Five-Year Study Shows ‘Healthy Worker Effect’ At US Paducah Plant
A five-year study into the causes of deaths of workers at
the Paducah Gaseous Diffusion Plant (PGDP) in the US state of Kentucky
shows significantly lower death rates from all causes and cancer in general
when compared to the overall US population.
However, death from lymphatic and bone marrow cancers such as leukemia or
multiple myeloma were slightly above national rates.This result is similar to those reported earlier.
The University of Louisville’s School of Public
Health and Information Sciences, the University of Cincinnati and the
University of Kentucky conducted the study.
Researchers compiled data from employees’ work history, demographic
records and records from the US Social Security Administration, the
National Death Index and individual state departments. They found complete
data for 6,759 of the 6,820 employees who worked at the plant for at least
30 days between September 1952 and December 2009.
Out of those 6,759 people, the researchers identified 1,638 deaths. This
is fewer than the 2,253 deaths that would have been expected in the general
public.
They also found that 461 of the deaths were attributed to cancer, much less than 592, to be expected from comparable sized group in the general public.
Researchers concluded that overall mortality and cancer rates were lower
than the reference population, reflecting a “strong healthy worker effect”.
This effect is well known by epidemiologists. Regular medical check-ups and
better early care for health problems among workers in industries such as
nuclear result in generally better health for these workers compared to the
average population.
PGDP is the only gas-diffusion enrichment facility still operating in the
US. Two other plants existed at Oak Ridge, Tennessee and Piketon, Ohio.
Studies had been conducted for these plants, but none had yet been
conducted for PGDP.
David Tollerud, professor of environmental and occupational health
sciences at the University of Louisville’s School of Public Health and
Information Sciences, said the study addressed lingering concerns about the
health of workers at the plant.
He said: “It is important for occupational health and public health
research to attempt to answer pressing concerns of impacted populations,
and we were able to report that we didn't find unexpectedly high rates of
disease in this workforce.”
Security workers had higher overall death rates than other employees,
while chemical operators had higher death rates from leukemia and multiple
myeloma than the rest of the workers.
The increased number of lymphatic and bone marrow cancer deaths is
consistent with what researchers expected, Mr Tollerud said. “Based on
other studies, these forms of cancer have been linked to low levels of
radiation exposure.”
The Paducah plant was commissioned in 1952 as part of a US government
programme to produce enriched uranium to fuel military reactors and nuclear
weapons.
The plant’s mission changed in the 1960s from enriching uranium for
nuclear weapons to enriching uranium for use in commercial nuclear reactors
to generate electricity. It is owned by the US. Department of Energy and is
leased and operated by the United States Enrichment Corporation, a
subsidiary of USEC Inc.
The study, titled ‘Mortality among PGDP workers,’ was published in the
July 2010 edition of the Journal of Occupational and Environmental Medicine
(www.joem.org).
>
Wednesday, August 11, 2010
Monday, August 9, 2010
FDA Gives Green Light to First Embryonic Stem Cell Trial in Humans
On July 30, 2010, Geron Corporation , a company developing biopharmaceuticals to treat cancer and chronic degenerative diseases, including spinal cord injury, heart failure and diabetes announced that the U.S. Food and Drug Administration (FDA) has notified them that the clinical hold placed on its Investigational New Drug (IND) application has been lifted and the company's Phase I clinical trial of GRNOPC1 in patients with acute spinal cord injury may proceed.
It is the first embryonic stem cell clinical trial approved by the FDA.
The Phase I multi-center trial may hopefully establish the safety of GRNOPC1 in patients with "complete" American Spinal Injury Association (ASIA) Impairment Scale grade A sub-acute thoracic spinal cord injuries.
"We are pleased with the FDA's decision to allow our planned clinical trial of GRNOPC1 in spinal cord injury to proceed," said Thomas B. Okarma, Ph.D., M.D., Geron's president and CEO. "Our goals for the application of GRNOPC1 in subacute spinal cord injury are unchanged - to achieve restoration of spinal cord function by the injection of hESC-derived oligodendrocyte progenitor cells directly into the lesion site of the patient's injured spinal cord. Additionally, we are now formally exploring the utility of GRNOPC1 in other degenerative CNS disorders including Alzheimer's, multiple sclerosis and Canavan disease."
