76 research outputs found
The use of oral recombinant feline interferon omega in two cats with type II diabetes mellitus and concurrent feline chronic gingivostomatitis syndrome
Articles in International JournalsFeline Chronic Gingivostomatitis Syndrome (FCGS) is a common disease in clinical practice. Among the therapeutic
options available, long-acting corticosteroids are frequently used due to their anti-inflammatory and
immunosuppressive properties. Although they may improve the clinical symptoms, they can lead to a progressive
form of the disease that becomes refractory to treatment. Furthermore, their direct relationship with type II diabetes
mellitus (DM) is well known. Consequently, these drugs are controversial and not recommended for routine
management of FCGS. Recombinant feline interferon-omega (rFeIFN-ω) is an immunomodulatory compound.
Recently, its daily oral administration has been shown to be successful in treating refractory cases of FCGS. This case
study describes two clinical cases of type II DM complicated by FCGS. Both animals were calicivirus positive and
they had been previously treated with long-acting corticosteroids, which may have been the major cause of DM.
The two cats were treated with glargine insulin (Lantus, starting dose 1 IU/cat twice daily (BID)), achieving remission
10 and 18 weeks later respectively. Considering the difficulty with control of FCGS in these animals, an oral daily
dose of rFeIFN-ω was started as an alternative to long-acting corticosteroids. In both cats oral clinical signs
gradually improved and 60 days after the start of therapy the owners reported a significant relief of pain during
mastication. According to the authors’ knowledge, this is the first case report that describes the successful use of
rFeIFN-ω in the management of FCGS in type II diabetic cats, in which long-acting corticosteroids are
contraindicated
Multiple populations in globular clusters. Lessons learned from the Milky Way globular clusters
Recent progress in studies of globular clusters has shown that they are not
simple stellar populations, being rather made of multiple generations. Evidence
stems both from photometry and spectroscopy. A new paradigm is then arising for
the formation of massive star clusters, which includes several episodes of star
formation. While this provides an explanation for several features of globular
clusters, including the second parameter problem, it also opens new
perspectives about the relation between globular clusters and the halo of our
Galaxy, and by extension of all populations with a high specific frequency of
globular clusters, such as, e.g., giant elliptical galaxies. We review progress
in this area, focusing on the most recent studies. Several points remain to be
properly understood, in particular those concerning the nature of the polluters
producing the abundance pattern in the clusters and the typical timescale, the
range of cluster masses where this phenomenon is active, and the relation
between globular clusters and other satellites of our Galaxy.Comment: In press (The Astronomy and Astrophysics Review
Specific prebiotics modulate gut microbiota and immune activation in HAART-naive HIV-infected adults: results of the “COPA” pilot randomized trial
Intestinal mucosal immune system is an early target for human immunodeficiency virus type 1 (HIV-1) infection, resulting in CD4+ T-cell depletion, deterioration of gut lining, and fecal microbiota composition. We evaluated the effects of a prebiotic oligosaccharide mixture in highly active antiretroviral therapy (HAART)-naive HIV-1-infected adults. In a pilot double-blind, randomized, placebo-controlled study, 57 HAART-naive HIV-1-infected patients received a unique oligosaccharide mixture (15 or 30 g short chain galactooligosaccharides/long chain fructooligosaccharides/pectin hydrolysate-derived acidic oligosaccharides (scGOS/lcFOS/pAOS) daily) or a placebo for 12 weeks. Microbiota composition improved significantly with increased bifidobacteria, decreased Clostridium coccoides/Eubacterium rectale cluster, and decreased pathogenic Clostridium lituseburense/Clostridium histolyticum group levels upon prebiotic supplementation. In addition, a reduction of soluble CD14 (sCD14), activated CD4+/CD25+ T cells, and significantly increased natural killer (NK) cell activity when compared with control group were seen in the treatment group. The results of this pilot trial highly significantly show that dietary supplementation with a prebiotic oligosaccharide mixture results in improvement of the gut microbiota composition, reduction of sCD14, CD4+ T-cell activation (CD25), and improved NK cell activity in HAART-naive HIV-infected individuals
