Clinical characteristics of pediatric cases infected with the SARS-CoV-2 Omicron variant in a tertiary children's medical center in Shanghai, China.

BACKGROUND: The number of pediatric cases of infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant has increased. Here, we describe the clinical characteristics of children in a tertiary children's medical center in Shanghai. METHODS: A total of 676 pediatric coronavirus disease 2019 (COVID-19) cases caused by the Omicron variant who were admitted to the Shanghai Children's Medical Center from March 28 to April 30, 2022 were enrolled in this single-center, prospective, observational real-world study. Patient demographics and clinical characteristics, especially COVID-19 vaccine status, were assessed. RESULTS: Children of all ages appeared susceptible to the SARS-CoV-2 Omicron variant, with no significant difference between sexes. A high SARS-CoV-2 viral load upon admission was associated with leukocytopenia, neutropenia, and thrombocytopenia (P = 0.003, P = 0.021, and P = 0.017, respectively) but not with physical symptoms or radiographic chest abnormalities. Univariable linear regression models indicated that comorbidities (P = 0.001) were associated with a longer time until viral clearance, and increasing age (P < 0.001) and two doses of COVID-19 vaccine (P = 0.001) were associated with a shorter time to viral clearance. Multivariable analysis revealed an independent effect of comorbidities (P < 0.001) and age (P = 0.003). The interaction effect between age and comorbidity showed that the negative association between age and time to virus clearance remained significant only in patients without underlying diseases (P < 0.001). CONCLUSION: This study describes the clinical characteristics of children infected with the Omicron variant of SARS-CoV-2 and calls for additional studies to evaluate the effectiveness and safety of vaccination against COVID-19 in children.

Microwave-Assisted Synthesis of Imidazo[4,5-f][1,10]phenanthroline Derivatives as Apoptosis Inducers in Chemotherapy by Stabilizing Bcl-2 G-quadruplex DNA.

Herein, a series of imidazo[4,5-f][1,10] phenanthroline derivatives RPIP (PIP = imidazo [4,5-f][1,10] phenanthroline, R = NO2, 1; CF3, 2; Cl, 3; OH, 4) have been synthesized in yields of 82.3-94.7% at 100 °C under the irradiation of microwave. MTT assay has been utilized to evaluate the inhibitory activity (IC50) of these compounds against the growth of various tumor cells, and the results revealed that these compounds, especially 1, exhibited excellent inhibitory activity against the growth of A549 cells with IC50 of 15.03 µM. Moreover, it's also confirmed that 1 can penetrate into the membrane of tumor cells and distribute in mitochondria when observed under microscopy, resulting apoptosis of tumor cells. The further studies showed that 1 can bind to bcl-2 G-quadruplex DNA, which demonstrated by the increase of melting point of bcl-2 G4 DNA in the presence of 1, as well as electronic titration and emission spectra. In a word, this kind of compound may develop as a potential apoptosis inducer in cancer chemotherapy via binding and stabilizing to the bcl-2 G-quadruplex DNA.

microRNA-155 acts as an oncogene by targeting the tumor protein 53-induced nuclear protein 1 in esophageal squamous cell carcinoma.

MicroRNA-155 (miR-155) is overexpressed in many human cancers; however, the function of miR-155 is largely unknown in esophageal squamous cell carcinoma (ESCC). In the present study, we found that miR-155 is dramatically increased in ESCC tissues compared with the paired adjacent normal tissues, which suggested that miR-155 acts as an oncogene in ESCC. We predicted that tumor protein p53-induced nuclear protein 1 (TP53INP1) is a candidate target gene of miR-155 given that miR-155 expression decreased mRNA and protein levels of TP53INP1 as determined by RT-PCR and Western blot analysis. In addition, miR-155 and TP53INP1 showed a negative relation in ESCC tissues. Dual luciferase-based reporter assay indicated direct regulation of TP53INP1 by miR-155. Furthermore, we demonstrated that RNA interference of TP53INP1 increased the proliferation and colonies formation of EC-1 cells. Up-regulation of TP53INP1 abrogated miR-155 induced growth in EC-1 cells and mutation of TP53INP1 in 3'-UTR restored the effects when co-transfected with miR-155. We also indicated that overexpression of miR-155 significantly promoted the proliferation of EC-1 cells in vitro and the development of tumors in nude mice. Taken together, our study reveals that miR-155 acts as an oncogene by targeting TP53INP1 in ESCC.

Musashi1 and hairy and enhancer of split 1 high expression cells derived from embryonic stem cells enhance the repair of small-intestinal injury in the mouse.

