47 resultados para Viral suppression
Resumo:
BACKGROUND AND PURPOSE We investigated the effect of the phosphodiesterase-5 inhibitor, tadalafil, on the acute hypernociception in rat models of arthritis. EXPERIMENTAL APPROACH Rats were treated with either an intra-articular injection of zymosan (1 mg) or surgical transection of the anterior cruciate ligament (as an osteoarthritis model). Controls received saline intra-articular or sham operation respectively. Joint pain was evaluated using the articular incapacitation test measured over 6 h following zymosan or between 4 and 7 days after anterior cruciate ligament transection. Cell counts, tumour necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), and the chemokine, cytokine-induced neutrophil chemoattractant-1 (CINC-1) were measured in joint exudates 6 h after zymosan. Groups received tadalafil (0.02-0.5 mg.kg(-1) per os) or saline 2 h after intra-articular zymosan. Other groups received the mu-opioid receptor antagonist naloxone or the cGMP inhibitor 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ) before tadalafil. KEY RESULTS Tadalafil dose-dependently inhibited hypernociception in zymosan and osteoarthritis models. In zymosan-induced arthritis, tadalafil significantly decreased cell influx and TNF-alpha release but did not alter IL-1 or CINC-1 levels. Pretreatment with ODQ but not with naloxone prevented the anti-inflammatory effects of tadalafil. CONCLUSIONS AND IMPLICATIONS Therapeutic oral administration of tadalafil provided analgesia mediated by guanylyl cyclase and was independent of the release of endogenous opioids. This effect of tadalafil was associated with a decrease in neutrophil influx and TNF-alpha release in inflamed joints.
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Depressed patients have reduced glucocorticoid receptor (GR) function, as demonstrated by resistance to the suppressive effects of the synthetic glucocorticoid hormone, and GR agonist, dexamethasone. We have developed a suppressive test with prednisolone, a synthetic glucocorticoid that is similar to cortisol in its pharmacodynamics and pharmacokinetics, and binds to both the GR and the mineralocorticoid receptor (MR). We have found that depressed patients suppress normally to prednisolone, unless they are particularly non-responsive to treatment. In the present study, we evaluated 28 inpatients with treatment-resistant depression (TRD), and compared salivary cortisol secretion (at 0900 h, 1200 h and 1700 h) after placebo or after prednisolone (5 mg), before and after an inpatient treatment admission. Half of the patients (n = 14) reached treatment response. When comparing the assessment between admission and discharge, cortisol output after placebo fell (-26% of area under the curve; p = 0.024) while the output after prednisolone did not change. Moreover, there was no change in the response to prednisolone (percentage suppression) between admission at discharge, and this was not influenced by treatment response. Finally, we could confirm and extend our previously published data with prednisolone (5 mg), showing that depressed patients (n = 12) and controls (n = 12) suppressed equally to both 5 and 10 mg doses of prednisolone. This study suggests that the response to prednisolone is similar in depressed patients and controls at different doses of prednisolone, and does not change with symptomatic improvement. This is in contrast with findings, from us and others, using other measures of hypothalamic-pituitary-adrenal axis function, such as basal cortisol levels or the response to dexamethasone. Thus, we propose that the prednisolone suppression test may offer specific biological and clinical information, related to its action at both the GR and the MR. (C) 2010 Elsevier Ltd. All rights reserved.
Resumo:
Purpose: Corticoids have been an option for phimosis treatment since 1993. However, long-term use or repeated cycles pose a concern regarding drug absorption and consequent systemic effects. The aim of this study was to investigate the effect of topical corticoids used in treating phimosis on the hypothalamus-pituitary-adrenal axis in children. Materials and Methods: A total of 31 children were included in the study. Cortisol secretion was evaluated by the measurement of salivary cortisol in saliva samples collected at 9:00 a.m, before starting treatment and after 8 weeks of topical treatment with 0.05% clobetasol propionate. Salivary cortisol was determined by radioimmunoassay. To confirm that use of clobetasol propionate was not detected by the assay, the presence of cortisol circadian rhythm was checked by an extra saliva sample obtained at 11:00 p.m. from 10 children, and was observed to be maintained in all of them. Results: No significant difference in salivary cortisol levels was observed between samples obtained at 9:00 a.m. before starting treatment and after completing treatment when the entire group was analyzed. However, in 2 children the salivary cortisol levels after treatment were lower than the cutoff value (358 ng/dl) assumed to be suggestive of hypothalamus-pituitary-adrenal axis suppression. Conclusions: Topical clobetasol propionate used twice daily for clinical treatment of phimosis does not affect the hypothalamus-pituitary-adrenal axis in most patients. However, salivary cortisol level should be considered as a laboratory marker in long-term treatment or during repeated cycles to detect possible hypothalamus-pituitary-adrenal axis suppression.
