The stoned age: Sex differences in the effects of adolescent cannabinoid exposure on prefrontal cortex structure and function in animal models.

Cannabis is the most used drug during adolescence, which is a period of enhanced cortical plasticity and synaptic remodeling that supports behavioral, cognitive, and emotional maturity. In this chapter, we review preclinical studies indicating that adolescent exposure to cannabinoids has lasting effects on the morphology and synaptic organization of the prefrontal cortex and associated circuitry, which may lead to cognitive dysfunction later in life. Additionally, we reviewed sex differences in the effects of adolescent cannabinoid exposure with a focus on brain systems that support cognitive functioning. The body of evidence indicates enduring sex-specific effects in behavior and organization of corticolimbic circuitry, which appears to be influenced by species, strain, drug, route of administration, and window/pattern of drug exposure. Caution should be exercised when extrapolating these results to humans. Adopting models that more closely resemble human cannabis use will provide more translationally relevant data concerning the long-term effects of cannabis use on the adolescent brain.

The impact of progesterone receptor negativity on oncological outcomes in oestrogen-receptor-positive breast cancer.

BACKGROUND: Oestrogen receptor (ER) status provides invaluable prognostic and therapeutic information in breast cancer (BC). When clinical decision making is driven by ER status, the value of progesterone receptor (PgR) status is less certain. The aim of this study was to describe clinicopathological features of ER-positive (ER+)/PgR-negative (PgR-) BC and to determine the effect of PgR negativity in ER+ disease. METHODS: Consecutive female patients with ER+ BC from a single institution were included. Factors associated with PgR- disease were assessed using binary logistic regression. Oncological outcome was assessed using Kaplan-Meier and Cox regression analysis. RESULTS: In total, 2660 patients were included with a mean(s.d.) age of 59.6(13.3) years (range 21-99 years). Median follow-up was 97.2 months (range 3.0-181.2). Some 2208 cases were PgR+ (83.0 per cent) and 452 were PgR- (17.0 per cent). Being postmenopausal (odds ratio (OR) 1.66, 95 per cent c.i. 1.25 to 2.20, P < 0.001), presenting with symptoms (OR 1.71, 95 per cent c.i. 1.30 to 2.25, P < 0.001), ductal subtype (OR 1.51, 95 per cent c.i. 1.17 to 1.97, P = 0.002) and grade 3 tumours (OR 2.20, 95 per cent c.i. 1.68 to 2.87, P < 0.001) were all associated with PgR negativity. In those receiving neoadjuvant chemotherapy (308 patients), pathological complete response rates were 10.1 per cent (25 of 247 patients) in patients with PgR+ disease versus 18.0 per cent in PgR- disease (11 of 61) (P = 0.050). PgR negativity independently predicted worse disease-free (hazard ratio (HR) 1.632, 95 per cent c.i. 1.209 to 2.204, P = 0.001) and overall survival (HR 1.774, 95 per cent c.i. 1.324 to 2.375, P < 0.001), as well as worse overall survival in ER+/HER2- disease (P = 0.004). CONCLUSIONS: In ER+ disease, PgR- tumours have more aggressive clinicopathological features and worse oncological outcomes. Neoadjuvant and adjuvant therapeutic strategies should be tailored according to PgR status.

Disease recurrence and oncological outcome of patients treated surgically with curative intent for estrogen receptor positive, lymph node negative breast cancer.

