Antibiotic production in Streptomyces is organized by a division of labor through terminal genomic differentiation.

One of the hallmark behaviors of social groups is division of labor, where different group members become specialized to carry out complementary tasks. By dividing labor, cooperative groups increase efficiency, thereby raising group fitness even if these behaviors reduce individual fitness. We find that antibiotic production in colonies of Streptomyces coelicolor is coordinated by a division of labor. We show that S. coelicolor colonies are genetically heterogeneous because of amplifications and deletions to the chromosome. Cells with chromosomal changes produce diversified secondary metabolites and secrete more antibiotics; however, these changes reduced individual fitness, providing evidence for a trade-off between antibiotic production and fitness. Last, we show that colonies containing mixtures of mutants and their parents produce significantly more antibiotics, while colony-wide spore production remains unchanged. By generating specialized mutants that hyper-produce antibiotics, streptomycetes reduce the fitness costs of secreted secondary metabolites while maximizing the yield and diversity of these products.

High variability of teicoplanin concentration in patients with continuous venovenous hemodiafiltration.

INTRODUCTION: Continuous venovenous hemodiafiltration (CVVHDF) may alter teicoplanin pharmacokinetics and increase the risk of incorrect dosing. The objective of this prospective observational study was to assess the effect of CVVHDF on the pharmacokinetics of teicoplanin as maintenance therapy. METHODS: Blood, urine, and dialysate samples were collected to measure teicoplanin levels. CVVHDF clearance (CLCVVHDF ), total clearance (CLTOTAL ), and volume of distribution (Vd) were calculated by simplex-linear modeling. The influence of CVVHDF dose on teicoplanin pharmacokinetics was assessed. FINDINGS: Ten samples from eight patients were studied. Creatinine clearance was 3.4 ± 5.1 ml/min/1.73 m2 . Three patients were anuria. The dose for CVVHDF was 32.1 ± 7.0 mL/kg/h. Vd was 1.6 ± 0.7 L/kg. T1/2 was 100.1 ± 42.7 hours. CLTOTAL of teicoplanin was 11.9 ± 5.4 mL/min and CLCVVHDF was 5.8 ± 4.2 mL/min. Contribution of CLCVVHDF to CLTOTAL was 51.2% ± 23.6%. CLCVVHDF of individual teicoplanin varied widely. Large intra-occasion differences were also observed. Dose of CLCVVHDF did not influence overall CLTOTAL , Vd, or half-life. The proportion of CLTOTAL due to CLCVVHDF varied widely. It was high in some cases. DISCUSSION: In patients receiving CVVHDF, there is great variability in teicoplanin pharmacokinetics which complicates empiric approach to dosing, suggesting the need for therapeutic drug monitoring.

Correction: The value of universally available raw NMR data for transparency, reproducibility, and integrity in natural product research.

Correction for 'The value of universally available raw NMR data for transparency, reproducibility, and integrity in natural product research' by James B. McAlpine et al., Nat. Prod. Rep., 2018, DOI: .

The value of universally available raw NMR data for transparency, reproducibility, and integrity in natural product research.

Covering: up to 2018With contributions from the global natural product (NP) research community, and continuing the Raw Data Initiative, this review collects a comprehensive demonstration of the immense scientific value of disseminating raw nuclear magnetic resonance (NMR) data, independently of, and in parallel with, classical publishing outlets. A comprehensive compilation of historic to present-day cases as well as contemporary and future applications show that addressing the urgent need for a repository of publicly accessible raw NMR data has the potential to transform natural products (NPs) and associated fields of chemical and biomedical research. The call for advancing open sharing mechanisms for raw data is intended to enhance the transparency of experimental protocols, augment the reproducibility of reported outcomes, including biological studies, become a regular component of responsible research, and thereby enrich the integrity of NP research and related fields.

Antistaphylococcal Prenylated Acylphoroglucinol and Xanthones from Kielmeyera variabilis.

