Resumen En un experimento de sobresalto potenciado por el miedo, los participantes fueron entrenados en una tarea de discriminación donde una imagen A se emparejó con un pulso eléctrico, mientras que otra imagen, B, se presentó por sí sola (i.e., A+ B-). En una prueba, la respuesta de sobresalto, medida como parpadeo, fue evaluada al presentar un soplo de aire o un ruido blanco en presencia o ausencia de las imágenes A y B. Los resultados muestran un mayor parpadeo al soplo de aire en presencia de A que en presencia de B, y en ausencia de cualquier estímulo, solo en aquellos participantes que percibieron el pulso eléctrico como altamente doloroso. En conclusión, estos hallazgos sugieren que el miedo condicionado se relaciona linealmente con la intensidad del pulso eléctrico.

Abstract In a fear-potentiated startle experiment, participants were trained in a discrimination task where image A was paired with an electrical pulse, while another image, B, presented itself (i.e., A+ B-). In a test, the startle response, measured as an eyeblink, was evaluated by presenting an air-puff or white noise in the presence or absence of images A and B. The results show a greater eyeblink to the air-puff in the presence of A than in the presence of B, and in the absence of any stimulus, only in those participants who perceived the electrical pulse as highly painful. In conclusion, these findings suggest that conditioned fear is linearly related to the intensity of the electrical pulse.

Abstract The redundancy effect is the finding of greater learning when an X stimulus is trained in an A+ AX+ blocking procedure, than when a Y stimulus is trained in a BY+ CY- discrimination procedure. These findings are new and theoretically challenging for all conditioning theories that calculate learning based on a common error. For this reason, we alternatively examined the possibility that the phenomenon is the result of a propositional reasoning. In an experiment, we replicated the basic effect and we found out that the addition of instructions on the occurrence of the consequences at a submaximal level does not have a significant impact on the redundancy effect. These findings are discussed with regard to a propositional and associative approach based on the assumption that the experimental stimuli share a common feature.

Resumen El efecto de redundancia es el hallazgo de un mayor aprendizaje a un estímulo X entrenado en un procedimiento de bloqueo A+ AX+, que a un estímulo Y entrenado en un procedimiento de discriminación BY+ CY-. Estos hallazgos son nuevos y teóricamente desafiantes para todas las teorías del condicionamiento que calculan el aprendizaje en base a un error común. Es por ello que examinamos alternativamente la posibilidad que el fenómeno sea el resultado de un razonamiento proposicional. En un experimento, replicamos el efecto básico y encontramos que la adición de instrucciones sobre la ocurrencia de las consecuencias a un nivel sub-máximo no tiene un efecto significativo sobre el efecto de redundancia. Estos hallazgos son discutidos en relación con una aproximación proposicional y asociativa basada en el supuesto que los estímulos experimentales comparten un elemento común.

Abstract The study examines the effects of context change on the habituation of the startle response in humans. In Experiment 1 the startle response was measured in three phases: pre-test, habituation, and post-test. For one group, the phases occurred in the same context, while for another, the habituation phase occurred in a different context. The results indicated that the different group had a more marked decrease between the pre-test and post-test than the same group. In Experiment 2, the same design was replicated, and the same results were obtained as in Experiment 1, although a different stimulus was used in the pre-test and post-test. Although the results are not statistically conclusive, they suggest that the context could be acquiring long-term potentiating properties that reduce the level of decrement that would be observed if only a habituation process existed.

Resumen El estudio examina los efectos del cambio de contexto en la habituación de la respuesta de sobresalto en humanos. En el Experimento 1 se midió la respuesta de sobresalto en tres fases: preprueba, habituación y posprueba. Para un grupo, las fases ocurrieron en el mismo contexto, mientras que para otro, la fase de habituación ocurrió en un contexto distinto. Los resultados indicaron que el grupo diferente tuvo una disminución más marcada entre la preprueba y la posprueba que el grupo igual. En el Experimento 2, se replicó el mismo diseño y se obtuvieron los mismos resultados que en el Experimento 1, pese a que en la preprueba y la posprueba se utilizó un estímulo distinto. Aunque los resultados no son estadísticamente concluyentes, estos sugieren que el contexto podría estar adquiriendo propiedades potenciadoras de largo plazo que reducen el nivel de decremento que se observaría si sólo existiera un proceso de habituación.

