[Analysis on the imported Coronavirus Disease 2019 related cluster epidemic in rural areas of Chengdu]

An epidemiological investigation was carried out on a local cluster of outbreak caused by imported cases of Coronavirus Disease 2019 (COVID-19) in rural areas of Chengdu in December 2020, to find out the source of infection and the chain of transmission. According to Prevention and Control Protocol for COVID-19 (Version 7), field epidemiological investigation was adopted, combined with big data technology, video image investigation, gene sequencing and other methods to carry out investigation into COVID-19 cases and infections source tracing, analyze the epidemiological association, and map the chain of transmission. From December 7 to 17, 2020, 13 local COVID-19 confirmed cases and 1 asymptomatic case were diagnosed in Chengdu, of which 12 cases (85.71%) had a history of residence and activity in the village courtyard of Taiping (TP), Pidu (P) District, Chengdu. From November 8, 2020 to November 28, 2020, a group of inbound people form Nepal were transferred to the designated entry personnel quarantine hotel of P District which was adjacent to the TP village. During quarantine, there were 5 cases who tested positive for COVID-19. Through gene sequencing alignment, genes of local cases and Nepalese imported cases from the same period are homologous, all belong to the lineage of L2.2.3 (B.1.36 according to Pangolin lineage typing method). According to the results of field epidemiological investigation and gene sequencing analysis, the index case was most likely infected by contact with household waste of quarantine site. Under the situation of normalization prevention and control of COVID-19, sentinel monitoring of fever clinics in primary medical institutions is the key to early detection of the epidemic. The multi-department joint epidemiological investigation and the application of gene technology are the core links of the investigation and traceability of modern infectious diseases. The allocation of public health resources in rural areas needs to be strengthened. We need to improve the capacity for early surveillance and early warning of the epidemic in rural areas.

[COVID-19 epidemic and its characteristics in Heilongjiang province]

Objective: To describe the COVID-19 epidemic and its characteristics in Heilongjiang province, and provide evidence for the further prevention and control of COVID-19 in the province. Methods: The information of COVID-19 cases and clusters were collected from national notifiable disease report system and management information system for reporting public health emergencies of China CDC. The Software's of Excel 2010 and SPSS 23.0 were applied for data cleaning and statistical analysis on the population, time and area distributions of COVID-19 cases. Results: On January 22, 2020, the first confirmed case of COVID-19 was reported in Heilongjiang. By March 11, 2020, a total of 482 cases domestic case of COVID-19, The incidence rate was 1.28/100 000, the mortality rate was 2.70% (13/482) in 13 municipalities in Heilongjiang. There were 81 clusters of COVID-19, The number of confirmed cases accounted for 79.25% (382/482) of the total confirmed cases and 12 cases of deaths. The family clusters accounted for 86.42% (70/81). Compared with the sporadic cases, the mortality rate, proportion of elderly cases aged 60 or above and severe or critical cases of clinical classification were all higher in the clusters especially the family clusters, but the differences were not significant (P>0.05). There were 34 clusters involving more than 5 confirmed cases accounted for 41.98% (34/81) of the total clusters, the involved cases accounted for 68.31% (261/382) of the total cases of clusters. There were significant differences in age distribution of the cases among the case clusters with different case numbers. In the clusters involving 6-9 cases, the proportion of cases aged 65 years or above was more (26.53%, 39/147). Conclusions: The incidence rate of COVID-19 was relatively high and the early epidemic was serious in Heilongjiang, The number of cases was large in clusters especially family clusters.

[Prevalence and risk factors of respiratory viral infection in acute exacerbation of chronic obstructive pulmonary disease]

Objective: To study the prevalence of respiratory viral infection in chronic obstructive pulmonary disease(COPD) exacerbations and to find the factors associated with susceptibility to viral infections. Methods: Eighty patients with exacerbations of COPD and 50 stable COPD patients were recruited. Nasopharyngeal swabs were tested for a range of 18 different respiratory viruses using PCR. Results: Among the COPD exacerbations, viral infection was detected in 18 episodes (22.5%) . The most common virus was rhinovirus (33.3%), followed by coronavirus(27.8%), parainfluenza(22.2%), metapneumovirus(11.1%) and influenza virus B(5.6%). The prevalence of viral infection was 8% in the stable COPD patients. In multivariate regression analysis fever was found to be significantly associated with viral infections in COPD exacerbations (Odds ratio 4.99, 95%CI 1.51-16.48, P=0.008). Conclusion: Viral respiratory pathogens were more often detected in respiratory specimens from hospitalized patients with AECOPD than those with stable COPD. Rhinovirus was the most common infecting agent identified. The symptom of fever was associated with viral detection.

