48 resultados para three-body interaction
em Scielo Saúde Pública - SP
Resumo:
There are few studies on the role of innate immune response in dermatophytosis. An investigation was conducted to define the involvement of Toll-Like Receptors (TLRs) 2 and 4 in localized (LD) and disseminated (DD) dermatophytosis due to T. rubrum. Fifteen newly diagnosed patients, eight patients with LD and seven with DD, defined by involvement of at least three body segments were used in this study. Controls comprised twenty skin samples from healthy individuals undergoing plastic surgery. TLR2 and TLR4 were quantified in skin lesions by immunohistochemistry. A reduced expression of TLR4 in the lower and upper epidermis of both LD and DD patients was found compared to controls; TLR2 expression was preserved in the upper and lower epidermis of all three groups. As TLR4 signaling induces the production of inflammatory cytokines and neutrophils recruitment, its reduced expression likely contributed to the lack of resolution of the infection and the consequent chronic nature of the dermatophytosis. As TLR2 expression acts to limit the inflammatory process and preserves the epidermal structure, its preserved expression may also contribute to the persistent infection and limited inflammation that are characteristic of dermatophytic infections.
Resumo:
Seven unrelated patients with hemoglobin (Hb) H disease and 27 individuals with alpha-chain structural alterations were studied to identify the alpha-globin gene mutations present in the population of Southeast Brazil. The -alpha3.7, --MED and -(alpha)20.5 deletions were investigated by PCR, whereas non-deletional alpha-thalassemia (alphaHphalpha, alphaNcoIalpha, aaNcoI, alphaIcalpha and alphaTSaudialpha) was screened with restriction enzymes and by nested PCR. Structural alterations were identified by direct DNA sequencing. Of the seven patients with Hb H disease, all of Italian descent, two had the -(alpha)20.5/-alpha3.7 genotype, one had the --MED/-alpha3.7 genotype, one had the --MED/alphaHphalpha genotype and three showed interaction of the -alpha3.7 deletion with an unusual, unidentified form of non-deletional alpha-thalassemia [-alpha3.7/(aa)T]. Among the 27 patients with structural alterations, 15 (of Italian descent) had Hb Hasharon (alpha47Asp->His) associated with the -alpha3.7 deletion, 4 (of Italian descent) were heterozygous for Hb J-Rovigo (alpha53Ala->Asp), 4 (3 Blacks and 1 Caucasian) were heterozygous for Hb Stanleyville-II (alpha78Asn->Lys) associated with the alpha+-thalassemia, 1 (Black) was heterozygous for Hb G-Pest (alpha74Asp->Asn), 1 (Caucasian) was heterozygous for Hb Kurosaki (alpha7Lys->Glu), 1 (Caucasian) was heterozygous for Hb Westmead (alpha122His->Gln), and 1 (Caucasian) was the carrier of a novel silent variant (Hb Campinas, alpha26Ala->Val). Most of the mutations found reflected the Mediterranean and African origins of the population. Hbs G-Pest and Kurosaki, very rare, and Hb Westmead, common in southern China, were initially described in individuals of ethnic origin differing from those of the carriers reported in the present study and are the first cases to be reported in the Brazilian population.
Resumo:
The nonlinear interaction between Görtler vortices (GV) and three-dimensional Tollmien-Schlichting (TS) waves nonlinear interaction is studied with a spatial, nonparallel model based on the Parabolized Stability Equations (PSE). In this investigation the effect of TS wave frequency on the nonlinear interaction is studied. As verified in previous investigations using the same numerical model, the relative amplitudes and growth rates are the dominant parameters in GV/TS wave interaction. In this sense, the wave frequency influence is important in defining the streamwise distance traveled by the disturbances in the unstable region of the stability diagram and in defining the amplification rates that they go through.
Resumo:
The unsteady, viscous, supersonic flow over a spike-nosed body of revolution is numerically investigated by solving the Navier-Stokes equations. The time-accurate computations are performed employing an implicit algorithm based on the second-order time-accurate LU-SGS scheme with the incorporation of a subiteration procedure to maintain time accuracy. The characteristics of the flow field for a Mach number of 3.0, Reynolds number of 7.87 x 10(6)/m, and angles of attack of 5 and 10 degrees are described. Self-sustained asymmetric shock wave oscillations were observed in the numerical computations for these angles of attack. The main characteristic of the flow field, as well as its influence on drag coefficient is discussed.
