Academic literature on the topic 'Teenagers – Physiology'

Depression is a psychiatric disorder that involves emotional disorders that often occur in Malaysian teenagers. Depression will cause a person to feel sad, tired, and angry, lose interest to do daily activities and tend to kill themselves. Depression can occur in male and female teenagers. It is often a sad feeling that occurs in a long period so that it can reach a period of two weeks. Symptoms of depression can be seen from the angle, cognitive, behavioural and physiology associated with each other in their daily lives. Teenagers are also not spared to face depression. In a variety of emotions facing teenagers, they face a variety of emotions that make them depressed and will result in depression. The objective of this article is to identify the symptoms of depression suffered by teenagers. To identify the objective of the content analysis method is done. The findings show that there are some symptoms of depression that cause discomfort and disrupt teenagers to function normally. The implication of the study giving knowledge about the symptoms of depression among teenagers and the kinds of treatment often used which are through counselling and psychotherapy.

(1) Background: Healthy teenagers are often sleepy. This can be explained by their physiology and behavioral changes; however, the influence of CO2 concentration above 1000 ppm should not be neglected with respect to sleep dissatisfaction. (2) Methods: CO2 concentrations were measured in two similar bedrooms occupied by girls aged 9 and 13 years old. The scheme of measurements included random opening and closing of the bedroom doors for the night. Additionally, the girls evaluated their sleep satisfaction in a post-sleep questionnaire. (3) Results: During the night, the CO2 concentration varied from 402 to 3320 ppm in the teenager’s bedroom and from 458 to 2176 ppm in the child’s bedroom. When the bedroom doors were open, inadequate indoor air quality (IEQIII and IEQIV categories) was observed in both the teenager’s and child’s bedroom during 11% and 25% of the night, respectively; however, closing the doors increased the contribution of moderate (IEQIII) and low (IEQIV) categories of air to 79% and 86%, respectively. The girls were dissatisfied only when the bedroom door was closed. The satisfied category of sleep was selected only by the younger girl. (4) Conclusions: Opening the bedroom door during the night can decrease the CO2 concentration 55–64% without reducing thermal comfort.

Requirements for cellular homeostasis appear to be unchanged between childhood and maturity. We hypothesized, therefore, that the kinetics of O2 uptake (VO2) in the transition from rest to exercise would be the same in young children as in teenagers. To test this, VO2 and heart rate kinetics from rest to constant work rate (75% of the subject's anaerobic threshold) in 10 children (5 boys and 5 girls) aged 7–10 yr were compared with values found in 10 teenagers (5 boys and 5 girls) aged 15–18 yr. Gas exchange was measured breath to breath, and phases I and II of the transition and phase III (steady-state exercise) were evaluated from multiple transitions in each child. Phase I (the VO2 at 20 s of exercise expressed as percent rest-to-steady-state exercise VO2) was not significantly correlated with age or weight [mean value 42.5 +/- 8.9% (SD)] nor was the phase II time constant for VO2 [mean 27.3 +/- 4.7 (SD) s]. The older girls had significantly slower kinetics than the other children but were also found to be less fit. When the teenagers exercised at work rates well below 75% of their anaerobic threshold, phase I VO2 represented a higher proportion of the overall response, but the phase II kinetics were unchanged. The temporal coupling between the cellular production of mechanical work at the onset of exercise and the uptake of environmental O2 appears to be controlled throughout growth in children.

Abstract Introduction School-age children (6-13yrs) and teenagers (14-17yrs) should receive 9-11hrs and 8-10hrs of sleep/day, respectively. Several studies have shown, however, that these age groups are chronically sleep deprived. Our study assessed the sleep patterns of a sample of children and teenagers in Athens, Greece. The study is part of a larger project investigating the association between orthodontic treatment and sleep disturbances. Methods Participants (N=27; 69% females; 21 school-age children 9-13yrs, 6 teenagers 14-17yrs) were under treatment in the Orthodontic Clinic of the National and Kapodistrian University. Sleep was assessed with actigraphy/logs for 59±19 days. Results Participants slept on average 7.36±0.42hrs/day. Nighttime sleep was on average 7.23±0.43hrs (percentage sleep: 87.3%±3.38%). Four (14.8%) participants napped at least once/week. Compared to the lowest sleep duration recommended for their age group, participants showed a chronic sleep deficit of 1.42±0.52hrs/day (range: 0.32-2.15hrs). The younger age group had an average sleep deficit of ~1.6hrs compared to ~0.8hrs for the teenagers (p=0.006). During the school year, daily sleep duration increased by ~0.73hrs on weekends (7.78±0.67hrs) compared to school nights (7.05±0.48hrs; p<0.001). On average, school-age participants slept from 23:13 (±31min) until 7:19 (±22min) on school nights and from 23:23 (±2:72hrs) until 8:49 (±39min) on weekends. Teenagers slept from 00:34 (±36min) until 7:40 (±14min) on school nights and from 01:34 (±41min) until 10:34 (±48min) on weekends. Conclusion Our findings verify earlier survey results showing that restricted sleep is a problem for children and adolescents in Greece. To our surprise, both age groups go to bed quite late. The impact of late bedtime on sleep duration, however, is larger in the younger group due to their larger sleep needs. In contrast to earlier research in rural areas, napping was not common in our urban sample, probably due to extracurricular activities and studying at home. Support N/A

