A Key Mediator and Imaging Target in Alzheimer's Disease: Unlocking the Role of Reactive Astrogliosis Through MAOB.

Astrocytes primarily maintain physiological brain homeostasis. However, under various pathological conditions, they can undergo morphological, transcriptomic, and functional transformations, collectively referred to as reactive astrogliosis. Recent studies have accumulated lines of evidence that reactive astrogliosis plays a crucial role in the pathology of Alzheimer's disease (AD). In particular, monoamine oxidase B, a mitochondrial enzyme mainly expressed in astrocytes, significantly contributes to neuronal dysfunction and neurodegeneration in AD brains. Moreover, it has been reported that reactive astrogliosis precedes other pathological hallmarks such as amyloid-beta plaque deposition and tau tangle formation in AD. Due to the early onset and profound impact of reactive astrocytes on pathology, there have been extensive efforts in the past decade to visualize these cells in the brains of AD patients using positron emission tomography (PET) imaging. In this review, we summarize the recent studies regarding the essential pathological importance of reactive astrocytes in AD and their application as a target for PET imaging.

Cardiovascular Risk Factors Among First-Degree Relatives of Patients with Premature Cardiovascular Disease in Malta. Baseline Findings from the CRISO Project.

Purpose: A family history of premature atherosclerotic cardiovascular disease (ASCVD) confers a greater risk of developing ASCVD. However, the prevalence of ASCVD risk factors among asymptomatic Maltese adults with parental or fraternal history of premature ASCVD is unknown. The study aimed to evaluate and compare their risk with the general population. Patients and Methods: Posters to market the project were distributed in cardiac rehabilitation areas. Patients with premature cardiovascular disease facilitated recruitment by informing their relatives about the project. Medical doctors and cardiac rehabilitation nurses referred first-degree relatives. Posters were put up in community pharmacies, and an explanatory video clip was shared on social media for interested individuals to contact researchers. Those eligible were enrolled in a preventive cardiology lifestyle intervention. Their data were compared with the risk in the general population. Results: Many first-degree relatives had a suboptimal risk profile, with 60% (N = 89) having a total cholesterol level of >5.0 mmol/L; 54% having a low-density lipoprotein-cholesterol level of >3 mmol/L; 70.5% being overweight/obese, with 62% having a waist circumference greater than the recommended values; 34.8% having hypertension; 56.2% being inadequately adherent to the Mediterranean diet; 62% being underactive, with 18% being sedentary; and 25.8% being smokers. First-degree relatives had significantly higher proportions of underactive lifestyle (p = 0.00016), high body mass index (>25kg/m2) (p = 0.006), and systolic blood pressure (p = 0.001) than the general population, with 30% having metabolic syndrome. Conclusion: This study determined the prevalence of lifestyle, biochemical, physiological, and anthropometric cardiovascular risk factors among asymptomatic first-degree relatives of Maltese patients with premature ASCVD. First-degree relatives had considerable prevalences of an underactive lifestyle, hypertension, and obesity, suggesting better screening and early risk factor intervention are needed to modify their risk of ASCVD.

This study was done to evaluate factors that can increase the risk of heart disease in siblings and offspring of Maltese patients who developed atherosclerotic cardiovascular disease (ASCVD) at a young age. Relatives were invited to meetings during which a risk evaluation was performed. The researchers found that relatives had a high prevalence of cardiometabolic risk factors, meaning they were at increased risk of developing the disease. The researchers have concluded that reducing the risk of ASCVD in individuals at increased risk requires developing and testing potentially sustainable risk factor modification strategies.

Negative Influence of the Hunger State on Rule-observance Behavior in Mice

Developing social strategies to share limited resources equally and maximize the long-term benefits of conflict resolution is critical for appropriate social interactions. During social interactions, social decision-making depends not only on the external environment, but also on internal factors, such as hunger, thirst, or fatigue. In particular, hunger, which is related to food as a physical need, plays a dominant role in social decision-making. However, the consequences of food deprivation on social decision-making are not well understood. We have previously shown that mice with rule-observance behavior are capable of resolving conflict during social decision-making by observing a well-established social strategy based on reward zone allocation. Here, we developed a rule-observance behavior paradigm wherein the hunger state is achieved by applying food restrictions on mice prior to social behavior experiments. We found that the hunger state in mice deteriorated the established social strategy by decreasing reaction time, implying an increase in impulsivity. In contrast, the hunger state did not affect reward zone allocation, indicating no effect on spatial memory. This decrease in reaction time led to a significant increase in the percentage of violations during rule observance and a significant decrease in the amount of reward (payoff equity). Our study proposes that the hunger state exerts a detrimental effect on appropriate social decisionmaking by decreasing reaction time, increasing violation, and decreasing payoff equity in rule-observance behavior.

