Advances, opportunities, and challenges in methods for interrogating the structure activity relationships of natural products.

Time span in literature: 1985-early 2024Natural products play a key role in drug discovery, both as a direct source of drugs and as a starting point for the development of synthetic compounds. Most natural products are not suitable to be used as drugs without further modification due to insufficient activity or poor pharmacokinetic properties. Choosing what modifications to make requires an understanding of the compound's structure-activity relationships. Use of structure-activity relationships is commonplace and essential in medicinal chemistry campaigns applied to human-designed synthetic compounds. Structure-activity relationships have also been used to improve the properties of natural products, but several challenges still limit these efforts. Here, we review methods for studying the structure-activity relationships of natural products and their limitations. Specifically, we will discuss how synthesis, including total synthesis, late-stage derivatization, chemoenzymatic synthetic pathways, and engineering and genome mining of biosynthetic pathways can be used to produce natural product analogs and discuss the challenges of each of these approaches. Finally, we will discuss computational methods including machine learning methods for analyzing the relationship between biosynthetic genes and product activity, computer aided drug design techniques, and interpretable artificial intelligence approaches towards elucidating structure-activity relationships from models trained to predict bioactivity from chemical structure. Our focus will be on these latter topics as their applications for natural products have not been extensively reviewed. We suggest that these methods are all complementary to each other, and that only collaborative efforts using a combination of these techniques will result in a full understanding of the structure-activity relationships of natural products.

Targeted use of postoperative discharge phone calls to reduce early readmission rates.

OBJECTIVES: Postoperative readmissions are common and costly. Office-initiated phone calls to patients shortly after discharge may identify concerns and allow for early intervention to prevent readmission. We sought to evaluate our 30-day readmission rate after the implementation of a standardized postoperative discharge phone call (PODPC) intervention, compared with a historical aggregated cohort. METHODS: From July 2020 to 21, postoperative patients were prospectively identified at 48 hour after discharge. Medical assistants performed PODPCs, administering a survey designed to identify medical/surgical issues that could signify a complication and warrant escalation to a nurse practitioner (NP) for further management. Demographics, comorbidities, and procedure type were obtained retrospectively. Descriptive statistics were used to evaluate PODPC responses, frequency of escalation, readmission, and reasons. The electronic medical record identified a historical aggregated cohort (July 2018 to 2019) and the 30-day readmission rate. A χ2 analysis was used to compare readmission rates between the preintervention historical and PODPC intervention groups. Predictors of 30-day readmission were modeled with multivariable logistic regression. RESULTS: Of 411 PODPCs conducted, 106 patients (26%) reported not feeling well; having concerns. Eighty-four PODPCs (20%) triggered escalation to a NP; of these, 60 patients (71%) were counseled over the phone by an NP, 16 (19%) were brought into clinic, 6 (7%) were sent to the emergency department, and 2 (2%) did not answer the NP call. Of 411 patients, 17% (n = 68) were readmitted within 30 days. Comparatively, the historical aggregated cohort readmission rate was significantly higher at 28% (n = 346; P < .001). On multivariable analysis, chronic obstructive pulmonary disease (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.01-3.65; P = .046), and feeling run down; having difficulty with movement; needing assistance for most activities (OR, 3.94; 95% CI, 2.09-7.43; P < .0001) were predictive of 30-day readmission when controlling for procedure type. CONCLUSIONS: Although readmissions remained common (>15%), being in the intervention cohort was associated with a significantly lower readmission rate compared with the historical aggregated cohort. One-fifth of PODPCs identified a concern; however, >90% of these could be managed by an NP by phone or in clinic. This PODPC intervention holds promise as a viable mechanism for decreasing readmissions.

Patterns of Social Needs Predict Quality-of-Life and Healthcare Utilization Outcomes in Patients from a Large Hospital System.