Bioactivity-guided fractionation of the EtOH extract of the branches of Kielmeyera variabilis led to the isolation of a new acylphoroglucinol (1), which was active against all the MRSA strains tested herein, with pronounced activity against strain EMRSA-16. Compound 1 displayed an MIC of 0.5 mg/L as compared with an MIC of 128 mg/L for the control antibiotic norfloxacin. The structure of the new compound was elucidated by 1D and 2D NMR spectroscopic analysis and mass spectrometry, and experimental and calculated ECD were used to determine the absolute configurations. The compounds ß-sitosterol (2), stigmasterol (3), ergost-5-en-3-ol (4), and osajaxanthone (5) also occurred in the n-hexane fraction. The EtOAc fraction contained nine known xanthones: 3,6-dihydroxy-1,4,8-trimethoxyxanthone (6), 3,5-dihydroxy-4-methoxyxanthone (7), 3,4-dihydroxy-6,8-dimethoxyxanthone (8), 3,4-dihydroxy-2-methoxyxanthone (9), 5-hydroxy-1,3-dimethoxyxanthone (10), 4-hydroxy-2,3-dimethoxyxanthone (11), kielcorin (12), 3-hydroxy-2-methoxyxanthone (13), and 2-hydroxy-1-methoxyxanthone (14), which showed moderate to low activity against the tested MRSA strains.

Zebrafish as a Model for Systems Medicine R&D: Rethinking the Metabolic Effects of Carrier Solvents and Culture Buffers Determined by (1)H NMR Metabolomics.

Zebrafish is a frequently employed model organism in systems medicine and biomarker discovery. A crosscutting fundamental question, and one that has been overlooked in the field, is the "system-wide" (omics) effects induced in zebrafish by metabolic solvents and culture buffers. Indeed, any bioactivity or toxicity test requires that the target compounds are dissolved in an appropriate nonpolar solvent or aqueous media. It is important to know whether the solvent or the buffer itself has an effect on the zebrafish model organism. We evaluated the effects of two organic carrier solvents used in research with zebrafish, as well as in drug screening: dimethyl sulfoxide (DMSO) and ethanol, and two commonly used aqueous buffers (egg water and Hank's balanced salt solution). The effects of three concentrations (0.01, 0.1, and 1%) of DMSO and ethanol were tested in the 5-day-old zebrafish embryo using proton nuclear magnetic resonance ((1)H NMR) based metabolomics. DMSO (1% and 0.1%, but not 0.01%) exposure significantly decreased the levels of adenosine triphosphate (ATP), betaine, alanine, histidine, lactate, acetate, and creatine (p < 0.05). By contrast, ethanol exposure did not alter the embryos' metabolome at any concentration tested. The two different aqueous media noted above impacted the zebrafish embryo metabolome as evidenced by changes in valine, alanine, lactate, acetate, betaine, glycine, glutamate, adenosine triphosphate, and histidine. These results show that DMSO has greater effects on the embryo metabolome than ethanol, and thus is used with caution as a carrier solvent in zebrafish biomarker research and oral medicine. Moreover, the DMSO concentration should not be higher than 0.01%. Careful attention is also warranted for the use of the buffers egg water and Hank's balanced salt solution in zebrafish. In conclusion, as zebrafish is widely used as a model organism in life sciences, metabolome changes induced by solvents and culture buffers warrant further attention for robust systems science, and precision biomarkers that will stand the test of time.

Natural product proteomining, a quantitative proteomics platform, allows rapid discovery of biosynthetic gene clusters for different classes of natural products.

Information on gene clusters for natural product biosynthesis is accumulating rapidly because of the current boom of available genome sequencing data. However, linking a natural product to a specific gene cluster remains challenging. Here, we present a widely applicable strategy for the identification of gene clusters for specific natural products, which we name natural product proteomining. The method is based on using fluctuating growth conditions that ensure differential biosynthesis of the bioactivity of interest. Subsequent combination of metabolomics and quantitative proteomics establishes correlations between abundance of natural products and concomitant changes in the protein pool, which allows identification of the relevant biosynthetic gene cluster. We used this approach to elucidate gene clusters for different natural products in Bacillus and Streptomyces, including a novel juglomycin-type antibiotic. Natural product proteomining does not require prior knowledge of the gene cluster or secondary metabolite and therefore represents a general strategy for identification of all types of gene clusters.

