Solving the Structure and Dynamics of Metal Nanoparticles by Combining X-Ray Absorption Fine Structure Spectroscopy and Atomistic Structure Simulations

Extended X-ray absorption fine structure (EXAFS) spectroscopy is a premiere method for analysis of the structure and structural transformation of nanoparticles. Extraction of analytical information about the three-dimensional structure and dynamics of metal-metal bonds from EXAFS spectra requires special care due to their markedly non-bulk-like character. In recent decades, significant progress has been made in the first-principles modeling of structure and properties of nanoparticles. In this review, we summarize new approaches for EXAFS data analysis that incorporate particle structure modeling into the process of structural refinement.

A milk-based self-assemble rotavirus VP6-ferritin nanoparticle vaccine elicited protection against the viral infection

BACKGROUND

Rotavirus is the leading cause of severe dehydrating diarrhea in young children and the inner capsid protein VP6 is a potential vaccine candidate that can induce cross-protective immune responses against different Rotavirus strains. The use of ferritin nanoparticles as the scaffold of the antigen can improve the immunogenicity of the subunit vaccines and provide broader protection. We here present a non-live and self-assemble recombinant rotavirus VP6-ferritin (rVP6-ferritin) nanoparticle vaccine.

RESULTS

The rVP6-ferritin nanoparticles were expressed in E. coli and self-assembled to uniform spherical structure which similar to ferritin, and oral administration of them induced efficient humoral and mucosal immunogenicity in mice. The nanoparticles were further transgenically expressed in the milk of mice, and pup mice breastfed by transgenic rVP6-ferritin mothers had strongly induced immunogenicity and-compared to pups breastfed by wild type mothers-the proportion of rotavirus challenged pups with diarrhea symptoms, the duration and intensity of the diarrhea, and the deleterious effects on overall growth resulting from the diarrhea were all significantly reduced.

CONCLUSIONS

These results suggest that this recombinant VP6-ferritin nanoparticle vaccine can efficiently prevent the death and malnutrition induced by the rotavirus infection in infants and is a promising candidate vaccine for rotavirus.

Epidemiology of human adenovirus infection in children hospitalized with lower respiratory tract infections in Hunan, China

To investigate the current genotypes of circulating human adenovirus (HAdV) strains, we molecularly genotyped HAdV in the nasopharyngeal aspirates (NPAs) of patients with acute lower respiratory tract infections (ALRTIs) and attempted to determine their associations with clinical symptoms. A total of 4751 NPA samples were collected from 4751 patients admitted to Hunan Provincial People's Hospital from September 2007 to March 2014, of which 447 (9.4%) samples were HAdV positive. Fourteen different HAdV types were identified; HAdV types 1 to 7 (HAdV 1‐7) were identified in 95.7% of the 447 NPA samples with HAdV‐7 and HAdV‐3 being the most prevalent. In addition, 93.3% (417 of 447) of patients were younger than 5 years. The incidence of HAdV infection peaked in summer. Different HAdV types showed a predilection for different age groups and different seasonal distribution patterns. Coinfection of HAdVs and other respiratory viruses was detected in 63.3% (283 of 447) of the HAdV‐positive samples. The most common clinical diagnosis was pneumonia and the most common symptoms were fever and cough. In comparison with children infected with HAdV‐3 alone, those infected with HAdV‐7 alone had an increased frequency of severe pneumonia involvement (11.6% vs 32.4%; P = 0.031), higher intensive care unit admission rates (7.0% vs 26.5%; P = 0.019), and a longer length of hospital stay (P = 0.03). Mixed infections in younger children were associated with a longer hospital stay (P = 0.023). Our results demonstrate the recent changes in the trends of circulating HAdV genotypes associated with ALRTIs in Hunan China.

Prevalence of rotavirus and rapid changes in circulating rotavirus strains among children with acute diarrhea in China, 2009-2015

BACKGROUND

Rotavirus is a leading cause of morbidity and mortality in young children worldwide. In China, the universal immunization of children with the rotavirus vaccine has not been introduced, and the two globally distributed vaccines (RotaTeq and Rotarix) are not licensed in the country. We aim to determine the prevalence and strain diversity of rotavirus in children with diarrhea aged ≤ five years across China.

