Mycoplasma pneumoniae infection and drug resistance in children: an analysis of 1026 cases / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the Mycoplasma pneumoniae (MP) infection and drug resistance in children with respiratory tract infection and to provide a rational basis for the clinical diagnosis and treatment of MP infection.</p><p><b>METHODS</b>Throat swabs were collected from 3529 children with respiratory tract infection, who visited the pediatric outpatient department or received treatment in the pediatric ward of our hospital from September 2010 to September 2011. The swabs were cultured to detect MP. The drug sensitivity of MP to azithromycin, roxithromycin, erythromycin, acetylspiramycin and clarithromycin was evaluated.</p><p><b>RESULTS</b>Of the 3529 children with respiratory tract infection, 1026 (29.07%) were MP-positive. There were cases of MP infection in all four seasons of the year but infection rates in summer and autumn were significantly higher than in spring and winter (P < 0.05). The infection rate in females was higher than in males (30.43% vs 28.32%; P > 0.05). The infection rate was negatively correlated with age in these children, and there were significant differences in the infection rate among all age groups (P < 0.05). For macrolide antibiotics suitable for children, the cultured MP developed the highest resistance to roxithromycin, followed by erythromycin, acetylspiramycin, clarithromycin, and azithromycin, with significant differences among them (P < 0.01).</p><p><b>CONCLUSIONS</b>MP infection rate is very high among children with respiratory tract infection. The incidence of MP infection is relatively low among school-age children and children are more susceptible to MP infection in summer and autumn than in spring and winter. Throat swabs should be cultured and drug sensitivity tests should be performed as early as possible in children with respiratory tract infection, so that proper intervention can be undertaken in time to reduce drug-resistant strains of MP.</p>

An epidemiologic survey on blood lead levels in preschool children living in towns of Hunan Province / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate blood lead levels (BLLs) and influencing factors of BLLs among preschool children living in towns of Hunan Province.</p><p><b>METHODS</b>A total of 2 044 preschool children (1,108 boys and 936 girls) from towns of 12 regions in Hunan Province were enrolled by a cluster sampling between September 2008 and June 2009. The average age of the children was 4.4 ± 1.1 years (range 2 to 6 years). BLLs were determined using the atomic absorption spectrographic method. The influencing factors of BLLs were investigated using a standard questionnaire and logistic regression analysis.</p><p><b>RESULTS</b>The mean BLLs of the children were 81.9 ± 34.5 μg/L. BLLs more than 100 μg/ L were noted in 482 children (23.58%). Of the 482 children, 472 (23.09%) showed BLLs of 100-199 μg/L and 10 (0.49%) showed BLLs ≥ 200 μg/L. There were significant differences in the prevalence of elevated BLLs (≥ 100 μg/L) among different age groups (P < 0.01). The prevalence of elevated BLLs in boys (28.99%) was significantly higher than that in girls (21.98%) (P < 0.01). There were significant differences in the prevalence of elevated BLLs in children from different regions (P < 0.01). The logistic regression analysis showed that the male (OR = 1.449, P < 0.01), father's occupational lead exposure (OR = 1.314, P < 0.01)and maternal frequent use of hair dyes (OR = 1.678, P < 0.05) were risk factor for elevated BLLs.</p><p><b>CONCLUSIONS</b>The prevalence of elevated BLLs is higher in preschool children living in towns of Hunan Province and is associated with a child's region and age. The male, father's occupational lead exposure and maternal frequent use of hair dyes are risk factor for elevated BLLs.</p>

