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Shang Y, Sun Q. Particulate air pollution: major research methods and applications in animal models. ENVIRONMENTAL DISEASE 2018; 3:57-62. [PMID: 31549002 DOI: 10.4103/ed.ed_16_18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Ambient air pollution is composed of a heterogeneous mixture of gaseous and solid particle compounds in which primary particles are emitted directly into the atmosphere, such as diesel soot, while secondary particles are created through physicochemical transformation. Particulate matter (PM), especially fine and ultrafine particles, can be inhaled and deposited in the alveolar cavities and penetrate into circulation. An association between high levels of air pollutants and human disease has been known for more than half a century and increasing evidences demonstrate a strong link between exposure on PM and the development of systemic diseases, such as cardiovascular and neurological disorders. Experimental animal models have been extensively used to study the underlying mechanism caused by environmental exposure to ambient PM. Due to their availability, quality, cost, and genetically modified strains, rodent models have been widely used. Some common exposure approaches include intranasal instillation, intratracheal instillation, nose-only inhalation, whole-body inhalation, and intravenous injection have been reviewed with brief summary of its performance, merit, limitation, and application. We hope this would provide useful reference in advancing experimental researches about air pollution human health and disease development.
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Affiliation(s)
- Yanan Shang
- Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, Ohio, USA
| | - Qinghua Sun
- Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, Ohio, USA.,Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio, USA.,Division of Cardiovascular Medicine, College of Medicine, The Ohio State University, Columbus, Ohio, USA
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Faro A, Wood RE, Schechter MS, Leong AB, Wittkugel E, Abode K, Chmiel JF, Daines C, Davis S, Eber E, Huddleston C, Kilbaugh T, Kurland G, Midulla F, Molter D, Montgomery GS, Retsch-Bogart G, Rutter MJ, Visner G, Walczak SA, Ferkol TW, Michelson PH. Official American Thoracic Society Technical Standards: Flexible Airway Endoscopy in Children. Am J Respir Crit Care Med 2015; 191:1066-80. [DOI: 10.1164/rccm.201503-0474st] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
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Kanotra SP, Propst EJ, Campisi P, Fisher JA, Forte V. Quantitative assessment of pulmonary aspiration: A novel porcine model. Int J Pediatr Otorhinolaryngol 2013; 77:2014-8. [PMID: 24148863 DOI: 10.1016/j.ijporl.2013.09.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 09/23/2013] [Accepted: 09/24/2013] [Indexed: 10/26/2022]
Abstract
OBJECTIVES Pulmonary aspiration is a common cause of ventilator-associated pneumonia in the intensive care setting. Current bench and animal models of aspiration are based on the qualitative assessments. The purpose of the present study was to develop a porcine model for the real-time quantitative assessment of aspiration. METHODS Five sus scrofa piglets were anaesthetized and underwent placement of a pH probe through the endotracheal tube so that the distal tip of the probe resided at the carina. The pH probe was sutured to the posterior tracheal wall via an open approach and the position of the probe tip was verified by flexible endoscopy. 10 mL of acidic solution (pH = 2.7) was delivered through a catheter attached to the outside of the endotracheal tube so that the solution remained between the endotracheal tube and trachea proximal to the inflated endotracheal tube cuff. The pH probe was connected to a pH metre, a multifunctional data acquisition device with an analogue output signal measuring the voltage generated, and a computer for analysis. Leakage of fluid past the endotracheal tube cuff (aspiration) was therefore continuously assessed quantitatively by detecting voltage changes over a period of time. RESULTS The mean voltage of the tracheal mucosa at the beginning of the experiment (maximum voltage) was 916.6 mV ± 24.5 mV (range 891.0-945.7 mV). There was a slight drop in voltage at the end of the 2 h period to 840.8 ± 22.6 mV (range = 812.3-867.3 mV). After deflation of the endotracheal tube cuff, the mean voltage dropped to 497.3 mV ± 24.8 mV (range 435.7-567.1 mV) with a mean drop in voltage of 419.3 mV ± 32.6 mV (range 368.9-455.3 mV). CONCLUSIONS This porcine model allows for the continuous quantitative assessment of aspiration over time. Such a model may be of value for the evaluation of techniques for reducing aspiration.
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Affiliation(s)
- Sohit P Kanotra
- Department of Otolaryngology - Head and Neck Surgery, The Hospital for Sick Children, Toronto, Canada.
