SHANE S QUE HEE - Academia.edu (original) (raw)
Papers by SHANE S QUE HEE
Radiation Research, Apr 1, 1971
A nondecaying weak luminescence of intensity 1.5 ± 0.1 photons rmsec−1rmml−1{\rm sec}^{-1}\ {\rm ml}^{-1}rmsec−1rmml−1 ha... more A nondecaying weak luminescence of intensity 1.5 ± 0.1 photons rmsec−1rmml−1{\rm sec}^{-1}\ {\rm ml}^{-1}rmsec−1rmml−1 has been observed from purified water exposed to ambient ionizing radiation. The structured emission spectrum and the observed quenching by dissolved oxygen, indicated that a substantial portion of the luminescence was non-Cerenkov emisson. Emission peaks were observed at 275 and 370 nm, and a broad emission band was observed between 400 and 700 nm. The peak at 275 nm was attributed to emission by excited triplet water molecules, and the peak at 370 nm was assigned to emission by OH radicals in the 2Sigma+{}^{2}\Sigma {}^{+}2Sigma+ state.
Clinical Chemistry, Feb 1, 1984
We investigated three methods for determination of cholinesterase (ChE) in human blood sera, usin... more We investigated three methods for determination of cholinesterase (ChE) in human blood sera, using reference sera, sera of known ChE content, and serum variously diluted with deactivated sera. The methods were the Du Pont aca analyzer, the Pfizer "ChE-tel" method, and the Michel method with and without direct reagent-blank correction. With respect to precision and reproducibility the methods ranked: aca greater than Michel method corrected directly for reagent pH changes (Michel) greater than ChE-tel method greater than Michel method corrected indirectly for reagent pH changes. The interrelationships derived, in terms of each method's individual units were: Michel = (0.054 +/- 0.001) aca - (0.043 +/- 0.086), r2 = 0.947 ChE-tel = (4.44 +/- 0.30) aca - (5.11 +/- 0.99), r2 = 0.959 ChE-tel = (80.2 +/- 5.8) Michel + (0.028 +/- 0.240), r2 = 0.947 The ChE-tel method was subject to variations due to the quality of different kits. The aca results were validated by a collaborative laboratory study. Sera of known activity can be used effectively for accurate calibration.
PubMed, 1986
The effect of disulfiram (DSF) pretreatment on the distribution of [14C]ethylene dichloride (EDC)... more The effect of disulfiram (DSF) pretreatment on the distribution of [14C]ethylene dichloride (EDC) in selected organs and/or tissues of control and EDC-pretreated rats was studied. The presence of EDC metabolites and their binding to an acid-insoluble extract of the tissues, as well as purified protein and DNA, were evaluated. Dietary DSF was found to modulate the distribution, excretion, and macromolecular binding of EDC and/or its metabolites at 4 and 24 hr following ip administration. The urinary excretion of [14C]EDC metabolites was not affected by subchronic inhalation exposure to nonradiolabeled EDC. However, DSF pretreatment increased the fat deposition of EDC and decreased the urinary excretion of its metabolites. DSF also increased the binding of EDC metabolites to DNA and decreased the binding to protein in the liver, kidneys, spleen, and testes. However, prior exposure to EDC alone increased the binding of its metabolites to DNA in the kidneys only.
American Journal of Industrial Medicine, 1998
The exposure-excretion relationship to carbon disulfide (CS2) vapor in 407 exposed workers was st... more The exposure-excretion relationship to carbon disulfide (CS2) vapor in 407 exposed workers was studied during the second half of the working week. Carbon disulfide concentrations were also determined in 50 nonexposed subjects. The geometric mean value for CS2 in urine samples from the latter was: 0.23 microgram/l (95% upper limit = 0.52 microgram/l) when log-normal distribution was assumed. Among the exposed workers, the CS2 level in urine samples collected after the first half shift exceeded the 95% upper limit of nonexposed subjects in every case. The time-weighted average intensity of exposure to CS2 vapor was measured using personal diffusive samplers (in which carbon cloth served as an adsorbent). CS2 concentrations in urine were determined in samples collected at the end of the first half shift from the 407 exposed cases as well as from 50 nonexposed controls. There was a significant correlation (p < 0.0001) between the exposure to CS2 vapor at concentrations of up to 64 mg/m3 and the levels of CS2 measured in the urine samples after four hours of exposure. The correlation indicated that a mean level of 15.5 micrograms CS2/l urine (95% confidence range, 13.8-17.1 micrograms/l) was excreted following an exposure to CS2 at 31 mg/m3 (the current occupational exposure limit).
