Scipion: A software framework toward integration, reproducibility and validation in 3D electron microscopy.

In the past few years, 3D electron microscopy (3DEM) has undergone a revolution in instrumentation and methodology. One of the central players in this wide-reaching change is the continuous development of image processing software. Here we present Scipion, a software framework for integrating several 3DEM software packages through a workflow-based approach. Scipion allows the execution of reusable, standardized, traceable and reproducible image-processing protocols. These protocols incorporate tools from different programs while providing full interoperability among them. Scipion is an open-source project that can be downloaded from http://scipion.cnb.csic.es.

Inter-laboratory study of human in vitro toxicogenomics-based tests as alternative methods for evaluating chemical carcinogenicity: a bioinformatics perspective.

The assessment of the carcinogenic potential of chemicals with alternative, human-based in vitro systems has become a major goal of toxicogenomics. The central read-out of these assays is the transcriptome, and while many studies exist that explored the gene expression responses of such systems, reports on robustness and reproducibility, when testing them independently in different laboratories, are still uncommon. Furthermore, there is limited knowledge about variability induced by the data analysis protocols. We have conducted an inter-laboratory study for testing chemical carcinogenicity evaluating two human in vitro assays: hepatoma-derived cells and hTERT-immortalized renal proximal tubule epithelial cells, representing liver and kidney as major target organs. Cellular systems were initially challenged with thirty compounds, genome-wide gene expression was measured with microarrays, and hazard classifiers were built from this training set. Subsequently, each system was independently established in three different laboratories, and gene expression measurements were conducted using anonymized compounds. Data analysis was performed independently by two separate groups applying different protocols for the assessment of inter-laboratory reproducibility and for the prediction of carcinogenic hazard. As a result, both workflows came to very similar conclusions with respect to (1) identification of experimental outliers, (2) overall assessment of robustness and inter-laboratory reproducibility and (3) re-classification of the unknown compounds to the respective toxicity classes. In summary, the developed bioinformatics workflows deliver accurate measures for inter-laboratory comparison studies, and the study can be used as guidance for validation of future carcinogenicity assays in order to implement testing of human in vitro alternatives to animal testing.

Influence of DNA-repair gene variants on the micronucleus frequency in thyroid cancer patients.

The role of different DNA-repair genes (OGG1, XRCC1, XRCC2 and XRCC3) on both the spontaneous and the induced frequency of micronuclei (MN) has been studied in the lymphocytes of a group of 114 patients with differentiated thyroid cancer (DTC). Induction of MN was achieved by treatment of the lymphocytes with 0.5Gy of gamma-radiation. The selected genes are involved in base-excision repair (BER) (OGG1, Ser326Cys; XRCC1, Arg280His and Arg399Gln), and in homologous recombination repair (HRR) (XRCC2, Arg188His and XRCC3, IVS5-14G). Genotyping was carried out by use of the iPLEX (Sequenom) technique. Results indicate that only the OGG1-Ser326Cys polymorphism was able to modulate the MN frequency. This effect was only observed in the spontaneous MN frequency (P=0.016), but not in the MN frequency induced after irradiation. In addition, a strong correlation was observed between spontaneous and induced MN frequency, which would suggest an underlying genetic background.

Human hepatocyte transplantation in patients with hepatic failure awaiting a graft.

BACKGROUND: Hepatocyte transplantation (HT) has the potential to become a promising treatment to temporarily support liver function in patients with liver failure. METHODS: Two patients, who had already received a liver transplant (LT) in the past, with an end-stage liver disease due to recurrent hepatitis C virus cirrhosis, suffering acute-on-chronic liver failure while on the waiting list for an LT, received HT as a bridge to whole-organ retransplantation. After HT and during intensive care unit admission, blood tests and ammonia levels were determined every 12 and 24 h, respectively, before and after each hepatocyte infusion. RESULTS: The present study describes monitoring of analytical and clinical parameters and improvement of liver function following HT. In both patients, we managed to lower the blood ammonia levels and clinically improve the degree of hepatic encephalopathy, thus serving as a bridge to liver retransplantation in 1 patient. CONCLUSIONS: We believe that this therapy may be an alternative treatment in patients with chronic liver disease who suffer episodes of acute decompensation as a bridge to conventional LT.