Synthesis and structure-activity relationship study of saponin-based membrane fusion inhibitors against SARS-CoV-2.

We previously discovered that triterpenoid saponin platycodin D inhibits the SARS-CoV-2 entry to the host cell. Herein, we synthesized various saponin derivatives and established a structure-activity relationship of saponin-based antiviral agents against SARS-CoV-2. We discovered that the C3-glucose, the C28-oligosaccharide moiety that consist of (→3)-ß-d-Xyl-(1 â†’ 4)-α-l-Rham-(1 â†’ 2)-ß-d-Ara-(1 â†’ ) as the last three sugar units, and the C16-hydroxyl group were critical components of saponin-based coronavirus cell entry inhibitors. These findings enabled us to develop minimal saponin-based antiviral agents that are equipotent to the originally discovered platycodin D. We found that our saponin-based antiviral agents inhibited both the endosomal and transmembrane protease serine 2-mediated cell surface viral entries. Cell fusion assay experiment revealed that our newly developed compounds inhibit the SARS-CoV-2 entry by blocking the fusion between the viral and host cell membranes. The effectiveness of the newly developed antiviral agents over various SARS-CoV-2 variants hints at the broad-spectrum antiviral efficacy of saponin-based therapeutics against future coronavirus variants.

Quantitative Determination of Ethylene Using a Smartphone-Based Optical Fiber Sensor (SOFS) Coupled with Pyrene-Tagged Grubbs Catalyst.

For rapid and portable detection of ethylene in commercial fruit ripening storage rooms, we designed a smartphone-based optical fiber sensor (SOFS), which is composed of a 15 mW 365 nm laser for fluorescence signal excitation and a bifurcated fiber system for signal flow direction from probe to smartphone. Paired with a pyrene-tagged Grubbs catalyst (PYG) probe, our SOFS showed a wide linearity range up to 350 ppm with a detection limit of 0.6 ppm. The common gases in the warehouse had no significant interference with the results. The device is portable (18 cm × 8 cm × 6 cm) with an inbuilt power supply and replaceable optical fiber sensor tip. The images are processed with a dedicated smartphone application for RGB analysis and ethylene concentration. The device was applied in detection of ethylene generated from apples, avocados, and bananas. The linear correlation data showed agreement with data generated from a fluorometer. The SOFS provides a rapid, compact, cost-effective solution for determination of the fruit ethylene concentration dynamic during ripening for better fruit harvest timing and postharvest management to minimize wastage.

Management of Severe Crush Injuries in Austere Environments: A Special Operations Perspective.

Crush injuries present a challenging case for medical providers and require knowledge and skill to manage the subsequent damage to multiple organ systems. In an austere environment, in which resources are limited and evacuation time is extensive, a medic must be prepared to identify trends and predict outcomes based on the mechanism of injury and patient presentation. These injuries occur in a variety of environments from motor vehicle accidents (at home or abroad) to natural disasters and building collapses. Crush injury can lead to compartment syndrome, traumatic rhabdomyolysis, arrythmias, and metabolic acidosis, especially for patients with extended treatment and extrication times. While crush syndrome occurs due to the systemic effects of the injury, the onset can be as early as 1 hour postinjury. With a comprehensive understanding of the pathophysiology, diagnosis, management, and tactical considerations, a prehospital provider can optimize patient outcomes and be prepared with the tools they have on hand for the progression of crush injury into crush syndrome.

Analgesia and Sedation in the Prehospital Setting A Critical Care Viewpoint.

