PubMed Health⌕ Search

Biomedical subjects

Marcus H Jones

Publications and source records attributed to Marcus H Jones.

10 recordsLinked to original sources
PubMed2005

Effect of Angiostrongylus costaricensis extract on eosinophilic pulmonary response in BALB/c mice.

Epidemiological and experimental studies have demonstrated an association between parasitic infections and the allergic diseases. A protective effect in asthma was shown in animals infected with helminths. The aim of this study was to determine the effect of Angiostrongylus costaricensis extract on inflammatory lung response to ovalbumin (OVA) in mice. Four BALB/c mice received A. costaricensis extract by intraperitoneal (i.p.) injection on the first day. Mice were immunised against OVA by i.p. injection on day (D) 5 and D12 and received a daily intranasal OVA challenge (40 microl) between the D19 and D21. On D23, we performed a bronchoalveolar lavage (BAL) on the mice. Four BALB/c mice (control group) were immunised against OVA using the same protocol, but did not receive parasite extract. Total cell counts (TCC) and differential cell counts were performed in BAL fluid samples. Eosinophil cell counts in BAL fluid were lower in the group that received A. costaricensis extract when compared with the control group (0.04 x 10(6) cells/ml and 0.01 x 10(6) cells/ml, respectively; p=0.04). TCC were not different between the groups studied. A. costaricensis extract in mice decreases eosinophilic response to OVA in BAL fluid.

Angiostrongylus↗
PubMed2005

Reduced lung function in healthy preterm infants in the first months of life.

RATIONALE: Preterm delivery has been associated with a higher incidence of respiratory morbidity even in infants that do not have significant respiratory disease during the neonatal period. Reduced flows have been reported in children and adolescents born prematurely. OBJECTIVE: The aim of this study was to assess lung function in healthy preterm infants in the first months of life. METHODS: Preterm infants with less than 48 h of supplemental oxygen were recruited. Lung function was assessed by the raised-volume rapid thoracic compression in the first months of life. The control group consisted of full-term infants without a history of respiratory diseases. MEASUREMENTS AND MAIN RESULTS: Sixty-two preterm (29 male) and 27 full-term (10 male) infants were tested. Adjusting for length, age, and sex, we found a mean significant reduction of 92 ml/s (22%) in FEF(50), 73 ml/s (21%) in FEF(25-75), and 19 ml (28%) in FEV(0.5) in the preterm group. These differences in expiratory flows remained significant using another model that adjusts for lung volume (p < 0.01 for FEF(50), FEF(25-75), and FEV(0.5), and p < 0.05 for FEF(75)). In the preterm group, after adjusting for length, male sex, lower gestational age, and increased weight were significantly and independently associated with reduced flows. CONCLUSIONS: Our findings confirm that prematurity is independently associated with reduced lung function and that this is detectable in the first months of life. Male sex, lower gestational age, and weight are important predictors for reduced expiratory flows in this group.

Child, Preschool↗
PubMed2005

Levels of Th1 and Th2 cytokines in children with post-infectious bronchiolitis obliterans.

BACKGROUND: Post-infectious bronchiolitis obliterans (BO) is a chronic obstructive airway disease associated with inflammation and fibrosis of the small airways; it is more common in children who have had acute viral bronchiolitis. No previous studies have reported the immune response of BO. Unbalanced Th1/Th2 immune response might be one of the risk factors for developing this illness. AIM: To compare the production of interferon (IFN)-gamma, interleukin (IL)-4 and IL-10 in peripheral blood mononuclear cell cultures in children with BO and in healthy children. METHODS: From March 2003 to October 2003, children with BO and healthy children were selected from the paediatric outpatient clinics in our centre. Peripheral blood was collected and mononuclear cells were separated and cultured (96 hours) with 1% phytohaemagglutinin stimulation. The supernatant was stored and cytokine levels were measured through ELISA. RESULTS: IFN-gamma, IL-4 and IL-10 levels were not significantly different between the groups studied. Family history of atopy was significantly associated with subjects with BO (p=0.02). CONCLUSIONS: Our results suggest that unbalanced peripheral blood Th1/Th2 immune response of children with post-infectious BO might not be associated with its pathophysiology. Further studies are required to better understand the role of risk factors, including viral genotype, viral load or tissue repair abnormalities in the development of post-infectious BO.

Acute Disease↗
PubMed2005

[Pulmonary prognosis in preterm infants].

OBJECTIVE: The increased survival of preterm infants poses the challenge of dealing with a wide range of chronic pulmonary diseases, including bronchopulmonary dysplasia, Wilson-Mikity syndrome and recurrent wheezing. This article reviews the pulmonary clinical and functional prognosis of preterm newborns in infancy and adolescence. SOURCE OF DATA: MEDLINE search for articles published between 1970 and 2004 that focused on lung growth and function of preterm infants, besides a clinical follow-up of this group. SUMMARY OF THE FINDINGS: Prenatal and postnatal events, such as placental insufficiency, tobacco exposure, infections, oxygen and mechanical ventilation, have an important effect on lung development and can lead to chronic lung diseases, of which bronchopulmonary dysplasia is the most severe complication. However, significant loss of lung function occurs in preterm infants who do not fulfill the criteria for bronchopulmonary dysplasia, and even in those who did not have significant respiratory disease during the neonatal period. The impact of prematurity on the respiratory system of these patients is usually underestimated. Clinically, preterm infants have an increased incidence of pneumonia and bronchiolitis, hospital readmissions due to respiratory diseases, chronic cough and wheezing and bronchial hyperresponsiveness. In adolescence, there is a tendency for normalization of the lung function, but they persist with reduced flows, lower exercise tolerance and bronchial hyperresponsiveness. CONCLUSIONS: Prematurity, the events that cause it and the interventions that follow it permanently change the development of the respiratory system. Studies are necessary to clarify the effect of each of these perinatal insults on the development of the respiratory system.