Resumo:
We consider two viral strains competing against each other within individual hosts (at cellular level) and at population level (for infecting hosts) by studying two cases. In the first case, the strains do not mutate into each other. In this case, we found that each individual in the population can be infected by only one strain and that co-existence in the population is possible only when the strain that has the greater basic intracellular reproduction number, R (0c) , has the smaller population number R (0p) . Treatment against the one strain shifts the population equilibrium toward the other strain in a complicated way (see Appendix B). In the second case, we assume that the strain that has the greater intracellular number R (0c) can mutate into the other strain. In this case, individual hosts can be simultaneously infected by both strains (co-existence within the host). Treatment shifts the prevalence of the two strains within the hosts, depending on the mortality induced by the treatment, which is, in turn, dependent upon the doses given to each individual. The relative proportions of the strains at the population level, under treatment, depend both on the relative proportions within the hosts (which is determined by the dosage of treatment) and on the number of individuals treated per unit time, that is, the rate of treatment. Implications for cases of real diseases are briefly discussed.
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Community-acquired pneumonia (CAP) is a common cause of morbidity among children. Evidence on seasonality, especially on the frequency of viral and bacterial causative agents is scarce; such information may be useful in an era of changing climate conditions worldwide. To analyze the frequency of distinct infections, meteorological indicators and seasons in children hospitalized for CAP in Salvador, Brazil, nasopharyngeal aspirate and blood were collected from 184 patients aged < 5 y over a 21-month period. Fourteen microbes were investigated and 144 (78%) cases had the aetiology established. Significant differences were found in air temperature between spring and summer (p = 0.02) or winter (p < 0.001), summer and fall (p = 0.007) or winter (p < 0.001), fall and winter (p = 0.002), and on precipitation between spring and fall (p = 0.01). Correlations were found between: overall viral infections and relative humidity (p = 0.006; r = 0.6) or precipitation (p = 0.03; r = 0.5), parainfluenza and precipitation (p = 0.02; r = -0.5), respiratory syncytial virus (RSV) and air temperature (p = 0.048; r = -0.4) or precipitation (p = 0.045; r = 0.4), adenovirus and precipitation (p = 0.02; r = 0.5), pneumococcus and air temperature (p = 0.04; r = -0.4), and Chlamydia trachomatis and relative humidity (p = 0.02; r = -0.5). The frequency of parainfluenza infection was highest during spring (32.1%; p = 0.005) and that of RSV infection was highest in the fall (36.4%; p < 0.001). Correlations at regular strength were found between several microbes and meteorological indicators. Parainfluenza and RSV presented marked seasonal patterns.
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We report an investigation for 16 bacteria and viruses among 184 children hospitalized with pneumonia in Salvador, Brazil. Etiology was established in 144 (78%) cases. Viral, bacterial, and mixed infections were found in 110 (60%), 77 (42%), and 52 (28%) patients, respectively. Rhinovirus (21%) and Streptococcus pneumoniae (21%) were the most common pathogens. Our results demonstrate the importance of viral and pneumococcal infections among those patients.
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The etiology of idiopathic peripheral facial palsy (IPFP) is still uncertain; however, some authors suggest the possibility of a viral infection. Aim: to analyze the ultrastructure of the facial nerve seeking viral evidences that might provide etiological data. Material and Methods: We studied 20 patients with peripheral facial palsy (PFP), with moderate to severe FP, of both genders, between 18-60 years of age, from the Clinic of Facial Nerve Disorders. The patients were broken down into two groups - Study: eleven patients with IPFP and Control: nine patients with trauma or tumor-related PFP. The fragments were obtained from the facial nerve sheath or from fragments of its stumps - which would be discarded or sent to pathology exam during the facial nerve repair surgery. The removed tissue was fixed in 2% glutaraldehyde, and studied under Electronic Transmission Microscopy. Results: In the study group we observed an intense repair cellular activity by increased collagen fibers, fibroblasts containing developed organelles, free of viral particles. In the control group this repair activity was not evident, but no viral particles were observed. Conclusion: There were no viral particles, and there were evidences of intense activity of repair or viral infection.
