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1.
Int J Clin Pract ; 69(1): 33-40, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25283604

ABSTRACT

PURPOSE: Few real-world data are available on the frequency and management of pain in Internal Medicine (IM). Aims of our study were to assess the prevalence of pain in IM, and to evaluate the effects on pain management of a standardised educational programme. MATERIALS AND METHODS: The study was performed in 26 IM Units in Italy, with two cross-sectional surveys (PRE phase and POST phase) interspersed with an educational programme. In PRE phase each Centre reviewed the hospital charts of the last 100 consecutive patients hospitalised for any cause. An educational programme was conducted in each Centre by means of the 'outreach visit', a face-to-face meeting between health personnel and a trained external expert. Six months after, each Centre repeated the data collection (POST phase), specular to the PRE. RESULTS: A total of 5200 medical charts were analysed. Pain was documented in 37.5% of the patients. After the educational intervention, the intensity of pain was appropriately assessed in a higher percentage of patients (77.4% vs. 47.8%, p = 0.0001), and it was more frequently monitored during hospitalisation. Qualitative definition of pain (pathogenesis, duration, etc.) increased in POST phase (75.4% vs. 62.7%, p = 0.0001). A 73.3% increase in the use of strong opioids was detected following educational programme. CONCLUSIONS: Pain affects 4 out of 10 patients hospitalised in IM. According to our large real-world study, to implement a standardised one-shot educational programme may persistently improve the attitude of health personnel towards the characterisation and management of pain.


Subject(s)
Education/methods , Health Knowledge, Attitudes, Practice , Internal Medicine/methods , Pain Management/methods , Pain Management/standards , Cross-Sectional Studies , Female , Health Education , Humans , Italy , Male
2.
Article in English | MEDLINE | ID: mdl-20087806

ABSTRACT

In vitro toxicological tests have been proposed as an approach to complement the chemical safety assessment of food contact materials, particularly those with a complex or unknown chemical composition such as paper and board. Among the concerns raised regarding the applicability of in vitro tests are the effects of interference of the extractables on the outcome of the cytotoxicity and genotoxicity tests applied and the role of known compounds present in chemically complex materials, such as paper and board, either as constituents or contaminants. To answer these questions, a series of experiments were performed to assess the role of natural substances (wood extracts, resin acids), some additives (diisopropylnaphthalene, phthalates, acrylamide, fluorescent whitening agents) and contaminants (2,4-diaminotoluene, benzo[a]pyrene) in the toxicological profile of paper and board. These substances were individually tested or used to spike actual paper and board extracts. The toxic concentrations of diisopropylnaphthalenes and phthalates were compared with those actually detected in paper and board extracts showing conspicuous toxicity. According to the results of the spiking experiments, the extracts did not affect the toxicity of tested chemicals nor was there any significant metabolic interference in the cases where two compounds were used in tests involving xenobiotic metabolism by the target cells. While the identified substances apparently have a role in the cytotoxicity of some of the project samples, their presence does not explain the total toxicological profile of the extracts. In conclusion, in vitro toxicological testing can have a role in the safety assessment of chemically complex materials in detecting potentially harmful activities not predictable by chemical analysis alone.


Subject(s)
Food Contamination/prevention & control , Food Packaging , Paper , Animals , Biological Assay , Cell Line, Tumor , Humans , Mutagens , Salmonella typhimurium/drug effects , Salmonella typhimurium/genetics , Wood/chemistry
3.
Eur Rev Med Pharmacol Sci ; 14(12): 1045-50, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21375137

ABSTRACT

BACKGROUND AND OBJECTIVES: Opioid-bowel dysfunction (OBD) is a broad range of symptoms potentially associated with opioid therapy. This prospective, multicentric study assesses the prevalence of OBD in patients on analgesic therapy for the treatment of pain from any cause and identifies the factors associated with the onset of this side effect. MATERIALS AND METHODS: Consecutive patients aged > 18 years, on analgesic treatment with opioids, non-steroidal anti-inflammatory drugs (NSAIDs) or other therapies for chronic pain of any aetiology were included in the study. The association of OBD with gender, age, pain aetiology and analgesic treatment was analyzed by multivariate analysis and logistic analysis. RESULTS: In total, 2324 patients were included in the study. The prevalence of OBD symptoms was 63.5%, despite that the wide majority of patients (89.5%) were receiving laxatives. OBD symptoms were judged as directly correlated with analgesic therapy in 85.1% of cases. The highest prevalence of constipation was reported with morphine, whereas the lowest was observed in patients on oxycodone CR and buprenorphine TTS. Statistical analysis showed that patients on opioids have a higher likelihood of experiencing OBD symptoms than those on NSAIDs or other treatments (66.2% vs 37.0%), and this probability is even higher in those with cancer-related pain (69.3%). Female gender and age > 70 years also appeared as risk factors. The logistic analysis indicated that cancer-related pain, increased age and the use of fentanyl are positive predictors of the presence of OBD, whereas the administration of oxycodone CR was associated with a decreased incidence of these symptoms. DISCUSSION: Even with the limitation of any observational experience, this study suggests, for the first time, the existence of some factors predictive of the onset of OBD symptoms in patients on analgesic treatment. Moreover, different opioids seem to be associated with a different risk of experiencing these symptoms.