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Kurland G, Deterding RR, Hagood JS, Young LR, Brody AS, Castile RG, Dell S, Fan LL, Hamvas A, Hilman BC, Langston C, Nogee LM, Redding GJ. An official American Thoracic Society clinical practice guideline: classification, evaluation, and management of childhood interstitial lung disease in infancy. Am J Respir Crit Care Med 2013; 188:376-94. [PMID: 23905526 DOI: 10.1164/rccm.201305-0923st] [Citation(s) in RCA: 290] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND There is growing recognition and understanding of the entities that cause interstitial lung disease (ILD) in infants. These entities are distinct from those that cause ILD in older children and adults. METHODS A multidisciplinary panel was convened to develop evidence-based guidelines on the classification, diagnosis, and management of ILD in children, focusing on neonates and infants under 2 years of age. Recommendations were formulated using a systematic approach. Outcomes considered important included the accuracy of the diagnostic evaluation, complications of delayed or incorrect diagnosis, psychosocial complications affecting the patient's or family's quality of life, and death. RESULTS No controlled clinical trials were identified. Therefore, observational evidence and clinical experience informed judgments. These guidelines: (1) describe the clinical characteristics of neonates and infants (<2 yr of age) with diffuse lung disease (DLD); (2) list the common causes of DLD that should be eliminated during the evaluation of neonates and infants with DLD; (3) recommend methods for further clinical investigation of the remaining infants, who are regarded as having "childhood ILD syndrome"; (4) describe a new pathologic classification scheme of DLD in infants; (5) outline supportive and continuing care; and (6) suggest areas for future research. CONCLUSIONS After common causes of DLD are excluded, neonates and infants with childhood ILD syndrome should be evaluated by a knowledgeable subspecialist. The evaluation may include echocardiography, controlled ventilation high-resolution computed tomography, infant pulmonary function testing, bronchoscopy with bronchoalveolar lavage, genetic testing, and/or lung biopsy. Preventive care, family education, and support are essential.
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Nagai T, Aoyagi M, Ochiai E, Sakai K, Maruyama-Maebashi K, Fukui K, Iwadate K. Longitudinal evaluation of immunohistochemical findings of milk aspiration: an experimental study using a murine model. Forensic Sci Int 2011; 209:183-5. [PMID: 21333474 DOI: 10.1016/j.forsciint.2011.01.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 11/19/2010] [Accepted: 01/20/2011] [Indexed: 12/21/2022]
Abstract
To examine the longitudinal change of pathological findings of the lung and other organs in milk aspiration, an experimental study using a murine model was carried out. Either 0.5 or 1.0 ml cow's milk was instilled into the trachea of rats. From immediately after to 14 days after instillation, the animals were sacrificed, and the lungs, liver, kidneys, and spleen were removed. The results of immunostaining with anti-human α lactalbumin antibody indicated that not only the lung but also the kidney and spleen showed a positive reaction against the antibody over time. Experimentally aspirated milk was detectable in alveoli until 2 days after instillation. It was also detectable in renal tubules from 1 to 6h after instillation. Macrophages containing granules of aspirated milk were observed in splenic red pulp from 3h to 14 days after instillation. Detection of aspirated milk in other organs except the lung would be clear evidence of intravital milk aspiration and would suggest previous or recurrent milk aspiration.
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Affiliation(s)
- Tomonori Nagai
- Department of Forensic Medicine, The Jikei University School of Medicine, Tokyo, Japan
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De Baets F, Aarts C, Van Daele S, Haerynck F, De Wachter E, De Schutter I, Malfroot A, Schelstraete P. Milk protein and Oil-Red-O staining of alveolar macrophages in chronic respiratory disease of infancy. Pediatr Pulmonol 2010; 45:1213-9. [PMID: 20717909 DOI: 10.1002/ppul.21310] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Revised: 05/09/2010] [Accepted: 06/01/2010] [Indexed: 01/11/2023]
Abstract
Aspiration is a suspected cause of chronic respiratory disease in infants. We assessed the probability of aspiration by immunocytochemical staining of alveolar macrophages for milk proteins (α-lactalbumin and β-lactoglobulin) and compared these findings with the Oil-Red-O staining score. Broncho-alveolar lavage (BAL), 24-hr esophageal pH-measurement and/or gastro-esophageal scintigraphy were performed in 111 children. Seventy-nine patients were enrolled. Ten exclusively soya milk formula fed children served as a control group. Individual scores, expressed as the mean percentage of positive staining macrophages counted by three blinded authors were made. Relying on the control group, a positive score was defined as a value higher than 1%. A positive score was found in 26% (18/69). Forty-four percent (8/18) of them had positive gastro-esophageal reflux (GER) tests. In 61% (11/18) a concomitant diagnosis of laryngo-/tracheomalacia was made. A positive score was found in 48% (11/23) of patients with laryngo-/tracheomalacia, compared to 15% (7/46) in infants with normal laryngeal and tracheal anatomy. No correlation was found between the immunocytochemical staining score for milk proteins and the Oil-Red-O staining score. We conclude that assuming the 1% criterion, persistent respiratory symptoms were associated with a positive immunostaining score, suggestive for aspiration, in 26% of infants, in 48% in case of concomitant laryngo- and/or tracheomalacia and in 15% of infants with normal laryngeal and tracheal anatomy. No correlation was found between the immunocytochemical staining score for cow milk proteins and the Oil-Red-O staining score.
