Muscle Metabolism and Enzyme Activities after Training in Boys 11–13 Years Old

The effect of training on the skeletal muscle metabolism of 11-to 13-year-old boys was examined. In one experiment changes in blood lactate, and muscle lactate, CP, ATP, and glycogen were determined at rest and following exercise before and after 4 months of training. The concentrations of glycogen, CP and ATP at rest were higher (P<0.01) following training. Blood and muscle lactate were 23 and 56 % higher after maximal work following training. A greater reduction in muscle glycogen occurred during maximal work after training but the pattern for ATP and CP depletion was unchanged. In a second experiment boys trained by pedalling a bicycle ergometer an average of 30 min 3 times a week for 6 weeks. Biopsy samples of the vastus lateralis were examined for oxidative (succinate dehydrogenase) and anaerobic (phosphofructokinase) capacity before and after training. The fiber composition and relative oxidative capacity in the fibers was determined histochemically. Succinate dehydrogenase and phosphofructokinase activities increased 30 and 83 %, respectively, following training. Fiber distribution was unchanged by training but the oxidative capacity of both fiber types appeared to increase.     

Response to Submaximal and Maximal Exercise at Different Levels of Carboxyhemoglobin

Five subjects performed submaximal and maximal bicycle and maximal treadmill exercise in normalcy and after carbon monoxide inhalation, giving different levels of carboxyhemoglobin (COHb) in the blood. During maximal treadmill exercise work time on a fixed work load and maximal oxygen uptake were decreased with increasing level of COHb (r = 0.79 and r = 0.85, respectively). Peak blood lactate concentration and pulmonary ventilation were unchanged. Highest measured heart rate was lower in parallell with the increased COHb level compared to control studies. During submaximal work heart rate was increased and oxygen uptake was unchanged at the various levels of COHb. At low submaximal work loads blood lactate concentrations and oxygen deficit was unchanged but increased as work load and COHb-level increased.     

Metabolic Response to Submaximal and Maximal Exercise in People with Severe Obesity,Prediabetes, and Diabetes

IntroductionMetabolic adaptations to maximal physical exercise in people with obesity (PwO) are scarcely described. This cross-sectional study evaluates the metabolic response to exercise via the respiratory exchange ratio (RER) in PwO and different degrees of glycemic control.MethodsEighty-five PwO (body mass index 46.0 [39.0–54.0] kg/m²), that is, 32 normoglycemic (Ob-N), 25 prediabetic (Ob-preDM), and 28 diabetic (Ob-T2DM) subjects and 18 healthy subjects performed an incremental, maximal cardiopulmonary exercise test. The RER was measured at rest (RERrest) and at peak exercise (RERpeak).ResultsRERpeak was significantly higher in healthy subjects than that in PwO. Among those, RERpeak was significantly higher in Ob-N than that in Ob-preDM and Ob-T2DM (1.20 [1.15–1.27] vs. 1.18 [1.10–1.22] p = 0.04 and vs. 1.14 [1.10–1.18] p < 0.001, respectively). Accordingly, ΔRER (RERpeak-RERrest) was lower in Ob-preDM and Ob-T2DM than that in Ob-N (0.32 [0.26–0.39] p = 0.04 and 0.29 [0.24–0.36] p < 0.001 vs. 0.38 [0.32–0.43], respectively), while no significant difference was found in ΔRER between Ob-preDM and Ob-T2DM and not even between Ob-N and healthy subjects. Moreover, ΔRER in PwO correlated with glucose area under curve (p = 0.002).ConclusionsPwO demonstrate restricted metabolic response during maximal exercise. Particularly, those with prediabetes already show metabolic inflexibility during exercise, similarly to those with type 2 diabetes. These findings also suggest a potential role of cardiopulmonary exercise testing in detecting early metabolic alterations in PwO.     

