Tony Bradshaw - Academia.edu (original) (raw)
Papers by Tony Bradshaw
Australian Journal of Chemistry, 1970
A study of the abundances of certain metastable peaks formed by the de- composition of ions in th... more A study of the abundances of certain metastable peaks formed by the de- composition of ions in the first and second field-free regions of a double-focusing mass spectrometer has shown that the M-1 ions (m/e 165) in the mass spectra of fluorene and phenalene have different structures. Correlations based on these structures have been obtained for C13H9+ species formed from different systems.
teb.org.tr
The purpose of the research described herein was to develop and validate a reversed-phase liquid ... more The purpose of the research described herein was to develop and validate a reversed-phase liquid chromatographic (RPLC) method for the commercially available spermicides nonoxynol-9 (1.90-2.10%, w/w) in a gel formulation. The chromatographic separation was achieved with methanol-water (83:17, v/v) as mobile phase through a Nucleosil Cyano column by UV detection at 289 nm. The calibration curve was linear over the concentration range of 0.05-0.35 mg/mL (R 2 = 0.9997). The recovery ranges were from 99.87-100.04% from a gel formulation. The mean percent relative standard deviation values for intra-and inter-day precision studies were less than 1.0%. The method was adequate sensitive with detection limit of 0.0065 µg/mL. The assay method remains unaffected by small but deliberate variations, thus it was robust.
Chemico-Biological Interactions, 1981
Incubation of 2-[9-14C]acetylaminofluorene (2-[9-14C]AAF) in vitro with rat liver microsomes, lea... more Incubation of 2-[9-14C]acetylaminofluorene (2-[9-14C]AAF) in vitro with rat liver microsomes, leads to covalent binding of label to microsomal proteins. The binding is NADPH-dependent, increases linearly with time, and is inhibited by SKF-525A and 7,8-benzoflavone (7,8-BF). Binding is increased more than 8-fold in microsomes from 3-methylcholanthrene(MC)-pretreated rats, but only less than 2-fold in those from phenobarbital(PB)-pretreated rats. In the presence of cytosolic proteins, there is slight enhancement of the labelling of microsomes and some labelling of the cytosolic proteins. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and 2-dimensional gel electrophoresis indicate that covalent labelling by 2-AAF derivatives is concentrated in specific proteins. The pattern of labelling varies between microsomes from animals pretreated with PB, MC and 2-AAF. Factors which may contribute to the specificity of labelling are discussed.
Chemico-Biological Interactions, 1990
Avian erythrocytes are terminally differentiated cells but they can be reactivated by fusion with... more Avian erythrocytes are terminally differentiated cells but they can be reactivated by fusion with actively metabolising cells. We have examined the effects of treating the erythrocytes with a carcinogenic methylating agent, N-methyl-N-Nitrosourea (MNU), on the process of reactivation of adult and embryonic nuclei. We have found that the rate of nuclear enlargement is slightly lower in nuclei from MNU-treated cells than from control cells and that there is a marked delay of about 24 h in the appearance of nucleoli in both adult and embryonic cells. This is not due to an effect of MNU on ribosomal (r)DNA: the number of rDNA genes appears to be similar in treated and control cells. Also, the number of rDNA genes appears to be similar in adult and embryonic cells and in unreactivated and reactivated embryonic nuclei: thus, differences in reactivation rate between adult and embryonic cells, observed by us and others, can not be attributed to a gross difference in their ribosomal DNA contents, and reappearance of nucleoli on reactivation can not be due to an amplification of rDNA (i.e., to recovery of such genes if lost on terminal differentiation). We suggest that MNU, although a monofunctional alkylating agent, may cause increased association-possibly cross-linkage-between DNA and protein in chromatin, thereby hindering access of host cell reactivating proteins, especially to the nucleolar regions.
