Whole-transcriptome sequencing analysis of placental differential miRNA expression profile in Down syndrome / 南方医科大学学报

OBJECTIVE@#To identify new biomarkers and molecular pathogenesis of Down syndrome (DS) by analyzing differentially expressed miRNAs in the placentas and their biological pathways.@*METHODS@#Whole transcriptome sequencing was used to identify the differentially expressed miRNAs in DS (n=3) and normal placental samples (n=3) diagnosed by prenatal diagnosis. The target genes were predicted using miRWalk, Targetscan and miRDB, and GO and KEGG pathway analyses were performed for gene enrichment studies.@*RESULTS@#We identified a total of 82 differentially expressed miRNAs in the placental tissues of DS, including 29 up-regulated miRNAs (fold change ≥2, P < 0.05) and 15 down-regulated miRNAs (fold change ≥2, P < 0.05), among which 10 miRNAs with relatively high expression abundance were selected for further analysis, including 4 up-regulated and 6 down-regulated miRNAs. These selected miRNAs shared the common target genes BTBD3 and AUTS2, both of which were associated with neurodevelopment. GO analysis showed that the target genes of the selected miRNAs were mainly enriched in protein binding, hydrolytic enzymes, metal ion binding protein combining, transferase activity, nucleotide, cytoplasmic constituents, nucleus composition, transcriptional regulation, RNA metabolism regulation, DNA-dependent RNA polymerase Ⅱ promoter transcriptional regulation, eye development, and sensory organ development. KEGG enrichment analysis showed that the target genes of these differentially expressed miRNAs were involved in the signaling pathways including tumor-related signaling pathway, PI3K-Akt signaling pathway, Ras signaling pathway, Rap1 signaling pathway, cytoskeletal regulatory signaling pathway, purine metabolization-related signaling pathway and P53 signaling pathway.@*CONCLUSION@#The differentially expressed miRNAs may play important roles in placental damage and pregnancy pathology in DS and provide clues for the prevention and treatment of mental retardation-related diseases.

Microstructural changes of olfactory mucosa in rat model with acute rhinosinusitis leading to olfactory dysfunction / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To observe the microstructural changes of olfactory mucosa in rat model with acute rhinosinusitis leading to olfactory dysfunction, and to provide foundation for further exploration of corresponding mechanism.</p><p><b>METHODS</b>On the basis of prior successfully established rat model of acute rhinosinusitis through inoculation with Streptococcus pneumoniae and with the help of merocel strips, one hundred healthy SD rats were randomly divided into experimental group (80) and control group (20). After inoculation, every 20 rats in the experimental groups were sacrificed in first week, second week, third week and fourth week respectively; and all rats in the control group were sacrificed in first week after the inoculation. Before the rats were sacrificed, the method called "buffed food pellet test, BFPT" was adopted, which was advanced by professor Nathan, to measure the rats' olfaction,and the time of every rat spending in finding out the food pellet was recorded and analyzed. BFPT showed that the rats in experimental group spent (402.9 ± 9.3), (453.7 ± 7.3), (351.9 ± 8.9), (278.7 ± 8.1) s respectively in searching the food pellet, which were more than the rats in the control group [(178.3 ± 6.6) s]. Then the olfactory mucosa was collected under anatomic microscope from all the rats to make frozen section and detect the changes of mature olfactory receptor neurons (ORN) and olfactory ensheathing cells (OEC) by immunofluorescence technique.</p><p><b>RESULTS</b>The reduction of ORN in various degrees could be detected in the tissue samples of olfactory mucosa among all the rats in experimental group, with a tendency to become thinner in the thickness of epithelial lamina during the inflammation developing course. This kind of pathology was most marked in the second week and it gradually developed into the stage showing the lesion being the feeblest in the forth week following the beginning of modeling. Although the number of olfactory ensheathing cells appeared reduction in the first week following the beginning of modeling as well,it came to increase from the second week before olfactory receptor neurons and almost completely recovered to normal in the fourth week. In addition, some olfactory ensheathing cells could be detected in the tissue samples of olfactory mucosa among all the rats in experimental group.</p><p><b>CONCLUSIONS</b>Both mature olfactory sensory neurons and olfactory ensheathing cells appeared to reduction when sinonasal mucosa taken place acute rhinosinusitis. But the number of olfactory ensheathing cells increased faster than olfactory sensory neurons. In addition, some olfactory ensheathing cells could be detected in the olfactory epithelium.</p>

Blood lead level and related risk factors among children aged 0-6 years in Beijing / 中华流行病学杂志

<p><b>OBJECTIVE</b>To observe blood lead level and related risk factors among children of 0 - 6-year old in Beijing.</p><p><b>METHODS</b>Stratified-clustered-random sampling and simple random sampling were used. A total of 2 262 children of 0 - 6 years old were investigated from May to July 2001. They were permanent residents in Beijing. Blood lead level was tested by graphite atomizer absorption spectrophotometer. At the same time, related factors were investigated using a standardized questionnaire.</p><p><b>RESULTS</b>The mean lead level of children in Beijing was 96.8 micro g/L with 35.7% of those >/= 100 micro g/L, and 2.5% >/= 200 micro g/L. The proportion of lead poisoning was significantly higher in rural children (P < 0.01). The proportion of lead poisoning in 2-year-old group was higher than that in other age groups. The proportion of lead poisoning in boys was significantly higher than that in girls (P < 0.01). The following factors might serve as major risk factors related to child lead poisoning, such as, never or rarely drinking milk, living in nearby highways (less than 50 meters) or living in the first floor/bungalow, and so on.</p><p><b>CONCLUSION</b>The blood lead level of >/= 100 micro g/L among Beijing children appeared to be a big problem. Decision-makers should pay more attention to prevent blood lead level being high, and to cure these children who suffered in lead poisoning. Effective intervention measures on these target populations should be taken.</p>

Clinical Analysis of Serratia Infections in 4 Newborn Infants / 实用儿科临床杂志

Objective To analyze the clinical characteristic and prognosis of Serratia infections in newborn infants and increase awareness of Serratia infections.Methods The clinical manifestations,diagnosis,complications,treatment and prognosis of Serratia infections were analyzed in 4 hospitalized newborn infants in neonatology center from Jul.2008 to Feb.2009.Results Among the 4 cases,blood culture revealed Serratia marcescens in 3 cases(1 case was preterm infant),cerebral spinal fluid culture revealed Serratia liquefacien in the fourth case.The main clinical manifestations were fever,convulsion and poor response,WBC and CRP were much higher,while obvious thrombocytopenia was only found in the preterm infant.Two cases of septicemia infection alone recovered after the treatment of the third-generation cephalosporin for at least 2 weeks,while the other 2 cases of septicemia infection combined with purulent meningitis,included 1 case of preterm infant and 1 case of Serratia liquefacien infection,developed meningoencephalitis and brain abscess confirmed by serial imaging,both of which had poor neurological sequelaes.Conclusions As a opportunistic pathogen,Serratia can cause severe infection in newborns.The patients complicated with meningitis should be followed up and pay more attention to the high incidence of neurological sequelaes.