Search

In collaboration with the American College of Veterinary Pathologists

We investigated the occurrence and pathologic findings of transmissible viral proventriculitis (TVP) associated with the chicken proventricular necrosis virus (CPNV) in commercial broiler chickens in southeastern Brazil. Seventy-three broilers, 25–36 d old, with a history of reduced growth, were referred to our veterinary pathology services from 2013 to 2017. Broilers were clinically examined, weighed, and euthanized for postmortem examination. Broilers of different ages with proventricular histologic lesions were positive for CPNV by RT-PCR; however, the intensity of histologic lesions was higher among 33-d-old animals, and viral RNA detection was more frequent among those that were 28 d old. In the proventriculi of 35 of 73 (48%) broilers, lesions were characterized by glandular epithelial necrosis, lymphoplasmacytic and histiocytic infiltrates, and metaplasia of glandular epithelium to ductal epithelium. In 24 of 73 (36%) broilers with histologic TVP-compatible lesions, CPNV was detected by RT-PCR for the viral protein 1 ( VP1) gene. Broilers with histologic lesions were lighter than expected compared to the Cobb 500 standard weight. TVP has not been reported previously in broiler chickens in Brazil, to our knowledge.

Nanostructured carriers have been widely used in pharmaceutical formulations for dermatological treatment. They offer targeted drug delivery, sustained release, improved biostability, and low toxicity, usually presenting advantages over conventional formulations. Due to its large surface area, small size and photothermal properties, graphene oxide (GO) has the potential to be used for such applications. Nanographene oxide (GOn) presented average sizes of 197.6 ± 11.8 nm, and a surface charge of -39.4 ± 1.8 mV, being stable in water for over 6 months. 55.5 % of the mass of GOn dispersion (at a concentration of 1 mg mL-1) permeated the skin after 6 h of exposure. GOn dispersions have been shown to absorb near-infrared radiation, reaching temperatures up to 45.7 °C, within mild photothermal therapy temperature range. Furthermore, GOn in amounts superior to those which could permeate the skin were shown not to affect human skin fibroblasts (HFF-1) morphology or viability, after 24 h of incubation. Due to its large size, no skin permeation was observed for graphite particles in aqueous dispersions stabilized with Pluronic P-123 (Gt-P-123). Altogether, for the first time, GOn potential as a topic administration agent and for delivery of photothermal therapy has been demonstrated.

One of the main problems with laser cutting equipment is related to the wrong setting of cutting parameters. The mismatching of these parameters leads to a loss of cut surface quality, which is hardly re-established. This loss of quality is usually related to a burr problem. Thus, this study is aimed to improve and optimize this process using a fibre laser equipment. Three important laser cutting parameters were studied in order to investigate their importance in the cut surface quality: radiation power, cutting speed and gas pressure. The different values were performed cutting a stainless steel AISI 316L and a cold rolled steel St12. Metallographic and cut surface analysis, burr and roughness measurements were carried out, supported by a Scanning Electron Microscopy and profilometry. Through the Taguchi statistical analysis model, it is possible to indicate the best set of laser cutting parameters. It was verified that the values recommended by the equipment manufacturer can be optimized, being possible to use less radiation power in the laser beam with greater speed of cut, providing a better cut surface quality, improving and optimizing the entire process.

Mitochondrial dysfunction, the inability to efficiently utilise metabolic fuels and oxygen, contributes to pathological changes following traumatic spinal cord or traumatic brain injury (TBI). In the present study, we tested the hypothesis that succinate supplementation can improve cellular energy state under metabolically stressed conditions in a robust, reductionist in vitro model of mitochondrial dysfunction in which primary mixed glial cultures (astrocytes, microglia and oligodendrocytes) were exposed to the mitochondrial complex I inhibitor rotenone. Cellular response was determined by measuring intracellular ATP, extracellular metabolites (glucose, lactate, pyruvate), and oxygen consumption rate (OCR). Rotenone produced no significant changes in glial ATP levels. However, it induced metabolic deficits as evidenced by lactate/pyruvate ratio (LPR) elevation (a clinically-established biomarker for poor outcome in TBI) and decrease in OCR. Succinate addition partially ameliorated these metabolic deficits. We conclude that succinate can improve glial oxidative metabolism, consistent our previous findings in TBI patients’ brains. The mixed glial cellular model may be useful in developing therapeutic strategies for conditions involving mitochondrial dysfunction, such as TBI.

