Neurogenesis is a process in which the neuronal stem cells differentiate into functional neurons including the cell proliferation,differentiation and migration.Previously,it was believed that neurogenesis is a prenatal process and the adult ependymal cells are incapable of regeneration.Now it is clear that mammalian brain retains the ability to generate new ceils in specific regions.One of the regions is subventricular zone of the lateral ventricles,new generated neurons and glial cells later migrate to olfactory and repair dysosmia through the RMS road.Here we will review the advances in adult neurogenesis in mammal subventficular zone.

Objective:The two detection method for the detection of hepatitis A virus (HAV) in strawberries were optimized and compared to select the best detection method for the detection of hepatitis A virus in strawberries.Methods:Different concentrations of HAV were inoculated on the surface of known negative frozen strawberry specimens, the concentration of beef extract powder in alkaline elution-PEG concentration method was optimized, the optimal nucleic acid extraction kit was selected, the optimal lysis buffer volume in direct lysis method was optimized, and the recovered viral load was detected by Real-time fluorescence quantitative RT-PCR. SPSS26.0 was used to statistically analyze the data, and the optimized two method were used for the detection of actual specimens.Results:The concentration of beef extract powder by the optimized alkaline elution-PEG concentration method was selected at 3%, and the viral nucleic acid extraction kit was selected as kit B. Six ml of lysis buffer was selected for the optimized direct lysis method. The recovery rates of HAV virus by alkaline elution-PEG concentration and direct lysis were compared with the HAV addition levels, and the HAV virus recovery rates of the two method were 21.50±1.06% and 5.82±0.01%, respectively, and the result showed that the differences were statistically significant. A total of 60 strawberry specimens from four regions were tested at the same time, and the result were all negative.Conclusions:The optimized alkaline elution-PEG concentration method has higher sensitivity and is more suitable for the detection of HAV in strawberry specimens.

Objective:To establish a digital droplet RT-PCR(dRT-PCR) method for Hepatitis A virus (HAV), and compare it with Real time RT-PCR(RT-qPCR) method, and select the best method for detecting hepatitis A virus in strawberry.Methods:Extract HAV vaccine RNA, optimize the reaction conditions of dRT-PCR and evaluate its specificity; Alkaline elution -PEG concentration method was used to extract nucleic acid from strawberry samples. At the same time, dRT-PCR and RT-qPCR method were used to detect the sensitivity and inhibition rate of HAV vaccine RNA in pure water and strawberry matrix, and the recovery rate of HAV in artificially contaminated strawberry was compared, which was applied to the detection of commercially available samples.Results:The optimal annealing temperature for dRT-PCR reaction was 60 ℃, and the optimal concentrations of primers and probes were 0.4 μmol/L、0.4 μmol/L and 0.2 μmol/L, with good specificity. There is no significant difference in sensitivity between the two method in detecting HAV vaccine RNA in pure water and strawberry matrix. The inhibition rate of dRT-PCR is low. The recovery rates of dRT-PCR and RT-qRCR in the detection of strawberry samples contaminated with HAV at higher concentrations were 12.90±0.006% and 30.12±0.02%, respectively. The recovery rates of lower concentrations of HAV contaminated strawberry samples were 18.27±0.07% and 10.85±0.03%, respectively, and the difference was statistically significant ( P<0.05). When strawberry samples on the market were tested, the result of both method were negative. Conclusions:The sensitivity of dRT-PCR method established in this study is not significantly different from that of RT-qPCR in detecting HAV RNA in different substrates, but dRT-PCR has good tolerance to PCR reaction inhibitors and high recovery rate when detecting low concentration HAV. Both detection method can be used for quantitative detection of hepatitis A virus in strawberry, and can be selected according to the actual situation.

