Epidemiological analysis of childhood cancer in China / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To analyze the epidemiological features of childhood cancer in China, and to provide some clues and basis for related academic research, the formulation of prevention and control strategy, and the construction of prevention and control system of childhood cancer.</p><p><b>METHODS</b>The data of childhood cancer in children aged 0-14 years which were published in Chinese Cancer Registry Annual Report in 2009-2012 and from GLOBOCAN2012 database were collected. A descriptive statistical analysis was done to determine the distributions of incidence and mortality by time, area, age, and sex.</p><p><b>RESULTS</b>In China, the incidence of childhood cancer showed a slight fluctuation with time, while the mortality rate remained stable. The incidence of childhood cancer in China was lower than the world average, and it was much lower than in the United States and Japan. However, the mortality of childhood cancer in China was higher than that in the United States and Japan. The incidence of childhood cancer in Chinese urban areas was about 2 times that in Chinese rural areas, while the mortality in the urban and rural areas was similar. The incidence and the mortality of childhood cancer both declined with increasing age. The incidence and the mortality of childhood cancer in boys were higher than those in girls.</p><p><b>CONCLUSIONS</b>The incidence and mortality of childhood cancer in China show distribution characteristics by time, area, age, and sex, which can help to make clear the future direction of childhood cancer research and provide some ideas for the comprehensive prevention and control.</p>

Mg(2+) inhibits ATP-activated current mediated by rat P2X4 receptors expressed in Xenopus oocytes / 生理学报

To investigate the modulation of Mg(2+) on rat P2X4 receptors and its underlying mechanism, we transcribed cDNA coding for wild-type and mutant P2X4 receptors to cRNA in vitro, injected the cRNA to oocytes of Xenopus laevis using the microinjection technique and revealed the effect of Mg(2+) on ATP-activated currents (I(ATP)) mediated by P2X4 receptors using the two-electrode whole-cell voltage clamp technique. The effects of extracellular Mg(2+) on I(ATP) were as follows: (1) In oocytes expressing P2X4 receptors, Mg(2+) with concentration ranging from 0.5-10 mmol/L inhibited the amplitude of I(ATP) in a concentration-dependent and reversible manner, with a 50% inhibitory concentration value (IC(50)) of (1.24 ± 0.07) mmol/L for current activated by 100 μmol/L ATP. (2) Mg(2+) (1 mmol/L) shifted the dose-response curve for I(ATP) right-downward without changing the EC(50), but reduced the maximal current (E(max)) by (42.0 ± 2.1)%. (3) After being preincubated with Mg(2+) for 80 s, the inhibitory effect of the Mg(2+) on I(ATP) reached the maximum. (4) The inhibition of Mg(2+) on I(ATP) was independent of membrane potential from -120 mV to +60 mV. (5) Compared with the current activated by 100 μmol/L ATP in the wild-type P2X4 receptors, mutant P2X4 D280Q responded to the application of 100 μmol/L ATP with a smaller current. The peak current was only (4.12 ± 0.15)% of that seen in wild-type receptors. Mutant P2X4 D280E responded to ATP stimulation with a current similar to that observed in cells expressing wild-type receptors. (6) When Asp280 was removed from P2X4, the current amplitude of I(ATP) was increased almost one-fold, and Mg(2+) with concentration ranging from 0.5-10 mmol/L did not affect the I(ATP) significantly. The results suggest that Mg(2+) inhibits I(ATP) mediated by P2X4 receptors non-competitively, reversibly, concentration-dependently, time-dependently and voltage-independently. The inhibitory effect of Mg(2+) might be realized by acting on the site Asp280 of the P2X4 receptors.

Effects of chronic multiple stress on learning and memory and the expression of Fyn, BDNF, TrkB in the hippocampus of rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The effect of chronic stress on cognitive functions has been one of the hot topics in neuroscience. But there has been much controversy over its mechanism. The aim of this study was to investigate the effects of chronic multiple stress on spatial learning and memory as well as the expression of Fyn, BDNF and TrkB in the hippocampus of rats.</p><p><b>METHODS</b>Adult rats were randomly divided into control and chronic multiple stressed groups. Rats in the multiple stressed group were irregularly and alternatively exposed to situations of vertical revolution, sleep expropriation and restraint lasting for 6 weeks, 6 hours per day with night illumination for 6 weeks. Before and after the period of chronic multiple stresses, the performance of spatial learning and memory of all rats was measured using the Morris Water Maze (MWM). The expression of Fyn, BDNF and TrkB proteins in the hippocampus was assayed by Western blotting and immunohistochemical methods. The levels of Fyn and TrkB mRNAs in the hippocampus of rats were detected by RT-PCR technique.</p><p><b>RESULTS</b>The escape latency in the control group and the stressed group were 15.63 and 8.27 seconds respectively. The performance of spatial learning and memory of rats was increased in chronic multiple stressed group (P < 0.05). The levels of Fyn, BDNF and TrkB proteins in the stressed group were higher than those of the control group (P < 0.05). The results of immunoreactivity showed that Fyn was present in the CA3 region of the hippocampus and BDNF positive particles were distributed in the nuclei of CA1 and CA3 pyramidal cells as well as DG granular cells. Quantitative analysis indicated that level of Fyn mRNA was also upregulated in the hippocampus of the stressed group (P < 0.05).</p><p><b>CONCLUSIONS</b>Chronic multiple stress can enhance spatial learning and memory function of rats. The expression of Fyn, BDNF and TrkB proteins and the level of Fyn mRNA are increased in the stessed rat hippocampus. These suggest that Fyn and BDNF/TrkB signal transduction pathways may participate in the process of the enhanced learning and memory during chronic multiple stress.</p>

Effect of Intravenous Nutrition on Immune Function in Premature Infants / 实用儿科临床杂志

Objective To observe the effect of intravenous nutrition on blood serum triglyceride (TG),humoral immunity and cellular immunity function in premature infants.Methods Sixty premature infants were randomly divided into 3 groups:amino acid group (group A),amino acid plus medium-long chain fatty group (group B) and amino acid plus long chain fatty group (group C).Amino acid and the fatty were used on them from 24 hours after their birth,started from 1.0 g/(kg?d),increased progressively 0.5 g/(kg?d) until 3.0 g/(kg?d),totally 7 days.TG and immunoglobulin IgA,IgM,IgG,complement C3,C4 and T-lymphocyte subsets CD3,CD4,CD4/CD8 and NK cell were checked in the first day before treatment and the ninth day after treatment.Results Compared with before treatment,TG of 3 groups were elevated(Pa0.05).Compared with group A and B,NK cell in group C were decreased obviously(Pa