Previous studies have found that smoking may have a negative effect on vitamin B-6 indices and have demonstrated a possible association between smoking and depressed plasma pyridoxal-5'-phosphate (PLP) concentration. Individuals with plasma PLP values below the adequate level of 30 nmoles/L might benefit from consumption of vitamin B-6 supplements, but no data are available on vitamin B-6 status in smokers consuming a controlled vitamin B-6 intake and receiving a vitamin B-6 supplement. The objectives of this research were to assess vitamin B-6 status in smokers as compared to non-smokers receiving a controlled diet and to evaluate the effect of an oral vitamin B-6 supplementation in these subjects. The vitamin B-6 (B-6) status of 5 (four males / one female) smokers (S) and 4 (three males / one female) non-smokers (NS) was assessed. A constant diet was fed for 20 days and provided 1.95 mg of B-6 or 1.65 mg of B-6 for males and females, respectively. For the last 10 days, an additional 2-mg of pyridoxine (PN) was given daily. Blood samples were collected on days 1.7, 11.14 and 21; and 24 hour urine samples were collected daily. Urinary 4-pyridoxic acid (4-PA) and total B-6 (UB6) excretion, plasma B-6 vitamers (PLP, PN, pyridoxal and 4-PA) and red blood cell PLP (RBC PLP) concentrations, as well as plasma alkaline phosphatase activity (APA) were determined. Mean plasma PLP, 4-PA, and RBC PLP concentrations were significantly lower (P [less than or equal to] 0.05) at all time points in S compared to NS. With a daily supplement of 2-mg vitamin B-6, the mean plasma PLP concentration of S increased 85.8% but was 48.5% lower than that of NS consuming 1.65-1.95 mg/d of B-6. Mean plasma pyridoxal concentrations were not different between S and NS before and after supplementation. Excretion of 4-PA was not significantly different between S and NS, but the mean values of 4-PA excretion were consistently greater in NS compared to that of S throughout the 20-day study. The percent of ingested B-6 excreted as 4-PA for the S and NS was 38 and 49 in the non-supplemented period, and 47 and 53 in the supplemented period, respectively, indicating that non-smokers excreted more 4-PA than smokers. However, the difference in 4-PA excretion between S and NS was not significantly different both before and after supplementation (P>0.05). In addition, there was no significant difference between S and NS for plasma PN concentration, AP, and UB6 excretion for both periods. Results suggested an adverse effect of smoking on B-6 metabolism, thus an increased requirement of vitamin B-6 in smokers. A 2-mg PN supplement was sufficient to bring the concentration of plasma PLP in smokers to the level suggested as adequate, but it didn't bring it to the level of non-smokers. / Graduation date: 1999

Graduation date: 1994

No description available.

