Detection of Influenza Virus Using a SOI-Nanoribbon Chip, Based on an N-Type Field-Effect Transistor.

The detection of influenza A virions with a nanoribbon detector (NR detector) has been demonstrated. Chips for the detector have been fabricated based on silicon-on-insulator nanoribbon structures (SOI nanoribbon chip), using a complementary metal-oxide-semiconductor (CMOS)-compatible technology-by means of gas-phase etching and standard optical photolithography. The surface of the SOI nanoribbon chip contains a matrix of 10 nanoribbon (NR) sensor elements. SOI nanoribbon chips of n-type conductance have been used for this study. For biospecific detection of target particles, antibodies against influenza virus have been covalently immobilized onto NRs. Influenza A virus detection was performed by real-time registration of the source-drain current through the NRs. The detection of the target viral particles was carried out in buffer solutions at the target particles concentration within the range from 107 to 103 viral particles per milliliter (VP/mL). The lowest detectable concentration of the target viral particles was 6 × 10-16 M (corresponding to 104 VP/mL). The use of solutions containing ~109 to 1010 VP/mL resulted in saturation of the sensor surface with the target virions. In the saturation mode, detection was impossible.

Ultrasensitive Electrical Detection of Hemagglutinin for Point-of-Care Detection of Influenza Virus Based on a CMP-NANA Probe and Top-Down Processed Silicon Nanowire Field-Effect Transistors.

Rather than the internal genome nucleic acids, the biomolecules on the surface of the influenza virus itself should be detected for a more exact and rapid point-of-care yes/no decision for influenza virus-induced infectious diseases. This work demonstrates the ultrasensitive electrical detection of the HA1 domain of hemagglutinin (HA), a representative viral surface protein of the influenza virus, using the top-down complementary metal oxide semiconductor (CMOS) processed silicon nanowire (SiNW) field-effect transistor (FET) configuration. Cytidine-5'-monophospho-N-acetylneuraminic acid (CMP-NANA) was employed as a probe that specifically binds both to the aldehyde self-aligned monolayer on the SiNWs and to HA1 simultaneously. CMP-NANA was serially combined with two kinds of linkers, namely 3-aminopropyltriethoxysilane and glutaraldehyde. The surface functionalization used was verified using the purification of glutathione S-transferase-tagged HA1, contact angle measurement, enzyme-linked immunosorbent assay test, and isoelectric focusing analysis. The proposed functionalized SiNW FET showed high sensitivities of the threshold voltage shift (ΔVT) ~51 mV/pH and the ΔVT = 112 mV (63 mV/decade) with an ultralow detectable range of 1 fM of target protein HA1.

Correlation between infectious disease and soil radiation in Japan: an exploratory study using national sentinel surveillance data.

We investigated the relationship between epidemics and soil radiation through an exploratory study using sentinel surveillance data (individuals aged <20 years) during the last three epidemic seasons of influenza and norovirus in Japan. We used a spatial analysis method of a geographical information system (GIS). We mapped the epidemic spreading patterns from sentinel incidence rates. We calculated the average soil radiation [dm (µGy/h)] for each sentinel site using data on uranium, thorium, and potassium oxide in the soil and examined the incidence rate in units of 0·01 µGy/h. The correlations between the incidence rate and the average soil radiation were assessed. Epidemic clusters of influenza and norovirus infections were observed in areas with relatively high radiation exposure. A positive correlation was detected between the average incidence rate and radiation dose, at r = 0·61-0·84 (P < 0·01) for influenza infections and r = 0·61-0·72 (P < 0·01) for norovirus infections. An increase in the incidence rate was found between areas with radiation exposure of 0 < dm < 0·01 and 0·15 ⩽ dm < 0·16, at 1·80 [95% confidence interval (CI) 1·47-2·12] times higher for influenza infection and 2·07 (95% CI 1·53-2·61) times higher for norovirus infection. Our results suggest a potential association between decreased immunity and irradiation because of soil radiation. Further studies on immunity in these epidemic-prone areas are desirable.

[Influenza, influenza-like illness: from theory to practice]. / Grippe, syndrome grippal : de la théorie à la pratique.

