Background: Nerol (C₁₀H₁₈O), an acyclic monoterpene, naturally presents in plant essential oils, and is used widely in food, cosmetics and pharmaceuticals as the valuable fragrance. Meanwhile, chemical synthesis is the only strategy for large-scale production of nerol, and the disadvantages of chemical synthesis greatly limit the production and its application. These defects drive the interests of researchers shift to the production of nerol by eco-friendly methods known as biosynthesis methods. However, the main technical bottleneck restricting the biosynthesis of nerol is the lacking of corresponding natural aroma-producing microorganisms. Results: In this study, a novel multi-stress-tolerant probiotics Meyerozymaguilliermondii GXDK6 with aroma-producing properties was identified by whole genome sequencing and metabolomics technology. GXDK6 showed a broad pH tolerance in the range of 2.5–10.0. The species also showed salt tolerance with up to 12% NaCl and up to 18% of KCl or MgCl₂. GXDK6 exhibited heavy-metal Mn²⁺ tolerance of up to 5494 ppm. GXDK6 could also ferment with a total of 21 kinds of single organic matter as the carbon source, and produce abundant aromatic metabolites. Results from the gas chromatography–mass spectrometry indicated the production of 8–14 types of aromatic metabolites (isopentanol, nerol, geraniol, phenylethanol, isobutanol, etc.) when GXDK6 was fermented up to 72 h with glucose, sucrose, fructose, or xylose as the single carbon source. Among them, nerol was found to be a novel aromatic metabolite from GXDK6 fermentation, and its biosynthesis mechanism had also been further revealed. Conclusion: A novel aroma-producing M. guilliermondii GXDK6 was identified successfully by whole genome sequencing and metabolomics technology. GXDK6 showed high multi-stress-tolerant properties with acid–base, salty, and heavy-metal environments. The aroma-producing mechanism of nerol in GXDK6 had also been revealed. These findings indicated the aroma-producing M. guilliermondii GXDK6 with multi-stress-tolerant properties has great potential value in the fermentation industry.

Context: Type I hypersensitivity affects approximately one-third of the global population. As the pathophysiology underlying the development of type I hypersensitivity (asthma, food allergy, and anaphylactic shock, etc.) is complex and heterogeneous, animal model studies continue to be the key to identifying novel molecular pathways and providing therapeutic strategies.Objective: Selection of the animal model should be done with careful consideration of the protocol variables, animal species, and strains to accurately reflect the clinical symptoms typical of humans.Methods: The following databases were searched: PubMed and Web of Science.Results and conclusion: Foreign allergens include allergenic proteins and chemical haptens. This review summarizes the various methods used for designing animal models of common allergenic protein-induced type I hypersensitivity, namely, passive anaphylaxis model, active systemic anaphylaxis/anaphylaxis shock model, food allergy model, asthma model, and IgE-mediated cell models. Additionally, we summarize shrimp tropomyosin-induced type I hypersensitivity models from our previous studies and discuss their advantages and limitations compared with that of ovalbumin-induced models.

Background: Birth defects (BDs) are associated with many potential risk factors, and its causes are complex.Objectives: This study aimed to explore the epidemiological characteristics of BDs in Guangxi of China and the associated risk factors of BDs.Methods: BDs data of perinatal infants (PIs) were obtained from the Guangxi birth defects monitoring network between 2016 and 2020. Univariate Poisson regression was used to calculate the prevalence-rate ratios (PRR) to explore the changing trends of BDs prevalence by year and the correlation between the regarding of characteristics of BDs (including infant gender, maternal age, and quarter) and BDs. Clinical characteristics of PIs with BDs and general characteristics of their mothers were documented, and Spearman correlation analysis was used to explore the potential associated risk factors of BDs.Results: Between 2016 and 2020, 44,146 PIs with BDs were monitored, with an overall BDs prevalence of 121.71 (95% CI: 120.58–122.84) per 10,000 PIs, showing a significant increase trend (PRR = 1.116, 95% CI: 1.108–1.123), especially the prevalence of congenital heart defects (CHDs) that most significantly increased (PRR = 1.300, 95% CI: 1.283–1.318). The 10 most common BDs were CHDs, polydactyly, congenital talipes equinovarus, other malformation of external ear, syndactyly, hypospadias, cleft lip with cleft palate, cleft lip, hemoglobin Bart's hydrops fetalis syndrome (BHFS), and congenital atresia of the rectum and anus. BDs were positively correlated with pregnant women's age (R = 0.732, P < 0.01) and education level (R = 0.586, P < 0.05) and having pre-gestational diabetes mellitus (PGDM)/gestational diabetes mellitus (GDM) (R = 0.711, P < 0.01), while when the pregnant women had a family history of a dead fetus (R = −0.536, P < 0.05) and a birth of a fetus with BDs (R = −0.528, P < 0.05) were negatively correlated with BDs.Conclusion: A significant increase in the prevalence of BDs was detected between 2016 and 2020 in Guangxi, especially the prevalence of CHDs that most significantly increased. Older maternal age, higher maternal education level, and having PGDM before pregnancy or GDM in early pregnancy were the risk factors for BDs.

