RESUMO

Individual ability to perceive airway obstruction varies substantially. The factors influencing the perception of asthma are probably numerous and not well established in children. The present study was designed to examine the influence of asthma severity, use of preventive medication, age and gender on the association between respiratory symptoms (RS) and peak expiratory flow (PEF) rates in asthmatic children. We followed 92 asthmatic children, aged 6 to 16 years, for five months. Symptom scores were recorded daily and PEF was measured twice a day. The correlations among variables at the within-person level over time were analyzed for each child and for the pooled data by multivariate analysis. After pooling the data, there was a significant (P<0.05) correlation between each symptom and PEF; 60% of the children were accurate perceivers (defined by a statistically significant correlation between symptoms and PEF across time) for diurnal symptoms and 37% for nocturnal symptoms. The accuracy of perception was independent of asthma severity, age, gender or the use of preventive medication. Symptom perception is inaccurate in a substantial number of asthmatic children, independently of clinical severity, age, gender or use of preventive medication. It is not clear why some asthmatic patients are capable of accurately perceiving the severity of airway obstruction while others are not.

Assuntos

RESUMO

Individual ability to perceive airway obstruction varies substantially. The factors influencing the perception of asthma are probably numerous and not well established in children. The present study was designed to examine the influence of asthma severity, use of preventive medication, age and gender on the association between respiratory symptoms (RS) and peak expiratory flow (PEF) rates in asthmatic children. We followed 92 asthmatic children, aged 6 to 16 years, for five months. Symptom scores were recorded daily and PEF was measured twice a day. The correlations among variables at the within-person level over time were analyzed for each child and for the pooled data by multivariate analysis. After pooling the data, there was a significant (P<0.05) correlation between each symptom and PEF; 60 percent of the children were accurate perceivers (defined by a statistically significant correlation between symptoms and PEF across time) for diurnal symptoms and 37 percent for nocturnal symptoms. The accuracy of perception was independent of asthma severity, age, gender or the use of preventive medication. Symptom perception is inaccurate in a substantial number of asthmatic children, independently of clinical severity, age, gender or use of preventive medication. It is not clear why some asthmatic patients are capable of accurately perceiving the severity of airway obstruction while others are not

Assuntos

RESUMO

During the period from 1994 to 1999 cutaneous leishmaniasis was reported in 32 (89%) out of 36 municipalities in the Metropolitan Region of Belo Horizonte, Brazil, of which one (2,8%) municipality was classified as a very high risk area, 16 (44,5%) as high risk, seven (19,4%) as moderate risk areas and 12 (33,3%) as low risk. From 1994 to 1995, visceral leishmaniasis was reported in six (16%) municipalities whereas in 1998 - 1999 this number increased to 15 (42%). Annual numbers of cases during 1994 to 1999 were 30, 53, 64, 53 and 84, respectively. In 19 (61.3%) municipalities no reference center for the diagnosis of the infection was available, so that most of the patients (80%) were referred to Belo Horizonte. Twelve (39%) municipalities have a center for leishmaniasis evaluation, however in only eight (67%) of these basic specific diagnostic tests were available. Rapid and extensive increase of leishmaniasis associated with low diagnosis capacity has been observed in the metropolitan area of Belo Horizonte.

Assuntos

RESUMO

During the period from 1994 to 1999 cutaneous leishmaniasis was reported in 32 (89%) out of 36 municipalities in the Metropolitan Region of Belo Horizonte, Brazil, of which one (2,8%) municipality was classified as a very high risk area, 16 (44,5%) as high risk, seven (19,4%) as moderate risk areas and 12 (33,3%) as low risk. From 1994 to 1995, visceral leishmaniasis was reported in six (16%) municipalities whereas in 1998 - 1999 this number increased to 15 (42%). Annual numbers of cases during 1994 to 1999 were 30, 53, 64, 53 and 84, respectively. In 19 (61.3%) municipalities no reference center for the diagnosis of the infection was available, so that most of the patients (80%) were referred to Belo Horizonte. Twelve (39%) municipalities have a center for leishmaniasis evaluation, however in only eight (67%) of these basic specific diagnostic tests were available. Rapid and extensive increase of leishmaniasis associated with low diagnosis capacity has been observed in the metropolitan area of Belo Horizonte.

