Progressive Ratio Research Articles

SURG-14. PATTERNS OF PROGRESSION OF TEMPORAL LOBE GLIOBLASTOMAS: EVIDENCE FOR THE ROLE OF TEMPORAL LOBECTOMY

Abstract Glioblastomas extend beyond the contrast-enhancing tumor, and supramaximal resections into non-enhancing (NE) tumor improves survival. Yet, supramaximal resection is difficult to achieve in most cases. For temporal lobe tumors, supramaximal anterior temporal lobe resection is feasible and safe. Case series have shown a survival advantage by resecting the anterior temporal lobe. This study aims to explore patterns of tumor progression in temporal lobe glioblastomas and whether the presence of NE tumor in the temporal tip could be used as a biomarker to predict the site of progression. We searched a single institution tumor database looking for patients who had glioblastomas in the temporal lobe, who underwent complete resection of enhancing tumor, and went on to have chemoradiotherapy. Patients needed to have imaging demonstrating first progression. We determined pre-operatively if NE tumor had extended into the temporal tip. At progression, the direction of tumor progression was recorded and assessed if it would have been resected should a lobectomy have been performed. We identified 55 patients that fulfilled our entry criteria (mean age 57.7 years, range 19.6-72.9; 37 male). In 16 cases, the anterior temporal lobe was resected; these patients were not used in further assessments. In 25 cases (64.1%), the tumor progressed into the residual anterior temporal lobe. In 16 cases (41.0%), a lobectomy would have encompassed the area of progression. NE tumor was seen in the tip in 28 cases (71.8%). This could predict progression into the anterior temporal lobe with a sensitivity of 76.2% (95%CI: 54.9-90.6%) and specificity of 33.1% (95%CI: 11.8-61.6%). The likelihood ratio of tumor progression was 1.14 (95%CI: 0.75-1.74). We conclude that temporal lobe glioblastomas most commonly progress into the anterior temporal lobe, but NE tumor is not a suitable predictive biomarker. Developing suitable biomarkers and biomarker-driven trials of temporal lobectomy for glioblastomas are needed.

Large-scale characterization of cocaine addiction-like behaviors reveals that escalation of intake, aversion-resistant responding, and breaking-points are highly correlated measures of the same construct.

Addiction is commonly characterized by escalation of drug intake, compulsive drug seeking, and continued use despite harmful consequences. However, the factors contributing to the transition from moderate drug use to these problematic patterns remain unclear, particularly regarding the role of sex. Many preclinical studies have been limited by small sample sizes, low genetic diversity, and restricted drug access, making it challenging to model significant levels of intoxication or dependence and translate findings to humans. To address these limitations, we characterized addiction-like behaviors in a large sample of >500 outbred heterogeneous stock (HS) rats using an extended cocaine self-administration paradigm (6 hr/daily). We analyzed individual differences in escalation of intake, progressive ratio (PR) responding, continued use despite adverse consequences (contingent foot shocks), and irritability-like behavior during withdrawal. Principal component analysis showed that escalation of intake, progressive ratio responding, and continued use despite adverse consequences loaded onto a single factor that was distinct from irritability-like behaviors. Categorizing rats into resilient, mild, moderate, and severe addiction-like phenotypes showed that females exhibited higher addiction-like behaviors, with a lower proportion of resilient individuals compared to males. These findings suggest that, in genetically diverse rats with extended drug access, escalation of intake, continued use despite adverse consequences, and PR responding are highly correlated measures of a shared underlying construct. Furthermore, our results highlight sex differences in resilience to addiction-like behaviors.

Transient impact of chronic social stress on effort-based reward motivation in non-food restricted mice: involvement of corticosterone.

Chronic stress has been connected to a reduced effort and motivational deficits. To study effort-based motivation in rodents, operant conditioning is often employed. However, caloric restriction is typically imposed simultaneously. Since caloric restriction is a stressor in its own right, this procedure interferes with data interpretation. Here, we investigate whether chronic social defeat stress (CSD), lasting 10 consecutive days, would alter effort-based reward motivation in mice trained under ad libitum food conditions. Utilizing operant FED3 boxes in home cages, mice were trained within eight days to nose poke for palatable food. After training completion, operant memory was retained for at least 16 days, and mice demonstrated sustained effort, as assessed with a progressive ratio schedule, to obtain reward pellets. Directly after CSD exposure (10th day), mice exhibited reduced effort for palatable food rewards, but also displayed reduced nose poking in general. The effects of CSD on effort were short-lived, with no lasting impact on effort-based reward motivation one week post-stress. As corticosterone (CORT) levels were increased at day 10 of CSD, but not at day 17, we hypothesized that CORT might mediate the acute effects of CSD on effort-based reward motivation. Indeed, CORT administration [100 μg/ml], supplied via the drinking water, mirrored the CSD-induced CORT spike and temporarily reduced reward motivation. Our findings emphasize that CSD does not result in long-term deficits in reward motivation, suggesting a resilient adaptive response in mice under unrestricted feeding conditions. This study underscores the necessity of considering temporal dynamics of stress impacts and highlights the modulating effects of CORT. These insights contribute to a deeper understanding of the resilience mechanisms in motivational impairments and pave the way for further research into factors facilitating this resilience.