The influence of vitamin C on the pharmacokinetics of caffeine was investigated in ten elderly males, age 66 to 86 years. Caffeine (4 mg kg⁻¹) was administered intravenously on three different occasions over a seven-week period: before vitamin C restriction, after approximately four weeks of vitamin C restriction (15 mg dietary intake per day), and after two weeks of vitamin C supplementation (500 mg orally, twice daily). Blood and urine samples were collected over a 48-hour period following each caffeine administration. The plasma half-life (t₁/₂), rate constant of elimination (K), apparent volume of distribution (V), total body clearance (TBC), renal clearance (RC), and metabolic clearance (MC) of caffeine were determined. Simultaneous plasma (PVC), whole blood (WBVC), and leukocyte (WBCVC) vitamin C concentrations were obtained. All of the mean vitamin C values determined at the first kinetic trial (KT-1) were within the normal ranges for the respective biologic fluid or tissue. All of the mean vitamin C values changed significantly during the study; decreasing to below the normal ranges by the second kinetic trial (KT-2) following dietary vitamin C restriction, and increasing to the normal ranges by the third kinetic trial (KT-3) following vitamin C supplementation. All of the decreases and increases in the individual and average vitamin C concentrations paralleled the observed decreases and increases in the daily vitamin C intake. None of the caffeine pharmacokinetic parameters evaluated changed significantly during the study. The mean rate constant of elimination was approximately 0.15 hr⁻¹, the average plasma half-life was approximately 4.5 hours, and the mean apparent volume of distribution was approximately 500 ml kg⁻¹ for all three kinetic trials. The average total body, renal, and metabolic clearances were approximately 76.9, 1.3, and 76.0 (ml hr⁻¹)kg⁻¹, respectively, for all three kinetic trials. With the exception of V and TBC, the various pharmacokinetic characteristics investigated were in general agreement with data reported for younger subjects. The average apparent volume of distribution determined at any of the kinetic trials was about 16% lower than the value reported for young, healthy subjects. Similarly, the mean total body clearance observed was about 21% lower than that observed in young, healthy subjects. Since the average elimination rate constant observed in these elderly subjects is similar to the values observed in younger subjects and since TBC is equal to the product of V times K, the reduced TBC observed in this study appears to be due to the reduction in V, rather than to a decrease in the intrinsic metabolic capacity of the liver with aging. No relationship between vitamin C intake and/or body levels and the pharmacokinetics of caffeine was observed. These results indicate that the elimination of caffeine in the elderly is not affected significantly by the concentrations of vitamin C achieved during the study.

No description available.

The purpose of this study was to examine collegiate female swimmers' attitudes toward gender and coaching. The study also examined the coaching styles of male and females coaches and determined whether a difference between styles existed. A purposeful sample of 250 female swimmers from the Mid-American Conference (MAC) during the 2001-2002 swimming season participated in the study. Swimmers were required to have been coached by both female and male coaches in order to be eligible to participate. Addressing the purpose of this study, participants were asked to complete a 30-item questionnaire developed by the researcher. Frequency counts revealed that 23 of the 57 participants preferred a male coach to a female coach. Only two individuals reported their preference for a female with 32 participants citing no gender preference. Two sections, including 14 questions for each gender on the Gender Preference Instrument, assessed coaching style. Independent t -tests were calculated on each question (p < .05). Eight significant gender differences were observed on coaching styles, with the participating athletes scoring the male coach higher on all of the eight categories. / School of Physical Education

No description available.