Purpose: To explore the changing trends in the prevalence and epidemiological characteristics of congenital heart defects (CHDs) in perinatal infants (PIs) in Guangxi, China. Patients and Methods: During 2016 and 2020, the Guangxi Birth Defects Monitoring Network (GXBDMN) monitored a total of 3627108 PIs in this study. The CHDs data for PIs can be obtained from the GXBDMN. The study analyzed the changing trends of total CHDs prevalence and each subtype of CHDs prevalence per year using prevalence-rate ratios (PRR). The correlation between characteristics (such as year, infant gender, maternal age, and quarter) and the prevalence of CHDs was also examined by the PRR. Results: Between 2016 and 2020, 10817 PIs were diagnosed with CHDs, resulting in an overall CHDs prevalence of 29.82 [95% confidence intervals (CI): 29.26– 30.38] per 10000 PIs. CHDs accounted for 24.50% of all types of BDs, making them the most common type of BDs. Atrial septal defect / patent foramen ovale (ASD/PFO), patent ductus arteriosus (PDA), ventricular septal defect (VSD), atrioventricular septal defect (AVSD), persistent left superior vena cava (PLSVC), and tetralogy of Fallot (TOF) were the 6 most common subtypes of CHDs. Together they accounted for 86.24% of all CHDs cases, with a total prevalence of 25.72 (95% CI: 25.20– 26.24) per 10000 PIs. The study period saw a significant increase in the prevalence of CHDs (PRR = 1.300, 95% CI: 1.283– 1.318), and the maternal age also played a significant role in this increase (PRR = 2.738, 95% CI: 2.428– 3.087). Conclusion: The prevalence of CHDs in Guangxi is rising and has an upward trend with maternal age. ASD/PFO, PDA, VSD, AVSD, PLSVC, and TOF were the top six subtypes of CHDs.

miR-144/451 and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) regulate two antioxidative systems that have been identified to maintain redox homeostasis in erythroid cells by removing excess reactive oxygen species (ROS). Whether these two genes coordinate to affect ROS scavenging and the anemic phenotype, or which gene is more important for recovery from acute anemia, has not been explored. To address these questions, we crossed miR-144/451 knockout (KO) and Nrf2 KO mice and examined the phenotype change in the animals as well as the ROS levels in erythroid cells either at baseline or under stress condition. Several discoveries were made in this study. First, Nrf2/miR-144/451 double-KO mice unexpectedly exhibit similar anemic phenotypes as miR-144/451 single-KO mice during stable erythropoiesis, although compound mutations of miR-144/451 and Nrf2 lead to higher ROS levels in erythrocytes than single gene mutations. Second, Nrf2/miR-144/451 double-mutant mice exhibit more dramatic reticulocytosis than miR-144/451 or Nrf2 single-KO mice during days 3 to 7 after inducing acute hemolytic anemia using phenylhydrazine (PHZ), indicating a synergistic effect of miR-144/451 and Nrf2 on PHZ-induced stress erythropoiesis. However, the coordination does not persist during the whole recovery stage of PHZ-induced anemia; instead, Nrf2/miR-144/451 double-KO mice follow a recovery pattern similar to miR-144/451 single-KO mice during the remaining period of erythropoiesis. Third, the complete recovery from PHZ-induced acute anemia in miR-144/451 KO mice takes longer than in Nrf2 KO mice. Our findings demonstrate that complicated crosstalk between miR-144/451 and Nrf2 does exist and the crosstalk of these two antioxidant systems is development-stage-dependent. Our findings also demonstrate that miRNA deficiency could result in a more profound defect of erythropoiesis than dysfunctional transcription factors.

We report a novel mutation on the α2-globin gene, Hb Debao [α31(B12)Arg→Trp; HBA2: c.94A>T] detected in a Chinese family. This mutation gives rise to a previously undescribed hemoglobin (Hb) variant that was undetectable by electrophoretic or chromatographic methods. Hb Debao was associated with an α⁺-thalassemia (α⁺-thal) deletion [−α^3.7 (rightward)] producing a mild phenotype with significant microcytosis and hypochromia, while the combination of this mutation with an α⁰-thal deletion (−−^SEA) resulting in a severe form of Hb H (β4) disease, which is consistent with a thalassemic phenotype associated with the novel mutation.