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Koo H.J.,University of Arizona | Koo H.J.,Salk Institute for Biological Studies | McDowell E.T.,University of Arizona | Ma X.,University of Arizona | And 14 more authors.
BMC Plant Biology

Background: Ginger (Zingiber officinale) and turmeric (Curcuma longa) accumulate important pharmacologically active metabolites at high levels in their rhizomes. Despite their importance, relatively little is known regarding gene expression in the rhizomes of ginger and turmeric.Results: In order to identify rhizome-enriched genes and genes encoding specialized metabolism enzymes and pathway regulators, we evaluated an assembled collection of expressed sequence tags (ESTs) from eight different ginger and turmeric tissues. Comparisons to publicly available sorghum rhizome ESTs revealed a total of 777 gene transcripts expressed in ginger/turmeric and sorghum rhizomes but apparently absent from other tissues. The list of rhizome-specific transcripts was enriched for genes associated with regulation of tissue growth, development, and transcription. In particular, transcripts for ethylene response factors and AUX/IAA proteins appeared to accumulate in patterns mirroring results from previous studies regarding rhizome growth responses to exogenous applications of auxin and ethylene. Thus, these genes may play important roles in defining rhizome growth and development. Additional associations were made for ginger and turmeric rhizome-enriched MADS box transcription factors, their putative rhizome-enriched homologs in sorghum, and rhizomatous QTLs in rice. Additionally, analysis of both primary and specialized metabolism genes indicates that ginger and turmeric rhizomes are primarily devoted to the utilization of leaf supplied sucrose for the production and/or storage of specialized metabolites associated with the phenylpropanoid pathway and putative type III polyketide synthase gene products. This finding reinforces earlier hypotheses predicting roles of this enzyme class in the production of curcuminoids and gingerols.Conclusion: A significant set of genes were found to be exclusively or preferentially expressed in the rhizome of ginger and turmeric. Specific transcription factors and other regulatory genes were found that were common to the two species and that are excellent candidates for involvement in rhizome growth, differentiation and development. Large classes of enzymes involved in specialized metabolism were also found to have apparent tissue-specific expression, suggesting that gene expression itself may play an important role in regulating metabolite production in these plants. © 2013 Koo et al.; licensee BioMed Central Ltd. Source

Xue Y.-J.,Celgene | Gao H.,Vertex Pharmaceuticals | Ji Q.C.,Bristol Myers Squibb | Lam Z.,QPS LLC | And 5 more authors.

Distribution of drugs into tissues is an important determinant of the overall PK and PD profile. Thus, bioanalysis of drugs and their metabolites in tissues can play an important role in understanding the pharmacological and toxicological properties of new drug candidates. Unlike liquid matrices, bioanalysis in tissues offers unique challenges such as proper tissue sampling, appropriate tissue sample preparation, efficient extraction of the analytes from the tissue homogenates, and demonstration of stability and recovery of analytes in intact tissues. This article provides a systematic review of tissue sample analysis for small molecules using LC-MS/MS. The authors provide rationale for tissue sample analysis, and discuss strategies for method development, method qualification or validation, and sample analysis. Unique aspects of method development and qualification/validation are highlighted based on authors' direct experiences and literature summary. Analysis using intact tissue samples such as MALDI imaging is also briefly discussed. © 2012 Future Science Ltd. Source

An accurate, reliable, and reproducible analytical method using HPLC/MS/MS for the determination of tulathromycin residues in bovine liver and porcine kidney via their common hydrolytic fragment (CP-60,300) was developed and validated. Briefly, the method involved an initial acid treatment of intact tissues, which yielded the common fragment (CP-60,300). A portion of the acid hydrolyzate was purified by SPE using a strong cation exchange cartridge. Evaporation of the purified extract was followed by reconstitution in aqueous buffer and analysis by HPLC/MS/MS under isocratic conditions. The developed method provided acceptable sensitivity for determinative surveillance of tulathromycin in porcine kidney and bovine liver with an LOQ of 7.50 and 2.75 μg/g, respectively. The overall recovery and precision of 45 determinations of each tissue were 97.8% (5.3%) for porcine kidney and 96.9% (7.9%) for bovine liver. Accuracy, precision, linearity, specificity, and ruggedness were demonstrated. An HPLC/MS/MS method was also developed for use in these tissues as a confirmatory assay following modifications to the MS detection parameters. The confirmatory method demonstrated acceptable sensitivity for confirmatory evaluation of tulathromycin in porcine kidney and bovine liver at tolerances of 15 and 5.5 μg/g, respectively. Source

Ji A.J.,XenoBiotic Laboratories Inc. | Ji A.J.,Pfizer | Jiang Z.,XenoBiotic Laboratories Inc. | Livson Y.,Pfizer | And 4 more authors.

Dr Allena Ji is the Director of Bioanalytical Services, XenoBiotic Laboratories, Inc., NJ, USA. She has worked in the bioanalytical field for many years and accumulated rich experience in LC-â€"MS/MS method development, method validation and sample analysis under GLP compliance in large pharmaceutical company and contract laboratory settings. In the past 10 years, Allena worked at Pfizer (Legacy of Wyeth) and investigated many small-molecule drug candidates for their nonspecific binding in urine assays. Nonspecific binding of compounds results in a severe underestimation of the compounds' concentrations and poor precision and accuracy in urine bioanalytical assays. To overcome nonspecific binding in urine assays, Allena and her colleagues developed a series of practical approaches for urine method development. By adding an appropriate anti-adsorptive agent at its optimum concentration to the urine collection containers, the nonspecific binding can be blocked. Urine assays have much higher hurdles than plasma assays due to nonspecific binding and variability of urine pH, salt concentration, volume and solubility of drug(s) in urine. A simple and systematic approach for urine method development is emphasized in this paper. © 2010 Future Science Ltd. Source

White R.E.,XenoBiotic Laboratories Inc. | Evans D.C.,Janssen Research and Development LLC | Hop C.E.C.A.,Genentech | Moore D.J.,Hoffman LaRoche | And 3 more authors.

The necessity of conducting traditional radiolabeled absorption, distribution, metabolism and excretion (ADME) studies in animals during development of new investigative agents has been questioned in a recent review. We present a compilation of the benefits of such studies in the understanding of the in vivo pharmacological activity and disposition of new drug candidates, including interpretation of preclinical toxicology findings, characterization of circulating metabolites, and determination of principal pathways of clearance. This understanding is valuable in anticipating the human disposition of the drugs and the planning of the clinical development program. Because of new technologies, evolving regulatory expectations, and increased scientific understanding of the disposition of drugs, the traditional design and timing of both animal and human ADME studies should be reviewed. Innovative "fit-for-purpose" studies may well be a better choice in a particular drug development program than a standard animal ADME "package". However, we submit that, at this time, radiolabeled animal ADME studies still provide a definitive and irreplaceable component of our understanding of the in vivo actions and behaviors of drugs and should continue to be performed prior to the exposure of large numbers of human subjects to investigative drugs. © 2013 Informa UK, Ltd. Source

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