BACKGROUND: The molecular era has identified four breast cancer subtypes. Luminal A breast cancer (LABC) is defined by estrogen-receptor positive (ER+), progesterone-receptor positive (PgR+) and human epidermal growth factor receptor-2 negative (HER2-) tumours; these cancers are the most common and carry favourable prognoses. AIMS: To describe clinicopathologic features, oncological outcome and relapse patterns in LABC. METHODS: Consecutive female patients diagnosed with ER/PgR+/HER2-, lymph node negative (LN-) breast cancer between 2005 and 2015 were included. Clinicopathological and recurrence data was recorded using descriptive statistics. Oncological outcome was determined using Kaplan-Meier and Cox-regression analyses. RESULTS: Analysis was performed for 849 patients with median follow-up of 102.1 months. Mean disease-free (DFS) and overall survival (OS) were 85.8% and 91.8%. Seventy patients died during this study (8.2%), while 58 patients had recurrence; 7 had local recurrence (0.8%) and 51 had distant recurrence (DDR) (6.0%). Patients developing DDR were likely to be postmenopausal (P = 0.028), present symptomatically (P < 0.001) and have larger tumours (P < 0.001). The mean time to DDR was 65.7 months, with fatal recurrence occurring in 66.6% of patients with DDR (34/51). Systemic chemotherapy prescription did not influence DDR (P = 0.053). Age >65 (hazards ratio (HR):1.66, 95% Confidence Interval (CI):1.07-2.55, P = 0.022), presenting symptomatically (HR:2.28, 95%CI:1.21-4.29, P = 0.011) and tumour size >20 mm (HR:1.81, 95%CI:1.25-2.62, P = 0.002) predicted DFS, while age>65 (HR:2.60, 95%CI:1.49-4.53, P = 0.001) and being postmenopausal at diagnosis (HR:3.13, 95%CI:1.19-8.22, P = 0.020) predicted OS. CONCLUSION: Our series demonstrated excellent survival outcomes for patients diagnosed with LN- LABC after almost a decade of follow-up. However, following DDR, fatal progression is often imminent.

Role of glucocorticoid receptor-mediated mechanisms in cocaine memory enhancement.

The basolateral amygdala (BLA) is a critical site for the reconsolidation of labile contextual cocaine memories following retrieval-induced reactivation/destabilization. Here, we examined whether glucocorticoid receptors (GR), which are abundant in the BLA, mediate this phenomenon. Rats were trained to lever press for cocaine reinforcement in a distinct environmental context, followed by extinction training in a different context. Rats were then briefly exposed to the cocaine-paired context (to elicit memory reactivation and reconsolidation) or their home cages (no reactivation control). Exposure to the cocaine-paired context elicited greater serum corticosterone concentrations than home cage stay. Interestingly, the GR antagonist, mifepristone (3-10 ng/hemisphere), administered into the BLA after memory reactivation produced a further, dose-dependent increase in serum corticosterone concentrations during the putative time of cocaine-memory reconsolidation but produced an inverted U-shaped dose-effect curve on subsequent cocaine-seeking behavior 72 h later. This effect was anatomically selective, dependent on memory reactivation (i.e., not observed after home cage exposure), and did not reflect protracted hyperactivity. However, the effect was also observed when mifepristone was administered after novelty stress that mimics drug context-induced hypothalamic-pituitary-adrenal (HPA) axis activation without explicit memory reactivation. Together, these findings suggest that, similar to explicit memory retrieval, a stressful event is sufficient to destabilize cocaine memories and permit their manipulation. Furthermore, BLA GR stimulation exerts inhibitory feedback upon HPA axis activation and thus suppresses cocaine-memory reconsolidation.

Human islets and dendritic cells generate post-translationally modified islet autoantigens.

The initiation of type 1 diabetes (T1D) requires a break in peripheral tolerance. New insights into neoepitope formation indicate that post-translational modification of islet autoantigens, for example via deamidation, may be an important component of disease initiation or exacerbation. Indeed, deamidation of islet autoantigens increases their binding affinity to the T1D highest-risk human leucocyte antigen (HLA) haplotypes HLA-DR3/DQ2 and -DR4/DQ8, increasing the chance that T cells reactive to deamidated autoantigens can be activated upon T cell receptor ligation. Here we investigated human pancreatic islets and inflammatory and tolerogenic human dendritic cells (DC and tolDC) as potential sources of deamidated islet autoantigens and examined whether deamidation is altered in an inflammatory environment. Islets, DC and tolDC contained tissue transglutaminase, the key enzyme responsible for peptide deamidation, and enzyme activity increased following an inflammatory insult. Islets treated with inflammatory cytokines were found to contain deamidated insulin C-peptide. DC, heterozygous for the T1D highest-risk DQ2/8, pulsed with native islet autoantigens could present naturally processed deamidated neoepitopes. HLA-DQ2 or -DQ8 homozygous DC did not present deamidated islet peptides. This study identifies both human islets and DC as sources of deamidated islet autoantigens and implicates inflammatory activation of tissue transglutaminase as a potential mechanism for islet and DC deamidation.

