Detection of in vivo hepatitis B virus surface antigen mutations-A comparison of four routine screening assays.

An important requirement for a state-of-the-art hepatitis B surface antigen (HBsAg) screening assay is reliable detection of mutated HBsAg. Currently, there is a striking shortage of data regarding the detection rates of in vivo HBsAg mutations for these clinically important assays. Therefore, we compared the detection rates of four commercial HBsAg screening assays using a global cohort of 1553 patients from four continents with known HBV genotypes. These samples, which represent the broadest spectrum of known and novel HBsAg major hydrophilic region (MHR) mutations to date, were analyzed for the presence of HBsAg using the Roche Elecsys® HBsAg II Qualitative, Siemens ADVIA Centaur XP HBsAg II, Abbott Architect HBsAg Qualitative II and DiaSorin Liaison® HBsAg Qualitative assays, respectively. Of the 1553 samples, 1391 samples could be sequenced; of these, 1013 (72.8%) carried at least one of the 345 currently known amino acid substitutions (distinct HBsAg mutation) in the HBsAg MHR. All 1553 patient samples were positive for HBsAg using the Elecsys® HBsAg II Qual assay, with a sensitivity (95% confidence interval) of 99.94% (99.64%-100%), followed by the Abbott Architect 99.81% (99.44%-99.96%), Siemens ADVIA 99.81% (99.44%-99.96%) and DiaSorin Liaison® 99.36% (98.82%-99.69%) assays, respectively. Our results indicate that the Elecsys® HBsAg II Qual assay exhibits the highest sensitivity among the commercial HBsAg screening assays, and demonstrate that its capacity to detect HBV infection is not compromised by HBsAg MHR mutants.

Outer membrane vesicles of Tannerella forsythia: biogenesis, composition, and virulence.

Tannerella forsythia is the only 'red-complex' bacterium covered by an S-layer, which has been shown to affect virulence. Here, outer membrane vesicles (OMVs) enriched with putative glycoproteins are described as a new addition to the virulence repertoire of T. forsythia. Investigations of this bacterium are hampered by its fastidious growth requirements and the recently discovered mismatch of the available genome sequence (92A2 = ATCC BAA-2717) and the widely used T. forsythia strain (ATCC 43037). T. forsythia was grown anaerobically in serum-free medium and biogenesis of OMVs was analyzed by electron and atomic force microscopy. This revealed OMVs with a mean diameter of ~100 nm budding off from the outer membrane while retaining the S-layer. An LC-ESI-TOF/TOF proteomic analysis of OMVs from three independent biological replicates identified 175 proteins. Of these, 14 exhibited a C-terminal outer membrane translocation signal that directs them to the cell/vesicle surface, 61 and 53 were localized to the outer membrane and periplasm, respectively, 22 were predicted to be extracellular, and 39 to originate from the cytoplasm. Eighty proteins contained the Bacteroidales O-glycosylation motif, 18 of which were confirmed as glycoproteins. Release of pro-inflammatory mediators from the human monocytic cell line U937 and periodontal ligament fibroblasts upon stimulation with OMVs followed a concentration-dependent increase that was more pronounced in the presence of soluble CD14 in conditioned media. The inflammatory response was significantly higher than that caused by whole T. forsythia cells. Our study represents the first characterization of T. forsythia OMVs, their proteomic composition and immunogenic potential.

Patterns of non-conductive olfactory disorders in eastern Austria: a study of 120 patients from the Department of Otorhinolaryngology at the University of Vienna.

BACKGROUND: About 1% of the population suffer from disorders of the chemosensory system. In the United States at least two million people have problems related to smell and taste. The sense of smell enables the individual to determine the flavour of food and beverages and is most important as a sophisticated warning system. For the present investigation, we collected data on the age pattern and causes of olfactory disorders in eastern Austria. METHODS: 120 patients with non-conductive olfactory disorders were examined over a 9-month period starting from July 1998 at the outpatient clinic of the Ear Nose and Throat Department of the University of Vienna. Data concerning the underlying population taken from the 1998 population census in Vienna were used for comparison, in order to gain a more representative estimation of the distribution of these disorders. The diagnosis was based on thorough history taking, physical examination, CT scan, and olfactory testing for sensitivity by means of so-called "sniffin' sticks". RESULTS: The patients' ages ranged from 16 to 86 years (mean, 54.5 years; 74 females, 46 males). Those older than 50 years seem to have a higher risk of developing olfactory disorders. Only 15 of the female patients were pre-menopausal. Olfactory disorders were most frequently caused by viral infections in the upper respiratory tract (n = 51). Fifteen patients reported head trauma as a cause of olfactory loss, and 45 causes were idiopathic. Most of those in whom the olfactory disorder had been in existence for less than 3 months were anosmic (84%), very few were hyposmic (16% of a total of 19 patients). In contrast, 38% (of a total of 29 patients) in whom the disease had been in existence for 3 and 6 months were hyposmic. Parosmia was reported in 16 cases. Most parosmias appeared after viral infection (56%). Eight of the 120 patients reported dysgeusia. CONCLUSIONS: The present study is a first step towards an assessment of olfactory disorders in Austria. We found similar causes of non-conductive olfactory disorders as have been reported in the literature for other countries, namely upper respiratory infection leading to postviral olfactory disorders, and head trauma. With increasing age women seem to suffer more often from chemosensory dysfunction than men, which may be related to hormonal factors.