In France, there are large discrepancies regarding flu between the severe disease described by Health Authorities and the disease that people face, considered as usual and benign. Flu prevention is useful, mainly through vaccination. For a well-established influenza-like illness, both individual measures dedicated to the limitation of the disease propagation and symptomatic treatment are to be initiated. Few clinical data are available regarding the most often used treatments for influenza-like illness (paracetamol, homeopathic and symptomatic treatments). The analysis did not show any decrease in the chances of success for patients with more often used drugs, either being under medical prescription, pharmacist advice or self-medication. In front of an influenza-like illness, the recommendations for daily practice can be based on 2 well-defined clinical situations: a specific management for patients at risk, and the influenza-like illness symptoms relief for the others, using a treatment specific for each patient.

3D printed chip for electrochemical detection of influenza virus labeled with CdS quantum dots.

In this study, we report a new three-dimensional (3D), bead-based microfluidic chip developed for rapid, sensitive and specific detection of influenza hemagglutinin. The principle of microfluidic chip is based on implementation of two-step procedure that includes isolation based on paramagnetic beads and electrochemical detection. As a platform for isolation process, streptavidin-modified MPs, which were conjugated via biotinylated glycan (through streptavidin-biotin affinity) followed by linkage of hemagglutinin to glycan, were used. Vaccine hemagglutinin (HA vaxi) was labeled with CdS quantum dots (QDs) at first. Detection of the isolation product by voltammetry was the end point of the procedure. The suggested and developed method can be used also for detection of other specific substances that are important for control, diagnosis or therapy of infectious diseases.

Evaluation of the antiviral drug susceptibility of influenza viruses in Italy from 2004/05 to 2009/10 epidemics and from the recent 2009 pandemic.

Antiviral monitoring of influenza viruses circulating in Italy has been carried out since 2007 by the National Influenza Centre (NIC), using both phenotypic and sequence-based assays. Here, we report results of the susceptibility evaluation to neuraminidase (NA) inhibitors (NAIs, zanamivir and oseltamivir) and adamantanes of nearly 300 influenza type A and B seasonal viruses isolated in Italy during six recent seasons, together with over 30 pandemic (H1N1) 2009 virus strains. The present work is the first such study conducted in Italy, aimed to develop national data on antiviral drug profile and to establish a nationwide surveillance programme on antiviral susceptibility. Sequencing of the NA gene was undertaken either to confirm the phenotypic findings or to identify any NA change, in potentially resistant viruses (outliers), which might be associated with reduced susceptibility to NAIs. The 50% inhibitory concentration values (IC(50)s) showed slightly different sensitivities of the seasonal Italian isolates to the two NAI drugs, depending on the specific NA subtype. We found mean zanamivir IC(50)s of 0.74, 1.33 and 7 nM, and oseltamivir IC(50)s of 0.67, 2.34 and 30.1 nM for the N2, N1 and B NAs, respectively. The pandemic (H1N1) 2009 viruses showed IC(50)values overall comparable to the seasonal N1 viruses from previous years, showing mean zanamivir IC(50)s of 1.02 nM and mean oseltamivir IC(50)s of 2.82 nM. Oseltamivir resistance was found in a total of 19 seasonal N1viruses of 2007/2008 and 2008/2009, and in three pandemic (H1N1) 2009 strains. A gradual increase of resistance to adamantanes was observed among the N2 viruses isolated in recent seasons; no resistant viruses were found among the seasonal N1 strains, whereas all the pandemic (H1N1) 2009 isolates analysed were resistant to the M2 blockers.

Frequency of drug-resistant viruses and virus shedding in pediatric influenza patients treated with neuraminidase inhibitors.

