Pathogen Identification: Ultrasensitive Nucleic Acid Detection via a Dynamic DNA Nanosystem-Integrated Ratiometric Electrochemical Sensing Strategy.

Sensitively determining trace nucleic acid is of great significance for pathogen identification. Herein, a dynamic DNA nanosystem-integrated ratiometric electrochemical biosensor was proposed to determine human immunodeficiency virus-associated DNA fragment (HIV-DNA) with high sensitivity and selectivity. The dynamic DNA nanosystem was composed of a target recycling unit and a multipedal DNA walker unit. Both of them could be driven by a toehold-mediated strand displacement reaction, enabling an enzyme-free and isothermal amplification strategy for nucleic acid determination. The target recycling unit could selectively recognize HIV-DNA and activate the multipedal DNA walker unit to roll on the electrode surface, which would lead to bidirectional signal variation for ratiometric readout with cascade signal amplification. Benefiting from the synergistic effect of the dynamic DNA nanosystem and the ratiometric output mode, the ultrasensitive detection of HIV-DNA was achieved in a wide linear range of 6 orders of magnitude with a limit of detection of 36.71 aM. The actual usability of the proposed sensor was also verified in complex biological samples with acceptable performance. This dynamic DNA nanosystem-integrated ratiometric sensing strategy might be promising in the development of reliable point-of-care diagnostic devices for highly sensitive and selective pathogen identification.

Rolling circle amplification-mediated in situ synthesis of palladium nanoparticles for the ultrasensitive electrochemical detection of microRNA.

Herein, an ultrasensitive and label-free electrochemical biosensor was developed for microRNA (miRNA) based on rolling circle amplification (RCA)-mediated palladium nanoparticles (PdNPs). The sensor was fabricated by immobilizing dual-functionalized hairpin probes onto an electrode. The specific recognition of target miRNA-21 by the hairpin probes could trigger the RCA reaction, which produced numerous guanine (G)-rich long single-stranded DNAs (ssDNAs). Based on the interaction of the PdII species with the nitrogen atoms of the G bases, these G-rich long ssDNAs served as specific templates in the in situ synthesis of massive PdNPs as electrochemical indicators. The formation of PdNPs was demonstrated to be exactly along the RCA products by high-resolution transmission electron microscopy. Using this cascade signal amplification strategy, the developed biosensor achieved a linear range of 50 aM-100 fM with an ultralow detection limit of 8.6 aM miRNA-21. Furthermore, the developed biosensor exhibited good selectivity, reproducibility, stability and satisfactory feasibility for miRNA-21 detection in human serum samples; this ensured significant potential of this biosensor in disease diagnosis and prognosis applications.

Using an Augmented Reality Device as a Distance-based Vision Aid-Promise and Limitations.

SIGNIFICANCE: For people with limited vision, wearable displays hold the potential to digitally enhance visual function. As these display technologies advance, it is important to understand their promise and limitations as vision aids. PURPOSE: The aim of this study was to test the potential of a consumer augmented reality (AR) device for improving the functional vision of people with near-complete vision loss. METHODS: An AR application that translates spatial information into high-contrast visual patterns was developed. Two experiments assessed the efficacy of the application to improve vision: an exploratory study with four visually impaired participants and a main controlled study with participants with simulated vision loss (n = 48). In both studies, performance was tested on a range of visual tasks (identifying the location, pose and gesture of a person, identifying objects, and moving around in an unfamiliar space). Participants' accuracy and confidence were compared on these tasks with and without augmented vision, as well as their subjective responses about ease of mobility. RESULTS: In the main study, the AR application was associated with substantially improved accuracy and confidence in object recognition (all P < .001) and to a lesser degree in gesture recognition (P < .05). There was no significant change in performance on identifying body poses or in subjective assessments of mobility, as compared with a control group. CONCLUSIONS: Consumer AR devices may soon be able to support applications that improve the functional vision of users for some tasks. In our study, both artificially impaired participants and participants with near-complete vision loss performed tasks that they could not do without the AR system. Current limitations in system performance and form factor, as well as the risk of overconfidence, will need to be overcome.