Note: Compact, two-dimension translatable slit aperture.

A compact, light-weight, two-dimension translatable slit aperture is described. The slit dimensions are scalable, allowing for wide application. With all metal construction, the device would be suitable for high temperature degassing and vacuum compatible. Alternatively, the main structure may be printed using a 3D printer for rapid prototyping and/or lighter weight. The precision of the slit movement is 0.014 mm.

Upregulation of CB1 receptor binding in the ventromedial prefrontal cortex promotes proactive stress-coping strategies following chronic stress exposure.

Accumulating evidence has revealed that dysregulation of the endocannabinoid system could contribute to the development of major depression. Studies carried out post-mortem in depressed suicide victims have revealed increased CB(1) receptor binding site density in the prefrontal cortex (PFC). Accordingly, exposure of rodents to chronic unpredictable stress (CUS) results in phenotypic changes that mirror those of human depression, including increased CB(1) receptor binding site density in the PFC. Our goal in these studies was to examine the effects of CUS on the density of CB(1) receptor binding sites in the rodent medial PFC and to explore the role of this alteration in the behavioral changes invoked by CUS. Rodents exposed to CUS exhibited increased CB(1) receptor maximal binding site density (B(max)) within the ventromedial PFC, but not the dorsomedial PFC. To determine whether this change in the ventromedial PFC is an adaptive response, or alternatively, a consequence of chronic stress that contributes to the adoption of passive coping, we examined whether local CB(1) receptor blockade within the ventromedial PFC following CUS would significantly alter behaviors in the forced swim test (FST). CUS exposure significantly increased passive coping in the FST, and this was further augmented by discrete ventromedial PFC microinfusions of the CB(1) receptor antagonist AM251 prior to swim stress. Moreover, local CB(1) receptor blockade reduced active coping responses in CUS-exposed rats. These findings suggest that the increase in CB(1) receptor B(max) observed in the ventromedial PFC of rodents exposed to CUS maintains proactive coping strategies following chronic stress exposure.

Cannabinoids and emotionality: a neuroanatomical perspective.

The endocannabinoid system has recently emerged as a promising therapeutic target for the treatment of stress-related emotional disorders. A growing literature base has collectively demonstrated that facilitation of endocannabinoid signaling promotes antidepressant- and anxiolytic-like responses in preclinical animal models, while disruption of this system profoundly affects emotion, cognition, and neuroendocrine functioning. Although these findings are encouraging, the role of endocannabinoid signaling within discrete corticolimbic brain structures is considerably complex. Consequently, researchers have recently shifted focus to examining the effects of local cannabinoid manipulations on emotion from a neuroanatomical standpoint. This review provides an overview of the site-specific effects of cannabinergic compounds in preclinical tests of emotionality, as well as the alterations in endocannabinoid signaling observed in animal models of depression. Broadly speaking, these studies indicate that CB(1) receptors in the medial prefrontal cortex and ventral hippocampus appear to be responsible for the antidepressant- and anxiolytic-like phenotype elicited by systemic CB(1) receptor agonists, which parallels biochemical studies showing that endocannabinoids are downregulated in these two regions following exposure to chronic stress. Conversely, CB(1) receptor activation within distinct amygdalar nuclei yields opposing effects on emotional behavior, such that local stimulation of CB(1) receptors in the basolateral amygdala and central amygdala promoting anxiogenesis and anxiolysis, respectively. Moreover, a series of elegant studies has revealed that cannabinoid transmission in the basolateral amygdala strongly modulates the acquisition and processing of associative fear memory via interactions with the medial prefrontal cortex. Given the crucial role of this corticolimbic network in regulating emotional behavior, it is palpable that alterations in endocannabinoid signaling within any of these structures could have profound implications for the pathophysiological development of affective illnesses. Accordingly, local pharmacological augmentation of endocannabinoid signaling within discrete corticolimbic subregions may serve as a promising therapeutic strategy for the treatment of these debilitating disorders.

Opposing roles for the nucleus accumbens core and shell in cue-induced reinstatement of food-seeking behavior.

