Sports participation plays a relevant role in the relationship between birth weight and bone mineral content in adolescents.

The Developmental Origins of Health and Disease hypothesis (DOHaD) proposes that growth during the prenatal period might play a critical role in health, affecting the development of diseases, such as osteoporosis. Bone health is particularly affected by human behaviors when sports participation constitutes the main manifestation of physical exercise. The aim of this study is to analyze the relationship between birth weight (BW) and bone mineral content (BMC) among adolescents, as well as to identify if sports participation and maturity can affect this relationship. The sample was composed of adolescents with ages ranging from 11 to 18 years, stratified according to normal birth weight (n = 331), low birth weight (n = 36), and macrosomia (n = 47), extracted from a wider cross-sectional study (ABCD Growth Study). BW was self-reported by the adolescent's parent. Sports participation was assessed by face-to-face interview. BMC was assessed using dual-energy X-ray absorptiometry. In the multivariate models, the relationships between BW and BMC remained non-significant, while sports participation was significantly related to BMC on lower limbs among boys (r = 0.154; p value = .001) and BMC of upper limbs among girls (r = 0.124; p value = .044). APHV was related to BMC of upper limbs among boys (r = 0.137; p value = .001). In conclusion, BMC was not affected by BW, while this phenomenon seems to be significantly affected by the positive impact of sports participation and maturation on it.

The Combined Relationship of Vitamin D and Weight-Bearing Sports Participation on Areal Bone Density and Geometry Among Adolescents: ABCD - Growth Study.

Osteoporosis is a public health problem, which negatively impacts society and national health services worldwide. Altered mineralization of the skeleton can be caused by persistent vitamin D deficiency. However, the combined impact of both on bone health is still under investigation. In fact, although there is compelling evidence in the literature about the positive effect of weight-bearing sports participation on bone mineral density, its impact on bone geometry gains more attention in pediatric population. The sports modalities that we evaluated were artistic gymnastics and track and field. Nonsports group was composed of 43 adolescents. Bone density was assessed using dual-energy X-ray absorptiometry. Vitamin D concentration was assessed by blood analysis. In the crude comparison of bone outcomes, the sport group presented higher aBMD only in the trochanter (p-value = 0.040). Considering the combination of the engagement in sports and vitamin D, adolescents in the sports group presented significantly higher values of aBMD in lower limbs, whole body, trochanter, shaft, and femur whole body (p-value = 0.024, 0.035, 0.001, 0.019 and 0.003 respectly). In contrast, only the sport group with high vitamin D presented a higher CSA (p-value = 0.015) and femur neck aBMD compared to the non-sport/low vitamin D group. Only adolescents with a combination of sports participation and higher serum concentrations of vitamin D presented better bone geometry, denoting the relevance of the combination of both factors to bone health.

Optimal reference genes for real-time quantitative PCR and the expression of sigma factors in Acidithiobacillus caldus under various conditions.

AIMS: Acidithiobacillus caldus is an important sulphur-oxidizing bacterium that plays crucial roles in the bioleaching industry. This study aims to analyse the optimal reference gene for real-time quantitative PCR (RT-qPCR) under different conditions and investigate the transcription levels of the sigma factor genes in the stress response. METHODS AND RESULTS: We selected six housekeeping genes and analysed them via RT-qPCR using two energy resources, under four stress conditions. Three statistical approaches BestKeeper, geNorm, and NormFinder were utilized to determine transcription stability of these reference genes. The gapdH gene was the best internal control gene using elemental sulphur as an energy resource and under heat stress, map was the best internal control gene under pH and osmotic stress, era was the best internal control gene for the K2 S4 O6 energy resource, and rpoC was the best internal control gene under Cu2+ stress. Furthermore, the expressional levels of 11 sigma factors were analysed by RT-qPCR in the stress response. CONCLUSIONS: Stable internal control genes for RT-qPCR analysis of A. caldus were determined, and the expression patterns of sigma factor genes of A. caldus were investigated. SIGNIFICANCE AND IMPACT OF THE STUDY: The identification of the optimal reference gene and analysis of transcription levels of sigma factors in A. caldus can provide clues for reference gene selection and the study of sigma factor function.

