Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
J Colloid Interface Sci ; 662: 438-445, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38364469

RESUMO

We investigate the impact of a magnetic field on surfactant concentration and interfacial forces across droplet surfaces within shear flows. Our analysis centers on a single two-dimensional ferrofluid droplet covered with surfactants, suspended in an immiscible, non-magnetizable liquid. The model combines incompressible Navier-Stokes equations and Maxwell's equations in the superparamagnetic limit in the single-fluid formulation, augmented by terms accounting for Marangoni, capillary, and magnetic forces at the droplet interface. We solve the surfactant convection-diffusion equation at the surface, while a non-linear Langmuir equation of state relates surfactant concentration to surface tension. The model is numerically solved using finite differences, a level-set method for multiphase flow computation, and the closest-point method for concentration equation. Our findings reveal that even though the surfactant is magnetically neutral, the presence of a magnetic field significantly modifies its distribution at the interface. A magnetic field perpendicular to the primary flow direction shifts the maximum concentration zone from the droplet tips toward the flow vorticity direction, while a parallel field produces the opposite effect. Alterations in surfactant distribution directly impact the surface tension field, offering a potential wireless means of controlling droplet dynamics.

2.
J Postgrad Med ; 68(4): 236-238, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36348607

RESUMO

Cystic bone lesions are the hallmark of skeletal abnormalities in patients with congenital generalized lipodystrophy (CGL). However, their pathophysiology is still unclear and theories about their origin remain largely speculative. This article reports on a patient with CGL and cystic bone lesions, some of them with unusual magnetic resonance imaging (MRI) findings that include elevated signal intensity on T1-weighted images and fluid-fluid levels, the latter evolving to a more "classic" cystic appearance on follow-up. Even though similar findings were first described almost 30 years ago, little attention was given to them back then; furthermore, other than the present report, no other study has performed sequential exams to follow their evolution in serial MRI. The authors conduct a review of the literature, hypothesizing that these remarkable findings may reflect an intermediate stage in the process of cystification of the abnormal bone marrow, incapable to perform adipose conversion, lending factual support to the modern theories about this issue.


Assuntos
Lipodistrofia Generalizada Congênita , Humanos , Lipodistrofia Generalizada Congênita/complicações , Imageamento por Ressonância Magnética , Tecido Adiposo/diagnóstico por imagem
3.
Poult Sci ; 100(2): 755-759, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33518129

RESUMO

Effects of the in ovo injection of organic microminerals (OM) (zinc, manganese, and copper) and posthatch holding time (HT) on the daily body temperature (bt) of broilers during grow out were determined. The hatching eggs from a Ross 708 breeder flock at 32 wk of age were incubated under standard commercial conditions. At 17 d of incubation, eggs were randomly allocated to 3 in ovo OM injection treatment (TRT) groups, and at 21 d of incubation, male hatchlings were randomly allocated to 2 posthatch HT treatment groups. Eggs were either not injected or were in ovo injected with diluent only or diluent containing the OM mixture. A 0-hour HT group had immediate access to water and feed, and a 24-hour HT (24HT) group contained birds that were kept in transport baskets in their pens without access to feed and water for 24 h before being released. Fifteen male birds were placed in each of 36 litter floor pens in a temperature-controlled facility. Approximately 2 birds in each of 6 replicate pens belonging to each TRT-HT combination had temperature transponders inserted subcutaneous in the mid-dorsal region of the neck. All birds were brooded under standard commercial conditions and had ad libitum access to feed and water after their respective HT. The bt of the same birds were determined daily at the same time each day beginning at hatch and ending on 39 d of posthatch age (AGE). There were no significant main or interactive effects involving TRT or HT for bt. However, there was a significant (P ≤ 0.0001) main effect because of AGE. A general increase in bt occurred during the 39 d grow out period. At hatch, bt was 40.54 ± 0.056°C and at AGE 39 was 41.46 ± 0.055°C. Under standard brooding conditions, a general increase in bt occurred in the Ross 708 broilers. However, these birds did not exhibit a significant bt response to TRT or a 24HT before placement.