PLOS Genetics, Jul 29, 2016
Concerns about the safety of Bisphenol A, a chemical found in plastics, receipts, food packaging ... more Concerns about the safety of Bisphenol A, a chemical found in plastics, receipts, food packaging and more, have led to its replacement with substitutes now found in a multitude of consumer products. However, several popular BPA-free alternatives, such as Bisphenol S, share a high degree of structural similarity with BPA, suggesting that these substitutes may disrupt similar developmental and reproductive pathways. We compared the effects of BPA and BPS on germline and reproductive functions using the genetic model system Caenorhabditis elegans. We found that, similarly to BPA, BPS caused severe reproductive defects including germline apoptosis and embryonic lethality. However, meiotic recombination, targeted gene expression, whole transcriptome and ontology analyses as well as ToxCast data mining all indicate that these effects are partly achieved via mechanisms distinct from BPAs. These findings therefore raise new concerns about the safety of BPA alternatives and the risk associated with human exposure to mixtures.
Weed Science, Mar 1, 1973
Sprayed aqueous emulsions of long chain amine salts of (2,4-dichlorophenoxy)acetic acid (2,4-D) p... more Sprayed aqueous emulsions of long chain amine salts of (2,4-dichlorophenoxy)acetic acid (2,4-D) penetrated faster into sunflower (Helianthus annuus L. ‘Peredovik’) leaves than did sprayed dimethylamine salt aqueous emulsions at 21 C and 5% relative humidity (RH). The initial absorption (65 to 70% in 13 hr) was independent of light, but the following much slower absorption was strongly light dependent. The long-chain amine salts sprayed in diesel oil as carrier were 90% absorbed in 4 hr. It was concluded that long chain amine salts should be sprayed in this carrier to facilitate penetration into leaves and to reduce possible environmental contamination.
Journal of Occupational and Environmental Hygiene, Nov 4, 2019
Skin exposure to chemicals in the workplace environment is a major concern, the hands being the m... more Skin exposure to chemicals in the workplace environment is a major concern, the hands being the major exposure sites. Employers purchase gloves that have permeation data generated from permeation “standards” of the American Society for Testing and Materials International (ASTM International), European Committee for Standardization (EN), and the International Organization for Standardization (ISO) that test pieces of glove material and allow a user-defined temperature. The relevant standards based on continuous contact are ASTM F739, ASTM D6978, EN 374, EN 16523, and ISO 6529. The aim was to analyze the current state of the scientific literature on glove permeation in the 21st century up to December 2018. The introduction sets out the background, objectives and rationale of the review and its methodology followed by presentation of basic glove chemical resistance terms and Fick’s first law of diffusion, the details of the major permeation standards, their comparison, their critique, their research gaps; the scientific literature on whole glove permeation, and final conclusions. The major recommendation was to harmonize all the permeation standards and perform them at realistic work conditions, especially temperature. The whole glove system would be most useful for testing the thinnest gloves.
AIHce 1997 - Taking Responsibility...Building Tomorrow's Profession Papers, 1999
Environmental Mutagenesis, 1988
In vivo sister chromatid exchange induced by 1,2-dichloroethane (DCE) was studied in bone marrow ... more In vivo sister chromatid exchange induced by 1,2-dichloroethane (DCE) was studied in bone marrow cells of mice after acute treatment for 24 hr. With the exception of the lowest concentration (0.5 mg/kg), each treated series exhibited a statistically significant increase in SCEs when compared with the control.
