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Journal of Toxicology and Environmental Health, Part A, 76:363–380, 2013Copyright Taylor & Francis Group, LLCISSN: 1528-7394 print / 1087-2620 onlineDOI: 10.1080/15287394.2013.765369 AUTOANTIBODIES TO NERVOUS SYSTEM-SPECIFIC PROTEINS ARE ELEVATED IN
SERA OF FLIGHT CREW MEMBERS: BIOMARKERS FOR NERVOUS SYSTEM INJURY
Mohamed B. Abou-Donia1, Martha M. Abou-Donia1, Eman M. ElMasry1, Jean A. Monro2,
Michel F. A. Mulder3
1Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, USA 2Breakspear Medical Group Ltd., Hemel Hempstead, Hertfordshire, United Kingdom 3Aviation Medical Consultation, Bussum, The Netherlands This descriptive study reports the results of assays performed to detect circulating
autoantibodies in a panel of 7 proteins associated with the nervous system (NS) in sera
of 12 healthy controls and a group of 34 flight crew members including both pilots and
attendants who experienced adverse effects after exposure to air emissions sourced to the
ventilation system in their aircrafts and subsequently sought medical attention. The pro-
teins selected represent various types of proteins present in nerve cells that are affected
by neuronal degeneration. In the sera samples from flight crew members and healthy con-
trols, immunoglobin (IgG) was measured using Western blotting against neurofilament triplet
proteins (NFP), tubulin, microtubule-associated tau proteins (tau), microtubule-associated
protein-2 (MAP-2), myelin basic protein (MBP), glial fibrillary acidic protein (GFAP), and glial
S100B protein. Significant elevation in levels of circulating IgG-class autoantibodies in flight
crew members was found. A symptom-free pilot was sampled before symptoms and then
again afterward. This pilot developed clinical problems after flying for 45 h in 10 d. Significant
increases in autoantibodies were noted to most of the tested proteins in the serum of this
pilot after exposure to air emissions. The levels of autoantibodies rose with worsening of his
condition compared to the serum sample collected prior to exposure. After cessation of fly-
ing for a year, this pilot's clinical condition improved, and eventually he recovered and his
serum autoantibodies against nervous system proteins decreased. The case study with this
pilot demonstrates a temporal relationship between exposure to air emissions, clinical con-
dition, and level of serum autoantibodies to nervous system-specific proteins. Overall, these
results suggest the possible development of neuronal injury and gliosis in flight crew members
anecdotally exposed to cabin air emissions containing organophosphates. Thus, increased cir-
culating serum autoantibodies resulting from neuronal damage may be used as biomarkers
for chemical-induced CNS injury.
Airline crew and passengers may be auxiliary power unit (APU). Such exposure has exposed to air emissions including engine oil been associated with a variety of symptoms contaminants, such as gaseous, vapor, and par- related to central nervous system (CNS) dys- ticulate constituents of pyrolyzed engine oil function, as well as effects on the gastrointesti- in the unfiltered ventilation air supply that is nal, respiratory, dermal, and perhaps immune extracted from either the aircraft engines or systems (Cox and Michaelis, 2002; Winder Received 16 April 2012; accepted 14 December 2012.
The authors thank all of the participants who volunteered to take part in this case study. The technical work of Dr. Hagir B. Suliman and the art work of Sheref M. Abou-Donia are appreciated. This study was supported in part by the Department of Pharmacology andCancer Biology, Duke University Medical Center, Durham, North Carolina, USA.
Address correspondence to Mohamed B. Abou-Donia, Department of Pharmacology and Cancer Biology, C173a Levine Science Research Center, Duke University Medical Center, Durham, NC 27710, USA. E-mail: [email protected] M. B. ABOU-DONIA ET AL.
and Balouet, 2002; Winder 2006; Murawski must be less than 0.2% of the total TCP and Supplee, 2008). Numerous reports over (Mattie et al., 1993). For more than a cen- the past 50 years documented neurological tury, TOCP was shown to induce OPIDN in complaints among commercial and military humans and experimental animals (Smith et al., cabin crews after exposure to air emissions 1930; Abou-Donia, 1981; Suwita and Abou- in aircraft (Kitzes, 1956; Montgomery et al., Donia, 1990). Ingestion studies have associ- 1977; Carletti et al., 2011). This condition is ated the neurotoxicity attributed to TCP mix- sometimes referred to as aerotoxic syndrome tures with its TOCP content (Craig and Barth, (Winder et al., 2002).
1999; Mackerer et al., 1999; Freudenthal Ross (2008) reported the outcome of et al., 1993). Inhalation neurotoxicity due to psychological assessments of 27 self-reported pyrolyzed engine oil/TCP was reported to be pilots who noted CNS symptoms. These higher than expected (Lipscomb et al., 1995).
symptoms were postulated to have resulted Hydraulic fluid is composed of a mixture from exposure to the organophosphates of tributyl phosphate (TBP), dibutyl phenyl (OP) compounds present in engine oil and phosphate (DPP), and butyl diphenyl phos- phate (BDP), all of which were detected in air three distinct neurotoxic actions (1) Cholinergic emissions on aircrafts (van Netten and Leung, neurotoxicity resulting from inhibition of acetyl- 2001; Winder et al., 2002; De Nola et al., cholinesterase (AChE) and over-stimulation of 2008). Organophosphate components of turbo muscarinic and nicotinic acetylcholine (ACh) oil and hydraulic oil produce relatively low receptors with subsequent development of cholinergic neurotoxicity. Vapors of TCP and cholinergic-associated toxicity (Abou-Donia, TBP produced neurotoxicity in rats (Lipscomb 2003); (2) Organophosphorus ester-induced et al., 1995). Workers exposed to 15 mg/m3 delayed neurotoxicity (OPIDN) that is a air containing TBP complained of nausea and central–peripheral axonopathy, characterized headaches (ACGIH, 1986). On the other hand, by primary Wallerian-type axonal degeneration some of these chemicals are capable of produc- of the CNS and peripheral nervous system ing OPIDN and/or OPICN. Tri-aryl phosphates (PNS), followed by secondary demyelination produced OPIDN in test animals only following (Smith et al., 1930; Abou-Donia, 1981, 1995; large doses (Weiner and Jortner, 1999).
Abou-Donia and Lapadula, 1990). The clinical The severity of symptoms reported after picture for OPIDN is manifested initially by an aircraft exposure is enhanced by com- mild sensory disturbances, ataxia, weakness, bined exposure to other toxicants, many of muscle fatigue, and twitching, which may which are undefined, but that include OP progress to paralysis. Improvement in OPIDN pyrolysis products (Abou-Donia et al., 1996).
is slow and may require years and recovery Trimethylolpropane phosphate (TMPP), one of may not be possible. (3) Organophosphorus these components, is a potent neurotoxicant ester-induced chronic neurotoxicity (OPICN) that is formed when engine oil reacts with TCP is characterized by long-term neurological and within the aircraft engine (Rubey et al., 1996).
neurobehavioral deficits accompanied by brain Other airborne contaminants include carbon neuronal cell death (Abou-Donia, 2003). This monoxide (CO) and carbon dioxide (CO2), long-lasting effect results primarily from injury acrolein, ozone, volatile organic compounds (VOC), and particulates that were detected Engine oil contains a mixture of tricre- in the airplane environment (van Netten and syl phosphate isomers (TCP, 2–6% by weight).
Leung, 2001; Rayman, 2002; Winder and TCP isomers are produced by the reaction Balouet, 2002).
of cresols and phosphorus oxychloride. The Conventional clinical neuroimaging is rela- cresol may be a mixture of three isomers: tively insensitive in detecting neuronal and glial ortho, meta, and para. By regulation, the injury following chemical-induced brain injury.
total tri-ortho-cresyl phosphate (TOCP) content Therefore, clinically available biomarkers for AUTOANTIBODIES IN SERA OF FLIGHT CREW
neuronal injury are essential in the diagnosis of autoantibodies against these proteins are and understanding of the temporal progres- (1) related to the degree of neurological deficits sion of the injury (Jauch et al., 2006). The and (2) associated with functional outcomes.
use of serum biomarkers, such as cytoskeletalproteins, in diagnosing brain injury has dramat-ically improved care for patients with traumatic MATERIALS AND METHODS
brain injury (TBI; Zurek and Fedora 2012).
