University of Naples Federico II

About: University of Naples Federico II is a education organization based out in Naples, Campania, Italy. It is known for research contribution in the topics: Population & Cancer. The organization has 29291 authors who have published 68803 publications receiving 1920149 citations. The organization is also known as: Università degli Studi di Napoli Federico II & Naples University.

Tomographic flow cytometry by digital holography.

Abstract: High-throughput single-cell analysis is a challenging task. Label-free tomographic phase microscopy is an excellent candidate to perform this task. However, in-line tomography is very difficult to implement in practice because it requires a complex set-up for rotating the sample and examining the cell along several directions. We demonstrate that by exploiting the random rolling of cells while they are flowing along a microfluidic channel, it is possible to obtain in-line phase-contrast tomography, if smart strategies for wavefront analysis are adopted. In fact, surprisingly, a priori knowledge of the three-dimensional position and orientation of rotating cells is no longer needed because this information can be completely retrieved through digital holography wavefront numerical analysis. This approach makes continuous-flow cytotomography suitable for practical operation in real-world, single-cell analysis and with a substantial simplification of the optical system; that is, no mechanical scanning or multi-direction probing is required. A demonstration is given for two completely different classes of biosamples: red blood cells and diatom algae. An accurate characterization of both types of cells is reported, despite their very different nature and material content, thus showing that the proposed method can be extended by adopting two alternate strategies of wavefront analysis to many classes of cells.

High-SNR power offset in multiantenna communication

Abstract: The analysis of the multiple-antenna capacity in the high-SNR regime has hitherto focused on the high-SNR slope (or maximum multiplexing gain), which quantifies the multiplicative increase as a function of the number of antennas. This traditional characterization is unable to assess the impact of prominent channel features since, for a majority of channels, the slope equals the minimum of the number of transmit and receive antennas. Furthermore, a characterization based solely on the slope captures only the scaling but it has no notion of the power required for a certain capacity. This paper advocates a more refined characterization whereby, as a function of SNR|/sub dB/, the high-SNR capacity is expanded as an affine function where the impact of channel features such as antenna correlation, unfaded components, etc., resides in the zero-order term or power offset. The power offset, for which we find insightful closed-form expressions, is shown to play a chief role for SNR levels of practical interest.

Angiogenesis as a Prognostic Indicator of Survival in Non-Small-Cell Lung Carcinoma: a Prospective Study

Abstract: Background: Tumors acquire nutrients that are essential for continued growth and an avenue for dissemination to the rest of the body by inducing angiogenesis (i.e., the formation of new blood vessels). Preliminary studies involving a number of different kinds of cancer have indicated that an assessment of tumor angiogenesis may be useful in predicting disease outcome. Purpose: In a prospective study, we evaluated the relationship between tumor angiogenesis and survival for 407 patients with non-small-cell lung carcinoma who were treated with potentially curative surgery. Methods: The study population consisted of 360 male and 47 female patients who underwent surgery consecutively at the Department of Surgery, University of Pisa, Italy, from March 1991 through December 1994. Follow-up lasted through February 1996, with a median follow-up for living patients of 29 months (range, 15-60 months). An anti-CD34 monoclonal antibody, which is specific for endothelial cells, and standard immunohistochemical techniques were used to measure angiogenesis in tumor samples. Angiogenesis was quantified in terms of microvessel counts; the counts for single, high- power microscopic fields (magnification x250) in the three most intense areas of blood vessel growth for each sample were averaged. The median microvessel count in this series was 20, and the counts were categorized as follows : 1) low versus high (≤20 versus >20 microvessels) or 2) in five categories (1-10, 11-20, 21-30, 31-40, and ≥41 microvessels). Disease-free and overall survival during follow-up were assessed. Kaplan-Meier survival curves were modeled in a univariate analysis of patient and tumor characteristics; the Cox proportional hazards model was used in multivariate analysis. Reported P values are two-sided. Results and Conclusions: In the univariate analysis, patients with larger tumors (P for trend <.00001), a more advanced tumor stage (P for trend <.00001), a greater degree of regional lymph node involvement (P for trend <.00001), or more vascularized tumors (high versus low microvessel count, P<.00001) experienced significantly reduced overall survival. When microvessel counts were analyzed in five categories, a highly significant trend (P<.00001) toward worse prognosis was observed with increasing tumor vascularity. In multivariate analysis, tumor microvessel count (P<.00001), tumor size (P = .0006), and regional lymph node status (P<.00001) retained independent prognostic value with respect to overall survival; among these variables, tumor microvessel count, considered as a continuous variable, was the most important, with a relative hazard of death of 8.38 (95% confidence interval = 4.19-16.78) associated with the highest microvessel counts. Implications: An evaluation of tumor angiogenesis may be useful in the postsurgical staging of patients with non-small-cell lung carcinoma and in identifying subsets of patients who may benefit from different postsurgical treatments.

Biological Mechanisms of Physical Activity in Preventing Cognitive Decline

Abstract: In order to guarantee better conditions for competition, the nervous system has developed not only mechanisms controlling muscle effectors, but also retrograde systems that, starting from peripheral structures, may influence brain functions. Under such perspective, physical activity could play an important role in influencing cognitive brain functions including learning and memory. The results of epidemiological studies (cross-sectional, prospective and retrospective) support a positive relationship between cognition and physical activities. Recent meta-analysis confirmed a significant effect of exercise on cognitive functions. However, the biological mechanisms that underlie such beneficial effects are still to be completely elucidated. They include supramolecular mechanisms (e.g. neurogenesis, synaptogenesis, and angiogenesis) which, in turn, are controlled by molecular mechanisms, such as BDNF, IGF-1, hormone and second messengers.

Bioavailability of trans-resveratrol from red wine in humans

Abstract: Many in vitro studies demonstrated significant biological effects of trans-resveratrol. Thus, understanding the rate of intestinal absorption and metabolization in vivo of trans-resveratrol is the prerequisite to evaluate its potential health impact. Bioavailability studies mainly in animals or in humans using the pure compound at very high doses were performed. In this work, trans-resveratrol bioavailability from a moderate consumption of red wine in 25 healthy humans has been studied by three different experiments. The wine ingestion was associated to three different dietary approaches: fasting, a standard meal, a meal with high and low amount of lipids. Trans-resveratrol 3- and 4'-glucuronides were synthesized, purified, and characterized as pure standards. Bioavailability data were obtained by measuring the concentration of free, 3-glucuronide and 4'-glucuronide trans-resveratrol by high-performance liquid chromatography (HPLC), both with ultraviolet (UV) and mass spectrometry (MS) detection, in serum samples taken at different times after red wine administration. Free trans-resveratrol was found, in trace amounts, only in some serum samples collected 30 min after red wine ingestion while after longer times resveratrol glucuronides predominated. Trans-resveratrol bioavailability was shown to be independent from the meal or its lipid content. The finding in human serum of trans-resveratrol glucuronides, rather than the free form of the compound, with a high interindividual variability, raises some doubts about the health effects of dietary resveratrol consumption and suggests that the benefits associated to red wine consumption could be probably due to the whole antioxidant pool present in red wine.