Pharmacokinetics of gemcitabine at fixed-dose rate infusion in patients with normal and impaired hepatic function

Background and objectives: Gemcitabine (2,2-difluorodeoxycytidine [dFdC]) can be administered in a standard 30-minute infusion or in a fixed-dose-rate (FDR) infusion to maximize the rate of accumulation of triphosphate, its major intracellular metabolite. The standard 30-minute infusion requires dose adjustment in patients with organ dysfunction, especially in patients with elevated baseline serum bilirubin levels. On the other hand, the FDR infusion is burdened by increased haematological toxicity. The primary aim of this study was to evaluate the pharmacokinetics of dFdC and its metabolite difluorodeoxyuridine (dFdU) in patients with normal and impaired hepatic function. Patients and methods: In this prospective study, patients with pancreatic or biliary tract carcinoma and normal or impaired hepatic function tests were considered eligible for recruitment. Patients were recruited according to the following criteria: (i) serum bilirubin <1.6 mg/dL and AST and ALT <2 times the upper the limit of normal (ULN) [cohort I]; and (ii) serum bilirubin >1.6 mg/dL and/or AST/ALT >2 times the ULN (cohort II). An FDR infusion of gemcitabine 1000 mg/m2 was administered on days 1, 8 and 15 every 4 weeks. The pharmacokinetic analysis of gemcitabine and dFdU was performed with high-performance liquid chromatography-tandem mass spectrometry assay in cycles 1 and 2. Results: Thirteen patients were enrolled, four in cohort I and nine in cohort II. All patients were assessable for toxicity and pharmacokinetic analysis. The grade and rate of toxicities were similar in both groups, and patients with elevation of bilirubin and/or transaminases did not require dose reduction of gemcitabine. Pharmacokinetic analysis revealed a reduction of the experimental area under the plasma concentration-time curve for gemcitabine and dFdU in patients with hepatic dysfunction when compared with patients with normal hepatic function. All other pharmacokinetic parameters were similar in the two cohorts. No statistical difference was demonstrated for all parameters evaluated between cycle 1 and cycle 2 in the two groups. Conclusion: Gemcitabine 1000 mg/m2 can be administered as an FDR infusion in patients with altered hepatic function without causing additional toxicity compared with patients with normal hepatic function

LALINET: The First Latin American–Born Regional Atmospheric Observational Network

Sustained and coordinated efforts of lidar teams in Latin America at the beginning of the 21st century have built LALINET (Latin American Lidar NETwork), the only observational network in Latin America created by the agreement and commitment of Latin American scientists. They worked with limited funding but an abundance of enthusiasm and commitment toward their joint goal. Before LALINET, there were a few pioneering lidar stations operating in Latin America, described briefly here. Bi-annual Latin American Lidar Workshops, held from 2001 to the present, supported both the development of the regional lidar community and LALINET. At those meetings, lidar researchers from Latin America meet to conduct regular scientific and technical exchanges among themselves and with experts from the rest of the world. Regional and international scientific cooperation has played an important role for the development of both the individual teams and the network. The current LALINET status and activities are described, emphasizing the processes of standardization of the measurements, methodologies, calibration protocols, and retrieval algorithms. Failures and successes achieved in the buildup of LALINET are presented. In addition, the first LALINET joint measurement campaign and a set of aerosol extinction profile measurements obtained from the aerosol plume produced by the Calbuco volcano eruption on April 22, 2015, are described and discussed.Fil: Antuña Marrero, Juan Carlos. Centro Meteorológico de Camagüey; CubaFil: Landulfo, Eduardo. Instituto de Pesquisas Energéticas e Nucleares; BrasilFil: Estevan, René. Centro Meteorológico de Camagüey; CubaFil: Barja, Boris. Centro Meteorológico de Camagüey; Cuba. Universidade de Sao Paulo; BrasilFil: Robock, Alan. State University of New Jersey; Estados UnidosFil: Wolfram, Elian Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; ArgentinaFil: Ristori, Pablo Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; ArgentinaFil: Clemesha, Barclay. Upper Atmosphere Research Group; BrasilFil: Zaratti, Francesco. Universidad Mayor de San Andrés; BoliviaFil: Forno, Ricardo. Universidad Mayor de San Andrés; BoliviaFil: Armandillo, Errico. ESTEC; Países BajosFil: Bastidas, Álvaro E.. Universidad Nacional de Colombia. Sede Medellin; ColombiaFil: de Frutos Baraja, Ángel Máximo. Universidad de Valladolid; EspañaFil: Whiteman, David N.. National Aeronautics and Space Administration; Estados UnidosFil: Quel, Eduardo Jaime. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; ArgentinaFil: Barbosa, Henrique M. J.. Universidade de Sao Paulo; BrasilFil: Lopes, Fabio. Comissao Nacional de Energia Nuclear. Centro de Lasers e Aplicacoes. Instituto de Pesquisas Energeticas e Nucleares.; BrasilFil: Montilla-Rosero, Elena. Universidad de Concepción; Chile. Universidad Escuela de Administración, Finanzas e Instituto Tecnológico; ColombiaFil: Guerrero Rascado, Juan L.. Comissao Nacional de Energia Nuclear. Centro de Lasers e Aplicacoes. Instituto de Pesquisas Energeticas e Nucleares.; Brasil. Universidad de Granada; Españ

