3855 research outputs found
Sort by
Formulation and efficacy of liposome-encapsulated azithromycin for pulmonary infection due to Pseudomonias Aeruginosa
Get PDFCystic fibrosis is the most common life-threatening autosomal recessive disorder in Caucasians. Recurrent pulmonary infection and inflammation are the major risk factors associated with cystic fibrosis. Microbial infection with highly resistant pathogens such as Burkholderia cenocepacia and Pseudomonas aeruginosa, is principally associated with cystic fibrosis. The effective management of pulmonary infection in cystic fibrosis patients is not controllable due to the multidrug-resistant strains and potential side effects of antibiotics usage. Liposomal encapsulation of macrolide antibiotics such as azithromycin show increased drug concentrations at the site of infection, along with reduced toxic effects. In this thesis work, liposome-loaded azithromycin formulation was prepared by dehydration-rehydration vesicle method and related characterizations including cytotoxicity were identified. The effects of liposomal azithromycin on biofilm community, purified bacterial virulence factors were determined and motility studies were performed in clinical isolate of P. aeruginosa. We found that liposomal azithromycin reduced biofilm activity, virulence factors production and bacterial motility. The liposomal formulation confirmed interactions between liposomes and bacterial membranes besides insignificant hemolysis or A549 cell toxicity. The end results collectively indicate that liposomal drug delivery systems could be a promising model to enhance the efficacy of antibiotics against resistant bacterial strains in lung infections
An EPR and DFT investigation of the products formed in the reaction of group 11 metal atoms with three-membered heterocyclic compounds
Get PDFTransition metals have been shown to be efficient catalysts in a variety of organic reactions. In particular, Group 11 metals have emerged as essential components in the carboxylation or metal-catalyzed ring expansion of three-membered heterocyclic compounds. Previous reports have speculated the presence of short-lived metal-substrate complexes and metallacyclic intermediates along the reaction path, yet to date there is no
direct evidence for their existence.
Using cryogenic matrix isolation EPR spectroscopy, we were able to characterize several highly reactive intermediates formed in the reactions of Group 11 metal atoms,
Cu, Ag, and Au, with small, strained, heterocyclic compounds, namely, oxiranes,
thiiranes, and aziridines. Experimental data indicates that the major products formed are mononuclear metal complexes, M-XCH2CH2 (X = O, S or NH). In addition, reaction
mixtures containing Cu atoms and oxiranes or thiirane yield novel metallacycles, i.e.,
cupraoxetane and cuprathietane, respectively. DFT calculations were also used to support the structural assignments of the M-XCH2CH2 complexes
Correlation between phenotypes or genotypes of Clostridium difficile and clinical outcome from Clostridium difficile infections at Health Sciences North
Get PDFClostridium difficile, a Gram-positive, anaerobic, spore producing bacillus is the leading cause of
nosocomial diarrhea in health-care facilities. Its effect on patients can be detrimental to their
recovery, sometimes leading to death; the catalyst to Clostridium difficile infection (CDI) is
treatment by antibiotics. Focusing research on some of C. difficile’s genotypes and phenotypes,
we hoped to be able to predict the severity and outcome of the infections based on the strain. C.
