Allan Smith - Academia.edu (original) (raw)

Papers by Allan Smith

Research paper thumbnail of Arsenic in drinking water

Bmj, 2011

... Sohel N, Persson LA, Rahman M, Streatfield PK, Yunus M, Ekstrom EC, et al. ... Joseph H Grazi... more ... Sohel N, Persson LA, Rahman M, Streatfield PK, Yunus M, Ekstrom EC, et al. ... Joseph H Graziano,; Faruque Parvez,; Mengling Liu,; Vesna Slavkovich,; Tara Kalra,; Maria Argos,; Tariqul Islam,; Alauddin Ahmed,; Muhammad Rakibuz-Zaman,; ...

Research paper thumbnail of Responses of Cerebellar Purkinje Cells to Slip of a Hand-Held Object

Journal of Neurophysiology, Apr 1, 1992

Research paper thumbnail of Association of genetic variation in cystathionine-�-synthase and arsenic metabolism

Research paper thumbnail of Seasonal variation of arsenic concentration in wells in Nevada

Environmental Research, Jul 1, 2007

Research paper thumbnail of Association of genetic variation in cystathionine-β-synthase and arsenic metabolism

Environmental Research, Aug 31, 2010

Research paper thumbnail of The Meissner Corpuscle Revised: A Multiafferented Mechanoreceptor with Nociceptor Immunochemical Properties

The Journal of Neuroscience, Sep 15, 2001

Research paper thumbnail of Arsenic-Related Cancer Mortality in Northern Chile, 1989???98

Research paper thumbnail of Evaluation of Two New Arsenic Field Test Kits Capable of Detecting Arsenic Water Concentrations Close to 10 μg/L

Environ Sci Technol, 2006

Research paper thumbnail of Probability estimates for the unique childhood leukemia cluster in Fallon, Nevada, and risks near other U.S. Military aviation facilities

Environmental Health Perspectives, May 1, 2004

A unique cluster of childhood leukemia has recently occurred around the city of Fallon in Churchi... more A unique cluster of childhood leukemia has recently occurred around the city of Fallon in Churchill County, Nevada. From 1999 to 2001, 11 cases were diagnosed in this county of 23,982 people. Exposures related to a nearby naval air station such as jet fuel or an infectious agent carried by naval aviators have been hypothesized as potential causes. The possibility that the cluster could be attributed to chance was also considered. We used data from the Surveillance, Epidemiology, and End Results Program (SEER) to examine the likelihood that chance could explain this cluster. We also used SEER and California Cancer Registry data to evaluate rates of childhood leukemia in other U.S. counties with military aviation facilities. The age-standardized rate ratio (RR) in Churchill County was 12.0 [95% confidence interval (CI), 6.0-21.4; p = 4.3 times symbol 10(-9)]. A cluster of this magnitude would be expected to occur in the United States by chance about once every 22,000 years. The age-standardized RR for the five cases diagnosed after the cluster was first reported was 11.2 (95% CI, 3.6-26.3). In contrast, the incidence rate was not increased in all other U.S. counties with military aviation bases (RR = 1.04; 95% CI, 0.97-1.12) or in the subset of rural counties with military aviation bases (RR = 0.72; 95% CI, 0.48-1.08). These findings suggest that the Churchill County cluster was unlikely due to chance, but no general increase in childhood leukemia was found in other U.S. counties with military aviation bases.

Research paper thumbnail of Kidney Cancer Mortality: Fifty-year Latency Patterns Related to Arsenic Exposure

Epidemiology, 2010

Arsenic in drinking water is associated with kidney cancer. Beginning in 1958, a region of Chile ... more Arsenic in drinking water is associated with kidney cancer. Beginning in 1958, a region of Chile experienced a rapid onset of high arsenic exposure in drinking water, followed by sharp declines when water treatment plants were installed in 1971. For the years 1950-1970, we obtained mortality data from death certificates for an exposed region and an unexposed region in Chile. We obtained computerized mortality data for all of Chile for 1971-2000. Kidney cancer risks for the exposed region compared with the unexposed started to increase about 10 years after high arsenic exposures began in 1958. The peak kidney cancer mortality rate ratio (RR) was 3.4 (95% confidence interval = 2.2-5.1) for men in 1981-1985, with subsequent declines to 1.6 (1.2-2.1) by 1996-2000. Mortality RRs among women were 2.9 (1.8-4.7) in 1981-1985 but remained high longer than for men, increasing further to a RR of 4.4 (3.0-6.4) in 1991-1995. Early-life exposure resulted in an increased RR of 7.1 (3.1-14) for young adults aged 30-39 years, born just before or during the high exposure period. This study shows a latency pattern of increased mortality from kidney cancer, continuing for at least 25 years after the high exposures began to decline. Early life exposure resulted in markedly higher kidney cancer mortality in young adults.