Reinstatement of previously extinguished instrumental responding for drug-related cues has been used as an animal model for relapse of drug abuse, and is differentially affected by inactivation of the core and shell subregions of the nucleus accumbens (NAc). To compare the roles of these subregions in reinstatement induced by cues associated with natural and drug rewards, the present study assessed the effects of inactivation of the NAc core and shell on cue-induced reinstatement of food-seeking behavior. Rats acquired a lever pressing response for food reward paired with a light/tone conditioned stimulus (CS). They were then subjected to extinction, where both food and the CS were withheld. Reinstatement of responding was measured during response-contingent presentations of the CS. Following saline infusions into the NAc core or shell, rats displayed a significant increase in lever pressing during reinstatement sessions. Inactivation of the core, induced by infusion of GABA agonists muscimol and baclofen, attenuated responding for the CS, but did not affect pavlovian approach toward the food receptacle. In contrast, inactivation of the shell had the opposite effect, potentiating responding relative to vehicle treatments. These data suggest that the NAc core and shell play opposing, yet complementary roles in mediating the influence that food-associated conditioned stimuli exert over behavior. The core enables reward-related stimuli to bias the direction and vigor of instrumental responding. In contrast, the shell facilitates alterations in behavior in response to changes in the incentive value of conditioned stimuli. The fact that the NAc core appears to play a similar role in cue-induced reinstatement induced by both natural and drug rewards suggests that this region of the ventral striatum may be a final common pathway through which both drug- and food-associated stimuli may influence the direction and magnitude of ongoing behavior.

The role of different subregions of the basolateral amygdala in cue-induced reinstatement and extinction of food-seeking behavior.

Reinstatement of previously extinguished instrumental responding for drug-related cues has been used as an animal model for relapse of drug abuse, and is disrupted by inactivation of the basolateral amygdala (BLA). However, the role that the BLA plays in reinstatement induced by cues associated with natural rewards is unclear. The present study assessed the effects of inactivation of different regions of the BLA in cue-induced reinstatement of food-seeking behavior and in the extinction of instrumental responding for food. In experiment 1, rats acquired a lever pressing response for food reward paired with a light/tone conditioned stimulus (CS). They were then subjected to extinction training, where both food and the CS were withheld. Reinstatement of extinguished responding was measured during response-contingent presentations of the CS alone. Following saline infusions into the caudal or rostral BLA, rats displayed a significant increase in lever pressing during reinstatement sessions. Inactivation of these subregions with bupivacaine did not attenuate responding for the CS in the absence of food delivery. In fact, inactivation of the caudal BLA potentiated responding relative to vehicle treatments. Analysis of within-session responding revealed that caudal BLA inactivation retarded extinction of lever pressing in response to the CS. In experiment 2, inactivation of the caudal BLA on the first or second day of extinction training significantly retarded the acquisition of extinction learning on the following day. These data indicate that that the caudal BLA may play a specific role in the extinction of appetitive conditioned responses, by monitoring changes in the reinforcing value of pavlovian conditioned stimuli linked to action-outcome associations once these associations have been formed. Moreover, these findings support a growing body of evidence indicating that separate neural circuits incorporating the BLA may play different roles in mediating reinstatement of reward-seeking behaviors induced by either drug or food related stimuli.

The detection of large HNO3-containing particles in the winter Arctic stratosphere.

Large particles containing nitric acid (HNO3) were observed in the 1999/2000 Arctic winter stratosphere. These in situ observations were made over a large altitude range (16 to 21 kilometers) and horizontal extent (1800 kilometers) on several airborne sampling flights during a period of several weeks. With diameters of 10 to 20 micrometers, these sedimenting particles have significant potential to denitrify the lower stratosphere. A microphysical model of nitric acid trihydrate particles is able to simulate the growth and sedimentation of these large sizes in the lower stratosphere, but the nucleation process is not yet known. Accurate modeling of the formation of these large particles is essential for understanding Arctic denitrification and predicting future Arctic ozone abundances.

Epiphytic colonization of pear stigmas and hypanthia by bacteria during primary bloom.