Lactobacillus rhamnosus GG modulates innate signaling pathway and cytokine responses to rotavirus vaccine in intestinal mononuclear cells of gnotobiotic pigs transplanted with human gut microbiota.

BACKGROUND: A better understanding of mechanisms underlying dose-effects of probiotics in their applications as treatments of intestinal infectious or inflammatory diseases and as vaccine adjuvant is needed. In this study, we evaluated the modulatory effects of Lactobacillus rhamnosus GG (LGG) on transplanted human gut microbiota (HGM) and on small intestinal immune cell signaling pathways in gnotobiotic pigs vaccinated with an oral attenuated human rotavirus (AttHRV) vaccine. RESULTS: Neonatal HGM transplanted pigs were given two doses of AttHRV on 5 and 15 days of age and were divided into three groups: none-LGG (AttHRV), 9-doses LGG (AttHRV + LGG9X), and 14-doses LGG (AttHRV + LGG14X) (n = 3-4). At post-AttHRV-inoculation day 28, all pigs were euthanized and intestinal contents and ileal tissue and mononuclear cells (MNC) were collected. AttHRV + LGG14X pigs had significantly increased LGG titers in the large intestinal contents and shifted structure of the microbiota as indicated by the formation of a cluster that is separated from the cluster formed by the AttHRV and AttHRV + LGG9X pigs. The increase in LGG titers concurred with significantly increased ileal HRV-specific IFN-γ producing T cell responses to the AttHRV vaccine reported in our previous publication, suggesting pro-Th1 adjuvant effects of the LGG. Both 9- and 14-doses LGG fed pig groups had significantly higher IkBα level and p-p38/p38 ratio, while significantly lower p-ERK/ERK ratio than the AttHRV pigs, suggesting activation of regulatory signals during immune activation. However, 9-doses, but not 14-doses LGG fed pigs had enhanced IL-6, IL-10, TNF-α, TLR9 mRNA levels, and p38 MAPK and ERK expressions in ileal MNC. Increased TLR9 mRNA was in parallel with higher mRNA levels of cytokines, p-NF-kB and higher p-p38/p38 ratio in MNC of the AttHRV + LGG9X pigs. CONCLUSIONS: The relationship between modulation of gut microbiota and regulation of host immunity by different doses of probiotics is complex. LGG exerted divergent dose-dependent effects on the intestinal immune cell signaling pathway responses, with 9-doses LGG being more effective in activating the innate immunostimulating TLR9 signaling pathway than 14-doses in the HGM pigs vaccinated with AttHRV.

Intranasal P particle vaccine provided partial cross-variant protection against human GII.4 norovirus diarrhea in gnotobiotic pigs.

UNLABELLED: Noroviruses (NoVs) are the leading cause of nonbacterial acute gastroenteritis worldwide in people of all ages. The P particle is a novel vaccine candidate derived from the protruding (P) domain of the NoV VP1 capsid protein. This study utilized the neonatal gnotobiotic pig model to evaluate the protective efficacies of primary infection, P particles, and virus-like particles (VLPs) against NoV infection and disease and the T cell responses to these treatments. Pigs either were vaccinated intranasally with GII.4/1997 NoV (VA387)-derived P particles or VLPs or were inoculated orally with a GII.4/2006b NoV variant. At postinoculation day (PID) 28, pigs either were euthanized or were challenged with the GII.4/2006b variant and monitored for diarrhea and virus shedding for 7 days. The T cell responses in intestinal and systemic lymphoid tissues were examined. Primary NoV infection provided 83% homologous protection against diarrhea and 49% homologous protection against virus shedding, while the P particle and VLP vaccines provided cross-variant protection (47% and 60%, respectively) against diarrhea. The protection rates against diarrhea are significantly inversely correlated with T cell expansion in the duodenum and are positively correlated with T cell expansion in the ileum and spleen. The P particle vaccine primed for stronger immune responses than VLPs, including significantly higher numbers of activated CD4+ T cells in all tissues, gamma interferon-producing (IFN-γ+) CD8+ T cells in the duodenum, regulatory T cells (Tregs) in the blood, and transforming growth factor ß (TGF-ß)-producing CD4+ CD25- FoxP3+ Tregs in the spleen postchallenge, indicating that P particles are more immunogenic than VLPs at the same dose. In conclusion, the P particle vaccine is a promising vaccine candidate worthy of further development. IMPORTANCE: The norovirus (NoV) P particle is a vaccine candidate derived from the protruding (P) domain of the NoV VP1 capsid protein. P particles can be easily produced in Escherichia coli at high yields and thus may be more economically viable than the virus-like particle (VLP) vaccine. This study demonstrated, for the first time, the cross-variant protection (46.7%) of the intranasal P particle vaccine against human NoV diarrhea and revealed in detail the intestinal and systemic T cell responses by using the gnotobiotic pig model. The cross-variant protective efficacy of the P particle vaccine was comparable to that of the VLP vaccine in pigs (60%) and to the homologous protective efficacy of the VLP vaccine in humans (47%). NoV is now the leading cause of pediatric dehydrating diarrhea, responsible for approximately 1 million hospital visits for U.S. children and 218,000 deaths in developing countries. The P particle vaccine holds promise for reducing the disease burden and mortality.