BACKGROUND: Embryonic stem cells have great plasticity. In this study, we repaired impaired small intestine by transplanting putative intestinal epithelial stem cells (Musashi1 and hairy and enhancer of split 1 high expression cells) derived from embryonic stem cells. METHODS: The differentiation of definitive endoderm in embryoid bodies, derived from male ES-E14TG2a cells by the hanging-drop method, was monitored to define a time point for maximal induction of putative intestinal epithelial stem cells by epidermal growth factor. Furthermore, to evaluate the regenerative potential of intestinal epithelium, these putative stem cells were engrafted into NOD/SCID mice and female mice with enteritis. Donor cells were located by SRY DNA in situ hybridization. RESULTS: The results revealed that definitive endodermal markers were highly expressed in 5-day embryoid bodies. These embryoid body cells were induced into putative intestinal epithelial stem cells on the 5th day of epidermal growth factor administration. Grafts from these cells consisted of adenoid structures and nonspecific structural cells with strong expression of small-intestinal epithelial cell markers. In situ hybridization revealed that the donor cells could specifically locate in damaged intestinal epithelium, contribute to epithelial structures, and enhance regeneration. CONCLUSIONS: In conclusion, the Musashi1 and hairy and enhancer of split 1 high expression cells, derived from mouse embryonic stem cells, locate predominantly in impaired small-intestinal epithelium after transplantation and contribute to epithelial regeneration.

Improved nude mouse models for green fluorescence human endometriosis.

AIM: To establish an improved noninvasive fluorescent animal model for endometriosis. MATERIAL AND METHODS: Adenovirus encoding enhanced green fluorescent protein (Ad-eGFP) was used to transfect primary culture endometrial glandular cells and stromal cells (purified cell transfection and mixed injection, Group 1) as well as endometrial fragments (tissues transfection and injection, Group 2). Transfection results were compared between the cells and tissues in vitro. The GFP-transfected cells suspension of Group 1 or endometrial fragments of Group 2, with similar weight, were injected into nude mice subcutaneously and noninvasively observed every 5 days until day 15 (Subgroup 1, N = 5), day 20 (Subgroup 2, N = 5) or day 25 (Subgroup 3, N =11). The positive rates and duration times of the fluorescent lesions were calculated. RESULTS: After 18 h of incubation, glandular cells and stromal cells all had higher GFP-positive rates. In vivo imaging showed that the GFP positive rates of Group 1 were significantly higher than those of Group 2. The fluorescent-positive durations of Groups 1 and 2 were 23.636 ± 4.523 days and 5.909 ± 5.394 days, respectively (P < 0.001). In vivo analysis demonstrated that on days 15, 20, and 25, there were more typical lesions and fluorescent-positive lesions formed in Group 1 and that the lesion weight in Group 1 was greater. The structures of the lesions were all identified as human origin. CONCLUSION: A noninvasive animal model for endometriosis created by subcutaneous injection of an Ad-eGFP-transfected endometrial glandular and stromal cells suspension had higher a positive rate, longer duration time of fluorescent imaging and greater lesion weight.

[Construction and selection of the most efficient siRNA interfering plasmid specific to mouse Qa-1 gene].

This study was purposed to construct three siRNA eukaryotic expression vector specific to mouse Qa-1 gene, to investigate its silencing effect on Qa-1 gene and to select the most efficient siRNA plasmid specific to mouse Qa-1 gene. Three siRNA peptides specific to mouse Qa-1 through siRNA Web design tools of Ambion company were chosed. Jingsai Company helped to complete the siRNA eukaryotic expression vector. The mouse NIH3T3 cells cultured in RPMI 1640 medium with 10% fetal bovine serum were divided into four groups: three groups of the cells were transfected with lipofectamine 2000 reagent and three different siRNA eukaryotic expression vectors, while one group cells were transfected with lipofectamine 2000 reagent alone as negative control. Cells were collected at 24, 48, 72 hours after transfection; the RNA level of Qa-1 was detected by RT-PCR, and the expression position was examined with flow cytometry analysis by using anti-Qa-1 monoclonal antibody. The results indicated that the constructed three siRNA eukaryotic expression vectors were found to be specific to mouse Qa-1 gene. The sequence analysis showed that the sequence was identical to what chosed from web tools. NIH3T3 cells in vitro were adhered in culture that cell shape appeared to change after transfection. RT-PCR and flow cytometry analysis by using anti-Qa-1 monoclonal antibody approved that both Qa-1 RNA and the expression of Qa-1 on cell surface decreased. The decreased levels in the three groups were different. At 24, 48 and 72 hours, the expression of Qa-1 on NIH3T3 cells decreased as in the following: H2-T231: 60.9%, 81.9%, 43.6%; H2-T232: 64.5%, 73.9%, 61.1%; H2-T233: 61.9%, 71.2%, 47.5%. H2-T232 was most efficient one in all three time points. It is concluded that all three siRNA eukaryotic expression vectors selected can successfully suppress the expression of the Qa-1, and from them H2-T232 is most efficient.

IL-1beta sensitizes rat intervertebral disc cells to Fas ligand mediated apoptosis in vitro.

