Publications by authors named "Hasler F"

Article Synopsis
  • Vaccines typically rely on T lymphocytes for B-cell activity and memory, but the study shows that specific peptide and adjuvant combinations can induce antibody responses without T-cell help.
  • Mice immunized with liposomes carrying 15mer peptides and monophosphoryl lipid A (MPLA) exhibited a rapid IgG class switch and long-lasting antibody responses, highlighting a novel mechanism of T-cell independent antibody production.
  • This T-cell independent response could be beneficial in situations where T-cell immunity is impaired or when immediate antibody protection is required, indicating potential for new vaccine strategies.
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Introduction: Since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), substantial effort has been made to gain knowledge about the immunity elicited by infection or vaccination.

Methods: We studied the kinetics of antibodies and virus neutralisation induced by vaccination with BNT162b2 in a Swiss cohort of SARS-CoV-2 naïve (n = 40) and convalescent (n = 9) persons. Blood sera were analysed in a live virus neutralisation assay and specific IgG and IgA levels were measured by enzyme-linked immunoassay and analysed by descriptive statistics.

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For a cytopathic virus such as severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), the neutralization capacity of serum from convalescent or vaccinated persons or of therapeutic antibodies can be tested on adherent cell cultures. Here, a simple and tissue culture infectious dose-derived protocol for assessment of neutralization of SARS-CoV-2 is described. Compared with the often applied plaque-forming unit assay, the working load is lower, and fewer manipulations of the infected cultures are required.

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The cytosolic metalloenzyme leukotriene A hydrolase (LTA4H) is the final and rate-limiting enzyme in the biosynthesis of pro-inflammatory leukotriene B (LTB). Preclinical studies have validated this enzyme as an attractive drug target in chronic inflammatory diseases. Despite several attempts, no LTA4H inhibitor has reached the market, yet.

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Hidradenitis suppurativa (HS) is a chronic, recurring inflammatory dermatosis characterized by abscesses, deep-seated nodules, sinus tracts, and fibrosis in skin lesions around hair follicles of the axillary, inguinal, and anogenital regions. Whereas the exact pathogenesis remains poorly defined, clear evidence suggests that HS is a multifactorial inflammatory disease characterized by innate and adaptive immune components. Bioactive lipids are important regulators of cutaneous homeostasis, inflammation, and resolution of inflammation.

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Cytotoxic T lymphocytes (CTLs) are key players in fighting cancer, and their induction is a major focus in the design of therapeutic vaccines. Yet, therapeutic vaccine efficacy is limited, in part due to the suboptimal vaccine processing by antigen-presenting cells (APCs). Such processing typically takes place via the MHC class II pathway for CD4 T-cell activation and MHC class I pathway for activation of CD8 CTLs.

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Increased airway hyperresponsiveness and epithelial remodeling in asthmatic LTAH-KO mice may be mediated by CysLTs rather than elevated tripeptide PGP.

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Leukotriene A4 Hydrolase (LTA4H) is a bifunctional zinc metalloenzyme that comprises both epoxide hydrolase and aminopeptidase activity, exerted by two overlapping catalytic sites. The epoxide hydrolase function of the enzyme catalyzes the biosynthesis of the pro-inflammatory lipid mediator leukotriene (LT) B4. Recent literature suggests that the aminopeptidase function of LTA4H is responsible for degradation of the tripeptide Pro-Gly-Pro (PGP) for which neutrophil chemotactic activity has been postulated.

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Background: Aggregation of peptide hormone precursors in the trans-Golgi network is an essential process in the biogenesis of secretory granules in endocrine cells. It has recently been proposed that this aggregation corresponds to the formation of functional amyloids. Our previous finding that dominant mutations in provasopressin, which cause cell degeneration and diabetes insipidus, prevent native folding and produce fibrillar aggregates in the endoplasmic reticulum (ER) might thus reflect mislocalized amyloid formation by sequences that evolved to mediate granule sorting.

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Neuroscience is a multidisciplinary effort to understand the structures and functions of the brain and brain-mind relations. This effort results in an increasing amount of data, generated by sophisticated technologies. However, these data enhance our , rather than improve our of brain functions.

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Background: Psoriatic arthritis (PsA) substantially impacts the management of psoriatic disease.

Objective: This study aimed to generate an interdisciplinary national consensus on recommendations of how PsA should be managed.

Methods: Based on a systematic literature search, an interdisciplinary expert group identified important domains and went through 3 rounds of a Delphi exercise, followed by a nominal group discussion to generate specific recommendations.

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Although alterations of serotonin (5-HT) system functioning have been proposed for a variety of psychiatric disorders, a direct method quantitatively assessing 5-HT release capacity in the living human brain is still lacking. Therefore, we evaluated a novel method to assess 5-HT release capacity in vivo using dexfenfluramine challenge and [(18)F]altanserin positron emission tomography (PET). Thirteen healthy male subjects received placebo and single oral doses of 40 mg (n = 6) or 60 mg (n = 7) of the potent 5-HT releaser dexfenfluramine separated by an interval of 14 days.

