LC Activity Research Articles

Inter- and intra-individual coupling between pupillary, electrophysiological, and behavioral responses in a visual oddball task.

Although the P3b component of the event-related brain potential is one of the most widely studied components, its underlying generators are not currently well understood. Recent theories have suggested that the P3b is triggered by phasic activation of the locus-coeruleus norepinephrine (LC-NE) system, an important control center implicated in facilitating optimal task-relevant behavior. Previous research has reported strong correlations between pupil dilation and LC activity, suggesting that pupil diameter is a useful indicator for ongoing LC-NE activity. Given the strong relationship between LC activity and pupil dilation, if the P3b is driven by phasic LC activity, there should be a robust trial-to-trial relationship with the phasic pupillary dilation response (PDR). However, previous work examining relationships between concurrently recorded pupillary and P3b responses has not supported this. One possibility is that the relationship between the measures might be carried primarily by either inter-individual (i.e., between-participant) or intra-individual (i.e., within-participant) contributions to coupling, and prior work has not systematically delineated these relationships. Doing so in the current study, we do not find evidence for either inter-individual or intra-individual relationships between the PDR and P3b responses. However, baseline pupil dilation did predict the P3b. Interestingly, both the PDR and P3b independently predicted inter-individual and intra-individual variability in decision response time. Implications for the LC-P3b hypothesis are discussed.

Enhancement of laccase immobilization onto wet chitosan microspheres using an iterative protocol and its potential to remove micropollutants

This study was focused on creating a new and effective immobilization method for Trametes versicolor laccase (Lc) by using chitosan (CS) microspheres activated with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride. The activation of the support alternated with immobilization of the enzyme, in repetitive procedures, led to obtaining three different products. Also, the physicochemical properties of the new products were investigated and compared with those of free laccase. The discoloration and reusability properties of the immobilized Lc were evaluated using indigo carmine (IC) as a model micropollutant. The ESEM and FT-IR methods demonstrated that the Lc was successfully immobilized. The relative reaction rate and the total amount of immobilized Lc were tripled using the iterative protocol as proved by specific and Bradford assays. The maximum amount of immobilized Lc was 8.4 mg Lc/g CS corresponding to the third immobilization procedure. Compared to the free Lc, the operational stability of the immobilized Lc was significantly improved, presenting a maximum activity plateau over a pH range of 3–5 and a temperature range of 25–50 °C. The thermal inactivation study at 55 °C proved that the immobilized enzyme is three times more stable than the free Lc. The isoconversional and Michaelis-Menten methods showed that the immobilization did not affect the enzyme catalytic properties. After 32 days of storage, the residual activities are 85% for the immobilized laccase and 40% for the free one. In similar conditions, the free and immobilized Lc (2.12 x 10−6 M) completely decolorized IC (7.15 x 10−5 M) within 14 min. The immobilized Lc activity remained almost constant (80%) during 10 reusability cycles. All these results highlight the substantial advantages of the new immobilization protocol and demonstrate that immobilized Lc can be used as a promising micropollutant removal from real wastewater.

Synthesis and activity of isoleucine sulfonamide derivatives as novel botulinum neurotoxin serotype A light chain inhibitors

The botulinum neurotoxin (BoNT) is the most lethal protein known to man causing the deadly disease botulinum. The neurotoxin, composed of a heavy (HC) and light (LC) chain, work in concert to cause muscle paralysis. A therapeutic strategy to treat individuals infected with the neurotoxin is inhibiting the catalytic activity of the BoNT LC. We report the synthesis, inhibition study and computational docking analysis of novel small molecule BoNT/A LC inhibitors. A structure activity relationship study resulted in the discovery of d-isoleucine functionalized with a hydroxamic acid on the C-terminal and a biphenyl with chlorine at C- 2 connected by a sulfonamide linker at the N-terminus. This compound has a measured IC50 of 0.587 µM for the BoNT/A LC. Computational docking analysis indicates the sulfonamide linker adopts a geometry that is advantageous for binding to the BoNT LC active site. In addition, Arg363 is predicted to be involved in key binding interactions with the scaffold in this study.