Wagner (1978) propuso que la habituación, definida como una disminución en la respuesta a un estímulo que se repite, dependería de la formación de una asociación entre el contexto y el estímulo. Según este enfoque, la habituación debería ser contexto-específica, es decir, la respuesta habituada en un contexto debería deshabituarse al presentar el estímulo en un contexto novedoso. Esta hipótesis fue examinada a través de un experimento donde se sometió a un grupo de estudiantes a una sesión de habituación consistente en 60 repeticiones de un estímulo provocador de reacciones de parpadeo y aceleración cardiaca. Posteriormente, en una sesión de prueba se midió la amplitud de estas respuestas, presentando el estímulo en el mismo contexto (Grupo Igual) o en un contexto distinto a aquel donde ocurrió la habituación (Grupo Diferente). Los resultados de la prueba arrojaron evidencia de especificidad contextual diferencial para ambas respuestas, ya que la respuesta de aceleración cardiaca resultó disminuida en el grupo igual pero no en el grupo diferente (revelando especificidad), mientras que la respuesta de parpadeo estuvo igualmente disminuida en ambos grupos (revelando ausencia de especificidad). Estos hallazgos confirman observaciones previas con ratas que demuestran que el control contextual de la habituación depende de la naturaleza de la respuesta.

Wagner (1978) proposed that habituation, defined as a decrease in responding to a repeated stimulus, would depend on the formation of an association between the stimulus and the context. According to this approach, habitua-tion should be context-specific; that is, a response that was habituated in a given context should dishabituate when the stimulus is presented in a novel context. This hypothesis was examined in an experiment in which a group of students received a habituation session consisting of 60 repetitions of a stimulus capable of evoking eyeblink and heart-rate acceleration reactions. Subsequently, in a testing session the amplitude of these responses was examined by presenting the stimulus in the same context used in the habituation session (Group Same) or in an alternative context (Group Different). The results provided evidence of differential context-specificity for the two responses, since the heart-rate acceleration response was diminished in the group same but not in the group different (revealing specificity), while the eyeblink response was diminished in both groups (revealing no specificity). These findings are consistent with previous observations in rats demonstrating that the contextual control of habituation depends on the nature of the measured response.

Introduction:There is a paucity of data on the occurrence of congenital toxoplasmosis in children born to mothers dually infected with HIV and Toxoplasma gondii.Objective:To evaluate aspects of the mother–infant pairs associated with vertical transmission of toxoplasmosis in women co-infected with HIV in a referral center for perinatally acquired infections in Belo Horizonte, Brazil.Methods:Descriptive study of HIV vertically exposed children, with congenital toxoplasmosis, followed at a referral center (cohort/Belo Horizonte). Prenatal and post-natal variables for the mother–infant pairs were evaluated. A literature review with no filtering for time and language was performed to identify reports of congenital toxoplasmosis in HIV vertically exposed children.Results:Among 2007 HIV vertically exposed children evaluated in the period from 1998 to 2011, 10 cases of congenital toxoplasmosis were identified (incidence: 0.5%, 95% confidence interval: 0.24–0.91). In searching the literature 22 additional cases in 17 reports were found. Combining the findings of our cohort with other reported cases, 50% (16/32) of congenital toxoplasmosis in HIV vertically exposed children were from Brazil. The cases of congenital toxoplasmosis in HIV vertically exposed children identified in Brazil occurred mainly in the post-Highly Active Antiretroviral Therapy era (p = 0.002) and presented a lower death rate (p = 0.003) than those from other countries. In the cohort/Belo Horizonte, HIV infection was identified mainly during gestation; T. gondii vertical transmission was observed in pregnant women with CD4+>500 cells/mm3 and latent toxoplasmosis. High rates of ocular lesions (87.5%) and central nervous system involvement (70%) were detected.Conclusions:The risk of vertical transmission of T. gondii in HIV-infected women is low and has been usually associated with maternal immunosuppression and elevated viral load. However, our findings of congenital toxoplasmosis in children born to HIV-infected mothers with latent toxoplasmosis and not immunosuppressed emphasize the need for careful follow-up in these cases.

