Comparison of Orexin 1 and Orexin 2 Ligand Binding Modes Using X-ray Crystallography and Computational Analysis.

The orexin system, which consists of the two G protein-coupled receptors OX1 and OX2, activated by the neuropeptides OX-A and OX-B, is firmly established as a key regulator of behavioral arousal, sleep, and wakefulness and has been an area of intense research effort over the past two decades. X-ray structures of the receptors in complex with 10 new antagonist ligands from diverse chemotypes are presented, which complement the existing structural information for the system and highlight the critical importance of lipophilic hotspots and water molecules for these peptidergic GPCR targets. Learnings from the structural information regarding the utility of pharmacophore models and how selectivity between OX1 and OX2 can be achieved are discussed.

Educators' evaluations of children's ideas on the social exclusion of classmates with intellectual and learning disabilities.

BACKGROUND: Reasons underlying the social exclusion of children with intellectual or learning disabilities are not entirely understood. Although it is important to heed the voices of children on this issue, it is also important to consider the degree to which these ideas are informed. The present authors invited educators to evaluate the content of children's ideas on the causes of social exclusion. METHOD: Educators thematically sorted and rated children's ideas on why classmates with intellectual or learning disabilities are socially excluded. Sorted data were analysed with multidimensional scaling and hierarchical cluster analysis. RESULTS: Six thematic clusters were identified differing in content to those provided by children in an earlier study. Educators generally rated children's ideas as showing somewhat uninformed ideas about why social exclusion occurs. CONCLUSIONS: Educators indicated that children need to be better informed about intellectual and learning disabilities. Limitations and implications are discussed.

Study of para-Quinone Methide Precursors toward the Realkylation of Aged Acetylcholinesterase.

Acetylcholinesterase (AChE) is an essential enzyme that can be targeted by organophosphorus (OP) compounds, including nerve agents. Following exposure to OPs, AChE becomes phosphylated (inhibited) and undergoes a subsequent aging process where the OP-AChE adduct is dealkylated. The aged AChE is unable to hydrolyze acetylcholine, resulting in accumulation of the neurotransmitter in the central nervous system (CNS) and elsewhere. Current therapeutics are only capable of reactivating inhibited AChE. There are no known therapeutic agents to reverse the aging process or treat aged AChE. Quinone methides (QMs) have been shown to alkylate phosphates under physiological conditions. In this study, a small library of novel quinone methide precursors (QMPs) has been synthesized and examined as potential alkylating agents against model nucleophiles, including a model phosphonate. Computational studies have been performed to evaluate the affinity of QMPs for the aged AChE active site, and preliminary testing with electric eel AChE has been performed.

Missing the target: DNAk is a dominant epitope in the humoral immune response of channel catfish (Ictalurus punctatus) to Flavobacterium columnare.

Vaccination remains a viable alternative for bacterial disease protection in fish; however additional work is required to understand the mechanisms of adaptive immunity in the channel catfish. To assess the humoral immune response to Flavobacterium columnare; a group of channel catfish were first immunized with F. columnare LV-359-01 cultured in iron-depleted media, before being challenged with wild type F. columnare LV-359-01. The immunization protocol did not confer increased protection against F. columnare; however both control and immunized responders generated serum and skin IgM antibodies against F. columnare proteins. Western blot analyses of individuals from both groups showed that IgM antibodies were generated to the same 70 kDa extracellular protein, which was identified to be the bacterial chaperonin protein DNAk. Antibodies generated were cross reactive to DNAk proteins found in other gram negative bacteria. Our data suggests that DNAk is the dominant epitope in the channel catfish B-cell response to F. columnare.

Ubiquitous assembly of amphiphilic baskets into unilamellar vesicles and their recognition characteristics.

An amphiphilic basket of type 1 (339 Å(3)) has been found to assemble into unilamellar vesicles in water. The assembled host encapsulates organophosphonates (OPs) (119-185 A(3)) with a particularly high affinity (Ka ∼ 10(5) M(-1)) toward dimethyl phenylphosphonate (185 Å(3)) whose size and shape resemble that of soman (186 Å(3)). Importantly, the entrapment of OPs prompts a phase transformation of vesicular 1 into nanoparticles or larger vesicles as a function of the shape of the host-guest complex.

Recognition characteristics of an adaptive vesicular assembly of amphiphilic baskets for selective detection and mitigation of toxic nerve agents.