Cell lines: a tool for in vitro drug metabolism studies.

Primary cultured hepatocytes are a valuable in vitro model for drug metabolism studies. However, their widespread use is greatly hindered by the scarcity of suitable human liver samples. Moreover, the well-known in vitro phenotypic instability of hepatocytes, the irregular availability of fresh human liver for cell harvesting purposes, and the high batch-to-batch functional variability of hepatocyte preparations obtained from different human liver donors, seriously complicate their use in routine testing. To overcome these limitations, different cell line models have been proposed for drug metabolism screening. Human liver-derived cell lines would be ideal models for this purpose given their availability, unlimited life-span, stable phenotype, and the fact that they are easy to handle. However, the human hepatoma cells currently used (i.e. HepG2, Mz-Hep-1) show negligible levels of drug-metabolizing and do not constitute a real alternative to primary hepatocytes. Different strategies have been proposed to generate metabolically competent immortalized hepatocytes (transformation of human hepatocytes with plasmids encoding immortalizing genes, hepatocyte-like cells derived from stem cells, cell lines generated from transgenic animals, hepatocyte/hepatoma hydrid cells). Moreover, recombinant models heterologously expressing P450 enzymes in different host cells have been developed and successfully used in drug metabolism testing. In addition, new strategies have recently been explored to upregulate the expression of drug-metabolizing enzymes in cell lines of a human origin (i.e. transfection with expression vectors encoding key hepatic transcription factors). Among metabolic-based drug-drug interactions, P450 inhibition seems to be the most important. A major application of recombinant models expressing a single P450 is the screening of potential enzyme inhibitors. Therefore, pharmaceutical companies increasingly make use of cell lines to speed up the selection of new drugs with favourable pharmacokinetic and metabolic properties.

Strategies to in vitro assessment of major human CYP enzyme activities by using liquid chromatography tandem mass spectrometry.

At the early stage of drug discovery, thousands of new chemical entities (NCEs) may be screened before a single candidate can be identified for development. Determining the role of CYP enzymes in the metabolism of a compound and evaluating the effect of NCEs on human CYP activities are key issues in pharmaceutical development as they may explain inter-subject variability, drug-drug interactions, non-linear pharmacokinetics and toxic effects. Reliable methods for determining enzyme activities are needed to characterize an individual CYP enzyme and to obtain a tool for the evaluation of its role in drug metabolism in humans. Different liquid chromatography tandem mass spectrometry methodologies have been developed for the fast and routine analysis of major in vivo and in vitro CYPs enzyme activities. The high sensitivity and selectivity of mass spectrometry allow traditional assays to be minimized, thus saving time, efforts and money. Therefore this technology has become the method of choice for the fast assessment of CYP enzyme activities in early drug discovery development. Our intention herein is to review the most recent approaches that have been developed to quickly assess CYPs activities using in vitro models and liquid chromatography coupled with mass spectrometry, as well as their application in early drug discovery.

Modulation of P450 enzymes by Cuban natural products rich in polyphenolic compounds in rat hepatocytes.

