Bone tissue is continuously remodeled by bone-forming osteoblasts and bone-resorbing osteoclasts, in processes tightly regulated by hormones, cytokines and growth factors. CD47, a ubiquitously expressed protein, and one of its ligands, signal-regulatory protein alpha (SIRPα), are two cell-surface proteins belonging to the immunoglobulin (Ig)-superfamily. The interaction between CD47 and SIRPα is important for, amongst other processes, the fusion of macrophages into giant cells, which are closely related to osteoclasts. The aim of the present study was to gain knowledge about the role of CD47–SIRPα interaction and resultant downstream signaling pathways in bone cell differentiation, formation and function. The addition of antibodies against CD47 or SIRPα inhibited the formation of multinucleated osteoclasts from bone marrow monocytes (BMMs) in culture. Moreover, a significant decrease in the number of osteoclasts was detected in CD47-/- BMM cultures compared to CD47+/+ cultures. In line with these in vitro results, we found fewer osteoclasts in vivo in the trabecular bone of CD47-/- mice, as compared to CD47+/+ bone. Interestingly, an extended analysis of the trabecular bone of CD47-/- mice revealed that the bone volume, mineralizing surface, mineral apposition rate, bone formation rate and osteoblast number were also significantly reduced compared with CD47+/+ mice, indicating the importance of CD47 in osteoblast differentiation. In vitro studies of bone marrow stromal (BMS) cells from CD47-/- mice or SIRPα-mutant mice (mice lacking the signaling domain of SIRPa) showed a blunted expression of osteoblast-associated genes. Moreover, these altered genotypes were associated with reduced activity of the bone mineralization-associated enzyme alkaline phosphatase as well as a reduced ability to form mineral. To reveal the molecular mechanisms by which CD47 activation of SIRPα is important for BMS cell differentiation, we studied signaling downstream of SIRPα in the absence of CD47. In BMS cells lacking CD47, a considerable reduction in the levels of tyrosine phosphorylated SIRPα was detected, and the subsequent recruitment of the Src-homology-2 (SH2) domain-containing protein tyrosine phosphatase (SHP-2)–phosphoinositide 3-kinase (PI3K)–Akt2 signaling module was nearly abolished. In conclusion, the interaction between CD47 and SIRPα results in the activation of the SHP-2–PI3K–Akt2 pathway, which is necessary for normal osteoblast differentiation. In CD47-/- mice and SIRPα-mutant mice, this interaction is perturbed, which prevents normal osteoblast differentiation and subsequent mineral formation. In addition, the altered BMS cell phenotype results in an impaired ability to stimulate osteoclast differentiation.

The goal of this study was to compare different anthropometric measures in terms of their ability to predict T2DM and to determine whether predictive ability was modified by ethnicity. Anthropometrics were measured at baseline on 1073 non-Hispanic Whites (nHW), African Americans (AA) and Hispanics (HA), of which 146 developed T2DM after 5.2 years. Logistic regression models were used with areas under the receiver operator characteristic curve (AROC) comparing the prediction of models. Overall, there was no clear distinction between measures of overall and central obesity in terms of T2DM prediction. Waist-height ratio (AROC=0.678) was the most predictive measure, followed by BMI (AROC=0.674). Results were similar in nHW and HA, although, in AA, central adiposity measures best predicted T2DM. Measures of central and overall adiposity predicted T2DM to a similar degree, except in AA where central measures were most predictive.

