It must be emphasized in the maternal serum prenatal screening that the quality is not only influenced by accuracy of biomarker assay,risk calculation parameters and biomarker database,but also influenced by clinical factors such as gestational weeks,weight and ect.The result of prenatal screening is just a risk evaluation,the subsequent diagnosis and the follow-up are more important.It is expected to improve screening efficiency by localization of prenatal screening database and making the quality management of the prenatal screening-diagnosis suitable for the national conditions.On the other hand,prenatal screening in the women of advanced maternal age and twin pregnancy,improve amniotic fluid cell culture method,chromosome analysis automation,the introduction and positioning of rapid prenatal molecular diagnosis techniques become the hot issues.

Objective： To clone rat cardiac myosin α he avy chain cDNA fragment encoding aa736-960 and construct its recombinant retrov irus vector(RV). Methods: The 681 bp target gene was amplified f rom heart tissue of young rats with RT-PCR, fusion gene of huIL-2/myosin was c onstructed by splicing with huIL-2 cDNA using ligation methods and its RV was constructed. RT-PCR and immunohistochemical assay were used to iden tify the expression of myosin protein in transfected cell. Results: The determination of nucleotide sequence showed that the nucleotide and ami no acid sequence of gene clone was the same as reported, its openin g reading frame was correct, the digesting result of pLNC-huIL-2-myosin was i dentical with the predicted. NIH3T3 cell was transfected with recombinant RV, and G418-resistant NIH3T3 cell was established.RT-PCR analysis indicated tha t mRNA of pLNC-huIL-2-myosin was present in cell transfected with RV. The im munohistochemical assay also showed that the myosin protein expression was highe r in the cell transfected with constructed RV. Conclusion: Rat cardiac myosin α heavy chain cDNA has been cloned and its RV has also been cons tructed and expressed in NIH3T3 successfully, it will contribute to research of prevention and treatment of heart immune injury by cardiac myosin gene transfer to induce specific tolerance.

Objective To investigate the diagnostic value and clinical significance of the three-dimensional contrast-enhanced MR angiography (3D-CE-MRA)in the infantile superficial hemangioma.Methods Forty-four children with superficial hemangioma un-derwent conventional and dynamic contrast-enhanced MRI.MRI scanning was started at the time of inj ection,and four dynamic pha-ses of images were acquired continually.Maximum intensity proj ection (MIP)images were reconstructed to show the blood vessels of the lesions in multiple phases.Results Forty-nine infantile superficial hemangiomas were detected by MRI,including a single le-sion in 41 patients and multiple ones in 3.3D-CE-MRA showed 37 lesions in 32 patients,and other 12 lesions were not found in 12 patients.Conclusion The conventional and dynamic contrast-enhanced MRI can reflect the location,number and the range of the su-perficial hemangioma,and show the relationship between the lesion and the surrounding tissues.3D-CE-MRA directly shows the blood supply of the tumors.

Objective To study the correlation between homocysteine levels and MTHFR C677T gene polymorphism of cerebral infarction.Methods Four hundred and fifty patients with cerebral infarction in our hospital were selected as the study group from February 2012 to August 2015,including 181 diabetes patients and 269 non-diabetic patients.Also 285 cases of physical examination healthy people in the outpatient department were selected as the control group.The MTHFR C677T polymorphism and the correlation between genotype and Hcy levels were analyzed by pyrosequencing.Results The difference of distributions of MTHFR genotype between the study group and the control group was statistically significant (P ＜ 0.05).The frequency of the T gene in the study group was significantly higher than the control group,the difference was statistically significant (x2 =13.67,P =0.00).The Hcy concentrations of the study group was significantly higher than the control group,and the difference was statistically significant (t =12.71,P =0.00).The Hcy levels of different MTHFR genotype in the cerebral infarction patients were statistically significant (F =17.68,P =0.00).Hcy levels in non-diabetic patients with cerebral infarction was significantly higher than in diabetic patients with cerebral infarction,and the difference was statistically significant (t =2.97,P =0.00).Hcy concentrations of TT genotype of non-diabetic group was significantly higher than the TT genotype of the diabetic group,CC type Hcy concentration significantly lower than the diabetic group,and the differences were statistically significant (t =5.67,2.18;P =0.00,0.03).In cerebral infarction patients both with non-diabetic and diabetic,the Hcy levels of MTHFR gene TT genotype were significantly higher than those of CC and CT genotype,and the differences were statistically significant (P ＜ 0.05),and the differences of Hcy levels between the genotype of CT and CC was not statistically significant (P ＞ 0.05).Conclusion The T allele frequency of MTHFR C677T in the cerebral infarction patients is much higher than healthy people.MTHFR TT genotype is related to serum Hcy levels.Maybe it is a risk factor for cerebral infarction.

