Resistance to CpG DNA-induced autoimmunity through tolerogenic B cell antigen receptor ERK signaling

CpG sequences in self-DNA are an important potential trigger for autoantibody secretion in systemic lupus and other systemic autoimmune disorders. It is not known how this ubiquitous threat may be controlled by active mechanisms for maintaining self tolerance. Here we show that two distinct mechanisms oppose autoantibody secretion induced by CpG DNA in anergic B cells that are constantly binding self-antigen. Uncoupling of the antigen receptor (BCR) from a calcineurin-dependent pathway prevents signals that synergize with CpG DNA for proliferation. The BCR does not become desensitized by activating the extracellular response kinase (ERK) MAP kinase pathway, however, and continuous self-antigen signaling to ERK inhibits CpG DNA-induced plasma cell differentiation. These two mechanisms seem to act as a general control against autoantibody production elicited by Toll-like receptors, and their regulation of T cell-independent responses to Toll-like receptor 9 (TLR9) is probably crucial for resistance to systemic autoimmunity.     

BRCA1 and BRCA2 mutation analysis in breast-ovarian cancer families from northeastern Poland

Sixty high-risk breast and/or ovarian cancer families from North-Eastern Poland were screened for germline mutations in BRCA1 (MIM# 113705) and BRCA2 (MIM# 600185), using a combination of protein truncation test, denaturing high-performance liquid chromatography and direct sequencing. Sixteen (27%) of the families were found to carry nine different BRCA mutations, including 14 families with BRCA1 mutation and two families with BRCA2 mutation. The results suggest the presence of two strong BRCA1 founder mutations in the Polish population - 5382insC (6 families) and 300T>G (Cys61Gly; 3 families). The remaining seven mutations were found in single families and included three previously reported BRCA1 mutations (185delAG, 2682C>T [Gln855Ter] and 3819del5), a novel BRCA1 mutation (IVS14+1G>A), as well as two BRCA2 mutations (4088delA and 7985G>A [Trp2586Ter]) not previously observed in Polish families. We confirm the strong influence of two Central-Eastern European BRCA1 founder mutations in familial breast and/or ovarian cancer in Poland. We also conclude that the Polish population has a more dispersed BRCA mutation spectrum than had been earlier thought. This warrants further careful BRCA mutation screening in order to optimise genetic counselling and disease prevention in affected families.     

Posttraumatic stress symptoms in parents of children with acute burns

OBJECTIVE: To develop a model of risk factors for posttraumatic stress disorder (PTSD) symptoms in parents of children with burns. METHODS: Immediately following the burn and 3 months later, parents reported on their children's and their own psychological functioning and traumatic stress responses. RESULTS: Approximately 47% of the parents reported experiencing significant posttraumatic stress symptoms 3 months after the burn. Our model indicates three independent pathways to PTSD symptoms (i.e., parent-child conflict, parents' dissociation, and children's PTSD symptoms). Additionally, parents' anxiety predicted increased parent-child conflict, conflict with extended family and size of the burn predicted parents' dissociation, and size of the burn and children's dissociation predicted children's PTSD symptoms. CONCLUSIONS: This study suggests that many parents of children with burns suffer from posttraumatic stress symptoms. Interventions that target factors such as family conflict, children's symptoms, and parents' acute anxiety and dissociation may diminish the risk for PTSD.     

Glial heme oxygenase-1 expression in Alzheimer disease and mild cognitive impairment

We determined whether oxidative stress is an early event in the pathogenesis of sporadic Alzheimer disease (AD), and correlated oxidative stress with neuropsychological functions and neurofibrillary pathology in AD and mild cognitive impairment (MCI). Oxidative stress was measured as the percentage of astrocytes expressing heme oxygenase-1 (HO-1) in post mortem temporal cortex and hippocampus after dual HO-1/glial fibrillary acidic protein (GFAP) immunohistochemistry. Glial HO-1 expression in the MCI temporal cortex and hippocampus was significantly greater than in the non-demented group and did not differ from AD values. Astroglial HO-1 expression in the temporal cortex was associated with decreased scores for global cognition, episodic memory, semantic memory and working memory. Hippocampal astroglial HO-1 expression was associated with lower scores for global cognition, semantic memory and perceptual speed. Glial HO-1 immunoreactivity in the temporal cortex, but not hippocampus, correlated with the burden of neurofibrillary pathology. Cortical and hippocampal oxidative stress is a very early event in the pathogenesis of sporadic AD and correlates with the development of specific cognitive deficits in this condition.     

Cellular and molecular actions of dinitroaniline and phosphorothioamidate herbicides on Plasmodium falciparum: tubulin as a specific antimalarial target

Microtubules play important roles in cell division, motility and structural integrity of malarial parasites. Some microtubule inhibitors disrupt parasite development at very low concentrations, but most of them also kill mammalian cells. However, the dinitroaniline family of herbicides, which bind specifically to plant tubulin, have inhibitory activity on plant cells but are relatively non-toxic to human cells. Certain dinitroanilines are also inhibitory to various protozoal parasites including Plasmodium. Here we demonstrate that the dinitroanilines trifluralin and oryzalin inhibited progression of erythrocytic Plasmodium falciparum through schizogony, blocked mitotic division, and caused accumulation of abnormal microtubular structures. Moreover, radiolabelled trifluralin interacted with purified, recombinant parasite tubulins but to a much lesser extent with bovine tubulins. The phosphorothioamidate herbicide amiprophos-methyl, which has the same herbicidal mechanism as dinitroanilines, also had antimalarial activity and a similar action on schizogony. These data suggest that P. falciparum tubulin contains a dinitroaniline/phosphorothioamidate-binding site that is not conserved in humans and might be a target for new antimalarial drugs.     