Research paper thumbnail of Evaluation of Two New Arsenic Field Test Kits Capable of Detecting Arsenic Water Concentrations Close to 10 ¿g/L

Environmental Science Technology, 2006

Research paper thumbnail of Case-Control Study of Bladder Cancer and Arsenic in Drinking Water

American Journal of Epidemiology, Mar 15, 1995

Research paper thumbnail of Case-Control Study of Bladder Cancer and Exposure to Arsenic in Argentina

American Journal of Epidemiology, Feb 15, 2004

Research paper thumbnail of Neuronal activity in somatosensory cortex of monkeys using a precision grip. III. Responses to altered friction perturbations

Journal of Neurophysiology, Feb 1, 1999

Research paper thumbnail of Genetic Polymorphisms in MTHFR 677 and 1298, GSTM1 and T1, and Metabolism of Arsenic

Journal of Toxicology and Environmental Health Part a, Feb 1, 2007

Methylation is the primary route of metabolism of inorganic arsenic in humans, and previous studi... more Methylation is the primary route of metabolism of inorganic arsenic in humans, and previous studies showed that interindividual differences in arsenic methylation may have important impacts on susceptibility to arsenic-induced cancer. To date, the factors that regulate arsenic methylation in humans are mostly unknown. Urinary arsenic methylation patterns and genetic polymorphisms in methylenetetrahydrofolate reductase (MTHFR) and glutathione S-transferase (GST) were investigated in 170 subjects from an arsenic-exposed region in Argentina. Previous studies showed that subjects with the TT/AA polymorphisms at MTHFR 677 and 1298 have lower MTHFR activity than others. In this study, it was found that subjects with the TT/AA variant of MTHFR 677/1298 excreted a significantly higher proportion of ingested arsenic as inorganic arsenic and a lower proportion as dimethylarsinic acid. Women with the null genotype of GSTM1 excreted a significantly higher proportion of arsenic as monomethylarsonate than women with the active genotype. No associations were seen between polymorphisms in GSTT1 and arsenic methylation. This is the first study to report (1) associations between MTHFR and arsenic metabolism in humans, and (2) gender differences between genetic polymorphisms and urinary arsenic methylation patterns. Overall, this study provides evidence that MTHFR and GSTM1 are involved in arsenic metabolism in humans, and polymorphisms in the genes that encode these enzymes may play a role in susceptibility to arsenic-induced cancer.

Research paper thumbnail of Case-Control Study of Bladder Cancer and Drinking Water Arsenic in the Western United States

American Journal of Epidemiology, Dec 1, 2003

Research paper thumbnail of Selenium and Lung Cancer: A Quantitative Analysis of Heterogeneity in the Current Epidemiological Literature

Cancer Epidemiology Biomarkers Prevention a Publication of the American Association For Cancer Research Cosponsored By the American Society of Preventive Oncology, May 1, 2004

While numerous laboratory investigations have shown that selenium may have anticarcinogenic activ... more While numerous laboratory investigations have shown that selenium may have anticarcinogenic activity, the epidemiological data have been inconsistent. In this report, meta-analysis was used to quantitatively summarize the existing epidemiological evidence on selenium and lung cancer and identify sources of heterogeneity among studies. When all studies were combined, the summary relative risk (RR) for subjects with higher selenium exposures was 0.74 [95% confidence interval (CI) 0.57-0.97]. In subgroup analyses based on the average selenium level in the study population, the summary RR for areas where selenium levels were low was 0.72 (95% CI 0.45-1.16), while the RR for areas where selenium levels were higher was 0.86 (95% CI 0.61-1.22). In both studies in high selenium areas where RRs were markedly below 1.0, protective effects were only found when subjects in the lowest category of selenium exposure were used as referents. No clear protective effects were seen when highly exposed subjects were compared with those in the middle exposure categories. The summary RR was lower in studies assessing selenium exposure using toenails (RR 0.46, 95% CI 0.24-0.87) than in studies using serum selenium (RR 0.80, 95% CI 0.58-1.10) or studies assessing dietary intake (RR 1.00, 95% CI 0.77-1.30). Overall, these results suggest that selenium may have some protective effect against lung cancer in populations where average selenium levels are low. The evidence for these findings is greater in studies of toenail selenium than in studies involving other measures of exposure.

