The Toxicologist - Society of Toxicology

1232 COMPARATIVE KINETICS USING DRIED BLOOD
SPOT TECHNIQUE (DBS) IN THE CYNOMOLGUS
MONKEY.
S. Grote-Wessels 1 , M. Niehoff 1 , W. Wilbois 1 , T. Pfaff 2 , H. Fischer 3 , A.
Welbers 2 and W. Mueller 1 . 1 Covance Laboratories GmbH, Muenster, Germany,
2 AiCuris GmbH & Co.KG, Wuppertal, Germany and 3 A&M Labor, Bergheim,
Germany. Sponsor: G. Weinbauer.
The generation of highly reliable TK exposure data is vital to success of a toxicology
programme. Within preclinical studies in small animals like juvenile cynomolgus
monkeys (Macaca fascicularis) or the common marmoset (Callithrix jacchus) it can
be a challenge to provide sufficient blood for the preparation of plasma or serum
whilst staying within acceptable volumes. Blood sampling strategies such as DBS
employs the use of small quantities of blood while providing powerful analytical capabilities.
In addition to ethical benefits and depending on characteristics of each
compound DBS offers the potential to overcome problems associated with the traditional
plasma/serum bioanalysis. We present a study within which the plasma
bioanalysis was compared to results generated by DBS for AIC090027, a HCMV
terminase inhibitor. The bioanalytical method was validated over the range of 1 to
1000 ng/mL AIC090027 in blood of the adult cynomolgus monkey by combining
extraction from the spotted card with quantification by LC/MS. The method displayed
good accuracy and precision over the concentration range and was successfully
employed in a preclinical study following oral administration of AIC090027
to cynomolgus monkeys. Overall, in vivo data generated with DBS samples showed
that Tmax and AUC (area under curve) following daily administration of 60 and
120 mg/kg (5 male animals/group) were comparable to plasma analysis. In addition,
DBS results were in good agreement with historical in vitro plasma data when
allowance was made for the plasma blood partition ratio. For DBS samples of the
high dose group (240 mg/kg) compound concentrations were in excess of those
previously observed values and data has to be interpreted with caution.
Nevertheless this comparison DBS and plasma data demonstrates the potential of
this technique to provide reliable data for systemic exposure apart from the matrix
used, blood or plasma.
1233 CHARACTERISATION OF BIOLOGICALLY AVAILABLE
WOOD COMBUSTION PARTICULATES IN CELL
CULTURE MEDIUM.
S. Gauggel 1 , C. Derreza-Greeven 1 , J. Wimmer 1 , M. Wingfield 2 and D. R.
Dietrich 1 . 1 Human & Environmental Toxicology, University of Konstanz, Konstanz,
Germany and 2 Malvern Instruments GmbH, Herrenberg, Germany.
Combustion of wood is one of the major sources of particulate matter (PM).
Exposures to this type of PM have the potential to induce respiratory tract diseases
in humans. The toxicity of the particles appears to be the result of their physicochemical
characteristics. Many in vitro studies address the particle toxicity by investigating
cytotoxic, inflammatory and genotoxic effects as well as their mechanisms
via submerse exposure. However, few if any submerse in vitro studies, including
those at the air liquid interface, characterised the actual particle fraction and characteristics
within the culture medium that finally induced the observed response.
Indeed, the fact that availability of particles, suspended in liquids, may be dramatically
altered due to particle agglomeration with a subsequent influence on their toxicity
was largely ignored. This study looks at the influence on the particle size distribution
on the bioavailability to cells. The particle size distribution and
agglomeration status of ambient PM (from wood furnaces), engineered nanoparticles
(inert latex particles) and amorphous and crystalline quartz of known size in
cell culture medium and water was determined using scanning Electron
Microscopy (SEM) and light scattering techniques such as dynamic light scattering
and laser diffraction (Zetasizer, Nanosight, Mastersizer). The analyses of the engineered
latex particles, amorphous quartz and crystalline quartz samples confirmed
the size defined by the manufacturer. While engineered latex particles (≤ 100 nm)
and amorphous quartz appeared to agglomerate in medium, this was less so for
crystalline quartz. In comparison measurement of complex mixtures e.g., wood
combustion PM in media demonstrated the presence of very small particles and a
small amount of large particles, formed through agglomeration as in the case of
crystalline quartz.
264 SOT 2011 ANNUAL MEETING
1234 DIESEL EXHAUST PARTICLE TOXICITY TO HUMAN
LUNG EPITHELIAL CELL LINE: SINGLE CELL
EXPOSURE ASSESSMENT WITH MORPHOLOGICAL
AND BIOPHYSICAL ANALYSIS.
