[Preimplantation genetic testing for a Chinese pedigree affected with Rett syndrome].

OBJECTIVE: To carry out preimplantation genetic testing (PGT) for a Chinese pedigree affected with Rett syndrome (RTT). METHODS: A pedigree affected with RTT who had presented at the First Hospital of Jilin University on June 4, 2021 was selected as the study subject. Variant of the MECP2 gene was analyzed by next generation sequencing (NGS) and Sanger sequencing. Direct sequencing was also used to determine the carrier status for the c.925C>T variant of the MECP2 gene in the blastocysts, and Sanger sequencing was used to validate the results. The MECP2 gene and 168 effective single nucleotide polymorphism (SNP) loci within 2 Mb ranges up- and downstream of the gene were used to construct a haplotype for analyzing the variant site in the embryos, and embryos without the variant were subjected to the analysis for chromosomal aneuploidies. RESULTS: PGT analysis revealed that five out of seven blastocysts did not harbor the pathogenic variant. The results of aneuploidy analysis indicated that two out of five blastocysts without the variant were euploid. Following genetic counselling, the couple had opted to transplant the optimal blastocyst. Following clinical pregnancy, prenatal diagnosis showed that the fetus has a normal chromosomal karyotype, and the c.925C>T variant was not detected in the amniotic fluid sample. A healthy girl was born by Cesarean section at full term. CONCLUSION: NGS can attain efficient PGT detection and reduce the risk of disease recurrence in families affected with RTT.

Rapid chiral purity identification of mandelic acid by Raman spectra in the O-H stretching region.

Chiral molecules play a very important role in biological systems, and more and more chiral drugs are used in the treatment of diseases. Mandelic acid (MA) is an important chiral starting substance or the key intermediate of some chiral drugs, and the rapid detection of its chiral purity is very important in the synthesis, separation and detection of drugs. In this study, we developed a method for rapid determination of chiral purity of MA by Raman spectroscopy, and measured a series of Raman spectra of different chiral MA. Through the analysis, it is found that the OH stretching vibration peak can be used to identify the components of chiral molecules, and the enantiomeric excess (ee value) obtained is in good agreement with the real value, and the error is about 5%. The experimental detection speed is fast and the efficiency is high. Our work firstly provides a new idea for the purity detection of chiral molecules by the original Raman spectrum.

Risk prediction of gestational diabetes mellitus in women with polycystic ovary syndrome based on a nomogram model.

Women with polycystic ovary syndrome are prone to develop gestational diabetes mellitus, a disease which may have significant impact on the postpartum health of both mother and infant. We performed a retrospective cohort study to develop and test a model that could predict gestational diabetes mellitus in the first trimester in women with polycystic ovary syndrome. Our study included 434 pregnant women who were referred to the obstetrics department between December 2017 and March 2020 with a diagnosis of polycystic ovary syndrome. Of these women, 104 were diagnosed with gestational diabetes mellitus in the second trimester. Univariate analysis revealed that in the first trimester, Hemoglobin A1c (HbA1C), age, total cholesterol(TC), low-density lipoprotein cholesterol (LDL-C), SBP (systolic blood pressure), family history, body mass index (BMI), and testosterone were predictive factors of gestational diabetes mellitus (P < 0.05). Logistic regression revealed that TC, age, HbA1C, BMI and family history were independent risk factors for gestational diabetes mellitus. The area under the ROC curve of the gestational diabetes mellitus risk prediction model was 0.937 in this retrospective analysis, demonstrating a great discriminatory ability. The sensitivity and specificity of the prediction model were 0.833 and 0.923, respectively. The Hosmer-Lemeshow test also showed that the model was well calibrated.

Development and validation of a rapid kit for authenticity of murine meat in meat products with a species-specific PCR assay.

Adulteration of meat products with murine meat poses a huge threat to consumer health and leads to serious disruption in food markets. Species authentication of murine meat is still technically challenging. We, therefore, developed a species-specific PCR kit consisting of murine meat DNA extraction, PCR reaction and identifying systems. We designed novel universal primers targeting highly conserved region on mitochondrial cytochrome b gene (cyt b) from four murines (lab rats, lab mice, wild rat and wild mice), as well as specific primers for meat from four widely consumed animal species, cattle, sheep, duck and donkey. Simultaneously, pasmid inserted specific cyt b fragment was cloned and used as the internal positve control in the kit. The kit parameters of specificity, sensitivity, stability and validity were determined using mimic counterfeiting meatball. The specificity of the DNA detection kit was 100% in authentication of the four fraudulent meats of cattle, sheep, duck and donkey mixed murine meat. The minimum detection limit of the sample DNA was 0.1 µg. The kit, which had freeze-thawed up to 20 times and stored for 1 year, also was powerful in detecting an amount of 0.1 mg in artificial counterfeited cattle, sheep, duck and donkey meat products. The murine-species DNA detection kit proposed in this study has proved to be a simple, accurate and effective assay, and can be applied to the identification of murine meat traces in common edible meat, to ensure the realisable implementation of meat product market supervision.