Sports participation improves metabolic profile in adolescents: ABCD growth study.

To analyze the impact of participation in sports with different cardiorespiratory fitness (CRF) demands on changes in metabolic and cardiovascular markers in adolescents. Longitudinal study with 12 months of follow-up (Analysis of Behaviors of Children During Growth [ABCD Growth Study]). Overall, 184 adolescents (age 15.6 ± 2.1) were classified according to sports participation: non-sport (control), low CRF sports, and high CRF sports. Metabolic outcomes were total cholesterol (TC) and its fractions, triacylglycerol (TG), glucose, insulin levels, and the insulin resistance index. Cardiovascular outcomes were arterial thickness (carotid and femoral [ultrasound]), blood pressure, and resting heart rate. Adolescents engaged in sports classified as high CRF demand presented a significant increase in HDL-c (1.2 mg/dL [95%CI: -0.5 to 3.0]) when compared to the non-sport group (-2.4 mg/dL [95%CI: -4.4 to -0.5]). Regular engagement in high CRF sports was significantly related to changes in TC (ß = -0.027 [95%CI: -0.048 to -0.005]), HDL-c (ß = 0.009 [95%CI: 0.001 to 0.019]), LDL-c (ß = -0.032 [95%CI: -0.049 to -0.016]), and glucose (ß = -0.017 [95%CI: -0.025 to -0.008]), while engagement in low CRF sports was related to changes in TG (ß = -0.065 [95%CI: -0.112 to -0.019]). No significant relationships for cardiovascular parameters were observed in the low CRF group, but one significant relationship was found between high CRF sports and changes in SBP (ß = -0.063 [95%CI: -0.117 to -0.009]). In conclusion, engagement in sports seems to be beneficial for improvements in metabolic and cardiovascular parameters in adolescents, mainly sports with higher CRF demand.

Sport-based physical activity recommendations and modifications in C-reactive protein and arterial thickness.

We analyzed the effects of 1 year of engagement in ≥ 300 min/week of organized sports on inflammatory levels and vascular structure in adolescents. The sample was composed of 89 adolescents (11.6 ± 0.7 years old [43 boys and 46 girls]), stratified according to engagement in ≥ 300 min/week of sport practice during at least 12 months of follow-up (n = 15, sport practice; n = 74, non-sport practice). Arterial thickness (carotid and femoral) was assessed by ultrasound scan, while high sensitive C-reactive protein levels were used to assess inflammatory status. Trunk fatness (densitometry scanner), biological maturation (age at peak height velocity), blood pressure, and skipping breakfast were treated as covariates. Independently of body fatness and biological maturation, the group engaged in sports presented a higher reduction in C-reactive protein (mean difference -1.559 mg/L [95%CI -2.539 to -0.579]) than the non-sport group (mean difference -0.414 mg/L [95%CI -0.846 to 0.017]) (p = 0.040). There was a significant relationship between changes in C-reactive protein and changes in femoral intima-media thickness in the non-sport group (r = 0.311 [95%CI 0.026 to 0.549]). CONCLUSION: Inflammation decreased in adolescents engaged in organized sports, independently of trunk fatness and biological maturation. Moreover, inflammation was related to arterial thickening only in adolescents not engaged in sports. What is Known: • Intima media thickness is a relevant marker of cardiovascular disease in pediatric groups, being affected by obesity and inflammation. • The importance of monitoring inflammatory markers from childhood is enhanced by the fact that alterations in these inflammatory markers in early life predict inflammation and alterations in carotid IMT in adulthood. What is New: • Anti-inflammatory properties related to physical exercise performed at moderate intensity, on inflammation and alterations in IMT are not clear in pediatric groups. • Due to the importance that sport participation has assumed as a promoter of improvements in health and quality of life, it is necessary to understand its potential benefits for cardiovascular health during human growth.

