The intestinal tract is in intimate contact with the commensal microflora. Nevertheless, how commensals communicate with cells to ensure immune homeostasis is still unclear. In this study, we found that gut flora DNA (gfDNA) plays a major role in intestinal homeostasis through Toll-like receptor 9 (TLR9) engagement. Tlr9(-/-) mice displayed increased frequencies of CD4(+)Foxp3(+) regulatory T (Treg) cells within intestinal effector sites and reduced constitutive IL-17- and IFN-gamma-producing effector T (Teff) cells. Complementing this, gfDNA limited lamina propria dendritic cell-induced Treg cell conversion in vitro. Further, Treg/Teff cell disequilibrium in Tlr9(-/-) mice led to impaired immune responses to oral infection and to oral vaccination. Impaired intestinal immune responses were recapitulated in mice treated with antibiotics and were reversible after reconstitution with gfDNA. Together, these data point to gfDNA as a natural adjuvant for priming intestinal responses via modulation of Treg/Teff cell equilibrium.

Complex behaviour change interventions are not well described; when they are described, the terminology used is inconsistent. This constrains scientific replication, and limits the subsequent introduction of successful interventions. Implementation Science is introducing a policy of initially encouraging and subsequently requiring the scientific reporting of complex behaviour change interventions.

Activating mutations in BRAF are the most common genetic alterations in melanoma. Inhibition of BRAF by small molecules leads to cell-cycle arrest and apoptosis. We show here that BRAF inhibition also induces an oxidative phosphorylation gene program, mitochondrial biogenesis, and the increased expression of the mitochondrial master regulator, PGC1α. We further show that a target of BRAF, the melanocyte lineage factor MITF, directly regulates the expression of PGC1α. Melanomas with activation of the BRAF/MAPK pathway have suppressed levels of MITF and PGC1α and decreased oxidative metabolism. Conversely, treatment of BRAF-mutated melanomas with BRAF inhibitors renders them addicted to oxidative phosphorylation. Our data thus identify an adaptive metabolic program that limits the efficacy of BRAF inhibitors.

Failure of immunization with the HIV-1 envelope to induce broadly neutralizing antibodies against conserved epitopes is a major barrier to producing a preventive HIV-1 vaccine. Broadly neutralizing monoclonal antibodies (BnAbs) from those subjects who do produce them after years of chronic HIV-1 infection have one or more unusual characteristics, including polyreactivity for host antigens, extensive somatic hypermutation and long, variable heavy-chain third complementarity-determining regions, factors that may limit their expression by host immunoregulatory mechanisms. The isolation of BnAbs from HIV-1-infected subjects and the use of computationally derived clonal lineages as templates provide a new path for HIV-1 vaccine immunogen design. This approach, which should be applicable to many infectious agents, holds promise for the construction of vaccines that can drive B cells along rare but desirable maturation pathways.

OBJECTIVE

The ADMIRE-HF (AdreView Myocardial Imaging for Risk Evaluation in Heart Failure) study prospectively evaluated iodine-123 meta-iodobenzylguanidine ((123)I-mIBG) imaging for identifying symptomatic heart failure (HF) patients most likely to experience cardiac events.

BACKGROUND

Single-center studies have demonstrated the poorer prognosis of HF patients with reduced (123)I-mIBG myocardial uptake, but these observations have not been validated in large multicenter trials.

METHODS

A total of 961 subjects with New York Heart Association (NYHA) functional class II/III HF and left ventricular ejection fraction (LVEF) < or =35% were studied. Subjects underwent (123)I-mIBG myocardial imaging (sympathetic neuronal integrity quantified as the heart/mediastinum uptake ratio [H/M] on 4-h delayed planar images) and myocardial perfusion imaging and were then followed up for up to 2 years. Time to first occurrence of NYHA functional class progression, potentially life-threatening arrhythmic event, or cardiac death was compared with H/M (either in relation to estimated lower limit of normal [1.60] or as a continuous variable) using Cox proportional hazards regression. Multivariable analyses using clinical, laboratory, and imaging data were also performed.