BACKGROUND: Unmet social needs (SNs) often coexist in distinct patterns within specific population subgroups, yet these patterns are understudied. OBJECTIVE: To identify patterns of social needs (PSNs) and characterize their associations with health-related quality-of-life (HRQoL) and healthcare utilization (HCU). DESIGN: Observational study using data on SNs screening, HRQoL (i.e., low mental and physical health), and 90-day HCU (i.e., emergency visits and hospital admission). Among patients with any SNs, latent class analysis was conducted to identify unique PSNs. For all patients and by race and age subgroups, compared with no SNs, we calculated the risks of poor HRQoL and time to first HCU following SNs screening for each PSN. PATIENTS: Adult patients undergoing SNs screening at the Mass General Brigham healthcare system in Massachusetts, United States, between March 2018 and January 2023. MAIN MEASURES: SNs included: education, employment, family care, food, housing, medication, transportation, and ability to pay for household utilities. HRQoL was assessed using the Patient-Reported Outcomes Measurement Information System Global-10. KEY RESULTS: Six unique PSNs were identified: "high number of social needs," "food and utility access," "employment needs," "interested in education," "housing instability," and "transportation barriers." In 14,230 patients with HRQoL data, PSNs increased the risks of poor mental health, with risk ratios ranging from 1.07(95%CI:1.01-1.13) to 1.80(95%CI:1.74-1.86). Analysis of poor physical health yielded similar findings, except that the "interested in education" showed a mild protective effect (0.97[95%CI:0.94-1.00]). In 105,110 patients, PSNs increased the risk of 90-day HCU, with hazard ratios ranging from 1.09(95%CI:0.99-1.21) to 1.70(95%CI:1.52-1.90). Findings were generally consistent in subgroup analyses by race and age. CONCLUSIONS: Certain SNs coexist in distinct patterns and result in poorer HRQoL and more HCU. Understanding PSNs allows policymakers, public health practitioners, and social workers to identify at-risk patients and implement integrated, system-wide, and community-based interventions.

Development and perception of surgery-specific goals of care discussions in the preoperative setting: A learning pilot.

BACKGROUND: Goals of care discussions are infrequently documented in the preoperative period. Furthermore, documentation does not consistently address what matters most to patients, although patient values (PV) are central to person-centered care. METHODS: A multidisciplinary working group was formed. An electronic note comprised of (1) topics of discussion, (2) PV, and (3) advance care planning (ACP), was created and embedded into existing note templates for Gynecologic Surgical Oncology. Surgeons and advanced practice providers (APPs) were educated to conduct and document these conversations in preoperative clinic for patients undergoing cancer surgery for a pilot period. Data were collected regarding usage of the template. Focus groups with surgeons, APPs, and patients were conducted. Qualitative analysis was performed on transcripts. RESULTS: During the pilot, 7 surgeon/APP teams utilized the template on a total of 55 notes. Average number of notes completed per surgeon was 7.8 (SD 8.5). Forty-six notes (84%) included topics of discussion, 15 (27%) included PV, 4 (7%) included ACP. Qualitative analysis of focus group transcripts revealed that clinicians and patients perceived the initiative to be useful and important, although implementation barriers were identified. CONCLUSION: Creating a surgery-specific GOC template is feasible. Iterative revisions are needed to increase utility in clinic workflows.

Assessment of diagnostic delay, morbidity, and mortality outcomes in 302 calciphylaxis patients over a 17-year period: A retrospective cohort study.

BACKGROUND: Calciphylaxis patients historically have experienced diagnostic challenges and high morbidity; however limited data is available examining these characteristics over time. OBJECTIVE: The primary goals were to a) investigate factors associated with diagnostic delay of calciphylaxis and b) assess morbidity outcomes. The secondary goal was to provide updated mortality rates. METHODS: A retrospective review of 302 adult patients diagnosed with calciphylaxis between January 1, 2006 and December 31, 2022 was conducted. Univariate and multivariate statistical analyses were performed. RESULTS: Nonnephrogenic calciphylaxis (P = .0004) and involvement of the fingers (P = .0001) were significantly associated with an increased diagnostic delay, whereas involvement of the arms (P = .01) and genitalia (P = .022) resulted in fewer days to diagnosis. Almost all patients with genitalia, finger, or toe involvement had nephrogenic disease. The number of complications per patient decreased with time, especially for wound infections (P = .028), increase in lesion number (P = .012), and recurrent hospitalizations (P = .020). Updated 1-year mortality rates were 36.70% and 30.77% for nephrogenic and nonnephrogenic calciphylaxis, respectively. LIMITATIONS: Limitations include the retrospective nature and data from a single institution. CONCLUSION: Diagnostic delay, particularly in nonnephrogenic calciphylaxis, and complications per patient decreased with time, highlighting the importance of continued awareness to expedite diagnosis. Mortality rates have continued to improve in recent years.

Altered Cortical Activity during a Finger Tap in People with Stroke.

