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At least 271 records · Page 15Linked to original sources
PubMed1996

Direct characterization of drug glucuronide isomers in human urine by HPLC-NMR spectroscopy: application to the positional isomers of 6,11-dihydro-11-oxodibenz[b,e]oxepin-2-acetic acid glucuronide.

In this work, 400 and 600 MHz 1H HPLC-NMR spectroscopic methods were developed and applied to separate and identify the positional glucuronide isomers and anomers of the model nonsteroidal antiinflammatory drug, 6,11-dihydro-11-oxodibenz[b,e]oxepin-2-acetic acid, in whole human urine. The HPLC methods utilized either an isocratic system, comprising 30% acetonitrile in water at pH 2.5, or a gradient elution system increasing from 30% to 60% acetonitrile, in order to achieve improved separation of the 2-, 3-, and 4-O-acylglucuronide isomers from the faster eluting endogenous urinary metabolites. Directly coupled stop-flow 1H HPLC-NMR spectroscopic measurements were made at the retention times indicated by the UV-monitored chromatographic peaks. The glucuronide isomers were identified from the 1H NMR spectra on the basis of their chemical shifts and spin-spin coupling patterns. The elution order was 4-O-acyl-, 3-O-acyl-, and finally 2-O-acylglucuronide, with tR values of 10.04, 11.68, and 12.64 min, respectively. Although the alpha- and beta-anomers of each of the positional isomers could not be separated in these solvent systems, they could be identified in the individual 1H NMR spectra. This work shows for the first time that directly coupled HPLC-NMR spectroscopy can be used directly to isolate and characterize acyl-migrated isomers of drug glucuronides in whole urine. This approach will be of value in the study of glucuronide acyl migration reactions of nonsteroidal antiinflammatory drugs and other xenobiotic ester glucuronides in whole biofluids.

Acetates↗
PubMed1996

Combined HPLC, NMR spectroscopy, and ion-trap mass spectrometry with application to the detection and characterization of xenobiotic and endogenous metabolites in human urine.

The direct coupling of HPLC with NMR spectroscopy has been extended by splitting the HPLC eluent after conventional UV detection and sending part to a NMR spectrometer and part to an ion-trap mass spectrometer in a "triplehyphenated" HPLC-NMR-MS system. Combined UV, 1H NMR, and positive-ion electrospray MS detection was achieved in the continuous-flow mode using whole human urine from a subject dosed with acetaminophen. By means of HPLC-NMR-MS, the structural information available from the complementary spectroscopic techniques provided rapid confirmation of the identity of the acetaminophen glucuronide and sulfate metabolites, together with a number of endogenous metabolites. In particular, the HPLC-NMR-MS approach allowed the unequivocal identification of phenylacetylglutamine in human urine, an endogenous metabolite not previously observed in 1H NMR spectra of urine because of extensive overlap with resonances from other metabolites. The analytical advantages and complementarity of NMR and MS techniques in direct hyphenation with HPLC are discussed. The new technique of HPLC-NMR-MS will provide the scope for more comprehensive and fully automated analysis of biofluids and other complex mixtures than was previously available from single hyphenation of these instruments.

Acetaminophen↗
PubMed2026

Urine and Serum Proteome and Lipidome Analysis of Naturally Aging Feline Species.

Aging in companion animals such as cats closely relates to human aging in environmental exposures and disease manifestation, providing a valuable model for identifying biomarkers of age-associated decline. This study provides a combined proteomic and lipidomic analysis of serum and urine from naturally aging domestic cats aged 3.8-16 years, grouped as adult, old, and senior, to identify age-related molecular changes across biofluids. Label-free quantitative proteomics identified 901 urinary and 238 serum proteins, with 75 urinary proteins significantly altered with age that are linked to kidney disease, hypertension, neurodegeneration, and metabolic disorders. In contrast, only six serum proteins differed significantly between adult and old/senior cats, including decreased Apolipoprotein A-I (APOA1) in seniors, a protein linked with cognitive function in aging. Untargeted lipidomics revealed increases in specific serum triacylglycerols, phosphatidylcholines (PCs), and sphingomyelins, while urinary lipid profiles showed limited age-related changes, with some PCs decreasing, and diacylglycerols increasing with age. These results demonstrate distinct systemic and renal molecular remodeling during feline aging and highlight the utility of integrated omics analyses of biological fluids for identifying molecular alterations relevant to both feline and human aging.

