Differential Seroprevalence of Human Bocavirus Species 1-4 in Beijing, China

BACKGROUND: Four species of human bocaviruses (HBoV1-4) have been identified based on phylogenetic analysis since its first report in 2005. HBoV1 has been associated with respiratory disease, whereas HBoV2-4 are mainly detected in enteric infections. Although the prevalence of HBoVs in humans has been studied in some regions, it has not been well addressed globally. METHODOLOGY/PRINCIPAL FINDINGS: Cross-reactivity of anti-VP2 antibodies was detected between HBoV1, 2, 3, and 4 in mouse and human serum. The prevalence of specific anti-VP2 IgG antibodies against HBoV1-4 was determined in different age groups of healthy individuals aged 0-70 years old in Beijing, China, using a competition ELISA assay based on virus-like particles of HBoV1-4. The seroprevalence of HBoV1-4 was 50%, 36.9%, 28.7%, and 0.8%, respectively, in children aged 0-14 years (n = 244); whereas the seroprevalence of HBoV1-4 was 66.9%, 49.3%, 38.7% and 1.4%, respectively, in healthy adults (≥ 15 years old; n = 142). The seropositive rate of HBoV1 was higher than that of HBoV2, HBoV3, and HBoV4 in individuals older than 0.5 years. Furthermore, IgG seroconversion of HBoV1 (10/31, 32.3%), HBoV2 (8/31, 25.8%), and HBoV3 (2/31, 6.5%) was found in paired sera collected from children with respiratory tract infections who were positive for HBoV1 according to PCR analysis. CONCLUSIONS/SIGNIFICANCE: Our data indicate that HBoV1 is more prevalent than HBoV2, HBoV3, and HBoV4 in the population we sampled in Beijing, China, suggesting that HBoV species may play differential roles in disease

Contribution of Microbe-Mediated Processes in Nitrogen Cycle to Attain Environmental Equilibrium

Nitrogen (N), the most important element, is required by all living organisms for the synthesis of complex organic molecules like amino acids, proteins, lipids etc. Nitrogen cycle is considered to be the most complex yet arguably important cycle next to carbon cycle. Nitrogen cycle includes oxic and anoxic reactions like organic N mineralization, ammonia assimilation, nitrification denitrification, anaerobic ammonium oxidation (anammox), dissimilatory nitrate reduction to ammonium (DNRA), comammox, codenitrification etc. Nitrogen cycling is one of the most crucial processes required for the recycling of essential chemical requirements on the planet. Soil microorganisms not only improve N-cycle balance but also pave the way for sustainable agricultural practices, leading to improved soil properties and crop productivity as most plants are opportunistic in the uptake of soluble or available forms of N from soil. Microbial N transformations are influenced by plants to improve their nutrition and vice versa. Diverse microorganisms, versatile metabolic activities, and varied biotic and abiotic conditions may result in the shift in the equilibrium state of different N-cycling processes. This chapter is an overview of the mechanisms and genes involved in the diverse microorganisms associated in the operation of nitrogen cycle and the roles of such microorganisms in different agroecosystems

Oncogenic KRAS Reduces Expression of FGF21 in Acinar Cells to Promote Pancreatic Tumorigenesis in Mice on a High-Fat Diet.

BACKGROUND & AIMS: Obesity is a risk factor for pancreatic cancer. In mice, a high-fat diet (HFD) and expression of oncogenic KRAS lead to development of invasive pancreatic ductal adenocarcinoma (PDAC) by unknown mechanisms. We investigated how oncogenic KRAS regulates the expression of fibroblast growth factor 21, FGF21, a metabolic regulator that prevents obesity, and the effects of recombinant human FGF21 (rhFGF21) on pancreatic tumorigenesis. METHODS: We performed immunohistochemical analyses of FGF21 levels in human pancreatic tissue arrays, comprising 59 PDAC specimens and 45 nontumor tissues. We also studied mice with tamoxifen-inducible expression of oncogenic KRAS in acinar cells (Kras RESULTS: Pancreatic tissues of mice expressed high levels of FGF21 compared with liver tissues. FGF21 and its receptor proteins were expressed by acinar cells. Acinar cells that expressed Kras CONCLUSIONS: Normal acinar cells from mice and humans express high levels of FGF21. In mice, acinar expression of oncogenic KRAS significantly reduces FGF21 expression. When these mice are placed on an HFD, they develop extensive inflammation, pancreatic cysts, PanINs, and PDACs, which are reduced by injection of FGF21. FGF21 also reduces the guanosine triphosphate binding capacity of RAS. FGF21 might be used in the prevention or treatment of pancreatic cancer