| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Animal Models |
From the Department of Anatomy, Physiology, and Cell
Biology;*
the Department of Pathology, Microbiology, and
Immunology;
the Department of Molecular
Biosciences;
and the California Regional
Primate Research Center Exposure Facility,§
School of Veterinary Medicine; and the Department of
Pediatrics,¶
School of Medicine, University of
California, Davis, California
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
|
Introduction |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
10% of the population currently being
affected.1
To better understand the mechanisms involved in
the pathogenesis and pathophysiology of allergic asthma, several
species of laboratory animals have been used as models. Although animal
models of asthma have been critical to the understanding of
immunological mechanisms, the investigation of pathophysiological
mechanisms of asthma has been hindered by the lack of an experimental
animal model that closely replicates the main features of the disease
found in human asthmatics, including: immunological alterations,
paroxysmal bronchoconstriction after allergen challenge, variable but
persistent airway hyperresponsiveness, and airways remodeling. Although
not used extensively as a model of allergic asthma, the rhesus monkey
(Macaca mulatta) would seem to be well suited for
this purpose for two reasons: 1) the immune system of nonhuman primates
is similar to that of humans,2-6
and 2) all of the
components of the intrapulmonary conducting airways that are altered in
human asthmatics are found throughout the intrapulmonary airway tree of
adult rhesus monkeys and, as in humans, undergo extensive postnatal
development and maturation.7-10
To establish whether
allergic asthma could be induced experimentally using a known human
allergen, we used a sensitization protocol similar to that described by
Yasue et al.6
We sensitized adult rhesus monkeys to
house-dust mite (Dermatophagoides farinae) allergen
by subcutaneous injection. We followed this sensitization with a series
of intranasal and aerosolized house-dust mite allergen (HDMA)
challenges. When compared to nonsensitized, nonexposed monkeys, the
HDMA-sensitized monkeys developed an allergic response with the
characteristics used to define allergic asthma in humans.1 |
Materials and Methods |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Young adult rhesus monkeys (4.9 to 7.0 kg body weight) were used
in this study. Three adult female monkeys were sensitized using an
expanded protocol consisting of subcutaneous injection and intranasal
placement of allergen as described in Table 1
. The animals were subsequently exposed
to HDMA as an aerosol (see Table 2
) at 17
weeks after the initial injection and weekly beginning on week 33 until
time of necropsy (week 42 or 45 after the initial injection). The
allergen was commercially available house-dust mite extract (Greer
Laboratories, Inc., Lenoir, NC) diluted in phosphate buffered saline
and nebulized with a high-flow rate nebulizer (HEART; Westmed, Inc.,
Tucson, AZ) immersed in an ice-water bath during operation to reduce
water evaporation from the solution. From the nebulizer, polydispersed
droplets with a volume median diameter of 2 µm were produced in an
air stream of 19.9 liters per minute. The electrostatic charge on the
droplets was reduced to the Boltzman equilibrium by conveyance through
a krypton-85 discharging column.11
The aerosol was then
mixed with the inlet air stream of a 4.2-m3
volume exposure chamber12
to yield an aerosol of dry
particles composed of allergen and salt residues in the chamber. During
exposure, air samples were drawn from the animal breathing zone of the
chamber to characterize this aerosol. Mass concentrations were measured
by weighing samples collected on preweighed Teflon-coated glass fiber
filters (Pallflex Emfab; Pall Gelman Sciences, Ann Arbor, MI). Selected
mass concentration samples were also submitted to the University of
California–Davis Molecular Structure Facility to determine the protein
content of the aerosol by amino acid analysis (System 6300, System Gold
software; Beckman Coulter, Inc., Fullerton, CA).13
Aerodynamic size distributions were determined using a seven-stage
Mercer-type cascade impactor (ARIES, Inc., Davis, CA).14
The content of chloride anion derived from saline residue in the
particles was measured on each impactor stage and the after-filter by
ion chromatography (Model DX-120; Dionex Corp., Sunnyvale, CA). A
log-normal distribution was fitted to each sample set of data, and the
values reported are the mass median aerodynamic diameter and the
geometric SD (
g) of the fitted distributions.
