879 resultados para critical point of growth
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BACKGROUND/AIMS Controversies still exist regarding the evaluation of growth hormone deficiency (GHD) in childhood at the end of growth. The aim of this study was to describe the natural history of GHD in a pediatric cohort. METHODS This is a retrospective study of a cohort of pediatric patients with GHD. Cases of acquired GHD were excluded. Univariate logistic regression was used to identify predictors of GHD persisting into adulthood. RESULTS Among 63 identified patients, 47 (75%) had partial GHD at diagnosis, while 16 (25%) had complete GHD, including 5 with multiple pituitary hormone deficiencies. At final height, 50 patients underwent repeat stimulation testing; 28 (56%) recovered and 22 (44%) remained growth hormone (GH) deficient. Predictors of persisting GHD were: complete GHD at diagnosis (OR 10.1, 95% CI 2.4-42.1), pituitary stalk defect or ectopic pituitary gland on magnetic resonance imaging (OR 6.5, 95% CI 1.1-37.1), greater height gain during GH treatment (OR 1.8, 95% CI 1.0-3.3), and IGF-1 level <-2 standard deviation scores (SDS) following treatment cessation (OR 19.3, 95% CI 3.6-103.1). In the multivariate analysis, only IGF-1 level <-2 SDS (OR 13.3, 95% CI 2.3-77.3) and complete GHD (OR 6.3, 95% CI 1.2-32.8) were associated with the outcome. CONCLUSION At final height, 56% of adolescents with GHD had recovered. Complete GHD at diagnosis, low IGF-1 levels following retesting, and pituitary malformation were strong predictors of persistence of GHD.
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OBJECTIVE In Europe, growth hormone (GH) treatment for children born small for gestational age (SGA) can only be initiated after 4 years of age. However, younger age at treatment initiation is a predictor of favourable response. To assess the effect of GH treatment on early growth and cognitive functioning in very young (<30 months), short-stature children born SGA. DESIGN A 2-year, randomized controlled, multicentre study (NCT00627523; EGN study), in which patients received either GH treatment or no treatment for 24 months. PATIENTS Children aged 19-29 months diagnosed as SGA at birth, and for whom sufficient early growth data were available, were eligible. Patients were randomized (1:1) to GH treatment (Genotropin(®) , Pfizer Inc.) at a dose of 0·035 mg/kg/day by subcutaneous injection, or no treatment. MEASUREMENTS The primary objective was to assess the change from baseline in height standard deviation score (SDS) after 24 months of GH treatment. RESULTS Change from baseline in height SDS was significantly greater in the GH treatment vs control group at both month 12 (1·03 vs 0·14) and month 24 (1·63 vs 0·43; both P < 0·001). Growth velocity SDS was significantly higher in the GH treatment vs control group at 12 months (P < 0·001), but not at 24 months. There was no significant difference in mental or psychomotor development indices between the two groups. CONCLUSIONS GH treatment for 24 months in very young short-stature children born SGA resulted in a significant increase in height SDS compared with no treatment.
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This thesis analyzes the sportswriting genre as a form of personal essay. It explores the art over time through writers Red Smith, A.J. Liebling, Roger Angell, George Plimpton, Bart Giamatti, Frank Deford, and Rick Reilly, as well as anthologized writers from 2008 and blogs.
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The prevalence of obesity has reached epidemic proportions in the United States. Twenty-five percent of school aged students are overweight. Schools have the opportunity to help slow this epidemic. School cafeterias in the United States feed millions of students every day through the National School Lunch Program.^ Point-of-sale machines are used in most school cafeterias to help streamline the process of purchasing school lunches. The point-of-sale software allows school personnel to place special notes on student's accounts to provide alerts about parental requests. This study investigated what the alerts are used for, who uses the alerts, and if there are any patterns by demographic characteristics. ^ Counts and percentages were used to determine what the alerts were used for and who used them. This study found that students who were white non-Hispanic, paid status, or in elementary school were most likely to have alerts placed on their accounts. Also, the majority of point-of-sale alerts were used as allowances (i.e., allowed to purchase snacks from the balance on the school lunch account), rather than restrictions (i.e., restricted from purchasing high calorie foods or specific food items). Using chi-square analysis, a total of 688 alerts were analyzed. There were significant differences in alert frequencies for intent category by grade level (p=0.000), snack access (p=0.000), and gender (p=0.002). Therefore, the results are significant, and one can conclude there is a significant relationship between gender, grade level, and snack access, and the presence of an alert on the school lunch account.^ Also, school administrators may want to take into consideration possible changes to their program, such as requiring more time to run the software. The results of this study can assist school administrators to better understand that a point-of-sale alert program may help their school lunch programs run more efficiently, while also providing parental influence on students’ food choices at the point-of-sale.^ School food service authorities should consider implementing a structured point-of-sale alert policy to encourage parental input on their children's food choices. When implementing the point-of-sale policy, schools should publicize this policy online, through school lunch menus, and parent communications increase participation throughout the school district.^
