The effects of individually ventilated cages on the respiratory systems of male and female Wistar rats from birth until adulthood

OBJECTIVE: To evaluate the respiratory systems of male and female rats maintained in individually ventilated cages (IVCs) from birth until adulthood. METHODS: Female Wistar rats were housed in individually ventilated cages or conventional cages (CCs) and mated with male Wistar rats. After birth and weaning, the male offspring were separated from the females and kept in cages of the same type until 12 weeks of age. RESULTS: The level of food consumption was lower in male offspring (IVC=171.7±9; CC=193.1±20) than in female offspring (IVC=100.6±7; CC=123.4±0.4), whereas the water intake was higher in female offspring (IVC=149.8±11; CC=99.2±0) than in male offspring (IVC=302.5±25; CC=249.7±22) at 11 weeks of age when housed in IVCs. The cage temperature was higher in individually ventilated cages than in conventional cages for both male (IVCs=25.9±0.5; CCs=22.95±0.3) and female (IVCs=26.2±0.3; CCs=23.1±0.3) offspring. The respiratory resistance (IVC=68.8±2.8; CC=50.6±3.0) and elastance (IVC=42.0±3.9; CC=32.4±2.0) at 300 µm/kg were higher in the female offspring housed in ventilated cages. The ciliary beat values were lower in both the male (IVCs=13.4±0.2; CC=15±0.4) and female (IVC=13.5±0.4; CC=15.9±0.6) offspring housed in individually ventilated cages than in those housed in conventional cages. The total cell (IVC=117.5±9.7; CC=285.0±22.8), neutrophil (IVC=13.1±4.8; CC=75.6±4.1) and macrophage (IVC=95.2±11.8; CC=170.0±18.8) counts in the bronchoalveolar lavage fluid were lower in the female offspring housed in individually ventilated cages than in those housed in conventional cages. CONCLUSIONS: The environmental conditions that exist in individually ventilated cages should be considered when interpreting the results of studies involving laboratory animals. In this study, we observed gender dimorphism in both the water consumption and respiratory mechanics of rats kept in ventilated cages.

Alterações placentárias em resposta à exposição de ratas Wistar à poluição atmosférica / Placental alterations in response to exposure of Wistar rats to air pollution

Introdução: A exposição à poluição atmosférica durante a gestação provoca alterações nas características da placenta e pode resultar em restrição de crescimento intrauterino. Sabe-se que o transforming growth factor beta 1 (TGFbeta1), o sistema renina-angiotensina uteroplacentário (SRA) e os fatores angiogênicos, tais como vascular endothelial growth factor A (VEGF-A) participam do processo de placentação e regulação do fluxo sanguíneo uteroplacentário. Assim, o objetivo do presente estudo foi investigar o efeito da exposição à poluição do ar sobre a morfologia, função e SRA placentários. Métodos: Ratas Wistar fêmeas foram expostas ao ar filtrado (F) ou ao material particulado 2.5um (P) durante 15 dias. Depois o cruzamento, as ratas foram divididas em 4 grupos e novamente expostas a F ou P (FF, FP, PF, PP). No 19º dia de gestação, as porções maternas e fetais das placentas foram coletadas. Estrutura da placenta, TGFbeta1, VEGF-A e seus receptores e os componentes do SRA foram avaliados. Resultados: A exposição ao material particulado diminuiu massa, tamanho e área de superfície placentária, um indicativo da interação materno-fetal. As concentrações placentárias de TGF beta1, VEGF-A e Flk-1 e os componentes do SRA foram alterados e isso pode indicar um prejuízo na invasão do trofoblasto, angiogênese placentária e troca de nutrientes e gases entre mãe e fetos. Discussão: Os resultados indicam que a exposição a partículas compromete a interação materno-fetal e pode refletir sobre a nutrição e crescimento fetal.

Introduction: Exposure to air pollution during pregnancy causes alterations in placental characteristics and may result in intrauterine growth restriction. It was suggested that transforming growth factor beta 1 (TGFbeta1), the uteroplacental renin-angiotensin system (RAS) and angiogenic factors, such as vascular endothelial growth factor A (VEGF-A) participates of the placentation process and regulation of the uteroplacental blood flow. Thus, the aim of the present study was to investigate the effect of exposure to air pollution on the placental morphology, function and placental RAS. Methods: Female Wistar rats were exposed to filtrated air (F) or to concentrated particulate matter 2.5um (P) for 15 days. After mating, rats were divided in 4 groups and again exposed to F or P (FF, FP, PF, PP). At 19th day of pregnancy, maternal and fetal portions of placenta were collected. Placental structure, TGFbeta1, VEGF-A and its receptors and RAS components were evaluated. Results: Exposure to particulate matter decreased placental mass, size and surface area, an indicative of maternal-fetal interaction. Placental TGFbeta1, RAS components and VEGF-A and receptors Flk-1 concentrations were altered and this may indicate a prejudice in the trophoblast invasion, placental angiogenesis and maternal-fetal nutrients and gases exchange. Discussion: These findings indicate that exposure to particulate matter compromises the maternal-fetal interaction and may reflect on fetal nutrition and growth.

