In vitro Studies and Clinical Observations Imply a Synergistic Effect Between Epstein-Barr Virus and Dengue Virus Infection.

Dengue virus (DENV) infection can lead to a complex spectrum of clinical outcomes, ranging from asymptomatic infection to life-threatening severe dengue. The reasons for thus drastically varying manifestations of the disease remain an enigma. Herein, we reported an original discovery of the synergistic effect between preexisting Epstein-Barr virus (EBV) infection and DENV superinfection in vitro and of a strong correlation of these two viruses in the clinical samples from dengue patients. We showed that (I) DENV-2 infection of an EBV-positive cell line (EBV + Akata cell) reactivated EBV, and it could be blocked by wortmannin treatment. (II) Examination of human peripheral blood mononuclear cell (PBMC) samples from dengue patients revealed significantly elevated cell-associated EBV DNA copy number at the time of hospitalization vs. at the time of disease recovery in most individuals. (III) EBV infection promoted DENV propagation in both EBV-hosting B cells and indirectly in THP-1 cells, supported by the following evidence: (A) EBV + Akata cells were more permissive to DENV-2 infection compared with Akata cells harboring no EBV virus (EBV- Akata cells). (B) Low-molecular weight fraction secreted from EBV + Akata cells could enhance DENV-2 propagation in monocytic THP-1 cells. (C) While reactivation of EBV in EBV + Akata cells further increased DENV-2 yield from this cell line, pharmacological inhibition of EBV replication by acyclovir had the opposite effect. To our knowledge, this is the first investigation demonstrating a positive correlation between EBV and DENV in vitro and in human biospecimens.

Intestinal bacterial overgrowth in the early stage of severe acute pancreatitis is associated with acute respiratory distress syndrome.

BACKGROUND: In the early stage of acute pancreatitis (AP), a large number of cytokines induced by local pancreatic inflammation seriously damage the intestinal barrier function, and intestinal bacteria and endotoxins enter the blood, causing inflammatory storm, resulting in multiple organ failure, infectious complications, and other disorders, eventually leading to death. Intestinal failure occurs early in the course of AP, accelerating its development. As an alternative method to detect small intestinal bacterial overgrowth, the hydrogen breath test is safe, noninvasive, and convenient, reflecting the number of intestinal bacteria in AP indirectly. This study aimed to investigate the changes in intestinal bacteria measured using the hydrogen breath test in the early stage of AP to clarify the relationship between intestinal bacteria and acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Early clinical intervention and maintenance of intestinal barrier function would be highly beneficial in controlling the development of severe acute pancreatitis (SAP). AIM: To analyze the relationship between intestinal bacteria change and ALI/ARDS in the early stage of SAP. METHODS: A total of 149 patients with AP admitted to the intensive care unit of the Digestive Department, Xuanwu Hospital, Capital Medical University from 2016 to 2019 were finally enrolled, following compliance with the inclusion and exclusion criteria. The results of the hydrogen breath test within 1 wk of admission were collected, and the hydrogen production rates at admission, 72 h, and 96 h were calculated. The higher the hydrogen production rates the more bacteria in the small intestine. First, according to the improved Marshall scoring system in the 2012 Atlanta Consensus on New Standards for Classification of Acute Pancreatitis, 66 patients with a PaO2/FiO2 score ≤ 1 were included in the mild AP (MAP) group, 18 patients with a PaO2/FiO2 score ≥ 2 and duration < 48 h were included in the moderately SAP (MSAP) group, and 65 patients with a PaO2/FiO2 score ≥ 2 and duration > 48 h were included in the SAP group, to analyze the correlation between intestinal bacterial overgrowth and organ failure in AP. Second, ALI (PaO2/FiO2 = 2) and ARDS (PaO2/FiO2 > 2) were defined according to the simplified diagnostic criteria proposed by the 1994 European Union Conference. The MSAP group was divided into two groups according to the PaO2/FiO2 score: 15 patients with PaO2/FiO2 score = 2 were included in group A, and three patients with score > 2 were included in group B. Similarly, the SAP group was divided into two groups: 28 patients with score = 2 were included in group C, and 37 patients with score > 2 were included in group D, to analyze the correlation between intestinal bacterial overgrowth and ALI/ARDS in AP. RESULTS: A total of 149 patients were included: 66 patients in the MAP group, of whom 53 patients were male (80.3%) and 13 patients were female (19.7%); 18 patients in the MSAP group, of whom 13 patients were male (72.2%) and 5 patients were female (27.8%); 65 patients in the SAP group, of whom 48 patients were male (73.8%) and 17 patients were female (26.2%). There was no significant difference in interleukin-6 and procalcitonin among the MAP, MSAP, and SAP groups (P = 0.445 and P = 0.399, respectively). There was no significant difference in the growth of intestinal bacteria among the MAP, MSAP, and SAP groups (P = 0.649). There was no significant difference in the growth of small intestinal bacteria between group A and group B (P = 0.353). There was a significant difference in the growth of small intestinal bacteria between group C and group D (P = 0.038). CONCLUSION: Intestinal bacterial overgrowth in the early stage of SAP is correlated with ARDS.

A novel approach for the forensic diagnosis of drowning by microbiological analysis with next-generation sequencing and unweighted UniFrac-based PCoA.

