Physical activity, body mass index and mental health in Chinese adolescents: a population based study

AIM

The aim of the present study was to examine the association between physical activity, BMI level and mental health among Chinese adolescents.

METHODS

Three thousand ninety-six adolescents aged 11 to 13 were analyzed from 6 middle schools of Xuzhou. Physical activity level was measured using self-designed questionnaires. BMI was calculated according to the results of these students' physical examinations. Anxiety symptoms were assessed by using the Screen for Child Anxiety Related Emotional Disorder, depression via the Children's Depression Inventory. Data were analyzed using chi-square test and logistic regression.

RESULTS

Adolescents' self-reported rate of insufficient physical activity was 58.1%. The overweight and obesity rates were 18.4%, 16.0%. The point prevalence rates on anxiety and depression were 15.2%, 11.5%. Insufficient physical activity was positively associated with anxiety and depression (OR [95%CI]: 1.31 [1.06-1.63]; 1.33 [1.04-1.70]). Obesity was positively associated with depression (OR [95%CI]: 1.48 [1.10-2.00]). IS-OB was positively associated with anxiety and depressive (OR [95%CI]: 1.71 [1.19-2.45]; 1.99 [1.33-2.97]).

CONCLUSION

Physical inactivity and overweight/obesity were negatively association with mental health of adolescents, respectively. Meanwhile, to explore the combined effects of physical inactivity and obesity would increase the risk of anxiety and depression in adolescents.

Ordered arrays of magnetic metal nanotubes and nanowires encapsulated with carbon tubes

The ordered arrays of magnetic metal (including Fe, Co and Ni) nanotubes and nanowires encapsulated with carbon tubes are controllably synthesized by employing the array of C tubes as second-order template and combining with electrodeposition technique. The wall thickness and diameter of carbon nanotubes are uniform along the whole tubes; also the wall thickness of inner metal nanotubes is adjustable from 25 nm to solid nanowires. These composite structures are characterized by X-ray diffractometer (XRD), energy-dispersive spectrometry (EDS), Raman scattering spectrum, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The magnetic properties show that coaxial nanotubes and nanocables composite arrays all exhibit magnetic anisotropy with the easy direction perpendicular to axis of the metal nanotubes or nanowires except the Ni at C coaxial nanotubes array that has no preferable magnetization axis.

Facile preparation method for rare earth phosphate hollow spheres and their photoluminescence properties

We have developed a template-free hydrothermal method of constructing rare earth phosphate hollow spheres using H(6)P(4)O(13) as the PO(4) (3-) source. The mechanism of hollow spheres formation was proposed on the basis of Ostwald ripening. The resulting hollow spheres, especially with the aid of doping of other lanthanide cations, exhibit emission spanning the whole UV-visible wavelength range.

3-D ordered macroporous cuprous oxide: Fabrication, optical, and photoelectrochemical properties

Cuprous oxide 3-D ordered macroporous material was constructed by electrochemical deposition using a polystyrene colloidal crystal as template. The highly ordered macroporous structure with a hexagonal array can be extended over hundreds of square micrometers. The photonic stop bands of both the PS colloidal crystal and Cu2O 3DOM were found. Due to the highly ordered porous structure, the optical absorption and the charge carrier transportation are better in Cu2O 3DOM than in bulk Cu2O, which makes the reduction of oxygen faster on Cu2O 3DOM than on bulk Cu2O under visible light illumination. The higher photocurrent efficiency under visible light illumination makes the 3DOM Cu2O more suitable for solar applications.

Synthesis of poly (3-hydroxybutyrate-co-3-hydroxyoctanoate) by a Sinorhizobium fredii strain

AIMS

The potential of a Sinorhizobium fredii strain to produce a copolymer from glucose and sodium dodecanoate substrates was investigated.