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Psilocybin and related hallucinogenic compounds are increasingly used in human research. However, due to limited information about potential subjective side effects, the controlled medical use of these compounds has remained controversial. We therefore analysed acute, short- and long-term subjective effects of psilocybin in healthy humans by pooling raw data from eight double-blind placebo-controlled experimental studies conducted between 1999 and 2008.

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[(18)F]altanserin is the preferred radiotracer for in-vivo labeling of serotonin 2A receptors by positron emission tomography (PET). We report a modified synthesis procedure suited for reliable production of multi-GBq amounts of [(18)F]altanserin useful for application in humans. We introduced thermal heating for drying of [(18)F]fluoride as well as for the reaction instead of microwave heating.

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Since the discovery of fullerenes in 1985, these carbon nanospheres have attracted attention regarding their physico/chemical properties. Despite little knowledge about their impact on the environment and human health, the production of fullerenes has already reached an industrial scale. However, the toxicity of C(60) is still controversially discussed.

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Serotonin (5-HT) release is the primary pharmacological mechanism of 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') action in the primate brain. Dopamine release and direct stimulation of dopamine D2 and serotonin 5-HT2A receptors also contributes to the overall action of MDMA. The role of 5-HT1A receptors in the human psychopharmacology of MDMA, however, has not yet been elucidated.

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Action of a hallucinogenic substance, psilocybin, on internal time representation was investigated in two double-blind, placebo-controlled studies: Experiment 1 with 12 subjects and graded doses, and Experiment 2 with 9 subjects and a very low dose. The task consisted in repeated reproductions of time intervals in the range from 1.5 to 5s.

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Objective: To test if a combination of biomarkers can increase the classification power of autoantibodies to cyclic citrullinated peptides (anti-CCP) in the diagnosis of rheumatoid arthritis (RA) depending on the diagnostic situation.

Methods: Biomarkers were subject to three inclusion/exclusion criteria (discrimination between RA patients and healthy blood donors, ability to identify anti-CCP-negative RA patients, specificity in a panel with major non-rheumatological diseases) before univariate ranking and multivariate analysis was carried out using a modelling panel (n = 906). To enable the evaluation of the classification power in different diagnostic settings the disease controls (n = 542) were weighted according to the admission rates in rheumatology clinics modelling a clinic panel or according to the relative prevalences of musculoskeletal disorders in the general population seen by general practitioners modelling a GP panel.

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Rationale: Binocular rivalry occurs when different images are simultaneously presented to each eye. During continual viewing of this stimulus, the observer will experience repeated switches between visual awareness of the two images. Previous studies have suggested that a slow rate of perceptual switching may be associated with clinical and drug-induced psychosis.

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Hallucinogenic psilocybin is known to alter the subjective experience of time. However, there is no study that systematically investigated objective measures of time perception under psilocybin. Therefore, we studied dose-dependent effects of the serotonin (5-HT)2A/1A receptor agonist psilocybin (4-phosphoryloxy-N, N-dimethyltryptamine) on temporal processing, employing tasks of temporal reproduction, sensorimotor synchronization and tapping tempo.

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Increasing evidence suggests a link between attention, working memory, serotonin (5-HT), and prefrontal cortex activity. In an attempt to tease out the relationship between these elements, this study tested the effects of the hallucinogenic mixed 5-HT1A/2A receptor agonist psilocybin alone and after pretreatment with the 5-HT2A antagonist ketanserin. Eight healthy human volunteers were tested on a multiple-object tracking task and spatial working memory task under the four conditions: placebo, psilocybin (215 microg/kg), ketanserin (50 mg), and psilocybin and ketanserin.

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Binocular rivalry occurs when different images are presented simultaneously to corresponding points within the left and right eyes. Under these conditions, the observer's perception will alternate between the two perceptual alternatives. Motivated by the reported link between the rate of perceptual alternations, symptoms of psychosis and an incidental observation that the rhythmicity of perceptual alternations during binocular rivalry was greatly increased 10 h after the consumption of LSD, this study aimed to investigate the pharmacology underlying binocular rivalry and to explore the connection between the timing of perceptual switching and psychosis.

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Objective: To identify a panel of candidate protein biomarkers of rheumatoid arthritis (RA) that can predict which patients will develop erosive, disabling disease.

Methods: A 2-step proteomic approach was used for biomarker discovery and verification. In the first step, 2-dimensional liquid chromatography-coupled tandem mass spectrometry was used to generate protein profiles of synovial fluid (SF) from patients with either erosive RA (n = 5) or nonerosive RA (n = 5).

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Patients suffering from schizophrenia are known to show an increased prevalence of nicotine addiction. The aim of this paper is to elucidate the relationship between schizophrenia and (chronic) use of nicotine. Nicotine seems to improve cognitive functions critically affected in schizophrenia, in particular sustained attention, focused attention, working memory, short-term memory, and recognition memory.

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