47,511 research outputs found
CALORIMETRIA DIFFERENZIALE A SCANSIONE DI MISCELE FOSFOLIPIDICHE DA MEMBRANE DI GLOBULI ROSSI
No full textNegli ultimi anni particolare attenzione è stata posta alle relazioni tra funzione delle membrane, le loro proprietà chimico-fisiche e la composizione in acidi grassi, prevalentemente della frazione fosfolipidica considerato il fatto che fosfolipidi, trovati nelle membrane biologiche, derivano le loro proprietà idrofobiche dagli acidi grassi costituenti.
Le correlazioni più frequentemente analizzate sono quelle tra componenti di membrana e i loro acidi grassi modificati, in vivo, da alterazioni della composizione lipidica della dieta o, in vitro, mediante opportune modifiche del mezzo di coltura.
Somministrando diete diverse a bovine da latte abbiamo creato una “banca” di campioni di membrane di globuli rossi a diversa composizione lipidica (1, 2).
Scopi di questo studio sono stati: 1) l’analisi della composizione delle miscele di fosfolipidi estratti dalle membrane, 2) la valutazione delle correlazioni tra composizione e proprietà termotropiche delle miscele.
I lipidi totali sono stati estratti dagli eritrociti bovini con miscele di cloroformio/metanolo in diversi rapporti e le miscele lipidiche sono state frazionate mediante cromatografia su colonna.
Le singole specie fosfolipidiche sono state separate in HPTLC e quantificate mediante densitometria a scansione.
La composizione in acidi grassi dei fosfolipidi di membrana è stata valutata mediante gas-liquido cromatografia e dispersioni acquose tamponate sono state esaminate mediante calorimetria differenziale a scansione.
Per ogni campione è stato calcolato il contenuto di acidi grassi saturi (S), insaturi (U) e l’indice di insaturazione (UI).
I principali acidi grassi presenti (mediamente ≥ 10% in peso) sono risultati: C16:0, C18:0, C18:1, C18:2 e C24:0.
Le miscele di fosfolipi mostrano una o due transizioni di fase a temperature comprese tra 17.7 e 40.0 °C. La prima temperatura di transizione è compresa tra 17.7 e 26.0 °C.
UI e U/S non risultano essere correlati al contenuto percentuale delle diverse specie molecolari di fosfolipidi (PC, PE, SM, PS+PI) e di PC+SM, costituenti principali del foglietto esterno del doppio strato lipidico.
Esiste, invece, una correlazione lineare tra la prima temperatura di transizione ed UI (P < 0.05) e U/S (P < 0.01). La prima temperatura di transizione diminuisce all’aumentare di UI o del rapporto U/S.
References
1. G. Monticelli, S. Rapelli, G. Montorfano, P. Magistretti and B. Berra- “Red blood cell membrane composition following diet manipulation in the cow” Riv. Ital. Sostanze Grasse 67: 507-515 (1990)
2. G. Monticelli, M. Masserini,G. Lercker, T. Beringhelli, P. Marciani, E. Calappi and B. Berra – “Red blood cell membrane composition following diet manipulation in the cow. II: phospholipid fatty acid distribution and physico-chemical characteristics of membrane and its constituents” Riv. Ital. Sostanze Grasse 69: 189-199 (1992
"Forced Behavior" as epileptic seizure: Description of a patient with neuronal migration disorder
No full textForced thinking and behavior can be true epileptic phenomena. Forced thinking, characterized by abrupt intrusion of thoughts, could be produced by an epileptic discharge in frontal or temporal lobes Epileptic forced thinking appears distinct from obsessive thoughts and compulsive urges. A male patient, teacher of optic pathophysiology, from the age of 40 showed short (2-3 minutes) episodes, characterized by a compulsive urge to speak technically as he would in his job. At the age of 43 he showed two nocturnal generalized seizures. An EEG was performed and it showed intercritical and critical anomalies on the left anterior regions. A magnetic resonance (MR) showed the presence of a neuronal migration disorder (sub-ependimal cotrical nodular heterotopia). Soon after, a therapy with carbamazepine 800 mg/die was started and all types of paroxystical manifestations disappeared. This case is interesting and intriguing because of the overlapping of epilepsy, forced behavior and neuronal migration disorders. Considering the anatomic systems involved in epilepsy and obsessive-compulsive disorder, we will discuss the differences and the common features of both disturbances
THERMOTROPIC CHARACTERISTICS OF PHOSPHOLIPID MIXTURES FROM RBC MEMBRANE
No full textThe relationships between membrane function, their physical properties and fatty acid distribution, mainly of the phospholipid fraction received particular attention in these last years. The correlations have been frequently studied analyzing the membrane components and their fatty acids changed in vivo by modification of the diet. With this type of treatment we created a collection of different composition membrane samples from bovine erythrocytes.