Additional adult rhesus monkeys from the colony, all of whom had
negative skin tests for HDMA, served as controls.
|
|
Monkeys were anesthetized with ketamine hydrochloride and hair was
clipped from an area of the thorax. Three separate intradermal
injections (0.1 ml each) of phosphate-buffered saline (PBS) containing
either HDMA (1:1000 w/v), histamine (1:1,000), or diluent alone were
made at the site. Injection sites were observed for 30 minutes and
wheal diameters were measured after 20 minutes (Table 3)
.
|
Monkeys were sedated using Telazol (8 mg/kg, i.m., Fort Dodge Labs, Fort Dodge, IA) and maintained (if necessary) with ketamine hydrochloride (5 to 10 mg/kg, i.m.). For evaluation of airway responsiveness and bronchoscopy, the monkeys were anesthetized using Diprivan (0.1 to 0.2 mg/kg/minutes, i.v., Astra Zeneca Pharmaceuticals, Wilmington, DE) with the dose adjusted as deemed necessary by the attending veterinarian, intubated with a cuffed endotracheal tube (4.5 to5.0 mm), and placed in a head-out body plethysmograph with the intubation tube or facemask attached to a pneumatic four-way valve/pneumotachograph assembly. For necropsy, sedated animals were deeply anesthetized with intravenous sodium pentobarbital, the trachea intubated, and the animal maintained on positive pressure respiration (15.0 ml/kg, 20.0 bpm, 10 to 20 minutes) until killed by exsanguination via the systemic aorta.
Fluorometric Determination of Histamine Concentration
Histamine was measured in plasma using a previously published fluorometric method.15 Histamine concentrations in samples were determined by comparison to a standard curve using known concentrations of histamine (range, 0.005 to 0.5 µg/ml).
Bronchoalveolar Lavage and Differential Cell Counts
Bronchoalveolar lavage specimens were obtained by bronchoscopy of sedated monkeys 24 hours after airway responsiveness testing by instillation of 10 ml of endotoxin-free PBS (Sigma, St. Louis, MO) and collected from the right caudal lobe at the time of necropsy (150 ml). For leukocyte differentials, lavage samples were cytocentrifuged, air dried, stained with a modified Wright’s stain (Diff-Quik) and the proportion of macrophages, neutrophils, eosinophils, lymphocytes, and epithelial cells determined by counting 300 cells/monkey by light microscopy (x1000).
Immunophenotyping of Leukocytes by Flow Cytometry
Peripheral blood mononuclear cells were freshly isolated using a Ficoll density gradient (Histopaque 1077; Sigma, St. Louis, MO), washed Ca/Mg-free Hanks’ balanced salt solution, counted, resuspended (1 to 2 x 105 cells per sample) in PBS (with 2.5% calf serum and 0.1% sodium azide) for multicolor immunophenotyping as previously described.16 Immunostaining for lymphocyte characterization using the following antibodies: mouse monoclonal anti-human CD2 (fluorescein isothiocyanate- conjugated), CD4 (phycoerythrin) and CD25 (DAKO, Carpinteria, CA), CD3 (fluorescein isothiocyanate-conjugated) (Pharmingen, San Diego, CA), and goat F(ab')2 anti-mouse immunoglobulins (phycoerythrin-Cy5) (Southern Biotechnology Associates, Inc., Birmingham, AL). Two- and three-color analysis was performed on a FACScan flow cytometer in list mode, acquiring 30,000 to 50,000 events per sample and analyzed with CELLQuest software (Becton Dickinson Immunocytometry Systems, San Jose, CA).
Pulmonary Mechanics and Airways Responsiveness Testing
Pulmonary mechanics were measured using a transfer impedance method17 with monkeys breathing spontaneously through a pneumotachograph (Fleisch no. 2) while the thorax is vibrated using a pseudo-random noise waveform encompassing frequencies of 2 to 128 Hz by two speakers mounted in the walls of the head-out plethysmograph (Pulmetrics Group, Boston, MA) and flow and pressure changes measured (4 second intervals) using a Microswitch transducer (model 743PC). Transfer impedance (Ztr) was calculated as the ratio of the Fourier transform of pressure inside the box versus the Fourier transform of airway flow at each frequency.17 Airway resistance (Raw) was obtained by fitting the impedance data to the six-element model of the respiratory tract proposed by DuBois and colleagues18 using a gradient optimization technique.19 Because only five of the six elements can be uniquely estimated20 using this technique, we restricted Cg to a constant value determined using a published regression equation relating functional residual capacity and body weight for rhesus monkeys.21 Tidal volume and breathing frequency were recorded on a breath-by-breath basis by integrating the output of the pneumotachograph using a digital data acquisition system (Po-Ne-Mah, Inc., Valley View, OH). Arterial oxygen saturation (O2Sat%) was monitored via a pulse oximeter (MOD II) and then recorded at the beginning and ending of each data collection period.