Animals↗
PubMed2026

Targeted Modulation of Abundant Proteins Enhances Proteomic Profiling of Ovarian Cancer Ascites: A Pilot Technical Workflow Comparison.

Ascites from ovarian cancer patients are increasingly recognized as a valuable biofluid for cancer research, as its protein composition reflects the disease state and may reveal biomarkers of treatment sensitivity and response. However, the detection of low-abundance proteins is hindered by the presence of highly abundant proteins such as albumin. In this study, we evaluated five protein preparation methods for their effectiveness in depleting high-abundance or enriching low-abundance proteins in ovarian cancer ascites. The Norgen (Nor), Minutes (Min), and Perchloric acid (PerCA) methods were based on abundant protein depletion, while the Urine (Uri) and Nanomics (Nano) kits focused on low-abundance protein enrichment. Processed samples were analyzed using label-free quantitative bottom-up proteomics by LC-MS/MS, followed by a bioinformatics assessment. Compared with undepleted ascites (UnD), Min, Nor, Nano, and PerCA increased protein identifications, whereas Uri produced profiles similar to those of UnD. Notably, PerCA and Nano enabled the identification of distinct protein subsets associated with cancer-related pathways, including immune responses and autophagy. PerCA enriched transmembrane and secreted immunomodulatory glycoproteins, whereas Nano enrichment primarily captured secreted, nuclear, and cytoplasmic soluble proteins. Overall, our results show that both high-abundance protein depletion and low-abundance enrichment improve ascites proteome coverage, each offering distinct advantages in identifying biologically relevant low-abundance proteins.

Female↗
PubMedDate not supplied

8-(omega-aminoalkyl)theophyllines and their use in preparing fluorescently labeled derivatives for applications in immunoassay.

Reaction of alkane-1, omega-diamines with 6-chloro-1,3-dimethylpyrimidine-2,4-dione under carefully controlled conditions gives 6-(omega-aminoalkylamino)-1,3-dimethylpyrimidine-2,4-diones, which can be readily separated from traces of products of disubstitution after benzyloxycarbonyl protection. A sequence of nitrosation at the pyrimidine 5-position, thermal cyclization, and deprotection affords 8-(omega-aminoalkyl) derivatives of theophylline, an important drug in the treatment of asthma and related diseases. These 8-(omega-aminoalkyl)theophyllines can be coupled to fluorescein-5-isothiocyanate and to dansyl chloride, giving fluorescent derivatives of theophylline with applications in automated immunoassay of the drug in biofluids using the fluorescence capillary fill device.

Fluorescent Dyes↗
PubMed2006

pH dependence and protein selectivity of poly(ethyleneimine)/poly(acrylic acid) multilayers studied by in situ ATR-FTIR spectroscopy.

The selective interaction between polyelectrolyte multilayers (PEM) consecutively adsorbed from poly(ethyleneimine) (PEI) and poly(acrylic acid) (PAC) and a binary mixture containing concanavalin A (COA) and lysozyme (LYZ) based on electrostatic interaction is reported. The composition and structure of the PEM and the uptake of proteins were analyzed by in situ attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy, and the morphology and thickness were characterized by atomic force microscopy (AFM) and ellipsometry. The PEM dissociation degree and charge state and the protein adsorption were shown to be highly dependent on the outermost layer type and the pH in solution. High protein uptake was obtained under electrostatically attractive conditions. This was used to bind selectively one protein from a binary mixture of LYZ/COA. In detail it could be demonstrated that six-layered PEM-6 at pH = 7.3 showed a preferential sorption of positively charged LYZ, while at PEM-5 and pH = 7.3 negatively charged COA could be selectively bound. No protein sorption from the binary mixture was observed at pH = 4.0 for both PEM, when COA, LYZ, and the outermost PEI layer of PEM-5 were positively charged or the outermost PAC layer of PEM-6 was neutral. Furthermore, from factor analysis of the spectral data the higher selectivity was found for PEM-5 compared to PEM-6. Increasing the ionic strength revealed a drastic decrease in the selectivity of both PEM. Evidence was found that the proteins were predominantly bound at the surface and to a minor extent in the bulk phase of PEM. These results suggest possible working regimes and application fields of PEI/PAC multilayer assemblies related to the preparative separation of binary and multicomponent protein mixtures (biofluids, food) as well as to the design of selective protein-resistant surfaces.