Subject(s)
Analgesics, Opioid/adverse effects , Constipation/chemically induced , Defecation/drug effects , Pain/drug therapy , Adult , Age Factors , Aged , Aged, 80 and over , Chronic Disease , Constipation/drug therapy , Constipation/epidemiology , Constipation/physiopathology , Female , Humans , Italy/epidemiology , Laxatives/therapeutic use , Logistic Models , Male , Middle Aged , Odds Ratio , Prevalence , Prospective Studies , Risk Assessment , Risk Factors , Sex Factors , Surveys and Questionnaires , Time Factors , Young Adult
4.
Article in English | MEDLINE | ID: mdl-20013449

ABSTRACT

This paper describes the use of a suite of extraction procedures applicable to the assessment of the in vitro toxicity of paper/board samples intended for food-contact applications. The sample is extracted with ethanol, water, or exposed to modified polyphenylene oxide (Tenax) for fatty, non-fatty and dry food applications, respectively. The water extracts are directly suitable for safety assessment using in vitro bioassays. The ethanol extracts of the paper/board and of the exposed Tenax require pre-concentration to give acceptable sensitivity. This is because the in vitro bioassays can tolerate only a small percentage of added organic solvent before the solvent itself inhibits. The extraction procedures have been selected such that they mimic the foreseeable conditions of use with foods and that they are also fully compatible with the battery of in vitro biological assays for the safety assessment of the total migrate. The application of the extraction protocols is illustrated by the results for one of the many paper/board samples provided by the BIOSAFEPAPER project industrial platform members. The assessment indicated that this sample should not be considered as suitable for use with fatty foodstuffs but was suitable for dry and non-fatty foods. Information subsequently received from the manufacturer revealed that this was a non-food-grade product included in the project to test the capabilities of the bioassay procedures. The selection criteria for the test conditions and the suite of methods developed have been prepared in Comité Européen de Normalisation (CEN) format and is currently being progressed by CEN/TC172 as a European Standard.


Subject(s)
Food Packaging , Paper , Toxicity Tests , Wood , Gas Chromatography-Mass Spectrometry , In Vitro Techniques
5.
Med. paliat ; 16(3): 164-177, mayo-jun. 2009. tab
Article in Spanish | IBECS | ID: ibc-76810

ABSTRACT

El estreñimiento es uno de los problemas más frecuentes en pacientes que reciben cuidados paliativos y puede ocasionar sufrimiento y molestias importantes. Los objetivos de este estudio son: profundizar sobre el conocimiento del estreñimiento en Cuidados Paliativos (CP), orientar de forma práctica y clara su tratamiento y fomentar la investigación en este campo. Un grupo de trabajo paneuropeo compuesto de médicos y enfermeros con importante experiencia en el control del estreñimiento en CP se reunió para evaluar los datos publicados y establecer unas recomendaciones clínicas. Se identificaron cuatro publicaciones potencialmente relevantes en las que destaca la ausencia de directrices clínicas claras y prácticas sobre la valoración, el diagnóstico y el tratamiento del estreñimiento en CP. Envista de los escasos datos disponibles, nuestras recomendaciones se basan en la opinión clínica de expertos, en los resultados pertinentes de investigaciones realizadas en otros ámbitos y en la mejor práctica de los países representados. Los pacientes que reciben cuidados paliativos tienen un riesgo elevado de estreñimiento y, aunque los principios generales de la prevención deben ser aplicados, a menudo es necesario el tratamiento farmacológico. Por lo general se recomienda la combinación de un laxante emoliente con otro estimulante, aunque los laxantes deben ser escogidos de forma individual. Las evidencias actuales son escasas y se necesitan más estudios sobre aspectos relativos a la valoración, el diagnóstico y el tratamiento del estreñimiento en CP (AU)