Research paper thumbnail of Neuronal Activity in Somatosensory Cortex of Monkeys Using a Precision Grip. I. Receptive Fields and Discharge Patterns

Journal of Neurophysiology, Feb 1, 1999

Research paper thumbnail of Activity in Ventral and Dorsal Premotor Cortex in Response to Predictable Force-Pulse Perturbations in a Precision Grip Task

Journal of Neurophysiology, Sep 1, 2001

Research paper thumbnail of Obesity and excess weight in early adulthood and high risks of arsenic-related cancer in later life

Environmental research, Jan 21, 2015

Elevated body mass index (BMI) is a risk factor for cardiovascular disease, diabetes, cancer, and... more Elevated body mass index (BMI) is a risk factor for cardiovascular disease, diabetes, cancer, and other diseases. Inflammation or oxidative stress induced by high BMI may explain some of these effects. Millions of people drink arsenic-contaminated water worldwide, and ingested arsenic has also been associated with inflammation, oxidative stress, and cancer. To assess the unique situation of people living in northern Chile exposed to high arsenic concentrations in drinking water and investigate interactions between arsenic and BMI, and associations with lung and bladder cancer risks. Information on self-reported body mass index (BMI) at various life stages, smoking, diet, and lifetime arsenic exposure was collected from 532 cancer cases and 634 population-based controls. In subjects with BMIs <90th percentile in early adulthood (27.7 and 28.6kg/m(2) in males and females, respectively), odds ratios (OR) for lung and bladder cancer combined for arsenic concentrations of <100, 100...

Research paper thumbnail of Arsenic in drinking water

Bmj, 2011

... Sohel N, Persson LA, Rahman M, Streatfield PK, Yunus M, Ekstrom EC, et al. ... Joseph H Grazi... more ... Sohel N, Persson LA, Rahman M, Streatfield PK, Yunus M, Ekstrom EC, et al. ... Joseph H Graziano,; Faruque Parvez,; Mengling Liu,; Vesna Slavkovich,; Tara Kalra,; Maria Argos,; Tariqul Islam,; Alauddin Ahmed,; Muhammad Rakibuz-Zaman,; ...

Research paper thumbnail of Responses of Cerebellar Purkinje Cells to Slip of a Hand-Held Object

Journal of Neurophysiology, Apr 1, 1992

Research paper thumbnail of Association of genetic variation in cystathionine-�-synthase and arsenic metabolism

Research paper thumbnail of Seasonal variation of arsenic concentration in wells in Nevada

Environmental Research, Jul 1, 2007

Research paper thumbnail of Association of genetic variation in cystathionine-β-synthase and arsenic metabolism

Environmental Research, Aug 31, 2010

Research paper thumbnail of The Meissner Corpuscle Revised: A Multiafferented Mechanoreceptor with Nociceptor Immunochemical Properties

The Journal of Neuroscience, Sep 15, 2001

Research paper thumbnail of Arsenic-Related Cancer Mortality in Northern Chile, 1989???98

Research paper thumbnail of Evaluation of Two New Arsenic Field Test Kits Capable of Detecting Arsenic Water Concentrations Close to 10 μg/L

Environ Sci Technol, 2006

Research paper thumbnail of Probability estimates for the unique childhood leukemia cluster in Fallon, Nevada, and risks near other U.S. Military aviation facilities