[Influence of subthalamic nucleus deep brain stimulation on cognition and acetylcholine in a rat model of Parkinson's disease]

Objective: To illustrate the effect of subthalamic nucleus deep brain stimulation (STN-DBS)on cognitionand its underlying mechanisms in a rat model of Parkinson's disease (PD). Methods: Thirty healthy male Sprague-Dawley rats were randomly divided into 3 groups: control group (healthy rats, n=10), model group (PD rats, n=10), and stimulation group (PD rats receiving high frequency stimulation, n=10). The cognitive functionof rats was tested through Morris water maze and acetylcholine levels in cortex, hippocampus and striatum have been examined through ELISA. Results: During Morris water mazetest, spatial learning and memory of PD ratsdeteriorated compared with healthy ones, withlonger escape latency[on day 4, (38±14) s vs (20±4) s, P=0.047; on day 5, (32±13) s vs (16±8) s, P=0.032]and shorter time in the platform region[(10±6) s vs (19±5) s, P=0.023], which could be restored by STN-DBS. Similar results demonstrated that the expression of Ach in hippocampus[(1 473±233) s vs (1 950±344) s, P=0.039]and striatum[(1 661±271) s vs (2 240±290) s, P=0.007]was significantly lower in PD rats than those in healthy rats, and STN-DBS treatment reversed this decline to insignificant. Conclusion: The rat model of PD suffer from a decline in cognition, and STN-DBS contributes to cognitive recovery, possibly due to regulating Ach levels in cognition-associated regions of the brain, includinghippocampus and striatum.

[The derivation and validation of a scoring system for identifying patients with bronchiectasis at risk of exacerbations]

OBJECTIVE

To create and verify a scoring system for identifying patients with bronchiectasis at risk of exacerbations.

METHODS

Derivation of the scoring system used data from a retrospective cohort study enrolling 228 patients with bronchiectasis. Multivariable logistic regression analysis was performed to identify independent predictors associated with exacerbations. β-coefficients derived from the independent predictors in our logistic regression model were applied to create a scoring system (Total score was 8). The scoring system was then validated in a prospective cohort enrolling 334 patients with bronchiectasis.

RESULTS

The derivation study showed that age ≥ 60 years (OR=2.583, 95%CI: 1.188-5.613), BMI<18.5 kg/m(2) (OR=2.991, 95%CI: 1.112-8.042), high medical research council dyspnea score (OR=7.905, 95%CI: 4.288-8.309), Pseudomonas aeruginosa colonization (OR=3.227, 95%CI: 1.041-9.004), the lobes involved on high-resolution computed tomography≥3 (OR=3.179, 95%CI: 1.449~6.976), prior intensive care unit admissions (OR=2.499, 95%CI: 1.301-4.801), and FEV1<50% predicted(OR=2.497, 95%CI: 1.421-5.080) were the independent predictors associated with exacerbations. The scoring system predicted exacerbations with an area under the receiver operator characteristic curve (AUC) of 0.79 (95% confidence interval, 0.74-0.84). In the validation cohorts, the total score ranged 0 to 6. There was significant difference in exacerbation frequency and quality of life between patients classified as low(0-2), intermediate(3-4), and high(5-8) risks by the scoring system (P<0.05). A higher score was associated with higher risk of exacerbations and poorer quality of life.

CONCLUSION

Our scoring system was an efficient clinical predictive tool to identify patients with bronchiectasis at risk of exacerbations. It may be useful for early prevention of bronchiectasis exacerbations and for proper management.

Association of nuclear factor κB expression with a poor outcome in nasopharyngeal carcinoma

The aim of this study was to determine the relationship between nuclear factor κB and the prognosis of patients with nasopharyngeal carcinoma. We used immunohistochemical studies to examine nuclear factor κB expression in 42 patients with nasopharyngeal carcinoma. The results showed that tumors positive for nuclear factor κB were associated with an increased relapse potential, poor disease-free survival, and reduced overall survival in nasopharyngeal carcinoma. Our study indicates that nuclear factor κB could be an independent molecular marker for predicting poor prognosis among patients with nasopharyngeal carcinoma. Understanding the biology of nuclear factor κB-mediated pathways may lead to the development of novel therapeutic strategies for nasopharyngeal carcinoma.

[Histological investigation of the ligamentum flavum]

The micro- and ultrastructures of the human ligamentum flavum were investigated. It was found that the ligamentum flavum is made of chiefly of elastic fibers. This kind of structure provides a basis for the important physiological functions of the ligamentum flavum. So the load is transmitted between the vertebrae and spinal stability is maintained by means of this ligament. Then clinical relevance was discussed.