Protein fragments from injured neuronal and glial cells are found in cerebral spinal fluid The sources of proteins were: NFP (mass, (CSF), but are unlikely to survive long enough in NFL, 70, NFM, 160, NFH, 200 kD; bovine blood to be practical markers because of their spinal cord), tau protein (mass, 45–68 kD; short half-lives.
human), MAP-2 (mass, 300 kD; bovine serum), The present descriptive study of flight crew tubulin (mass, 55 kD; bovine brain), and members was undertaken to test the hypoth- MBP (mass, 33 kD; human brain), from esis that following brain injury, neuronal and Sigma-Aldrich (Saint Louis, MO), GFAP (mass glial proteins that are normally present in the 52 kD; human) from Biotrend Chemikalien CNS and PNS leak from injured areas through GmbH (Cologne, Germany), and S100B (mass the damaged blood–brain barrier (BBB; Abdel- 9–14 kD; human brain) from American Rahman et al., 2002) and from degenerated Qualex International, Inc. (San Clemente, CA).
peripheral nerves. Once in circulation, these Horseradish peroxidase-conjugated goat anti- proteins act as autoantigens and react with human IgG, and enhanced chemilumines- B lymphocytes that are normally produced cence reagent were obtained from Amersham in bone marrow to form autoantibodies also Pharmacia Biotech (Piscataway, NJ). Sodium known as immunoglobin (IgG), or "memories" dodecyl sulfate (SDS) gels, 2–20% gradi- of these specific proteins. This test converts ent (8 × 8), and tris-glycine at 15 mM the short-lived nervous-system-specific proteins were obtained from Invitrogen (Carlsbad, CA).
in the serum into long-term biomarkers for All other materials were purchased from neurologic damage.
The presence of circulating IgG-class autoantibodies in sera from a sample ofhealthy controls and flight crew members Western Blot Assay
was assayed against cytoskeletal proteins associated with (1) neurogenesis, that is, autoantibodies against the battery of proteins, neurofilament triplet proteins (NFP), tubulin, the proteins were separated using Western blot tau, and microtubule-associated protein-2 assay. Each serum sample was analyzed in trip- (MAP-2); (2) myelinogenesis, that is, myelin licate. All proteins were loaded at 10 ng/lane basic protein (MBP); and (3) astrogliogenesis, except for albumin, which was loaded at that is, glial fibrillary acidic protein (GFAP) and 100 ng/lane. Proteins were denatured and glial S100B protein. Both GFAP and S100B electrophoresed in SDS–polyacrylamide gel are secreted by astrocytes and are the only electrophoresis (PAGE) (4% to 20% gradient) two antigens studied not present in the PNS purchased from Invitrogen (Carlsbad, CA).
and therefore reflect effects on only the CNS.
One gel was used for each serum sample. The Autoantibodies against these neuronal and glial proteins were transferred into polyvinylidene proteins were reported to monitor brain injury and correlated with human brain disorders Nonspecific binding sites were blocked with (Ingram et al., 1974; Hoshi et al., 1988; Lee Tris-buffered saline-Tween (TBST) (40 mM Tris et al., 1988; Ahlsen et al., 1993; Dotevall [pH 7.6], 300 mM NaCl, and 0.1% Tween et al., 1999; Spillantini and Goedert, 1998).
20) containing 5% nonfat dry milk for 1 h It is also postulated that serum concentrations at 22◦C. Membranes were incubated with M. B. ABOU-DONIA ET AL.
serum samples at 1:100 dilutions in TBST as subjects in the following, who experienced with 3% nonfat dry milk overnight at 4◦C.
symptoms and sought medical attention, After 5 washes in TBST, the membranes were approximately 2–4 wk after last exposure to air incubated in a 1:2000 dilution of horseradish emissions and onset of symptoms. The controls peroxidase-conjugated goat anti-human IgG were of both genders, had no connection with (Amersham). The membranes were developed the aviation industry, were age-matched with by enhanced chemiluminescence using the the subjects, and did not report exposures to manufacturer's (Amersham) protocol and a air emissions or any neurological symptoms.
Typhoon 8600 variable mode imager. The The subjects were pilots and flight attendants signal intensity was quantified using Bio-Rad from commercial airlines, with cumulative image analysis software (Hercules, California).
flying hours ranging from 4,000 to 16,500. The All tests were performed with the investigators subjects in this study were seen by physicians masked to diagnosis.
and self-reported their complaints in question-naires. Individuals reported that that they didnot have any known neurological symptoms Specificity of Sera Autoantibodies
previously, and provided consent to participate To check the specificity of the sera autoanti- in this study. Subjects included both genders body, a peptide/antigen competition assay was and ranged from 31 to 63 years in age. Blood performed. In this assay sera were mixed with was drawn at the time of diagnosis. Sera were the target protein or peptide with the objective stored at −70◦C.
of eliminating the binding of the autoantibodyto the protein in the serum. Briefly, 50 μl of CASE STUDY SUBJECT
serum from random three subjects was mixedwith or without 2 μg of tau, MAP, or MBP in A healthy 50-year-old male professional 100 μl PBS and rotated overnight at 4◦C. The airline pilot, with 25 yr and approximately serum/protein mix was centrifuged at 12,000 15,000 cumulative hours of flying, had been × g to pellet any immune complexes. The on vacation for 2 mo and did not fly during supernatant was then removed and used for that period as a passenger. Table 1 shows flying Western blotting.
activity, serum sampling, and clinical conditionof the pilot. In total, four serum samples weretaken in this study. The pilot was symptom free prior to the flight in question, felt "fit to fly," and Optical density measurement for subjects provided consent to participate in the study and and healthy controls was divided by serum the first serum sample number 1 at time "0" albumin density concentration; this value for before flying.
each subject was normalized to controls and He then embarked on a set of flights total- expressed as fold-change from healthy controls.
ing 45 h in 10 d, during which he reported Thus, the results are expressed as mean values episodes of air emissions. Average concentra- of triplicate assays of optical density arbitrary tion of TCP isomers in cabin air during these units normalized to albumin optical density as flights was 0.65 ng/m3 (Spectrex PAS 500 + fold of healthy controls.
SKC 106 Chromosorb test tube); dust on a sam-ple tissue from the aircraft floor yielded 1270 ngTCP isomers. (TNO, Utrecht, The Netherlands).
Controls and Subjects
His only complaint at that time was bad mem- Under a protocol approved by the ory. He gave a serum sample number 2 at Institutional Review Board (IRB) at Duke University Medical Center, sera were collected He continued to fly for 9 mo despite from 12 healthy controls, referred to as controls worsening of his memory deficits. A month below, and 34 flight crew members, referred to later, he complained of a sudden deafness AUTOANTIBODIES IN SERA OF FLIGHT CREW
TABLE 1. Flying Activity, Serum Sampling, and Clinical Condition of the Case Study Pilot
No symptoms, able to fly 2, Onset of memory deficits After the pilot had flown 45 h total over a period of 10 d. Exposure to air emission; average concentration of TCP isomers during these flights was incabin air 0.65 ng/m3 and in cabin dust 1270 ng of TCP isomers. The onlycomplaint was bad memory.
Worsening of memory More symptoms: Nine months later, after having flown normal duties during the following months, memory deficits became worse.
Deafness, vertigo After another month (total of 10 mo): sudden deafness and vertigo on one side.
He was grounded as a result.
3, Severe symptoms After a period of 6 mo, with extended spells of nausea, vomiting, nystagmus, and loss of equilibrium, neurosurgery was suggested (not done) on theaffected inner ear leading to a permanent state of "unfit to fly.". Full-fledgedsymptoms.