Pain is one of the most common complaints of battlefield casualties, and unique considerations apply in the tactical environment when managing the pain of wounded service members. The resource constraints commonly experienced in an operational setting, plus the likelihood of prolonged casualty care by medics or corpsmen on future battlefields, necessitates a review of analgesia and sedation in the prehospital setting. Four clinical scenarios highlight the spectrum of analgesia and sedation that may be necessary in this prehospital and/or austere environment.

Identification of a Novel SARS-CoV-2 Delta-Omicron Recombinant Virus in the United States

Recombination between SARS-CoV-2 virus variants can result in different viral properties (e.g., infectiousness or pathogenicity). In this report, we describe viruses with recombinant genomes containing signature mutations from Delta and Omicron variants. These genomes are the first evidence for a Delta-Omicron hybrid Spike protein in the United States.

Unaltered Tonic Inhibition in the Arcuate Nucleus of Diet-induced Obese Mice

The principal inhibitory transmitter, γ-aminobutyric acid (GABA), is critical for maintaining hypothalamic homeostasis and released from neurons phasically, as well as from astrocytes tonically. Although astrocytes in the arcuate nucleus (ARC) of the hypothalamus are shown to transform into reactive astrocytes, the tonic inhibition by astrocytic GABA has not been adequately investigated in diet-induced obesity (DIO). Here, we investigated the expression of monoamine oxidase- B (MAOB), a GABA-synthesizing enzyme, in reactive astrocytes in obese mice. We observed that a chronic high-fat diet (HFD) significantly increased astrocytic MAOB and cellular GABA content, along with enhanced hypertrophy of astrocytes in the ARC. Unexpectedly, we found that the level of tonic GABA was unaltered in chronic HFD mice using whole-cell patch-clamp recordings in the ARC. Furthermore, the GABA-induced current was increased with elevated GABA A receptor α5 (GABRA5) expression. Surprisingly, we found that a nonselective GABA transporter (GAT) inhibitor, nipecotic acid (NPA)-induced current was significantly increased in chronic HFD mice. We observed that GAT1 inhibitor, NO711-induced current was significantly increased, whereas GAT3 inhibitor, SNAP5114-induced current was not altered. The unexpected unaltered tonic inhibition was due to an increase of GABA clearance in the ARC by neuronal GAT1 rather than astrocytic GAT3. These results imply that increased astrocytic GABA synthesis and neuronal GABA A receptor were compensated by GABA clearance, resulting in unaltered tonic GABA inhibition in the ARC of the hypothalamus in obese mice. Taken together, GABA-related molecular pathways in the ARC dynamically regulate the tonic inhibition to maintain hypothalamic homeostasis against the HFD challenge.

Generation of Astrocyte-Specific MAOB Conditional Knockout Mouse with Minimal Tonic GABA Inhibition

Monoamine oxidase B (MAOB) is a key enzyme for GABA production in astrocytes in several brain regions. To date, the role of astrocytic MAOB has been studied in MAOB null knockout (KO) mice, although MAOB is expressed throughout the body. Therefore, there has been a need for genetically engineered mice in which only astrocytic MAOB is targeted. Here, we generated an astrocyte-specific MAOB conditional KO (cKO) mouse line and characterized it in the cerebellar and striatal regions of the brain. Using the CRISPR-Cas9 gene-editing technique, we generated Maob floxed mice (B6-Maob em1Cjl /Ibs) which have floxed exons 2 and 3 of Maob with two loxP sites. By crossing these mice with hGFAP-CreER T2 , we obtained Maob floxed::hGFAP-CreER T2 mice which have a property of tamoxifen-inducible ablation of Maob under the human GFAP (hGFAP) promoter. When we treated Maob floxed::hGFAP-CreER T2 mice with tamoxifen for 5 consecutive days, MAOB and GABA immunoreactivity were significantly reduced in striatal astrocytes as well as in Bergmann glia and lamellar astrocytes in the cerebellum, compared to sunflower oil-injected control mice. Moreover, astrocyte-specific MAOB cKO led to a 74.6% reduction in tonic GABA currents from granule cells and a 76.8% reduction from medium spiny neurons. Our results validate that astrocytic MAOB is a critical enzyme for the synthesis of GABA in astrocytes. We propose that this new mouse line could be widely used in studies of various brain diseases to elucidate the pathological role of astrocytic MAOB in the future.