RESULTS

A total of 237 subjects (25%) experienced events (median follow-up 17 months). The hazard ratio for H/M>> or =1.60 was 0.40 (p < 0.001); the hazard ratio for continuous H/M was 0.22 (p < 0.001). Two-year event rate was 15% for H/M>> or =1.60 and 37% for H/M <1.60; hazard ratios for individual event categories were as follows: HF progression, 0.49 (p = 0.002); arrhythmic events, 0.37 (p = 0.02); and cardiac death, 0.14 (p = 0.006). Significant contributors to the multivariable model were H/M, LVEF, B-type natriuretic peptide, and NYHA functional class. (123)I-mIBG imaging also provided additional discrimination in analyses of interactions between B-type natriuretic peptide, LVEF, and H/M.

CONCLUSIONS

ADMIRE-HF provides prospective validation of the independent prognostic value of (123)I-mIBG scintigraphy in assessment of patients with HF. (Meta-Iodobenzylguanidine Scintigraphy Imaging in Patients With Heart Failure and Control Subjects Without Cardiovascular Disease, NCT00126425; Meta-Iodobenzylguanidine [123I-mIBG] Scintigraphy Imaging in Patients With Heart Failure and Control Subjects Without Cardiovascular Disease, NCT00126438).

To determine the protective potential of the humoral immune response against HIV-1 in vivo we evaluated the potency of three neutralizing antibodies (2G12, 2F5 and 4E10) in suppressing viral rebound in six acutely and eight chronically HIV-1-infected individuals undergoing interruption of antiretroviral treatment (ART). Only two of eight chronically infected individuals showed evidence of a delay in viral rebound during the passive immunization. Rebound in antibody-treated acutely infected individuals upon cessation of ART was substantially later than in a control group of 12 individuals with acute infection. Escape mutant analysis showed that the activity of 2G12 was crucial for the in vivo effect of the neutralizing antibody cocktail. By providing further direct evidence of the potency, breadth and titers of neutralizing antibodies that are required for in vivo activity, these data underline both the potential and the limits of humoral immunity in controlling HIV-1 infection.

Acid soils significantly limit crop production worldwide because approximately 50% of the world's potentially arable soils are acidic. Because acid soils are such an important constraint to agriculture, understanding the mechanisms and genes conferring tolerance to acid soil stress has been a focus of intense research interest over the past decade. The primary limitations on acid soils are toxic levels of aluminum (Al) and manganese (Mn), as well as suboptimal levels of phosphorous (P). This review examines our current understanding of the physiological, genetic, and molecular basis for crop Al tolerance, as well as reviews the emerging area of P efficiency, which involves the genetically based ability of some crop genotypes to tolerate P deficiency stress on acid soils. These are interesting times for this field because researchers are on the verge of identifying some of the genes that confer Al tolerance in crop plants; these discoveries will open up new avenues of molecular/physiological inquiry that should greatly advance our understanding of these tolerance mechanisms. Additionally, these breakthroughs will provide new molecular resources for improving crop Al tolerance via both molecular-assisted breeding and biotechnology.

BACKGROUND

Comprehensive and contemporary estimates of the number of pregnancies at risk of malaria are not currently available, particularly for endemic areas outside of Africa. We derived global estimates of the number of women who became pregnant in 2007 in areas with Plasmodium falciparum and P. vivax transmission.

RESULTS

A recently published map of the global limits of P. falciparum transmission and an updated map of the limits of P. vivax transmission were combined with gridded population data and growth rates to estimate total populations at risk of malaria in 2007. Country-specific demographic data from the United Nations on age, sex, and total fertility rates were used to estimate the number of women of child-bearing age and the annual rate of live births. Subregional estimates of the number of induced abortions and country-specific stillbirths rates were obtained from recently published reviews. The number of miscarriages was estimated from the number of live births and corrected for induced abortion rates. The number of clinically recognised pregnancies at risk was then calculated as the sum of the number of live births, induced abortions, spontaneous miscarriages, and stillbirths among the population at risk in 2007. In 2007, 125.2 million pregnancies occurred in areas with P. falciparum and/or P. vivax transmission resulting in 82.6 million live births. This included 77.4, 30.3, 13.1, and 4.3 million pregnancies in the countries falling under the World Health Organization (WHO) regional offices for South-East-Asia (SEARO) and the Western-Pacific (WPRO) combined, Africa (AFRO), Europe and the Eastern Mediterranean (EURO/EMRO), and the Americas (AMRO), respectively. Of 85.3 million pregnancies in areas with P. falciparum transmission, 54.7 million occurred in areas with stable transmission and 30.6 million in areas with unstable transmission (clinical incidence <1 per 10,000 population/year); 92.9 million occurred in areas with P. vivax transmission, 53.0 million of which occurred in areas in which P. falciparum and P. vivax co-exist and 39.9 million in temperate regions with P. vivax transmission only.