Graduation date: 2004

During extreme exercise, athletes experience increased inflammation that is similar to the acute phase response. Endurance athletes, distance runners in particular, are also more susceptible to compromised iron stores. This study evaluated inflammation, immune function and iron status in athletes completing a 50K ultramarathon. Twenty-two well-trained distance runners, 11 males and 11 females, were randomized in a double blind manner into--1) those who consumed 300 mg vitamin E and 1000 mg vitamin C (500 mg twice daily) or 2) placebos--for six weeks before and one week following a 50K ultramarathon race. Blood samples were obtained on 13 separate occasions throughout the study: before supplementation, during supplementation, the day before the race, pre-race, mid-race, immediately post-race, 2 hours following the race, and daily for six days following the race. Plasma levels of ascorbic acid and ��-tocopherol were measured by HPLC with electrochemical detection. Inflammatory cytokines, interleukin-6 (IL-6), tumor necrosis factor-�� (TNF-��), and interleukin-1�� (IL-1��) were measured using standard clinical assays. Each subject recorded immune function in an activity log and incidence of illness was tabulated as number of days ill. Ferritin was measured by enzyme immunoassay. Hemoglobin, hematocrit, and total-iron binding capacity (TIBC) and serum total iron were analyzed by standard procedures. Plasma concentrations of ascorbic acid and ��-tocopherol increased significantly in supplemented subjects (p<0.0001). Although the ultramarathon race elicited an inflammatory response, antioxidant supplementation did not alter the responses of IL-6 and TNF-��, which both increased from pre-race to mid-race, post- and post-2 h (Scheffe post-hoc analysis, p<0.0001) and returned to pre-race concentrations by 1 day after the race. Male supplemented subjects had lower IL-1�� concentrations compared to females consuming the supplement or to males consuming the placebo (ANCOVA, gender/time/treatment interaction; p<0.01) at mid-race (p<0.05 females, p<0.005 males), post 1 and 2 days (all p<0.002). Males had significantly higher ferritin levels than the female subjects (ANOVA, p<0.0001); supplementation resulted in lower ferritin concentrations at post-5 days (p<0.02, ANCOVA treatment time interaction, p<0.005). Supplementation did not reduce the days illness among those consuming antioxidants compared to those consuming the placebos. Ferritin not only increases during inflammation, it also is a measure of iron stores. Females had significantly lower levels of iron than the male subjects for each of the iron parameters measured (hemoglobin and hematocrit both p<0.0001, ferritin p<0.001, TIBC p<0.02) excluding serum total iron. The ferritin concentrations measured in the women were indicative of depleted iron stores (<12 ��g/l), and antioxidant supplementation increased hematocrit levels in the female subjects (p<0.05). This investigation indicates that female distance runners need to be aware of an increased susceptibility to iron depletion compared to their male counterparts. Antioxidant supplementation improved hematocrit levels (p<0.05) among female runners and may improve iron status among females with depleted stores. Although other investigations have suggested that antioxidant vitamins decrease exercise induced inflammation, no profound benefit of supplementation was found in this investigation though a response similar to the acute phase response was elicited by the ultramarathon race. Improvements in IL-i and ferritin in response to antioxidant supplementation may indicate that the supplementation was beneficial, but more research is needed to draw definitive conclusions. / Graduation date: 2003

Two studies were conducted to determine the effect of varying vitamin B-6 (B- 6) status on lymphocyte mitogenic response and pyridoxal 5'-phosphate (PLP) concentration in peripheral blood mononuclear cells (PBMC) in young women. In the first study, women were fed 1 mg/d for the first week and 1.5, 2.1 and 2.7 mg/d during 2 weeks of each of the subsequent 3 experimental periods. Plasma PLP and urinary 4: pyridoxic acid (4-PA) were increased with increasing B-6 intake. B-6 intake > 2.1 mg significantly enhanced lymphocyte proliferation, and non-significantly increased plasma interleukin-2 concentration. Lymphocyte proliferation was significantly correlated with B-6 intake, erythrocyte aminotransferase activity coefficients and plasma PLP. PBMC PLP tended to increase after 2 weeks of 2.7 mg B-6 intake, and was significantly correlated with plasma PLP. In the second study, women consumed their normal diets whose estimated mean dietary B-6 intake was 0.9 mg for 27 d. For the last 20 d, all subjects were given a multivitamin supplement containing 1.8 mg B- 6, and half of the subjects were given an additional 50 mg of B-6 supplement. Plasma PLP and urinary 4-PA were significantly higher in the group with 50 mg B-6, but lymphocyte proliferation did not significantly differ between the groups. After 10 d of supplementation, lymphocyte proliferation was significantly higher than the other time points. A significant increase in PBMC PLP was observed after 3 days and 20 days following 50 mg and multivitamin supplementation only, respectively. After 20 days of supplementation, there was no significant difference of mean PBMC PLP between the groups. PBMC PLP was significantly correlated with plasma PLP, PL and 4-PA. In both studies, no strong relationship was found between PBMC PLP and lymphocyte proliferation. The findings from these studies demonstrate no further benefit of a higher B-6 intake than 2.1 mg on lymphocyte mitogenic response, once the response was significantly enhanced with B-6 intake 0.8 mg higher than the current recommendation. Finally, results from two studies suggest that the current recommendation of vitamin B-6 for young women may not be adequate to maximize lymphocyte mitogenic response and PLP concentration in PBMC. / Graduation date: 2002