Breast cancer has the highest incidence rate in women, accounting for more than 22% of all cancers and possessing a strong disposition to metastasize to bone. These skeletal metastases become a significant cause of morbidity and mortality in patients with the primary symptom being pain. Pain is a major concern in determining a patient’s quality of life and there have been many attempts to understand and control bone pain with little success. Previous studies have shown that glutamate plays a role in bone cancer pain, with an excess in free glutamate able to cause pain either directly through excitotoxic pathways or indirectly though the dysregulation of osteoclasts and osteoblasts, causing bone dysregulation. TRPV-1 receptors have also has been implicated in the mechanisms of bone cancer pain, as osteoclasts release protons during bone remodeling which can elicit a TRPV-1-related nociceptive response from neurons in the surrounding periosteum. Capsazepine was identified during a high throughput screen of 30,000 compounds to be a potent inhibitor of breast cancer cell-mediated glutamate release, a neurotransmitter with known associations in neural signaling, bone homeostasis, and pain. Capsazepine also has antagonistic effects on transient receptor potential vanilloid type 1 (TRPV-1) receptors which act as key players in both heat and vanilloid-induced nociception. These findings suggest that Capsazepine may provide a multi-site effect for the treatment of cancer-induced bone pain. An animal model of breast cancer-induced bone pain involved intrafemorally injecting MDA-MB-231 cancer cells to measure pain. Behavioural tests are then performed measuring dynamic weight bearing and paw withdrawal thresholds. These measurements are used to demonstrate both movement-evoked and spontaneous pain-related behaviour of the affected limb. Using Capsazepine, we demonstrate a dose-dependent attenuation of pain behaviour in vivo, while confirming tumour presence using immunohistochemistry (IHC). We show that TRPV-1 and glutamate play an important role in the onset and severity of bone cancer pain and blocking these pain pathways provide relief from pain commonly associated with cancer in the bone. / Thesis / Master of Health Sciences (MSc)

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ABSTRACT COMPLETION OF AN IN VIVO DIGESTIBILITY TRIAL IN HORSES AND IN VITRO DIGESTIBILITY ASSAY DEVELOPMENT Cassandra Renee Sweeney In vivo analysis of equine feed digestibility has been the gold standard since the late 1800's, although it can be time consuming, costly, and labor intensive. In vitro digestibility analysis may be more economical and beneficial to both feed manufacturers and consumers. The availability of accurate in vivo data is crucial for critical evaluation and validation of any potential in vitro method (Coles et al., 2005). Ten adult American quarter horse geldings were used in the in vivo digestibility evaluation of two complete pelleted feeds fed as 100% of intake. The ingredients of the two treatments were similar: wheat middlings, rice hulls, alfalfa and beet pulp. The treatments differed in added mineral sources, yeast, direct fed microbials, and Yucca schidigera extract, added to enhance dry matter digestibility of the test diet. The in vivo evaluation consisted of two phases in a randomized crossover design. Total daily dry matter intake (DMI) and daily dry matter excretion (DME) were measured. Apparent digestibility (aDig) of % DM, % NDF, % ADF, % ADLom, and % OM (DM) were also calculated. No differences were seen in aDig of NDF, ADF, ADLOM or OM between the two experimental diets (P > 0.05). There was also no difference in DMI or DME, as a percentage of body weight (BW), between the two experimental diets. The effect of phase was not significant for all tests run on aDig, DMI, and DME (P > 0.05). BW was not significantly different (P > 0.05) between diets, however there was a trend for v heavier BW during phase 2 (P = 0.073). In vitro digestibility assay development followed the in vivo evaluation. A three-stage batch system as briefly described by Boisen and Fernandez (1997) was utilized. Through literature review, trial and error, personal communication with other labs and product and chemical manufactures, careful documentation of the methods were detailed. Using the control feed from the in vivo evaluation, variation in the methods was significantly reduced, and estimations of DML began to approach those seen in vivo throughout method development. Although further method development may be needed for species-specific use, the methods described here can provide the foundation for future in vitro digestibility studies.