Constipation is one of the most common problems in patients receiving palliative care and can cause extreme suffering and discomfort. The aims of this study are to raise awareness of constipation in palliative care, provide clear, practical guidance on management and encourage further research in the area. A pan-European working group of physicians and nurses with significant experience in the management of constipation in palliative care met to evaluate the published evidence and produce these clinical practice recommendations. Four potentially relevant publications were identified, highlighting a lack of clear, practical guidance on the assessment, diagnosis and management of constipation in palliative care patients. Given the limited data available, our recommendations are based on expert clinical opinion, relevant research findings from other settings and best practice from the countries represented. Palliative care patients are at a high risk of constipation, and while general principles of prevention should be followed, pharmacological treatment is often necessary. The combination of a softener and stimulant laxative is generally recommended, and the choice of laxatives should be made on an individual basis. The current evidence base is poor and further research is required on many aspects of the assessment, diagnosis and management of constipation in palliative care (AU)


Subject(s)
Humans , Palliative Care , Constipation/therapy , Evidence-Based Medicine , Expert Testimony
6.
Palliat Med ; 22(7): 796-807, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18838491

ABSTRACT

Constipation is one of the most common problems in patients receiving palliative care and can cause extreme suffering and discomfort. The aims of this study are to raise awareness of constipation in palliative care, provide clear, practical guidance on management and encourage further research in the area. A pan-European working group of physicians and nurses with significant experience in the management of constipation in palliative care met to evaluate the published evidence and produce these clinical practice recommendations. Four potentially relevant publications were identified, highlighting a lack of clear, practical guidance on the assessment, diagnosis and management of constipation in palliative care patients. Given the limited data available, our recommendations are based on expert clinical opinion, relevant research findings from other settings and best practice from the countries represented. Palliative care patients are at a high risk of constipation, and while general principles of prevention should be followed, pharmacological treatment is often necessary. The combination of a softener and stimulant laxative is generally recommended, and the choice of laxatives should be made on an individual basis. The current evidence base is poor and further research is required on many aspects of the assessment, diagnosis and management of constipation in palliative care.


Subject(s)
Cathartics/therapeutic use , Constipation/drug therapy , Palliative Care , Constipation/chemically induced , Constipation/prevention & control , Humans
7.
Food Chem Toxicol ; 46(7): 2498-509, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18508176

ABSTRACT

Nineteen food contact papers and boards and one non-food contact board were extracted following test protocols developed within European Union funded project BIOSAFEPAPER. The extraction media were either hot or cold water, 95% ethanol or Tenax, according to the end use of the sample. The extractable dry matter content of the samples varied from 1200 to 11,800 mg/kg (0.8-35.5 mg/dm2). According to GC-MS the main substances extracted into water were pulp-derived natural products such as fatty acids, resin acids, natural wood sterols and alkanols. Substances extracted into ethanol particularly, were diisopropylnaphthalenes, alkanes and phthalic acid esters. The non-food contact board showed the greatest number and highest concentrations of GC-MS detectable compounds. The extracts were subjected to a battery of in vitro toxicity tests measuring both acute and sublethal cytotoxicity and genotoxic effects. None of the water or Tenax extracts was positive in cytotoxicity or genotoxicity assays. The ethanol extract of the non-food contact board gave a positive response in the genotoxicity assays, and all four ethanol extracts gave positive response(s) in the cytotoxicity assays to some extent. These responses could not be pinpointed to any specific compound, although there appeared a correlation between the total amount of extractables and toxicity.


Subject(s)
Environmental Exposure/adverse effects , Food Contamination/analysis , Food Packaging , Paper , Animals , Biological Assay , Ethanol/chemistry , Fatty Acids/analysis , Gas Chromatography-Mass Spectrometry/methods , Humans , Mutagenicity Tests , Polymers/chemistry , Risk Assessment , Safety , Sterols/analysis , Toxicity Tests , Water
8.
Food Addit Contam ; 22(10): 1032-41, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16227187

ABSTRACT

An European Union (EU)-funded project QLK1-CT-2001-00930 (BIOSAFEPAPER) involves the development, validation and intercalibration of a short-term battery of toxicological tests for the safety assessment of food-contact paper and board. Dissemination of the results to industry, legislators (e.g. DG Consumer Protection, DG Enterprises, DG Research), standardization bodies such as CEN, and consumers will create an agreed risk evaluation procedure. The project involves pre-normative research in order to establish a set of in-vitro cytotoxicity and genotoxicity tests that will be easily adaptable to food-contact fibre-based materials and have endpoints relevant to consumer safety, including sub-lethal cellular events. These tests will be performed on samples representing actual migration conditions from food-contact paper and board with respect to different foodstuffs, and should form an experimental basis for scientifically sound recommendations for a harmonized system of risk evaluation and product testing.


