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1. 1+1+1=300The Effect of Multiple Environmental Toxins on the DevelopingBrain, Bowel, and Immune System Cindy Schneider, MD
Medical Director
Center for Autism Research and Education
2. Regression
3. Emerging Symptoms digestive problems
self-limited diets
allergies
sleep disorders
hyperactivity
hypotonia
4. Environmental Factors infections
nutritional deficiencies
prenatal events
perinatal events
toxins
5. Toxins Lead
Mercury
Arsenic
Cadmium
Organoposphate pesticides
Alcohol
Tobacco
6.
Lead
7. Lead Lead pipes or solder
Brass
Pre 1978 paint
Soil
Crystal
Candle wicks
8. Lead Fish
Cigarette smoke
Ceramics
Toys
Lipstick
9. Lead Municipal water in more than 800 US cities has Pb levels exceeding EPA action level
Over half of US cities still have Pb lined pipes and/or Pb solder
10. Lead Toxicity and Pregnancy Outcomes Infertility
Miscarriages
Low birth weight
Preterm labor
Stillbirths
Macrocephaly
HTN at age 7-8
11. Lead Toxicity Mental retardation
Developmental delays
Hypertension/CAD/stroke
Kidney disease
Anemia
12. Lead Toxicity Adults absorb 10% of ingested lead
Children absorb up to 40%
Immature neurons are more at risk
Absorption increases when Fe, Ca, or Zn are deficient
Fetal concentrations = maternal
13. Symptoms of Lead Toxicity Anorexia
Constipation
Headaches
Sleep disorders
Joint pain/gout
Irritability
Tremor
14. Lead Toxicity Impairs mitochondrial function
Disrupts amino acid metabolism
Alters neurotransmiter metabolism
Inhibits microtubule synthesis
Causes NFT in prefrontal cortex, hippocampus, and cerebellum
15. Neurological InflammationDiana Vargas 2005 11 postmortem exams
Patients age 5-44
6 CSF studies on living patients
Activation of glial and microglial cells
Increased inflammatory cytokines
16. Neurological Sequelae Blood levels poor reflection of brain levels
Toxic at levels well below current acceptable blood level of 10
Children with blood level of 10 had IQs 7.4 points below children with levels of 1
17. University of BristolEmond A et al Archives of Dis in Child Sept 17, 2009 Measured lead levels in 488 2˝ y.o.
Performed IQ testing at age 7-8
Children with blood levels of 5-10:
Reading scores were 49% lower
Writing scores were 51% lower
Authors recommend lowering acceptable serum lead level to 0-5
18. Risk Factors for Lead Toxicity Young age
Pica: Fe, Ca, Zn deficiency
Smoking
Maternal fish consumption
ALAD2 allele (delta aminolevulinic acid dehydratase)
19. Washington DC 2001-2004 Pb contaminated drinking water in thousands of homes
> 400% increased in cases of Pb poisoning
2007 CDC study again documented high prevalence of Pb poisoning in DC children
20. Lead Toxicity and Brain Size Prospective study of 120 children
Gray matter volume was inversely proportional to Pb levels
Prefrontal cortex affected
Executive functioning
Impulse control
Mood
Males more affected
21. Cigarette Smoking Nicotine, lead, mercury, and cadmium
Increases risk of stillbirths, SIDS, preterm labor, IUGR, and placental abruption
Cord blood lead levels increase 15% for every 10 cigarettes smoked per day
Doubles cadmium content of breast milk
22. Screening for Lead Toxicity Delta aminolevulinic acid
Coproporphyrin
Serum lead
Hair lead level
EDTA challenge
23. Urinary Porphyrins Derivatives of heme synthesis
Levels increase with exposure to mercury and/or lead
Nataf found elevated in children with autism (n-106)
Geier identified elevated porphyrin levels in children with ASD (n=26) and CP correlated with CARS scores
J of Toxicology and Env Health, Part A 72: 1585-1591, 2009
24. Detoxification of Lead Primary excretion is in urine
Half life is 3-7 weeks in soft tissue, up to 20 years in bone
IV CaEDTA or oral DMSA
Glutathione
Optimize zinc levels
25.