AIM: To determine the apoptotic effect of recombinant rat Fas Ligand on rat intervertebral disc cells pre-treated with IL-1beta in vitro, and the expression of Fas in cultured rat intervertebral disc cells. METHODS: Cells were isolated from the inner annulus fibrosus and transition zones of lumbar discs from Sprague-Dawley rats. The cells were grown in monolayer and divided in 5 treatment groups. IL-1beta (10 ng/mL), FasL (5, 20 ng/mL) with/without IL-1beta (10 ng/mL) pre-treatment was respectively added in Dulbeccoos modified Eagleos medium and Hamos F-12 medium with 1% fetal bovine serum. After 32 h, the cells were stained with annexin V-FITC and propidium iodide to evaluate apoptosis using flow cytometry and to analysis transcription of Fas using RT-PCR. RESULTS: Compared with control group, FasL (20 ng/mL), IL-1beta (10 ng/mL)+FasL (5 ng/mL), and IL-1beta (10 ng/mL)+FasL (20 ng/mL) induced significant apoptosis of the disc cells (P<0.01). Apoptosis was also induced by FasL 5 ng/mL (P<0.05); whereas, apoptosis was not induced by IL-1beta (10 ng/mL) (P>0.05). IL-1beta (10 ng/mL) enhanced the apoptosis-inducing effects of FasL (5 ng/mL) and FasL (20 ng/mL) in disc cells. Fas gene transcription in all groups and Fas expression in the 5 treatment groups were approximately 1.2-2.1-fold greater than control group (respectively, P<0.05). Additionally, Fas expression in FasL with IL-1beta pre-treatment groups were significantly up-regulated than in FasL groups (P<0.01). CONCLUSION: The results of this study showed disc cells pre-treated with IL-1beta increased apoptotic rate in response to FasL in vitro and provided insights to understand Fas/FasL system-mediated apoptosis in disc cells which would be enhanced due to inflammation factor in degenerative disc.

[Human mucin 1 promoter drives human sodium/iodide symporter gene targeting expression in pancreatic carcinoma cells].

OBJECTIVE: To clone human mucin 1 (MUC1) gene promoter and apply to drive human sodium/iodide symporter (hNIS) gene targeting expression in pancreatic carcinoma cells. METHODS: Human Mucin1 (MUC1) promoter was cloned from the 5' flanking region of the MUC1 gene by two-step nest PCR from human pancreatic carcinoma cells of the line CAPAN-I, II and then linked to pDC316 plasmid (pDC316-MUC1). Subsequently, a recombinant plasmid containing MUC1 and hNIS was constructed (pDC316-MUC1/hNIS). The recombinant plasmid pDC316-MUC1/hNIS, pD316-mCMV/NIS plasmid, and pDC316-mCMV/hNIS plasmid were transfected into the CAPAN-II cells, human pancreatic carcinoma cells of the line PANC-1, and human cervical carcinoma cells of the line HeLa respectively as experimental group, positive control group, and negative control group. 48 h after the transfection RT-PCR and immunofluorescence were used to confirm the expression of hNIS mRNA and hNIS protein. Then the cells were cultured in solution with 125I. The 125I uptake in the cells was measured by gamma-counting. RESULTS: The sequence data of regulatory element in MUC1 promoter genes was corresponded to those of reference report. The hNIS protein expression level was high in the MUC1 positive cells, as CAPAN-II cells and PANC-1 cells, but very low in the MUC1 negative cells, such as the HeLa cells. Two days after the transfection, the CAPAN-II cells and PANC-1 cells showed a high level of 125I uptake after transfection with pDC316-MUC1/hNIS, and the CAPAN-II cells, PANC-1 cells, and HeLa cells showed a high level of 125I uptake after transfection with pDC316-MCMV/hNIS. A7-12-fold increase in 125I uptake was observed in the pDC316-MUC1/hNIS transfected cells compared with the pDC316-MUC1 transfected cells. CONCLUSION: MUC1 promoter cloned from CAPAN-2 cells can be used to drive NIS genes expression in MUC1 positive pancreatic carcinoma cells. Therefore, this strategy can be used as a novel and potent gene-targeting therapy in the MUC1 positive pancreatic carcinoma in vivo.

Cloning and high expression of hbFGF with a new strategy.

Computer program DNASIS v2.5 was used to help designing the site-directed mutations for optimizing the expression of hbFGF in E. coli. The secondary structure of the translation initiation region (TIR) is a determinant factor for translation initiation rate, meanwhile, codon preference plays an important role, too. According to the two principles, 4 sites in 5' end of hbFGF cDNA were definitely changed, and another 4 sites randomly changed. These mutations will lead to potential variation in the secondary structure of TIR. Then computer program DNASIS v2.5 was utilized to analyse the total 32 TIR sequences resulted from the combination of the 4 randomly mutated sites. Ten sequences with highest free formation energy (delta G0) were chosen for subsequent cloning. By PCR using synthetic primers containing the 8 changed sites described above, ten hbFGF cDNA were amplified and cloned to pET-3c respectively. E. coli strain BL21 (DE3) was transformed and induced to express recombinant hbFGF. Two high-expression clones were obtained by SDS-PAGE and MTT assay, indicating that computer program-aided design for optimizing expression of foreign genes in E. coli is useful.