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We investigate the impact of the existence of a primordial magnetic field on the filter mass, characterizing the minimum baryonic mass that can form in dark matter (DM) haloes. For masses below the filter mass, the baryon content of DM haloes are severely depressed. The filter mass is the mass when the baryon to DM mass ratio in a halo is equal to half the baryon to DM ratio of the Universe. The filter mass has previously been used in semi-analytic calculations of galaxy formation, without taking into account the possible existence of a primordial magnetic field. We examine here its effect on the filter mass. For homogeneous comoving primordial magnetic fields of B(0) similar to 1 or 2 nG and a re-ionization epoch that starts at a redshift z(s) = 11 and is completed at z(r) = 8, the filter mass is increased at redshift 8, for example, by factors of 4.1 and 19.8, respectively. The dependence of the filter mass on the parameters describing the re-ionization epoch is investigated. Our results are particularly important for the formation of low-mass galaxies in the presence of a homogeneous primordial magnetic field. For example, for B(0) similar to 1 nG and a re-ionization epoch of z(s) similar to 11 and z(r) similar to 7, our results indicate that galaxies of total mass M similar to 5 x 108 M(circle dot) need to form at redshifts z(F) greater than or similar to 2.0, and galaxies of total mass M similar to 108 M(circle dot) at redshifts z(F) greater than or similar to 7.7.
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Ocimum basilicum L., popularly known as sweet basil, is a Lamiaceae species whose essential oil is mainly composed of monoterpenes, sesquiterpenes and phenylpropanoids. The contents of these compounds can be affected by abiotic and biotic factors such as infections caused by viruses. The main goal of this research was an investigation of the effects of viral infection on the essential oil profile of common basil. Seeds of O. basilicum L. cv. Genovese were sowed and kept in a greenhouse. Plants presenting two pairs of leaves above the cotyledons were inoculated with an unidentified virus isolated from a field plant showing chlorotic yellow spots and foliar deformation. Essential oils of healthy and infected plants were extracted by hydrodistillation and analyzed by GCMS. Changes in essential oil composition due to viral infection were observed. Methyleugenol and p-cresol,2,6-di-tert-butyl were the main constituents. However, methyleugenol contents were significantly decreased in infected plants.
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Little is known about clinical differences associated with cytomegalovirus (CMV) infection by distinct strains in renal transplant patients. Different clinical pictures may be associated with specific viral genotypes. viral load, as well as host factors. The objective of this study was to identify CMV strains to determine viral load (antigenemia), and their correlation with clinical data in renal transplant recipients. Seventy-one patients were enrolled, comprising 91 samples. After selection, polymorphonuclear cells were used to amplify and sequence the gB region of CMV DNA. The sequences were analyzed to ascertain the frequency of different genotypes. Additionally, the results of this Study showed that the gB coding gene presents a great variability, revealing a variety of patterns: classical gB (1.4%), gB1V (46.4%), classical gB2 (35.2%), gB2V (2.8%), gB3 (1.4%), classical gB4 (4.9%) and gB4V (4.9%). The mean viral load in kidney transplant patient was 75.1 positive cells (1-1000). A higher viral load was observed in patients with genotype 4 infection. Statistically significant differences were detected between gB1 and gB4 (p=0.010), and between gB2 and gB4 (p=0.021). The average numbers of positive cells in relation to clinical presentation were: 34.5 in asymptomatic, 49.5 in CMV associated syndrome and 120.7 in patients with invasive disease (p=0.048). As a group, gB1 was the most frequent strain and revealed a potential risk for developing invasive disease. Viral load also seemed to be important as a marker associated with clinical presentation of the disease. (C) 2008 Elsevier B.V. All rights reserved.
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Bovine Viral Diarrhea Virus (BVDV) is widespread in cattle in Brazil and research shows its large antigenic variability. Available vaccines are produced with virus strains isolated in other countries and may not be effective. In this study, inactivated vaccines containing the Brazilian BVDV-Ib IBSP11 isolate were developed and tested on 6 groups of 10 guinea pigs (Cavia porcellus). Animals in groups A and C received an aqueous vaccine (aluminum hydroxide); B and D groups received an oily vaccine (Montanide ISA50); Group E positive-control animals were given an imported commercial vaccine with BVDV-la Singer; Group F animals were sham vaccinated (negative control). Groups A, B and E received two doses, and Groups C and D, three, every 21 days. Twelve blood samples were taken, at 21-day intervals over 231 days, and evaluated for antibody titer through virus-neutralization (VN), using a homologous strain (IBSP11), and a heterologous strain (BVDV-la NADL). Most animals, 42 days following the first dose, seroconverted to both strains and, after the second dose, there was a significant increase of titers in all groups. The oily formulation induced greater response after the third administration. This increase was not observed with the aqueous vaccines, regardless of the virus used in the VN. Antibody decline was more rapid in animals that received aqueous vaccines. The results showed the importance of studying the influence of endemic strains of commercial vaccines, to improve the efficacy of BVD vaccination. Use of the endemic strain in vaccine formulation presented promising results, as well as the use of guinea pigs as a laboratory model. (C) 2011 Elsevier Ltd. All rights reserved.