Assuntos
Temperatura Corporal , Galinhas , Cobre/administração & dosagem , Manganês/administração & dosagem , Zinco/administração & dosagem , Animais , Galinhas/crescimento & desenvolvimento , Masculino , Distribuição Aleatória , Temperatura , Fatores de Tempo , Zigoto/efeitos dos fármacos
4.
Transbound Emerg Dis ; 66(3): 1360-1369, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30864242

RESUMO

Senecavirus A (SVA) belonging to the family Picornaviridae, genus Senecavirus was incidentally isolated in 2002 from the PER.C6 (transformed foetal retinoblast) cell line. However, currently, this virus is associated with vesicular disease in swine and it has been reported in countries such as the United States of America, Canada, China, Thailand and Colombia. In Brazil, the SVA was firstly reported in 2015 in outbreaks of vesicular disease in swine, clinically indistinguishable of Foot-and-mouth disease, a contagious viral disease that generates substantial economic losses. In the present work, it was standardized a diagnostic tool for SVA based on RNA reverse transcriptase droplet digital PCR (RT-ddPCR) using one-step and two-step approaches. Analytical sensitivity and specificity were done in parallel with real-time PCR, RT-qPCR (one-step and two-step) for comparison of sensitivity and specificity of both methods. In the standardization of RT-ddPCR, the double-quenched probe and the temperature gradient were crucial to reduce background and improve amplitude between positive and negative droplets. The limit of detection and analytical specificity of techniques of one-step techniques showed superior performance than two-step methods described here. Additionally, the results showed 94.2% concordance (p < 0.001) for RT-ddPCR and RT-qPCR using the one-step assay approach and biological samples from Brazilian outbreaks of Senecavirus A. However, ddRT-PCR had a better performance than RT-PCR when swine serum pools were tested. According to the results, the one-step RT-ddPCR and RT-qPCR is highlighted to be used as an auxiliary diagnostic tool for Senecavirus A and for viral RNA absolute quantification in biological samples (RT-ddPCR), being a useful tool for vesicular diseases control programs.


Assuntos
Doenças Transmissíveis Emergentes/veterinária , Surtos de Doenças/veterinária , Infecções por Picornaviridae/veterinária , Picornaviridae/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Doenças dos Suínos/epidemiologia , Animais , Brasil/epidemiologia , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/virologia , Enterovirus Humano B/genética , Enterovirus Humano B/isolamento & purificação , Picornaviridae/genética , Infecções por Picornaviridae/epidemiologia , Infecções por Picornaviridae/virologia , RNA Viral/análise , Sensibilidade e Especificidade , Suínos , Doenças dos Suínos/virologia , Doença Vesicular Suína/epidemiologia , Doença Vesicular Suína/virologia
5.
Biol Trace Elem Res ; 187(1): 163-171, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29707746

RESUMO

Cadmium exposure is related to cardiovascular diseases, including hypertension, atherosclerosis, increased oxidative stress, endothelial dysfunction, and specific biochemical changes induced by this metal. Thus, we aimed to investigate whether cadmium exposure induces endothelial dysfunction, accelerates atherosclerotic plaque formation in the aorta, and enhances oxidative stress in apolipoprotein E knockout (ApoE-/-) mice. Experiments were performed in 14-week-old male wild-type and ApoE-/- mice. ApoE-/- mice received cadmium (CdCl2 100 mg/L in drinking water for 28 days) or vehicle (distilled water). After treatment, vascular reactivity to phenylephrine, acetylcholine, and sodium nitroprusside was analyzed using isolated aorta. Bone marrow cells were isolated to assess the production of nitric oxide and reactive oxygen and nitrogen species. ApoE-/- cadmium-treated mice had higher cholesterol levels than non-exposed mice. Cadmium exposure decreased the vasodilatation response to acetylcholine in aortic ring of ApoE-/- mice, though no changes in phenylephrine or sodium nitroprusside responses were observed. L-NAME reduced vasodilator responses to acetylcholine; this effect was lower in ApoE-/- cadmium-treated mice, suggesting reduction in nitric oxide (NO) bioavailability. Moreover, in bone marrow cells, cadmium decreased cytoplasmic levels of NO and increased superoxide anions, hydrogen peroxide, and peroxynitrite in ApoE-/- mice. Morphological analysis showed that cadmium exposure increased plaque deposition in the aorta by approximately 3-fold. Our results suggest that cadmium exposure induces endothelial dysfunction in ApoE-/- mice. Moreover, cadmium increased total cholesterol levels, which may promote the early development of atherosclerosis in the aorta of ApoE-/- mice. Our findings support the hypothesis that cadmium exposure might increase the risk of atherosclerosis.