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Affiliation(s)
- Frans De Baets
- Department of Pediatric Pulmonology, Ghent University Hospital, Ghent, Belgium.
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Bachman MA, Miller VL, Weiser JN. Mucosal lipocalin 2 has pro-inflammatory and iron-sequestering effects in response to bacterial enterobactin. PLoS Pathog 2009; 5:e1000622. [PMID: 19834550 PMCID: PMC2757716 DOI: 10.1371/journal.ppat.1000622] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Accepted: 09/17/2009] [Indexed: 11/24/2022] Open
Abstract
Nasal colonization by both gram-positive and gram-negative pathogens induces expression of the innate immune protein lipocalin 2 (Lcn2). Lcn2 binds and sequesters the iron-scavenging siderophore enterobactin (Ent), preventing bacterial iron acquisition. In addition, Lcn2 bound to Ent induces release of IL-8 from cultured respiratory cells. As a countermeasure, pathogens of the Enterobacteriaceae family such as Klebsiella pneumoniae produce additional siderophores such as yersiniabactin (Ybt) and contain the iroA locus encoding an Ent glycosylase that prevents Lcn2 binding. Whereas the ability of Lcn2 to sequester iron is well described, the ability of Lcn2 to induce inflammation during infection is unknown. To study each potential effect of Lcn2 on colonization, we exploited K. pneumoniae mutants that are predicted to be susceptible to Lcn2-mediated iron sequestration (iroA ybtS mutant) or inflammation (iroA mutant), or to not interact with Lcn2 (entB mutant). During murine nasal colonization, the iroA ybtS double mutant was inhibited in an Lcn2-dependent manner, indicating that the iroA locus protects against Lcn2-mediated growth inhibition. Since the iroA single mutant was not inhibited, production of Ybt circumvents the iron sequestration effect of Lcn2 binding to Ent. However, colonization with the iroA mutant induced an increased influx of neutrophils compared to the entB mutant. This enhanced neutrophil response to Ent-producing K. pneumoniae was Lcn2-dependent. These findings suggest that Lcn2 has both pro-inflammatory and iron-sequestering effects along the respiratory mucosa in response to bacterial Ent. Therefore, Lcn2 may represent a novel mechanism of sensing microbial metabolism to modulate the host response appropriately. Bacterial pathogens such as Klebsiella pneumoniae require iron and use secreted molecules called siderophores to strip iron from mammalian proteins. When bacteria colonize the upper respiratory tract, the mucosa secretes the protein lipocalin 2 (Lcn2) that binds to the siderophore enterobactin (Ent) and disrupts bacterial iron acquisition. In addition, Lcn2 bound to Ent stimulates release of the neutrophil-recruitment signal IL-8 from cultured respiratory cells. Some pathogens avoid Lcn2 binding by attaching glucose to Ent (to make Gly-Ent) or by making alternative siderophores. To determine the effect of Lcn2 on bacterial colonization, we colonized mice that express or lack Lcn2 with K. pneumoniae mutants that express or lack Ent, Gly-Ent and the alternative siderophore Yersiniabactin (Ybt). Our results indicate that mucosal Lcn2 inhibits colonization through iron sequestration and increases the influx of neutrophils in response to K. pneumoniae producing Ent. Therefore, Lcn2 acts as a barrier to colonization that pathogens must overcome to persist in the upper respiratory tract.