Vigilancia de hepatitis virales en Argentina: análisis de información obtenida por las Unidades Centinela 2007-2010 / [Surveillance of viral hepatitis in Argentina: analysis of information from sentinel units 2007-2010].

In Argentina, the four strategies of epidemiological surveillance from the National System of Health Surveillance (SNVS) are Diseases of Mandatory Report (C2), Sentinel Units (SU), Laboratory Surveillance (SIVILA) and National Programs (National Plan of Blood, information from blood banks). They collect information about viral hepatitis (VH). The objective of this work was to analyze the information recorded by the SUs of VH for hepatitis B and C in the period between January 1th 2007 and December 31h 2010. In this period, out of the 1,769 cases recorded (entered by 21 of 24 SUs), 806 entries were hepatitis B, 848 hepatitis C and 115 belonged to other definitions. The relative proportions between hepatitis B and hepatitis C were heterogeneous between the SUs. The age distribution was homogeneous, being the predominant group in acute hepatitis B the 25- to 34-year-old group. In hepatitis C, the age distribution was broader. The distribution by sex and risk factors was heterogeneous between the different SUs. In hepatitis C, genotype 1 was the predominant one. In conclusion, the information provided by the SUs contributes as an evidence of the public health problem posed by this pathology in our country.

Effects of mycophenolate sodium on mucociliary clearance using a bronchial section and anastomosis rodent model

OBJECTIVE: To study the effects of mycophenolate sodium on mucociliary clearance. INTRODUCTION: Mycophenolate is one of the most commonly used immunosuppressive drugs in lung transplantation. Although its pharmacokinetic properties are well defined, its side effects on mucociliary clearance have not yet been studied. METHODS: Sixty rats were subjected to left bronchial section and anastomosis. The right bronchus was used as a control. After surgery, the rats were assigned to two groups based on whether they received saline solution (n = 30) or mycophenolate sodium (n = 30). After 7, 15, or 30 days of treatment, 10 animals from each group were sacrificed, and in vitro mucus transportability, in situ mucociliary transport velocity and ciliary beat frequency were measured. RESULTS: The analysis of mucus transportability revealed that neither mycophenolate nor bronchial section altered any transportability related property for up to 30 days of treatment after surgery (p>0.05). With regard to ciliary beat frequency, the operated left bronchi from the mycophenolate group showed a significant decrease on post-surgical day 30 (p = 0.003). In addition, we found a significant reduction in the in situ mucociliary transport velocity in the mycophenolate-treated group (p = 0.0001). DISCUSSION: These data add important information regarding mucociliary clearance dysfunction following mycophenolate therapy and suggest that mycophenolate might contribute to the high incidence of respiratory tract infections in lung transplant patients. Further studies are needed to investigate the combined action of mycophenolate with other immunosuppressive drugs and to establish methods to protect and recover mucociliary clearance, an important airway defense mechanism.

Duración de la viremia y la excreción fecal del virus en niños con Hepatitis A / Duration of viremia and fecal shedding of the virus in Hepatitis A infected children

La infección por el virus de hepatitis A (HAV) es endémica en Argentina. El uso de técnicas moleculares permitió extender la detección del RNA del HAV en sueroy heces en pacientes con diferentes presentaciones clínicas. Comparamos la sensibilidad del protocolo de RT-PCR que usamos con cebadores dirigidos a distintas regiones del genoma, resultando la detección de la región VP3 C terminal la más sensible. Se obtuvieron prospectivamente muestras de suero y materia fecal de 20 niños con hepatitis aguda autolimitada por HAV. El RNA del HAV fue detectado en 18/20 niños en muestras basales y en 19/20 sumando una muestra posterior. El RNA del HAV fue detectable en 9/20 acientes hasta 30 días en suero; en materia fecal en 2/20 hasta 60 días y en 1/20 hasta 90 días. La secuencia genómica para la región VP1/2A en 8 muestras demostró que todas pertenecían al subgenotipo IA, aunque eran diferentes entre sí. Solo en 1/11 niños con falla hepatica fulminante fue posible la detección del RNA del HAV utilizando la región VP3 C terminal y el genotipo fue I. La reciente introducción de la vacunación universal en niños de 1 año de edad en Argentina podría disminuir drásticamente la circulación del virus, emergiendo nuevas fuentes de infección y permitiendo la introducción de nuevos genotipos. Las técnicas moleculares aplicadas al estudio de la historia natural de la infección y a la vigilancia epidemiológica contribuyenal control y la toma de decisiones eficientes en políticas de Salud Pública.