Hypothyroidism attenuates protein tyrosine nitration, oxidative stress and renal damage induced by ischemia and reperfusion: effect unrelated to antioxidant enzymes activities
BACKGROUND: It has been established that hypothyroidism protects rats against renal ischemia and reperfusion (IR) oxidative damage. However, it is not clear if hypothyroidism is able to prevent protein tyrosine nitration, an index of nitrosative stress, induced by IR or if antioxidant enzymes have involved in this protective effect. In this work it was explored if hypothyroidism is able to prevent the increase in nitrosative and oxidative stress induced by IR. In addition the activity of the antioxidant enzymes catalase, glutathione peroxidase, and superoxide dismutase was studied. Control and thyroidectomized (HTX) rats were studied 24 h of reperfusion after 60 min ischemia. METHODS: Male Wistar rats weighing 380 ± 22 g were subjected to surgical thyroidectomy. Rats were studied 15 days after surgery. Euthyroid sham-operated rats were used as controls (CT). Both groups of rats underwent a right kidney nephrectomy and suffered a 60 min left renal ischemia with 24 h of reperfusion. Rats were divided in four groups: CT, HTX, IR and HTX+IR. Rats were sacrificed and samples of plasma and kidney were obtained. Blood urea nitrogen (BUN) and creatinine were measured in blood plasma. Kidney damage was evaluated by histological analysis. Oxidative stress was measured by immunohistochemical localization of protein carbonyls and 4-hydroxy-2-nonenal modified proteins. The protein carbonyl content was measured using antibodies against dinitrophenol (DNP)-modified proteins. Nitrosative stress was measured by immunohistochemical analysis of 3-nitrotyrosine modified proteins. The activity of the antioxidant enzymes catalase, glutathione peroxidase, and superoxide dismutase was measured by spectrophotometric methods. Multiple comparisons were performed with ANOVA followed by Bonferroni t test. RESULTS: The histological damage and the rise in plasma creatinine and BUN induced by IR were significantly lower in HTX+IR group. The increase in protein carbonyls and in 3-nitrotyrosine and 4-hydroxy-2-nonenal modified proteins was prevented in HTX+IR group. IR-induced decrease in renal antioxidant enzymes was essentially not prevented by HTX in HTX+IR group. CONCLUSION: Hypothyroidism was able to prevent not only oxidative but also nitrosative stress induced by IR. In addition, the antioxidant enzymes catalase, glutathione peroxidase, and superoxide dismutase seem not to play a protective role in this experimental model
True versus False Parasite Interactions: A Robust Method to Take Risk Factors into Account and Its Application to Feline Viruses
International audienceBACKGROUND: Multiple infections are common in natural host populations and interspecific parasite interactions are therefore likely within a host individual. As they may seriously impact the circulation of certain parasites and the emergence and management of infectious diseases, their study is essential. In the field, detecting parasite interactions is rendered difficult by the fact that a large number of co-infected individuals may also be observed when two parasites share common risk factors. To correct for these "false interactions", methods accounting for parasite risk factors must be used. METHODOLOGY/PRINCIPAL FINDINGS: In the present paper we propose such a method for presence-absence data (i.e., serology). Our method enables the calculation of the expected frequencies of single and double infected individuals under the independence hypothesis, before comparing them to the observed ones using the chi-square statistic. The method is termed "the corrected chi-square." Its robustness was compared to a pre-existing method based on logistic regression and the corrected chi-square proved to be much more robust for small sample sizes. Since the logistic regression approach is easier to implement, we propose as a rule of thumb to use the latter when the ratio between the sample size and the number of parameters is above ten. Applied to serological data for four viruses infecting cats, the approach revealed pairwise interactions between the Feline Herpesvirus, Parvovirus and Calicivirus, whereas the infection by FIV, the feline equivalent of HIV, did not modify the risk of infection by any of these viruses. CONCLUSIONS/SIGNIFICANCE: This work therefore points out possible interactions that can be further investigated in experimental conditions and, by providing a user-friendly R program and a tutorial example, offers new opportunities for animal and human epidemiologists to detect interactions of interest in the field, a crucial step in the challenge of multiple infections