All allergen and histamine challenges were administered as aerosols at a set tidal volume and breathing frequency (15.0 ml/kg and 20.0 bpm) using a compressed air nebulizer (Vortran, Inc.) in series with a positive pressure ventilator (Bird Mark 7A respirator). Allergen challenges used a set HDMA concentration (0.02 mg protein/ml) delivered at repeated 5-minute intervals separated by 60-second data collection periods and were terminated when Raw doubled. Data were expressed as the cumulative dose of allergen (mass concentration of allergen in mg protein/ml x tidal volume in ml x number of breaths) that doubles Raw (CDA200Raw). Histamine challenges used repeated 30-second challenge periods separated by 240-second data collection periods, beginning with saline followed by doubling concentrations starting at 0.0625 mg/ml and ending at the concentration that doubles Raw. Data were expressed as the concentration that increases Raw by 150% (EC150Raw). The CDA200Raw and EC150Raw were determined by linear interpolation on the log-log plot of the dose-response curve with the response expressed as the percent of baseline Raw.
HDMA-Specific IgE Concentrations in Serum
Allergen-specific IgE was measured in serum samples by enzyme-linked immunosorbent assay. Briefly, 96-well microtiter plates were sensitized with 3 µg/well HDMA in carbonate/bicarbonate buffer. Samples were precipitated with 35% saturated ammonium sulfate to remove interfering IgG, and supernatants were used as sample without further dilution. Binding of IgE was detected with a goat anti-human IgE-horseradish peroxidase conjugated antibody (Bethyl Laboratories, Inc., Montgomery, TX) Positive controls consisted of pooled human HDMA IgE-positive sera (RAST tested high level). Negative controls consisted of PBS and serum from 18 HDMA skin test-negative monkeys. Data are presented as ratios of sample to negative monkey serum.
Necropsy and Histopathology
After exsanguination, the thorax was opened by midline incision and the entire mediastinal contents removed en bloc. The trachea and extrapulmonary bronchi were exposed and the lobar bronchi cannulated. Separate lobes were fixed by airway infusion with 1% paraformaldehyde (left cranial lobe), 4% paraformaldehyde (right cranial lobe), or glutaraldehyde/paraformaldehyde (1%/1%) (right middle lobe) at 30-cm hydrostatic pressure. A cross-section of the trachea was also fixed in each fixative. The airway tree of the caudal segment of the left cranial lobe was exposed by microdissection and stored in PBS for whole mount histochemistry.22 The other fixed lobes were sliced (5 to 10 mm thick) perpendicular to the long axis of the axial intrapulmonary airway and all slices embedded in paraffin (left and right cranial) or Araldite (right middle).22 Whole mounts of the airways exposed by microdissection were evaluated for the presence of major basic protein (antibody no. RDI-CBL 419; Research Diagnostics,Inc., Flanders, NJ) by whole mount immunoperoxidase22 or for mucus glycoproteins by periodic acid-Schiff (PAS)/Alcian blue.23 After evaluation by stereomicroscopy, portions of the whole mounts were embedded in methacrylate and sectioned at 1 µm. Araldite sections (1 µm) were stained with toluidine blue or methylene blue/azure II.
Immunohistochemical Detection of IgE-Producing Cells in Monkey Lung Sections
Paraffin sections of paraformaldehyde-fixed lung from airway generations 2, 3, and 4 were examined for the presence of IgE-producing cells by immunoperoxidase staining with anti-human IgE (Bethyl Laboratories, Inc.) using a standard protocol.24 Two sections were examined for each airway generation of lung from the three sensitized and three nonsensitized monkeys.
Statistical Analysis
All data are reported as mean ± SD. Groups were compared using Student’s t-test with the significance level set at P < 0.05.
|
Results |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
As presented in Table 3
, all three sensitized monkeys developed
positive intradermal skin tests to HDMA on day 105 after initiation of
the sensitization protocol. In sensitized monkeys, wheal size was
greater than either the positive histamine control or the negative
diluent. This was not the case for control monkeys from the colony.