Objective To estimate the application value of colony PCR in the detection of pathogenic filamentous fungi. Methods Colony PCR was established and performed to amplify the internal transcribed spacer (ITS) region of 19 species (strains) of filamentous fungus followed by sequencing analysis. At the same time, DNA extracts from 8 of the 19 species of filamentous fungus were subjected to conventional PCR. Hha I and Hinf I endonucleases were used for restriction fragment length polymorphism (RFLP) analysis of the conventional and colony PCR products. Comparison analysis was carried out between the colony and conventional PCR. Results Of the 19 strains, 16(84.2%) yielded positive results by colony PCR; sequence analysis of the PCR products of ITS region revealed a 96% - 100% similarity with the reference sequence (NCBI database)of corresponding fungi. The amplification product length and RFLP profile of these products from the 8 species of filamentous fungus, except for those from Aspergillus nidulans, were consistent between the colony and conventional PCR. Conclusions Compared with conventional PCR, colony PCR-based detection of filamentous fungi is easy to operate, time and labor-saving, with high accuracy and reliability, and can be applied to the rapid identification of filamentous fungi.

Objective To investigate the effect of electron transfer system on the hyphal formation of Candida albicans. Methods Candida albicans was cultured in RPMI 1640 supplemented with 10% new-born calf serum in 5% CO2 at 37 ℃ with or without the presence of inhibitors or activators of electron transfer system. Growth curve, morphology and percent of filamentation were observed for Candida albicans. MTT assay was used to assess the viability of Candida albicans. Results The solvents (chloroform and dimethyl sulfoxide) had no significant effect on the growth of and filamentation in Candida albicans. After incubation with thenoyltrifluoroacetone (TTFA) or benzhydroxamic acid for 24 hours, yeast cells of Candida albicans predominated in the culture. The growth of Candida albicans was significantly inhibited in log phase by the incubation with classic respiratory chain inhibitors such as rotenone, antimycin A, oligomycin, sodium azide, TTFA and sodium malonate, compared with the controls (all P < 0.01). Benzhydroxamic acid, an inhibitor of alternative oxidative pathway, also significantly inhibited the growth of Candida albicans in log phase (t = 10.92, P < 0.01). After incubation with rotenone, antimycin A, oligomycin, sodium azide, TTFA, sodium malonate, benzhydroxamic acid and disodium gnanylate, the percentage of filamentation in Candida albicans at 12 hours was 87.49 ± 0.52, 48.75 ± 4.44, 50.33 ± 8.50, 99.00 ± 1.00, 1.60 ± 0.53, 94.01 ± 0.99, 0.00 ± 0.00 and 92.33 ± 2.08, respectively, and the growth of Candida albicans at 7 hours was inhibited by (1.34 ± 0.15)%, (70.61 ± 1.02)%, (50.63 ± 5.38)%, (17.80 ± 7.89)%, (45.17 ± 1.27)%, (10.75 ± 3.62)%, (72.46 ± 1.14)% and -(5.96 ± 4.07)%, respectively. Conclusions Hyphal formation of Candida albicans could be suppressed by inhibitors of classic respiratory chain or alternative oxidative pathway, and is mainly regulated by alternative oxidative pathway.

