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Objective To investigate the relationship between spontaneous miscarriage and embryonic chromosome abnormalities,and to evaluate the clinical application of karyotype analysis by chorionic villus cell culture. Methods The chorionic villus karyotype of 1983 cases of miscarriage from January 2010 to July 2016 in Guangzhou Women and Children′ s Mecical Center were analyzed retrospectively. The miscarried chorionic villi were obtained by curettage under sterilized condition. The chromosome specimens were prepared after chorionic villus cell culture. Karyotype analysis was performed by G-banding technique. Results In the 1983 samples, successful karyotype analysis was performed in 1770 cases, with the successful rate of 89.98%. Chromosomal abnormalities were found in 1038 cases (58.64%,1038/1770). Chromosomal structural abnormalities were found in 37 cases. The numeral abnormalities were more common than structural abnormalities, and most of the numeral abnormalities were aneupoidies. In turn, they were trisomy 16, 45,X, trisomy 22, trisomy 2, trisomy 21, trisomy 15. The most common structural abnormality was balanced translocation, including Robersonian translocation. Female embryoes accounted for 61.02%(1080/1770) miscarriages and for 57.4%(596/1770) of chromosomal abnormalities, while male embroyes acoounted for 61.02%(1080/1770),57.4%(596/1770)respectively. The proportion of female embryoes was higher than male embryoes. The median age of the patients was 30 years old(16-46 years old). As the maternal age increased, the proportion chromosomal abnormalities increased. The incidence of chromosomal abnormalities in the advanced age group (≥35 years) was 68.38%(240/351), which was significantly higher than that in the younger group (56.24% ,798/1419; χ2=17.10, P<0.01). Conclusions Embryonic chromosomal abnormalities are the most common cause of early spontaneous miscarriage. The abnormalities centralize in some karyotypes. There is certain relationship between maternal age and the incidence of miscarriage, as well as the embryonic gender. Chorionic villus cell culture and karyotype analysis are helpful in finding the cause of miscarriage and counsel the patients.
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Objective To screen and identify the aptamers of the recombinant transpeptidase domain of PBP2a(penicillin binding protein 2a ,PBP2a) .Methods By using the recombinant transpeptidase domain of PBP2a as the screening target ,oligonucle-otides which were capable of specifically binding to the protein were screened by a random oligonucleotide library through the stem -atic evolution of ligand by exponential enrichment (SELEX )technique .The ssDNA was cloned and sequenced ,and the secondary structure of aptamer clones was predicted with mfold program .Results After 11 cycles of the selection ,the aptamers which were capable of binding to PBP2a with high affinity have been selected .40 clones from the 8 and 10 cycles were selected randomly and se-quenced .The aptamers obtained had no obvious homology according to their sequences by the sequence alignments ,and the 40 aptamers were classified to three groups according to their secondary structures .The aptamer 13 was found to be specific for the target protein with the highest affinity .Conclusion Aptamers for the recombinant transpeptidase domain of PBP2a with high affili-ty and specificity were successfully screened by SELEX ,which lays a foundation for exploring new ways of diagnosis and treatment of MRSA infection .
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Objective To study the etiology and antibiotic resistance of bloodstream infections in low birth weight preterm infants .Methods A total of 95 cases of bloodstream infections in low birth weight preterm infants were treated in our hospital from January 2011 to April 2014 .The clinical data of these patients were analyzed retrospectively .Results A total of 96 pathogens were isolated ,including 57 strains of gram‐negative bacilli ,38 strains of gram‐positive cocci ,and 1 strains of Trichosporon asahii .The most frequently isolated pathogens were Klebsiella pneumoniae (40 strains)and coagulase‐negative Staphylococcus(31 strains).All gram‐negative bacilli were sensitive to carbapenems such as imipenem and panipenem . Streptococcus isolates were sensitive to most antibiotics .Most Staphylococcus isolates were methicillin‐resistant ,which were highly resistant to common antibiotics but all sensitive to linezolid , vancomycin and teicoplanin . Conclusions The most important pathogens responsible for bloodstream infections in low birth weight preterm infants in our hospital are K lebsiella pneumoniae and coagulase‐negative Staphylococcus . Early identification of responsible pathogen and rational antimicrobial therapy are critical for good prognosis of bloodstream infections in low birth weight preterm infants .
