Retinal hyperspectral imaging in mouse models of Parkinson's disease and healthy aging.

Retinal hyperspectral imaging (HSI) is a non-invasive in vivo approach that has shown promise in Alzheimer's disease. Parkinson's disease is another neurodegenerative disease where brain pathobiology such as alpha-synuclein and iron overaccumulation have been implicated in the retina. However, it remains unknown whether HSI is altered in in vivo models of Parkinson's disease, whether it differs from healthy aging, and the mechanisms which drive these changes.

Nutrient-sensitizing drug repurposing screen identifies lomerizine as a mitochondrial metabolism inhibitor of chronic myeloid leukemia.

In chronic myeloid leukemia (CML), the persistence of leukemic stem cells (LSCs) after treatment with tyrosine kinase inhibitors (TKIs), such as imatinib, can lead to disease relapse. It is known that therapy-resistant LSCs rely on oxidative phosphorylation (OXPHOS) for their survival and that targeting mitochondrial respiration sensitizes CML LSCs to imatinib treatment. However, current OXPHOS inhibitors have demonstrated limited efficacy or have shown adverse effects in clinical trials, highlighting that identification of clinically safe oxidative pathway inhibitors is warranted.

Bacteroidota inhibit microglia clearance of amyloid-beta and promote plaque deposition in Alzheimer's disease mouse models.

The gut microbiota and microglia play critical roles in Alzheimer's disease (AD), and elevated Bacteroides is correlated with cerebrospinal fluid amyloid-β (Aβ) and tau levels in AD. We hypothesize that Bacteroides contributes to AD by modulating microglia. Here we show that administering Bacteroides fragilis to APP/PS1-21 mice increases Aβ plaques in females, modulates cortical amyloid processing gene expression, and down regulates phagocytosis and protein degradation microglial gene expression.

Do Bacterial Outer Membrane Vesicles Contribute to Chronic Inflammation in Parkinson's Disease?

Parkinson's disease (PD) is an increasingly common neurodegenerative disease. It has been suggested that the etiology of idiopathic PD is complex and multifactorial involving environmental contributions, such as viral or bacterial infections and microbial dysbiosis, in genetically predisposed individuals. With advances in our understanding of the gut-brain axis, there is increasing evidence that the intestinal microbiota and the mammalian immune system functionally interact.

Isolated rapid eye movement sleep behaviour disorder (iRBD) in the Island Study Linking Ageing and Neurodegenerative Disease (ISLAND) Sleep Study: protocol and baseline characteristics.

Isolated rapid eye movement (REM) sleep behaviour disorder (iRBD) is a sleep disorder that is characterised by dream enactment episodes during REM sleep. It is the strongest known predictor of α-synuclein-related neurodegenerative disease (αNDD), such that >80% of people with iRBD will eventually develop Parkinson's disease, dementia with Lewy bodies, or multiple system atrophy in later life. More research is needed to understand the trajectory of phenoconversion to each αNDD.

Using F-AV-133 VMAT2 PET Imaging to Monitor Progressive Nigrostriatal Degeneration in Parkinson Disease.

Background And Objectives: There are limited validated biomarkers in Parkinson disease (PD) which substantially hinders the ability to monitor disease progression and consequently measure the efficacy of disease-modifying treatments. Imaging biomarkers, such as vesicular monoamine transporter type 2 (VMAT2) PET, enable enhanced diagnostic accuracy and detect early neurodegenerative changes associated with prodromal PD. This study sought to assess whether F-AV-133 VMAT2 PET is sensitive enough to monitor and quantify disease progression over a 2-year window.

How Well Do Rodent Models of Parkinson's Disease Recapitulate Early Non-Motor Phenotypes? A Systematic Review.

The prodromal phase of Parkinson's disease (PD) is characterised by many non-motor symptoms, and these have recently been posited to be predictive of later diagnosis. Genetic rodent models can develop non-motor phenotypes, providing tools to identify mechanisms underlying the early development of PD. However, it is not yet clear how reproducible non-motor phenotypes are amongst genetic PD rodent models, whether phenotypes are age-dependent, and the translatability of these phenotypes has yet to be explored.

ATH434 Rescues Pre-motor Hyposmia in a Mouse Model of Parkinsonism.