With the development of the Internet era, the application of smartphones in life is quite useful, and the penetration rate of smartphones will be further increased in the future, making teenagers increasingly dependent on mobile phones. Teenagers are under great academic pressure, and excessive reliance on mobile phones will inevitably affect the formation of normal values. Teenagers, as a special group, deserve our attention. Mobile phone dependence has become a social problem. In this paper, the Pittsburgh Sleep Quality Index was used to evaluate the sleep quality of adolescents, and the factors affecting the sleep quality of adolescents were explored from three dimensions of behaviour, physiology, and emotion based on the sleep quality model. In this study, structural equation modelling was used to test the multiple mediating effects and analyze the relationship between mobile phone anxiety and sleep quality. Through the analysis of the internal mechanism of the two, the results show that the average score of adolescents’ anxiety about mobile phone use is 32.87, and the standard deviation is 10.67. The difference between mobile phone anxiety and sleep quality was statistically significant ( P < 0.001 ); good sleep quality can alleviate the prediction effect of mobile phone anxiety on anxiety and provide reference for promoting the physical and mental health development of adolescents.

Background: Physical activity is defined as any bodily movement that requires the use of energy, where it is recommended, that teenagers get 60 minutes of moderate to severe physical activity. However, almost majority of the teenagers around the globe are getting inadequate physical activity. Objectives: • To analyze social, cultural and religious factors that affect physical activity. • To identify different personal factors such as body image, self esteem and their effects on physical activity. • To identify ecological and academic factors leading to decrease physical activity and its associated comorbidities. • To identify the role of government in evaluating the availability of sports centres and other facilities for adolescents /teenagers. Study Design: A cross sectional study Place and Duration: Conducted Jinnah College Peshawar and Islamia College Peshawar, during from the period March 2018 to May 2018. Methodology: Sample under study was based on teenage students (16 to 19 years) with a total size of 150 students that were part of bachelor program (BS Botany) , who were obese or over-weight by appearance. The students were given standardized questionnaires randomly, regardless of gender. Collected data obtained from questionnaire were analyzed. Results: According to the results, 94.41% students had barriers to physical activities while 5.68% had none. 75 students (50%) said that they did not have any previous bad experiences with their appearance while 30 students (21.7%) said that they did. More- over, 59 students (39.3%) said that their reduced activity was due to lack of time while 55 students (36.7%) felt that the lack of safe places was the causative factor. 60 students (40%) students felt that they needed a partner while 57 students (38%) just felt de-moti- vated. Conclusion: On the basis of this study, we conclude that majority of the students have various barriers regarding their physical activities. 94.31% of the students reportedly have barriers while 5.69% had no barrier whatsoever, and they were well aware of the consequences such as obesity, diabetes etc. Keywords: Physical activity, Barriers, Over-weight, Obese.

This article examines the phenomenology of the secondary benefits of anorexia, namely, the use of this symptom to suppress libido in adolescents and young girls with hypertrophied internal and external religious prohibition on the part of parents to manifest their growing sexuality, due to physiology. The causes of anorexia are described in many scientific works, but the peculiarities of the influence of religious attitudes of parents on the formation of anorexia in adolescents are poorly disclosed. This article reveals the psychological mechanisms (replacing aggression and secondary benefits) that keep the problem and make it impossible to achieve a result in the treatment of this ailment. The article presents a sample of those who applied to a psychological center for help from parents of adolescents suffering from anorexia and at the same time having strong religious prejudices, which, in our opinion, affects the occurrence and retention of a negative symptom under certain circumstances. For successful therapy and prevention of anorexia, we have established what circumstances can contribute to the occurrence of anorexia in adolescents from families with a strong religious orientation. The key point in working with the girls with whom we managed to conduct psychoanalytic sessions was their temporary disconnection from their religious beliefs until a conscious choice in the future. This serves as a prerequisite for an effective solution to the problem, since the existing doubts about religion, what is good / bad, right / wrong, create a certain neurotic pressure and can lead to consequences such as anorexia.