Lactobacillus rhamnosus GG Dosage Affects the Adjuvanticity and Protection Against Rotavirus Diarrhea in Gnotobiotic Pigs.

OBJECTIVES: The use of immunostimulatory strains of probiotics as adjuvants has been increasingly recognized as a promising approach in enhancing vaccine immunogenicity; however, dose effects of probiotic adjuvants are not well defined. In the present study, we examined dose effects of a commonly used probiotic strain, Lactobacillus rhamnosus GG (LGG), on immunomodulation with 2 different dosages. METHODS: Neonatal gnotobiotic pigs were inoculated with 2 oral doses of attenuated human rotavirus (AttHRV) vaccines and fed with 5 doses (LGG5X; total 2.1 × 10(6) colony-forming units) or 9 doses (LGG9X; total 3.2 × 10(6) colony-forming units) of LGG, starting at 3 days of age. RESULTS: Both LGG feeding regimens enhanced the protection rate of AttHRV vaccine against diarrhea on virulent human rotavirus challenge. LGG5X, but not LGG9X, significantly enhanced rotavirus-specific intestinal memory B-cell responses to AttHRV; LGG5X also significantly enhanced virus-specific intestinal immunoglobulin A (IgA) antibody-secreting cell responses. Both regimens significantly enhanced rotavirus-specific serum IgA antibody responses to AttHRV. They also enhanced rotavirus-specific interferon-γ-producing effector/memory T-cell responses to AttHRV vaccine, with LGG9X being more effective than LGG5X, and both regimens downregulated CD4+CD25-FoxP3+ regulatory T (Treg) cell responses in most lymphoid tissues examined prechallenge and postchallenge and maintained the CD4+CD25+FoxP3+ Treg population in the ileum and intraepithelial lymphocyte postchallenge. LGG9X, however, did not significantly reduce total CD4+CD25-FoxP3+ Treg frequencies in the intestine and transforming growth factor-ß-producing and interleukin (IL)-10-producing Treg frequencies in the blood. CONCLUSIONS: These results indicate that LGG at both dosages functioned as effective probiotic adjuvant for AttHRV vaccine, but different dosages differentially modulated immune responses to favor either the mucosal IgA response (LGG5X) or the T-cell response (LGG9X).

Dual functions of Lactobacillus acidophilus NCFM as protection against rotavirus diarrhea.

