Studio clinico sul coinvolgimento aortico nelle metastasi linfonodali lombo-aortiche da carcinoma testicolare

Gli Autori passano brevemente in rassegna la letteratura interna - zionale sulla frequenza dell’interessamento vascolare (vena cava infe - riore ed aorta) nelle metastasi linfoghiandolari lombo-aortiche da neoplasie del testicolo. Presentano, quindi, un caso venuto alla loro osservazione ed operato di linfoadenectomia lombo-aortica da carci - noma misto del testicolo sinistro con infiltrazione dell’aorta sottorenale e, quindi, con conseguente resezione in blocco anche di un trat - to dell’aorta e sua sostituzione con protesi in dacron. Sulla base dei casi riportati in letteratura e del paziente da loro operato, gli Autori rilevano la possibilità di ottenere discreti risultati di sopravvivenza anche in questi stadi avanzati della malattia

Association between attention and heart rate fluctuations in pathological worriers

Recent data suggests that several psychopathological conditions are associated with alterations in the variability of behavioral and physiological responses. Pathological worry, defined as the cognitive representation of a potential threat, has been associated with reduced variability of heart beat oscillations (i.e., decreased heart rate variability; HRV) and lapses of attention indexed by reaction times (RTs). Clinical populations with attention deficit show RTs oscillation around 0.05 and 0.01 Hz when performing a sustained attention task. We tested the hypothesis that people who are prone to worry do it in a predictable oscillating pattern revealed through recurrent lapses in attention and concomitant oscillating HRV. Sixty healthy young adults (50% women) were recruited: 30 exceeded the clinical cut-off on the Penn State Worry Questionnaire (PSWQ; High-Worry, HW); the remaining 30 constituted the Low-Worry (LW) group. After a diagnostic assessment, participants performed two 15-min sustained attention tasks, interspersed by a standardized worry-induction procedure. RTs, HRV and moods were assessed. The analyses of the frequency spectrum showed that the HW group presents a significant higher and constant peak of RTs oscillation around 0.01 Hz (period 100 s) after the induction of worry, in comparison with their baseline and with the LW group that was not responsive to the induction procedure. Physiologically, the induction significantly reduced high-frequency HRV and such reduction was associated with levels of self-reported worry. Results are coherent with the oscillatory nature of the default mode network (DMN) and further confirm an association between cognitive rigidity and autonomic nervous system inflexibility

Effects of Chickpea in Substitution of Soybean Meal on Milk Production, Blood Profile and Reproductive Response of Primiparous Buffaloes in Early Lactation

This study aimed to evaluate the effects of the use of chickpea meal in substitution of soybean meal on plasma metabolites, reproductive response, milk yield and composition and milk coagulation traits of primiparous buffaloes in early lactation. Eighteen primiparous buffaloes were blocked by age, body weight and days in milk and equally allotted to two experimental groups from 10 to 100 days of lactation. The experimental diets consisted of the same forage integrated with two different isonitrogenous and isoenergetic concentrates containing either 210 g/kg of soybean meal or 371 g/kg chickpea. The use of chickpea meal had no negative effects on dry matter intake (p = 0.69), body condition score (p = 0.33) and milk yield (p = 0.15). Neither milk composition nor blood metabolites were influenced by dietary treatments (p > 0.05), but an increment of urea concentrations in milk (p 0.05) of the dietary treatment was highlighted on milk coagulation traits as well as buffalo reproductive responses. We concluded that soybean meal can be replaced by chickpea meal in the diet for primiparous dairy buffaloes in the early lactation period without impairing their productive and reproductive performance

Neurotransmitter profiling with high and ultra-high field magnetic resonance spectroscopy : optimization for clinical and translational studies in schizophrenia