The aims of the Thesis were: to investigate and quantify the factors influencing the production of maximum isometric grip strength force in a sample of Australian teenagers when using JamarTM-like handgrip dynamometers; to determine the reliability of this measure over long and short retest intervals; to establish a database of anthropometric and strength values for this group and prediction equations for premorbid strengths to aid assessment of recovery in those with upper limb pathologies. The history of these handgrip dynamometers demonstrates that they have been employed in one form or another for over three hundred years and are still widely used today in hand rehabilitation and medical examinations. Many new types of dynamometers have been constructed subsequent to the ubiquitous JamarTM and have all been briefly reviewed here. Handedness (dominance) was thought to be a possible factor influencing grip strength performance and was later evaluated. But first, the Edinburgh Handedness Inventory was tested with 658 teenagers and 64 adults and confirmed to be a valid tool for assessing handedness. Its validity was improved by substituting the tasks of sweeping and opening the lid of a box for hammering and use of a screwdriver. Its excellent reliability (ICC = .78, p < 0.01) was confirmed with 45 teenagers and 45 adults. There were 235 teenagers who performed maximal isometric grip strength tests and from the results a local database was created. It was confirmed that the grip strength difference in males and females becomes significant after the age of 13 years, and that the average teenaged male is stronger than the average teenaged female by 11.2 Kg force (p < .01). Height, weight, BMI, hand dimensions, past upper limb injuries, degrees of handedness and exercise levels were measured and compared with known norms to establish that the grip strength tested sample of teenagers was representative of urban teenagers in Australia. The influence of handedness on maximal grip strength in dominant and non-dominant hands was unable to be completely ascertained due to the vast majority of the sample of teenagers being right-handed. Only 13 of the 235 teenagers used their left hand for most tasks, with another 20 using their left hands for a small majority of tasks. There was a grip strength bias towards the dominant hand of 2.63 kg force (p < .01). The most accurate way to predict the grip strength of one hand is by knowing the grip strength of the other hand. Prediction models found that 90% (R2 adj .902) and 70% (R2adj .702) of the variance in one hand could be accounted for by the grip strength of their other hand for male and female teenagers, respectively. Prediction equations were also created to assist in estimating the pre-morbid grip strength of teenagers suffering from bilateral hand injuries. If for the males, measurements for height and hand surface area were entered into these models, the grip strength of the dominant and non-dominant hands could be estimated with 62.6 and 63.5% of the variance between the real and predicted scores accounted for, respectively. For the females the prediction models using height and hand surface area could only account for 33.9 and 42.8% of the variances, with no other independent variables improving the prediction equations. The reliability of the maximal grip strength performance of 154 of these teenagers was retested after one or four weeks. A number of sub-group permutations were created for age, gender, retest time interval and handedness groups. The measures of grip strength for males were highly reliable with ICC (3,1) values ranging from .91 to .97. These measures were significantly higher than that obtained from the females, where reliability values ranged from .69 to .83. Handedness played a significant part in grip strength reliability. The dominant hand of right-handed teenagers achieved an ICC (3,1) of .97, as contrasted with the non-dominant hand of left-handers who attained a very poor ICC (3,1) of .27. The shape of the hands of the males did not influence their grip strength or their reliability values, which ranged from .954 to .973. The shape of female hands did not affect their ability to generate maximal grip strength, only its reliability. The females with hands shaped squarer-than-average had mean grip strength reliability values of ICC (3,1) at only .48, in contrast to those with longer-than-average hands who achieved a mean ICC (3,1) of .92. The handle shape of the dynamometer may disadvantage square-handed females, and this should be further investigated.

Doctor of Philosophy
The aims of the Thesis were: to investigate and quantify the factors influencing the production of maximum isometric grip strength force in a sample of Australian teenagers when using JamarTM-like handgrip dynamometers; to determine the reliability of this measure over long and short retest intervals; to establish a database of anthropometric and strength values for this group and prediction equations for premorbid strengths to aid assessment of recovery in those with upper limb pathologies. The history of these handgrip dynamometers demonstrates that they have been employed in one form or another for over three hundred years and are still widely used today in hand rehabilitation and medical examinations. Many new types of dynamometers have been constructed subsequent to the ubiquitous JamarTM and have all been briefly reviewed here. Handedness (dominance) was thought to be a possible factor influencing grip strength performance and was later evaluated. But first, the Edinburgh Handedness Inventory was tested with 658 teenagers and 64 adults and confirmed to be a valid tool for assessing handedness. Its validity was improved by substituting the tasks of sweeping and opening the lid of a box for hammering and use of a screwdriver. Its excellent reliability (ICC = .78, p < 0.01) was confirmed with 45 teenagers and 45 adults. There were 235 teenagers who performed maximal isometric grip strength tests and from the results a local database was created. It was confirmed that the grip strength difference in males and females becomes significant after the age of 13 years, and that the average teenaged male is stronger than the average teenaged female by 11.2 Kg force (p < .01). Height, weight, BMI, hand dimensions, past upper limb injuries, degrees of handedness and exercise levels were measured and compared with known norms to establish that the grip strength tested sample of teenagers was representative of urban teenagers in Australia. The influence of handedness on maximal grip strength in dominant and non-dominant hands was unable to be completely ascertained due to the vast majority of the sample of teenagers being right-handed. Only 13 of the 235 teenagers used their left hand for most tasks, with another 20 using their left hands for a small majority of tasks. There was a grip strength bias towards the dominant hand of 2.63 kg force (p < .01). The most accurate way to predict the grip strength of one hand is by knowing the grip strength of the other hand. Prediction models found that 90% (R2 adj .902) and 70% (R2adj .702) of the variance in one hand could be accounted for by the grip strength of their other hand for male and female teenagers, respectively. Prediction equations were also created to assist in estimating the pre-morbid grip strength of teenagers suffering from bilateral hand injuries. If for the males, measurements for height and hand surface area were entered into these models, the grip strength of the dominant and non-dominant hands could be estimated with 62.6 and 63.5% of the variance between the real and predicted scores accounted for, respectively. For the females the prediction models using height and hand surface area could only account for 33.9 and 42.8% of the variances, with no other independent variables improving the prediction equations. The reliability of the maximal grip strength performance of 154 of these teenagers was retested after one or four weeks. A number of sub-group permutations were created for age, gender, retest time interval and handedness groups. The measures of grip strength for males were highly reliable with ICC (3,1) values ranging from .91 to .97. These measures were significantly higher than that obtained from the females, where reliability values ranged from .69 to .83. Handedness played a significant part in grip strength reliability. The dominant hand of right-handed teenagers achieved an ICC (3,1) of .97, as contrasted with the non-dominant hand of left-handers who attained a very poor ICC (3,1) of .27. The shape of the hands of the males did not influence their grip strength or their reliability values, which ranged from .954 to .973. The shape of female hands did not affect their ability to generate maximal grip strength, only its reliability. The females with hands shaped squarer-than-average had mean grip strength reliability values of ICC (3,1) at only .48, in contrast to those with longer-than-average hands who achieved a mean ICC (3,1) of .92. The handle shape of the dynamometer may disadvantage square-handed females, and this should be further investigated.

Thesis (M.S. in Operations Research)--Naval Postgraduate School, September 2006.
Thesis Advisor(s): Nita Lewis Miller. "September 2006." Includes bibliographical references (p. 67-83). Also available in print.