Airway Responsiveness to Allergen and Histamine
As previously shown by Madwed and Jackson,17
the
DuBois six element model of the respiratory tract18
provided an excellent fit to the Ztr data collected in rhesus monkeys
in both control and obstructed conditions. All of the HDMA-sensitized
monkeys developed marked airway obstruction after inhalation of a HDMA
aerosol compared to nonsensitized monkeys that show no obstructive
response (Figures 1 and 2)
. Two of the monkeys (MMU4 and MMU6)
demonstrated an obstructive response to HDMA aerosol with their first
HDMA challenge whereas one did not develop this response until after
multiple HDMA challenges (MMU5). The obstructive response in
HDMA-sensitized monkeys was associated with a marked tachypnea and a
decrease in arterial oxygen saturation (Figure 2)
. The tachypnea was
often associated with apnea, bradycardia, and hypotension. Forty-eight
to 72 hours after a HDMA aerosol challenge inhalation of doubling doses
of histamine resulted in a progressive increase in Raw in all monkeys
studied (Figure 3)
. The concentration of
histamine aerosol required to produce a 150% increase in Raw was
significantly less (P < 0.03) in
HDMA-sensitized monkeys than that required in nonsensitized monkeys
(Figure 3B)
.
|
|
|
Plasma concentrations of histamine in all three sensitized monkeys
were elevated above levels in plasma of nonsensitized monkeys within 30
minutes after completion of an aerosol challenge, although the
responses did not always occur at the same time points in the exposure
protocol (Figure 4)
.
|
Concentrations of specific IgE in serum were significantly
(P < 0.05) greater than negative control after
week 6 of sensitization for all three sensitized monkeys (Figure 5)
. At week 33 after aerosol challenge,
the serum level of HDMA-specific IgE in MMU6 surpassed the mean value
of the positive control. At necropsy MMU4 and MMU6 showed markedly
elevated IgE serum concentrations.
|
At necropsy, all three allergen-sensitized monkeys exhibited an
increase in eosinophils within lavage specimens, as compared with
control animals (Figure 6)
. Within lavage
obtained at 6 months after initial sensitization with HDMA, there
was an increase in number of epithelial cells, predominantly large
patches of ciliated columnar epithelium, from two out of three dust
mite-sensitized monkeys, as compared with control animals. There were
no differences in overall numbers of lymphocytes and granulocytes
within blood samples among all monkeys studied, regardless of the time
point during the exposure protocol when specimens were taken for
evaluation.
|
At necropsy, the proportion of the CD4+
lymphocyte population in peripheral blood of sensitized monkeys that
were CD25+ (IL-2 receptor) increased over that observed in
nonsensitized monkeys (Figure 7)
. This
functional shift in the expression of CD25 on CD4-positive cells within
blood was variable among the three sensitized monkeys, with two of the
monkeys having threefold to fourfold increases and the other being at
the upper range for nonsensitized monkeys. However, this latter monkey
had an increase in CD2+/CD25+ cells that were not either a CD4 or CD8
phenotype.
|
Compared to nonsensitized control animals (Figure 8A)
, there was mucous goblet cell
hyperplasia, thickening of the basement membrane zone, and
hypercellularity in the epithelium and subepithelial connective tissue
in the trachea and in proximal and distal intrapulmonary bronchi of
allergen-sensitized rhesus monkeys (Figure 8B)
. These changes were
focal and varied greatly within various portions of the airway wall in
the same airway generation, between airway generations in an individual
sensitized and challenged animal, and from animal to animal in the
sensitized and challenged group. Based on staining with PAS/Alcian
blue, mucous goblet cells in the intrapulmonary airways of sensitized
monkeys (Figure 8D)
were not only more abundant, but contained more
stored secretory product, than did mucous cells in nonsensitized
monkeys (Figure 8C)
. In areas of the airway walls with elevated
cellular infiltrates, many of the infiltrating cells had multilobed
nuclei and were positive for immunodetectable major basic protein
(Figure 8F)
. In areas of the airway wall of sensitized animals where
inflammatory cells were abundant, the basement membrane zone was
markedly reduced compared to control animals. In contrast, the basement
membrane zone appeared to be thickened in many areas that were free of
inflammatory cells. Immunoreactive IgE was detected within mononuclear
cells present in airway epithelium and in accumulations of lymphoid
cells within peribronchial interstitial spaces of HDMA-sensitized
monkeys (Figure 9)
.