Effect of Physical Training on Circulation during Prolonged Severe Exercise1

Before, and after 22 weeks of physical training, oxygen uptake, heart rate and cardiac output (dye dilution technique) were measured in 7 male subjects (22 to 26 years old) during pro longed severe exercise (60 min on 75 % of the individual's maximal oxygen uptake) and during exhausting work loads of about 5 min duration. Maximal oxygen uptake increased from 3.41 l/min (48.0 mllkg per min) before to 3.64 I/min (52.0 ml/kg per min) after the training (p<0.05). Maximal heart rate decreased from 201 beats/min before to 194 beats/min after the training (p<0.05). During the 1 hr work period after the training the stroke volume and mean blood pressure became higher (p<0.05) and (a—v)O₂ diff. lower (p<0.05) than before the training. From the 5th to the 60th min of the prolonged work the heart rate increased about 20 beatslmin before as well as after the training.     

Effect of Temperature on Muscle Metabolism During Submaximal Exercise in Humans

To study the effect of temperature on muscle metabolism during submaximal exercise, six endurance-trained men had one thigh warmed and the other cooled for 40 min prior to exercise using water-perfused cuffs. One cuff was perfused with water at 50-55 degrees C (HL) with the other being perfused with water at 0 degree C (CL). With the cuffs still in position, subjects performed cycling exercise for 20 min at a work load corresponding to 70% VO2,peak (where VO2,peak is peak pulmonary oxygen uptake) in comfortable ambient conditions (20-22 degrees C). Muscle biopsies were obtained prior to and following exercise and forearm venous blood was collected prior to and throughout the exercise period. Muscle temperature (Tmus) was not different prior to treatment, but treatment resulted in a large difference in pre-exercise Tmus (difference = 6.9 +/- 0.9 degrees C; P < 0.01). Although this difference was reduced following exercise; it was nonetheless significant (difference = 0.4 +/- 0.1 degree C; P < 0.05). Intramuscular [ATP] was not affected by either exercise or muscle temperature. [Phosphocreatine] decreased (P < 0.01) and [creatine] increased (P < 0.01) with exercise but were not different when comparing HL with CL. Muscle lactate concentration was not different prior to treatment nor following exercise when comparing HL with CL. Muscle glycogen concentration was not different when comparing the trials before treatment, but the post-exercise value was lower (P < 0.05) in HL compared with CL. Thus, net muscle glycogen use was greater during exercise with heating (208 +/- 23 vs. 118 +/- 22 mmol kg-1 for HL and CL, respectively; P < 0.05). These data demonstrate that muscle glycogen use is augmented by increases in intramuscular temperature despite no differences in high energy phosphagen metabolism being observed when comparing treatments. This suggests that the increase in carbohydrate utilization occurred as a direct effect of an elevated muscle temperature and was not secondary to allosteric activation of enzymes mediated by a reduced ATP content.     

体力活动对老年人甲襞微循环的影响

目的 :探讨长期体力活动对老年机体微循环的影响。方法 :对门诊老干部体检、年龄 6 0～ 6 9岁的 31名健康老年人对甲襞微循环常规进行检查。嘱其进行有规律的体力活动 ,如太极拳、慢跑、跳舞等。每日活动 1h以上。一年后复查。结果 :长期体力活动能使老年人的微循环得到明显的改善 ,各项指标与活动前比较差异显著 (P <0 .0 5～0 .0 1)。结论 :老年人长期适当的体力活动能改善机体的微循环 ,从而提高其生活质量。     

Deletion of chromosome 15 (q11 – 13) in a Prader-Labhart-Willi syndrome clinic population

Deletion of the long arm of chromosome 15 has recently been reported in a number of patients with the Prader-Labhart-Willi syndrome who were studied with prometaphase banding. We performed cytogenetic analysis on 12 patients with this disorder in whom the clinical diagnosis was certain. A specific cytogenetic anomaly, del(15q11 – 13) was found in all of the 12 patients. In nine of the 12, the deletion was noted in all cells examined; in two, there was mosaicism, some cells having the deletion and others being normal; one patient had a 7;15 translocation. No clinical differences were evident between individuals with mosaicism for the translocation and those with the typical deletion in all cells examined. The finding that all of our patients with Prader-Labhart-Willi syndrome have a cytogenetic anomaly, with some patients having mosaicism, distinguishes the results of this study from those of previous reports. Prometaphase chromosome analysis is recommended in all individuals clinically suspected of having Prader-Labhart-Willi syndrome and should be considered in hypotonic infants without a specific diagnosis.     