The use of highly active antiretroviral therapy (HAART) for human immunodeficiency virus (HIV)-infected patients has reduced the number of acquired immune deficiency syndrome-related deaths worldwide. This study assessed the impact of HAART on the survival and death rates of vertically HIV-infected children and adolescents in Belo Horizonte, Brazil. Data were obtained from a historic cohort of vertically HIV-infected children and adolescents aged zero-19 years old who were admitted from March 1989-December 2004 and were followed until June 2006. Patients who used HAART were included if they were treated for at least 12 weeks. Of 359 patients, 320 patients met the inclusion criteria. The overall mortality rate was 9.7% [31/320; 95% confidence interval (CI): 6.0-13%]. The median survival for the non-HAART and HAART groups was 31.5 and 55.9 months, respectively (log rank = 22.11, p < 0.0001). In the multivariate analysis, the statistically significant variables were HAART and the weight-for-age Z score < -2, with HAART constituting a protective factor [relative risk (RR): 0.13; CI 95%: 0.05-0.33] and malnutrition constituting a risk factor (RR: 3.44; CI 95%: 1.60-7.40) for death. The incidence of death was 5.1/100 person-years in the non-HAART group and 0.8/100 person-years in the HAART group (p < 0.0001).

The goal of this study was to evaluate changes in plasma human immunodeficiency virus (HIV) RNA concentration [viral load (VL)] and CD4+ percentage (CD4%) during 6-12 weeks postpartum (PP) among HIV-infected women and to assess differences according to the reason for receipt of antiretrovirals (ARVs) during pregnancy [prophylaxis (PR) vs. treatment (TR)]. Data from a prospective cohort of HIV-infected pregnant women (National Institute of Child Health and Human Development International Site Development Initiative Perinatal Study) were analyzed. Women experiencing their first pregnancy who received ARVs for PR (started during pregnancy, stopped PP) or for TR (initiated prior to pregnancy and/or continued PP) were included and were followed PP. Increases in plasma VL (> 0.5 log10) and decreases in CD4% (> 20% relative decrease in CD4%) between hospital discharge (HD) and PP were assessed. Of the 1,229 women enrolled, 1,119 met the inclusion criteria (PR: 601; TR: 518). At enrollment, 87% were asymptomatic. The median CD4% values were: HD [34% (PR); 25% (TR)] and PP [29% (PR); 24% (TR)]. The VL increases were 60% (PR) and 19% (TR) (p < 0.0001). The CD4% decreases were 36% (PR) and 18% (TR) (p < 0.0001). Women receiving PR were more likely to exhibit an increase in VL [adjusted odds ratio (AOR) 7.7 (95% CI: 5.5-10.9) and a CD4% decrease (AOR 2.3; 95% CI: 1.6-3.2). Women receiving PR are more likely to have VL increases and CD4% decreases compared to those receiving TR. The clinical implications of these VL and CD4% changes remain to be explored.

Introduction. Quality of life (QoL) is an important consideration in the management of chronic progressive illnesses such as acquired immunodeficiency syndrome (AIDS). It provides the opportunity to understand the effects of disease and treatment to include their impact on physical, psychological and social functioning. We evaluated the QoL of HIV-infected children and established the association between QoL and CD4 cell counts, viral load, clinical status and antiretroviral therapy (ART). Methods. QoL was assessed by the General Health Assessment for Children developed for PACTG 219 and examined domains of health perceptions, functional status, social and role functioning, health care utilization, symptoms and associated events. Children were divided into groups according to their AIDS status, viral load, CD4 and ART. Results. One hundred seventy four children and adolescents were evaluated. Good scores were obtained in all domains. No difference was found in QoL scores among patients with different AIDS status. Patients with higher CD4 cell percentages had better QoL in health perceptions and symptoms domains. Low viral load was related to better QoL in social and role functioning. No relationship was found between ART and QoL. Patients receiving highly active antiretroviral therapy (HAART) showed similar QoL scores in comparison with those without HAART. Conclusion. HIV children reached high scores in all QoL domains. CD4 and viral load presented positive association with some of the domains assessed. HAART was able to provide similar QoL compared to other treatment groups, pointing to a balance between clinical benefits and side effects of therapy.

