Oral epidermal growth factor receptor tyrosine kinase inhibitors for the treatment of non-small cell lung cancer: comparative pharmacokinetics and drug-drug interactions.

The development of orally active small molecule inhibitors of the epidermal growth factor receptor (EGFR) has led to new treatment options for non-small cell lung cancer (NSCLC). Patients with activating mutations of the EGFR gene show sensitivity to, and clinical benefit from, treatment with EGFR tyrosine kinase inhibitors (EGFR-TKls). First generation reversible ATP-competitive EGFR-TKls, gefitinib and erlotinib, are effective as first, second-line or maintenance therapy. Despite initial benefit, most patients develop resistance within a year, 50-60% of cases being related to the appearance of a T790M gatekeeper mutation. Newer, irreversible EGFR-TKls - afatinib and dacomitinib - covalently bind to and inhibit multiple receptors in the ErbB family (EGFR, HER2 and HER4). These agents have been mainly evaluated for first-line treatment but also in the setting of acquired resistance to first-generation EGFR-TKls. Afatinib is the first ErbB family blocker approved for patients with NSCLC with activating EGFR mutations; dacomitinib is in late stage clinical development. Mutant-selective EGFR inhibitors (AZD9291, CO-1686, HM61713) that specifically target the T790M resistance mutation are in early development. The EGFR-TKIs differ in their spectrum of target kinases, reversibility of binding to EGFR receptor, pharmacokinetics and potential for drug-drug interactions, as discussed in this review. For the clinician, these differences are relevant in the setting of polymedicated patients with NSCLC, as well as from the perspective of innovative anticancer drug combination strategies.

New finding of Giardia intestinalis (Eukaryote, Metamonad) in Old World archaeological site using immunofluorescence and enzyme-linked immunosorbent assays

In this study, nine organic sediment samples from a medieval archaeological site at Pineuilh, France, were examined for Giardia intestinalis using two commercially available immunological kits [enzyme-linked immuno sorbent and immunofluorescence (IFA) assays]. Both techniques detected G. intestinalis in one sample, dated to 1,000 Anno Domini. This is the first time IFA was successfully used to detect protozoa in Old World archaeological samples. Such immunological techniques offer important perspectives concerning ancient protozoa detection and identification.

Evaluation of an enzyme-linked immunoelectrotransfer blot test for the confirmatory serodiagnosis of human toxocariasis

To improve the serodiagnosis of human toxocariasis, a sensitive and specific enzyme-linked immunoelectrotransfer blot (EITB-IgG) test was developed and evaluated using Toxocara canislarvae excretory-secretory antigens for detecting anti-Toxocara IgG antibodies. The EITB-IgG profile of toxocariasis was characterized by comparing 27 sera from patients with toxocariasis, 110 sera from healthy subjects and 186 sera from patients with other helminth diseases (ascariasis, ancylostomiasis, trichuriasis, enterobiasis, strongyloidiasis, hymenolepiasis, diphyllobothriasis, taeniasis, cysticercosis, hydatidosis and fascioliasis). Antigenic bands of 24, 28, 30, 35, 56, 117, 136 and 152 kDa were predominantly recognized in sera from all patients with toxocariasis. However, only bands of 24-35 kDa were highly specific for Toxocara infection (98.3%), whereas other antigenic bands observed displayed cross-reactivity. Additionally, when the results of the EITB-IgG test were compared to those of the ELISA-IgG test, a 100% concordance was observed for positive results in human toxocariasis cases. The concordance for negative results between the two tests for healthy subjects and patients with other helminth diseases were 96.3% and 53.7%, respectively, showing that the EITB-IgG test has a higher specificity than ELISA. In conclusion, the EITB-IgG test is a very useful tool to confirm the serological diagnosis of human toxocariasis.