Wastewater sequencing uncovers early, cryptic SARS-CoV-2 variant transmission

As SARS-CoV-2 continues to spread and evolve, detecting emerging variants early is critical for public health interventions. Inferring lineage prevalence by clinical testing is infeasible at scale, especially in areas with limited resources, participation, or testing/sequencing capacity, which can also introduce biases. SARS-CoV-2 RNA concentration in wastewater successfully tracks regional infection dynamics and provides less biased abundance estimates than clinical testing. Tracking virus genomic sequences in wastewater would improve community prevalence estimates and detect emerging variants. However, two factors limit wastewater-based genomic surveillance: low-quality sequence data and inability to estimate relative lineage abundance in mixed samples. Here, we resolve these critical issues to perform a high-resolution, 295-day wastewater and clinical sequencing effort, in the controlled environment of a large university campus and the broader context of the surrounding county. We develop and deploy improved virus concentration protocols and deconvolution software that fully resolve multiple virus strains from wastewater. We detect emerging variants of concern up to 14 days earlier in wastewater samples, and identify multiple instances of virus spread not captured by clinical genomic surveillance. Our study provides a scalable solution for wastewater genomic surveillance that allows early detection of SARS-CoV-2 variants and identification of cryptic transmission.

Central nervous system infection in the intensive care unit: Development and validation of a multi-parameter diagnostic prediction tool to identify suspected patients.

BACKGROUND: Central nervous system infections (CNSI) are diseases with high morbidity and mortality, and their diagnosis in the intensive care environment can be challenging. Objective: To develop and validate a diagnostic model to quickly screen intensive care patients with suspected CNSI using readily available clinical data. METHODS: Derivation cohort: 783 patients admitted to an infectious diseases intensive care unit (ICU) in Oswaldo Cruz Foundation, Rio de Janeiro RJ, Brazil, for any reason, between 01/01/2012 and 06/30/2019, with a prevalence of 97 (12.4%) CNSI cases. Validation cohort 1: 163 patients prospectively collected, between 07/01/2019 and 07/01/2020, from the same ICU, with 15 (9.2%) CNSI cases. Validation cohort 2: 7,270 patients with 88 CNSI (1.21%) admitted to a neuro ICU in Chicago, IL, USA between 01/01/2014 and 06/30/2019. Prediction model: Multivariate logistic regression analysis was performed to construct the model, and Receiver Operating Characteristic (ROC) curve analysis was used for model validation. Eight predictors-age <56 years old, cerebrospinal fluid white blood cell count >2 cells/mm3, fever (≥38°C/100.4°F), focal neurologic deficit, Glasgow Coma Scale <14 points, AIDS/HIV, and seizure-were included in the development diagnostic model (P<0.05). RESULTS: The pool data's model had an Area Under the Receiver Operating Characteristics (AUC) curve of 0.892 (95% confidence interval 0.864-0.921, P<0.0001). CONCLUSIONS: A promising and straightforward screening tool for central nervous system infections, with few and readily available clinical variables, was developed and had good accuracy, with internal and external validity.

Coronary risk reduction intervention for siblings and offspring of patients with premature coronary heart disease: the CRISO study protocol for a randomised controlled pilot study.

