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70 result(s) for "Peterson, Hannah R."
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Sex-specific role of the 5-HT2A receptor in psilocybin-induced extinction of opioid reward
Emerging evidence suggests that classical psychedelics may offer therapeutic potential for opioid use disorder (OUD) by alleviating key hallmarks such as altered reward processing and dependence. However, the mechanisms behind these effects remain unclear. Our data demonstrate that a single administration of the psychedelic psilocybin (PSI) reduces conditioned behavior and withdrawal induced by the opioid oxycodone (OXY) in male mice but not in females, and this effect is mediated via the 5-HT 2A receptor (5-HT 2A R). We show that the sex-specific attenuation of OXY preference is driven by 5-HT 2A R activation in frontal cortex pyramidal neurons projecting to the nucleus accumbens (NAc). Additionally, PSI modulates epigenomic regulation following repeated OXY exposure and induces sex-specific NAc dendritic structural plasticity independently of 5-HT 2A R. Notably, female frontal cortex and NAc show fewer changes at gene enhancer regions in response to PSI, repeated OXY, or combined PSI-OXY treatment compared to males, with the frontal cortex exhibiting more pronounced sex differences than the NAc at the epigenomic level. Together, these results provide new insights into the neural and epigenetic mechanisms of psychedelic-induced plasticity in OUD, while also highlighting sex differences in PSI’s modulation of reward pathways and its therapeutic potential. Here Jaster et al., show a single psilocybin dose produce sex-specific post-acute changes in opioid reward and withdrawal via 5-HT2A receptors in frontal cortex-to–nucleus accumbens circuits, with epigenetic and synaptic changes shaping therapeutic potential.
Sex-specific role of the 5-HT 2A receptor in psilocybin-induced extinction of opioid reward
Emerging evidence suggests that classical psychedelics may offer therapeutic potential for opioid use disorder (OUD) by alleviating key hallmarks such as altered reward processing and dependence. However, the mechanisms behind these effects remain unclear. Our data demonstrate that a single administration of the psychedelic psilocybin (PSI) reduces conditioned behavior and withdrawal induced by the opioid oxycodone (OXY) in male mice but not in females, and this effect is mediated via the 5-HT receptor (5-HT R). We show that the sex-specific attenuation of OXY preference is driven by 5-HT R activation in frontal cortex pyramidal neurons projecting to the nucleus accumbens (NAc). Additionally, PSI modulates epigenomic regulation following repeated OXY exposure and induces sex-specific NAc dendritic structural plasticity independently of 5-HT R. Notably, female frontal cortex and NAc show fewer changes at gene enhancer regions in response to PSI, repeated OXY, or combined PSI-OXY treatment compared to males, with the frontal cortex exhibiting more pronounced sex differences than the NAc at the epigenomic level. Together, these results provide new insights into the neural and epigenetic mechanisms of psychedelic-induced plasticity in OUD, while also highlighting sex differences in PSI's modulation of reward pathways and its therapeutic potential.
Origins of direction selectivity in the primate retina
From mouse to primate, there is a striking discontinuity in our current understanding of the neural coding of motion direction. In non-primate mammals, directionally selective cell types and circuits are a signature feature of the retina, situated at the earliest stage of the visual process. In primates, by contrast, direction selectivity is a hallmark of motion processing areas in visual cortex, but has not been found in the retina, despite significant effort. Here we combined functional recordings of light-evoked responses and connectomic reconstruction to identify diverse direction-selective cell types in the macaque monkey retina with distinctive physiological properties and synaptic motifs. This circuitry includes an ON-OFF ganglion cell type, a spiking, ON-OFF polyaxonal amacrine cell and the starburst amacrine cell, all of which show direction selectivity. Moreover, we discovered that macaque starburst cells possess a strong, non-GABAergic, antagonistic surround mediated by input from excitatory bipolar cells that is critical for the generation of radial motion sensitivity in these cells. Our findings open a door to investigation of a precortical circuitry that computes motion direction in the primate visual system. Neural coding for motion direction has been studied intensively in the visual cortex of non-human primates. Here, the authors establish an origin for direction selectivity in the retina of the macaque monkey.
Whole genome CRISPRi screening identifies druggable vulnerabilities in an isoniazid resistant strain of Mycobacterium tuberculosis
Drug-resistant strains of Mycobacterium tuberculosis are a major global health problem. Resistance to the front-line antibiotic isoniazid is often associated with mutations in the katG -encoded bifunctional catalase-peroxidase. We hypothesise that perturbed KatG activity would generate collateral vulnerabilities in isoniazid-resistant katG mutants, providing potential pathway targets to combat isoniazid resistance. Whole genome CRISPRi screens, transcriptomics, and metabolomics were used to generate a genome-wide map of cellular vulnerabilities in an isoniazid-resistant katG mutant strain of M. tuberculosis . Here, we show that metabolic and transcriptional remodelling compensates for the loss of KatG but in doing so generates vulnerabilities in respiration, ribosome biogenesis, and nucleotide and amino acid metabolism. Importantly, these vulnerabilities are more sensitive to inhibition in an isoniazid-resistant katG mutant and translated to clinical isolates. This work highlights how changes in the physiology of drug-resistant strains generates druggable vulnerabilities that can be exploited to improve clinical outcomes. In this work, authors utilise genome-wide CRISPRi screening to identify vulnerabilities in isoniazid-resistant strains of Mycobacterium tuberculosis .