BACKGROUND: Although influenza virus resistance to the neuraminidase inhibitor zanamivir is reported less frequently than is resistance to the neuraminidase inhibitor oseltamivir in clinical settings, it is unknown whether this difference is due to the limited use of zanamivir or to an inherent property of the drug. We therefore compared the prevalence of drug-resistant viruses and virus shedding in seasonal influenza virus-infected children treated with either oseltamivir or zanamivir. METHODS: Clinical specimens (throat or nasal swab) were collected from a total of 144 pediatric influenza patients during the 2005-2006, 2006-2007, 2007-2008, and 2008-2009 influenza seasons. Neuraminidase inhibitor-resistant mutants were detected among the isolated viruses by sequencing the viral hemagglutinin and neuraminidase genes. Sensitivity of the viruses to neuraminidase inhibitors was tested by neuraminidase inhibition assay. RESULTS: In oseltamivir- or zanamivir-treated influenza patients who were statistically comparable in their age distribution, vaccination history, and type or subtype of virus isolates, the virus-shedding period in zanamivir-treated patients was significantly shorter than that in oseltamivir-treated patients. Furthermore, the frequency of zanamivir-resistant viruses was significantly lower than that of oseltamivir-resistant viruses. CONCLUSION: In comparison with treatment with oseltamivir, treatment of pediatric patients with zanamivir resulted in the emergence of fewer drug-resistant influenza viruses and a shorter virus-shedding period. We conclude that zanamivir shows promise as a better therapy for pediatric influenza patients.

In vitro anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis.

In this paper, in vitro anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis were investigated. Cytotoxicities and antiviral activities of Gracilaria lemaneiformis polysaccharides (PGL), Gracilaria lemaneiformis polysaccharide fraction-1 (GL-1), Gracilaria lemaneiformis polysaccharide fraction-2 (GL-2) and Gracilaria lemaneiformis polysaccharide fraction-3 (GL-3) were studied by the Methyl thiazolyl tetrazolium (MTT) method, and the inhibitory effect against Human influenza virus H1-364 induced cytopathic effect (CPE) on MDCK cells were observed by the CPE method. In addition, the antiviral mechanism of PGL was explored by Plaque forming unit (PFU), MTT and CPE methods. The results showed: i) Cytotoxicities were not significantly revealed, and H1-364 induced CPE was also reduced treated with sulfated polysaccharide fractions from Gracilaria lemaneiformis; ii) Antiviral activities were associated with the mass percentage content of sulfate groups in polysaccharide fractions, which was about 13%, in polysaccharides (PGL and GL-2) both of which exhibited higher antiviral activity; iii) A potential antiviral mechanism to explain these observations is that viral adsorption and replication on host cells were inhibited by sulfated polysaccharides from Gracilaria lemaneiformis. In conclusion, Anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis were revealed, and the antiviral activities were associated with content of sulfate groups in polysaccharide fractions.

Seasonal invasive pneumococcal disease in children: role of preceding respiratory viral infection.

OBJECTIVE: Our objective was to demonstrate correlations between invasive pneumococcal disease in children and circulating respiratory viruses. METHODS: This retrospective study included 6 winter respiratory viral seasons (2001-2007) in Intermountain Healthcare, an integrated health system in the Intermountain West, including Primary Children's Medical Center in Salt Lake City, Utah. Children <18 years of age who were hospitalized with either invasive pneumococcal disease in any Intermountain Healthcare facility or culture-confirmed invasive pneumococcal disease at Primary Children's Medical Center were included. We analyzed the correlation between invasive pneumococcal disease and circulating respiratory viruses. RESULTS: A total of 435 children with invasive pneumococcal disease and 203 with culture-confirmed invasive pneumococcal disease were hospitalized in an Intermountain Healthcare facility or Primary Children's Medical Center during the study period. During the same period, 6963 children with respiratory syncytial virus, 1860 with influenza virus, 1459 with parainfluenza virus, and 818 with adenoviruses were evaluated at Primary Children's Medical Center. A total of 253 children with human metapneumovirus were identified during the last 5 months of the study. There were correlations between invasive pneumococcal disease and seasonal respiratory syncytial virus, influenza virus, and human metapneumovirus activity. The correlation with invasive pneumococcal disease was strong up to 4 weeks after respiratory syncytial virus activity. For influenza virus and human metapneumovirus, the correlations were strong at 2 weeks after activity of these viruses. Pneumonia was the most common clinical disease associated with culture-confirmed invasive pneumococcal disease, mostly attributable to serotypes 1, 19A, 3, and 7F. CONCLUSIONS: In the post-pneumococcal conjugate vaccine era, seasonal increases in respiratory syncytial virus, influenza virus, and human metapneumovirus infections in children were associated with increased pediatric admissions with invasive pneumococcal disease, especially pneumonia caused by nonvaccine serotypes.