Objective To report a case of vaginal colonization due to Trichosporon inkin. Methods A 34-year-old female presented with increased vaginal discharge accompanied by abnormal odor for 2 months. Clinical laboratory examination was carried out. Cultures of vaginal discharge yielded yeast-like colony. Subsequently, the isolate underwent the following mycological examinations: purification, slide micro-culture, temperature test, urea enzyme test, biochemistry identification, antifungal susceptibility test, and gene sequencing. Results Gynecological examination revealed white homogeneous secretions attached to mucous membrane of the vagina. Nugent scores of vaginal discharge amounted to 5-6. Two rounds of culture of vaginal discharge resulted in stramineous, reductus and yeast-like colony. The isolate could grow in 42 ℃. Appressorium on the top of hypha and typical sarcinae formed in slide microculture of corn agar, and yeast malt agar was the optimal growth medium for it. Urea enzyme test was positive. API 20C AUX biochemical test and gene sequencing revealed that the isolate was consistent with Trichosporon inkin. The isolate was sensitive to amphotericin B and azoles such as clotrimazole and fluconazole, but resistant to flucytosine and caspofungin. Conclusions It is the first report of vaginal colonization due to T. Inkin in China. The accu-rate identification of T. Inkin relies on synthetic analysis of phenotype characteristics, biochemistry test and molecular sequencing.

Objective To investigate the growth inhibition of Aspergillns fumigatus by Candida albicans in vitro and to develop the selective medium for clinical isolation of Aspergillus fumigatus.Methods Aspergillus fumigatus and Candida albicans were single or co-cultured in sabouraud dextrose agar(SDA) medium and SDA broth in dark at 25 ℃,and fungal growth,pigmentation,as well as colony diameter weredocumented.Results ①The sensitivity of culture of Aspergillus fumigatus and Candida albicans on SDAplate was 100CFU/ml.②The growth of 106CFU/ml and 103CFU/ml Aspergills fumigatus was completely inhibited by 106CFU/ml Candida albicans.③Growth inhibition of Aspergillus fumigatus was correlated with the concentration of Candida albicans.④SDA containing 1 mg/L fluconazole inhibited growth of Candida albicans,and no Candida albicans was detected on SDA containing 5 mg/L and 25 mg/L fluconazole.Growth of Aspergillus fumigatus was partially inhibited on SDA containing 25 mg/L fluconazole.Conclusions Candida albicans can inhibit the growth of Aspergillus fumigatus in vitro.SDA containing 5 mg/L fluconazole can be used as the selective medium for the isolation of Aspergillus fumigatus.

Objective To develop a PCR-RFLP method to rapidly identify filamentous fungi causing deep infection. Methods Universal fungal primers were used to amplify the internal transcribed spacer (ITS) region of Aspergillus fumigatus, Aspergillus Bavus, Aspergillus terreus, Aspergillus niger, Aspergillus versicolor, Aspergillus nidulans, Scedosporium apiospermum and Fusarium moniliforme followed by restriction fragment length polymorphism (RFLP) analysis with restrictive endonucleases Hha I, Hae III, Hinf I, Taq I and Msp I. Then, 22 clinical and 2 environmental fungal isolates were identified with the developed PCR-RFLP method. Results The RFLP analysis of PCR products with restrictive endonucleases Hha I and Hinf I allowed discrimination of 8 filamentous fungi causing invasive infection, and it took only 1 day to carry out the whole procedure from DNA extraction to PCR and restriction digestion. The identification results of 22 clinical strains and 2 environmental isolates with this PCR-RFLP method were completely consistent with those with conventional morphological method. Conclusion PCR-RFLP analysis is an efficient method for rapid identification of cultured filamentous fungi.