FDA placed a hold on the trial following results from a single preclinical animal study in which Geron observed a higher frequency of small cysts within the injury site in the spinal cord of animals injected with GRNOPC1 than had previously been noted in numerous foregoing studies.
In response to those results, Geron developed new markers and assays as additional release specifications for GRNOPC1. The company completed an additional confirmatory preclinical animal study to test the new markers and assays, and subsequently submitted a request to the FDA for the clinical hold to be lifted.
GRNOPC1, Geron's lead hESC-based therapeutic candidate, contains hESC-derived oligodendrocyte progenitor cells that have demonstrated remyelinating and nerve growth stimulating properties leading to restoration of function in animal models of acute spinal cord injury (Journal of Neuroscience, Vol. 25, 2005).
"The neurosurgical community is ready to begin the clinical testing of this new approach to treating devastating spinal cord injury," said Richard Fessler, M.D., Ph.D., professor of neurological surgery at the Feinberg School of Medicine at Northwestern University. "We know that demyelination is central to the pathology of the injury, and its reversal by means of injecting oligodendrocyte progenitor cells would be revolutionary for the field. If found to be safe and effective, the therapy would provide a viable treatment option for thousands of patients who suffer severe spinal cord injuries each year."
The GRNOPC1 Clinical Program
Patients eligible for the Phase I trial must have documented evidence of functionally complete spinal cord injury with a neurological level of T3 to T10 spinal segments and agree to have GRNOPC1 injected into the lesion sites between seven and 14 days after injury.
Although the primary endpoint of the trial is safety, the protocol includes secondary endpoints to assess efficacy, such as improved neuromuscular control or sensation in the trunk or lower extremities. Once safety in this patient population has been established, Geron plans to seek FDA approval to extend the study to increase the dose of GRNOPC1, enroll subjects with complete cervical injuries and expand the trial to include patients with severe incomplete (ASIA Impairment Scale grade B or C) injuries to enable access to the therapy for as broad a population of severe spinal cord-injured patients as is medically appropriate.
Geron has selected up to seven U.S. medical centers as candidates to participate in this study and in planned protocol extensions. The sites will be identified as they come online and are ready to enroll subjects into the study.
Other Potential Neurological Indications for GRNOPC1
Geron claimed that in addition to spinal cord injury, GRNOPC1 may have therapeutic utility for other central nervous system indications. It has established many collaborations with academic groups to test GRNOPC1 in selected animal models of human disease for which there is a strong rationale for the approach.
The company listed other areas of work in which it is actively involved.
Alzheimer's Disease: Alzheimer's disease is a progressive, fatal, degenerative disorder that attacks the neurons in the brain, resulting in loss of memory, cognitive function such as reasoning and language, and behavioral changes. According to the Alzheimer's Association an estimated five million people in the United States have Alzheimer's disease. GRNOPC1 is being evaluated in animal models of Alzheimer's disease in collaboration with Professor Frank M. LaFerla, Director of the Institute for Memory Impairments and Neurological Disorders (UCI MIND) at the University of California, Irvine.
Multiple Sclerosis (MS): MS is an autoimmune disease that causes demyelination of nerve axons in the brain and spinal cord often progressing to physical and cognitive disability. There is currently no known cure for the disease. According to the National Multiple Sclerosis Society there are about 400,000 people in the United States with MS. GRNOPC1 is being tested in a non-human primate model of MS in collaboration with Professor Jeffery D. Kocsis of the Departments of Neurology and Neurobiology at Yale University School of Medicine and the Department of Veterans Affairs.