Perturbation of polyamine catabolism affects grape ripening of Vitis vinifera cv. Trincadeira.

Grapes are economically the most important fruit worldwide. However, the complexity of biological events that lead to ripening of nonclimacteric fruits is not fully understood, particularly the role of polyamines' catabolism. The transcriptional and metabolic profilings complemented with biochemical data were studied during ripening of Trincadeira grapes submitted to guazatine treatment, a potent inhibitor of polyamine oxidase activity. The mRNA expression profiles of one time point (EL 38) corresponding to harvest stage was compared between mock and guazatine treatments using Affymetrix GrapeGen(®) genome array. A total of 2113 probesets (1880 unigenes) were differentially expressed between these samples. Quantitative RT-PCR validated microarrays results being carried out for EL 35 (véraison berries), EL 36 (ripe berries) and EL 38 (harvest stage berries). Metabolic profiling using HPLC and (1)H NMR spectroscopy showed increase of putrescine, proline, threonine and 1-O-ethyl-ß-glucoside in guazatine treated samples. Genes involved in amino acid, carbohydrate and water transport were down-regulated in guazatine treated samples suggesting that the strong dehydrated phenotype obtained in guazatine treated samples may be due to impaired transport mechanisms. Genes involved in terpenes' metabolism were differentially expressed between guazatine and mock treated samples. Altogether, results support an important role of polyamine catabolism in grape ripening namely in cell expansion and aroma development.

CXCR4, but not CXCR7, discriminates metastatic behavior in non-small cell lung cancer cells.

UNLABELLED: Chemokines have been implicated as key contributors of non-small cell lung cancer (NSCLC) metastasis. However, the role of CXCR7, a recently discovered receptor for CXCL12 ligand, in the pathogenesis of NSCLC is unknown. To define the relative contribution of chemokine receptors to migration and metastasis, we generated human lung A549 and H157 cell lines with stable knockdown of CXCR4, CXCR7, or both. Cancer cells exhibited chemotaxis to CXCL12 that was enhanced under hypoxic conditions, associated with a parallel induction of CXCR4, but not CXCR7. Interestingly, neither knockdown cell line differed in the rate of proliferation, apoptosis, or cell adherence; however, in both cell lines, CXCL12-induced migration was abolished when CXCR4 signaling was abrogated. In contrast, inhibition of CXCR7 signaling did not alter cellular migration to CXCL12. In an in vivo heterotropic xenograft model using A549 cells, expression of CXCR4, but not CXCR7, on cancer cells was necessary for the development of metastases. In addition, cancer cells knocked down for CXCR4 (or both CXCR4 and CXCR7) produced larger and more vascular tumors as compared with wild-type or CXCR7 knockdown tumors, an effect that was attributable to cancer cell-derived CXCR4 out competing endothelial cells for available CXCL12 in the tumor microenvironment. These results indicate that CXCR4, not CXCR7, expression engages CXCL12 to mediate NSCLC metastatic behavior. IMPLICATIONS: Targeting CXCR4-mediated migration and metastasis may be a viable therapeutic option in NSCLC.

Differential tissue distribution of metabolites in Jacobaea vulgaris, Jacobaea aquatica and their crosses.