Resumo:
With the purpose of at lowering costs and reendering the demanded information available to users with no access to the internet, service companies have adopted automated interaction technologies in their call centers, which may or may not meet the expectations of users. Based on different areas of knowledge (man-machine interaction, consumer behavior and use of IT) 13 propositions are raised and a research is carried out in three parts: focus group, field study with users and interviews with experts. Eleven automated service characteristics which support the explanation for user satisfaction are listed, a preferences model is proposed and evidence in favor or against each of the 13 propositions is brought in. With balance scorecard concepts, a managerial assessment model is proposed for the use of automated call center technology. In future works, the propositions may become verifiable hypotheses through conclusive empirical research.
Resumo:
This article presents the results of a research to understand the conditions of interaction between work and three specific information systems (ISs) used in the Brazilian banking sector. We sought to understand how systems are redesigned in work practices, and how work is modified by the insertion of new systems. Data gathering included 46 semi-structured interviews, together with an analysis of system-related documents. We tried to identify what is behind the practices that modify the ISs and work. The data analysis revealed an operating structure: a combination of different practices ensuring that the interaction between agents and systems will take place. We discovered a structure of reciprocal conversion caused by the increased technical skills of the agent and the humanization of the systems. It is through ongoing adjustment between work and ISs that technology is tailored to the context and people become more prepared to handle with technology.
Resumo:
OBJECTIVE: To determine the best cut-offs of body mass index for identifying alterations of blood lipids and glucose in adolescents. METHODS: A probabilistic sample including 577 adolescent students aged 12-19 years in 2003 (210 males and 367 females) from state public schools in the city of Niterói, Southeastern Brazil, was studied. The Receiver Operating Characteristic curve was used to identify the best age-adjusted BMI cut-off for predicting high levels of serum total cholesterol (>150mg/dL), LDL-C (>100mg/dL), serum triglycerides (>100mg/dL), plasma glucose (>100mg/dL) and low levels of HDL-C (< 45mg/dL). Four references were used to calculate sensitivity and specificity of BMI cut-offs: one Brazilian, one international and two American. RESULTS: The most prevalent metabolic alterations (>50%) were: high total cholesterol and low HDL-C. BMI predicted high levels of triglycerides in males, high LDL-C in females, and high total cholesterol and the occurrence of three or more metabolic alterations in both males and females (areas under the curve range: 0.59 to 0.67), with low sensitivity (57%-66%) and low specificity (58%-66%). The best BMI cut-offs for this sample (20.3 kg/m² to 21.0 kg/m²) were lower than those proposed in the references studied. CONCLUSIONS: Although BMI values lower than the International cut-offs were better predictor of some metabolic abnormalities in Brazilian adolescents, overall BMI is not a good predictor of these abnormalities in this population.
Resumo:
OBJECTIVE To comprehend the perception of body image in adolescence. METHODS A qualitative study was conducted with eight focus groups with 96 students of both sexes attending four public elementary school institutions in the city of Rio de Janeiro, Southeastern Brazil, in 2013. An interview guide with questions about the adolescents’ feelings in relation to: their bodies, standards of idealized beauty, practice of physical exercise and sociocultural influences on self-image. In the data analysis we sought to understand and interpret the meanings and contradictions of narratives, understanding the subjects’ context and reasons and the internal logic of the group. RESULTS Three thematic categories were identified. The influence of media on body image showed the difficulty of achieving the perfect body and is viewed with suspicion in face of standards of beauty broadcast; the importance of a healthy body was observed as standards of beauty and good looks were closely linked to good physical condition and result from having a healthy body; the relationship between the standard of beauty and prejudice, as people who are not considered attractive, having small physical imperfections, are discriminated against and can be rejected or even excluded from society. CONCLUSIONS The standard of perfect body propagated by media influences adolescents’ self-image and, consequently, self-esteem and is considered an unattainable goal, corresponding to a standard of beauty described as artificial and unreal. However, it causes great suffering and discrimination against those who do not feel they are attractive, which can lead to health problems resulting from low self-esteem.
Resumo:
In the present study the frequencies of immunity against hepatitis B (HB) and of potentially contaminating accidents among medical students of a Brazilian public university were evaluated. Of all the 400 students who should have been immunized, 303 (75.7%), 66.3% of whom were women, answered an anonymous, self-administered questionnaire. Serum anti-HBs were determined in 205 of them and titers > 10 UI/L were considered to be protective. A total of 86.8% of students had received three doses of HB vaccine. The frequency of immunity among women (96.4%) was higher (p = 0.04) than that among men (87.7%). Among those who did not have immunity, 12/13 (92.3%) had been vaccinated before entering medical school. Only 11% of the students with complete vaccination had previously verified serological response to the vaccine. A total of 23.6% reported having been somehow exposed to blood or secretions. Among final-year students, this frequency was 45.0%, being similar among men (47.8%) and women (43.2%). Of all these accidents, 57.7% were due to body fluids coming in contact with mucosa and 42.3% due to cut and puncture accidents. The results from this study show that: 1) the frequency of immunity against HB is high among the evaluated medical students, although verification of response to vaccination is not a concern for them; 2) anti-HBs titers should be verified after complete vaccination and on a regular basis, especially by men; and 3) the frequency of potentially contaminating accidents is high.