Catalytic Transformations of Alkynes via Ruthenium Vinylidene and Allenylidene Intermediates
NOTICE: This is the peer reviewed version of the following book chapter: Varela J. A., González-Rodríguez C., Saá C. (2014). Catalytic Transformations of Alkynes via Ruthenium Vinylidene and Allenylidene Intermediates. In: Dixneuf P., Bruneau C. (eds) Ruthenium in Catalysis. Topics in Organometallic Chemistry, vol 48, pp. 237-287. Springer, Cham. [doi: 10.1007/3418_2014_81]. This article may be used for non-commercial purposes in accordance with Springer Verlag Terms and Conditions for self-archiving.Vinylidenes are high-energy tautomers of terminal alkynes and they can be stabilized by coordination with transition metals. The resulting metal-vinylidene species have interesting chemical properties that make their reactivity different to that of the free and metal π-coordinated alkynes: the carbon α to the metal is electrophilic whereas the β carbon is nucleophilic. Ruthenium is one of the most commonly used transition metals to stabilize vinylidenes and the resulting species can undergo a range of useful transformations. The most remarkable transformations are the regioselective anti-Markovnikov addition of different nucleophiles to catalytic ruthenium vinylidenes and the participation of the π system of catalytic ruthenium vinylidenes in pericyclic reactions. Ruthenium vinylidenes have also been employed as precatalysts in ring closing metathesis (RCM) or ring opening metathesis polymerization (ROMP).
Allenylidenes could be considered as divalent radicals derived from allenes. In a similar way to vinylidenes, allenylidenes can be stabilized by coordination with transition metals and again ruthenium is one of the most widely used metals. Metalallenylidene complexes can be easily obtained from terminal propargylic alcohols by dehydration of the initially formed metal-hydroxyvinylidenes, in which the reactivity of these metal complexes is based on the electrophilic nature of Cα and Cγ, while Cβ is nucleophilic. Catalytic processes based on nucleophilic additions and pericyclic reactions involving the π system of ruthenium allenylidenes afford interesting new structures with high selectivity and atom economy
Supernova remnants: the X-ray perspective
Supernova remnants are beautiful astronomical objects that are also of high
scientific interest, because they provide insights into supernova explosion
mechanisms, and because they are the likely sources of Galactic cosmic rays.
X-ray observations are an important means to study these objects.And in
particular the advances made in X-ray imaging spectroscopy over the last two
decades has greatly increased our knowledge about supernova remnants. It has
made it possible to map the products of fresh nucleosynthesis, and resulted in
the identification of regions near shock fronts that emit X-ray synchrotron
radiation.
In this text all the relevant aspects of X-ray emission from supernova
remnants are reviewed and put into the context of supernova explosion
properties and the physics and evolution of supernova remnants. The first half
of this review has a more tutorial style and discusses the basics of supernova
remnant physics and thermal and non-thermal X-ray emission. The second half
offers a review of the recent advances.The topics addressed there are core
collapse and thermonuclear supernova remnants, SN 1987A, mature supernova
remnants, mixed-morphology remnants, including a discussion of the recent
finding of overionization in some of them, and finally X-ray synchrotron
radiation and its consequences for particle acceleration and magnetic fields.Comment: Published in Astronomy and Astrophysics Reviews. This version has 2
column-layout. 78 pages, 42 figures. This replaced version has some minor
language edits and several references have been correcte
Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model
We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society
Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model
We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO’s second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h95%0=3.47×10−25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering
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