Plants are attacked by many different herbivores. Some will consume whole leaves or roots, while others will attack specific types of tissue. Thus, insight into the metabolite profiles of different types of leaf tissues is necessary to understand plant resistance against herbivores. Jacobaea vulgaris, J. aquatica and three genotypes of their crossings were used to study the variation in metabolomic profiles between epidermis and mesophyll tissues. Extracts of epidermis and mesophyll tissues were obtained using carborundum abrasion (CA). Subsequently, (1)H nuclear magnetic resonance (NMR) spectroscopy and multivariate data analyses were applied to compare the metabolome profiles. Orthogonal partial least-squares-discriminant analysis (OPLS-DA) resulted in a clear separation of epidermis and mesophyll extracts. The epidermis contained significantly higher amounts of jacaranone and phenylpropanoids, specifically chlorogenic (5-O-CQA) and feruloyl quinic (FQA) acids compared to the mesophyll. In contrast, the mesophyll showed significantly higher concentrations of pyrrolizidine alkaloids (PAs), specifically jacobine and jaconine. The tissue specific distribution of these compounds was constant over all genotypes tested. Phenylpropanoids, 5-O-CQA and FQA, as well as PAs are known for their inhibitory effect on herbivores, especially against thrips. Thrips feeding commences with the penetration of the epidermis, followed by ingestion of sub-epidermal or mesophyll. Thrips thus may have to encounter phenylpropanoids in the epidermis as the first line of defence, before encountering the PAs as the ultimate defence in the mesophyll. The finding of tissue specific defense may have a major impact on studies of plant resistance. We cannot judge resistance using analyses of a whole roots, leafs or flowers. In such a whole-organism approach, the levels of potential defense compounds are far below the real ones encountered in tissues involved in the first line of defense. Instead, it is of great importance to study the defence compounds in the specific tissue to which the herbivore is confined.

Pharmacokinetic and pharmacodynamic interaction between nifedipine and metformin in rats: competitive inhibition for metabolism of nifedipine and metformin by each other via CYP isozymes.

It has been reported that hypertension exponentially increases in the patients with type 2 diabetes mellitus. Thus, this study was performed to investigate the pharmacokinetic and pharmacodynamic interactions between nifedipine and metformin, since both drugs were commonly metabolized via hepatic CYP2C and 3A subfamilies in rats. Nifedipine (3 mg/kg) and metformin (100 mg/kg) were simultaneously administered intravenously or orally to rats. Concentrations (I) of each drug in the liver and intestine, maximum velocity (V(max)), Michaelis-Menten constant (K(m)), and intrinsic clearance (CL(int)) for the disappearance of each drug, apparent inhibition constant (K(i)) and [I]/K(i) ratios of each drug in liver and intestine were determined. Also the metabolism of each drug in rat and human CYPs and blood pressure were also measured. After the simultaneous single intravenous administration of both drugs together, the AUCs of each drug were significantly greater than that in each drug alone due to the competitive inhibition for the metabolism of nifedipine by metformin via hepatic CYP3A1/2 and of metformin by nifedipine via hepatic CYP2C6 and 3A1/2. After the simultaneous single oral administration of both drugs, the significantly greater AUCs of each drug than that in each drug alone could have mainly been due to the competitive inhibition for the metabolism of nifedipine and metformin by each other via intestinal CYP3A1/2 in addition to competitive inhibition for the hepatic metabolism of each drug as same as the intravenous study.

Transcript and metabolite analysis in Trincadeira cultivar reveals novel information regarding the dynamics of grape ripening.