MATERIALS AND METHODS

Sentinel-based surveillance of acute diarrhea was conducted at 213 participating hospitals in China from January 1, 2009, through December 31, 2015. Group A rotavirus (RVA) was tested by using enzyme-linked immunosorbent assays, and G- and P-genotype of RVA were tested by RT-PCR methods.

RESULTS

Of 33,616 children with diarrhea, 10,089 (30%) were positive for RVA; RVA-associated diarrhea was identified in 2247 (39.5%, n = 2247/5685) inpatients and 7842 (28.1%, n = 7842/27931) outpatients. Children living in low-middle-income regions suffered from the highest burden of rotavirus, with 40.7% of diarrhea cases attributed to rotavirus infection, followed by 31.3% in upper-middle-income and 11.2% in high-income regions. The majority of children (88.9%, n = 8976/10089) who tested positive for RVA were children aged ≤ 2 years. The seasonal peak of RVA was in the winter. Among all 2533 RVA strains genotyped, five strain combinations, G9P[8], G3P[8], G1P[8], G2P[4] and G3P[4], contributed to 71.3% (1807/2533) of the RVA-associated diarrhea cases. The predominant strain of RVA has rapidly evolved from G3P[8] and G1P[8] to G9P[8] in the recent years, with the proportion of G9P[8] having increased remarkably from 3.4% in 2009 to 60.9% in 2015.

CONCLUSIONS

The burden of diarrhea attributed to rotavirus is high in China, highlighting the potential value of vaccination. The rapid shift of RVA strains highlights the importance of conducting rotavirus surveillance to ensure that currently marketed vaccines provide protective efficacy against the circulating strains.

Tetramethylpyrazine inhibited hypoxia-induced expression of calcium-sensing receptors in pulmonary artery smooth muscle cells in chickens

Tetramethylpyrazine (TMP) is a biologically active ingredient, which is isolated from a popularChinese medicinal plant. It has been used effectively to treat ischemic heart problems, cerebrovascular and thrombotic vascular diseases. This study was designed to evaluate the effect of TMP on calciumsensing receptors in pulmonary artery smooth muscle in chickens. For this purpose forty day-old chicks were distributed into five groups: the control group, the hypoxia group (kept under low Oxygen treatment), and TMP groups (kept under low Oxygen treatment along with treatment of different concentrations of TMP). The pulmonary artery smooth muscle cells were also cultured on 6-well plates in high glucose culture medium and divided into the same five groups. We used in vivo and in vitro study models by applying immunohistochemistry, RT-qPCR assay and Western blotting analysis. Our results showed that pre-incubation with hypoxia markedly stimulated the activation of calcium-sensing receptor (CaSR) in pulmonary artery smooth muscle cells (PASMCs). The TMP decreased the mRNA and protein levels of CaSR. Treatment with TMP clearly inhibited the activation of all CaSR in a dose-dependent manner. Our data demonstrated that TMP can down-regulate the expression of CaSR. Therefore, these findings provide a new target to treat pulmonary arterial hypertension (PAH) under hypoxic conditions.

Two novel bocaparvovirus species identified in wild Himalayan marmots

Bocaparvovirus (BOV) is a genetically diverse group of DNA viruses and a possible cause of respiratory, enteric, and neurological diseases in humans and animals. Here, two highly divergent BOVs (tentatively named as Himalayan marmot BOV, HMBOV1 and HMBOV2) were identified in the livers and feces of wild Himalayan marmots in China, by viral metagenomic analysis. Five of 300 liver samples from Himalayan marmots were positive for HMBOV1 and five of 99 fecal samples from these animals for HMBOV2. Their nearly complete genome sequences are 4,672 and 4,887 nucleotides long, respectively, with a standard genomic organization and containing protein-coding motifs typical for BOVs. Based on their NS1, NP1, and VP1, HMBOV1 and HMBOV2 are most closely related to porcine BOV SX/1-2 (approximately 77.0%/50.0%, 50.0%/53.0%, and 79.0%/54.0% amino acid identity, respectively). Phylogenetic analysis of these three proteins showed that HMBOV1 and HMBOV2 formed two distinctly independent branches in BOVs. According to these results, HMBOV1 and HMBOV2 are two different novel species in the Bocaparvovirus genus. Their identification expands our knowledge of the genetic diversity and evolution of BOVs. Further studies are needed to investigate their potential pathogenicity and their impact on Himalayan marmots and humans.

