[Influence of sleep fragmentation in infancy and toddler period on emotional and behavioral problem at the age of 6 years: a birth cohort study].

Objective: To investigate the influence of sleep fragmentation in infancy and toddler period on emotional and behavioral problems at the age of 6 years. Methods: Using a prospective cohort design, 262 children were extracted from mother-child birth cohort recruited from May 2012 to July 2013 in Renji Hospital, School of Medicine, Shanghai Jiao Tong University. Children's sleep and physical activities were assessed using actigraphy at 6, 12, 18, 24, and 36 months of age, from which the sleep fragmentation index (FI) at each follow-up point was calculated. Children's emotional and behavioral problems at 6 years of age were assessed using the strengths and difficulties questionnaire. Group-based trajectory model was applied to determine sleep FI in infancy and toddler period trajectory groups with Bayesian information criteria being used to determine the best fitting model. Children's emotional and behavioral problems between groups were examined with independent t test and linear regression models, etc. Results: A total of 177 children, with 91 boys and 86 girls, were included in the final analysis and were divided into 2 groups: high FI group (n=30) and low FI group (n=147). Compared with children in the low FI group, those in the high FI group presents with higher total difficulties score and higher hyperactivity or inattention score ((11.0±4.9) vs. (8.9±4.1), (4.9±2.7) vs. (3.7±2.3) scores, t=2.17, 2.23, both P<0.05, respectively), with the differences remaining significant after adjusting for covariates (t=2.08, 2.09, both P<0.05 respectively). Conclusion: High sleep fragmentation in infancy and toddler period is associated with more emotional and behavioral problems, especially hyperactivity or inattention problems, at 6 years of age.

[Investigation of dose-dependent association between bedtime routines and sleep outcomes in infants and toddlers].

Objective: To investigate the current bedtime routine among Chinese children less than 3 years of age and explore its dose-dependent association with sleep duration and sleep quality. Method: Healthy full-term born children aged 0-35 months were selected by stratified cluster random sampling method from 8 provinces in China following the "Hospital of Province-City-County" sampling technical route during 2012-2013.Brief Infant Sleep Questionnaire(BISQ) was used to assess sleep conditions of these children.Children's personal and family information was obtained by Shanghai Children's Medical Center Socio-demographic Questionnaire.Both of these questionnaires were filled in by parents. The effects of bedtime routine on children's sleep duration and quality were analyzed by multivariate analysis of variance. Result: The children's average age was(12±10) months(n=1 304), of whom 689 were males (52.8%, 689/1 304). There were 48.5%(632/1 304)of the parents reported that their children had not established regular sleep routines. There was a consistent dose-dependent association between bedtime routine and sleep duration, as well as other indicators for sleep quality (all P<0.05). The more regular the sleep routines, the longer the sleep duration, the earlier the children went to sleep, the shorter the sleep onset latency, the fewer the nighttime wakeup and the shorter the nighttime waking.The nighttime sleep duration was significantly longer for those with a bedtime routine 'every night' than those who 'never' had a bedtime routine (9.5(95%CI: 9.4-9.6)vs. 8.9(95%CI: 8.6-9.3)h, t=3.345, P=0.001). Compared with children who never had bedtime routines, children with regular bedtime routines had fewer night wakeup (1.3(95%CI: 1.2-1.4) vs. 2.4( 95%CI: 2.0-2.9), t=3.182, P=0.001) and shorter night waking duration(16.6(95%CI: 14.6-18.8) vs. 59.2 (95%CI: 47.0-72.7)min, t=6.383, P<0.01). Conclusion: The percentage of children who have established regular bedtime routine is low in China. There is significant dose-dependent association between regular bedtime routine and sleep outcomes, especially sleep quality. The more regular the sleep routines, the better the sleep quality.

Effect and mechanism of different ways of transplanting bone marrow mesenchymal stem cells in cardiopulmonary resuscitation in rats.

