cDNA clones encoding the precursor of the Rieske FeS protein of the chloroplast thylakoid membran... more cDNA clones encoding the precursor of the Rieske FeS protein of the chloroplast thylakoid membrane have been isolated from a pea leaf cDNA library in lambda gt 11, following screening with antibodies to purified pea chloroplast Rieske FeS protein. The longest cDNA insert of 880 bp encodes a polypeptide of 230 amino acid residues, of which 50 residues constitute an N-terminal cleavable presequence and 180 residues make up the mature protein. Transcription and translation of the cDNA in vitro produced a polypeptide of 26 kDa which was efficiently imported by isolated pea chloroplasts and processed to the mature 20 kDa protein. Southern hybridisation to pea genomic DNA indicated the presence of a single gene encoding the Rieske FeS protein in the haploid genome.
cDNA clones encoding the precursor of the Rieske FeS protein of the chloroplast thylakoid membran... more cDNA clones encoding the precursor of the Rieske FeS protein of the chloroplast thylakoid membrane have been isolated from a pea leaf cDNA library in lambda gt 11, following screening with antibodies to purified pea chloroplast Rieske FeS protein. The longest cDNA insert of 880 bp encodes a polypeptide of 230 amino acid residues, of which 50 residues constitute an N-terminal cleavable presequence and 180 residues make up the mature protein. Transcription and translation of the cDNA in vitro produced a polypeptide of 26 kDa which was efficiently imported by isolated pea chloroplasts and processed to the mature 20 kDa protein. Southern hybridisation to pea genomic DNA indicated the presence of a single gene encoding the Rieske FeS protein in the haploid genome.
The use of genomics to improve molecular strategies in safety assessment has immense promise, wit... more The use of genomics to improve molecular strategies in safety assessment has immense promise, with increased mechanistic understanding and improved prediction of unknown compounds possible. Several public initiatives in toxicogenomics are now underway, and mechanistic findings are clearly emerging. A number of databases and standards are emerging to support these initiatives. Significant attention to standardization, both for biologic and technical issues, will be necessary for effective community database(s) to be fully operational.
Seven patients diagnosed with erythromelalgia (EM) were investigated by microneurography to recor... more Seven patients diagnosed with erythromelalgia (EM) were investigated by microneurography to record from unmyelinated nerve fibers in the peroneal nerve. Two patients had characterized variants of sodium channel Nav1.7 (I848T, I228M), whereas no mutations of coding regions of Navs were found in 5 patients with EM. Irrespective of Nav1.7 mutations, more than 50% of the silent nociceptors in the patients with EM showed spontaneous activity. In the patient with mutation I848T, all nociceptors, but not sympathetic efferents, displayed enhanced early subnormal conduction in the velocity recovery cycles and the expected late subnormality was reversed to supranormal conduction. The larger hyperpolarizing shift of activation might explain the difference to the I228M mutation. Sympathetic fibers that lack Nav1.8 did not show supranormal conduction in the patient carrying the I848T mutation, confirming in human subjects that the presence of Nav1.8 crucially modulates conduction in cells expressing EM mutant channels. The characteristic pattern of changes in conduction velocity observed in the patient with the I848T gain-of function mutation in Nav1.7 could be explained by axonal depolarization and concomitant inactivation of Nav1.7. If this were true, activity-dependent hyperpolarization would reverse inactivation of Nav1.7 and account for the supranormal CV. This mechanism might explain normal pain thresholds under resting conditions.
The application of genomics methods to toxicology holds great promise. Toxicogenomics data mappin... more The application of genomics methods to toxicology holds great promise. Toxicogenomics data mapping gene expression to predict toxicity and understand mechanisms are emerging, with data suggesting the possibility to classify, and eventually predict, toxic responses. The overall process of informatics analysis of microarray data is summarized. The relationship between the bioinformatics of gene expression and toxicogenomics is discussed, with reference to emerging themes that may be important as the field of toxicogenomics evolves. Emerging themes include the choice and validation of statistical methods, the use of gene annotation and the impact of genome sequence projects.