CONCLUSIONS

In 2007, 54.7 million pregnancies occurred in areas with stable P. falciparum malaria and a further 70.5 million in areas with exceptionally low malaria transmission or with P. vivax only. These represent the first contemporary estimates of the global distribution of the number of pregnancies at risk of P. falciparum and P. vivax malaria and provide a first step towards a more informed estimate of the geographical distribution of infection rates and the corresponding disease burden of malaria in pregnancy.

OBJECTIVE

To assess the effects of pictures on health communications.

METHODS

Peer reviewed studies in health education, psychology, education, and marketing journals were reviewed. There was no limit placed on the time periods searched.

RESULTS

Pictures closely linked to written or spoken text can, when compared to text alone, markedly increase attention to and recall of health education information. Pictures can also improve comprehension when they show relationships among ideas or when they show spatial relationships. Pictures can change adherence to health instructions, but emotional response to pictures affects whether they increase or decrease target behaviors. All patients can benefit, but patients with low literacy skills are especially likely to benefit. Patients with very low literacy skills can be helped by spoken directions plus pictures to take home as reminders or by pictures plus very simply worded captions.

CONCLUSIONS

Educators should: (1) ask "how can I use pictures to support key points?", (2) minimize distracting details in pictures, (3) use simple language in conjunction with pictures, (4) closely link pictures to text and/or captions, (5) include people from the intended audience in designing pictures, (6) have health professionals plan the pictures, not artists, and (7) evaluate pictures' effects by comparing response to materials with and without pictures.

Quantitative measurements of environmental factors greatly improve the quality of epidemiologic studies but can pose challenges because of the presence of upper or lower detection limits or interfering compounds, which do not allow for precise measured values. We consider the regression of an environmental measurement (dependent variable) on several covariates (independent variables). Various strategies are commonly employed to impute values for interval-measured data, including assignment of one-half the detection limit to nondetected values or of "fill-in" values randomly selected from an appropriate distribution. On the basis of a limited simulation study, we found that the former approach can be biased unless the percentage of measurements below detection limits is small (5-10%). The fill-in approach generally produces unbiased parameter estimates but may produce biased variance estimates and thereby distort inference when 30% or more of the data are below detection limits. Truncated data methods (e.g., Tobit regression) and multiple imputation offer two unbiased approaches for analyzing measurement data with detection limits. If interest resides solely on regression parameters, then Tobit regression can be used. If individualized values for measurements below detection limits are needed for additional analysis, such as relative risk regression or graphical display, then multiple imputation produces unbiased estimates and nominal confidence intervals unless the proportion of missing data is extreme. We illustrate various approaches using measurements of pesticide residues in carpet dust in control subjects from a case-control study of non-Hodgkin lymphoma.

Interferon-inducible transmembrane proteins 1, 2, and 3 (IFITM1, 2, and 3) are recently identified viral restriction factors that inhibit infection mediated by the influenza A virus (IAV) hemagglutinin (HA) protein. Here we show that IFITM proteins restricted infection mediated by the entry glycoproteins (GP(1,2)) of Marburg and Ebola filoviruses (MARV, EBOV). Consistent with these observations, interferon-β specifically restricted filovirus and IAV entry processes. IFITM proteins also inhibited replication of infectious MARV and EBOV. We observed distinct patterns of IFITM-mediated restriction: compared with IAV, the entry processes of MARV and EBOV were less restricted by IFITM3, but more restricted by IFITM1. Moreover, murine Ifitm5 and 6 did not restrict IAV, but efficiently inhibited filovirus entry. We further demonstrate that replication of infectious SARS coronavirus (SARS-CoV) and entry mediated by the SARS-CoV spike (S) protein are restricted by IFITM proteins. The profile of IFITM-mediated restriction of SARS-CoV was more similar to that of filoviruses than to IAV. Trypsin treatment of receptor-associated SARS-CoV pseudovirions, which bypasses their dependence on lysosomal cathepsin L, also bypassed IFITM-mediated restriction. However, IFITM proteins did not reduce cellular cathepsin activity or limit access of virions to acidic intracellular compartments. Our data indicate that IFITM-mediated restriction is localized to a late stage in the endocytic pathway. They further show that IFITM proteins differentially restrict the entry of a broad range of enveloped viruses, and modulate cellular tropism independently of viral receptor expression.