ABSTRACT Pear blossoms were sampled during various stages of bloom in 1991 and 1992 from orchards at Cashmere, WA, and Corvallis and Medford, OR, for epiphytic populations of culturable bacteria. On stigmatic surfaces, bacteria were isolated from 2 to 32% of blossoms prior to petal expansion and from 47 to 94% of blossoms by petal fall. In general, a lower percentage of hypanthia than stigmas supported bacterial populations. Randomly selected bacteria isolated at population levels of >/=10(4) CFU/tissue were identified by fatty acid methyl ester analysis. Diverse genera of gram-negative and -positive bacteria were identified from the Medford and Cashmere field sites. Pseudomonas syringae and Pseudomonas viri-diflava were isolated from all sites and were the predominant species detected at Corvallis, where they were isolated from 28% of the blossoms sampled on a given date. Because most pear blossoms do not support detectable populations (>/=10(2) CFU/tissue) of culturable bacteria prior to petal expansion, we speculate that introduced biocontrol agents may become established with minimal competition from indigenous epiphytes at early bloom stages.

Training school counselors in substance abuse risk reduction techniques for use with children and adolescents.

A training project prepared school counselors for expanded roles in the prevention, early detection, and appropriate referral of students at high risk of substance abuse. The project trained middle and high school counselors to work as facilitators of support groups for students at greatest risk for substance abuse; the results were: 1) greater perceived self-efficacy, comfort, confidence, and competence by counselors as a result of Initial, Experiential, and Concurrent training, and 2) improved ability to use group counseling techniques as a result of training.

Teacher ratings of student risk for substance use as a function of specialized training.

The purpose of this study was to determine if teachers' abilities to identify accurately students who are at risk for substance abuse can be improved through attendance at a specialized training program. Sixty-three eighth-grade teachers participated in the study. Of these, thirty-six teachers participated in the training sequence (intervention group), while the remaining twenty-seven teachers served as a comparison group. All eighth-grade students in the school district were surveyed regarding their substance usage. Teachers rated the students regarding their risk for substance usage. Teachers' ratings and students' reported substance usage were compared to assess the percentage of matching responses. After training, the intervention teachers provided more accurate ratings among usage categories than did the comparison teachers. The trained teachers were better at correctly identifying the students who were at risk for substance use.

Reducing substance abuse risk factors among children through a teacher as facilitator program.

A Teachers as Facilitators (TAF) Program used classroom teachers as leaders of small groups that promoted social, emotional, and academic development of children at high risk of adopting potentially destructive substance abuse patterns. The program was intended to increase participating students' positive socialization experiences and academic achievement by successfully integrating these students into the school's social system. A longer-range goal was to increase students' sense of worth as it affects their attitudes toward relationships with other people and academic demands. Program results were: 1) school personnel were found capable of accurately identifying and referring to the TAF Program children who were at risk of substance usage and in need of assistance; 2) the TAF Program was effective in improving at-risk students' perceived academic self-concept, but was less effective in increasing students' perceived sense of social support; and 3) the program was endorsed by participating teachers, counselors, and administrators.

Risk factors and their relation to initiation of alcohol use among early adolescents.

This study examined the relationship between risk factors and initiation of alcohol use over a 15-month period among a cohort of 7th graders who were abstainers at the time of initial testing. The relationship between risk factors and alcohol use was examined using a discriminant function analysis. At the univariate level, rejection of parental authority, deviant behavior, and sensation seeking were statistically significant. The discriminant function retained only three of the risk factors: rejection of parental authority, deviant behavior, and religious commitment. Implications for school-based prevention programs are discussed, particularly the need to target primary prevention programs based upon adolescents' risk.

Reversible and irreversible elongation of ischemic, infarcted, and healed myocardium in response to increases in preload and afterload.