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Affiliation(s)
- Michael A. Bachman
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Pathology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Virginia L. Miller
- Department of Genetics, The University of North Carolina, Chapel Hill, North Carolina, United States of America
- Department of Microbiology and Immunology, The University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Jeffrey N. Weiser
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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PINTO LA, DIAS ACO, MACHADO DC, JONES MH, STEIN RT, PITREZ PM. Diagnosis of pulmonary aspiration: A mouse model using a starch granule test in bronchoalveolar lavage. Respirology 2008; 13:594-8. [DOI: 10.1111/j.1440-1843.2008.01285.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kim CK, Kim HB, Kurian T, Chung JY, Yoo Y, Koh YY. Increased laryngeal lavage lipid-laden macrophage index during acute bronchiolitis. Acta Paediatr 2007; 96:1025-9. [PMID: 17498191 DOI: 10.1111/j.1651-2227.2007.00314.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM To investigate aspiration risks associated with bronchiolitis in infants using the lipid-laden macrophage index (LLMI) from laryngeal lavages. METHODS Laryngeal lavages from 29 infants with acute bronchiolitis caused by respiratory syncytial virus were evaluated (acute stage). Repeated studies were then performed at 3-4 weeks after the initial study (remission stage). Lavage cell counts and differentials were determined. The amount of lipid per single macrophage was evaluated and the LLMI was determined by evaluating 100 cells. In addition, 24-h pH monitoring (pHm) was performed in 16 patients. RESULTS The LLMIs in the acute stage were significantly higher than those in the remission stage (p < 0.05). The neutrophil percentage of the laryngeal lavage correlated significantly with the LLMI (r = 0.707, p < 0.0001) during the acute stage of bronchiolitis. When patients were divided into pHm-positive (n = 5) and pHm-negative (n = 11) subgroups, a significant decrease in LLMI between acute and remission stages was noted among the pHm-positive (p < 0.01) subgroup, but not in the pHm-negative subgroup. CONCLUSION These findings suggest that there is a transient increased LLMI in patients with bronchiolitis, which could be caused by gastroesophageal reflux.
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Affiliation(s)
- Chang Keun Kim
- Department of Pediatrics, Inje University Sanggye Paik Hospital, Seoul, Korea
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Koh JY, Kang H, Chung JY, Han TH, Kim CK. The evaluation of risk for aspiration using lipid-laden macrophage index in infants with bronchiolitis. KOREAN JOURNAL OF PEDIATRICS 2006. [DOI: 10.3345/kjp.2006.49.7.763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Ji Yeon Koh
- Department of Pediatrics and Asthma Allergy Center, Sanggye Paik Hospital, College of Medicine, Inje University, Seoul, Korea
| | - Hee Kang
- Department of Pediatrics and Asthma Allergy Center, Sanggye Paik Hospital, College of Medicine, Inje University, Seoul, Korea
| | - Ju Young Chung
- Department of Pediatrics and Asthma Allergy Center, Sanggye Paik Hospital, College of Medicine, Inje University, Seoul, Korea
| | - Tae Hee Han
- Department of Clinical Pathology, Sanggye Paik Hospital, College of Medicine, Inje University, Seoul, Korea
| | - Chang Keun Kim
- Department of Pediatrics and Asthma Allergy Center, Sanggye Paik Hospital, College of Medicine, Inje University, Seoul, Korea
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Springer C, Benita S, Sherman Y, Gursoy N, Gilhar D, Avital A. Poly-lactic-glycolic acid microspheres: a biodegradable marker for the diagnosis of aspiration in hamsters. Pediatr Res 2005; 58:537-41. [PMID: 16148070 DOI: 10.1203/01.pdr.0000176910.62067.a0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Aspiration is a major cause of lung disease in infants and young children. As the symptoms and signs of aspiration are not specific, the diagnosis is delayed due to a low index of suspicion and low sensitivity and specificity of the available diagnostic tests. In the present study, we evaluated the utility of microspheres composed of a degradable polymer, polylactic glycolic acid (PLGA), as a marker to diagnose aspiration in hamsters. Thirty hamsters underwent direct tracheal instillation of 0.1 mL of a suspension of PLGA. Eighteen other animals served as controls and underwent tracheal instillation of 0.1 mL of saline. Three animals served as naive controls and had no tracheal instillation. Five animals from the PLGA group and three from the saline group underwent whole-lung lavage (WLL) on days 1, 8, 15, 29, 43, and 58. PLGA microspheres were easily identified under light microscopy inside the alveolar macrophages obtained from WLL in all PLGA-instilled animals during all studied days. The number and size of PLGA microspheres within the alveolar macrophages decreased gradually with time with a 90% rate of disappearance of about 36 d. There was a marked neutrophilic response in lung lavage and a mild peribronchial neutrophil infiltration on the first day after tracheal instillation of PLGA which subsequently disappeared. We conclude that PLGA microspheres are a sensitive and specific marker for aspiration in hamsters. The usefulness of this test in diagnosing aspiration in humans should be further evaluated in clinical studies.
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Affiliation(s)
- Chaim Springer
- Institute of Pulmonology, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel.
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Abstract
The spectrum of pediatric interstitial lung disease (PILD) includes a diverse group of rare disorders characterized by diffuse infiltrates and disordered gas exchange. Children with these conditions typically present with tachypnea, crackles, and hypoxemia. Recent advances have been made in the identification of different types of PILD that are unique to infancy. More exciting has been the discovery of genetic abnormalities of surfactant function, now described in both children and adults. A systematic evaluation of the child presenting with diffuse infiltrates of unknown etiology is essential to the diagnosis. Most often, lung biopsy is required. Current treatment options remain less than satisfactory, and morbidity and mortality remain considerable.