Acrylic Resins↗
PubMed2003

NMR-based metabolomics: a powerful approach for characterizing the effects of environmental stressors on organism health.

It is important to assess the chronic effects of chemical, physical, and biological stressors on organisms in the environment. Appropriate methods must enable rapid, inexpensive, and multibiomarker analyses of organism health. Here we investigate withering syndrome in red abalone (Haliotis rufescens), an important wild and farmed shellfish species along the Pacific coast, using a metabolomic approach that combines the metabolic profiling capabilities of nuclear magnetic resonance spectroscopy (NMR) with pattern recognition methods. Foot muscle, digestive gland, and hemolymph samples were collected from healthy, stunted, and diseased abalone, and the extracts were analyzed by NMR. Following spectral preprocessing, principal components analyses of the metabolite profiles were conducted. Our results confirm that NMR-based metabolomics can successfully distinguish the biochemical profiles of the three groups of animals, in every type of tissue or biofluid studied. Furthermore, this discovery-based approach successfully identified novel metabolic biomarker profiles associated with withering syndrome. The application of these methods for investigating other environmental stressors is discussed, as are the advantages of NMR-based metabolomics for biomonitoring, particularly in conjunction with gene and protein expression profiling.

Animals↗
PubMed2005

Risk ranking of bioaccessible metals from fly ash dissolved in simulated lung and gut fluids.

Power plant fly ash from two fuels, coal and a mixture of coal and shredded tires, were evaluated for trace metal solubility in simulated human lung and gut fluids (SLF and SGF, respectively) to estimate bioaccessibility. The proportion of bioaccessible to total metal ranged from zero (V) to 80% (Zn) for coal-derived ash in SLF and from 2 (Th) to 100% (Cu) for tire-derived fly ash in SGF. The tire-derived ash contained much more Zn. However, Zn ranked only 5th of the various toxic metals in SGF compared with international regulations for ingestion. On the basis of total concentrations, the metals closestto exceeding limits based on international regulations for inhalation were Cr, Pb, and Al. On dissolution in SLF, the most limiting metals were Pb, Cu, and Zn. For metals exposed to SGF there was no relative change in the top metal, Al, before and after dissolution but the second-ranked metal shifted from Pb to Ni. In most cases only a proportion of the total metal concentrations in either fly ash was soluble, and hence bioaccessible, in either biofluid. When considering the regulatory limits for inhalation of particulates, none of the metal concentrations measured were as hazardous as the fly ash particulates themselves. However, on the basis of the international ingestion regulations for Al, the maximum mass of fly ash that could be ingested is only 1 mg per day (10 mg based on bioaccessibility). It is possible that such a small mass could be consumed by exposed individuals or groups.

Air Pollutants, Occupational↗
PubMed2006

A supramolecular ON-OFF-ON fluorescence assay for selective recognition of GTP.

With the objective of developing small molecule based receptors for nucleosides and nucleotides, interactions of a cyclic donor-acceptor conjugate 1 with adenosine, AMP, ADP, CTP, UTP, ITP, ATP, and GTP have been investigated by absorption, steady-state, and time-resolved fluorescence, cyclic voltammetry (CV), NMR, and fluorescence indicator displacement techniques. Titration of 1 with the fluorescent indicator, 8-hydroxy-1,3,6-pyrene trisulfonate (HPTS), resulted in nearly complete fluorescence quenching of HPTS, along with 25% hypochromicity in its absorption spectrum. Benesi-Hildebrand analysis gave a 1:1 stoichiometry for the complex between the receptor 1 and HPTS with an association constant (Kass) of 4.66 x 104 M-1 in buffer. The driving force for such a complexation was evaluated to be the synergistic effects of pi-stacking and electrostatic interactions inside the cavity as confirmed by the effect of ionic strength, temperature, and the negative results obtained with the model compound 2. Titration of the nonfluorescent complex [1.HPTS] with various nucleosides and nucleotides resulted in revival of fluorescence of the indicator, HPTS. It was observed that GTP induces maximum displacement of HPTS from the complex [1.HPTS] with an overall fluorescence enhancement of ca. 150-fold. The addition of adenosine, AMP, ADP, CTP, and UTP showed negligible changes, whereas ca. 45- and 50-fold enhancement was observed with ATP and ITP, respectively. The competitive displacement of the indicator by various analytes is found to be in the order GTP (buffer) approximately GTP (biofluid) > ITP approximately ATP > UTP > CTP approximately ADP approximately AMP approximately Ade. By virtue of having a better pi-electron cloud, GTP undergoes effective electronic, pi-stacking, and electrostatic interactions inside the cavity and forms a stable complex with the receptor 1. The uniqueness of this assay is that it differentiates GTP from ATP and other nucleotides and signals the event through a visual "turn on" fluorescence mechanism in buffer as well as in biological fluids.