Development of predisposition, injury, response, organ failure model for predicting acute kidney injury in acute on chronic liver failure

BACKGROUND AND AIM

There is limited data on predictors of acute kidney injury in acute on chronic liver failure. We developed a PIRO model (Predisposition, Injury, Response, Organ failure) for predicting acute kidney injury in a multicentric cohort of acute on chronic liver failure patients.

PATIENTS AND METHODS

Data of 2360 patients from APASL-ACLF Research Consortium (AARC) was analysed. Multivariate logistic regression model (PIRO score) was developed from a derivation cohort (n=1363) which was validated in another prospective multicentric cohort of acute on chronic liver failure patients (n=997).

RESULTS

Factors significant for P component were serum creatinine[(≥2 mg/dL)OR 4.52, 95% CI (3.67-5.30)], bilirubin [(<12 mg/dL,OR 1) vs (12-30 mg/dL,OR 1.45, 95% 1.1-2.63) vs (≥30 mg/dL,OR 2.6, 95% CI 1.3-5.2)], serum potassium [(<3 mmol/LOR-1) vs (3-4.9 mmol/L,OR 2.7, 95% CI 1.05-1.97) vs (≥5 mmol/L,OR 4.34, 95% CI 1.67-11.3)] and blood urea (OR 3.73, 95% CI 2.5-5.5); for I component nephrotoxic medications (OR-9.86, 95% CI 3.2-30.8); for R component,Systemic Inflammatory Response Syndrome,(OR-2.14, 95% CI 1.4-3.3); for O component, Circulatory failure (OR-3.5, 95% CI 2.2-5.5). The PIRO score predicted acute kidney injury with C-index of 0.95 and 0.96 in the derivation and validation cohort. The increasing PIRO score was also associated with mortality (P<.001) in both the derivation and validation cohorts.

CONCLUSIONS

The PIRO model identifies and stratifies acute on chronic liver failure patients at risk of developing acute kidney injury. It reliably predicts mortality in these patients, underscoring the prognostic significance of acute kidney injury in patients with acute on chronic liver failure.

Liver failure determines the outcome in patients of acute-on-chronic liver failure (ACLF): comparison of APASL ACLF research consortium (AARC) and CLIF-SOFA models

BACKGROUND AND AIMS

Acute-on-chronic liver failure (ACLF) is a progressive disease associated with rapid clinical worsening and high mortality. Early prediction of mortality and intervention can improve patient outcomes. We aimed to develop a dynamic prognostic model and compare it with the existing models.

METHODS

A total of 1402 ACLF patients, enrolled in the APASL-ACLF Research Consortium (AARC) with 90-day follow-up, were analyzed. An ACLF score was developed in a derivation cohort (n = 480) and was validated (n = 922).

RESULTS

The overall survival of ACLF patients at 28 days was 51.7%, with a median of 26.3 days. Five baseline variables, total bilirubin, creatinine, serum lactate, INR and hepatic encephalopathy, were found to be independent predictors of mortality, with AUROC in derivation and validation cohorts being 0.80 and 0.78, respectively. AARC-ACLF score (range 5-15) was found to be superior to MELD and CLIF SOFA scores in predicting mortality with an AUROC of 0.80. The point scores were categorized into grades of liver failure (Gr I: 5-7; II: 8-10; and III: 11-15 points) with 28-day cumulative mortalities of 12.7, 44.5 and 85.9%, respectively. The mortality risk could be dynamically calculated as, with each unit increase in AARC-ACLF score above 10, the risk increased by 20%. A score of ≥11 at baseline or persisting in the first week was often seen among nonsurvivors (p = 0.001).

CONCLUSIONS

The AARC-ACLF score is easy to use, dynamic and reliable, and superior to the existing prediction models. It can reliably predict the need for interventions, such as liver transplant, within the first week.

Norovirus GII.P16/GII.2-Associated Gastroenteritis, China, 2016

During October–December 2016, the number of norovirus outbreaks in China increased sharply from the same period during the previous 4 years. We identified a recombinant norovirus strain, GII.P16-GII.2, as the cause of 44 (79%) of the 56 outbreaks, signaling that this strain could replace the predominant GII.4 viruses.

Joint Association of Obesity and Hypertension with Disability in the Elderly-- A Community-Based Study of Residents in Shanghai, China

BACKGROUND

Although both obesity and hypertension are known risk factors for disability, the joint association of obesity and hypertension with risk of disability is unknown. This paper is aim to examine the joint association of obesity and hypertension with risk of disability.