HSV-2 may have adverse consequences in HIV. I evaluated the impact of HSV-2 co-infection on (highly active antiretroviral therapy)-untreated HIV infection in a systematic review of observational studies (study 1) and a retrospective cohort (study 2). I further evaluated whether HSV reactivation rates in co-infected persons differ by use of suppressive cART (study 3). Study 1 found modest evidence that HSV-2 seropositivity may be associated with accelerated progression to opportunistic infection or clinical AIDS, but not with increased HIV viral load. Some evidence suggests that HSV-2 disease activity is associated with increased HIV viral load and decreased CD4 counts. Study 2 compared rates of CD4 count change by HSV-2 status (Focus HerpeSelect ELISA) among 218 patients with a past period of ART-untreated follow-up using mixed linear regression models. No significant difference in the rate of CD4 count change was observed in HSV-2 seropositives at +13.6 cells/mm3/year (p=0.12) in univariate analysis, and -4.5 cells/mm3/year (p=0.68) in analysis adjusted for sex, HSV-1, oral and genital HSV symptoms, immigrant status, and immigrant*time interaction. These findings support the need for carefully designed and executed studies of HSV-2 suppression as an adjunctive management strategy for HIV disease, but raise questions regarding the exact mechanism of negative synergy between these viruses and the relative importance of HSV-2 latency and replication in driving these effects. In Study 3, 44 cART-naïve and 41 treated (HIV RNA<50 copies/mL) HIV+ adults with HSV-1 and/or 2 co-infection collected oral, genital and anal swabs daily for 28 days. Negative binomial models were used to quantify the relationship between cART and HSV shedding (Roche LightCycler HSV1/2). Overall HSV shedding was low, at a median (IQR) of 3.6% (0, 14.3%) of days. No relationship was seen between cART and HSV-1 or 2 shedding in univariate (RR=1.55, 95%CI=0.83,2.87) or multivariate analysis adjusted for sex, baseline CD4, recent immigrant status, and time since HIV diagnosis (aRR=1.05, 95%CI=0.43,2.58). Null results were also observed for HSV-1 and HSV-2 considered separately. That HSV shedding persists despite cART suggests that trials of anti-HSV drugs for improving HIV outcomes may be warranted in such patients.

The goal of this study was to compare different anthropometric measures in terms of their ability to predict T2DM and to determine whether predictive ability was modified by ethnicity. Anthropometrics were measured at baseline on 1073 non-Hispanic Whites (nHW), African Americans (AA) and Hispanics (HA), of which 146 developed T2DM after 5.2 years. Logistic regression models were used with areas under the receiver operator characteristic curve (AROC) comparing the prediction of models. Overall, there was no clear distinction between measures of overall and central obesity in terms of T2DM prediction. Waist-height ratio (AROC=0.678) was the most predictive measure, followed by BMI (AROC=0.674). Results were similar in nHW and HA, although, in AA, central adiposity measures best predicted T2DM. Measures of central and overall adiposity predicted T2DM to a similar degree, except in AA where central measures were most predictive.

Purpose: The prevalence of diabetes (DM) is increasing globally with type 2 diabetes (T2DM) being primarily responsible for this alarming trend. Age and DM have been associated with an increased prevalence of AR cataract in earlier studies but T2DM has not been considered separately from type 1 diabetes. Furthermore, study results have been inconsistent in terms of whether nuclear sclerosis (NS), cortical cataract (CC) or posterior subcapsular (PSC) are specifically associated with DM. The purpose of this thesis was to provide Canadian data on these issues while considering the limitations found in earlier studies in terms of variable age group selection and cataract definition. Logistic regression analysis was extended beyond risk analysis to model the prevalence of AR cataract across the human age range. Finally, as statins are commonly prescribed for patients with T2DM, the impact of using this pharmaceutical on AR cataract prevalence was investigated. Methods: A file review of over 6397 clinic files was performed to create the Waterloo Eye Study (WatES) database. Abstracted data included patient age and sex, the presence of early to late AR cataract (NS, CC, PSC or related lens extraction-LE), systemic health diagnoses including a diagnosis of T2DM or type 1 diabetes, and any medication used. Data quality was looked at through repeatability with double-entry of files and calculation of missing data rates. Comparisons were done between the study population demographics (age and sex) and those available on the general population and representative Canadian optometric patients. Prevalence of AR cataract was determined for the entire study group and for yearly age-groups. The probability of AR cataract generated from logistic regression analysis was used to model the prevalence of AR cataract over the entire age range of patients. Similar functions were determined for T2DM and non-diabetic (ND) subgroups and then again after further subdividing them into patients who did and did not use statins. The age of 50% prevalence of AR cataract were determined for each of these functions. Distribution rates of mixed and uniform cataract were calculated and compared for the T2DM and ND subgroups. Age of first lens extraction and differences in LE rates were also determined for these groups. Multivariable logistic regression analysis was done to determine odds ratios (OR) for associations between variables (patient age, being female, having a diagnosis of T2DM, smoking, systemic hypertension, and statin use) and the outcome of AR cataracts or its subtypes. Results: Data abstraction repeatability was found to be high and missing data rates were found to be low. While significant differences existed between the demographics of the general population and this clinic population, the sex and age distributions were comparable to optometric practices in Canada. The overall prevalence of AR cataract, NS, CC,and PSC in this population was 35.3%, 28.8%, 9.9%, and 3.6% respectively. The yearly prevalence of AR cataract in this population was found to increase in a sigmoid trend over the course of the human age span that began to rise after 38 years of age and approached 100% by 75 years of age. When modelled into a probability of cataract function, 50% prevalence of AR cataract occurred at 56.6 years of age. T2DM was reported in 452 WatES patients; 97% of whom were over 38 years of age. The probability of 50% AR cataract, NS, and CC prevalence occurred almost four years earlier in the T2DM subgroup compared to those without diabetes. PSC was much less prevalent and did not reach 50% levels, but the age of 10% prevalence was eight year earlier in the T2DM group compared to the ND group. Patients with T2DM had more mixed cataract, a higher rate of LE and an earlier age of first LE than non-diabetics. Statin use was reported in 761 patients; 96% who were over 38 years of age. Statin use was 3.5 times more common in patients with T2DM compared to non-diabetics. When the diabetic subgroups were further subdivided by those who do and do not use statins, the age of 50% probability of AR cataracts was now almost eight years earlier in the T2DM patients using statins compared to the ND patients who did not. The probability functions were similar between T2DM patients not using statins and ND patients who did report statin use. Having a diagnosis of T2DM was significantly associated with early to late NS and CC when controlling for statin use, whereas statin use was significantly associated with NS and PSC when controlling for a diagnosis of T2DM. Conclusions: AR cataract, T2DM and statin use were prevalent conditions in this clinic population, especially over 38 years of age. Modelling the prevalence of AR cataract over a broad age range could assist predicting cataract in Canadian optometric patients. A diagnosis of T2DM resulted in an earlier development of all three cataract subtypes, resulting in increased rates of LE and mixed cataract. However, the association was only significant for NS and CC when controlling for statin use. Given the frequent use of statins in patients with T2DM, the significant association found between statin use and increased risk of AR cataract warrants further study.

