Synergistic interaction between the Arp2/3 complex and cofilin drives stimulated lamellipod extension

Both the Arp2/3 complex and cofilin are believed to be important for the generation of protrusive force at the leading edge; however, their relative contributions have not been explored in vivo. Our results with living cells show that cofilin enters the leading edge immediately before the start of lamellipod extension, slightly earlier than Arp2/3, which begins to be recruited slightly later as the lamellipod is extended. Blocking either the Arp2/3 complex or cofilin function in cells results in failure to extend broad lamellipods and inhibits free barbed ends, suggesting that neither factor on its own can support actin polymerization-mediated protrusion in response to growth factor stimulation. High-resolution analysis of the actin network at the leading edge supports the idea that both the severing activity of cofilin and the specific branching activity of the Arp2/3 complex are essential for lamellipod protrusion. These results are the first to document the relative contributions of cofilin and Arp2/3 complex in vivo and indicate that cofilin begins to initiate the generation of free barbed ends that act in synergy with the Arp2/3 complex to create a large burst in nucleation activity

Bionics-based surgical training using 3D printed photopolymers and smart devices

Additive manufacturing technologies support the realization of surgical training devices using, typically, photopolymers-based materials. Unfortunately, the material jetting family, able to print a large range of soft and hard polymers, requires expensive machines and materials, which are not always available. On the other hand, vat polymerization fails in the resolution/volume ratio and in the mechanical properties reconstruction. Stereolithographic 3D printers, mostly used in dental surgery, make possible to realize cheap and sustainable models for training activity using only one material, reducing the possibility to obtain different mechanical characteristics. Moreover, the printed objects have to be treated (i.e. curing post-processing) in order to obtain the required performances, that could be preserved for long term storing. The aim of the proposed approach is to assure the surgeons' skills improvement through bionic-based surgical 3D printed models and smart devices, able to reproduce the same perception of a real surgical activity. We demonstrated how it is possible develop smart devices capable to take into account the same characteristics of different materials (i.e. bone and spongy bone) even if stored for a long time

Processing of targets in smooth or apparent motion along the vertical in the human brain: an fMRI study

Neural substrates for processing constant speed visual motion have been extensively studied. Less is known about the brain activity patterns when the target speed changes continuously, for instance under the influence of gravity. Using functional MRI (fMRI), here we compared brain responses to accelerating/decelerating targets with the responses to constant speed targets. The target could move along the vertical under gravity (1g), under reversed gravity (-1g), or at constant speed (0g). In the first experiment, subjects observed targets moving in smooth motion and responded to a GO signal delivered at a random time after target arrival. As expected, we found that the timing of the motor responses did not depend significantly on the specific motion law. Therefore brain activity in the contrast between different motion laws was not related to motor timing responses. Average BOLD signals were significantly greater for 1g targets than either 0g or -1g targets in a distributed network including bilateral insulae, left lingual gyrus, and brain stem. Moreover, in these regions, the mean activity decreased monotonically from 1g to 0g and to -1g. In the second experiment, subjects intercepted 1g, 0g, and -1g targets either in smooth motion (RM) or in long-range apparent motion (LAM). We found that the sites in the right insula and left lingual gyrus, which were selectively engaged by 1g targets in the first experiment, were also significantly more active during 1g trials than during -1g trials both in RM and LAM. The activity in 0g trials was again intermediate between that in 1g trials and that in -1g trials. Therefore in these regions the global activity modulation with the law of vertical motion appears to hold for both RM and LAM. Instead, a region in the inferior parietal lobule showed a preference for visual gravitational motion only in LAM but not RM

Alkaline phosphatase survey in pecorino siciliano PDO cheese

The determination of alkaline phosphatase (ALP) in cheeses has become an official method for controlling cheeses with a protected designation of origin (PDO), all of which use raw milk. PDO cheeses, characterized by high craftsmanship, usually have an uneven quality. However, for these cheeses, it is necessary to establish ALP values so that they can be defined as a raw milk product. In this study, a dataset with Pecorino Siciliano PDO samples was analyzed to determine ALP both at the core and under the rind. The results showed that there was no significant difference between the different zones in Pecorino cheese. A second dataset of 100 pecorino cheese samples determined that ALP was only at the core of the cheese. Moreover, there was a statistically significant difference between the ALP values of cheeses produced with raw milk and those produced with pasteurized milk. Furthermore, according to the temperatures, a wide variability of ALP values was observed in the Pecorino Siciliano PDO samples from the core of the cheeses. This was a result of several under scotta whey cooking methodologies adopted by cheesemakers, which do not permit a clear range. Therefore, further investigation is desirable

Effect of Exercise on Fatty Acid Metabolism and Adipokine Secretion in Adipose Tissue

