[Application of Ion Torrent PGM™ System in Detection of Fetal DNA in Maternal Plasma].

OBJECTIVE: To explore the feasibility of detecting of Y-STR of fetal DNA in maternal plasma using Ion Torrent PGM™ System. METHODS: A total of 16 fetal DNA samples from maternal plasmas (8 cases from 38 weeks gestational age and 8 ones from 12 weeks) were prepared and a multiplex assay with 7 STR loci (DYS390, DYS391, DYS393, DYS438, DYS437, DYS456, DYS635) was designed for multiplex-PCR amplification. Using Ion Torrent PGM™ System, the results of Y-STR sequences and capillary electrophoresis were obtained and compared. RESULTS: Y-STR specific alleles were detected in the maternal plasma of all the pregnant women having male babies of second and third trimester, which were higher than that detected by capillary electrophoresis. Consistent Y-STR genotypes were observed between fetal DNA from maternal plasma and genomic DNA from the newborn babies. CONCLUSION: Based on Ion Torrent PGM™ System, the prenatal Y-STR detection method may provide a high-sensitive and high-throughput choice for prenatal STR detection in forensic testing.

[AS-PCR assay for 20 mtDNA SNP typing and haplotype frequency].

OBJECTIVE: To develop a multiplex allele-specific PCR (AS-PCR) assay with three-color fluorescence labeling for mitochondrial DNA (mtDNA) SNP typing. METHODS: Based on the principle of AS-PCR, the primer sets were designed for 20 SNP located on the coding region of mtDNA and divided into 2 groups labeled with FAM and HEX fluorescence, respectively. A primer set included two forward (reverse) allelic specific primers with different sizes and a generic reverse (forward) primer. Blood samples from 200 unrelated individuals were analyzed by AS-PCR and capillary electrophoresis. Three random samples at least for each SNP site were examined and verified by direct sequencing. The haplotype frequency was investigated. RESULTS: Distinct electropherograms of 200 blood samples were obtained successfully. The typing results of direct sequencing were identical to those obtained from AS-PCR. The minimum detectable DNA concentration was 0.2 pg under the system of 10 microL. The sensitivity of the DNA concentrations ranged from 0.5 to 5 pg. The 200 individuals were assigned into 15 haplotype, and the haplotype diversity was 0.906 0. CONCLUSION: AS-PCR is a simple, rapid and efficient method for mtDNA SNP typing, and can be applied to forensic practice.

[Determination of the biological attribute of evidence at the scene using reverse transcription PCR and real-time fluorescent quantitative PCR].

OBJECTIVE: To explore the feasibility of biological method to identify the biological attribute of samples at crime scene. METHODS: Thirty samples of ten blood stains, ten saliva stains and ten semen stains were selected, and all the samples were processed by the routine method and biomolecular method, respectively. Both RNA and DNA were isolated using DNA-RNA co-extraction technology and the mRNA was converted into cDNA using reverse transcription PCR (RT-PCR). Three pairs of specific primers were designed for blood stain, saliva stain and semen stain based on the different target genes in three specific tissues and the primers were amplified using real-time fluorescent quantitative PCR. The differences in these biological samples were evaluated by melting temperature (Tm) values and the size of the amplification fragment. RESULTS: The Tm values of blood stain, saliva stain and semen stain were (84.5 +/- 0.2) degrees C, (76.9 +/- 0.3) degrees C and (88.5 +/- 0.2) degrees C, respectively. The length of PCR fragments of them was 177bp, 134bp and 294bp, respectively. CONCLUSION: Compared with the routine method, RT-PCR with real-time fluorescent quantitative PCR is highly specific, sensitive and reliable to identify the biological attribute of evidence, and can be potentially applied to determine evidence attribute in forensic practice.

[Research status and prospects of DNA test on difficult specimens].

This paper reviews the advances of DNA detection on three types of difficult biological specimens including degraded samples, trace evidences and mixed samples. The source of different samples, processing methods and announcements were analyzed. New methods such as mitochondrial test system, changing the original experimental conditions, low-volume PCR amplification and new technologies such as whole genome amplification techniques, laser capture micro-dissection, and mini-STR technology in recent years are introduced.

Lifestyle and Social Factors Exacerbated on the Prevalence of Mood Disorders and Functional Dyspepsia Among Neonatal Nurses in China.

Background: Nursing is a high-stress occupation that can have an impact on mental health, particularly for neonatal nurses. Job-related stress factors and work-related behaviors have played a critical role in nurses' mental health. This study aimed to explore the prevalence of mood disorders and the impact of social factors, lifestyle on mood disorders among neonatal nurses. Methods: A total of 260 participants comprising neonatal nurses and nurses who work in neonatal intensive care units (NICU) were recruited. Data were collected using a validated generalized anxiety disorder questionnaire, patient health questionnaire-9, Pittsburgh sleep quality index, and social factors and lifestyle assessments. Results: In total, 49.23% of neonatal nurses exhibited mood disorders, particularly a combination of depression and anxiety. Female, poor interpersonal relationships and unhappy marital status, preference for smoking, alcohol, irregular diet, and poor sleep were common in neonatology nurses who exhibited mood disorders; preference for coffee and tea were lower in neonatology nurses without mood disorders (all P < 0.05). Interpersonal relationships, marital status, irregular diet, and poor sleep were independent factors associated with mood disorders among neonatal nurses (all P < 0.05). Mood disorders presented as functional dyspepsia (FD) among 50.78% of the participants (P < 0.05). Poor sleep and preference for smoking were common among neonatal nurses who had FD with mood disorders (all P < 0.05). Furthermore, the preference for sugary beverages was lower in participants with FD and mood disorders (P < 0.05). Poor sleep was independently associated with FD with mood disorders in neonatology nurses (P < 0.05). Conclusion: Prevalence of anxiety and depression was higher among neonatal nurses. Furthermore, most cases of mood disorders presented as FD. Thus, social factors and lifestyle have an impact on mood disorders which can manifest through somatic symptoms.

