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The purpose of this study was to investigate the alterations and relationships among training variables, performance variables, and physiological variables. Nine (9) D-1 collegiate throwers and 4 control subjects participated in the study. The throwers participated in an 11-week periodized resistance training and throws program. Volume load was recorded throughout the study. Measurements of maximal strength (isometric mid-thigh pull), vertical jumping ability, dynamic mid-thigh pulls (across a spectrum of loads), hormones (testosterone and cortisol), and adipokines (adiponectin, leptin, and resistin) were taken at weeks 1, 7, and 11. The throwers demonstrated several statistically significant alterations over time for performance variables. The throwers realized increases across time in maximum strength and peak power output. Hormone values did not exhibit statistically significant changes across time; however, there were trends across time for cortisol, the testosterone:cortisol ratio and adiponectin. These alterations would indicate a more anabolic environment and less obesity associated inflammation.

The magnitude of improvements in muscular strength and size are influenced by the volume and intensity of a resistance training program. While it is clearly advantageous for resistance-trained individuals to utilize programming specific to these goals, it not clear which is more important. Therefore the purpose of the present investigation was to determine the effect of focusing on training volume versus intensity on changes in muscle size and strength. Changes in muscular strength and size were examined in 29 resistance-trained men following 8 weeks of resistance training. Participants were randomly assigned to either a high volume (VOL, n = 14, 4 x 10 – 12RM, 1min rest) or high intensity (INT, n = 15, 4 x 3 – 5RM, 3min rest) resistance training program. Lean body mass, lean arm and leg mass, were assessed by dual energy X-ray absorptiometry, while ultrasound images (VL-vastus lateralis, RF-rectus femoris, PM-pectoralis major, and TB-triceps brachii) were used to assess changes in muscle cross-sectional area (CSA) and thickness (MT). Strength was measured by one repetition-maximum (1RM) squat (SQ) and bench press (BP). Changes in muscular (RF & VL) activation in response to increases in submaximal SQ intensity (40-, 60-, 80-, & 100%-1RM) were assessed via surface electromyography. Blood samples were collected at baseline, immediately post, 30min post, and 60min post-exercise at week 3 (WK3) and week 10 (WK10), to assess plasma/serum testosterone, growth hormone (GH), insulin-like growth factor-1 (IGF1), cortisol (CORT), and insulin. Area under the curve analysis revealed a greater (p < 0.05) increase for VOL (WK3: GH & CORT; WK10: CORT) compared to INT. Compared to WK3, WK10 showed reduced responses for VOL (GH and CORT) and INT (IGF1). Significant group differences were observed for changes in lean arm mass (INT: 5.2 ± 2.9%, VOL: 2.2 5.6%) and BP 1RM (INT: 14.8 ± 9.7%, VOL: 6.9 ± 9.0%). Over the course of 8 weeks, our data indicate that trained men would benefit more when focusing on training intensity, rather than volume, for strength and size improvements.

To gain a better understanding of the role of steroid hormones in vertebrate reproduction, we quantified steroid hormone concentrations in a free ranging population of the Northern Pacific rattlesnake, Crotalus oreganus. Plasma steroid hormone concentrations were quantified for both male and female snakes throughout the active season (Mar-Oct). We measured testosterone (T), 5α-dihydrotestosterone (DHT), and corticosterone (B) concentrations in male and female snakes. 17β-estradiol (E2) and progesterone (P) were measured in females only. We also observed breeding behaviors (e.g. consortship, courtship, and copulation) in the field and measured testis and follicle size in male and female snakes from museum collections. Our results indicate that C. oreganus in central California utilizes a bimodal pattern of breeding, with mating and agonistic behavior occurring in the spring and the late summer/fall. Each breeding season corresponds with elevated or highly variable androgen (T and DHT) levels. Several female snakes had high E2 concentrations in the spring and fall, coincident with vitellogenesis and mating. Females with high E2 concentrations also had high T and DHT concentrations. Corticosterone concentrations in males are not related to either time of year or concentrations of any other hormones quantified. This suggests that the breeding season in this population may not demand a significant increase in energy mobilization by glucocorticoids. Measurements of testis volume show that testes are regressed in the spring when the majority of breeding was observed in this population and reach peak volume in August and September during spermatogenesis. Multiple regression analyses revealed that in female snakes, P is positively correlated with T and DHT, and E2 is correlated with T. Since these results are strictly descriptive, experimental studies are needed to identify the functional significance of these results.