Hepatitis A virus (HAV) infection is endemic in Argentina. Molecular tools have allowed HAV RNA detection to be extent to sera and feces from patients with different clinical backgrounds. We compare the sensitivity of the RT-PCR protocol we follow using primers targeting different genomic regions and VP3 C terminal was the most sensitive. Sequential sera and fecal samples were obtained from 20 children with acute self limited Hepatitis A. HAV RNA was detectable in 18/20 children if sera and stool specimens were collected at the onset of symptoms and in 19/20 if a later sample was considered. HAV RNA was detectable in serum from 9/20 patients until day 30 and in feces from 2 patients until day 60 and until day 90 in one. Genomic sequences from VP1/2A region in 8 samples showed they all belong to subgenotype IA although they were different between them. HAV RNA was detectable only in 1/11 sera from children with acute liverfailure when VP3 C terminal fragment was searched and it belonged to genotype I. Universal vaccination in one year old children was recently implemented in Argentinaand it will dramatically enable the decrease of the viral circulation, making new sources of infection emerge and allowing the introduction of new genotypes. The application of molecular tools to the study of the natural history of infection and to the epidemiologicsurveillance may contribute to efficient control and lead to rational decisions in public health policies.

Caracterización molecular del virus de hepatitis E en tres casos de falla hepática fulminante en niños de Argentina / Molecular characterization of hepatitis E virus in three acute liver failure cases in children in Argentina

Las cepas de virus de hepatitis E (HEV) encontradas en casos esporádicos humanos y en cerdos en Argentina corresponden al genotipo 3. Se han descripto variantes de este genotipo asociadas a fallas hepáticas fulminantes (FHF) en adultos de Japón e Inglaterra. En Argentina el 30% de las FHF en adultos y en niños es de etiología desconocida. Para estudiar si el HEV podría ser el agente etiológico asociado a FHF en niños se analizaron el suero y/o la materia fecal de 35 niños (edad media 6 años, 20 mujeres, 15 varones) durante 2003 y 2004. El HEV RNA fue detectado por RT-nested PCR con cebadores dirigidos a las regiones ORF 1 y ORF 2. El HEV RNA pudo detectarse en 3 casos. Dos eran varones de 12 años residentes en la provincia de Buenos Aires y el tercero, una niña de 3 años de la provincia de Corrientes. El análisis de las secuencias muestra que las 3 variantes son distintas, pero pertenecen todas al genotipo 3 y están muy relacionadas a las cepas encontradas previamente en casos esporádicos en humanos y en cerdos de Argentina. Estos datos sugieren una posible relación entre FHF y HEV en niños de Argentina e indican la necesidad de considerar la infección con HEV en el diagnóstico diferencial de las FHF. Se necesitan más estudios que demuestren el verdadero impacto de esta infección y el beneficio potencial de na vacuna para HEV, actualmente en fase III.

Strains of hepatitis E virus (HEV) isolated from Argentinian patients with sporadic hepatitis, as well as from swine from Argentina, belong to genotype 3. HEV genotype 3 variants have been described associated with acute liver failure (ALF) in adults from Japan and the United Kingdom. In Argentina, 30% of ALF in adults and children are of unknown aetiology. To study if HEV could be an aetiological agent associated with ALF in children, serum and/or fecal samples from 35 children (mean age: 6 years, 20 female, 15 male) were analyzed during 2003 and 2004. HEV RNA was detected by RT-nested PCR with primers designed within ORF 1 and ORF 2 regions. HEV RNA could be detected in three cases. Two were 12-year-old boys from Buenos Aires province and the third was a 3- year-old girl from Corrientes province. Sequence analysis indicates that the three isolates are distinct from each other but all belong to genotype 3, exhibiting a close relationship with swine and human strains from sporadic cases of HEV, previously reported in Argentina. This data suggests a potential link between ALF and HEV in children in Argentina and indicates the need for the determination of HEV status in the differential diagnosis in ALF. Further studies would aid in determining the true impact of this infection in Argentina and the potential benefits of a vaccine against HEV, presently in phase III trials.