This paper reports cytotoxic effects and changes in the P450 system after exposing rat hepatocytes to four polyphenol-rich products widely used in Cuban traditional medicine (Mangifera indica L. (MSBE), Thalassia testudinum (Tt), Erythroxylum minutifolium and confusum extracts). Effects of mangiferin, the main polyphenol in MSBE, were also evaluated. Cytotoxicity was assayed by the MTT test after exposure of cells to the products (50-1000 microg/mL) for 24 or 72 h. The results showed that 500 microg/mL MSBE was moderately cytotoxic after 72 h, while mangiferin was not. Marked reductions in cell viability were produced by Erythroxylum extracts at concentrations > or = 200 microg/mL, whereas only moderate effects were induced by 1000 microg/mL Tt. Seven specific P450 activities were evaluated after 48 h exposure of cells to the products. MSBE reduced phenacetin O-deethylation (POD; CYP1A2) activity in a concentration-dependent manner (IC(50)=190 microg/mL). No decreases were observed in other activities. In contrast, mangiferin produced reductions in five P450 activities: IC(50) values of 132, 194, >200, 151 and 137 microg/ml for POD (CYP1A2), midazolam 1'-hydroxylation (M1OH; CYP3A1), diclofenac 4'-hydroxylation (D4OH; CYP2C6), S-mephenytoin 4'-hydroxylation (SM4OH), and chlorzoxazone 6-hydroxyaltion (C6OH; CYP2E1), respectively. E. minutifolium, E. confusum and Tt extracts produced small reductions in SM4OH and C6OH activities, but no significant changes were noted in the other P450 activities. On the other hand, all the products increased the benzyloxyresorufin O-debenzylation (BROD; CYP2B1) activity, with MSBE, mangiferin or E. minutifolium showing the highest effects (about 2-fold over control). Our results showed in vitro effects of these natural products on P450 systems, possibly leading to potential metabolic-based interactions.

Potential hepatoprotective effects of new Cuban natural products in rat hepatocytes culture.

The protective effects of five Cuban natural products (Mangifera indica L. (MSBE), Erythroxylum minutifolium, Erythroxylum confusum, Thalassia testudinum and Dictyota pinnatifida extracts and mangiferin) on the oxidative damage induced by model toxicants in rat hepatocyte cultures were studied. Cells were pre-incubated with the natural products (5-200 microg/mL) for 24 h. Then hepatotoxins (tert-butyl hydroperoxide, ethanol, carbon tetrachloride and lipopolysaccharide) were individually added and post-incubated for another 24 h. After treatments, cell viability was determined using the MTT assay. Mangiferin and MSBE exhibited the highest cytoprotective potential (EC50 between 50 and 125 microg/mL), followed by T. testudinum and Erythroxylum extracts, whereas no significant protective effects was produced by Dictyota extract treatment. Antioxidant properties of the natural products against lipid peroxidation and GSH depletion induced by tert-butyl hydroperoxide were then investigated. The results show that at 36 h pre-treatment of cells with mangiferin or MSBE, concentrations of T. testudinum and Erythroxylum extracts ranging from 25 to 100 microg/mL significantly inhibited lipid peroxidation induced by tert-butyl hydroperoxide (100 and 250 microM) and increased the GSH levels reduced by the toxicant. D. pinnatifida inhibited lipid peroxidation, but did not preserve GSH levels. In conclusion, MSBE, E. minutifolium, E. confusum and T. testudinum extracts and mangiferin showed hepatoprotective activity against induced damage in all the experimental series, where mangiferin and the extracts of MSBE and T. testudinum were the best candidates to inhibit "in vitro" damage to rat hepatocytes. This hepatoprotective effect found could be associated with the antioxidant properties observed for the products.

Coordinated induction of drug transporters and phase I and II metabolism in human liver slices.

Although regulation of phase I drug metabolism in human liver is relatively well studied, the regulation of phase II enzymes and of drug transporters is incompletely characterized. Therefore, we used human liver slices to investigate the PXR, CAR and AhR-mediated induction of drug transporters and phase I and II metabolic enzymes. Precision-cut human liver slices were incubated for 5 or 24h with prototypical inducers: phenobarbital (PB) (50 microM) for CAR, beta-naphthoflavone (BNF) (25 microM) for AhR, and rifampicin (RIF) (10 microM) for PXR, and gene expression of the phase I enzymes CYP1A1, 1A2, 3A4, 3A5, 2B6, 2A6, the phase II enzymes UGT1A1 and 1A6, and the transporters MRP2, MDR1, BSEP, NTCP and OATP8 was measured. BNF induced CYP1A1, UGT1A1 and UGT1A6 and MRP2, NTCP and MDR1. RIF induced CYP3A4, 3A5, 2B6, 2A6, UGT1A1, UGT1A6 and BSEP, MRP2 and MDR1 and slightly downregulated OATP8. PB induced CYP3A4, 3A5, 2B6 and 2A6, UGT1A1 and all transporters. Large interindividual differences were found with respect to the level of induction. Enzyme activity of CYP3A4, measured by testosterone metabolism, was increased after 24h by RIF. 7-Ethoxycoumarin O-deethylation activity, mediated predominantly by CYP 1A1/1A2 but also by other CYPs, was increased after 24h with PB. We have shown that regulation of all phases of the (in)activation of a drug via the CAR, AhR and the PXR pathways can be studied in human liver slices. The concomitant induction of metabolic enzymes and transporters shows that also in the human liver transporters and metabolic enzymes are regulated coordinately.