The purpose of the research described herein was to develop and validate a reversed-phase liquid ... more The purpose of the research described herein was to develop and validate a reversed-phase liquid chromatographic (RPLC) method for the commercially available spermicides nonoxynol-9 (1.90-2.10%, w/w) in a gel formulation. The chromatographic separation was achieved with methanol-water (83:17, v/v) as mobile phase through a Nucleosil Cyano column by UV detection at 289 nm. The calibration curve was linear over the concentration range of 0.05-0.35 mg/mL (R = 0.9997). The recovery ranges were from 99.87-100.04% from a gel formulation. The mean percent relative standard deviation values for intraand inter-day precision studies were less than 1.0%. The method was adequate sensitive with detection limit of 0.0065 μg/mL. The assay method remains unaffected by small but deliberate variations, thus it was robust.
A new reversed-phase liquid chromatographic (RPLC) method for the determination of methyl salicyl... more A new reversed-phase liquid chromatographic (RPLC) method for the determination of methyl salicylate in a medicated cream formulation was developed and validated. The separation was achieved using an isocratic mobile phase, on a Lichrosorb C8 column. The eluent was monitored by photodiode array detection at 304 nm. The calibration curve showed excellent linearity (R2 = 0.9999) over the concentration range of 25-175 pLg/mL. The recovery of methyl salicylate was in the range from 99.78100.0%. The percent relative standard deviation values for intra- and inter-day precision studies were <2.0%. The method is very simple, sensitive and robust with short runtime (<3.0 min) to enable the processing of numerous quality control samples.
5-Bromodeoxyuridine (BrdUrd) increased interferon production by the Namalwa line of human lymphob... more 5-Bromodeoxyuridine (BrdUrd) increased interferon production by the Namalwa line of human lymphoblastoid cells treated with Sendai virus, but inhibited their growth. Thymidine, which also inhibited cell growth had no effect on interferon production, so that growth inhibition per se was not the cause of the stimulation. BrdUrd was incorporated into cellular DNA; 5-chlorodeoxyuridine and 5-iodo-deoxyuridine (which are also incorporated) increased the interferon yield, but 5-fluorodeoxyuridine (which is not incorporated) did not. Thymidine reduced both the incorporation of BrdUrd and its stimulatory effect on interferon pro-duction. Deoxycytidine (which prevents the cytotoxic effects of BrdUrd) had no effect on the stimulation. BrdUrd also stimulated interferon production in response to poly(rI).poly(rC) in growing human diploid fibroblasts but not in SV4o virus-transformed human cells. Since BrdUrd was incorporated into the DNA of all these cells, we concluded that incorporation is ne...
Advances in experimental medicine and biology, 1981
Advances in our understanding of the mechanisms of chemical carcinogenesis are now being applied ... more Advances in our understanding of the mechanisms of chemical carcinogenesis are now being applied to improve the quality of prospective risk assessment. The contribution of Ehrenberg and his colleagues (at the University of Stockholm) probably represents the most comprehensive application of mechanistic knowledge to this field during the past 20 years. The strategic approach developed by the Swedish group was based on the identification of differences between man and experimental risk models in factors that determine the relationships between exposure and biological response and the development of methods to compensate for these differences. Many of the critical stages in chemical carcinogenesis and the cellular determinants of these stages have now been identified. As a first step in seeking to improve risk assessment, Ehrenberg introduced the target dose concept, in which the doses of carcinogens penetrating to the cellular target (DNA) are determined. This approach provides an imp...
Mutagenesis, 1986
An attempt is made to draw together diverse areas of biological research which have recently conv... more An attempt is made to draw together diverse areas of biological research which have recently converged and opened up new experimental approaches to understanding the nature of cancer. In particular, the powerful techniques of molecular biology have been brought to bear on tissue culture systems. The case is made for the continued use of cell transformation in vitro as a real and useful model for cancer development. The hallmark of all cancer cells is loss of control over the cell cycle and the cellular elements involved, growth factors, growth factor receptors and signal transducers have been identified and in some instances shown to be encoded in cellular oncogenes. Moreover, as the molecular mechanisms underlying cell growth control are unravelled, those aspects involved in neoplastic change will be identified and this will lead to the development of definitive short-term tests for the detection of chemical carcinogens.