|
|
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
"A chronic inflammatory disorder of the airways in which many cells and cellular elements play a role, in particular, mast cells, eosinophils, T lymphocytes, macrophages, neutrophils, and epithelial cells. In susceptible individuals, this inflammation causes recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning. These episodes are usually associated with widespread but variable airflow obstruction that is often reversible either spontaneously or with treatment. The inflammation also causes an associated increase in the existing bronchial hyperresponsiveness to a variety of stimuli. Moreover, recent evidence indicates that remodeling of the airway may occur in some patients with asthma and that these changes contribute to persistent abnormalities in lung function."
Based on this definition, we established eight formal physiological, immunological, and pathological criteria for evaluating the presence of an asthma-like condition in allergen-exposed rhesus monkeys. First, the sensitized monkeys developed a positive skin test for HDMA. In addition, we found elevated levels of IgE in serum of these animals and IgE-positive cells within the tracheobronchial airway walls. Second, the animals developed airway obstruction after the inhalation of aerosolized allergen that was associated with cough, rapid shallow breathing, and decreased arterial oxygen saturation. The latter was reversible by treatment with aerosolized albuterol. In addition, elevations in serum histamine concentrations could be detected in sensitized monkeys after allergen aerosol exposures. Third, shed epithelial cells were detected in the exudates and bronchoalveolar lavage of the sensitized monkeys immediately after allergen aerosol challenge. As with human asthmatics, the majority of the cells were ciliated cells. Fourth, there was a marked increase in the abundance of immune cells, specifically eosinophils, in airway exudates and bronchoalveolar lavage. This was accompanied by elevations in CD25 expression on CD4+ lymphocytes in both lavage and serum. Fifth, the animals developed nonspecific airways responsiveness, which was characterized as a fourfold reduction in the dose of histamine aerosol required too produce a 150% increase in airway resistance. Sixth, histopathological evaluation of intra- and extra-pulmonary conducting airways found marked mucous cell hyperplasia accompanied by general epithelial hypertrophy. Seventh, these same intrapulmonary bronchi had thickening of the basement membrane zone. Eighth, there were marked accumulations of eosinophils in the epithelial and subepithelial matrix compartments of the airway walls. All three of these histopathological features were focal and distributed throughout the conducting airway trees of the three sensitized monkeys studied.
In human patients with allergic asthma, inhalation of allergen induces
an immediate bronchoconstriction that is followed in 50% of
patients by a delayed bronchoconstriction 4 to 8 hours
later.25,26
Mast cell degranulation and the release of
bronchoconstrictive mediators, including histamine, are thought to be
important in the immediate bronchoconstriction.27,28
The
HDMA-sensitized monkeys in the present study demonstrated a similar
immediate bronchoconstrictive response to inhaled allergen (Figure 1 and 2)
that was associated with increased serum histamine levels
(Figure 4)
. During early stages of asthma exacerbation in human
patients alveolar ventilation is maintained and arterial
CO2 may be reduced secondary to onset of
tachypnea.29
However, as breathing pattern becomes more
rapid and shallow and bronchoconstriction intensifies, mismatches of
ventilation and perfusion develop and hypoxemia and respiratory
insufficiency ensue.29
Inhalation of HDMA resulted in
marked tachypnea that was associated with the development of mild
hypoxemia (Figure 2)
. As in human asthmatics,25,26
we
observed in our HDMA-sensitized monkeys that a delay of 48 to 72 hours
after HDMA aerosol challenge was characterized by the development of
airway hyperresponsiveness to histamine, a nonspecific stimuli. An
important similarity between humans and rhesus monkeys is that they
both produce histamine as the primary early mediator of type 1
hypersensitivity, whereas, the mouse and rat produce serotonin instead
of histamine.30
Elevated levels of histamine in plasma of
monkeys after HDMA aerosol substantiate the importance of this mediator
in allergic asthma of primates.