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Affiliation(s)
- Leland L Fan
- Pediatric Pulmonary Section, Department of Pediatrics, Baylor College of Medicine, Texas Children's Hospital, Houston 77030-2399, USA.
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Midulla F, Guidi R, Tancredi G, Quattrucci S, Ratjen F, Bottero S, Vestiti K, Francalanci P, Cutrera R. Microaspiration in Infants with Laryngomalacia. Laryngoscope 2004; 114:1592-6. [PMID: 15475788 DOI: 10.1097/00005537-200409000-00017] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES/HYPOTHESIS Laryngomalacia is the most common congenital laryngeal anomaly and the most frequent cause of stridor in infants. Infants with laryngomalacia may have associated respiratory symptoms other than stridor. In this study, we evaluated whether infants with laryngomalacia have episodes of microaspiration by calculating the amount of lipids present in the alveolar macrophages. STUDY DESIGN We reviewed bronchoalveolar lavage (BAL) findings obtained in 14 infants with laryngomalacia and in 11 control children. METHODS BAL was performed during flexible fiberoptic bronchoscopy (FFB) to diagnose persistent stridor. The presence of microaspiration was determined by evaluating the amount of lipid per single macrophage, assigning each cell a score from 0 to 4 according to the amount of lipid in the cytoplasm. RESULTS The lipid-laden macrophage index was similar in patients and controls (31.5, range 12-177 vs. 45, range 35-106). In 5 of the 14 (36%) patients the index exceeded 100, and more than 25% of the cells were graded 3 and 4, indicating the presence of microaspiration. The lipid-laden macrophage index correlated significantly with the number and percentage of BAL neutrophils (Pearson correlation test, r = 0.83, P < .001 and r = 0.925, P < .001) as a marker of lung inflammation. CONCLUSIONS Infants with laryngomalacia may have episodes of microaspiration. BAL performed during FFB to evaluate stridor may add helpful therapeutic information without increasing the risks of the procedure.
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Affiliation(s)
- Fabio Midulla
- Servizio Speciale Fibrosi Cistica, Istituto di Clinica Pediatrica, Università di Roma La Sapienza, Italy.
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Abstract
Chronic interstitial lung disease (ILD) in infants and children is a challenging diagnostic clinical problem. There are many unresolved and controversial issues in the diagnosis of this heterogeneous group of uncommon disorders in children. Diagnosis requires a high index of suspicion as the initial clinical manifestations are subtle, highly variable and non-specific. There is no consensus for the clinical diagnostic criteria of paediatric ILD. The spectrum of clinical findings is highly variable. The diagnostic evaluation of a child with suspected ILD includes a comprehensive history, physical examination, oxygen saturation (at rest, during exercise or during feeding), a plain chest x ray and a high-resolution thin-cut tomography scan of the chest. Pulmonary function studies can be useful in older children; these typically show a restrictive pattern with a decreased forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC) and total lung capacity, but normal FEV(1)/FVC. A systematic approach to diagnosis is useful in the evaluation of an infant or child with suspected chronic ILD. Due to the rarity of most of these disorders, multi-centre collaboration is needed to improve our understanding of this orphan lung disease.
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Affiliation(s)
- Bettina C Hilman
- Department of Pediatrics, The University of Texas Health Center at Tyler, 11937 US Highway 271, Tyler, TX 75708-3154, USA.
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Boss LP, Wheeler LSM, Williams PV, Bartholomew LK, Taggart VS, Redd SC. Population-based screening or case detection for asthma: are we ready? J Asthma 2003; 40:335-42. [PMID: 12870828 DOI: 10.1081/jas-120018627] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Asthma is a prevalent health problem for which there are effective treatments. By identifying people with asthma and treating them effectively, the burden of asthma in the United States should be reduced. Detecting people with asthma through screening programs seems a logical approach to the problem. This article assesses our readiness for population-based screening and case detection programs for asthma and examines these activities in relation to World Health Organization criteria for determining the appropriateness of screening programs. Given that, at this time, a number of the criteria have not been met, we conclude that population-based approaches to screening and case detection of asthma are of unproven benefit and need further research. A more appropriate focus may be to ensure that all people who are diagnosed with asthma receive appropriate medical care.