Chemischer Informationsdienst
Chemischer Informationsdienst
Journal of General Virology, 1979
5-Bromodeoxyuridine (BrdUrd) increased interferon production by the Namalwa line of human lymphob... more 5-Bromodeoxyuridine (BrdUrd) increased interferon production by the Namalwa line of human lymphoblastoid cells treated with Sendai virus, but inhibited their growth. Thymidine, which also inhibited cell growth had no effect on interferon production, so that growth inhibition per se was not the cause of the stimulation. BrdUrd was incorporated into cellular DNA; 5-chlorodeoxyuridine and 5-iododeoxyuridine (which are also incorporated) increased the interferon yield, but 5-fluorodeoxyuridine (which is not incorporated) did not. Thymidine reduced both the incorporation of BrdUrd and its stimulatory effect on interferon production. Deoxycytidine (which prevents the cytotoxic effects of BrdUrd) had no effect on the stimulation. BrdUrd also stimulated interferon production in response to poly(rI).poly(rC) in growing human diploid fibroblasts but not in SV4o virus-transformed human cells. Since BrdUrd was incorporated into the DNA of all these cells, we concluded that incorporation is necessary, but not sufficient for the stimulation of interferon formation.
Journal of the Chemical Society D: Chemical Communications
Journal of the Chemical Society, Perkin Transactions 2
... The losses of methyl radicals from both the molecular and M - 1 ions of diphenylmethane have ... more ... The losses of methyl radicals from both the molecular and M - 1 ions of diphenylmethane have been noted by many Johnstone and Millard suggested that the loss of methyl from C13Hll+ came from the central CH unit together with loss of ortho-hydrogens ... AS Siegel, J . Amer. ...
![Research paper thumbnail of Crystal structure of 8-phenyl-3,4,8-triaza-9-oxatricyclo[5,2,1,02,6]dec-3-ene](https://attachments.academia-assets.com/68950139/thumbnails/1.jpg)
](Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry, 1973
Discussion. Les distances et les angles interatomiques de l'h6t6rocycle pentagonal et de son ento... more Discussion. Les distances et les angles interatomiques de l'h6t6rocycle pentagonal et de son entourage sont group6s dans les Tableaux 2 et 3. Tableau 3. Principaux angles en degrds
Advances in experimental medicine and biology, 1981
Cell biology international reports, 1984
A systematic molecular phenotyping approach based on two-dimensional gel electrophoresis is being... more A systematic molecular phenotyping approach based on two-dimensional gel electrophoresis is being applied in an attempt to identify protein changes associated with malignant transformation. Using the C3H10T1/2 mouse cell line, two-dimensional polypeptide maps of the non-transformed cell line, several chemically transformed lines and a tumour cell line were compared. Although there is a large degree of similarity between the protein profiles of all cell lines, clear differences are evident. Initial results are consistent with the view that many of the protein changes are incidental to malignant transformation. Changes induced by 3-methylcholanthrene are retained after transplantation of the cells into nude mice.
IARC scientific publications, 1988
Advances in our understanding of the mechanisms of chemical carcinogenesis are now being applied ... more Advances in our understanding of the mechanisms of chemical carcinogenesis are now being applied to improve the quality of prospective risk assessment. The contribution of Ehrenberg and his colleagues (at the University of Stockholm) probably represents the most comprehensive application of mechanistic knowledge to this field during the past 20 years. The strategic approach developed by the Swedish group was based on the identification of differences between man and experimental risk models in factors that determine the relationships between exposure and biological response and the development of methods to compensate for these differences. Many of the critical stages in chemical carcinogenesis and the cellular determinants of these stages have now been identified. As a first step in seeking to improve risk assessment, Ehrenberg introduced the target dose concept, in which the doses of carcinogens penetrating to the cellular target (DNA) are determined. This approach provides an imp...