Regulation of Placental Leptin Expression by Cyclic Adenosine 5 '-Monophosphate Involves Cross Talk between Protein Kinase A and Mitogen-Activated Protein Kinase Signaling Pathways

Leptin, a 16-kDa protein mainly produced by adipose tissue, has been involved in the control of energy balance through its hypothalamic receptor. However, pleiotropic effects of leptin have been identified in reproduction and pregnancy, particularly in placenta, where it was found to be expressed. In the current study, we examined the effect of cAMP in the regulation of leptin expression in trophoblastic cells. We found that dibutyryl cAMP [(Bu)(2)cAMP], a cAMP analog, showed an inducing effect on endogenous leptin expression in BeWo and JEG-3 cell lines when analyzed by Western blot analysis and quantitative RT-PCR. Maximal effect was achieved at 100 microM. Leptin promoter activity was also stimulated, evaluated by transient transfection with a reporter plasmid construction. Similar results were obtained with human term placental explants, thus indicating physiological relevance. Because cAMP usually exerts its actions through activation of protein kinase A (PKA) signaling, this pathway was analyzed. We found that cAMP response element-binding protein (CREB) phosphorylation was significantly increased with (Bu)(2)cAMP treatment. Furthermore, cotransfection with the catalytic subunit of PKA and/or the transcription factor CREB caused a significant stimulation on leptin promoter activity. On the other hand, the cotransfection with a dominant negative mutant of the regulatory subunit of PKA inhibited leptin promoter activity. We determined that cAMP effect could be blocked by pharmacologic inhibition of PKA or adenylyl ciclase in BeWo cells and in human placental explants. Thereafter, we decided to investigate the involvement of the MAPK/ERK signaling pathway in the cAMP effect on leptin induction. We found that 50 microm PD98059, a MAPK kinase inhibitor, partially blocked leptin induction by cAMP, measured both by Western blot analysis and reporter transient transfection assay. Moreover, ERK 1/2 phosphorylation was significantly increased with (Bu)(2)cAMP treatment, and this effect was dose dependent. Finally, we observed that 50 microm PD98059 inhibited cAMP-dependent phosphorylation of CREB in placental explants. In summary, we provide some evidence suggesting that cAMP induces leptin expression in placental cells and that this effect seems to be mediated by a cross talk between PKA and MAPK signaling pathways.

Dynamic graphics of parametrically linked multivariate methods used in compositional data analysis

Many multivariate methods that are apparently distinct can be linked by introducing oneor more parameters in their definition. Methods that can be linked in this way arecorrespondence analysis, unweighted or weighted logratio analysis (the latter alsoknown as "spectral mapping"), nonsymmetric correspondence analysis, principalcomponent analysis (with and without logarithmic transformation of the data) andmultidimensional scaling. In this presentation I will show how several of thesemethods, which are frequently used in compositional data analysis, may be linkedthrough parametrizations such as power transformations, linear transformations andconvex linear combinations. Since the methods of interest here all lead to visual mapsof data, a "movie" can be made where where the linking parameter is allowed to vary insmall steps: the results are recalculated "frame by frame" and one can see the smoothchange from one method to another. Several of these "movies" will be shown, giving adeeper insight into the similarities and differences between these methods

Demyelination induced by protein kinase C-activating tumor promoters in aggregating brain cell cultures.

The plasticity of mature oligodendrocytes was studied in aggregating brain cell cultures at the period of maximal expression of myelin marker proteins. The protein kinase C (PKC)-activating tumor promoters mezerein and phorbol 12-myristate 13-acetate (PMA), but not the inactive phorbol ester analog 4alpha-PMA, caused a pronounced decrease of myelin basic protein (MBP) content and 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP) activity. In contrast, myelin/oligodendrocyte protein (MOG) content was affected relatively little. Northern blot analyses showed a rapid reduction of MBP and PLP gene expression induced by mezerein, and both morphological and biochemical findings indicate a drastic loss of compact myelin. During the acute phase of demyelination, only a relatively small increase in cell death was perceptible by in situ end labeling and in situ nick translation. Basic fibroblast growth factor (bFGF) also reduced the levels of the oligodendroglial differentiation markers and enhanced the demyelinating effects of the tumor promoters. The present results suggest that PKC activation resulted in severe demyelination and partial loss of the oligodendrocyte-differentiated phenotype.