This study describes electroencephalography (EEG) measurements during a simple finger movement in people with stroke to understand how temporal patterns of cortical activation and network connectivity align with prolonged muscle contraction at the end of a task. We investigated changes in the EEG temporal patterns in the beta band (13-26 Hz) of people with chronic stroke (N = 10, 7 F/3 M) and controls (N = 10, 7 F/3 M), during and after a cued movement of the index finger. We quantified the change in beta band EEG power relative to baseline as activation at each electrode and the change in task-based phase-locking value (tbPLV) and beta band task-based coherence (tbCoh) relative to baseline coherence as connectivity between EEG electrodes. Finger movements were associated with a decrease in beta power (event related desynchronization (ERD)) followed by an increase in beta power (event related resynchronization (ERS)). The ERS in the post task period was lower in the stroke group (7%), compared to controls (44%) (p < 0.001) and the transition from ERD to ERS was delayed in the stroke group (1.43 s) compared to controls (0.90 s) in the C3 electrode (p = 0.007). In the same post movement period, the stroke group maintained a heightened tbPLV (p = 0.030 for time to baseline of the C3:Fz electrode pair) and did not show the decrease in connectivity in electrode pair C3:Fz that was observed in controls (tbPLV: p = 0.006; tbCoh: p = 0.023). Our results suggest that delays in cortical deactivation patterns following movement coupled with changes in the time course of connectivity between the sensorimotor and frontal cortices in the stroke group might explain clinical observations of prolonged muscle activation in people with stroke. This prolonged activation might be attributed to the combination of cortical reorganization and changes to sensory feedback post-stroke.

Moderate and Severe Chronic Kidney Disease Predict Greater 5-Year Mortality following Major Lower-Extremity Amputation.

BACKGROUND: Severe chronic kidney disease (CKD) predicts greater mortality after major lower-extremity amputation (LEA), but it remains poorly understood whether patients with earlier stages of CKD share similar risk. METHODS: We assessed long-term postoperative outcomes for patients with CKD in a retrospective chart review of 565 patients who underwent atraumatic major LEA at a large tertiary referral center from 2015 to 2021. We stratified patients by renal function and compared outcomes including survival. RESULTS: Preoperative CKD diagnosis was related to many patient characteristics, co-occurred with many comorbidities, and was associated with less follow-up and survival. Kaplan-Meier and Cox Regression analyses showed significantly worse 5-year survival for major LEA patients with mild, moderate, or severe CKD compared to major LEA patients with no history of CKD at the time of amputation (P < 0.001). Severe CKD independently predicted worse mortality at 1-year (odds ratio [OR] 2.91; P = 0.003) and 5-years (OR 3.08; P < 0.001). Moderate CKD independently predicted worse 5-year mortality (OR 2.66; P = 0.029). CONCLUSIONS: This study demonstrates that moderate and severe CKD predict greater long-term mortality following major LEA when controlling for numerous potential confounders. This finding raises questions about the underlying mechanism if causal and highlights an opportunity to improve outcomes with earlier recognition and optimization CKD preoperatively.

Sex differences in laterality of motor unit firing behavior of the first dorsal interosseous muscle in strength-matched healthy young males and females.

PURPOSE: The purpose of this study was to compare laterality in motor unit firing behavior between females and males. METHODS: Twenty-seven subjects (14 females) were recruited for this study. The participants performed ramp up and hold isometric index finger abduction at 10, 30, and 60% of their maximum voluntary contraction (MVC). High-density surface electromyography (HD-sEMG) signals were recorded in the first dorsal interosseous (FDI) muscle and decomposed into individual motor unit (MU) firing behavior using a convolution blind source separation method. RESULTS: In total, 769 MUs were detected (females, n = 318 and males, n = 451). Females had a significantly higher discharge rate than males at each relative torque level (10%: male dominant hand, 13.4 ± 2.7 pps vs. female dominant hand, 16.3 ± 3.4 pps; 30%: male dominant hand, 16.1 ± 3.9 pps vs. female dominant hand, 20.0 ± 5.0 pps; and 60%: male dominant hand, 19.3 ± 3.8 vs. female dominant hand, 25.3 ± 4.8 pps; p < 0.0001). The recruitment threshold was also significantly higher in females than in males at 30 and 60% MVC. Furthermore, males exhibited asymmetrical discharge rates at 30 and 60% MVC and recruitment thresholds at 30 and 60% MVC, whereas no asymmetry was observed in females. CONCLUSION: In the FDI muscle, compared to males, females exhibited different neuromuscular strategies with higher discharge rates and recruitment thresholds and no asymmetrical MU firing behavior. Notably, the findings that sex differences in neuromuscular activity also occur in healthy individuals provide important information for understanding the pathogenesis of various diseases.

