Shale deposits exist in many parts of the world and contain relatively large amounts of natural g... more Shale deposits exist in many parts of the world and contain relatively large amounts of natural gas and oil. Recent technological developments in the process of horizontal hydraulic fracturing (hydrofracturing or fracking) have suddenly made it economically feasible to extract natural gas from shale. While natural gas is a much cleaner burning fuel than coal, there are a number of significant threats to human health from the extraction process as currently practiced. There are immediate threats to health resulting from air pollution from volatile organic compounds, which contain carcinogens such as benzene and ethyl-benzene, and which have adverse neurologic and respiratory effects. Hydrogen sulfide, a component of natural gas, is a potent neuro- and respiratory toxin. In addition, levels of formaldehyde are elevated around fracking sites due to truck traffic and conversion of methane to formaldehyde by sunlight. There are major concerns about water contamination because the chemica...
Particulate air pollution is an important public health issue. Population-based studies have docu... more Particulate air pollution is an important public health issue. Population-based studies have documented health short-term exposure to particulate matter. This study investigated the short-term effects of PM2.5, black carbon in ambient air on hospital admissions and emergency room (ER) visits among residents living in one of the largest developing world, Karachi, Pakistan. Daily records of hospitalizations and ER visits for cardiovascular diseases hospitals serving the city were collected. The 24 h concentrations of PM2.5 were collected at two commercial/ industrial/residential sites. BC and DC measurements were obtained from PM2.5 filters using an optical transm and multi-pollutant lagged generalized linear time-series models were utilized to analyze daily counts of hospital and pollutant data. PM2.5 , BC, and DC concentrations in the city ranged 27 - 279 μg/m3, 1 - 32 μg/m3 , and respectively. Analysis showed the evidence of positive associations of fine particle air pollution, met...
We have studied rates of diabetes in 601 members of the Mohawk Nation at Akwesasne, ages 18-84 ye... more We have studied rates of diabetes in 601 members of the Mohawk Nation at Akwesasne, ages 18-84 years, in relation to serum concentrations of 101 polychlorinated biphenyl (PCB) congeners and three chlorinated pesticides [dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB) and mirex]. Diabetes was determined from either a diagnosis by a physician or by having a fasting glucose concentration of >125 mg/dL. Rates of diabetes are high in this community. Three models were used. In the first model rate ratios (RR) were determined for quartiles of total PCBs after adjustment for age, sex, body mass index (BMI) and total serum lipids. For total PCBs RR=2.21 (1.2-4.2), while for total pesticides RR=3.75 (1.3-10.7). When the total PCB results were also adjusted for total pesticides and the total pesticide results were also adjusted for total PCBs (Model 2) the RRs were somewhat reduced. In Model 3 we considered subgroups of PCBs based on numbers of chlorines on the molecule (tri...
Exposure to persistent organic pollutants (POPs) is known to increase risk of diabetes. To determ... more Exposure to persistent organic pollutants (POPs) is known to increase risk of diabetes. To determine which POPs are most associated with prevalence of diabetes in 601 Akwesasne Native Americans. Multiple logistic regression analysis was used to assess associations between quartiles of concentrations of 101 polychlorinated biphenyl (PCBs) congeners, congener groups and three chlorinated pesticides [dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB) and mirex] with diabetes. In Model 1 the relationship between quartiles of exposure and diabetes were adjusted only for sex, age, body mass index (BMI) and total serum lipids. Model 2 included additional adjustment for either total PCBs or total pesticides. Total serum PCB and pesticide concentrations were each significantly associated with prevalence of diabetes when adjusted only for covariates (Model 1), but neither showed a significant OR for highest to lowest quartiles after additional adjustment for the other (Model 2). ...
After transient ischemia, synaptic activation of neurons in CA1 results in an abnormally long dep... more After transient ischemia, synaptic activation of neurons in CA1 results in an abnormally long depolarization. This is due to the appearance of an NMDA component which results from a decrease in the normal voltage-dependent blockade by Mg2+. The reduction of NMDA channel blockade is likely the cause of the hyperexcitability which follows transient ischemia and the subsequent delayed neuronal cell death, resulting from entry of calcium through hyperactive NMDA channels.
... Abstract Carpenter, D., I. Engberg and A. Lundberg. Dzfferential supraspinal control of inhib... more ... Abstract Carpenter, D., I. Engberg and A. Lundberg. Dzfferential supraspinal control of inhibitory and excitatory action from the FRA to ascending spinal pathways. ... 565-584. HOLMQVIST, B. Crossed spinal reflex actions evoked by volleys in somatic afferents. Ada physiol. scand. ...