Diurnal Circulation of the Bolivan Altiplano. Part I: Observations

In July and August 2003 a field campaign was conducted to explore the diurnal circulation of the Bolivian Altiplano. Vertical soundings by remote-controlled aircraft yielded profiles of temperature, pressure, and humidity at six passes and in a valley. Pilot balloon observations provided wind profiles. Two permanent stations collected additional data. Typically, inflow toward the Altiplano commences a few hours after sunrise at about the time when the stable nocturnal layer near the ground is transformed by the solar heating into an almost neutrally stratified convective boundary layer. The depth of the inflow layer is comparable to but normally less than that of this boundary layer. There are indications of return flow aloft. The inflow continues at least until sunset. Moisture is imported at the passes leading to the Yungas in the east. Strong upvalley flows were found in the valley of the Rio de La Paz, which connects the wide canyon of La Paz with the tropical lowlands to the east. Inflow was absent at one of the passes despite favorable synoptic conditions. Cases of synoptically forced flows are presented as well where the diurnal signal is difficult to separate. A simple flow scheme is presented that fits the observations reasonably well

Proposal for a modification of the UVI risk scale

The standardisation of UV information to the public through the UV Index (UVI) has been hugely beneficial since its endorsement by multiple international agencies more than 10 years ago. It has now gained widespread acceptance, and UVI values are available throughout the world from satellite instruments, ground-based measurements, and from forecasts based on model calculations. These have been useful for atmospheric scientists, health professionals (skin and eye specialists), and the general public. But the descriptors and health messages associated with the UVI scale are targeted towards European skin types and UV regimes, and are not directly applicable to the population living closer to the equator, especially for those in the high-altitude Altiplano region of South America. This document arose from discussions at the Latin American Society of Photobiology and Photomedicine´s Congress, which was held in Arequipa, Peru, in November 2013. A major outcome of the meeting was the Arequipa Accord, which is intended as a unifying document to ensure co-ordination of UV and health research decisions in Latin America. A plank of that agreement was the need to tailor the UVI scale to make it more relevant to the region and its population. Here we make some suggestions to improve the international applicability of the UVI scale.Fil: Zaratti, Francesco. Universidad Mayor de San Andres; BoliviaFil: Piacentini, Ruben Dario Narciso. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); ArgentinaFil: Guillén, Héctor A.. Sociedad Peruana de Fotobiología y Fotomedicina; PerúFil: Cabrera, Sergio H.. Universidad de Chile. Facultad de Medicina. Instituto de Ciencias Biomédicas. Programa de Biología Celular y Molecular; ChileFil: Liley, J. Ben. National Institute of Water & Atmospheric Research; Nueva ZelandaFil: Mckenzie, Richard L.. National Institute of Water & Atmospheric Research; Nueva Zeland

Mattel’s Barbie. Investigation of a symbol analysis of polymeric matrices and degradation phenomena for sixteen dolls from 1959 to 1976

Mattel’s Barbie dolls are the most famous and iconic dolls since 1959. Today, they are being collected by individuals and often conserved in museum environments due to their cultural and historical significance reflecting everyday life and historical events. However, just like most museum objects made of plastics, both historical and more recent Barbies show evident degradation phenomena. Firstly, Barbies were made of plasticized polyvinyl chloride (PVC), affected by the migration of additives—mostly the plasticizers—from the bulk phase to the outermost layer, appearing as a tacky and glossy exudate. Over the years, Barbies’ polymeric constituents were replaced with more stable ones, whose additives migration is limited compared to PVC, even though still occurring. Multispectral photography in visible (VIS) and ultraviolet (UV) light, microscopical observations in VIS and UV light, and Fourier Transform Infrared spectroscopy in the Attenuated Total Reflectance mode (FT-IR ATR) were performed to characterize the constituent materials of 15 Barbies produced between 1959 and 1976, bridging the information gap on their processing over the years. The micro-invasive multi-analytical approach also allowed for the characterization of the degradation products, permitting the reference of the exudated compound to the specific bulk polymer

Evaluation of Fatty Acid Methyl Esters (FAME) as a Green Alternative to Common Solvents in Conservation Treatments

This study investigates the potential of fatty acid methyl esters (FAME) as environmentally sustainable alternatives to traditional solvents for the removal of low-polarity materials commonly found in cultural heritage artefacts. Recognizing the environmental and health concerns associated with conventional solvents, this research focuses on FAME to remove low/non-polarity or non-polar substances used in cultural heritage preservation. Laboratory samples coated with low molecular synthetic resins (LMW) such as Regalrez 1094 and microcrystalline wax were treated with FAME applied in gel to prevent solvent–substrate interactions. Photographic documentation under UV-vis light, optical microscope observations, and spectrocolorimetric analysis were used for assessing surface “cleanness”, while FTIR-ATR spectroscopy was used to detect possible residue from treatment. Moreover, SEM analysis was used for a better understanding of the results. The best results were obtained using FAME base on methyl stearate according to Hansen-RED