Fatty acid status in captive and free-ranging black rhinoceroses (Diceros bicornis).

The fatty acid (FA) patterns of plasma/serum triglycerides (TG), phospholipids (PL) and cholesteryl esters (CE) of captive and free-ranging black rhinoceroses (Diceros bicornis) were investigated. Free-ranging animals (n = 28) stemmed from four different regions. Captive animals sampled included specimens from North American (n = 11) and three different European facilities (n = 6). The European animals were tested on 1-4 different diets, resulting in a total of 15 blood samples. Regardless of differences between the free-ranging animals from different regions, differences between captive and free-ranging animals were relatively uniform: captive animals had higher overall proportions of polyunsaturated fatty acid (PUFA), due to levels of linoleic acid (LA, 18:2n6) that were drastically increased as compared to free-ranging animals. In contrast, levels of alpha-linolenic acid (ALA, 18:3n3) were consistently lower on conventional zoo diets. n6/n3 ratios for TG, PL and CE were 1.6, 10 and 8 in samples from free-ranging animals, respectively, as compared to 4.1-16.3, 16-148 and 40-277 in samples from captive animals. There was a distinct correlation between the proportion of grain-based products (commercial concentrates, plain grains and bread) in the diets of the European animals and the measured levels of n6 PUFA. An animal from a facility with a very low proportion of grain products in the diet nevertheless had high LA readings, most probably due to the use of sunflower oil as 2% (dry matter basis) of its diet. One animal that received a high proportion of grass meal pellets due to an oral disease had increased ALA contents after the diet change. These results allow conclusions on the suitability of diets fed in captivity: the black rhinoceros is prone to several uncommon diseases that have been suspected to be linked to oxidative damage, possibly due to the disposition of this species to excessive iron storage. An unnatural dietary loading with PUFAs would exacerbate this problem. Additionally, n6 FAs are known as precursors of pro-inflammatory mediators, and their overrepresentation could therefore exacerbate any inflammatory processes. Therefore, the current practice of using grain-based feeds as major ingredients in captive rhinoceros diets is discouraged. Diet items containing ALA (a precursor of anti-inflammatory mediators) such as, fresh grass, fresh browse, the respective silages should be included at higher levels in diets for captive black rhinoceroses. Grass meal pellets, although a good source of ALA and linked with high levels of ALA in an animal of this study, must be chosen with care for black rhinoceroses due to their particular proneness for high iron contents.

Quantification of Enterobacteriaceae in faeces of captive black rhinoceros (Diceros bicornis) in relation to dietary tannin supplementation.