This study examined the effects of pre-exercise carbohydrate (CHO) supplementation on anaerobic exercise performance in adolescent males (n =11; 15.0 ± 0.9 yrs). On separate days, subjects consumed either a CHO or a placebo (PL) beverage followed by 2 Wingate anaerobic tests (WAnT) separated with ten by 10-second sprints. Peak (PP), mean power (MP) and fatigue index (FI) were assessed. Venous blood samples were obtained and analyzed for glucose, lactate, insulin, and catecholamines. A trial by time ANOVA (P < 0.05) was used in the analysis. PP and MP tended to be higher (P < 0.09) in CHO versus PL, and MP tended to decline more in CHO (P < 0.06); Fl for the two WAnT were similar. Glucose concentration significantly increased after CHO consumption and then returned to baseline post-exercise, whereas glucose level remained unchanged over time during PL; similarly observed for insulin. Lactate and catecholamine levels significantly increased over time, but a trial difference was only observed in epinephrine. The tendency for PP and MP to be higher in CHO might suggest a potential ergogenic benefit of pre-exercise CHO although the change in MP over time in CHO and the similarity in Fl might suggest otherwise.
School of Physical Education, Sport, and Exercise Science

The purpose of this study is to determine physiological adaptations in trained male high-school runners before and after high-intensity training associated with a crosscountry season. Testing occurred on five separate occasions at the Human Performance Laboratory. After the first familiarization session, the subjects performed a treadmill graded exercise test in which maximal oxygen consumption and ventilatory threshold was measured. Submaximal oxygen consumption and blood lactate concentration at three running speeds (10, 12, and 14 km'hf 1 at 0% grade) was determined in a second testing session. After the cross-country season (13 weeks) the subjects returned to the laboratory and performed the same graded exercise and submaximal exercise tests. VO2max significantly increased, VT tended to increased, however, not significant. There were no changes in submaximal economy or lactate except for significant decline in blood lactate at 14 km hf' . Although these variables are associated with endurance performance in adults, there is very little information available regarding the effects of endurance training on these variables in the adolescent age group. Knowing the extent of the adaptations will help to optimize the training programs for age group.
School of Physical Education

Individuals with NIDDM and low insulin sensitivity (Si) have altered fuel use, which may appear in NIDDM relatives. Adolescent males, six with NIDDM relatives (POS) and six controls (CON), matched for fitness and fatness, participated. Peak oxygen uptake (V02pea), ventilatory threshold (VT) and body composition were measured. Insulin and glucose values were used for Si estimates. Oxygen consumption (V02) and respiratory exchange ratio (RER) measurements were made at rest and during exercise at 80,100 and 120% of VT for substrate use. No group differences were found in anthropometric data, V02pea, VT or blood measurements, although fat free mass (FFM) tended to be greater in CON. CON tended to use a higher percentage carbohydrate and a lower percentage of fat than POS, but differences were no longer present after normalization to FFM. Trends towards fuel use differences may suggest metabolic abnormalities are present in POS, but further investigation is necessary.
School of Physical Education, Sport, and Exercise Science

La complexité des patients de réanimation justifie le recours à des systèmes d’aide à la décision thérapeutique. Ces systèmes rassemblent des protocoles automatisés de prise en charge permettant le respect des recommandations et des simulateurs physiologiques ou patients virtuels, utilisables pour personnaliser de façon sécuritaire les prises en charge. Ces dispositifs fonctionnant à partir d’algorithmes et d’équations mathématiques ne peuvent être développés qu’à partir d’un grand nombre de données de patients. Le principal objectif de cette thèse était la mise en place d’une base de données haute résolution automatiquement collectée de patients de réanimation pédiatrique dont le but sera de servir au développement et à la validation d’un simulateur physiologique : SimulResp© . Ce travail présente l’ensemble du processus de mise en place de la base de données, du concept jusqu’à son utilisation
The complexity of the patients in the intensive care unit requires the use of clinical decision support systems. These systems bring together automated management protocols that enable adherence to guidelines and virtual physiological or patient simulators that can be used to safely customize management. These devices operating from algorithms and mathematical equations can only be developed from a large number of patients’ data. The main objective of the work was the elaboration of a high resolution database automatically collected from critically ill children. This database will be used to develop and validate a physiological simulator called SimulResp© . This manuscript presents the whole process of setting up the database from concept to use

Discordance in bone mass between young adult swimmers and soccer players may be a direct result of differences in bone loading patterns that influence bone mineralization during growth. Our aim was to evaluate whether sports participation (soccer and swimming) had an independent effect on bone mass accrual at the hip and lumbar spine in adolescent female athletes. We recruited boys and girls 10 to 14-years of age from Corvallis, Albany, Sweet Home, Salem, Eugene, and the greater Portland area. Bone mineral content (BMC, g) and bone mineral density (BMD, g/cm²) of the proximal left hip, spine, and whole body were assessed by dual energy x-ray absorptiometry (Hologic QDR 4500A; Hologic Inc., Waltham, MA, USA). We used ANCOVA and report that baseline BMC and BMD values of girl soccer players at the greater trochanter were significantly higher compared to controls and the swim group, and femoral neck BMC was significantly greater than the swimmers. At baseline, all boy groups were similar at the hip and spine. After 12-months, ANCOVA was also used to assess absolute change for BMC and BMD at the hip and spine. The girl soccer players had significantly more BMC and BMD at the greater trochanter as well as total hip BMD and lumbar spine BMC compared to the swimmers, but not the controls. The girl control group showed a significantly greater 12-month change for femoral neck and greater trochanter BMC than swimmers. Overall, the girl swimmers demonstrated a lower accumulation of bone mass during the 12-month study period. As for the boys, soccer players had a significantly higher 12-month change for femoral neck BMC than swimmers, but were similar at the spine. There were no differences between the boy control subjects and the swimmers for 12-month change values at the hip and spine. While preliminary and limited by the small sample size, our results indicate that after controlling for growth, soccer players gained significantly more BMC at the femoral neck than swimmers. Furthermore, exposing the young skeleton to impact loading exercise has site-specific benefits at the hip whereas prolonged training in a non-weight bearing environment may compromise skeletal acquisition.
Graduation date: 2004

