1,119 research outputs found
The symbiotic star H1-36. A composite model of line and continuum spectra from radio to ultraviolet
In this paper we analyse the spectra of D-type SS H1-36 within a
colliding-wind scenario. We aim to analyse the properties of this object taking
into account the observational data along the whole electromagnetic spectrum,
in order to derive a self-consistent picture able to interpret the nature of
the system as a whole. After constraining the relative physical conditions by
modelling more than 40 emission lines from radio to UV, we are able to explain
the continuum spectral energy distribution by taking into account all the
emitting contributions arising from both the stars, the dust shells and the
gaseous nebulae. A comprehensive model of the radio spectra allows to reproduce
the different slopes of the radio profile and the turnover frequency, as well
as the different size of the observed shocked envelope at different frequencies
in the light of the different contributions from the expanding and reverse
nebulae. The IR continuum unveils the presence of two dust shells with
different radii and temperatures, which might be a distinctive feature of
D-type symbiotic systems as a class of objects. The broad profiles of IR lines
direct us to investigate whether an X-ray jet may be present. This insight
leads us to indicate H1-36 as a promising X-ray target and to encourage
observations and studies which consistently take into account the complex
nature of symbiotic stars throughout the whole electromagnetic spectrum.Comment: 8 pages, 3 figures, 5 tables, accepted for publication in A&A on 2th
May 200
The complementary role of imaging and tumor biomarkers in gynecological cancers: an update of the literature
Gynecological tumors, including endometrial, cervical and ovarian cancer, have increased in incidence over
time. The widespread introduction of screening programs and advances in diagnostic imaging methods has lead to a
progressive increase in gynecological cancer detection. Accurate diagnosis and proper monitoring of disease remain
the primary target for a successful treatment. In the last years, knowledge about cancer biomarkers has considerably
increased providing great opportunities for improving cancer detection and treatment. In addition, in the last few years
there has been an important development of imaging techniques. Nowadays, a multimodal approach including the
evaluation of serum tumor biomarkers combined with imaging techniques, seems to be the best strategy for assessing
tumor presence, spread, recurrence, and/or the response to treatment in female cancer patients In this review we provide
an overview of the application of biomarkers combined with novel imaging methods and highlight their roles in female
cancer diagnosis and follow-up
New mechanisms of action of natural antioxidants in health and disease II
Epidemiological studies have demonstrated an association between natural antioxidants and human health [...]
New mechanisms of action of natural antioxidants in health and disease
Natural antioxidants have been proposed to have beneficial effects on health and on different disease states, such as neurodegenerative and cardiovascular diseases, diabetes and cancer [...]
Combined treatment with three natural antioxidants enhances neuroprotection in a SH-SY5Y 3D culture model
Currently, the majority of cell-based studies on neurodegeneration are carried out on two-dimensional cultured cells that do not represent the cells residing in the complex microenvironment of the brain. Recent evidence has suggested that three-dimensional (3D) in vitro microenvironments may better model key features of brain tissues in order to study molecular mechanisms at the base of neurodegeneration. So far, no drugs have been discovered to prevent or halt the progression of neurodegenerative disorders. New therapeutic interventions can come from phytochemicals that have a broad spectrum of biological activities. On this basis, we evaluated the neuroprotective effect of three phytochemicals (sulforaphane, epigallocatechin gallate, and plumbagin) alone or in combination, focusing on their ability to counteract oxidative stress. The combined treatment was found to be more effective than the single treatments. In particular, the combined treatment increased cell viability and reduced glutathione (GSH) levels, upregulated antioxidant enzymes and insulin-degrading enzymes, and downregulated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 1 and 2 in respect to peroxide-treated cells. Our data suggest that a combination of different phytochemicals could be more effective than a single compound in counteracting neurodegeneration, probably thanks to a pleiotropic mechanism of action
Protein induced by vitamin K absence or antagonist-II (PIVKA-II) specifically increased in Italian hepatocellular carcinoma patients
OBJECTIVE: As a marker for Hepatocellular Carcinoma (HCC), Protein Induced by Vitamin K Absence II (PIVKA-II) seems to be superior to alpha fetoprotein (AFP). To better characterize the role of PIVKA-II, both AFP and PIVKA-II have been measured in Italian patients with diagnosis of HCC compared with patients affected by non-oncological liver pathologies.
MATERIALS AND METHODS: Sixty serum samples from patients with HCC, 60 samples from patients with benign liver disease and 60 samples obtained from healthy blood donors were included in the study. PIVKA-II and AFP were measured by LUMIPULSE(®) G1200 (Fujirebio-Europe, Belgium). We considered as PIVKA-II cutoff 70 mAU/ml (mean +3SD) of the values observed in healthy subjects.