Subject(s)
Food Contamination , Food Packaging , Paper , Toxicity Tests/methods , Animals , Cell Line, Tumor , Cells/drug effects , Cells, Cultured , Dimethyl Sulfoxide/analysis , Dimethyl Sulfoxide/toxicity , Environmental Exposure/adverse effects , Ethanol/analysis , European Union , Food Analysis/methods , Gas Chromatography-Mass Spectrometry/methods , Humans , Mammals , Mice , Models, Biological , Mutagenicity Tests/methods , Risk Assessment/methods , Safety , Water
9.
Cell Biol Toxicol ; 21(1): 1-26, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15868485

ABSTRACT

The human intestinal Caco-2 cell line has been extensively used over the last twenty years as a model of the intestinal barrier. The parental cell line, originally obtained from a human colon adenocarcinoma, undergoes in culture a process of spontaneous differentiation that leads to the formation of a monolayer of cells, expressing several morphological and functional characteristics of the mature enterocyte. Culture-related conditions were shown to influence the expression of these characteristics, in part due to the intrinsic heterogeneity of the parental cell line, leading to selection of sub-populations of cells becoming prominent in the culture. In addition, several clonal cell lines have been isolated from the parental line, exhibiting in general a more homogeneous expression of differentiation traits, while not always expressing all characteristics of the parental line. Culture-related conditions, as well as the different Caco-2 cell lines utilized in different laboratories, often make it extremely difficult to compare results in the literature. This review is aimed at summarizing recent, or previously unreviewed, data from the literature on the effects of culture-related factors and the influence of line sub-types (parental vs. different clonal lines) on the expression of differentiation traits important for the use of Caco-2 cells as a model of the absorptive and defensive properties of the intestinal mucosa. Since the use of Caco-2 cells has grown exponentially in recent years, it is particularly important to highlight these methodological aspects in order to promote the standardization and optimisation of this intestinal model.


Subject(s)
Cell Physiological Phenomena , Intestinal Mucosa/physiology , Autocrine Communication/physiology , Caco-2 Cells , Cell Adhesion/drug effects , Cell Adhesion/physiology , Cell Count , Cell Culture Techniques/methods , Cell Differentiation/drug effects , Cell Differentiation/physiology , Clone Cells/cytology , Clone Cells/drug effects , Clone Cells/physiology , Culture Media/chemistry , Culture Media/pharmacology , Enterocytes/cytology , Enterocytes/drug effects , Enterocytes/physiology , Extracellular Matrix/metabolism , Humans , Intestinal Mucosa/cytology , Intestinal Mucosa/drug effects , Membrane Transport Proteins/metabolism , Paracrine Communication/physiology , Sucrase-Isomaltase Complex/metabolism
10.
Toxicon ; 45(3): 285-91, 2005 Mar 01.
Article in English | MEDLINE | ID: mdl-15683866

ABSTRACT

The aim of the present paper is to evaluate the absorption of fumonisin B1 and its principal metabolite, aminopentol on a human intestinal model, Caco-2 cells, cultured on semi-permeable inserts, that reproduces the two different intestinal compartments: luminal (apical) and serosal (basolateral) side. Following separate exposure in apical and in basolateral compartments, aminopentol passage through the cell layer (in particular from basolateral to apical direction) was shown, while it was not observed for the parent compound. The different aminopentol distribution between the two compartments of the culture system, and its variation in presence of verapamil or probenecid (P-gp and MRP inhibitors respectively), strongly suggests the involvement of P-glycoprotein in the influx/efflux mechanisms of aminopentol in the intestinal cells, reducing its oral bioavailability.


