Simultaneous LC-MS/MS quantification of P-glycoprotein and cytochrome P450 probe substrates and their metabolites in DBS and plasma.

BACKGROUND: An LC-MS/MS method has been developed for the simultaneous quantification of P-glycoprotein (P-gp) and cytochrome P450 (CYP) probe substrates and their Phase I metabolites in DBS and plasma. P-gp (fexofenadine) and CYP-specific substrates (caffeine for CYP1A2, bupropion for CYP2B6, flurbiprofen for CYP2C9, omeprazole for CYP2C19, dextromethorphan for CYP2D6 and midazolam for CYP3A4) and their metabolites were extracted from DBS (10 µl) using methanol. Analytes were separated on a reversed-phase LC column followed by SRM detection within a 6 min run time. RESULTS: The method was fully validated over the expected clinical concentration range for all substances tested, in both DBS and plasma. The method has been successfully applied to a PK study where healthy male volunteers received a low dose cocktail of the here described P-gp and CYP probes. Good correlation was observed between capillary DBS and venous plasma drug concentrations. CONCLUSION: Due to its low-invasiveness, simple sample collection and minimal sample preparation, DBS represents a suitable method to simultaneously monitor in vivo activities of P-gp and CYP.

Evaluation of different Cypermethrin formulations and concentrations in the control of Musca domestica

Cypermethrin (4 g/l, 5 g/l wettable powder and 7 ml/l, 10 ml/l emulsifiable concentrate) was tested, under laboratory conditions, against the adult Musca domestica. As a standard for comparison, a 6 ml/l concentrate suspension formulation of deltamethrin was used. One and twenty-four hours after application, mortality counts showed that the substances under test killed, respectively, more than 80% and 85% of the exposed insects. Under the conditions of the test, cypermethrin was considered effective in the control of the house fly.

Establiment de bases científiques per al desenvolupament d'una estratègia integrada per avaluar toxicitat en reproducció

Report for the scientific sojourn at the National Institute for Public Health and the Environment (RIVM), Netherlands, from 2006 to 2008. This project aimed at creating scientific elements that could help deriving an integrated testing strategy for reproductive toxicity. Part of the project focused on the use of alternative tests for regulatory purposes. An in vitro-in vivo extrapolation method for embryotoxicity was proposed and evaluated. In vitro and in vivo dose descriptors were correlated; however, the scatter in the correlation was too large to allow an accurate estimation of an in vivo dose from an in vitro dose. The in vitro-in vivo extrapolation method together with toxicokinetic data was also applied to a category of substances (phthalates). Although based on a limited number of substances, the results suggested that in vitro-in vivo extrapolation for embryotoxicity is possible within a category of compounds if adequate toxicokinetic data is available. Because of the limitations that still remain in the use of alternative tests for reproductive toxicicity, other approaches to reduce animal testing were explored. Thus, a database of reproductive toxicity studies was created to retrospectively evaluate the comparative value of some studies or elements in a particular study. When compared to the subchronic toxicity study, the rat two-generation reproductive toxicity study had a considerable impact on the identification of hazard for reproductive toxicity, but not on the overall NOAEL. Among the two-generation studies included in our database, the second generation affected neither the overall NOAEL nor the critical effect. The rat and the rabbit developmental toxicity studies were, on average, similarly sensitive. However, for certain substances the developmental study in either one of the two species appeared to be more sensitive than in the other species.

