Antimicrobial peptides and complement in neonatal hypoxia-ischemia induced brain damage

Hypoxic-ischemic encephalopathy (HIE) is a clinical condition in the neonate, resulting from oxygen deprivation around the time of birth. HIE affects 1-5/1000 live births worldwide and is associated with the development of neurological deficits, including cerebral palsy, epilepsy, and cognitive disabilities. Even though the brain is considered as an immune-privileged site, it has innate and adaptive immune response and can produce complement (C) components and antimicrobial peptides (AMPs). Dysregulation of cerebral expression of AMPs and C can exacerbate or ameliorate the inflammatory response within the brain. Brain ischemia triggers a prolonged inflammatory response affecting the progression of injury and secondary energy failure and involves both innate and adaptive immune systems, including immune-competent and non-competent cells. Following injury to the central nervous system (CNS), including neonatal hypoxia-ischemia (HI), resident microglia, and astroglia are the main cells providing immune defense to the brain in a stimulus-dependent manner. They can express and secrete pro-inflammatory cytokines and therefore trigger prolonged inflammation, resulting in neurodegeneration. Microglial cells express and release a wide range of inflammation-associated molecules including several components of the complement system. Complement activation following neonatal HI injury has been reported to contribute to neurodegeneration. Astrocytes can significantly affect the immune response of the CNS under pathological conditions through production and release of pro-inflammatory cytokines and immunomodulatory AMPs. Astrocytes express β-defensins, which can chemoattract and promote maturation of dendritic cells (DC), and can also limit inflammation by controlling the viability of these same DC. This review will focus on the balance of complement components and AMPs within the CNS following neonatal HI injury and the effect of that balance on the subsequent brain damage

Exclusive electroproduction of J/psi mesons

A nonperturbative calculation of elastic electroproduction of the J/psi meson is presented and compared to the experimental data. Our model describes well the observed dependences of the cross sections on the photon virtuality Q2 and on the energy, and the measured ratio R of longitudinal to transverse cross sections.Comment: Five *.eps figure

Nonperturbative QCD treatment of J/ψJ/\psi photoproduction

We present a nonperturbative QCD calculation of elastic $J/\psi$ meson production in photon-proton scattering at high energies. Using light cone wave functions of the photon and vector mesons, and the framework of the model of the stochastic QCD vacuum, we calculate the differential and integrated elastic cross sections for \gamma p \goto J/\psi p . With an energy dependence following the two-pomeron model we are able to give a consistent description of the integrated cross sections and the differential cross sections at low $|t|$ in the range from 20 GeV up to the highest HERA energies. We discuss different approaches to introduce saturation and find no specific effects up to energies presently available. We also calculate and compare to experiments the cross section for $\upsilon$ photoproduction.Comment: 24 pages, 10 figures, 4 table

Exploring the consistency of the SF-6D

Objective: The six dimensional health state short form (SF-6D) was designed to be derived from the short-form 36 health survey (SF-36). The purpose of this research was to compare the SF-6D index values generated from the SF 36 (SF-6D(SF-36)) with those obtained from the SF-6D administered as an independent instrument (SF-6D(Ind)). The goal was to assess the consistency of respondents answers to these two methods of deriving the SF-6D. Methods: Data were obtained from a sample of the Portuguese population (n = 414). Agreement between the instruments was assessed on the basis of a descriptive system and their indexes. The analysis of the descriptive system was performed by using a global consistency index and an identically classified index. Agreement was also explored by using correlation coefficients. Parametric tests were used to identify differences between the indexes. Regression models were estimated to understand the relationship between them. Results: The SF-6D(Ind) generates higher values than does the SF-6D(SF-36), There were significant differences between the indexes across sociodemographic groups. There was a significant ceiling effect in the SF-6D(Ind) a but not in the SF-6D(SF-36). The correlation between the indexes was high but less than what was anticipated. The global consistency index identified the dimensions with larger differences. Considerable differences were found in two dimensions, possibly as a result of different item contexts. Further research is needed to fully understand the role of the different layouts and the length of the questionnaires in the respondents' answers. Conclusions: The results show that as the SF-6D was designed to derive utilities from the SF-36 it should be used in this way and not as an independent instrument.Fundacao para a Ciencia e a Tecnologia (FCT