Impact of Martial Arts (Judo, Karate, and Kung Fu) on Bone Mineral Density Gains in Adolescents of Both Genders: 9-Month Follow-Up.

PURPOSE: To compare bone mineral density (BMD) gains in adolescents of both genders stratified according to different martial art styles in a 9-month follow-up study. METHODS: The longitudinal study consisted of 29 adolescents of both genders and age between 11 and 17 years stratified into a control group (not engaged in any sport) and 50 fighters (kung fu/karate, n = 29; judo, n = 21). All 79 subjects underwent anthropometric measures (weight, height, leg length, and height set) and dual-energy X-ray absorptiometry (BMD, in g/cm2) at 2 moments, baseline and 9 months later. Maturity offset (age at peak height velocity), lean soft tissue, chronological age, and resistance training were treated as covariates. RESULTS: Male judoists presented higher gains in BMD-spine [0.098 g/cm2 (95% confidence interval, 0.068-0.128)] than control group [0.040 g/cm2 (95% confidence interval, 0.011-0.069)] (post hoc test with P = .030). There was no effect of martial art on BMD gains among girls. Independently of gender, in all multivariate models, lean soft tissue constituted the most relevant covariate. CONCLUSIONS: Judo practice in adolescents affected the bone accrual significantly after 9-month follow-up compared with controls, mainly in boys.

Impact sports and bone fractures among adolescents.

The objective of the present study was to investigate the effects of different sports on stress fractures among adolescents during a 9-month follow-up period. The sample was composed of 184 adolescents divided into three groups (impact sports [n = 102]; swimming [n = 35]; non-sports [n = 47]). The occurrence of stress fracture was reported by participants and coaches. As potential confounders we considered age, sex, resistance training, body composition variables and age at peak of height velocity. There were 13 adolescents who reported fractures during the 9-month period. Bone mineral density values were higher in adolescents engaged in impact sports (P-value = 0.002). Independently of confounders, the risk of stress fracture was lower in adolescents engaged in impact sports than in non-active adolescents (hazard ratio [HR] = 0.23 [95% confidence interval (CI) = 0.05 to 0.98]), while swimming practice was not associated to lower risk of fracture (HR = 0.49 [95% CI = 0.09 to 2.55]). In conclusion, the findings from this study indicate the importance of sports participation among adolescents in the reduction of stress fracture risk, especially with impact sports. More importantly, these results could be relevant for recognising adolescents in danger of not reaching their potential for peak bone mass and later an increased risk of fractures.

Changes in body fatness affect cardiovascular outcomes more than changes in physical activity.

OBJECTIVE: The aim of this study was to analyse whether changes in physical activity and body fatness are related to modifications in cardiovascular risk factors among adolescents. Material and methods A sample of 89 healthy adolescents was recruited for this study. We assessed habitual physical activity, body fat percentage, arterial thickness, blood sample, and biological maturation. Multivariate models were used to analyse the relationships between independent and dependent variables. RESULTS: Physical activity (mean difference: 429.4 steps [95% confidence interval=-427 to 1286]) and body fatness (mean difference: -0.7% [95% confidence interval=-1.6-0.2]) remained stable during the study period. Independent of changes in physical activity, for each percentage increase in body fatness, femoral intima-media thickness increased by 0.007 mm (ß=0.007 [95% confidence interval=0.001-0.013]). Longitudinal relationships were found for high-density lipoprotein-cholesterol (ß=-0.477 mg/dl [95% confidence interval=-0.805 to -0.149]) and triacylglycerol (ß=2.329 mg/dl [95% confidence interval=0.275-4.384]). CONCLUSION: Changes in body fatness are more important than the amount of physical activity on cardiovascular and metabolic risks.

First Report of Potato Virus H on Solanum muricatum in China.