Assuntos
Aorta/efeitos dos fármacos , Apolipoproteínas E/deficiência , Aterosclerose/induzido quimicamente , Cádmio/administração & dosagem , Cádmio/toxicidade , Endotélio Vascular/efeitos dos fármacos , Administração Oral , Animais , Aorta/metabolismo , Aterosclerose/metabolismo , Endotélio Vascular/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Estresse Oxidativo/efeitos dos fármacos
6.
Int J Oral Maxillofac Surg ; 47(6): 708-714, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29246423

RESUMO

The aim of this study was to evaluate the precision of bimaxillary surgery performed to correct vertical maxillary excess, when the procedure is sequenced with mandibular surgery first or maxillary surgery first. Thirty-two patients, divided into two groups, were included in this retrospective study. Group 1 comprised patients who received bimaxillary surgery following the classical sequence with repositioning of the maxilla first. Patients in group 2 received bimaxillary surgery, but the mandible was operated on first. The precision of the maxillomandibular repositioning was determined by comparison of the digital prediction and postoperative tracings superimposed on the cranial base. The data were tabulated and analyzed statistically. In this sample, both surgical sequences provided adequate clinical accuracy. The classical sequence, repositioning the maxilla first, resulted in greater accuracy for A-point and the upper incisor edge vertical position. Repositioning the mandible first allowed greater precision in the vertical position of pogonion. In conclusion, although both surgical sequences may be used, repositioning the mandible first will result in greater imprecision in relation to the predictive tracing than repositioning the maxilla first. The classical sequence resulted in greater accuracy in the vertical position of the maxilla, which is key for aesthetics.


Assuntos
Anormalidades Maxilomandibulares/cirurgia , Maxila/anormalidades , Maxila/cirurgia , Procedimentos Cirúrgicos Ortognáticos , Adolescente , Adulto , Cefalometria , Estética Dentária , Feminino , Humanos , Anormalidades Maxilomandibulares/diagnóstico por imagem , Masculino , Maxila/diagnóstico por imagem , Pessoa de Meia-Idade , Modelos Dentários , Radiografia Panorâmica , Reprodutibilidade dos Testes , Estudos Retrospectivos , Resultado do Tratamento
7.
Int J Oral Maxillofac Surg ; 46(9): 1088-1093, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28499507

RESUMO

This retrospective study evaluated the nasolabial changes in patients who underwent surgically assisted rapid maxillary expansion (SARME) using two different approaches. Nineteen patients were included in the study, divided into two groups according to the kind of surgical approach performed: group 1 (n=9), SARME performed through the standard Le Fort I circumvestibular approach followed by the alar base cinch, and group 2 (n=10), SARME performed through a subtotal vestibular approach associated to a V-shaped incision at the maxillary midline in the labial frenulum region, without alar base cinch. Measurements of width, length, and nasal projection as well as upper lip length were taken from cone beam tomographic images obtained before surgery (T1) and 6 months postoperatively (T2). Both groups presented an increase in the alar base width postoperatively (P<0.05). The approach used in group 2 resulted in smaller changes in the alar base width as measured at the superior alar curvature (P<0.05). Nasal length and projection and upper lip length were not altered by SARME. The type of surgical approach influenced nasolabial changes, but did not eliminate increase in width of the alar base.