METHODS AND RESULTS

Using an orthogonal design in a flask-shaker culture system, the vital regulation conditions for copolymer synthesis were optimized. These optimal results were applied to further studies in a two-stage fed-batch fermentation with a 10-l fermentor. When the biomass approached 33.5 g l(-1) dry cells at 35 h, 7 mmol l(-1) sodium dodecanoate was added into the broth to trigger the copolymer synthesis. After further culturing for 3 h, the copolymer product could be 17.14 g l(-1). The molecular structure of the copolymer was determined to be a poly (3-hydroxybutyrate-co-3-hydroxyoctanoate) [P (HB-HO)] by nuclear magnetic resonance. The content of HB and HO in P (HB-HO) was 79.2% (w/w) and 20.8% (w/w) respectively. The molecular weight of the P (HB-HO) was measured as 1.85 x 10(5) Da by a viscosity method.

CONCLUSION

The results demonstrated that the S. fredii strain used could be a potential candidate for the industrial production of the copolymer.

SIGNIFICANCE AND IMPACT OF THE STUDY

Some basic fermentation parameters were acquired through the fed-batch culturing experiments and they should be applicable in developing large-scale fermentation technologies for producing the P (HB-HO) copolymers.

Differential roles of neuronal and endothelial nitric oxide synthases during carrageenan-induced inflammatory hyperalgesia

The present study investigated the role of neuronal nitric oxide synthase (nNOS) in carrageenan-induced inflammatory pain by combining genomic and pharmacological strategies. Intrathecal injection of the nNOS inhibitor 7-nitroindazole dose-dependently inhibited carrageenan-induced thermal hyperalgesia in both early and late phases in wild-type mice. However in nNOS knockout mice, carrageenan-induced thermal hyperalgesia remained intact in the early phase but was reduced in the late phase. Spinal Ca2+ -dependent nitric oxide synthase (NOS) activity in nNOS knockout mice was significantly lower than that in wild-type mice. Following carrageenan injection, although the spinal Ca2+ -dependent NOS activity in both wild-type and knockout mice increased, the enzyme activity in nNOS knockout mice reached a level similar to that in wild-type mice. On the other hand, no significant difference in spinal Ca2+ -independent NOS activity was noted between wild-type and nNOS knockout mice before and after carrageenan injection. Furthermore, intrathecal administration of the endothelial NOS (eNOS) inhibitor L-N5-(1-iminoethyl)-ornithinein nNOS knockout mice inhibited the thermal hyperalgesia in both early and late phases, though this inhibitor had no effect in wild-type mice. Meanwhile, Western blot showed that eNOS expression in the spinal cord of nNOS knockout mice was up-regulated compared with wild-type mice; immunohistochemical staining showed that the spinal eNOS was mainly distributed in superficial laminae of the dorsal horn. Finally, double staining with confocal analysis showed that the enhanced spinal eNOS was expressed in astrocytes, but not in neurons. Our current results indicate that nNOS plays different roles in the two phases of carrageenan-induced inflammatory pain. In this model, enhanced spinal eNOS appears to compensate for the role of nNOS in nNOS knockout mice.

Efficient preparation of L-cysteic acid and its esters

L-Cysteic acid and its esters were prepared in good yields from the oxidation of L-cystine by chlorine in water and in alcohols. When the reaction was carried out in alcohols the corresponding esters were produced.

Evidence of neuronal excitatory amino acid carrier 1 expression in rat dorsal root ganglion neurons and their central terminals

The expression and distribution of the neuronal glutamate transporter, excitatory amino acid carrier-1 (EAAC1), are demonstrated in the dorsal root ganglion neurons and their central terminals. Reverse transcriptase-polymerase chain reaction shows expression of EAAC1 mRNA in the dorsal root ganglion. Immunoblotting analysis further confirms existence of EAAC1 protein in this region. Immunocytochemistry reveals that approximately 46.6% of the dorsal root ganglion neurons are EAAC1-positive. Most EAAC1-positive neurons are small and around 250-750 microm2 in surface area, and some co-label with calcitonin gene-related peptide (CGRP) or isolectin IB4. In the spinal cord, EAAC-1 immunoreactive small dot- or patch-like structures are mainly localized in the superficial dorsal horn, and some are positive for CGRP or labeled by isolectin IB4. Unilateral dorsal rhizotomy experiments further show that EAAC1 immunoreactivity is less intense in superficial dorsal horn on the side ipsilateral to the dorsal rhizotomy than on the contralateral side. The results indicate the presence of EAAC1 in the dorsal root ganglion neurons and their central terminals. Our findings suggest that EAAC1 might play an important role in transmission and modulation of nociceptive information via the regulation of pre-synaptically released glutamate.