OBJECTIVE: The aim of the study was to examine the dose effects of Lactobacillus acidophilus (LA) NCFM strain on rotavirus-specific antibody and B-cell responses in gnotobiotic pigs vaccinated with an oral attenuated human rotavirus (AttHRV). METHODS: Pigs were inoculated with AttHRV vaccine in conjunction with high-dose LA (14 doses, total 2.2 × 10(6) colony-forming units [CFU]), intermediate-dose LA (MidLA) (9 doses, total 3.2 × 10(9) CFU), low-dose LA (LoLA) (5 doses, total 2.1 × 10(6) CFU), or without LA feeding. Protection against rotavirus shedding and diarrhea was assessed upon challenge with a virulent HRV. Rotavirus-specific immunoglobulin A (IgA) and IgG antibodies in serum and rotavirus-specific IgA and IgG antibody-secreting cells (ASCs) and memory B cells in ileum, spleen, and blood of the pigs were measured and compared among treatment groups. RESULTS: The MidLA, but not high-dose LA or LoLA, significantly reduced rotavirus diarrhea (MidLA-only group) and significantly improved the protection conferred by AttHRV vaccine (MidLA + AttHRV group). Associated with the increased protection, MidLA significantly enhanced rotavirus-specific antibody, ASCs, and memory B-cell responses to AttHRV vaccine. High-dose LA or LoLA did not enhance virus-specific antibody and ASC responses, and hence did not improve the vaccine efficacy. CONCLUSIONS: These findings highlight the importance of dose selection and indicate that certain specific lactobacilli strains at the appropriate dose have the dual function of reducing rotavirus diarrhea and enhancing the immunogenicity and protective efficacy of rotavirus vaccines.

An immunochromatographic strip sensor for marbofloxacin residues.

Marbofloxacin (MBF) was once widely used as a veterinary drug to control diseases in animals. MBF residues in animal food endanger human health. In the present study, an immunochromatographic strip assay (ICSA) utilizing a competitive principle was developed to rapidly detect MBF in beef samples. The 50% inhibitory concentration (IC50) and the limit of detection (LOD) of the ICSAs were 2.5 ng/mL and 0.5 ng/mL, respectively. The cross-reactivity (CR) of the MBF ICSAs to Ofloxacin (OFL), enrofloxacin (ENR), norfloxacin (NOR), and Ciprofloxacin (CIP) were 60.98%, 32.05%, 22.94%, and 23.58%, respectively. The CR for difloxacin (DIF) and sarafloxacin (SAR) was less than 0.1%. The recovery rates of MBF in spiked beef samples ranged from 82.0% to 90.4%. The intra-assay and interassay coefficients of variation (CVs) were below 10%. In addition, when the same authentic beef samples were detected in a side-by-side comparison between the ICSAs and HPLC‒MS, no statistically significant difference was observed. Therefore, the proposed ICSAs can be a useful tool for monitoring MBF residues in beef samples in a qualitative and quantitative manner.

Median infectious dose of human norovirus GII.4 in gnotobiotic pigs is decreased by simvastatin treatment and increased by age.

Human noroviruses (NoVs), a major cause of viral gastroenteritis, are difficult to study due to the lack of a cell-culture and a small-animal model. Pigs share with humans the types A and H histo-blood group antigens on the intestinal epithelium and have been suggested as a potential model for studies of NoV pathogenesis, immunity and vaccines. In this study, the effects of age and a cholesterol-lowering drug, simvastatin, on the susceptibility of pigs to NoV infection were evaluated. The median infectious dose (ID50) of a genogroup II, genotype 4 (GII.4) 2006b variant was determined. The ID50 in neonatal (4-5 days of age) pigs was ≤2.74×10(3) viral RNA copies. In older pigs (33-34 days of age), the ID50 was 6.43×10(4) but decreased to <2.74×10(3) in simvastatin-fed older pigs. Evidence of NoV infection was obtained by increased virus load in the intestinal contents, cytopathological changes in the small intestine, including irregular microvilli, necrosis and apoptosis, and detection of viral antigen in the tip of villi in duodenum. This GII.4 variant was isolated in 2008 from a patient from whom a large volume of stool was collected. GII.4 NoVs are continuously subjected to selective pressure by human immunity, and antigenically different GII.4 NoV variants emerge every 1-2 years. The determination of the ID50 of this challenge virus is valuable for evaluation of protection against different GII.4 variants conferred by NoV vaccines in concurrence with other GII.4 variants in the gnotobiotic pig model.

Lactobacillus rhamnosus GG on rotavirus-induced injury of ileal epithelium in gnotobiotic pigs.