Immediate effect of local vibration on motor unit firing behavior and muscle strength in healthy young adult males.

PURPOSE: The aim of this study was to examine the effect of vibration on motor unit (MU) firing behavior and physical performance of antagonist muscles in healthy young adult males. METHODS: Fourteen males (age = 24.3 ± 3.6 years) were included in this study. There were two conditions, one in which participants received 80 Hz vibration in the distal tendon of the hamstring for 30 s and the control condition (no vibration). High-density surface electromyography (HD-SEMG) signals and maximal voluntary contraction (MVC) of knee extensor muscles were evaluated before and after the respective conditions and recorded from the vastus lateralis muscle during submaximal ramp-up and sustained contractions at 30% MVC. Convolution blind source separation was used to decompose the HD-SEMG signals into individual MU firing behaviors. RESULTS: In total, 739 MUs were detected (control; 360 MUs and vibration; 379 MUs), and a total of 312 matched MUs were identified across both submaximal contraction conditions (control: 150 MUs; vibration: 162 MUs). Vibration significantly increased the discharge rate (p = 0.047) and decreased the recruitment threshold before and after intervention (p = 0.001) but not in the control condition. Furthermore, the recruitment threshold is a factor that influences discharge rate. Significant correlations were observed between the recruitment threshold and both the ∆ discharge rate and the ∆ recruitment threshold under the vibration condition (p < 0.001). CONCLUSION: Vibration increased in the discharge rate and decreased the recruitment threshold of the antagonist muscle. These findings suggested that vibration contributes to immediate changes in the neural control of antagonist muscles.

Dural arteriovenous fistula in the setting of cerebral venous sinus thrombosis and COVID-19 infection.

OBJECTIVE: The aim of this study was to examine the presence of concurrent venous thrombosis and COVID-19 infections in patients with dural arteriovenous fistulas (dAVFs). METHODS: An analysis of all patients diagnosed with dAVF via cerebral angiography by the senior author was conducted, with special attention given to the presence of cerebral venous sinus thrombosis (CVST) and COVID-19 infection. General demographics, clinical presentation, presence of CVST, and COVID-19 infection status were reported. RESULTS: A total of 30 patients with dAVFs were included in this study. Three patients were diagnosed with COVID-19 (10%), with one of these patients developing CVST (33%) at 6 months postinfection. Of the 27 patients not infected with COVID-19, one was diagnosed with a likely chronic CVST at the time of presentation of dAVF (4%). A total of 11 case reports and 3 retrospective studies describing patients diagnosed with CVST at or after diagnosis of dAVFs have been reported in the literature. The incidence of dAVFs in patients with CVST has been reported as 2.4%, and the incidence of dAVF has reportedly increased five- to tenfold since the COVID-19 pandemic. CONCLUSIONS: COVID-19 infections may pose as an emerging risk factor for the development of CVST and subsequent dAVF development. To the authors' knowledge, this study presents the first cases in the literature describing a temporal relationship between COVID-19 and development of a dAVF with CVST. The effect of both COVID-19 and associated vaccines should be further assessed in future studies to examine its impact as an effect modifier on the association of dAVF and CVST.

Socioeconomic Disparities in Postoperative Outcomes of Osteocutaneous Fibula Free Flaps for Head and Neck Reconstruction.

