Search

Abstract: At present, the goal of stroke research is the identification of a potential recoverable tissue surrounding the ischemic core, suggested as ischemic penumbra, with the aim of applying a treatment that attenuates the growth of this area. Our purpose was to determine whether a combination of imaging techniques, including 18F-FDG PET and MRI could identify the penumbra area. Longitudinal studies of 18F-FDG PET and MRI were performed in rats 3h, 24h and 48h after the onset of ischemia. A transient and a permanent model of focal cerebral ischemia were performed. Regions of interest were located, covering the ischemic core, the border that progresses to infarction (recruited tissue), and the border that recovers (recoverable tissue) with early reperfusion. Analyses show that permanent ischemia produces severe damage, whereas the transient ischemia model does not produce clear damage in ADC maps at the earliest time studied. The only significant differences between values for recoverable tissue, 18F-FDG (84±2%), ADC (108±5%) and PWI (70±8%), and recruited tissue, 18F-FDG (77±3%), ADC (109±4%) and PWI (77±4%), are shown in 18F-FDG ratios. We also show that recoverable tissue values are different from those in non-infarcted tissue. The combination of 18F-FDG PET, ADC and PWI MRI is useful for identification of ischemic penumbra, with 18F-FDG PET being the most sensitive approach to its study at early times after stroke, when a clear DWI deficit is not observed. [Copyright &y& Elsevier]

The modulation of the host's metabolism to protect tissue from damage induces tolerance to infections increasing survival. Here, we examined the role of the thyroid hormones, key metabolic regulators, in the outcome of malaria. Hypothyroidism confers protection to experimental cerebral malaria by a disease tolerance mechanism. Hypothyroid mice display increased survival after infection with Plasmodium berghei ANKA, diminishing intracranial pressure and brain damage, without altering pathogen burden, blood-brain barrier disruption, or immune cell infiltration. This protection is reversed by treatment with a Sirtuin 1 inhibitor, while treatment of euthyroid mice with a Sirtuin 1 activator induces tolerance and reduces intracranial pressure and lethality. This indicates that thyroid hormones and Sirtuin 1 are previously unknown targets for cerebral malaria treatment, a major killer of children in endemic malaria areas.

The objective of the present study was to evaluate whether gender determination in two amphibian species ( Kaloula pulchra and Xenopus laevis ) can be reliably carried out by means of magnetic resonance imaging (benchtop magnetic resonance imaging; BT-MRI) or ultrasound (high-resolution ultrasound; HR-US) techniques. Two species of healthy, sexually mature anurans have been used in the present study. Eight Kaloula (blind study) and six Xenopus were used as controls. Magnetic resonance imaging experiments were carried out on a low-field (1 Tesla) benchtop-MRI (BT-MRI) system. HR-US examination was performed with high-resolution equipment. Low-field BT-MRI images provided a clear and quantifiable identification of all the sexual organs present in both genders and species. The HR-US also allowed the identification of testes and ovaries in both species. Results indicate that BT-MRI allowed a very precise sex identification in both anuran species, although its use is limited by the cost of the equipment and the need for anesthesia. HR-US allowed an accurate identification of ovaries of both species whereas a precise identification of testes is limited by the ultrasonographer experience. The main advantages of this technique are the possibility of performing it without anesthesia and the higher availability of equipment in veterinary and zoo institutions.

The aims of this study were to investigate the effect of vitamin D 3 administration in drinking water during lairage time prior to slaughter on physiological stress, oxidative status, and pork quality characteristics. Two experiments were carried out. The first one was performed to examine the effect of vitamin D 3 supplementation in drinking water, and the second one to check the effect of supplementation dose (500,000 IU/L vs. 700,000 IU/L). Serum calcium concentration was greater in pigs receiving vitamin D 3 in water when compared to the control group. In experiment 1, a 40% α-tocopherol increase in meat from the group supplemented with vitamin D 3 (500,000 IU/animal) was observed, that resulted in a tendency of decreased meat malondialdehyde (MDA) values at days 5 and 8 after refrigerated storage. In experiment 2, since water intake was higher (800,000 IU and 1,120,000 IU/animal of vitamin D 3 consumption) effects on oxidative status were more profound and vitamin D 3 supplementation increased serum α-tocopherol and decreased cortisol and serum TBARS. These effects were also observed in meat; TBARS levels were decreased after 3 days of refrigerated storage. In both experiments meat from pigs that received vitamin D 3 in drinking water had a lower proportion of total free-polyunsaturated fatty acids (mainly n-6) when compared to the unsupplemented pigs, and these were positively correlated with TBARS production at day 5 of refrigerated storage ( r = 0.53 and 0.38 for experiments 1 and 2, respectively). Meat from pigs receiving vitamin D 3 in water showed reduced cohesiveness, gumminess, and chewiness values compared to the control group. The magnetic resonance imaging study of muscle confirmed the effects on water retention with lesser transverse relaxation time in pigs supplemented with vitamin D 3 . No vitamin D 3 dose effect was observed, apart from muscle α-tocopherol concentration that was higher in pigs supplemented with 700,000 compared to those supplemented with 500,000 UI/L.

Standard 2D NMR experiments suffer from the many t1 increments needed for spectra with sufficient digital resolution in the indirect dimension. Despite the different methodological approaches to overcome this problem, these increments have prevented studies of fast reactions. The development of ultrafast NMR (UF-NMR) has decisively speeded up the time scale of standard NMR to allow the study of organic reactions as they happen in real time to reveal mechanistic details. This mini-review summarizes the results achieved in monitoring organic reactions through this exciting technique., (Copyright © 2015 John Wiley & Sons, Ltd.)

Ultrafast 2D HMBC spectroscopy permits real-time monitoring of a reaction based on the structural changes produced in a carbonyl carbon atom. This new technique was used to study the reaction of ketones, nitriles, and Tf(2)O, affording relevant information about new intermediates and kinetic data.