Free-ranging browsing herbivores ingest a range of secondary plant compounds, such as tannins, with their natural diet. As many of these substances have been shown to have antibacterial properties, it could be speculated that a lack of such compounds in captive zoo diets could favour the growth of potentially pathogenic intestinal bacteria. The effect of a supplementation of a conventional diet (N, consisting mainly of grass hay and/or lucerne hay and pelleted compound feeds) fed to eight captive black rhinoceroses (Diceros bicornis) from three zoological institutions with either tannic acid (T), a source of hydrolysable tannins, or quebracho (Q), a source of condensed tannins, was investigated. The number of faecal colony forming units (CFU) of Enterobactericeae was determined by colony count of dilution series from fresh faeces applied to MacConkey agar plates. Tannins were added to the diets at approximately 5-15 g/kg dry matter, depending on the varying intake of roughage and compound feeds by the animals. There was no difference in the number of CFU between diets N (95.0 x 10(5) +/- 225.3 x 10(5)/g fresh faeces) and T (164.3 x 10(5) +/- 225.1 x 10(5)/g fresh faeces); in contrast, diet Q led to a significant reduction in CFU (4.3 x 10(5) +/- 6.5 x 10(5)/g fresh faeces) compared with the other diets. These findings suggest that condensed tannins could have the potential to reduce the number of potentially pathogenic intestinal bacteria, and that the deliberate inclusion of tannin sources in the diets of captive wild animals should be further investigated. The fact that tannic acid, shown to have antibacterial effects in various in vitro studies, did not have an effect in this study, emphasizes that the relevance of tannin supplementation for intestinal health must be verified in vivo.

[Risks factors for pediatric malignant liver tumors]. / Factores de riesgo para los tumores hepáticos malignos pediátricos.

OBJECTIVE: Pediatric Hepatic Malignancies (PHMs) are the result of the interaction between constitutional and environmental risk factors (RFs). We review the evidence on the main RFs associated to PHMs. METHOD: Systematic review of the literature published in the last 25 years on Medline, Embase, Cancerlit, Lilacs and SciElo using the following key words: "etiology/risk factor/epidemiology" and "malignant liver tumors/hepatic cancer" or "hepatoblastoma/hepatocarcionoma". RESULTS: PHMs account for 1 % of all pediatric malignancies. The main types, hepatoblastoma (HB) and hepatocarcionma (HCC) make up 98-99 % of PHM. The main constitutional RFs are: a) Beckwith-Wiedemann (BW) syndrome; b) isolated hemihyperplasia syndrome (IHS); c) adenomatous polyps of the colon; d) hemochromatosis; e) Hereditary Tyrosinemia Type 1; f) a -1-antitrypsin deficiency; g) porphyrias; h) cirrhosis; i) nonalcoholic steatosis; and j) primary sclerosing cholangitis. The main environmental RFs are: a) hepatitis B virus (HBV) and C virus (HCV); b) B1 aflatoxin (B1AF); c) ionizing radiation; d) alcohol; e) hormonal treatments; f) occupational exposure to pesticides, solvents, vinyl chloride and metals; g) smoking; h) arsenic; i) prematury and very low birth weight; and j) trematodes. CONCLUSIONS: The clinical, analytical and ultrasound screening facilitate the early diagnosis of HB in the previously mentioned genetic syndromes, particularly BW and IHS during the first years of life. HBV universal vaccination of newborns provides the biggest opportunity to prevent a substantial proportion of PHMs. Also systematic monitoring of HBV and HCV in blood, hemoderivates, donated organs and drug addicts, are very useful. Other effective measures are: the reduction/elimination of B(1)AF in food, zero alcohol intake during childhood and adolescence as well decreasing prenatal exposure to the tobacco, solvents, pesticides, vinyl chloride, metals, ionizing radiation and hormonal treatments.

[Neonatal tumours and congenital malformations]. / Tumores neonatales y malformaciones congénitas.

