Formation of atypical podosomes in extravillous trophoblasts regulates extracellular matrix degradation

Throughout pregnancy the cytotrophoblast, the stem cell of the placenta, gives rise to the differentiated forms of trophoblasts. The two main cell lineages are the syncytiotrophoblast and the invading extravillous trophoblast. A successful pregnancy requires extravillous trophoblasts to migrate and invade through the decidua and then remodel the maternal spiral arteries. Many invasive cells use specialised cellular structures called invadopodia or podosomes in order to degrade extracellular matrix. Despite being highly invasive cells, the presence of invadapodia or podosomes has not previously been investigated in trophoblasts. In this study these structures have been identified and characterised in extravillous trophoblasts. The role of specialised invasive structures in trophoblasts in the degradation of the extracellular matrix was compared with well characterised podosomes and invadopodia in other invasive cells and the trophoblast specific structures were characterised by using a sensitive matrix degradation assay which enabled visualisation of the structures and their dynamics. We show trophoblasts form actin rich protrusive structures which have the ability to degrade the extracellular matrix during invasion. The degradation ability and dynamics of the structures closely resemble podosomes, but have unique characteristics that have not previously been described in other cell types. The composition of these structures does not conform to the classic podosome structure, with no distinct ring of plaque proteins such as paxillin or vinculin. In addition, trophoblast podosomes protrude more deeply into the extracellular matrix than established podosomes, resembling invadopodia in this regard. We also show several significant pathways such as Src kinase, MAPK kinase and PKC along with MMP-2 and 9 as key regulators of extracellular matrix degradation activity in trophoblasts, while podosome activity was regulated by the rigidity of the extracellular matrix.

Atypical processing of voice sounds in infants at risk for Autism Spectrum Disorder

Adults diagnosed with autism spectrum disorder (ASD) show a reduced sensitivity (degree of selective response) to social stimuli such as human voices. In order to determine whether this reduced sensitivity is a consequence of years of poor social interaction and communication or is present prior to significant experience, we used functional MRI to examine cortical sensitivity to auditory stimuli in infants at high familial risk for later emerging ASD (HR group, N = 15), and compared this to infants with no family history of ASD (LR group, N = 18). The infants (aged between 4 and 7 months) were presented with voice and environmental sounds while asleep in the scanner and their behaviour was also examined in the context of observed parent-infant interaction. Whereas LR infants showed early specialisation for human voice processing in right temporal and medial frontal regions, the HR infants did not. Similarly, LR infants showed stronger sensitivity than HR infants to sad vocalisations in the right fusiform gyrus and left hippocampus. Also, in the HR group only, there was an association between each infant's degree of engagement during social interaction and the degree of voice sensitivity in key cortical regions. These results suggest that at least some infants at high-risk for ASD have atypical neural responses to human voice with and without emotional valence. Further exploration of the relationship between behaviour during social interaction and voice processing may help better understand the mechanisms that lead to different outcomes in at risk populations.

Clonal Relationship among Atypical Enteropathogenic Escherichia coli Strains Isolated from Different Animal Species and Humans

Forty-nine typical and atypical enteropathogenic Escherichia coli (EPEC) strains belonging to different serotypes and isolated from humans, pets (cats and dogs), farm animals (bovines, sheep, and rabbits), and wild animals (monkeys) were investigated for virulence markers and clonal similarity by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The virulence markers analyzed revealed that atypical EPEC strains isolated from animals have the potential to cause diarrhea in humans. A close clonal relationship between human and animal isolates was found by MLST and PFGE. These results indicate that these animals act as atypical EPEC reservoirs and may represent sources of infection for humans. Since humans also act as a reservoir of atypical EPEC strains, the cycle of mutual infection of atypical EPEC between animals and humans, mainly pets and their owners, cannot be ruled out since the transmission dynamics between the reservoirs are not yet clearly understood.

