4,412 research outputs found

    Inclusive electron scattering off 4He

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    Inclusive electron scattering off 4He is calculated exactly with a complete treatment of the final state interaction within a simple semirealistic potential model. We discuss results for both the longitudinal and the transverse response functions, at various momentum transfers. A consistent meson exchange current is implemented. Good agreement with available experimental data is found for the longitudinal response function, while some strength is still missing in the transverse response function.Comment: 4 pages, 3 figures. to appear in the proceedings of the 18th International IUPAP Conference on Few-Body Problems in Physics, Santos-S.Paulo, August 21-26, 200

    Immunosenescence, inflammation and Alzheimer’s disease

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    Ageing impacts negatively on the development of the immune system and its ability to fight pathogens. Progressive changes in the T-cell and B-cell systems over the lifespan of individuals have a major impact on the capacity to respond to immune challenges. The cumulative age-associated changes in immune competence are termed immunosenescence that is characterized by changes where adaptive immunity deteriorates, while innate immunity is largely conserved or even upregulated with age. On the other hand, ageing is also characterized by “inflamm-ageing”, a term coined to explain the inflammation commonly present in many age-associated diseases. It is believed that immune inflammatory processes are relevant in Alzheimer’s disease, the most common cause of dementia in older people. In the present paper we review data focusing on changes of some immunoinflammatory parameters observed in patients affected by Alzheimer’s diseas

    Leucoreduction of blood components. an effective way to increase blood safety?

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    Over the past 30 years, it has been demonstrated that removal of white blood cells from blood components is effective in preventing some adverse reactions such as febrile non-haemolytic transfusion reactions, immunisation against human leucocyte antigens and human platelet antigens, and transmission of cytomegalovirus. In this review we discuss indications for leucoreduction and classify them into three categories: evidence-based indications for which the clinical efficacy is proven, indications based on the analysis of observational clinical studies with very consistent results and indications for which the clinical efficacy is partial or unproven

    Geometry Diagnostics of a Stellar Flare from Fluorescent X-rays

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    We present evidence of Fe fluorescent emission in the Chandra HETGS spectrum of the single G-type giant HR 9024 during a large flare. In analogy to solar X-ray observations, we interpret the observed Fe Kα\alpha line as being produced by illumination of the photosphere by ionizing coronal X-rays, in which case, for a given Fe photospheric abundance, its intensity depends on the height of the X-ray source. The HETGS observations, together with 3D Monte Carlo calculations to model the fluorescence emission, are used to obtain a direct geometric constraint on the scale height of the flaring coronal plasma. We compute the Fe fluorescent emission induced by the emission of a single flaring coronal loop which well reproduces the observed X-ray temporal and spectral properties according to a detailed hydrodynamic modeling. The predicted Fe fluorescent emission is in good agreement with the observed value within observational uncertainties, pointing to a scale height 0.3\lesssim 0.3\rstar. Comparison of the HR 9024 flare with that recently observed on II Peg by Swift indicates the latter is consistent with excitation by X-ray photoionization.Comment: accepted for publication on the Astrophysical Journal Letter

    Human parvovirus B19 and blood product safety. A tale of twenty years of improvements

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    Parvovirus B19 (B19V), long known to be the causative agent of erythema infectiosum (fifth disease), is not a newly emerging agent. The aim of this review is to analyse the role played by this virus in compromising safety in transfusion medicine and the progressive measures to reduce the risks associated with the virus

    Effect of obesity and metabolic syndrome on plasma oxysterols and fatty acids in human

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    BACKGROUND: Obesity and the related entity metabolic syndrome are characterized by altered lipid metabolism and associated with increased morbidity risk for cardiovascular disease and cancer. Oxysterols belong to a large family of cholesterol-derived molecules known to play crucial role in many signaling pathways underlying several diseases. Little is known on the potential effect of obesity and metabolic syndrome on oxysterols in human. OBJECTIVES: In this work, we questioned whether circulating oxysterols might be significantly altered in obese patients and in patients with metabolic syndrome. We also tested the potential correlation between circulating oxysterols and fatty acids. METHODS: 60 obese patients and 75 patients with metabolic syndrome were enrolled in the study along with 210 age- and sex-matched healthy subjects, used as control group. Plasma oxysterols were analyzed by isotope dilution GC/MS, and plasma fatty acids profiling was assessed by gas chromatography coupled with flame ionization detection. RESULTS: We found considerable differences in oxysterols profiling in the two disease groups that were gender-related. Compared to controls, males showed significant differences only in 4α- and 4β-hydroxycholesterol levels in obese and metabolic syndrome patients. In contrast, females showed consistent differences in 7-oxocholesterol, 4α-hydroxycholesterol, 25-hydroxycholesterol and triol. Concerning fatty acids, we found minor differences in the levels of these variables in males of the three groups. Significant changes were observed in plasma fatty acid profile of female patients with obesity or metabolic syndrome. We found significant correlations between various oxysterols and fatty acids. In particular, 4β-hydroxycholesterol, which is reduced in obesity and metabolic syndrome, correlated with a number of saturated and mono-unsaturated fatty acids that are end-products of de novo lipogenesis. CONCLUSIONS: Our data provide the first evidence that obesity and metabolic syndrome are associated with major, gender-specific, changes in circulating oxysterols and fatty acids. These findings suggest a metabolic link between oxysterols and fatty acids, and that oxysterols may contribute to the epidemic diseases associated with obesity and metabolic syndrome in female

