Publications by authors named "Stefan Hader"

Article Synopsis
  • Primary aldosteronism (PA) is a condition that can cause high blood pressure, often linked to a growth in the adrenal gland, and surgery can help fix it.
  • A study compared a safer, non-invasive test called MTO scanning with a more invasive test called AVS to see which one does a better job at predicting successful surgery outcomes for people with PA.
  • The results showed that the MTO scanning was just as good at predicting success as the invasive test, making it a useful option for diagnosing PA without the need for surgery first.
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The metabotropic glutamate receptor 5 (mGluR5) is a key regulator of excitatory (E) glutamate and inhibitory (I) γ-amino butyric acid (GABA) signalling in the brain. Despite the close functional ties between mGluR5 and E/I signalling, no-one has directly examined the relationship between mGluR5 and glutamate or GABA in vivo in the human brain of autistic individuals. We measured [F] FPEB (F-3-fluoro-5-[(pyridin-3-yl)ethynyl]benzonitrile) binding in 15 adults (6 with Autism Spectrum Disorder) using two regions of interest, the left dorsomedial prefrontal cortex and a region primarily composed of left striatum and thalamus.

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The receptor for advanced glycation end products (RAGE) is a viable target for early Alzheimer's disease (AD) diagnosis using positron emission tomography (PET) as RAGE overexpression precedes Aβ plaque formation. The development of a carbon-11 analog of FPS-ZM1 (N-benzyl-4-chloro-N-cyclohexylbenzamide, [C]FPS-ZM1), possessing nanomolar affinity for RAGE, may enable the imaging of RAGE for early AD detection. Herein we report an optimized [C]CO-to-[C]CO chemical conversion for the synthesis of [C]FPS-ZM1 and brain autoradiography.

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Ebselen, a potential new lithium-like drug, treatment reduced brain glutamate, as measured by PET imaging using the mGluR5 radioligand [ F]FPEB in rats.

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Competitive inhibitors of the influenza neuraminidase (NA) were discovered almost 20 years ago, with zanamivir and oseltamivir licensed globally. These compounds are based on a transition state analogue of the sialic acid substrate. We recently showed that 5- N-(acetylamino)-2,3,5-trideoxy-2,3-difluoro-d-erythro-β-l-manno-2-nonulopyranosonic acid (DFSA) and its derivatives are also potent inhibitors of the influenza NA.

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Cyclotron-produced carbon-11 is a highly valuable radionuclide for the production of positron emission tomography (PET) radiotracers. It is typically produced as relatively unreactive carbon-11 carbon dioxide ([ C]CO ), which is most commonly converted into a more reactive precursor for synthesis of PET radiotracers. The development of [ C]CO fixation methods has more recently enabled the direct radiolabelling of a diverse array of structures directly from [ C]CO , and the advantages afforded by the use of a loop-based system used in C-methylation and C-carboxylation reactions inspired us to apply the [ C]CO fixation "in-loop.

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Here we describe the successful syntheses of a series of 4-, 7-, 8- and 9-deoxygenated 2,3-difluoro-N-acetylneuraminic acid derivatives as potential mechanism-based inhibitors of sialidases. The syntheses commenced utilising an enzyme-catalysed aldolase reaction between N-acetyl mannosamine and β-fluoropyruvic acid to give 3-fluoro-N-acetyl-neuraminic acid. This common intermediate was then used in selective protection protocols and Barton-McCombie deoxygenations to generate the complete set of mono-deoxygenated 3-fluoro-N-acetylneuraminic acid derivatives.

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Aspergillus fumigatus is a filamentous fungus that can cause severe respiratory disease in immunocompromised individuals. A putative sialidase from A. fumigatus was recently cloned and shown to be relatively poor in cleaving N-acetylneuraminic acid (Neu5Ac) in comparison with bacterial sialidases.

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