Endurance training in humans leads to fiber type-specific increases in levels of peroxisome proliferator-activated receptor-[gamma] coactivator-1 and peroxisome proliferator-activated receptor-[alpha] in skeletal muscle

The peroxisome proliferator-activated receptor (PPAR)-γ coactivator-1 (PGC-1) can induce mitochondria biogenesis and has been implicated in the development of oxidative type I muscle fibers. The PPAR isoforms α, β/δ, and γ control the transcription of genes involved in fatty acid and glucose metabolism. As endurance training increases skeletal muscle mitochondria and type I fiber content and fatty acid oxidative capacity, our aim was to determine whether these increases could be mediated by possible effects on PGC-1 or PPAR-α, -β/δ, and -γ. Seven healthy men performed 6 weeks of endurance training and the expression levels of PGC-1 and PPAR-α, -β/δ, and -γ mRNA as well as the fiber type distribution of the PGC-1 and PPAR-α proteins were measured in biopsies from their vastus lateralis muscle. PGC-1 and PPAR-α mRNA expression increased by 2.7- and 2.2-fold (P < 0.01), respectively, after endurance training. PGC-1 expression was 2.2- and 6-fold greater in the type IIa than in the type I and IIx fibers, respectively. It increased by 2.8-fold in the type IIa fibers and by 1.5-fold in both the type I and IIx fibers after endurance training (P < 0.015). PPAR-α was 1.9-fold greater in type I than in the II fibers and increased by 3.0-fold and 1.5-fold in these respective fibers after endurance training (P < 0.001). The increases in PGC-1 and PPAR-α levels reported in this study may play an important role in the changes in muscle mitochondria content, oxidative phenotype, and sensitivity to insulin known to be induced by endurance training.

Puberty and the onset of substance use and abuse

Objective: Substance abuse remains one of the major threats to adolescent health in Western cultures. The study aim was to ascertain the extent of association between pubertal development and early adolescent substance use.

Methods: The design was a cross-sectional survey of 10- to 15-year-old subjects in the states of Washington, United States, and Victoria, Australia. Participants were 5769 students in grades 5, 7, and 9, drawn as a 2-stage cluster sample in each state, and the questionnaire was completed in the school classrooms. The main outcomes of the study were lifetime substance use (tobacco use, having been drunk, or cannabis use), recent substance use (tobacco, alcohol, or cannabis use in the previous month), and substance abuse (daily smoking, any binge drinking, drinking at least weekly, or cannabis use at least weekly).

Results: The odds of lifetime substance use were almost twofold higher (odds ratio [OR]: 1.7; 95% confidence interval [CI]: 1.4–2.1) in midpuberty (Tanner stage III) and were threefold higher (OR: 3.1; 95% CI: 2.4–4.2) in late puberty (Tanner stage IV/V), after adjustment for age and school grade level. Recent substance use was moderately higher (OR: 1.4; 95% CI: 1.0–1.9) in midpuberty and more than twofold higher (OR: 2.3; 95% CI: 1.7–3.3) in late puberty. The odds of substance abuse were twofold higher (OR: 2.0; 95% CI: 1.2–3.2) in midpuberty and more than threefold higher (OR: 3.5; 95% CI: 2.2–5.4) in late puberty. Reporting most friends as substance users was more likely in the later stages of pubertal development, a relationship that accounted in part for the association found between later pubertal stage and substance abuse.

Conclusions: Pubertal stage was associated with higher rates of substance use and abuse independent of age and school grade level. Early maturers had higher levels of substance use because they entered the risk period at an earlier point than did late maturers. The study findings support prevention strategies and policies that decrease recreational substance use within the peer social group in the early teens.

Cyclic GMP modulates stomatal opening induced by natriuretic peptides and immunoreactive analogues

In this paper we demonstrate that compounds that promote stomatal opening such as kinetin, atrial natriuretic peptide (ANP) and plant natriuretic peptide immunoanalogues (irPNP) significantly elevate cGMP in guard cell protoplasts. Stomata opened by irPNP are induced to close in the presence of the guanylate cyclase inhibitor, LY 83583. The effect of cGMP on stomatal opening appears to be linked with Ca2+ levels. ANP, irPNP and 8-Br-cGMP all induce stomatal opening and this is inhibited by compounds that lower intracellular Ca2+ levels such as ethylene glycol bis(β-aminoethyl ether) N,N,N’,N’-tetraacetic acid (EGTA), ruthenium red and procaine.

Sustained low-efficiency dialysis with filtration (SLEDD-f) in the management of acute sodium valproate intoxication

Hemodialysis is only infrequently used in drug overdosage situations. The efficacy of hemodialysis to remove the drug depends upon the pharmacokinetics and pharmacodynamics of the drug. At normal therapeutic concentrations, valproic acid is predominantly protein bound and therefore removal by hemodialysis is limited. In an overdose situation, protein binding is rapidly saturated and therefore the substantially larger quantities of the free drug can rapidly cause toxicity. Slow low-efficient daily diafiltration (SLEDD) has not previously been utilized in a drug overdose situation. We report the effective use of SLEDD to remove high toxic concentrations of valproic acid in an overdose situation. Slow low-efficient daily diafiltration also prevented the rebound phenomenon that can occur as the excess drug is released from its protein-bound stores. Hybrid dialysis therapies deserve further evaluation in the management of other poisonings where extra-corporeal therapy is indicated.

