Faculty Opinions recommendation of Highly conserved protective epitopes on influenza B viruses.

Author(s):  
Albert Osterhaus
Keyword(s):  
Author(s):  
P.M. Frederik ◽  
K.N.J. Burger ◽  
M.C.A. Stuart ◽  
A.J. Verkleij

Cellular membranes are often composed of phospholipid mixtures in which one or more components have a tendency to adopt a type II non-bilayer lipid structure such as the inverted hexagonal (H||) phase. The formation of a type II non-bilayer intermediate, the inverted lipid micel is proposed as the initial step in membrane fusion (Verkleij 1984, Siegel, 1986). In the various forms of cellular transport mediated by carrier vesicles (e.g. exocytosis, endocytosis) the regulation of membrane fusion, and hence of inverted lipid micel formation, is of vital importance.We studied the phase behaviour of simple and complex lipid mixtures by cryo-electron microscopy to gain more insight in the ultrastructure of different lipid phases (e.g. Pβ’, Lα, H||) and in the complex membrane structures arising after Lα < - > H|| phase changes (e.g. isotropic, cubic). To prepare hydrated thin films a 700 mesh hexagonal grid (without supporting film) was dipped into and withdrawn from a liposome suspension. The excess fluid was blotted against filter paper and the thin films that form between the bars of the specimen grid were immediately (within 1 second) vitrified by plunging of the carrier grids into ethane cooled to its melting point by liquid nitrogen (Dubochet et al., 1982). Surface active molecules such as phospholipids play an important role in the formation and thinning of these aqueous thin films (Frederik et al., 1989). The formation of two interfacial layers at the air-water interfaces requires transport of surface molecules from the suspension as well as the orientation of these molecules at the interfaces. During the spontaneous thinning of the film the interfaces approach each other, initially driven by capillary forces later by Van der Waals attraction. The process of thinning results in the sorting by size of the suspended material and is also accompanied by a loss of water from the thinner parts of the film. This loss of water may result in the concentration and eventually in partial dehydration of suspended material even if thin films are vitrified within 1 sec after their formation. Film formation and vitrification were initiated at temperatures between 20-60°C by placing die equipment in an incubator provided widi port holes for the necessary manipulations. Unilamellar vesicles were made from dipalmitoyl phosphatidyl choline (DPPC) by an extrusion method and showed a smooth (Lα) or a rippled (PB’.) structure depending on the temperature of the suspensions and the temperature of film formation (50°C resp. 39°C) prior to vitrification. The thermotropic phases of hydrated phospholipids are thus faithfully preserved in vitrified thin films (fig. a,b). Complex structures arose when mixtures of dioleoylphosphatidylethanol-amine (DOPE), dioleoylphosphatidylcholine (DOPC) and cholesterol (molar ratio 3/1/2) are heated and used for thin film formation. The tendency of DOPE to adopt the H|| phase is responsible for the formation of complex structures in this lipid mixture. Isotropic and cubic areas (fig. c,d) having a bilayer structure are found in coexistence with H|| cylinders (fig. e). The formation of interlamellar attachments (ILA’s) as observed in isotropic and cubic structures is also thought to be of importance in biological fusion events. Therefore the study of the fusion activity of influenza B virus with liposomes (DOPE/DOPC/cholesterol/ganglioside in a molar ratio 1/1/2/0.2) was initiated. At neutral pH only adsorption of virus to liposomes was observed whereas 2 minutes after a drop in pH (7.4 - > 5.4) fusion between virus and liposome membranes was demonstrated (fig. f). The micrographs illustrate the exciting potential of cryo-electron microscopy to study lipid-lipid and lipid-protein interactions in hydrated specimens.