Objective To construct a carbon dioxide(CO2)laser-induced corneal injury model in mice and observe the process of corneal wound healing.Methods Twenty eyes of ten C57BL/6J mice were divided into 4 groups.The cen-tral corneas in each group were irradiated by CO2 laser with a wavelength of 10.6 μm,spot diameter of 2 mm and power of 0.94 W.The exposure doses were 3.0 J·cm-2,4.5 J·cm-2,7.5 J·cm-2 and 10.5 J·cm-2,with corresponding expo-sure durations of 0.10 s,0.15 s,0.25 s and 0.35 s.Corneal injury severity was assessed using a slit lamp microscope,opti-cal coherence tomography and histopathological evaluation at 1 day after the exposure to determine the proper exposure dose for constructing a corneal injury model.Subsequently,the corneal injury model was constructed and the same meth-ods were used to monitor wound healing before,and 0 hours to 6 months after the exposure.Results No obvious corne-al injury was observed at an exposure dose of 3.0 J·cm-2.At an exposure dose of 4.5 J·cm-2,an off-white injury area appeared on the central cornea with loss of epithelium and endothelium.At an exposure dose of 7.5 J·cm-2 or 10.5 J·cm-2,the injury area became porcelain white,the cornea was thickened,and the iris was seen adhering to the margin of the cornea.Therefore,4.5 J·cm-2 CO2 laser was selected to construct a corneal injury model.At this exposure dose,the cornea swelled and thickened rapidly after injury,reached the maximum thickness 1 day after the exposure,and then grad-ually recovered,returning to normal by 14 days after the exposure.In the early stage(0 hours to 3 days after the expo-sure),the cornea showed shedding of injured epithelium and endothelium,migration of new epithelium and endothelium,and infiltration and regression of inflammatory cells.At the late stage(7 days to 6 months after the exposure),the cornea gradually returned to a normal physiological state,but some of the injured cornea exhibited stromal hyperplasia.Conclu-sion A CO2 laser with an exposure dose of 4.5 J·cm-2 can be used to construct a corneal injury model in mice.The a-cute phase of corneal injury primarily occurs within 3 days after the exposure.The cornea tends to restore its original physi-ological structure,but the corneal transparency cannot return to a normal state.

Objective: To detect WNT10A gene mutations in patients with oligodontia or anodontia (≥6 teeth missing) and analyze their dental phenotype. Methods: Patients with oligodontia or anodontia were enrolled from the clinic for oral examination, genetic history collection and whole exon sequencing, and patients with WNT10A gene mutations were included. Sanger sequencing was utilized to validate the WNT10A gene variations in probands and family members compared with the normal sequence. The pathogenicity of WNT10A mutations was evaluated by functional prediction, conservation analysis and structure prediction of protein mutants. Implant rehabilitation was applied to restore the patients' oral function. Results: Five WNT10A gene mutations were detected in six unrelated patients, and c.26G>A (p. Trp9X) and c.1036delT (p. Cys346fs) were novel mutations with pathogenic potential. The mean number of missing teeth was (15.33±8.64) per case. The most frequently missing permanent teeth were maxillary canines (100%), and the least frequently missing teeth were mandibular first molars (25%). Implant rehabilitation was applied in five patients, and patients were found to have ideal implant osseointegration and functional restoration. Conclusion This study identified novel WNT10A gene pathogenic variants, enriching the WNT10A gene spectrum and providing new evidence for genetic diagnosis and prenatal consultation. Implant rehabilitation was also proven to be a treatment option for these patients.

Oligodontia is the congenital absence of six or more teeth and comprises the more severe forms of tooth agenesis. Many genes have been implicated in the etiology of tooth agenesis, which is highly variable in its clinical presentation. The purpose of this study was to identify associations between genetic mutations and clinical features of oligodontia patients. An online systematic search of papers published from January 1992 to June 2021 identified 381 oligodontia cases meeting the eligibility criteria of causative gene mutation, phenotype description, and radiographic records. Additionally, ten families with oligodontia were recruited and their genetic etiologies were determined by whole-exome sequence analyses. We identified a novel mutation in WNT10A (c.99_105dup) and eight previously reported mutations in WNT10A (c.433 G > A; c.682 T > A; c.318 C > G; c.511.C > T; c.321 C > A), EDAR (c.581 C > T), and LRP6 (c.1003 C > T, c.2747 G > T). Collectively, 20 different causative genes were implicated among those 393 cases with oligodontia. For each causative gene, the mean number of missing teeth per case and the frequency of teeth missing at each position were calculated. Genotype-phenotype correlation analysis indicated that molars agenesis is more likely linked to PAX9 mutations, mandibular first premolar agenesis is least associated with PAX9 mutations. Mandibular incisors and maxillary lateral incisor agenesis are most closely linked to EDA mutations.
Humans ; Phenotype ; Wnt Proteins