Pupil dilation during visuospatial orienting differentiates between autism spectrum disorder and attention-deficit/hyperactivity disorder.

Previous research demonstrated atypical attention in children with attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). Regarding visual orienting, findings suggest a differential impairment: Atypical orienting to relatively unexpected targets in ASD, and atypical processing of alerting cues in ADHD. The locus coeruleus-norepinephrine (LC-NE) system plays an important role in exploiting alerting cues to increase attention and task performance. The present study's aim was to examine differential subcortical processes underlying visual orienting in ASD and ADHD with pupil dilation (PD) as index of LC activity. Pupil dilation (PD) progression metrics during visual orienting were calculated for task-evoked PD locked to cue, stimulus onset, and behavioral response. Group differences in PD and reaction time (RT) were compared between children with ASDwithout ADHD (ASD-) (N=18), ADHDwithout ASD (ADHD-) (N=28), both disorders(ASD+ADHD) (N=14), and typically developing children(TD) (N=31) using linear mixed models (LMM). To further explore the modulatory role of the LC-NE system group differences in theeffect of task-evoked PD metrics on RT were examined exploratively. ASD (+ADHD) showed slower orienting responses to relatively unexpected spatial target stimuli as compared to TD, which was accompanied by higher PD amplitudes relative to ADHD- and TD. In ADHD-, shorter cue-evoked PD latencies relative to ASD-, ASD+ADHD, and TD were found. Group differences in the effect of cue- and stimulus-evoked PD amplitudes on RT were found in ASD- relative to TD. Study findings provide new evidence for a specific role of the LC-NE system in impaired reflexive orienting responses in ASD, and atypical visual processing of alerting cues in ADHD.

Coffee flavour modification through controlled fermentation of green coffee beans by Lactococcus lactis subsp. cremoris

To achieve controlled coffee flavour biotransformation, direct fermentations of sterilized green coffee beans by a lactic acid bacterium (LAB), Lactococcus lactis subsp. cremoris, with and without 0.5% w/w glucose supplementation were investigated. The major metabolic activity of Lc. lactis subsp. cremoris was lactic acid production, and 2,3-butanedione (diacetyl) was also formed from amino acid metabolism and mixed acid fermentation. Glucose supplementation boosted lactic acid production but repressed 2,3-butanedione formation. The modifications of flavour-related constituents in green coffee beans were translated into modulations of roasted coffee flavour. The glucose-supplemented- and non-supplemented-fermented coffees features enhanced productions of O-heterocyclic and N-heterocyclic volatiles upon roasting, respectively. In particular, the highest level of total furfurals of coffees roasted at 235 °C for 12 min was found in glucose-supplemented-fermented sample, which was 1.4-fold of that in the untreated coffee. The 12-min roasted non-supplemented-fermented coffee featured the highest level of pyrazines, which was 2-fold of that in the untreated coffee. Glucose-supplemented fermentation yielded roasted coffee with an enhanced caramel aroma, together with preserved acidity and sweetness. Non-supplemented fermentation resulted in roasted coffee with an elevated nutty aroma. The undesirable smokiness in the untreated coffee was reduced by both fermentations.

Effect of clomiphene citrate treatment on the Sertoli cells of dysmetabolic obese men with low testosterone levels