Aims of this research were: 1) the analysis of phospholipid mixtures extracted from the membranes, 2) the correlation of the composition to the thermotropic properties of the mixtures.
Total lipids were extracted from red blood cell (RBC) membranes with chloroform/methanol and the complex lipid mixture was fractionated by column chromatography. The single phospholipid molecular species were resolved by HPTLC and quantitated by scanning densitometry. Fatty acid composition of the phospholipid mixtures was determined by means of gas liquid chromatography and buffered aqueous dispersions of the phospholipids were examined by differential scanning calorimetry. For each sample saturated (S) and unsaturated (U) fatty acid contents as well as unsaturation index (UI) were calculated.
Phospholipid samples showed one or two phase transitions at temperatures between 17.7 and 40 °C. The first transition temperature ranged from 17.7 to 26.0 °C. UI and U/S resulted unrelated to the percent content of the different phospholipid molecular species (PC, PE, SM, PS + PI) as well as PC + SM, the predominant constituents of the RBC membrane outer monolayer. A significative linear correlation was found when the first transition temperature was plotted against UI (P< 0,05) and U/S (P< 0,01). The first transition temperature decreased with the increase of UI or of the ratio U/S
Fisiologia
No full textPrefazione
1 - Introduzione allo studio della Fisiologia umana (Gianluigi Monticelli)
2 - I componenti dellâ organismo umano (Lucia Martinoli)
3 - Meccanismi di trasporto e barriere biologiche (Paola Marciani, Gianluigi Monticelli)
5 - Fisiologia del muscolo (Maristella Gussoni, Gianluigi Monticelli, Alessandra Vezzoli)
6 - Il sistema nervoso: organizzazione e funzione (Maria Mariggiò)
7 - Il sistema nervoso centrale: le funzioni sensoriali (Maristella Gussoni, Gianluigi Monticelli, Alessandra Vezzoli)
8 - Il sistema nervoso: le funzioni motorie (Maria Mariggiò)
9 - Il sistema nervoso autonomo (Maria Mariggiò)
10 - Le funzioni nervose integrate (Maria Mariggiò)
11 - Il sistema endocrino (Maristella Gussoni, Gianluigi Monticelli)
12 - Il sangue e la linfa (Stefano Vassanelli)
13 - Il sistema cardiovascolare (Stefano Vassanelli)
14 - La respirazione (Patrizia Ambrogini, Carla Cuppini, Andrea Minelli)
15 - Le funzioni renali (Antonio Caretta, Carla Mucignat)
16 - La regolazione del pH ematico (Antonio Caretta, Carla Mucignat)
17 - La funzione gastrointestinale (Paola Marciani, Gianluigi Monticelli)
18 - Nutrizione e metabolismo (Lucia Martinoli)
19 - Metabolismo e ambiente: lavoro muscolare e controllo della temperatura (Maristella Gussoni, Gianluigi Monticelli, Alessandra Vezzoli)
20 - L'apparato riproduttore (Antonio Caretta, Carla Mucignat
Continuities and discontinuities at the Oscurusciuto rock shelter (Ginosa, Taranto). The last Neanderthals in Southern Italy
No full textThe Oscurusciuto rock shelter, located in the Ginosa ravine (Taranto, Apulia), is a very important site for the understanding of Neandertal subsistence and settlement strategies in Southern Italy. The deposit, about 6 m thick and with a base of 60 m2 , is made up of several levels Middle Palaeolithic in age (fig. 1). The series so far investigated (between SU 1 and SU 15) ranges between 42,724±716 cal BP (Beta 181165 AMS) (SU 1) and 55 ± 2 kyrs (40Ar/39Ar) (SU 14 – tephra identified as the Mount Epomeo Ischia green tuff; Allen et alii 2000). Such a chronological interval is crucial in European prehistory as it falls upon the period of disappearance of Homo neanderthalensis and of the dispersal of the first groups of Anatomically Modern Humans. Excavations and studies on the Oscurusciuto Shelter are being led by the Unità di Ricerca di Preistoria e Antropologia of the Dipartimento di Scienze Fisiche, della Terra e dell’Ambiente of the University of Siena (Boscato, Ronchitelli 2008; Villa et alii 2009; Boscato et alii 2011; Ronchitelli et alii 2011; Spagnolo et alii 2015). The study comprises: taxonomic and taphonomic investigations on faunal remains, analysis of lithic production through a technological and techno-functional approach, micromorphological analyses of hearths and assessment of the spatial meaning of these features. The aim of this work is to individuate, from a diachronic point of view, the continuities and discontinuities inside the lithic