174 research outputs found

    Magnetism and its microscopic origin in iron-based high-temperature superconductors

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    High-temperature superconductivity in the iron-based materials emerges from, or sometimes coexists with, their metallic or insulating parent compound states. This is surprising since these undoped states display dramatically different antiferromagnetic (AF) spin arrangements and NeËŠ\rm \acute{e}el temperatures. Although there is general consensus that magnetic interactions are important for superconductivity, much is still unknown concerning the microscopic origin of the magnetic states. In this review, progress in this area is summarized, focusing on recent experimental and theoretical results and discussing their microscopic implications. It is concluded that the parent compounds are in a state that is more complex than implied by a simple Fermi surface nesting scenario, and a dual description including both itinerant and localized degrees of freedom is needed to properly describe these fascinating materials.Comment: 14 pages, 4 figures, Review article, accepted for publication in Nature Physic

    Studies of a co-chaperone of the androgen receptor, FKBP52, as candidate for hypospadias

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    BACKGROUND: Hypospadias is a common inborn error of the male urethral development, for which the aetiology is still elusive. Polymorphic variants in genes involved in the masculinisation of male genitalia, such as the androgen receptor, have been associated with some cases of hypospadias. Co-regulators of the androgen receptor start being acknowledged as possible candidates for hormone-resistance instances, which could account for hypospadias. One such molecule, the protein FKBP52, coded by the FKBP4 gene, has an important physiological role in up-regulating androgen receptor activity, an essential step in the development of the male external genitalia. The presence of hypospadias in mice lacking fkbp52 encouraged us to study the sequence and the expression of FKBP4 in boys with isolated hypospadias. PATIENTS AND METHODS: The expression of FKBP52 in the genital skin of boys with hypospadias and in healthy controls was tested by immunohistochemistry. Mutation screening in the FKBF4 gene was performed in ninety-one boys with non syndromic hypospadias. Additionally, two polymorphisms were typed in a larger cohort. RESULTS: Immunohistochemistry shows epithelial expression of FKBP52 in the epidermis of the penile skin. No apparent difference in the FKBP52 expression was detected in healthy controls, mild or severe hypospadias patients. No sequence variants in the FKBP4 gene have implicated in hypospadias in our study. CONCLUSION: FKBP52 is likely to play a role in growth and development of the male genitalia, since it is expressed in the genital skin of prepubertal boys; however alterations in the sequence and in the expression of the FKBP4 gene are not a common cause of non-syndromic hypospadias

    Self-reported health status and access to health services in a sample of prisoners in Italy

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    <p>Abstract</p> <p>Background</p> <p>Self-reported health status in underserved population of prisoners has not been extensively explored. The purposes of this cross-sectional study were to assess self-reported health, quality of life, and access to health services in a sample of male prisoners of Italy.</p> <p>Methods</p> <p>A total of 908 prisoners received a self-administered anonymous questionnaire pertaining on demographic and detention characteristics, self-reported health status and quality of life, access to health services, lifestyles, and participation to preventive, social, and rehabilitation programs. A total of 650 prisoners agreed to participate in the study and returned the questionnaire.</p> <p>Results</p> <p>Respectively, 31.6% and 43.5% of prisoners reported a poor perceived health status and a poor quality of life, and 60% admitted that their health was worsened or greatly worsened during the prison stay. Older age, lower education, psychiatric disorders, self-reported health problems on prison entry, and suicide attempts within prison were significantly associated with a perceived worse health status. At the time of the questionnaire delivery, 30% of the prisoners self-reported a health problem present on prison entry and 82% present at the time of the survey. Most frequently reported health problems included dental health problems, arthritis or joint pain, eye problems, gastrointestinal diseases, emotional problems, and high blood pressure. On average, prisoners encountered general practitioners six times during the previous year, and the frequency of medical encounters was significantly associated with older age, sentenced prisoners, psychiatric disorders, and self-reported health problems on prison entry.</p> <p>Conclusions</p> <p>The findings suggest that prisoners have a perceived poor health status, specific care needs and health promotion programs are seldom offered. Programs for correction of risk behaviour and prevention of long-term effects of incarceration on prisoners' health are strongly needed.</p