Assuntos
Lábio/anatomia & histologia , Maxila/cirurgia , Nariz/anatomia & histologia , Procedimentos Cirúrgicos Ortognáticos/métodos , Técnica de Expansão Palatina , Adolescente , Adulto , Tomografia Computadorizada de Feixe Cônico , Feminino , Humanos , Lábio/diagnóstico por imagem , Masculino , Nariz/diagnóstico por imagem , Osteotomia de Le Fort , Estudos Retrospectivos , Resultado do Tratamento
8.
J Fish Dis ; 40(6): 785-795, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27670740

RESUMO

Despite the worldwide occurrence of Francisella noatunensis subsp. orientalis (Fno) infection in farmed tilapia, sensitivity and specificity estimates of commonly used diagnostic tests have not been reported. This study aimed to estimate the sensitivity and specificity of bacteriological culture and qPCR to detect Fno infection. We tested 559 fish, sampled from four farms with different epidemiological scenarios: (i) healthy fish in a hatchery free of Fno; (ii) targeted sampling of diseased fish with suggestive external clinical signs of francisellosis during an outbreak; (iii) convenience sampling of diseased and clinically healthy fish during an outbreak; and (iv) sampling of healthy fish in a cage farm without a history of outbreaks, but with francisellosis reported in other farms in the same reservoir. The qPCR had higher median sensitivity (range, 48.8-99.5%) than culture (range, 1.6-74.4%). Culture had a substantially lower median sensitivity (1.6%) than qPCR (48.8%) to detect Fno in carrier tilapia (farm 4). Median specificity estimates for both tests were >99.2%. The qPCR is the superior test for use in surveillance and monitoring programmes for francisellosis in farmed Nile tilapia, but both tests have high sensitivity and specificity which make them fit for use in the diagnosis of Fno outbreaks.


Assuntos
Ciclídeos , Doenças dos Peixes/microbiologia , Francisella/classificação , Infecções por Bactérias Gram-Negativas/veterinária , Animais , Aquicultura , Brasil , DNA Bacteriano/genética , Surtos de Doenças/veterinária , Doenças dos Peixes/patologia , Francisella/genética , Francisella/isolamento & purificação , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/patologia , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade
9.
Int J Oral Maxillofac Surg ; 45(4): 490-6, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26688294

RESUMO

This study aimed to assess the potential effects of two different osteotomy designs of the maxillary lateral wall on dental and skeletal changes after surgically assisted rapid maxillary expansion (SARME). Thirty adult patients were divided into two groups according to the lateral osteotomy design: group 1 (n=16) underwent lateral osteotomy performed in a horizontal straight fashion, and group 2 (n=14) underwent lateral osteotomy performed in parallel to the occlusal plane with a step at the zygomatic buttress. Cone beam computed tomography scans were obtained preoperatively (T1), immediately after expansion (T2), and 6 months after expansion (T3). Mixed analysis of variance (ANOVA) was used for the statistical analysis. The results showed no significant interaction effect between groups and time points. Therefore, maxillary expansion was effective in both groups. Statistically significant increases in all dental and skeletal measurements were observed immediately after expansion (P<0.001). Relapse of the nasal floor width, tipping of the supporting teeth, and an increase in root distance in molars occurred at T3 (P<0.05). In summary, the maxillary lateral osteotomy design did not influence the results of SARME, which occurred mainly through the inclination of maxillary segments.


