs found
Biodiesel: a critical overview on the current status and perspectives at the academy and industry
This article presents a bibliographic review of research carried out on different alternative processes for biodiesel production. The supercritical and subcritical (non catalytic) reaction conditions, the use of solid basic, solid acid and other heterogeneous catalysts, including the use of immobilized enzymes and whole-cell catalysts are also critically compared with the traditional homogeneous alkaline or acid catalysts that are common on industrial applications. Advantages and limitations of all these processes for the transference from the laboratory to the industry are discussed. A correlation of the chemical composition with the quality parameters of the produced biodiesel is done with aim to stablish adequate procedures for the right selection of the raw-material. Castor bean oil is used as an example of inappropriate oil in order to produce a B100 that fulfill all the international physico-chemical quality standards. In this article are presented research results to adequate the values of viscosity, density and iodine number of the castor and soybean biodiesel to the international standard limits by means blending these both biodiesels at the right ratio
Detection of pathological lesions in slaughtered rabbits
The slaughterhouse is considered an important control point for the monitoring of rabbit diseases. In our study, 59,440 rabbit carcasses were examined, but only 1% of pathological lesions were recorded at postmortem inspection. Mainly affected were tegumentary, digestive and urinary systems. The most consistent lesion was the subcutaneous abscess; nephritis, probably caused by Encephalitozoon cuniculi, was also frequent. Pathological alterations of the liver, classified as "necrotizing hepatitis" and localized at the caudate lobe, were observed for the first time
Recent advances in KEAP1/Nrf2-targeting strategies by phytochemical antioxidants, nanoparticles, and biocompatible scaffolds for the treatment of diabetic cardiovascular complications
Abstract
Significance: Modulation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-mediated antioxidant response is
a key aspect in the onset of diabetes-related cardiovascular complications. With this review, we provide an
overview of the recent advances made in the development of Nrf2-targeting strategies for the treatment of
diabetes, with particular attention toward the activation of Nrf2 by natural antioxidant compounds, nanoparticles,
and oxidative stress-modulating biocompatible scaffolds.
Recent Advances: In the past 30 years, studies addressing the use of antioxidant therapies to treat diabetes have
grown exponentially, showing promising but yet inconclusive results. Animal studies and clinical trials on the
Nrf2 pathway have shown promising results, suggesting that its activation can delay or reverse some of the
cardiovascular impairments in diabetes.
Critical Issues: Hyperglycemia- and oscillating glucose levels-induced reactive oxygen species (ROS) accumulation
is progressively emerging as a central factor in the onset and progression of diabetes-related cardiovascular
complications, including endothelial dysfunction, retinopathy, heart failure, stroke, critical limb
ischemia, ulcers, and delayed wound healing. In this context, accumulating evidence suggests a central role for
Nrf2-mediated antioxidant response, one of the most studied cellular defensive mechanisms against ROS
accumulation.
Future Directions: Innovative approaches such as tissue engineering and nanotechnology are converging
toward targeting oxidative stress in diabetes. Antioxid. Redox Signal. 36, 707–72
Dimethyl-2-oxoglutarate improves redox balance and mitochondrial function in muscle pericytes of individuals with diabetes mellitus
Aims/hypothesis Treatment of vascular complications of diabetes remains inadequate. We reported that muscle pericytes (MPs) from limb muscles of vascular patients with diabetes mellitus display elevated levels of oxidative stress causing a dysfunctional phenotype. Here, we investigated whether treatment with dimethyl-2-oxoglutarate (DM-2OG), a tricarboxylic acid cycle metab- olite with antioxidant properties, can restore a healthy metabolic and functional phenotype.
Methods MPs were isolated from limb muscles of diabetes patients with vascular disease (D-MPs) and from non-diabetic control participants (ND-MPs). Metabolic status was assessed in untreated and DM-2OG-treated (1 mmol/l) cells using an extracellular flux analyser and anion-exchange chromatography–mass spectrometry (IC-MS/MS). Redox status was measured using commercial kits and IC-MS/MS, with antioxidant and metabolic enzyme expression assessed by quanti- tative RT-PCR and western blotting. Myogenic differentiation and proliferation and pericyte–endothelial interaction were assessed as functional readouts.
Results D-MPs showed mitochondrial dysfunction, suppressed glycolytic activity and reduced reactive oxygen species- buffering capacity, but no suppression of antioxidant systems when compared with ND-MP controls. DM-2OG supple- mentation improved redox balance and mitochondrial function, without affecting glycolysis or antioxidant systems. Nonetheless, this was not enough for treated D-MPs to regain the level of proliferation and myogenic differentiation of ND-MPs. Interestingly, DM-2OG exerted a positive effect on pericyte–endothelial cell interaction in the co-culture angiogenesis assay, independent of the diabetic status.