In addition to the aforementioned physiological features of the respiratory system, the molecular nature and distribution of inflammatory cells within the rhesus monkey closely parallel that of humans. Phylogenetic conservation of leukocyte cell surface proteins between rhesus monkeys and humans is evident by the high degree of cross-reactivity to monoclonal antibodies generated against human antigens (range of 45 to 53% reactivity of antibodies tested).4,31 Further, T helper and T cytotoxic lymphocyte subsets in peripheral blood and lymphoid tissue from normal monkeys are similar to values obtained in humans; this feature is important for evaluating immunological mechanisms for analogous allergic responses.4 Our observation of elevated levels of CD25+ T helper cells in the circulation of allergen-sensitized monkeys is consistent with previous reports of activated T lymphocytes in the peripheral blood of individuals with severe acute asthma.32,33 Moreover, the development of HDMA-specific IgE in serum coupled with the increased numbers of IgE-producing cells within the walls of tracheobronchial airways of sensitized monkeys, parallels the development of circulating allergen-specific IgE in human patients with allergic asthma. The presence of IgE-producing cells within tracheobronchial airways combined with the elevated serum histamine levels after HDMA inhalation in the sensitized monkeys is supportive of the importance of local IgE production for the initiation of type 1 hypersensitivity-mediated reactivity to inhaled allergen in rhesus monkeys. These findings cumulatively suggest that an allergen-mediated immune response within the microenvironment of the rhesus lung is comparable to that of humans.
An additional feature of allergic asthma in humans is dramatic remodeling of the walls of the conducting airways. Mucous goblet cells and submucosal glands, normally present in human bronchi, undergo extensive hyperplasia and hypersecretion. We found the same changes in sensitized monkeys. Basal cells, which play a role in the epithelial sloughing observed in human asthmatics, are present and altered throughout the airways in both humans and monkeys. Mesenchymal components of the intrapulmonary conducting airways, including a distinct subepithelial basement membrane, an extensive layer of attenuated fibroblasts and myofibroblasts beneath the basement membrane, and large bands of smooth muscle interspersed with cartilage, are modified in human asthmatics. These airway components are also present in tracheobronchial airways of healthy rhesus monkeys and underwent extensive thickening and hyperplasia in the allergen-sensitized and -challenged monkeys in this study.
This study confirms our initial premise that nonhuman primates would be appropriate models of allergic asthma because they share with humans characteristics of the immune and respiratory systems that seem critical for the development of allergic asthma. This model will permit definition of the roles of all of the components of the conducting airway wall and their interaction with physiological and immunological responses that are characteristic of human allergic asthma as the allergic response develops and the role that exposure to environmental pollutants could play in the exacerbation of allergic asthma. Further, application of this model to infant monkeys has the potential for establishing the mechanisms by which allergen exposure of young children during postnatal lung development modulates cellular differentiation and morphogenesis to create allergic asthma in children.
|
Acknowledgements |
|---|
|
Footnotes |
|---|
Supported in part by National Institute of Environmental Health and Safety grant P01 ES00628, and NCRR grant RR00169, and the NIEHS Center for Environmental Health Sciences (ES 05707).
Accepted for publication September 26, 2000.