The effect and mechanism of different ways of transplanting bone marrow mesenchymal stem cells (MSCs) were explored for treating cardiopulmonary resuscitation in a rat model. Rats were divided into the cardiopulmonary resuscitation group (Group Con), the stereotactic lateral ventricle transplantation group (Group LV), the internal carotid artery transplantation group (Group A), and the femoral vein transplantation group (Group V). MSCs were transplanted in Groups LV, A, and V. The MSC transplantation groups had a significantly higher neurological score than Group Con on days 3 and 7 after recovery (P < 0.05), and the Group LV score was the highest in all groups (P < 0.05). On day 3 after recovery, the MSC count of Group LV was significantly higher than those of Groups A and V (P < 0.01). On day 7 after recovery, the MSC count in the hippocampus of Group LV was significantly higher than those of Groups A and V (P < 0.05). On day 3 after recovery, the S100B level of Group LV was significantly lower than those of Groups A and V (P < 0.05). On day 7 after recovery, the S100B level was not significantly different between the MSC transplantation groups (P > 0.05). The expressions of vascular endothelial growth factor and brain-derived neurotrophic factor did increased significantly in the MSC transplantation groups on day 7 after recovery, particularly Group LV. Therefore, MSC therapy could significantly improve nerve function after cardiopulmonary resuscitation, and stereotactic lateral ventricle injection transplantation is an optimal method.

Kinetics of iron release from pig spleen ferritin with bare platinum electrode reduction.

Several anaerobic electrochemical cells were employed to study the kinetics of iron release from pig spleen ferritin (PSF) at a bare platinum electrode. Controlled potential microcoulometry (CPM) is the principal technology used to investigate the kinetics in the absence of a mediator. A kinetic study of iron release by microcoulometry has revealed that ferritin undergoes direct electron transfer at the electrode in the absence of a mediator, indicating that ferritin is an electroactive protein. Several experiments failed to show that alpha'alpha-bipyridyl has the capacity to reduce hydrolyzed Fe(3+) within the ferritin core after it has been reduced by the electrode at -600 mV vs. NHE in the absence of mediator. PSF is known to bind heme to generate a hemeoprotein, named pig spleen hemeoferritin (PSF(ho)). The rate of iron release is accelerated by the heme binding to PSF(ho) without the need for small mediators. Under similar conditions, two kinetic processes for iron release from PSF and bacterial ferritin of Azoaobacter vinelandii (AvBF) were studied and both fit a zero-order law. In addition, the rate of iron release in PSF can be accelerated two-fold by a specific reduction system consisting of ascorbic acid (AA) and the bare platinum electrode at -600 mV. However, this kinetic process does not follow zero-, half-, first, or second-order rate laws. A model is proposed to explain a mechanism of direct electron transfer between ferritin and the electrode is derived to describe the kinetics of iron release.

Construction of a ferritin reactor: an efficient means for trapping various heavy metal ions in flowing seawater.

An apparatus consisting of two pumps, a mixer, a ferritin reactor, and a spectrophotometer was constructed to study the ability to trap various heavy metal ions (M2+) and the dynamics of a reconstituted ferritin reactor in flowing seawater. Reconstituted pig spleen ferritin (PSFr) is assembled from apo-protein shell to form a reconstituted iron core. The main components of the PSFr are its core, which contains an Fe2+:Pi stoichiometry of 6.0 +/- 0.5, reconstituted from pig spleen apoferritin (apo PSF), Fe2+, inorganic phosphate (Pi), and O2 (0.6 atm). The Fe3+-Pi clusters within the PSFr core exhibit resistance to salt ranging from 1% to 6% NaCl. The ferritin reactor consists of PSFr and an oscillating bag. Using the reactor, M2+ ions such as Cd2+, Zn2+, Co2+, and Mn2+ are directly trapped by the ferritin. We found a 1:2 +/- 0.2 stoichiometry of the trapped M2+ to the released iron as measured by chemical analysis or atomic absorption spectrometry; nontransient elements such as Na+, K+, Ca2+, etc., were scarcely trapped by the reactor. This study provides basic conditions for establishing a ferritin reactor and a convenient means for monitoring the pollution of heavy metal ions in seawater.

Effect of redox mediators on nitrogenase and hydrogenase activities in Azotobacter vinelandii.