Solanum muricatum, commonly known as pepino, pepino dulce, or tree melon, is a perennial shrub well known for its attractive, sweet, flavorful fruits and is frequently cultivated as an annual. It has gained increasing popularity in China and is grown as a cash crop in many provinces. S. muricatum belongs to the family Solanaceae and is closely related to tomato, eggplant, and potato. In 2012, during a study of serological relationships between PVH and PVM on potatoes, potato virus H (PVH) was detected serendipitously in symptomless pepino plantlets in Beijing, grown from tissue culture stocks. PVH is a recently discovered carlavirus reported from potato plants from Huhhot, Inner Mongolia Autonomous Region. Since then, it was found on potatoes in Yunnan, Hebei, Liaoning, Heilongjiang, and Xinjiang provinces. PVH induces mild symptoms with a slight leaf curl in systemic leaves, but most often it is almost symptomless or latent on potatoes (2). To confirm the presence of PVH on S. muricatum, surveys were conducted in 2012 and 2013 in Gansu, Yunnan, and Guangxi provinces and Beijing. Fruits and leaves were collected randomly from pepino plants displaying no obvious symptoms. For PVH detection, a combination of RT-PCR, genome sequencing and serological assays were used. RNAs extracted from fruits and leaves were amplified using RT-PCR with primer pairs PVHCPF and PVHCPR (2), and extracted samples were probed by Western blotting with the specific polyclonal antiserum against PVH (2). Among the 50 plants randomly collected, fruits and leaves of nine plants tested positive for PVH. Subsequently, an RT-PCR product of the expected size (2.6 kb) encompassing the triple-gene block, the capsid protein gene, and the cysteine-rich protein gene, was amplified with a specific primer pair (PVHB1F 5'-TGATGGAATTTACAAAAAC-3' and PVHUR 5'-CTTATGCGCATCTATCAATC-3'), and then cloned into pMD19-T (TaKaRa, Dalian, China) and sequenced (PVH-Pepino with GenBank Accession No. KF546312). Further sequence comparison showed that PVH-Pepino shared 91 to 98% nucleotide sequence identity in the genes mentioned above with those of the reported potato isolates PVH-Ho and PVH-YN (HM584819 and JQ904630, respectively). PVH-Pepino shared deduced amino acid identity of 98 to 99% in CP gene with PVH-Ho and PVH-YN, respectively, but only shared 57 to 67% amino acid identities with other reported carlaviruses (1,2). Thus, latent infection of PVH on S. muricatum was confirmed. To our knowledge, this is the first report of S. muricatum as a natural host of PVH. Our results suggest that PVH, as a new member of the genus Carlavirus, has a wider host range than originally expected. Potatoes and pepinos are crops widely grown in China. The fact that no symptoms were expressed by PVH in pepino plants (symptomless carrier) and only mild symptoms expressed by PVH in diseased potatoes makes detection and remediation of this disease more difficult. Although this finding does not show that PVH is economically important to pepino, this cannot be excluded in the presence of other viruses (2). References: (1) A. King et al. Page 881 in: Virus Taxonomy, Ninth Report of the International Committee on Taxonomy of Viruses. Elsevier Academic Press, London, 2011. (2) Y. Y. Li et al. PLOS ONE 8(6):e69255, 2013.

First Report on the Occurrence of Cucumber mosaic virus on Fragaria ananassa in China.