Environmental Health Perspectives, May 1, 2004

A unique cluster of childhood leukemia has recently occurred around the city of Fallon in Churchi... more A unique cluster of childhood leukemia has recently occurred around the city of Fallon in Churchill County, Nevada. From 1999 to 2001, 11 cases were diagnosed in this county of 23,982 people. Exposures related to a nearby naval air station such as jet fuel or an infectious agent carried by naval aviators have been hypothesized as potential causes. The possibility that the cluster could be attributed to chance was also considered. We used data from the Surveillance, Epidemiology, and End Results Program (SEER) to examine the likelihood that chance could explain this cluster. We also used SEER and California Cancer Registry data to evaluate rates of childhood leukemia in other U.S. counties with military aviation facilities. The age-standardized rate ratio (RR) in Churchill County was 12.0 [95% confidence interval (CI), 6.0-21.4; p = 4.3 times symbol 10(-9)]. A cluster of this magnitude would be expected to occur in the United States by chance about once every 22,000 years. The age-standardized RR for the five cases diagnosed after the cluster was first reported was 11.2 (95% CI, 3.6-26.3). In contrast, the incidence rate was not increased in all other U.S. counties with military aviation bases (RR = 1.04; 95% CI, 0.97-1.12) or in the subset of rural counties with military aviation bases (RR = 0.72; 95% CI, 0.48-1.08). These findings suggest that the Churchill County cluster was unlikely due to chance, but no general increase in childhood leukemia was found in other U.S. counties with military aviation bases.

Research paper thumbnail of Kidney Cancer Mortality: Fifty-year Latency Patterns Related to Arsenic Exposure

Epidemiology, 2010

Arsenic in drinking water is associated with kidney cancer. Beginning in 1958, a region of Chile ... more Arsenic in drinking water is associated with kidney cancer. Beginning in 1958, a region of Chile experienced a rapid onset of high arsenic exposure in drinking water, followed by sharp declines when water treatment plants were installed in 1971. For the years 1950-1970, we obtained mortality data from death certificates for an exposed region and an unexposed region in Chile. We obtained computerized mortality data for all of Chile for 1971-2000. Kidney cancer risks for the exposed region compared with the unexposed started to increase about 10 years after high arsenic exposures began in 1958. The peak kidney cancer mortality rate ratio (RR) was 3.4 (95% confidence interval = 2.2-5.1) for men in 1981-1985, with subsequent declines to 1.6 (1.2-2.1) by 1996-2000. Mortality RRs among women were 2.9 (1.8-4.7) in 1981-1985 but remained high longer than for men, increasing further to a RR of 4.4 (3.0-6.4) in 1991-1995. Early-life exposure resulted in an increased RR of 7.1 (3.1-14) for young adults aged 30-39 years, born just before or during the high exposure period. This study shows a latency pattern of increased mortality from kidney cancer, continuing for at least 25 years after the high exposures began to decline. Early life exposure resulted in markedly higher kidney cancer mortality in young adults.

Research paper thumbnail of Evaluation of Two New Arsenic Field Test Kits Capable of Detecting Arsenic Water Concentrations Close to 10 ¿g/L

Environmental Science Technology, 2006

Research paper thumbnail of Case-Control Study of Bladder Cancer and Arsenic in Drinking Water

American Journal of Epidemiology, Mar 15, 1995

Research paper thumbnail of Case-Control Study of Bladder Cancer and Exposure to Arsenic in Argentina

American Journal of Epidemiology, Feb 15, 2004

Research paper thumbnail of Neuronal activity in somatosensory cortex of monkeys using a precision grip. III. Responses to altered friction perturbations

Journal of Neurophysiology, Feb 1, 1999

Research paper thumbnail of Genetic Polymorphisms in MTHFR 677 and 1298, GSTM1 and T1, and Metabolism of Arsenic