Sexual dysfunction among young men : prevalence and associated factors

Les dysfonctions sexuelles représentent une préoccupation importante et parfois mésestimée dans la population masculine générale. L'éjaculation précoce et les dysfonctions érectiles faisant partie des dysfonctions sexuelles les plus fréquentes, nous avons choisi, dans le présent article, de nous concentrer sur ces deux aspects. Selon plusieurs études, la prévalence d'éjaculation précoce se situe entre 17 et 30%. Les associations décrites avec l'éjaculation précoce concernent le stress, la dépression et un jeune âge (<25 ans). La prévalence de dysfonction érectile, quant à elle, oscille entre 2 et plus de 80% dépendant principalement de l'âge. Beaucoup d'autres facteurs associés ont été décrits dans la littérature, tels que le diabète, les pathologies cardiovasculaires ou neurologiques, les médicaments, l'obésité ou l'inactivité physique. Tous ces facteurs étant plus fréquents au sein de populations vieillissantes, nous disposons de peu d'études concernant la dysfonction érectile chez de jeunes hommes. Notre étude propose donc d'évaluer la prévalence d'éjaculation précoce et de dysfonction érectile chez une population de jeunes hommes et d'étudier les associations possibles avec les consommations de substances, l'index de masse corporelle (IMC), l'activité physique ou la santé mentale. Chaque homme suisse entre 18 et 25 ans est appelé à participer à 2 journées de recrutement militaire. De septembre 2010 à mai 2011, les jeunes hommes recrutés à Lausanne et à Zürich (N= 9761) ont été invités à participer à l'étude C-SURF (Cohort Study on Substance Use Risk Factors). 5276 d'entre eux acceptèrent de répondre au questionnaire complet, et 73% (N=3886) le firent de manière effective. Le but de notre recherche étant d'étudier les dysfonctions sexuelles, nous nous sommes concentrés sur les participants sexuellement actifs (N=2507) et les avons divisés en 2 groupes, selon qu'ils présentaient ou non la dysfonction étudiée. Pour chaque dysfonction (éjaculation précoce et dysfonction érectile), nous avons utilisé une analyse bivariée afin de comparer les deux groupes (avec ou sans trouble) quant à d'éventuels facteurs associés. A cause de la nature transversale de l'étude, nous ne pouvions pas postuler de lien de cause à effet entre ces facteurs et les dysfonctions sexuelles, raison pour laquelle nous avons choisi d'utiliser des modèles log-linéaires pour mettre en exergue les associations significatives. Nos résultats montrent une prévalence d'éjaculation précoce de 11.4% avec comme associations principales la consommation de tabac et de drogues illégales (autres que le cannabis). La prévalence des dysfonctions érectiles est quant à elle proche du 30% et s'associe principalement avec l'usage de médicaments, ainsi qu'avec la santé physique et la santé mentale. Un jeune homme suisse sur trois souffre ainsi d'au moins une dysfonction sexuelle. Beaucoup de facteurs compromettants pour la santé y sont possiblement associés, raison pour laquelle les professionnels de la santé devraient saisir chaque occasion pour parler de sexualité avec leurs jeunes patients de sexe masculin.

Anatomy of contaminated aquifers of an industrial site: insights from the stable isotope compositions of waters and dissolved inorganic carbon

The hydrogen and oxygen isotopes of water and the carbon isotope composition of dissolved inorganic carbon (DIC) from different aquifers at an industrial site, highly contaminated by organic pollutants representing residues of the former gas production, have been used as natural tracers to characterize the hydrologic system. On the basis of their stable isotope compositions as well as the seasonal variations, different groups of waters (precipitation, surface waters, groundwaters and mineral waters) as well as seasonably variable processes of mixing between these waters can clearly be distinguished. In addition, reservoir effects and infiltration rates can be estimated. In the northern part of the site an influence of uprising mineral waters within the Quaternary aquifers, presumably along a fault zone, can be recognized. Marginal infiltration from the Neckar River in the cast and surface water infiltration adjacent to a steep hill on the western edge of the site with an infiltration rate of about one month can also be resolved through the seasonal variation. Quaternary aquifers closer to the centre of the site show no seasonal variations, except for one borehole close to a former mill channel and another borehole adjacent to a rain water channel. Distinct carbon isotope compositions and concentrations of DIC for these different groups of waters reflect variable influence of different components of the natural carbon cycle: dissolution of marine carbonates in the mineral waters, biogenic, soil-derived CO2 in ground- and surface waters, as well as additional influence of atmospheric CO2 for the surface waters. Many Quaternary aquifer waters have, however, distinctly lower delta(13)C(DIC) values and higher DIC concentrations compared to those expected for natural waters. Given the location of contaminated groundwaters at this site but also in the industrially well-developed valley outside of this site, the most likely source for the low C-13(DIC) values is a biodegradation of anthropogenic organic substances, in particular the tar oils at the site.