No período de 1994 a 1999, foram notificados casos de leishmaniose tegumentar em 32 (89%) dos 36 municípios da Região Metropolitana de Belo Horizonte. Em um (2,8%) município o risco de adquirir a doença foi considerado muito alto, em 16 (44.5%), médio em sete (19,4%) e baixo em 12 (33.3%). Leishmaniose visceral foi notificada em seis (17%) dos 36 municípios, nos anos 94 e 95, elevando-se para 15 (42%) no biênio 98/99. O total de casos de leishmaniose visceral notificados anualmente no período 94 a 99 foi 30, 53, 64, 60, 53, 84, respectivamente. Não há serviços referenciados para atendimento da doença em 19 (61,3%) de 31 municípios, sendo 80% dos pacientes encaminhados para Belo Horizonte. Em 12 (39%) municípios com serviços referenciados, somente oito (67%) dispõem de testes diagnósticos específicos para leishmaniose. Verificou-se rápida e extensa expansão das leishmanioses na região metropolitana de Belo Horizonte e baixa capacidade de resolução diagnóstica pelos seus municípios.

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Prions have been extensively studied since they represent a new class of infectious agents in which a protein, PrPsc (prion scrapie), appears to be the sole component of the infectious particle. They are responsible for transmissible spongiform encephalopathies, which affect both humans and animals. The mechanism of disease propagation is well understood and involves the interaction of PrPsc with its cellular isoform (PrPc) and subsequently abnormal structural conversion of the latter. PrPc is a glycoprotein anchored on the cell surface by a glycosylphosphatidylinositol moiety and expressed in most cell types but mainly in neurons. Prion diseases have been associated with the accumulation of the abnormally folded protein and its neurotoxic effects; however, it is not known if PrPc loss of function is an important component. New efforts are addressing this question and trying to characterize the physiological function of PrPc. At least four different mouse strains in which the PrP gene was ablated were generated and the results regarding their phenotype are controversial. Localization of PrPc on the cell membrane makes it a potential candidate for a ligand uptake, cell adhesion and recognition molecule or a membrane signaling molecule. Recent data have shown a potential role for PrPc in the metabolism of copper and moreover that this metal stimulates PrPc endocytosis. Our group has recently demonstrated that PrPc is a high affinity laminin ligand and that this interaction mediates neuronal cell adhesion and neurite extension and maintenance. Moreover, PrPc-caveolin-1 dependent coupling seems to trigger the tyrosine kinase Fyn activation. These data provide the first evidence for PrPc involvement in signal transduction

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RESUMO

The regulation of glucocorticoid receptor gene expression by members of the AP-1 family was examined in glucocorticoid-free NIH3T3 cells transfected with the human glucocorticoid receptor gene promoter driving expression of a CAT reporter gene. c-Jun inhibited the promoter activity by 80% and JunB by 30%, whereas c-Fos and JunD had no inhibitory effect. Electrophoretic mobility shift assays showed that c-Jun is unable to efficiently interact with the AP-1-like site present in the human glucocorticoid receptor promoter. Moreover, c-Jun was still able to repress promoter mutants in which the region containing the AP-1-like site was deleted. NIH3T3 cell clones overexpressing c-Jun exhibited lower glucocorticoid receptor mRNA levels, which suggests that the murine glucocorticoid receptor gene can also be regulated by AP-1. These results provide a new mechanism for cross-talk between the glucocorticoid receptor and the AP-1 family of transcription factors in the absence of glucocorticoid ligands.

Assuntos

RESUMO

Prions have been extensively studied since they represent a new class of infectious agents in which a protein, PrPsc (prion scrapie), appears to be the sole component of the infectious particle. They are responsible for transmissible spongiform encephalopathies, which affect both humans and animals. The mechanism of disease propagation is well understood and involves the interaction of PrPsc with its cellular isoform (PrPc) and subsequently abnormal structural conversion of the latter. PrPc is a glycoprotein anchored on the cell surface by a glycosylphosphatidylinositol moiety and expressed in most cell types but mainly in neurons. Prion diseases have been associated with the accumulation of the abnormally folded protein and its neurotoxic effects; however, it is not known if PrPc loss of function is an important component. New efforts are addressing this question and trying to characterize the physiological function of PrPc. At least four different mouse strains in which the PrP gene was ablated were generated and the results regarding their phenotype are controversial. Localization of PrPc on the cell membrane makes it a potential candidate for a ligand uptake, cell adhesion and recognition molecule or a membrane signaling molecule. Recent data have shown a potential role for PrPc in the metabolism of copper and moreover that this metal stimulates PrPc endocytosis. Our group has recently demonstrated that PrPc is a high affinity laminin ligand and that this interaction mediates neuronal cell adhesion and neurite extension and maintenance. Moreover, PrPc-caveolin-1 dependent coupling seems to trigger the tyrosine kinase Fyn activation. These data provide the first evidence for PrPc involvement in signal transduction.