Clomiphene citrate (CC) has been shown to restore the hypothalamic-pituitary-gonadal (HPG) axis by increasing testosterone (T) levels to physiological levels in patients with dysmetabolic conditions such as obesity, metabolic syndrome and type 2 diabetes mellitus (T2DM). However, the data are unclear regarding the effects on Sertoli cell (SC) function. To study SC function by assessing Inhibin B (IB) and anti-Mullerian hormone (AMH) levels at baseline and after 3months of CC treatment. This is an ancillary study of a cross-over, randomised, double-blind, placebo-controlled trial performed to evaluate androgen response to CC treatment in dysmetabolic obese subjects with low T levels treated with metformin. We evaluated SC function by assessing IB and AMH levels at baseline and after 3months of each treatment in ten dysmetabolic obese subjects with low T levels. In all subjects, the influence of the clinical characteristics, metabolic and hormonal baseline parameters on SC and Leydig (LC) function, evaluated respectively with AMH, IB, follicle-stimulating hormone (FSH) and T levels, was tested. No significant changes were observed for IB and AMH concentrations after each treatment period. Whereas T and oestradiol (E2) levels were shown to be significantly higher in the CC plus metformin phase (CC/Met) only. No clinical, metabolic or hormonal parameters showed significant effects on serum AMH at baseline or after treatments. However, baseline T, dihydrotestosterone (DHT) and E2 positively affected IB levels during CC/Met therapy (P=.003, P=.038 and P=.049, respectively). Baseline leptin and FSH had a negative (P=031) and positive (P=.048) respectively role on T levels during CC/Met, as they were statistically significant compared to the placebo period (Plac/Met). Unlike the LC activity, CC was unable to influence SC function, as shown by the lack of IB and AMH serum modifications, thus suggesting an intrinsic nonreversible defect of SC cells in patients with dysmetabolic conditions.

Behavioral correlates of activity of optogenetically identified locus coeruleus noradrenergic neurons in rats performing T-maze tasks

The nucleusLocus Coeruleus (LC) is the major source of forebrain norepinephrine. LC is implicated in arousal, response to novelty, and cognitive functions, including decision-making and behavioral flexibility. One hypothesis is that LC activation promotes rapid shifts in cortical attentional networks following changes in environmental contingencies. Recent recordings further suggest LC is critical for mobilizing resources to deal with challenging situations. In the present study optogenetically identified LC neuronal activity was recorded in rats in a self-paced T-maze. Rats were trained on visual discrimination; then place-reward contingencies were instated. In the session where the animal shifted tasks the first time, the LC firing rate after visual cue onset increased significantly, even as the animal adhered to the previous rule. Firing rate also increased prior to crossing photodetectors that controlled stimulus onset and offset, and this was positively correlated with accelerations, consistent with a role in mobilizing effort. The results contribute to the growing evidence that the noradrenergic LC is essential for behavioral adaptation by promoting cognitive flexibility and mobilizing effort in face of changing environmental contingencies.

Reduction Sugar of Tuber Paste Flour Additional α-Amylase from Lc. mesenteroides EN17–11 and Fr. fructosus EN17–20 to Protect People from Diabetes Mellitus

Local tuber flour as wheat flour alternative can be used to produce food with low sugar which good to protect people from Diabetes Mellitus. To know that flour carbohydrate degradation in order to produce tuber flour with low sugar, reduction sugar of tuber paste flour additional α-amylase from Leuconostoc mesenteroides EN17–11 and Fructobacillus fructosus EN17–20 to protect people from Diabetes Mellitus were researched. Flour used were cassava (Manihot esculenta), sweet potato (Ipomoea batatas) and yam taro (Colocasia esculenta) with wheat (Triticum) as comparison. The crude α-amylase was characterized. The detection of α-amylase activities and reduction sugar contents used 3, 5-Dinitrosalicylic Acid (DNS) methods. Data were analyzed with three replicates. The research results showed that optimum activity of Lc. mesenteroides EN17–11 α-amylase was reached at 30°C, pH: 4.5; while that Fr. fructosus EN17–20. was 60°C, pH 7.0. In 60 minutes incubation time, Lc. mesenteroides EN17–11 α-amylase stability was reached at 25–40°C, pH: 4.5–5.0; while that Fr. fructosus EN17–20 was at 40–70°C, pH 5.0–7.0. Reduction sugar contents increase of cassava, sweet potato and yam taro paste flour additional Lc. mesenteroides EN17–11 α-amylase were sequently 1.27%, 40.35% and 3.90%; while that Fr. fructosus EN17–20 were 34.44%, 52.22% and 55.27%; with that wheat additional Lc. mesenteroides EN17–11 was 17.40% and Fr. fructosus EN17–20 was 44.53%. Based on the result, it is concluded that the treatment may reduce sugar on cassava and yam taro flour. The low sugar flour might be an alternative diet for diabetic persons.