Prise en charge par une équipe pluridisciplinaire des patients avec multiples vulnérabilités dans un service d'urgence

Introduction: Les centres d'urgence se trouvent régulièrement confrontés à des patients avec de multiples vulnérabilités médico-sociales qui recourent préférentiellement aux urgences pour y recevoir des soins de bases. Leurs fréquentes consultations contribuent à encombrer les urgences : dans notre service d'urgence entre avril 2008 et mars 2009, une étude ayant pour but de caractériser ces patients a montré que 14 % de l'ensemble des consultations ont été causées par 5 % des patients admis > 4 x/an.Matériel et méthode: Cohorte prospective des patients admis aux urgences et présentant des critères touchant > 3 axes de vulnérabilités sur les 5 axes reconnus habituellement (déterminants somatiques, de santé mentale, comportemental, social, de consommation de soins). Les patients inclus ont été soit signalés par le personnel médico-infirmier des urgences, soit dépistés par une équipe pluridisciplinaire (2 infirmières, 1 assistant social, 1 médecin) durant les jours ouvrables du 1.9.2010 au 14.12.2010.Résultats: 75 patients ont été inclus (65 % d'hommes). La moyenne d'âge était de 43 ans. 59 % étaient des migrants en provenance de : Europe (22 %), Afrique (22 %), Asie (12 %), Amériques du Sud (6 %) et du Nord (1 %). Les vulnérabilités les plus fréquentes étaient: somatiques 76 % (maladies aiguës/chroniques sévères 50 %, mauvaise adhérence thérapeutique 40 %), liées à la santé mentale 65 % (troubles anxieux et dépressifs 54 %), comportementales 80 % (addictions aux substances 73 %), sociales 93 % (absence de domicile fixe 31 %, absence d'assurance-maladie 15 %, barrières linguistiques 24 %, à l'assistance sociale 46 %) et consommation de soins (> 4 visites aux urgences/an 57 %, absence de médecin de premier recours 33 %). La charge de travail moyenne pour orienter ces patients vers des structures de santé primaire était de 3 heures/cas. Les interventions ont été d'évaluer le réseau de soins déjà impliqué (98 %), de réorienter dans le réseau ambulatoire (64 %) ou vers les services sociaux (37 %).Conclusion: Les vulnérabilités multiples sont relativement peu fréquentes dans notre service d'urgence mais leur complexité requiert des ressources qui dépassent ce que peuvent offrir des équipes de soins habituelles aux urgences. Une prise en charge individuelle par une équipe pluridisciplinaire est susceptible de fournir ces ressources et de réorienter ces patients vers des structures ambulatoires adaptées à leurs besoins.

Endogenous opioid peptides in parasympathetic, sympathetic and sensory nerves in the guinea-pig heart.

Research has suggested that exogenous opioid substances can have direct effects on cardiac muscle or influence neurotransmitter release via presynaptic modulation of neuronal inputs to the heart. In the present study, multiple-labelling immunohistochemistry was employed to determine the distribution of endogenous opioid peptides within the guinea-pig heart. Approximately 40% of cardiac ganglion cells contained immunoreactivity for dynorphin A (1-8), dynorphin A (1-17) and dynorphin B whilst 20% displayed leu-enkephalin immunoreactivity. Different populations of opioid-containing ganglion cells were identified according to the co-existence of opioid immunoreactivity with immunoreactivity for somatostatin and neuropeptide Y. Immunoreactivity for prodynorphin-derived peptides was observed in many sympathetic axons in the heart and was also observed, though to a lesser extent, in sensory axons. Leu-enkephalin immunoreactivity was observed in occasional sympathetic and sensory axons. No immunoreactivity was observed for met-enkephalin-arg-gly-leu or for beta-endorphin. These results demonstrate that prodynorphin-derived peptides are present in parasympathetic, sympathetic and sensory nerves within the heart, but suggest that only the prodynorphin gene is expressed in guinea-pig cardiac nerves. This study has shown that endogenous opioid peptides are well placed to regulate cardiac function via both autonomic and sensory pathways.