BACKGROUND: Osteocutaneous fibula free flaps (FFFs) are a fundamental component of reconstructive surgery in the head and neck region, particularly after traumatic injuries or oncologic resections. Despite their utility, FFFs are associated with various postoperative complications, such as infection, flap failure, and donor site morbidity, impacting up to 54% of cases. This study aimed to investigate the influence of socioeconomic variables, with a particular focus on median household income (MHI), on the incidence of postoperative complications in FFF reconstruction for head and neck cancer. METHODS: A retrospective analysis of 80 patients who underwent FFF reconstruction for head and neck cancer at a single center from 2016 to 2022 was conducted. Demographic and patient characteristics, including race, MHI, insurance type, history of radiation therapy, and TNM (tumor, node, metastasis) cancer stage, were evaluated. Logistic regression, controlling for comorbidities, was used to assess the impact of MHI on 30-, 90-, and 180-day postoperative complications. RESULTS: The patient population was predominantly male (n = 51, 63.8%) and White (n = 63, 78.8%), with the majority falling within the $55,000 to $100,000 range of MHI (n = 51, 63.8%). Nearly half of the patients had received neoadjuvant radiation treatment (n = 39, 48.75%), and 36.25% (n = 29) presented with osteoradionecrosis. Logistic regression analysis revealed that the $55,000-$100,000 MHI group had significantly lower odds of developing complications in the 0- to 30-day postoperative period when compared with those in the <$55,000 group (odds ratio [OR], 0.440; 95% confidence interval [CI], 0.205-0.943; P = 0.035). This trend persisted in the 31- to 90-day period (OR, 0.136; 95% CI, 0.050-0.368; P < 0.001) and was also observed in the likelihood of flap takeback. In addition, the $100,000-$150,000 group had significantly lower odds of developing complications in the 31- to 90-day period (OR, 0.182; 95% CI, 0.035-0.940; P = 0.042). No significant difference was found in the >$150,000 group. CONCLUSIONS: Median household income is a significant determinant and potentially a more influential factor than neoadjuvant radiation in predicting postoperative complications after FFF reconstruction. Disparities in postoperative outcomes based on income highlight the need for substantial health care policy shifts and the development of targeted support strategies for patients with lower MHI.

The role of cochlear and vestibular afferents in long-latency cervical vestibular evoked myogenic potentials.

OBJECTIVE: To examine the origin of cervical vestibular evoked myogenic potential (cVEMP) late waves (n34-p44) elicited with air-conducted click stimuli. DESIGN: Using a retrospective design, cVEMPs from normal volunteers were compared to those obtained from patients with vestibular and auditory pathologies. STUDY SAMPLE: (1) Normal volunteers (n = 56); (2) severe-to-profound sensorineural hearing loss (SNHL) with normal vestibular function (n = 21); (3) peripheral vestibular impairment with preserved hearing (n = 16); (4) total vestibulocochlear deficit (n = 23). RESULTS: All normal volunteers had ipsilateral-dominant early p13-n23 peaks. Late peaks were present bilaterally in 78%. The p13-n23 response was present in all patients with SNHL but normal vestibular function, and 43% had late waves. Statistical comparison of these patients to a subset of age-matched controls showed no significant difference in the frequencies, amplitudes or latencies of their ipsilateral early and late peaks. cVEMPs were absent in all patients with vestibular impairment. CONCLUSION: The presence of long-latency cVEMP waves was not dependent on the integrity of sensorineural hearing pathways, but instead correlated with intact vestibular function. This finding conflicts with the view that these late waves are cochlear in origin, and suggests that vestibular afferents may assume a more prominent role in their generation.

Changing the "scope" of diagnosing endometriosis: the new frontier of noninvasive markers.

Endometriosis affects 1 in 9 women, and diagnosis is often delayed using conventional laparoscopy. Noninvasive markers of endometriosis have the potential to enable earlier diagnosis, leading to more timely treatment and better surgical planning. This issue's Views and Reviews seek to summarize the current status of noninvasive markers of endometriosis. Experts in reproductive medicine with prior work in this field summarize the key literature on endometrial biomarkers, blood biomarkers, and advanced imaging, including ultrasound and magnetic resonance imaging. At present, there is no single definitive biomarker that can diagnose endometriosis with high sensitivity and specificity. Advancing endometriosis biomarkers beyond the discovery phase is challenging, and more work is needed. Clinicians who have an improved understanding of noninvasive imaging and biomarkers will be able to identify endometriosis earlier and more easily, allowing for prompt consideration of treatment options. We believe that continued research, innovation, and development will lead to improved diagnostic accuracy and guidance toward the best treatments for endometriosis-related pain and infertility.

Rivastigmine for treatment-refractory posttraumatic stress disorder: a systematic review.