BACKGROUND: Research has consistently demonstrated that preventive cardiology programs have limited success, and healthy practices among high-risk individuals remain suboptimal. Furthermore, there are no current programmes in Malta that offer support to first-degree relatives of patients with premature coronary heart disease. This internal pilot study will determine the feasibility, acceptability, and potential effectiveness of a preventative intervention. METHODS/DESIGN: We are conducting a 12-month single-centre, two-armed group randomised controlled trial (RCT), recruiting a sample of 100 asymptomatic first-degree relatives of patients with premature coronary heart disease (CHD). The study seeks to test an evidence-based intervention to reduce modifiable risk and determine its feasibility and acceptability. The Intervention will be delivered at an outpatient office based in a large acute academic hospital. It will comprise risk communication using an online risk calculator, a counselling style adapted from motivational interviewing, and 12 weekly telephone goal reinforcement calls (3 months). Control subjects will receive verbal lifestyle advice only. Feasibility will be assessed through recruitment and retention. Qualitative evaluation interviews will be conducted with a subsample of 24 purposefully selected participants at 12 months. Assessment for risk factor changes will be measured at pre-intervention and 6 and 12 months. Associations between variables will also be assessed descriptively. DISCUSSION: Preventive cardiology guidelines highlighted the importance of lifestyle interventions, and lifestyle intervention adherence was proven to reduce atherosclerotic cardiovascular disease (ASCVD) risk, regardless of the individual's genetic risk. Preventive cardiology programmes may fail to adequately support persons in modifying risky behaviours, and research demonstrates that healthy practices among high-risk individuals can remain suboptimal. Siblings and offspring of patients with premature CHD are at increased risk of ASCVD. Despite this, there is no process in place for routine screening and support to modify risk. It is hypothesised that participants assigned to the intervention arm will show more cardio-protective lifestyle-related improvement from the baseline than those in the control group. To date, this is the first trial being conducted amongst Maltese first-degree relatives. This study addresses the needed research, and the results will inform a definitive trial. The funding institution is the University of Malta. TRIAL REGISTRATION: ISRCTN, ISRCTN21559170 ; Registered 06/08/2020.

Search Trends and Quality of Online Resources Regarding Thyroidectomy.

OBJECTIVE: Thyroidectomy is one of the most common procedures performed in head and neck surgery. The quality of online resources for thyroidectomy is unknown. We aim to evaluate search trends and online resource quality regarding thyroidectomy. STUDY DESIGN: Cross-sectional analysis. SETTING: Websites appearing on Google search. METHODS: The first 30 Google websites for thyroidectomy were reviewed, excluding research, video, and restricted sites. Search patterns were obtained with Google Trends. Quality was measured by readability (Flesch Reading Ease and Flesch-Kinkaid Grade Level), understandability and actionability (Patient Education Materials Assessment Tool), and clinical practice guideline (CPG) compatibility. Fleiss kappa interrater reliability analysis was performed for 2 raters. RESULTS: Twenty-one sites were evaluated. Search popularity for thyroidectomy has increased since 2004. Median reading ease was 42.2 (range, 15.4-62.7) on a scale from 1 to 100, with 100 indicating maximum readability. Median reading grade level was 12 (range, 7-16). Thyroidectomy resources were poorly understandable (median, 66%; range, 21%-88%) and actionable (median, 10%; range, 0%-60%). Median CPG compatibility was 4 out of 5 (range, 0-5). Interrater reliability ranged from substantial to moderate for understandability (0.78), actionability (0.57), and CPG compatibility (0.58), with P < .05 for all results. CONCLUSION: Online resources about thyroidectomy vary in quality and reliability and are written at grade levels above the average reading level of the public. Providers should be aware of existing resources and work to create education resources that meet universal health literacy guidelines. The framework provided in this article may also serve as a guide and provide tangible steps that providers can take to help patients access care.

A Deafness Associated Protein TMEM43 Interacts with KCNK3 (TASK-1) Two-pore Domain K+ (K2P) Channel in the Cochlea

The TMEM43 has been studied in human diseases such as arrhythmogenic right ventricular cardiomyopathy type 5 (ARVC5) and auditory neuropathy spectrum disorder (ANSD). In the heart, the p.(Ser358Leu) mutation has been shown to alter intercalated disc protein function and disturb beating rhythms. In the cochlea, the p.(Arg372Ter) mutation has been shown to disrupt connexin-linked function in glia-like supporting cells (GLSs), which maintain inner ear homeostasis for hearing. The TMEM43-p.(Arg372Ter) mutant knock-in mice displayed a significantly reduced passive conductance current in the cochlear GLSs, raising a possibility that TMEM43 is essential for mediating the passive conductance current in GLSs. In the brain, the two-pore-domain potassium (K2P) channels are generally known as the “leak channels” to mediate background conductance current, raising another possibility that K2P channels might contribute to the passive conductance current in GLSs. However, the possible association between TMEM43 and K2P channels has not been investigated yet. In this study, we examined whether TMEM43 physically interacts with one of the K2P channels in the cochlea, KCNK3 (TASK-1). Utilizing co-immunoprecipitation (IP) assay and Duolink proximity ligation assay (PLA), we revealed that TMEM43 and TASK-1 proteins could directly interact. Genetic modifications further delineated that the intracellular loop domain of TMEM43 is responsible for TASK-1 binding. In the end, gene-silencing of Task-1 resulted in significantly reduced passive conductance current in GLSs. Together, our findings demonstrate that TMEM43 and TASK-1 form a protein-protein interaction in the cochlea and provide the possibility that TASK-1 is a potential contributor to the passive conductance current in GLSs.