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Affiliation(s)
- Leslie P Boss
- Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
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Miller J, Colasurdo GN, Khan AM, Jajoo C, Patel TJ, Fan LL, Elidemir O. Immunocytochemical detection of milk proteins in tracheal aspirates of ventilated infants: a pilot study. Pediatr Pulmonol 2002; 34:369-74. [PMID: 12357481 DOI: 10.1002/ppul.10189] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In this study, we evaluated immunocytochemical staining for milk proteins (alpha-lactalbumin and beta-lactoglobulin) in tracheal aspirates of mechanically ventilated infants, and assessed whether this staining technique supported a clinical diagnosis of aspiration in infants receiving orogastric feedings. All newborns requiring mechanical ventilation in the neonatal intensive care unit of a major tertiary care hospital were potential subjects for this study. Tracheal aspirates were obtained prior to the introduction of enteral feeding and at various time points thereafter in newborns requiring mechanical ventilation. Cells were obtained and processed for immunocytochemical staining of alpha-lactalbumin and beta-lactoglobulin. In total, 88 specimens recovered from 34 infants were adequate for staining. Alveolar macrophages recovered from most of the infants who were never fed (true negative controls) did not display immunoreactivity for milk proteins: 4/34 or 12% of infants' aspirates demonstrated presence of milk proteins before enteral feeding was commenced. Tracheal aspirates obtained from 12 infants after introduction of enteral feedings appeared to support clinical and radiological findings suggestive of aspiration events, with positive immunostaining on several occasions. These observations support our work in a murine model and demonstrate that immunocytochemical staining of tracheal aspirates for milk proteins may enhance the ability to diagnose pulmonary aspiration. Further studies are needed to define the clinical significance of our findings and the effects of single and repeated aspiration events on respiratory status.
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Affiliation(s)
- Jamey Miller
- Department of Pediatrics, University of Texas-Houston Medical School, Houston, Texas 77030, USA
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Ding Y, Simpson PM, Schellhase DE, Tryka AF, Ding L, Parham DM. Limited reliability of lipid-laden macrophage index restricts its use as a test for pulmonary aspiration: comparison with a simple semiquantitative assay. Pediatr Dev Pathol 2002; 5:551-8. [PMID: 12370770 DOI: 10.1007/s10024-002-0025-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2002] [Accepted: 07/15/2002] [Indexed: 11/25/2022]
Abstract
The lipid-laden macrophage index (LLMI) is a semiquantitative evaluation of alveolar macrophage lipid content used in diagnosis of pulmonary aspiration. To date, there are no published reports regarding the reliability of LLMI. We sought to evaluate the interobserver and intraobserver variability and validity of LLMI and to compare it to a simpler macrophage lipid content index (LCI). To evaluate reliability we compared both the LLMI and LCI of 26 bronchoalveolar lavage (BAL) specimens from 14 aspirators and 12 non-aspirators on 10 separate occasions by two observers. The ranges of means and standard deviations (SD) of LLMI for observer 1 (Obs 1) were 19-160 (5-31) for aspirators, and 0-48 (0-15) for non-aspirators; and those of observer 2 (Obs 2) were 77-249 (13-33) for aspirators and 47-170 (8-37) for non-aspirators. The ranges of means and SD of LCI for Obs 1 were 2-8 (0-2) for aspirators and 0-4 (0-1) for non-aspirators, compared with 2-9 (0-2) for aspirators and 1-6 (0-2) for non-aspirators for Obs 2. No statistical significance was found between LLMI and LCI by comparing coefficients of variation (CV) in either groups or observers. Poor agreement between the two observers was found using a Bland Altman analysis, with the difference of the two observations mostly exceeding zero and becoming larger as the average of the two observations became bigger. The combined sensitivity, specificity, and positive and negative predictive value (PPV and NPV) for both observers of the LLMI were 57%, 75%, 84%, and 69% and those of LCI were 58%, 92%, 93%, and 69%. We conclude that there is poor reliability for both methods. The LCI is simpler and appears to be at least as good as the LLMI.
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Affiliation(s)
- Yiling Ding
- Department of Pathology, Arkansas Children's Hospital, University of Arkansas for Medical Sciences, 800 Marshall Street, Little Rock, AR 72202, USA.
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Avital A, Shapiro E, Doviner V, Sherman Y, Margel S, Tsuberi M, Springer C. Polystyrene microspheres as a specific marker for the diagnosis of aspiration in hamsters. Am J Respir Cell Mol Biol 2002; 27:511-4. [PMID: 12356586 DOI: 10.1165/rcmb.2002-0028oc] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The diagnosis of recurrent aspiration in young children is problematic because there is no specific gold standard test to be used. In the present work, normal saline or a suspension of white polystyrene microspheres in normal saline was instilled into hamsters' trachea (n = 42), and bronchoalveolar lavage (BAL) cytology, microsphere index (total microspheres/100 macrophages), and lung histology were followed for 90 d. Naive animals (n = 6) had no tracheal instillation. On Days 1, 3, 10, 32, 60, and 90 after tracheal instillation, animals were killed (saline-instilled animals, n = 3; and microsphere-instilled animals, n = 4), and BAL was performed. There was a marked inflammatory response in BAL on Day 1 after tracheal instillation of saline or microsphere suspension. White microspheres were clearly identified within alveolar macrophages in all studied days. Microsphere numbers showed a 50% disappearance rate of 10 d. A mild peribronchial inflammation was noted in lung histology only on Day 1 after instillation. Microspheres were not detected in extrapulmonary organs. We conclude that polystyrene microspheres instilled in hamsters' trachea can be easily identified in BAL macrophages for as long as 3 mo and could potentially be used as a sensitive, specific, and stable marker for the diagnosis of aspiration.