Stimulation of the sensorimotor cortex evokes dorsal root potentials (DRP) in the lumbo-sacral co... more Stimulation of the sensorimotor cortex evokes dorsal root potentials (DRP) in the lumbo-sacral cord. Primary afferent depolarization is evoked in group Ib and group II muscle af-ferents and cutaneous afferents but not in Ia afferents. The effects are mediated by the pyramidal tract. There is spatial facilitation between the paths from primary afferents and cortex. It is concluded that the pyramidal tract acts on primary afferents by giving excitatory action to interneurones of spinal reflex arcs to primary afferents.
Serum lipid levels are major risk factors for cardiovascular disease. In addition to diet, exerci... more Serum lipid levels are major risk factors for cardiovascular disease. In addition to diet, exercise, genetics, age and race, serum concentrations of persistent organic pollutants (POPs) influence concentrations of serum lipids. We investigated associations between fasting concentrations of 35 polychlorinated biphenyl (PCB) congeners and nine organochlorine pesticides in relation to total serum lipids, total cholesterol, low-density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol and triglycerides in 525 Caucasian and African American residents of Anniston, Alabama, who were not on any lipid-lowering medication. In Model 1, data were adjusted for age, age quadratic, gender, BMI, alcohol consumption, smoking and exercise, while in Model 2, additional adjustment was done for other POPs. As compared to Caucasians, African Americans had lower levels of total lipids and triglycerides with higher concentrations of HDL cholesterol, but higher concentrations of PCBs...
Environmental health : a global access science source, Jan 11, 2013
Anniston, Alabama, is the site of a former Monsanto plant where polychlorinated biphenyls (PCBs) ... more Anniston, Alabama, is the site of a former Monsanto plant where polychlorinated biphenyls (PCBs) were manufactured from 1929 until 1971. Residents of Anniston are known to have elevated levels of PCBs. The objective of the study was to test the hypothesis that levels of the various lipid components (total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides) are differentially associated with concentrations of total PCBs and total pesticides, and further that different congeners, congener groups and different pesticides do not have identical associations in serum samples obtained from Anniston residents in a cross-sectional study. Fasting serum samples were obtained from 575 residents of Anniston who were not on any lipid-lowering medication and were analyzed for 35 PCB congeners, nine chlorinated pesticides, total cholesterol, LDL and HDL cholesterol and triglyceride concentrations. Associations between toxicant concentrations and lipid levels were determined using multiple...
Shale deposits exist in many parts of the world and contain relatively large amounts of natural g... more Shale deposits exist in many parts of the world and contain relatively large amounts of natural gas and oil. Recent technological developments in the process of horizontal hydraulic fracturing (hydrofracturing or fracking) have suddenly made it economically feasible to extract natural gas from shale. While natural gas is a much cleaner burning fuel than coal, there are a number of significant threats to human health from the extraction process as currently practiced. There are immediate threats to health resulting from air pollution from volatile organic compounds, which contain carcinogens such as benzene and ethyl-benzene, and which have adverse neurologic and respiratory effects. Hydrogen sulfide, a component of natural gas, is a potent neuro- and respiratory toxin. In addition, levels of formaldehyde are elevated around fracking sites due to truck traffic and conversion of methane to formaldehyde by sunlight. There are major concerns about water contamination because the chemica...
Particulate air pollution is an important public health issue. Population-based studies have docu... more Particulate air pollution is an important public health issue. Population-based studies have documented health short-term exposure to particulate matter. This study investigated the short-term effects of PM2.5, black carbon in ambient air on hospital admissions and emergency room (ER) visits among residents living in one of the largest developing world, Karachi, Pakistan. Daily records of hospitalizations and ER visits for cardiovascular diseases hospitals serving the city were collected. The 24 h concentrations of PM2.5 were collected at two commercial/ industrial/residential sites. BC and DC measurements were obtained from PM2.5 filters using an optical transm and multi-pollutant lagged generalized linear time-series models were utilized to analyze daily counts of hospital and pollutant data. PM2.5 , BC, and DC concentrations in the city ranged 27 - 279 μg/m3, 1 - 32 μg/m3 , and respectively. Analysis showed the evidence of positive associations of fine particle air pollution, met...
We have studied rates of diabetes in 601 members of the Mohawk Nation at Akwesasne, ages 18-84 ye... more We have studied rates of diabetes in 601 members of the Mohawk Nation at Akwesasne, ages 18-84 years, in relation to serum concentrations of 101 polychlorinated biphenyl (PCB) congeners and three chlorinated pesticides [dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB) and mirex]. Diabetes was determined from either a diagnosis by a physician or by having a fasting glucose concentration of >125 mg/dL. Rates of diabetes are high in this community. Three models were used. In the first model rate ratios (RR) were determined for quartiles of total PCBs after adjustment for age, sex, body mass index (BMI) and total serum lipids. For total PCBs RR=2.21 (1.2-4.2), while for total pesticides RR=3.75 (1.3-10.7). When the total PCB results were also adjusted for total pesticides and the total pesticide results were also adjusted for total PCBs (Model 2) the RRs were somewhat reduced. In Model 3 we considered subgroups of PCBs based on numbers of chlorines on the molecule (tri...