Nylon wool column: a tool for obtaining monokine-rich eluates in the absence of serum

Diverse conditions for stimulating human mononuclear cells to release thymocyte costimulatory factors were tested for their contribution to the generation of supernatants high titers of these monokines. Activity titers increased with LPS concentration, reaching a plateau between 1 and 10 microng/ml. Indomethacin did not modify the monokine, but the assay for thymocyte costimulatory activity was substantially affected by inhibitory substances produced by the monocytes in the absence of indomethacin. The use of nylon wool columns to trap the cells was shown to be effective in raising cellular densities without decreasing activity titers. As result, the yield per cell could be maintained even in the absence of serum, an important step toward the goal of purifiying bioactive from crude broths.

Gas emission during laparoscopic colorectal surgery using a bipolar vessel sealing device: A pilot study on four patients.

BACKGROUND: Dissection during laparoscopic surgery produces smoke containing potentially toxic substances. The aim of the present study was to analyze smoke samples produced during laparoscopic colon surgery using a bipolar vessel sealing device (LigaSuretrade mark). METHODS: Four consecutive patients undergoing left-sided colectomy were enrolled in this pilot study. Smoke was produced by the use of LigaSuretrade mark. Samples (5,5l) were evacuated from the pneumoperitoneum in a closed system into a reservoir. Analysis was performed with CO2-laser-based photoacoustic spectroscopy and confirmed by a Fourier-transform infrared spectrum. The detected spectra were compared to the available spectra of known toxins. RESULTS: Samples from four laparoscopic sigmoid resections were analyzed. No relevant differences were noted regarding patient and operation characteristics. The gas samples were stable over time proven by congruent control measurements as late as 24 h after sampling. The absorption spectra differed considerably between the patients. One broad absorption line at 100 ppm indicating H2O and several unknown molecules were detected. With a sensitivity of alpha min ca 10-5 cm-1 no known toxic substances like phenol or indole were identified. CONCLUSION: The use of a vessel sealing device during laparoscopic surgery does not produce known toxic substances in relevant quantity. Further studies are needed to identify unknown molecules and to analyze gas emission under various conditions.