More than 20 viruses are known to infect strawberry (Fragaria ananassa), and a substantial number of these include new viruses identified since 2000 that can contribute to disease complexes (2). The most serious virus related losses in commercial strawberries are caused by aphid transmitted viruses (3,4,5). A survey was undertaken from 2012 to 2013 to investigate virus prevalence in commercial strawberries in rural areas of Hebei Province around Beijing, China, that were exhibiting virus symptoms. Visual observations revealed that the incidence of virus-like symptoms ranged from 30 to 50% of the plants and these symptoms included yellowing, leaf malformation, sometimes combined with severe stunting and deformed flowers or fruits. Leaf samples were tested for Strawberry vein banding virus (SVBV), Strawberry mottle virus (SMoV), Strawberry mild yellow edge virus (SMYEV), and Strawberry crinkle virus (SCV), which are the four most prevalent aphid-transmitted viruses in single or mixed infections (2). Testing was conducted by RT-PCR using total RNA extracted from fresh symptomatic strawberry leaves (3). SVBV was detected in 58 of 190 samples, but all of the samples tested negative for SMoV, SMYEV, and SCV. Aphids were present on many of the plants, so the samples were tested for Cucumber mosaic virus (CMV) because CMV is prevalent in Beijing gardens and farms, and recently had been shown to infect maize in China (5). This RT-PCR was carried out with the CMV primer pair CM420-F (5'-TGATTCTACCGTGTGGGTGA-3') and CM420-R (5'-CCGTAAGCTGGATGGACAAC-3') to amplify a portion of the capsid protein coding region and the conserved 3'non-translated regions of the genomic RNAs. This test revealed the presence of 43 CMV-positives out of 190 samples, and only 16 of these samples were co-infected with both SVBV and CMV. Samples infected with CMV only had leaf malformations and yellowing, while no CMV was found in symptomless samples. One of the amplified, CMV-specific DNA fragments was sequenced directly from the PCR product and showed 93.8% nucleotide sequence identity and 100% amino acid sequence identity to the CMV subgroup I (GenBank Accession No. D10538) (1). Subsequent ELISA tests for the CMV presence verified the RT-PCR results (Agdia, Elkhart, IN), and transmission electron microscopy observations revealed 28 nm spherical particles characteristic of CMV in strawberry samples tested positive for CMV. However, we were unable to detect either CMV or SVBV in 89 of the 169 samples from symptomatic plants, which suggested possible presence of the other pathogen(s). To the best of our knowledge, this is the first report of natural infections of CMV in strawberry plants. These data suggests that CMV is a potential threat to strawberry production. References: (1) M. Q. K. Andrew et al. Virus taxonomy: IXth Report of the ICTV, 970, Elsevier, 2012. (2) R. R. Martin and I. E. Tzanetakis. Plant Dis. 97:1358, 2013. (3) J. R. Thompson et al. J. Virol. Methods 111:85, 2003. (4) I. E. Tzanetakis et al. Plant Dis. 90:1343, 2006. (5) R. Wang et al. J. Phytopathol. 161: 880, 2013.

Advertisement and knowledge of tobacco products among Ellisras rural children aged 11 to 18 years: Ellisras Longitudinal study.

BACKGROUND: Tobacco products use is the leading cause of chronic diseases morbidity and mortality. This study explores an exposure to tobacco advertisements factors and knowledge, an association with snuff/pipe usage and cigarette smoking among Ellisras rural children aged between 11 to 18 years. METHODS: A total of 1654 subjects (854 boys and 800 girls) who were part of the Ellisras Longitudinal Study completed the questionnaire. RESULTS: A significant (p < 0.05) number of boys (11.7%) compared to girls (8.8%) received free cigarettes from the members of the community. Bill boards were successful in advertising tobacco products among the Ellisras rural boys (17% boys and 12.8% for girls, p < 0.022). Multivariate analyses found significant association between cigarette smoking (OR = 1.7 95%CI 1.1-2.7 and Model 2 OR 1.6 95%CI 1.0-2.6 adjusted for age and gender) and advertisements of tobacco products on the TV screens, videos or movies. CONCLUSIONS: Exposure to tobacco products advertisements was high among Ellisras rural children. Though tobacco products legislation exists in South Africa, efforts should be taken by the health professionals to emphasize the danger of using tobacco products even among the illiterate. Teachers and parents should refrain from advertising tobacco products at schools and at homes.

Changes in aerobic fitness in boys and girls over a period of 25 years: data from the Amsterdam Growth And Health Longitudinal Study revisited and extended.