BACKGROUND: Grapes (Vitis vinifera L.) are economically the most important fruit crop worldwide. However, the complexity of molecular and biochemical events that lead to the onset of ripening of nonclimacteric fruits is not fully understood which is further complicated in grapes due to seasonal and cultivar specific variation. The Portuguese wine variety Trincadeira gives rise to high quality wines but presents extremely irregular berry ripening among seasons probably due to high susceptibility to abiotic and biotic stresses. RESULTS: Ripening of Trincadeira grapes was studied taking into account the transcriptional and metabolic profilings complemented with biochemical data. The mRNA expression profiles of four time points spanning developmental stages from pea size green berries, through véraison and mature berries (EL 32, EL 34, EL 35 and EL 36) and in two seasons (2007 and 2008) were compared using the Affymetrix GrapeGen® genome array containing 23096 probesets corresponding to 18726 unique sequences. Over 50% of these probesets were significantly differentially expressed (1.5 fold) between at least two developmental stages. A common set of modulated transcripts corresponding to 5877 unigenes indicates the activation of common pathways between years despite the irregular development of Trincadeira grapes. These unigenes were assigned to the functional categories of "metabolism", "development", "cellular process", "diverse/miscellanenous functions", "regulation overview", "response to stimulus, stress", "signaling", "transport overview", "xenoprotein, transposable element" and "unknown". Quantitative RT-PCR validated microarrays results being carried out for eight selected genes and five developmental stages (EL 32, EL 34, EL 35, EL 36 and EL 38). Metabolic profiling using 1H NMR spectroscopy associated to two-dimensional techniques showed the importance of metabolites related to oxidative stress response, amino acid and sugar metabolism as well as secondary metabolism. These results were integrated with transcriptional profiling obtained using genome array to provide new information regarding the network of events leading to grape ripening. CONCLUSIONS: Altogether the data obtained provides the most extensive survey obtained so far for gene expression and metabolites accumulated during grape ripening. Moreover, it highlighted information obtained in a poorly known variety exhibiting particular characteristics that may be cultivar specific or dependent upon climatic conditions. Several genes were identified that had not been previously reported in the context of grape ripening namely genes involved in carbohydrate and amino acid metabolisms as well as in growth regulators; metabolism, epigenetic factors and signaling pathways. Some of these genes were annotated as receptors, transcription factors, and kinases and constitute good candidates for functional analysis in order to establish a model for ripening control of a non-climacteric fruit.

An overview of NMR-based metabolomics to identify secondary plant compounds involved in host plant resistance.

Secondary metabolites provide a potential source for the generation of host plant resistance and development of biopesticides. This is especially important in view of the rapid and vast spread of agricultural and horticultural pests worldwide. Multiple pests control tactics in the framework of an integrated pest management (IPM) programme are necessary. One important strategy of IPM is the use of chemical host plant resistance. Up to now the study of chemical host plant resistance has, for technical reasons, been restricted to the identification of single compounds applying specific chemical analyses adapted to the compound in question. In biological processes however, usually more than one compound is involved. Metabolomics allows the simultaneous detection of a wide range of compounds, providing an immediate image of the metabolome of a plant. One of the most universally used metabolomic approaches comprises nuclear magnetic resonance spectroscopy (NMR). It has been NMR which has been applied as a proof of principle to show that metabolomics can constitute a major advancement in the study of host plant resistance. Here we give an overview on the application of NMR to identify candidate compounds for host plant resistance. We focus on host plant resistance to western flower thrips (Frankliniella occidentalis) which has been used as a model for different plant species.

Pharmacokinetics of mirodenafil and its two metabolites, SK3541 and SK3544, in spontaneously or DOCA-salt-induced hypertensive rats.

Hypertension is the most common comorbidity and major risk factor in patients with erectile dysfunction. The pharmacokinetics of mirodenafil, used for the treatment of erectile dysfunction, after the intravenous and oral administration (20 mg/kg) to 6-week-old rats (with blood pressure within the normotensive range) and 16-week-old spontaneously hypertensive rats (SHRs) and their age-matched control normotensive Kyoto-Wistar (KW) rats, and 16-week-old deoxycorticosterone acetate-salt-induced hypertensive rats (DOCA-salt rats) and their age-matched control Sprague-Dawley (SD) rats were compared. It was found that time-averaged renal clearance (Cl(r)) was of minor importance and that time-averaged non-renal clearance (Cl(nr)) was dominant. In both 6- and 16-week-old SHRs, the Cl(nr)s and areas under the curve (AUCs) of intravenous mirodenafil were significantly smaller and greater than those of the controls, but in 16-week-old DOCA-salt rats, they were comparable to the controls. Although the AUC of oral mirodenafil in 16-week-old SHRs was comparable to the controls, the Cl(nr)s (or total body clearances, Cls) of intravenous mirodenafil and intestinal intrinsic clearances were significantly smaller than the controls and comparable to the controls for both 6- and 16-week-old SHRs, unlike in the 16-week-old DOCA-salt rats. The above data suggest that the significantly smaller Cl(nr) and greater AUC of intravenous mirodenafil and comparable AUC of oral mirodenafil in 16-week-old SHR could be due to the hereditary characteristics of SHRs, and not due to the hypertensive state itself.