Exposure to persistent organic pollutants (POPs) is known to increase risk of diabetes. To determ... more Exposure to persistent organic pollutants (POPs) is known to increase risk of diabetes. To determine which POPs are most associated with prevalence of diabetes in 601 Akwesasne Native Americans. Multiple logistic regression analysis was used to assess associations between quartiles of concentrations of 101 polychlorinated biphenyl (PCBs) congeners, congener groups and three chlorinated pesticides [dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB) and mirex] with diabetes. In Model 1 the relationship between quartiles of exposure and diabetes were adjusted only for sex, age, body mass index (BMI) and total serum lipids. Model 2 included additional adjustment for either total PCBs or total pesticides. Total serum PCB and pesticide concentrations were each significantly associated with prevalence of diabetes when adjusted only for covariates (Model 1), but neither showed a significant OR for highest to lowest quartiles after additional adjustment for the other (Model 2). ...
After transient ischemia, synaptic activation of neurons in CA1 results in an abnormally long dep... more After transient ischemia, synaptic activation of neurons in CA1 results in an abnormally long depolarization. This is due to the appearance of an NMDA component which results from a decrease in the normal voltage-dependent blockade by Mg2+. The reduction of NMDA channel blockade is likely the cause of the hyperexcitability which follows transient ischemia and the subsequent delayed neuronal cell death, resulting from entry of calcium through hyperactive NMDA channels.
... Abstract Carpenter, D., I. Engberg and A. Lundberg. Dzfferential supraspinal control of inhib... more ... Abstract Carpenter, D., I. Engberg and A. Lundberg. Dzfferential supraspinal control of inhibitory and excitatory action from the FRA to ascending spinal pathways. ... 565-584. HOLMQVIST, B. Crossed spinal reflex actions evoked by volleys in somatic afferents. Ada physiol. scand. ...
Stimulation of the sensorimotor cortex evokes dorsal root potentials (DRP) in the lumbo-sacral co... more Stimulation of the sensorimotor cortex evokes dorsal root potentials (DRP) in the lumbo-sacral cord. Primary afferent depolarization is evoked in group Ib and group II muscle af-ferents and cutaneous afferents but not in Ia afferents. The effects are mediated by the pyramidal tract. There is spatial facilitation between the paths from primary afferents and cortex. It is concluded that the pyramidal tract acts on primary afferents by giving excitatory action to interneurones of spinal reflex arcs to primary afferents.
Serum lipid levels are major risk factors for cardiovascular disease. In addition to diet, exerci... more Serum lipid levels are major risk factors for cardiovascular disease. In addition to diet, exercise, genetics, age and race, serum concentrations of persistent organic pollutants (POPs) influence concentrations of serum lipids. We investigated associations between fasting concentrations of 35 polychlorinated biphenyl (PCB) congeners and nine organochlorine pesticides in relation to total serum lipids, total cholesterol, low-density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol and triglycerides in 525 Caucasian and African American residents of Anniston, Alabama, who were not on any lipid-lowering medication. In Model 1, data were adjusted for age, age quadratic, gender, BMI, alcohol consumption, smoking and exercise, while in Model 2, additional adjustment was done for other POPs. As compared to Caucasians, African Americans had lower levels of total lipids and triglycerides with higher concentrations of HDL cholesterol, but higher concentrations of PCBs...
Environmental health : a global access science source, Jan 11, 2013
Anniston, Alabama, is the site of a former Monsanto plant where polychlorinated biphenyls (PCBs) ... more Anniston, Alabama, is the site of a former Monsanto plant where polychlorinated biphenyls (PCBs) were manufactured from 1929 until 1971. Residents of Anniston are known to have elevated levels of PCBs. The objective of the study was to test the hypothesis that levels of the various lipid components (total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides) are differentially associated with concentrations of total PCBs and total pesticides, and further that different congeners, congener groups and different pesticides do not have identical associations in serum samples obtained from Anniston residents in a cross-sectional study. Fasting serum samples were obtained from 575 residents of Anniston who were not on any lipid-lowering medication and were analyzed for 35 PCB congeners, nine chlorinated pesticides, total cholesterol, LDL and HDL cholesterol and triglyceride concentrations. Associations between toxicant concentrations and lipid levels were determined using multiple...
Uploads
Papers by D. Carpenter