Klinefelter syndrome (KS) (47,XXY) is the most common sex chromosomal anomaly in males with a prevalence of 1 in 650 males. This clinically relevant condition represents 3%-4% of the total patient population in male reproductive medicine practices. Klinefelter syndrome can manifest in different physical, cognitive, and behavioral phenotypes. The classical phenotypic descriptions are gynecomastia, hypotonia, tall stature, and hypogonadism. Currently there is no known treatment plan for adolescents who are diagnosed with this genetic condition. However, it has been hypothesized that early intervention through androgen replacement therapy can emulate a normal progression of puberty and improve the academic, social, and behavioral aspects of these adolescents. Using standardized instruments, in the form of the Children Behavior Checklist (CBCL) and the Youth Self Report (YSR), we captured data on the patient’s competence and behavior, as well as the parents’ views on their child’s competence and behavior. These data were converted into percentile scores, T scores, and categorical data (normal, intermediate, and clinical). Difference of means was used to test for statistically significant differences between the scores of the KS patients and their parents on competence and behavioral aspects. T test for equality of means was run to determine if there was a significant difference between group scores. Pearson correlation tests were done to see if there was an association between demographics of patients and competence/behavioral scores. We believed that there would be no statistically significant difference between how the parents score their child in the CBCL and how the child scores himself in the YSR in terms of demographics. We also believed that there would be no statistically significant difference or correlation between demographics and individual competence/behavioral scores. A total of 39 groups of surveys were collected, together with demographic information on the maternal and paternal ages when the child was born, patient age, patient age when starting testosterone, patient age when starting anastrazole, and patient height and weight. We examined concordance frequencies in specific areas of the competence and behavioral questionnaires. Concordance was when the parent and the child agreed and evaluated the child as normal, intermediate, or clinical. Discordance was when the parents and the child disagreed; for example, the parent evaluated the child as “clinical,” but the child evaluated himself as “normal.” This study, to our knowledge, is the first chart review study that involves a wide age range of males with KS. The study extends previous findings by providing data on how early hormonal intervention can improve the outlook of these patients’ lives. When taking aromatase inhibitors, the KS adolescents showed an overall reduction of aggression and rule-breaking behavior. When taking testosterone at an earlier age, the patient was less likely to have withdrawal depression. We also found the most discordance in total competence scores, suggesting that some parents may have unrealistic academic expectations for their child. Thus, when examining the data, we had to be aware that there were varying views of success, which can shape how parents and child answer their respective surveys. Our findings demonstrate the significance of early detection and treatment of Klinefelter syndrome, a disorder that is severely under-diagnosed throughout the world. The results also show that the desire of parents for their KS child to do well in school may affect their opinions on how their child is actually performing. Some limitations to this study include the decision to receive early hormonal intervention that was made exclusively between parents and their urologist. Furthermore, the socioeconomic status (SES) and educational characteristics of the families were not properly controlled, although the patient population was mostly likely similar because of the location of the clinic. Future Klinefelter syndrome studies will need to focus on identifying the factors that contribute to the variability of behavioral symptoms. In turn, these studies will support the continuing development of evidence-based treatments for adolescents with Klinefelter syndrome.

Green anoles are small lizards of the Southeastern United States. They possess an extensible throat-fan called a dewlap. Males have larger dewlaps and display them more often than females. Displays occur during courtship, during agonistic interaction, and during encounters with potential predators. The size of the dewlap of male green anoles is positively correlated with maximum bite force capacity. Bite force capacity, in turn, is predictive of the winner during agonistic interactions. The correlation between these traits suggests that dewlap size may be used as a reliable signal of maximum bite force capacity. In this dissertation, I address three components of this system. First, I manipulate dewlap size and stage interactions between male green anoles. By removing the correlation between dewlap size and bite force, I was able to show that during staged encounters, bite force is predictive of the winner, but dewlap size is not. In the second chapter, I test for potential costs due to an increased predation risk as a result of dewlap displays. I observed no difference in recapture rates between animals that were experimentally prevented from extending their dewlaps and control counterparts. However, other data suggest that the presence of a pink dewlap may increase risk of predation. These results suggest that though there may be a predation-based cost to dewlap displays, green anoles use behavioral means to ameliorate this risk. Finally, I use a castration and hormone-replacement experiment to test whether testosterone mediates seasonal changes in dewlap size and bite force. I hypothesized that testosterone would mediate changes in both traits in order to maintain the correlation between them. However, I found no effect of testosterone on change in dewlap size or bite force performance. Another trait, sprint speed performance, was affected by hormone treatment in the breeding season such that animals with high levels of testosterone ran faster than animals from the other treatment groups. My results corroborate other research showing that hormones regulate plasticity in some systems, while other systems are insensitive. However, the mechanisms that regulate changes in the two components of the reliable signaling system in green anoles remain unknown.

(1) Background: From a young age, boys are more often affected by tooth wear than girls. This suggests an influence of the male sex hormone (testosterone) on the aetiology of tooth wear. The aim of the present study was to investigate the incidence of tooth wear in relation to steroid hormone levels in children. (2) Methods: 1022 test persons aged between 10 and 18 (491 male, 531 female) from the LIFE Child study underwent medical and dental examination. Tooth wear was measured through clinical inspection. Blood samples were taken to determine hormone levels (testosterone, SHBG). The level of free testosterone was calculated from the ratio of testosterone to SHBG. Using multivariable methods, the incidence of tooth wear was analyzed as a function of hormone levels, while controlling for confounders such as age, sex, social status, and orthodontic treatment. (3) Results: The incidence of tooth wear increased with age in both sexes. Boys showed significantly more often attrition facets than girls (17.5% vs. 13.2%, p < 0.001). Subjects with tooth wear showed significantly higher free testosterone levels than those without (males: p < 0.001, females: p < 0.05). After controlling for confounding variables, the risk of tooth wear increased by approximately 30.0% with each year of life (odds ratio [OR]boys = 1.29, 95% confidence interval [CI] = 1.04–1.56; [OR]girls = 1.32, 95% CI = 1.08–1.61). In addition, the risk of tooth wear increased by 6.0% per free testosterone scale score only in boys (OR = 1.06, 95% CI = 1.01–1.12). (4) Conclusions: Tooth wear is common in children and in adolescents, and it increases steadily with age in both sexes. The stronger increase and the higher prevalence among male adolescents can be explained by the additional effect of free testosterone.

No description available.