techno-complexes, the site space management and the mobility patterns within the territory. Such objectives are reached by a multidisciplinary approach. The different datasets which have been gathered are statistically elaborated within a GIS platform in order to determine the modalities of space management. The different datasets which have been gathered are statistically elaborated within a GIS platform in order to determine the modalities of space management. The application of the RMU method (lithic raw material units), on technological and spatial bases, allows the recognition of single activities (Marciani 2013; Spagnolo 2013; Spagnolo et alii 2015). This research comprises the integrated study of the lower section of the series so far investigated in the Shelter: SU 15, SU 14, SU 13 and SU 11. These stratigraphic units are particularly interesting for the reconstruction of Neandertal behaviour, given that each of them shows peculiarities in terms of structural elements, spatial management, type of occupation and lithic production systems. SU 15 is a living floor in which a phase of abandonment is recorded and is sealed by the deposition of the SU 14 tephra. This surface is characterized by stone alignments which define two possible structures. SU 14 (fig. 2) is an almost sterile layer about 60 cm thick, made of volcanic ashes. Traces of a short frequentation can be seen only few centimetres under the top of the layer. SU 13 is a short palimpsest which represents the first stable re-colonization of the site after the environmental impact created by volcanic ash deposition. In this layer, 10 aligned hearths were found which divide up the site into areas devoted to different activities. The overlying SU 11 is a palimpsest about 30 cm thick, characterized by the superimposition of tens of hearths. The results of these studies will bring important and useful advances in research on the behavioural and settlement features of Neandertals, particularly at this time when there are many Italian and international projects which face these questions by means of different and innovative approaches
Effetti sul sonno notturno e sulla sonnolenza diurna del trattamento cronico con Lamotrigina
No full textLamotrigine (LTG) is a new antiepileptic drug, currently used in medically intractable patients. We studied nocturnal sleep and daytime somnolence in 13 patients undergoing add-on therapy with LTG for seizures resistant to common antiepileptic drugs (AEDs). LTG caused a significant increase of REM sleep and a significant decrease of SWS, of the number of stage shifts and of the number of entries in REM. No significant changes were observed in daytime sleepiness and cognitive functions after 3 months of treatment. The increased stability of nocturnal sleep could play an important role in the anticonvulsant effect of LTG
A data streaming approach to link mining in criminal networks
No full textThe ability to discover patterns of interest in criminal networks can support and ease the investigation tasks by security and law enforcement agencies. By considering criminal networks as a special case of social networks, we can properly reuse most of the state-of-the-art techniques to discover patterns of interests, i.e., hidden and potential links. Nevertheless, in time-sensible scenarios, like the one involving criminal actions, the ability to discover patterns in a (near) real-time manner can be of primary importance.In this paper, we investigate the identification of patterns for link detection and prediction on an evolving criminal network. To extract valuable information as soon as data is generated, we exploit a stream processing approach. To this end, we also propose three new similarity social network metrics, specifically tailored for criminal link detection and prediction. Then, we develop a flexible data stream processing application relying on the Apache Flink framework; this solution allows us to deploy and evaluate the newly proposed metrics as well as the ones existing in literature. The experimental results show that the new metrics we propose can reach up to 83% accuracy in detection and 82% accuracy in prediction, resulting competitive with the state of the art metrics
MICROSTRUTTURA DEL SONNO ED ATTIVITA EPILETTIFORME EEG NELL'EPILESSIA GIOVANILE MIOCLONICA
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