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Background. Research into methods for recovery from fatigue due to exercise is a popular topic among sport medicine, kinesiology and physical therapy. However, both the quantity and quality of studies and a clear solution of recovery are lacking. An analysis of the statistical methods in the existing literature of performance recovery can enhance the quality of research and provide some guidance for future studies. Methods: A literature review was performed using SCOPUS, SPORTDiscus, MEDLINE, CINAHL, Cochrane Library and Science Citation Index Expanded databases to extract the studies related to performance recovery from exercise of human beings. Original studies and their statistical analysis for recovery methods including Active Recovery, Cryotherapy/Contrast Therapy, Massage Therapy, Diet/Ergogenics, and Rehydration were examined. Results: The review produces a Research Design and Statistical Method Analysis Summary. Conclusion: Research design and statistical methods can be improved by using the guideline from the Research Design and Statistical Method Analysis Summary. This summary table lists the potential issues and suggested solutions, such as, sample size calculation, sports specific and research design issues consideration, population and measure markers selection, statistical methods for different analytical requirements, equality of variance and normality of data, post hoc analyses and effect size calculation.^
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Point-of-decision signs to promote stair use have been found to be effective in various environments. However, these signs have been more consistently successful in public access settings that use escalators, such as shopping centers and transportation stations, compared to worksite settings, which are more likely to contain elevators that are not directly adjacent to the stairs. Therefore, this study tested the effectiveness of two point-of-decision sign prompts to increase stair use in a university worksite setting. Also, this study investigated the importance of the message content of the signs. One sign displayed a general health promotion message, while the other sign presented more specific information. Overall, this project examined whether the presence of the point-of-decision signs increases stair use. In addition, this research determined whether the general or specific sign promotes greater stair use. ^ Inconspicuous observers measured stair use both before the signs were present and while they were posted. The study setting was the University of Texas School of Nursing, and the target population was anyone who entered the building, including employees, students, and visitors. The study was conducted over six weeks and included two weeks of baseline measurement, two weeks with the general sign posted, and two weeks with the specific sign posted. Each sign was displayed on a stand in the decision point area near the stairs and the elevator. Logistic regression was used to analyze the data. ^ After adjustment for covariates, the odds of stair use were significantly greater during the intervention period than the baseline period. Furthermore, the specific sign period showed significantly greater odds of stair use than the general sign period. These results indicate that a point-of-decision sign intervention can be effective at promoting stair use in a university worksite setting and that a sign with a specific health information message may be more effective at promoting stair use than a sign with a general health promotion message. These findings can be considered when planning future worksite and university based stair promotion interventions.^
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The fine balance between proliferation and apoptosis plays a primary role in carcinogenesis. Proto-oncogenes that induce both proliferation and apoptosis provide a powerful inbuilt system to inhibit clonal expansion of cells with high proliferation rates. This provides a restraint to the development of neoplasms. C-myc expressing cells undergo apoptosis in low serum by an unknown mechanism. Several lines of evidence suggested that c-myc induces apoptosis by a transcriptional mechanism. However, the target genes of this program have not been fully defined. Protein synthesis inhibitors induce apoptosis in c-myc over-expressing cells at high serum levels suggesting that inhibition of synthesis of a survival factor may induce apoptosis. We show that the expression of c-myc directly correlates with an increase in the level of a survival protein, bcl-$\rm x\sb{L},$ and a decrease in the pro-apoptotic protein, bax, at both the protein and mRNA level. Furthermore, a significant decrease of the bcl-$\rm x\sb{L}$ protein levels is observed under low serum conditions. In order to investigate the mechanism of regulation of bcl-$\rm x\sb{L}$ and bax by c-myc, the bcl-x and bax promoters were cloned, sequenced and shown to contain c-myc binding sites. The chloramephenicol acetyl transferase (CAT) reporter assay was used to demonstrate activation of the bcl-x promoter by increasing levels of c-myc when co-transfected in COS cells. The bax promoter was also shown to be transrepressed in c-myc expressing cells. The role of bcl-$\rm x\sb{L}$ in apoptosis regulation in c-myc cell lines in normal and low serum was then investigated. Cells lines expressing c-myc and bcl-$\rm x\sb{L}$ were generated and were shown to be resistant to apoptosis induction in low serum. Furthermore, cell lines expressing c-myc, anti-sense bcl-$\rm x\sb{L}$ and $\beta$-galactosidase demonstrated significantly enhanced rates of apoptosis in high serum compared to c-myc Rat 1a cells. These findings suggest that c-myc activates a survival program involving bcl-$\rm x\sb{L}$ upregulation and bax downregulation. However, this survival signal is reduced under low serum conditions by the relative downregulation of bcl-$\rm x\sb{L}$ allowing for apoptosis to proceed. These data also directly demonstrates that downregulation in the level of bcl-$\rm x\sb{L}$ associated with low serum conditions is a critical determinant of c-myc induced apoptosis. ^
