Relationship between physical activity and resting secretory immunity in children

This study examined relationships among physical activity, body fat and salivary immonoglobulin A (sIgA) levels in adolescent children of Southern Ontario. Gender differences on these factors were also assessed. Sixty-one grade-five students (10-1 lyrs), males (n=29) and females (n=31), who had not received a flu vaccination in the past 12 months, participated in the study. They were assessed for: aerobic power (20-m shuttle run), relative body fat (bioelectrical impedance analysis), sIgA, sIgA/albumin ratio, and salivary Cortisol. Each subject completed the Habitual Activity Estimation Scale and the Participation Questioimaire. Students wore a pedometer for 48h to estimate their average total distance traveled per day. The results show 40% of the children were over 25% body fat and 50% of them spend less than five hours per day in any physical activities. Salivary IgA was not related to salivary Cortisol, physical activity, fitness level or body fat in this age group. There were no gender differences in sIgA and Cortisol levels. Boys had a significantly higher aerobic power and daily distance traveled, but reported similar organized and fi-ee time activity participation levels as the girls. The test-retest reproducibility for salivary Cortisol was 0.663 (p<0.01), while long term sIgA and sIgA/albumin ratio reproducibility was non-significant for repeated measurements taken after six weeks. It was found that salivary IgA has not been shovm to be a stable measure in children, in contrast to the results found in the literatiu-e that tested adults and the relationship with physical activity, fitness level and body fat.

Salivary testosterone and cortisol : role of athletic setting, game outcome, and game location /

Many studies investigating the relationship between hormones and competition have focused on athletic competition. The athletic setting enables r researchers to investigate the hormone-behaviour relationship in a relatively controlled environment. However, research to date has been based on observations made from single status contests and/or weekend tournaments and as such, does not provide a clear picture of an individual's average hormonal responses to both victory and defeat. In appreciation of this limitation, the current study tracked elite hockey players throughout a hockey season, measuring pre- and post-game salivary testosterone and Cortisol as well as psychological measures. I was interested in determining whether status outcome (win vs. loss) would influence an individual's testosterone and Cortisol responses to competition. Furthermore, I was also interested in assessing whether testosterone and Cortisol responses were specific to the competitive environment or whether similar hormonal responses would occur during non-competitive practice sessions. Last, I was interested in whether there were any differences in pre-game hormonal and psychological states depending on where the status contest was held: home versus away. The results indicated that game outcome moderated the testosterone responses to competition. That is, testosterone increased significantly more after a victory compared to a defeat. Furthermore, a loss of status produced significantly hreports, the players did not show an anticipatory rise in either Cortisol or testosterone prior to competition. In addition to the effects of status outcome on hormonal levels, it was also found that these hormonal responses were specific to competition. The athletes in the current study did not demonstrate any hormonal responses to the practice sessions. Last, there were significant differences in pre-game testosterone as well as in selfconfidence, cognitive, and somatic anxiety levels depending on the location at which the status contest took place. Pre-game testosterone and self-confidence levels were significantly higher prior to games played in the home venue. In contrast, pre-game somatic and cognitive anxiety levels were significantly higher prior to games played in the away venue. The current findings add to the developing literature on the relationship between hormones and competition. This was the first study to detect a moderating effect of status outcome on testosterone responses in a team sport. Furthermore, this was also the first study in humans to demonstrate that post-contest Cortisol levels were significantly higher after a loss of status. Last, the current study also adds to the sport psychology literature by demonstrating that pre-game psychological variables differ depending on where the status contest is being held: higher self-confidence at home and higher somatic and cognitive anxiety away. Taken together, the results from the current thesis may have important practical relevance to coaches, trainers and sport psychologists who are always trying to find ways to maximize performance. post-game Cortisol levels than did an increase in status. In contrast to previous

Relationship between photoperiod, plasma concentration of ionic calcium and the histology of the prolactin-secreting cells of the rostral pars distalis of the pituitary gland, the corpuscles of stannius and the ultimobranchial gland in the goldfish, Carassius auratus L. /

The relationship between photoperiod, plasma concentration of ionic calcium and the histology of the prolactin-secreting cells of the rostral pars distalis of the pituitary gland, the Corpuscles of Stannius and the Ultimobranchial gland were investigated. Neither the plasma concentration of ionic calcium nor histologically apparent prolactin cell activity could be correlated with photoperiod. Some evidence of a photoperiodic effect on both the Corpuscles of Stannius and the Ultimobranchial gland was obtained. The expected reciprocal relationship between the activity of these glands was not obvious at the histological level . Quantitative and qualitative analysis at the light microscope level revealed, however, that the hormone prolactin-secreting eta cells of the rostral pars distalis and the hypocalcin-secreting cells of the Corpuscles of Stannius may be arranged in a lamellar pattern comprized of synchronous bands of cells in like-phase of a secretory cycle consisting of four stages - synthesis, storage, release and reorganization. Such synchronized cell cycles in these glands have not heretofore been described in literature. It is suggested that the maintenance of at least 255? of the cells in any one phase of the cycle ensures a supply of the required hormone at all times.

