ERK1/2 antagonizes glycogen synthase kinase-3beta-induced apoptosis in cortical neurons

Inhibition of glycogen synthase kinase-3beta (GSK3beta) is one of the mechanisms by which phosphatidylinositol 3-kinase (PI3K) activation protects neurons from apoptosis. Here, we report that inhibition of ERK1/2 increased the basal activity of GSK3beta in cortical neurons and that both ERK1/2 and PI3K were required for brain-derived neurotrophic factor (BDNF) suppression of GSK3beta activity. Moreover, cortical neuron apoptosis induced by expression of recombinant GSK3beta was inhibited by coexpression of constitutively active MKK1 or PI3K. Activation of both endogenous ERK1/2 and PI3K signaling pathways was required for BDNF to block apoptosis induced by expression of recombinant GSK3beta. Furthermore, cortical neuron apoptosis induced by LY294002-mediated activation of endogenous GSK3beta was blocked by expression of constitutively active MKK1 or by BDNF via stimulation of the endogenous ERK1/2 pathway. Although both PI3K and ERK1/2 inhibited GSK3beta activity, neither had an effect on GSK3beta phosphorylation at Tyr-216. Interestingly, PI3K (but not ERK1/2) induced the inhibitory phosphorylation of GSK3beta at Ser-9. Significantly, coexpression of constitutively active MKK1 (but not PI3K) still suppressed neuronal apoptosis induced by expression of the GSK3beta(S9A) mutant. These data suggest that activation of the ERK1/2 signaling pathway protects neurons from GSK3beta-induced apoptosis and that inhibition of GSK3beta may be a common target by which ERK1/2 and PI3K protect neurons from apoptosis. Furthermore, ERK1/2 inhibits GSK3beta activity via a novel mechanism that is independent of Ser-9 phosphorylation and likely does not involve Tyr-216 phosphorylation.     

The assessment of LIF in uterine flushing--a possible new diagnostic tool in states of impaired fertility

The objective of this study was to assess the LIF (leukemia inhibitory factor) concentration in uterine flushing and serum (ELISA) of women with proven fertility, infertile women and women with recurrent miscarriage. In addition, progesterone level was determined in serum. A decreased production of LIF in the uterine microenvironment was found in states of impaired fertility. With a cut-off point of 8.23 pg/ml for LIF level in uterine flushings we have achieved 86.7% sensitivity and 100% specificity in detection of women with idiopathic infertility compared to fertile controls. No correlation between LIF in serum and uterine flushing was demonstrated, rendering LIF measurements in serum useless for diagnosis of impaired infertility. We conclude that LIF measurement in uterine flushing could be a useful diagnostic tool to predict unsuccessful implantation.     

Synthesis of New Styrylquinoline Cellular Dyes,Fluorescent Properties,Cellular Localization and Cytotoxic Behavior

New styrylquinoline derivatives with their photophysical constants are described. The synthesis was achieved via Sonogashira coupling using the newly developed heterogeneous nano-Pd/Cu catalyst system, which provides an efficient synthesis of high purity products. The compounds were tested in preliminary fluorescent microscopy studies to in order to identify their preferable cellular localization, which appeared to be in the lipid cellular organelles. The spectroscopic properties of the compounds were measured and theoretical TD-DFT calculations were performed. A biological analysis of the quinolines that were tested consisted of cytotoxicity assays against normal human fibroblasts and colon adenocarcinoma cells. All of the compounds that were studied appeared to be safe and indifferent to cells in a high concentration range. The presented results suggest that the quinoline compounds that were investigated in this study may be valuable structures for development as fluorescent dyes that could have biological applications.     

Delayed reconstruction of the upper digestive tract in a patient following total pharyngolaryngectomy with resection of the cervical oesophagus

Carcinoma of the hypopharynx is an uncommon disease, with an annual incidence of approximately 1 in 100,000. Post-cricoid carcinoma is more common in women and is not usually associated with tobacco and alcohol abuse. Reconstruction of large pharyngeal defects following surgery for squamous cell carcinoma is complex and often requires microvascular free tissue transfer to achieve the best oncological and functional outcomes. The most common complications of such procedures include fistulas and strictures of the neopharynx. Here, we describe a case of a female patient admitted to the Head and Neck Department at our hospital to undergo delayed reconstruction following pharyngolaryngectomy and removal of the cervical oesophagus. Several complications occurred during post-operative care, including stricture and skin dehiscence. At present, the patient is able to swallow saliva and is currently being prepared to return to a normal diet.     

Genetic Analysis and Species Specific Amplification of the Artemisinin Resistance-Associated Kelch Propeller Domain in P. falciparum and P. vivax

Plasmodium falciparum resistance to artemisinin has emerged in the Greater Mekong Subregion and now poses a threat to malaria control and prevention. Recent work has identified mutations in the kelch propeller domain of the P. falciparum K13 gene to be associated artemisinin resistance as defined by delayed parasite clearance and ex vivo ring stage survival assays. Species specific primers for the two most prevalent human malaria species, P. falciparum and P. vivax, were designed and tested on multiple parasite isolates including human, rodent, and non- humans primate Plasmodium species. The new protocol described here using the species specific primers only amplified their respective species, P. falciparum and P. vivax, and did not cross react with any of the other human malaria Plasmodium species. We provide an improved species specific PCR and sequencing protocol that could be effectively used in areas where both P. falciparum and P. vivax are circulating. To design this improved protocol, the kelch gene was analyzed and compared among different species of Plasmodium. The kelch propeller domain was found to be highly conserved across the mammalian Plasmodium species.     

PBX1 is dispensable for neural commitment of RA-treated murine ES cells

Experimentation with PBX1 knockout mice has shown that PBX1 is necessary for early embryogenesis. Despite broad insight into PBX1 function, little is known about the underlying target gene regulation. Utilizing the Cre–loxP system, we targeted a functionally important part of the homeodomain of PBX1 through homozygous deletion of exon-6 and flanking intronic regions leading to exon 7 skipping in embryonic stem (ES) cells. We induced in vitro differentiation of wild-type and PBX1 mutant ES cells by aggregation and retinoic acid (RA) treatment and compared their profiles of gene expression at the ninth day post-reattachment to adhesive media. Our results indicate that PBX1 interactions with HOX proteins and DNA are dispensable for RA-induced ability of ES to express neural genes and point to a possible involvement of PBX1 in the regulation of imprinted genes.     

Ecological validity of social interaction tests in rats and mice

Different rat and mouse models are used in studies of social interactions. Simple behavioral measures, which are commonly used in the laboratory, allow to perform relatively short experiments and to use multiple brain manipulation techniques. However, too much focus on the simplest behavioral models generates a serious risk of reducing ecological validity or even studying phenomena which would never happen outside of the laboratory. In this review, we discuss the suitability of mice and rats as model organisms for studying social behaviors, with focus on social transmission of fear paradigms. First, we briefly introduce the concept of domestication and what impact it had on laboratory rodents. Then, we present two aspects of social behaviors, sociability and dominance, which are crucial for social organization in these species. Finally, we present experimental models used for studying how animals transmit information about danger between each other, and how these models may reflect what happens in the natural environment. We discuss the difficulties that arise from our limited knowledge of rat and mouse ecology, especially their social life. We also explore the subject of balancing ecological validity and controllability in rodent models of social behaviors, the latter being particularly important for studying brain activity. Although it is very challenging, an efficient program for social neuroscience research should, in our opinion, aim at bridging the gap between laboratory and field studies.