METHODS

Cross-sectional study with 8060 elderly community-dwelling individuals participating in the survey initiated by Shanghai Health and Family Planning Commission from March to September 2013. Obesity was measured using the body mass index (BMI) in World Health Organization (WHO) Asia criteria. Hypertension, based on the doctor's diagnosis, was obtained through face-to-face interview. Disability was measured using the self-reported physical self-maintenance scale (PSMS) and the instrumental activities of daily living (IADL) scale developed by Lawton and Brody.

RESULTS

A total of 8.97% of participants reported ADL disability, and 15.18% for IADL disability. After adjusting social demographics and chronic conditions, the risk of ADL disability was progressively greater in obese persons with hypertension (OR=1.40, 95% CI=1.05-1.89), underweight persons without hypertension (OR=2.05, 95% CI=1.29-3.25), and underweight persons with hypertension (OR=2.14, 95% CI=1.36-3.36). For IADL disability, only underweight persons with hypertension were significantly associated (OR=1.65, 95% CI=1.23-2.21).

CONCLUSIONS

Low or extremely high BMI, independent of its metabolic consequences, is a risk factor for disability among the elderly. Simple hypertension wasn't significantly associated with disability. In addition, having hypertension significantly increased the risk of ADL disability in obese individuals and IADL disability in underweight individuals.

Phenotype and function of CXCR5+CD45RA-CD4+ T cells were altered in HBV-related hepatocellular carcinoma and elevated serum CXCL13 predicted better prognosis

The present study reveals an immunological characterization of circulating and tumor-infiltrating T follicular helper cells (Tfh), namely CXCR5⁺CD45RA⁻CD4⁺ T cells, and their related cytokines in hepatitis B virus-related hepatocellular carcinoma (HCC) patients. In HCC patients, circulating Tfh cells showed a CCR7⁺ and/or ICOS⁺ phenotype with increased Th2-like cells and decreased Th1-like and Th17-like subsets. Although the bulk frequency of circulating Tfh cells was not altered in HCC patients, the frequency of infiltrated CXCR5⁺CD45RA⁻CD4⁺ CD3⁺cells was higher in tumor than in para-tumor tissues, and Th1-like cells were the predominant phenotype. Circulating Tfh cells in HCC patients were defective in the production of IL-21 in vitro, which was in accordance with lower IL-21 levels in tumor tissues than in para-tumor tissues. Serum CXCL13 was increased in HCC patients and associated with recurrence-free survival after hepatectomy. This was confirmed in an additional HCC cohort of 111 patients with up to 5 years follow-up. Immunohistochemical staining indicated that the percentage of CXCR5⁺ or CXCL13⁺ cells was higher in poorly differentiated than in well-differentiated tumors. In conclusion, patients with HBV-related HCC showed altered phenotypes and impaired function of Tfh cells or subpopulations. CXCL13 could be a potential biomarker for predicting recurrence in HCC patients after hepatectomy.

Epidemiology and outcomes of hepatitis C infection in elderly US Veterans

The chronic hepatitis C (CHC) cohort in the United States is getting older. Elderly patients with CHC may be at a high risk of cirrhosis and hepatocellular carcinoma (HCC), but also other nonhepatic comorbidities that negatively impact their likelihood of receiving or responding to antiviral treatment. There is little information on the clinical epidemiology or outcomes of CHC and its treatment in the elderly. We conducted a retrospective cohort study of 1 61 744 patients with a positive Hepatitis C virus RNA in the Veterans Health Administration Hepatitis C Clinical Case Registry to examine the association between age subgroups (20-49, 50-64, 65-85 years) and risk of cirrhosis, HCC or death using Cox proportional hazards models. We also examined the effect of treatment with a sustained viral response (SVR) on these outcomes in each age subgroup. The age distribution was 36.8% 20- to 49-year-olds, 57.6% 50- to 64-year-olds and 5.6% 65- to 85-year-olds (i.e. elderly). Risk of cirrhosis, HCC and death was significantly elevated in elderly patients [HR cirrhosis = 1.14 (1.00-1.29), HR HCC = 2.44 (1.99-2.99); HR death 2.09 (1.98-2.22)] compared with younger patients. The incidence of HCC was than 8.4 per 1000 PY in the elderly compared with 2.6 per 1000 PY and 5.7 per 1000 PY, among the 20-49 and 50-64 age groups, respectively. Elderly patients were significantly less likely to receive antiviral treatment (3.8% vs 14.8% and 19.1%, P < 0.0001), but among those who received treatment SVR was not different among the age groups (33.5% vs 33.2% and 32.1%). In an analysis limited to those who received treatment, SVR compared to treatment receipt with no SVR was associated with a reduction in risk of developing cirrhosis (HR = 0.34; 0.18-0.66) and HCC (HR = 0.60; 0.22-1.61) and all-cause mortality risk (HR = 0.52, 0.33-0.82). Elderly patients with CHC are more likely to develop HCC than younger patients but have traditionally received less antiviral treatment than younger patients. However, receipt of curative treatment is associated with a benefit in reducing cirrhosis, HCC and overall mortality, irrespective of age.