DNA replication licensing proteins: Saints and sinners in cancer.

DNA replication is all-or-none process in the cell, meaning, once the DNA replication begins it proceeds to completion. Hence, to achieve maximum control of DNA replication, eukaryotic cells employ a multi-subunit initiator protein complex known as "pre-replication complex or DNA replication licensing complex (DNA replication LC). This complex involves multiple proteins which are origin-recognition complex family proteins, cell division cycle-6, chromatin licensing and DNA replication factor 1, and minichromosome maintenance family proteins. Higher-expression of DNA replication LC proteins appears to be an early event during development of cancer since it has been a common hallmark observed in a wide variety of cancers such as oesophageal, laryngeal, pulmonary, mammary, colorectal, renal, urothelial etc. However, the exact mechanisms leading to the abnormally high expression of DNA replication LC have not been clearly deciphered. Increased expression of DNA replication LC leads to licensing and/or firing of multiple origins thereby inducing replication stress and genomic instability. Therapeutic approaches where the reduction in the activity of DNA replication LC was achieved either by siRNA or shRNA techniques, have shown increased sensitivity of cancer cell lines towards the anti-cancer drugs such as cisplatin, 5-Fluorouracil, hydroxyurea etc. Thus, the expression level of DNA replication LC within the cell determines a cell's fate thereby creating a paradox where DNA replication LC acts as both "Saint" and "Sinner". With a potential to increase sensitivity to chemotherapy drugs, DNA replication LC proteins have prospective clinical importance in fighting cancer. Hence, in this review, we will shed light on importance of DNA replication LC with an aim to use DNA replication LC in diagnosis and prognosis of cancer in patients as well as possible therapeutic targets for cancer therapy.

Phasic locus coeruleus activity regulates cortical encoding of salience information

Phasic activation of locus coeruleus (LC)-norepinephrine (NE) neurons is associated with focused attention and behavioral responses to salient stimuli. We used cell-type-specific optogenetics and single-unit neurophysiology to identify how LC activity influences neural encoding of sensory information. We found that phasic, but not tonic, LC-NE photoactivation generated a distinct event-related potential (ERP) across cortical regions. Salient sensory stimuli (which innately trigger phasic LC activity) produced strong excitatory cortical responses during this ERP window. Application of weaker, nonsalient stimuli produced limited responses, but these responses were elevated to salient stimulus levels when they were temporally locked with phasic LC photoactivation. These results demonstrate that phasic LC activity enhances cortical encoding of salient stimuli by facilitating long-latency signals within target regions in response to stimulus intensity/salience. The LC-driven salience signal identified here provides a measure of phasic LC activity that can be used to investigate the LC's role in attentional processing across species.

Effect of Deep Brain Stimulation of the ventromedial prefrontal cortex on the noradrenergic system in rats

BackgroundDeep Brain Stimulation (DBS) of the subgenual cingulate cortex (SCC) is a promising therapeutic alternative to treat resistant major depressive disorder. In preclinical studies, DBS of the ventromedial prefrontal cortex (vmPFC, the rodent SCC correlate) provokes an antidepressant-like effect, along with changes in noradrenaline levels at the site of stimulation. Hence, DBS appears to activate the noradrenergic-locus coeruleus (LC) system. Objective/HypothesisThe aim of this study was to evaluate the effect of vmPFC DBS on the electrical activity of noradrenergic LC neurons, cortical oscillations and coherence between both brain areas in male rats. MethodsThe antidepressant-like effect of vmPFC DBS was evaluated through the forced swimming test. Tonic and evoked activity of LC neurons, LC activity of alpha2-adrenoceptors, local field potentials from LC and electrocorticogram signals were studied after DBS by electrophysiological recordings in anaesthetized rats. The effect of DBS on tyrosine hydroxylase (TH), noradrenaline transporters (NAT), phosphorylation of the extracellular signal–regulated kinase (ERK) and corticotropin releasing factor (CRF) expression in the LC were measured by western blot assays. ResultsDBS induced an antidepressant-like effect increasing climbing behaviour in the FST that was accompanied by a robust increase of TH expression in the rat LC. The tonic and evoked activity of LC neurons was enhanced by DBS, which impaired alpha2-adrenoceptors activity. DBS also promoted an increase in slow LC oscillations, as well as a shift in LC-cortical coherence. ConclusionDBS of the vmPFC appears to affect the LC, producing changes that may underlie its antidepressant-like effects.