J. Neurochem. (2010) 113, 735–748. Abstract Disruption of brain energy metabolism is the hallmark of cerebral ischemia, a major cause of death worldwide. Astrocytes play a key role in the regulation of brain metabolism and their vulnerability to ischemia has been described. Aiming to quantify the effects of an ischemic insult in astrocytic metabolism, primary cultures of astrocytes were subjected to 5 h of oxygen and glucose deprivation in a bioreactor. Flux distributions, before and after ischemia, were estimated by metabolic flux analysis using isotopic information and the consumption/secretion rates of relevant extracellular metabolites as constraints. During ischemia and early recovery, 30% of cell death was observed; several metabolic alterations were also identified reflecting a metabolic response by the surviving cells. In the early recovery (∼10 h), astrocytes up-regulated glucose utilization by 30% and increased the pentose phosphate pathway and tricarboxylic acid cycle fluxes by three and twofold, respectively. Additionally, a two to fivefold enhancement in branched-chain amino acids catabolism suggested the importance of anaplerotic molecules to the fast recovery of the energetic state, which was corroborated by measured cellular ATP levels. Glycolytic metabolism was predominant in the late recovery. In summary, this work demonstrates that changes in fluxes of key metabolic pathways are implicated in the recovery from ischemia in astrocytes.

This work investigates to which extent different carbon sources are metabolized and used for lipid biosynthesis in retrovirus producer cells, with the ultimate goal of understanding its importance regarding the stability/productivity of the vectors. For that purpose, isotopically labeled substrates (U- 13 C glucose, U- 13 C galactose, U- 13 C fructose, and U- 13 C glutamine) were used in combination with 13 C nuclear magnetic resonance (NMR) spectroscopy and gas chromatography–mass spectrometry (GC–MS). Our results show that glucose plays the major role in lipid biosynthesis, whereas glutamine, fructose and galactose are not significantly incorporated into lipids. Moreover, a correlation between medium osmolality (imposed by the presence of sorbitol) and virus stability and productivity was verified, apparently due to an enhancement in sugar metabolism. Since low stability and short half-life constitute the major bottleneck in process development for retrovirus and other enveloped viral vectors, this work presents useful knowledge for improved process robustness for these essential gene therapy vectors.

Enhancing central nervous system (CNS) myelin regeneration is recognized as an important strategy to ameliorate the devastating consequences of demyelinating diseases such as multiple sclerosis. Previous findings have indicated that myelin proteins, which accumulate following demyelination, inhibit remyelination by blocking the differentiation of rat oligodendrocyte progenitor cells (OPCs) via modulation of PKCα. We therefore screened drugs for their potential to overcome this differentiation block. From our screening, tamoxifen emerges as a potent inducer of OPC differentiation in vitro. We show that the effects of tamoxifen rely on modulation of the estrogen receptors ERα, ERβ, and GPR30. Furthermore, we demonstrate that administration of tamoxifen to demyelinated rats in vivo accelerates remyelination. Tamoxifen is a well-established drug and is thus a promising candidate for a drug to regenerate myelin, as it will not require extensive safety testing. In addition, Tamoxifen plays an important role in biomedical research as an activator of inducible genetic models. Our results highlight the importance of appropriate controls when using such models.