Mercury
26. High Mercury Fish Tuna
Shark
Swordfish
Mackerel
Tilefish
27. Fish Intake 8% of US women of childbearing age have Hg levels above the EPA threshold of concern (5.8 mcg/L)
3 or more servings per month increase Hg level 4-fold
28. Other Sources of Mercury Amalgams
Coal burning power plants
Drinking water
Ear, nose, and eye drops
Fabric softeners
Fertilizers
Mascara
29. Other Sources of Mercury Latex paint prior to 1990
Fungicides and some pesticides
Thermometers
Fluorescent light bulbs
Thimerosal
30. Amalgam Fillings Release 43.5 mcg Hg/cm2/day
Chewing, grinding, brushing, and consuming hot food or liquids increase level of Hg vapors
May enter brain through CP
Infant hair Hg levels correlate with # of maternal fillings
31. Mercury Toxicity Accumulates in brain, kidneys, liver, heart, and blood
Half life in blood is 3 days
Suppresses T lymphocytes
Increases allergy/autoimmune responses
Fetal levels higher than maternal
32. Symptoms of Mercury Toxicity Tremor
Anorexia and weight loss
Agitation/mania
Insomnia
Speech disorders
Memory loss
Sensory sensitivities
33. Symptoms of Mercury Toxicity Poor coordination
Chewing
Swallowing
Gait
Blurred vision
Restricted visual fields
Involuntary motor movements
34.
Thimerosal
35. Thimerosal Toxicity Destroys tubulin in axons ? NFTs
Destroys actin
Neurotoxic at levels 10,000 times lower than those in vaccines
Toxicity increased by Ampicillin, Tetracycline, and acetaminophen
36. Thimerosal Toxicity Ethyl mercury in thimerosal inactivates intracellular proteins by binding to their cysteine SH groups
GSHs SH group binds to Hg and protects essential proteins
Hg bound to GSH is excreted in the urine and bile
37. Variation in Vulnerability Age/timing of exposure
Gender
Total body burden: cumulative and concurrent exposures
Nutritional status
Methylation and detoxification genetics
Lifestyle
Antibiotics, Tylenol, and other drug use
39. Jill James, PhD NAC and GSH protect against the toxicity of Hg in neuronal cells
33 children with ASD tested had low levels of methionine, cysteine, and GSH with high SAH
8 entered a trial of supplement designed to increase MS activity
41. Treating a Genetic Weakness 800 mcg of folinic acid BID and 1000 mg of betaine BID for 3 months
Methionine, cysteine, and SAM increased
GSH levels significantly improved,
but did not normalize
Further improvement noted with MeB12: GSH and cysteine levels normalized
42. Methionine Synthase Inhibited by thimerosal at levels well below those in vaccines
Providing methyl B12 bypasses this inhibition. Other forms of B12 do not.
Also inhibited by adenosine
43. Gender Females have higher MS activity
Females have higher GSH levels
Estrogen is protective
Testosterone increases toxicity of mercury
44.
MTHFR
46. Adding a methyl group CH3 Methylation:
49. MTHFR Alleles C677T: 50-60% less active than normal variant
Less common in females
A1298C and C677T mutations
frequent
50. MTHFR C677T Allele <1% of African Americans
20% of Italians
21% of US Latinos
11% of Irish Caucasians
13% of British Caucasians
8% of German Caucasians
10-14% of other Caucasians
11% of Asians
51. MTHFR C677T Allele RR of spina bifida = 1.8
Anencephaly and other cranial defects
Heart defects, cleft lip/palate, limb red
Down syndrome
Miscarriage
IUGR
Placental abruption
52. Decreased MTHFR Activity Heart disease, high cholesterol, high triglycerides
Diabetes and insulin resistance
Inflammatory bowel disease
Psychiatric disorders
Colon cancer and leukemias
Childhood brain cancers
54. RR of Autism C677T Allele: 2.8
C677T and A1298C alleles: 8
55.
Arsenic
56. Arsenic Toxicity Bladder, lung, kidneys, and colon cancer
Heart disease
10 PPB acceptable
Risk of carcinogenesis 1 in 2000
Up to 50 PPB allowed until 2006
57. Arsenic Chromated copper arsenate in pretreated lumber: stricter regulations put in place in 2004
Chicken: 75% are fed arsenic
Soil
Rice
58.
Cadmium
59. Cadmium Water pipes
Paints, glazes, and pigments
Nickel/cadmium batteries
Cigarettes: 0.1-0.2 mcg/cigarette
PVC
Rubber tires
Electroplating: nuts, bolts
Shellfish
60. Cadmium Dentures
Bridges
Levels often elevated in smokers and dentists
61. Cadmium Toxicity Hypertension
Kidney damage
Proteinuria
Glucosuria
Calciuria
Fatigue
Weight loss
Muscle weakness: poisons mitochondria
62. Cadmium Detoxification Primarily excreted through feces
Half-life in body 10-33 years
Zinc is protective
Oral DMSA or IV EDTA effective
Glutathione
63.