MUTZ-3 Langerhans cell maturation and CXCL12 independent migration in reconstructed human gingiva.

Here we describe a reconstructed full thickness human oral mucosa (gingiva) equivalent with integrated Langerhans Cells (GE-LC) and use it to compare LC activation and migration from oral versus skin epithelium. The physiologically representative models consist of differentiated reconstructed epithelium (keratinocytes and Langerhans-like cells derived from the MUTZ-3 cell line) on a fibroblast-populated collagen hydrogel which serves as a lamina propria for gingiva and dermis for skin. Topical exposure of GE-LC and the skin equivalent (SE-LC) to sub-toxic concentrations of the allergens cinnamaldehyde, resorcinol and nickel sulphate, resulted in LC migration out of the epithelia. Neutralizing antibody to CXCL12 blocked allergen-induced LC migration in SE-LC but not in GE-LC. Also, gingival fibroblasts secreted very low amounts of CXCL12 compared to skin fibroblasts even when stimulated with rhTNFα or rhIL-1α. Surprisingly, cinnamaldehyde exposure of GE-LC resulted in an increase in MUTZ-3 LC and CD83 mRNA in the hydrogel but did not result in an increase in CD1a+ cells in the collagen hydrogel (as was observed for SE-LC. These results indicate that in gingiva, upon allergen exposure, MUTZ-3 LC migrate in a CXCL12 independent manner from epithelium-to-lamina propria and in doing so mature become CD1a- and increase CD83+ mRNA. These physiologically relevant in vitro models which not only are human but which also resemble specific tissues, may aid in the identification of factors regulating immune stimulation which in turn will aid the development of therapeutic interventions for allergy and inflammation, anti-cancer vaccines as well as improving diagnostics for skin and oral allergy.

Reprint of: Locus coeruleus neuronal activity determines proclivity to consume alcohol in a selectively-bred line of rats that readily consumes alcohol.

Sprague-Dawley rats selectively-bred for susceptibility to stress in our laboratory (Susceptible, or SUS rats) voluntarily consume large amounts of alcohol, and amounts that have, as shown here, pharmacological effects, which normal rats will not do. In this paper, we explore neural events in the brain that underlie this propensity to readily consume alcohol. Activity of locus coeruleus neurons (LC), the major noradrenergic cell body concentration in the brain, influences firing of ventral tegmentum dopaminergic cell bodies of the mesocorticolimbic system (VTA-DA neurons), which mediate rewarding aspects of alcohol. We tested the hypothesis that in SUS rats alcohol potently suppresses LC activity to markedly diminish LC-mediated inhibition of VTA-DA neurons, which permits alcohol to greatly increase VTA-DA activity and rewarding aspects of alcohol. Electrophysiological single-unit recording of LC and VTA-DA activity showed that in SUS rats alcohol decreased LC burst firing much more than in normal rats and as a result markedly increased VTA-DA activity in SUS rats while having no such effect in normal rats. Consistent with this, in a behavioral test for reward using conditioned place preference (CPP), SUS rats showed alcohol, given by intraperitoneal (i.p.) injection, to be rewarding. Next, manipulation of LC activity by microinfusion of drugs into the LC region of SUS rats showed that (a) decreasing LC activity increased alcohol intake and increasing LC activity decreased alcohol intake in accord with the formulation described above, and (b) increasing LC activity blocked both the rewarding effect of alcohol in the CPP test and the usual alcohol-induced increase in VTA-DA single-unit activity seen in SUS rats. An important ancillary finding in the CPP test was that an increase in LC activity was rewarding by itself, while a decrease in LC activity was aversive; consequently, effects of LC manipulations on alcohol-related reward in the CPP test were perhaps even larger than evident in the test. Finally, when increased LC activity was associated with (i.e., conditioned to) i.p. alcohol, subsequent alcohol consumption by SUS rats was markedly reduced, indicating that SUS rats consume large amounts of alcohol because of rewarding physiological consequences requiring increased VTA-DA activity. The findings reported here are consistent with the view that the influence of alcohol on LC activity leading to changes in VTA-DA activity strongly affects alcohol-mediated reward, and may well be the basis of the proclivity of SUS rats to avidly consume alcohol.