Growing interest in the research community has been shown in clinical neuroscience to assess neurotransmitter profiling both in healthy and diseased subjects. A large body of research in this field focuses on schizophrenia to characterise its glutamatergic level according to the most recent hypothesis of NMDA (N-Methyl-D-aspartic acid) receptors hypofunction. Magnetic Resonance Spectroscopy (MRS) is able to detect some of the most common neurotransmitters but a number of issues, such as low signal to noise ratio (SNR), spectra overlapping and line broadening prevents MRS from being clinically relevant for neuropsychiatry. Four important aims were considered relevant for this work. Firstly, we aimed to compare the reliability of conventional and timing-optimized sequences for the detection and measurement of most of the visible metabolites and, in particular, for glutamate (Glu), glutamine (GIn) and gamma-aminobutyric acid (GABA) to assess the best available sequence for a study in schizophrenia. Secondly, we also intended to investigate whether glutamatergic activity might predict the oscillatory activity and how this link might survive or not in schizophrenia. Thirdly, we wanted to study whether the well known animal model of schizophrenia, the rearing in isolation model, exacerbates the effect of ketamine and determines more profound changes on neurotransmitter profile in rats. Fourthly, a further goal focuses on the improved data acquisition and on the data processing to reliably resolve GABA and to be able to quantify a wider range of metabolites. To address those points five studies were performed. The first work (Chapter 3) describes a study of reproducibility on sequences which have been reported in the literature to be capable to detect Glu and GIn. The study was performed on 14 healthy subjects by scanning them twice and repositioning between the two scans. The absolute percentage difference was then computed to assess the accuracy per sequence and metabolite. A good compromise was found in PRESS sequence (TE=80 ms) which was exploited subsequently for the following study on schizophrenic patients (Chapter 4). Twenty-seven early stage schizophrenic patients and twenty-three aged-matched controls were recruited to undergo a protocol including, in two separate sessions, MRS and electroencephalography (EEG). Anterior Cingulate Cortex Glu was found to predict the induced theta activity in healthy controls but not in patients. Furthermore, the NAA values have also been found to be reduced in schizophrenia and linked to N100, an Event Related Potential (ERP) which is well known to be decreased in schizophrenia. Following on from the findings of the study on the early stage of schizophrenia, further investigations were undertaken to study the psychotic state occurring in the disease via a functional MRS, where 25mg/kg of ketamine (NMDA antagonist) injection was administered to two groups of rats. The two groups were group-housed and reared in isolation. This work was able to show increase of prefrontal GIn levels in both groups but showed a selective GABA decrease only in isolated rats. It would have been very interesting to be able to detect GABA changes in the study at 3T but the used protocol did not allow its accurate quantification. Simulations and reliability tests (Chapter 6)were then utilized to optimize a standard sequence to obtain an accurate and reliable GABA concentration. The optimized sequence reproduces the quantification with 12% of accuracy. The preliminary results of the last study (Chapter 7) give an evidence of the potential of combined use of Monte Carlo, Levenberg-Marquardt and NNLS methods embedded in a novel fitting approach for two-dimensional spectra. The three appendices at the end of this work illustrate the details of some of the algorithms and softwares used throughout the studies

Activity Budgets and Forage Selection of Podolian Cattle, a Semiwild Bovine Breed

This study aimed to describe the behaviour of Podolian breed, a semiwild cattle breed kept in a natural environment (as either a small group of young bulls or cows within a family herd), and the interaction of these animals with the environment in terms of ingestion from natural pastures. Diurnal grazing behavioural pattern was monitored through continuous focal animal recording method. The activity budget of free-ranging animals was characterized by high locomotor and feeding activities. They exhibited a high degree of adaptability to the local phytocoenosis with high levels of ferns' and tree foliage intakes performed by cows and the selection of a diet more nutritious than pasture performed by young bulls. These results along with the low levels of agonistic interactions recorded in the two experiments suggest that extensive systems based on grazing allow social stability and provide a natural environment for the expression of cattle species-specific behaviour

Neurotransmitter profiling with high and ultra-high field magnetic resonance spectroscopy : optimization for clinical and translational studies in schizophrenia