Journal of Alzheimer's disease : JAD, Jan 26, 2015
Alzheimer's disease (AD) is the most common form of dementia, with no disease-modifying treat... more Alzheimer's disease (AD) is the most common form of dementia, with no disease-modifying treatment yet available. Early detection of patients at risk of developing AD is of central importance. Blood-based genetic signatures can serve as early detection and as population-based screening tools. In this study, we aimed to identify genetic markers and gene signatures associated with cerebrospinal fluid (CSF) biomarkers levels of t-tau, p-tau181, and with the two ratios t-tau/Aβ1-42 and p-tau181/Aβ1-42 in the context of progression from mild cognitive impairment (MCI) to AD, and to identify a panel of genetic markers that can predict CSF biomarker p-tau181/Aβ1-42 ratio with consideration of APOE4 stratification. We analyzed genome-wide the Alzheimer's Disease Neuroimaging Initiative dataset with up to 48 months follow-up. In the first part of the analysis, the main effect of single nucleotide polymorphisms (SNPs) under an additive genetic model was assessed for each of the four CS...
Earlier publication suggested that IgG2a and IgG2c (coding for Igh-1a and Igh-1b) are organized i... more Earlier publication suggested that IgG2a and IgG2c (coding for Igh-1a and Igh-1b) are organized in tandem on the same chromosome as two distinct loci in mice. Our data suggest that IgG2a and IgG2c are not physically linked on the chromosome and are allelic - single locus in majority strains of mice. In another word, IgG2b-IgG2c-IgG2a haplotype proposed by Morgado et al. (1989) may exist in some strains of mice, but IgG2b-IgG2a and IgG2b-IgG2c are likely to be most common haplotypes in mice. Therefore, inbred mice may produce different IgG2a isotypes dependent on their origin (strain); C57B/6 and SJL mice secrete IgG2c while NMRI and DBA/2 mice secrete IgG2a only. The situation is more complicated for Swiss Webster mice (outbred) and Alzheimer's disease transgenic (AD/Tg) mice with multi-genetic backgrounds; mice may secrete only IgG2a, or IgG2c, or both IgG2a and IgG2c. IgG2a and IgG2c likely have different immune profile (response, immune-decoration) in mice due to their divergence of protein sequence. If antibodies based on IgG2a (or IgG2c) are used in chronic studies for preclinical evaluation of antibody efficacy, characterization of IgG2a isotypes in advance becomes critical in the design of such biopharmaceutical projects in order to avoid immune response.
cDNA clones encoding the precursor of the Rieske FeS protein of the chloroplast thylakoid membran... more cDNA clones encoding the precursor of the Rieske FeS protein of the chloroplast thylakoid membrane have been isolated from a pea leaf cDNA library in lambda gt 11, following screening with antibodies to purified pea chloroplast Rieske FeS protein. The longest cDNA insert of 880 bp encodes a polypeptide of 230 amino acid residues, of which 50 residues constitute an N-terminal cleavable presequence and 180 residues make up the mature protein. Transcription and translation of the cDNA in vitro produced a polypeptide of 26 kDa which was efficiently imported by isolated pea chloroplasts and processed to the mature 20 kDa protein. Southern hybridisation to pea genomic DNA indicated the presence of a single gene encoding the Rieske FeS protein in the haploid genome.
cDNA clones encoding the precursor of the Rieske FeS protein of the chloroplast thylakoid membran... more cDNA clones encoding the precursor of the Rieske FeS protein of the chloroplast thylakoid membrane have been isolated from a pea leaf cDNA library in lambda gt 11, following screening with antibodies to purified pea chloroplast Rieske FeS protein. The longest cDNA insert of 880 bp encodes a polypeptide of 230 amino acid residues, of which 50 residues constitute an N-terminal cleavable presequence and 180 residues make up the mature protein. Transcription and translation of the cDNA in vitro produced a polypeptide of 26 kDa which was efficiently imported by isolated pea chloroplasts and processed to the mature 20 kDa protein. Southern hybridisation to pea genomic DNA indicated the presence of a single gene encoding the Rieske FeS protein in the haploid genome.
The use of genomics to improve molecular strategies in safety assessment has immense promise, wit... more The use of genomics to improve molecular strategies in safety assessment has immense promise, with increased mechanistic understanding and improved prediction of unknown compounds possible. Several public initiatives in toxicogenomics are now underway, and mechanistic findings are clearly emerging. A number of databases and standards are emerging to support these initiatives. Significant attention to standardization, both for biologic and technical issues, will be necessary for effective community database(s) to be fully operational.