Resumo:
The clearance of apoptotic cells by phagocytes is a fundamental process during tissue remodeling and resolution of inflammation. In turn, the phagocytosis of apoptotic cells generates signals that suppress pro-inflammatory activation of macrophages. These events occur during the resolution phase of inflammation and therefore the malfunctioning of this process may lead to inflammation-related tissue damage. Here, we demonstrate that the calcium-binding protein S100A9, normally abundant in the cytoplasm of neutrophils and also released by apoptotic neutrophils, is involved in the suppression of macrophages after the uptake of apoptotic neutrophils. Both, spontaneous and induced production of inflammatory species (nitric oxide, hydrogen peroxide and TNF-alpha) as well as the phagocytic activity were inhibited when macrophages were in presence of apoptotic neutrophils, conditioned medium from neutrophil cultures or a peptide corresponding to the C-terminal region of S100A9 protein. On the other hand, macrophages kept in the conditioned medium of neutrophils that was previously depleted of S100A9 were shown to resume the activated status. Finally, we demonstrate that the calcium-binding property of S100A9 might play a role in the suppression process, since the stimulation of intracellular calcium release with ionomycin significantly reversed the effects of the uptake of apoptotic neutrophils in macrophages. In conclusion, we propose that S100A9 is a novel component of the regulatory mechanisms of inflammation, acting side-by-side with other suppressor factors generated upon ingestion of apoptotic cells. (C) 2009 Elsevier GmbH. All rights reserved.
Resumo:
We show that halo effects enhance fusion cross sections of weakly bound systems, comparing with the situation when there is no-halo. We introduce dimensionless fusion functions and energy variable quantity to investigate systematical trends in the fusion cross sections of weakly bound nuclei at near-barrier energies. We observe very clearly complete fusion suppression at energies above the barrier due to dynamic effects of the breakup on fusion. We explain this suppression in terms of the repulsive polarization potential produced by the breakup.
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Realistic coupled-channel calculation results for the (18)[O] + (58,60,64)Ni systems in the bombarding energy range 34.5 <= E(Lab) <= 6-5 MeV are presented. The overall agreement with existing experimental data is quite good. Our calculations predict an unexpected fusion suppression for above-barrier energies, with an important contribution of the two neutron ((18)O, (16)O) transfer channel couplings. The sub-barrier fusion enhancement and the above barrier suppression, predicted by the calculations, are consistent with the nuclear structure of the Ni region. Comparisons with recently reported similar effects in reactions induced by the (6)He projectile are discussed. (C) 2009 Elsevier B.V. All rights reserved.
Resumo:
We have studied the spectroscopic properties of hair (white, blond, red, brown, and black) under illumination with visible light, giving special emphasis to the photoinduced generation of singlet oxygen ((1)O(2)). Irradiation of hair shafts (lambda(ex)>400 nm) changed their properties by degrading the melanin. Formation of C3 hydroperoxides in the melanin indol groups was proven by (1)H NMR. After 532-nm excitation, all hair shafts presented the characteristic (1)O(2) emission (lambda(em) = 1270 nm), whose intensity varied inversely with the melanin content. (1)O(2) lifetime was also shown to vary with hair type, being five times shorter in black hair than in blond hair, indicating the role of melanin as a (1)O(2) suppressor. Lifetime ranged from tenths of a nanosecond to a few microseconds, which is much shorter than the lifetime expected for (1)O(2) in the solvents in which the hair shafts were suspended, indicating that (1)O(2) is generated and suppressed inside the hair structure. Both eumelanin and pheomelanin were shown to produce and to suppress (1)O(2), with similar efficiencies. The higher amount of (1)O(2) generated in blond hair and its longer lifetime is compatible with the stronger damage that light exposure causes in blond hair. We propose a model to explain the formation and suppression of (1)O(2) in hair by photosensitization of melanin with visible light and the deleterious effects that an excess of visible light may cause in hair and skin. 2011 Published by Elsevier Inc.