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.

Identification of miRNAs as prognostic factors for esophageal squamous cell carcinoma.

Objective: The prognostic value of microRNAs for esophageal squamous cell carcinoma (ESCC) is still not be well identified. Methods: The microRNA expression profiles of 119 paired ESCC tissue samples and para-carcinoma tissues from GEO database under accession number of GSE43732. A mutation information based feature selection method was applied to identify the discriminative microRNAs between paired ESCC tissues and para-carcinoma tissues. Results: In para-carcinoma tissues, patients had better survival with higher has-miR-410 (log-rank p = 0.0123), has-miR-411-5p (log-rank p = 0.0152), has-miR-193b-5p (log-rank p = 0.0188) and has-miR-4486 (log-rank p = 0.0307) expression levels. When compared with para-carcinoma tissues, there has more correlations between miRNA expression levels and survival in tumor tissues. We identified 20 potential miRNAs associated with prognosis. Besides, a heatmap was draw to explore miRNA expression levels in tumor tissues and survival. Conclusions: The present study identified 24 miRNAs in 119 paired ESCC tissue samples and para-carcinoma tissues, including 4 miRNAs in para-carcinoma tissues and 20 in tumor tissues, respectively. The dysregulation of these miRNAs were associated with different outcomes. We thought this study could provide novel noninvasive early biomarkers for ESCC patients.

Delayed gastric emptying after esophagectomy for malignancy.

BACKGROUND: Controversy still exists about the need for pyloric drainage procedures after esophagectomy with gastric conduit reconstruction. Although pyloric drainage may prevent postoperative delayed gastric emptying (DGE), it may also promote dumping syndrome and bile reflux. The aims of this study were to audit the incidence and management of DGE in patients without routine pyloric drainage after esophagectomy in a university medical center. PATIENTS AND METHODS: From July 2006 to June 2012, data from 356 consecutive patients who underwent esophagectomy with a gastric conduit without pyloric drainage for esophageal or gastric cardia carcinoma were reviewed. Major observation parameters were the incidence, management, and outcomes of DGE. RESULTS: Overall incidence of DGE was 15.7% (56 of 356). Early DGE developed in 26 patients, and late DGE developed in 30 patients. There were no differences in demographic and intraoperative data between the two groups with or without DGE. More DGE was documented in patients with an intra-right thoracic gastric conduit (P=.031). A higher incidence of postoperative pneumonia was observed in patients exhibiting early DGE, but without significance (P=.254). There were also no significant impacts on respiratory failure (P=.848) and anastomotic leakage (P=.257). There was an increased postoperative hospital stay with DGE, but without significance (P=.089). Endoscopic balloon dilatation of the pylorus was used to manage 33.9% of patients with DGE, yielding a 78.9% (15 of 19) success rate without complications. In 3 patients endoscopy showed the pylorus was open, and their symptoms improved over time. One patient with tumor-related DGE was treated by pyloric stent. The remaining patients were adequately treated with conservative management. CONCLUSIONS: Omitting the operative drainage procedure does not lead to an increased frequency of DGE after esophagectomy with a gastric conduit. Many patients responded to conservative management, and endoscopic balloon pyloric dilatation can be effective in managing the DGE postoperatively.

Clinical application of mucosal valve technique for anastomosis during esophagogastrostomy.

BACKGROUND: The study aims to compare the efficacy in prevention of anastomotic complications using layer-to-layer mucosal valve technique versus circular stapled technique for esophagogastric intrathoracic anastomosis after resection for esophageal and gastric cardiac carcinoma. METHODS: From January 2005 to December 2010, 136 patients received layer-to-layer mucosal valve technique (LM group), 219 received circular stapled anastomosis (CS group) after curative intent resection for esophageal and gastric cardiac carcinoma. The technique details were reported and the clinical results were analyzed. RESULTS: The two groups were comparable on clinical baseline characteristics. The average duration of operation was longer with LM technique by 16 min, but without statistical significance (P = 0.073). There was no anastomotic leakage in the LM group, while in the CS group, leakage occurred in seven patients (3.2 %, P = 0.047). Both the incidence and grade of postoperative dysphagia were significantly lower in the LM group (P < 0.05). Significantly fewer patients experienced stricture after LM technique (3.8 %) compared with CS anastomosis (18.2 %, P < 0.001). CS anastomosis was associated with a significantly higher incidence of persistent stricture requiring more dilatation (P < 0.001). Symptoms of reflux were better controlled by LM technique; 82.7 % of patients were asymptomatic with respect to reflux compared to 58.9 % in the CS group, P < 0.001. And there was a significant reduction in the incidence of esophagitis in remnant esophagus in the LM group (P = 0.001). CONCLUSIONS: The layered mucosal valve anastomosis could significantly diminish the incidence of anastomotic complications and could be used as an alternative for esophagogastric anastomosis after resection of esophageal and gastric cardiac carcinoma.

Alcohol Consumption and Breast Cancer Survival: A Meta- analysis of Cohort Studies.

BACKGROUND AND OBJECTIVES: Evidence for associations between alcohol consumption with breast cancer survival are conflicting, so we conducted the present meta-analysis. METHODS: Comprehensive searches were conducted to find cohort studies that evaluated the relationship between alcohol consumption with breast cancer survival. Data were analyzed with meta-analysis software. RESULTS: We included 25 cohort studies. The meta-analysis results showed that alcohol consumption was not associated with increased breast cancer mortality and recurrence after pooling all data from highest versus lowest comparisons. Subgroup analyses showed that pre-diagnostic or post-diagnostic consumpotion, and ER status did not affect the relationship with breast cancer mortality and recurrence. Although the relationships of different alcohol consumption with breast cancer mortality and recurrence were not significant, there seemed to be a dose-response relationship of alcohol consumption with breast cancer mortality and recurrence. Only alcohol consumption of >20 g/d was associated with increased breast cancer mortality, but not with increased breast cancer recurrence. CONCLUSION: Although our meta-analysis showed alcohol drinking was not associated with increased breast cancer mortality and recurrence, there seemed to be a dose-response relationship of alcohol consumption with breast cancer mortality and recurrence and alcohol consumption of >20 g/d was associated with increased breast cancer mortality.

Reducing the gastroesophageal reflux with lip-type reinforcement technique during intrathoracic esophagogastrostomy.

BACKGROUND/AIMS: Gastroesophageal reflux is a significant problem after esophagogastrostomy, and impact considerably upon the quality of patients' lives. Aims of this study were to evaluate the operative effects in prevention of reflux with lip-type reinforcement during intrathoracic esophagogastric anastomosis. METHODOLOGY: From January 2005 to December 2009, 216 patients received circular stapled esophagogastrostomy with lip-type reinforcement (LR group), and 69 patients with standard reinforcement (SR group) at our hospital. Major observation parameters were symptoms of reflux and dysphagia. RESULTS: No differences in clinicopathologic characteristics between two groups, in addition to the incidence of anastomotic leakage was less in LR group (p = 0.039). Grade of dysphagia and anastomotic stricture also were not different between two groups (p >0.05). Symptoms of reflux were better controlled in patients with lip-type reinforcement than standard reinforcement (p <0.001). In LR group, 71.3% were asymptomatic with respect to reflux compared to 29.7% in SR group (p <0.001). The incidence of reflux esophagitis was 23.5% in LR group and 58.3% in SR group (p <0.001). There was a significant correlation between reflux symptoms and endoscopic findings of reflux esophagitis (p = 0.001). CONCLUSIONS: Lip-type reinforcement is simple to perform, and effective in controlling gastroesophageal reflux and decreasing anastomotic leakage in majority of patients after esophagogastrostomy.