Flaxseed oil (FO), rich in α-linolenic acid, has been shown to inhibit breast cancer growth. One suggested mechanism is through modulation of HER2 expression and signalling. This study determined the effect of FO on the growth of established HER2-overexpressing breast tumours (BT-474) and its interaction with two doses of a primary anti-HER2 therapy, trastuzumab (TRAS), in athymic mice. FO alone had no effect on tumour size, cell proliferation and apoptosis. TRAS (2.5 and 5 mg/kg) reduced tumour size and cell proliferation but had no effect on apoptosis. TRAS (2.5 mg/kg) combined with FO reduced tumour size and cell proliferation and increased apoptosis compared to TRAS (2.5 mg/kg) alone and was just as effective as 5 mg/kg TRAS. TRAS (5 mg/kg) resulted in almost complete tumour regression with or without FO. In conclusion, FO has no effect on BT-474 tumour growth but can enhance the effectiveness of low dose TRAS.

Flaxseed oil (FO), rich in α-linolenic acid, has been shown to inhibit breast cancer growth. One suggested mechanism is through modulation of HER2 expression and signalling. This study determined the effect of FO on the growth of established HER2-overexpressing breast tumours (BT-474) and its interaction with two doses of a primary anti-HER2 therapy, trastuzumab (TRAS), in athymic mice. FO alone had no effect on tumour size, cell proliferation and apoptosis. TRAS (2.5 and 5 mg/kg) reduced tumour size and cell proliferation but had no effect on apoptosis. TRAS (2.5 mg/kg) combined with FO reduced tumour size and cell proliferation and increased apoptosis compared to TRAS (2.5 mg/kg) alone and was just as effective as 5 mg/kg TRAS. TRAS (5 mg/kg) resulted in almost complete tumour regression with or without FO. In conclusion, FO has no effect on BT-474 tumour growth but can enhance the effectiveness of low dose TRAS.

Caffeine has been implicated in a number of health conditions, but the mechanisms and physiological pathways affected are not all well understood. Genetic variation in the caffeine metabolizing gene, CYP1A2 (rs762551), is associated with differences in caffeine metabolism and disease risk. The objectives of this thesis were to determine the association between caffeine intake and the plasma proteome and whether CYP1A2 genotype modifies any associations. Subjects (n=1095) were from the Toronto Nutrigenomics and Healthy Study. Initially, no significant associations were seen between caffeine intake and 54 high-abundance plasma proteins. After stratification by CYP1A2 genotype, plasma gelsolin levels decreased significantly with increasing caffeine intake among the slow metabolizers (A/C +C/C). These results suggest that plasma gelsolin levels are affected by caffeine intake and this association is only evident among slow metabolizers. Gelsolin may have a role in mediating some of the biological effects of caffeine.

Caffeine has been implicated in a number of health conditions, but the mechanisms and physiological pathways affected are not all well understood. Genetic variation in the caffeine metabolizing gene, CYP1A2 (rs762551), is associated with differences in caffeine metabolism and disease risk. The objectives of this thesis were to determine the association between caffeine intake and the plasma proteome and whether CYP1A2 genotype modifies any associations. Subjects (n=1095) were from the Toronto Nutrigenomics and Healthy Study. Initially, no significant associations were seen between caffeine intake and 54 high-abundance plasma proteins. After stratification by CYP1A2 genotype, plasma gelsolin levels decreased significantly with increasing caffeine intake among the slow metabolizers (A/C +C/C). These results suggest that plasma gelsolin levels are affected by caffeine intake and this association is only evident among slow metabolizers. Gelsolin may have a role in mediating some of the biological effects of caffeine.