Introducción. La calidad de vida (QoL) es una consideración importante en el manejo de enfermedades progresivas crónicas como el síndrome de inmunodeficiencia adquirida (SIDA). Proporciona la oportunidad de entender el efecto de la enfermedad y el tratamiento en el impacto del funcionamiento físico, psicológico y social. En este estudio se evalúa la QoL de niños infectados con virus de inmunodeficiencia humana y la asociación entre QoL y células CD4+, carga viral, estadio clínico y tratamiento antirretroviral (TAR). Métodos. La QoL fue medida por el instrumento Evaluación de Salud General para Niños (General Health Assessment for Children, GHAC) desarrollada por PACTG 219, el cual examina dominios de percepción de la salud, estatus funcional, función social y el rol en la misma, así como utilización de servicios de salud, síntomas y eventos asociados. Los niños fueron clasificados en grupos de acuerdo a su categoría de SIDA, carga viral, células CD4 y TAR. Resultados. Se evaluaron 174 niños y adolescentes. Se obtuvieron buenos puntajes en todos los dominios. No se observaron diferencias en los puntajes de QoL entre pacientes en diferentes categorías de SIDA. Los pacientes con mayor porcentaje de células CD4+ tuvieron mejor QoL en los dominios de percepción de la salud y síntomas. No hubo asociación entre TAR y QoL. Los pacientes que recibieron el tratamiento antirretroviral altamente activo (TARAA) mostraron similares puntajes de QoL en comparación con aquellos sin TARAA. Conclusión. Los niños con virus de inmunodeficiencia humana obtuvieron elevados puntajes en todos los dominios de QoL, células CD4 y carga viral, presentando asociación positiva con algunos de los dominios evaluados. El TARAA fue capaz de proporcionar similar QoL, comparado a otros grupos de tratamiento, indicando un balance entre beneficios clínicos y eventos adversos de la terapia.

OBJETIVO: Analisar a utilidade da contagem total de linfócitos, contagem global de leucócitos, hemoglobina, estado nutricional, contagem de linfócitos T CD4+ e carga viral como marcadores de progressão da doença e/ou óbito em crianças infectadas pelo HIV. MÉTODOS: Estudo de coorte retrospectiva em população de crianças infectadas pelo HIV, assintomáticas ou com sintomas leves e/ou moderados e virgens de tratamento antirretroviral. Os eventos de interesse foram: progressão para categoria clínica C (de acordo com a classificação dos Centers for Disease Control and Prevention - CDC, de 1994) ou óbito. Valores da contagem global de leucócitos, contagem total de linfócitos, hemoglobina, escore z peso/idade, contagem de linfócitos T CD4+ e carga viral plasmática obtidos à admissão foram considerados na análise do risco de ocorrência dos eventos de interesse. A população foi estratificada em faixas etárias: <12, > 12 e < 36, > 36 e < 60 meses. RESULTADOS: Cento e vinte pacientes, admitidos entre 1997 e 2003, preencheram os critérios para inclusão deste estudo. A mediana global do tempo de acompanhamento foi de 7,4 meses (intervalo interquartil 25-75% = 3,8-21,1). Em análise multivariada, apenas a contagem de linfócitos T CD4+, segundo as categorias da Organização Mundial da Saúde, e o escore z peso/idade ≤ -2 foram preditores do risco de progressão da doença em crianças maiores de 12 meses de idade. Em menores de 12 meses, nenhuma das variáveis analisadas esteve associada ao risco de progressão. CONCLUSÃO: Evidencia-se a importância do estado nutricional na avaliação do risco de progressão da doença em crianças maiores de 12 meses de idade infectadas pelo HIV.

OBJECTIVE: To analyze total lymphocyte count, total leukocyte count, hemoglobin levels, nutritional status, CD4+ T-lymphocyte count and viral load as markers of disease progression and/or death in HIV-infected children. METHODS: This retrospective cohort study assessed antiretroviral naïve HIV-infected children who were asymptomatic or had mild and/or moderate symptoms. The events of interest were: progression to clinical category C (according to the classification of the Centers for Disease Control and Prevention - CDC, 1994) or death. Values of total leukocyte count, total lymphocyte count, hemoglobin, weight-for-age z score, CD4+ T-lymphocyte count and plasma viral load obtained at admission were considered in the risk analysis of events of interest. The population was stratified into age groups: < 12, > 12 to < 36, > 36 to < 60 months. RESULTS: One hundred and twenty patients, admitted between 1997 and 2003, met the inclusion criteria for the present study. The total median of follow-up duration was 7.4 months (25-75% interquartile range = 3.8-21.1). In the multivariate analysis, only CD4+ T-lymphocytes count, according to the categories of the World Health Organization, and weight-for-age z score ≤ -2 were predictors of risk for disease progression in children older than 12 months. In children younger than 12 months, none of the variables was associated with risk of progression. CONCLUSION: Nutritional status is an important aspect in the assessment of risk of disease progression in HIV-infected children older than 12 months.