Onset of recovery After 1.5 months (at 17.5 months of first sample) of treatment, clinical improvement was noted; vomiting stopped and he could walk upright again,without falling over to one side.
He became fit to fly and regained his Airline Transport Pilot License Medical Certificate and is still able to perform his flying duties and remain free ofsymptoms, while on a regular daily treatment. Recovery.
and vertigo on one side. As a result, the pilot was grounded, 10 mo after giving the first The results of this descriptive study report serum sample. During the following 6 mo, with an association between self-reported neuro- extended spells of nausea, vomiting, nystag- logic deficits and levels of autoantibodies mus and loss of equilibrium, and inner ear against neuron- and glia-specific proteins in problems, he was given a permanent state of sera from a sample of flight crew members "unfit to fly". He gave the third serum sam- (pilots and flight attendants).
ple at "16 months" after the first serum sam-ple with severe symptoms. With medical care,vomiting stopped 1.5 mo later; he could walk Specificity of Sera Autoantibodies
upright again, without falling over to one side.
To detect the presence and specificity of This was followed by recovery, becoming fit autoantibodies in sera samples, a study was ini- to fly, and regaining his Airline Transport Pilot tially carried out to demonstrate the specificity License Medical Certificate. He is still able to of serum autoantibodies to the tested target perform his flying duties and remains free of proteins: tau, MAP-2, or MBP; the results are symptoms while still remaining under medi- presented in Figures 1A–1E. Human serum cal care. He gave the fourth serum sample at (unbound) from a subject with neurological deficits showed increased band signal in tau,MAP-2, and MBP (Figure 1A). When nor- mal rabbit serum was used no band sig- Grouped data are reported as mean ± stan- nals were detected in tau, MAP-2, and MBP dard error. The values from subjects were com- (Figure 1B). The serum bound to tau elimi- pared to controls using a paired t-test. Mean nated the tau band in the Western blot, while values for autoantibodies from the subject the band of MAP-2 or MBP was present and group were compared to controls using two- not affected (Figure 1C). The serum bound way analysis of variance (ANOVA; SigmaStat, to MAP-2 eliminated the MAP-2 band in the Systat Software). A p value <.05 was set as the Western blot while the band of tau or MBP was criterion for significance.
present (Figure 1D). The serum bound to MBP M. B. ABOU-DONIA ET AL.
Tau MAP MBP Tau MAP MBP Tau MAP MBP Tau MAP MBP Tau MAP MBP FIGURE 1. Characterization of presence and specificity of autoantibody in human serum samples. (A) Western blot of unbound serum
shows band signals in tau, MAP, and MBP. (B) Normal rabbit serum shows no band signals detected. (C) Serum bound to tau shows no
band signal with tau protein. (D) Serum bound to MAP shows no band signal with MAP protein. (E) Serum bound to MBP shows no band
signal with MBP.
eliminated the MBP band in the Western blot and ear ringing. Between 12% and 15% of sub- while the bands of tau and MAP-2 were present jects reported depression, tachycardia, slurred (Figure 1E). These results indicate that each speech, nausea, and urinary frequency. The autoantibody in the serum was specifically neu- following complaints were cited by 9% of tralized by its target protein in sera samples and subjects: speech/spelling difficulties, dyslexia, was no longer available to bind to the epitope fear/panic, tremors, and skin problems. Six per- present in the protein on the Western blot. This cent of subjects complained of stress, stomach confirmed that the assay used in this study was pain, chemical sensitivity, and sexual impair- specific and reliably determined autoantibodies ment. Only 3% of subjects reported a single against tested proteins in sera samples.
complaint of: falling asleep, hair loss, Herpesafter flight, mood swinging, temperature con-trol, diarrhea, or high blood pressure. Many of Self-Reported Clinical Symptoms
theses symptoms persisted long after exposure.
by Subjects
The subjects reported that 2–4 wk after
exposure to air emissions they went to physi- Autoantibodies in Sera from Subjects
cians with initial symptoms related to choliner- and Controls
gic toxicity; however, the individuals continued Increased levels of these autoantibodies to have chronic symptoms. Figure 2 shows the were detected in subjects who reported symp- self-reported complaints of the airline crews.
toms related to their exposure to air emis- The hallmark of their symptoms consisted of sions in aircrafts compared to healthy con- the following three complaints, which were trols. Table 2 and Figure 3 present the levels reported by more than half of the subjects: of the sera-circulating IgG-class autoantibodies memory deficits, headaches, and fatigue. The against neuronal and glial proteins from con- frequencies of these three symptoms were trols and flight crew members. Sera from higher than the following complaints that were healthy controls had no or low levels of circulat- reported by approximately one-third of the ing autoantibodies to nervous system proteins.
subjects: muscle weakness/pain, imbalance, In contrast, there were significant increases in respiratory problems, and tingling hands and levels of autoantibodies of all tested proteins in feet. Approximately 20% of subjects reported sera of the subjects compared to healthy con- the following complaints: dizziness, vision trols. Mean levels of autoantibodies in the sub- problems, anxiety, confusion, anger/aggression, jects and controls are presented in Table 2 and AUTOANTIBODIES IN SERA OF FLIGHT CREW
High blood Pres.
Temperature Con.
Herpes after flight Sexual Impairment Chemical Sensitivity Frequent Urination Tingling hand fee Respiratory Prob.
Percentage of Complaint Frequency Reported by 34 Aircrew Members
FIGURE 2. Frequency of complaints reported by 34 flight crew members (color figure available online).
TABLE 2. Sera Autoantibodies Against Neuronal and Glial Proteins From Subjects and Controls
Autoantibodies to proteins Microtubule-associated protein-2 (MAP-2) 6.20 ± 0.77a Myelin basic protein (MBP) 5.65 ± 0.72a 4.18 ± 0.48a Glial fibrillary acidic protein (GFAP) 3.41 ± 0.53a Neurofilament proteins (NFP) 3.10 ± 0.43a 0.45 ± 0.07a Note. Autoantibodies are expressed as optical density arbitrary units normalized to albumin in each human serum, and represent the mean values ± SE of triplicate assays.
aSignificant at p < .001.
were in descending order: MAP-2 > tubulin > serum sample with severe symptoms, and (E) MBP > tau > GFAP > NFP > S100B.
the pilot at 21 months, after the first serumsample following recovery.
Table 3 quantifies the results of Western CASE STUDY SUBJECT
immunoblots of autoantibodies to nervous- Figure 4 presents the results of Western system proteins for all four serum sam- immunoblots of autoantibodies against the ples. Results show significant increases in tested nervous system proteins in sera of a autoantibodies against nervous-system-specific control and case-study pilot before and after proteins, 12 d after flying and exposure to air exposure to cockpit air emissions: (A) control, emissions, in the following descending order: (B) the symptoms-free pilot at time "0," (C) the tubulin > MBP > MAP-2 > tau > S-100 > pilot after 12 h of flying after exposure to air GFAP. Data also demonstrate that after 16 mo emission, (D) the pilot after 16 mo from first of flying with severe symptoms compared to M. B. ABOU-DONIA ET AL.
S-100 > tubulin > MBP > GFAP. In con-trast, after recovery, only autoantibodies againsttubulin and MBP were still higher than beforeexposure levels, but at lower levels in serumtaken at 21 mo than in earlier serum sam-ples. It is noteworthy that when the original twosera samples, stored in a −70◦C freezer, wereassayed 2 yr after their collection, there waslittle change in their levels of autoantibodies.
FIGURE 3. The levels of the sera circulating Ig-G-class
autoantibodies against neuronal and glial proteins from controlsand flight crew members. The results are expressed as means of Although this study was designed to be optical density arbitrary units normalized to albumin optical den-sity from each serum as fold of healthy controls and represent descriptive rather than statistically powered, means ± SE of triplicate assays (color figure available online).
statistically significant elevations in serumautoantibodies to neuronal and glial proteins levels at "0" serum, the pilot's serum still con- were detected in sera of the subjects (pilots tained higher levels of autoantibodies against and attendants) who were exposed to air the following nervous-system-specific proteins: emissions during their flights and subsequently FIGURE 4. Western immunoblots of autoantibodies against tested nervous system proteins in sera of control and case-study pilot before
and after exposure to cockpit air emissions: (A) control, (B) the pilot serum before flying, time "0," (C) the pilot after "12 days" of flying,
(D) the subject "16 months" after the first sample, and (E) the subject "21 months" after the first sample.