C3b inactivator accelerator (A-C3bINA) was isolated from human plasma. An antiserum produced against the purified protein gave a reaction of identity with beta 1 H, a well-documented contaminant of C3 preparations. Beta 1 H appears to be composed of a single polypeptide chain containing a significant quantity of carbohydrate, and having a sedimentation coefficient of 5.6 on analytical, and 6.4 on sucrose density gradient ultracentrifugation. Its mol wt based on SDS polyacrylamide gel electrophoresis and equilibrium sedimentation is approximately 150,000, whereas it elutes from Sephadex G200 with an apparent mol wt of 300,000, suggesting that beta 1 H is an asymmetric molecule. Beta 1 H potentiates the inactivation of C3b by C3b inactivator, binds to EAC43 to limit the formation of EAC43bB and EAC43bBP, and in contrast to C3b inactivator, it increases the rate of loss of hemolytic sites from EAC43bB and EAC43bBP. For the C3b inactivator-potentiating effect, beta 1 H and C3b inactivator must necessarily be simultaneously present. The kinetics of inactivation of C3b by C3b inactivator and beta 1 H are first order, suggesting that potentiation is not a multistep process. The mechanisms of binding to C3b and inhibition of the alternative pathway convertases C3bB and C3bBP are currently unknown.

We present a new local density functional, called M06-L, for main-group and transition element thermochemistry, thermochemical kinetics, and noncovalent interactions. The functional is designed to capture the main dependence of the exchange-correlation energy on local spin density, spin density gradient, and spin kinetic energy density, and it is parametrized to satisfy the uniform-electron-gas limit and to have good performance for both main-group chemistry and transition metal chemistry. The M06-L functional and 14 other functionals have been comparatively assessed against 22 energetic databases. Among the tested functionals, which include the popular B3LYP, BLYP, and BP86 functionals as well as our previous M05 functional, the M06-L functional gives the best overall performance for a combination of main-group thermochemistry, thermochemical kinetics, and organometallic, inorganometallic, biological, and noncovalent interactions. It also does very well for predicting geometries and vibrational frequencies. Because of the computational advantages of local functionals, the present functional should be very useful for many applications in chemistry, especially for simulations on moderate-sized and large systems and when long time scales must be addressed.

Glutathione (GSH) plays an important role in a multitude of cellular processes, including cell differentiation, proliferation, and apoptosis, and as a result, disturbances in GSH homeostasis are implicated in the etiology and/or progression of a number of human diseases, including cancer, diseases of aging, cystic fibrosis, and cardiovascular, inflammatory, immune, metabolic, and neurodegenerative diseases. Owing to the pleiotropic effects of GSH on cell functions, it has been quite difficult to define the role of GSH in the onset and/or the expression of human diseases, although significant progress is being made. GSH levels, turnover rates, and/or oxidation state can be compromised by inherited or acquired defects in the enzymes, transporters, signaling molecules, or transcription factors that are involved in its homeostasis, or from exposure to reactive chemicals or metabolic intermediates. GSH deficiency or a decrease in the GSH/glutathione disulfide ratio manifests itself largely through an increased susceptibility to oxidative stress, and the resulting damage is thought to be involved in diseases, such as cancer, Parkinson's disease, and Alzheimer's disease. In addition, imbalances in GSH levels affect immune system function, and are thought to play a role in the aging process. Just as low intracellular GSH levels decrease cellular antioxidant capacity, elevated GSH levels generally increase antioxidant capacity and resistance to oxidative stress, and this is observed in many cancer cells. The higher GSH levels in some tumor cells are also typically associated with higher levels of GSH-related enzymes and transporters. Although neither the mechanism nor the implications of these changes are well defined, the high GSH content makes cancer cells chemoresistant, which is a major factor that limits drug treatment. The present report highlights and integrates the growing connections between imbalances in GSH homeostasis and a multitude of human diseases.