Subject(s)
ATP Binding Cassette Transporter, Subfamily B, Member 1/physiology , Carboxylic Acids/pharmacokinetics , Fumonisins/pharmacokinetics , Intestinal Absorption/physiology , Mycotoxins/pharmacokinetics , ATP Binding Cassette Transporter, Subfamily B, Member 1/antagonists & inhibitors , Caco-2 Cells , Carboxylic Acids/pharmacology , Fumonisins/pharmacology , Humans , Membrane Potentials/drug effects , Models, Biological , Mycotoxins/pharmacology , Probenecid/pharmacology , Verapamil/pharmacology
11.
Toxicol In Vitro ; 18(2): 153-63, 2004 Apr.
Article in English | MEDLINE | ID: mdl-14757105

ABSTRACT

From almost 20 years the "in vitro" model has gained a wide ground in toxicological investigation, providing advanced tools, reliable protocols, mechanistic information. These advancements have been done thanks to different approaches, addressed at improving chemical testing and validating procedures, at exploring the cellular and molecular basis of toxicity, at studying the modifications that xenobiotics undergo in the cellular environment. In this review the most advanced cellular models, the mechanisms of cell death, the techniques to monitor gene activation, following chemical exposure, is highlighted. Moreover the more recent in vitro models to approach the biotransformation issue will be presented.


Subject(s)
Cells, Cultured , Toxicology/trends , Animals , Biomedical Engineering , Biotransformation , Cell Death , Humans , Toxicogenetics
13.
Toxicon ; 40(8): 1181-188, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12165322

ABSTRACT

The aim of the present paper is to investigate intestinal absorption and toxicity of Fumonisin B(1) (FB(1)) and its partially (PHFB(1) and PHFB(2)) and totally hydrolyzed (HFB(1)) metabolites, using the human intestinal cell line Caco-2, a very well known in vitro model of intestinal epithelium for absorption and metabolism studies. Caco-2 cells were treated for 48 h with several toxin concentrations (in the range of 1-138 microM). At the end of exposure period, no significant variation on cell viability has been observed with all chemicals tested, either in undifferentiated cells or in differentiated ones, suggesting a poor toxicity of these mycotoxins for intestinal cells. In any case, FB(1) appears the most active in this respect. For which concerns the cellular absorption, FB(1), PHFB(1) and PHFB(2) are never detected into Caco-2 cells. On the contrary, a dose-dependent absorption of HFB(1) has been observed in differentiated cells, which express enzymatic and metabolic characteristics of mature enterocytes. Thus HFB(1), losing the tricarballylic acid chain, is more bioavailable than FB(1) on intestinal cell, supporting the hypothesis that in risk evaluation of fumonisins exposure its metabolites are also relevant.


Subject(s)
Carcinogens, Environmental/toxicity , Fumonisins/toxicity , Intestinal Absorption/drug effects , Biotransformation , Caco-2 Cells , Carcinogens, Environmental/pharmacokinetics , Cell Differentiation/drug effects , Cell Membrane/drug effects , Cell Survival/drug effects , Chromatography, High Pressure Liquid , Colony-Forming Units Assay , Fumonisins/chemistry , Fumonisins/pharmacokinetics , Humans , Hydrolysis
14.
Toxicol Lett ; 127(1-3): 153-60, 2002 Feb 28.
Article in English | MEDLINE | ID: mdl-12052653

ABSTRACT

The impressive advancement of technologies in biomedical research, and particularly in the area of in vitro experimental models, has opened up new possibilities related to co-cultures, micromass or stem cell cultures. Engineered cells to study specific targets and/or mechanisms are also available. Moreover, a very subtle approach in the study of toxicological effects is represented by the very recent genomics and proteomics techniques. New mechanistically based methods could be established from all these approaches, which, once validated, could enter the regulatory procedure. So far, in toxicology, only a few in vitro tests are accepted for regulatory purposes, such as those related to corrosion, phototoxicity and absorption. Many others are in the pre-validation or validation phase. An area where in vitro tests play a key role is the genetic toxicology. In this context, the most recent testing strategies and test methods will be presented, with particular attention to the recently updated guidelines for food additives by the EU Scientific Committee on Food. An improvement in the implementation of validated methods could arise from a better coordination on the matter at national and international levels, the harmonisation of different legislations, and a strict control of the national rules in order to make them up-to-date with respect to validated methods.


Subject(s)
Culture Techniques/methods , Toxicology/methods , Animals , Embryo, Mammalian/drug effects , Humans , Mutagenicity Tests/methods , Skin Absorption/drug effects , Xenobiotics/adverse effects , Xenobiotics/toxicity
15.
Toxicol In Vitro ; 15(4-5): 289-95, 2001.
Article in English | MEDLINE | ID: mdl-11566551