    PRIMARY ORAL MUCOSA MELANOMA: A REPORT OF AN UNUSUAL CLINICOPATHOLOGICAL CASE

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    Primary oral melanoma is a rare malignancy with an aggressive behaviour. Up to date, the wide clinicalhistological variability of this oncological entity does not clarify the etiopathogenetic characteristics of these cancers and limit the therapeutic strategies. We report a case of a 64-year-old white female referred to the Dept. of Surgical, Oncological and Oral Sciences for a pigmented lesion of the mandibular gingiva, already arising 20 years ago but dimensionally increased in the last three months. Clinically, a black plaque-like pigmentation of the vestibular alveolar mucosa of the mandible (from 3.6 to 3.3) was observed. This lesions was still painless. CT dentalscan and ecography of the head and neck lymph nodes have showed no signs of bone and lymph nodes involvement. An incisional biopsy of the lesion was performed under local anaesthesia. Histopathologic examination showed a nodular proliferation of atypical melanocytic elements with epithelioid aspect and nuclear alterations; numerous abnormal mitotic figures were evident and the malignant melanocytes were characterized by marked intra/extracellular pigmentation. Immunohistochemical staining showed strong and diffuse positivity for Melan A and HMB45, 40% positive for Ki67 and positive/negative result for p16. These histopathologic features were suggestive for animal-type invasive melanoma. After diagnosis, the patient was referred to the Dept. of Head and Neck Surgery for staging and chirurgical approach of the lesion. At the best of our knowledge, only a very small number of animal-type melanomas have been reported in the oral cavity and usually with a more indolent behavior than conventional melanoma and a better prognosis. However, future reports are necessary to characterize the features of this cancer and to determine any factors that may correlate with outcome

    Paraneoplastic Acanthosis Nigricans Maligna

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    Acanthosis Nigricans Maligna (ANM) is a paraneoplastic syndrome, defined as a condition that arises in association with a malignancy elsewhere in the body but without malignant nature per se. It’s a rare dermatopathy that occurs in men and women over age 40, without racial predilection or known familial association. Clinically, ANM showed symmetric,hyperpigmented plaques with variable amounts of epidermal hypertrophy, ranging in color from yellow to brown or black, often with overlaid papillomas. The most common affected sites are body flexures and the posterior neck, but also mucosal surface involvement is frequent and may be the only clinical symptom present. Any mucosal surface can be involved, and as regards the oral cavity, disease affects the lips, tongue, palate, buccal and gingival mucosa.ANM is primarily associated with adenocarcinomas, mostly of gastric origin. Accordingly, the progression of the tumor will lead to a worsening of the ANM, while regress in case of tumour treatment, and resurface with recurrence and metastases. A 62-year-old man was referred for evaluation of papillomatous lesions of the oral mucosa, appeared in previous months. The patient was diagnosed a gastric adenocarcinoma at an advanced stage 6 months before. Clinical examination showed diffuse papillomatous or wart-like areas of normal mucosal color and soft consistency involving lips,oral mucosa and hard palate. The tongue and the vestibular mucosa were thickened and furrowed. The lesions are asymptomatic. A biopsy was performed, and histopathological analysis revealed acanthosis and papillomatosis, hyperkeratosis,and lymphohistiocytic infiltrate. The patient was clinically diagnosed with ANM, according to clinical and histologic findings, and the patient’s medical history. Isotretinoin 0,05% was prescribed for local therapy. The patient did not return to follow-up due to complications of gastric adenocarcinoma, and died 6 months late

    Role of cyclooxygenae-2 and 5-lypoxygenase polymorphisms in Alzheimer's disease in a population from northern Italy:implications for pharmacogenomics

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    Alzheimer's disease (AD) is a neurodegenerative disorder clinically characterized by cognitive deficit with progressive worsening of memory. Recent data indicate that neurons, as well as other brain cells, can express enzymes such as cyclooxygenases (COXs) and 5-lipoxygenase (5-LO) which are considered important in inflammatory cells. Moreover, it has been demonstrated that COX-2 and 5-LO enzymes play a considerable role in the pathophysiology of AD. In order to assess the possible role of COX-2 and 5-LO single nucleotide polymorphisms (SNPs) in AD, we examined their distribution in 341 AD patients and 190 controls from Northern Italy. A significant difference was observed in the distribution of the -765G COX-2 and -1708A 5-LO alleles between AD cases and controls (p=0.03 for -765G/C COX-2 SNP; and p=0.007 for -1708G/A 5-LO SNP). Hence, COX-2 -765G and 5-LO -1708A alleles were overrepresented in AD patients and underrepresented in controls. Our data suggest that these alleles of COX-2 and 5-LO could be risk factors for AD. These results seem of some importance for a pharmacogenomic approach
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