α-N-acetylglucosamine-linked O-glycans of sialoglycoproteins (Tc-mucins) from Trypanosoma cruzi Colombiana strain

Trypanosoma cruzi sialoglycoproteins (Tc-mucins) are mucin-like molecules linked to a parasite membrane via a glycosylphosphatidylinositol anchor. We previously determined the structures of Tc-mucin O-glycan domains from several T. cruzi strains and observed significant differences among them. We now report the amino acid content and structure of Tc-mucin O-glycan chains from T. cruzi Colombiana, a strain resistant to common trypanocidal drugs. Amino acid analysis demonstrated the predominance of threonine residues (42%) and helped to identify the O-glycans as belonging to a Tc-mucin family that contain a ²-galactofuranose (²-Galf) residue attached to an α-N-acetylglucosamine (α-GlcNAc) O-4, with the most complex glycan, a pentasaccharide-GlcNAc-ol with a branched trigalactopyranose chain, on the GlcNAc O-6. The presence of ²-Galf on O-glycans from T. cruzi Colombiana mucins supports the use of glycosylation as a phylogenetic marker for the classification of Colombiana in the T. cruzi I group.

The nuclear receptor DHR3 modulates dS6 kinase-dependent growth in Drosophila.

S6 kinases (S6Ks) act to integrate nutrient and insulin signaling pathways and, as such, function as positive effectors in cell growth and organismal development. However, they also have been shown to play a key role in limiting insulin signaling and in mediating the autophagic response. To identify novel regulators of S6K signaling, we have used a Drosophila-based, sensitized, gain-of-function genetic screen. Unexpectedly, one of the strongest enhancers to emerge from this screen was the nuclear receptor (NR), Drosophila hormone receptor 3 (DHR3), a critical constituent in the coordination of Drosophila metamorphosis. Here we demonstrate that DHR3, through dS6K, also acts to regulate cell-autonomous growth. Moreover, we show that the ligand-binding domain (LBD) of DHR3 is essential for mediating this response. Consistent with these findings, we have identified an endogenous DHR3 isoform that lacks the DBD. These results provide the first molecular link between the dS6K pathway, critical in controlling nutrient-dependent growth, and that of DHR3, a major mediator of ecdysone signaling, which, acting together, coordinate metamorphosis.

Use of heterologous antigens for the immunodiagnosis of abdominal angiostrongyliasis by an enzyme-linked immunosorbent assay

Angiostrongylus costaricensis has a broad geographic distribution spanning from North to South America and the infections of vertebrates with this nematode can result in abdominal complications. Human infections are diagnosed by histological or serological methods because the isolation of larvae from feces is not feasible, as most parasites become trapped in intestinal tissues due to intense eosinophilic inflammation. Because A. costaricensis is difficult to maintain in the laboratory, an immunodiagnostic IgG enzyme-linked immunosorbent assay (ELISA) using antigens from the congeneric Angiostrongylus cantonensis species was evaluated against a panel of serum samples from patients who were histologically diagnosed with A. costaricensis infections. Sera from uninfected individuals and individuals infected with other parasites were used as controls. The sensitivity and specificity of the assay were estimated at 88.4% and 78.7%, respectively. Because the use of purified or cloned antigens has not been established as a reliable diagnostic tool, the use of heterologous antigens may provide a viable alternative for the development of an ELISA-based immunodetection system for the diagnosis of abdominal angiostrongyliasis.

Perinatal Hypoxia Enhances Cyclic Adenosine Monophosphate-mediated BKCa Channel Activation in Adult Murine Pulmonary Artery.

Exposure to perinatal hypoxia results in alteration of the adult pulmonary circulation, which is linked among others to alterations in K channels in pulmonary artery (PA) smooth muscle cells. In particular, large conductance Ca-activated K (BKCa) channels protein expression and activity were increased in adult PA from mice born in hypoxia compared with controls. We evaluated long-term effects of perinatal hypoxia on the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway-mediated activation of BKCa channels, using isoproterenol, forskolin, and dibutyryl-cAMP. Whole-cell outward current was higher in pulmonary artery smooth muscle cells from mice born in hypoxia compared with controls. Spontaneous transient outward currents, representative of BKCa activity, were present in a greater proportion in pulmonary artery smooth muscle cells of mice born in hypoxia than in controls. Agonists induced a greater relaxation in PA of mice born in hypoxia compared with controls, and BKCa channels contributed more to the cAMP/PKA-mediated relaxation in case of perinatal hypoxia. In summary, perinatal hypoxia enhanced cAMP-mediated BKCa channels activation in adult murine PA, suggesting that this pathway could be a potential target for modulating adult pulmonary vascular tone after perinatal hypoxia.