OBJECTIVE: The aim of this study was to study the effect of continued Lactobacillus rhamnosus GG strain (LGG) feeding on rotavirus gastroenteritis in the gnotobiotic (Gn) pig model of virulent human rotavirus (HRV) infection. METHODS: Gn pigs were assigned to treatment groups: mock control, LGG only, HRV only, or LGG plus HRV. Nine days before HRV inoculation (3 days of age), pigs were fed LGG with a daily dose increase of 10-fold from 10³ to 10¹² colony-forming units (CFU). The 10¹² CFU/dose of LGG feeding continued until post-HRV inoculation day (PID) 6. Clinical sign (diarrhea), rotavirus fecal shedding, histopathology of the ileum, adherent junction and tight junction protein expression in the ileal epithelial cells, mucin production in the large and small intestinal contents, and serum cytokine responses from PID 2 to 6 were examined and compared among the treatment groups. RESULTS: Clinically, the percentage of pigs developing diarrhea, the mean duration of diarrhea, and the mean cumulative fecal scores were lower in the LGG fed pigs compared to the nonfed pigs after HRV inoculation. LGG partially protected ileal epithelium against HRV-induced compensatory increases of the adherent junction protein α-catenin and ß-catenin, tight junction protein occludin, claudin-3 and claudin-4, and leak protein claudin-2. LGG promoted mucin production because the mucin levels in the large intestinal contents of the LGG+HRV pigs were significantly higher than the HRV-only pigs on PID 2. Additionally, LGG maintained the anti-inflammatory cytokine transforming growth factor-ß level in serum after HRV infection. CONCLUSIONS: LGG is moderately effective for ameliorating rotavirus diarrhea by partially preventing injuries to the epithelium.

CD4+ CD25- FoxP3+ regulatory cells are the predominant responding regulatory T cells after human rotavirus infection or vaccination in gnotobiotic pigs.

The distribution and dynamic changes of CD4(+) CD25(+) FoxP3(+) and CD4(+) CD25(-) FoxP3(+) regulatory T (Treg) cells induced by human rotavirus (HRV) infection and vaccination were examined in neonatal gnotobiotic pigs infected with virulent HRV (VirHRV) or vaccinated with attenuated HRV (AttHRV). Subsets of gnotobiotic pigs in the AttHRV and control groups were challenged with VirHRV at post-inoculation day (PID) 28. We demonstrated that VirHRV infection or AttHRV vaccination reduced frequencies and numbers of tissue-residing Treg cells, and decreased the frequencies of interleukin-10 (IL-10) and transforming growth factor-ß (TGF-ß) producing CD4(+) CD25(-) Treg cells in ileum, spleen and blood at PID 28. The frequencies of IL-10 and TGF-ß producing CD4(+) CD25(-) Treg cells in all sites at PID 28 were significantly inversely correlated with the protection rate against VirHRV-caused diarrhoea (r = -1, P < 0.0001). Hence, higher frequencies of functional CD4(+) CD25(-) Treg cells can be an indicator for poorer protective immunity against rotavirus. Our results highlighted the importance of CD4(+) CD25(-) Treg cells over CD4(+) CD25(+) Treg cells in rotavirus infection and immunity. AttHRV vaccination (induction of immune effector responses) reduced the expansion of CD4(+) CD25(-) Treg cells in ileum seen in the challenged naive pigs during the acute phase of VirHRV infection and preserved normal levels of intestinal TGF-ß producing Treg cells post-challenge. The reduced suppressive effect of Treg cells in AttHRV-vaccinated pigs would unleash effector/memory T-cell activation upon challenge. Preserving TGF-ß producing CD4(+) CD25(-) Treg cells is important in maintaining homeostasis. Based on our findings, a model is proposed to depict the dynamic equilibrium course of Treg and effector T-cell responses after primary rotavirus infection/vaccination and challenge.

IDO Vaccine Ablates Immune-Suppressive Myeloid Populations and Enhances Antitumor Effects Independent of Tumor Cell IDO Status.