difficile strains isolated from patients were characterized for the presence of the toxin genes and
classified by ribotype. They were also tested for antibiotic susceptibility (E-test), toxin
production levels, and microbial spore load in stools. The patients symptoms were evaluated to
determine if there were any correlations between the genotypes/phenotypes and the infection
outcomes. No significant correlation was found between the severity of disease and
phenotypic/genotypic attributes of the C. difficile strain involved. Thus, other defining factors
appear to affect patient prognosis such as the severity of the patients’ disease and the presence of
co-morbidities. A key finding however was that 30% of the population was at risk of developing
CDI due to carriage of toxigenic C. difficile
Investigating coxiella burnetii at the livestock - wildlife interface
No full textThe intent of this project was to better understand the role of wildlife in the epidemiology of the zoonotic bacterium, Coxiella burnetii, at the livestock-wildlife interface. In Chapter 1, I compared the prevalence of C. burnetii DNA in dairy goats, other domestic animals, and wildlife on goat farms and adjacent natural areas. In Chapter 2, I compared the prevalence of C. burnetii DNA in different sample types from goats and wildlife, and assessed the level of agreement among the different samples. From April to August 2014, genital, fecal and milk samples were collected from goats on 16 Ontario dairy goat farms. Fecal and genital samples were also collected from other resident animals (cats, chickens, cows, dogs, horses, pigs), and from wildlife (deer mice, house mice, opossums, raccoons, red-backed voles, red squirrels and skunks) live-trapped on farms and from 14 adjacent natural areas. Coxiella burnetii was detected by PCR in samples from 89.2% (404/453) of goats, 68.8% (33/48) of other farm animals, 64.7% (44/68) of wild animals sampled on farms, and 58.1% (165/284) of wild animals sampled in natural areas. Coxiella burnetii was detected at all study sites and the prevalence in wildlife was similar on farms and adjacent natural areas, independent of site distances. These findings provide evidence to support the hypothesis that wildlife are able to maintain C. burnetii independent of livestock and may act as possible maintenance or reservoir hosts of C. burnetii at the livestock-wildlife interface. I determined that genital and fecal swab samples, which yielded the highest proportion positives, were optimal sample types to use for the detection of C. burnetii DNA in deer mice, eastern chipmunks, and raccoons. Genital swab, fecal swab and fecal material sample types were all suitable for detecting C. burnetii DNA in house mice and red squirrels. On the other hand, genital swab samples were optimal for detecting C. burnetii DNA in dairy goats and were significantly more likely to be positive for C. burnetii DNA than the other sample types. Additional studies need to be conducted to further elucidate the epidemiology of C. burnetii at the livestock-wildlife interface in southern Ontario and to confirm the optimal sample types to use for C. burnetii detection in wildlife and dairy goats
Challenges in the remediation of compromised housing situations in individuals exhibiting hoarding behaviours
No full textHoarding has been estimated to affect 2 to 5 percent of the population. There are
considerable health and safety implications for those who hoard, others living with them, and for
the community. For this reason, public health inspectors (PHIs) respond to situations involving
vulnerable individuals living in these potentially adverse housing situations. Earlier research
found that PHIs responding to these housing health hazards face many challenges in the
remediation of these conditions including client health, structural factors, and policy issues. The purpose of this case study, approached from a social constructionist perspective, is to
further explore the challenges in remediation of compromised housing health hazards in hoarding
situations. The study included PHI’s documented reports of 40 cases referred to them between
2013 and 2015 as well as field observations and semi-structured interviews with an individual
who hoards, his family, members of agencies involved with this case, and PHIs who respond to
hoarding cases. This data is part of a larger two-year case study examining an Environmental
Health Division’s response to housing health hazards in vulnerable populations. There were significant challenges in the remediation of hoarding. Client factors such as
advancing age, infirmity, living alone, and lack of formal and informal supports hampered
resolution of cases as did lack of training for PHIs about hoarding and its psychological
ramifications. The lack of coordination of services within the City of Greater Sudbury, the
magnitude of the cleanup required, and the chronic nature of hoarding also posed difficulties.
The creation of a coalition to provide a more comprehensive response to hoarding is required to
support this vulnerable population.Master of Social Work (MSW
A comparison of magnetic susceptibility meters using samples from the Thompson Nickel Belt, Canada
No full textNSERC, Vale, Sudbury Integrated Nickel Operations (a Glencore company), KGHM International, Wallbridge Mining and the Centre for Excellence in Mining Innovation (CEMI
An exploration of accident/failure at attribution and the potential implications for future research in occupational health psychology with psychiatric nurses
No full textThe current review of the literature provides an overview of Attribution Theory (AT)
and the themes, trends and gaps that have emerged for this construct within the field of
occupational health psychology. AT is a widely published area of research and has
served as a theoretical framework to investigate how individuals interpret accidents
and their causes. Within this framework, researchers have investigated cognitive
biases such as the selfserving
bias, the false consensus effect, the actorobserver
bias,
the fundamental attribution error, the ultimate attribution error, Fischoff’s hindsight
bias, the hedonic relevance bias, the optimism bias, and defensive attribution theory.
Themes and trends of this review include subjective attribution tendencies, the types
of attributions and their relation to safety behaviours, controversies regarding the
assumptions of responsibility and the importance of accurate accident appraisals.