Fluoroestradiol (FES) and Fluorodeoxyglucose (FDG) PET imaging in patients with ER+, HER2-positive or HER2-negative metastatic breast cancer
Background 18 F-Fluorodeoxyglucose (FDG) and 18 F-Fluorestradiol (FES) have been FDA approved for measuring tumor glycolytic activity and estrogen receptor (ER) uptake, respectively, in clinical positron emission tomography (PET) imaging for patients with hormone-receptor (HR) positive metastatic breast cancer (MBC), but little is known about its utility in patients with breast tumors that overexpress human epidermal growth factor 2 (HER2). We hypothesize that comparing patterns of FDG and FES uptake in patients with HER2-positive versus HER2-negative MBC can guide further biologic and clinical studies into the HR/HER2-positive phenotype. Methods We conducted a retrospective study examining uptake in matched lesions for FES and FDG-PET scans, assessing these parameters in 213 patients with ER-positive/HER2-positive ( n  = 33) versus ER-positive/HER2-negative MBC ( n  = 180). We employed log-rank and t-tests to assess the association of HER2 status with outcome variables and the hypotheses that patients expressing HER2-positive disease lived longer than patient with HER2-negative disease. Results No difference in FES or FDG avidity was observed between patients with HER2-negative or HER2-positive tumor status. Limited data also suggests that patients with HER2-positive disease had better overall survival ( p  = 0.024), than those with HER2-negative disease, but not time-to-progression between the same patient cohorts. Conclusion This retrospective analysis suggests that there is a possible role for future trials using FES-PET in helping to select patients with ER+/HER2-positive primary tumors who retain ER expression at all sites of disease and may benefit from endocrine therapy.
Multimodal prediction of neoadjuvant treatment outcome by serial FDG PET and MRI in women with locally advanced breast cancer
Purpose To investigate combined MRI and 18 F-FDG PET for assessing breast tumor metabolism/perfusion mismatch and predicting pathological response and recurrence-free survival (RFS) in women treated for breast cancer. Methods Patients undergoing neoadjuvant chemotherapy (NAC) for locally-advanced breast cancer were imaged at three timepoints (pre, mid, and post-NAC), prior to surgery. Imaging included diffusion-weighted and dynamic contrast-enhanced (DCE-) MRI and quantitative 18 F-FDG PET. Tumor imaging measures included apparent diffusion coefficient, peak percent enhancement (PE), peak signal enhancement ratio (SER), functional tumor volume, and washout volume on MRI and standardized uptake value (SUVmax), glucose delivery (K 1 ) and FDG metabolic rate (MRFDG) on PET, with percentage changes from baseline calculated at mid- and post-NAC. Associations of imaging measures with pathological response (residual cancer burden [RCB] 0/I vs. II/III) and RFS were evaluated. Results Thirty-five patients with stage II/III invasive breast cancer were enrolled in the prospective study (median age: 43, range: 31–66 years, RCB 0/I: N = 11/35, 31%). Baseline imaging metrics were not significantly associated with pathologic response or RFS ( p  > 0.05). Greater mid-treatment decreases in peak PE, along with greater post-treatment decreases in several DCE-MRI and 18 F-FDG PET measures were associated with RCB 0/I after NAC ( p  < 0.05). Additionally, greater mid- and post-treatment decreases in DCE-MRI (peak SER, washout volume) and 18 F-FDG PET (K 1 ) were predictive of prolonged RFS. Mid-treatment decreases in metabolism/perfusion ratios (MRFDG/peak PE, MRFDG/peak SER) were associated with improved RFS. Conclusion Mid-treatment changes in both PET and MRI measures were predictive of RCB status and RFS following NAC. Specifically, our results indicate a complementary relationship between DCE-MRI and 18 F-FDG PET metrics and potential value of metabolism/perfusion mismatch as a marker of patient outcome.