Study on molecular mechanism of inhibitory effect of baicalin on proliferation of insulinoma cell line in rats / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To investigate the effect of baicalin on insulinoma cell line and the molecular mechanism involved.</p><p><b>METHODS</b>Light microscope, MTT assay, flow cytometry, gene analysis and Western Blot were applied to investigate the effects of baicalin on the cell proliferation, the cell cycle and the involved molecular mechanism.</p><p><b>RESULTS</b>After treatment with baicalin, the number of cells in mitotic stage and the survival rate of cells obviously decreased, and cell proliferation was inhibited in a drug concentration- and acting time-dependent manner, with the appearance of apoptotic insulinoma cells. During the apoptotic process, the activity of caspase-3 was elevated by baicalin in a time-dependent manner; with the increase of the concentration of baicalin, the number of cells in S-phase obviously decreased from 38.2% to 9.4%, while the percentage of cells in G0/G1 phase increased from 56.4% to 85.9%, indicating cells were arrested in G1-phase. Meanwhile, the activity of cyclin gene promoter obviously declined, and the expression of cyclin reduced remarkably.</p><p><b>CONCLUSION</b>Baicalin could induce apoptosis of insulinoma cells, which might be correlated with the activity of caspase-3, and inhibiting proliferation of insulinoma cells in a concentration- and time-dependent manner, in which the action of baicalin in down-regulating the gene transcription and expression of cyclin may play an important role.</p>

Protective effects of baicalin pretreatment on hypoxic-ischemic brain damage in neonatal rats / 中国当代儿科杂志

<p><b>OBJECTIVE</b>Previous research suggests that dexamethasone (Dex) pretreatment protects neonatal rats against hypoxic-ischemic brain damage (HIBD). Some of the pharmacological effects of baicalin (a traditional Chinese medicine extracted from Scutellaria baicalensis Georgi) are similar to Dex. This study was designed to explore the effect of baicalin on the neuronal apoptosis following HIBD in neonatal rats.</p><p><b>METHODS</b>Six-day-old Sprague-Dawley rats were randomly assigned into Control (without HI), HIBD, Dex-pretreatment and post-treatment, Baicalin-pretreatment and -post-treatment groups. HIBD was induced by ligating the left common carotid artery, followed by exposure to hypoxia. In the pretreatment groups either baicalin (16 mg/kg) or Dex (0.1 mg/kg) was administered to the rats 24 hrs before HIBD; in the post-treatment groups baicalin or Dex was given 30 minutes after HIBD. The rat pups were sacrificed on postnatal day 10, and brain tissues were harvested. Brain water content was determined, morphological changes were observed under a light microscope, and neuronal apoptosis was measured by terminal deoxynucleotidyl transferase mediated dUTP biotin nick end labeling (TUNEL) staining.</p><p><b>RESULTS</b>The brain water content and the number of apoptotic cells were significantly higher in the HIBD group than those of the Control group (P < 0.05). Both baicalin and Dex pretreatment decreased the brain water content from 88.9 +/- 1.7 % (HIBD group) to 87.4 +/- 0.7% (baicalin) or 87.3 +/- 0.6% (Dex) (P < 0.05) and the number of apoptotic cells were reduced from 251 +/- 28 (HIBD group) to 102 +/- 47 (baicalin) or 75 +/- 26 (Dex) (P < 0.05). Baicalin and Dex post-treatment had no effects on the brain water content and the number of apoptotic cells. Loss and degeneration of neurons could be observed in the HIBD group. Baicalin and Dex pretreatment significantly alleviated neuronal injury, but post-treatment did not.</p><p><b>CONCLUSIONS</b>Pretreatment with baicalin, as with Dex, has a protective effect against HIBD in neonatal rats, but baicalin or Dex post-treatment do not reverse the neuronal injuries.</p>

Factors influencing successful isolation of mesenchymal stem cells from human umbilical cord blood / 中华儿科杂志