Physical activity has been found to have a positive effect on the clinical outcomes of patients with chronic diseases, including end-stage renal disease (ESRD). The purpose of this study was to describe end-stage renal disease patients on hemodialysis and describe, as well, their physical activity levels.Participants were recruited from the renal unit of Hospital Universitario in San Juan. The variables of interest were 1) socio-demographic and health status information and 2) physical activity levels and patterns.Thirty-one participants with end-stage renal disease completed the questionnaires (17 men and 14 women). The average age of the participants was 54+17 years. Eighty-seven percent (87%) answered that they were not active before beginning hemodialysis treatment. Only 4 patients were employed. These four patients performed activities of moderate intensity ranging from 0 to 2267 MET-mins/week. Nineteen participants reported that they performed a variety of household chores. Home physical activity scores consisted of an average of 1025+1856 MET-mins/week (median 200 MET-mins/week). The total physical activity energy expenditure in leisure-time activities was an average of 111+167 MET-mins/ week. The average total physical activity for all the categories from the IPAQ was an average of 1688+2250 MET-mins/week (median 544 MET-mins/week). They sat for about 454+293 minutes per day (approximately 7.5 hours daily). A Spearman's correlation test found there to be a significant inverse relationship between total physical activity energy expenditure and years in hemodialysis treatment, regardless of age (p = -0.301; p0.05).In this study, the author describes the physical inactivity in a group of ESRD patients receiving hemodialysis and the significant physical activity variability among them. Moreover, those participants who had been on hemodialysis the longest tended to be the most sedentary, regardless of age. Therefore, it is important to raise awareness, educate and assess, and, if warranted, recommend physical activity to chronic kidney disease patients, including those with end-stage renal disease who are receiving hemodialysis.

Whereas astrocytes have been in the limelight on the metabolic glucose interaction scene for a while, oligodendrocytes are still waiting for a place. We would like to call oligodendrocyte interaction with astrocytes and neurons: NOA (neuron – oligodendrocyte – astrocyte) interactions. One of the reasons to find out more about oligodendrocyte interaction with neurons and astrocytes is to detect markers of healthy oligodendrocyte metabolism, to be used in diagnosis and treatment assessment in diseases such as Perinatal hypoxic-ischemic encephalopathy and multiple sclerosis in which oligodendrocyte function is impaired, possibly due to glutamate toxicity. Glutamate receptors are expressed in oligodendrocytes and also vesicular glutamate release in the white matter has received considerable attention. It is also important to establish if the glial precursor cells recruited to damaged areas are developing oligodendrocyte characteristics or those of astrocytes. Thus, it is important to study astrocytes and oligodendrocytes separately to be able to differentiate between them. This is of particular importance in the white matter where the number of oligodendrocytes is considerable. The present review summarizes the not very extensive information published on glucose metabolism in oligodendrocytes in an attempt to stimulate research into this important field.

Whereas astrocytes have been in the limelight of scientific interest in brain energy metabolism for a while, oligodendrocytes are still waiting for a place on the metabolic stage. We propose to term the interaction of oligodendrocytes with astrocytes and neurons: NOA (neuron–oligodendrocyte–astrocyte) interactions. One of the reasons to find out more about metabolic interactions between oligodendrocytes, neurons, and astrocytes is to establish markers of healthy oligodendrocyte metabolism that could be used for the diagnosis and assessment of white matter disease. The vesicular release of glutamate in the white matter has received considerable attention in the past. Oligodendrocyte lineage cells express glutamate receptors and glutamate toxicity has been implicated in diseases affecting oligodendrocytes such as hypoxic-ischaemic encephalopathy, inflammatory diseases and trauma. As oligodendrocyte precursor cells vividly react to injury it is also important to establish whether cells recruited into damaged areas are able to regenerate lost myelin sheaths or whether astrocytic scarring occurs. It is therefore important to consider metabolic aspects of astrocytes and oligodendrocytes separately. The present review summarizes the limited evidence available on metabolic cycles in oligodendrocytes and so hopes to stimulate further research interests in this important field.