Bronchopulmonary dysplasia (BPD), the chronic lung disease that develops in premature babies following mechanical ventilation and oxygen exposure, is the most common complication of extreme prematurity. Currently, there is no cure for BPD. Increasing evidence indicates early-onset emphysema and pulmonary vascular disease in survivors with BPD (Aukland et al., 2006; Wong et al., 2008), suggesting an irreversible arrest in lung growth and/or premature lung aging resulting in life-long health problems (J. Sucre et al., 2021). Transient in vivo cellular reprogramming through the activation of the Yamanaka reprogramming factors Oct4, Sox2, Klf4, c-Myc (OSKM), ameliorate cellular and physiological hallmarks of aging and to promote tissue regeneration and improve organ function after injury. (Chen et al., 2021a; Hishida et al., 2022b; Lu et al., 2020) This thesis focuses on determining if transient in vivo cellular reprogramming can regenerate an established lung injury in a BPD mouse model. Two strategies, (a) Adeno-Associated virus (AAV) mediated transient overexpression of the OSK factors and (b) using a transgenic reprogrammable mouse line to overexpress the OSKM factors were employed to test the efficiency of in vivo cellular reprogramming in regenerating the lungs. Both the strategies, under the conditions tested, did not regenerate established lung injury in a BPD mouse model but the feasibility of both these strategies was established here laying a foundation for the next phase of the study.

Das Ziel der experimentellen Studie war die Erprobung der (bereits in vitro erfolgreich getesteten) Ca(OH)2-Beschichtung In vivo unter dem Aspekt, ob und inwieweit die antibakteriellen und somit auch antiinflammatorischen bzw. entzündungsmoderierenden Eigenschaften der Ca(OH)2-Beschichtung eine sinnvolle und effektive Ergänzung zu den bisher erfolgreich eingesetzten Calciumphosphat(CaP)-Beschichtungen mit bewiesenen, guten proosseointegrativen Eigenschaften bei lasttragenden Implantaten sein können. Zusammenfassend kann festgestellt werden, dass die Ergebnisse der In vitro Untersuchung durch die In vivo Versuche in den Bereichen 0-100 KBE grundsätzlich als gestützt gelten können. Die Zuverlässigkeit der Wirkung durch Ca(OH)2 nimmt jedoch mit steigender KBE-Zahl ab, sodass weitere Testreihen sinnvoll sind. / The aim of the experimental study was to test the Ca(OH)2-coating (which has already been successfully tested in vitro) in vivo under the aspect of whether and to what extent the antibacterial and thus also anti-inflammatory or inflammation-moderating properties of the Ca(OH)2-coating can be a useful and effective addition to the common successfully used calcium phosphate (CaP)-coatings with proven, good proosseointegrative properties in load-bearing implants. In summary, it can be stated that the results of the in vitro investigation can generally be considered supported through the in vivo tests in the range of 0 -100 CFU. However, the reliability of the effect caused by Ca(OH)2 decreases as the CFU number increases, so further series of tests make sense.

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No description available.

It is well known that lead is toxic. Since the full effects, particularly of long term, low level exposure are not well understood, further knowledge of lead metabolism has significant public health implications. Traditionally, clinical studies of lead's effect on health have relied heavily on blood lead levels as an indicator of lead exposure. However, this is unsatisfactory, because blood lead levels principally reflect only recent exposure and lead in serum is more readily bioavailable than whole blood. Over 90% of the lead body burden is in bone, where it has a long residence time. Therefore, bone lead measurements are reflective of cumulative exposure. The bone lead detection system at McMaster University uses a ¹⁰⁹Cd source, which is positioned at the centre of the detector face (HPGE). This arrangement allows great flexibility, since one can sample lead in a range of different bone sites due to a robust normalization technique that eliminates the need to correct for bone geometry, thickness of overlying tissue, and other related factors. Lead in both the tibia and the calcaneus, whole blood lead, and serum lead have been measured in a group of 49 active lead workers (Nova Pb bone lead survey). Before studying the interrelationships between the above measurements, work was done to improve the programs which fit the bone lead spectra. That is, work was done to link the amplitudes of the alpha and beta peaks and to investigate the sensitivity of the analysis on the channel ranges and start parameters. The main goal of this project was to carefully study the interrelationships between the major components of any human lead metabolism model, bone, whole blood, and serum, in order to establish a solid basis for computer modelling of lead metabolism. / Thesis / Master of Science (MSc)