Journal of Toxicology and Environmental Health Part a, Feb 1, 2007

Methylation is the primary route of metabolism of inorganic arsenic in humans, and previous studi... more Methylation is the primary route of metabolism of inorganic arsenic in humans, and previous studies showed that interindividual differences in arsenic methylation may have important impacts on susceptibility to arsenic-induced cancer. To date, the factors that regulate arsenic methylation in humans are mostly unknown. Urinary arsenic methylation patterns and genetic polymorphisms in methylenetetrahydrofolate reductase (MTHFR) and glutathione S-transferase (GST) were investigated in 170 subjects from an arsenic-exposed region in Argentina. Previous studies showed that subjects with the TT/AA polymorphisms at MTHFR 677 and 1298 have lower MTHFR activity than others. In this study, it was found that subjects with the TT/AA variant of MTHFR 677/1298 excreted a significantly higher proportion of ingested arsenic as inorganic arsenic and a lower proportion as dimethylarsinic acid. Women with the null genotype of GSTM1 excreted a significantly higher proportion of arsenic as monomethylarsonate than women with the active genotype. No associations were seen between polymorphisms in GSTT1 and arsenic methylation. This is the first study to report (1) associations between MTHFR and arsenic metabolism in humans, and (2) gender differences between genetic polymorphisms and urinary arsenic methylation patterns. Overall, this study provides evidence that MTHFR and GSTM1 are involved in arsenic metabolism in humans, and polymorphisms in the genes that encode these enzymes may play a role in susceptibility to arsenic-induced cancer.

Research paper thumbnail of Case-Control Study of Bladder Cancer and Drinking Water Arsenic in the Western United States

American Journal of Epidemiology, Dec 1, 2003

Research paper thumbnail of Selenium and Lung Cancer: A Quantitative Analysis of Heterogeneity in the Current Epidemiological Literature

Cancer Epidemiology Biomarkers Prevention a Publication of the American Association For Cancer Research Cosponsored By the American Society of Preventive Oncology, May 1, 2004

While numerous laboratory investigations have shown that selenium may have anticarcinogenic activ... more While numerous laboratory investigations have shown that selenium may have anticarcinogenic activity, the epidemiological data have been inconsistent. In this report, meta-analysis was used to quantitatively summarize the existing epidemiological evidence on selenium and lung cancer and identify sources of heterogeneity among studies. When all studies were combined, the summary relative risk (RR) for subjects with higher selenium exposures was 0.74 [95% confidence interval (CI) 0.57-0.97]. In subgroup analyses based on the average selenium level in the study population, the summary RR for areas where selenium levels were low was 0.72 (95% CI 0.45-1.16), while the RR for areas where selenium levels were higher was 0.86 (95% CI 0.61-1.22). In both studies in high selenium areas where RRs were markedly below 1.0, protective effects were only found when subjects in the lowest category of selenium exposure were used as referents. No clear protective effects were seen when highly exposed subjects were compared with those in the middle exposure categories. The summary RR was lower in studies assessing selenium exposure using toenails (RR 0.46, 95% CI 0.24-0.87) than in studies using serum selenium (RR 0.80, 95% CI 0.58-1.10) or studies assessing dietary intake (RR 1.00, 95% CI 0.77-1.30). Overall, these results suggest that selenium may have some protective effect against lung cancer in populations where average selenium levels are low. The evidence for these findings is greater in studies of toenail selenium than in studies involving other measures of exposure.

Research paper thumbnail of Neuronal Activity in Somatosensory Cortex of Monkeys Using a Precision Grip. I. Receptive Fields and Discharge Patterns

Journal of Neurophysiology, Feb 1, 1999

Research paper thumbnail of Activity in Ventral and Dorsal Premotor Cortex in Response to Predictable Force-Pulse Perturbations in a Precision Grip Task

Journal of Neurophysiology, Sep 1, 2001

Research paper thumbnail of Obesity and excess weight in early adulthood and high risks of arsenic-related cancer in later life

Environmental research, Jan 21, 2015

Elevated body mass index (BMI) is a risk factor for cardiovascular disease, diabetes, cancer, and... more Elevated body mass index (BMI) is a risk factor for cardiovascular disease, diabetes, cancer, and other diseases. Inflammation or oxidative stress induced by high BMI may explain some of these effects. Millions of people drink arsenic-contaminated water worldwide, and ingested arsenic has also been associated with inflammation, oxidative stress, and cancer. To assess the unique situation of people living in northern Chile exposed to high arsenic concentrations in drinking water and investigate interactions between arsenic and BMI, and associations with lung and bladder cancer risks. Information on self-reported body mass index (BMI) at various life stages, smoking, diet, and lifetime arsenic exposure was collected from 532 cancer cases and 634 population-based controls. In subjects with BMIs <90th percentile in early adulthood (27.7 and 28.6kg/m(2) in males and females, respectively), odds ratios (OR) for lung and bladder cancer combined for arsenic concentrations of <100, 100...