Australian Journal of Chemistry, 1970
A study of the abundances of certain metastable peaks formed by the de- composition of ions in th... more A study of the abundances of certain metastable peaks formed by the de- composition of ions in the first and second field-free regions of a double-focusing mass spectrometer has shown that the M-1 ions (m/e 165) in the mass spectra of fluorene and phenalene have different structures. Correlations based on these structures have been obtained for C13H9+ species formed from different systems.
teb.org.tr
The purpose of the research described herein was to develop and validate a reversed-phase liquid ... more The purpose of the research described herein was to develop and validate a reversed-phase liquid chromatographic (RPLC) method for the commercially available spermicides nonoxynol-9 (1.90-2.10%, w/w) in a gel formulation. The chromatographic separation was achieved with methanol-water (83:17, v/v) as mobile phase through a Nucleosil Cyano column by UV detection at 289 nm. The calibration curve was linear over the concentration range of 0.05-0.35 mg/mL (R 2 = 0.9997). The recovery ranges were from 99.87-100.04% from a gel formulation. The mean percent relative standard deviation values for intra-and inter-day precision studies were less than 1.0%. The method was adequate sensitive with detection limit of 0.0065 µg/mL. The assay method remains unaffected by small but deliberate variations, thus it was robust.
Chemico-Biological Interactions, 1981
Incubation of 2-[9-14C]acetylaminofluorene (2-[9-14C]AAF) in vitro with rat liver microsomes, lea... more Incubation of 2-[9-14C]acetylaminofluorene (2-[9-14C]AAF) in vitro with rat liver microsomes, leads to covalent binding of label to microsomal proteins. The binding is NADPH-dependent, increases linearly with time, and is inhibited by SKF-525A and 7,8-benzoflavone (7,8-BF). Binding is increased more than 8-fold in microsomes from 3-methylcholanthrene(MC)-pretreated rats, but only less than 2-fold in those from phenobarbital(PB)-pretreated rats. In the presence of cytosolic proteins, there is slight enhancement of the labelling of microsomes and some labelling of the cytosolic proteins. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and 2-dimensional gel electrophoresis indicate that covalent labelling by 2-AAF derivatives is concentrated in specific proteins. The pattern of labelling varies between microsomes from animals pretreated with PB, MC and 2-AAF. Factors which may contribute to the specificity of labelling are discussed.
Chemico-Biological Interactions, 1990
Avian erythrocytes are terminally differentiated cells but they can be reactivated by fusion with... more Avian erythrocytes are terminally differentiated cells but they can be reactivated by fusion with actively metabolising cells. We have examined the effects of treating the erythrocytes with a carcinogenic methylating agent, N-methyl-N-Nitrosourea (MNU), on the process of reactivation of adult and embryonic nuclei. We have found that the rate of nuclear enlargement is slightly lower in nuclei from MNU-treated cells than from control cells and that there is a marked delay of about 24 h in the appearance of nucleoli in both adult and embryonic cells. This is not due to an effect of MNU on ribosomal (r)DNA: the number of rDNA genes appears to be similar in treated and control cells. Also, the number of rDNA genes appears to be similar in adult and embryonic cells and in unreactivated and reactivated embryonic nuclei: thus, differences in reactivation rate between adult and embryonic cells, observed by us and others, can not be attributed to a gross difference in their ribosomal DNA contents, and reappearance of nucleoli on reactivation can not be due to an amplification of rDNA (i.e., to recovery of such genes if lost on terminal differentiation). We suggest that MNU, although a monofunctional alkylating agent, may cause increased association-possibly cross-linkage-between DNA and protein in chromatin, thereby hindering access of host cell reactivating proteins, especially to the nucleolar regions.