In bioelectrochemical studies, redox mediators such as methylene blue, natural red, and thionine are used to studying the redox characteristics of enzymes in the living cell. Here we show that nitrogenase activity in Azotobacter vinelandii is completely inhibited by oxidized methylene blue (MBo) when the concentration of this mediator in the medium is increased up to 72 microM. This activity in A. vinelandii is somewhat inhibited by a coenzyme, ascorbic acid (AA). However, the nitrogenase activity within the A. vinelandii cell is unchanged even for a high concentration of oxidized natural red (NRo) alone. Interestingly, these mediators and AA do not have the capacity to inhibit the H2 uptake activity of the hydrogenase in A. vinelandii. Average active rates of 66 nM H2 evolved/mg cell protein/min from the nitrogenase and 160 nM H2-uptake/mg cell protein/min from the hydrogenase in A. vinelandii are found in aid of the activities of the enzymes for H2 evolution and for H2 uptake are compared. The activities of both enzymes in A. vinelandii are strongly inhibited by thionine having high oxidative potential. Mechanisms of various mediators acting in vivo for both enzymes in A. vinelandii are discussed.

Role of phosphate and kinetic characteristics of complete iron release from native pig spleen ferritin-Fe.

The kinetics for complete iron release showing biphasic behavior from pig spleen ferritin-Fe (PSFF) was measured by spectrophotometry. The native core within the PSFF shell consisted of 1682 hydroxide Fe3+ and 13 phosphate molecules. Inhibition kinetics for complete iron release was measure by differential spectrophotometry in the presence of phosphate; the process was clearly divided into two phases involving a first-order reaction at an increasing rate of 46.5 Fe3+/PSFF/min on the surface of the iron core and a zero-order reaction at a decreasing rate of 6.67 Fe3+/PSFF/min inside the core. The kinetic equation [C(PSFF-Fe3+)max - C(PSFF-Fe3+)t](1/2) = Tmax - Tt gives the transition time between the two rates and represents the complex kinetic characteristics. The rate was directly accelerated twofold by a mixed reducer of dithionite and ascorbic acid. These results suggest that the channel of the PSFF shell may carry out multiple functions for iron metabolism and storage and that the phosphate strongly affects the rate of iron release.

Studies on the heme and H2-uptake reaction from Azotobacter vinelandii bacterial ferritin.

Bacterial ferritin of Azotobacter vinelandii (AvBF) is directly able to pick electrons up for iron release from or transfer them for storage to a platinum electrode in the absence of mediator or other reducer. The ferritin containing the structure of heme-Co2+ in part shows weakened activity to electrode and decreases the rate of iron release greatly. A reversible reduction process of the ferritin is observed by the spectral change regularly ranging from 310 to 260 nm under mixed gases containing 98% H2 and 2% to O2. The activity of nitrogen fixation from the whole cell of A. vinelandii increases greatly by H2 reduction with potentials ranging from -397 to -425 mV vs. NHE, indicating two important roles of H2-uptake reaction of the ferritin in increasing activity of nitrogen fixation and in supplying iron to synthesize nitrogenase.

H2-uptake activity, spectra, reduction potentials, and kinetics of iron release on the surface of iron core from Azotobacter vinelandii bacterial ferritin.

Bacterial ferritin from Azotobacter vinelandii (AvBFo) has a function in H2 uptake. The Fe3+ reduction on the surface of the iron core from AvBFo is accompanied simultaneously by H2 uptake, with a maximum activity of H2 uptake of 450 H2/AvBFo. A reduction potential of -402 mV for iron reduction on the surface of the core is found. A shift to the red the protein absorbance peaks ranging from 280 to 290 nm is observed between pH 5 and 9 under 100% H2 reduction. The reduction potential for iron release becomes negative at a rate of 0.025 mV/Fe2+ released. The kinetics of iron release on the surface of the core is a first-order reaction.

Hormonal regulation of oocyte development and maturation of amphioxus.

Using the electron microscopic technique and radioimmunoassay, the hormonal regulation of the oocyte development and maturation of the amphioxus has been investigated. The results indicate that the exogenous GnRH-A can stimulate the oocyte development and maturation as well as the spawning of the amphioxus. It has further been revealed by radioimmunoassay that GnRH-A can increase the context of sex steroid hormone, especially, estradiol-17 beta, by 1-3 times. The increase of estradiol-17 beta coordinates with the synthesis of oocyte into yolk substance. The results further justify that the hormonal regulation in the oocyte development and maturation of amphioxus is similar to that of vertebrates. This is of great theoretical significance for reproductive endocrine physiology of amphioxus.