This thesis examined the function of the urinary bladder in vivo in the freshwater rainbow trout. In the first part of the study two new techniques were developed to examine the possible urine storage and ionoregulatory roles of the bladder in vivo. An indirect approach, using non-catheterized fish, involved "spot sampling" from the bladder to determine urine composition, and measurement of the appearance of ^3H polyethylene glycol-4000 (a glomerular filtration marker) in surrounding water to quantify urination events. The direct approach employed a new external catheterization technique to collect naturally discharged urine. Both methods demonstrated that resting trout urinate in intermittent bursts at 20-30 min intervals, and that natural urine flow rate (U.F.R.) is at least 20 % lower and urinary Na^+ and Cl^- excretion rates at least 40% lower than determined by the traditional internal bladder catheter technique. The urine is stored for approximately 25 min prior to discharge, and significant reabsorption of water and ions (Na^+, Cl^-, K^+, urea, and possibly other substances) occurs via the bladder epithelium during this period; a small residual volume is likely always maintained. The second part of the study employed the new external catheter and the traditional internal catheter to quantify the responses of the bladder, relative to those of the kidney, to two experimental disturbances. Chronic (32 h) infusion with 140 mM NaCl produced isosmotic volume loading without a change in plasma [Na^+], [Cl^-], or acid-base status. The kidney responded with a large increase in glomerular filtration rate (G.F.R.), a smaller increase in U.F.R., and increased reabsorption of water and ions. The bladder responded with a small increase in urination burst volume, a larger increase in burst frequency, and therefore a decreased urine storage time. Despite this increased throughput, Na^+ and Cl^- reabsorption rates across the bladder epithelium actually increased. Reabsorption of urea and K^+ remained constant, despite expected decreases due to decreased urine storage time. A similar infusion with 140 mM NaHCO_3 produced isosmotic volume loading together with metabolic alkalosis reflected m increased blood pH, increased plasma [HCO_3^-], decreased plasma [Cl^-], with no change in plasma [Na^+]. The response of the kidney was similar, though HCO_3^- filtration, reabsorption, and excretion rates all increased, while rates for Cl^- were proportionately lowered; renal Na^+ handling was unaffected. Bladder urination patterns and Na^+ reabsorption were also similar, but there was no evidence of bladder involvement in HCO_3^- secretion or reabsorption (ie. in acid-base regulation). It is concluded that previous studies using internal catheterization have greatly underestimated the ionoregulatory effectiveness of the entire renal system by negating bladder function. The external catheterization technique developed in this thesis provides researchers with a method to collect naturally vented urine, and thereby evaluate the role of the entire renal system, including the bladder, in response to experimental manipulations. / Thesis / Master of Science (MS)

The use of polymeric biomaterials in regenerative medicine and drug delivery is a continually growing practice. Alginic acid (alginate) is widely used in these fields because of its beneficial properties from an engineering and mechanical perspective. Still, alginate has not yet been fully investigated from a biological perspective. For disciplines that anticipate in vivo use of their devices, it is crucial to understand the biological interactions between the device and the host. In this project, the in vitro and in vivo immunological effects of alginate are examined in two model systems: one with a protein antigen and one with a xenogeneic cell antigen. The former system is used as a proof of principle study for alginate's immunological effect on simple protein-based systems, similar to those found in protein/drug deli very applications and certain types of vaccines. This model uses bovine serum albumin (BSA) as the protein antigen. The latter system is used to demonstrate alginate's effect on more complex antigens, such as whole cells. Thus, Chinese hamster ovary (CHO) cells are used as the as the cell antigen. This model represents a system that may be found in tissue engineering applications, where whole cells are delivered with a biomaterial scaffold. Antibody production from blood serum indicated that alginate solution has adjuvant abilities while alginate microspheres do not. Thus, alginate solution possesses great potential in the field of vaccines. In addition, in vivo alginate challenges were found to have effects on second-set responses of splenocytes to in vitro alginate and antigen challenges. Splenocytes from alginate-injected mice were overall equally or less responsive to in vitro challenges than splenocytes without previous alginate immunization. Therefore, alginate solution may also have immunosuppressive effects, although the results from this project merely speculate on this possibility. Still, this ability would be helpful in overcoming current transplantation problems as well as certain tissue engineering hurdles. / Thesis / Master of Science (MS)