<p><b>OBJECTIVE</b>Emerging evidences suggest that mesenchymal stem cells (MSCs) can be isolated from human umbilical cord blood (HUCB) and cultured in vitro, the same as the MSCs derived from bone marrow. However previous attempts to isolate MSCs from UCB showed a low rate of success (less than 30%). The present study was conducted to clarify the factors that influence the yields of MSCs from HUCB of different gestational age deliveries and to observe the bioactivity of MSCs derived from UCB.</p><p><b>METHODS</b>HUCB units were divided into three groups: gestational age (GA) 40 w group (n = 11); GA 36 w group (n = 6); GA 32 w or less than 32 w group (n = 5), cultured with optimal culture conditions. The relationship of the yields of MSCs derived from HUCB with several factors such as GA, the collected volume of HUCB and the mononuclear cells (MNCs) count of UCB, and the relationship among these factors were investigated. The bioactivity was observed by drawing the growth curve, calculating the population doubling, counting the fibroblast colony forming units (CFU-F) and detecting the surface antigen expression of MSCs by flow cytometry.</p><p><b>RESULTS</b>The success rate of generating MSCs cells was up to 54.5%. There were some correlations between the success rate and such factors as the MNCs count, the GA and the volume of UCB. The rate could be enhanced to 83.3% when the MNCs count was more than 1.25 x 10(8)/L. There was a negative correlation between the MNCs count in the same HUCB volume and the gestational age. The count of CFU-F varied with gestational age, the count of CFU-F was higher in smaller gestational age than the older. In the primary culture some cells displayed a fibroblast-like morphology and expressed MSCs-related antigens CD29, CD105, and the expression rate of these antigens were enhanced from 62.1% to 85.0% in one passage. The hematopoietic cells antigens CD34 and CD45 were less than 3% all the time.</p><p><b>CONCLUSIONS</b>The success rate could be increased when the MNCs count was more then 1.25 x 10(8)/L. There was a negative correlation between the MNCs count of the same UCB volume and the gestational age, the activity to form the CFU-F of UCB varied with gestational age; isolation of MSCs from UCB of pre-term deliveries may be relatively easier as compared to those from full term deliveries.</p>

Expression of exogenous gene in bone marrow stromal cells by liposome / 中南大学学报(医学版)

OBJECTIVE@#To transform eukaryotic expression vector pEGFP-PDX-1 into marrow stromal cells by liposome and to optimize the conditions of transformation.@*METHODS@#The recombinant vector was identified by enzyme digestion analysis and sequencing. The recombinant plasmid was transformed into bone marrow stromal cells and it changed the quantity of DNA or liposome. The expression of PDX-1 gene in the transformed cells was detected by immunocytochemical staining.@*RESULTS@#Enzyme digestion analysis and sequencing showed that the interesting gene was integreted into the recombinant vector. We obtained satisfactory efficiency of transfection when the ratio of DNA and liposome was 1 : 1 or 1 : 2. The PDX-1 in the transformed cells was expressed by immunocytochemical staining.@*CONCLUSION@#The eukaryotic expression vector pEGFP-PDX-1 was constructed for the first time in China. We have enhanced the efficiency of transfection by optimizing the transformation conditions. It is possible to use the bone marrow stromal cells as seed cells in tissue-engineering.

Effect of baicalin on the proliferation of insulinoma cell line / 中南大学学报(医学版)

OBJECTIVE@#To investigate the effect of baicalin on the proliferation of insulinoma cell line and the molecular mechanism involved.@*METHODS@#Such methods as light microscope, MTT assay, flow cytometry and Western blotting were applied to investigate the effects of baicalin (0, 100, 200, and 400 microg/ml baicalin treated for 24 h or 200 microg/ml baicalin treated at different time points) on the cell proliferation, cell survival rate, the cell cycle and related molecular mechanisms.@*RESULTS@#The number of proliferating cells obviously decreased with the increase of baicalin under the light microscope, and the survival rate of cells decreased as determined by MTT assay. After being treated with baicalin, the number of insulinoma cells in S-phase obviously decreased from 38.2% (0 microg/ml) to 9.4% (400 microg/ml), and the number of cells in phase G1 increased from 56.4% (0 microg/ml) to 85.9% (400 microg/ml). In the meantime, the expression of cyclin D1 was obviously declined by Western blotting.@*CONCLUSION@#Baica-lin can inhibit the proliferation of insulinoma cells, and the down-regulation of the expression of cyclin D1 might also be involved in these events.