The purpose of the research described herein was to develop and validate a reversed-phase liquid ... more The purpose of the research described herein was to develop and validate a reversed-phase liquid chromatographic (RPLC) method for the commercially available spermicides nonoxynol-9 (1.90-2.10%, w/w) in a gel formulation. The chromatographic separation was achieved with methanol-water (83:17, v/v) as mobile phase through a Nucleosil Cyano column by UV detection at 289 nm. The calibration curve was linear over the concentration range of 0.05-0.35 mg/mL (R = 0.9997). The recovery ranges were from 99.87-100.04% from a gel formulation. The mean percent relative standard deviation values for intraand inter-day precision studies were less than 1.0%. The method was adequate sensitive with detection limit of 0.0065 μg/mL. The assay method remains unaffected by small but deliberate variations, thus it was robust.
A new reversed-phase liquid chromatographic (RPLC) method for the determination of methyl salicyl... more A new reversed-phase liquid chromatographic (RPLC) method for the determination of methyl salicylate in a medicated cream formulation was developed and validated. The separation was achieved using an isocratic mobile phase, on a Lichrosorb C8 column. The eluent was monitored by photodiode array detection at 304 nm. The calibration curve showed excellent linearity (R2 = 0.9999) over the concentration range of 25-175 pLg/mL. The recovery of methyl salicylate was in the range from 99.78100.0%. The percent relative standard deviation values for intra- and inter-day precision studies were <2.0%. The method is very simple, sensitive and robust with short runtime (<3.0 min) to enable the processing of numerous quality control samples.
5-Bromodeoxyuridine (BrdUrd) increased interferon production by the Namalwa line of human lymphob... more 5-Bromodeoxyuridine (BrdUrd) increased interferon production by the Namalwa line of human lymphoblastoid cells treated with Sendai virus, but inhibited their growth. Thymidine, which also inhibited cell growth had no effect on interferon production, so that growth inhibition per se was not the cause of the stimulation. BrdUrd was incorporated into cellular DNA; 5-chlorodeoxyuridine and 5-iodo-deoxyuridine (which are also incorporated) increased the interferon yield, but 5-fluorodeoxyuridine (which is not incorporated) did not. Thymidine reduced both the incorporation of BrdUrd and its stimulatory effect on interferon pro-duction. Deoxycytidine (which prevents the cytotoxic effects of BrdUrd) had no effect on the stimulation. BrdUrd also stimulated interferon production in response to poly(rI).poly(rC) in growing human diploid fibroblasts but not in SV4o virus-transformed human cells. Since BrdUrd was incorporated into the DNA of all these cells, we concluded that incorporation is ne...
Advances in experimental medicine and biology, 1981
Advances in our understanding of the mechanisms of chemical carcinogenesis are now being applied ... more Advances in our understanding of the mechanisms of chemical carcinogenesis are now being applied to improve the quality of prospective risk assessment. The contribution of Ehrenberg and his colleagues (at the University of Stockholm) probably represents the most comprehensive application of mechanistic knowledge to this field during the past 20 years. The strategic approach developed by the Swedish group was based on the identification of differences between man and experimental risk models in factors that determine the relationships between exposure and biological response and the development of methods to compensate for these differences. Many of the critical stages in chemical carcinogenesis and the cellular determinants of these stages have now been identified. As a first step in seeking to improve risk assessment, Ehrenberg introduced the target dose concept, in which the doses of carcinogens penetrating to the cellular target (DNA) are determined. This approach provides an imp...
Mutagenesis, 1986
An attempt is made to draw together diverse areas of biological research which have recently conv... more An attempt is made to draw together diverse areas of biological research which have recently converged and opened up new experimental approaches to understanding the nature of cancer. In particular, the powerful techniques of molecular biology have been brought to bear on tissue culture systems. The case is made for the continued use of cell transformation in vitro as a real and useful model for cancer development. The hallmark of all cancer cells is loss of control over the cell cycle and the cellular elements involved, growth factors, growth factor receptors and signal transducers have been identified and in some instances shown to be encoded in cellular oncogenes. Moreover, as the molecular mechanisms underlying cell growth control are unravelled, those aspects involved in neoplastic change will be identified and this will lead to the development of definitive short-term tests for the detection of chemical carcinogens.