In the Amsterdam Growth And Health Longitudinal Study (AGAHLS), a group of approximately 650 12- to 14-year-old boys and girls was followed in their growth, and development of their health their lifestyle including diet, physical activity and smoking. One of the main interests was the change in their aerobic fitness. From 12 to 36 years of age in total, eight repeated measurements were performed to measure peak oxygen uptake (peak VO2). In this study the data of peak VO2 are revisited and extended: We made use of all collected data as a mixed longitudinal design including cross-sectionally measured subjects as well as longitudinally measured subjects. This led to the availability of 1,194 boys and 1356 girls. With Generalized Estimating Equations (GEE) the longitudinal changes with chronological age and differences between boys and girls were analyzed. Teenage boys and girls increased their peak VO2 (ml/min) significantly (p < .001) until age 14 in girls and until age 17 in boys. However peak VO2 relative to bodyweight (peak VO2/BW) had significantly (p < .001) decreased over the whole age range from 12 to 36 in both sexes. Vigorous physical activity (VPA) also showed a decrease and was significantly (p < .001) related with lower peak VO2/BW (Beta = 0.001). This relation was stronger in boys than in girls. Because at the start of AGAHLS no fast responding metabolic instruments were available, future longitudinal studies about aerobic fitness should include also measurement of VO2 kinetics.

Trichosanthes kirilowii: A New Host of Cucurbit mild mosaic virus in China.

Chinese cucumber (Trichosanthes kirilowii Maxim.) is a type of perennial liana plant of the Cucurbitaceae family that is mainly distributed in East Asia and northern Australia. It is an important medicinal plant and commonly used in Chinese herbalism, where it is considered to be one of the 50 fundamental herbs (2). During the summer and autumn of 2012, T. kirilowii plants showing symptoms of mild mosaic on the upper leaves and bright yellow color on the lower leaves were observed in the Haidian district of Beijing, China. Recently similar symptoms induced by Cucurbit mild mosaic virus (CuMMV) on squash have been reported. CuMMV is a new member of the genus Fabavirus in the Comovirinae subfamily, discovered in China in 2006 (1). Total RNA was extracted from five leaf samples of independent plants and used for reverse transcription with an oligo (dT)18 primer, followed by PCR with a pair of CuMMV virus-specific primers FaR13012F (5'-CGAGTGCGAGTTAGAAATTGGGATG-3') and FaR15783R (5'-TCACTTTGAGGTGATAAAACAATCC-3') to amplify a 2,772-bp fragment including RNA-dependent RNA polymerase (RdRp) coding region. The expected target fragment was obtained in all symptomatic plant samples but not from an asymptomatic plant. Nucleotide sequence comparison analysis showed that the virus isolated from T. kirilowii (GenBank Accession No. KC959843) had 95.33% nucleotide identity and 99.15% amino acid identity in the RdRp sequence with a CuMMV isolate from squash (GenBank Accession No. FJ194941) (1). In addition, symptomatic samples tested positive for CuMMV by Western blot using CuMMV small coat protein (SCP) specific polyclonal antibody (1). To our knowledge, this is the first report of T. kirilowii as natural host of CuMMV in China. The impact of CuMMV on T. kirilowii production remains to be determined; however, the extended host range for this virus suggests a potential threat of CuMMV to cucurbit crops in China. References: (1) S. W. Dong et al. Arch. Virol.157:597, 2012. (2) J. H. Hong et al. China Pharmacist 7:561, 2004.

Comparison of the Cardiovascular Effects of Extreme Psychological and Physical Stress Tests in Male Soccer Players.

BACKGROUND: The purpose of our study was to compare the physiological effects of extreme physical and psychological stress tests in male soccer players, since these two types of stress apply to athletes with high performance requirements. METHODS: A total of 63 healthy male soccer players participated in this study, all of whom underwent both of the tests. A physical stress test was carried out in an exercise physiology laboratory, where subjects completed an incremental treadmill running test to full exhaustion, and a psychological test was performed in a military tactical room, where subjects met a street offence situation. Heart rate variability (HRV) and blood pressure (BP) were recorded directly before, immediately after, and 30 min after the stress tests. RESULTS: The majority of HRV indices changed significantly in both stress protocols. Inverse, significant changes (positive for the physical test, negative for the psychological test, p < 0.001) were found when comparing the alterations of HRV indices between the tests. Significant differences were found in the changes in systolic (p = 0.003) and diastolic (p < 0.001) BP between the test protocols, and also between the baseline and post-test measurements (p < 0.001). CONCLUSION: Both HRV and BP are sensitive physiological parameters to measure the impact of extreme physical and/or psychological stress.

