Evaluation of Quatsome Morphology, Composition, and Stability for Pseudomonas aeruginosa Biofilm Eradication.

Biofilm infections are a major cause of food poisoning and hospital-acquired infections. Quaternary ammonium compounds are a group of effective disinfectants widely used in industry and households, yet their efficacy is lessened when used as antibiofilm agents compared to that against planktonic bacteria. It is therefore necessary to identify alternative formulations of quaternary ammonium compounds to achieve an effective biofilm dispersal. Quaternary ammonium amphiphiles can form vesicular structures termed "quatsomes" in the presence of cholesterol. In addition to their intrinsic antimicrobial properties, quatsomes can also be used for the delivery of other types of antibiotics or biomarkers. In this study, quatsomes were prepared from binary mixtures of cholesterol and mono- or dialkyl-quaternary ammonium compounds; then, the integrity and stability of their vesicular structure were assessed and related to monomer chain number and chain length. The quatsomes were used to treat Pseudomonas aeruginosa biofilms, showing effective antibiofilm abilities comparable to those of their monomers. A systematic liquid chromatography-mass spectrometry method for quantifying quatsome vesicle components was also developed and used to establish the significance of cholesterol in the quatsome self-assembly processes.

Personality and Alcohol Use across College: Examining Context-Dependent Pathways toward Alcohol Problems.

BACKGROUND: College life is characterized by marked increases in alcohol consumption. Extraversion and neuroticism are associated with alcohol use problems in college and throughout adulthood, each with alcohol use patterns consistent with an externalizing and internalizing pathway respectively. Students higher in extraversion drink more frequently and consume more alcohol, while neuroticism is paradoxically not consistently associated with elevated alcohol use. OBJECTIVE: This study examined whether students higher in neuroticism may drink the day before stressors, namely tests and assignment deadlines. METHOD: Multilevel generalized linear models were performed using data from a longitudinal study of first-time, first-year undergraduates assessing alcohol use across four years of college, with daily diary bursts each semester. RESULTS: Students higher in extraversion had heavier alcohol use and greater alcohol use problems in their fourth year of college. Neuroticism was not associated with drinking behaviors or with drinking before a test or assignment, but was associated with greater fourth year alcohol problems. Students lower in extraversion who reduced heavy drinking the day before academic events had fewer alcohol use problems at the fourth year of college relative to students higher in extraversion. CONCLUSIONS: Students higher in extraversion appear to exhibit a continuity of established alcohol use patterns from adolescence, predisposing them to a more hazardous trajectory of college alcohol use. Characteristics of low extraversion may afford some protection from alcohol-positive college culture. High neuroticism appears associated with a hazardous trajectory of college alcohol use, but continued research into situational factors of alcohol use in high neuroticism is warranted.

Perinatal versus adult loss of ULK1 and ULK2 distinctly influences cardiac autophagy and function.

Impairments in macroautophagy/autophagy, which degrades dysfunctional organelles as well as long-lived and aggregate proteins, are associated with several cardiomyopathies; however, the regulation of cardiac autophagy remains insufficiently understood. In this regard, ULK1 and ULK2 are thought to play primarily redundant roles in autophagy initiation, but whether their function is developmentally determined, potentially having an impact on cardiac integrity and function remains unknown. Here, we demonstrate that perinatal loss of ULK1 or ULK2 in cardiomyocytes (cU1-KO and cU2-KO mice, respectively) enhances basal autophagy without altering autophagy machinery content while preserving cardiac function. This increased basal autophagy is dependent on the remaining ULK protein given that perinatal loss of both ULK1 and ULK2 in cU1/2-DKO mice impaired autophagy causing age-related cardiomyopathy and reduced survival. Conversely, adult loss of cardiac ULK1, but not of ULK2 (i.e., icU1-KO and icU2-KO mice, respectively), led to a rapidly developing cardiomyopathy, heart failure and early death. icU1-KO mice had impaired autophagy with robust deficits in mitochondrial respiration and ATP synthesis. Trehalose ameliorated autophagy impairments in icU1-KO hearts but did not delay cardiac dysfunction suggesting that ULK1 plays other critical, autophagy-independent, functions in the adult heart. Collectively, these results indicate that cardiac ULK1 and ULK2 are functionally redundant in the developing heart, while ULK1 assumes a more unique, prominent role in the adult heart.Abbreviations: ATG4: autophagy related 4, cysteine peptidase; ATG5: autophagy related 5; ATG7: autophagy related 7; ATG9: autophagy related 9; ATG13: autophagy related 13; CYCS: Cytochrome C; DNM1L, dynamin 1-like; MAP1LC3A: microtubule-associated protein 1 light chain 3 alpha; MAP1LC3B: microtubule-associated protein 1 light chain 3 beta; MFN1: mitofusin 1; MFN2: mitofusin 2; MT-CO1: mitochondrially encoded cytochrome c oxidase I; MYH: myosin, heavy polypeptide; NBR1: NBR1 autophagy cargo receptor; NDUFA9: NADH:ubiquinone oxidoreductase subunit A9; OPA1: OPA1, mitochondrial dynamin like GTPase; PPARGC1A, peroxisome proliferator activated receptor, gamma, coactivator 1 alpha; SDHA: succinate dehydrogenase complex, subunit A, flavoprotein (Fp); SQSTM1: sequestosome 1; ULK1: unc-51 like kinase 1; ULK2: unc-51 like kinase 2; UQCRC1: ubiquinol-cytochrome c reductase core protein 1.