Master of Science / Department of Animal Sciences and Industry / K C Olson / Our objective was to evaluate the effects of pre- and post-partum bolus injections of a trace mineral solution on beef cow reproductive performance, body weight (BW) change, and body condition score (BCS) change and on performance of suckling calves. Mature beef cows (n = 460; initial BW = 497 ± 89 kg, initial BCS = 5.4 ± 0.74) were stratified by BCS, parity, and predicted calving date and assigned randomly to 1 of 2 treatments: 1) subcutaneous trace mineral (TM) injection containing 15 mg/mL Cu, 5 mg/mL Se, 10 mg/mL Mn, and 60 mg/mL Zn or 2) subcutaneous injection of physiological saline (SA). Injections were administered to cows (1 mL / 90 kg BW) 105 days before the first projected calving date and again 30 days before fixed-time AI. Calves received the same treatment as their dams and were injected (1 mL / 45 kg BW) at birth and again at 71 ± 21 days of age. Cows grazed native pastures for the duration of the study; trace mineral supplements and white salt were available to all cattle ad libitum before and during the study. Ovulation was synchronized using a 5-d CO-Synch + CIDR protocol and cows were inseminated 60 to 64 hours after CIDR removal. Cows were exposed to fertile bulls for natural-service breeding 10 days after AI for 35 to 50 days. Conception to AI and final pregnancy rate were assessed 36 days after AI with ultrasound and 120 days after AI via rectal palpation. Change in BW and BCS from initiation of the study to calving and from AI to weaning did not differ (P ≥ 0.15) between TM and SA cows. Conversely, TM cows had greater (P = 0.04) BCS increase than SA cows between calving and AI. Calf BW at birth, ADG, and age-adjusted weaning BW did not differ (P ≥ 0.36) between treatments. Proportion of cows with estrus cycles 17 and 8 days before ovulation synchronization was similar (P ≥ 0.51) between treatments. Conception to AI was greater (P = 0.05) for cows receiving TM (60.2%) than for cows receiving SA (51.2%); however, overall pregnancy did not differ (P = 0.24) between treatments and averaged 92%. Under the conditions of our study, pre- and post-partum TM injections improved conception to fixed-time AI by beef cows.

Blood CORT is commonly used to assess stress in rodents, but sampling can trigger a rapid stress response. This study aims to identify whether faecal CORT metabolites (FCM) can reflect changes in CORT induced by 7-day food restriction (FR) and an ACTH challenge. Blood and 24hr faecal samples were collected at baseline and Day 7 for control (n=8) and FR (n=10) rats. On Day 8, after a baseline blood sample, an ACTH injection was administered and followed by blood and fecal sampling. Results showed increased serum CORT and FCM in response to FR. Increased adrenal sensitivity with FR was illustrated by a greater increase in serum CORT compared to control in response to ACTH. Lastly, although it appeared that ACTH induced an increase in FCM in FR and control, only the latter reached statistical significance. Thus FCM might be better suited for quantifying chronic rather than acute changes in CORT.

Blood CORT is commonly used to assess stress in rodents, but sampling can trigger a rapid stress response. This study aims to identify whether faecal CORT metabolites (FCM) can reflect changes in CORT induced by 7-day food restriction (FR) and an ACTH challenge. Blood and 24hr faecal samples were collected at baseline and Day 7 for control (n=8) and FR (n=10) rats. On Day 8, after a baseline blood sample, an ACTH injection was administered and followed by blood and fecal sampling. Results showed increased serum CORT and FCM in response to FR. Increased adrenal sensitivity with FR was illustrated by a greater increase in serum CORT compared to control in response to ACTH. Lastly, although it appeared that ACTH induced an increase in FCM in FR and control, only the latter reached statistical significance. Thus FCM might be better suited for quantifying chronic rather than acute changes in CORT.

Low vitamin D status has been consistently associated with an increased risk of multiple sclerosis (MS). Further, preclinical and in vitro data demonstrate immune regulatory properties of 1,25-dihydroxyvitamin D that may be beneficial for patients with MS. To date evidence of beneficial in vivo immunomodulation by supplementation with vitamin D3 in humans is lacking. In a one-year, open-label, phase I/II dose-escalation study of vitamin D3 (average ~14,000 IU/d over one year) with calcium (1,200mg/d) in patients with MS, we compared the effects of treatment on safety outcomes, clinical outcomes and selected biomarkers of immune system activity, relative to matched MS patients [age, sex, disease duration, disease modifying therapy, and expanded disability status scale (EDSS)] randomized to receive no supplementation. Mean serum 25(OH)D concentrations were 78.1±27.0 nmol/L at baseline and at one-year were 82.7±34.8 and 179.1±76.1 nmol/L in control and treated groups, respectively. Serum and urinary calcium and all other safety outcomes were unchanged throughout the trial. Compared to controls, treated patients tended to have fewer relapses (McNemar, p=0.09) and a greater proportion had a stable or improved EDSS at study end (p=0.018). We observed significantly reduced lymphocyte proliferative responses to antigenic challenge in the treatment group at one year, compared to baseline and control group responses. High serum 25(OH)D concentrations were not associated with short-term adverse effects in patients with MS, but with evidence of clinical improvement and beneficial immunomodulation.