INTRODUCTION: The association between pediatric cancer and congenital abnormalities is well known but, there is no exclusive data on the neonatal period and the underlying etiopathogenic mechanisms are unknown. OBJECTIVES: First, to analyze the frequency of neonatal tumours associated with congenital abnormalities; and second, to comment on the likely etiopathogenic hypotheses of a relationship between neonatal tumours and congenital abnormalities. MATERIALS AND METHOD: Historical series of neonatal tumours from La Fe University Children's Hospital in Valencia (Spain), from January 1990 to December 1999. Histological varieties of neonatal tumours and associated congenital abnormalities were described. A systematic review of the last 25 years was carried out using Medline, Cancerlit, Index Citation Science and Embase. The search profile used was the combination of "neonatal/congenital-tumors/cancer/neoplasms" and "congenital malformations/birth defects". RESULTS: 72 neonatal tumours were identified (2.8% of all pediatric cancers diagnosed in our hospital) and in 15 cases (20.8%) there was some associated malformation, disease or syndrome. The association between congenital abnormalities and neonatal tumours were: a) angiomas in three patients: two patients with congenital heart disease with a choanal stenosis, laryngomalacia; b) neuroblastomas in two patients: horseshoe kidney with vertebral anomalies and other with congenital heart disease; c) teratomas in two patients: one with cleft palate with vertebral anomalies and other with metatarsal varus; d) one tumour of the central nervous system with Bochdaleck hernia; e) heart tumours in four patients with tuberous sclerosis; f) acute leukaemia in one patient with Down syndrome and congenital heart disease; g) kidney tumour in one case with triventricular hydrocephaly, and h) adrenocortical tumour: hemihypertrophy. The publications included the tumours diagnosed in different pediatric periods and without unified criteria to classify the congenital abnormalities. Little data exist on the neonatal period and the majority are from medical institutions registers. The prevalence varies from 15 to 31.6%. To explain this association, the hypotheses are based on prenatal exposures (preconceptional and transplacental exposure), to mutagenic and carcinogenic risk factors. CONCLUSIONS: Neonatal tumours are more often associated to congenital abnormalities than other pediatric cancers. The inclusion and classification criteria needs to be unified to better understand the association between the neonatal tumours and congenital abnormalities. The environmental history in all neonatal tumours associated to congenital abnormalities, including the constitutional and environmental risk factors, will help to improve our knowledge of the underlying prenatal mechanisms and to an advance in its prevention.

Bladder cancer recurrence surveillance by urine metabolomics analysis.

Non Muscle Invasive Bladder Cancer (NMIBC) is among the most frequent malignant cancers worldwide. NMIBC is treated by transurethral resection of the bladder tumor (TURBT) and intravesical therapies, and has the highest recurrence rate among solid tumors. It requires a lifelong patient monitoring based on repeated cystoscopy and urinary cytology, both having drawbacks that include lack of sensitivity and specificity, invasiveness and care costs. We conducted an investigative clinical study to examine changes in the urinary metabolome of NMBIC patients before and after TURBT, as well during the subsequent surveillance period. Adjusting by prior probability of recurrence per risk, discriminant analysis of UPLC-MS metabolic profiles, displayed negative predictive values for low, low-intermediate, high-intermediate and high risk patient groups of 96.5%, 94.0%, 92.9% and 76.1% respectively. Detailed analysis of the metabolome revealed several candidate metabolites and perturbed phenylalanine, arginine, proline and tryptophan metabolisms as putative biomarkers. A pilot retrospective analysis of longitudinal trajectories of a BC metabolic biomarkers during post TURBT surveillance was carried out and the results give strong support for the clinical use of metabolomic profiling in assessing NMIBC recurrence.

Determination of major human cytochrome P450s activities in 96-well plates using liquid chromatography tandem mass spectrometry.

At the early stage of drug discovery, thousands of new chemical entities (NCEs) may be screened before a single candidate can be identified for development. Evaluation of the effect of NCEs on human CYP450 enzyme activities is a key issue in pharmaceutical development as it may explain inter-subject variability, drug-drug interactions, non-linear pharmacokinetics and toxic effects. A liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method has been developed for the fast and routine analysis of major human CYP450s enzyme activities (CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and CYP3A4) in primary hepatocyte cell cultures. The high sensitivity and selectivity of mass spectrometry has allowed traditional assays to be minimized, thus enabling the use of 96-well plate format which markedly reduced the number of hepatocytes needed for each cytochrome CYP450 activity measurement, a fact that is particularly critical concerning human hepatocytes.

[Intravenous immunoglobulin: another therapeutic application]. / Inmunoglobulina intravenosa: una nueva aplicación terapéutica.