Sex-specific microhabitat use is associated with sex-biased thermal physiology in Anolis lizards.

If fitness optima for a given trait differ between males and females in a population, sexual dimorphism may evolve. Sex-biased trait variation may affect patterns of habitat use, and if the microhabitats used by each sex have dissimilar microclimates, this can drive sex-specific selection on thermal physiology. Nevertheless, tests of differences between the sexes in thermal physiology are uncommon, and studies linking these differences to microhabitat use or behavior are even rarer. We examined microhabitat use and thermal physiology in two ectothermic congeners that are ecologically similar but differ in their degree of sexual size dimorphism. Brown anoles (Anolis sagrei) exhibit male-biased sexual size dimorphism and live in thermally heterogeneous habitats, whereas slender anoles (Anolis apletophallus) are sexually monomorphic in body size and live in thermally homogeneous habitats. We hypothesized that differences in habitat use between the sexes would drive sexual divergence in thermal physiology in brown anoles, but not slender anoles, because male and female brown anoles may be exposed to divergent microclimates. We found that male and female brown anoles, but not slender anoles, used perches with different thermal characteristics and were sexually dimorphic in thermal tolerance traits. However, field-active body temperatures and behavior in a laboratory thermal arena did not differ between females and males in either species. Our results suggest that sexual dimorphism in thermal physiology can arise from phenotypic plasticity or sex-specific selection on traits that are linked to thermal tolerance, rather than from direct effects of thermal environments experienced by males and females.

Ectoparasite extinction in simplified lizard assemblages during experimental island invasion.

Introduced species can become invasive, damaging ecosystems and disrupting economies through explosive population growth. One mechanism underlying population expansion in invasive populations is 'enemy release', whereby the invader experiences relaxation of agonistic interactions with other species, including parasites. However, direct observational evidence of release from parasitism during invasion is rare. We mimicked the early stages of invasion by experimentally translocating populations of mite-parasitized slender anole lizards (Anolis apletophallus) to islands that varied in the number of native anoles. Two islands were anole-free prior to the introduction, whereas a third island had a resident population of Gaige's anole (Anolis gaigei). We then characterized changes in trombiculid mite parasitism over multiple generations post-introduction. We found that mites rapidly went extinct on one-species islands, but that lizards introduced to the two-species island retained mites. After three generations, the two-species island had the highest total density and biomass of lizards, but the lowest density of the introduced species, implying that the 'invasion' had been less successful. This field-transplant study suggests that native species can be 'enemy reservoirs' that facilitate co-colonization of ectoparasites with the invasive host. Broadly, these results indicate that the presence of intact and diverse native communities may help to curb invasiveness.

Update in the Treatment of Chronic Pain within Pediatric Patients.

Pediatric chronic pain is a challenging entity to evaluate and treat as it encompasses a wide variety of presentations often with overlapping psychosocial implications. Chronic pain may have significant effects upon a child's involvement in academic, athletic, and social participation. If unrecognized, it may have deleterious effects upon family interactions and stability. The treatment of pediatric chronic pain is focused on not only providing analgesia, but also on assisting the child and family with reintegrating into a more functional lifestyle. Given the complex multifactorial causes of pain, a comprehensive multidisciplinary treatment plan is often the most effective way to achieve remission. This paper will discuss two examples of pediatric pain that have shown the good response to treatment with a multidisciplinary team approach: complex regional pain syndrome (CRPS) and amplified pain due to Ehlers-Danlos syndrome-hypermobility type (EDS-HT). Treatment of these patients often encompasses a multimodal approach that incorporates physical therapy (PT), occupational therapy (OT), medication(s), pain psychology, procedure(s), sleep hygiene, education, and encouragement of overall physiologic wellness. Management principles are to reduce pain and help prevent future occurrences.

The delivered promise of prenatal imaging and a challenge to the utility of sildenafil for severe lymphatic malformations.

We report the case of an infant with severe lymphatic malformation necessitating ex-utero intrapartum treatment (EXIT) procedure and examine recent advances in high resolution ultrasonography and magnetic resonance imaging, which allow for improved prenatal diagnosis of lesions that cause critical airway obstruction in the neonate. Treatments for lymphatic malformations including surgical resection, sclerotherapy, coblation, and sildenafil are discussed. Our patient did not have any reduction in the size of the lymphatic malformation from sildenafil as suggested in another series.

