Virus discovery in chronic inflammatory demyelinating polyneuropathy.

The events triggering and/or sustaining the auto-immune response underlying chronic inflammatory demyelinating polyneuropathy (CIDP) are unknown. Similar to Guillain-Barré syndrome (GBS), a viral infection might play a role in CIDP. In this study, an virus detection method (VIDISCA-next generation sequencing) capable of detecting known and unknown viruses, was used to analyze the virome in serum of 47 CIDP patients at different time points of the disease and, when available, in cerebrospinal fluid (CSF) samples (N: 17). Serum samples of GBS patients (N:24) and healthy controls (N:114) were used for comparisons. In 5/47 (10.6%; 95% CI: 4-23) CIDP samples, 10/24 (42%; 95% CI: 22-63) GBS samples and 32/114 (28.1%; 95% CI: 20-37) healthy controls samples, anelloviruses were detected, generally regarded as a non-pathogenic species. Parvovirus B19 and GB virus C were found in two CIDP samples (4%). Parvovirus B19, HIV-1 and GB virus C were found in three GBS samples (13%). In 2/17 CIDP CSF samples, an anellovirus and polyomavirus were detected, probably due to contamination during lumbar puncture. No sequences of other viruses were detected in serum or CSF. A (persistent) viral infection sustaining the auto-immune response in CIDP seems therefore unlikely.

Diagnostic accuracy of VIDISCA-NGS in patients with suspected central nervous system infections.

OBJECTIVES: Confirming the diagnosis in viral central nervous system (CNS) infections can be difficult with the currently available diagnostic tools. Virus discovery cDNA-amplified fragment length polymorphism next-generation sequencing (VIDISCA-NGS) is a promising viral metagenomic technique that enables the detection of all viruses in a single assay. We performed a retrospective study on the diagnostic accuracy of VIDISCA-NGS in cerebrospinal fluid (CSF) of individuals with suspected CNS infections. METHODS: Consecutive adult patients presenting to the Emergency Department or inpatients, who underwent a lumbar puncture for the suspicion of a CNS infection, were included if they were diagnosed with a viral CNS infection, or if a viral CNS infection was initially suspected but eventually a different diagnosis was made. A quantitative PCR panel of the most common causative viruses was performed on CSF of these patients as reference standard and compared with the results of VIDISCA-NGS, the index test. RESULTS: We included 38 individuals with viral CNS infections and 35 presenting with suspected CNS infection for whom an alternative aetiology was finally established. Overall sensitivity and specificity were 52% (95% CI 31%-73%) and 100% (95% CI 91%-100%), respectively. One enterovirus, detected by VIDISCA-NGS, was only identified by quantitative PCR upon retesting. Additional viruses identified by VIDISCA-NGS consisted of GB virus C, human papillomavirus, human mastadenovirus C, Merkel cell polyoma virus and anelloviruses. CONCLUSION: In patients for whom routine diagnostics do not yield a causative pathogen, VIDISCA-NGS can be of additional value as it can detect a broader range of viruses, but it does not perform well enough to replace quantitativePCR.

Flexible and static wrist units in upper limb prosthesis users: functionality scores, user satisfaction and compensatory movements.

BACKGROUND: The current study examines the relevance of prosthetic wrist movement to facilitate activities of daily living or to prevent overuse complaints. Prosthesis hands with wrist flexion/extension capabilities are commercially available, but research on the users' experiences with flexible wrists is limited. METHODS: In this study, eight transradial amputees using a myoelectric prosthesis tested two prosthesis wrists with flexion/extension capabilities, the Flex-wrist (Otto Bock) and Multi-flex wrist (Motion Control), in their flexible and static conditions. Differences between the wrists were assessed on the levels of functionality, user satisfaction and compensatory movements after two weeks use. RESULTS: No significant differences between flexible and static wrist conditions were found on activity performance tests and standardized questionnaires on satisfaction. Inter-individual variation was remarkably large. Participants' satisfaction tended to be in favour of flexible wrists. All participants but one indicated that they would choose a prosthesis hand with wrist flexion/extension capabilities if allowed a new prosthesis. Shoulder joint angles, reflecting compensatory movements, showed no clear differences between wrist conditions. CONCLUSIONS: Overall, positive effects of flexible wrists are hard to objectify. Users seem to be more satisfied with flexible wrists. A person's needs, work and prosthesis skills should be taken into account when prescribing a prosthesis wrist. TRIAL REGISTRATION: Nederlands Trial Register NTR3984 .

Changes in microbiota during experimental human Rhinovirus infection.

BACKGROUND: Human Rhinovirus (HRV) is responsible for the majority of common colds and is frequently accompanied by secondary bacterial infections through poorly understood mechanisms. We investigated the effects of experimental human HRV serotype 16 infection on the upper respiratory tract microbiota. METHODS: Six healthy volunteers were infected with HRV16. We performed 16S ribosomal RNA-targeted pyrosequencing on throat swabs taken prior, during and after infection. We compared overall community diversity, phylogenetic structure of the ecosystem and relative abundances of the different bacteria between time points. RESULTS: During acute infection strong trends towards increases in the relative abundances of Haemophilus parainfluenzae and Neisseria subflava were observed, as well as a weaker trend towards increases of Staphylococcus aureus. No major differences were observed between day-1 and day 60, whereas differences between subjects were very high. CONCLUSIONS: HRV16 infection is associated with the increase of three genera known to be associated with secondary infections following HRV infections. The observed changes of upper respiratory tract microbiota could help explain why HRV infection predisposes to bacterial otitis media, sinusitis and pneumonia.

Localization and membrane topology of coronavirus nonstructural protein 4: involvement of the early secretory pathway in replication.

The coronavirus nonstructural proteins (nsp's) derived from the replicase polyproteins collectively constitute the viral replication complexes, which are anchored to double-membrane vesicles. Little is known about the biogenesis of these complexes, the membrane anchoring of which is probably mediated by nsp3, nsp4, and nsp6, as they contain several putative transmembrane domains. As a first step to getting more insight into the formation of the coronavirus replication complex, the membrane topology, processing, and subcellular localization of nsp4 of the mouse hepatitis virus (MHV) and severe acute respiratory syndrome-associated coronavirus (SARS-CoV) were elucidated in this study. Both nsp4 proteins became N glycosylated, while their amino and carboxy termini were localized to the cytoplasm. These observations imply nsp4 to assemble in the membrane as a tetraspanning transmembrane protein with a Nendo/Cendo topology. The amino terminus of SARS-CoV nsp4, but not that of MHV nsp4, was shown to be (partially) processed by signal peptidase. nsp4 localized to the endoplasmic reticulum (ER) when expressed alone but was recruited to the replication complexes in infected cells. nsp4 present in these complexes did not colocalize with markers of the ER or Golgi apparatus, while the susceptibility of its sugars to endoglycosidase H indicated that the protein had also not traveled trough the latter compartment. The important role of the early secretory pathway in formation of the replication complexes was also demonstrated by the inhibition of coronaviral replication when the ER export machinery was blocked by use of the kinase inhibitor H89 or by expression of a mutant, Sar1[H79G].