Hyposmia is a prevalent prodromal feature of Parkinson's disease (PD), though the neuropathology that underlies this symptom is poorly understood. Unlike the substantia nigra, the status of metal homeostasis in the olfactory bulbs has not been characterized in PD. Given the increasing interest in metal modulation as a therapeutic avenue in PD, we sought to investigate bulbar metals and the effect of AT434 (formerly PBT434) an orally bioavailable, small molecule modulator of metal homeostasis on hyposmia in a mouse model of parkinsonism (the tau knockout (tau) mouse).

5-Aminolevulinic acid-assisted resection of pediatric dysembryoplastic neuroepithelial tumor: illustrative case.

Background: 5-Aminolevulinic acid (5-ALA) is approved as an adjunct for the resection of high-grade gliomas and is associated with improved outcomes. Dysembryoplastic neuroepithelial tumors (DNETs) are benign glioneural tumors occurring primarily in pediatric patients and often manifesting with seizure disorder. The goal of the surgical intervention is to obtain gross-total resection, which is associated, in the majority of cases, with seizure freedom.

Methohexital for procedural sedation of cardioversions in the emergency department.

Background: Procedural sedation for electrical cardioversion is a common practice in the emergency department (ED). Ideal sedative properties for this procedure are a short half-life and minimal hemodynamic effects. There is limited literature examining methohexital for this use.

Reshaping the Preterm Heart: Shifting Cardiac Renin-Angiotensin System Towards Cardioprotection in Rats Exposed to Neonatal High-Oxygen Stress.

Background: Approximately 10% of infants are born preterm. Preterm birth leads to short and long-term changes in cardiac shape and function. By using a rat model of neonatal high-oxygen (80%O) exposure, mimicking the premature hyperoxic transition to the extrauterine environment, we revealed a major role of the renin-angiotensin system peptide Angio II (angiotensin II) and its receptor AT1 (angiotensin receptor type 1) on neonatal O-induced cardiomyopathy.

Loss-of-function and gain-of-function studies refute the hypothesis that tau protein is causally involved in the pathogenesis of Huntington's disease.

Tubulin-associated unit (Tau) is a microtubule-associated protein, whose abnormal phosphorylation and deposition in the brain characterizes a range of neurodegenerative diseases called tauopathies. Recent clinical (post-mortem) and pre-clinical evidence suggests that Huntington's disease (HD), an autosomal dominant neurodegenerative disorder, could be considered as a tauopathy. Studies have found the presence of hyperphosphorylated tau, altered tau isoform ratio and aggregated tau in HD brains.

Mitochondrial metabolism as a potential therapeutic target in myeloid leukaemia.

While the understanding of the genomic aberrations that underpin chronic and acute myeloid leukaemia (CML and AML) has allowed the development of therapies for these diseases, limitations remain. These become apparent when looking at the frequency of treatment resistance leading to disease relapse in leukaemia patients. Key questions regarding the fundamental biology of the leukaemic cells, such as their metabolic dependencies, are still unresolved.

Reduced striatal vesicular monoamine transporter 2 in REM sleep behavior disorder: imaging prodromal parkinsonism.

Motor deficits in parkinsonism are caused by degeneration of dopaminergic nigral neurons. The success of disease-modifying therapies relies on early detection of the underlying pathological process, leading to early interventions in the disease phenotype. Healthy (n = 16), REM sleep behavior disorder (RBD) (n = 14), dementia with Lewy bodies (n = 10), and Parkinson's disease (PD) (n = 20) participants underwent F-AV133 vesicular monoamine transporter type-2 (VMAT2) PET to determine the integrity of the nigrostriatal pathway.

Parkinsonism as a Third Wave of the COVID-19 Pandemic?

Since the initial reports of COVID-19 in December 2019, the world has been gripped by the disastrous acute respiratory disease caused by the SARS-CoV-2 virus. There are an ever-increasing number of reports of neurological symptoms in patients, from severe (encephalitis), to mild (hyposmia), suggesting the potential for neurotropism of SARS-CoV-2. This Perspective investigates the hypothesis that the reliance on self-reporting of hyposmia has resulted in an underestimation of neurological symptoms in COVID-19 patients.

S-Adenosylmethionine Rescues Cognitive Deficits in the rTg4510 Animal Model by Stabilizing Protein Phosphatase 2A and Reducing Phosphorylated Tau.