Influence of peers on breastfeeding discontinuation among new parents : the Melbourne InFANT Program

OBJECTIVE We aimed to investigate whether the proportion of breastfeeding mothers in first-time parent groups influenced the likelihood of ceasing breastfeeding and whether this was independent of socioeconomic position.
METHODS Data were from 501 mothers (from 62 first-time parent groups initiated ~6 weeks after birth) who provided data at the baseline and mid-intervention assessments of the Melbourne Infant Feeding, Activity, and Nutrition Trial. Parent groups were divided into those in which ≤25% of mothers had ceased breastfeeding by 6 weeks (low-cessation groups) and those in which >25% had ceased by 6 weeks (high-cessation groups).
RESULTS With the exclusion of mothers who had already ceased breastfeeding by 6 weeks, the proportion of mothers who ceased breastfeeding between the time of parent group initiation (6 weeks) and 6 months was higher in high-cessation groups than in low-cessation groups (37.4% vs 21.7%; P = .001). After adjustment for maternal age, BMI, employment, and education and area-level socioeconomic position, membership in a group in which a large proportion of mothers had ceased breastfeeding by 6 weeks was strongly related to cessation of breastfeeding before 6 months (odds ratio: 2.1 [95% confidence interval: 1.3–3.3]).
CONCLUSIONS Attendance at parent groups where peers are breastfeeding infants of a similar age may have an important influence on the continuation of breastfeeding to 6 months. First-time parent groups or other similar groups may be an important setting in which to promote the continuation of breastfeeding.

Pubertal stage and the prevalence of violence and social/relational aggression

OBJECTIVE We examined associations between pubertal stage and violent adolescent behavior and social/relational aggression.

METHODS The International Youth Development Study comprises statewide representative student samples in grades 5, 7, and 9 (N = 5769) in Washington State and Victoria, Australia, drawn as a 2-stage cluster sample in each state. We used a school-administered, self-report student survey to measure previous-year violent behavior (ie, attacking or beating up another person) and social/relational aggression (excluding peers from the group, threatening to spread lies or rumors), as well as risk and protective factors and pubertal development. Cross-sectional data were analyzed.

RESULTS Compared with early puberty, the odds of violent behavior were approximately threefold higher in midpuberty (odds ratio [OR]: 2.87 [95% confidence interval (CI): 1.81–4.55]) and late puberty (OR: 3.79 [95% CI: 2.25–6.39]) after adjustment for demographic factors. For social/relational aggression, there were weaker overall associations after adjustment, but these associations included an interaction between pubertal stage and age, and stronger associations with pubertal stage at younger age were shown (P = .003; midpuberty OR: 1.78 [95% CI: 1.20–2.63]; late puberty OR: 3.00 [95% CI: 1.95–4.63]). Associations between pubertal stage and violent behavior and social/relational aggression remained after the inclusion of social contextual mediators in the analyses.

CONCLUSIONS Pubertal stage was associated with higher rates of violent behavior and social/relational aggression, with the latter association seen only at younger ages. Puberty is an important phase at which to implement prevention programs to reduce adolescent violent and antisocial behaviors.

Traditional knowledge, traditional cultural expressions and intellectual property law in the Asia-Pacific region

Contents

* The international debate about traditional knowledge and approaches in the Asia-Pacific region / Christoph Antons
* How are the different views of traditional knowledge linked by international law and global governance? / Christopher Arup
* Protection of traditional knowledge by geographical indications / Michael Blakeney
* An analysis of WIPO's latest proposal and the Model Law 2002 of the Pacific Community for the Protection of Traditional Cultural Expressions / Silke von Lewinski
* The role of customary law and practice in the protection of traditional knowledge related to biological diversity / Brendan Tobin
* Can modern law safeguard archaic cultural expressions? : observations from a legal sociology perspective / Christoph Beat Graber
* Branding identity and copyrighting culture : orientations towards the customary in traditional knowledge discourse / Martin Chanock
* Being indigenous' in Indonesia and the Philippines / Gerard A. Persoon
* Indigenous heritage and the digital commons / Eric Kansa
* Traditional cultural expression and the internet world / Brian Fitzgerald and Susan Hedge
* Cultural property and "the public domain" : case studies from New Zealand and Australia / Susy Frankel and Megan Richardson
* The recognition of traditional knowledge under Australian biodiscovery regimes : why bother with intellectual property rights? / Natalie Stoianoff
* Protection of traditional knowledge in the SAARC region and India's efforts / S.K. Verma
* The protection of expressions of folklore in Sri Lanka / Indunil Abeyesekere
* Traditional medicine and intellectual property rights : a case study of the Indonesian jamu industry / Christoph Antons and Rosy Antons-Sutanto.