Current gaps in the literature include somewhat dated research and only partial use of
Weiner’s AT model (1985; 2010). In addition, there seems to be a paucity of research
on AT as it applies to occupations with a high prevalence of accidents such as
psychiatric nursing. The review further describes the extent to which the theory may
be useful for occupational health and safety, accident prevention and in psychiatric
nursing where practitioners face not only the common risks inherent to the profession
but also the significant and unique risks in mental health facilities such as patient
aggression and violence. This paper concludes by suggesting avenues of possible
research as it applies to this profession, methodological challenges and the
implications for future studies
Do portable anti-fatigue mats affect the mechanics or discomfort of walking
No full textProlonged periods of standing and walking creates loading on the muscles of the back and legs
causing pain and discomfort to many employees who stand on hard surfaces such as cement floors.
Portable anti-fatigue mats are an ergonomic intervention that is thought to be a solution for
musculoskeletal injuries. Thirteen healthy subjects ranging from 18-55 years of age were recruited
for the study to represent a working population. Subject completed two 3 hour sessions, one with
work boots, and the other with the combination of work boots and portable anti-fatigue mats.
Subjects walked for a 3 hour period to simulate a prolonged walking period. Participants were
instrumented with reflective marker to collect kinematic data and walked on the force plate to
collect kinetic forces acting on the body. They also completed a discomfort questionnaire for “pre”,
“during” and “post” exercise. Results showed no significant differences in mechanical variables,
and showed significant differences in discomfort ratings for the ankle/foot and knee between
conditions; while showing significant differences for the ankle/foot and low back over time
The use of surface plasmon resonance spectroscopy in characterizing small molecule-based nerve growth factor inhibitors
No full textNeurotrophins are well known for their effects on neuronal survival and growth. Over the
past two decades, considerable evidence has accumulated from both human and animal
models that one neurotrophin, nerve growth factor (NGF), is a peripheral pain mediator,
particularly in inflammatory pain states. NGF is upregulated in a wide variety of
inflammatory conditions, and NGF-neutralizing molecules are effective analgesic agents in
many models of persistent pain. Such molecules are now being evaluated in clinical trials
and although seemingly effective in early clinical studies, many deteriorating side effects are
now being brought to light. Thus, a need still remains for novel NGF-quenching therapeutics.
In the past two decades, a handful of small molecule NGF-inhibitors have been described,
however, their effects are still quite minimal compared to other inhibitory agents. The
central aim of this thesis was to use novel screening strategies to identify small molecule
NGF-inhibitors capable of modulating NGF signalling with greater efficiency than previously
reported compounds for the purpose of therapeutic development. Using surface plasmon resonance (SPR) spectroscopy, established NGF-inhibitors and a series of novel compounds
were analyzed for their specificity to NGF and their inhibitory properties of NGF binding to
the TrkA receptor. In vitro techniques confirmed the high nanomolar inhibitory properties of
a novel compound, BVNP-0197. Molecular modeling techniques also described a putative
binding domain for BVNP-0197 to NGF at the loop II/IV cleft, an alternative domain than
previously described by small molecule compounds. This binding domain describes an area with higher specificity for TrkA over binding for p75NTR. Serum albumin was also described as
having a role in the binding events that occur between small molecule compounds to NGF in
vitro. SPR kinetic analysis established that the addition of serum albumin into solution with
small molecule compounds increased their specificity for NGF, as well as decreased their
potential toxicity. The findings presented in this thesis will contribute to the future
development of small molecule NGF-inhibitors
The impact of intergroup similarity on prosocial behaviour
No full textIndividuals are frequently asked to provide aid to those in need and social networking sites have
become a popular vehicle for requesting such aid. The question of who is likely to receive help
has applied implications, and research addressing this in an online context is timely. This study
therefore evaluated the impact of intergroup similarity on online prosocial behaviour. Intergroup
similarity was manipulated by altering the national identity of a recipient of aid ingroup
(Canada), similar outgroup (United States), and dissimilar outgroup (South Africa). Prosocial
behaviour was assessed on three measures: Facebook support (clicking ‘like’ or ‘share’ on
Facebook), prosocial intentions (willingness to engage in prosocial behaviours with real world
consequences: signing a petition, volunteering, donating, or fundraising), and prosocial action
(behaviours with real world consequences: signing a petition, volunteering, donating or
fundraising). Moderated multiple regression analyses assessed whether prosocial personality,
civic engagement, and conservatism moderated the relationship between intergroup similarity
and the three measures of prosociality. Main effects and moderation effects were generally
consistent with the common ingroup identity model. Implications are discussed in relation to
increasing the effectiveness of charitable campaigns and educational programs aimed at
promoting prosocial behaviour