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Exogenous ligands that bind to the estrogen receptor (ER) exhibit unique pharmacologies distinct from that observed with the endogenous hormone, 17β-estradiol (ED. Differential activity among ER ligands has been observed at the level of receptor binding, promoter interaction and transcriptional activation. Furthermore, xenoestrogens can display tissue-specific agonist activity on the cellular level, functioning as an agonist in one tissue and as an antagonist in another. That the same ligand, functioning through the same receptor, can produce differing agonist responses on the cellular level indicates that there are tissue-specific determinants of agonist activity. In these studies critical molecular determinants of agonist activity were characterized for several cell types. In the normal and neoplastic myometrium a proliferative response was dependent upon activation of AF2 of the ER, functioning as a determinant of agonism in this cell type. Progesterone receptor (PR) ligands transdominantly suppressed ER-mediated transcription and proliferation in uterine leiomyoma cells, indicating that ER/PR cross-talk can modulate agonist activity in a myometrial cell background. In the breast, the agonist response to ER ligands was investigated by employing a functional genomics approach to generate gene expression profiles. Treatment of breast cancer cells with the selective estrogen receptor modulator tamoxifen largely recapitulated the expression profile induced by treatment with the agonist E2, despite the well-characterized antiproliferative effects produced by tamoxifen in this cell type. While the expression of many genes involved in regulating cell cycle progression, including fos, myc, cdc25a, stk15 and cyclin A, were induced by both E2 and tamoxifen in breast cells, treatment with the agonist E2 specifically induced the expression of cyclin D1, fra-1 , and uracil DNA glycosylase. These results suggest that the inability of tamoxifen to transactivate expression of only a few key genes, functioning as cellular gatekeepers, prevent tamoxifen-treated breast cells from entering the cell cycle. Thus, the expression of these agonist-specific marker genes is a potential determinant of agonist activity at the cellular level in the breast. Collectively, studies in the breast and uterine myometrium have identified several mechanisms whereby ER ligands modulate ER-mediated signaling and provide insights into the biology of tissue-specific agonist activity in hormone-responsive tissues. ^
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The normal boiling point is a fundamental thermo-physical property, which is important in describing the transition between the vapor and liquid phases. Reliable method which can predict it is of great importance, especially for compounds where there are no experimental data available. In this work, an improved group contribution method, which is second order method, for determination of the normal boiling point of organic compounds based on the Joback functional first order groups with some changes and added some other functional groups was developed by using experimental data for 632 organic components. It could distinguish most of structural isomerism and stereoisomerism, which including the structural, cis- and trans- isomers of organic compounds. First and second order contributions for hydrocarbons and hydrocarbon derivatives containing carbon, hydrogen, oxygen, nitrogen, sulfur, fluorine, chlorine and bromine atoms, are given. The fminsearch mathematical approach from MATLAB software is used in this study to select an optimal collection of functional groups (65 functional groups) and subsequently to develop the model. This is a direct search method that uses the simplex search method of Lagarias et al. The results of the new method are compared to the several currently used methods and are shown to be far more accurate and reliable. The average absolute deviation of normal boiling point predictions for 632 organic compounds is 4.4350 K; and the average absolute relative deviation is 1.1047 %, which is of adequate accuracy for many practical applications.
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How organisms may adapt to rising global temperatures is uncertain, but concepts can emerge from studying adaptive physiological trait variations across existing spatial climate gradients. Many ectotherms, particularly fish, have evolved increasing genetic growth capacities with latitude (i.e. countergradient variation (CnGV) in growth), which are thought to be an adaptation primarily to strong gradients in seasonality. In contrast, evolutionary responses to gradients in mean temperature are often assumed to involve an alternative mode, 'thermal adaptation'. We measured thermal growth reaction norms in Pacific silverside populations (Atherinops affinis) occurring across a weak latitudinal temperature gradient with invariant seasonality along the North American Pacific coast. Instead of thermal adaptation, we found novel evidence for CnGV in growth, suggesting that CnGV is a ubiquitous mode of reaction-norm evolution in ectotherms even in response to weak spatial and, by inference, temporal climate gradients. A novel, large-scale comparison between ecologically equivalent Pacific versus Atlantic silversides (Menidia menidia) revealed how closely growth CnGV patterns reflect their respective climate gradients. While steep growth reaction norms and increasing growth plasticity with latitude in M. menidia mimicked the strong, highly seasonal Atlantic coastal gradient, shallow reaction norms and much smaller, latitude-independent growth plasticity in A. affinis resembled the weak Pacific latitudinal temperature gradient.