Measurement of ultraweak chemiluminescence emitted from isolated and perfused rat hearts

Summary This paper describes the use of a single-photon counting apparatus (SPCA) for the continuous monitoring of the ultraweak chemiluminescence (UWC) emitted by isolated and perfused rat hearts and deriving from phospholipid peroxydation. Specifically the SPCA was used to assess the peroxidative stress induced in the heart by the addition of an hydroperoxide to the perfusing medium. To this purpose, different hydroperoxides were used and each one produced a tipical and highly reliable temporal evolution of UWC. It was also found that the oxygen availability strongly influences the intensity and the kinetic of the UWC emission. UWC was proved to be a very interesting and promising tool for monitoring the peroxidative damage of biological membranes, both because it makes a continuous assessment possible and because the sensitivity of this method is approximately ten times greater than usual analytical chemistry methods.

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Riassunto è stato usato un apparato di misurazione a un fotone per misurare la chemiluminescenza emessa durante la perossidazione dei fosfolipidi della membrana cellulare di un cuore di ratto isolato e perfuso sottoposto ad uno stress perossidativo. Lo stress perossidativo è stato ottenuto aggiungendo idroperossidi al liquido di perfusione. I differenti idroperossidi usati hanno prodotto tipiche evoluzioni temporali di chemi-luminescenza altamente riproducibili. La disponibilità di ossigeno influenza fortemente l'intensità e la cinetica di emissione della chemiluminescenza. Nell'àmbito di uno studio sull'effetto di differenti idroperossidi sul cuore di ratto isolato e perfuso, la misura della chemiluminescenza si è dimostrata un interessante e promettente strumento per il monitoraggio in continuo dei danni perossidativi nelle membrane biologiche. La sensibilità di questo metodo per la valutazione della perossidazione dei fosfolipidi delle biomembrane è circa dieci volte maggiore rispetto agli ordinari metodi di chimica analitica.

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Резюме В этой статъе описывается аппаратура для ретистрации отделъных фотонов для непрерывного мониторнта улътраслабой хемилюминесценции, испус-каемой во время пероксидации фосфолипидов клеточной мембраны изолированного и перфузированного сердца крысы. В частности, аппаратура для ретистрации отделъ-ных фотонов исполъзуется для оценки напряжениь, индуцированных в сердце при добавлении тидроперекиси в пербузирующую жидкостъ. для этого исполъзуутся различные тидропероксиды, которые дают типичные временные эволюции улътса-слабой хемиюминесценции. Также получается, что наличие кислорода силъно влияет на интенсивиостъ и кинетику улътраслабои хемилюминесценции. Показывается, что улътраслабая хемилюминесценция представляет оченъ интересный и перспективный инструмент для мониторинга пероксидативных повреждений биологических мембран. Чувствителъностъ этого метода для пценки пероксидации босболинидов биомембран почти в десятъ раз выше, чем обычнын методов аналитической химии.

     

Sulla stabilità dell'equilibrio nei casi critici

Sunto Con questa Memoria l'A. studia la stabilità dell'equilibrio nei casi critici attraverso la ricerca di funzioni di Lyapunov pervenendo a risultati che completano e-generalizzano sia risultati classici che precedenti ricerche dell'A. Lavoro eseguito nell'ambito dell'attività dei Gruppi di ricerca matematica del C.N.R.     

Implementation of a quality assurance system according to GMP and ISO 9001:2008 standard for radiopharmaceutical production in a public research centre

The production of pharmaceuticals is one of the most highly regulated fields in terms of quality. The body of good manufacturing practice (GMP) represents the standard required by law; GMP embraces the guidelines that regulate all activities related to the production and quality control of medicinal products for human and veterinary use. This paper deals with the implementation of a quality management system (QMS) in compliance with GMP and ISO 9001 standards for the production and distribution of radiopharmaceuticals in a public research institute. The production of 2-[18F]fluoro-2-deoxy-d-glucose has been implemented according to GMP standards and has been licensed by the national Authority in 2007. In 2010, a project to orient the system??s GMP compliance to ISO 9001 standards has been approved. A QMS conforming to ISO 9001:2008 should be considered an important additional step in terms of quality, because ISO 9001 also takes into account economic and financial aspects, design and development aspects and introduces management review for measurement and analysis of the process with the aim of improving performances. The harmonization between GMP and ISO has been defined following the Pharmaceutical Quality System Q10 guideline developed by International Conference on Harmonization.     

The control of the growth of Pt clusters in solution: A way to prepare Pt particles of tailored size

The growth of Pt particles in mesitylene-solvated metal atoms, obtained by metal vapour synthesis (MVS), has been followed at two temperatures (−40 and 25 °C) by NMR DOSY technique. The addition of 1,3-divinyltetramethyldisiloxane (DVS) at different time allows to quench the growth process and to make the resulting thermally stable solutions suitable for the evaluation of the Pt particles size at that moment. These solutions can be conveniently used to prepare supported Pt systems containing Pt particles of tailored size.     

Analytical procedure for mapping the distribution of B and Tc markers in cryo-sections of animal tissue samples by secondary ion mass spectrometry

The development of a complete, standard analytical procedure for a quantitative use of secondary ion mass spectrometry to map the distribution in animal tissues of exogenous isotopes presents difficulties inherently related to sample preparation and preservation, as well as to the specific application being considered. We have tested in two very different cases a procedure based on the cryo-preparation of samples and calibration standards. The applications under investigation were the mapping of ¹⁰B in mouse brain tissue, with relevance to the boron neutron capture therapy, and of the perfusion tracer ⁹⁹Tc in mouse heart tissue, with relevance to the study of microcirculation and cardiovascular pathologies. Scanning electron microscopy and inductively coupled mass spectrometry analysis were used as reference techniques for secondary ion mass spectrometry images and analyte measurements, respectively. Cryo-preparation of tissue sections for ion microscopy proved to be simple and efficient (in terms of structural and chemical integrity) for both brain and heart samples derived from fresh organs. This technique, however, turned out to be reliable only on the brain tissue when applied to the preparation of standards, which required chemical fixation of portions of organs. Brain and heart tissues showed a totally different response to chemical fixation, from both a structural and an analytical point of view. On the one hand, we were able to estimate a relative sensitivity factor for ¹⁰B in the cryo-sectioned brain matrix; on the other hand, even without the possibility of an absolute quantification of the ⁹⁹Tc signal and notwithstanding the presence of an isobaric interference, secondary ion mass spectrometry mapping however proved to be capable to resolve the specific response of the cardiac tissue to the perfusion mechanism.     

Errata

Angular distributions of protons emitted in the (e, e'p) reaction on ⁴⁰Ca at an incident electron energy of 710 MeV and for missing energies e_m = 39 MeV and E_M = 81 MeV are presented. The interpretation of these angular distributions in terms of momentum distributions for the struck protons in the original target nucleus indicates l ≠ 0 protons at E_M = 39 MeV and l = 0 protons at E_M = 81 MeV. Finally (p, 2p) and (e, e'p) results in calcium are compared.