ABSTRACT

The involvement of the NO pathway in several intestinal inflammatory diseases is under investigation. In vitro models may provide a useful approach to better characterise this pathway at the cellular level. For this purpose, we have used Caco-2 cells, which are able to spontaneously differentiate in long-term culture to small intestine enterocytes. The effect of different NO pathway inducers [gamma-interferon (IFN-gamma) and phorbol myristate acetate (PMA)] has been studied. Our results demonstrate that Caco-2 cells constitutively express NOS at very low levels, while the induction with PMA+IFN-gamma triggers the expression of the inducible isoform with a stronger effect starting from day 14 of differentiation. The use of specific inhibitors of gene expression, at transcriptional and translational level, suggests that new synthesis of iNOS mRNA is required, through direct activation of the gene or new synthesis of transcription-required factors, as indicated by CHX inhibition. The morphological alteration induced by PMA+IFN-gamma is reversed by iNOS inhibitor, suggesting that the NO pathway may be involved in the cytoskeletal alterations. The DSP toxins, OA and DTX-1, induce NO production at levels corresponding to their different toxicity, previously detected in Caco-2 cells.


Subject(s)
Caco-2 Cells/drug effects , Caco-2 Cells/metabolism , Enzyme Inhibitors/pharmacology , Marine Toxins/pharmacology , Nitric Oxide/biosynthesis , Blotting, Western , Caco-2 Cells/pathology , Cell Survival/drug effects , Dose-Response Relationship, Drug , Drug Combinations , Enzyme Induction/drug effects , Gene Expression Regulation, Enzymologic/drug effects , Humans , Interferon-gamma/pharmacology , NG-Nitroarginine Methyl Ester/pharmacology , Nitric Oxide Synthase/biosynthesis , Nitric Oxide Synthase/genetics , Nitric Oxide Synthase Type II , Nitric Oxide Synthase Type III , Okadaic Acid/pharmacology , Pyrans/pharmacology , RNA, Messenger/metabolism , Tetradecanoylphorbol Acetate/pharmacology , omega-N-Methylarginine/pharmacology
16.
Pharmacol Res ; 43(4): 393-8, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11352544

ABSTRACT

In the present investigation the identification of beta -adrenoceptor (beta -ARs) subtypes in the Caco-2 cell line was performed using radiometric assays. beta -ARs were measured using increasing concentrations of the highly specific beta -AR antagonist (-)[(3)H]CGP 12177 (0.06-4 nM), whereas the beta(1)- and beta(2)-AR subtypes discriminated through selective binding assays using the highly selective unlabelled antagonists CGP 20712A and ICI 118551. Atypical beta -ARs were measured using an incubation system formed by higher concentrations (0.6-20 nM) of (-)[(3)H]CGP 12177. beta - Atypical binding site concentrations (69 +/- 5 fmol mg ml(-1)of membrane protein) were higher than beta(1)-ARs (7 +/- 1) and beta(2)-ARs (24 +/- 2), respectively. The different beta -AR subtype affinities were characterized by binding inhibition experiments and the adrenergic agonists displaced the radioligand from its specific binding sites in the following order of potency: isoproterenol > clenbuterol > dobutamine > SR 58611A; for antagonists the order of potency was: propranolol approximately = ICI118551 approximately = CGP20712A. For atypical beta -ARs the order was: SR 58611A > clenbuterol > dobutamine > isoproterenol for agonists and propranolol > CGP 20712A > ICI 118551 for antagonists. As far as in vitro functional studies are concerned, beta -AR subtypes were shown to be coupled to adenylyl cyclase as their stimulation produced cAMP in an amount significantly higher than basal values. cAMP production after stimulation with dobutamine, clenbuterol, isoproterenol, and SR 58611A was measured using a cAMP radioassay kit. The order of efficacy suggested that the stimulation of beta(2)-ARs was the most effective in inducing the activation of cell signalling mechanisms. The identification of functional beta -ARs in a cancer cell line represents the first step in the study of the possible adrenergic control of cellular activities (e.g. proliferation and/or differentiation), which could suggest the use of this cancer cell line as a model for the study of cell activity or possibly new therapeutic strategies.


Subject(s)
Adenylyl Cyclases/metabolism , Cell Membrane/enzymology , Cell Membrane/metabolism , Propanolamines/metabolism , Adrenergic beta-Agonists/metabolism , Adrenergic beta-Agonists/pharmacology , Adrenergic beta-Antagonists/metabolism , Adrenergic beta-Antagonists/pharmacology , Binding Sites , Caco-2 Cells , Cell Membrane/drug effects , Cyclic AMP/metabolism , Humans , Propanolamines/antagonists & inhibitors , Protein Binding/drug effects , Substrate Specificity
17.
Chem Biol Interact ; 127(2): 109-24, 2000 Jul 03.
Article in English | MEDLINE | ID: mdl-10936227