    Protein C Inhibitor—A Novel Antimicrobial Agent

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    Protein C inhibitor (PCI) is a heparin-binding serine proteinase inhibitor belonging to the family of serpin proteins. Here we describe that PCI exerts broad antimicrobial activity against bacterial pathogens. This ability is mediated by the interaction of PCI with lipid membranes, which subsequently leads to their permeabilization. As shown by negative staining electron microscopy, treatment of Escherichia coli or Streptococcus pyogenes bacteria with PCI triggers membrane disruption followed by the efflux of bacterial cytosolic contents and bacterial killing. The antimicrobial activity of PCI is located to the heparin-binding site of the protein and a peptide spanning this region was found to mimic the antimicrobial activity of PCI, without causing lysis or membrane destruction of eukaryotic cells. Finally, we show that platelets can assemble PCI on their surface upon activation. As platelets are recruited to the site of a bacterial infection, these results may explain our finding that PCI levels are increased in tissue biopsies from patients suffering from necrotizing fasciitis caused by S. pyogenes. Taken together, our data describe a new function for PCI in innate immunity

    Contribution of TAT System Translocated PhoX to Campylobacter jejuni Phosphate Metabolism and Resilience to Environmental Stresses

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    Campylobacter jejuni is a common gastrointestinal pathogen that colonizes food animals; it is transmitted via fecal contamination of food, and infections in immune-compromised people are more likely to result in serious long-term illness. Environmental phosphate is likely an important sensor of environmental fitness and the ability to obtain extracellular phosphate is central to the bacteria's core metabolic responses. PhoX is the sole alkaline phosphatase in C. jejuni, a substrate of the TAT transport system. Alkaline phosphatases mediate the hydrolytic removal of inorganic phosphate (Pi) from phospho-organic compounds and thereby contribute significantly to the polyphosphate kinase 1 (ppk1) mediated formation of poly P, a molecule that regulates bacterial response to stresses and virulence. Similarly, deletion of the tatC gene, a key component of the TAT system, results in diverse phenotypes in C. jejuni including reduced stress tolerance and in vivo colonization. Therefore, here we investigated the contribution of phoX in poly P synthesis and in TAT-system mediated responses. The phoX deletion mutant showed significant decrease (P<0.05) in poly P accumulation in stationary phase compared to the wild-type, suggesting that PhoX is a major contributor to the inorganic phosphate pool in the cell which is essential for poly P synthesis. The phoX deletion is sufficient for a nutrient stress defect similar to the defect previously described for the ΔtatC mutant. Additionally, the phoX deletion mutant has increased resistance to certain antimicrobials. The ΔphoX mutant was also moderately defective in invasion and intracellular survival within human intestinal epithelial cells as well as in chicken colonization. Further, the ΔphoX mutant produced increased biofilm that can be rescued with 1 mM inorganic phosphate. The qRT-PCR of the ΔphoX mutant revealed transcriptional changes that suggest potential mechanisms for the increased biofilm phenotype

    Why do we treat adolescent idiopathic scoliosis? What we want to obtain and to avoid for our patients. SOSORT 2005 Consensus paper

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    BACKGROUND: Medicine is a scientific art: once science is not clear, choices are made according to individual and collective beliefs that should be better understood. This is particularly true in a field like adolescent idiopathic scoliosis, where currently does not exist definitive scientific evidence on the efficacy either of conservative or of surgical treatments. AIM OF THE STUDY: To verify the philosophical choices on the final outcome of a group of people believing and engaged in a conservative treatment of idiopathic scoliosis. METHODS: We performed a multifaceted study that included a bibliometric analysis, a questionnaire, and a careful Consensus reaching procedure between experts in the conservative treatment of scoliosis (SOSORT members). RESULTS: The Consensus reaching procedure has shown to be useful: answers changed in a statistically significant way, and 9 new outcome criteria were included. The most important final outcomes were considered Aesthetics (100%), Quality of life and Disability (more than 90%), while more than 80% of preferences went to Back Pain, Psychological well-being, Progression in adulthood, Breathing function, Scoliosis Cobb degrees (radiographic lateral flexion), Needs of further treatments in adulthood. DISCUSSION: In the literature prevail outcome criteria driven by the contingent treatment needs or the possibility to have measurement systems (even if it seems that usual clinical and radiographic methods are given much more importance than more complex Disability or Quality of Life instruments). SOSORT members give importance to a wide range of outcome criteria, in which clinical and radiographic issues have the lowest importance. CONCLUSION: We treat our patients for what they need for their future (Breathing function, Needs of further treatments in adulthood, Progression in adulthood), and their present too (Aesthetics, Disability, Quality of life). Technical matters, such as rib hump or radiographic lateral alignment and rotation, but not lateral flexion, are secondary outcomes and only instrumental to previously reported primary outcomes. We advocate a multidimensional, comprehensive evaluation of scoliosis patients, to gather all necessary data for a complete therapeutic approach, that goes beyond x-rays to reach the person and the family
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