Adenosine Triphosphate↗
PubMed2006

DFTMP, an NMR reagent for assessing the near-neutral pH of biological samples.

A new NMR chemical shift standard and pH indicator, difluorotrimethylsilanylphosphonic acid (DFTMP), is described, and the utility of this reagent is demonstrated for in situ determination of pH in complex biofluids. The pH dependence of this reagent allows accurate in situ determination of aqueous solution pH to within an RMSE of 0.02 pH units over a pH range of 5 to 8. Advantages of this reagent over previously described pH-sensitive components include (1) lack of metal binding affinity, (2) minimal disturbance of endogenous spectral regions, and (3) the potential to function as a multinuclear pH indicator and chemical shift reference point for 19F, 1H, and 31P nuclei. This reagent will be generally useful for NMR experiments on biological systems where the pH needs to be accurately measured at the moment of data acquisition.

Animals↗
PubMed2003

NMR-based metabonomic studies on the biochemical effects of epicatechin in the rat.

Flavonoid consumption via tea drinking has been attributed a number of potential health benefits including cancer prevention, anti-inflammatory action, and cardioprotectant activity. Although the predominant flavonoids in fresh leaf and green tea are known to be flavan-3-ols and flavan-3-O-gallates ("the catechins"), the biochemical effects of tea polyphenol consumption on living systems are generally poorly understood. Metabonomic methods utilizing (1)H NMR spectroscopy of biofluids and principal component analysis (PCA) have been applied to investigate the bioavailability and metabolic responses of rats to a single dose of 22 mg of epicatechin (EC) dissolved in water. Urine samples were collected twice daily (0-8 and 8-24 h) from male Sprague-Dawley rats (n = 10) prior to dosing and for 2 days after dosing. A series of subtle urinary biochemical effects were evident from the (1)H NMR spectra showing that EC was both bioavailable and biochemically active. The identifiable biochemical effects associated with EC dosing included decreased urinary concentrations of taurine, citrate, dimethylamine, and 2-oxoglutarate. These effects were predominately seen within the first 8 h after dosing. EC metabolites were also observed in the urine during this time period. PCA of later time points after dosing (24-32 and 32-48 h) showed that the effects of EC were reversible. This is the first in vivo study demonstrating the overall endogenous metabolic effects of EC consumption and shows the bioavailability of EC via metabolic effects and excretion of EC metabolites.

Animals↗
PubMedDate not supplied

Utilizing human blood plasma for proteomic biomarker discovery.

Candidate proteomic biomarker discovery from human plasma holds both incredible clinical potential as well as significant challenges. The dynamic range of proteins within plasma is known to exceed 10(10), and many potential biomarkers are likely present at lower protein abundances. At present, proteomic based MS analyses provide a dynamic range typically not exceeding approximately 10(3) in a single spectrum, and approximately 10(4)-10(6) when combined with on-line separations (e.g., reversed-phase gradient liquid chromatography), and thus are generally insufficient for low level biomarker detection directly from human plasma. This limitation is providing an impetus for the development of experimental methodologies and strategies to increase the possible number of detections within this biofluid. Discussed is the diversity of available approaches currently used by our laboratory and others to utilize human plasma as a viable medium for biomarker discovery. Various separation, depletion, enrichment, and quantitative efforts as well as recent improvements in MS capabilities have resulted in measurable improvements in the detection and identification of lower abundance proteins (by approximately 10-10(2)). Despite these improvements, further advances are needed to provide a basis for discovery of candidate biomarkers at very low levels. Continued development of depletion and enrichment techniques, coupled with improved pre-MS separations (both at the protein and peptide level) holds promise in extending the dynamic range of proteomic analysis.

Biomarkers↗
PubMedDate not supplied

Investigation of the mouse serum proteome.