The immunosuppressive tumor microenvironment (TME) does not allow generation and expansion of antitumor effector cells. One of the potent immunosuppressive factors present in the TME is the indoleamine-pyrrole 2,3-dioxygenase (IDO) enzyme, produced mainly by cancer cells and suppressive immune cells of myeloid origin. In fact, IDO+ myeloid-derived suppressor cells (MDSC) and dendritic cells (DC) tend to be more suppressive than their IDO- counterparts. Hence, therapeutic approaches that would target the IDO+ cells in the TME, while sparing the antigen-presenting functions of IDO- myeloid populations, are needed. Using an IDO-specific peptide vaccine (IDO vaccine), we explored the possibility of generating effector cells against IDO and non-IDO tumor-derived antigens. For this, IDO-secreting (B16F10 melanoma) and non-IDO-secreting (TC-1) mouse tumor models were employed. We showed that the IDO vaccine significantly reduced tumor growth and enhanced survival of mice in both the tumor models, which associated with a robust induction of IDO-specific effector cells in the TME. The IDO vaccine significantly enhanced the antitumor efficacy of non-IDO tumor antigen-specific vaccines, leading to an increase in the number of total and antigen-specific activated CD8+ T cells (IFNγ+ and granzyme B+). Treatment with the IDO vaccine significantly reduced the numbers of IDO+ MDSCs and DCs, and immunosuppressive regulatory T cells in both tumor models, resulting in enhanced therapeutic ratios. Together, we showed that vaccination against IDO is a promising therapeutic option for both IDO-producing and non-IDO-producing tumors. The IDO vaccine selectively ablates the IDO+ compartment in the TME, leading to a significant enhancement of the immune responses against other tumor antigen-specific vaccines.

Probiotic as Adjuvant Significantly Improves Protection of the Lanzhou Trivalent Rotavirus Vaccine against Heterologous Challenge in a Gnotobiotic Pig Model of Human Rotavirus Infection and Disease.

This preclinical study in the gnotobiotic (Gn) pig model of human rotavirus (HRV) infection and disease evaluates the effect of probiotic Lactobacillus rhamnosus GG (LGG) as a mucosal adjuvant on the immunogenicity and cross-protective efficacy of the Lanzhou live oral trivalent (G2, G3, G4) vaccine (TLV, aka LLR3). Gn pigs were immunized with three doses of TLV with or without concurrent administration of nine doses of LGG around the time of the first dose of the TLV vaccination, and were challenged orally with the virulent heterotypic Wa G1P[8] HRV. Three doses of TLV were highly immunogenic and conferred partial protection against the heterotypic HRV infection. LGG significantly enhanced the intestinal and systemic immune responses and improved the effectiveness of protection against the heterotypic HRV challenge-induced diarrhea and virus shedding. In conclusion, we demonstrated the immune-stimulating effects of probiotic LGG as a vaccine adjuvant and generated detailed knowledge regarding the cross-reactive and type-specific antibody and effector B and T cell immune responses induced by the TLV. Due to the low cost, ease of distribution and administration, and favorable safety profiles, LGG as an adjuvant has the potential to play a critical role in improving rotavirus vaccine efficacy and making the vaccines more cost-effective.

In-plasma-catalysis for NO x degradation by Ti3+ self-doped TiO2-x /γ-Al2O3 catalyst and nonthermal plasma.

In an attempt to realize the efficient treatment of NO x , a mixed catalyst of Ti3+ self-doped TiO2-x and γ-Al2O3 was constructed by reducing commercial TiO2. The degradation effect on NO x was evaluated by introducing the mixed catalyst into a coaxial dual-dielectric barrier reactor. It was found that the synthesized TiO2-x could achieve considerable degradation effects (84.84%, SIE = 401.27 J L-1) in a plasma catalytic system under oxygen-rich conditions, which were better than those of TiO2 (73.99%) or a single plasma degradation process (26.00%). The presence of Ti3+ and oxygen vacancies in TiO2-x resulted in a relatively narrow band gap, which contributed to catalyzing deeply the oxidation of NO x to NO2 - and NO3 - during the plasma-induced "pseudo-photocatalysis" process. Meanwhile, the TiO2-x showed an improved discharge current and promoted discharge efficiency, explaining its significant activation effect in the reaction. Reduced TiO2-x could achieve an impressive degradation effect in a long-time plasma-catalysis process, and still maintained its intrinsic crystal structure and morphology. This work provides a facile synthesis procedure for preparing Ti3+ self-doped TiO2-x with practical and scalable production potential; moreover, the novel combination with plasma also provides new insights into the low-temperature degradation of NO x .