Size regulation of double and half embryos in the mice musculus

Genetic chimeras made by aggregating early mouse embryos have many uses in developmental biology and have also provided insights into embryonic growth regulation. There is an indication that the embryo can regulate for an increase in size because although aggregation chimeras are twice as big as normal embryos when made, they are born of normal size. Upward regula..... tion of size reduced embryos is also possible. Half embryos made by the isolation or destruction of one of the blastomeres of a 2-cell embryo are also born of normal size. Little is known about the timing or the mechanism of this size regulation. In this study, the timing of size regulation in double and half embryos was clearly established by comparison of cell numbers derived from serial reconstruction of light microscope sections of control and experimental embryos. It was shown that size regulation in double embryos occurred around 6dl6h and in half embryos by 7dOh. Size regulation occurred in all tissues at the same time indicating a single control mechanism for the entire embryo. More detailed examination of the growth of double embryos revealed that size regulation occurred by alteration in cell cycle length~ No excessive cell death was found in double embryos compared to the controls and continuous labelling with [3H] thymidine showed no large non-dividing cell population in double embryos. However, a comparison of the mitotic index of double and control embryos after colcemid treatment, revealed a large difference between the two around 5dl6h to 6d16h. During this period, control embryos underwent a proliferative burst not shown by the double embryos. The mechanism for cell cycle control is not clear; it may be intrinsic to the embryo or determined by the uterine environment. Evidence was found suggesting that differentiation in the postimplantation embryo was cell number dependent. The timing of differentiative events was examined in half, double and control embryos. Proamnion formation, which occurs prior to size regulation, occurs at the same cell number but at different times in the three groups of embryos. However mesoderm which appears after size regulation was seen at the same time in all grollps of embryos.

Characterization of black fly (Diptera: Simuliidae) silk proteins

Black fly (Simuliidae) silk is produced by the larvae and pharate pupae and is used for anchorage and cocoon production. There exists limited information on simuliid silks, including protein composition and genetic sequences encoding such proteins. The present study aimed to expand what is known about simuliid silks by examining the silks of several simuliid species and by making comparisons to the silk of non-biting midges (Chironomidae). Silk glands were dissected out of larval and pupal simuliids, and protein contents were separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and visualized with silver stain. Protein contents were compared by mass in kilodaltons (kDa) between life stages and among species. Polymerase chain reaction (PCR) was used to expand upon known gene sequence information, and to determine the presence of genes homologous to chironomid silk. SDS-PAGE of cocoons revealed the presence of a 56 kDa and a 67 kDa protein. Silk gland contained as many as 28 different proteins ranging from 319 kDa to 8 kDa. Protein profiles vary among species, and group into large (>200), intermediate(>100), and small (<100) protein classes as is found in chironomids. It is likely that silk evolved in a common ancestor of simuliids and chironomids

EARLY LIFE EXPOSURE TO GENISTEIN AND DAIDZEIN DISRUPTS STRUCTURAL DEVELOPMENT OF REPRODUCTIVE ORGANS IN FEMALE MICE

In mice, exposure to isoflavones (ISO), abundant in soy infant formula, during the first 5 d of life alters structural and functional development of reproductive organs. Effects of longer exposures are unknown. The study objective was to evaluate whether exposure to a combination of daidzein and genistein in the first 10 compared to 5 d of life results in greater adverse effects on ovarian and uterine structure in adult mice. Thirteen litters of 8–12 pups were cross-fostered and randomized to corn oil or ISO (2 mg daidzein + 5 mg genistein/kg body weight/d) for the first 5 or 10 d of life. The 10-d protocol mimicked the period when infants are fed soy protein formula (SPF) but avoids the time when suckling pups can consume the mother’s diet. Body and organ weights and histology of ovaries and uteri were analyzed. There were no differences in the ovary or uterus weight, number of ovarian follicles, number of multiple oocyte follicles, or percent of ovarian cysts with 5 or 10 d of ISO intervention compared to respective controls. The 10-d ISO group had higher body weights from 6 d to 4 mo. of age and a higher percent of hyperplasia in the oviduct than the respective control. Lower numbers of ovarian corpus lutea and a higher incidence of abnormal changes were reported in the uteri of both ISO groups compared to their respective controls. Five- and 10-d exposure to ISO had similar long-lasting adverse effects on the structures of ovaries and uterus in adult mice. Only the 10-d ISO exposure resulted in greater body weight gain at adulthood.

Associations Between Personal Cancer History and Lung Cancer Risk

The study aim was to investigate the relationship between factors related to personal cancer history and lung cancer risk as well as assess their predictive utility. Characteristics of interest included the number, anatomical site(s), and age of onset of previous cancer(s). Data from the Prostate, Lung, Colorectal and Ovarian Screening (PLCO) Cancer Screening Trial (N = 154,901) and National Lung Screening Trial (N = 53,452) were analysed. Logistic regression models were used to assess the relationships between each variable of interest and 6-year lung cancer risk. Predictive utility was assessed through changes in area-under-the-curve (AUC) after substitution into the PLCOall2014 lung cancer risk prediction model. Previous lung, uterine and oral cancers were strongly and significantly associated with elevated 6-year lung cancer risk after controlling for confounders. None of these refined measures of personal cancer history offered more predictive utility than the simple (yes/no) measure already included in the PLCOall2014 model.