Locus coeruleus neuronal activity determines proclivity to consume alcohol in a selectively-bred line of rats that readily consumes alcohol

Sprague–Dawley rats selectively-bred for susceptibility to stress in our laboratory (Susceptible, or SUS rats) voluntarily consume large amounts of alcohol, and amounts that have, as shown here, pharmacological effects, which normal rats will not do. In this paper, we explore neural events in the brain that underlie this propensity to readily consume alcohol. Activity of locus coeruleus neurons (LC), the major noradrenergic cell body concentration in the brain, influences firing of ventral tegmentum dopaminergic cell bodies of the mesocorticolimbic system (VTA-DA neurons), which mediate rewarding aspects of alcohol. We tested the hypothesis that in SUS rats alcohol potently suppresses LC activity to markedly diminish LC-mediated inhibition of VTA-DA neurons, which permits alcohol to greatly increase VTA-DA activity and rewarding aspects of alcohol. Electrophysiological single-unit recording of LC and VTA-DA activity showed that in SUS rats alcohol decreased LC burst firing much more than in normal rats and as a result markedly increased VTA-DA activity in SUS rats while having no such effect in normal rats. Consistent with this, in a behavioral test for reward using conditioned place preference (CPP), SUS rats showed alcohol, given by intraperitoneal (i.p.) injection, to be rewarding. Next, manipulation of LC activity by microinfusion of drugs into the LC region of SUS rats showed that (a) decreasing LC activity increased alcohol intake and increasing LC activity decreased alcohol intake in accord with the formulation described above, and (b) increasing LC activity blocked both the rewarding effect of alcohol in the CPP test and the usual alcohol-induced increase in VTA-DA single-unit activity seen in SUS rats. An important ancillary finding in the CPP test was that an increase in LC activity was rewarding by itself, while a decrease in LC activity was aversive; consequently, effects of LC manipulations on alcohol-related reward in the CPP test were perhaps even larger than evident in the test. Finally, when increased LC activity was associated with (i.e., conditioned to) i.p. alcohol, subsequent alcohol consumption by SUS rats was markedly reduced, indicating that SUS rats consume large amounts of alcohol because of rewarding physiological consequences requiring increased VTA-DA activity. The findings reported here are consistent with the view that the influence of alcohol on LC activity leading to changes in VTA-DA activity strongly affects alcohol-mediated reward, and may well be the basis of the proclivity of SUS rats to avidly consume alcohol.

CRH Engagement of the Locus Coeruleus Noradrenergic System Mediates Stress-Induced Anxiety

The locus coeruleus noradrenergic (LC-NE) system is one of the first systems engaged following a stressful event. While numerous groups have demonstrated that LC-NE neurons are activated by many different stressors, the underlying neural circuitry and the role of this activity in generating stress-induced anxiety has not been elucidated. Using a combination of invivo chemogenetics, optogenetics, and retrograde tracing, we determine that increased tonic activity ofthe LC-NE system is necessary and sufficient forstress-induced anxiety and aversion. Selective inhibition of LC-NE neurons during stress prevents subsequent anxiety-like behavior. Exogenously increasing tonic, but not phasic, activity of LC-NE neurons is alone sufficient for anxiety-like and aversive behavior. Furthermore, endogenous corticotropin-releasing hormone(+) (CRH(+)) LC inputs from the amygdala increase tonic LC activity, inducing anxiety-like behaviors. These studies position the LC-NE system as a critical mediator of acute stress-induced anxiety and offer a potential intervention for preventing stress-related affective disorders.