Knockdown of spinal cord postsynaptic density protein-95 prevents the development of morphine tolerance in rats

The activation of spinal cord N-methyl-D-aspartate (NMDA) receptors and subsequent intracellular cascades play a pivotal role in the development of opioid tolerance. Postsynaptic density protein-95 (PSD-95), a molecular scaffolding protein, assembles a specific set of signaling proteins around NMDA receptors at neuronal synapses. The current study investigated the possible involvement of PSD-95 in the development of opioid tolerance. Opioid tolerance was induced by intrathecal injection of morphine sulfate (20 microg/10 microl) twice a day for 4 consecutive days. Co-administration of morphine twice daily and PSD-95 antisense oligodeoxynucleotide (50 microg/10 microl) once daily for 4 days not only markedly reduced the PSD-95 expression and its binding to NMDA receptors in spinal cord but also significantly prevented the development of morphine tolerance. In contrast, co-administration of morphine twice daily and PSD-95 missense oligodeoxynucleotide (50 microg/10 microl) once daily for 4 days did not produce these effects. The PSD-95 antisense oligodeoxynucleotide at the doses we used did not affect baseline response to noxious thermal stimulation or locomotor function. The present study indicates that the deficiency of spinal cord PSD-95 attenuates the development of opioid tolerance. These results suggest that PSD-95 might be involved in the central mechanisms of opioid tolerance and provide a possible new target for prevention of development of opioid tolerance.

Intact carrageenan-induced thermal hyperalgesia in mice lacking inducible nitric oxide synthase

To date, the exact role of inducible nitric oxide synthase (iNOS) in inflammatory pain remains controversial. In the present study, we combined a pharmacological strategy (using a selective iNOS inhibitor) with a genomic strategy (using mice lacking the iNOS gene) to address the function of iNOS in the central mechanism of carrageenan-induced persistent inflammatory pain. In the wild type mice, intrathecal administration of L-N(6)-(1-iminoethyl)-lysine, a selective iNOS inhibitor, significantly inhibited thermal hyperalgesia in the late phase but not in the early phase of carrageenan inflammation. Moreover, iNOS mRNA expression in the lumbar enlargement segments of the spinal cord was dramatically induced at 24 h (late phase) after injection of carrageenan into a hind paw. Interestingly, targeted disruption of iNOS gene did not affect carrageenan-induced thermal hyperalgesia in either the early (2-6 h) or late phase. In the lumbar enlargement segments of iNOS knockout mice, nitric oxide synthase (NOS) enzyme activity remained at a similar level to that of the wild type mice at 24 h after carrageenan injection. We found that intrathecal administration of 7-nitroindazole (a selective neuronal NOS inhibitor), but not L-N(5)-(1-iminoethyl)-ornithine (a selective endothelial NOS inhibitor), significantly reduced carrageenan-induced thermal hyperalgesia in both the early phase and the late phase in iNOS knockout mice. We also found that expression of neuronal NOS but not endothelial NOS in the lumbar enlargement segments was significantly increased in iNOS knockout mice compared with wild type mice at 24 h after carrageenan injection. Our results indicate that neuronal NOS might compensate for the function of iNOS in the late phase of carrageenan-induced inflammatory pain in iNOS knockout mice. This suggests that iNOS may be sufficient, but not essential, for the late phase of the carrageenan-induced thermal hyperalgesia.