We conducted a systematic review evaluating the efficacy of rivastigmine augmentation for treatment-refractory posttraumatic stress disorder (PTSD). The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. The databases Ovid MEDLINE, PubMed, CINAHL, and EMBASE were searched using key words: 'rivastigmine' OR 'Exelon' OR 'rivastigmine augmentation' OR 'Exelon augmentation' AND 'posttraumatic stress disorder*' OR 'post-traumatic stress disorder*' OR 'PTSD' OR 'combat disorder*' OR 'post-traumatic symptoms'. The asterisk specified plural forms of the relevant word. Four papers were identified, comprising one double-blind randomised controlled trial, one non-controlled open trial, one case series (presenting three case studies), and one paper with two case studies. The randomised controlled trial found no statistically significant difference in efficacy, using the PTSD CheckList-Military Version as the relevant outcomes measure, between the active add-on rivastigmine interventions and placebo or treatment as usual. The open trial, although reporting relatively positive outcomes, had a weak study design and lacked reporting of key information, including participant sex and age and pre-rivastigmine PTSD measures. The assessment of efficacy was based on participants' reporting of subjective benefits, and clinician-rating using a Clinical Global Impression, rather than established PTSD assessments scales. Although the five case studies reported improvement in PTSD symptoms, there were confounding factors and limitations in clinical and demographic data, warranting caution regarding attributed benefits. There is a lack of methodologically robust evidence supporting the efficacy of add-on rivastigmine for the treatment of refractory PTSD. Additional research may help in further evaluating its possible clinical efficacy.

Predicting fungal secondary metabolite activity from biosynthetic gene cluster data using machine learning.

Fungal secondary metabolites (SMs) contribute to the diversity of fungal ecological communities, niches, and lifestyles. Many fungal SMs have one or more medically and industrially important activities (e.g., antifungal, antibacterial, and antitumor). The genes necessary for fungal SM biosynthesis are typically located right next to each other in the genome and are known as biosynthetic gene clusters (BGCs). However, whether fungal SM bioactivity can be predicted from specific attributes of genes in BGCs remains an open question. We adapted machine learning models that predicted SM bioactivity from bacterial BGC data with accuracies as high as 80% to fungal BGC data. We trained our models to predict the antibacterial, antifungal, and cytotoxic/antitumor bioactivity of fungal SMs on two data sets: (i) fungal BGCs (data set comprised of 314 BGCs) and (ii) fungal (314 BGCs) and bacterial BGCs (1,003 BGCs). We found that models trained on fungal BGCs had balanced accuracies between 51% and 68%, whereas training on bacterial and fungal BGCs had balanced accuracies between 56% and 68%. The low prediction accuracy of fungal SM bioactivities likely stems from the small size of the data set; this lack of data, coupled with our finding that including bacterial BGC data in the training data did not substantially change accuracies currently limits the application of machine learning approaches to fungal SM studies. With >15,000 characterized fungal SMs, millions of putative BGCs in fungal genomes, and increased demand for novel drugs, efforts that systematically link fungal SM bioactivity to BGCs are urgently needed.IMPORTANCEFungi are key sources of natural products and iconic drugs, including penicillin and statins. DNA sequencing has revealed that there are likely millions of biosynthetic pathways in fungal genomes, but the chemical structures and bioactivities of >99% of natural products produced by these pathways remain unknown. We used artificial intelligence to predict the bioactivities of diverse fungal biosynthetic pathways. We found that the accuracies of our predictions were generally low, between 51% and 68%, likely because the natural products and bioactivities of only very few fungal pathways are known. With >15,000 characterized fungal natural products, millions of putative biosynthetic pathways present in fungal genomes, and increased demand for novel drugs, our study suggests that there is an urgent need for efforts that systematically identify fungal biosynthetic pathways, their natural products, and their bioactivities.

Cannabidiol as a potential cessation therapeutic: Effects on intravenous nicotine self-administration and withdrawal symptoms in mice.

Cigarette smoking remains a leading cause of preventable disease and death worldwide. Due to the devastating negative health effects of smoking, many users attempt to quit, but few are successful in the long-term. Thus, there is a critical need for novel therapeutic approaches. In these investigations, we sought to examine whether cannabidiol (CBD) has the potential to be repurposed as a nicotine cessation therapeutic. In the first study, male and female mice were trained to respond for intravenous nicotine infusions at either a low or moderate nicotine dose and then were pretreated with CBD prior to their drug-taking session. We found that CBD produced a significant decrease in the number of nicotine rewards earned, and this effect was evidenced across CBD doses and with both the low and moderate levels of nicotine intake. These effects on drug intake were not due to general motor-related effects, since mice self-administering food pellets did not alter their behavior with CBD administration. The potential effects of CBD in mitigating nicotine withdrawal symptoms were then investigated. We found that CBD attenuated the somatic signs of nicotine withdrawal and prevented nicotine's hyperalgesia-inducing effects. Taken together, these results demonstrate that modulation of cannabinoid signaling may be a viable therapeutic option as a smoking cessation aid.