2007 ◽  
Vol 41 (5) ◽  
pp. 17
Author(s):  
MARY ANN MOON
Keyword(s):  

2008 ◽  
Vol 08 (02) ◽  
pp. 105-107
Author(s):  
Andreas Merkenschlager ◽  
Wolfgang Hirsch ◽  
Volker Schuster ◽  
Matthias Bernhard

ZusammenfassungDie akute disseminierte Enzephalomyelitis (ADEM) ist eine meist monophasische demyelinisierende Erkrankung des ZNS, welche häufig zeitlich 1–4 Wochen nach einer Infektion oder sehr selten nach einer Impfung auftritt. Das klinische Bild einer ADEM kann sehr variabel sein, was insbesondere bei initial unauffälligen oder untypischen Befunden der Magnetresonanztomographie (MRT) des Schädel die Diagnose erschwert.Fallbericht: Ein 12-jähriger Junge klagte über seit 3 Wochen bestehende progrediente Kopfschmerzen und zunehmendes Nüchternerbrechen. Im initialen Magnetresonanztomogramm des Schädel waren nur zwei unspezifische hyperdense Signalintensitäten zu erkennen, die zunächst als Hamartome interpretiert wurden. Die ophthalmologische Untersuchung zeigte ein Papillödem mit einer maximalen Prominenz von 1,5 mm beidseits. Im Liquor war eine Pleozytose mit 41 Mpt/l Zellen nachweisbar, der Liquorausflussdruck war deutlich erhöht. Die Titer für Influenza B wiesen auf eine akute beziehungsweise kürzlich abgelaufene Infektion hin. Eine bei bestehender Klinik veranlasste MRTSchädel- Kontrolle nach drei Wochen zeigte multiple neue hyperdense Areale im Sinne einer ADEM. Unter einer Methylprednisolon- Stoßtherapie wurde der Patient wieder beschwerdefrei, die MRT-Auffälligkeiten und das Papillödem bildeten sich wieder vollständig zurück.Diskussion: Ein erhöhter Hirndruck mit begleitendem Papillödem sowie Kopfschmerzen und Nüchternerbrechen sind als hervorstechende Symptomatik einer ADEM sehr selten beschrieben. Die der ADEM zuzuschreibende Klinik kann sich offenbar auch langsam über mehrere Wochen entwickeln. Da in diesen Fällen möglicherweise im initialen Magnetresonanztomogramm des Schädels teilweise noch keine eindeutigen Demyelinisierungsherde zu sehen sind, sollte bei fortbestehenden klinischen Auffälligkeiten die zerebrale Bildgebung großzügig kontrolliert werden.


2013 ◽  
Vol 19 (3) ◽  
pp. 511-512 ◽  
Author(s):  
Rogier Bodewes ◽  
Danny Morick ◽  
Gerrie de Mutsert ◽  
Nynke Osinga ◽  
Theo Bestebroer ◽  
...  

Author(s):  
Benjamin W Teh ◽  
Vivian K Y Leung ◽  
Francesca L Mordant ◽  
Sheena G Sullivan ◽  
Trish Joyce ◽  
...  

Abstract Background Seroprotection and seroconversion rates are not well understood for 2-dose inactivated influenza vaccination (IIV) schedules in autologous hematopoietic stem cell transplantation (autoHCT) patients. Methods A randomized, single-blind, controlled trial of IIV in autoHCT patients in their first year post-transplant was conducted. Patients were randomized 1:1 to high-dose (HD) IIV followed by standard dose (SD) vaccine (HD-SD arm) or 2 SD vaccines (SD-SD arm) 4 weeks apart. Hemagglutination inhibition (HI) assay for IIV strains was performed at baseline, 1, 2, and 6 months post–first dose. Evaluable primary outcomes were seroprotection (HI titer ≥40) and seroconversion (4-fold titer increase) rates and secondary outcomes were geometric mean titers (GMTs), GMT ratios (GMRs), adverse events, influenza-like illness (ILI), and laboratory-confirmed influenza (LCI) rates and factors associated with seroconversion. Results Sixty-eight patients were enrolled (34/arm) with median age of 61.5 years, majority male (68%) with myeloma (68%). Median time from autoHCT to vaccination was 2.3 months. For HD-SD and SD-SD arms, percentages of patients achieving seroprotection were 75.8% and 79.4% for H1N1, 84.9% and 88.2% for H3N2 (all P &gt; .05), and 78.8% and 97.1% for influenza-B/Yamagata (P = .03), respectively. Seroconversion rates, GMTs and GMRs, and number of ILI or LCIs were not significantly different between arms. Adverse event rates were similar. Receipt of concurrent cancer therapy was independently associated with higher odds of seroconversion (OR, 4.3; 95% CI, 1.2–14.9; P = .02). Conclusions High seroprotection and seroconversion rates against all influenza strains can be achieved with vaccination as early as 2 months post-autoHCT with either 2-dose vaccine schedules. Clinical Trials Registration Australian New Zealand Clinical Trials Registry: ACTRN12619000617167.