We used isothermal titration calorimetry to investigate the affinity of basket 1 (470 Å(3)) for trapping variously sized and shaped organophosphonates (OPs) 2-12 (137-244 Å(3)) in water at 298.0 K. The encapsulation is, in each case, driven by favorable entropy (TΔS° = 2.9 kcal/mol), while the enthalpic component stays small and in some cases endothermic (ΔH° ≥ -1 kcal/mol). Presumably, a desolvation of basket 1 and OP guests permits the inclusion complexation at room temperature via a "classical" hydrophobic effect. The amphiphilic basket 1 shows a greater affinity (ΔG° ≈ -5 to -6 kcal/mol), both experimentally and computationally, for encapsulating larger organophosphonates whose size and shape correspond to VX-type agents (289 A(3)). Importantly, baskets assemble into a vesicular nanomaterial (DH ≈ 350 nm) that in the presence of neutral OP compounds undergoes a phase transition to give nanoparticles (DH ≈ 250 nm). Upon the addition of an anionic guest to basket 1, however, there was no formation of nanoparticles and the vesicles grew into larger vesicles (DH ≈ 750 nm). The interconversion of the different nanostructures is reversible and, moreover, a function of the organophosphonate present in solution. On the basis of (1)H NMR spectroscopic data, we deduced that neutral guests insert deep into the basket's cavity to change its shape and thereby promote the conversion of vesicles into nanoparticles. On the contrary, the anionic guests reside at the northern portion of the host to slightly affect its shape and geometric properties, thereby resulting in the vesicles merely transforming into larger vesicles.

Trapping of organophosphorus chemical nerve agents in water with amino acid functionalized baskets.

We prepared eleven amino-acid functionalized baskets and used (1) H NMR spectroscopy to quantify their affinity for entrapping dimethyl methylphosphonate (DMMP, 118 Å(3) ) in aqueous phosphate buffer at pH=7.0±0.1; note that DMMP guest is akin in size to chemical nerve agent sarin (132 Å(3) ). The binding interaction (Ka ) was found to vary with the size of substituent groups at the basket's rim. In particular, the degree of branching at the first carbon of each substituent had the greatest effect on the host-guest interaction, as described with the Verloop's B1 steric parameter. The branching at the remote carbons, however, did not perturb the encapsulation, which is important for guiding the design of more effective hosts and catalysts in future.

Assembly of amphiphilic baskets into stimuli-responsive vesicles. Developing a strategy for the detection of organophosphorus chemical nerve agents.

We designed basket 1 to comprise a C3-symmetric hydrophobic cage (477 Å(3)) at its southern edge and three polar ammonium caps at the northern edge. This amphiphilic molecule was observed to assemble into large unilamellar vesicles (350 nm, TEM) in water and thereby entrap dimethyl phenylphosphonate (184 Å(3)) in its cavity (K(app) = (1.97 ± 0.02) × 10(3) M(-1)). The entrapment of the organophosphonate, akin to soman in size (186 Å(3)), triggers the transformation of the vesicular material into nanoparticles (100 nm, TEM). Stimuli-responsive vesicles, containing baskets of type 1 in their bilayer membrane, are unique assemblies and important for obtaining novel sensing devices.

"A kid way": strategies for including classmates with learning or intellectual disabilities.

Thirty-six children between 9 and 12 years of age were invited to share their ideas on how to socially include classmates with learning or intellectual disabilities at school. Participants generated 80 strategies which were categorized into seven major themes. Thematic categories focused on the need for teachers to intervene in academic and social situations, child-to-child instructional strategies, being supportive, focusing on similarities between children with and without disabilities, modelling appropriate behaviors and intervening in negative interactions, structured inclusive activities, and noninclusive activities. Participants were aware of the challenges experienced by classmates with disabilities, and recognized the need to work with classmates and teachers towards the social inclusion of children with intellectual and learning disabilities. Educational implications are addressed.

Scalable production of biliverdin IXα by Escherichia coli.

BACKGROUND: Biliverdin IXα is produced when heme undergoes reductive ring cleavage at the α-methene bridge catalyzed by heme oxygenase. It is subsequently reduced by biliverdin reductase to bilirubin IXα which is a potent endogenous antioxidant. Biliverdin IXα, through interaction with biliverdin reductase, also initiates signaling pathways leading to anti-inflammatory responses and suppression of cellular pro-inflammatory events. The use of biliverdin IXα as a cytoprotective therapeutic has been suggested, but its clinical development and use is currently limited by insufficient quantity, uncertain purity, and derivation from mammalian materials. To address these limitations, methods to produce, recover and purify biliverdin IXα from bacterial cultures of Escherichia coli were investigated and developed. RESULTS: Recombinant E. coli strains BL21(HO1) and BL21(mHO1) expressing cyanobacterial heme oxygenase gene ho1 and a sequence modified version (mho1) optimized for E. coli expression, respectively, were constructed and shown to produce biliverdin IXα in batch and fed-batch bioreactor cultures. Strain BL21(mHO1) produced roughly twice the amount of biliverdin IXα than did strain BL21(HO1). Lactose either alone or in combination with glycerol supported consistent biliverdin IXα production by strain BL21(mHO1) (up to an average of 23. 5mg L(-1) culture) in fed-batch mode and production by strain BL21 (HO1) in batch-mode was scalable to 100L bioreactor culture volumes. Synthesis of the modified ho1 gene protein product was determined, and identity of the enzyme reaction product as biliverdin IXα was confirmed by spectroscopic and chromatographic analyses and its ability to serve as a substrate for human biliverdin reductase A. CONCLUSIONS: Methods for the scalable production, recovery, and purification of biliverdin IXα by E. coli were developed based on expression of a cyanobacterial ho1 gene. The purity of the produced biliverdin IXα and its ability to serve as substrate for human biliverdin reductase A suggest its potential as a clinically useful therapeutic.