Canavan Disease: Canavan disease is a fatal neurological disorder that belongs to a group of genetic disorders called leukodystrophies, characterized by the abnormal development or degeneration of myelin. Symptoms of Canavan disease present in the first six months of life and death usually occurs at 3 - 10 years of age. GRNOPC1 is being tested in a rodent model of Canavan disease in collaboration with Dr. Paola Leone, Director of the Cell and Gene Therapy Center, at the University of Medicine and Dentistry of New Jersey.
It is the first embryonic stem cell clinical trial approved by the FDA.
The Phase I multi-center trial may hopefully establish the safety of GRNOPC1 in patients with "complete" American Spinal Injury Association (ASIA) Impairment Scale grade A sub-acute thoracic spinal cord injuries.
"We are pleased with the FDA's decision to allow our planned clinical trial of GRNOPC1 in spinal cord injury to proceed," said Thomas B. Okarma, Ph.D., M.D., Geron's president and CEO. "Our goals for the application of GRNOPC1 in subacute spinal cord injury are unchanged - to achieve restoration of spinal cord function by the injection of hESC-derived oligodendrocyte progenitor cells directly into the lesion site of the patient's injured spinal cord. Additionally, we are now formally exploring the utility of GRNOPC1 in other degenerative CNS disorders including Alzheimer's, multiple sclerosis and Canavan disease."
FDA placed a hold on the trial following results from a single preclinical animal study in which Geron observed a higher frequency of small cysts within the injury site in the spinal cord of animals injected with GRNOPC1 than had previously been noted in numerous foregoing studies.
In response to those results, Geron developed new markers and assays as additional release specifications for GRNOPC1. The company completed an additional confirmatory preclinical animal study to test the new markers and assays, and subsequently submitted a request to the FDA for the clinical hold to be lifted.
GRNOPC1, Geron's lead hESC-based therapeutic candidate, contains hESC-derived oligodendrocyte progenitor cells that have demonstrated remyelinating and nerve growth stimulating properties leading to restoration of function in animal models of acute spinal cord injury (Journal of Neuroscience, Vol. 25, 2005).
"The neurosurgical community is ready to begin the clinical testing of this new approach to treating devastating spinal cord injury," said Richard Fessler, M.D., Ph.D., professor of neurological surgery at the Feinberg School of Medicine at Northwestern University. "We know that demyelination is central to the pathology of the injury, and its reversal by means of injecting oligodendrocyte progenitor cells would be revolutionary for the field. If found to be safe and effective, the therapy would provide a viable treatment option for thousands of patients who suffer severe spinal cord injuries each year."
The GRNOPC1 Clinical Program
Patients eligible for the Phase I trial must have documented evidence of functionally complete spinal cord injury with a neurological level of T3 to T10 spinal segments and agree to have GRNOPC1 injected into the lesion sites between seven and 14 days after injury.
Although the primary endpoint of the trial is safety, the protocol includes secondary endpoints to assess efficacy, such as improved neuromuscular control or sensation in the trunk or lower extremities. Once safety in this patient population has been established, Geron plans to seek FDA approval to extend the study to increase the dose of GRNOPC1, enroll subjects with complete cervical injuries and expand the trial to include patients with severe incomplete (ASIA Impairment Scale grade B or C) injuries to enable access to the therapy for as broad a population of severe spinal cord-injured patients as is medically appropriate.
Geron has selected up to seven U.S. medical centers as candidates to participate in this study and in planned protocol extensions. The sites will be identified as they come online and are ready to enroll subjects into the study.
Other Potential Neurological Indications for GRNOPC1
Geron claimed that in addition to spinal cord injury, GRNOPC1 may have therapeutic utility for other central nervous system indications. It has established many collaborations with academic groups to test GRNOPC1 in selected animal models of human disease for which there is a strong rationale for the approach.
The company listed other areas of work in which it is actively involved.
Alzheimer's Disease: Alzheimer's disease is a progressive, fatal, degenerative disorder that attacks the neurons in the brain, resulting in loss of memory, cognitive function such as reasoning and language, and behavioral changes. According to the Alzheimer's Association an estimated five million people in the United States have Alzheimer's disease. GRNOPC1 is being evaluated in animal models of Alzheimer's disease in collaboration with Professor Frank M. LaFerla, Director of the Institute for Memory Impairments and Neurological Disorders (UCI MIND) at the University of California, Irvine.