TABLE 3. Sera Autoantibodies Against Neuronal and Glial Proteins From Case-Study Pilot Before and After Exposurea
12 d after exposure 16 mo after exposure 21 mo after exposure exposure, levela aAutoantibodies are expressed as optical density arbitrary units normalized to albumin in each human serum, and represent the mean values of triplicate assays.
bFold change from values before exposure at time "0."cValues showed significance at p < .001.
AUTOANTIBODIES IN SERA OF FLIGHT CREW
developed neurologic symptoms compared to neurodegeneration above the threshold level healthy controls. The early symptoms such to induce neurologic deficits and release of as shortness of breath, irritation of eye, nervous system-specific proteins leading to for- nose, and throat, headache, nausea, dizzi- mation of autoantibodies and release into cir- ness, stomach cramping, and muscle weakness reported by the subjects are consistent with Increased levels of autoantibodies circu- OP-induced cholinergic neurotoxicity. Chronic lating in sera of the subjects who reported symptoms included headache, memory impair- symptoms related to their exposure to air emis- ment, vision changes, vertigo, neuromuscular sions in aircrafts compared to healthy controls pain, fatigue, and tremors and are in agreement followed the pattern given next: with OPIDN and/or OPICN (Abou-Donia,2003). The results for healthy controls are in • Autoantibodies to MBP, an abundant mem- agreement with previous finding in healthy brane proteolipid produced by oligoden- individuals of no or low-level quantities of droglia in the CNS and Schwann cells in the circulating serum autoantibodies to neuronal PNS (Jauch et al., 2006), showed the high- and glial proteins (Ingram et al., 1974), sug- est level in subjects compared to controls.
gesting that controls had no or little expo- These findings correlate with demyelination sure to OP. In contrast, marked increases in following axonal degeneration in both CNS autoantibodies to nervous-system-specific pro- and PNS that was induced by exposure to teins were observed in pilots and attendants OPs (Abou-Donia, 1981).
compared to controls. These elevations in the • MAP-2 proteins are present almost exclu- autoantibodies were consistent with their neu- sively in the somatodendritic compartments rological complaints and are listed in descend- on neurons and these exhibited high lev- ing order: MBP, MAP-2, tubulin, NFP, GFAP, tau, els of autoantibodies to MAP-2 in the sub- jects. The microtubule-associated proteins, Although preexposure serum samples were MAP-2 and tau, function in promoting poly- unavailable, it is unlikely that a single exposure merization and stabilization of microtubules or an exposure for a few days before sampling in axons, cross bridge neurofilaments, and would yield the results of IgG autoantibodies microtubules connecting themselves to each presented in Figure 3. The differences in other. These functions maintain axonal trans- autoantibody concentrations reported are most port (Hoshi et al., 1988).
likely the result of nervous-system damage, • Autoantibodies to tubulin which is present rather than the product of time between in virtually all eukaryotic cells in addition to exposure and sampling. The development of neurons exhibited high levels in flight crew autoantibodies may be likely to result from members. Microtubules are composed of α- release of nervous-system-specific proteins pro- and β-tubulin that constitute approximately duced by tissue injury following multiple expo- 10% of total brain proteins, and are respon- sures to air emissions, over a long time.
sible for axonal migration and longitudinal Production of autoantibodies in flight-crew per- growth and are involved in axonal transport sonnel seems to be an ongoing process over (Laferrière et al., 1997; Damodaran et al., an extended period of exposure to air emis- 2009, 2011).
sions before onset of symptoms and seeking • Increased autoantibodies to neurofilaments medical treatment. Initially, little IgG is formed; in subjects are in agreement with the finding cells producing antibodies need to go through that their destruction is involved in neurode- class-switching before producing IgG (Pollard generation (Jensen et al., 1992, Brady, 1993).
et al., 2010). Following immunization (deliber- NFP subunits are the major component of ate or, in this case, accidental), IgG titers rise the neuronal cytoskeleton, accounting for over time. Therefore, it is concluded that recent 85% of total protein in neuronal cell (Fuchs exposure of subjects to air emissions produced and Cleveland, 1998); NFP consist of three M. B. ABOU-DONIA ET AL.
polypeptides: low-molecular-weight (NF-l), neuroprotective capacity. Such findings were middle or medium-molecular weight protein documented in cases of dementia, particu- (NF-M), and outer or high-molecular weight larly Alzheimer's disease (Griffin et al., 1989), protein (NF-H) (Lee et al., 1988). NF sub- schizophrenia and major depression (Grabe units regulate axonal caliber; neurofilaments et al., 2001), and mania (Machado-Vieira therefore affect both axonal transport and et al. 2002).
neuronal function (Tagliaferro et al., 2005).
• The levels of autoantibodies to tau proteins The case study of the one pilot demonstrates observed in subjects were less than those the temporal relationship between exposure against MAP-2. Tau proteins are cytoskele- to the airliner's air emissions, development tal proteins localized primarily in the axonal of neurologic deficits, and increased serum compartment in neuronal cells, and are autoantibodies against nervous system specific composed of six isoforms. Tau proteins proteins. The timing of when serum samples (1) bind to axonal microtubules to form were taken relative to exposure is important microtubule bundles, (2) are more abundant to establish a plausible link between expo- in white matter than gray matter, (3) are ele- sure, damage, and presence of IgG circulating vated in the cerebrospinal fluid (CSF) and autoantibodies. It is not likely that blood sam- serum following traumatic brain injury (TBI) ples taken within days of exposure would con- (Liliang et al., 2010), and (4) are used for tain IgG circulating autoantibodies to neoanti- diagnosis of Alzheimer's disease (Shiiya et al., gens at the levels found in this study. The results of the pilot's serum exhibit high levels • Autoantibodies to astrocytic proteins—GFAP of autoantibodies to nervous system proteins and S-100—were significantly elevated in 12 d after exposure to air emissions. At that flight crew members compared to controls, time he exhibited only memory deficits, sug- although less than neuronal proteins lev- gesting that autoantibodies production was an els. Increased levels of autoantibodies in ongoing process and resulted from the break- serum to GFAP are associated with gliosis.
down of nervous system proteins over a long GFAP is released from astrocytes after CNS period of time during the pilot's 25 yr and injury, cellular disintegration, and degrada- 15,000 of cumulative flying hours. Further, high tion of the cytoskeleton (Kovesdi et al., 2010).
levels of IgG autoantibodies to nervous-system- Elevated levels of GFAP are regarded as a specific proteins were still detected in serum nonspecific biomarker for brain injury in sev- samples taken 16 mo after the first serum sam- eral CNS diseases including dementia (Eng, ple. At that time he exhibited severe symptoms and Ghirnikar, 1994), brain infarction (Aurell, that were related to nervous-system damage et al., 1991), Lyme neuroborreliosis (Dotevall and subsequent autoantibodies formation. His et al., 1999), and neuropsychiatric disorders condition began to improve 17.5 mo after (Ahlsen et al., 1993).
the first serum sample and was completely • S100B autoantibodies were elevated in sera recovered by 21 mo when the last serum of subjects. S-100B interacts with and sta- sample was taken. Autoantibodies against the bilizes microtubule-associated proteins, tau, nervous system proteins at 21 months were and MAP-2. S100B is labeled as a marker of lower than found in previous serum samples.
generalized BBB dysfunction (Kapural et al., The results from this case study subject indi- 2002). Traumatic acute injury that results cate that improvement in the clinical condition, in extensive destruction of astrocytes leads and even recovery, are possible within 21 mo to a significant release (50- to 100-fold) of following nervous system injury. This improve- S100B into serum, whereas S100B levels ment may be followed by assaying the subject's in psychiatric disorders were approximately serum autoantibodies levels.