Risk of birth defects increased in multiple births.

BACKGROUND: Previous studies inconsistently suggest that there may be an association between birth defects and multiple births. METHODS: Data were obtained from Zhejiang Hospital-Based Birth Defects Surveillance System during 2007 to 2009. There was a total of 545,018 pregnancies, including 537,593 singleton pregnancies, and 7425 multiple pregnancies (14,606 twins and 366 triplets). Odds ratio (OR)and confidence interval (CI) for birth defects were calculated for the singletons and multiple births. RESULTS: The rate of birth defects in multiple births was 444.16 per 10,000 births versus 266.97 per 10,000 births in singletons (OR, 1.69; 95% CI, 1.57-1.84). A significant risk of birth defects was observed in 9 of 23 categories in multiple births. Both the multiple births and singletons with birth defects exhibited a similar proportion of single malformation, male children, and the mother living in a city. The multiple births with birth defects were delivered earlier (t = 7.90, p < 0.001) at a lower birth weight (t = 17.53, p < 0.001) compared to singletons with birth defects. The proportion of an antenatal diagnosis was higher in singletons compared with multiple births (p < 0.001). The multiple births with birth defects had a higher proportion of live birth and early neonatal death (p < 0.001). CONCLUSIONS: An increased risk of birth defects in multiple births compared with singletons was confirmed.

New cell separation technique for the isolation and analysis of cells from biological mixtures in forensic caseworks.

AIM: To isolate mucosal cells of the perpetrator in a sexual assault case from a complex mixture of his mucosal cells and the victim's skin by micromanipulation prior to genomic analysis. METHODS: To capture and analyze mucosal cells we used the micromanipulation with on-chip low volume polymerase chain reaction (LV-PCR). Consensus DNA profiles were generated from 5 replicate experiments. RESULTS AND CONCLUSIONS: We validated the use of micromanipulation with on-chip LV-PCR for genomic analysis of complex biological mixtures in a fatal rape case. The perpetrator's mucosal cells were captured from nipple swabs of the victim, and a single-source DNA profile was generated from cell mixtures. These data suggest that micromanipulation with on-chip LV-PCR is an effective forensic tool for the analysis of specific cells from complex samples.

Green tea and the prevention of breast cancer: a case-control study in Southeast China.

Breast cancer is the most common malignancy in women worldwide. Tea has anticarcinogenic effects against breast cancer in experimental studies. However, epidemiologic evidence that tea protects against breast cancer has been inconsistent. A case-control study was conducted in Southeast China between 2004 and 2005. The incidence cases were 1009 female patients aged 20-87 years with histologically confirmed breast cancer. The 1009 age-matched controls were healthy women randomly recruited from breast disease clinics. Information on duration, frequency, quantity, preparation, type of tea consumption, diet and lifestyle were collected by face-to-face interview using a validated and reliable questionnaire. Conditional logistic regression analyses were used to estimate odds ratios (ORs) and associated 95% confidence intervals. Compared with non-tea drinkers, green tea drinkers tended to reside in urban, have better education and have higher consumption of coffee, alcohol, soy, vegetables and fruits. After adjusting established and potential confounders, green tea consumption was associated with a reduced risk of breast cancer. The ORs were 0.87 (0.73-1.04) in women consuming 1-249 g of dried green tea leaves per annum, 0.68 (0.54-0.86) for 250-499 g per annum, 0.59 (0.45-0.77) for 500-749 g per annum and 0.61 (0.48-0.78) for >or=750 g per annum, with a statistically significant test for trend (P < 0.001). Similar dose-response relationships were observed for duration of drinking green tea, number of cups consumed and new batches prepared per day. We conclude that regular consumption of green tea can protect against breast cancer. More research to closely examine the relationship between tea consumption and breast cancer risk is warranted.

Dietary carotenoids and risk of breast cancer in Chinese women.

There has been considerable interest in the role of carotenoids in the chemoprevention of cancer. However, the protective effect of carotenoids on breast cancer has been inconclusive. To investigate whether intake of lycopene, alpha-carotene, beta-carotene, beta-cryptoxanthin, and lutein/zeaxanthin is inversely associated with breast cancer risk, a case-control study was conducted in China during 2004-2005. The cases were 122 female patients aged 24-87 years with histopathologically confirmed breast cancer. 632 healthy women age-matched were randomly recruited from outpatient clinics. Habitual dietary intake and lifestyle were collected by face-to-face interview using a validated and reliable food frequency questionnaire. The USDA nutrient composition database was used to calculate intake of the specific carotenoids. Unconditional logistic regression analyses were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs), accounting for age, locality, education, body mass index, smoking, passive smoking, physical activity, number of children breastfed, menopausal status, oral contraceptive use, biopsy-confirmed benign breast diseases, family history of breast cancer, and total energy intake. Compared with the highest versus lowest quartile of intake, the adjusted ORs were 0.26 (95% CI 0.14-0.46) for lycopene, 0.38 (95% CI 0.21-0.71) for beta-carotene, 0.43 (95% CI 0.23-0.82) for beta-cryptoxanthin, and 0.37 (95% CI 0.20-0.68) for total carotenoids, with statistically significant tests for trend. There was no association with breast cancer for alpha-carotene and lutein/zeaxanthin. It is concluded that higher intake of lycopene, beta-carotene and beta-cryptoxanthin is associated to a lower risk of breast cancer among Chinese women. More research to examine the relationship between carotenoids and breast cancer risk is warranted.