Inavolisib-Based Therapy in PIK3CA-Mutated Advanced Breast Cancer

BackgroundInavolisib is a highly potent and selective inhibitor of the alpha isoform of the p110 catalytic subunit of the phosphatidylinositol 3-kinase complex (encoded by PIK3CA) that also promotes the degradation of mutated p110α. Inavolisib plus palbociclib–fulvestrant has shown synergistic activity in preclinical models and promising antitumor activity in early-phase trials.MethodsIn a phase 3, double-blind, randomized trial, we compared first-line inavolisib (at an oral dose of 9 mg once daily) plus palbociclib–fulvestrant (inavolisib group) with placebo plus palbociclib–fulvestrant (placebo group) in patients with PIK3CA-mutated, hormone receptor–positive, human epidermal growth factor receptor 2 (HER2)–negative locally advanced or metastatic breast cancer who had had relapse during or within 12 months after the completion of adjuvant endocrine therapy. The primary end point was progression-free survival as assessed by the investigator.ResultsA total of 161 patients were assigned to the inavolisib group and 164 to the placebo group; the median follow-up was 21.3 months and 21.5 months, respectively. The median progression-free survival was 15.0 months (95% confidence interval [CI], 11.3 to 20.5) in the inavolisib group and 7.3 months (95% CI, 5.6 to 9.3) in the placebo group (hazard ratio for disease progression or death, 0.43; 95% CI, 0.32 to 0.59; P<0.001). An objective response occurred in 58.4% of the patients in the inavolisib group and in 25.0% of those in the placebo group. The incidence of grade 3 or 4 neutropenia was 80.2% in the inavolisib group and 78.4% in the placebo group; grade 3 or 4 hyperglycemia, 5.6% and 0%, respectively; grade 3 or 4 stomatitis or mucosal inflammation, 5.6% and 0%; and grade 3 or 4 diarrhea, 3.7% and 0%. No grade 3 or 4 rash was observed. Discontinuation of any trial agent because of adverse events occurred in 6.8% of the patients in the inavolisib group and in 0.6% of those in the placebo group.ConclusionsIn patients with PIK3CA-mutated, hormone receptor–positive, HER2-negative locally advanced or metastatic breast cancer, inavolisib plus palbociclib–fulvestrant led to significantly longer progression-free survival than placebo plus palbociclib–fulvestrant, with a greater incidence of toxic effects. The percentage of patients who discontinued any trial agent because of adverse events was low. (Funded by F. Hoffmann–La Roche; INAVO120 ClinicalTrials.gov number, NCT04191499.)

Neutrophil‑to‑lymphocyte ratio and risk of disease progression in patients with nivolumab‑treated unresectable or recurrent gastric cancer.

Studies have associated neutrophil-to-lymphocyte ratio (NLR) with overall survival (OS) and progression-free survival (PFS) in patients with gastric cancer (GC). The present study aimed to examine the relationship between dynamic changes in NLR during treatment and disease progression in patients with unresectable or recurrent GC treated with nivolumab monotherapy as a third-line or later regimen. Patients treated with nivolumab as a third-line or later therapy for unresectable or recurrent GC at Gifu University Hospital (Gifu, Japan) from April 2017 to December 2021 were included. Pretreatment data and those obtained every 2 weeks after the treatment commenced were evaluated. The association between all NLR values and disease progression for each patient was evaluated using a time-dependent Cox proportional hazards model and restricted cubic spline (RCS) curves. The study included 44 patients (23 men and 21 women). The response and disease control rates were 6.8 and 27.3%, respectively. The median PFS and OS of all patients were 1.84 months [95% confidence interval (CI), 1.32-2.14] and 5.93 months (95% CI, 3.75-10.75), respectively. The risk for progressive disease (PD) increased with higher NLR (hazard ratio, 2.25; 95% CI, 1.3-3.87). The RCS curves also indicated that the higher the NLR, the higher the risk for PD, especially if the NLR value was <3.0. NLR during treatment could predict the risk of PD, suggesting that NLR could be integrated with tumor markers, computed tomographic images and other modalities to enable treatment selection without delay.