Objective: The use of antiretroviral therapy in HlV-infected children has been a widely discussed issue. The aim of this study was to compare the effectiveness of dual nucleoside analogue reverse transcriptase inhibitor (NRTI) regimens and three-drug regimens [2NRTI+ non-nucleoside reverse transcriptase inhibitor (NNRTI) or protease inhibitor (PI)] in a cohort of HlV-infected children. Methods: The study was carried out in a referral center for the management of infected children, which is affiliated with the School of Medicine of Universidade Federal de Mnas Gerais (UFMG). Those children whose antiretroviral therapy was implemented between January 1998 and December 2000 and who were followed until December 2001 were included in the study. Therapeutic failure or death was regarded as the endpoint in our analysis. Results: A total of 101 patients were assessed, 58 (57.4%) on dual therapy and 43 (42.6%) on triple therapy. No statistically significant difference was observed between the groups in terms of gender, age, CD4+ count and baseline viral load. The average duration of dual therapy was 26.3 months (95%CI 21.3-31.3) and that of triple therapy was 34.3 months (95%CI 29.2-39.5%). There was therapeutic failure in 33 (56.9%) patients on dual therapy and in 11 (25.6%) patients on triple therapy (log rank = 5.03; p = 0.025). The relative risk of therapeutic failure of the dual therapy was 2.2 times higher (95%CI 1.3-3.9). The percentage of initial CD4+ T cells was a predictor of risk for therapeutic failure (p = 0.001). Patients on triple therapy showed a more remarkable reduction in their viral load (p = 0.001). Conclusión: Triple therapy was efficient for a longer time period and showed better virologic response than dual therapy in this cohort of HlV-infected children. Therefore, triple therapy should be the treatment of choice.

Objetivos: Como iniciar a terapia anti-retroviral é uma questao amplamente discutida no manejo de criangas infectadas pelo HIV. O objetivo deste estudo foi comparar a efetividade da terapia dupla e tríplice em uma coorte de criangas infectadas pelo HIV. Método: Este estudo foi realizado em um servigo de referencia para assisténcia á crianga infectada da Facul-dade de Medicina da UFMG. Foram incluídas criangas que iniciaram o primeiro regime anti-retroviral entre janeiro de 1998 e dezembro de 2000, com seguimento até dezembro de 2001. O evento final para análise foi a pri-meira falha terapéutica ou óbito. Resultados: Foram analisados 101 pacientes, sendo 58 (57,4%) e 43 (42,6%) com terapia dupla e tríplice, respectivamente. Nao houve diferenga entre os grupos quanto ao sexo, idade, contagem de linfócitos CD4+ e carga viral basal. A média de duragao da terapia dupla foi de 26,3 meses (IC95% 21,3-31,3) e da terapia tríplice, de 34,3 meses (IC95% 29,2-39,5%). Falha terapéutica ocorreu em 33 (56,9%) pacientes em terapia dupla e 11 (25,6%) em terapia tríplice (log rank 5,03; p = 0,025). O risco relativo de falha para terapia dupla foi 2,2 vezes maior (IC = 1,3-3,9). O percentual de linfócitos T CD4+ inicial foi preditor de risco para falha terapéutica (p = 0,001). Pacientes em terapia tríplice apresentaram maior redugao da carga viral (p = 0,001). Conclusáo: A terapia tríplice permaneceu eficaz por mais tempo e apresentou melhor resposta virológica do que a terapia dupla nesta coorte de criangas infectadas pelo HIV, justificando a sua escolha como regime preferencial de tratamento.