Multiple Sclerosis (MS): MS is an autoimmune disease that causes demyelination of nerve axons in the brain and spinal cord often progressing to physical and cognitive disability. There is currently no known cure for the disease. According to the National Multiple Sclerosis Society there are about 400,000 people in the United States with MS. GRNOPC1 is being tested in a non-human primate model of MS in collaboration with Professor Jeffery D. Kocsis of the Departments of Neurology and Neurobiology at Yale University School of Medicine and the Department of Veterans Affairs.
Canavan Disease: Canavan disease is a fatal neurological disorder that belongs to a group of genetic disorders called leukodystrophies, characterized by the abnormal development or degeneration of myelin. Symptoms of Canavan disease present in the first six months of life and death usually occurs at 3 - 10 years of age. GRNOPC1 is being tested in a rodent model of Canavan disease in collaboration with Dr. Paola Leone, Director of the Cell and Gene Therapy Center, at the University of Medicine and Dentistry of New Jersey.
Saturday, August 7, 2010
Genes from sweet pepper can fortify African banana against devastating wilt disease
Genes from sweet pepper can fortify African banana against devastating wilt disease
The BXW or Banana Xanthomonas Wilt is the tongue twisting name of a disease which wipes out banana in vast areas in the Great lake region of Africa. It costs about half a billion dollars worth of damage every year across East and Central Africa. The leaves of affected crops turn yellow and then wilt, and the fruit ripens unevenly and prematurely. Eventually the entire plant withers and rots.
Crop scientists announced today the successful transfer of green pepper genes to bananas, conferring on the popular fruit the means to resist the disease.
Dr. Leena Tripathi, a biotechnologist with International Institute of Tropical Agriculture (IITA) and lead author of the paper, said there is still a long way to go before the transgenic bananas find their way onto farmers' fields, but she called the breakthrough "a significant step in the fight against the deadly banana disease."
The transformed bananas, newly-infused with one of two proteins from the green pepper, have shown strong resistance to Xanthomonas wilt in the laboratory and in screen houses. The researchers are poised to begin confined field trials in Uganda soon.
Some of the findings on the protective impact of the two proteins—plant ferredoxin-like amphipathic protein (Pflp) and hypersensitive response-assisting protein (Hrap)—were published recently in the journal Molecular Plant Pathology.
"The Hrap and Pflp genes work by rapidly killing the cells that come into contact with the disease-spreading bacteria, essentially blocking it from spreading any further," Tripathi said. "Hopefully, this will boost the arsenal available to fight BXW and help save millions of farmers' livelihoods in the Great Lakes region."
The novel green pepper proteins that give crops enhanced resistance against deadly pathogens can also provide effective control against other BXW-like bacterial diseases in other parts of the world. Tripathi adds that the mechanism known as Hypersensitivity Response also activates the defenses of surrounding and even distant uninfected banana plants leading to a systemic acquired resistance.
Scientists from the IITA and the National Agricultural Research Organisation (NARO) of Uganda, in partnership with African Agricultural Technology Foundation (AATF), will soon begin evaluating these promising new banana lines under confined field trials. The Ugandan National Biosafety Committee recently approved the tests, which can now move forward.
The genes used in this research were acquired under an agreement from the Academia Sinica in Taiwan.
The highly destructive BXW affects all varieties, including the East African Highland bananas and exotic dessert, roasting, and beer bananas. The crop is also under threat from another deadly disease, the banana bunchy top.
Dr. Tripathi says that there are presently no commercial chemicals, biocontrol agents or resistant varieties that can control the spread of BXW. "Even if a source of resistance is identified today," Tripathi said, "developing a truly resistant banana through conventional breeding would be extremely difficult and would take years, even decades, given the crop's sterility and its long gestation period."