In the current global AIDS pandemic, more than half of new human immunodeficiency virus type 1 (HIV-1) infections are acquired by women through intravaginal HIV exposure. For this study, we explored pathogenesis issues relevant to the development of effective vaccines to prevent infection by this route, using an animal model in which female rhesus macaques were exposed intravaginally to a high dose of simian immunodeficiency virus (SIV). We examined in detail the events that transpire from hours to a few days after intravaginal SIV exposure through week 4 to provide a framework for understanding the propagation, dissemination, and establishment of infection in lymphatic tissues (LTs) during the acute stage of infection. We show that the mucosal barrier greatly limits the infection of cervicovaginal tissues, and thus the initial founder populations of infected cells are small. While there was evidence of rapid dissemination to distal sites, we also show that continuous seeding from an expanding source of production at the portal of entry is likely critical for the later establishment of a productive infection throughout the systemic LTs. The initially small founder populations and dependence on continuous seeding to establish a productive infection in systemic LTs define a small window of maximum vulnerability for the virus in which there is an opportunity for the host, vaccines, or other interventions to prevent or control infection.

Genotyping errors occur when the genotype determined after molecular analysis does not correspond to the real genotype of the individual under consideration. Virtually every genetic data set includes some erroneous genotypes, but genotyping errors remain a taboo subject in population genetics, even though they might greatly bias the final conclusions, especially for studies based on individual identification. Here, we consider four case studies representing a large variety of population genetics investigations differing in their sampling strategies (noninvasive or traditional), in the type of organism studied (plant or animal) and the molecular markers used [microsatellites or amplified fragment length polymorphisms (AFLPs)]. In these data sets, the estimated genotyping error rate ranges from 0.8% for microsatellite loci from bear tissues to 2.6% for AFLP loci from dwarf birch leaves. Main sources of errors were allelic dropouts for microsatellites and differences in peak intensities for AFLPs, but in both cases human factors were non-negligible error generators. Therefore, tracking genotyping errors and identifying their causes are necessary to clean up the data sets and validate the final results according to the precision required. In addition, we propose the outline of a protocol designed to limit and quantify genotyping errors at each step of the genotyping process. In particular, we recommend (i) several efficient precautions to prevent contaminations and technical artefacts; (ii) systematic use of blind samples and automation; (iii) experience and rigor for laboratory work and scoring; and (iv) systematic reporting of the error rate in population genetics studies.

We present a new estimator for computing free energy differences and thermodynamic expectations as well as their uncertainties from samples obtained from multiple equilibrium states via either simulation or experiment. The estimator, which we call the multistate Bennett acceptance ratio estimator (MBAR) because it reduces to the Bennett acceptance ratio estimator (BAR) when only two states are considered, has significant advantages over multiple histogram reweighting methods for combining data from multiple states. It does not require the sampled energy range to be discretized to produce histograms, eliminating bias due to energy binning and significantly reducing the time complexity of computing a solution to the estimating equations in many cases. Additionally, an estimate of the statistical uncertainty is provided for all estimated quantities. In the large sample limit, MBAR is unbiased and has the lowest variance of any known estimator for making use of equilibrium data collected from multiple states. We illustrate this method by producing a highly precise estimate of the potential of mean force for a DNA hairpin system, combining data from multiple optical tweezer measurements under constant force bias.