Nivolumab+AVD in Advanced-Stage Classic Hodgkin’s Lymphoma

BackgroundIncorporating brentuximab vedotin into the treatment of advanced-stage classic Hodgkin’s lymphoma improves outcomes in adult and pediatric patients. However, brentuximab vedotin increases the toxic effects of treatment in adults, more than half of pediatric patients who receive the drug undergo consolidative radiation, and relapse remains a challenge. Programmed death 1 blockade is effective in Hodgkin’s lymphoma, including in preliminary studies involving previously untreated patients.MethodsWe conducted a phase 3, multicenter, open-label, randomized trial involving patients at least 12 years of age with stage III or IV newly diagnosed Hodgkin’s lymphoma. Patients were randomly assigned to receive brentuximab vedotin with doxorubicin, vinblastine, and dacarbazine (BV+AVD) or nivolumab with doxorubicin, vinblastine, and dacarbazine (N+AVD). Prespecified patients could receive radiation therapy directed to residual metabolically active lesions. The primary end point was progression-free survival, defined as the time from randomization to the first observation of progressive disease or death from any cause.ResultsOf 994 patients who underwent randomization, 970 were included in the intention-to-treat population for efficacy analyses. At the second planned interim analysis, with a median follow-up of 12.1 months, the threshold for efficacy was crossed, indicating that N+AVD significantly improved progression-free survival as compared with BV+AVD (hazard ratio for disease progression or death, 0.48; 99% confidence interval [CI], 0.27 to 0.87; two-sided P=0.001). Owing to the short follow-up time, we repeated the analysis with longer follow-up; with a median follow-up of 2.1 years (range, 0 to 4.2 years), the 2-year progression-free survival was 92% (95% CI, 89 to 94) with N+AVD, as compared with 83% (95% CI, 79 to 86) with BV+AVD (hazard ratio for disease progression or death, 0.45; 95% CI, 0.30 to 0.65). Overall, 7 patients received radiation therapy. Immune-related adverse events were infrequent with nivolumab; brentuximab vedotin was associated with more treatment discontinuation.ConclusionsN+AVD resulted in longer progression-free survival than BV+AVD in adolescents and adults with stage III or IV advanced-stage classic Hodgkin’s lymphoma and had a better side-effect profile. (Funded by the National Cancer Institute of the National Institutes of Health and others; S1826 ClinicalTrials.gov number, NCT03907488.)

Catalase, superoxide dismutase and butylated hydroxytoluene benefit mid-term storage of red-legged partridge sperm (Alectoris rufa)

ABSTRACT 1. The present study assessed the effect of different antioxidants on the quality of chilled/frozen-thawed sperm of red-legged partridge. 2. Sperm samples from 40 red-legged partridges were collected and extended 1:1 (v:v) with Lake and Ravie 84, supplemented with ascorbic acid or butylated hydroxytoluene (BHT) at 0, 0.2, 0.4, 0.8 mM and catalase (CAT) or superoxide dismutase (SOD) at 0, 100, 200 and 300 IU/ml. Ten sperm samples were used per concentration. Motility and viability were evaluated in fresh and after 6 h of chilling at 5°C or after freezing-thawing. 3. For chilled sperm, the presence of ascorbic acid decreased viability and several motility variables; BHT 0.8 mM increased non-progressive motility (NPM, 26.7 ± 1.99 vs. 20.7 ± 2.12); CAT 200 IU/ml improved the rectilinear velocity (40.4 ± 4.63 μ/s vs. 29.9 ± 4.62 μ/s) and linear progression ratio (52.8 ± 3.11% vs. 45.4 ± 2.98%); SOD 100 IU/ml increased NPM (24.5 ± 1.21% vs. 19.3 ± 1.75%) and tended to improve total progressive motility (42.7 ± 3.33% vs. 33.2 ± 3.26%, p = 0.07). Using an extender supplemented with CAT 200 or SOD 100 did not improve the post-thawed sperm quality. 4. The present work provides an advance in the optimisation of chilling and freezing protocols for red-legged partridge sperm.

Durvalumab after Chemoradiotherapy in Limited-Stage Small-Cell Lung Cancer.