BackSwipe: Back-of-device Word-Gesture Interaction on Smartphones.

Back-of-device interaction is a promising approach to interacting on smartphones. In this paper, we create a back-of-device command and text input technique called BackSwipe, which allows a user to hold a smartphone with one hand, and use the index finger of the same hand to draw a word-gesture anywhere at the back of the smartphone to enter commands and text. To support BackSwipe, we propose a back-of-device word-gesture decoding algorithm which infers the keyboard location from back-of-device gestures, and adjusts the keyboard size to suit the gesture scales; the inferred keyboard is then fed back into the system for decoding. Our user study shows BackSwipe is feasible and a promising input method, especially for command input in the one-hand holding posture: users can enter commands at an average accuracy of 92% with a speed of 5.32 seconds/command. The text entry performance varies across users. The average speed is 9.58 WPM with some users at 18.83 WPM; the average word error rate is 11.04% with some users at 2.85%. Overall, BackSwipe complements the extant smartphone interaction by leveraging the back of the device as a gestural input surface.

Simvastatin Reduces Protection and Intestinal T Cell Responses Induced by a Norovirus P Particle Vaccine in Gnotobiotic Pigs.

Noroviruses (NoVs) are a leading cause of acute gastroenteritis worldwide. P particles are a potential vaccine candidate against NoV. Simvastatin is a cholesterol-reducing drug that is known to increase NoV infectivity. In this study, we examined simvastatin's effects on P particle-induced protective efficacy and T-cell immunogenicity using the gnotobiotic pig model of human NoV infection and diarrhea. Pigs were intranasally inoculated with three doses (100 µg/dose) of GII.4/VA387-derived P particles together with monophosphoryl lipid A and chitosan adjuvants. Simvastatin-fed pigs received 8 mg/day orally for 11 days prior to challenge. A subset of pigs was orally challenged with 10 ID50 of a NoV GII.4/2006b variant at post-inoculation day (PID) 28 and monitored for 7 days post-challenge. Intestinal and systemic T cell responses were determined pre- and postchallenge. Simvastatin abolished the P particle's protection and significantly increased diarrhea severity after NoV infection. Simvastatin decreased proliferation of virus-specific and non-specific CD8 T cells in duodenum and virus-specific CD4 and CD8 T cells in spleen and significantly reduced numbers of intestinal mononuclear cells in vaccinated pigs. Furthermore, simvastatin significantly decreased numbers of duodenal CD4+IFN-γ+, CD8+IFN-γ+ and regulatory T cells and total duodenal activated CD4+ and CD8+ T cells in vaccinated pigs pre-challenge at PID 28. Following challenge, simvastatin prevented the IFN-γ+ T cell response in spleen of vaccinated pigs. These results indicate that simvastatin abolished P particle vaccine-induced partial protection through, at least in part, impairing T cell immunity. The findings have specific implications for the development of preventive and therapeutic strategies against NoV gastroenteritis, especially for the elderly population who takes statin-type drugs.

Hapten Synthesis and the Development of an Ultrasensitive Indirect Competitive ELISA for the Determination of Diethylstilbestrol in Food Samples.

An ultrasensitive indirect competitive enzyme-linked immunosorbent assay (ic ELISA) using monoclonal antibodies (mAbs) was developed for the specific detection of diethylstilbestrol (DES) residues. To establish an ELISA based on mAbs, hapten diethylstilbestrol mono-carboxypropyl-ether (DES-MCPE) was chemically synthetized and then conjugated to bovine serum albumin (BSA) for immunization in mice. This ic ELISA was further optimized for DES determination. The sensitivity of the ic ELISA was found to be 0.49 µg/kg and the limit of detection was 0.075 µg/kg. DES residues in salmon meat and pork were tested with the recovery range from 74.0 to 85.2% and the coefficient of variation (CV) was less than 10%. Parallel analysis of DES samples from salmon meat showed comparable results from the ic ELISA with high-performance liquid chromatography. The ic ELISA provides a useful screening method for the quantitative detection of DES residues in animal-derived food.