Shiga toxin-producing Escherichia coli and atypical enteropathogenic Escherichia coli strains isolated from healthy sheep of different populations in Sao Paulo, Brazil

Aims: Sheep are important carriers of Shiga toxin-producing Escherichia coli (STEC) in several countries. However, there are a few reports about ovine STEC in American continent. Methods and Results: About 86 E. coli strains previously isolated from 172 healthy sheep from different farms were studied. PCR was used for detection of stx(1), stx(2), eae, ehxA and saa genes and for the identification of intimin subtypes. Restriction fragment length polymorphism (RFLP)-PCR was performed to investigate the variants of stx(1) and stx(2), and the flagellar antigen (fliC) genes in nonmotile isolates. Five isolates were eae(+) and stx(-), and belonged to serotypes O128:H2/beta-intimin (2), O145:H2/gamma, O153:H7/beta and O178:H7/epsilon. Eighty-one STEC isolates were recovered, and the stx genotypes identified were stx(1c)stx(2d-O118) (46.9%), stx(1c) (27.2%), stx(2d-O118) (23.4%), and stx(1c)stx(2dOX3a) (2.5%). Pulsed-field gel electrophoresis (PFGE) revealed 27 profiles among 53 STEC and atypical enteropathogenic Escherichia coli (EPEC) isolates. Conclusions: This study demonstrated that healthy sheep in Sao Paulo, Brazil, can be carriers of potential human pathogenic STEC and atypical EPEC. Significance and Impact of the Study: As some of the STEC serotypes presently found have been involved with haemolytic uraemic syndrome (HUS) in other countries, the important role of sheep as sources of STEC infection in our settings should not be disregarded.

BYC, an atypical aspartic endopeptidase from Rhipicephalus (Boophilus) microplus eggs

An aspartic endopeptidase was purified in our laboratory from Rhipicephalus (Boophilus) microplus eggs [Logullo, C., Vaz, I.S., Sorgine, M.H., Paiva-Silva, G.O., Faria, F.S., Zingali, R.B., De Lima, M.F., Abreu, L., Oliveira, E.F., Alves, E.W, Masuda, H., Gonzales, J.C., Masuda, A., and Oliveira, P.L., 1998. Isolation of an aspartic proteinase precursor from the egg of a hard tick, Rhipicephalus (Boophilus) microplus. Parasitology 116, 525-532]. Boophilus yolk cathepsin (BYC) was tested as component of a protective vaccine against the tick, inducing a significant immune response in cattle [da Silva, VI., Jr., Logullo, C., Sorgine, M., Velloso, F.F., Rosa de Lima, M.F., Gonzales, J.C., Masuda, H., Oliveira, P.L., and Masuda, A., 1998. Immunization of bovines with an aspartic proteinase precursor isolated from Rhipicephalus (Boophilus) microplus eggs. Vet. Immunol. Immunopathol. 66,331-341]. In this work, BYC was cloned and its primary sequence showed high similarity with other aspartic endopeptidases. In spite of this similarity, BYC sequence shows many important differences in relation to other aspartic peptidases, the most important being the lack of the second catalytic Asp residue, considered to be essential for the catalysis of this class of endopeptidases. When we determined BYC cleavage specificity by LC-MS, we found out that it presents a preference for hydrophobic residues in P1 and P1` in accordance to most aspartic endopeptidases. Also, when analyzed by circular dicroism, BYC presented high beta sheet content, also a characteristic of aspartic endopeptidases. On the other hand, although both native and recombinant BYC are catalytically active, they present a very low specific activity, what seems to indicate that this peptidase will digest its natural substrate, vitellin, very slowly. We speculate that such a slow Vn degradative process might constitute an important strategy to preserve egg protein content to the hatching larvae. (c) 2007 Elsevier Inc. All rights reserved.