Metabolic models have been used to elucidate important aspects of brain metabolism in recent years. This work applies for the first time the concept of isotopic transient 13C metabolic flux analysis (MFA) to estimate intracellular fluxes in primary cultures of astrocytes. This methodology comprehensively explores the information provided by 13C labeling time-courses of intracellular metabolites after administration of a 13C-labeled substrate. Cells were incubated with medium containing [1-13C]glucose for 24 h and samples of cell supernatant and extracts collected at different time points were then analyzed by mass spectrometry and/or high performance liquid chromatography. Metabolic fluxes were estimated by fitting a carbon labeling network model to isotopomer profiles experimentally determined. Both the fast isotopic equilibrium of glycolytic metabolite pools and the slow labeling dynamics of TCA cycle intermediates are described well by the model. The large pools of glutamate and aspartate which are linked to the TCA cycle via reversible aminotransferase reactions are likely to be responsible for the observed delay in equilibration of TCA cycle intermediates. Furthermore, it was estimated that 11% of the glucose taken up by astrocytes was diverted to the pentose phosphate pathway. In addition, considerable fluxes through pyruvate carboxylase [PC; PC/pyruvate dehydrogenase (PDH) ratio = 0.5], malic enzyme (5% of the total pyruvate production), and catabolism of branched-chained amino acids (contributing with ∼40% to total acetyl-CoA produced) confirmed the significance of these pathways to astrocytic metabolism. Consistent with the need of maintaining cytosolic redox potential, the fluxes through the malate–aspartate shuttle and the PDH pathway were comparable. Finally, the estimated glutamate/α-ketoglutarate exchange rate (∼0.7 μmol mg prot−1 h−1) was similar to the TCA cycle flux. In conclusion, this work demonstrates the potential of isotopic transient MFA for a comprehensive analysis of energy metabolism. Copyright: © 2011 Amaral, Teixeira, Håkonsen, Sonnewald and Alves. This is an open-access article subject to a non-exclusive license between the authors and Frontiers Media SA, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and other Frontiers conditions are complied with.

Metabolic models have been used to elucidate important aspects of brain metabolism in recent years. This work applies for the first time the concept of isotopic transient 13C metabolic flux analysis (MFA) to estimate intracellular fluxes in primary cultures of astrocytes. This methodology comprehensively explores the information provided by 13C labeling time-courses of intracellular metabolites after administration of a 13C-labeled substrate. Cells were incubated with medium containing [1-13C]glucose for 24 h and samples of cell supernatant and extracts collected at different time points were then analyzed by mass spectrometry and/or high performance liquid chromatography. Metabolic fluxes were estimated by fitting a carbon labeling network model to isotopomer profiles experimentally determined. Both the fast isotopic equilibrium of glycolytic metabolite pools and the slow labeling dynamics of TCA cycle intermediates are described well by the model. The large pools of glutamate and aspartate which are linked to the TCA cycle via reversible aminotransferase reactions are likely to be responsible for the observed delay in equilibration of TCA cycle intermediates. Furthermore, it was estimated that 11% of the glucose taken up by astrocytes was diverted to the pentose phosphate pathway. In addition, considerable fluxes through pyruvate carboxylase [PC; PC/pyruvate dehydrogenase (PDH) ratio = 0.5], malic enzyme (5% of the total pyruvate production), and catabolism of branched-chained amino acids (contributing with ∼40% to total acetyl-CoA produced) confirmed the significance of these pathways to astrocytic metabolism. Consistent with the need of maintaining cytosolic redox potential, the fluxes through the malate–aspartate shuttle and the PDH pathway were comparable. Finally, the estimated glutamate/α-ketoglutarate exchange rate (∼0.7 μmol mg prot−1 h−1) was similar to the TCA cycle flux. In conclusion, this work demonstrates the potential of isotopic transient MFA for a comprehensive analysis of energy metabolism.