The diagnosis of drowning is one of the major challenges in forensic practice, especially when the corpse is in a state of decomposition. Novel indicators of drowning are desired in the field of forensic medicine. In the past decade, aquatic bacteria have attracted great attention from forensic experts because they can easily enter the blood circulation with drowning medium, and some of them can proliferate in the corpse. Recently, the advent of next-generation sequencing (NGS) has created new opportunities to efficiently analyze whole microbial communities and has catalyzed the development of forensic microbiology. We presumed that NGS could be a potential method for diagnosing drowning. In the present study, we verified this hypothesis by fundamental experiments in drowned and postmortem-submersed rat models. Our study revealed that detecting the bacterial communities with NGS and processing the data in a transparent way with unweighted UniFrac-based principal coordinates analysis (PCoA) could clearly discriminate the skin, lung, blood, and liver specimens of the drowning group and postmortem submersion group. Furthermore, the acquired information could be used to identify new cases. Taken together, these results suggest that we could build a microbial database of drowned and postmortem-submersed victims by NGS and subsequently use a bioinformatic method to diagnose drowning in future forensic practice.

Epidemiological investigation of Helicobacter pylori infection in elderly people in Beijing.

BACKGROUND: The Helicobacter pylori (H. pylori) infection rate in China is approximately 50%. H. pylori is a pathogenic factor of peptic ulcer and chronic gastritis. In addition, H. pylori infection may also be associated with a variety of cardiovascular diseases in elderly people, such as arteriosclerosis, coronary heart disease, and cerebral infarction, having deleterious effect on their health. With the aging of the population, the disease characteristics of the elderly population have been increasingly valued by the whole society. We conducted an epidemiological survey of H. pylori infection among elderly people in Beijing to provide a basis for health management of H. pylori infection. AIM: To understand the epidemiological characteristics of H. pylori infection in elderly people in Beijing. METHODS: A total of 1090 elderly people aged more than 60 years from different parts of Beijing (urban and rural areas) were selected using the random cluster sampling method. Structured questionnaires were completed during home visits and the 13C-urea breath test was conducted for H. pylori detection. RESULTS: The prevalence of H. pylori infection was 46.5% (507/1090). The infection rate in men was 51.8%, which was significantly higher than that in women (42.5%; P < 0.05). The H. pylori infection rate in illiterate people was significantly higher than that in literate persons (53.5% vs 44.8%, P < 0.05). The total infection rate of H. pylori gradually increased with age and the difference was statistically significant (P < 0.01). The H. pylori infection rate in smokers was significantly higher than that in non-smokers and those who had quit smoking (P < 0.05). CONCLUSION: The prevalence of H. pylori infection among elderly people is 46.5% and the infection rate gradually increases with age. Sex, education level, age, and smoking were determined to be H. pylori infection risk factors. The relationship of H. pylori infection with region, occupation, drinking, and diet structure needs to be further studied.

[Spatial and temporal changes of farmland soil acidification and their influencing factors in different regions of Guangdong Province, Chin]. / å¹¿ä¸œçœä¸åŒåŒºåŸŸå†œç”°åœŸå£¤é ¸åŒ–æ—¶ç©ºå˜åŒ–åŠå ¶å½±å“å› ç´ .

Based on the three datasets from 1980s, 2010 and 2015 in Guangdong Province, we analyzed the spatial and temporal variations of soil pH in farmlands in different regions of Guangdong Province and analyzed the driving factors for such variations. The results showed that the spatial distribution of soil pH in Guangdong Province changed significantly in different periods. During 1980s to 2010, soil pH showed an acidification trend with a decline of 0.3, and increased by 0.09 from 2010 to 2015, with more uneven trend and more obvious acid base differentiation. From the perspective of each region, there was generally a trend of acidification from the 1980s to 2010. From 2010 to 2015, the average pH value of farmland soil in the Pearl River Delta increased by 0.27, while that on the east wing and west wing decreased by 0.05 and 0.15 respectively, showing a unapparent change of soil pH in the mountainous area. Our results showed that soil acidification in diffe-rent areas of Guangdong Province was affected by natural factors such as soil itself and precipitation. In addition, anthropogenic factors such as acid rain, unreasonable fertilization and the planting structure of high-yielding crops were also the main causes of soil acidification. Industrialization, urbanization, mining development, and the spread of soil testing formula fertilization increased soil pH in local areas. Our results could provide theoretical guidance for controlling and alleviating soil acidification and improving the quality of cultivated land in different areas.

[Progress in the detection of selenium-containing trace proteins].

Essential trace element selenium (Se) exerts its biological functions in vivo mainly through selenoproteins. Thus highly sensitive detection of Se-containing trace proteins is the key step toward the confirmation of selenoproteins predicted bioinformatically from genomes or separated electrophoretically in the study of selenoproteomics. This review mainly describes the principle of a new technique of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), which has been fast developed in recent years, and its application to the detection of Se in proteins separated by gel electrophoresis. The paper also summarizes the progress of mass spectrometry in the identification and characterization of Se-containing proteins after gel electrophoresis, including the detection of Se-containing peptides by ICP-MS hyphenated with either capillary high performance liquid chromatography or nano HPLC, the identification of Se-containing proteins by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and the characterization and confirmation of selenoproteins by nano HPLC-electrospray tandem mass spectrometry. Problems presented in those methods are also discussed in this paper for further study.