Pneumothorax sur prise de cocaïne

Introduction: Les complications dues à la cocaïne inhalée se¦rencontrent de plus en plus fréquemment dans les services d'urgence¦et dans la pratique des médecins de premier recours. La survenue de¦complications pulmonaires aiguës de type pneumothorax est¦méconnue.¦Vignette clinique: Un patient de 25 ans consulte aux urgences en¦raison d'une gêne pharyngée, une odynodysphagie et une dysphonie¦en progression depuis 12 h. Il avoue une prise de cocaïne sniffée à 5¦reprises dans les 6 heures précédant l'apparition des symptômes. Des¦crépitations sous-cutanées sont mise en évidence à la palpation du¦creux sus-claviculaire droit, remontant jusqu'à la base du cou. La¦radiographie thoracique confirme un emphysème sous-cutané des¦creux sus-claviculaires (fig. 1). Le patient bénéficie d'une¦oxygénothérapie et d'une observation, avec une évolution¦spontanément favorable.¦Discussion: Après une prise de cocaïne par inhalation profonde, des¦manoeuvres de Valsalva intenses répétées contre glotte fermée sont¦pratiquées, afin d'augmenter la quantité de substance absorbée et donc¦ses effets. Ceci engendre un gradient de pression entre les alvéoles et¦l'interstitium pulmonaire, entraînant une augmentation de la pression¦intra-alvéolaire, puis une rupture des alvéoles avec libération d'air à¦travers les tissus péri-bronchiques dans le médiastin et les tissus¦sous cutanés. En cas de rupture dans la cavité pleurale, il en résulte¦un pneumothorax. Un tabagisme actif est souvent associé, laissant¦suspecter un effet favorisant du tabac sur la survenue des lésions¦pulmonaires. Un traitement conservateur associant antalgie et¦oxygénothérapie s'avère en général suffisant. En présence d'une¦augmentation de la taille du pneumothorax ou de signes de mise¦sous tension, la pose d'un drain thoracique est indiquée. L'arrêt de la¦consommation de cocaïne et du tabac doit être encouragé.¦Conclusion: Un emphysème sous-cutané ou un pneumothorax¦spontané chez un jeune patient doivent faire suspecter une éventuelle¦consommation de cocaïne. Les questions concernant la prise de¦cocaïne ou d'autres substances (alcool, amphétamines, etc.), ainsi¦que son mode d'utilisation et sa fréquence, doivent être formulées¦clairement et réitérées à plusieurs reprises. Le risque de pneumothorax¦existe également lors de consommation occasionnelle et peut entraîner¦des complications pulmonaires importantes.

Administering brief motivational interventions to young men: Results from a pilot census transmissible study among 19 year-old francophone Swiss men.

AIMS - To pilot the implementation of brief motivational intervention (BMI) among conscripts, and to test the effectiveness of BMI in young men voluntarily showing up for a single face-to-face alcohol BMI session. Participants were conscripts attending the army recruitment process in Lausanne. This process is mandatory for all Swiss males at age 19 and Lausanne serves all francophone Swiss men. METHODS - Of 3'227 young men that were seen during the army recruitment procedures, 445 voluntarily showed up for a BMI and 367 were included in the study (exclusions were random and unsystematic and related to organizational aspects in the recruitment center). After an initial assessment, subjects were randomized into two groups: an immediate BMI and a 6-month delayed BMI (waiting list design). A 6-month follow-up assessment was conducted in both groups. BMI was a face-to-face 20 minutes counseling session with a psychologist trained in motivational interviewing at baseline and a telephone session for the control group at follow-up. Strategies of BMI included the exploration and evocation of a possible behavior change, importance of future change, readiness to change, and commitment to change. A filmed example of such an intervention is available in French at www.alcoologie.ch. RESULTS - All procedures are now fully implemented and working and the provision of preventive efforts found general approval by the army. 3'227 were eligible for BMI and 445 of them (13.8%) showed up for receiving a BMI. 367 were included in the study, 181 in the BMI group and 186 in the control group. More than 86% of those included were reached at follow-up. With one exception all findings on alcohol use went in the expected direction, i.e. a stronger decrease in alcohol use (or a smaller increase as for usual weekly drinking amount) in the BMI group. The risk for risky single occasion drinking (RSOD) decreased from 57% at-risk users at baseline to 50.6%, i.e. a 6.4% point decrease in the BMI group, while there was only a 0.6% point decrease (from 57.5% to 56.9%) in the control group. Moreover, the study showed that there was a likelihood of crossover effects for other substances like tobacco smoking and cannabis use. Despite these encouraging and consistent positive findings, none reached significance at conventional levels (p < 0.05). DISCUSSION - Data suggest a beneficial impact of BMI on alcohol use outcomes and potential effect on other substance use in 19-year old men attending the army recruitment and showing up voluntarily for BMI. As the main aim was to implement and test feasibility of conducting BMI in this setting none of our findings reached statistical significance. The consistency of findings across measures and substances, however, raises hope that non-significance in the present study does not mean no effect, but mainly insufficient power of this pilot study. [Authors]