Resumo:
Introduction: Highly Active Antiretroviral Therapy (HAART) has improved and extended the lives of thousands of people living with HIV/AIDS around the world. However, this treatment can lead to the development of adverse reactions such as lipoatrophy/lipohypertrophy syndrome (LLS) and its associated risks. Objective: This study was designed to assess the prevalence of self-reported lipodystrophy and nutritional status by anthropometric measurements in patients with HIV/AIDS. Methods: An observational study of 227 adult patients in the Secondary Immunodeficiencies Outpatient Department of Dermatology, Hospital das Clínicas, Faculty of Medicine, University of São Paulo (3002 ADEE-HCFMUSP). The sample was divided into three groups; Group 1 = 92 patients on HAART and with self-reported lipodystrophy, Group 2 = 70 patients on HAART without self-reported lipodystrophy and Group 3 = 65 patients not taking HAART. The nutritional status of individuals in the study sample was determined by body mass index (BMI) and percentage of body fat (% BF). The cardiovascular risk and diseases associated with abdominal obesity were determined by waist/hip ratio (WHR) and waist circumference (WC). Results: The prevalence of self-reported lipoatrophy/lipohypertrophy syndrome was 33% among women and 59% among men. Anthropometry showed depletion of fat mass in the evaluation of the triceps (TSF) in the treatment groups with HAART and was statistically independent of gender; for men p = 0.001, and for women p = 0.007. Similar results were found in the measurement of skin folds of the upper and lower body (p = 0.001 and p = 0.003 respectively). In assessing the nutritional status of groups by BMI and % BF, excess weight and body fat were more prevalent among women compared to men (p = 0.726). The WHR and WC revealed risks for cardiovascular and other diseases associated with abdominal obesity for women on HAART and with self-reported LLS (p = 0.005) and (p = 0.011). Conclusions: Anthropometric measurements were useful in the confirmation of the prevalence of LLS. BMI alone does not appear to be a good parameter for assessing the nutritional status of HIV-infected patients on HAART and with LLS. Other anthropometric measurements are needed to evaluate patients with the lipoatrophy/lipohypertrophy syndrome.
Resumo:
In this study, I investigated the reproductive biology of fish species from the family Characidae of the order Characiformes. I also investigated the relationship between reproductive biology and body weight and interpreted this relationship in a phylogenetic context. The results of the present study contribute to the understanding of the evolution of the reproductive strategies present in the species of this family. Most larger characid species and other characiforms exhibit a reproductive pattern that is generally characterized by a short seasonal reproductive period that lasts one to three months, between September and April. This is accompanied by total spawning, an extremely high fecundity, and, in many species, a reproductive migration. Many species with lower fecundity exhibit some form of parental care. Although reduction in body size may represent an adaptive advantage, it may also require evolutionary responses to new biological problems that arise. In terms of reproduction, smaller species have a tendency to reduce the number of oocytes that they produce. Many small characids have a reproductive pattern similar to that of larger characiforms. On the other hand they may also exhibit a range of modifications that possibly relate to the decrease in body size and the consequent reduction in fecundity. Examples of changes in the general reproductive pattern include the following: reduction in the size of mature oocytes; increase in fecundity; production of several batches of oocytes; an extended reproductive period or even continuous reproduction that allows individuals to reproduce more than once a year; high growth rates; rapid recruitment of juveniles; presence of more than one reproductive cohort that increases the sexually active population; and multiple independent development of insemination as a reproductive strategy. These changes are possibly associated with adaptive pressures that are related to the reduction in body size. In addition, such reproductive characteristics or novelties may reflect the phylogenetic history of a given species.
Resumo:
Animals (122 mice) were infected each with eighty cercariae of S. mansoni and subsequently challenged intravenously eight weeks later with the following gram-negative organisms. S. typhi, E. coli, Klebsiella-enterobacter species, Proteus mirabilis and Pseudomonas aeruginosa. Enumeration of bacteria in the liver, spleen and blood and S. mansoni from the portal sistem was performed from one to four weeks later in infected animals. A significant difference between infection produced by S. typhi and other gram negative organisms was observed: S. typhi persisted longer in the spleen and liver and could be recovered from S. mansoni worms up to three weeks following bacterial infection. Other gram negative bacteria disappeared from S. mansoni worms after two weeks of initial challenge. Additional animals (51 mice) infected with S. mansoni were given S. typhi, E. coli or sterile saline. After two weeks, animals were sacrificed and the recovery rate of worms from the portal system, and the mesenteric and hepatic oogram were determined. in animals infected with E. coli a significant decrease in the number of worms was observed compared to the saline control group; thirty worms were recovered in the control group compared to two worms in e. coli infected animals. In addition, the patterns of oviposition was significantly different in these latter animals suggesting complete inhibition of this process. Following S. typhi infection the difference in recovery of worms and pattern of oviposition was minimal. These findings suggest a difference in the interaction of various gram negative bacteria and S. mansoni and are consistent with the clinical observation of prolonged salmonella bacteremia in patients with schistosomiasis.