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Affiliation(s)
- Avraham Avital
- Institute of Pulmonology and Department of Pathology, Hadassah University Hospital and Hadassah-Hebrew University Medical School, Jerusalem, Israel.
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Avital A, Yoav S, Springer C. Charcoal is a sensitive, specific, and stable marker for the diagnosis of aspiration in hamsters. Pediatr Res 2002; 51:397-401. [PMID: 11861948 DOI: 10.1203/00006450-200203000-00021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The diagnosis of recurrent aspiration in young children is a perpetual challenge because there is no specific gold standard test to be used. The finding of lipid-laden alveolar macrophages in bronchoalveolar lavage (BAL) is a sensitive but nonspecific marker for the diagnosis of aspiration. We conducted a short-term study comparing tracheal instillation of saline, milk, or a milk-charcoal mixture in hamsters. BAL cytology, lipid-laden alveolar macrophage index, charcoal alveolar macrophage index, and lung histology were monitored for 10 d. A long-term study was performed, and hamsters were monitored for 92 d after milk-charcoal tracheal instillation. Baseline animals (n = 4) had no tracheal instillation. Saline- and milk-instilled animals had BAL performed after 1 (n = 4), 3 (n = 4), and 10 (n = 4) d. Milk-charcoal-instilled animals had BAL performed after 1 (n = 4), 3 (n = 4), 10 (n = 4), 30 (n = 2), 58 (n = 2), and 92 (n = 2) d after tracheal instillation. Total cell counts and percent neutrophils in BAL fluid increased significantly and similarly after milk and milk-charcoal instillation on d 1 compared with baseline and saline-instilled animals. Lipid-laden alveolar macrophage index increased significantly only on d 3 after milk and milk-charcoal instillation compared with all days in the saline-instillation group. Charcoal alveolar macrophage index increased significantly after milk-charcoal instillation (d 1-58) from baseline or all days in the saline-instillation group. We conclude that charcoal particles instilled in tracheas of hamsters can be easily identified in BAL fluid and in lung parenchyma for as long as 3 mo after a single instillation and could potentially be used as a sensitive, specific, and stable marker for the diagnosis of aspiration, although the issue of its applicability to humans is still unsolved.
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Affiliation(s)
- Avraham Avital
- Institute of Pulmonology, Hadassah University Hospital and the Hadassah-Hebrew University Medical School, Jerusalem, Israel.
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Epstein CE, Elidemir O, Colasurdo GN, Fan LL. Time course of hemosiderin production by alveolar macrophages in a murine model. Chest 2001; 120:2013-20. [PMID: 11742936 DOI: 10.1378/chest.120.6.2013] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
STUDY OBJECTIVES The diagnosis of alveolar hemorrhage is assisted by the presence of hemosiderin-laden macrophages (HLMs) in the BAL fluid or lung tissue. Despite the importance of this diagnostic method in clinical settings, limited information is available on the formation and clearance of HLMs as a function of time. The objectives of this study are to determine the time course of HLMs within the BAL and lung tissue, and to evaluate the effect of a single blood aspiration on the recruitment of inflammatory cells within the BAL. DESIGN Under light anesthesia, Balb/c mice received a single intranasal instillation of species-specific blood (50 microL). Control animals received heparinized sterile saline solution in a similar manner. At several time points after blood aspiration, BAL was recovered for cell differentials and determination of HLMs. The time course for HLMs was also established in the lung tissue. RESULTS Hemosiderin staining within alveolar macrophages was first detected in the BAL and lung tissue at day 3, peaked at day 7, and persisted through 2 months. The analysis of the BAL revealed an increased number of total cells, with an acute inflammatory reaction that resolved within 2 weeks. CONCLUSIONS Our findings demonstrate the validity of this model for the study of HLM production after blood aspiration. Additional work using animal models of lung hemorrhage is needed to further characterize the cellular events leading to clearance of erythrocytes within the lung.