Ecotoxicology and Environmental Safety, Nov 1, 2001
The standard Microtox test involving the bioluminescent bacterium Vibrio fischeri is a frequently... more The standard Microtox test involving the bioluminescent bacterium Vibrio fischeri is a frequently used ecotoxicological bioassay whose EC 50 values have been correlated to acute toxicity parameters of vertebrates, to irritancy measures, and to cytotoxicity indices. The aims were to explore the dependence of light output on viable cell number, with the latter estimated with the naked eye using a colorimetric tetrazolium salt method, the e4ects of dust on the bioluminescence and cell viability, how the viability of the cells is a4ected after spills, and how spills can be sampled. The lower limit of the linear dynamic range of the light-emitting bacterium was 5rst de5ned to be 3.7 ؋ 10 7 cells/ mL, compared with 37 ؋ 10 7 cells/mL in the Microtox assay. The e4ects of dust were then explored in the working range by the method of standard additions by adding 5-, 10-, and 20-mg amounts of Standard Reference Material Urban Dust 1649a. This simulated dust samples collected by a cordless vacuum technique involving a 5lter cassette. A mass of 20 mg dust totally inhibited the Microtox test at all times (5, 15, and 30 min). Masses of 5 and 10 mg dust lowered the luminescence signi5cantly by 20 and 64%, respectively, after 30 min. However, the viability test was totally inhibited by 5 mg of dust. A spectrophotometric modi5cation of the viability test using a wavelength of 508 nm was developed that was twice as sensitive as the naked eye test, and was as sensitive as the Microtox test. Mechanical shock involved with spilling and sampling bacterial reagent on hard surfaces killed the luminescent bacteria as shown by inhibition of luminescence. The optimum 5lter cassette for Microtox reagent collection was a 25-mm 1.00-m PTFE 5lter in a 25-mm Delrin holder operated at 4.0 L/min, with a Tygon sampling probe.
Radiation Research, Apr 1, 1971
A nondecaying weak luminescence of intensity 1.5 ± 0.1 photons rmsec−1rmml−1{\rm sec}^{-1}\ {\rm ml}^{-1}rmsec−1rmml−1 ha... more A nondecaying weak luminescence of intensity 1.5 ± 0.1 photons rmsec−1rmml−1{\rm sec}^{-1}\ {\rm ml}^{-1}rmsec−1rmml−1 has been observed from purified water exposed to ambient ionizing radiation. The structured emission spectrum and the observed quenching by dissolved oxygen, indicated that a substantial portion of the luminescence was non-Cerenkov emisson. Emission peaks were observed at 275 and 370 nm, and a broad emission band was observed between 400 and 700 nm. The peak at 275 nm was attributed to emission by excited triplet water molecules, and the peak at 370 nm was assigned to emission by OH radicals in the 2Sigma+{}^{2}\Sigma {}^{+}2Sigma+ state.
Clinical Chemistry, Feb 1, 1984
We investigated three methods for determination of cholinesterase (ChE) in human blood sera, usin... more We investigated three methods for determination of cholinesterase (ChE) in human blood sera, using reference sera, sera of known ChE content, and serum variously diluted with deactivated sera. The methods were the Du Pont aca analyzer, the Pfizer &amp;quot;ChE-tel&amp;quot; method, and the Michel method with and without direct reagent-blank correction. With respect to precision and reproducibility the methods ranked: aca greater than Michel method corrected directly for reagent pH changes (Michel) greater than ChE-tel method greater than Michel method corrected indirectly for reagent pH changes. The interrelationships derived, in terms of each method&amp;#39;s individual units were: Michel = (0.054 +/- 0.001) aca - (0.043 +/- 0.086), r2 = 0.947 ChE-tel = (4.44 +/- 0.30) aca - (5.11 +/- 0.99), r2 = 0.959 ChE-tel = (80.2 +/- 5.8) Michel + (0.028 +/- 0.240), r2 = 0.947 The ChE-tel method was subject to variations due to the quality of different kits. The aca results were validated by a collaborative laboratory study. Sera of known activity can be used effectively for accurate calibration.