Background: Alterations in the methionine cycle and abnormal tau phosphorylation are implicated in many neurodegenerative diseases, including Alzheimer's disease and frontotemporal dementia. rTg4510 mice express mutant human P301L tau and are a model of tau hyperphosphorylation. The cognitive deficit seen in these animals correlates with a burden of hyperphosphorylated tau and is a model to test therapies aimed at lowering phosphorylated tau.

Practical Considerations for Radiologists in Implementing a Patient-friendly MRI Experience.

For many patients, numerous unpleasant features of the magnetic resonance imaging (MRI) experience such as scan duration, auditory noise, spatial confinement, and motion restrictions can lead to premature termination or low diagnostic quality of imaging studies. This article discusses practical, patient-oriented considerations that are helpful for radiologists contemplating ways to improve the MRI experience for patients. Patient friendly scanner properties are discussed, with an emphasis on literature findings of effectiveness in mitigating patient claustrophobia, other anxiety, or motion and on reducing scan incompletion rates or need for sedation.

Sweet and Sour: Impact of Early Glycemic Control on Outcomes in Necrotizing Soft-Tissue Infections.

Necrotizing soft-tissue infection (NSTI) is a devastating disease associated with high rates of morbidity and mortality. Hyperglycemia is associated with poor wound healing; however, there are no studies evaluating glycemic control outcomes in patients with NSTI. The objective of this study was to examine disease progression and death in patients with NSTI who achieved early glycemic control (EGC) compared with patients that did not.

Ablation of tau causes an olfactory deficit in a murine model of Parkinson's disease.

Parkinson's disease is diagnosed upon the presentation of motor symptoms, resulting from substantial degeneration of dopaminergic neurons in the midbrain. Prior to diagnosis, there is a lengthy prodromal stage in which non-motor symptoms, including olfactory deficits (hyposmia), develop. There is limited information about non-motor impairments and there is a need for directed research into these early pathogenic cellular pathways that precede extensive dopaminergic death in the midbrain.

Auto-Commentary on: "Targeting mitochondrial oxidative phosphorylation eradicates therapy-resistant chronic myeloid leukemia stem cells".

We have recently uncovered an abnormal increase in mitochondrial oxidative metabolism in therapy-resistant chronic myeloid leukaemia stem cells (LSCs). By simultaneously disrupting mitochondrial respiration and inhibiting BCR-ABL kinase activity using the antibiotic tigecycline and imatinib respectively, we effectively eradicated LSCs and prevented disease relapse in pre-clinical animal models.

Hidden sources of grapefruit in beverages: potential interactions with immunosuppressant medications.

Purpose: The interaction between grapefruit-containing beverages and immunosuppressants is not well defined in the literature. This study was conducted to investigate possible sources of grapefruit juice or grapefruit extract in common US-manufactured beverages. The goal was to identify those products that might serve as hidden sources of dietary grapefruit intake, increasing a transplant patient's risk for drug interactions.

An arrayed RNA interference genome-wide screen identifies candidate genes involved in the MicroRNA 21 biogenesis pathway.

MicroRNAs (miRNAs) are evolutionary conserved noncoding molecules that regulate gene expression. They influence a number of diverse biological functions, such as development and differentiation. However, their dysregulation has been shown to be associated with disease states, such as cancer.

Selection of hyperfunctional siRNAs with improved potency and specificity.

One critical step in RNA interference (RNAi) experiments is to design small interfering RNAs (siRNAs) that can greatly reduce the expression of the target transcripts, but not of other unintended targets. Although various statistical and computational approaches have been attempted, this remains a challenge facing RNAi researchers. Here, we present a new experimentally validated method for siRNA design.

LNA incorporated siRNAs exhibit lower off-target effects compared to 2'-OMethoxy in cell phenotypic assays and microarray analysis.

Despite the promise of short interfering RNAs (siRNA), contending with off-target is a challenge for RNAi users. To alleviate these problems, we have developed locked nucleic acid (LNA) modified siRNAs and optimized performance using cellular phenotypic assays as well as microarray analysis. During development, we compared LNA and 2'OMethoxy (2'OMe) chemistries placed strategically throughout the siRNA molecule and found a novel pattern of LNA placement that greatly improved the specificity of the siRNA and reduced it's toxicity in culture while preserving the potency of the siRNA.