Thursday, August 16, 2012

Mercury in vaccines and specific brain injury


Mercury in vaccines and specific brain injury

Historic facts about mercury and vaccines:
The highly toxic heavy metal mercury has for years been added to vaccines in the form of thimerosal. Thimerosal consists of 49.6% ethylmercury and was launched by the pharmaceutical company Eli Lilly in 1929, despite the fact that adequate safety studies of the drug had never been carried out. Even today the FDA refers to a study from 1930 where the drug was injected intravenously in 22 patients with meningitis of which many died. The researchers who were affiliated with Eli Lilly concluded that the drug had only a minor toxic effect on humans.
New study claims that thimerosal disturb certain vital areas of the brain:
A recently published Japanese study (2012) looks at the neurotoxic effects of mercury exposure in rat foetuses. Pregnant rats were given intramuscular injections of the mercury-containing substance thimerosal. The offspring were examined 50 days after birth. The exposed group was found to have lasting chemical changes in the brain structure known as the hippocampus. Elevated levels of the transmittor substance serotonin and dopamine were observed in the mentioned brain area. Based on these findings, the study concluded:
“Analysis on postnatal day 50 showed significant increase in hippocampal serotonin following thimerosal administration on embryonic day 9. Furthermore, not only serotonin, striatal dopamine was significantly increased. These results indicate that embryonic exposure to thimerosal produces lasting impairment of brain monoaminergic system, and thus every effort should be made to avoid the use of thimerosal.”
Hippocampus and Alzheimer:
The hippocampus is part of the limbic system in the brain. This area has many different functions, including a key-role as regards short-term memory. In AD patients, this structure is often affected early and procession of short term memory is severely affected.
A link between Alzheimer’s and mercury has been found in a number of studies. It is believed that mercury plays a key role in this, in combination with various co-factors:
Thirty-two studies, out of 40 testing memory in individuals exposed to inorganic mercury, found significant memory deficits. Some autopsy studies found increased mercury levels in brain tissues of AD patients. Measurements of mercury levels in blood, urine, hair, nails, and cerebrospinal fluid were inconsistent. In vitro models showed that inorganic mercury reproduces all pathological changes seen in AD, and in animal modelsinorganic mercury produced changes that are similar to those seen in AD. Its high affinity for selenium and selenoproteins suggests that inorganic mercury may promote neurodegenerative disorders via disruption of redox regulation. Inorganic mercury may play a role as a co-factor in the development of AD. It may also increase the pathological influence of other metals. Our mechanistic model describes potential causal pathways. As the single most effective public health primary preventive measure, industrial, and medical usage of mercury should be eliminated as soon as possible.
Hippocampus and reading-writing difficulties:
Our ability to interpret the environment in terms of spatial perception is also related to the hippocampus. Impairment of these abilities will partly be reflected in “clumsness” bumping into things without this being related to visual problems or defects. This also results in diffulties in reading and writing, in that the child is struggling to see and render letters correctly.
It is well known that mercury as well as other heavy metals plays a role according to children’s learning abilities and in terms of reading and writing difficulties in geneal.
Spatial memory serves as a foundation for reading and writing skills. Impairment caused by mercury exposure was clearly evident in this study in that the exposed group had significantly impaired short-term verbal and spatial memory, impaired sustained attention and divided and impaired motor speed.
The Exposed group had significantly impaired short term verbal and spatial memory, impaired sustained attention and Divided, and impaired motor speed.
The general tendency is related to diverse learning problems and several aspects like attention span, memory and coordination are often affected:
Mercury can cause irreversible impairment to brain function in children in the womb and as they grow.
Infants and children exposed to toxic doses of mercury have problems with attention span, language, visual-spatial skills, memory and coordination.
Mercury exposure during development is associated with cell death in the hippocampus and subsequent effects during puberty related to learning is associated. According to this study there is found a degenerative effect on these brain areas:
“Developmental mercury exposure elicts acute hippocampal cell death, reduction in neurogenesis, and severe learning deficits during puberty.  Toxicity was associated acutely with caspase-dependent programmed cell death. MeHg exposure led to reductions in hippocampal size (21%) and cell numbers 2 weeks later, especially in the granule cell layer (16%) and hilus (50%) of the dentate gyrus defined stereologically, suggesting that neurons might be particularly vulnerable. Consistent with this, perinatal exposure led to profound deficits in juvenile hippocampal-dependent learning during training on a spatial navigation task. In aggregate, these studies indicate that exposure to one dose of MeHg during the perinatal period acutely induces apoptotic cell death, which results in later deficits in hippocampal structure and function.”
The evidence show that early exposure to mercury has serious consequences for brain development in relation to both general and more specific aspects of learning.
Hippocampus and autism:
Both the brainstructures amygdala and hippocampus can be affected in autistic children. In many cases there is seen discrepancies in both of these structures associated with autism. The structures are frequently enlarged, which corresponds to the Japanese findings indicating hyper function.
The abnormal enlargement of the amygdala and hippocampus in adolescents with autism adds to previous findings of enlargement of these structures in children with autism. This may reflect increased activity of these structures and thereby altered emotion perception and regulation. Our results could therefore be interpreted in light of developmental adaptation of the autistic brain to a continuous overflow of emotional learning experiences.
Autism is a behaviorally defined syndrome in which neuropathological abnormalities have been identified in the limbic system and cerebellum.
According to this pilot study it was found changes in the amygdala in vaccinated rhesus macaque infant. The vaccines were added mercury. It was also found changes according to the receptors in this area of the brain:
This longitudinal, case-control pilot study examined amygdala growth in rhesus macaque infants receiving the complete US childhood vaccine schedule (1994-1999). Longitudinal structural and functional neuroimaging was undertaken to examine central effects of the vaccine regimen on the developing brain. Vaccine-exposed and saline-injected control infants underwent MRI and PET imaging at approximately 4 and 6 months of age, representing two specific timeframes within the vaccination schedule. Volumetric analyses showed that exposed animals did not undergo the maturational changes over time in amygdala volume that was observed in unexposed animals.
Some sources claims the pathology regarding autism is consistent with mercury exposure and toxicity:
Autism is a syndrome characterized by impairments in social relatedness, language and communication, a need for routine and sameness, abnormal movements, and sensory dysfunction. Mercury (Hg) is a toxic metal that can exist as a pure element or in a variety of inorganic and organic forms and can cause immune, sensory, neurological, motor, and behavioral dysfunctions similar to traits defining or associated with autism. Thimerosal, a preservative frequently added to childhood vaccines, has become a major source of Hg in human infants and toddlers
There has been some controversy concerning a link between mercury in vaccines and autism. Regardless of the overall conclusion that there is no evidence of a connection, there is a wide range of studies looking at possible relationships. The general tendency points to a link between mercury and autism and hippocampal pathology – functionally as well as structurally:
Still mercury in vaccines:
Mercury in vaccines is no longer recommended, but is still added in multidose vaccines like the Pandemrix vaccine used in 2009. Retrospectively, we have seen an increase of the brain disease narcolepsy. It seems that the vaccine manufacturers are for some reason extremely reluctant to completely phase out the mercury in vaccines.
Ragnhild Madsen © 2012

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