Growing interest in the research community has been shown in clinical neuroscience to assess neurotransmitter profiling both in healthy and diseased subjects. A large body of research in this field focuses on schizophrenia to characterise its glutamatergic level according to the most recent hypothesis of NMDA (N-Methyl-D-aspartic acid) receptors hypofunction. Magnetic Resonance Spectroscopy (MRS) is able to detect some of the most common neurotransmitters but a number of issues, such as low signal to noise ratio (SNR), spectra overlapping and line broadening prevents MRS from being clinically relevant for neuropsychiatry. Four important aims were considered relevant for this work. Firstly, we aimed to compare the reliability of conventional and timing-optimized sequences for the detection and measurement of most of the visible metabolites and, in particular, for glutamate (Glu), glutamine (GIn) and gamma-aminobutyric acid (GABA) to assess the best available sequence for a study in schizophrenia. Secondly, we also intended to investigate whether glutamatergic activity might predict the oscillatory activity and how this link might survive or not in schizophrenia. Thirdly, we wanted to study whether the well known animal model of schizophrenia, the rearing in isolation model, exacerbates the effect of ketamine and determines more profound changes on neurotransmitter profile in rats. Fourthly, a further goal focuses on the improved data acquisition and on the data processing to reliably resolve GABA and to be able to quantify a wider range of metabolites. To address those points five studies were performed. The first work (Chapter 3) describes a study of reproducibility on sequences which have been reported in the literature to be capable to detect Glu and GIn. The study was performed on 14 healthy subjects by scanning them twice and repositioning between the two scans. The absolute percentage difference was then computed to assess the accuracy per sequence and metabolite. A good compromise was found in PRESS sequence (TE=80 ms) which was exploited subsequently for the following study on schizophrenic patients (Chapter 4). Twenty-seven early stage schizophrenic patients and twenty-three aged-matched controls were recruited to undergo a protocol including, in two separate sessions, MRS and electroencephalography (EEG). Anterior Cingulate Cortex Glu was found to predict the induced theta activity in healthy controls but not in patients. Furthermore, the NAA values have also been found to be reduced in schizophrenia and linked to N100, an Event Related Potential (ERP) which is well known to be decreased in schizophrenia. Following on from the findings of the study on the early stage of schizophrenia, further investigations were undertaken to study the psychotic state occurring in the disease via a functional MRS, where 25mg/kg of ketamine (NMDA antagonist) injection was administered to two groups of rats. The two groups were group-housed and reared in isolation. This work was able to show increase of prefrontal GIn levels in both groups but showed a selective GABA decrease only in isolated rats. It would have been very interesting to be able to detect GABA changes in the study at 3T but the used protocol did not allow its accurate quantification. Simulations and reliability tests (Chapter 6)were then utilized to optimize a standard sequence to obtain an accurate and reliable GABA concentration. The optimized sequence reproduces the quantification with 12% of accuracy. The preliminary results of the last study (Chapter 7) give an evidence of the potential of combined use of Monte Carlo, Levenberg-Marquardt and NNLS methods embedded in a novel fitting approach for two-dimensional spectra. The three appendices at the end of this work illustrate the details of some of the algorithms and softwares used throughout the studies

Time-frequency representations of generalized almost-cyclostationary signals

Nous proposons dans cet article une contribution à la théorie récemment introduite des signaux quasi-cyclostationnaires généralisés. Cette classe de signaux étend la classe des signaux quasi-cyclostationnaires au cas de signaux dont les fréquences cycliques dépendent du temps. Des représentations temps-fréquence de ces signaux sont données en fonction des statistiques cycliques généralisées. Notamment, la distribution de Wigner-Ville et la fonction d'ambiguïté sont examinées en détail. Le problème de l'extraction des caractéristiques des signaux quasi-cyclostationnaires généralisés, basée sur l'estimation d'un seul enregistrement, est également traité

Time-resolved EPR investigation of oxygen and temperature effects on synthetic eumelanin

Synthetic eumelanin produced using 5,6-dihydroxyindole-2-carboxylic acid as precursor and H2O2/horseradish peroxidase as oxidative reagent, in form of dry powder, has been investigated under photoexcitation by TR-EPR spectroscopy. The formation of spin polarized radical pairs from triplet excited states of melanin has been observed both in absence and in presence of oxygen and has been followed as a function of the temperature in the range 140–290 K. The triplet mechanism explains the observed polarization pattern in net emission. In the presence of oxygen new radical pairs are formed by interaction of melanin with molecular oxygen