ABSTRACT

Thiabendazole (TBZ), an anthelmintic and fungicide benzimidazole, was recently demonstrated to be extensively metabolized by cytochrome P450 (CYP) 1A2 in man and rabbit, yielding 5-hydroxythiabendazole (5OH-TBZ), the major metabolite furtherly conjugated, and two minor unidentified metabolites (M1 and M2). In this study, exposure of rabbit and human cells to 14C-TBZ was also shown to be associated with the appearance of radioactivity irreversibly bound to proteins. The nature of CYP isoforms involved in this covalent binding was investigated by using cultured rabbit hepatocytes treated or not with various CYP inducers (CYP1A1/2 by beta-naphthoflavone, CYP2B4 by phenobarbital, CYP3A6 by rifampicine, CYP4A by clofibrate) and human liver and bronchial CYP-expressing cells. The covalent binding to proteins was particularly increased in beta-naphthoflavone-treated rabbit cells (2- to 4-fold over control) and human cells expressing CYP1A2 (22- to 42-fold over control). Thus, CYP1A2 is a major isoenzyme involved in the formation of TBZ-derived residues bound to protein. Furthermore, according to the good correlation between covalent binding and M1 or 5OH-TBZ production, TBZ would be firstly metabolized to 5OH-TBZ and subsequently converted to a chemically reactive metabolic intermediate binding to proteins. This metabolic activation could take place preferentially in liver and lung, the main biotransformation organs, rather than in intestines where TBZ was shown to be not metabolized. Moreover, TBZ was rapidly transported by passive diffusion through the human intestinal cells by comparison with the protein-bound residues which were not able to cross the intestinal barrier. Consequently, the absence of toxicity measured in intestines could be related to the low degree of TBZ metabolism and the lack of absorption of protein adducts. Nevertheless, caution is necessary in the use of TBZ concurrently with other drugs able to regulate CYP1A2, particularly in respect to liver and lung tissues, recognised as sites of covalent-binding.


Subject(s)
Antinematodal Agents/metabolism , Cytochrome P-450 CYP1A2/metabolism , Intestinal Absorption/physiology , Proteins/metabolism , Thiabendazole/analogs & derivatives , Thiabendazole/metabolism , Animals , Antinematodal Agents/pharmacokinetics , Antinematodal Agents/toxicity , Biological Transport , Bronchi/drug effects , Bronchi/enzymology , Caco-2 Cells/drug effects , Caco-2 Cells/enzymology , Cells, Cultured , Colony-Forming Units Assay , Cytochrome P-450 CYP1A2/biosynthesis , Enzyme Induction/drug effects , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Humans , Intestinal Mucosa/drug effects , Intestinal Mucosa/enzymology , Intestinal Mucosa/metabolism , Isoenzymes/biosynthesis , Isoenzymes/metabolism , Liver/drug effects , Liver/enzymology , Liver/metabolism , Male , Protein Binding , Rabbits , Thiabendazole/pharmacokinetics , Thiabendazole/toxicity
18.
Cell Biol Toxicol ; 16(1): 53-62, 2000.
Article in English | MEDLINE | ID: mdl-10890506

ABSTRACT

The recent increase in understanding of cell death has promoted new approaches in toxicological studies, mainly those dealing with in vitro systems where the evaluation of cell death has been the most widely adopted end-point in measuring the effects of chemical toxicants. The aim of this study was to investigate the possibility of improving the traditional cytotoxicity test protocols in order to produce more specific information on the type of cell death induced by exposure to toxicants. In particular, we characterized the mode of cell death in an established epithelial cell line, HEp-2 cells, which is frequently used in cytotoxicity testing owing to its easy handling and standardization of culture conditions. Reference chemicals for apoptosis and necrosis were selected as controls, together with other molecules that have been shown, in preliminary studies, to induce various morphological and structural modifications in relation to cell death. The results obtained show that: (a) the floating fraction of treated cells gives the clearest picture of the necrotic/apoptotic distribution; (b) morphological analysis is crucial for characterization of apoptosis; (c) more than one cytotoxic end-point is necessary to clearly identify the type of cell death.