PubMed, 1986
The effect of disulfiram (DSF) pretreatment on the distribution of [14C]ethylene dichloride (EDC)... more The effect of disulfiram (DSF) pretreatment on the distribution of [14C]ethylene dichloride (EDC) in selected organs and/or tissues of control and EDC-pretreated rats was studied. The presence of EDC metabolites and their binding to an acid-insoluble extract of the tissues, as well as purified protein and DNA, were evaluated. Dietary DSF was found to modulate the distribution, excretion, and macromolecular binding of EDC and/or its metabolites at 4 and 24 hr following ip administration. The urinary excretion of [14C]EDC metabolites was not affected by subchronic inhalation exposure to nonradiolabeled EDC. However, DSF pretreatment increased the fat deposition of EDC and decreased the urinary excretion of its metabolites. DSF also increased the binding of EDC metabolites to DNA and decreased the binding to protein in the liver, kidneys, spleen, and testes. However, prior exposure to EDC alone increased the binding of its metabolites to DNA in the kidneys only.
American Journal of Industrial Medicine, 1998
The exposure-excretion relationship to carbon disulfide (CS2) vapor in 407 exposed workers was st... more The exposure-excretion relationship to carbon disulfide (CS2) vapor in 407 exposed workers was studied during the second half of the working week. Carbon disulfide concentrations were also determined in 50 nonexposed subjects. The geometric mean value for CS2 in urine samples from the latter was: 0.23 microgram/l (95% upper limit = 0.52 microgram/l) when log-normal distribution was assumed. Among the exposed workers, the CS2 level in urine samples collected after the first half shift exceeded the 95% upper limit of nonexposed subjects in every case. The time-weighted average intensity of exposure to CS2 vapor was measured using personal diffusive samplers (in which carbon cloth served as an adsorbent). CS2 concentrations in urine were determined in samples collected at the end of the first half shift from the 407 exposed cases as well as from 50 nonexposed controls. There was a significant correlation (p < 0.0001) between the exposure to CS2 vapor at concentrations of up to 64 mg/m3 and the levels of CS2 measured in the urine samples after four hours of exposure. The correlation indicated that a mean level of 15.5 micrograms CS2/l urine (95% confidence range, 13.8-17.1 micrograms/l) was excreted following an exposure to CS2 at 31 mg/m3 (the current occupational exposure limit).
PLOS Genetics, Jul 29, 2016
Concerns about the safety of Bisphenol A, a chemical found in plastics, receipts, food packaging ... more Concerns about the safety of Bisphenol A, a chemical found in plastics, receipts, food packaging and more, have led to its replacement with substitutes now found in a multitude of consumer products. However, several popular BPA-free alternatives, such as Bisphenol S, share a high degree of structural similarity with BPA, suggesting that these substitutes may disrupt similar developmental and reproductive pathways. We compared the effects of BPA and BPS on germline and reproductive functions using the genetic model system Caenorhabditis elegans. We found that, similarly to BPA, BPS caused severe reproductive defects including germline apoptosis and embryonic lethality. However, meiotic recombination, targeted gene expression, whole transcriptome and ontology analyses as well as ToxCast data mining all indicate that these effects are partly achieved via mechanisms distinct from BPAs. These findings therefore raise new concerns about the safety of BPA alternatives and the risk associated with human exposure to mixtures.