This study examined the influence of maturation on the oxygen uptake efficiency slope (OUES) in healthy male subjects. The variables comprising the OUES are known to be affected by metabolism which in turn is influenced by maturation. The subjects performed a graded exercise test on a cycle ergometer to determine the OUES and VO2max. Subjects were divided into groups based on maturation status: early-pubertal (EP, n = 15), mid-pubertal (MP, n = 20), late-pubertal (LP, n = 17), and young-adult (YA, n = 19) males. Cardiorespiratory fitness (measured as VO2max mL·min-1·kg-1) was not significantly different between groups. OUES values in absolute terms were higher in groups LP and YA versus MP and EP. Scaling OUES relative to body mass failed to eliminate between group differences whereby LP and YA had lower mass relative OUES values compared to LP and YA. Scaling OUES relative to fat free mass also failed to eliminate between group differences with EP group values being higher versus LP and YA, but only MP values being higher than YA. Differences in OUES values between male across maturation status remained after accounting for differences in body size, suggesting an affect of maturation on this measurement.
School of Physical Education, Sport, and Exercise Science

青少年特發性脊柱側凸(Adolescent idiopathic scoliosis , AIS)是一種複雜的脊柱三維畸形，常見於10-16 歲處於生長發育高峰期的青少年女性。儘管AIS 發生率較高並且臨床影響較大，但是到目前為止其病因未明。在眾多關於AIS 病因學的假設和理論研究中，普遍認為低骨密度是AIS 的一個重要影響因素。然而近年來對於AIS 患者低骨密度研究不足，其潛在的機制尚不明確。我們之前初步的組織學研究發現，AIS 患者的松質骨中成骨細胞功能下降，此研究為AIS中存在骨礦化異常提供了初步依據。
骨橋蛋白是骨組織中一種重要的非膠原細胞外基質蛋白，其在骨礦化過程中起著重要作用。近期的研究報導AIS 患者血漿中骨橋蛋白水準高於年齡匹配的正常對照。因此本研究假設AIS 患者血漿及骨組織中骨橋蛋白高於正常對照，并可能影響了骨基質的礦化，從而導致低骨密度。
本系列研究的第一部分旨在通過外周定量電腦斷層掃描（pQCT）明確AIS患者中皮質骨密度及松質骨密度是否均低於正常對照。pQCT 可以準確地三維評估皮質骨密度，松質骨密度及其他骨品質的相關參數。採用雙能X 線骨密度儀（DXA）測量受試者的非優勢側近端股骨面積骨密度（包括股骨頸，Ward’s 三角及大轉子）。而採用pQCT 測量受試者非優勢側橈骨遠端容積骨密度，包括皮質骨密度及松質骨密度。結果顯示AIS 患者面積骨密度，皮質骨密度及松質骨密度在不同年齡段和月經時間分組中均低於正常對照。並且AIS 與正常對照皮質骨密度的差異隨著年齡增長越來越大，而松質骨密度差異則隨著年齡增長越來越小。
第二部分通過顯微CT 及組織形態測定研究AIS 及正常骨組織的骨礦化及骨微結構。採用顯微CT 檢測骨組織的三維結構參數，包括材料骨密度及骨微結構。未脫鈣骨組織的切片通過Goldner’s 染色進行組織形態學測量。結果顯示AIS患者的骨體積分數，骨小梁數目，骨小梁厚度及結構模型指數與正常對照之間均無顯著差異，而材料骨密度顯著低於正常對照。組織形態學分析結果顯示AIS中低礦化骨顯著多於正常對照。
第三部分旨在研究AIS 及正常對照血漿中骨橋蛋白水準及其與骨密度的關係。採用酶聯吸附免疫法測量AIS 患者及年齡匹配的正常對照血漿中的骨橋蛋白水準。血漿骨橋蛋白水準與骨密度的關係採用多元回歸分析。研究結果顯示AIS 患者及正常對照血漿骨橋蛋白水平均與年齡及月經時間呈負相關。AIS 患者的血漿骨橋蛋白水準顯著高於正常對照，並且與松質骨密度呈顯著負相關。
本研究第四部分旨在探討骨組織中的骨橋蛋白表達與骨形態學及骨礦化指標在AIS 及正常對照中的關係。骨組織中骨橋蛋白的表達採用半定量免疫組織化學法評估。研究結果顯示在AIS 中血漿骨橋蛋白水準與骨組織中骨橋蛋白的表達呈正相關。且AIS 骨組織中骨橋蛋白的表達也顯著高於正常對照。進一步的研究發現骨組織中骨橋蛋白的表達與材料骨密度呈負相關，而與低礦化骨量呈正相關。
本研究明確了AIS 中骨礦化水準低於正常對照，進一步證明AIS 患者中的皮質骨及松質骨密度下降可能與骨礦化的調控異常有關。本研究發現的骨橋蛋白與低骨密度及低骨礦化水準的關係，可以推測AIS 患者中異常升高的骨橋蛋白水準可能在骨礦獲取的調解中起重要作用。本系列研究提供證據支援AIS 患者中骨橋蛋白的異常表達可能影響了骨基質的礦化，從而導致低骨密度。本研究為AIS 中低骨密度可能的機制提供了全新的見解，並可能進一步解釋AIS 的發病機理及其發生，發展。
Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional deformity of the spine occurring most commonly in girls between ages 10-16 during the pubertal growth spurt. Despite its high prevalence and clinical impact, etiology of AIS remains largely unknown. Among the number of proposed hypothesis and observations on the etiopathogenesis of AIS, low bone mineral density (BMD) is one of the most reported factor (Cheng et al. 1999; Hung et al. 2005; Cheung et al. 2006; Hui et al. 2011). However, the underlying mechanism of low BMD in AIS has not been sufficiently studied scientifically and its link to the etiopathogenesis is still not clear. From a previous pilot study, our group has reported the histological features of reduced osteoblastic activity in bone biopsy specimens obtained from AIS subjects intraoperatively, thus providing the early evidence of abnormal bone mineral acquisition and mineralization (Cheng et al. 2001).
Osteopontin (OPN) has been recognized as one the major non-collagen extracellular matrix proteins in bone and plays an important role in bone mineralization. Recent report suggested that AIS patients have higher OPN level than normal controls (Moreau et al. 2009). It was hypothesized that the low BMD in AIS is associated with abnormal bone matrix mineralization which may be related to abnormal expression of OPN in the plasma and at tissue level.
In this series of studies, the first part aimed to investigate the differential cortical and trabecular bone mineral density of AIS Vs normal controls. The non-dominant proximal femur areal BMD (aBMD) (femoral neck, Ward’s triangle and greater trochanter) of the subjects were measured with dual-energy x-ray absorptiometry (DXA). The volumetric bone mineral density (vBMD) in non-dominant distal radius was measured with peripheral quantitative computed tomography (pQCT) that allows accurate three dimensional assessment of the cortical and trabecular bone mineral density and other parameters of bone quality. AIS was found to have lower aBMDs, trabecular BMD (TBMD) and cortical BMD (CBMD) in different age groups and year since menarche (YSM) groups. Furthermore, the percentage difference of CBMD between AIS and controls was increased with age while a decreasing trend was observed in the TBMD.