G. D. McEwen 1 , Y. Wu 1 , R. A. Coulombe 2 and A. Zhou 1 . 1 Biological
Engineering, Utah State University, Logan, UT and 2 Animal, Dairy, and Veterinary
Sciences, Utah State University, Logan, UT.
Single cell level investigation of cell membrane properties under toxic exposure is
important in basic understanding of the roles of cell biophysical properties (e.g.,
cell adhesion and biomechanics) in cytotoxicity and genotoxicity. In this study,
electric cell-substrate impedance sensing (ECIS), Raman microspectroscopy (RM),
and atomic force microscopy (AFM) were applied to in vitro monitor the changes
of cell morphology, cellular bio-components and biomechanical and nano-architectural
properties of viable human lung epithelial (A549) cells exposed to diesel exhaust
particles (DEP) over time. ECIS results indicated that DEP treatment (125,
250, 500 μg/ml) on an adherent cellular monolayer, decreased cellular viability;
whereas, DEP treatment (5, 17, 50, 125, 250, and 500 μg/ml) prior to attachment
and spreading result in a decrease of adhesion and cellular proliferation rates. For
two single cell analyses, RM revealed changes of cellular bio-components based on
characteristic Raman band intensity at 785 cm -1 (DNA), 939 cm -1 (carbohydrates),
1006 cm -1 (proteins), and 1092 cm -1 (lipids) for both DEP treated and untreated
A549 cells; AFM results indicated that DEP treatments induced variations in the
cellular membrane surface hydrophobicity, a significant decrease in the membrane
surface adhesion force over treatment time, and some alteration in cell elasticity. In
conclusion, this study demonstrated a (sub-)cellular toxicity assessment via multiinstrumental
approach to help further reveal and understand potential links among
morphological, biochemical, and cyto-architectural/biomechanical changes of
human lung carcinoma epithelial cells induced by DEP.
1235 SUPERCOARSE WORLD TRADE CENTER PARTICLE
EFFECTS ON RAT BRONCHIAL AIRWAY FUNCTION.
B. Garrett, J. Vaughan, M. Cohen and L. Chen. Environmental Health Science,
New York University, New York, NY.
The World Trade Center (WTC) collapse on 9-11-01 released copious amounts of
particles into the air. In the first few days after the disaster, First Responders (police,
firefighters, civilians) - many without respiratory protection - worked for hours
under strenuous conditions that resulted in heavy oral breathing. In the period
since the disaster, responders have complained of various health issues ranging from
chronic cough to debilitating ailments. Using a WTC dust mixture bearing primarily
(>85%) supercoarse (10-53 μm) particles collected on-site over the first 3 days
post-collapse, inhalation exposures in rodent models were performed. Here, exposures
were followed by methacholine (Mch) challenge to ascertain if these mostly
particles affected bronchial airway activity. To mimic an average Responder exposure
of ≈4 hr/d at Ground Zero in the period of maximal dust levels, 8-wk-old
F344 rats were sedated with isoflurane (ISO) and then dosed via intratracheal inhalation
with WTC dust particles for 2 hr/d for 3 days. To verify that use of long sedation
in a supine position was not affecting airway reactivity, a subset of rats were
placed on their backs and maintained at 1.5% ISO for 2 hr/d for 3 d. At days 1, 3,
7, and 14 after the final ISO exposure, the rats underwent aerosol Mch challenge
and response analyses via whole body plethsmography. Air-exposed controls were
challenged in parallel. For the WTC dusts, a set of rats underwent exposure to a single
high dose (100 mg/m3) of particles (MMAD=25 μm) for 2 hr/d for 3 days. The
rats then underwent Mch challenge at days 1, 3, 7, and 14 post exposure. Rats
dosed solely with ISO did not exhibit any changes in bronchial airway reactivity in
comparison to air controls. Alterations in airway reactivity were noted in rats dosed
with the WTC dust mixture; these rats exhibited significant differences in reaction
time to lower doses of Mch in comparison with controls. This indicated that the
large WTC particles caused significant changes in airway function (specifically hyperreactivity)
and potentially caused other damage.
1236 ASSESSMENT OF PUBLIC HEALTH RISKS
ASSOCIATED WITH NAPHTHALENE ENTERING
RESIDENCES AND COMMERCIAL SPACE FROM
VAPOR INTRUSION AT MGP SITES.
R. B. DeHate 1 , B. Skelly 1 , G. T. Johnson 2 and R. D. Harbison 2 . 1 GEI
Consultants, Tampa, FL and 2 Environmental and Occupational Health, University of
South Florida, Tampa, FL.
Naphthalene is a constituent of coal tar and often a contaminant found at former
manufactured gas plants (MGP). Development at these sites has resulted in residential
and commercial areas with potential exposures from vapor intrusion.