Genetic linkage analysis of schizophrenia using chromosome 11q13–24 markers in Israeli pedigrees

It is generally agreed that there is a genetic component in the etiology of schizophrenia which may be tested by the application of linkage analysis to multiply-affected families. One genetic region of interest is the long arm of chromosome 11 because of previously reported associations of genetic variation in this region with schizophrenia, and because of the fact that it contains the locus for the dopamine D2 receptor gene. In this study we have examined the segregation of schizophrenia with microsatellite dinucleotide repeat DNA markers along chromosome 11q in 5 Israeli families multiply-affected for schizophrenia. The hypothesis of linkage under genetic homogeneity of causation was tested under a number of genetic models. Linkage analysis provided no evidence for significant causal mutations within the region bounded by INT and D11S420 on chromosome 11q. It is still possible, however, that a gene of major effect exists in this region, either with low penetrance or with heterogeneity. © 1995 Wiley-Liss, Inc.     

Effect of Ceruloplasmin on the Number and Resistance of Erythrocytes during Acute Physical Exercise

Acute physical exercise was followed by a decrease in the osmotic resistance of erythrocytes, shortening of the time-to-onset of erythrocyte hemolysis, and increase in the sorption capacity of the cell membrane. Administration of ceruloplasmin 24 h before physical exercise normalizes membrane resistance in red blood cells.     

t(10;11)(p13–14;q14–21): A New Recurrent Translocation in T-Cell Acute Lymphoblastic Leukemias

A workshop held by the ?Groupe Français de Cytogénétique Hématologique”? has identified a t( 10; 11)(p13–14;q14–21) in four acute lymphoblastic leukemias of T-cell lineage. The immunophenotypes were consistent with immature thymocytes. This translocation is therefore a new candidate for a recurrent translocation in early T-cell leukemia. A similar translocation has been reported as a rare change in early pre-B lymphoid leukemias and also in myeloid leukemias. It is not known whether the similar cytogenetic changes involve different molecular breakpoints or whether the same rearrangement affects a multipotential stem cell capable of lymphoid and myeloid differentiation.     

Presence of antibodies to human papillomavirus virus-like particles (VLPs) in 11–13-year-old schoolgirls

To allow meaningful approaches to vaccine development, it is important to know the extent of exposure to human papillomavirus (HPV) within the general population, and particularly the age at which the at risk population is infected. The humoral response to human papillomavirus is directed largely to conformationally-dependent epitopes on the whole virion. Virus-like particles (VLPs) of HPV types 1, 2, and 16 were produced using a baculovirus expression system, and were used in the intact state as antigen in an indirect ELISA. Anonymised serum samples from a cohort of Edinburgh schoolgirls were tested for the presence of IgG antibodies directed against the VLPs. The reproducibility of the ELISA was assured by repeated testing of control samples, and by testing all samples in duplicate and, where possible, on several occasions. Of 1,192 tested with the HPV16 VLPs, 90 (7.6%) were classified as clearly positive, and a further 87 (7.3%) were positive but close to the cutoff calculated by comparison with a group of consistently negative sera. Antibodies to HPV2 were detected in 37.5% (407/1,139) and antibodies to HPV 1 in 51.9% (558/1,076) of the schoolgirls. Antibodies to both HPV1 and HPV2 were found frequently, being present in 29.7% (295/993) of samples tested; 40 samples had antibodies to all three types. The significance of these results is discussed. J. Med. Virol. 56:210–216, 1998. © 1998 Wiley-Liss, Inc.     

Physical activity and levels of inactivity in adolescent females ages 11–16 years in the United Arab Emirates