BACKGROUND:Researchers have done much work to investigate semantic priming with event-related potentials (ERPs) method. The ERPs component of N400 is of great importance in this research domain. N400 is a negative wave occurs at about 400 ms after the stimulus onset. It has been accepted that N400 represents the processing of semantic information. In many studies, amplitude of N400 could be reduced by semantic priming. Relatively, ERPs studies on phonological priming, especially by auditory stimuli, deserve to be further investigated. OBJECTIVE: To investigate the EPR characteristics of semantic and phonological priming with spoken two-character Chinese words, and also to testify theories about auditory word recognition.DESIGN: Repeated measurement experiment.SETTING: Center for Psychology and Behavior Studies, Tianjin Normal University. PARTICIPANTS: This experiment was carried out between August and October 2003 in Tianjin Normal University. Seventeen healthy college students (8 male and 9 female, age ranging from 19 to 23 years) with no hearing defect were involved in this experiment. All of them were Chinese native speakers. All except one male participant were right handed. Informed consents of detected items were obtained from all the participants.METHODS: In the study, lexical dicision task which required participants was used to judge if the latter words were real words or pseudowords in the auditorily presented word-pairs by pressing buttons. The stimuli materials were 640 two-character word-pairs including semantic related, initial phonological overlap, final phonological overlap, phonological and semantic unrelated and word-pseudoword (control) conditions. These five kinds of word-pairs presented randomly in the experiment. The presentation of stimuli and recording of behavioral data were realized by STIM software. The error rate and mean reaction time (RT) of reaction of subjects were calculated under four experimental conditions. The word-pseudoword items were not included in the analysis (just served as fillers). EEG were recorded referring to linked mastoids with Scan 4.3 software made by Neuroscan company in America. Participants wore the Quick-Cap32 electrode cap (International 10/20 System). EEG data were amplified and acquired with a sampling rate of 500 Hz. Offline exclusion of occular artifacts was done on the acquired continuous EEG data after experiment. Then the EEG data were segmented to epochs of 1 700 ms, each epoch was time-locked to the onset of target stimulus with a 200 ms pre-target baseline. Then the operation of baseline (with a 200ms pre-target baseline), artifact rejection (epochs with amplitude exceeded the range of -100 μV to +100 μV were rejected) and average were realized. MAIN OUTCOME MEASURES: Error rate, reaction time and caused N400 waveform change of target words under different experimental conditions.RESULTS: Data from 17 subjects were involved in the final analysis. The error rate of subjects under semantic related condition was lower (P＜ 0.05) while RT was shorter (P＜ 0.01) than that under phonological and semantic unrelated condition. The error rates of subjects under initial phonological overlap and final phonological over lap conditions were higher than that under phonological and semantic unrelated condition (P ＜ 0.01). The error reactions were discarded and the mean value of RT under 4 conditions (semantic related, initial phonological overlap, final phonological overlap and phonological and semantic unrelated) were 830 ms, 891 ms, 864 ms and 903 ms, respectively. There were significant differences of error rate and RT between semantic related and phonological and semantic unrelated conditions (P ＜ 0.01). Error rate and RT under final phonological overlap condition were significantly different from those under initial phonological overlap and phonological and semantic unrelated conditions (P ＜ 0.01). Since the largest amplitude of N400 occurred at FCZ electrode, FCZ was chosen for analyzing the effects under four different experimental conditions. The LSD multiple comparison showed that amplitude under control condition was significantly higher than that under semantic related condition (P ＜ 0.01). Latency under the control condition was the longest, then decreased gradually according to the sequence of semantic related, final phonological overlap and initial phonological overlap condition. As the results of LSD multiple comparison revealed, initial phonological overlap condition had a tendency of shortened latency, with significant difference when compared with control condition (P ＜ 0.05). Another five electrodes were selected besides FCZ standing for anterior, parietal, posterior, left and right brain area in order to investigate the scalp distribution difference of N400 under different experimental conditions. Two factors repeated measured ANOVA (Analysis of variance) was carried out for amplitude analysis, with different experimental conditions (4 levels) as the first factor and electrode positions (6 levels) as the second factor. The main effect of electrode positions was significant [F(5,80)= 13.376, P =0.000]. Among the chosen electrodes, FCZ had the largest amplitude (-7.946 μV), the second was CZ (-7.285 μV) and the other top-downsequence was FZ (-6.849 μV), PZ (-4.324 μV), T8 (-3.501 μV ) and T7 (-3.484 μV), respectively. Results of LSD multiple comparison revealed that the amplitude of FCZ was higher than all other electrodes but CZ. CONCLUSION: Two-character Chinese words presented auditorily in lexical decision task. Semantic relationship can facilitate the recognition of target words, which is shown by lower error rate, shorter RT and decreased amplitude of N400 component. Phonological congruence between prime and target words has both facilitory and interferential effects on target words, which is shown by increased error rate, shorter RT and the tendency of decreasing N400 amplitude.Interferential effect of initial phonological overlap between prime and target words is stronger than that of final phonological overlap. This finding provides evidence for initial phonological information's special function during auditory word recognition which is supported by Cohort Theory. No evidence for the existence of separate intracranial sources of semantic priming and phonological priming has been found. However, Cohort Theory should be revised while applying to the recognition of two-character words of Chinese.