Adjuvant therapy with durvalumab, with or without tremelimumab, may have efficacy in patients with limited-stage small-cell lung cancer who do not have disease progression after standard concurrent platinum-based chemoradiotherapy. In a phase 3, double-blind, randomized, placebo-controlled trial, we assigned patients to receive durvalumab at a dose of 1500 mg, durvalumab (1500 mg) plus tremelimumab at a dose of 75 mg (four doses only), or placebo every 4 weeks for up to 24 months. Randomization was stratified according to disease stage (I or II vs. III) and receipt of prophylactic cranial irradiation (yes vs. no). Results of the first planned interim analysis of the two primary end points of overall survival and progression-free survival (assessed on the basis of blinded independent central review according to the Response Evaluation Criteria in Solid Tumors, version 1.1) with durvalumab as compared with placebo (data cutoff date, January 15, 2024) are reported; results in the durvalumab-tremelimumab group remain blinded. A total of 264 patients were assigned to the durvalumab group, 200 to the durvalumab-tremelimumab group, and 266 to the placebo group. Durvalumab therapy led to significantly longer overall survival than placebo (median, 55.9 months [95% confidence interval {CI}, 37.3 to not reached] vs. 33.4 months [95% CI, 25.5 to 39.9]; hazard ratio for death, 0.73; 98.321% CI, 0.54 to 0.98; P = 0.01), as well as to significantly longer progression-free survival (median 16.6 months [95% CI, 10.2 to 28.2] vs. 9.2 months [95% CI, 7.4 to 12.9]; hazard ratio for progression or death, 0.76; 97.195% CI, 0.59 to 0.98; P = 0.02). The incidence of adverse events with a maximum grade of 3 or 4 was 24.4% among patients receiving durvalumab and 24.2% among patients receiving placebo; adverse events led to discontinuation in 16.4% and 10.6% of the patients, respectively, and led to death in 2.7% and 1.9%. Pneumonitis or radiation pneumonitis with a maximum grade of 3 or 4 occurred in 3.1% of the patients in the durvalumab group and in 2.6% of those in the placebo group. Adjuvant therapy with durvalumab led to significantly longer overall survival and progression-free survival than placebo among patients with limited-stage small-cell lung cancer. (Funded by AstraZeneca; ADRIATIC ClinicalTrials.gov number, NCT03703297.).

Chronic inflammatory pain reduces fentanyl intake during early acquisition of fentanyl self-administration, but does not change motivation to take fentanyl in male and female rats

The co-occurrence of chronic pain and opioid misuse has led to numerous preclinical investigations of pain-opioid interactions to examine how pain manipulations alter the reinforcing properties of opioids. However, preclinical investigations of chronic pain effects on opioid drug self-administration have produced inconsistent results. Our previous work demonstrated that established fentanyl self-administration is resistant to change by induction of chronic inflammatory pain (Complete Freund's Adjuvant; CFA) in male and female rats, while other laboratories have shown that CFA increased fentanyl self-administration in male but not female rats when pain induction precedes self-administration, which may be a critical factor in determining the effects of chronic pain on self-administration. The present study was designed similarly to Higginbotham et al. (2022) to test the effects of CFA on fentanyl self-administration in rats that underwent pain prior to acquisition of fentanyl self-administration. Male and female rats treated with hindpaw CFA or saline were trained to intravenously self-administer (IVSA) fentanyl for 3 weeks under limited access to fentanyl (2 h per day) conditions. After 3 weeks of fentanyl IVSA acquisition, we tested motivation to take fentanyl using progressive ratio testing and dose-response testing. CFA male and female rats self-administered less fentanyl than saline-treated controls during week 1 of acquisition, but not during weeks 2–3 of acquisition. Intra-session analysis of week 1 data demonstrated that chronic inflammatory pain suppressed fentanyl intake towards the end of week 1 and at the end of each operant session. We also report no effects of chronic inflammatory pain on motivation to take fentanyl. We discuss potential methodological explanations for differences between these results and prior reports. Our findings demonstrate that CFA temporarily suppresses fentanyl IVSA in animals without changing motivation to take fentanyl or promoting escalation of opioid use, suggesting that chronic inflammatory pain is unlikely to promote long-term risk of opioid misuse.

Anticipated buffer time – An evasive surrogate safety indicator for risk assessment of unsignalized intersections under heterogeneous traffic and aggressive driving conditions

Risk assessment of unsignalized intersections is particularly challenging when confronted with a combination of factors such as heavy traffic, diverse vehicle types, lane indiscipline, aggressive driving, and evasive manoeuvres. Understanding how people drive in these situations is crucial for accurately assessing the risks at unsignalized intersections. This study introduces a novel surrogate safety indicator, i.e. Anticipated Buffer Time (ABT), designed to account for these various factors. Additionally, three new indicators derived from ABT are introduced, namely ABT Negation Ratio, ABT Extremity Ratio, and ABT Progression Ratio. A risk assessment measure, denoted as UnSigRisk Score, is formulated using these three indicators for unsignalized intersections. Three intersections in Ahmedabad, India, were selected for the study due to their manifestation of these challenging conditions. Spearman Rank Correlation Coefficient was estimated to find out how well can UnSigRisk Score measure is able to quantify evasive behaviour. The results indicate that this score proficiently measures evasive behaviour, exhibiting coefficients exceeding 0.6 in all cases—significantly outperforming the current evasive indicators, Yaw Rate Ratio and Jerk. The proposed risk assessment score could serve as a practical tool for transportation authorities, enabling them to identify the most vulnerable intersections and allocate resources for targeted safety interventions wisely. The study unequivocally demonstrates that the use of ABT paves the way for a thorough examination of safety at unsignalized intersections, regardless of driving behaviour and traffic conditions.