BACKGROUND: Left ventricular aneurysm formation after myocardial infarction (MI) has been associated with elongation of infarcted tissue in response to wall stress. Such elongation most commonly occurs in acutely infarcted or partially healed regions during the early post-MI period; however, recent reports have indicated that mature (15-week-old) healed infarct regions also undergo elongation after stress. METHODS AND RESULTS: To assess factors contributing to post-MI left ventricular aneurysm formation, we subjected isolated strips (n = 50) of rabbit myocardial tissue from acutely ischemic (noninfarcted left ventricular), acutely infarcted (24 hours after MI), and healed infarct (3 and 15 weeks after MI) regions to a range of loading conditions and measured the reversible and irreversible length changes that occurred. The isolated strips were repetitively stretched for 1 hour at 4 Hz to impose cyclical physiological peak and resting stresses of 2.0 and 0.2 g/mm2. During a second hour, either peak stress ("afterload") or resting stress ("preload") was tripled, and the increase in strip length (strain) was measured. During a third hour, peak and resting stresses were returned to the initial values to assess the reversibility of length changes occurring during increased load. Elongation was expressed as the increase in natural strain from the first hour. Increasing afterload caused similar irreversible length increases of 4-5%/hr in acutely infarcted and 3- and 15-week-old healed infarct strips; acutely ischemic tissue length increased by 7.4%/hr (p less than 0.05 versus acutely infarcted tissue and scars). Increasing preload in acutely ischemic and acutely infarcted tissue caused a reversible length increase of less than 1%/hr. (Scar strips were not tested for the effect of preload.) CONCLUSIONS: Since an irreversible length increase may represent an early event in aneurysm formation, our results suggest that 1) afterload increases are more likely to lead to aneurysm development than preload increases, 2) acutely ischemic tissue is the most vulnerable to increased afterload, and 3) for a given wall stress level, healing scar tissue is as susceptible to irreversible length changes as is acutely infarcted tissue. The observation that even mature post-MI scar elongated in response to increases in afterload implies that long-term pharmacological management of afterload in post-MI patients may be beneficial in preventing tissue elongation and aneurysm formation and that factors that increase wall stress (e.g., hypertension and exercise stress) have the potential to promote aneurysm formation in healed infarct scars.

Characterization and reclassification of yeasts used for biological control of postharvest diseases of fruits and vegetables.

In previous studies workers have shown that three yeast strains (strains US-7, 82, and 101) have biological control activity against various postharvest fungal pathogens of fruits and vegetables, including Penicillium rots of apples and citrus and Botrytis rot of apples. In these reports the researchers have described these strains as Debaryomyces hansenii (anamorph, Candida famata) or Candida sp. strains. In this study we performed additional physiological, DNA reassociation, and mannan characterization tests that clearly established a new taxonomic classification for these strains, Candida guilliermondii. We also propose amendment of the physiological test profile in the taxonomic description of C. guilliermondii.

Effect of myocyte necrosis on strength, strain, and stiffness of isolated myocardial strips.

Cardiac rupture accounts for 8% to 10% of patient deaths after acute myocardial infarction, suggesting that myocyte necrosis weakens the ventricular wall in the initial days after occlusion. To test this theory, permanent occlusion of the left anterior descending coronary artery was performed in dogs. Twenty-four hours after occlusion, the tensile strength, strain at rupture, and stiffness of necrotic epicardium, midmyocardium, endocardium, subepicardium, and the visceral pericardium (VP) were quantified and compared with those of noninfarcted cardiac tissue. The relationship between tensile strength, stiffness, and collagen content was also examined. These material properties did not differ between necrotic and normal myocardium in any of the layers, indicating that myocyte necrosis, per se, does not weaken the myocardium. In both necrotic and normal tissue, marked transmural heterogeneity was observed; tensile strength of the endo- and epicardium (21.3 +/- 3.3 and 21.3 +/- 3.2 gm/mm2) was significantly greater (p less than 0.01) than that of the midmyocardium (4.0 +/- 0.3 gm/mm2) and subepicardium (5.0 +/- 0.5 gm/mm2), whereas the VP was substantially stronger (greater than 100 gm/mm2) than any myocardial layer. Similar results were obtained for stiffness. In contrast, strain at rupture did not vary significantly among myocardial layers and ranged from 0.40 +/- 0.03 (VP) to 0.53 +/- 0.03 (endocardium). Both tensile strength and stiffness of the myocardial layers were found to correlate directly with their collagen content: the higher the hydroxyproline concentration, the greater the tensile strength (r = 0.83). These results support the concept that the collagen fibroskeleton is an important determinant of the material properties of the myocardium. As myocyte necrosis, per se, did not affect tensile strength, we tentatively conclude that cardiac rupture may be a consequence of a defect or weakness in the collagenous framework of the heart.