Arginine supplementation enhances mitogen-induced splenocyte proliferation but does not affect in vivo indicators of antigen-specific immunity in mice.

Arginine is a conditionally essential amino acid with many physiologic roles. Its role in immune function has been one of major focus with conflicting results. Early in vitro immune studies demonstrated increased mitogen-induced lymphocyte proliferation with dietary arginine supplementation; however, not all studies confirmed this effect. Even less is known about the effect of arginine supplementation on in vivo immune responses. To test whether arginine supplementation enhances in vivo indicators of immune function, young female BALB/c mice were fed either the AIN-93G rodent diet (6.4 g arginine/kg diet) or the same diet with 20 g total arginine/kg diet for 15 d before delayed-type hypersensitivity (DTH) testing with 2,4-dinitrofluorobenzene (n = 16-18/diet group). The same mice were challenged with influenza virus A/Port Chalmers/1/73 (H3N2) 15 d later. Mice were killed 3, 6, or 31 d postinfluenza challenge (5-6/diet group on each day). Mitogen-induced splenocyte proliferation, body weight, anti-influenza serum antibody, lung viral titers, and serum arginine were measured. DTH did not differ between diet groups. On d 6 and 31 postchallenge, mitogen-induced proliferation of splenocytes from mice fed the arginine diet was >1.5-fold that of mice fed the control diet (P < 0.05). Body weight and influenza lung viral and serum antibody titers did not differ between diet groups. These data suggest that despite significant enhancement of in vitro mitogen-induced splenocyte proliferation, arginine supplementation does not have a biologically significant effect on antigen-specific in vivo indicators of immune function in this model.

[History of influenza epidemics and discovery of influenza virus].

Influenza epidemics occur almost annually, sometimes taking on a global scale and turning into pandemics. According to Noble, the first clearly recorded epidemic was one that struck Europe in 1173 to 1174. In Japan the first comprehensive review of epidemic records was made by Fujikawa in the early 20th century, who listed 46 epidemics between 862 and 1868. Of the ten pandemics since the 1700s that have been certified by Beveridge nine have struck Japan as well. The human influenza A virus was discovered in 1933 soon after Shope succeeded in isolating swine influenza A virus in 1931. Since the discovery studies in the influenza have made immense progress and have contributed greatly to not only virology but also immunology and molecular biology.

Vitamin E supplementation decreases lung virus titers in mice infected with influenza.

Effects of vitamin E (E) supplementation on influenza infection were examined in young and old C57BL/6NIA mice fed 30 or 500 ppm of E for 6 weeks and subsequently infected with influenza A/Port Chalmers/1/73 (H3N2). Old mice fed 30 ppm of E had significantly higher lung virus titers on days 2 and 7 after infection than young mice fed 30 ppm of E. Titers on all 3 days were significantly lower in old mice fed 500 ppm of E than in those fed 30 ppm. Significant effects of E on lung virus titers in young mice were observed on only day 5, but E caused more reduction of virus titers in old than in young mice (25-fold vs. 15-fold). An age-associated decline in NK cell activity was restored by 500 ppm of E in old but not young mice. Pulmonary cytotoxic T lymphocyte activity on day 7 was not affected by age or E. These experiments demonstrate that high doses of E significantly enhance influenza viral clearance in aged mice but only modestly affect young mice.

[Studies on respiratory infections in primary care clinic (V). The pattern of distribution on bacteria, Mycoplasma pneumoniae and virus isolated from patients with respiratory infections, who were seen in six private clinics, and clinical efficacy of ciprofloxacin and roxithromycin].