[EV71 Infection and Innate Antiviral Innate Immunity]

Enterovirus 71 (EV71) is a major agent of hand, foot, and mouth disease in children under five years of age. In some cases,infection with EV71 can result in herpangina, pulmonary edema and/or brainstem encephalitis. In recent years, many advances have been made towards an understanding of EV71 pathogenesis. In this review, we summarize the cell types targeted by EV71,the activation of signaling pathways, the innate antiviral immune response and immune evasion by EV71 to better understand the immunopathogenesis of EV71 and to aid in the development of antiviral drugs.

[Metagenomic Analysis of Wild Rhesus Monkey Virome in Longhu Mountain in Guangxi Area, China]

Several viruses have been found in non-human primates, among which some are pathogenic to humans. To further characterize the spectrum of viruses present in wild rhesus monkeys, MiSeq high-throughput sequencing were used to analyze 280 fecal samples collected from Guangxi, China. A total of 23,372,679 reads were obtained, of which 4,641 were annotated to 27 viral families or subfamilies, including five vertebrate viruses families(78.2%),six insect virus families(5.5%),eleven plant virus families(10.4%),and other viruses(9.8%).Further analysis revealed that these reads best fit with the sapelovirus, enterovirus, parvovirus, adeno-associated virus read sequences shared a high similarity with the known viruses. However, some reads presented obvious differences from these viruses. Moreover, PCR amplification was conducted to confirm these potentially novel viruses. This study had explored the viral spectrum of rhesus monkey feces in the Guangxi area, which laid the foundation for the potential public health significance of these viruses.

[The Expression and Purification of P[4],P[6] and P[8] Rotavirus VP8 * core Proteins]

P[4], P[6] and P[8] rotaviruses (RVs) are the most prevalent RV genotypes in the population. In order to further investigate the receptor binding and structural character of P[4], P[6] and P[8] RVs, VP8 * core proteins of the P[4], P[6] and P[8] RV strains isolated directly in the stool samples in China were expressed and purified with the GST and His-tag respectively. The GST-fusion protein was approximately 46 kDa while the His-tag proteins approximately 20 kDa. In conclusion, the recombinant plasmids of PGEX4T-1-VP8 * core and pET30a-VP8 * core were constructed and the VP8 * core proteins were successfully expressed in the soluble form by using E.coli expression system. These findings provide the basis for the futhure functional and structural studies of VP8 * proteins.

[Proinflammatory Cytokine and Chemokine Production of Mouse Macrophages in Response to EV-A71 Infection]

To study the replication and antiviral innate immunity of EV-A71 in mouse macrophages, we selected the mouse macrophage RAW264.7cell line as a model. An absolute quantitative PCR detection method was constructed to detect the viral load of EV-A71 in RAW264.7cells.RT-qPCR detected the fold changes of the proinflammatory cytokine, chemokine, and pattern recognition receptors at different time points post-infection in RAW264.7cells infected with EV-A71 and UV-inactivated EV-A71.The results revealed that the viral load of EV-A71 in RAW264.7cells decreased as the time post-infection increased. Proinflammatory cytokines, including IL-1β,IL-6,TNF-α,and chemokines, including IP-10,MCP-1,and MIP-1αwere induced, and the mRNA expression levels of TLR2,TLR1,TLR6,MDA5,and RIG-I were up-regulated. These results indicate that EV-A71 could replicate in mouse macrophages at a lower level, and proinflammatory cytokine and chemokine responses were induced.