Intravenous immunoglobulin (IVIG) has immunoregulatory functions. In renal transplant, IVIG has been used as an immunosupressor agent only during short period of time and frequently associated to others immunosupressor drugs. In renal transplant IVIG has been used to treat refractory rejection but not as maintenance immunosupressor treatment. We report a case in which IVIG was used as principal immunosupressor agent close to low doses of iv methylprednisolone. The patient could not receive anything by oral way during three months, so she only could be treated by intravenous way. It is the first time that IVIG is used as maintenance immunosupressortreatment for a long time (three months) without secondary effects.

Sperm whale long-range echolocation sounds revealed by ANTARES, a deep-sea neutrino telescope.

Despite dedicated research has been carried out to adequately map the distribution of the sperm whale in the Mediterranean Sea, unlike other regions of the world, the species population status is still presently uncertain. The analysis of two years of continuous acoustic data provided by the ANTARES neutrino telescope revealed the year-round presence of sperm whales in the Ligurian Sea, probably associated with the availability of cephalopods in the region. The presence of the Ligurian Sea sperm whales was demonstrated through the real-time analysis of audio data streamed from a cabled-to-shore deep-sea observatory that allowed the hourly tracking of their long-range echolocation behaviour on the Internet. Interestingly, the same acoustic analysis indicated that the occurrence of surface shipping noise would apparently not condition the foraging behaviour of the sperm whale in the area, since shipping noise was almost always present when sperm whales were acoustically detected. The continuous presence of the sperm whale in the region confirms the ecological value of the Ligurian sea and the importance of ANTARES to help monitoring its ecosystems.

In vitro ADME medium/high-throughput screening in drug preclinical development.

The study of the ADME features of the huge number of new chemical entities (NCEs) produced mainly by combinatorial chemistry has become a bottleneck in the drug development process. In response the pharmaceutical industry is involved in the development of new medium/high-throughput screening capabilities. The aim of this paper is to review some of the available in vitro ADME systems adapted to screening requirements together with the technological approaches which can be linked to medium/high-throughput molecular screening.

Polypodium leucotomos extract: antioxidant activity and disposition.

The extract of the fern Polypodium leucotomos (PL, Fernblock) is an oral photoprotectant with strong antioxidative properties. Recent studies to determine its chemical composition have shown 4-hydroxycinnamic acid (p-coumaric), 3 methoxy-4-hydroxycinnamic acid (ferulic), 3,4-dihydroxycinnamic acid (caffeic), 3-methoxy-4-hydroxybenzoic acid (vanillic) and 3-caffeoilquinic acid (chlorogenic) to be among its major phenolic components. No conclusive data are available, however, on the H2O2-scavenging capacity of these compounds, or on their absorption and metabolism following their oral intake. In the present work, their antioxidative capacity was assessed by the luminol/H2O2 assay, their absorption studied using Caco-2 cells to resemble the intestinal barrier, and their metabolism investigated using cultured primary rat hepatocytes. The antioxidant capacity of PL components increased in a concentration-dependent manner, with ferulic and caffeic acids the most powerful antioxidants. The apparent permeability results correspond to a human post-oral administration absorption of 70-100% for all tested substances. Coumaric, ferulic and vanillic acids were metabolized by CYP450-dependent mono-oxygenases and partially conjugated to glucuronic acid and sulfate. These phenolic compounds may contribute to the health benefits afforded by this oral photoprotectant.

Correlation between the radiologic and histologic size of hepatocellular carcinoma in patients eligible for liver transplantation.

Hepatocellular carcinoma is the most prevalent primary hepatic tumor. Early diagnosis and staging is of paramount importance to obtain favorable survivals. So far, there is no general agreement on the most appropriate imaging technique to detect the tumor for correlation between pretransplant radiologic and pathologic size of the tumor, which remains inadequate. With greater clinical experience and increasing accuracy of imaging methods, magnetic resonance (MR) appears to be the most accurate method, yielding a correlation in 67% of cases.