Assuntos
Osteotomia Maxilar/métodos , Técnica de Expansão Palatina , Adulto , Pontos de Referência Anatômicos , Tomografia Computadorizada de Feixe Cônico , Feminino , Humanos , Masculino , Estudos Retrospectivos , Resultado do Tratamento
10.
Poult Sci ; 94(11): 2677-85, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26450915

RESUMO

Effects of the in ovo injection of organic Mn, Zn, and Cu in association with post-hatch (POH) feed and water restriction on the performance and physical-chemical bone parameters of male Ross × Ross 708 broilers were examined. On 17 d of incubation, a total of 1,872 eggs were subjected to in ovo injection using a commercial multi-egg injector. Treatments (TRT) includingd non-injected and diluent-injected controls. The respective Zn, Mn, and Cu levels (mg/mL) added to the diluent of the low (LMD) and high mineral (HMD) TRT groups were 0.181, 0.087, and 0.010, and 0.544, 0.260, and 0.030, respectively. The 4 TRT groups were then sub-divided into 2 POH holding time (HT) groups, with 15 birds randomly allocated to each of 6 replicate pens in each of the 8 groups. The first HT group (0HT) had immediate access to water and feed, and the second HT group (24HT) contained birds that were kept in transport baskets for 24 h before being released. Performance was determined and selected birds were subsequently necropsied and their tibiae extracted for analysis. In comparison to birds from 24HT group, those in the 0HT group had a higher BW gain and feed intake, and a lower FCR through 21 d POH. The percentage of bone ash of the birds belonging to the HMD group was higher than all other TRT on d 1 POH and was higher than the non-injection control group on d 21 POH. On d 1, the LMD and HMD groups had higher tibial Mn concentrations than those of the control groups. On d 7, bones from the HMD group had a higher concentration of Mn than did the non-injected control group, and likewise, on d 21 POH, had a higher concentration of Zn than did the control groups. In conclusion, a 24HT negatively affected the performance of the birds during the first 2 wk POH; however, the LMD and HMD TRT had a positive influence on bone mineralization.


Assuntos
Osso e Ossos/efeitos dos fármacos , Galinhas/fisiologia , Cobre/metabolismo , Manganês/metabolismo , Oligoelementos/farmacologia , Zinco/metabolismo , Animais , Osso e Ossos/química , Osso e Ossos/fisiologia , Embrião de Galinha , Galinhas/crescimento & desenvolvimento , Ingestão de Líquidos , Ingestão de Alimentos , Masculino , Distribuição Aleatória
11.
Poult Sci ; 94(10): 2488-94, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26330613

RESUMO

Effects of the in ovo injection of commercial diluent containing supplemental microminerals (Zn, Mn, and Cu) on hatchability and hatching chick quality variables in Ross × Ross 708 broilers were examined. On 17 d of incubation (doi) eggs were subjected to 1 of 4 treatments using a commercial multi-egg injector. Treatments included non-injected (treatment 1) and diluent-injected (treatment 2) control groups. Those in treatment 3 received diluent containing 0.181, 0.087, and 0.010 mg/mL of Zn, Mn, and Cu, respectively, and those in treatment 4 received diluent containing 0.544, 0.260, and 0.030 mg/mL of Zn, Mn, and Cu, respectively. A total of 1,872 eggs were distributed among 4 treatment groups on each of 6 replicate tray levels. Hatchability of fertile eggs set (HF) was determined on 20.5 and 21.5 doi. On 21.5 doi, HF and mean hatching chick weight (MHW) were determined. One bird from each treatment replicate group was randomly selected, weighed, and necropsied for the extraction of their livers and tibiae. The tibiae fresh and dry weight, length, width, bone breaking strength (BBS), and percentage of bone ash (PBA) were determined. The dry livers were weighed and ashed. Injection treatment had no significant effect on HF at 20.5 doi. However, there was a significant injection treatment effect on HF at 21.5 doi. The HF of eggs at 21.5 doi in treatment 4 was significantly lower than that of the non-injected control group, with treatment 3 being intermediate. Furthermore, there were no significant treatment effects noted for MHW fresh and dry tibia weights, tibia length and width, tibia length to weight ratio, BBS, liver ash content, or percentage of minerals (Ca, P, Mg, Mn, and Zn) in the tibia ash. However, embryos from eggs that received treatment 4 had a significantly higher PBA in comparison to all other treatments. In conclusion, although treatment 4 negatively affected HF, the injection of diluent containing the high micromineral concentration has the potential to improve bone mineralization.