Chemischer Informationsdienst
Chemischer Informationsdienst
Journal of General Virology, 1979
5-Bromodeoxyuridine (BrdUrd) increased interferon production by the Namalwa line of human lymphob... more 5-Bromodeoxyuridine (BrdUrd) increased interferon production by the Namalwa line of human lymphoblastoid cells treated with Sendai virus, but inhibited their growth. Thymidine, which also inhibited cell growth had no effect on interferon production, so that growth inhibition per se was not the cause of the stimulation. BrdUrd was incorporated into cellular DNA; 5-chlorodeoxyuridine and 5-iododeoxyuridine (which are also incorporated) increased the interferon yield, but 5-fluorodeoxyuridine (which is not incorporated) did not. Thymidine reduced both the incorporation of BrdUrd and its stimulatory effect on interferon production. Deoxycytidine (which prevents the cytotoxic effects of BrdUrd) had no effect on the stimulation. BrdUrd also stimulated interferon production in response to poly(rI).poly(rC) in growing human diploid fibroblasts but not in SV4o virus-transformed human cells. Since BrdUrd was incorporated into the DNA of all these cells, we concluded that incorporation is necessary, but not sufficient for the stimulation of interferon formation.
Journal of the Chemical Society D: Chemical Communications
Journal of the Chemical Society, Perkin Transactions 2
... The losses of methyl radicals from both the molecular and M - 1 ions of diphenylmethane have ... more ... The losses of methyl radicals from both the molecular and M - 1 ions of diphenylmethane have been noted by many Johnstone and Millard suggested that the loss of methyl from C13Hll+ came from the central CH unit together with loss of ortho-hydrogens ... AS Siegel, J . Amer. ...
Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry, 1973
Discussion. Les distances et les angles interatomiques de l'h6t6rocycle pentagonal et de son ento... more Discussion. Les distances et les angles interatomiques de l'h6t6rocycle pentagonal et de son entourage sont group6s dans les Tableaux 2 et 3. Tableau 3. Principaux angles en degrds
Advances in experimental medicine and biology, 1981
Cell biology international reports, 1984
A systematic molecular phenotyping approach based on two-dimensional gel electrophoresis is being... more A systematic molecular phenotyping approach based on two-dimensional gel electrophoresis is being applied in an attempt to identify protein changes associated with malignant transformation. Using the C3H10T1/2 mouse cell line, two-dimensional polypeptide maps of the non-transformed cell line, several chemically transformed lines and a tumour cell line were compared. Although there is a large degree of similarity between the protein profiles of all cell lines, clear differences are evident. Initial results are consistent with the view that many of the protein changes are incidental to malignant transformation. Changes induced by 3-methylcholanthrene are retained after transplantation of the cells into nude mice.
IARC scientific publications, 1988
Advances in our understanding of the mechanisms of chemical carcinogenesis are now being applied ... more Advances in our understanding of the mechanisms of chemical carcinogenesis are now being applied to improve the quality of prospective risk assessment. The contribution of Ehrenberg and his colleagues (at the University of Stockholm) probably represents the most comprehensive application of mechanistic knowledge to this field during the past 20 years. The strategic approach developed by the Swedish group was based on the identification of differences between man and experimental risk models in factors that determine the relationships between exposure and biological response and the development of methods to compensate for these differences. Many of the critical stages in chemical carcinogenesis and the cellular determinants of these stages have now been identified. As a first step in seeking to improve risk assessment, Ehrenberg introduced the target dose concept, in which the doses of carcinogens penetrating to the cellular target (DNA) are determined. This approach provides an imp...