Assuntos

RESUMO

Laminin (LN) plays a major role in neuronal differentiation, migration and survival. Here, we show that the cellular prion protein (PrPc) is a saturable, specific, high-affinity receptor for LN. The PrPc-LN interaction is involved in the neuritogenesis induced by NGF plus LN in the PC-12 cell line and the binding site resides in a carboxy-terminal decapeptide from the gamma-1 LN chain. Neuritogenesis induced by LN or its gamma-1-derived peptide in primary cultures from rat or either wild type or PrP null mice hippocampal neurons, indicated that PrPc is the main cellular receptor for that particular LN domain. These results point out to the importance of the PrPc-LN interaction for the neuronal plasticity mechanism.

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RESUMO

The prevalence of exercise-induced bronchospasm (EIB) in asthmatic individuals has been reported to vary from 40% to 90%. There are, however, few studies addressing the effects of asthma severity on airway responsiveness to exercise. The purpose of the present study was to investigate the effects of asthma severity on EIB in children. We studied 164 children classified as having intermittent (n = 63), mild persistent (n = 30), moderate persistent (n = 40), and severe persistent asthma (n = 31) according to the Global Initiative for Asthma classification. Subjects exercised for 6 min on a cycle ergometer at 80% of their maximum heart rate, and spirometry was performed before and 5, 10, and 20 min after exercise challenge. The prevalence of EIB in children with moderate or severe persistent asthma was significantly greater than in children with intermittent asthma (p < 0.001). EIB-positive children with intermittent asthma exhibited smaller changes in FEV1 than children in the other three groups (p < 0.001). There was no significant relationship between baseline FEV1 and the decline in FEV1 after exercise. We conclude that the prevalence of EIB is greater in children with more severe asthma, and that the intensity of response to exercise is not consistently related to the clinical severity of asthma.

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RESUMO

BACKGROUND: Aerobic training has a number of well known beneficial effects in both normal and asthmatic children. However, the impact of training on the clinical management of the underlying bronchial asthma remains controversial, particularly in the most severe patients. METHODS: Clinical evaluation, spirometric tests, symptom limited maximum exercise testing, and exercise challenge tests were performed in a group of children with stable moderate to severe asthma. Forty two patients (24 boys) aged 8-16 were evaluated twice: before and after supervised aerobic training (group 1, n = 26) and two months apart (untrained group 2, n = 16). RESULTS: Spirometric and maximal exercise variables in the initial evaluation were significantly reduced in group 1 (p < 0.05) but medication and clinical scores and the occurrence of exercise induced bronchospasm (EIB) did not differ between the two groups. Aerobic improvement with training (maximal oxygen uptake and/or anaerobic threshold increment > 10% and 100 ml) was inversely related to the baseline level of fitness and was independent of disease severity. Although the clinical score and the occurrence of EIB did not change after training, aerobic improvement was associated with a significant reduction in the medication score and the daily use of both inhaled and oral steroids (p < 0.05). CONCLUSIONS: Aerobic improvement with training in less fit asthmatic children is related to a short term decrease in the daily use of inhaled and oral steroids, independent of the severity of the disease.

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RESUMO

The present study was designed to evaluate the effectiveness of International Asthma Guidelines in low-income asthmatic children in the city of São Paulo, Brazil. Fifty children with moderate or severe asthma were evaluated. Patients were evaluated before and after a 1 yr follow-up period using a pre- and post-education design with patients acting as their own controls. Parents were interviewed before and 1 yr after the programme. Most of the children were receiving inadequate medical care from their primary physicians, based mainly on bronchodilators. After the educational programme combined with a medical treatment based mainly on inhaled steroids, there was a decrease in emergency room visits and no need for hospital admissions. There was also a significant decrease in asthma severity and impairment scores (p<.0001). The combination of good medical care and an educational programme can reduce the symptoms of asthma and significantly increase the quality of life, as well as decreasing the costs of asthma treatment. We conclude that by applying the International Asthma Guidelines substantial success was achieved, resulting in moving the patients from crises-orientated management into a chronic care and preventive management mode.

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