The second part of the study investigated the bone mineralization and bone micro-architecture with micro-computed tomography (micro-CT) and histomorphometry study of bone biopsies obtained from AIS and normal controls. Three-dimensional structural parameters including material bone mineral density (mBMD) and bone architecture were evaluated by micro-CT. Bone histomorphometry was assessed by undecalcified sectioning with Goldner’s trichrome staining. mBMD of trabecular bone in AIS was found to be significantly lower than the normal control while no difference could be demonstrated in BV/TV, Tb.N, Tb.Th and SMI measurement between the two groups. It was also shown that the percentage of low-mineralized bone in AIS was significantly higher than that in normal controls.
The third part aimed to study the plasma OPN level and its association with the BMD in AIS Vs normal controls. Plasma OPN level in AIS and age-matched controls was measured by ELISA. With multivariate regression analysis, the plasma OPN level was found to be negatively correlated with Age and YSM in both AIS and normal controls. In addition, the plasma OPN level in AIS was significantly higher and correlated with the low trabecular BMD.
The fourth part of the study investigated the OPN expression in bone tissues level and its association with histomorphometric bone mineralization and bone micro-architectural parameters in AIS Vs normal controls. OPN expression in bone biopsy was semi-quantified by immunohistochemistry. It was found that the bone tissue OPN level was significantly higher in AIS and also positively correlated with plasma OPN level. In addition, in this pilot study, we found the trend that OPN expression in trabecular bone was negatively associated with mBMD, and positively with the percentage of low-mineralized bone.
The present study showed that AIS had lower bone mineralization than normal controls. The low cortical and trabecular BMD found in AIS is likely to be resulting from abnormal regulation of bone mineralization. The association of OPN with abnormal BMD and bone mineralization further suggested that abnormal OPN level might play an important role in affecting the bone mineral acquisition in AIS. All of these findings strongly supported the hypothesis that the low BMD in AIS is associated with abnormal bone matrix mineralization which could be related to abnormal expression of OPN. This study provided important additional insight into the possible mechanism of lower bone mineral density that might be linked to theetiopathogenesis, development and progression of the spinal deformity in AIS.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Sun, Guangquan.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2012.
Includes bibliographical references (leaves 143-160).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract and appendix A also in Chinese.
THE CHINESE UNIVERSITY OF HONG KONG --- p.I
ACKNOWLEDGEMENTS --- p.II
ABSTRACT --- p.IV
ABBREVIATION --- p.XI
TABLE OF CONTENTS --- p.XIII
LIST OF TABLES --- p.XVII
LIST OF FIGURES --- p.XIX
LIST OF PUBLICATIONS --- p.XXI
Chapter CHAPTER 1 --- STUDY BACKGROUND --- p.1
Chapter 1.1 --- GENERAL OVERVIEW OF ADOLESCENT IDIOPATHIC SCOLIOSIS (AIS) --- p.2
Chapter 1.1.1 --- NATURAL HISTORY --- p.4
Chapter 1.1.2 --- CURRENT TREATMENTS --- p.6
Chapter 1.1.2.1 --- Observation --- p.7
Chapter 1.1.2.2 --- Bracing --- p.7
Chapter 1.1.2.3 --- Surgical treatments --- p.9
Chapter 1.1.3 --- CURRENT HYPOTHESIS ON THE ETIOLOGY OF AIS --- p.11
Chapter 1.1.3.1 --- Genetic factors --- p.12
Chapter 1.1.3.2 --- Neuromuscular impairment --- p.14
Chapter 1.1.3.3 --- Abnormalities in skeletal development --- p.16
Chapter 1.1.3.4 --- Low bone mineral density in AIS --- p.16
Chapter 1.2 --- BONE MINERALIZATION --- p.18
Chapter 1.2.1 --- Overview of bone mineralization --- p.18
Chapter 1.2.2 --- Bone modeling --- p.18
Chapter 1.2.3 --- Bone remodeling --- p.19
Chapter 1.2.4 --- Factors affecting bone mineralization --- p.21
Chapter 1.3 --- OSTEOPONTIN --- p.23
Chapter 1.3.1 --- Structure of osteopontin --- p.23
Chapter 1.3.2 --- Osteopontin - cellular and tissue distribution --- p.24
Chapter 1.3.3 --- Osteopontin functions --- p.25
Chapter 1.3.4 --- Osteopontin functions in bone --- p.25
Chapter 1.3.5 --- Osteopontin and bone mineral density in human --- p.29
Chapter CHAPTER 2 --- STUDY HYPOTHESIS AND PLAN --- p.31
Chapter 2.1 --- INTRODUCTION --- p.32
Chapter 2.2 --- HYPOTHESIS --- p.33
Chapter 2.3 --- OBJECTIVES --- p.34
Chapter 2.4 --- STUDY PLAN --- p.34
Chapter CHAPTER 3 --- LOW BONE MINERAL DENSITY IN ADOLESCENT IDIOPATHIC SCOLIOSIS - AREAL VS VOLUMETRIC, CORTICAL VS TRABECULAR BONE MINERAL DENSITY --- p.36