With the rapid assimilation of genomic information and the equally impressive developments in the field of proteomics, there is an unprecedented interest in biomarker discovery. Although human biofluids represent increasingly attractive samples from which new and more accurate disease biomarkers may be found, the intrinsic person-to-person variability in these samples complicates their discovery. One of the most extensively used animal models for studying human disease is mouse because, unlike humans, they represent a highly controllable experimental model system. Unfortunately, very little is known about the proteomic composition of mouse serum. In this study, a multidimensional fractionation approach on both the protein and the peptide level that does not require depletion of highly abundant serum proteins was combined with tandem mass spectrometry to characterize proteins within mouse serum. Over 12 300 unique peptides that originate from 4567 unique proteins-approximately 16% of all known mouse proteins-were identified. The results presented here represent the broadest proteome coverage in mouse serum and provide a foundation from which quantitative comparisons can be made in this important animal model.

Amino Acid Sequence↗
PubMedDate not supplied

Discovery of biomarker candidates within disease by protein profiling: principles and concepts.

Proteins and peptides present within clinical samples represent a valuable library of information regarding the ongoing processes within cells and tissues in health and disease. We have developed and validated novel technology applications that can be used to characterize the patterns of global protein expression in tissue and biofluids in either gel-based systems or by automated multidimensional nanocapillary liquid chromatography. Mass spectrophotometry platforms using MALDI MS and MS/MS or LTQ ion trap MS were capable of delivering sensitive and accurate identifications of hundreds of proteins contained in individual samples including individual forms of processing intermediates such as phospho peptides. The Systems Biology approach of integrating protein expression data with clinical data such as histopathology, clinical functional measurements, medical imaging scores, patient demographics, and clinical outcome provides a powerful tool for linking biomarker expression with biological processes that can be segmented and linked to disease presentation.

Animals↗
PubMed2001

Metabonomic characterization of genetic variations in toxicological and metabolic responses using probabilistic neural networks.

Current emphasis on efficient screening of novel therapeutic agents in toxicological studies has resulted in the evaluation of novel analytical technologies, including genomic (transcriptomic) and proteomic approaches. We have shown that high-resolution 1H NMR spectroscopy of biofluids and tissues coupled with appropriate chemometric analysis can also provide complementary data for use in in vivo toxicological screening of drugs. Metabonomics concerns the quantitative analysis of the dynamic multiparametric metabolic response of living systems to pathophysiological stimuli or genetic modification [Nicholson, J. K., Lindon, J. C., and Holmes, E. (1999) Xenobiotica 11, 1181-1189]. In this study, we have used 1H NMR spectroscopy to characterize the time-related changes in the urinary metabolite profiles of laboratory rats treated with 13 model toxins and drugs which predominantly target liver or kidney. These 1H NMR spectra were data-reduced and subsequently analyzed using a probabilistic neural network (PNN) approach. The methods encompassed a database of 1310 samples, of which 583 comprised a training set for the neural network, with the remaining 727 (independent cases) employed as a test set for validation. Using these techniques, the 13 classes of toxicity, together with the variations associated with strain, were distinguishable to >90%. Analysis of the 1H NMR spectral data by multilayer perceptron networks and principal components analysis gave a similar but less accurate classification than PNN analysis. This study has highlighted the value of probabilistic neural networks in developing accurate NMR-based metabonomic models for the prediction of xenobiotic-induced toxicity in experimental animals and indicates possible future uses in accelerated drug discovery programs. Furthermore, the sensitivity of this tool to strain differences may prove to be useful in investigating the genetic variation of metabolic responses and for assessing the validity of specific animal models.

Animals↗
PubMed2002

Analytical reproducibility in (1)H NMR-based metabonomic urinalysis.