Basal cortisol level modulates stress-induced opioid-seeking behavior

In preclinical studies and our human laboratory, the α2-noradrenergic autoreceptor antagonist yohimbine was found to promote drug-seeking behavior. This study evaluated effects of dose-combinations of yohimbine and the glucocorticoid receptor agonist hydrocortisone to model intensity-dependent effects of stimulating each neurochemical system, alone and together, on stress-reactivity and opioid-seeking. Twelve regular heroin-using participants diagnosed with opioid use disorder (OUD) were stabilized on sublingual buprenorphine (8-mg/day), then passed a hydromorphone 18-mg vs. placebo intramuscular reinforcement screen. Across 9 experimental conditions (3 × 3 within-subject, randomized crossover, placebo-controlled, double-blind design) during inpatient buprenorphine maintenance, combinations of oral pretreatment doses of yohimbine (0, 27, 54-mg; t = 0 min) then hydrocortisone (0, 20, 40-mg; t = 45 min) were administered. In each condition, subjective drug and mood effects, cardiovascular responses, and saliva cortisol and α-amylase levels were assessed to evaluate stress-reactivity, and participants completed a 12-trial choice progressive ratio task during which they could earn units of hydromorphone (1.5-mg intramuscular) and/or money ($2.00). Yohimbine dose-dependently increased blood pressure, α-amylase, and anxiety scores, and decreased opioid agonist symptoms; hydrocortisone dose-dependently increased cortisol levels. Yohimbine/hydrocortisone dose-combinations significantly shifted within-session responding from money to opioid-seeking among participants with lower basal cortisol levels. These findings replicate yohimbine effects on stress biomarkers and demonstrate that noradrenergic/glucocorticoid-potentiated opioid-seeking is modulated by basal cortisol level. In persons with OUD stabilized on buprenorphine, basal HPA-axis activity and acute stressors can enhance opioid relative reinforcing efficacy. These factors may limit OUD treatment efficacy and highlight the need for novel interventions that prevent stress-induced opioid-seeking.

Incentive motivation for palatable food blocked by intra-accumbens melanin-concentrating hormone (MCH) receptor-1 antagonist in female rats

Melanin-concentrating hormone (MCH) activity in the nucleus accumbens (Acb) has been shown to influence feeding behavior, yet this has not been characterized in terms of homeostatic vs. hedonic feeding processes. Hedonic feeding, driven by palatability rather than energy deficit, can be modeled through intra-Acb administration of the selective μ-opioid receptor agonist d-Ala2, NMe-Phe4, Glyol5-enkephalin (DAMGO), which preferentially increases consumption and incentive motivation to obtain preferred palatable food. Pharmacological activation of MCH 1 receptors (MCHR1) within Acb has been shown to promote general feeding of chow in males, but not females. However, the effects of MCH on the incentive motivation to obtain preferred palatable food have not been explored. Here, we investigated the role of MCHR1 within the Acb in DAMGO-induced incentive motivation to obtain a sucrose pellet reward. Female Sprague Dawley rats were trained and tested for operant responding under a progressive ratio (PR) breakpoint in response to concurrent intra-Acb administration of DAMGO (0 μg and 0.025 μg/.5 μl/side) immediately following intra-Acb administration of the MCHR1 antagonist (N-(3-{1-[4-(3,4-difluoro-phenoxy)-benzyl]-piperdin-4-yl}-4-methyl-phenyl)-isobutyramide (SNAP-94847; 0 μg, 1.5 μg, and 15 μg/.5 μl/side), in a counterbalanced fashion. As expected, DAMGO significantly increased PR breakpoint and overall active lever presses. SNAP-94847 did not influence PR breakpoint by itself, compared to vehicle; however, both 1.5 and 15 μg doses of SNAP-94847 significantly blocked the increased PR breakpoint produced by intra-Acb DAMGO. The results of the study demonstrate that Acb MCHR1 may play a specific role in the hedonically-driven motivation for palatable food in females.