Chapter 3.1 --- INTRODUCTION --- p.37
Chapter 3.2 --- SUBJECTS AND METHODS --- p.39
Chapter 3.2.1 --- Subjects --- p.39
Chapter 3.2.2 --- BMD Measurement --- p.40
Chapter 3.2.3 --- Statistical Analysis --- p.41
Chapter 3.3 --- RESULTS --- p.42
Chapter 3.3.1 --- aBMD of AIS and normal controls by age groups --- p.42
Chapter 3.3.2 --- TBMD and CBMD in AIS and normal controls by age groups --- p.42
Chapter 3.3.3 --- aBMD in AIS and normal controls by year since menarche --- p.43
Chapter 3.3.4 --- TBMD and CBMD in AIS and normal controls by year since menarche --- p.43
Chapter 3.3.5 --- Correlation between CBMD & TBMD and chronological age or year since menarche --- p.44
Chapter 3.3.6 --- Comparisons adjusted for chronological age or year since menarche --- p.44
Chapter 3.4 --- DISCUSSION --- p.45
Chapter 3.5 --- TABLES AND FIGURES --- p.50
Chapter CHAPTER 4 --- ABNORMAL BONE MATRIX MINERALIZATION AND BONE MICROARCHITECTURE IN ADOLESCENT IDIOPATHIC SCOLIOSIS - A HISTOMORPHOMETRIC AND MICRO-CT STUDY --- p.60
Chapter 4.1 --- INTRODUCTION --- p.61
Chapter 4.2 --- SUBJECTS AND METHODS --- p.62
Chapter 4.2.1 --- Subjects --- p.62
Chapter 4.2.2 --- Micro-computed tomography --- p.63
Chapter 4.2.3 --- Bone histomorphometry --- p.64
Chapter 4.2.4 --- Statistical analysis --- p.68
Chapter 4.3 --- RESULTS --- p.68
Chapter 4.3.1 --- Results of micro-CT analysis --- p.68
Chapter 4.3.2 --- Results of histomorphometric analysis --- p.69
Chapter 4.3.3 --- Relationship of mBMD and percentage of low-mineralized bone --- p.69
Chapter 4.4 --- DISCUSSION --- p.70
Chapter 4.5 --- TABLES AND FIGURES --- p.74
Chapter CHAPTER 5 --- PLASMA OSTEOPONTIN LEVEL AND ITS ASSOCIATION WITH BONE MINERAL DENSITY IN ADOLESCENT IDIOPATHIC SCOLIOSIS --- p.82
Chapter 5.1 --- INTRODUCTION --- p.83
Chapter 5.2 --- SUBJECTS AND METHODS --- p.84
Chapter 5.2.1 --- Subjects --- p.84
Chapter 5.2.2 --- Anthropometric assessment --- p.84
Chapter 5.2.3 --- Plasma osteopontin measurement --- p.85
Chapter 5.2.4 --- BMD Measurement --- p.86
Chapter 5.2.5 --- Statistical Analysis --- p.86
Chapter 5.3 --- RESULTS --- p.86
Chapter 5.3.1 --- Comparison of anthropometric parameters between AIS and controls --- p.86
Chapter 5.3.2 --- Correlation between OPN plasma level with age or YSM in AIS and controls --- p.87
Chapter 5.3.3 --- Comparison of OPN plasma level between AIS and controls --- p.87
Chapter 5.3.4 --- Correlation between OPN plasma level and curve severity in AIS --- p.87
Chapter 5.3.5 --- Relationship between OPN plasma level and vBMD --- p.88
Chapter 5.4 --- DISCUSSION --- p.88
Chapter 5.5 --- TABLES AND FIGURES --- p.94
Chapter CHAPTER 6 --- OSTEOPONTIN EXPRESSION IN BONE TISSUE AND ITS ASSOCIATION WITH BONE MATRIX MINERALIZATION IN ADOLESCENT IDIOPATHIC SCOLIOSIS - A PILOT STUDY --- p.102
Chapter 6.1 --- INTRODUCTION --- p.103
Chapter 6.2 --- SUBJECTS AND METHODS --- p.104
Chapter 6.2.1 --- Subjects --- p.104
Chapter 6.2.2 --- Micro-computed tomography --- p.104
Chapter 6.2.3 --- Bone histomorphometry --- p.104
Chapter 6.2.4 --- Semi-quantification of OPN expression in bone biopsy by immunohistochemistry --- p.105
Chapter 6.2.5 --- Plasma osteopontin measurement --- p.107
Chapter 6.2.6 --- Statistical Analysis --- p.108
Chapter 6.3 --- RESULTS --- p.108
Chapter 6.3.1 --- Comparison of anthropometric parameters between AIS and control subjects --- p.108
Chapter 6.3.2 --- Comparison of OPN expression detected by immunohistochemistry in bone biopsy between AIS and control groups --- p.108
Chapter 6.3.3 --- Comparison of histomorphometric and micro-CT results between AIS and control groups --- p.109
Chapter 6.3.4 --- Relationship between plasma OPN level and OPN expression in bone biopsy --- p.109
Chapter 6.3.5 --- Relationship between percentage of low-mineralized bone and OPN expression in bone biopsy --- p.109
Chapter 6.3.6 --- Relationship between material bone mineral density and OPN expression in bone biopsy --- p.110
Chapter 6.4 --- DISCUSSION --- p.110
Chapter 6.5 --- TABLES AND FIGURES --- p.114
Chapter CHAPTER 7 --- SUMMARY STUDY FLOWCHART, OVERALL DISCUSSION, CONCLUSIONS, LIMITATIONS AND FURTHER STUDIES --- p.119
Chapter 7.1 --- SUMMARY OF THE STUDY FLOW CHART WITH KEY FINDINGS --- p.120
Chapter 7.2 --- OVERALL DISCUSSION --- p.125
Chapter 7.2.1 --- The novel findings on bone mineralization abnormality in AIS in this study --- p.125
Chapter 7.2.2 --- OPN is a key modulator in AIS --- p.128
Chapter 7.3 --- OVERALL CONCLUSIONS --- p.130
Chapter 7.4 --- LIMITATION OF THIS STUDY AND FUTURE RESEARCH --- p.131
Chapter APPENDIX A. --- CONSENT FORM OF AIS RESEARCH --- p.135
Chapter APPENDIX B. --- CONSENT FORM OF BONE BIOPSY COLLECTION --- p.137
Chapter APPENDIX C. --- MATERIALS AND REAGENTS INFORMATION AND PROTOCOL FOR SOLUTIONS PREPARATION --- p.138
BIBLIOGRAPHY --- p.143