threefold higher in patients compared to con- The clinical improvement observed in the trols (Arolt et al., 2003), correlating with a pilot may be attributed to (1) regeneration of AUTOANTIBODIES IN SERA OF FLIGHT CREW
the PNS, (2) regeneration of the GFAP- and TCP and tri-n-butyl phosphate (Solbu et at, S100B-forming astrocytes, and (3) other CNS 2007). The presence of TCP and TOCP in cabin neuronal cells assuming the function of dam- air on commercial and military aircraft was con- aged cells (Abou-Donia 1981, 2003). Although firmed by in-flight air sampling in the absence clinical improvement was observed in the of overt adverse symptoms (van Nettten, 1998; pilot's CNS injury, the loss of neurons may 2009; IEH, 2011).
have rendered his CNS more prone to dam- The present results are consistent with the age following any future chemical exposure, development of neuronal damage and gliosis including air emissions. Improvement in the in pilots and attendants. The fivefold increase pilot's health was accompanied by the return of in autoantibodies against S100B is in agree- most autoantibodies to nervous system proteins ment with development of a recent brain injury to their preexposure levels, except for those followed by long-term neurological deficits against tubulin and MBP. These changes sug- (Arolt et al., 2003). The temporal rise in both gest some neuronal recovery consistent with no autoantibodies and neurologic deficits suggests further chemical exposure. The persistence of a pathophysiologic connection between expo- autoantibodies against tubulin may be related sure to cabin air emissions, neuronal degenera- to the presence of tubulin in all eukaryotic tion, and reported complaints. Increased num- cells in addition to neurons. The observation bers of autoantibodies against neurofilament, that autoantibodies against tubulin and MBP tau, tubulin, and myelin basic proteins, which were less than right after exposure suggests that are biomarkers for axonal degeneration, in axonal degeneration and demyelination may brain regions such as the cerebral cortex have peaked and were not continuing.
account for motor and sensory abnormalities, It is possible that a low-level, symptom- ataxia, weakness, and loss of strength reported free exposure might result in similar patterns by the subjects. Damage to the hippocam- of autoantibodies. If that does occur, then a pal circuitry leads to learning and memory numerical rise in autoantibodies may only sig- deficits. Neuronal degeneration of the limbic nal exposure but not actual damage, or it may system and central motor system associated reflect ongoing chronic exposure that results in with mood, judgment, emotion, posture, loco- neurodegeneration below the threshold where motion, and skilled movements results in psy- neurologic deficits occur. This observation is chiatric disorders. Autoantibodies against GFAP consistent with the presence of autoantibodies are elevated in CNS diseases including demen- against some nervous-system proteins in the tia and brain infarction. Finally, the elevation in pilot's serum prior to episodes of toxic air S100B levels in flight crew members is consis- emissions and absence of observable neuro- tent with psychiatric disorders occurrence.
logic deficits. This finding is also in agreement The present results are in agreement with with detection of low-level exposures to TCP a study that detected autoantibodies to NFP on aircraft that do not result in overt acute in a child who became quadriplegic fol- symptoms (IEH, 2011). Of 100 flights stud- lowing exposure to TOCP (Abou-Donia and ied on 4 aircraft, detectable airborne levels of Garretson, 2000) and with another investiga- these chemicals were found for TOCP on 14, tion that detected increases in myelin of PNS TCP (non-TOCP, multiple isomers) on 23, and and CNS in personnel chronically exposed to TBP on 73. This observation is also in agree- chlorpyrifos (Thrasher et al., 2002). In addi- ment with recent detection of plasma butyryl- tion, autoantibodies against NFP, GFAP, and cholinesterase (BChE)-phosphorylated adduct MBP were detected in the serum of a 16-yr-old with cresyl saligenin phosphate (a biomarker for boy poisoned with the OP insecticide methami- TOCP exposure) in jet airplane passengers who dophos who developed OPIDN (McConnell did not have clinically overt neurologic symp- et al., 1999). Autoantibodies to NFP, MBP, and toms (Liyasova et al., 2011). Air samples col- GFAP were elevated in hens that developed lected from aviation mechanics areas contained OPIDN following exposure to phenyl saligenin M. B. ABOU-DONIA ET AL.
phosphate, the active neurotoxic metabolite of et al., 1984). Increased phosphorylation of tau TOCP (El-Fawal et al., 1999).
diminishes the ability to bind to microtubules Since the recognition of TOCP-induced and results in destabilization with subsequent neurotoxicity, designated as OPIDN in 1981 axonal degeneration (Gupta and Abou-Donia, (Abou-Donia, 1981), numerous studies have 1999). Enhanced phosphorylation of tubulin been carried out to elucidate mechanisms prevents its binding to MAP-2 or its poly- of action (MOA). Because early studies on merization to microtubules (Wandosell et al., the involvement of esterases, including AChE 1986) and induces their aggregation into (Bloch and Hottinger, 1943), BChE (Earl and twisted polymers distinct from microtubules Thompson, 1952), and neurotoxicity target (DeLorenzo et al., 1982). Hence, chlorpyrifos- esterase (NTE; Johnson 1969), did not enhance induced tubulin phosphorylation that did not the understanding of MOA of OPIDN, stud- dephosphorylate formed stable adducts (Jiang ies in the past 30 years focused on kinases.
et al., 2010). Increased phosphorylation of The results of these studies identified a major neurofilaments prevents their assembly into fil- role for Ca2+-calmodulin kinase II (CaMKII) in aments (Hisanaga and Hirokawa, 1990); how- the pathogenesis of OPIDN. An early event ever, these neurofilaments form aggregates in OPIDN is increased Ca2+ concentration (Jensen et al., 1992; Gupta et al., 2000a) and in neuronal mitochondria of hen spinal cord exhibit slow axonal transport (Gupta et al., (LoPachin et al., 1988). This is followed by 1997). This abnormal axonal transport is also enhanced autophosphorylation (Patton et al., consistent with inhibition of caplain activity 1983, 1985, 1986), by elevated CaMKII activ- in hen sciatic nerve (Gupta and Abou-Donia, ity (Lapadula et al., 1991, 1992; Abou-Donia 1995a), leading to a decrease of neurofilament et al., 1993) and mRNA expression (Gupta proteins in spinal cord of hens after treatment et al., 1998), and by increased activity of pro- with DFP (Gupta and Abou-Donia, 1995b).
tein kinase A (PKA; Gupta and Abou-Donia, These sequences of events lead to axonal 2001) and c-fos mRNA (Gupta et al., 2000b) degeneration and subsequent demyelination.
in brain and spinal cord of hens treated The results of this descriptive study support with TOCP or O,O-diisopropyl phosphorofluo- an association between neurologic deficits and ridate (DFP). Activated CaMKII produces hyper- levels of autoantibodies against neuron- and phosphorylation of cytoskeletal proteins: MAP- glia-specific proteins circulating in sera from a 2 (Patton et al., 1983, 1985, 1986), tau small cross-sectional sample of affected flight (Gupta and Abou-Donia, 1999), α- and β- crew personnel compared to a small group tubulin (Gupta and Abou-Donia, 1994; Suwita of healthy controls. The results of testing four et al., 1986a, 1986b), neurofilament triplet pro- samples from a single pilot at different time teins (Gupta and Abou-Donia, 1995a; Gupta points suggest a temporal association between et al., 1999), and myelin basic protein (Abou- exposure and biological damage. Data suggest Donia, 1995). This CaMKII-mediated aber- that, although not diagnostic for a specific ill- rant phosphorylation of cytoskeletal proteins ness, the presence of circulating autoantibodies fits all of the criteria for OPIDN such as against neuronal and glial proteins may serve as test compound specificity, dose dependence, further confirmation of chemical-induced ner- time course of clinical condition, species vous system injury in the absence of other specificity, and age sensitivity (Abou-Donia and neurologic diseases. These autoantibodies also Lapadula, 1990). Aberrant hyperphosphoryla- may be used to monitor the progression of tion leads to alterations in these proteins that injury and recovery. Since autoantibodies iden- are pathognomic representation of OPIDN.