Subject(s)
Apoptosis/drug effects , Epithelial Cells/cytology , Epithelial Cells/drug effects , Cell Adhesion , Cell Line , Cell Membrane/drug effects , Cell Survival , Epithelial Cells/enzymology , Humans , L-Lactate Dehydrogenase/metabolism , Necrosis
19.
Ital Heart J Suppl ; 1(1): 97-102, 2000 Jan.
Article in Italian | MEDLINE | ID: mdl-10832125

ABSTRACT

BACKGROUND: Spinal cord stimulation has been used for many years in the treatment of refractory angina pectoris. Its anti-anginal and anti-ischemic effect has been well documented in several studies, but the long-term efficacy, safety and survival rate are not well known. The aim of this study was to carry out a retrospective analysis of a series of patients from the Italian Multicenter Registry, the data of which were collected in five centers, by means of a questionnaire. METHODS: One hundred and thirty patients (83 males, 47 females, mean age 74.8 +/- 9.8 years) were submitted to spinal cord stimulator implantation for refractory angina pectoris in the period 1988-1995 and controlled during a mean follow-up of 31.4 +/- 25.9 months. A previous myocardial infarction had already occurred in 69.3% of patients, whereas in 67.6% multivessel coronary artery disease was documented. A left ventricular dysfunction (ejection fraction < 0.40) was present in 34% of patients; bypass surgery and coronary angioplasty were performed in 49.6% and in 27% of patients respectively. In 96.3% of cases revascularization procedures were not advisable. RESULTS: A complete follow-up of 116 patients (89.2%) was available. The spinal cord stimulator induced a significant reduction in NYHA functional class from 2.5 +/- 1.2 to 1.5 +/- 0.9 (p < 0.01). During the follow-up 41 patients (35.3%) died, and in 14.2% a new acute myocardial infarction developed. The total percentage of minor spinal cord stimulation-related complications was 6.8%. No major complications occurred. The annual total mortality rate was 6.5%, whereas the cardiac mortality rate was 5%. Compared to the survivors, patients who died showed a higher incidence of left ventricular dysfunction, previous myocardial infarction and bypass surgery at implantation. CONCLUSIONS: In our experience, spinal cord stimulation is an effective therapy in patients affected by refractory angina pectoris and who cannot undergo revascularization procedure. The complication rate is low, with the total and cardiac mortality showing a trend as that reported for patients with similar coronary disease.


Subject(s)
Angina Pectoris/therapy , Electric Stimulation Therapy/methods , Aged , Aged, 80 and over , Angina Pectoris/mortality , Electric Stimulation Therapy/adverse effects , Epidural Space , Female , Humans , Italy/epidemiology , Male , Middle Aged , Retrospective Studies , Risk Factors , Treatment Outcome
20.
Xenobiotica ; 29(11): 1157-69, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10598749

ABSTRACT

1. The metabolism and cytotoxicity of the antimicrobial nitrofuran drug furazolidone have been studied in Caco-2, HEp-2 and V79 cell lines. Free radical production, metabolite pattern, formation of bound residues, inhibition of cellular replication and protection by the antioxidant glutathione were compared for the three cell lines. 2. All three cell lines produced the same nitro-anion radical with similar kinetics. Little further metabolic breakdown was observed in V79 cells, whereas Caco-2 and HEp-2 cells showed extensive degradation of furazolidone, but with different end patterns. 3. Under hypoxic conditions, the colony-forming ability was extensively impaired in HEp-2 cells whereas the other two cell lines were less affected, suggesting that irreversible damage to DNA occurred prevalently in HEp-2 cells. In V79 cells the absence of oxygen caused a 25-fold increase in the formation of protein-bound residues. 4. Brief exposure to furazolidone caused a 50% loss of endogenous glutathione in Caco-2 cells, but no loss could be detected in V79 and HEp-2 cells. Consistently, when glutathione was depleted by buthionine-[S,R]-sulphoximine (BSO) and diethylmaleate (DEM) treatment, the viability of V79 and HEp-2 cells was minimally affected by furazolidone, whereas that of Caco-2 cells was substantially reduced. 5. It is concluded that the cytotoxicity of furazolidone in these cell lines can be exerted by a number of different mechanisms, possibly related to different metabolic pathways. The cytotoxicity of nitrofuran drugs, therefore, cannot be ascribed to a single toxic intermediate, but in Caco-2 cells furazolidone is extensively metabolized and detoxified by GSH, in V79 is only partially activated and then bound to proteins, whereas in HEp-2, once activated, may react with DNA.


Subject(s)
Anti-Infective Agents, Local/metabolism , Anti-Infective Agents, Local/toxicity , Furazolidone/metabolism , Furazolidone/toxicity , Biotransformation , Caco-2 Cells , Cell Division/physiology , Cell Hypoxia/physiology , Cell Line , Colony-Forming Units Assay , Electron Spin Resonance Spectroscopy , Free Radicals/metabolism , Glutathione/metabolism , Humans , Protein Binding
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