BXW was first reported in Ethiopia 40 years ago on Ensete, a crop relative of banana, before it moved on to bananas. Outside of Ethiopia, it was first reported in Uganda in 2001, then rapidly spread to the Democratic Republic of Congo, Rwanda, Kenya, Tanzania, and Burundi, leaving behind a trail of destruction in Africa's largest banana producing and consuming region.
BXW can be managed by de-budding the banana plant (removing the male bud as soon as the last hand of the female bunch is revealed) and sterilizing farm implements used. However, the adoption of these practices has been inconsistent at best as farmers believe that de-budding affects the quality of the fruit and sterilizing farm tools is a tedious task.
The research to fortify bananas against BXW using genes from sweet pepper was initiated in 2007.
The BXW or Banana Xanthomonas Wilt is the tongue twisting name of a disease which wipes out banana in vast areas in the Great lake region of Africa. It costs about half a billion dollars worth of damage every year across East and Central Africa. The leaves of affected crops turn yellow and then wilt, and the fruit ripens unevenly and prematurely. Eventually the entire plant withers and rots.
Crop scientists announced today the successful transfer of green pepper genes to bananas, conferring on the popular fruit the means to resist the disease.
Dr. Leena Tripathi, a biotechnologist with International Institute of Tropical Agriculture (IITA) and lead author of the paper, said there is still a long way to go before the transgenic bananas find their way onto farmers' fields, but she called the breakthrough "a significant step in the fight against the deadly banana disease."
The transformed bananas, newly-infused with one of two proteins from the green pepper, have shown strong resistance to Xanthomonas wilt in the laboratory and in screen houses. The researchers are poised to begin confined field trials in Uganda soon.
Some of the findings on the protective impact of the two proteins—plant ferredoxin-like amphipathic protein (Pflp) and hypersensitive response-assisting protein (Hrap)—were published recently in the journal Molecular Plant Pathology.
"The Hrap and Pflp genes work by rapidly killing the cells that come into contact with the disease-spreading bacteria, essentially blocking it from spreading any further," Tripathi said. "Hopefully, this will boost the arsenal available to fight BXW and help save millions of farmers' livelihoods in the Great Lakes region."
The novel green pepper proteins that give crops enhanced resistance against deadly pathogens can also provide effective control against other BXW-like bacterial diseases in other parts of the world. Tripathi adds that the mechanism known as Hypersensitivity Response also activates the defenses of surrounding and even distant uninfected banana plants leading to a systemic acquired resistance.
Scientists from the IITA and the National Agricultural Research Organisation (NARO) of Uganda, in partnership with African Agricultural Technology Foundation (AATF), will soon begin evaluating these promising new banana lines under confined field trials. The Ugandan National Biosafety Committee recently approved the tests, which can now move forward.
The genes used in this research were acquired under an agreement from the Academia Sinica in Taiwan.
The highly destructive BXW affects all varieties, including the East African Highland bananas and exotic dessert, roasting, and beer bananas. The crop is also under threat from another deadly disease, the banana bunchy top.
Dr. Tripathi says that there are presently no commercial chemicals, biocontrol agents or resistant varieties that can control the spread of BXW. "Even if a source of resistance is identified today," Tripathi said, "developing a truly resistant banana through conventional breeding would be extremely difficult and would take years, even decades, given the crop's sterility and its long gestation period."
BXW was first reported in Ethiopia 40 years ago on Ensete, a crop relative of banana, before it moved on to bananas. Outside of Ethiopia, it was first reported in Uganda in 2001, then rapidly spread to the Democratic Republic of Congo, Rwanda, Kenya, Tanzania, and Burundi, leaving behind a trail of destruction in Africa's largest banana producing and consuming region.
BXW can be managed by de-budding the banana plant (removing the male bud as soon as the last hand of the female bunch is revealed) and sterilizing farm implements used. However, the adoption of these practices has been inconsistent at best as farmers believe that de-budding affects the quality of the fruit and sterilizing farm tools is a tedious task.
The research to fortify bananas against BXW using genes from sweet pepper was initiated in 2007.
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