Publications by authors named "L Johnsen"
Intracranial atherosclerotic stenosis (ICAS) and intracranial aneurysms are prevalent conditions in the cerebrovascular system. ICAS causes a narrowing of the arterial lumen, thereby restricting blood flow, while aneurysms involve the ballooning of blood vessels. Both conditions can lead to severe outcomes, such as stroke or vessel rupture, which can be fatal.
View Article and Find Full Text PDFThroughout the COVID-19 pandemic, the emergence of new viral variants has challenged public health efforts, often evading antibody responses generated by infections and vaccinations. This immune escape has led to waves of breakthrough infections, raising questions about the efficacy and durability of immune protection. Here we focus on the impact of SARS-CoV-2 Delta and Omicron spike mutations on ACE-2 receptor binding, protein stability, and immune response evasion.
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- - Familial hemiplegic migraine type 2 (FHM2) is associated with mutations in the Na,K-ATPase α isoform, like G301R, which causes issues in blood flow regulation in the brain by affecting Src kinase signaling.
- - In a study with mice carrying the G301R mutation, increased cerebral artery tone and exaggerated responses to stimulation were observed; however, treatment with pNaKtide normalized these issues by targeting the problematic signaling pathway.
- - The treatment with pNaKtide improved cerebral blood flow and neurovascular coupling in the mutant mice, while only slightly affecting blood pressure, indicating it as a promising therapeutic approach for FHM2.
Regulation of cerebrospinal fluid (CSF) pH and brain pH are vital for all brain cells. The acute regulation of CSF pH is dependent on the transport of HCO across the choroid plexus in the brain ventricles. Acute regulation in response to acidosis is dependent on H export and HCO import across the plasma membrane.
View Article and Find Full Text PDFBackground: Quantitative imaging biomarkers (QIBs) can characterize tumor heterogeneity and provide information for biological guidance in radiotherapy (RT). Time-dependent diffusion MRI (TDD-MRI) derived parameters are promising QIBs, as they describe tissue microstructure with more specificity than traditional diffusion-weighted MRI (DW-MRI). Specifically, TDD-MRI can provide information about both restricted diffusion and diffusional exchange, which are the two time-dependent effects affecting diffusion in tissue, and relevant in tumors.
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