Estudi de la desadsorció del pirè amb diferents surfactants en tres sòls artificials

Un dels problemes associats a la remeiació de contaminants hidròfobs és la seva poca disponibilitat. Es considera que un contaminant està disponible quan roman a la fase líquida del medi, ja sigui solubilitzat o en forma d’emulsió. Els surfactants són substàncies anfifíliques que promouen la transferència de compostos hidròfobs de la fase sòlida a la líquida. En aquest estudi s’escull el pirè com a representant dels hidrocarburs aromàtics policíclics i tres surfactants no iònics: un àmpliament citat a la bibliografia científica (Tween 80) i dos comercials (Gold Crew, BS-400). L’estudi es fa amb tres mescles d’argila i sorra amb diferents proporcions. La concentració micel·lar crítica (CMC) s’assoleix abans en sòls amb poc contingut en argila. L’eficiència dels surfactants està estretament relacionada amb la proporció d’argila i sorra. A concentracions molt per sobre de la CMC no s’observa una relació entre l’eficiència i la quantitat d’argila. El Tween 80 ha donat millors resultats que el Gold Crew i el BS-400, sense que aquest darrer no hagi presentat desadsorció de pirè.

Medium-term protocols for in vivo evaluation of chemical modifiers of carcinogenesis

Cancer development is a long-term multistep process which allows interventional measure before the clincial disease emerges. the detection of natural substances which can block the process of carcinogenesis is a important as the identification of anti-tumoral drugs since they might be used in chemoprevention of cancer in high-risk groups. In vivo rodent models of chemical caecinogenesis have been used to study plant-derived inhibitors of carcinofenesis such as indols, coumarins, isothiocyanates, flavones, phenols and allyl-sulfides. Since the standard in vivo rodent bioassay is prolonged and expensive, shorter reliable protocols are needed. Two in vivo medium-term protocols for evaluation of modifiers of carcinogenesis are presented, one related to liver and the other to bladder cancer. Both protocols use rats, last 8 and 36 weeks and are based on the two-step concept of carcinogenesis: initiation and promotion. The protocols use respectively the development of altered foci of hepatocytes expressing immunochistochemically the placental form of gluthation S-transferase and the appearence of pre-neoplastic urothelium and papillomas as the "end-points". the use of these protocols for detection of plantpderived inhibitors of carcinogenesis appear warranted.

Antitumor activity of chemical modified natural compounds

Search of new activity substances starting from chemotherapeutic agents, continously appears in international literature. Perhaps this search has been done more frequently in the field of anti-tumor chemotherapy on account of the unsuccess in saving advanced stage patients. The new point in this matter during the last decade was computer aid in planning more rational drugs. In near future "the accessibility of supercomputers and emergence of computer net systems, willopen new avenues to rational drug design" (Portoghese, P. S. J. Med. Chem. 1989, 32, 1). Unknown pharmacological active compounds synthetized by plants can be found even without this eletronic devices, as tradicional medicine has pointed out in many contries, and give rise to a new drug. These compounds used as found in nature or after chemical modifications have produced successful experimental medicaments as FAA, "flavone acetic acid" with good results as inibitors of slow growing animal tumors currently in preclinical evaluation for human treatment. In this lecture some international contributions in the field of chemical modified compounds as antineoplasic drugs will be examined, particularly those done by Brazilian researches.

Réactions cutanées allergiques et toxiques aux plantes [Allergic and toxic cutaneous reactions to plants]

Numerous professional or leisure activities expose individuals to plants susceptible to provoke contact allergies. The immunological mechanisms that are responsible for these ailments (delayed cellular reaction linked to allergic dermatitis or immediate IgE mediated reaction of the allergic urticaria) differ according to the plant families involved. A differential diagnosis must be made in the case of the even more frequent non-allergic reactions implying either a simple mechanical irritation, or a contact with toxic substances. The role of UV (phytophotodermatosis), as well as the contact allergy to wood is also evoked in this paper.