Effect of acrylamide on glucose homeostasis in female rats and its mechanisms.

Acrylamide (AA), a food contaminant, caused islet remodeling and increased hepatic glycogen content in male rats, but the effect of AA on glucose homeostasis in female rats remains unclear. In this study, female SD rats were orally treated with 0, 15, or 30 mg/kg·bw AA for 3 weeks. The levels of fasting blood glucose (FBG), blood glucose after oral administration of glucose, plasma insulin and hepatic glycogen were measured. The histology of the pancreas was observed, and the transcription of key genes involved in glucose metabolism and insulin signaling in liver were determined. Compared with the control, exposure to 30 mg/kg·bw of AA significantly increased FBG level, reduced hepatic glycogen content and impaired glucose tolerance. Moreover, damaged islets were observed at 15 and 30 mg/kg·bw AA-exposed groups. In addition, AA exposure significantly promoted gluconeogenesis and glycogenolysis (up-regulation of pc, g6p and gp) and decreased glycolysis (down-regulation of gck and pfk). Alternations in these processes may be associated with decreased plasma insulin levels and inhibited insulin-regulated IRS/PI3K/Akt/Foxo1 signaling transduction under AA exposure. Overall, our findings demonstrated that AA disrupted glucose homeostasis and elevated FBG level in female rats possibly by interfering with glucose metabolism and hampering the physiological effect of insulin.

NR4A1 Methylation Associated Multimodal Neuroimaging Patterns Impaired in Temporal Lobe Epilepsy.

DNA hypermethylation has been widely observed in temporal lobe epilepsy (TLE), in which NR4A1 knockdown has been reported to be able to alleviate seizure severity in mouse model, while the underlying methylation-imaging pathway modulated by aberrant methylation levels of NR4A1 remains to be clarified in patients with TLE. Here, using multi-site canonical correlation analysis with reference, methylation levels of NR4A1 in blood were used as priori to guide fusion of three MRI features: functional connectivity (FC), fractional anisotropy (FA), and gray matter volume (GMV) for 56 TLE patients and 65 healthy controls. Post-hoc correlations were further evaluated between the identified NR4A1-associated brain components and disease onset. Results suggested that higher NR4A1 methylation levels in TLE were related with impaired temporal-cerebellar and occipital-cerebellar FC strength, lower FA in cingulum (hippocampus), and reduced GMV in putamen, temporal pole, and cerebellum. Moreover, findings were also replicated well in both patient subsets with either right TLE or left TLE only. Particularly, right TLE patients showed poorer cognitive abilities and more severe brain impairment than left TLE patients, especially more reduced GMV in thalamus. In summary, this work revealed a potential imaging-methylation pathway modulated by higher NR4A1 methylation in TLE via data mining, which may impact the above-mentioned multimodal brain circuits and was also associated with earlier disease onset and more cognitive deficits.

Pre-existing immunity to influenza virus hemagglutinin stalk might drive selection for antibody-escape mutant viruses in a human challenge model.

The conserved region of influenza hemagglutinin (HA) stalk (or stem) has gained attention as a potent target for universal influenza vaccines1-5. Although the HA stalk region is relatively well conserved, the evolutionarily dynamic nature of influenza viruses6 raises concerns about the possible emergence of viruses carrying stalk escape mutation(s) under sufficient immune pressure. Here we show that immune pressure on the HA stalk can lead to expansion of escape mutant viruses in study participants challenged with a 2009 H1N1 pandemic influenza virus inoculum containing an A388V polymorphism in the HA stalk (45% wild type and 55% mutant). High level of stalk antibody titers was associated with the selection of the mutant virus both in humans and in vitro. Although the mutant virus showed slightly decreased replication in mice, it was not observed in cell culture, ferrets or human challenge participants. The A388V mutation conferred resistance to some of the potent HA stalk broadly neutralizing monoclonal antibodies (bNAbs). Co-culture of wild-type and mutant viruses in the presence of either a bNAb or human serum resulted in rapid expansion of the mutant. These data shed light on a potential obstacle for the success of HA-stalk-targeting universal influenza vaccines-viral escape from vaccine-induced stalk immunity.