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Affiliation(s)
- C E Epstein
- Department of Pediatrics, Division of Pulmonary Medicine, Baylor College of Medicine, Houston, TX 77030-2399, USA
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Tobin MJ. Pediatrics, surfactant, and cystic fibrosis in AJRCCM 2000. Am J Respir Crit Care Med 2001; 164:1581-94. [PMID: 11719294 DOI: 10.1164/ajrccm.164.9.2108125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- M J Tobin
- Division of Pulmonary and Critical Care Medicine, Loyola University of Chicago Stritch School of Medicine and Hines Veterans Affairs Hospital, Hines, Illinois 60141, USA.
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Abstract
Introdução: Quando o mecanismo protetor da laringe está comprometido, o paciente pode apresentar aspiração traqueal, com graves complicações pulmonares. Objetivo: Relatar 15 casos de tratamento cirúrgico para o controle da aspiração crônica, incluindo as técnicas cirúrgicas empregadas, seus resultados e complicações. Forma de estudo: Avaliação retrospectiva. Material e método: No período de 1997 a 2000, 15 pacientes foram submetidos à cirurgia para controle da aspiração, na AACD - São Paulo/SP. As técnicas cirúrgicas empregadas foram classificadas em: oclusão laríngea supraglótica; oclusão laríngea glótica; oclusão subglótica ou separação laringotraqueal. Foi avaliado o perfil dos pacientes em relação a sexo, idade, etiologia de base, traqueotomia prévia, via preferencial de alimentação, redução das infecções pulmonares, tempo de seguimento pós-operatório e complicações. Resultados: Oito pacientes eram do sexo masculino e sete do feminino, com idade média de nove anos e dois meses. A doença etiológica de base mais comum foi a encefalopatia crônica. Dez pacientes foram submetidos à traqueotomia previamente à cirurgia. Nove pacientes apresentaram, no pós-operatório, dieta via oral de pelo menos 50% do volume requerido. Os 15 pacientes evoluíram com diminuição no número e na gravidade das infecções pulmonares. O tempo de seguimento pós-operatório variou de quatro a 36 meses. Um paciente evoluiu com deiscência parcial na técnica de oclusão laríngea supraglótica. Conclusão: A cirurgia para controle da aspiração traqueal, nas três técnicas utilizadas, foi eficaz para prevenção da aspiração, refletindo na melhora clínica e na qualidade de vida dos pacientes.
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Affiliation(s)
- Dayse Manrique
- Universidade Federal de São Paulo - Escola Paulista de Medicina; Hospital do Servidor Público Estadual - Francisco Morato de Oliveira; AACD
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Janahi IA, Elidemir O, Shardonofsky FR, Abu-Hassan MN, Fan LL, Larsen GL, Blackburn MR, Colasurdo GN. Recurrent milk aspiration produces changes in airway mechanics, lung eosinophilia, and goblet cell hyperplasia in a murine model. Pediatr Res 2000; 48:776-81. [PMID: 11102546 DOI: 10.1203/00006450-200012000-00013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Recurrent aspiration of milk into the respiratory tract has been implicated in the pathogenesis of a variety of inflammatory lung disorders including asthma. However, the lack of animal models of aspiration-induced lung injury has limited our knowledge of the pathophysiological characteristics of this disorder. This study was designed to evaluate the effects of recurrent milk aspiration on airway mechanics and lung cells in a murine model. Under light anesthesia, BALB/c mice received daily intranasal instillations of whole cow's milk (n = 7) or sterile physiologic saline (n = 9) for 10 d. Respiratory system resistance (Rrs) and dynamic elastance (Edyn,rs) were measured in anesthetized, tracheotomized, paralyzed and mechanically ventilated mice 24 h after the last aspiration of milk. Rrs and Edyn,rs were derived from transrespiratory and plethysmographic pressure signals. In addition, airway responses to increasing concentrations of i.v. methacholine (Mch) were determined. Airway responses were measured in terms of PD(100) (dose of Mch causing 100% increase from baseline Rrs) and Rrs,max (% increase from baseline at the maximal plateau response) and expressed as % control (mean +/- SE). We found recurrent milk aspiration did not affect Edyn and baseline Rrs values. However, airway responses to Mch were increased after milk aspiration when compared with control mice. These changes in airway mechanics were associated with an increased percentage of lymphocytes and eosinophils in the bronchoalveolar lavage, mucus production, and lung inflammation. Our findings suggest that recurrent milk aspiration leads to alterations in airway function, lung eosinophilia, and goblet cell hyperplasia in a murine model.
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Affiliation(s)
- I A Janahi
- Department of Pediatrics, Section of Pediatric Pulmonology, Baylor College of Medicine, Houston, Texas 77030, USA
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