The psychedelic drug DOI reduces heroin motivation by targeting 5-HT2A receptors in a heroin and alcohol co-use model

There has been a recent renewed interest in the potential use of psychedelic drugs as therapeutics for certain neuropsychiatric disorders, including substance use disorders. The psychedelic drug 2,5-dimethoxy-4-iodoamphetamine (DOI) has demonstrated therapeutic efficacy in preclinical models of opioid use disorder (OUD). Alcohol is commonly co-used in individuals with OUD, but preclinical models that recapitulate this comorbidity are lacking. We developed a polydrug model wherein male and female rats were allowed to self-administer intravenous heroin and oral alcohol (or saccharin control solution) over weeks of behavioral training, and then we conducted a series of progressive ratio tests to assess the animals' motivational state for heroin and alcohol. In this model, motivation for heroin is higher than alcohol, and DOI (0.4 mg/kg) administered prior to testing significantly reduced heroin motivation measured as the animals’ break point, or maximum effort the animal is willing to expend to obtain a single infusion of heroin. The 5-HT2A receptor antagonist MDL 100,907 (0.3 mg/kg), but not the 5-HT2C receptor antagonist SB-242084 (0.5 mg/kg), blocked the therapeutic effect of DOI on heroin motivation. No significant effects on alcohol break points were observed, nor did MDL 100,907 or SB-242084 have any effect on break points on their own. These data support the view that psychedelic drugs like DOI may have therapeutic effects on opioid use in individuals with OUD and comorbid alcohol use, by acting as a 5-HT2A receptor agonist.

Sex Differences in Home-Cage Ethanol Drinking and Operant Self-Administration in C57BL/6J Mice but Equivalent Regulation by Glutamate AMPAR Activity.

Considering sex as a biological variable (SABV) in preclinical research can enhance understanding of the neurobiology of alcohol use disorder (AUD). However, the behavioral and neural mechanisms underlying sex-specific differences remain unclear. This study aims to elucidate SABV in ethanol (EtOH) consumption by evaluating its reinforcing effects and regulation by glutamate AMPA receptor activity in male and female mice. C57BL/6J mice (male and female) were assessed for EtOH intake under continuous and limited access conditions in the home cage. Acute sensitivity to EtOH sedation and blood clearance were evaluated as potential modifying factors. Motivation to consume EtOH was measured using operant self-administration procedures. Sex-specific differences in neural regulation of EtOH reinforcement were examined by testing the effects of a glutamate AMPA receptor antagonist on operant EtOH self-administration. Female C57BL/6J mice exhibited a time-dependent escalation in EtOH intake under both continuous and limited access conditions. They were less sensitive to EtOH sedation and had lower blood levels post-EtOH administration (4 g/kg) despite similar clearance rates. Females also showed increased operant EtOH self-administration and progressive ratio performance over a 30-day baseline period compared to males. The AMPAR antagonist GYKI 52466 (0 - 10 mg/kg, IP) dose-dependently reduced EtOH-reinforced lever pressing in both sexes, with no differences in potency or efficacy. These findings confirm that female C57BL/6J mice consume more EtOH than males in home-cage conditions and exhibit reduced acute sedation, potentially contributing to higher EtOH intake. Females demonstrated increased operant EtOH self-administration and motivation, indicating higher reinforcing efficacy. The lack of sex differences in the relative effects of GYKI 52466 suggests that AMPAR activity is equally required for EtOH reinforcement in both sexes.

Role of serotonin neurons in the dorsal raphe nucleus in heroin self-administration and punishment.

One hallmark of substance use disorder is continued drug use despite negative consequences. When drug-taking behavior is punished with aversive stimuli, i.e. footshock, rats can also be categorized into punishment-resistant or compulsive vs. punishment-sensitive or non-compulsive phenotypes. The serotonin (5-hydroxytryptamine, 5-HT) system modulates responses to both reward and punishment. The goal of the current study was to examine punishment phenotypes in heroin self-administration and to determine the role of dorsal raphe nucleus (DRN) 5-HT neurons in both basal and punished heroin self-administration. First, rats were exposed to punished heroin self-administration and neuronal excitability of DRN 5-HT neuronswas compared between punishment-resistant and punishment-sensitive phenotypes using ex vivo electrophysiology. Second, DRN 5-HT neuronal activity was manipulated in vivo during basal and punished heroin self-administration using chemogenetic tools in a Tph2-iCre rat line. While rats separated into punishment-resistant and punishment-sensitive phenotypes for punished heroin self-administration, DRN 5-HT neuronal excitability did not differ between the phenotypes. While chemogenetic inhibition of DRN 5-HT neurons was without effect, chemogenetic activation of DRN 5-HT neurons increased both basal and punished heroin self-administration selectively in punishment-resistant animals. Additionally, the responsiveness to chemogenetic activation of DRN 5-HT neurons in basal self-administration and motivation for heroin in progressive ratio each predicted resistance to punishment. Therefore, our data support the role for the DRN 5-HT system in compulsive heroin self-administration.

The Relative Reinforcing Value of Menthol Among Young Adult Cigarette Smokers: Results From a Behavioral Choice Task.