tify damage to specific cells, these changes may Elevated phosphorylation of MAP-2 reduces help to identify cellular mechanisms underlying its ability to induce tubulin polymerization to form microtubules (Hoshi et al., 1988) and It needs to be emphasized that although promotes disassembly of microtubules (Burns this study has presented intriguing findings, it AUTOANTIBODIES IN SERA OF FLIGHT CREW
has its limitations. The sample size in this study human serum following chemically induced was too small to examine important covariates neurologic disorder: A case report. Environ. like age and exposure. Another limitation in this Epidemiol. Toxicol. 2: 1–5.
study is the lack of availability of the identity of Abou-Donia, M. B., and Lapadula, D. M.
the chemicals and the levels to which the flight 1990. Mechanisms of organophosphorus crew members were exposed. Development ester-induced delayed neurotoxicity: Type I of biomarkers will help assess exposure, and and Type II. Annu. Rev. Pharmacol. Toxicol.
also may help determine individual differences 30: 404–440.
which may affect whether or not clinical ill- Abou-Donia, M. B., Viana, M., E., Gupta, nesses develop (Schoper et al., 2010; Liyasova et al., 2011; Marisillach et al., 2011).
Although the findings of the study have certain limitations, it is clear that certain risks phosphorylation of cytoskeletal proteins may be associated with exposure to cabin air following a single subcutaneous injection of emissions. Certain groups, including infants, the diisopropyl phosphorofluoridate (DFP) in elderly, and the chronically ill, that are espe- hens. Neuochem. Int. 22: 165–173.
cially susceptible to toxic exposure to pyrolyzed Abou-Donia, M .B., Wilmarth, K. R., Jensen, engine oil and hydraulic fluid need to be K. F., Oehme, F. W., and Kurt, T. L. 1996.
protected by either operating planes with a Neurotoxicity resulting from coexposure to nonbleed ventilation system or filtering the pyridostigmine bromide, DEET, and perme- engine bleed air before it gets to the cabin and thrin: Implications of Gulf War chemical exposures. J. Toxicol. Environ. Health 48:35–56.
Ahlsen, G., Rosengren, L., Belfrage, M. Palm, A. Haglid, K., Hamberger, A., and Gillberg, C. 1993. Glial fibrillary acidic protein in the Abdel-Rahman, A., Shetty, A. K., and Abou- cerebrospinal fluid of children with autism Donia, M. B. 2002. Acute exposure to sarin and other neuropsychiatric disorders. Biol. increases blood brain barrier permeability Psychiatry 33: 734–743.
and induces neuropathological changes in the rat brain: Dose response relationship.
Industrial Hygienists. 1986. Documentation Neuroscience 113: 721–741.
of the threshold limit values and biological Abou-Donia, M. B. 1981. Organophosphorus exposure indices. Cincinnati, OH: ACGIH.
ester-induced delayed neurotoxicity. Annu. Arolt, V., Peters, M., Erfurth, A., Weismann, Rev. Pharmacol. Toxicol. 21: 511–548.
M., Missler, U., Rudolf, S., Kirchner, H., Abou-Donia, M. B. 1993. The cytoskeleton as and Rothermundt, M. 2003. S100B and a target for organophosphorus ester-induced response to treatment in major depression: A delayed neurotoxicity (OPIDN). Chem. Biol. pilot study. Eur. Neuropsychopharmacol. 13: Interact. 87: 383–393.
Abou-Donia, M. B. 1995. Involvement of Aurell, A., Rosengren, L. E., Karlsson, B., cytoskeletal proteins in the mechanisms Olsson, J. E., and Zbornikova, V., and Haglid, of organophosphorus ester-induced delayed K. G. 1991. Determination of S-100 and glial neurotoxicity. Clin. Exp. Pharmacol. Physiol.
fibrillary acidic protein concentration in cere- 22: 358–359.
brospinal fluid after brain infarction. Stroke Abou-Donia, M. B. 2003. Organophosphorus 22: 1254–1258.
ester-induced chronic neurotoxicity. Arch. Environ. Health 58: 484–497.
Abou-Donia, M. B., and Garretson, L. K. 2000.
Hummung durch Tri-o-kresyl-phosphat. Z. Detection of neurofilament autoantibodies in Vitaminforsch. 13: 142–155.
M. B. ABOU-DONIA ET AL.
Brady, S. T. 1993. Motor neurons and and mass spectrometry. J. Chromatogr. A neurofilament in sickness and health. Cell 1200: 211–216.
Dotevall, L., Hagberg, L., Karlsson, J. E., and Burns, R. G., Islam, K., and Chapman R.
Rosengren, L. E. 1999. Astroglial and neu- 1984. The multiple phosphorylation of the ronal proteins in cerebrospinal fluid as mark- microtubule-associated protein MAP-2 con- ers of CNS involvement in Lyme neuroborre- trols the MAP2: Tubulin interaction. Eur. J. liosis. Eur. J. Neurol. 6: 169–178.
Biochem. 141: 609–615.
Earl, C. J., and Thompson, R. H. S. 1952.
Carletti, E., Schopfer L. M., Colletier, J.-P., The inhibitory action of tri-ortho-cresyl phos- Froment, M.-T., Nachon, F., Weik, M., phate and cholinesterases. Br. J. Pharmacol. Lockridge, O., and Masson, P. 2011.
Reaction of cresyl saligenin phosphate, El-Fawal, H. A., Waterman S. J., De Foe, A., the organophosphorus agent implicated and Shamy, M. Y. 1999. Neuroimmuno- cholinesterases: Mechanistic studies employ- neurotoxicity and autoimmune mecha- ing kinetics, mass spectrometry, an x-ray nisms. Environ. Health Perspect. 107(suppl.
structure analysis. Chem. Res. Toxicol. 24, 5): 767–775.
Eng, L. F., and Ghirnikar, R. S. 1994. GFAP and Cox, L., and Michaelis, S. 2002. A survey astrogliosis. Brain Pathol .4: 229–237.
of health symptoms in BAe 146 aircrew.
Freudenthal, R. I., Rausch, L., Gerhart, J. M., J. Occup. Health Safety Aust. N. Z. 18: Barth, M. L., Mackerer, C. R., and Bisinger, E. C. 1993. Subchronic neurotoxicity of oil Craig, P. H., and Barth, M. L. 1999. Evaluation formulations containing either tricresyl phos- of the hazards of industrial exposure to tricre- phate or tri-orthocresyl phosphate. J. Am. syl phosphate. J. Toxicol. Environ. Health B 2: College Toxicol. 12: 409–501 Fuchs, E., and Cleveland, D. W. 1988. A struc- Damadaran, T. V., Attia, M. K. M., and Abou- tural scaffolding of intermediate filaments in Donia, M. B. 2011. Early differential cell health and disease. Science 279:514–519.
death and survival mechanisms initiate and Grabe, H. J., Ahrens, N., Rose, H. J., contribute to the development of OPIDN: A Kessler, C., and Freyberger, H. J. 2001.
study of molecular, cellular, and anatomical Neurotrophic factor S100beta in major parameters. Toxicol. Appl. Pharmacol. 256: depression. Neuropsychobiology 44: 88–90.
Griffin, W. S. T., Stanley, L. C., Ling, C., Damodaran, T. V., Gupta, R. P., Attia, M. K., White, C., Macleod, V., Perrot, L. J., White, and Abou-Donia, M. B. 2009. DFP initi- C. L. III, and Aroaz, C. 1989. Brain inter- ated early alterations of PKA/p-CREB path- lukin 1 and S-100 immunoreactivity are ele- way and differential persistence of β-tubulin vated in Down's syndrome and Alzheimer's subtypes in the CNS of hens contributes disease. Proc. Natl. Acad. Sci. USA 86: to OPIDN. Toxicol. Appl. Pharmacol. 240: Gupta, R. P., Abdel-Rahman, A., Wilmarth, K.