Bronchopulmonary Dysplasia↗
PubMed2003

Sensitivity of spirometric measurements to detect airway obstruction in infants.

We evaluated the ability of forced expiratory flow volume curves from raised lung volumes to assess airway function among infants with differing severities of respiratory symptoms. Group 1 (n = 33) had previous respiratory symptoms but were currently asymptomatic; group 2 (n = 36) was symptomatic at the time of evaluation. As a control group, we used our previously published sample of 155 healthy infants. Flow volume curves were quantified by FVC, FEF50, FEF75, FEF25-75, FEV0.5, and FEV0.5/FVC, which were expressed as Z scores. All variables except FVC had Z scores that were significantly less than zero and distinguished groups 1 and 2 with progressively lower Z scores. The mean Z scores of the flow variables (FEF50%, FEF75%, and FEF25-75%) were more negative than the Z scores for the timed expired volumes (FEV0.5 or FEV0.5/FVC) for both groups. In general, measures of flow identified a greater number of infants with abnormal lung function than measures of timed volume; FEF50 had the highest performance in detecting abnormal lung function. In summary, forced expiratory maneuvers obtained by the raised volume rapid compression technique can discriminate among groups of infants with differing severity of respiratory symptoms, and measures of forced expiratory flows were better than timed expiratory volume in detecting abnormal airway function.

Age Factors↗
PubMedDate not supplied

[Rhinovirus and acute bronchiolitis in young infants].

OBJECTIVE: To determine the prevalence of rhinovirus infection in hospitalized young infants with acute bronchiolitis. METHODS: Hospitalized children with acute bronchiolitis admitted to the Hospital São Lucas/PUCRS between May and September 2002 were selected prospectively. Nasopharyngeal samples were assayed for respiratory syncytial virus, parainfluenza, influenza and adenovirus by immunofluorescence. For rhinovirus test a reverse transcription-polymerase chain reaction for picornavirus was used, followed by hybridization with rhinovirus specific probes. RESULTS: Forty-five patients were selected for the study. The median age of the subjects studied was 2 months. Positive samples for respiratory viruses were found in 35/45 (77.8%) subjects and 7/35 (20%) patients had dual infection. Respiratory syncytial virus was detected in 33/35 (94%) cases. Rhinovirus was detected in 6/35 patients (17%). CONCLUSIONS: Rhinovirus was the second most common agent detected in nasal secretions from young infants hospitalized with acute bronchiolitis.

Acute Disease↗
PubMedDate not supplied

[Plastic bronchitis in a child with thalassemia alpha].

OBJECTIVE: Plastic bronchitis is an unusual condition in children, associated with formation of mucofibrinous casts and mucous plugging of the tracheobronchial tree. Given that this illness is part of the differential diagnosis of acute respiratory failure, early treatment is important for improved prognosis. The aim of this report is to describe a case of plastic bronchitis in a child with alpha-thalassemia that was treated successfully with endoscopy. DESCRIPTION: A three year old, black, male child, previously healthy, presented with acute respiratory failure and a chest x-ray showing pulmonary atelectasis. There was no evidence of respiratory symptoms or previous allergy state. The diagnosis of plastic bronchitis was made using flexible and rigid bronchoscopy, and confirmed by histopathologic findings. The child progressed well, treatment was based on supportive care and antibiotics were not used. Ten days after discharge, radiographic appearance was normal. Alpha thalassemia was diagnosed through hemoglobin electrophoresis. COMMENTS: Plastic bronchitis is clinically important because has similar presentation to other prevalent diseases, such as foreign body aspiration and asthma. When plastic bronchitis is suspected, endoscopy is indicated in order to confirm diagnosis and define treatment. Plastic bronchitis has been previously described in patients with cystic fibrosis, cardiac surgery and sickle cell disease. In this case, an association with alpha-thalassemia was observed.

Bronchitis↗
PubMedDate not supplied

[Upper airway cellular pattern in infants with acute bronchiolitis: neutrophils or eosinophils?].

OBJECTIVE: To analyze the cellular pattern of nasopharyngeal secretions in infants with acute bronchiolitis (AB), focusing on the presence or absence of neutrophils and eosinophils. METHOD: Hospitalized children with AB admitted to Hospital São Lucas, Porto Alegre, Brazil, between May and July 2002 were recruited. Nasopharyngeal aspirates were collected during the first 48 hours after admission. Slides were stained with May Grunwald and Giemsa. Total cell count and cellular viability were obtained in all samples. RESULTS: Thirty-eight infants with AB were enrolled. The mean age was 2.2 months (interquartile range: 1.2-3.5), and 21 subjects were male. Neutrophils were the predominant cells in the nasopharyngeal aspirates (median 95%, interquartile: 94-97). No eosinophils were found in the samples studied. CONCLUSION: Our results suggest that eosinophils do not play a significant role in the pathophysiogenesis of AB. Infants with AB present a specific inflammatory response to viral infections, which is distinct from the immune response observed in asthma.

Acute Disease↗