Weed Science, Mar 1, 1973
Sprayed aqueous emulsions of long chain amine salts of (2,4-dichlorophenoxy)acetic acid (2,4-D) p... more Sprayed aqueous emulsions of long chain amine salts of (2,4-dichlorophenoxy)acetic acid (2,4-D) penetrated faster into sunflower (Helianthus annuus L. ‘Peredovik’) leaves than did sprayed dimethylamine salt aqueous emulsions at 21 C and 5% relative humidity (RH). The initial absorption (65 to 70% in 13 hr) was independent of light, but the following much slower absorption was strongly light dependent. The long-chain amine salts sprayed in diesel oil as carrier were 90% absorbed in 4 hr. It was concluded that long chain amine salts should be sprayed in this carrier to facilitate penetration into leaves and to reduce possible environmental contamination.
Journal of Occupational and Environmental Hygiene, Nov 4, 2019
Skin exposure to chemicals in the workplace environment is a major concern, the hands being the m... more Skin exposure to chemicals in the workplace environment is a major concern, the hands being the major exposure sites. Employers purchase gloves that have permeation data generated from permeation “standards” of the American Society for Testing and Materials International (ASTM International), European Committee for Standardization (EN), and the International Organization for Standardization (ISO) that test pieces of glove material and allow a user-defined temperature. The relevant standards based on continuous contact are ASTM F739, ASTM D6978, EN 374, EN 16523, and ISO 6529. The aim was to analyze the current state of the scientific literature on glove permeation in the 21st century up to December 2018. The introduction sets out the background, objectives and rationale of the review and its methodology followed by presentation of basic glove chemical resistance terms and Fick’s first law of diffusion, the details of the major permeation standards, their comparison, their critique, their research gaps; the scientific literature on whole glove permeation, and final conclusions. The major recommendation was to harmonize all the permeation standards and perform them at realistic work conditions, especially temperature. The whole glove system would be most useful for testing the thinnest gloves.
AIHce 1997 - Taking Responsibility...Building Tomorrow's Profession Papers, 1999
Environmental Mutagenesis, 1988
In vivo sister chromatid exchange induced by 1,2-dichloroethane (DCE) was studied in bone marrow ... more In vivo sister chromatid exchange induced by 1,2-dichloroethane (DCE) was studied in bone marrow cells of mice after acute treatment for 24 hr. With the exception of the lowest concentration (0.5 mg/kg), each treated series exhibited a statistically significant increase in SCEs when compared with the control.
Ecotoxicology and Environmental Safety, Nov 1, 2001
The standard Microtox test involving the bioluminescent bacterium Vibrio fischeri is a frequently... more The standard Microtox test involving the bioluminescent bacterium Vibrio fischeri is a frequently used ecotoxicological bioassay whose EC 50 values have been correlated to acute toxicity parameters of vertebrates, to irritancy measures, and to cytotoxicity indices. The aims were to explore the dependence of light output on viable cell number, with the latter estimated with the naked eye using a colorimetric tetrazolium salt method, the e4ects of dust on the bioluminescence and cell viability, how the viability of the cells is a4ected after spills, and how spills can be sampled. The lower limit of the linear dynamic range of the light-emitting bacterium was 5rst de5ned to be 3.7 ؋ 10 7 cells/ mL, compared with 37 ؋ 10 7 cells/mL in the Microtox assay. The e4ects of dust were then explored in the working range by the method of standard additions by adding 5-, 10-, and 20-mg amounts of Standard Reference Material Urban Dust 1649a. This simulated dust samples collected by a cordless vacuum technique involving a 5lter cassette. A mass of 20 mg dust totally inhibited the Microtox test at all times (5, 15, and 30 min). Masses of 5 and 10 mg dust lowered the luminescence signi5cantly by 20 and 64%, respectively, after 30 min. However, the viability test was totally inhibited by 5 mg of dust. A spectrophotometric modi5cation of the viability test using a wavelength of 508 nm was developed that was twice as sensitive as the naked eye test, and was as sensitive as the Microtox test. Mechanical shock involved with spilling and sampling bacterial reagent on hard surfaces killed the luminescent bacteria as shown by inhibition of luminescence. The optimum 5lter cassette for Microtox reagent collection was a 25-mm 1.00-m PTFE 5lter in a 25-mm Delrin holder operated at 4.0 L/min, with a Tygon sampling probe.