Objective: The use of antiretroviral therapy in HIV-infected children has been a widely discussed issue. The aim of this study was to compare the effectiveness of dual nucleoside analogue reverse transcriptase inhibitor (NRTI) regimens and three-drug regimens [2NRTI+ non-nucleoside reverse transcriptase inhibitor (NNRTI) or protease inhibitor (PI)] in a cohort of HIV-infected children. Methods: The study was carried out in a referral center for the management of infected children, which is affiliated with the School of Medicine of Universidade Federal de Minas Gerais (UFMG). Those children whose antiretroviral therapy was implemented between January 1998 and December 2000 and who were followed until December 2001 were included in the study. Therapeutic failure or death was regarded as the endpoint in our analysis. Results: A total of 101 patients were assessed, 58 (57.4%) on dual therapy and 43 (42.6%) on triple therapy. No statistically significant difference was observed between the groups in terms of gender, age, CD4+ count and baseline viral load. The average duration of dual therapy was 26.3 months (95%CI 21.3-31.3) and that of triple therapy was 34.3 months (95%CI 29.2-39.5%). There was therapeutic failure in 33 (56.9%) patients on dual therapy and in 11 (25.6%) patients on triple therapy (log rank = 5.03; p = 0.025). The relative risk of therapeutic failure of the dual therapy was 2.2 times higher (95%CI 1.3-3.9). The percentage of initial CD4+ T cells was a predictor of risk for therapeutic failure (p = 0.001). Patients on triple therapy showed a more remarkable reduction in their viral load (p = 0.001). Conclusion: Triple therapy was efficient for a longer time period and showed better virologic response than dual therapy in this cohort of HIV-infected children. Therefore, triple therapy should be the treatment of choice.

Significant decrease in human immunodeficiency virus type 1 (HIV-1) vertical transmission has been observed worldwide in centers where interventions such as antiretroviral therapy (ART), elective cesarean section, and avoidance of breastfeeding have been implemented. This prospective cohort study aimed to assess the determinants of and the temporal trends in HIV-1 vertical transmission in the metropolitan area of Belo Horizonte, Brazil from January 1998 to December 2005. The rate of HIV-1 vertical transmission decreased from 20% in 1998 to 3% in 2005. This decline was associated with increased use of more complex ART regimens during pregnancy. Multivariate analysis restricted to clinical variables demonstrated that non ART, neonatal respiratory distress/sepsis and breastfeeding were independently associated with HIV-1 vertical transmission. When laboratory parameters were included in the model, high maternal viral load and non maternal ART were associated with HIV-1 vertical transmission. The results from this study confirm the impact of ART in the reduction of HIV-1 vertical transmission and indicate the need for improvement in the care and monitoring of mother and infant pairs affected by HIV-1.

OBJETIVO: Respirador bucal é o indivíduo que utiliza a cavidade oral como principal via aérea durante a respiração. Trata-se de síndrome de múltiplas etiologias, dentre as quais a rinite alérgica merece destaque por sua alta prevalência. Este trabalho teve como objetivo avaliar a presença de atopia entre respiradores bucais encaminhados a serviço de referência da região metropolitana de Belo Horizonte. MÉTODOS: Estudo transversal e descritivo, realizado no Hospital das Clínicas da Universidade Federal de Minas Gerais. Foram incluídos pacientes de 2 a 12 anos de idade, com período de admissão entre novembro de 2002 e abril de 2004. Os responsáveis responderam a um questionário completo, e os pacientes foram submetidos a teste alérgico cutâneo para inalantes. Houve 140 participantes do estudo. Foram classificados como atópicos aqueles que apresentaram teste positivo para, no mínimo, um alérgeno. As análises estatísticas foram feitas no programa SPSS, usando análises univariadas seguidas pela regressão logística. RESULTADOS: Entre os 140 pacientes, 44,3% (62/140) tiveram teste alérgico positivo. Ácaros foram os alérgenos predominantes, apresentando positividade em 100% dos atópicos. Em análise multivariada, atopia esteve significativamente associada ao sexo masculino (p = 0,05), presença de asma (p = 0,014), menor número de pessoas dormindo no mesmo cômodo que o paciente (p = 0,005), ausência de tabagismo passivo (p = 0,005) e ausência de apnéia noturna (p = 0,003). CONCLUSÃO: A alta prevalência de positividade no teste alérgico enfatiza a importância da investigação alergológica em respiradores bucais, pois a alergia tem formas específicas de tratamento que podem reduzir a morbidade desses pacientes quando adequadamente utilizadas.