Pyrazolopyridazine alpha-2-delta-1 ligands for the treatment of neuropathic pain.

Optimization of the novel alpha-2-delta-1 ligand 4 provided compounds 37 and 38 which have improved DMPK profiles, good in vivo analgesic activity and in vitro selectivity over alpha-2-delta-2. An in-house P-gp prediction programme and the MetaSite software package were used to help solve the specific problems of high P-gp efflux and high in vivo clearance.

An innovative summer camp program improves weight and self-esteem in obese children.

To determine the potential benefits of a residential summer camp to treat childhood obesity, 21 obese, multiethnic children (aged 11.4+/-1.4 years; body mass index [BMI] percentile 98.5+/-1.4; BMI z score 2.30+/-0.33) from a diverse socioeconomic background were enrolled in a 2-week summer camp program. Significant improvements (P<0.04) were observed in self-esteem (+0.27+/-0.33 point), body weight (-3.7+/-1.2 kg), BMI (-1.60+/-0.48 kg/m), BMI z score (-0.12+/-0.06), number of curl ups (+10.9+/-21.5), systolic and diastolic blood pressure (-10.8+/-13.4 and -9.4+/-5.5 mmHg, respectively), and heart rate (-8.2+/-12.7 bpm).

Challenges of transcultural placements: foster parent perspectives.

A random sample of licensed foster parents in a central Canadian province was asked, "What are the challenges of fostering children who have different values, beliefs, and traditions than you?" In response to this question, 49 unique responses were made and grouped together by foster parents. Seven themes emerged from the analysis: understanding, respecting, learning, compromising, disagreements, child's feelings, and teaching. Several differences were found between the literature and study participants, suggesting areas worthy of future research.

TRPM2 channel opening in response to oxidative stress is dependent on activation of poly(ADP-ribose) polymerase.

1. TRPM2 (melastatin-like transient receptor potential 2 channel) is a nonselective cation channel that is activated under conditions of oxidative stress leading to an increase in intracellular free Ca(2+) concentration ([Ca(2+)](i)) and cell death. We investigated the role of the DNA repair enzyme poly(ADP-ribose) polymerase (PARP) on hydrogen peroxide (H(2)O(2))-mediated TRPM2 activation using a tetracycline-inducible TRPM2-expressing cell line. 2. In whole-cell patch-clamp recordings, intracellular adenine 5'-diphosphoribose (ADP-ribose) triggered an inward current in tetracycline-induced TRPM2-human embryonic kidney (HEK293) cells, but not in uninduced cells. Similarly, H(2)O(2) stimulated an increase in [Ca(2+)](i) (pEC(50) 4.54+/-0.02) in Fluo-4-loaded TRPM2-expressing HEK293 cells, but not in uninduced cells. Induction of TRPM2 expression caused an increase in susceptibility to plasma membrane damage and mitochondrial dysfunction in response to H(2)O(2). These data demonstrate functional expression of TRPM2 following tetracycline induction in TRPM2-HEK293 cells. 3. PARP inhibitors SB750139-B (patent number DE10039610-A1 (Lubisch et al., 2001)), PJ34 (N-(6-oxo-5,6-dihydro-phenanthridin-2-yl)-N,N-dimethylacetamide) and DPQ (3, 4-dihydro-5-[4-(1-piperidinyl)butoxy]-1(2H)-isoquinolinone) inhibited H(2)O(2)-mediated increases in [Ca(2+)](i) (pIC(50) vs 100 microm H(2)O(2): 7.64+/-0.38; 6.68+/-0.28; 4.78+/-0.05, respectively), increases in mitochondrial dysfunction (pIC(50) vs 300 microm H(2)O(2): 7.32+/-0.23; 6.69+/-0.22; 5.44+/-0.09, respectively) and decreases in plasma membrane integrity (pIC(50) vs 300 microm H(2)O(2): 7.45+/-0.27; 6.35+/-0.18; 5.29+/-0.12, respectively). The order of potency of the PARP inhibitors in these assays (SB750139>PJ34>DPQ) was the same as for inhibition of isolated PARP enzyme. 4. SB750139-B, PJ34 and DPQ had no effect on inward currents elicited by intracellular ADP-ribose in tetracycline-induced TRPM2-HEK293 cells, suggesting that PARP inhibitors are not interacting directly with the channel. 5. SB750139-B, PJ34 and DPQ inhibited increases in [Ca(2+)](i) in a rat insulinoma cell line (CRI-G1 cells) endogenously expressing TRPM2 (pIC(50) vs 100 microm H(2)O(2): 7.64+/-0.38; 6.68+/-0.28; 4.78+/-0.05, respectively). 6. These data suggest that oxidative stress causes TRPM2 channel opening in both recombinant and endogenously expressing cell systems via activation of PARP enzymes.