The inhibitory effect of 50 mg/kg lysyl acetylsalicylic acid (ASA) intravenously injected 24 and 4 h before 80 μg/kg adrenaline, 40 mg/kg indobufen injected 15 min before, or a combination of ASA plus indobufen on the platelet aggregation and kinetics was evaluated in anaesthetized dogs previously injected with 111indium- (111In-) labelled platelets using γ-camera dynamics studies. The highest degree of inhibition, indicated by the lowest platelet aggregation ratio decrease and the most significant 111In-labelled platelet mobilization from hepatic and splenic stores with a corresponding increase of labelled and unlabelled platelet counts in blood, was obtained in ASA-treated dogs. Such changes were less marked when ASA plus indobufen was injected. In indobufen-treated dogs a similar mobilization of 111In-labelled platelets with an increase in circulating platelet numbers was evident only after the second adrenaline injection. It is concluded that platelet mobilization is mainly dependent on the production of an ASA-sensitive substance.

The author reviews the difficulties in diagnosing tuberculosis infection with the current BCG National Vaccination Plan. The author points out some directions that, in her point of view, may provide a clearer interpretation of the tuberculin skin test, bearing in mind the child's clinical, epidemiologic and social background.

The authors review the main imaging findings of aneurysms and dissections of the aorta. Based on the experience and imaging techniques available in their institution (Conventional Radiology, Sonography and Computed Tomography), they try to make a decision tree of radiologic procedures in ambulatory and emergency patients. Nowadays, in the majority of situations, these techniques allow the Radiologist to make the correct diagnosis, detect the complications and evaluate the patients in the pre and post-surgical phases. Other imaging techniques not available in their institution, such as Magnetic Resonance Imaging and Aortography, will be mentioned in view of their usefulness in some specific situations.

The authors review the main imaging findings of aneurysms and dissections of the aorta. Based on the experience and imaging techniques available in their institution (Conventional Radiology, Sonography and Computed Tomography), they try to make a decision tree of radiologic procedures in ambulatory and emergency patients. Nowadays, in the majority of situations, these techniques allow the Radiologist to make the correct diagnosis, detect the complications and evaluate the patients in the pre and post-surgical phases. Other imaging techniques not available in their institution, such as Magnetic Resonance Imaging and Aortography, will be mentioned in view of their usefulness in some specific situations.

Background: We aimed to estimate the incidence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) seroconversion after baseline screening among oncology healthcare workers (HCW). Methods: This is a prospective longitudinal cohort study of HCW, applied at Centro de Terapia Oncologica (CTO), an Oncology clinic in Petropolis, Brazil. Baseline screening for SARS-CoV-2 occurred between April 9 -29, 2020 using rapid IgM and IgG serological tests for all HCW. Follow-up serology testing took place once between November 5-December 28, 2020 and included retesting with indirect chemiluminescence immunoassay LIAISON SARS-CoV-2 S1/S2 IgG all HCW for seroconversion incidence. Reverse transcriptase–polymerase chain reaction (RT-PCR) testing was offered at baseline and follow-up for all symptomatic staff. The McNemar test was used to assess the change in positive serology incidence in both tests. Results: The study included 60 HCW, with 40 females (66.7%). Mean age was of 43.4 years old (SD =14.5). At baseline SARS-CoV-2 antibody assessment, 57 (95%) were negative and 3 (5%) positive;59 (98%) asymptomatic HCW, and 1 symptomatic (1.6%) tested positive in RT-PCR. A total of 11 RT-PCR were performed since baseline until follow-up in symptomatic HCW, with 9 (81.8%) positive results, all of them with seroconversion. 6 (10%) asymptomatic HCW were seropositive at follow-up screening. None of baseline positive-serology asymptomatic HCW sustained their serology. Seroconversion occurred in 15 (25%) HCW - Table. The incidence of positive serologies in follow-up screening was statistically higher than at baseline (p = 0.008). [Formula presented] Conclusions: Most seroconversions were in symptomatic HCW, although the substantial number of positive serologies in asymptomatic HCW accent the importance and direct impact of regular universal testing. Seropositivity increased five-fold compared to baseline results. This detected increase in infections reflects a national pattern, suggesting community-based and not nosocomial transmission. Legal entity responsible for the study: The authors. Funding: Has not received any funding. Disclosure: All authors have declared no conflicts of interest.