The tumor necrosis factor-related apoptosis-inducing ligand receptors TRAIL-R1 and TRAIL-R2 have distinct cross-linking requirements for initiation of apoptosis and are non-redundant in JNK activation.

Overexpression of the tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) receptors, TRAIL-R1 and TRAIL-R2, induces apoptosis and activation of NF-kappaB in cultured cells. In this study, we have demonstrated differential signaling capacities by both receptors using either epitope-tagged soluble TRAIL (sTRAIL) or sTRAIL that was cross-linked with a monoclonal antibody. Interestingly, sTRAIL was sufficient for induction of apoptosis only in cell lines that were killed by agonistic TRAIL-R1- and TRAIL-R2-specific IgG preparations. Moreover, in these cell lines interleukin-6 secretion and NF-kappaB activation were induced by cross-linked or non-cross-linked anti-TRAIL, as well as by both receptor-specific IgGs. However, cross-linking of sTRAIL was required for induction of apoptosis in cell lines that only responded to the agonistic anti-TRAIL-R2-IgG. Interestingly, activation of c-Jun N-terminal kinase (JNK) was only observed in response to either cross-linked sTRAIL or anti-TRAIL-R2-IgG even in cell lines where both receptors were capable of signaling apoptosis and NF-kappaB activation. Taken together, our data suggest that TRAIL-R1 responds to either cross-linked or non-cross-linked sTRAIL which signals NF-kappaB activation and apoptosis, whereas TRAIL-R2 signals NF-kappaB activation, apoptosis, and JNK activation only in response to cross-linked TRAIL.

Neural crest cell survival is dependent on Rho kinase and is required for development of the mid face in mouse embryos.

Neural crest cells (NCC) give rise to much of the tissue that forms the vertebrate head and face, including cartilage and bone, cranial ganglia and teeth. In this study we show that conditional expression of a dominant-negative (DN) form of Rho kinase (Rock) in mouse NCC results in severe hypoplasia of the frontonasal processes and first pharyngeal arch, ultimately resulting in reduction of the maxilla and nasal bones and severe craniofacial clefting affecting the nose, palate and lip. These defects resemble frontonasal dysplasia in humans. Disruption of the actin cytoskeleton, which leads to abnormalities in cell-matrix attachment, is seen in the RockDN;Wnt1-cre mutant embryos. This leads to elevated cell death, resulting in NCC deficiency and hypoplastic NCC-derived craniofacial structures. Rock is thus essential for survival of NCC that form the craniofacial region. We propose that reduced NCC numbers in the frontonasal processes and first pharyngeal arch, resulting from exacerbated cell death, may be the common mechanism underlying frontonasal dysplasia.

Identification of CARDIAK, a RIP-like kinase that associates with caspase-1.

Members of the tumor necrosis factor receptor (TNFR) superfamily have an important role in the induction of cellular signals resulting in cell growth, differentiation and death. TNFR-1 recruits and assembles a signaling complex containing a number of death domain (DD)-containing proteins, including the adaptor protein TRADD and the serine/threonine kinase RIP, which mediates TNF-induced NF-kappa B activation. RIP also recruits caspase-2 to the TNFR-1 signaling complex via the adaptor protein RAIDD, which contains a DD and a caspase-recruiting domain (CARD). Here, we have identified a RIP-like kinase, termed CARDIAK (for CARD-containing interleukin (IL)-1 beta converting enzyme (ICE) associated kinase), which contains a serine/threonine kinase domain and a carboxy-terminal CARD. Overexpression of CARDIAK induced the activation of both NF-kappa B and Jun N-terminal kinase (JNK). CARDIAK interacted with the TNFR-associated factors TRAF-1 and TRAF-2, and a dominant-negative form of TRAF-2 inhibited CARDIAK-induced NF-kappa B activation. Interestingly, CARDIAK specifically interacted with the CARD of caspase-1 (previously known as ICE), and this interaction correlated with the processing of pro-caspase-1 and the formation of the active p20 subunit of caspase-1. Together, these data suggest that CARDIAK may be involved in NF-kappa B/JNK signaling and in the generation of the proinflammatory cytokine IL-1 beta through activation of caspase-1.