|
References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
This article has been cited by other articles:
 |
|
 |
|
  C. M. Lloyd and D. S. Robinson Allergen-induced airway remodelling Eur. Respir. J., May 1, 2007; 29(5): 1020 - 1032. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. G. Plopper, S. M. Smiley-Jewell, L. A. Miller, M. V. Fanucchi, M. J. Evans, A. R. Buckpitt, M. Avdalovic, L. J. Gershwin, J. P. Joad, R. Kajekar, et al. Asthma/Allergic Airways Disease: Does Postnatal Exposure to Environmental Toxicants Promote Airway Pathobiology? Toxicol Pathol, January 1, 2007; 35(1): 97 - 110. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. M. Hyde, L. A. Miller, E. S. Schelegle, M. V. Fanucchi, L. S. Van Winkle, N. K. Tyler, M. V. Avdalovic, M. J. Evans, R. Kajekar, A. R. Buckpitt, et al. Asthma: a comparison of animal models using stereological methods Eur. Respir. Rev., December 1, 2006; 15(101): 122 - 135. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. V. Avdalovic, L. F. Putney, E. S. Schelegle, L. Miller, J. L. Usachenko, N. K. Tyler, C. G. Plopper, L. J. Gershwin, and D. M. Hyde Vascular Remodeling Is Airway Generation-Specific in a Primate Model of Chronic Asthma Am. J. Respir. Crit. Care Med., November 15, 2006; 174(10): 1069 - 1076. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. R. Van Scott, D. Aycock, E. Cozzi, K. Salleng, and H. W. Stallings III Separation of bronchoconstriction from increased ventilatory drive in a nonhuman primate model of chronic allergic asthma J Appl Physiol, December 1, 2005; 99(6): 2080 - 2086. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Gupta, S. Schulz-Maronde, C. Kutzleb, R. Richter, W.-G. Forssmann, A. Kapp, U. Forssmann, and J. Elsner Cloning, expression, and functional characterization of cynomolgus monkey (Macaca fascicularis) CC chemokine receptor 1 J. Leukoc. Biol., November 1, 2005; 78(5): 1175 - 1184. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. L. Chou, B. L. Daugherty, E. K. McKenna, W. M. Hsu, N. K. Tyler, C. G. Plopper, D. M. Hyde, E. S. Schelegle, L. J. Gershwin, and L. A. Miller Chronic Aeroallergen during Infancy Enhances Eotaxin-3 Expression in Airway Epithelium and Nerves Am. J. Respir. Cell Mol. Biol., July 1, 2005; 33(1): 1 - 8. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. L. Coffman and E. M. Hessel Nonhuman primate models of asthma J. Exp. Med., June 20, 2005; 201(12): 1875 - 1879. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. S. V. Winkle, M. V. Fanucchi, L. A. Miller, G. L. Baker, L. J. Gershwin, E. S. Schelegle, D. M. Hyde, M. J. Evans, and C. G. Plopper Epithelial cell distribution and abundance in rhesus monkey airways during postnatal lung growth and development J Appl Physiol, December 1, 2004; 97(6): 2355 - 2363. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. V. Fanucchi, E. S. Schelegle, G. L. Baker, M. J. Evans, R. J. McDonald, L. J. Gershwin, E. Raz, D. M. Hyde, C. G. Plopper, and L. A. Miller Immunostimulatory Oligonucleotides Attenuate Airways Remodeling in Allergic Monkeys Am. J. Respir. Crit. Care Med., December 1, 2004; 170(11): 1153 - 1157. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. D. Larson, C. G. Plopper, G. Baker, B. K. Tarkington, K. C. Decile, K. Pinkerton, J. K. Mansoor, D. M. Hyde, and E. S. Schelegle Proximal airway mucous cells of ovalbumin-sensitized and -challenged Brown Norway rats accumulate the neuropeptide calcitonin gene-related peptide Am J Physiol Lung Cell Mol Physiol, August 1, 2004; 287(2): L286 - L295. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. R. Van Scott, J. L. Hooker, D. Ehrmann, Y. Shibata, C. Kukoly, K. Salleng, G. Westergaard, A. Sandrasagra, and J. Nyce Dust mite-induced asthma in cynomolgus monkeys J Appl Physiol, April 1, 2004; 96(4): 1433 - 1444. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. T Holgate The epidemic of asthma and allergy J R Soc Med, March 1, 2004; 97(3): 103 - 110. [Full Text] [PDF]
|
|
|
|
|
|
M. J. Evans, M. V. Fanucchi, G. L. Baker, L. S. Van Winkle, L. M. Pantle, S. J. Nishio, E. S. Schelegle, L. J. Gershwin, L. A. Miller, D. M. Hyde, et al. Atypical development of the tracheal basement membrane zone of infant rhesus monkeys exposed to ozone and allergen Am J Physiol Lung Cell Mol Physiol, October 1, 2003; 285(4): L931 - L939. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. R. Reader, J. S. Tepper, E. S. Schelegle, M. C. Aldrich, L. F. Putney, J. W. Pfeiffer, and D. M. Hyde Pathogenesis of Mucous Cell Metaplasia in a Murine Asthma Model Am. J. Pathol., June 1, 2003; 162(6): 2069 - 2078. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. M. Smiley-Jewell, M. U. Tran, A. J. Weir, Z. A. Johnson, L. S. Van Winkle, and C. G. Plopper Three-dimensional mapping of smooth muscle in the distal conducting airways of mouse, rabbit, and monkey J Appl Physiol, October 1, 2002; 93(4): 1506 - 1514. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