The pattern of distribution of bacteria, Mycoplasma pneumoniae and virus isolated from the same specimen recovered from the throat swab or the sputum of 479 patients with respiratory infections who were seen in six private clinics in Sendai City of Japan during the period from October to November in 1992 (period I) and from January to February in 1993 (period II) was documented. Of the 479 patients, 234 had acute pharyngitis, 145 had acute bronchitis, 96 had influenza, 21 had acute tonsillitis, 5 had acute pneumonia and 9 had other respiratory infections. One hundred (42.4%) strains of potential pathogen and one strain of M. pneumoniae were recovered from 236 cases in period I, and 66 (27.2%) strains of potential pathogen, one strain of M. pneumonae and 73 strains of Influenza virus (30.0%: 43 of type A Hong-Kong and 30 of type B) from 243 cases in period II. Of the 166 strains, major isolates were Staphylococcus aureus (56 strains), Streptococcus pneumoniae (12 strains), Streptococcus pyogenes (15 strains), Haemophilus influenzae (17 strains), Esherichia coli (4 strains), Klebsiella spp. (35 strains), Pseudomonas aeruginosa (4 strains) and Acinetobacter spp. (23 strains). Only one strain of S. aureus was resistant to methicillin (MIC: 50 micrograms/ml). None of S. pneumoniae was resistant to 1 microgram/ml of ampicillin. Ciprofloxacin was administered to 113 cases and roxythromycin to 220 cases by doctors in charge.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of three highly purified influenza virus strains by electron microscopy.

Mass determinations on highly purified influenza virus preparations were performed using the technique of scanning transmission electron microscopy. The masses of the three strains, X49, B/Singapore/222/79 and B/Hong Kong/8/73 were determined. The average value was 174 X 10(6) daltons with only small differences between the three strains. The mass of virus particles after removal of the protruding spike proteins, haemagglutinin and neuraminidase by bromelain treatment was determined to be 86 X 10(6) daltons. From the mass difference and the known molecular weight of the spike proteins the number of spikes was estimated to lie in the range 400 to 500.

Purification of influenza virus with Arcton 113.

Arcton 113 has proved effective in the removal of host membrane fragments which cosediment with influenza virus during differential centrifugation. The virus appeared morphologically undamaged by the procedure and retained its infectivity, neuraminidase, and hemagglutinating activity. Pyrogenicity, however, was considerably reduced.

Host defenses against influenza virus: the role of anti-hemagglutinin antibody.

In CBA mice the protection provided by transferred immune spleen cells or by antibody has been investigated in immunologically intact, cyclophosphamide-treated and thymus-deprived animals infected with A/PR8 virus. The degree of protection was more closely related to serum antibody levels than to the presence of immune lymphocytes in recipients. Comparison of the protective efficiency of various anti-influenza antisera with different specificities within an influenza A subtype indicated that antibodies recognizing the strain-specific determinants of the influenza hemagglutinin have an important role in protection. Physiologic amounts of transferred antibodies were shown to protect immunodepressed mice, suggesting that, provided a sufficient amount of specific antibodies is secreted, the participation of effectors of cell-mediated immunity is not essential. However, our results suggest that thymus-derived lymphocytes have an indirect role in protection by enhancing, through their helper effect, the secretion of anti-influenza antibodies.

Influence of antibody-mediated immune suppression on clinical, viral, and immune responses to swine influenza infection.

Antibody-mediated immune suppression occurred when newborn pigs with naturally acquired passive antibody were exposed to seine influenza virus. Frequency and relative ease of recovery of virus from nasal secretions were inversely related to the concentration of specific passive antibody existing at time of exposure. Severe overt respiratory signs during the acute stages of the disease were observed only in pigs with low passive antibody concentrations. The concentration of passive antibody at the time of exposure determined the immune status of the pig during the convalescent stage of disease. Infection could occur in the presence of high passive antibody concentrations, but the pig was not immunologically stimulated. Reexposure after the decay of passive antibody produced primary immune respone, severe clinical reinfection, and recovery of virus from nasal secretions for a period of time similar to that seen in pigs having their first exposure. Infection of newborn pigs with low passive antibody concentrations led to immunologic priming. A second exposure to virus produced a secondary immune response, mild clinical disease, and shortened time during which virus was recovered from nasal secretions. The relevance of these studies for the practice of vaccination or infections of the dam before parturition so that the neonate will have specific passive immunity is discussed.