De Lorenzo, R. J., Albert, J. P., and DeLucia, P. R.
W., and Abou-Donia, M. B. 1997. Alteration 1982. Ca2+/calmodulin Kinase dependent in neurofilament axonal transport in the filamentous polymerization of tubulin. Soc.
sciatic nerve of the diisopropyl phospho- Neurosci. 12th Annual Meeting Abstract, rofluoridate (DFP)-treated hens. Biochem. Minneapolis, MN, 281.
De Nola G, Kibby J., and Mazurek, W. 2008.
Gupta, R. P., Abdel-Rahman, A., Jensen, K.
Determination of ortho-cresyl phosphate iso- F., and Abou-Donia, M. B. 2000a. Altered mers of tricresyl phosphate used in aircraft expression of neurofilament subunits in turbine engine oils by gas chromatography diisopropyl phosphorofluoridate-treated hen AUTOANTIBODIES IN SERA OF FLIGHT CREW
spinal cord and their presence in axonal Hoshi, M., Akiyama, T., Shinohara, Y., Miyata, aggregates. Brain Res. 878: 32–47.
Y., Ogawara, H., Nishida, E., and Sakai, Gupta, R. P., and Abou-Donia, M. B. 1994. In H. 1988. Protein kinase C catalyzed vivo and in vitro effects of diisopropyl phos- phosphorylation of the microtubule-binding phorofluoridate (DFP) on the rate of hen domain of microtubule associated pro- brain tubulin polymerization. Neurochem. tein 2 inhibits its ability to induce tubulin Res. 19: 435–444.
Gupta, R. P., and Abou-Donia, M. B. 1995a.
Diisopropyl phosphorofluoridate (DFP) treat- Ingram, C. R, Phegan, K. J., and Blumenthal, ment alters calcium-activated proteinase H. T. 1974. Significance of an aging-linked activity and cytoskeletal proteins in the hen neuron-binding gamma globulin fraction of sciatic nerve. Brain Res. 677: 162–166.
human serum. J. Gerontol. 29: 20–27.
Gupta, R. P., and Abou-Donia, M. B. 1995b.
Institute of Environment & Health. 2011.
Neurofilaments phosphorylation and [125I] Aircraft cabin air sampling study: Parts 1 and calmodulin binding by Ca2+/calmodulin- 2 of the final report. Cranfield, England: dependent protein kinase in the brain sub- Institute of Environment & Health, Cranfield cellular fractions of diisopropyl phospho- rofluoridate (DFP)-treated hens. Neurochem. Jauch, E. C., Lindsell, C., Broderick, J., Fagan, Res. 20: 1095–1110.
S. C., Tilley, B. C., and Levine, S. R.
Gupta, R. P., and Abou-Donia, M. B. 1999. Tau 2006. Association of serial biochemical mark- phosphorylation by diisopropyl phospho- ers with acute ischemic stroke. Stroke 37: rofluoridate (DFP)-treated hen brain super- natant inhibits its binding with microtubules: Jensen, K. F., Lapadula, D. M., Anderson, Role of Ca2+/calmodulin-dependent pro- J. K., Haykal-Coates, N., and Abou-Donia, tein kinase II in tau phosphorylation. Arch. M. B. 1992. Anomalous phosphorylated Biochem. Biophys. 365: 268–278.
neurofilament aggregations in central and Gupta, R. P., and Abou-Donia, M. B. 2001.
peripheral axons of hens treated with tri- Enhanced activity and level of protein ortho-cresyl phosphate (TOCP). J. Neurosci. kinase A in the spinal cord supernatant Res. 33: 455–460.
of diisopropyl phosphorofluoridate (DFP)- Jiang, W., Duysen, E. G., Hansen, H., treated hen. Distribution of protein kinases and phosphatases in spinal cord subcellular Lockridge, O. 2010. Mice treated with fractions. Mol. Cell. Biochem. 220: 15–23.
chlorpyrifos or chlorpyrifos oxon have Gupta, R. P., Bing, G., Hong, J.-S., and Abou- organophosphorylated tubulin in brain and Donia, M. B. 1998. cDNA cloning and disrupted microtubule structures, suggesting sequencing of Ca2+/calmodulin-dependent a role for tubulin in neurotoxicity associated protein kinase IIα subunit and its expression with exposure to organophosphate agent.
in diisopropyl phosphorofluoridate (DFP)- Toxicol. Sci. 115: 183–193.
treated hen central nervous system. Mol. Johnson, M. K. 1969. A phosphorylation site in Cell. Biochem. 181: 29–39.
brain and delayed neurotoxic effect of some Gupta, R. P., Damodaran, T. V., and Abou- organophosphorus compounds. Biochem. J.
Donia, M. B. 2000b. c-fos mRNA induction 111: 487–495.
in the central and peripheral nervous system Kapural, M., Krizanac-Bengez, L., and Barnet, of diisopropyl phosphorofluoridate (DFP)- G. 2002. Serum S100beta as a possi- treated hens. Neurochem. Res. 25: 327–334.
ble marker of blood-brain-barrier disruption.
Hisanaga, S.-L., and Hirokawa, N. 1990.
Brain Res. 940: 102–104.
Dephosphorylation-Induced interactions of Kitzes, G. 1956. Cabin air contamination prob- neurofilaments with microtubules. J. Biol. lems in jet aircraft. Aviation medicine, J. Aero Chem. 265: 21852–21858.
Med. Assoc. 2: 53–58.
M. B. ABOU-DONIA ET AL.
Kovesdi, E., Lucki, J., Bukovics, P.,Orsolya, F., Toronto, Canada, Abstracts Proceedings, Pal, J., Czeiter, E., Szellar, D., Doczi, T., Vol. 4, 775.
Komoly, S., and Buki, A. 2010. Update on Machado-Vieira, R., Lara, D. R., Portela, protein biomarkers in traumatic brain injury L. V., Goncalves, C. A., Soares, J. C., with emphasis on clinical use in adults and Kapczinski, F., and Souza, D. O. 2002.
pediatrics. Acta Neurochir. 152: 1–17.
Elevated serum S100 protein in drug-free Laferrière, N. B., McRae T. H., and Brown D. L.
bipolar patients during first manic episode: A 1997. Tubulin synthesis and assembly in dif- pilot study. Eur.Neuropsychopharmacol. 12: ferentiating neurons. Biochem. Cell Biol. 75: Mackerer, C. R., Barth, M. L., Krueger, A. J., Lapadula, E. S., Lapadula, D. M., and Abou- Chawla, B., and Roy, T. A. 1999. Comparison Donia, M. B. 1991. Persistent alterations of neurotoxic effect and potential risks from of calmodulin kinase II activity in chicken oral administration or ingestion of tricresyl after an oral dose of tri-o-cresyl phosphate.
phosphate and jet engine oil containing tri- Biochem. Pharmacol. 42: 171–180.
cresyl phosphate. J. Toxicol. Environ. Health Lapadula, E. S., Lapadula, D. M., and Abou- A 57: 293–382.
Donia, M. B. 1992. Biochemical changes Marisillach, J., Richtter, R. S., Kim, J. H., in sciatic nerve of hens treated with tri-o- Stevens, R. C., MacCoss, M. J., Tomazela, D., cresyl phosphate: Increased phosphorylation Suzuki, S. M., Schopfer, L. M., Lockridge, of cytoskeletal proteins. Neurochem. Int. 20: O., and Furlong, C. E. 2011. Biomarkers of organophosphates (OP) exposures in Lee, V. M.-Y., Otvos, L., Jr., Carden, J. J., humans. Neurotoxicology 32: 656–660.