Pseudo-plane strain compression tests are carried out on rolled plate Zircaloy-2 using different combinations of loaded and constrained sample directions relative to the plate principal directions. Lattice strains are measured for 17 out of 18 possible measureable sample directions. The inability to obtain true plane strain led to little effect of the compression rig on deformation during elastic loading; however noticeable differences are seen when compared to similar uniaxial data for Zircaloy-2 in the plastic region. Work hardening increased with increased constraint and was affected by the configuration of loaded and constrained sample directions. Constraint showed significant effects on twinning when twinning was present. For the RD loaded cases the initiation of twinning occurs at -318 MPa for the RD/ND case (RD loaded, ND constrained direction) and -420 MPa for the RD/TD case. Intensity profiles of the (0002) and {101 ̅ 0} indicate that more twinning occurs in the RD/TD case than the RD/ND case. For TD/YD an amplification of twinning was seen in the TD/RD when compared to the TD/ND. This is indicated both by texture results as well as the intensity profiles of the (0002) and {101 ̅ 0}. Using the experimental data an elastic-plastic self-consistent (EPSC) code was used to probe the micromechanical processes that are occurring when the compression rig is operated. The experimental data was used further to constrain the hardening parameters of the EPSC code using an inverse approach. The EPSC code was able to capture the relative activity of the twinning characteristics found by the experimental data but unable to truly capture the evolution of the (0002) lattice strains when twinning occurs. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2014-01-13 11:24:21.692

Coacervation is a mild process for developing protein NPs. Bovine serum albumin (BSA) NPs formed via this technique were stabilized using poly-L-Lysine (PLL); short interfering ribonucleic acid (siRNA) was used as a model drug for encapsulation. Specific and non-specific degradation of these coated and uncoated BSA NPs were carried using matrix metalloproteinase-2 (MMP-2) and trypsin, respectively. The particles were characterized with atomic force microscopy, zeta-potential, and photon correlation spectroscopy measurements. There was a significant increase in the zeta potential of BSA NPs upon coating. Trypsin digested the uncoated and coated BSA NPs and resulted in higher BSA release from the particles. However, MMP-2 treatment did not result in higher release of BSA from coated NPs despite the cleavability of coated polymer by MMP-2. This study described a method for obtaining BSA NPs in a controllable size range. Such particles showed degradability in the presence of trypsin and could be promising for targeted drug delivery applications. / Chemical Engineering

This study sought to determine whether caffeine combined with choline could improve short-term memory in healthy adults. The study tested the effect of choline (2 gm) alone and in combination with several concentrations of caffeine (25 mg, 50mg and 100mg) on short-term verbal and visual memory and attention. The Wide Range Assessment of Memory and Learning-2 was utilized. Choline 2 gm + caffeine 25 mg group showed significantly (p&lt;0.05) higher overall memory performance whereas memory performance in the choline 2 gm + caffeine 50 mg group was significantly impaired compared to placebo. The data suggest that specific combinations of caffeine and choline can either facilitate or impair short-term memory in adults with normal cognitive function. Future studies of caffeine and choline combinations will test memory performance in subjects with memory impairment. / Mylan School of Pharmacy and the Graduate School of Pharmaceutical Sciences / Pharmacology / MS / Thesis

