OBJECTIVE: To establish a simple, sensitive in vitro method to evaluate oxygen/glucose deprivation (OGD)-induced injury of brain hippocampal slices in rats. METHODS: Rat hippocampal slices were incubated in 2% 2, 3, 5-triphenyltetrazolium chloride (TTC) solution after oxygen/glucose deprivation. They were then soaked in a measured volume of ethanol and dimethylsulfoxide (50:50) to extract the TTC formazan Product which was then measured by spectrophotometry. OGD induced LDH release was simultaneously measured. RESULTS: Progressive prolongation of OGD induced hippocampal injury resulted in decreased formazan coloration as determined by spectrophotometry. There was a parallel increase in LDH release, thus a negative correlation in these two products was noted. (r=-0.933,P <0.01). The injury was attenuated in the brain slices pre-treated with nimodipine, dexamethasone, and ketamine, but not ONO-1078. CONCLUSION: Solvent extraction and spectrophotometric quantification of formazan represents an objective measurement of OGD-induced injury of rat hippocampal slices.

Objective:To construct the liver organoid infected with hepatitis D virus (HDV), and to investigate the role of the sodium taurocholate cotransporting polypeptide (NTCP) receptor inhibitor bulevirtide in inhibiting viral replication.Methods:Hepatocyte-like cells (HLC) differentiated from induced pluripotent stem cells (iPSC) were seeded onto inverted colloidal crystal polyethylene glycol scaffolds (ICC) to construct liver organoids. After transfecting human hepatocelluar carcinoma cells (HuH7 cells) with plasmids, HDV particles were harvested from the supernatant, while HBV particles were extracted from the HepG2.2.15 cell supernatant. The liver organoids were infected with both HBV and HDV particles, and the negative control group without HDV infection was set up. The microstructure of the liver organoid units and the expression of hepatitis D antigen (HDAg) and hepatitis B surface antigen (HBsAg) were observed under laser scanning confocal microscope by immunofluorescence method. The protein levels of NTCP and HDAg in the liver organoids were detected by Western blotting. Bulevirtide was added before HDV infection (bulevirtide pre group) and 24 hours after infection (bulevirtide post group), and interferon-alpha (IFN-α) was also added after 24 hours infection (IFN-α group), and a control group without drug treatment was set up. HDV replication was compared among the four groups after drug intervention. Real-time fluorescent quantitative polymerase chain reaction (RT-qPCR) was used to measure the relative mRNA expression levels of Nanog homeobox (NANOG), sex determining region Y-box (SOX)2, SOX17, forkhead box protein A2 (FOXA2), hepatocyte nuclear factor 4 alpha (HNF-4α), albumin (ALB), alpha-fetoprotein (AFP), NTCP during the differentiation of iPSC, and the mRNA expression of HDV after the drug intervention of the four groups. Statistical analysis was performed using two independent sample t tests. Results:Within 21 days of the differentiation of iPSC into HLC, the mRNA expression level of NANOG gradually decreased, while the expression levels of SOX17, FOXA2 initially increased then decreased, and the expression levels of the HNF-4α, ALB, AFP and NTCP progressively increased. The protein level of NTCP in iPSC (0.118±0.003) was lower than that in HLC (1.315±0.073), and the difference was statistically significant ( t=11.92, P<0.001).The protein level of HDAg in the liver organoids after HDV infection was higher than that in the negative control group without HDV infection (1.284±0.128 vs 0.157±0.040), and the difference was statistically significant ( t=23.27, P<0.001).Laser scanning confocal microscopy showed three-dimensional spheroid structures and high expressions of HDAg and HBsAg at the 14th day of infection.Compared with the control group (1.000±0.077), the HDV mRNA expressions in both IFN-α group (0.453±0.028) and bulevirtide pre group (0.136±0.012) decreased after three days of drug intervention. The differences were statistically significant ( t=19.95 and 33.15, respectively, both P<0.001). However, there was no significant difference in HDV mRNA expressions between the bulevirtide post group (0.968±0.069) and the control group ( t=0.94, P>0.05). Conclusions:The liver organoids constructed from iPSC-derived HLC and ICC can simulate human liver functions and successfully be infected by HDV particles. Early blockade with bulevirtide can effectively reduce the level of viral replication in the HDV-infected liver organoids.

OBJECTIVES: To investigate the incidence of extrauterine growth retardation (EUGR) and its risk factors in very preterm infants (VPIs) during hospitalization in China. METHODS: A prospective multicenter study was performed on the medical data of 2 514 VPIs who were hospitalized in the department of neonatology in 28 hospitals from 7 areas of China between September 2019 and December 2020. According to the presence or absence of EUGR based on the evaluation of body weight at the corrected gestational age of 36 weeks or at discharge, the VPIs were classified to two groups: EUGR group (n=1 189) and non-EUGR (n=1 325). The clinical features were compared between the two groups, and the incidence of EUGR and risk factors for EUGR were examined. RESULTS: The incidence of EUGR was 47.30% (1 189/2 514) evaluated by weight. The multivariate logistic regression analysis showed that higher weight growth velocity after regaining birth weight and higher cumulative calorie intake during the first week of hospitalization were protective factors against EUGR (P<0.05), while small-for-gestational-age birth, prolonged time to the initiation of total enteral feeding, prolonged cumulative fasting time, lower breast milk intake before starting human milk fortifiers, prolonged time to the initiation of full fortified feeding, and moderate-to-severe bronchopulmonary dysplasia were risk factors for EUGR (P<0.05). CONCLUSIONS It is crucial to reduce the incidence of EUGR by achieving total enteral feeding as early as possible, strengthening breastfeeding, increasing calorie intake in the first week after birth, improving the velocity of weight gain, and preventing moderate-severe bronchopulmonary dysplasia in VPIs.
Female ; Fetal Growth Retardation ; Gestational Age ; Hospitalization ; Humans ; Incidence ; Infant ; Infant, Newborn ; Infant, Premature ; Infant, Very Low Birth Weight ; Prospective Studies ; Risk Factors