Equine herpesvirus-2 E10 gene product, but not its cellular homologue, activates NF-kappaB transcription factor and c-Jun N-terminal kinase.

We have previously reported on the death effector domain containing E8 gene product from equine herpesvirus-2, designated FLICE inhibitory protein (v-FLIP), and on its cellular homologue, c-FLIP, which inhibit the activation of caspase-8 by death receptors. Here we report on the structure and function of the E10 gene product of equine herpesvirus-2, designated v-CARMEN, and on its cellular homologue, c-CARMEN, which contain a caspase-recruiting domain (CARD) motif. c-CARMEN is highly homologous to the viral protein in its N-terminal CARD motif but differs in its C-terminal extension. v-CARMEN and c-CARMEN interact directly in a CARD-dependent manner yet reveal different binding specificities toward members of the tumor necrosis factor receptor-associated factor (TRAF) family. v-CARMEN binds to TRAF6 and weakly to TRAF3 and, upon overexpression, potently induces the c-Jun N-terminal kinase (JNK), p38, and nuclear factor (NF)-kappaB transcriptional pathways. c-CARMEN or truncated versions thereof do not appear to induce JNK and NF-kappaB activation by themselves, nor do they affect the JNK and NF-kappaB activating potential of v-CARMEN. Thus, in contrast to the cellular homologue, v-CARMEN may have additional properties in its unique C terminus that allow for an autonomous activator effect on NF-kappaB and JNK. Through activation of NF-kappaB, v-CARMEN may regulate the expression of the cellular and viral genes important for viral replication.

Efficacy of iclaprim against wild-type and thymidine kinase-deficient methicillin-resistant Staphylococcus aureus isolates in an in vitro fibrin clot model.

Iclaprim is a novel diaminopyrimidine antibiotic that is active against methicillin-resistant Staphylococcus aureus (MRSA). However, it is known that the activity of diaminopyrimidines against S. aureus is antagonized by thymidine through uptake and conversion to thymidylate by thymidine kinase. Unlike with humans, for whom thymidine levels are low, thymidine levels in rodents are high, thus precluding the accurate evaluation of iclaprim efficacy in animal models. We have studied the bactericidal activity of iclaprim against an isogenic pair of MRSA isolates, the wild-type parent AW6 and its thymidine kinase-deficient mutant AH1252, in an in vitro fibrin clot model. Clots, which were aimed at mimicking vegetation structure, were made from human or rat plasma containing either the parent AW6 or the mutant AH1252, and they were exposed to homologous serum supplemented with iclaprim (3.5 microg/ml), trimethoprim-sulfamethoxazole (TMP-SMX; 8/40 microg/ml), vancomycin (40 microg/ml), or saline, each of which was added one time for 48 h. In rat clots, iclaprim and TMP-SMX were bacteriostatic against the parent, AW6. In contrast, they were bactericidal (> or = 3 log10 CFU/clot killing of the original inoculum) against the mutant AH1252. Vancomycin was the most active drug against AW6 (P < 0.05), but it showed an activity similar those of iclaprim and TMP-SMX against AH1252. In human clots, iclaprim was bactericidal against both AW6 and AH1252 strains and was as effective as TMP-SMX and vancomycin (P > 0.05). Future studies of animals using simulated human kinetics of iclaprim and thymidine kinase-deficient MRSA, which eliminate the thymidine-induced confounding effect, are warranted to support the use of iclaprim in the treatment of severe MRSA infections in humans.