Bösartiges Katarrhalfieber ist eine unheilbare Virusinfektion bei Paarhufern, die wiederholt in zoologischen Gärten auftrat, ohne dass die erkrankten Fehlwirte Kontakt zu Reservoirwirten hatten. Die BKF-auslösenden Gammaherpesviren sind eng miteinander verwandt und werden von verschiedenen klinisch gesunden Reservoirwirten latent beherbergt und ausgeschieden. Einige dieser Reservoirwirte sind seit längerem bekannt, andere wurden erst kürzlich identifiziert und es wird vermutet, dass es noch weitere unerkannte Reservoirwirte für BKF-Viren gibt. Hervorzuheben ist, dass die Viren normalerweise eng an ihre Reservoirwirte gebunden sind. Es traten in letzter Zeit jedoch immer wieder Fälle auf, in denen auch Fehlwirte zwar infiziert waren, aber nicht erkrankten oder das Virus sogar ausschieden. Der Zusammenhang zwischen dem Verhalten der BKF-Viren bei Fehl- und Reservoirwirten und den ungeklärten BKF-Fällen in zoologischen Gärten wurde in der hier vorliegenden Studie näher untersucht. Es sollte herausgefunden werden, ob Wildwiederkäuer, die bisher nicht als Reservoirwirte für BKF-Viren galten, diese Viren ausscheiden und so möglicherweise für die oben erwähnten BKF-Fälle verantwortlich waren. / Malignant catarrhal fever (MCF) is an incurable infectious disease in even-toed ungulates, which occurred repeatedly in zoological gardens in Europe without any contact between known hosts and animals with clinical MCF. The causative agents are closely related viruses of the family gamma-herpesviridae, which are latently carried and shed by different clinically healthy ruminant species. Some of the hosts for MCF viruses have been known for many years, while others have been identified only recently. Yet, there are probably still more host species to be discovered. It has to be pointed out that generally MCF viruses are strictly associated with their hosts. However, it has been reported that known susceptible species were infected with MCF viruses without showing any signs of MCF, some of which even excreted the virus. This present study investigates the relationship between the behaviour of MCF viruses in hosts and susceptible species and the nebulous cases of MCF in zoological gardens. The goal was to determine whether wild ruminants, which are normally not known as hosts for MCF, shed these viruses and are possibly responsible for MCF cases mentioned above.

Recently, research has postulated that stuttering is a motor disorder that results from brain abnormalities within the central nervous system. Based on evidence of numerous irregularities within various motor systems, it has been suggested that other motor domains may be comprised. In particular, research in individuals who stutter has found fine, gross, and visual-spatial motor impairment. These studies, though, are dated, have numerous methodological concerns, or yielded contradictory results. Thus, this study investigated whether motor skills in children who stutter (CWS) were compromised. Fine motor skills are important in a school environment because students are required to utilize these skills to complete various assignments and projects, such as cutting and folding paper. Gross motor skills are equally as important as children use these skills to move around their environment. Visual-spatial motor skills are vital for children as they are often required to copy notes off of the board. Deficits in any of these areas may have potentially harmful effects on school performance. Thus, in a school setting, school psychologists are a valuable asset, as they are trained to consult and work with "at risk" populations to prevent long-term problems. Given the potential motor deficits in CWS, school psychologists can intervene and provide appropriate accommodations to remediate any motor deficits. Participants included 12 CWS and 12 children who do not stutter (CWNS). Participants were recruited from a large urban school district and were administered the Bruininks-Oseretsky Test of Motor Proficiency-Second Edition (Bruininks & Bruininks, 2005; BOT-2). Parents completed a demographic questionnaire. One Way Analyses of Variance (ANOVAs) were calculated to compare group means. Results indicated that CWS performed poorer on all but one motor area. Given these results, when a child is identified with a disfluency problem, a broader consideration of issues that may be facing the child is warranted. In particular, school psychologists are in a position to intervene and provide appropriate services to an "at risk" population (i.e., CWS) by conducting a brief motor assessment to identify motor strengths and weaknesses. If warranted, school psychologists can provide accommodations and services to address any identified weaknesses in motor areas.