Nursing care of clients treated with atypical antipsychotics who have a risk of developing metabolic instability and/or type 2 diabetes

Objective : The aim of this article is to present a current discussion related to the nursing care of clients treated with atypical antipsychotic medicines and who have a risk of developing metabolic instability and/or Type 2 diabetes. The importance of such a discussion is to provide both the novice and the experienced nurse with additional knowledge of this current health issue with which to inform their nursing practice.

Discussion : The potential for psychosis to be a chronic condition is very high, and often people require antipsychotic medicine for lengthy periods throughout their lives. Sometimes, treatment is for life. The second generation of antipsychotic medicines was greeted with much enthusiasm since it was better tolerated than the first generation. However, each medication has desired and adverse effects and, when taken for lengthy periods, these effects may produce physical illness. Studies show that the prevalence of Type 2 diabetes and the metabolic syndrome was significantly higher in clients with a chronic psychiatric disorder, particularly schizophrenia.

Conclusions : Metabolic instability, especially weight gain, is associated with some psychotropic medicines. Nursing interventions need to include care assessment, planning, intervention, and evaluation for clients treated with antipsychotic medicines in terms of risk minimization strategies in routine nursing care.

Efficacy of atypical antipsychotics in bipolar disorder

Bipolar disorder is a severe and recurrent disorder. Atypical antipsychotics have emerged as both an alternative and adjunct to conventional mood stabilisers. The manic phase of the illness is the best studied, and it appears that a class effect with regards to efficacy is present in both monotherapy and augmentation studies. Evidence for efficacy of atypical antipsychotics in depression is emerging. At this stage controlled data are available for both olanzapine and quetiapine. Maintenance data demonstrating efficacy are available for olanzapine. Atypical antipsychotics have utility in treating acute agitation and aggression in manic episodes of bipolar disorder. Subgroup analyses from trials treating manic phase bipolar disorder, and an open-label study of rapid cycling, have suggested that atypical antipsychotics may be useful for the treatment of mixed states and rapid cycling. Several studies have suggested that atypical antipsychotics may be useful in treatment-refractory episodes of bipolar disorder. The current available data suggest greater efficacy of the atypical antipsychotics in mania than in depression, although the data are fairly clear that induction of depression is not an issue with the atypical antipsychotics. A number of trials are underway that will hopefully address many of the questions still pending.

Atypical mood stabilizers : a 'typical' role for atypical antipsychotics

Objective: To assess the potential role of atypical antipsychotics as mood stabilizers.

Method: A MedLine, PsychLIT, PubMed, and EMBASE literature search of papers published up to December 2004 was conducted using the names of atypical antipsychotics and a number of key terms relevant to bipolar disorder. Additional articles were retrieved by scrutinizing the bibliographies of review papers and literature known to the authors. Data pertinent to the objective was reviewed according to the various phases of bipolar disorder.

Results: The data is most substantive for the use of atypical antipsychotics in mania, to the extent that an argument for a class effect of significant efficacy can be made. This does not extend to bipolar depression, however, good data is now emerging for some agents and will need to be considered for each individual agent as it accumulates. As regards mixed states and rapid cycling the evidence is thus far sparse and too few maintenance studies have been conducted to make any firm assertions. However, with respect to long-term therapy the atypical antipsychotics do have clinically significant side-effects of which clinicians need to be aware.

Conclusion: Based on the evidence thus far it is perhaps premature to describe the atypical antipsychotics as mood stabilizers. Individual agents may eventually be able to claim this label, however, much further research is needed especially with respect to maintenance and relapse prevention.

Atypical antipsychotics for bipolar disorder : overblown or blown over?

Objective：Developments in the pharmacological treatment of bipolar disorder are of much interest, as the chronicity and disability of the disorder become better understood, and as treatment goals have shifted to emphasise early control of illness course and maintenance of euthymia in addition to acute episodic remission. Atypical antipsychotics have emerged as treatment options, and this paper aims to review the evidence for their role in bipolar disorder.