Tertiary amine and N-heterocyclic carbene coordinated haloalanes--synthesis, structure, and application.

The preparation of several tertiary amine and N-heterocyclic carbene coordinated chloro- and bromoalanes has been studied and routes to their gram-scale synthesis optimized. This provides a catalogue of well-characterized, thermally stable haloalanes for future application. All complexes have been investigated by spectroscopy (IR, NMR) and, where possible, single-crystal X-ray diffraction structure determination. A particular focus of this article is the relative thermal stabilities of the complexes, which provides a useful handle for the aerobic stability of Group 13 hydride complexes. These thermal data have been elucidated in full and rationalized relative to one another on the basis of Lewis base donation, steric shielding, and relative inductive halide strengthening of the aluminum hydride bonds by halides. All of the four-coordinate complexes reported exist as distorted tetrahedra in the solid state with aluminum to N/C-donor bonds that shorten with the increasing Lewis acidity of the aluminum Lewis acid. The five-coordinate complexes [AlBrH(2)(Quin)(2)] and [AlBr(2)H(Quin)(2)] (Quin = quinuclidine) exist in a trigonal-bipyramidal geometry in the solid state with the amine donors situated in the apical positions. Five chloroalanes; [AlClH(2)(Quin)], [AlClH(2)(Quin)(2)], [AlCl(2)H(Quin)(2)], [AlClH(2)(IMes)], and [AlCl(2)H(IMes)] (IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene), the latter two of which are aerobically stable, have been applied to the hydroalumination of carbonyl and heterocycle substrates and their chemo-, regio-, and stereoselectivities compared to those of Group 13 hydride reagents cited in the literature. Overall, the reactivities of these species are comparable to non-halogenated alane complexes with the additional benefit of aerobic stability, non-pyrophoricity, and enhanced regioselectivity borne out of greater Lewis acidity.

Hydride-bromide exchange at an NHC-a new route to brominated alanes and gallanes.

The reaction of [MH(3)(Quinuclidine)] (M = Al or Ga) with an air stable dibrominated N-heterocyclic carbene (NHC) affords the hydride-bromide exchange product [MBr(2)H(NHC)].

Bulky triazenide complexes of alumino- and gallohydrides.

The sterically bulky triazenes DitopN(3)(H)pTol, DitopN(3)(H)Mes, DmpN(3)(H)pTol and DmpN(3)(H)Mes, where Ditop = 2,6-di-p-tolylphenyl, Dmp = 2,6-dimesitylphenyl, pTol = p-MeC(6)H(4) and Mes = 2,4,6-Me(3)C(6)H(2), have been prepared. The reactivity of these triazenide precursors with LiAlH(4) and, in the cases of DmpN(3)(H)pTol and DmpN(3)(H)Mes, LiGaH(4), with diethyl ether as the solvent, has been examined. All reactions were undertaken in a 1:1 ratio giving rise to a variety of aluminium and gallium complexes that either incorporate LiH with a metal to triazenide ratio of 1:1 or generate 'LiH-free' aluminohydrides with aluminium to triazenide ratios of 1:1 or 1:2 dependant on triazenide bulk. Increasing triazenide bulk from DitopN(3)pTol through to DmpN(3)Mes results in a transition from complexes of structure [{Li(OEt(2))(mu-H)(mu-L)AlH (mu-H)}(n)] (L = triazenide ligand; n = 2 DitopN(3)pTol, n = 1 DitopN(3)Mes, DmpN(3)pTol), to bis(triazenide) monohydride complexes [AlH(L)(2)], through to monotriazenide dihydride complexes [AlH(2)(L)]. By contrast, both DmpN(3)(H)Ar (Ar = pTol or Mes) triazenides react with LiGaH(4) to afford the monomeric, lithium hydride containing, complexes [Li(ether)(mu-H)(mu-L)GaH(2)] (L = triazenide, ether = OEt(2) or THF). The molecular structures of [AlH(DitopN(3)Mes)(2)], [AlH(DmpN(3)pTol)(2)], [AlH(2)(DmpN(3)Mes)(THF)] and [Li(THF)(mu-H)(mu-DmpN(3)Mes)GaH(2)] are reported, as well as the structure of the triazene DmpN(3)(H)Mes which exists in the E-syn isomeric form in the solid-state.

The synthesis of a dichloroalane complex and its reaction with an alpha-diimine.

Reaction of an alpha-diimine, {MesN=CH}2 (Mes=2,4,6-trimethylphenyl), with the dichloroalane [AlCl2H(IMes)] (IMes=1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene) affords an N-heterocyclic carbene (NHC) transfer complex [AlCl2{MesNC(=IMes)C(H)NMes}] rather than the expected hydroalumination product.