Resumo:
Megazol, nifurtimox, benznidazol and allopurinol were investigated, by light and electron µscopy, for their action on T. cruzi. Both the direct effect upon amastigote and trypomastigote forms and the effect upon the interaction of heart muscle cells (HMC) with bloodstream trypomastigotes were studied. The proliferation of amastigotes in Warren medium was inhibited in a dose-dependent manner by megazol, nifurtimox and benznidazol. Treatment of amastigotes (25-50 µM/24 h) and trypomastigotes (25 µM/24h) led to several ultrastructural alterations in the parasites. These three drugs also had a potent effect on the treatment of infected heart muscle cells when added at the beginning of the interaction or after one or three days of infection. The interiorized parasites showed a similar pattern of ultrastructural alterations as observed by the direct effect on the amastigotes. The primary heart muscle cell culture proved to be a suitable model for the study of drugs on intracellular parasites. Likewise, the amastigote proliferation in axenic medium was shown to be an adequate assay for an initial trial of drugs. These parameters seem very reliable to us for a systematic investigation of the mechanism of action of new drugs.
Resumo:
We herein present an improved assay for detecting the presence of Trypanosoma cruzi in infected cultures. Using chagasic human sera (CHS), we were able to detect T. cruzi infection in primary cultures of both peritoneal macrophages and heart muscle cells (MHC). To avoid elevated background levels - hitherto observed in all experiments especially in those using HMC - CHS were preincubated with uninfected cells in monolayers or suspensions prior to being used for detection of T. cruzi in infected monolayers. Preincubation with cell suspensions gave better results than with monolayers, reducing background by up to three times and increasing sensitivity by to twenty times. In addition, the continous fibroplastic cell line L929 was shown to be suitable for preadsorption of CHS. These results indicate that the high background levels observed in previous reports may be due to the presence of human autoantibodies that recognize surface and/or extracellular matrix components in cell monolayers. We therefore propose a modified procedure that increases the performance of the ELISA method, making it an useful tool even in cultures that would otherwise be expected to present low levels of infection or high levels of background
Resumo:
Three isosporan species are described from the double-collared seedeater, Sporophila caerulescens from Eastern Brazil. Isospora sporophilae n. sp. oocysts spherical to subspherical; oocyst wall bi-layered, smooth, inner layer colorless to pale yellowish, 21.6 × 20.9 (19.20-23.20 × 18.40-22.60) µm, shape-index 1.03 ± 0.02 (1-1.10), with no micropyle or oocyst residuum. Polar bodies splinter-like or comma-like. Sporocysts ovoidal, 15.2 × 10.6 (17.40-12.80 × 12.60-8.40) µm, shape-index 1.43 ± 0.14 (1.17-1.81), with knob-like Stieda body and residuum. Large crystalloid body in the center of the sporocyst. Isospora flausinoi n. sp. oocysts spherical to subspherical, oocyst wall bi-layered, smooth, colorless, 17.30 x 16.53 (14-20 × 13.60-20) µm, shape-index 1.05 ± 0.04 (1-1.21). Micropyle and oocyst residuum absent; presence of a large polar body. Sporocyst piriform, 14.88 x 10.70 (11.80-18 × 8-12.40) µm, shape-index 1.40 ± 0.18 (1.07-1.77), with smooth, thin, single-layered wall. Sporocyst with rounded Stieda body with no substieda body, and residuum composed of granular material. Isospora teixeirafilhoi n. sp. oocysts spherical to subspherical, oocyst wall bi-layered, smooth, colorless, 17.41 x 16.81 (15.60 19.40 × 14.20-18.80) µm. Shape-index 1.04 ± 0.08 (1-1.12). Micropyle and oocyst residuum absent; presence of a small double-lobuled polar body. Sporocyst ovoid, 11.74 × 8.12 (9-14.20 × 6.20-9.40) µm. Shape-index 1.46 ± 0.23 (1.06-1.88). Sporocyst with knob-like Stieda body, no sub-Stieda body and residuum composed of granular material.