Nature of Monomeric Molybdenum(VI) Cations in Acid Solutions Using Theoretical Calculations and Raman Spectroscopy.

The composition and structures of the two protonated species formed from uncharged molybdic acid, MoO2(OH)2(OH2)20, in strongly acidic solutions have been investigated using a combination of density functional theory calculations, first-principles molecular dynamics simulations, and Raman spectroscopy. The calculations show that both protonated species maintain the original octahedral structure of molybdic acid. Computed p Ka values indicated that the ═O moieties are the proton acceptor sites and, therefore, that MoO(OH)3(OH2)2+ and Mo(OH)4(OH2)22+ are the probable protonated forms of Mo(VI) in strong acid solutions, rather than the previously accepted MoO2(OH)2- x(OH2)2+ x x+ ( x = 1, 2) species. This finding is shown to be broadly consistent with the observed Raman spectra. Structural details of MoO(OH)3(OH2)2+ and Mo(OH)4(OH2)22+ are reported.

Development of a PCR-based assay for detection of Chinese mink tissue in meat products based on the mitochondrial DNA cytochrome-b gene.

Species authentication of meat product origins has become an important subject for ensuring the health of consumers. Based on the cytochrome b gene, we developed a PCR-based assay kit for identification of Chinese mink tissues from 10 animal species in meat products, and to evaluate its quality indices including specificity, stability, sensitivity, and repeatability. Kits were made up of DNA extraction and PCR amplification systems based on species-specific, and universal primers. The reference meat mixtures and commercial samples were extracted by the kit and PCR technique was performed to identify the species of mink authenticity. The kit was effective after 20 repeated freeze-thaw cycles and it could be stored at -20 °C for 1 year. The sensitivity showed that a concentration as low as 0.1 ng/µL still can amplify the target band. The specificity test confirmed that the kit was 100% specific. The kit proved to be effective, stable, and reliable for extraction of efficient contents of the genomic DNA and routine analysis of Chinese mink source composition from meat products.

[Development on DNA detection kit of fox and its application in common meat products].

OBJECTIVE: To develop a kind of DNA extraction and detection kit for identification of fox source composition. METHODS: Using the modern DNA fingerprint technology, the DNA extraction method was improved, and DNA extraction and detection reagent was developed to obtain the fox polymerase chain reaction( PCR)detection kit. The performance parameters of the kit were evaluated. Finally, 42 samples of fox meat and its mixture with commercial meat products were detected. RESULTS: The kit was proved effective after 20 times of the repeated frozen-thaw and it could be stored at-20 ℃ for 1 year. The specificity test confirmed that fox source composition were detected from 42 samples of fox meat and its mixture with commercial meat. The specificity of the kit was 100%. The minimum detection limit of DNA was 0. 1 ng/µL. CONCLUSION: The fox DNA detection kit could be applied in rapid detection commonmeat of fox source composition, which are good specificity, high sensitivity and good stability.

Placenta accreta spectrum disorder trends in the context of the universal two-child policy in China and the risk of hysterectomy.

OBJECTIVE: To identify both the trends in placenta accreta spectrum (PAS) disorders in the context of the universal two-child policy in China and risk factors for hysterectomy. METHODS: The present retrospective analysis included confirmed PAS disorders during cesarean delivery at a tertiary hospital in Changsha, Hunan, China, from January 1, 2007, to December 31, 2016. Multivariable logistic regression was used to estimate the risk of hysterectomy. RESULTS: During the 10-year study period, the overall incidence of cesarean delivery was 51.6% (13 530/26 214) and that of PAS disorders was 1.2% (302/26 214). The PAS rate increased from 0.1% (5/4617) in 2007-2008 to 2.1% (133/6351) in 2015-2016, alongside a rise in elective repeat cesarean delivery from 5.0% (106/2124) to 38.4% (1385/3603). Previous cesarean delivery greatly increased the likelihood of PAS disorders (odds ratio [OR] 97.4; P<0.001). Invasive depth (OR 92.0; P<0.001), inter-cesarean interval less than 36 months (OR 7.0; P=0.002), rural residence (OR 5.3; P=0.018), and advanced maternal age (OR 3.0; P=0.045) were independent risk factors for hysterectomy among women with PAS disorders. CONCLUSION: The increasing incidence of elective repeat cesarean delivery combined with a high overall rate of cesarean delivery implies a high prevalence of PAS disorders within the context of the universal two-child policy in China. The main predictor of hysterectomy was invasive depth.