There have always been teenagers. But it was only in 1904 that American psychologist G. Stanley Hall’s ground-breaking publication, Adolescence: its Psychology and its Relations to Physiology, Anthropology, Sex, Crime and Education, established the existence of a hitherto undocumented period of ‘storm and stress’ between childhood and adulthood (Hall 1904: 2). As the case studies in later chapters will demonstrate, it is this sense of liminality that motivates my interest in the construction of identity found in the Hollywood teen movie. Here, I address both the evolution of the on-screen teenager in Hollywood cinema and, in tandem, the various ways in which film scholars have conceived the teen movie as a genre. With this understanding of how the field has developed over time, I explain how this book aims to rethink the Hollywood teen movie.

Abstract For the young Pavlov, certainty resided in the Orthodox Christian faith, which he imbibed from his family and in religious school and seminary. As a teenager, however, he embraced the popular new creed of science, modernization, and Westernization propounded by the “people of the 1860s.” He abandoned seminary for scientific studies in St. Petersburg, where he learned from his mentor Il’ia Tsion a style of physiology that emphasized vivisection, experimentation, and quantitative precision in the search for precise, mechanistic laws of vital activity. Tsion’s career was abruptly destroyed, and Pavlov was forced to make his own way. He was defeated by better-connected candidates for positions in physiology. Always high-strung and depressive, he suffered nervous symptoms that physicians diagnosed as “hysteria.” In 1891, however, another series of unforeseeable events raised him suddenly to the directorship of Russia’s new, lavishly financed physiological laboratory at the Imperial Institute of Experimental Medicine.

Abstract Born in Hanover into a family of wealthy, Jewish, textile merchants, the Meyerhofs moved to Berlin when Otto was very young. He spent an unremarkable boyhood until contracting nephritis as a teenager. During a prolonged convalescence, he became influenced by his artistic mother, read literature, wrote poetry, and visited Egypt on doctor’s orders. He attended various German medical schools before graduating in 1909. He wrote his doctorate on psychological aspects of mental illness, and also edited a student philosophical journal. Otto Warburg, a difficult colleague and friend, persuaded him to switch from psychiatry to physiology; they spent summers at the Marine Zoological Station in Naples, studying the metabolism of sea urchin eggs and fermentation. He sent Hill a copy of his first paper and soon visited Cambridge. In 1912, Meyerhof became an unpaid Privatdozent at Kiel University and then married Hedwig Schallenberg, an artistic woman from Cologne whom he met in Heidelberg.