Alcohol
64. Alcohol 32% of infants born to heavy drinkers have birth defects
14% of infants born to moderate drinkers have birth defects
Individual variations in metabolism make risk impossible to calculate
65. Fetal Alcohol Syndrome IUGR
Microcephaly
MR or DD
Malformations of upper jaw and lip
Heart defects
Close-set eyes
67. Met Receptor
Tyrosine Kinase
68. Hepatocyte Growth Factor Embryogenesis
Metastasis
Regeneration of hepatic cells
Intestinal epithelial integrity
Immune function
GABA interneuron migration and organization
69. Embryogenesis Placenta
Liver
Muscle
Tolerance of foreign tissue
Development of cortex, hippocampus, and cerebellum
70. Regeneration of Hepatic Cells Up to 2/3 liver may be regenerated
Met mutant mice die after resection
Weak activity would compromise ability to clear toxins
71. Intestinal Epithelial Integrity HGF enhances epithelial proliferation
Inhibits apoptosis
Decreases inflammation
Suppresses Th1 cytokines: IL-12, IF-?, TNF-a
72. MET C Allele Associated with autism and GI disease, but not with autism without GI disease
MET protein levels are significantly decreased in temporal cortex gray matter
73. C Allele 50% reduction of Met receptor protein
RR of autism is 2.27 for CC genotype
Association confined to multiplex families
74. MET C Allele 1st vulnerability gene to explain the multisystem complications of autism:
Neurological changes
GI pathology
Immune disregulation
Impaired detoxification
75.
Organophosphate
Pesticides
76. Developmental NT Conducted on only 9 pesticides in use today
Most pesticide testing is performed on adult animals
Single animal species data
No burden of proof of safety exists
77. Single Species Studies Ability to clear toxins varies
Structure and development of brain varies
78. Organophosphate Pesticides 80-90% of households use pesticides
20 of 20 newborn meconium samples contained OPP metabolites
79. Prenatal Pesticide Exposure Reduced head circumference
Memory deficits
Increased reaction time
Hypertension in childhood
Diminished ability to copy geometric figures at age 7-8 (DD of 4 years)
80. Paraoxonase
PON1
81.
Metabolizes OPP
Reverses damage caused by HCTL
Weak activity associated with increased inflammation
Weak enzyme common in individuals with ASD living in areas of high OPP usage
PON1/HCYTLase
82. PON1/HCYTLase Protective activity of good cholesterol
Reduces inflammation in blood vessels and other tissues
Protects against tissue damage that could lead to autoimmune disease
84. Paraoxonase Gene Reelin activity is potently inhibited by organophosphates
PON1 gene maps to 7q31
40-fold inter-individual variance in paraoxonase activity
Expression low until 12-18 months
85. Regression
86. Paraoxonase gene variants are associated with autism in North America, but not in Italy: possible regional specificity in gene-environment interactions
Persico AM et al
Molecular Psychiatry (2005) 1-11
87. Weak PON1 Activity Associated with autism in US
Not associated with autism in Italian children
Coinheritance of less active reelin and PON1 genes associated with autism in the US
89. PON1 R192 Allele Preferentially transmitted to affected offspring
Associated with lower serotonin levels, lower urinary peptides, and increased HC (95th %ile) in US children, but not Italians
Macrocephaly = neural inflammation?
90. MacrocephalyMartha Herbert 20% of children with autism experience accelerated head growth after birth
White matter is 28% of total brain volume, but represents 65% of this increase
The cortex is typically 54% of total brain volume, but represents only 18% of this increase
91. Combined Toxicities Lead arsenate pesticides: used until late 1950s
Cd, Pb in cigarette smoke/Hg in fillings
Al, Hg, formaldehyde in vaccines
Thimerosal and live viral vaccines
92. Synergistic Toxicity Hermans: Combined 33 chemicals at concentrations only 4% of NOEC
Produced 50% mortality in fish
93. Synergistic Toxicity Varying vs same mode of toxicity
Simultaneous vs sequential exposure
Critical stage of development
94. Synergistic Toxicity Alcohol increases the toxicity of arsenic 100-fold
LD1 of Hg + 1/20 LD1 of Pb ? 100% mortality Schubert 1978
Cd, Hg, and Pb: DNA damage
Fl and Al: synergistic neurotoxicity
95. Summary Unprecedented number of toxins
Individuals with certain genetic backgrounds will be less able to clear these toxins
Common nutritional deficiencies are risk factors
Enhancing methylation capacity can be very beneficial
96. Reduction
in exposure
is critical
97. Center for AutismResearch and Education www.center4autism.org
(602) 277- care