Assuntos
Osso e Ossos/efeitos dos fármacos , Galinhas/fisiologia , Cobre/farmacologia , Manganês/farmacologia , Zinco/farmacologia , Animais , Desenvolvimento Ósseo/efeitos dos fármacos , Embrião de Galinha , Injeções/veterinária , Masculino , Óvulo/efeitos dos fármacos , Reprodução/efeitos dos fármacos
12.
Sci Total Environ ; 442: 509-14, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23201605

RESUMO

This paper compared and evaluated seasonal variations in physico-chemical parameters and metals at a hydroelectric power station reservoir by applying Multivariate Analyses and Artificial Neural Networks (ANN) statistical techniques. A Factor Analysis was used to reduce the number of variables: the first factor was composed of elements Ca, K, Mg and Na, and the second by Chemical Oxygen Demand. The ANN showed 100% correct classifications in training and validation samples. Physico-chemical analyses showed that water pH values were not statistically different between the dry and rainy seasons, while temperature, conductivity, alkalinity, ammonia and DO were higher in the dry period. TSS, hardness and COD, on the other hand, were higher during the rainy season. The statistical analyses showed that Ca, K, Mg and Na are directly connected to the Chemical Oxygen Demand, which indicates a possibility of their input into the reservoir system by domestic sewage and agricultural run-offs. These statistical applications, thus, are also relevant in cases of environmental management and policy decision-making processes, to identify which factors should be further studied and/or modified to recover degraded or contaminated water bodies.


Assuntos
Monitoramento Ambiental/métodos , Metais/análise , Centrais Elétricas , Poluentes Químicos da Água/análise , Análise da Demanda Biológica de Oxigênio , Brasil , Fenômenos Químicos , Tomada de Decisões Assistida por Computador , Monitoramento Ambiental/estatística & dados numéricos , Concentração de Íons de Hidrogênio , Metais/química , Análise Multivariada , Redes Neurais de Computação , Oxigênio/análise , Estações do Ano , Poluentes Químicos da Água/química
13.
Bull Environ Contam Toxicol ; 89(6): 1154-60, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23052584

RESUMO

Mullet (Mugil liza) were sampled in five different areas along the Guanabara Bay, southeastern Brazil, classified as non-contaminated, moderately contaminated and contaminated. Morphometric (Fulton condition factor, relative condition factor and weight to length scaling coefficient) and organosomatic (hepatosomatic index) indices of environmental stress were analysed. Fish from the differentially contaminated areas show statistically different Fulton and relative condition factors and hepatosomatic indices, but not the weight to length scaling coefficient. The Kn and the FCF followed the same trend, with fish from São Gonçalo (1.07 ± 0.04 and 0.89 ± 0.03), Itaipu (0.84 ± 0.01 and 0.86 ± 0.01) and the Rodrigo de Freitas Lagoon (1.03 ± 0.01 and 0.87 ± 0.20) showing higher FCFs than fish from Magé (0.96 ± 0.01 and 0.81 ± 0.01). Fish from Itaipu showed significantly higher HSI values than the other sampling sites (1.68 ± 0.07), with fish from Olaria and Ipiranga showing the lowest (1.56 ± 0.12 and 1.60 ± 0.07, respectively).


Assuntos
Monitoramento Ambiental , Smegmamorpha/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Brasil , Poluição Química da Água/estatística & dados numéricos
14.
J Med Virol ; 83(10): 1826-33, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21837801