Src family kinases play multiple roles in differentiation of trophoblasts from human term placenta

Tyrosine phosphorylation plays a major role in controlling many biological processes in different cell types. Src family kinases (SFKs) are one of the most studied groups of tyrosine kinases and can mediate a variety of signalling pathways. However, little is known about the expression of SFKs in human term placenta and their implication in trophoblast differentiation. Therefore, we examined the expression profile of SFK members over time in culture and their implication in differentiation. In vitro , freshly isolated cytotrophoblast cells, cultured in 10% fetal bovine serum (FBS), spontaneously aggregate and fuse to form multinucleated cells that resemble phenotypically mature syncytiotrophoblasts, that concomitantly produce human chorionic gonadotropin (hCG) and human placental lactogen (hPL). In this study, we showed that trophoblasts expressed all SFK members and some of them are expressed as different splice variants. Moreover, using real-time PCR, this study showed two different expression profiles of SFKs in human trophoblasts during culture. In addition, the protein level and phosphorylation status of Src were evaluated using specific antibodies. Src was rapidly phosphorylated at Tyr-416 and dephosphorylated at Tyr-527 after FBS addition. Surprisingly, inhibition of SFKs by 4-amino-5-(4-chlorophenyl)-7-( t -butyl) pyrazolo[3,4-d] pyrimidine (PP2) or herbimycin A had different effects on trophoblast differentiation. While herbimycin A inhibited morphological and hormonal differentiation, PP2 stimulated hormonal differentiation and inhibited cell adhesion and spreading with no effect on cell fusion. In summary, this study showed that SFKs play different roles in trophoblast differentiation, probably depending on SFK members activated. Thus, this study increases our knowledge and understanding of pathology related to impaired trophoblast differentiation such as pre-eclampsia and trophoblast neoplasm.     

Rapid detection and characterization from field cases of infectious laryngotracheitis virus by real-time polymerase chain reaction and restriction fragment length polymorphism.

A real-time polymerase chain reaction (PCR) assay was developed to specifically amplify infectious laryngotracheitis virus (ILTV) DNA from field samples. The 222-base-pair PCR fragment was amplified using primers located in a conserved region of the infected cell protein 4 gene that was demonstrated in this work to encompass a single nucleotide polymorphism. Subsequent restriction fragment length polymorphism (RFLP) analysis of real-time PCR amplified fragments from a range of ILTV isolates using the restriction endonuclease MspI enabled differentiation between older ILTV isolates that were prevalent in the 1960s prior to the availability of vaccine strains and more recent isolates that predominantly are identical to vaccine strains. The assay, using real-time PCR, RFLP and sequence analysis, was used to characterize two recent field cases of infectious laryngotracheitis from Northern Ireland. One of the field cases was demonstrated to be similar to older "wild-type" isolates, while the other field case was identified to have a concurrent ILTV infection of both "wild-type" and vaccinal type origin. The assay described here using real-time PCR and RFLP provides a rapid, specific method that enables detection and characterization of ILTV directly from field cases.     

The emergence of critical health psychology: can it contribute to promoting public health?

The purpose of this article is twofold: first to provide an overview of the emergence of critical health psychology for those working in the related social and health sciences and as a review of its major developments for health psychology; and second to discuss critically the potential for critical health psychology to contribute to promoting public health with specific reference to the directives espoused by Prilleltensky (2003) and Murray and Campbell (2003). The identification of three philosophical phases of the emergence of critical health psychology is used to examine the directions of the field and the challenges facing critical health psychology in order to contribute to public and global health.     

Measurement of effector protein injection by type III and type IV secretion systems by using a 13-residue phosphorylatable glycogen synthase kinase tag

Numerous bacterial pathogens use type III secretion systems (T3SSs) or T4SSs to inject or translocate virulence proteins into eukaryotic cells. Several different reporter systems have been developed to measure the translocation of these proteins. In this study, a peptide tag-based reporter system was developed and used to monitor the injection of T3S and T4S substrates. The glycogen synthase kinase (GSK) tag is a 13-residue phosphorylatable peptide tag derived from the human GSK-3beta kinase. Translocation of a GSK-tagged protein into a eukaryotic cell results in host cell protein kinase-dependent phosphorylation of the tag, which can be detected with phosphospecific GSK-3beta antibodies. A series of expression plasmids encoding Yop-GSK fusion proteins were constructed to evaluate the ability of the GSK tag to measure the injection of Yops by the Yersinia pestis T3SS. GSK-tagged YopE, YopH, LcrQ, YopK, YopN, and YopJ were efficiently phosphorylated when translocated into HeLa cells. Similarly, the injection of GSK-CagA by the Helicobacter pylori T4SS into different cell types was measured via phosphorylation of the GSK tag. The GSK tag provides a simple method to monitor the translocation of T3S and T4S substrates.