Current smoking behaviour among rural South African children: Ellisras Longitudinal Study.

BACKGROUND: The use of tobacco products is the major cause of chronic diseases morbidity and mortality. Most smokers start the smoking habits from childhood and adolescent stages. METHOD: This was a cross-sectional study. A total of 1654 subjects (854 boys and 800 girls), aged 11 to 18 years, who were part of the Ellisras Longitudinal Study completed the questionnaire. Association between tobacco products use and habits, attitudes and beliefs were explored in this study. Logistic regression was used to estimate the association. RESULTS: The prevalence of tobacco product use increases with increasing (4.9 to 17.1%) age among boys whereas girls do not smoke cigarette but only considerable number (1.0 to 4.1%) use home made tobacco products (pipe and snuff) among the Ellisras rural children. Parents and grand parents play a significant (about 50%) role in influencing smoking behaviour among the Ellisras rural children. Seeing actors smoking on TV shows was positively associated (p < 0.05) with smoking (OR = 2.3 95%CI (1.3-4.1 and OR = 2.3 95%CI 1.3-4.1 after adjusting for age and gender). However, women who smoke cigarette were significantly (p < 0.001) associated with success and success and wealth (OR = 2.8, 95% CI 1.5-5.2) even after adjusting for age and gender (OR = 2.9 95% CI 1.5-5.4). CONCLUSION: The usage of tobacco products was high among older boys. Girls did not smoke cigarette. This tobacco use behaviour mirrors the cultural norms and adult behaviour. The association of this tobacco used products with biological parameters will shed more light on the health of these children over time.

Studies on interaction of cucurbit aphid-borne yellow virus proteins using yeast two-hybrid system and bimolecular fluorescence complementation.

In this article, yeast two-hybrid system (YTHS) and bimolecular fluorescence complementation (BiFC) were used to analyze the interactions of cucurbit aphid-borne yellows virus (CABYV)-encoded proteins. P0, P1, P1-2, P3, P4, and P5 were tested by YTHS in all possible pairwise combinations, and only P3/P3 interaction was detected. Results obtained by BiFC further confirmed the self-interaction of P3, and the subcellular localization of reconstituted YFP fluorescence was observed mainly in nuclei of Nicotiana benthamiana leaf epidermal cells. Domains involved in P3/P3 self-interaction were analyzed by YTHS and BiFC using deletion mutants. The results showed that R domain (residues 1-61) in the N-terminus could self-interact, and it also interacted with the S domain (residues 62-199) in the C-terminus of P3. The present work would serve as a molecular basis for further characterization of CABYV proteins, and the regions involved in P3/P3 self-interaction could provide the clue for understanding the capsid assembly pathway of CABYV.

Effect of mechanical and thermal treatments on the microstructure and rheological properties of carrot, broccoli and tomato dispersions.

BACKGROUND: The food industry has shown an increased interest in the manufacture of healthier and more natural food products. By tailored processing fruit and vegetables can be used as structurants thus reducing artificial gums and stabilisers. The effect of different thermal and mechanical treatments, including high-pressure homogenisation, on the microstructural and rheological properties of carrot, broccoli and tomato dispersions was studied. As part of the rheological characterisation small oscillatory deformation as well as shear flow measurements were performed. RESULTS: Carrot and broccoli showed a different behaviour from tomato under the conditions studied. Changing the order of thermal and mechanical treatment led to microstructures with different flow properties. The resulting microstructures differed in the manner of cell wall separation: either breaking across the cell walls or through the middle lamella. High-pressure homogenisation decreased the viscosity of carrot and broccoli dispersions, while it increased the viscosity of tomato. Cryo-scanning electron microscopy showed that the cell walls of carrot and broccoli remained as compact structures after homogenisation whereas tomato cell walls were considerably swollen. CONCLUSIONS: Based on the type of vegetable, the different processes applied led to microstructures with different rheological properties. This study shows that particle size distribution, morphology and phase volume are important parameters to explain the complex relationship between rheology and microstructure for these types of systems.