Low vitamin D status has been consistently associated with an increased risk of multiple sclerosis (MS). Further, preclinical and in vitro data demonstrate immune regulatory properties of 1,25-dihydroxyvitamin D that may be beneficial for patients with MS. To date evidence of beneficial in vivo immunomodulation by supplementation with vitamin D3 in humans is lacking. In a one-year, open-label, phase I/II dose-escalation study of vitamin D3 (average ~14,000 IU/d over one year) with calcium (1,200mg/d) in patients with MS, we compared the effects of treatment on safety outcomes, clinical outcomes and selected biomarkers of immune system activity, relative to matched MS patients [age, sex, disease duration, disease modifying therapy, and expanded disability status scale (EDSS)] randomized to receive no supplementation. Mean serum 25(OH)D concentrations were 78.1±27.0 nmol/L at baseline and at one-year were 82.7±34.8 and 179.1±76.1 nmol/L in control and treated groups, respectively. Serum and urinary calcium and all other safety outcomes were unchanged throughout the trial. Compared to controls, treated patients tended to have fewer relapses (McNemar, p=0.09) and a greater proportion had a stable or improved EDSS at study end (p=0.018). We observed significantly reduced lymphocyte proliferative responses to antigenic challenge in the treatment group at one year, compared to baseline and control group responses. High serum 25(OH)D concentrations were not associated with short-term adverse effects in patients with MS, but with evidence of clinical improvement and beneficial immunomodulation.

Doctor of Philosophy / Department of Animal Sciences and Industry / James S. Drouillard / Two trials were conducted to evaluate the effects of crude glycerin in feedlot cattle. The objectives of this research were to determine the effects of crude glycerin on animal performance, carcass characteristics, ruminal metabolism, and diet digestibility when fed in steam-flaked corn finishing diets. Trial one utilized crossbred heifers (n = 373) fed finishing diets containing 0, 2, 4, 8, 12, or 16% crude glycerin. Feeding heifers crude glycerin at 8% or less of the diet resulted in improvements in body weight gain and feed efficiency. Dry matter intake decreased linearly (P < 0.001) when glycerin was included at increasing levels from 0 to 16%. Average daily gains of heifers fed crude glycerin increased when glycerin was fed at 2, 4, or 8% of diet DM, but reductions in ADG were noted when glycerin increased to 12 or 16% (linear, P = 0.013; quadratic, P = 0.010). Feeding glycerin had a quadratic effect on G:F, and was optimal when fed at 2% of DM (P = 0.46). Hot carcass weights increased when glycerin was fed at 2, 4, and 8% of the diet, but decreases in HCW were observed with 12 and 16% crude glycerin (linear, P = 0.009; quadratic, P = 0.006). Low concentrations of glycerin can be fed without negatively impacting animal performances. Trial two consisted of a 3 × 3 Latin Square and utilized cannulated crossbred steers (n = 9) fed finishing diets containing 0, 2, or 4% crude glycerin. Apparent total tract digestibilities of DM, OM, starch, CP, and crude fat were unaffected by the addition of glycerin at 0, 2, or 4% of cannulated steer diets (linear, P > 0.51). Apparent total tract digestibilities of NDF tended to decrease as glycerin concentrations increased to 2 and 4% (linear, P <0.13). Ruminal pH increased as glycerin concentrations increased (linear, P < 0.05), and concentrations of butyrate and valerate decreased (linear, P < 0.03). Acetate production also tended to decrease when glycerin increased from 0 to 2 or 4% of the diet (linear, P =0.06). Collectively, these results suggest that glycerin may negatively influence fiber digestion.