Abstract P5-19-25: Multi-institutional retrospective analysis of clinical and pathological factors predicting resistance to lapatinib-based therapy in HER2 positive metastatic breast cancer (HER2+ MBC)

Abstract Background The combination of the dual HER1/HER2 inhibitor lapatinib (L) and capecitabine (C) is a therapeutic option for patients (pts) with HER2+MBC whose disease progresses after treatment with the monoclonal antibody trastuzumab. At present time, no clinical or pathological factors except HER2 status are clearly recognized as predictors of the activity of LC. We conducted a retrospective analysis of pts with HER2-positive metastatic breast cancer receiving LC after trastuzumab failure to identify factors associated with resistance to LC. Materials and methods We collected clinical and pathological data from 151 pts with HER2+ MBC receiving LC after failing a prior trastuzumab-based treatment (either adjuvant or for metastatic disease) treated at 13 Italian Institutions between March 2007 and December 2013. Time to progression (TTP) and overall survival (OS), calculated by the Kaplan Meier (KM) method, were from LC treatment beginning to disease progression or to death in the absence of progression (TTP), and to the date of death or to the date of last follow-up (OS), respectively. LC resistance was defined as TTP from treatment initiation lower or equal to the median TTP for the overall population. KM curves were compared by the Log-rank test. Logistic regression analysis was used to study predictors of TTP below the median value for patients receiving LC. Analyses were performed using SPSS version 17.0 (SPSS Inc., Chicago, IL). Results At a median follow-up of 41 months (IQR 23-62), median TTP to LC therapy was 7 months (IQR 5.5-8.5) and median OS was 18 months (IQR 10-28). Fifteen pts were excluded because of short follow-up (i.e. on LC treatment and <7 months of fu). Of the remaining 136, a total of 74 pts with a PFS≤7 months were defined LC-resistant (LC-R) and a total of 62 pts were defined LC-sensitive (LC-S). All clinical and pathological variables analyzed resulted evenly distributed between the two groups, except best tumor response (CR+PR) to LC, which was higher in patients with LC-S disease (72% vs 29%, p<0.001). Conversely, best tumor response in LC-R patients showed higher rates of PD (43% vs 2%, p<0.001). Median OS was 14 months (IC 95% 11.4-22.6) and 26 months (IC 95% 22.5-29.5) in LC-R and LC-S pts, respectively (p<0.001). Although we could not find independent predictors of LC-R, factors indicating failure of the first-line trastuzumab based therapy, as PD as best tumor response and short duration of first-line trastuzumab, were associated to LC-R. Conclusions A short time to progression during capecitabine and lapatinib (LC-R) is associated with reduced OS in patients failing prior trastuzumab based therapy for HER2+ MBC. Patients who had modest clinical benefit from previous trastuzumab-based therapy could experience LC-R indicating the possibility of primary resistance to anti HER2-treatment. For these patients, alternative targeting strategies are urgently needed. Citation Format: Stefania Gori, Valentina Rossi, Monica Turazza, Elena Fiorio, Alessandra Fabi, Giancarlo Bisagni, Jennifer Foglietta, Daniele Santini, Ida Pavese, Alberto Zambelli, Patrizia Vici, Vita Leonardi, Sandro Barni, Silvana Saracchini, Giuseppe Bogina, Simona Duranti, Alessandro Inno, Gianluigi Lunardi, Filippo Montemurro. Multi-institutional retrospective analysis of clinical and pathological factors predicting resistance to lapatinib-based therapy in HER2 positive metastatic breast cancer (HER2+ MBC) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-19-25.

Molecular analysis of human papillomavirus virus-like particle activated Langerhans cells in vitro.

Langerhans cells (LC) are the resident antigen-presenting cells in human epithelium, and are therefore responsible for initiating immune responses against human papillomaviruses (HPV) entering the epithelial and mucosal layers in vivo. Upon proper pathogenic stimulation, LC become activated causing an internal signaling cascade that results in the up-regulation of co-stimulatory molecules and the release of inflammatory cytokines. Activated LC then migrate to lymph nodes where they interact with antigen-specific T cells and initiate an adaptive T-cell response. However, HPV manipulates LC in a suppressive manner that alters these normal maturation responses. Here, in vitro LC activation assays for the detection of phosphorylated signaling intermediates, the up-regulation of activation-associated surface markers, and the release of inflammatory cytokines in response to HPV particles are described.