Approximately two thirds of U.S. adults and one fifth of U.S. children are obese or overweight. During 1980--2004, obesity prevalence among U.S. adults doubled, and recent data indicate an estimated 33% of U.S. adults are overweight (body mass index [BMI] 25.0-29.9), 34% are obese (BMI>>or=30.0), including nearly 6% who are extremely obese (BMI>>or=40.0). The prevalence of being overweight among children and adolescents increased substantially during 1999-2004, and approximately 17% of U.S. children and adolescents are overweight (defined as at or above the 95% percentile of the sex-specific BMI for age growth charts). Being either obese or overweight increases the risk for many chronic diseases (e.g., heart disease, type 2 diabetes, certain cancers, and stroke). Reversing the U.S. obesity epidemic requires a comprehensive and coordinated approach that uses policy and environmental change to transform communities into places that support and promote healthy lifestyle choices for all U.S. residents. Environmental factors (including lack of access to full-service grocery stores, increasing costs of healthy foods and the lower cost of unhealthy foods, and lack of access to safe places to play and exercise) all contribute to the increase in obesity rates by inhibiting or preventing healthy eating and active living behaviors. Recommended strategies and appropriate measurements are needed to assess the effectiveness of community initiatives to create environments that promote good nutrition and physical activity. To help communities in this effort, CDC initiated the Common Community Measures for Obesity Prevention Project (the Measures Project). The objective of the Measures Project was to identify and recommend a set of strategies and associated measurements that communities and local governments can use to plan and monitor environmental and policy-level changes for obesity prevention. This report describes the expert panel process that was used to identify 24 recommended strategies for obesity prevention and a suggested measurement for each strategy that communities can use to assess performance and track progress over time. The 24 strategies are divided into six categories: 1) strategies to promote the availability of affordable healthy food and beverages), 2) strategies to support healthy food and beverage choices, 3) a strategy to encourage breastfeeding, 4) strategies to encourage physical activity or limit sedentary activity among children and youth, 5) strategies to create safe communities that support physical activity, and 6) a strategy to encourage communities to organize for change.

We report here the genome sequence of an ancient human. Obtained from approximately 4,000-year-old permafrost-preserved hair, the genome represents a male individual from the first known culture to settle in Greenland. Sequenced to an average depth of 20x, we recover 79% of the diploid genome, an amount close to the practical limit of current sequencing technologies. We identify 353,151 high-confidence single-nucleotide polymorphisms (SNPs), of which 6.8% have not been reported previously. We estimate raw read contamination to be no higher than 0.8%. We use functional SNP assessment to assign possible phenotypic characteristics of the individual that belonged to a culture whose location has yielded only trace human remains. We compare the high-confidence SNPs to those of contemporary populations to find the populations most closely related to the individual. This provides evidence for a migration from Siberia into the New World some 5,500 years ago, independent of that giving rise to the modern Native Americans and Inuit.

BACKGROUND

The efficient allocation of financial resources for malaria control using appropriate combinations of interventions requires accurate information on the geographic distribution of malaria risk. An evidence-based description of the global range of Plasmodium falciparum malaria and its endemicity has not been assembled in almost 40 y. This paper aims to define the global geographic distribution of P. falciparum malaria in 2007 and to provide a preliminary description of its transmission intensity within this range.

RESULTS

The global spatial distribution of P. falciparum malaria was generated using nationally reported case-incidence data, medical intelligence, and biological rules of transmission exclusion, using temperature and aridity limits informed by the bionomics of dominant Anopheles vector species. A total of 4,278 spatially unique cross-sectional survey estimates of P. falciparum parasite rates were assembled. Extractions from a population surface showed that 2.37 billion people lived in areas at any risk of P. falciparum transmission in 2007. Globally, almost 1 billion people lived under unstable, or extremely low, malaria risk. Almost all P. falciparum parasite rates above 50% were reported in Africa in a latitude band consistent with the distribution of Anopheles gambiae s.s. Conditions of low parasite prevalence were also common in Africa, however. Outside of Africa, P. falciparum malaria prevalence is largely hypoendemic (less than 10%), with the median below 5% in the areas surveyed.

CONCLUSIONS

This new map is a plausible representation of the current extent of P. falciparum risk and the most contemporary summary of the population at risk of P. falciparum malaria within these limits. For 1 billion people at risk of unstable malaria transmission, elimination is epidemiologically feasible, and large areas of Africa are more amenable to control than appreciated previously. The release of this information in the public domain will help focus future resources for P. falciparum malaria control and elimination.