Menthol cigarettes are associated with experimentation and progression to regular use. Although reinforcement processes likely underlie menthol's appeal, the reinforcing value of menthol cigarettes remains unknown. This study examined the relative reinforcing value (RRV) of menthol versus nonmenthol cigarettes in young adult menthol (n = 54) and nonmenthol (n = 53) smokers, and differences in menthol's RRV by race, ethnicity, and sexual orientation. Overnight abstinent participants completed a choice task assessing willingness to "work" to click targets on a computer screen to earn menthol or nonmenthol cigarette puffs. A progressive ratio schedule was used where the menthol target had to be clicked progressively more times, over 10 trials, to earn a menthol cigarette puff, while clicks for the nonmenthol target were fixed across trials. RRV for menthol was defined by the breakpoint, or the highest trial (out of to 10) completed for a menthol cigarette puff. Number of clicks for menthol and nonmenthol puffs were also examined. Menthol smokers worked harder for menthol versus nonmenthol cigarette puffs (breakpoint = 9.17; ~1236 clicks vs. 24 clicks). Breakpoint was higher among Hispanic (6.49) versus NH White (4.83) and NH non-White smokers (4.43). In exploratory analyses of interactions of menthol preference with race and ethnicity, nonmenthol Hispanic smokers worked harder for menthol cigarette puffs versus NH non-White and NH White nonmenthol smokers. Menthol cigarettes are highly reinforcing for young adult menthol and Hispanic smokers. A menthol ban may reduce addiction risk among younger individuals and some minoritized groups of smokers. This study provides evidence of the greater relative reinforcing value of menthol compared to nonmenthol cigarettes among young adults who had a cigarette flavor preference, suggesting increased addiction risk of menthol cigarettes. Young adult menthol smokers and Hispanic (vs. non-Hispanic) smokers worked harder to earn menthol (vs. nonmenthol) cigarette puffs. Findings add to the evidence base supporting the U.S. Food and Drug Administration's (FDA) intent to ban menthol in cigarettes. Further, prevention messaging campaigns and cessation programs should take into account the reinforcing value of menthol in cigarettes, especially in vulnerable and at-risk populations.

Expression of sensitized β2 nAChR subunits in VTA neurons enhances intravenous nicotine self-administration in male rats

Ventral tegmental area (VTA) nicotinic acetylcholine receptors (nAChRs) are important for nicotine reinforcement. To determine whether and to what extent these receptors are sufficient for nicotine reinforcement, we expressed β2Leu9′Ser (i.e. sensitized) nAChR subunits in the VTA of adult male rats and assessed the nicotine dose-response relationship in intravenous self-administration (SA). β2Leu9′Ser rats self-administered nicotine doses 50–100 fold lower than the lowest doses that control rats would respond for. Expression of WT β2 subunits confirmed that this enhanced sensitivity to nicotine was due to the Leu9′Ser mutation in β2. Higher unit doses were associated with strong escalation in β2Leu9′Ser rats over 17 fixed ratio sessions. Escalation was minimal or absent in control rats at the same unit doses. In progressive ratio SA, β2Leu9′Ser rats exhibited higher breakpoints than control rats when the nicotine unit dose was 1.5 μg/kg/inf or higher. In intermittent access SA, β2Leu9′Ser rats exhibited response patterns very similar to control rats. By adding nicotine dose-response data, progressive ratio assays, and intermittent access results that rule out stereotypy, these data significantly extend our previous finding that nicotine activation of the mesolimbic dopamine pathway is sufficient for nicotine reinforcement.

Phase 3 Trial of Cabozantinib to Treat Advanced Neuroendocrine Tumors.

Treatment options for patients with advanced neuroendocrine tumors are limited. The efficacy of cabozantinib in the treatment of previously treated, progressive extrapancreatic or pancreatic neuroendocrine tumors is unclear. We enrolled two independent cohorts of patients - those with extrapancreatic neuroendocrine tumors and those with pancreatic neuroendocrine tumors - who had received peptide receptor radionuclide therapy or targeted therapy or both. Patients were randomly assigned in a 2:1 ratio to receive cabozantinib at a dose of 60 mg daily or placebo. The primary end point was progression-free survival as assessed by blinded independent central review. Key secondary end points included objective response, overall survival, and safety. In the cohort of 203 patients with extrapancreatic neuroendocrine tumors, the median progression-free survival with cabozantinib was 8.4 months, as compared with 3.9 months with placebo (stratified hazard ratio for progression or death, 0.38; 95% confidence interval [CI], 0.25 to 0.59; P<0.001). In the cohort of 95 patients with pancreatic neuroendocrine tumors, the median progression-free survival with cabozantinib was 13.8 months, as compared with 4.4 months with placebo (stratified hazard ratio, 0.23; 95% CI, 0.12 to 0.42; P<0.001). The incidence of confirmed objective response with cabozantinib was 5% and 19% among patients with extrapancreatic and pancreatic neuroendocrine tumors, respectively, as compared with 0% with placebo. Grade 3 or higher adverse events were noted in 62 to 65% of the patients treated with cabozantinib, as compared with 23 to 27% of the patients who received placebo. Common treatment-related adverse events of grade 3 or higher included hypertension, fatigue, diarrhea, and thromboembolic events. Cabozantinib, as compared with placebo, significantly improved progression-free survival in patients with previously treated, progressive advanced extrapancreatic or pancreatic neuroendocrine tumors. Adverse events were consistent with the known safety profile of cabozantinib. (Funded by the National Cancer Institute and others; CABINET ClinicalTrials.gov number, NCT03375320.).