RESUMO

Respiratory syncytial virus (RSV) is a major cause of acute respiratory disease in infants and young children. Considering that several aspects of the humoral immune response to RSV infection remain unclear, this study aimed to investigate the occurrence, levels, and avidity of total IgG, IgG1, and IgG3 antibodies against RSV in serum samples from children ≤5 years old. In addition, a possible association between antibody avidity and severity of illness was examined. The occurrence and levels of RSV-specific IgG depended on age, with infants <3 months old displaying high levels of antibodies, which were probably acquired from the mother. Children ≥24 months old also showed frequent occurrence and high levels of IgG, which was produced actively during infection. In addition, the avidity assay showed that the avidity of RSV-specific total IgG and IgG1 was lower in infants <3 months old who had acute respiratory disease than in age-matched controls. The avidity of RSV-specific IgG detected in children ≥24 months old with lower respiratory infection was lower than that in children with upper respiratory infection. These results indicate that the presence of high avidity RSV-specific IgG antibodies may lead to better protection against RSV infection in children <3 months old, who may have a lower probability of developing disease of increased severity. In addition, children ≥24 months old with RSV-specific IgG antibodies of low avidity tended to develop more severe RSV illness. These findings may be helpful in establishing vaccination schedules when a vaccine becomes available.


Assuntos
Anticorpos Antivirais/imunologia , Afinidade de Anticorpos , Imunoglobulina G/imunologia , Infecções por Vírus Respiratório Sincicial/imunologia , Vírus Sinciciais Respiratórios/imunologia , Infecções Respiratórias/imunologia , Anticorpos Antivirais/sangue , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/classificação , Lactente , Masculino , Infecções Respiratórias/virologia , Índice de Gravidade de Doença
15.
Mem Inst Oswaldo Cruz ; 103(5): 417-22, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18797752

RESUMO

Respiratory syncytial virus (RSV) is well recognized as the most important pathogen causing acute respiratory disease in infants and young children, mainly in the form of bronchiolitis and pneumonia. Two major antigenic groups, A and B, have been identified; however, there is disagreement about the severity of the diseases caused by these two types. This study investigated a possible association between RSV groups and severity of disease. Reverse transcription-polymerase chain reaction was used to characterize 128 RSV nasopharyngeal specimens from children less than five years old experiencing acute respiratory disease. A total of 82 of 128 samples (64.1%) could be typed, and, of these, 78% were group A, and 22% were group B. Severity was measured by clinical evaluation associated with demographic factors: for RSV A-infected patients, 53.1% were hospitalized, whereas for RSV B patients, 27.8% were hospitalized (p = 0.07). Around 35.0% of the patients presented risk factors for severity (e.g., prematurity). For those without risk factors, the hospitalization occurred in 47.6% of patients infected with RSV A and in 18.2% infected with RSV B. There was a trend for RSV B infections to be milder than those of RSV A. Even though RSV A-infected patients, including cases without underlying condition and prematurity, were more likely to require hospitalization than those infected by RSV B, the disease severity could not to be attributed to the RSV groups.


Assuntos
Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano/classificação , Infecções Respiratórias , Doença Aguda , Brasil/epidemiologia , Criança , Pré-Escolar , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Lactente , Masculino , Nasofaringe/virologia , Prevalência , RNA Viral/genética , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estações do Ano , Índice de Gravidade de Doença
16.
Mem. Inst. Oswaldo Cruz ; 103(5): 417-422, Aug. 2008. graf, tab
Artigo em Inglês | LILACS | ID: lil-491960

RESUMO

Respiratory syncytial virus (RSV) is well recognized as the most important pathogen causing acute respiratory disease in infants and young children, mainly in the form of bronchiolitis and pneumonia. Two major antigenic groups, A and B, have been identified; however, there is disagreement about the severity of the diseases caused by these two types. This study investigated a possible association between RSV groups and severity of disease. Reverse transcription-polymerase chain reaction was used to characterize 128 RSV nasopharyngeal specimens from children less than five years old experiencing acute respiratory disease. A total of 82 of 128 samples (64.1 percent) could be typed, and, of these, 78 percent were group A, and 22 percent were group B. Severity was measured by clinical evaluation associated with demographic factors: for RSV A-infected patients, 53.1 percent were hospitalized, whereas for RSV B patients, 27.8 percent were hospitalized (p = 0.07). Around 35.0 percent of the patients presented risk factors for severity (e.g., prematurity). For those without risk factors, the hospitalization occurred in 47.6 percent of patients infected with RSV A and in 18.2 percent infected with RSV B. There was a trend for RSV B infections to be milder than those of RSV A. Even though RSV A-infected patients, including cases without underlying condition and prematurity, were more likely to require hospitalization than those infected by RSV B, the disease severity could not to be attributed to the RSV groups.