The purpose of this study was to investigate patterns of physical activity and levels of inactivity in adolescent females in the United Arab Emirates (UAE). A total of 58 adolescent females, age 11–16 years, were recruited from two female‐only governmental schools in Abu‐Dhabi. Subjects were divided into two groups: 11–13 years (n = 22) and 14–16 years (n = 36). Physical activity patterns were determined from a 3‐day activity diary. Total energy expenditure (TEE) was estimated using a factorial approach. The amount of physical activity was expressed as the physical activity level (PAL) and the activity‐related energy expenditure (AEE). The number of hours spent watching television was estimated from the activity diaries. There were no significant differences in the energy expenditure parameters between age groups or between schooldays and weekends. PAL was low in both age groups. Television was the predominant leisure time pursuit. The number of hours per day spent watching television (median and interquartile range) was 2.5 (2.3–3.1) in 11–13 years and 2.5 (2.3–2.8) in 14–16 years. Television‐watching was significantly higher during the weekend than schooldays: 11–13 years (P = 0.006) and 14–16 years (P < 0.001). In conclusion, the amount of physical activity undertaken by adolescent females in the UAE was very low. Cultural and weather restrictions and social change of the community in the UAE are not conducive to physical activity and play a major role in levels of physical inactivity. This may explain, in part, the rise in the incidence of obesity in this population. Am. J. Hum. Biol. 16:346–353, 2004. © 2004 Wiley‐Liss, Inc.     

The Nature of the Training Response; Peripheral and Central Adaptations to One-Legged Exercise

13 male subjects were studied and placed in 3 groups. Each group exercised one leg with sprint (S), or endurance (E) training and the other leg oppositely or not at all (NT). Oxygen uptake (Vo₂), heart rate and blood lactate were measured for each leg separately and for both legs together during submaximal and maximal bicycle work before and after 4 weeks of training with 4–5 sessions per week. Muscle samples were obtained from the quadriceps muscle and assayed for succinate dehydrogenase (SDH) activity, and stained for myofibrillar AT Pase. In addition eight of the subjects performed after the training two-legged exercise at 70% Vo₂ max for one hour. The measurements included muscle glycogen and lactate concentrations of the two legs as well as the blood flow and the a-v difference for O₂, glucose and lactate. The improvement in Vo₂ max, the lowered heart rate and blood lactate response at submaximal work levels were only found when exercising with a trained leg (E or S). Part of the variables studied were markedly more changed with E as compared with S-training. Although muscle fibre composition did not change a pronounced muscle adaptation took place with the training with enhancement of the SDH activity of the S and E legs while the NT-leg did not change. Blood flow and oxygen uptake were similar in NT and S–E legs while femoral vein oxygen content was slightly lower in the trained as compared to the NT-leg. Glycogen utilization was lowest in the trained leg with similar glucose uptake in all legs regardless of training status. Moreover, lactate was only continuously released from the NT-leg. It is concluded that training induces marked local adaptations which not only affects the metabolic response to exercise but also are of importance eliciting an improved cardiovascular function.     

中小学生欺侮行为方式与特点研究

目的　了解中小学生欺侮行为的方式与特点。方法　采用自编的欺侮问卷对 1 1～ 1 6岁 6 88名学生进行调查。结果　 1 1～ 1 6岁学生主要以直接欺侮尤其是直接言语欺侮为主 ,间接欺侮的方式应用较少 ;教室、上学与回家途中等地点极易发生欺侮行为 ;男生欺侮女生较多地采用直接身体欺侮的方式 ;而女生欺侮男生较多地采用直接言语欺侮的方式 ;随着年龄增长 ,受欺侮和欺侮他人的比例呈现下降的趋势 ,小学比初中要高 ,卷入欺侮行为的程度也更严重。男生卷入欺侮他人的程度比女生严重 ,而在受欺侮程度上 ,男生和女生间未见显著性差异。结论　欺侮行为在中小学生中具有普遍性 ,应引起教育工作者足够的重视。     

Maternal origin of 15q11–13 deletions in Angelman syndrome suggests a role for genomic imprinting

Six persons with the classical Angelman syndrome (AS) phenotype and de novo deletions of chromosome 15q11-q13 were studied to determine the parental origin of the chromosome deletion. Four of the 6 patients had informative cytogenetic studies and all demonstrated maternal inheritance of the deletion. These findings, together with other reported cases of the origin of the chromosome 15 deletion in AS, suggest that deletion of the maternally contributed chromosome leads to the AS phenotype. This contrasts with the Prader-Willi syndrome (PWS) in which a similar deletion of the paternally contributed chromosome 15 is observed. In deletion cases, a parental gamete effect such as genomic imprinting may be the best model to explain why apparently identical 15q11-q13 deletions may develop the different phenotypes of AS or PWS.