Facial protection for healthcare workers during pandemics: a scoping review
BackgroundThe coronavirus disease 2019 (COVID-19) pandemic has led to personal protective equipment (PPE) shortages, requiring mask reuse or improvisation. We provide a review of medical-grade facial protection (surgical masks, N95 respirators and face shields) for healthcare workers, the safety and efficacy of decontamination methods, and the utility of alternative strategies in emergency shortages or resource-scarce settings.MethodsWe conducted a scoping review of PubMed and grey literature related to facial protection and potential adaptation strategies in the setting of PPE shortages (January 2000 to March 2020). Limitations included few COVID-19-specific studies and exclusion of non-English language articles. We conducted a narrative synthesis of the evidence based on relevant healthcare settings to increase practical utility in decision-making.ResultsWe retrieved 5462 peer-reviewed articles and 41 grey literature records. In total, we included 67 records which met inclusion criteria. Compared with surgical masks, N95 respirators perform better in laboratory testing, may provide superior protection in inpatient settings and perform equivalently in outpatient settings. Surgical mask and N95 respirator conservation strategies include extended use, reuse or decontamination, but these strategies may result in inferior protection. Limited evidence suggests that reused and improvised masks should be used when medical-grade protection is unavailable.ConclusionThe COVID-19 pandemic has led to critical shortages of medical-grade PPE. Alternative forms of facial protection offer inferior protection. More robust evidence is required on different types of medical-grade facial protection. As research on COVID-19 advances, investigators should continue to examine the impact on alternatives of medical-grade facial protection.
Safety and Efficacy of Platelet Rich Plasma for Treatment of Lumbar Discogenic Pain: A Prospective, Multicenter, Randomized, Double-blind Study
Interventions for chronic discogenic spine pain are currently insufficient in lowering individual patient suffering and global disease burden. A 2016 study of platelet rich plasma (PRP) for chronic discogenic pain previously demonstrated clinically significant response among active group patients compared with controls. To replicate the previous research to move this intervention forward as a viable option for patient care. A double-blind, randomized, placebo-controlled study. Multicenter private practices. Twenty-six (12 men, 14 women) human patients, ages 25 to 71 with a diagnosis of chronic lumbar discogenic pain, were randomly assigned to active (PRP) or control (saline) groups in a ratio of 2 active to 1 control. Baseline and follow-up Oswestry Disability Index and Numeric Pain Rating Scale questionnaires were obtained to track patient outcomes at 8 weeks postoperatively. Within group assessment showed clinically significant improvement in 17% of PRP patients and clinically significant decline in 5% (1 patient) of the active group. Clinically significant improvement was seen in 13% of placebo group patients and no placebo patients had clinically significant decline secondary to the procedure. Possible explanations may include a range of factors including differences in patient demographics, outcome-measure sensitivity, or misalignment of statistical analyses. These findings are markedly different than the highly promising results of the 2016 PRP study. This study posits necessary caution for researchers who wish to administer PRP for therapeutic benefit and may ultimately point to necessary redirection of interventional research for discogenic pain populations.
Efficacy and breadth of adjuvanted SARS-CoV-2 receptor-binding domain nanoparticle vaccine in macaques
Emergence of novel variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) underscores the need for next-generation vaccines able to elicit broad and durable immunity. Here we report the evaluation of a ferritin nanoparticle vaccine displaying the receptor-binding domain of the SARS-CoV-2 spike protein (RFN) adjuvanted with Army Liposomal Formulation QS-21 (ALFQ). RFN vaccination of macaques using a two-dose regimen resulted in robust, predominantly Th1 CD4+ T cell responses and reciprocal peak mean serum neutralizing antibody titers of 14,000 to 21,000. Rapid control of viral replication was achieved in the upper and lower airways of animals after high-dose SARS-CoV-2 respiratory challenge, with undetectable replication within 4 d in seven of eight animals receiving 50 μg of RFN. Cross-neutralization activity against SARS-CoV-2 variant B.1.351 decreased only approximately twofold relative to WA1/2020. In addition, neutralizing, effector antibody and cellular responses targeted the heterotypic SARS-CoV-1, highlighting the broad immunogenicity of RFN-ALFQ for SARS-CoV−like Sarbecovirus vaccine development.
Extinction risk from climate change
Climate change over the past ∼30 years has produced numerous shifts in the distributions and abundances of species 1 , 2 and has been implicated in one species-level extinction 3 . Using projections of species' distributions for future climate scenarios, we assess extinction risks for sample regions that cover some 20% of the Earth's terrestrial surface. Exploring three approaches in which the estimated probability of extinction shows a power-law relationship with geographical range size, we predict, on the basis of mid-range climate-warming scenarios for 2050, that 15–37% of species in our sample of regions and taxa will be ‘committed to extinction’. When the average of the three methods and two dispersal scenarios is taken, minimal climate-warming scenarios produce lower projections of species committed to extinction (∼18%) than mid-range (∼24%) and maximum-change (∼35%) scenarios. These estimates show the importance of rapid implementation of technologies to decrease greenhouse gas emissions and strategies for carbon sequestration.