Repeated social stress increases reward salience and impairs encoding of prediction by rat locus coeruleus neurons.

Stress is implicated in psychopathology characterized by cognitive dysfunction. Cognitive responses to stress are regulated by the locus coeruleus-norepinephrine (LC-NE) system. As social stress is a prevalent human stressor, this study determined the impact of repeated social stress on the relationship between LC neuronal activity and behavior during the performance of cognitive tasks. Social stress-exposed rats performed better at intradimensional set shifting (IDS) and made fewer perseverative errors during reversal learning (REV). LC neurons of control rats were task responsive, being activated after the choice and before reward. Social stress shifted LC neuronal activity from being task responsive to being reward responsive during IDS and REV. LC neurons of stressed rats were activated by reward and tonically inhibited by reward omission with incorrect choices. In contrast, LC neurons of stress-naive rats were only tonically inhibited by reward omission. Reward-related LC activation in stressed rats was unrelated to predictability because it did not habituate as learning progressed. The findings suggest that social stress history increases reward salience and impairs processes that compute predictability for LC neurons. These effects of social stress on LC neuronal activity could facilitate learning as indicated by improved performance in stressed rats. However, the ability of social stress history to enhance responses to behavioral outcomes may have a role in the association between stress and addictive behaviors. In addition, magnified fluctuations in LC activity in response to opposing behavioral consequences may underlie volatile changes in emotional arousal that characterize post-traumatic stress disorder.

Hepatoprotective activity of LC–ESI-MS standardized Iris spuria rhizome extract on its main bioactive constituents

The study was designed to evaluate the hepatoprotective activity of Iris spuria against paracetamol induced toxicity at two different doses 100 and 200mg/kg. The extract showed significant protective activity (p>0.01) at both the doses in dose dependent manner. Administration of the plant extract restored the paracetamol induced elevated levels of serum marker and distorted hepatic tissue architecture. The lipid peroxides (LPO) and glutathione (GSH) levels were also restored towards normal in liver tissue significantly. The main chemical constituents of the extract identified by the liquid chromatography–tandem mass spectrometry (LC–ESI-MSMS) were found to be flavones and isoflavonoids. Tectoridin and iristectorigenin A were the principal compounds present in the methanolic extract of Iris spuria.

Locus coeruleus neuromodulation of memories encoded during negative or unexpected action outcomes

When people experience surprising or sub-optimal performance outcomes, an increase in autonomic arousal helps allocate cognitive resources to adjust behavior accordingly. The locus-coeruleus–norepinephrine (LC–NE) system regulates a central orienting response to behaviorally relevant events, and might therefore signal the need to attend to and learn from performance feedback. Memories of such events also rely on elevated NE, suggesting that LC activity not only responds to salient performance outcomes but also strengthens memory for stimuli associated with their occurrence. In the present study, we used a monetary incentive delay paradigm to determine whether LC functional connectivity during reaction time feedback relates to trial-by-trial memory of preceding photo-objects. We used one psychophysiological interaction (PPI) analysis to examine patterns of LC functional connectivity that were associated with subsequent memory for picture trials in which negative or positive feedback was given, and a second PPI analysis to investigate whether successfully encoded objects from trials with uncertain outcomes were related to distinct patterns of LC functional connectivity across the brain. The PPI results revealed that successfully encoded negative feedback trials (i.e., responses exceeding the response deadline) were uniquely associated with enhanced functional coupling between the LC and left anterior insula. Furthermore, successful memory for objects in low reaction time certainty trials (i.e., responses closest to the response deadline) were linked to positive LC functional coupling with left dorsolateral prefrontal cortex. These findings suggest that noradrenergic influences help facilitate memory encoding during outcome processing via dynamic interactions with regions that process negative or unexpected feedback.