Physiological and Psychological Responses to a Maximal Swimming Exercise Test in Adolescent Elite Athletes.

BACKGROUND: Continuously rising performances in elite adolescent athletes requires increasing training loads. This training overload without professional monitoring, could lead to overtraining in these adolescents. METHODS: 31 elite adolescent athletes (boys: n = 19, 16 yrs; girls: n = 12, 15 yrs) participated in a field-test which contained a unified warm-up and a 200 m maximal freestyle swimming test. Saliva samples for testosterone (T) in boys, estradiol (E) in girls and cortisol (C) in both genders were collected pre-, post- and 30 min post-exercise. Lactate levels were obtained pre- and post-exercise. Brunel Mood Scale, Perceived Stress Scale and psychosomatic symptoms questionnaires were filled out post-exercise. RESULTS: Lactate levels differed between genders (boys: pre: 1.01 ± 0.26; post: 8.19 ± 3.24; girls: pre: 0.74 ± 0.23; post: 5.83 ± 2.48 mmol/L). C levels increased significantly in boys: pre- vs. post- (p = 0.009), pre- vs. 30 min post-exercise (p = 0.003). The T level (p = 0.0164) and T/C ratio (p = 0.0004) decreased after field test which draws attention to the possibility of overtraining. Maximal and resting heart rates did not differ between genders; however, heart rate recovery did (boys: 29.22 ± 7.4; girls: 40.58 ± 14.50 beats/min; p = 0.008). CONCLUSIONS: Our models can be used to explain the hormonal ratio changes (37.5-89.8%). Based on the results this method can induce hormonal response in elite adolescent athletes and can be used to notice irregularities with repeated measurements.

Change in the Mindset of a Paediatric Exercise Physiologist: A Review of Fifty Years Research.

In this review, the career of a pediatric exercise physiologist (HCGK) is given over a period of almost 50 years. His research was concentrated on the relationship of physical activity (physical education, sport, and daily physical activity) with health and fitness in teenagers in secondary schools. (1) His first experiment was an exercise test on a bicycle ergometer to measure aerobic fitness by estimating physical work capacity at a heart rate of 170 beats/minute (PWC170). (2) Secondly, a randomized control trial (RCT) was performed with an intervention of more intensive physical education (PE) with circuit interval training during three lessons per week over a period of six weeks. (3) Thereafter, a second RCT was performed with an intervention of two extra PE lessons per week over a whole school year. The results of these two RCTs appeared to be small or nonsignificant, probably because the effects were confounded by differences in maturation and the habitual physical activity of these teenagers. (4) Therefore, the scope of the research was changed into the direction of a long-term longitudinal study (the Amsterdam Growth And Health Longitudinal Study). This study included male and female teenagers that were followed over many years to get insight into the individual changes in biological factors (growth, fitness, obesity, hypercholesterolemia, and hypertension) and lifestyle parameters such as nutrition, smoking, alcohol usage, and daily physical activity. With the help of new advanced statistical methods (generalized estimating equations, random coefficient analysis, and autoregression analysis) suitable for longitudinal data, research questions regarding repeated measurements, tracking, or stability were answered. New measurement techniques such as mineral bone density by means of dual-energy X-ray absorptiometry (DEXA) showed that bone can also be influenced by short bursts of mechanical load. This changed his mind: In children and adolescents, not only can daily aerobic exercise of at least 30 to 60 minutes duration increase the aerobic power of muscles, but very short highly intensive bursts of less than one minute per day can also increase the strength of their bones.