Feruginozna tjelešca u plućima gradskih pasa

The aim of the study was to assess health hazards induced by environmental exposure to asbestos using urban dogs as biological indicators. Samples of the lung tissue taken from 36 randomly chosen urban dogs were examined. In the group of dogs aged up to four years (n=15) ferruginous bodies were identified in only two. In the dogs older than four years (n=21) 17 were ferruginous body positive. According to Fisher\u27s exact test the difference between the two groups was significant (P<0,001). The presence of asbestos bodies in the lungs of dogs is considered to be evidence of serious contamination of urban areas with respirable mineral fibres. The more frequent presence of asbestos bodies in the lungs of the older dogs indicates long-term accumulation of mineral fibres exceeding 10 µm in length. Continuous environmental exposure of the city\u27s population to respirable mineral fibres may therefore pose a health risk.Uzorci pluća 36 slučajno izabranih gradskih pasa pretraženi su na prisutnost feruginoznih tjelešaca s namjerom da se procijeni da li izloženost vlaknatim organskim prašinama, uglavnom azbestu, iz gradskog okoliša, nosi opasnost za zdravlje. U skupini od 15 pasa do četir godine starosti, u dva su nađena feruginozna tjelešca. U drugoj skupini koja je sadržavala 21 psa starija od četiri godine, sedamnaest njih je imalo pozitivan nalaz. Prema Fisherovu egzaktnom testu postoji značajna statistička razlika (P<0.001) između dviju skupina životinja. Prisutnost azbestnih tjelešaca u plućima pasa svjedoči da su javne gradske površine yisoko kontaminirane vlaknatim mineralnim prašinama respirabilne veličine, uglavnom azbestom. Češći nalaz azbestnih tjelešaca u plućima starijih pasa upozorava na akumulaciju vlakana duljih od 10 cm tijekom duljeg vremena, a predvidive su i posljedice takve kontinuirane izloženosti vlaknatim mineralnim kontaminantima za zdravlje gradskog stanovništva

Poisson -- Boltzmann Brownian Dynamics of Charged Colloids in Suspension

We describe a method to simulate the dynamics of charged colloidal particles suspended in a liquid containing dissociated ions and salt ions. Regimes of prime current interest are those of large volume fraction of colloids, highly charged particles and low salt concentrations. A description which is tractable under these conditions is obtained by treating the small dissociated and salt ions as continuous fields, while keeping the colloidal macroions as discrete particles. For each spatial configuration of the macroions, the electrostatic potential arising from all charges in the system is determined by solving the nonlinear Poisson--Boltzmann equation. From the electrostatic potential, the forces acting on the macroions are calculated and used in a Brownian dynamics simulation to obtain the motion of the latter. The method is validated by comparison to known results in a parameter regime where the effective interaction between the macroions is of a pairwise Yukawa form

Activation of store-operated calcium entry in airway smooth muscle cells: insight from a mathematical model

Intracellular dynamics of airway smooth muscle cells (ASMC) mediate ASMC contraction and proliferation, and thus play a key role in airway hyper-responsiveness (AHR) and remodelling in asthma. We evaluate the importance of store-operated entry (SOCE) in these dynamics by constructing a mathematical model of ASMC signaling based on experimental data from lung slices. The model confirms that SOCE is elicited upon sufficient depletion of the sarcoplasmic reticulum (SR), while receptor-operated entry (ROCE) is inhibited in such conditions. It also shows that SOCE can sustain agonist-induced oscillations in the absence of other influx. SOCE up-regulation may thus contribute to AHR by increasing the oscillation frequency that in turn regulates ASMC contraction. The model also provides an explanation for the failure of the SERCA pump blocker CPA to clamp the cytosolic of ASMC in lung slices, by showing that CPA is unable to maintain the SR empty of . This prediction is confirmed by experimental data from mouse lung slices, and strongly suggests that CPA only partially inhibits SERCA in ASMC

Antineoplastic Drugs as a Potential Risk Factor in Occupational Settings: Mechanisms of Action at the Cell Level, Genotoxic Effects, and Their Detection Using Different Biomarkers

U članku je prikazana osnovna podjela antineoplastičnih lijekova prema mehanizmima djelovanja na razini stanice. Objašnjeni su mehanizmi genotoksičnosti najvažnijih vrsta lijekova koji se primjenjuju u okviru uobičajenih protokola za liječenje zloćudnih novotvorina. Navedena je važeća klasifi kacija antineoplastika prema kancerogenom potencijalu, podaci o mutagenom potencijalu te je prikazana njihova podjela u skladu s anatomsko-terapijsko-kemijskim sustavom klasifi kacije. Sustavno su prikazani najvažniji rezultati svjetskih i hrvatskih istraživanja na populacijama radnika izloženih antineoplasticima, provedenih u razdoblju 1980.-2009. s pomoću četiri najčešće primjenjivane metode: analize izmjena sestrinskih kromatida, analize kromosomskih aberacija, mikronukleus-testa i komet-testa. Objašnjena su osnovna načela navedenih metoda te raspravljene njihove prednosti i nedostaci. Biološki pokazatelji daju važne podatke o individualnoj osjetljivosti profesionalno izloženih ispitanika koji mogu poslužiti unaprjeđenju postojećih uvjeta rada i upravljanju rizicima pri izloženosti genotoksičnim agensima. Na osnovi prednosti i nedostataka citogenetičkih metoda zaključeno je da je mikronukleus-test, koji podjednako uspješno dokazuje klastogene i aneugene učinke, jedna od najboljih metoda dostupnih za otkrivanje štetnih djelovanja antineoplastičnih lijekova koji su u aktivnoj primjeni.This article brings an overview of the mechanisms of action of antineoplastic drugs used in the clinical setting. It also describes the genotoxic potentials of the most important classes of antineoplastic drugs involved in standard chemotherapy protocols. Classifi cation of antineoplastic drugs according to the IARC monographs on the evaluation of carcinogenic risks to humans is accompanied by data on their mutagenicity and the most recent updates in the Anatomical Therapeutic Chemical (ATC) Classifi cation System. We report the main fi ndings of biomonitoring studies that were conducted in exposed healthcare workers all over the world between 1980 and 2009 using four biomarkers: sister chromatid exchanges, chromosome aberrations, micronuclei. and the comet assay. The methods are briefl y explained and their advantages and disadvantages discussed. Biomarkers provide important information on individual genome sensitivity, which eventually might help to improve current working practices and to manage the risks related with exposure to genotoxic agents. Taking into consideration all known advantages and drawbacks of the existing cytogenetic methods, the micronucleus assay, which is able to detect both clastogenic and aneugenic action, is the most suitable biomarker for assessing harmful effects of antineoplastic drugs currently used in health care

Modalité de l'accouchement du deuxième jumeau après 35 SA à la maternité de Port-Royal, à propos d'une série de 391 cas

PARIS-BIUM (751062103) / SudocCentre Technique Livre Ens. Sup. (774682301) / SudocSudocFranceF