Metabonomic analysis of biofluids and tissues utilizing high-resolution NMR spectroscopy and chemometric techniques has proven valuable in characterizing the biochemical response to toxicity for many xenobiotics. To assess the analytical reproducibility of metabonomic protocols, sample preparation and NMR data acquisition were performed at two sites (one using a 500 MHz and the other using a 600 MHz system) using two identical (split) sets of urine samples from an 8-day acute study of hydrazine toxicity in the rat. Despite the difference in spectrometer operating frequency, both datasets were extremely similar when analyzed using principal components analysis (PCA) and gave near-identical descriptions of the metabolic responses to hydrazine treatment. The main consistent difference between the datasets was related to the efficiency of water resonance suppression in the spectra. In a 4-PC model of both datasets combined, describing all systematic dose- and time-related variation (88% of the total variation), differences between the two datasets accounted for only 3% of the total modeled variance compared to ca. 15% for normal physiological (pre-dose) variation. Furthermore, <3% of spectra displayed distinct inter-site differences, and these were clearly identified as outliers in their respective dose-group PCA models. No samples produced clear outliers in both datasets, suggesting that the outliers observed did not reflect an unusual sample composition, but rather sporadic differences in sample preparation leading to, for example, very dilute samples. Estimations of the relative concentrations of citrate, hippurate, and taurine were in >95% correlation (r(2)) between sites, with an analytical error comparable to normal physiological variation in concentration (4-8%). The excellent analytical reproducibility and robustness of metabonomic techniques demonstrated here are highly competitive compared to the best proteomic analyses and are in significant contrast to genomic microarray platforms, both of which are complementary techniques for predictive and mechanistic toxicology. These results have implications for the quantitative interpretation of metabonomic data, and the establishment of quality control criteria for both regulatory agencies and for integrating data obtained at different sites.

Animals↗
PubMed2006

Metabolites and safety: What are the concerns, and how should we address them?

The issue of the safety of drug metabolites in humans is a complex one. In this commentary, a proposal is made regarding how to deal with drug metabolites observed in humans such that the safety of these molecules can be assured. The human radiolabeled ADME study, in which metabolites are identified and quantified in circulation and excreta, is proposed as the primary source of information on human metabolites from which decisions can be made regarding the need for further risk assessment. Although radiolabel ADME studies yield quantitative metabolite profiles that are commonly reported as a percentage of the total drug related material (for circulating metabolites) and a percentage of total dose (for excretory metabolites), it is essential to convert these values into absolute abundances. The structure of a metabolite, its abundance, the biofluid in which it is observed (circulation or excreta), and the toxicity mechanism of concern serve as the four most important characteristics for determination as to whether further safety consideration is warranted. Metabolites in circulation require consideration for toxicity that can arise by effects on specific receptors and/or enzymes (either target or off-target). Metabolites in excreta require consideration for their potential to indicate a body-burden to chemically reactive intermediary metabolites, which can yield toxicities of nonspecific mechanisms commonly associated with covalent binding (e.g., carcinogenicity, immunoallergic response, etc.). Through an analysis of 24 drugs removed from the market because of human toxicity, it was concluded that further testing of human metabolites would not have yielded any additional information that could have predicted human safety findings because human metabolites would have been present in the animal species routinely used in toxicology testing after the administration of the parent compound.

Animals↗
PubMed1990

A comparative study of isolated liver perfusion versus hepatic artery infusion with mitomycin C in rats.

Systemic toxicity is usually the dose-limiting factor in cancer chemotherapy. Regional chemotherapy is therefore an attractive strategy in the treatment of liver metastasis. Two ways of regional chemotherapy, hepatic artery infusion (HAI) and isolated liver perfusion (ILP), were compared investigating the difference in toxicity with tissue and biofluid concentrations of mitomycin C (MMC). In wistar derived WAG rats the maximally tolerated dose of mitomycin C via HAI was 1.2 mg kg-1. Body weight measurements after HAI with doses higher than 1.2 mg kg-1 suggest both an acute and delayed toxic effect of mitomycin C since the time weight curves were triphasic: a rapid weight loss, a steady state and a second fall in weight phase. These rats died due to systemic toxicity. ILP with 4.8 mg kg-1 was associated with no signs of systemic toxicity and only transient mild hepatotoxicity. ILP with 6.0 mg kg-1 was fatal mainly due to hepatic toxicity. The four times higher maximally tolerated dose in ILP resulted in a 4-5 times higher peak concentration of mitomycin C in liver tissue, while the plasma concentration remained significantly lower than in the HAI treated rats. In the tumour tissue a 500% higher concentration of mitomycin C was measured in the ILP with 4.8 mg kg-1 than in HAI with 1.2 mg kg-1 treated rats. We demonstrated that when mitomycin C was administered by ILP a 400% higher dose could be safely administered and resulted in a five times higher tumour tissue concentration. In view of the steep dose-response curve of this alkylating agent this opens new perspectives for the treatment of liver metastasis.

Animals↗