RESULTS: The evaluation of PIVKA-II showed a positivity of 70% in patients with HCC and 5% in patients with benign diseases (p < 0.0001) whereas high levels of AFP were observed in 55% of HCC patients and in 47% of patients with benign diseases. The combined Receiver Operating Characteristic (ROC) analysis of the two analytes revealed a higher sensitivity (75%) compared to those observed for the individual biomarkers. In conclusion, we demonstrate that as a marker for HCC, PIVKA-II is more specific for HCC and less prone to elevation during chronic liver diseases.
CONCLUSIONS: The combination of the two biomarkers, evaluated by the ROC analysis, improved the specificity compared to a single marker. These data suggest that the combined analysis of the two markers could be a useful tool in clinical practice
The use of dietary supplements among soccer referees: How much do they know?
Referees are essential for the correct execution of each soccer match and national soccer associations support them with physical training guidelines in order to improve agility, aerobic and sprint capacity, to reduce the risk of injury and to meet the minimum required performance levels. Despite the importance given to performance skills no specific nutritional guideline is provided to support the performance required. This study was aimed to investigate soccer field and assistant referees knowledge and consumption of dietary supplements. Seventy-one European referees participated to this survey by filling a short and quick anonymous questionnaire designed to collect information about their refereeing category, educational level, frequency of supplement consumption, type of supplement consumed. Moreover, a sub-group of 20 participants wore a training watch to record energy expenditure, distance, and heart rate during training sessions and matches. Our data show that referees frequently consume supplements especially those refereeing in lower categories, moreover they often follow a friend\u2019s suggestion when deciding to take a supplement instead of trusting a professional prescription. According to our survey, national and international soccer federations should care more about their referee nutritional education
Antioxidant and Anti-Inflammatory Profiles of Spent Coffee Ground Extracts for the Treatment of Neurodegeneration
Spent coffee grounds (SCGs), waste products of coffee beverage production, are rich in organic compounds such as phenols. Different studies have demonstrated phenol beneficial effects in counteracting neurodegenerative diseases. These diseases are associated with oxidative stress and neuroinflammation, which initiates the degeneration of neurons by overactivating microglia. Unfortunately, to date, there are no pharmacological therapies to treat these pathologies. The aim of this study was to evaluate the phenolic content of 4 different SCG extracts and their ability to counteract oxidative stress and neuroinflammation. Caffeine and 5-O-caffeoylquinic acid were the most abundant compounds in all extracts, followed by 3-O-caffeoylquinic acid and 3,5-O-dicaffeoylquinic acid. The four extracts demonstrated a different ability to counteract oxidative stress and neuroinflammation in vitro. In particular, the methanol extract was the most effective in protecting neuron-like SH-SY5Y cells against H2O2-induced oxidative stress by upregulating endogenous antioxidant enzymes such as thioredoxin reductase, heme oxygenase 1, NADPH quinone oxidoreductase, and glutathione reductase. The water extract was the most effective in counteracting lipopolysaccharide-induced neuroinflammation in microglial BV-2 cells by strongly reducing the expression of proinflammatory mediators through the modulation of the TLR4/NF-kappa B pathway. On these bases, SCG extracts could represent valuable nutraceutical sources for the treatment of neurodegeneratio
Modulation of different clusterin isoforms in human colon tumorigenesis
Clusterin is a ubiquitous secretory heterodimeric disulfide-linked glycoprotein, which is implicated in several physiological processes, including immune regulation, cell adhesion and morphological transformation, lipid transportation, tissue remodelling, membrane recycling and cell-cell interactions. A large number of studies have focused their interest on clusterin gene products as mediators of cell cycle progression and cell death induction, although data on the different isoforms and their role in the different cell processes are still obscure. Recently, an increased clusterin expression in breast cancer has been reported. In order to elucidate the role of clusterin in tumor progression and whether one of its isoforms is preferentially expressed in tumorigenesis, we examined its presence throughout the different steps of human colon carcinoma, one of the best-characterized models of human tumor progression. The immunohistochemical observation of 30 bioptic and surgical colon specimens demonstrated a cell compartment clusterin translocation from the nucleus to the cytoplasm directly related to tumor progression. In fact, a nuclear localization found in healthy colonic mucosa is consistent with the involvement of the proapoptotic nuclear form in the regulation of cell cycle progression and in cell death induction. The progression towards high-grade and metastatic carcinoma leads to cytoplasmic clusterin distribution. Protein extracts from freshly isolated cells of the same patients confirm in high-grade carcinomas with metastatic nodes the complete loss of the proapoptotic nuclear form and a cytoplasmic overexpression of the highly glycosylated form. Data obtained from in vitro experiments confirm that this form is released in the extracellular space and corresponded to the fully glycosylated one. These data suggest that the controversial data on clusterin function in tumors may be related to the pattern shift of its isoform production. As the secreted form of clusterin is correlated to cell matrix formation, cell membrane remodeling and cell-cell adhesion, the overexpression of this form in highly aggressive tumors and metastatic nodes could be a potential new prognostic and predictive marker for colon carcinoma aggressiveness
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