Metabolic alterations in different developmental stages of Pilocarpus microphyllus.

Pilocarpine is an imidazole alkaloid that has been used for more than a century in glaucoma treatment. It is present in several species of the Pilocarpus genus (jaborandi), with its highest concentrations in P. microphyllus. In addition to pilocarpine, pilosine--an imidazole alkaloid without pharmacological use--is produced in high concentrations in mature plants. A metabolomic study was carried out on juvenile and mature plants to obtain information about pilocarpine metabolism at different developmental stages. Methanol-water and alkaloid extracts were analyzed by ¹H NMR and ESI-MS. Metabolic profiles from both techniques showed clear differences between various developmental stages. Intense signals in the aromatic region of the ¹H NMR spectrum and ions from pilosine and related alkaloids by ESI/MS were found only in extracts from mature plant. Two new imidazole alkaloids were identified by MS(n). Our results suggest that pilosine is produced exclusively in mature developmental stage, and juvenile plant material seems to be appropriate for further studies on pilocarpine biosynthesis.

Effects of tesmilifene, a substrate of CYP3A and an inhibitor of P-glycoprotein, on the pharmacokinetics of intravenous and oral docetaxel in rats.

OBJECTIVES: It has been reported that docetaxel is a P-glycoprotein substrate and is metabolized via the cytochrome P450 (CYP) 3A subfamily in rats. Tesmilifene is a substrate of the CYP3A subfamily and is an inhibitor of P-glycoprotein. Thus, the effects of various doses of tesmilifene on the pharmacokinetics of intravenous and orally administered docetaxel have been investigated in rats. METHODS: Docetaxel (20 mg/kg as base) was administered intravenously and orally without and with tesmilifene (5, 10, and 20 mg/kg) in rats. KEY FINDINGS: After intravenous administration of docetaxel with tesmilifene, the values of nonrenal clearance (CL(NR)) and area under the plasma concentration-time (AUC) for docetaxel were comparable with those without tesmilifene. Tesmilifene did not increase the values of AUC or of absolute oral bioavailability (F) for docetaxel after oral administration of docetaxel with tesmilifene. CONCLUSIONS: The inhibition for the metabolism of docetaxel via hepatic and intestinal CYP3A subfamily, and inhibition of P-glycoprotein-mediated efflux of docetaxel in the intestine by tesmilifene were almost negligible. The extremely low value of F for docetaxel was due to the incomplete absorption from the gastrointestinal tract and considerable first-pass metabolism of docetaxel in rats.

Dose-dependent pharmacokinetics of SP-8203 in rats.

The pharmacokinetics of SP-8203, a potential protective agent for the treatment of cerebral infarction, were evaluated after its intravenous (10, 20 and 30 mg/kg) and oral (10, 20, 30 and 100 mg/kg) administration in rats. After the intravenous administration of SP-8203, the AUCs of SP-8203 were dose-dependent; the dose-normalized AUCs were significantly greater with increasing doses. After the oral administration of SP-8203, plasma concentrations of SP-8203 were much lower than those after intravenous administration. This could be due to considerable hepatic and intestinal metabolism and the high percent of the dose recovered from the gastrointestinal tract (including its contents and feces) at 24 h as unchanged drug.

Shoot differentiation from protocorm callus cultures of Vanilla planifolia (Orchidaceae): proteomic and metabolic responses at early stage.