PLoS ONE ◽  
2015 ◽  
Vol 10 (1) ◽  
pp. e0116302 ◽  
Author(s):  
Nipaporn Tewawong ◽  
Kamol Suwannakarn ◽  
Slinporn Prachayangprecha ◽  
Sumeth Korkong ◽  
Preeyaporn Vichiwattana ◽  
...  

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Guohong Zhu ◽  
Dan Xu ◽  
Yuanyuan Zhang ◽  
Tianlin Wang ◽  
Lingyan Zhang ◽  
...  

Abstract Background Viruses are the main infectious agents of acute respiratory infections in children. We aim to describe the epidemiological characteristics of viral pathogens of acute respiratory tract infections in outpatient children. Methods From April 2018 to March 2019, the results of viral detection using oral pharyngeal swabs from 103,210 children with acute respiratory tract infection in the outpatient department of the Children’s Hospital, Zhejiang University School of Medicine, were retrospectively analyzed. Viral antigens, including adenovirus (ADV), influenza A (FLUA), influenza B (FLUB) and respiratory syncytial virus (RSV), were detected by the colloidal gold method. Results At least one virus was detected in 38,355 cases; the positivity rate was 37.2%. A total of 1910 cases of mixed infection with two or more viruses were detected, and the positivity rate of multiple infection was 1.9%. The ADV positivity rate was highest in the 3–6-year-old group (18.7%), the FLUA positivity rate was highest in the > 6-year-old group (21.6%), the FLUB positivity rate was highest in the > 6-year-old group (6.6%), and the RSV positivity rate was highest in the < 1-year-old group (10.6%). There was a significant difference in the positivity rate of viral infection among different age groups (χ2 = 1280.7, P < 0.001). The rate of positive viral infection was highest in winter (47.1%). The ADV infection rate was highest in spring (18.2%). The rates of FLUA and FLUB positivity were highest in winter (28.8% and 3.6%, respectively). The rate of RSV positivity was highest in autumn (17.4%). The rate of positive viral infection in different seasons was significantly different (χ2 = 6459.1, P < 0.001). Conclusions Viral infection rates in children differ for different ages and seasons. The positivity rate of ADV is highest in the preschool period and that of RSV is highest in infants; that of FLU increases with age. The total positive rate of viral infection in different seasons is highest in winter, as is the rate of FLU positivity.


Author(s):  
Emily S. Bailey ◽  
Xinye Wang ◽  
Mai-juan Ma ◽  
Guo-lin Wang ◽  
Gregory C. Gray

AbstractInfluenza viruses are an important cause of disease in both humans and animals, and their detection and characterization can take weeks. In this study, we sought to compare classical virology techniques with a new rapid microarray method for the detection and characterization of a very diverse, panel of animal, environmental, and human clinical or field specimens that were molecularly positive for influenza A alone (n = 111), influenza B alone (n = 3), both viruses (n = 13), or influenza negative (n = 2) viruses. All influenza virus positive samples in this study were first subtyped by traditional laboratory methods, and later evaluated using the FluChip-8G Insight Assay (InDevR Inc. Boulder, CO) in laboratories at Duke University (USA) or at Duke Kunshan University (China). The FluChip-8G Insight multiplexed assay agreed with classical virologic techniques 59 (54.1%) of 109 influenza A-positive, 3 (100%) of the 3 influenza B-positive, 0 (0%) of 10 both influenza A- and B-positive samples, 75% of 24 environmental samples including those positive for H1, H3, H7, H9, N1, and N9 strains, and 80% of 22 avian influenza samples. It had difficulty with avian N6 types and swine H3 and N2 influenza specimens. The FluChip-8G Insight assay performed well with most human, environmental, and animal samples, but had some difficulty with samples containing multiple viral strains and with specific animal influenza strains. As classical virology methods are often iterative and can take weeks, the FluChip-8G Insight Assay rapid results (time range 8 to 12 h) offers considerable time savings. As the FluChip-8G analysis algorithm is expected to improve over time with addition of new subtypes and sample matrices, the FluChip-8G Insight Assay has considerable promise for rapid characterization of novel influenza viruses affecting humans or animals.


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