Hollosi, M., Duetzschold, B., and Lazzarini Mattie, D. R., Hoeflich, T. J., Jones, C. E., R. A. 1988. Identification of the major mul- Horton, M. L., and Whitmire, R. E. 1993.
tiphosphorylation sites in mammalian neu- The comparative toxicity of operational Air ron filaments. Proc Natl. Acad. Sci. USA 85: Force hydraulic fluids. Toxicol. Ind. Health 9: Liliang, P.-C., Liang, C.-L., Weng, H.-C., Lu, K., McConnell, R., Delgado-Tellez, E., Cuadra, Wang, K. W., Chen, H.-J., and Chang, J.-H.
R., Torres, E., Keifer, M., Almendarez, 2010. Proteins in serum predicts outcome J., Miranda, J., El-Fawal, H. A., Wolff, after severe traumatic brain injury. J. Surg. M., Simpson, D., and Lundberg, I. 1999 Res. 160: 302–307.
Lipscomb, J., Walsh, M., Caldwell, D., and methamidophos: Biochemical and neuro- Narayanan, L. 1995. Inhalation toxicity physiological markers. Arch. Toxicol. 73: of vapor phase lubricants. Report no.
AL/OE-TR-1997-0090. Wright-Patterson Air Montgomery, M. R., Wier, G. T., Zieve, F. J., and Force Base, OH: U.S. Air Force Armstrong Anders, M. W. 1977. Human intoxication fol- Laboratory, Occupational and Environmental lowing inhalation exposure to synthetic jet Health Directorate, Toxicology Division.
lubricating oil. Clin. Toxicol. 11: 423–426.
Liyasova, M., Li, B., Schopfer, L. M., Nachon, Murawski, J. T. L. and Supplee, D. S. 2008. An F., Masson, P., Furlong, C. E., and Lockridge, attempt to characterize the frequency, health O. 2011. Exposure to tri-o-cresyl phosphate impact, and operational costs of oil in the detected in jet airplane passengers. Toxicol. flight deck and cabin supply air on US com- Appl. Pharmacol. 256: 337–347.
mercial aircraft. J. Am. Soc. Test Mater., paper LoPachin, R. M., Lapadula, D. M., and Abou- Donia, M. B. 1988. Organophosphate Patton, S. E., O'Callaghan, J. P., Miller, D.
B., and Abou-Donia, M. B. 1983. Effect of ments in chicken peripheral axons. Society oral administration of tri-o-cresyl phosphate for Neuroscience 18th Annual Meeting, on in vitro phosphorylation of membrane AUTOANTIBODIES IN SERA OF FLIGHT CREW
and cytosolic proteins from chicken brain. J. Solbu, K., Thorud, S., Hersson, M., Ovrebø, S., Neurochem. 41: 897–901.
Ellingsen, D. G., Lundanes, E., and Molander, Patton, S. E., Lapadula, D. M., O'Callaghan, P. 2007. Determination of airborne trialkyl J. P., Miller, D. B., and Abou-Donia, M. B.
and triaryl organophosphates originating 1985. Changes in vitro brain and spinal cord from hydraulic fluids by gas chromatography- protein phosphorylation after a single oral mass spectrometry. Development of method- administration of tri-o-cresyl phosphate to ology for combined aerosol and vapor sam- hens. J. Neurochem. 45: 1567–1577.
pling. J. Chromatogr. A 17: 275–283.
Patton, S. E., Lapadula, D. M., and Abou- Suwita, W. L., and Abou-Donia, M. B. 1990.
Pharmacokinetics and metabolism of a single subneurotoxic dose of tri-o-cresyl phosphate.
neurotoxicity to enhancement of in vitro Arch. Toxicol. 64: 237–241.
phosphorylation of hen brain and spinal Suwita, E., Lapadula, D. M., and Abou-Donia, cord proteins. J. Pharmacol. Exp. Ther. 239: M. B. 1986a. Calcium and calmodulin- enhanced in vitro phosphorylation of hen Pollard, K. M., Haltman, P., and Kono, D. H.
brain cold-stable microtubules and spinal 2010. Toxicology of autoimmune diseases.
cord neurofilament triplet proteins after a sin- Chem. Res. Toxicol. 23: 455–466.
gle dose of tri-o-cresyl phosphate. Proc. Natl. Rayman, R. 2002. Cabin quality: An overview.
Acad. Sci. USA 76: 4350–4354.
Aviation Space Environ. Med. 73: 211–215.
Suwita, E., Lapadula, D. M., and Abou-Donia Ross, S. M. 2008. Cognitive function following M. B. 1986b. Calcium and calmodulin stim- exposure to contaminated air on commercial ulate in vitro phosphorylation of rooster brain aircraft: A case series of 27 pilots seen for tubulin and MAP-2 following a single oral clinical purpose. J. Nutr. Environ. Med. 17: dose of tri-o-cresyl phosphate. Brain Res. Rubey, W. A., Striebich, R. C., Bush, J., Centers, Thrasher, J. D., Heuser, G., and Broughton, P. W., and Wright, R. L. 1966. Neurotoxin A. 2002. Immunological abnormalities in formation from pilot-scale incineration of human chronically exposed to chlorpyrifos.
synthetic ester turbine lubricants with tricre- Arch. Environ. Health 57:181–187.
syl phosphate additives. Arch. Toxicol. 70: Wendosell, F., Serrano, L., Hernandez, M. A., and Avila, J. 1986. Phosphorylation of tubulin Schoper, l. M., Furlong, C. E., and Lockridge, by a calmodulin-dependent protein kinase. J. O. 2010. Development of diagnostics in the Biol. Chem. 261: 10332–10339.
search for an explanation of aerotoxic syn- Tagliaferro, P., Ramos, A. J., Onaivi, E. S, Evrard, drome. Anal. Biochem. 404: 64–74.
S. G., Lujilde, J., and Brusco, A. 2005.
Neuronal cytoskeleton and synaptic densi- Matsuzaki, K., and Yasuda, K. 2004.
ties are altered after a chronic treatment with Tau Protein in the cerebrospinal fluid is a cannabinoid receptor agonist WIN 55,212-2.
marker of brain injury after aortic surgery.
Brain Res. 1085: 163–176.
Ann. Thorac. Surg. 77: 2034–2038.
Van Netten, C. 1998. Air quality and health Smith, M. I., Elvove, I., Valaer, P. J., Frazier, W.
effects associated with operation of BAe H., and Mallory G. E. 1930. Pharmacologic 146-200 aircraft. Appl. Occup. Environ. Hyg. and chemical studies of the cause of the 13: 733–739.
so-called ginger paralysis. U.S. Public Health van Netten C. 2009. Design of a small air mon- Rep. 45: 1703–1716.
itor and its application in aircraft. Sci. Total Spillantini, M. G., and Goedert, M. 1998. Tau Environ. 407: 1206–1210.
protein pathology in neurodegenerative dis- van Netten C., and Leung V. 2001. Hydraulic eases. Trends Neurosci. 21: 428–433.
fluids and jet engine oil: Pyrolysis and M. B. ABOU-DONIA ET AL.
aircraft air quality. Arch. Environ. Health 56: Winder, C., and Balouet, J. 2002. The toxic- ity of commercial jet oils. Environ. Res. 89: Wandosell, F., Serrano, L., Hernandez, M. A., and Avila, J. 1986. Phosphorylation of tubulin Winder, C., Fonteyn, P., and Balouet, J. 2002.
by a calmodulin-dependent protein kinase.
Aerotoxic syndrome: A descriptive epidemi- J. Biol. Chem. 261: 10332–10339.
ological survey of aircrew exposed to in- Weiner, M. L., and Jortner, B. S. 1999. Organo- cabin airborne contaminants. J. Occup. phosphate-induced delayed neurotoxicity Health Safety Aust. N. Z. 18:321–338.
ot triarylphosphate. NeuroToxicology 20: Zurek, J., and Fedora, M. 2012. The usefulness of S100B, NSE, GFAP, NFH secretagogue and Winder, C. 2006. Hazardous chemicals on jet Hsp70 as a predictive biomarker of outcome aircraft: case study—Jet engine oils and aerot- in children with traumatic brain injury. Acta oxic syndrome. Curr. Topics Toxicol. 3: 65–88.
Neurochem. 154: 93–103.

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