OBJECTIVE: A mouth breather is someone who uses his/her oral cavity as main airway during breathing. This is a syndrome with several etiologies, but allergic rhinitis plays a key role due to its high prevalence. The aim of this study was to assess the presence of atopy among mouth-breathing patients referred to a tertiary care center in the metropolitan region of Belo Horizonte, Brazil. METHODS: Cross-sectional, descriptive study carried out at Hospital das Clínicas of Universidade Federal de Minas Gerais. Patients aged 2 to 12 years, admitted between November 2002 and April 2004, were included. Parents or surrogates completed a comprehensive questionnaire, and patients were submitted to a skin test for inhalant allergens. A total of 140 patients participated in the study. Those with a positive result for at least one allergen were regarded as atopic. The statistical analyses were made using SPSS, with univariate analyses followed by logistic regression. RESULTS: Of 140 patients, 44.3% (62/140) obtained positive results on the allergic test. Mites were the most predominant allergens, with a positive rate of 100% among atopic patients. In the multivariate analysis, atopy was significantly associated with the male sex (p = 0.05), presence of asthma (p = 0.014), lower number of people sleeping in the same room with the patient (p = 0.005), absence of passive smoking (p = 0.005) and absence of sleep apnea (p = 0.003). CONCLUSION:The high prevalence of positive results on the allergic test highlights the importance of allergologic investigation in mouth-breathers, since allergy has specific treatments that may reduce morbidity in these patients when properly used.

OBJETIVOS: Como iniciar a terapia anti-retroviral é uma questão amplamente discutida no manejo de crianças infectadas pelo HIV. O objetivo deste estudo foi comparar a efetividade da terapia dupla e tríplice em uma coorte de crianças infectadas pelo HIV. MÉTODO: Este estudo foi realizado em um serviço de referência para assistência à criança infectada da Faculdade de Medicina da UFMG. Foram incluídas crianças que iniciaram o primeiro regime anti-retroviral entre janeiro de 1998 e dezembro de 2000, com seguimento até dezembro de 2001. O evento final para análise foi a primeira falha terapêutica ou óbito. RESULTADOS: Foram analisados 101 pacientes, sendo 58 (57,4%) e 43 (42,6%) com terapia dupla e tríplice, respectivamente. Não houve diferença entre os grupos quanto ao sexo, idade, contagem de linfócitos CD4+ e carga viral basal. A média de duração da terapia dupla foi de 26,3 meses (IC95% 21,3-31,3) e da terapia tríplice, de 34,3 meses (IC95% 29,2-39,5%). Falha terapêutica ocorreu em 33 (56,9%) pacientes em terapia dupla e 11 (25,6%) em terapia tríplice (log rank 5,03; p = 0,025). O risco relativo de falha para terapia dupla foi 2,2 vezes maior (IC = 1,3-3,9). O percentual de linfócitos T CD4+ inicial foi preditor de risco para falha terapêutica (p = 0,001). Pacientes em terapia tríplice apresentaram maior redução da carga viral (p = 0,001). CONCLUSÃO: A terapia tríplice permaneceu eficaz por mais tempo e apresentou melhor resposta virológica do que a terapia dupla nesta coorte de crianças infectadas pelo HIV, justificando a sua escolha como regime preferencial de tratamento.

OBJECTIVE: The use of antiretroviral therapy in HIV-infected children has been a widely discussed issue. The aim of this study was to compare the effectiveness of dual nucleoside analogue reverse transcriptase inhibitor (NRTI) regimens and three-drug regimens [2NRTI+ non-nucleoside reverse transcriptase inhibitor (NNRTI) or protease inhibitor (PI)] in a cohort of HIV-infected children. METHODS: The study was carried out in a referral center for the management of infected children, which is affiliated with the School of Medicine of Universidade Federal de Minas Gerais (UFMG). Those children whose antiretroviral therapy was implemented between January 1998 and December 2000 and who were followed up until December 2001 were included in the study. Therapeutic failure or death was regarded as the endpoint in our analysis. RESULTS: A total of 101 patients were assessed, 58 (57.4%) on dual therapy and 43 (42.6%) on triple therapy. No statistically significant difference was observed between the groups in terms of gender, age, CD4+ count and baseline viral load. The average duration of dual therapy was 26.3 months (95%CI 21.3-31.3) and that of triple therapy was 34.3 months (95%CI 29.2-39.5%). There was therapeutic failure in 33 (56.9%) patients on dual therapy and in 11 (25.6%) patients on triple therapy (log rank = 5.03; p = 0.025). The relative risk of therapeutic failure of the dual therapy was 2.2 times higher (95%CI = 1.3-3.9). The percentage of initial CD4+ T cells was a predictor of risk for therapeutic failure (p = 0.001). Patients on triple therapy showed a more remarkable reduction in their viral load (p = 0.001). CONCLUSION: Triple therapy was efficient for a longer time period and showed better virologic response than dual therapy in this cohort of HIV-infected children. Therefore, triple therapy should be the treatment of choice.