Recent advances in the study of a novel Omicron variant of SARS-CoV-2 / 中国热带医学

@#Abstract: Due to the continued emergence of multiple variants of SARS-CoV-2, the ongoing pandemic has resulted in severe mortality over the past two years. After the Alpha, Beta, Gamma and Delta variants, the most recent new variant of concern (VOC) strain to emerge is Omicron (B.1.1.529), which evolved as a result of the accumulation of a large number of mutations. The Omicron variant, which has a much higher transmission rate than the Delta variant, soon replaced the Delta variant and others, is now the dominant variant worldwide. The emergence of Omicron poses new challenges for the prevention and control of COVID-19 and has raised a number of concerns worldwide. Recently, cases of Omicron infection have been reported in several parts of China, and therefore this paper provides a comprehensive analysis and summary of the epidemiology and immune escape mechanisms of the Omicron variant. We also suggest some therapeutic strategies against the Omicron variant, including rapid diagnosis, genome analysis of emerging variants, ramping up of vaccination drives and receiving booster doses, updating the available vaccines, designing of multivalent vaccines able to generate hybrid immunity, up-gradation of medical facilities and strict implementation of adequate prevention and control measures need to be given high priority to handle the on-going COVID-19 pandemic successfully.

In Vitro Study of Adipose-Derived Mesenchymal Stem Cells Transduced with Lentiviral Vector Carrying the Brain-Derived Neurotrophic Factor Gene

Brain-derived neurotrophic factor (BDNF) exerts its survival-promoting effects on photoreceptors and retinal ganglion cells, however, delivery systems with little-to-no side effect are needed to sustain its controlled release and long-term efficacy. Our previous studies demonstrated that adipose-derived stem cells (ADSCs) are ideal delivery systems for gene therapy; moreover, ADSCs present unique properties like migration to damaged tissue sites, immunomodulation and anti-inflammation. Herein, we propose to employ ADSCs as the BDNF gene delivery vehicle. Different Analyses like flow cytometry, differentiation and cell proliferation assays etc demonstrated that BDNF were successfully transduced into ADSCs and the stemness of ADSCs was maintained even with the transduction. Real Time PCR and Western blot were used to measure mRNA and protein expressions of the BDNF-transduced ADSCs. The results demonstrated that the BDNF expression level of the lentiviral-BDNF transduced ADSCs is significantly increased and, moreover, enhanced the expression of other neurotrophic and downstream signaling factors. The data suggest that ADSCs are a reliable delivery vehicle for BDNF and could be used for the treatment of various diseases.

Effects of tongfu decoction on rats' rapid gastric emptying / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the effects of Tongfu Decoction (TFD) on the gastric emptying of normal rats, thus exploring whether it could promote gastric emptying rapidly.</p><p><b>METHODS</b>Thirty Sprague-Dawley (SD) rats were randomly divided into 3 groups, i.e., the normal control group, the domperidone group, and the TFD group, 10 in each group. They were respectively administered with normal saline, the domperidone suspension, and TFD by gastrogavage. Thirty min later the gastric emptying of mice was detected by single photon emission computed tomography technology (SPECT) labeled with 99m Tc-DTPA, and the gastric half-emptying time and the gastric emptying rate were calculated.</p><p><b>RESULTS</b>The gastric half-emptying time was (19.0 +/-1.7) min in the normal control group, (12.9 +/- 3.4) min in the domperidone group, and (12.7 +/- 4.1) min in the TFD group. Compared with the normal control group, the gastric half-emptying time was significantly shortened in the domperidone group and the TFD group (P <0.05). The gastric emptying rate at 15 min was 41.1% +/- 5. 8% in the normal control group, 52.9% +/- 10.9% in the domperidone group, and 56.0% +/- 10.3% in the TFD group, while at 30 min it was 65.6% +/- 2.8%, 72.9% +/- 2.6%, and 72.4% +/- 4.9%, respectively. Compared with the normal control group, the gastric emptying rate at 15 min and 30 min both significantly increased in the domperidone group and the TFD group (P <0.05). There was no statistical difference in the gastric half-emptying time or the gastric emptying rate between the two groups (P >0.05).</p><p><b>CONCLUSION</b>TFD showed similar effects as domperidone in rapidly promoting gastric emptying, and could shorten the gastric half-emptying time in normal rats.</p>

Experimental study on the effect of Glycyrrhiza on small intestinal motility in rats / 中国应用生理学杂志

<p><b>AIM</b>To investigate the effects of glycyrrhiza decoction on migrating myoelectric complex (MMC) and gastrointestinal hormone in small intestine in rats.</p><p><b>METHODS</b>We observed MMC cycle,phase Ill duration,fast wave numbers of phase III of MMC in one minute, fast wave numbers of one cluster in phase III of MMC of small intestine of glycyrrhiza group and control group rats with electrophysiology method, and immunohistochemistry to examine relative content of serotonin (5-HT), substance p(SP) and vasoactive intestinal polypeptide (VIP) in small intestinal chromophil (EC) and myenteric nerve plexus in small intestine of control group and glycyrrhiza group rats.</p><p><b>RESULTS</b>Compared glycyrrhiza group with control group,we found that glycyrrhiza was able to decrease fast wave numbers in one minute and fast wave numbers in one cluster in phase III of MMC of small intestine (P < 0.05), and evidently extend small intestinal cycle of MMC (P < 0.05), it also shortened the phase III III duration (P < 0.05) or made the phase III of MMC absent. Compared glycyrrhiza group with control group it was indicated that content of 5-HT in small intestinal mucous membrane and myenteric nerve plexus was evidently decreased (P < 0.05), and content of SP in myenteric nerve plexus of small intestine of rats was evidently decreased (P < 0.05), and content of VIP in small intestine of rats was evidently increased (P < 0.05).</p><p><b>CONCLUSION</b>Glycyrrhiza is able to inhibit small intestinal motility, this inhibition is related with the amount of 5-HT, SP, VIP secreted by small intestinal mucous membrane of rats.</p>