[The influence of meteorological factors on SARS-CoV-2 transmission: evidence from laboratory and epidemiological studies]

SARS-CoV-2 has infected more than 600 million people worldwide and caused more than 6 million deaths. The emerging novel variants have made the epidemic rebound in many places. Meteorological factors can affect the epidemic spread by changing virus activity, transmission dynamic parameters and host susceptibility. This paper systematically analyzed the currently available laboratory and epidemiological studies on the association between the meteorological factors and COVID-19 incidence, in order to provide scientific evidence for future epidemic control and prevention, as well as developing early warning system.

A Systematic Inflammation-based Model in Advanced Pancreatic Ductal Adenocarcinoma

Emerging evidence revealed the critical role of systematic inflammation in pancreatic ductal adenocarcinoma (PDAC). In the present study, we reviewed the records of 279 patients with advanced PDAC. Among them, 147 cases were used as the training cohort and another 132 as the validation cohort. In the training cohort, distant metastasis, carbohydrate antigen 19-9 (CA19-9), Glasgow prognostic score (GPS), neutrophil-to-lymphocyte ratio (NLR), and lymphocyte-to-monocyte ratio (LMR) were independent prognostic factors in Cox regression. A nomogram based on these factors was generated to predict median survival time and survival probabilities at 6, 12, and 18 months. The nomogram showed a better discriminatory ability than the American Joint Committee on Cancer (AJCC) TNM staging (C-index: 0.727 vs. 0.610). In the validation cohort, a nomogram composed of the same variables also showed a high discriminatory ability (C-index: 0.784). In the low-risk group with a nomogram total point (NTP) value of more than 175, patients receiving combination therapy showed better prognosis than those receiving monotherapy (P=0.015). In conclusion, the nomogram based on inflammatory biomarkers can serve as useful prognostic tool for advanced PDAC. In addition, patients with high NTP can greater benefit from combination chemotherapy than monotherapy.

Significance of resistin expression in acute pancreatitis

The aim of the present study was to detect the expression of resistin in rats with acute pancreatitis (AP) and investigate its significance in the pathogenesis of AP. In total, 40 Sprague-Dawley rats were randomly divided into four groups (n=10), including the normal control, sham-operated, acute edematous pancreatitis (AEP) and acute necrotizing pancreatitis (ANP) groups. Following the establishment of animal models, the levels of serum resistin, C-reactive protein (CRP), tumor necrosis factor-α (TNF-α) and interleukin (IL)-1β were measured using ELISA. Resistin expression in the pancreatic tissues was detected using an immunohistochemical method. In addition, the mRNA expression of resistin in the pancreatic tissues was analyzed with quantitative polymerase chain reaction. The levels of serum amylase, serum resistin, TNF-α, IL-1β and CRP were all significantly higher in the AEP and ANP groups when compared with the control and sham-operated groups (P<0.01), as were the pancreas/body weight ratios and pathological scores of the pancreas. These increases were more significant in the ANP group than in the AEP group (P<0.05). The mRNA expression levels of resistin in the pancreatic tissues were markedly higher in the AEP and ANP groups when compared with the control and sham-operated groups (P<0.01), particularly in the pancreatic tissues of the ANP group, which exhibited notably higher levels compared with the AEP group. The serum resistin level was found to positively correlate with the serum levels of CRP, TNF-α and IL-1β, and the pathological scores of the pancreatic tissues. In conclusion, the results indicated that resistin may be associated with the occurrence and development of AP; thus, the protein may be a valuable indicator for assessing the severity of AP.

Associations between vitamin D receptor polymorphisms and susceptibility to ulcerative colitis and Crohn's disease: a meta-analysis

BACKGROUND

Several polymorphisms have been identified in the vitamin D receptor (VDR) gene, while their roles in the incidence of ulcerative colitis (UC) and Crohn's disease (CD) are conflicting. This meta-analysis was designed to clarify the impact of these polymorphisms on UC and CD risk.

METHODS

The PubMed, Embase, and Cochrane electronic databases were searched from February 1995 to August 2011 for studies on the four VDR polymorphisms: TaqI, BsmI, FokI, and ApaI. Data were extracted and pooled odd ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

Nine studies were included. In Asians, the ff genotype of FokI was associated with increased UC risk (OR = 1.65; 95% CI, 1.11- 2.45). The "a" allele carrier status of ApaI appeared to be a protective factor for CD (OR = 0.81; 95% CI, 0.67-0.97). The tt genotype increased the risk of CD in Europeans (OR = 1.23; 95% CI, 1.02-1.49). Moreover, the tt genotype of TaqI in males had a moderate elevated risk of UC (OR = 1.56; 95% CI, 1.02-2.39) and CD (OR = 1.84; 95% CI, 1.19-2.83).

CONCLUSIONS

The meta-analysis reveals a significant increase in CD risk for Europeans carrying TaqI tt genotype and a significant decrease in CD risk for all carriers of the Apal "a" allele. For Asians, the VDR FokI polymorphism appears to confer susceptibility to UC. For males, the TaqI tt genotype is associated with susceptibilities to both UC and CD. Our study explored the genetic risk prediction in UC and CD, and may provide valuable insights into IBD therapy.

Significance of expression of Toll-like receptor 4 in the intestinal tract of pigs with acute necrotizing pancreatitis

AIM: To detect the expression of Toll-like receptor 4 gene (TLR4) in the ileum of pigs with acute necrotizing pancreatitis (ANP).

METHODS: Eight pigs were randomized into ANP group and control group. ANP was induced by retrograde injection of sodium taurocholate. Blood levels of DAO were measured at various time points. Endotoxin concentration was determined using a commercial kit. The expression of tumor necrosis factor alpha (TNF-α), interleukin (IL)-6 and Toll-like receptor (TLR) 4 mRNAs in the ileum was assayed by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS: Compared to the control group, plasma endotoxin concentrations and serum DAO levels increased significantly (both P < 0.05), DAO levels in the ileal tissue homogenate decreased (P < 0.05), and expression of TLR4, TNF-α, and IL-6 mRNAs was significantly up-regulated (all P < 0.05) in the ANP group. The expression levels of TLR4 mRNA were correlated with DAO levels in ideal tissue (r = -0.762, P = 0.028) and plasma endotoxin concentrations (r = 0.778, P = 0.023).

CONCLUSION: Expression of TLR4 mRNA increased in the ileum of ANP pigs, and TLR4 mRNA overexpression may correlate with intestinal mucosa injury and development of enterogenic infection.