Differential Proximity of Perisynaptic Astrocytic Best1at the Excitatory and Inhibitory Tripartite Synapses in APP/PS1 and MAOB-KO Mice Revealed by Lattice Structured Illumination Microscopy

Bestrophin-1 (Best1) is a GABA- and glutamate-permeable, Ca 2+ -activated Cl - channel, which is mainly expressed in astrocytes and localized at the microdomain or perisynaptic junction of the tripartite synapse. Distribution of Best1 is dramatically changed in pathological conditions such as Alzheimer’s disease. However, it is still unknown whether Best1 is located at the glutamatergic or GABAergic tripartite synapses. Here, we utilized the Lattice structured illumination microscopy (Lattice SIM) to visualize Best1 expression at the perisynaptic junctions of the tripartite synapses in CA1 of mouse hippocampus. We performed co-labeling with antibodies against 1) Best1 and vesicular glutamate transporter-2 (vGLUT2) or 2) Best1 and vesicular GABA transporter (vGAT) to measure the proximity of Best1-containing perisynapse to glutamatergic or GABAergic presynapse, respectively. In addition, we examined two transgenic mouse lines of 1) APP/PS1 mouse showing high astrocytic MAOB activity and cytosolic GABA and 2) MAOB-KO mouse showing low astrocytic GABA. Lattice SIM images were further processed by Imaris, which allowed 3Drendering and spot identification. We found that astrocytic Best1 was distributed closer to the glutamatergic synapses than GABAergic synapses in the wild-type mice. In APP/PS1 mice, Best1 distribution was significantly changed by moving away from the glutamatergic synapses while moving closer to the GABAergic synapses. On the contrary, in MAOB-KO mice, the Best1 distribution was dramatically changed by moving closer to the glutamatergic synapses and moving far away from the GABAergic synapses. Our findings propose that the proximity of Best1-containing perisynapses to presynapses dynamically changes according to the level of astrocytic cytosolic GABA.

Adenovirus-induced Reactive Astrogliosis Exacerbates the Pathology of Parkinson’s Disease

Parkinson’s disease (PD) is the most prevalent neurodegenerative motor disorder. While PD has been attributed to dopaminergic neuronal death in substantia nigra pars compacta (SNpc), accumulating lines of evidence have suggested that reactive astrogliosis is critically involved in PD pathology. These pathological changes are associated with α-synuclein aggregation, which is more prone to be induced by an A53T mutation. Therefore, the overexpression of A53T-mutated α-synuclein (A53T-α-syn) has been utilized as a popular animal model of PD. However, this animal model only shows marginal-to-moderate extents of reactive astrogliosis and astrocytic α-synuclein accumulation, while these phenomena are prominent in human PD brains. Here we show that Adeno-GFAP-GFP virus injection into SNpc causes severe reactive astrogliosis and exacerbates the A53Tα-syn-mediated PD pathology. In particular, we demonstrate that AAV-CMV-A53T-α-syn injection, when combined with Adeno-GFAP-GFP, causes more significant loss of dopaminergic neuronal tyrosine hydroxylase level and gain of astrocytic GFAP and GABA levels. Moreover, the combination of AAV-CMV-A53T-α-syn and Adeno-GFAP-GFP causes an extensive astrocytic α-syn expression, just as in human PD brains. These results are in marked contrast to previous reports that AAV-CMV-A53T-α-syn alone causes α-syn expression mostly in neurons but rarely in astrocytes. Furthermore, the combination causes a severe PD-like motor dysfunction as assessed by rotarod and cylinder tests within three weeks from the virus injection, whereas Adeno-GFAP-GFP alone or AAV-CMV-A53T-α-syn alone does not. Our findings implicate that inducing reactive astrogliosis exacerbates PD-like pathologies and propose the virus combination as an advanced strategy for developing a new animal model of PD.