BACKGROUND: Vanilla planifolia is an important Orchid commercially cultivated for the production of natural vanilla flavour. Vanilla plants are conventionally propagated by stem cuttings and thus causing injury to the mother plants. Regeneration and in vitro mass multiplication are proposed as an alternative to minimize damage to mother plants. Because mass production of V. planifolia through indirect shoot differentiation from callus culture is rare and may be a successful use of in vitro techniques for producing somaclonal variants, we have established a novel protocol for the regeneration of vanilla plants and investigated the initial biochemical and molecular mechanisms that trigger shoot organogenesis from embryogenic/organogenic callus. RESULTS: For embryogenic callus induction, seeds obtained from 7-month-old green pods of V. planifolia were inoculated on MS basal medium (BM) containing TDZ (0.5 mg l(-1)). Germination of unorganized mass callus such as protocorm -like structure (PLS) arising from each seed has been observed. The primary embryogenic calli have been formed after transferring on BM containing IAA (0.5 mg l(-1)) and TDZ (0.5 mg l(-1)). These calli were maintained by subculturing on BM containing IAA (0.5 mg l(-1)) and TDZ (0.3 mg l(-1)) during 6 months and formed embryogenic/organogenic calli. Histological analysis showed that shoot organogenesis was induced between 15 and 20 days after embryogenic/organogenic calli were transferred onto MS basal medium with NAA (0.5 mg l(-1)). By associating proteomics and metabolomics analyses, the biochemical and molecular markers responsible for shoot induction have been studied in 15-day-old calli at the stage where no differentiating part was visible on organogenic calli. Two-dimensional electrophoresis followed by matrix-assisted laser desorption ionization time-of-flight-tandem mass spectrometry (MALDI-TOF-TOF-MS) analysis revealed that 15 protein spots are significantly expressed (P < 0.05) at earlier stages of shoot differentiation. The majority of these proteins are involved in amino acid-protein metabolism and photosynthetic activity. In accordance with proteomic analysis, metabolic profiling using 1D and 2D NMR techniques showed the importance of numerous compounds related with sugar mobilization and nitrogen metabolism. NMR analysis techniques also allowed the identification of some secondary metabolites such as phenolic compounds whose accumulation was enhanced during shoot differentiation. CONCLUSION: The subculture of embryogenic/organogenic calli onto shoot differentiation medium triggers the stimulation of cell metabolism principally at three levels namely (i) initiation of photosynthesis, glycolysis and phenolic compounds synthesis; (ii) amino acid-protein synthesis, and protein stabilization; (iii) sugar degradation. These biochemical mechanisms associated with the initiation of shoot formation during protocorm-like body (PLB) organogenesis could be coordinated by the removal of TDZ in callus maintenance medium. These results might contribute to elucidate the complex mechanism that leads to vanilla callus differentiation and subsequent shoot formation into PLB organogenesis. Moreover, our results highlight an early intermediate metabolic event in vanillin biosynthetic pathway with respect to secondary metabolism. Indeed, for the first time in vanilla tissue culture, phenolic compounds such as glucoside A and glucoside B were identified. The degradation of these compounds in specialized tissue (i.e. young green beans) probably contributes to the biosynthesis of glucovanillin, the parent compound of vanillin.

Slower clearance of intravenous metformin in rats with acute renal failure induced by uranyl nitrate: contribution of slower renal and non-renal clearances.

It has been reported that metformin was primarily metabolized via hepatic CYP2C11, 2D1, and 3A1/2 in rats. It has also been reported that the protein expression and/or mRNA levels of hepatic CYP2C11, 2D subfamily, and 3A1 have decreased, decreased, and increased, respectively, in U-ARF rats. Thus, pharmacokinetic changes of intravenous metformin in U-ARF rats were evaluated. Metformin was administered intravenously at a dose of 50mg/kg to control and U-ARF rats. After i.v. administration of metformin to U-ARF rats, its time-averaged total body clearance was significantly slower (95.2% decrease) than controls. This could have been due to both significantly slower time-averaged renal clearance (99.1% decrease; due to a urine flow rate-dependent timed-interval renal clearance of the drug, a decrease in renal OCT2, and/or an impaired kidney function in U-ARF rats) and time-averaged non-renal clearance (83.8% decrease; due to a decrease in hepatic CYP2C11 and 2D subfamily in U-ARF rats).