Hidden consequences of political discourse at work: How and why ambient political conversations impact employee outcomes.

Discussions of politics have become increasingly common in the workplace, likely due to increasing political polarization around the world. Because of this, political conversations have the potential to be emotionally charged and disruptive, creating tension in the workplace and negatively affecting employee productivity and well-being. In light of this possibility, the goal of the current investigation was to examine the costs of ambient political conversations in the workplace, assuming that simply overhearing such discussions-without being a participant in them-may have unintended consequences for employees. Across three studies, our findings indicated that employees experience negative affect after overhearing political conversations at work, with these effects being attenuated (amplified) in contexts where employees perceive that their coworkers are more (less) similar to them. In addition to unpacking the mechanisms through which ambient workplace political conversations might impact employee outcomes, our findings from Studies 3A-B provide evidence that under certain circumstances (i.e., when employees agree with the content of ambient workplace political conversations), employees may experience a boost in positive affect after overhearing such conversations at work. Altogether, our findings provide insight into the costs and potential benefits associated with overhearing coworkers discussing politics in the workplace, particularly for those employees who perceive themselves to be dissimilar from their coworkers. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

People with degenerative cervical myelopathy have impaired reactive balance during walking.

BACKGROUND: People with degenerative cervical myelopathy are known to have impaired standing balance and walking abilities, but less is known about balance responses during walking. RESEARCH QUESTION: The aim of this project was to assess reactive balance impairments during walking in people with degenerative cervical myelopathy (PwDCM). We hypothesized that center of mass motion following perturbations would be larger in PwDCM and gluteus medius electromyographic amplitude responses would be decreased in PwDCM. METHODS: Reactive balance responses were quantified during unanticipated lateral pulls to the waist while treadmill walking. Walking biomechanics data were collected from 10 PwDCM (F=6) and 10 non-myelopathic controls (F=7) using an 8 camera Vicon System (Vicon MX T-Series). Electromyography was collected from lower limb muscles. Participants walked on an instrumented treadmill and received lateral pulls at random intervals and in randomized direction at 5% and 2.5% body mass. Participants walked at 3 prescribed foot placements to control for effects of the size of base of support. RESULTS: As compared with controls, the perturbation-related positional change of the center of mass motion (ΔCOM) was increased in PwDCM (p=0.001) with similar changes in foot placement (p>0.05). Change in gluteus medius electromyography, however, was less in PwDCM than in controls (p<0.001). SIGNIFICANCE: After experimentally controlling step width, people with mild-to-moderate degenerative cervical myelopathy at least 3 months following cervical spine surgery have impaired reactive balance during walking likely coupled with reduced gluteus medius electromyographic responses. Rehabilitation programs focusing on reactive balance and power are likely necessary for this population.

The RNA cargo of Myxococcus outer membrane vesicles.

The outer membrane vesicles (OMVs) secreted by some Gram-negative bacteria contain RNA cargo, which can be introduced into target cells, affecting their cellular processes. To test whether the antimicrobial OMVs secreted by predatory myxobacteria might contain cargo RNA with a role in prey killing, we purified OMVs and cells from four different strains of Myxococcus spp. for RNA-seq transcriptome sequencing. Myxobacterial OMVs contained distinct sets of RNA molecules. The abundance of major cellular transcripts correlated strongly with their abundance in OMVs, suggesting non-specific packaging into OMVs. However, many major cellular transcripts were absent entirely from OMVs and some transcripts were found exclusively in OMVs, suggesting OMV RNA cargo loading is not simply a consequence of sampling the cellular transcriptome. Despite considerable variation in OMV RNA cargo between biological replicates, a small number of transcripts were found consistently in replicate OMV preparations. These 'core' OMV transcripts were often found in the OMVs from multiple strains, and sometimes enriched relative to their abundance in cellular transcriptomes. In addition to providing the first transcriptomes for myxobacterial OMVs, and the first cellular transcriptomes for three strains of Myxococcus spp., we highlight five transcripts for further study. These transcripts are 'core' for at least two of the three strains of M. xanthus studied, and encode two alkyl hydroperoxidase proteins (AhpC and AhpD), two ribosome-associated inhibitors (RaiA-like) and a DO-family protease. It will be interesting to test whether the transcripts serve a biological function within OMVs, potentially being transported into prey cells for translation into toxic proteins.