Conclusions/interpretation These novel findings support the concept of using DM-2OG supplementation to improve pericyte redox balance and mitochondrial function, while concurrently allowing for enhanced pericyte–endothelial crosstalk. Such effects may help to prevent or slow down vasculopathy in skeletal muscles of people with diabetes
Conditional corticotropin-releasing hormone overexpression in the mouse forebrain enhances rapid eye movement sleep
Impaired sleep and enhanced stress hormone secretion are the hallmarks of stress-related disorders, including major depression. The central neuropeptide, corticotropin-releasing hormone (CRH), is a key hormone that regulates humoral and behavioral adaptation to stress. Its prolonged hypersecretion is believed to play a key role in the development and course of depressive symptoms, and is associated with sleep impairment. To investigate the specific effects of central CRH overexpression on sleep, we used conditional mouse mutants that overexpress CRH in the entire central nervous system (CRH-COE-Nes) or only in the forebrain, including limbic structures (CRH-COE-Cam). Compared with wild-type or control mice during baseline, both homozygous CRH-COE-Nes and -Cam mice showed constantly increased rapid eye movement (REM) sleep, whereas slightly suppressed non-REM sleep was detected only in CRH-COE-Nes mice during the light period. In response to 6-h sleep deprivation, elevated levels of REM sleep also became evident in heterozygous CRH-COE-Nes and -Cam mice during recovery, which was reversed by treatment with a CRH receptor type 1 (CRHR1) antagonist in heterozygous and homozygous CRH-COE-Nes mice. The peripheral stress hormone levels were not elevated at baseline, and even after sleep deprivation they were indistinguishable across genotypes. As the stress axis was not altered, sleep changes, in particular enhanced REM sleep, occurring in these models are most likely induced by the forebrain CRH through the activation of CRHR1. CRH hypersecretion in the forebrain seems to drive REM sleep, supporting the notion that enhanced REM sleep may serve as biomarker for clinical conditions associated with enhanced CRH secretion
The innate immunity receptor TIR8/SIGIRR is expressed in the early developmental stages of chicken embryos
The orphan receptor TIR8, also known as SIGIRR (Single Immunoglobulin IL-1R-Related molecule), belongs to the IL-1R/TLR (TIR) superfamily and plays an important role in the inflammatory responses. The signaling pathways of the receptors belonging to the TIR family are tightly regulated by both extracellular and intracellular mechanisms. TIR8 does not activate the transcription factors NFkB (nuclear factor kB) and IRF3 (interferon regulatory factor 3), although it negatively modulates the inflammatory responses. It acts as an antagonist for the IL-1 receptor family and triggers a negative pathway of the Toll-like/IL-1 receptor system, crucial for dampening inflammation stimuli in the gastrointestinal (GI) tract and in other organs (e.g. lung and kidney). The recent findings of TLRs expression in ovary and embryos of different species (mammals and chickens) are very important for an understanding of reproductive physiology and transovarian pathogen transmission. TIR8 was well characterized in mouse, humans and in other mammalian species, but it is still poorly characterized in the chicken. When TIR8 expression was measured in selected organs of chicken embryos of both broiler and layer types at different time points a unique pattern of expression was observed. Interestingly, TIR8 was detected during the first stages of chicken development (day 1 of incubation), and reached a remarkable level of expression by day 10. We observed this receptor to be ubiquitously expressed in the kidney, GI tract, Bursa of Fabricius, with the highest expression levels in liver and kidney. This pattern was comparable to those observed in post-hatching chickens and in mammals examined to date. No expression differences were observed between the two different chicken breeds (layer- and broiler-type) in the first incubation period (8 days). Whereas in some organs starting from day 10, higher TIR8 expression was observed in broiler-type compared to layer-type. These are the first findings concerning TIR8 expression in developmental stages and therefore they are of comparative value
Prevalence of pathological lesions in meat rabbit at slaughtering
The slaughterhouse is considered an important control point for the monitoring of rabbit diseases. In our study, 59,440 rabbit carcasses were examined, but only 1% of pathological lesions were recorded
at post-mortem inspection. Mainly tegumentary, digestive and urinary systems were affected. The most consistent lesion was the subcutaneous abscess; nephritis, probably caused by Encephalitozoon
cuniculi, was also frequent. A pathological alteration of the liver, classified as \u201cnecrotizing hepatitis\u201d, localized at the caudate lobe, was observed and here firstly described
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