Increased physical activity is an optimal way to maintain a good health. During exercise, triacylglycerols, an energy reservoir in adipose tissue, are hydrolyzed to free fatty acids (FAs) which are then released to the circulation, providing a fuel for working muscles. Thus, regular physical activity leads to a reduction of adipose tissue mass and improves metabolism. However, the reduction of lipid reservoir is also associated with many other interesting changes in adipose tissue FA metabolism. For example, a prolonged exercise contributes to a decrease in lipoprotein lipase activity and resultant reduction of FA uptake. This results in the improvement of mitochondrial function and upregulation of enzymes involved in the metabolism of polyunsaturated fatty acids. The exercise-induced changes in adipocyte metabolism are associated with modifications of FA composition. The modifications are adipose tissue depot-specific and follow different patterns in visceral and subcutaneous adipose tissue. Moreover, exercise affects adipokine release from adipose tissue, and thus, may mitigate inflammation and improve insulin sensitivity. Another consequence of exercise is the recently described phenomenon of adipose tissue “beiging,” i.e., a switch from energy-storing white adipocyte phenotype to thermogenic FA oxidizing beige adipocytes. This process is regulated by myokines released during the exercise. In this review, we summarize published evidence for the exercise-related changes in FA metabolism and adipokine release in adipose tissue, and their potential contribution to beneficial cardiovascular and metabolic effects of physical activit

Representation of visual gravitational motion in the human vestibular cortex

How do we perceive the visual motion of objects that are accelerated by gravity? We propose that, because vision is poorly sensitive to accelerations, an internal model that calculates the effects of gravity is derived from graviceptive information, is stored in the vestibular cortex, and is activated by visual motion that appears to be coherent with natural gravity. The acceleration of visual targets was manipulated while brain activity was measured using functional magnetic resonance imaging. In agreement with the internal model hypothesis, we found that the vestibular network was selectively engaged when acceleration was consistent with natural gravity. These findings demonstrate that predictive mechanisms of physical laws of motion are represented in the human brain

Ultrafast Transient Infrared Spectroscopy of Photoreceptors with Polarizable QM/MM Dynamics

Ultrafast transient infrared (TRIR) spectroscopy is widely used to measure the excitation-induced structural changes of protein-bound chromophores. Here, we design a novel and general strategy to compute TRIR spectra of photoreceptors by combining μs-long MM molecular dynamics with ps-long QM/AMOEBA Born-Oppenheimer molecular dynamics (BOMD) trajectories for both ground and excited electronic states. As a proof of concept, the strategy is here applied to AppA, a blue-light-utilizing flavin (BLUF) protein, found in bacteria. We first analyzed the short-time evolution of the embedded flavin upon excitation revealing that its dynamic Stokes shift is ultrafast and mainly driven by the internal reorganization of the chromophore. A different normal-mode representation was needed to describe ground- and excited-state IR spectra. In this way, we could assign all of the bands observed in the measured transient spectrum. In particular, we could characterize the flavin isoalloxazine-ring region of the spectrum, for which a full and clear description was missing

Analisi filogenetica condotta su ceppi di Bovine Diarrhea Virus (BVDV) isolati in Sicilia

La Diarrea Virale del Bovino-Malattia delle Mucose, è una malattia infettiva che colpisce i bovini, ampiamente diffusa a livello mondiale. L’agente infettivo responsabile è un virus provvisto di envelope e con un genoma ad RNA a singolo filamento e a polarità positiva, appartenente al genere Pestivirus, famiglia Flaviviridae. A causa dell’elevata capacità di andare in contro a mutazioni genetiche, esistono numerose varianti di BVDV con diverso assetto antigenico e differente patogenicità. Ad oggi sono noti due genotipi: il BVDV-I e il BVDV-II. Il BVDV-I comprende almeno 13 sottotipi, mentre ne sono stati descritti solo 2 per il BVDV-II. Quest’ultimo, poco diffuso nel nostro territorio, è responsabile di una sindrome emorragica altamente letale. In Italia è stato isolato da bovini che erano stati trattati con vaccini anti-IBR contaminati. Recentemente è stata anche ipotizzata la presenza in Italia di una terza variante, il BVDV-III. L’infezione da BVDV spesso è associata con disordini a livello riproduttivo e nelle bovine gravide può esitare in aborto, malformazioni fetali o nascita di vitelli persistentemente infetti (PI). Scopo del presente lavoro è stato quello di genotipizzare i ceppi di BVDV isolati, al fine di approfondire la conoscenza circa la diffusione delle diverse varianti virali in Sicilia. Sono stati sequenziati ed analizzati filogeneticamente 18 ceppi, isolati su linee cellulari MDBK, da campioni di animali che erano risultati positivi in RT-PCR specifica per una porzione della regione 5’ UTR e in ELISA per la ricerca dell’antigene virale. Per il sequenziamento, i ceppi virali sono stati sottoposti ad estrazione dell’RNA ed amplificazione di una porzione della regione 5’ UTR, secondo quanto descritto da Vilcek et al. (1994). Le sequenze ottenute sono state successivamente allineate e comparate con altre sequenze di riferimento disponibili in GeneBank. L’analisi filogenetica condotta attraverso il metodo Neighbour-Joining, ha permesso di evidenziare la presenza di due sottotipi virali appartenenti al genotipo BVDV-I: BVDV-Ib e BVDV-Ie. Nessun ceppo virale è risultato appartenere al genotipo BVDV-II. Una successiva analisi di restrizione condotta sugli amplificati utilizzando l’enzima di restrizione AvaI, ha confermato infine l’origine bovina di ciascun isolato. L’analisi filogenetica dei ceppi virali isolati in un determinato territorio, rappresenta un valido strumento per il monitoraggio di una malattia infettiva, permettendo l’evidenziazione di nuove eventuali varianti causa di emergenze sanitarie, la realizzazione di test diagnostici specifici e la realizzazione di una profilassi vaccinale mirata