Seven patients diagnosed with erythromelalgia (EM) were investigated by microneurography to recor... more Seven patients diagnosed with erythromelalgia (EM) were investigated by microneurography to record from unmyelinated nerve fibers in the peroneal nerve. Two patients had characterized variants of sodium channel Nav1.7 (I848T, I228M), whereas no mutations of coding regions of Navs were found in 5 patients with EM. Irrespective of Nav1.7 mutations, more than 50% of the silent nociceptors in the patients with EM showed spontaneous activity. In the patient with mutation I848T, all nociceptors, but not sympathetic efferents, displayed enhanced early subnormal conduction in the velocity recovery cycles and the expected late subnormality was reversed to supranormal conduction. The larger hyperpolarizing shift of activation might explain the difference to the I228M mutation. Sympathetic fibers that lack Nav1.8 did not show supranormal conduction in the patient carrying the I848T mutation, confirming in human subjects that the presence of Nav1.8 crucially modulates conduction in cells expressing EM mutant channels. The characteristic pattern of changes in conduction velocity observed in the patient with the I848T gain-of function mutation in Nav1.7 could be explained by axonal depolarization and concomitant inactivation of Nav1.7. If this were true, activity-dependent hyperpolarization would reverse inactivation of Nav1.7 and account for the supranormal CV. This mechanism might explain normal pain thresholds under resting conditions.
The application of genomics methods to toxicology holds great promise. Toxicogenomics data mappin... more The application of genomics methods to toxicology holds great promise. Toxicogenomics data mapping gene expression to predict toxicity and understand mechanisms are emerging, with data suggesting the possibility to classify, and eventually predict, toxic responses. The overall process of informatics analysis of microarray data is summarized. The relationship between the bioinformatics of gene expression and toxicogenomics is discussed, with reference to emerging themes that may be important as the field of toxicogenomics evolves. Emerging themes include the choice and validation of statistical methods, the use of gene annotation and the impact of genome sequence projects.
Journal of Alzheimer's disease : JAD, Jan 26, 2015
Alzheimer's disease (AD) is the most common form of dementia, with no disease-modifying treat... more Alzheimer's disease (AD) is the most common form of dementia, with no disease-modifying treatment yet available. Early detection of patients at risk of developing AD is of central importance. Blood-based genetic signatures can serve as early detection and as population-based screening tools. In this study, we aimed to identify genetic markers and gene signatures associated with cerebrospinal fluid (CSF) biomarkers levels of t-tau, p-tau181, and with the two ratios t-tau/Aβ1-42 and p-tau181/Aβ1-42 in the context of progression from mild cognitive impairment (MCI) to AD, and to identify a panel of genetic markers that can predict CSF biomarker p-tau181/Aβ1-42 ratio with consideration of APOE4 stratification. We analyzed genome-wide the Alzheimer's Disease Neuroimaging Initiative dataset with up to 48 months follow-up. In the first part of the analysis, the main effect of single nucleotide polymorphisms (SNPs) under an additive genetic model was assessed for each of the four CS...
Earlier publication suggested that IgG2a and IgG2c (coding for Igh-1a and Igh-1b) are organized i... more Earlier publication suggested that IgG2a and IgG2c (coding for Igh-1a and Igh-1b) are organized in tandem on the same chromosome as two distinct loci in mice. Our data suggest that IgG2a and IgG2c are not physically linked on the chromosome and are allelic - single locus in majority strains of mice. In another word, IgG2b-IgG2c-IgG2a haplotype proposed by Morgado et al. (1989) may exist in some strains of mice, but IgG2b-IgG2a and IgG2b-IgG2c are likely to be most common haplotypes in mice. Therefore, inbred mice may produce different IgG2a isotypes dependent on their origin (strain); C57B/6 and SJL mice secrete IgG2c while NMRI and DBA/2 mice secrete IgG2a only. The situation is more complicated for Swiss Webster mice (outbred) and Alzheimer's disease transgenic (AD/Tg) mice with multi-genetic backgrounds; mice may secrete only IgG2a, or IgG2c, or both IgG2a and IgG2c. IgG2a and IgG2c likely have different immune profile (response, immune-decoration) in mice due to their divergence of protein sequence. If antibodies based on IgG2a (or IgG2c) are used in chronic studies for preclinical evaluation of antibody efficacy, characterization of IgG2a isotypes in advance becomes critical in the design of such biopharmaceutical projects in order to avoid immune response.
Uploads