Relationship between hypertransmission defect size and progression in eyes with intermediate age-related macular degeneration.

To determine the associations between the presence of various-sized hypertransmission defects (hyperTDs) and progression to incomplete retinal pigment epithelial (RPE) and outer retinal atrophy (iRORA) and complete RORA (cRORA) in eyes with intermediate age-related macular degeneration (iAMD). Optical coherence tomography (OCT) data from consecutive iAMD patients, were retrospectively reviewed. All of iAMD eyes with or without iRORA (but not cRORA) at baseline were included. Graders evaluated the presence of hyperTDs at baseline (small: 63-124 µm; medium: 125-249 µm; large: ≥250 µm in diameter on choroidal en face OCT) and the progression two years later. Of the 145 eyes that not developed neovascular AMD at two years, the eyes that progressed to or developed iRORA or cRORA included 13 eyes (10.7%), 5 eyes (83.3%), 9 eyes (81.8%), and 6 eyes (85.7%) in the groups with no, small, medium, and large hyperTDs at baseline, respectively (P-value < 0.001). The odds ratios (95% CI) for progression were 41.6 (4.5-383.6), 37.4 (7.3-192.0), and 49.9 (5.6-447.1) in the small, medium, and large hyperTDs groups, compared to no hyperTDs (P-value ≤ 0.001). Eyes with ≥2 hyperTDs also showed more frequent progression than eyes with one or no hyperTDs (100% vs. 16.4%; P-value < 0.001). While most iAMD eyes with no hyperTDs remained stable on OCT over two years, eyes with hyperTDs of any size appeared to be at a higher risk for progression. HyperTDs may provide an important OCT biomarker for identifying high-risk iAMD patients.

Perioperative Durvalumab with Neoadjuvant Chemotherapy in Operable Bladder Cancer.

Neoadjuvant chemotherapy followed by radical cystectomy is the standard treatment for cisplatin-eligible patients with muscle-invasive bladder cancer. Adding perioperative immunotherapy may improve outcomes. In this phase 3, open-label, randomized trial, we assigned, in a 1:1 ratio, cisplatin-eligible patients with muscle-invasive bladder cancer to receive neoadjuvant durvalumab plus gemcitabine-cisplatin every 3 weeks for four cycles, followed by radical cystectomy and adjuvant durvalumab every 4 weeks for eight cycles (durvalumab group), or to receive neoadjuvant gemcitabine-cisplatin followed by radical cystectomy alone (comparison group). Event-free survival was one of two primary end points. Overall survival was the key secondary end point. In total, 533 patients were assigned to the durvalumab group and 530 to the comparison group. The estimated event-free survival at 24 months was 67.8% (95% confidence interval [CI], 63.6 to 71.7) in the durvalumab group and 59.8% (95% CI, 55.4 to 64.0) in the comparison group (hazard ratio for progression, recurrence, not undergoing radical cystectomy, or death from any cause, 0.68; 95% CI, 0.56 to 0.82; P<0.001 by stratified log-rank test). The estimated overall survival at 24 months was 82.2% (95% CI, 78.7 to 85.2) in the durvalumab group and 75.2% (95% CI, 71.3 to 78.8) in the comparison group (hazard ratio for death, 0.75; 95% CI, 0.59 to 0.93; P = 0.01 by stratified log-rank test). Treatment-related adverse events of grade 3 or 4 in severity occurred in 40.6% of the patients in the durvalumab group and in 40.9% of those in the comparison group; treatment-related adverse events leading to death occurred in 0.6% in each group. Radical cystectomy was performed in 88.0% of the patients in the durvalumab group and in 83.2% of those in the comparison group. Perioperative durvalumab plus neoadjuvant chemotherapy led to significant improvements in event-free survival and overall survival as compared with neoadjuvant chemotherapy alone. (Funded by AstraZeneca; NIAGARA ClinicalTrials.gov number, NCT03732677; EudraCT number, 2018-001811-59.).