Assuntos
Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Infecções por Vírus Respiratório Sincicial , Infecções Respiratórias , Vírus Sincicial Respiratório Humano/classificação , Doença Aguda , Brasil/epidemiologia , Técnica Indireta de Fluorescência para Anticorpo , Nasofaringe/virologia , Prevalência , Reação em Cadeia da Polimerase Via Transcriptase Reversa , RNA Viral/genética , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Estações do Ano , Índice de Gravidade de Doença
17.
Mem Inst Oswaldo Cruz ; 101(3): 301-6, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16862327

RESUMO

The main viruses involved in acute respiratory diseases among children are: respiratory syncytial virus (RSV), influenzavirus (FLU), parainfluenzavirus (PIV), adenovirus (AdV), human rhinovirus (HRV), and the human metapneumovirus (hMPV). The purpose of the present study was to identify respiratory viruses that affected children younger than five years old in Uberlândia, Midwestern Brazil. Nasopharyngeal aspirates from 379 children attended at Hospital de Clínicas (HC/UFU), from 2001 to 2004, with acute respiratory disease, were collected and tested by immunofluorescence assay (IFA) to detect RSV, FLU A and B, PIV 1, 2, and 3 and AdV, and RT-PCR to detect HRV. RSV was detected in 26.4% (100/379) of samples, FLU A and B in 9.5% (36/379), PIV 1, 2 and 3 in 6.3% (24/379) and AdV in 3.7% (14/379). HRV were detected in 29.6% (112/379) of the negative and indeterminate samples tested by IFI. RSV, particularly among children less than six months of life, and HRV cases showed highest incidence. Negative samples by both IFA and RT-PCR might reflect the presence of other pathogens, such as hMPV, coronavirus, and bacteria. Laboratorial diagnosis constituted an essential instrument to determine the incidence of the most common viruses in respiratory infections among children in this region.


Assuntos
Infecções Respiratórias/virologia , Doença Aguda , Brasil/epidemiologia , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Nasofaringe/virologia , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/epidemiologia
18.
Acta Haematol ; 113(4): 228-33, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15983428

RESUMO

Analgesia and hydration remain the only safe treatment for painful crises of sickle cell disease; hydroxyurea is effective, but the toxicity is still a problem. Piracetam is a nootropic drug that has reportedly been effective and non-toxic in sickle cell patients, but most studies were not placebo-controlled and included a small number of patients. The present study evaluated the drug in a double-blind crossed placebo-controlled clinical trial in 73 children and adolescents suffering from moderate to severe painful crises for 13 months. Information regarding frequency and severity of pain was acquired through monthly clinical evaluation, visits and house calls, and 4,300 weekly questionnaires filled out by the patients in their domiciles. A monthly pain score was calculated for each patient. Pain was the most frequent adverse manifestation of the disease stressing its significant bio-psycho-social impact. Although nearly all patients and relatives reported a better clinical course throughout the whole study, the drug was ineffective in the prevention of painful crises. This placebo effect may be ascribed to an unplanned and unsystematic 'cognitive-behavioural' management of the children. The pain score in the second semester of the study - both in the experimental and in the control groups - was significantly smaller than that in the first semester. In conclusion, piracetam was found to be ineffective in the prevention of painful crises; a powerful placebo effect due to adequate patient care was demonstrated.


Assuntos
Anemia Falciforme/tratamento farmacológico , Dor/tratamento farmacológico , Piracetam/uso terapêutico , Adolescente , Adulto , Anemia Falciforme/complicações , Anemia Falciforme/fisiopatologia , Criança , Pré-Escolar , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Masculino , Dor/etiologia , Placebos , Inquéritos e Questionários
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...