Zinc-finger nucleases (ZFNs) are targetable DNA cleavage reagents that have been adopted as gene-targeting tools. ZFN-induced double-strand breaks are subject to cellular DNA repair processes that lead to both targeted mutagenesis and targeted gene replacement at remarkably high frequencies. This article briefly reviews the history of ZFN development and summarizes applications that have been made to genome editing in many different organisms and situations. Considerable progress has been made in methods for deriving zinc-finger sets for new genomic targets, but approaches to design and selection are still being perfected. An issue that needs more attention is the extent to which available mechanisms of double-strand break repair limit the scope and utility of ZFN-initiated events. The bright prospects for future applications of ZFNs, including human gene therapy, are discussed.

Brain-derived neurotrophic factor (BDNF) has potent effects on neuronal survival and plasticity during development and after injury. In the nervous system, neurons are considered the major cellular source of BDNF. We demonstrate here that in addition, activated human T cells, B cells, and monocytes secrete bioactive BDNF in vitro. Notably, in T helper (Th)1- and Th2-type CD4(+) T cell lines specific for myelin autoantigens such as myelin basic protein or myelin oligodendrocyte glycoprotein, BDNF production is increased upon antigen stimulation. The BDNF secreted by immune cells is bioactive, as it supports neuronal survival in vitro. Using anti-BDNF monoclonal antibody and polyclonal antiserum, BDNF immunoreactivity is demonstrable in inflammatory infiltrates in the brain of patients with acute disseminated encephalitis and multiple sclerosis. The results raise the possibility that in the nervous system, inflammatory infiltrates have a neuroprotective effect, which may limit the success of nonselective immunotherapies.

Understanding the pathophysiogenesis of temporal lobe epilepsy (TLE) largely rests on the use of models of status epilepticus (SE), as in the case of the pilocarpine model. The main features of TLE are: (i) epileptic foci in the limbic system; (ii) an "initial precipitating injury"; (iii) the so-called "latent period"; and (iv) the presence of hippocampal sclerosis leading to reorganization of neuronal networks. Many of these characteristics can be reproduced in rodents by systemic injection of pilocarpine; in this animal model, SE is followed by a latent period and later by the appearance of spontaneous recurrent seizures (SRSs). These processes are, however, influenced by experimental conditions such as rodent species, strain, gender, age, doses and routes of pilocarpine administration, as well as combinations with other drugs administered before and/or after SE. In the attempt to limit these sources of variability, we evaluated the methodological procedures used by several investigators in the pilocarpine model; in particular, we have focused on the behavioural, electrophysiological and histopathological findings obtained with different protocols. We addressed the various experimental approaches published to date, by comparing mortality rates, onset of SRSs, neuronal damage, and network reorganization. Based on the evidence reviewed here, we propose that the pilocarpine model can be a valuable tool to investigate the mechanisms involved in TLE, and even more so when standardized to reduce mortality at the time of pilocarpine injection, differences in latent period duration, variability in the lesion extent, and SRS frequency.

Cystic fibrosis is associated with a defect in epithelial chloride ion transport which is caused by mutations in a membrane protein called CFTR (cystic fibrosis transmembrane conductance regulator). Heterologous expression of CFTR produces cyclicAMP-sensitive Cl(-)-channel activity. Deletion of phenylalanine at amino-acid position 508 in CFTR (delta F508 CFTR) is the most common mutation in cystic fibrosis. It has been proposed that this mutation prevents glycoprotein maturation and its transport to its normal cellular location. We have expressed both CFTR and delta F508 CFTR in Vero cells using recombinant vaccinia virus. Although far less delta F508 CFTR reached the plasma membrane than normal CFTR, sufficient delta F508 CFTR was expressed at the plasma membrane to permit functional analysis. delta F508 CFTR expression induced a reduced activity of the cAMP-activated Cl- channel, with conductance, anion selectivity and open-time kinetics similar to those of CFTR, but with much greater closed times, resulting in a large decrease of open probability. The delta F508 mutation thus seems to have two major consequences, an abnormal translocation of the CFTR protein which limits membrane insertion, and an abnormal function in mediating Cl- transport.