Methods：A MEDLINE search was conducted for publications up till October 2006.

Results：The search yielded a number of randomised, controlled clinical trials of various atypical antipsychotics as monotherapy or adjunctive therapy in bipolar disorder. The majority of such trials have investigated their efficacy in acute mania, with fewer studies devoted to acute bipolar depression or maintenance treatment. There are no specific trials on mixed states, which have mainly been studied together with bipolar mania. The most robust evidence supports a class effect of atypical agents in the treatment of mania.

Conclusions：There are placebo-controlled trials that support the efficacy of olanzapine and quetiapine in bipolar depression, and of olanzapine and aripiprazole as maintenance treatment. There is strong support for the role of atypical antipsychotics in bipolar disorder management despite a relatively narrow literature base, chiefly for the treatment of mania. However, these findings need to be replicated, and further investigation is warranted to clarify their spectrum of efficacy in bipolar disorder.

Identification and genetic determination of an early life risk disposition for depressive disorder : atypical stress-related behaviour in early childhood

Progress in psychiatric genetics has been slow despite evidence of high heritability for most mental disorders. We argue that greater use of early detectable intermediate traits (endophenotypes) with the highest likely aetiological significance to depression, rather than complex clinical phenotypes, would be advantageous. Longitudinal data from the Western Australian Pregnancy Cohort (Raine) Study were used to identify an early life behavioural endophenotype for atypical hypothalamic-pituitaryadrenocortical function in adolescence, a neurobiological indicator of anxiety and depression. A set of descriptors representing rigid and reactive behaviour at age 1 year discriminated those in the top 20% of the free salivary cortisol exposure at age 17 years. Genetic association analysis revealed a male-sensitive effect to variation in three specific single nucleotide polymorphisms within selected genes underpinning the overall stress response. Furthermore, support for a polygenic effect on stress-related behaviour in childhood is presented.

Alternative TEL-JAK2 fusions associated with T-cell acute lymphoblastic leukemia and atypical chronic myelogenous leukemia dissected in zebrafish

Background Chromosomal translocations resulting in alternative fusions of the human TEL (ETV6) and JAK2 genes have been observed in cases of acute lymphoblastic leukemia and chronic myelogenous leukemia, but a full understanding of their role in disease etiology has remained elusive. In this study potential differences between these alternative TEL-JAK2 fusions, including their lineage specificity, were investigated.

Design and Methods TEL-JAK2 fusion types derived from both T-cell acute lymphoblastic leukemia and atypical chronic myelogenous leukemia were generated using the corresponding zebrafish tel and jak2a genes and placed under the control of either the white blood cell-specific spi1 promoter or the ubiquitously-expressed cytomegalovirus promoter. These constructs were injected into zebrafish embryos and their effects on hematopoiesis examined using a range of molecular approaches. In addition, the functional properties of the alternative fusions were investigated in vitro.

Results Injection of the T-cell acute lymphoblastic leukemia-derived tel-jak2a significantly perturbed lymphopoiesis with a lesser effect on myelopoiesis in zebrafish embryos. In contrast, injection of the atypical chronic myelogenous leukemia-derived tel-jak2a resulted in significant perturbation of the myeloid compartment. These phenotypes were observed regardless of whether expressed in a white blood cell-specific or ubiquitous manner, with no overt cellular proliferation outside of the hematopoietic cells. Functional studies revealed subtle differences between the alternative forms, with the acute lymphoblastic leukemia variant showing higher activity, but reduced downstream signal transducer and activator of transcription activation and decreased sensitivity to JAK2 inhibition. JAK2 activity was required to mediate the effects of both variants on zebrafish hematopoiesis.

Conclusions This study indicates that the molecular structure of alternative TEL-JAK2 fusions likely contributes to the etiology of disease. The data further suggest that this class of oncogene exerts its effects in a cell lineage-specific manner, which may be due to differences in downstream signaling.