Fos response of the tail of the ventral tegmental area to food restriction entails a prediction error processing.

The tail of the ventral tegmental area (tVTA) or rostromedial tegmental nucleus (RMTg) receives lateral habenula inputs and projects heavily to midbrain dopamine neurons. Midbrain dopamine and lateral habenula neurons participate in learning processes predicting the outcomes of actions, placing the tVTA in a critical location into prediction error pathways. tVTA GABA neurons show electrophysiological inhibition or activation after reward and aversive stimuli, respectively, and their predictive cues. tVTA molecular recruitment, however, is not elicited by all aversive stimuli. Indeed, precipitated opioid withdrawal, repeated footshocks or food restriction raise tVTA Fos expression, whereas various other unpleasant, stressful or painful stimuli does not elicit that molecular response. However, the basis of that difference remains unknown. In the present study, we tried to disentangle whether the tVTA c-Fos induction observed after food restriction was due to the aversive state of food restriction or to procedure-related reward prediction error. To this end, male Sprague-Dawley rats were food-restricted for 7-8 days. During this period, animals were handled and weighed every day before feeding. On the test day, rats underwent several behavioral procedures to explore the impact of food restriction and food-predictive cue exposure on tVTA c-Fos expression. We showed that food restriction per se was not able to recruit c-Fos in the tVTA. On the contrary, the food-predicting cues induced c-Fos locally in the absence of feeding, whereas the food-predicting cues followed by feeding evoked lower c-Fos expression. Overall, our results support the proposed involvement of the tVTA in reward prediction error.

Identifying comorbidities and lifestyle factors contributing to the cognitive profile of early Parkinson's disease.

BACKGROUND: Identifying modifiable risk factors for cognitive impairment in the early stages of Parkinson's disease (PD) and estimating their impact on cognitive status may help prevent dementia (PDD) and the design of cognitive trials. METHODS: Using a standard approach for the assessment of global cognition in PD and controlling for the effects of age, education and disease duration, we explored the associations between cognitive status, comorbidities, metabolic variables and lifestyle variables in 533 PD participants from the COPPADIS study. RESULTS: Among the overall sample, 21% of participants were classified as PD-MCI (n = 114) and 4% as PDD (n = 26). The prevalence of hypertension, diabetes and dyslipidemia was significantly higher in cognitively impaired patients while no between-group differences were found for smoking, alcohol intake or use of supplementary vitamins. Better cognitive scores were significantly associated with regular physical exercise (p < 0.05) and cognitive stimulation (< 0.01). Cognitive performance was negatively associated with interleukin 2 (Il2) (p < 0.05), Il6 (p < 0.05), iron (p < 0.05), and homocysteine (p < 0.005) levels, and positively associated with vitamin B12 levels (p < 0.005). CONCLUSIONS: We extend previous findings regarding the positive and negative influence of various comorbidities and lifestyle factors on cognitive status in early PD patients, and reinforce the need to identify and treat potentially modifiable variables with the intention of exploring the possible improvement of the global cognitive status of patients with PD.

Prospective analysis of liquid biopsies of advanced non-small cell lung cancer patients after progression to targeted therapies using GeneReader NGS platform.

BACKGROUND: In a significant percentage of advanced non-small cell lung cancer (NSCLC) patients, tumor tissue is unavailable or insufficient for genetic analyses at time to progression. We prospectively analyzed the appearance of genetic alterations associated with resistance in liquid biopsies of advanced NSCLC patients progressing to targeted therapies using the NGS platform. METHODS: A total of 24 NSCLC patients were included in the study, 22 progressing to tyrosine kinase inhibitors and two to other treatments. Liquid biopsies samples were obtained and analyzed using the GeneReadTM QIAact Lung DNA UMI Panel, designed to enrich specific target regions and containing 550 variant positions in 19 selected genes frequently altered in lung cancer tumors. Previously, a retrospective validation of the panel was performed in clinical samples. RESULTS: Of the 21 patients progressing to tyrosine kinase inhibitors with valid results in liquid biopsy, NGS analysis identified a potential mechanism of resistance in 12 (57%). The most common were acquired mutations in ALK and EGFR, which appeared in 8/21 patients (38%), followed by amplifications in 5/21 patients (24%), and KRAS mutations in one patient (5%). Loss of the p.T790M was also identified in two patients progressing to osimertinib. Three of the 21 (14%) patients presented two or more concomitant alterations associated with resistance. Finally, an EGFR amplification was found in the only patient progressing to immunotherapy included in the study. CONCLUSIONS: NGS analysis in liquid biopsies of patients progressing to targeted therapies using the GeneReader platform is feasible and can help the oncologist to make treatment decisions.

Improvement of impulse control disorders associated with levodopa-carbidopa intestinal gel treatment in advanced Parkinson's disease.

Impulse control behaviors are a frequent comorbidity for patients with Parkinson's disease (PD). The objective of the present study was to evaluate the effectiveness levodopa-carbidopa intestinal gel (LCIG) therapy on impulse control disorders (ICDs) in patients with advanced PD. We conducted a multicenter, observational, and prospective (6 months follow-up) study that included consecutive PD patients assigned to LCIG through routine medical practice. Patients completed visits at baseline, 1, 3, and 6 months after percutaneous endoscopic gastrostomy procedure. The following outcomes were evaluated: presence and severity of ICDs and other neuropsychiatric disorders, sleep disturbances, patients' quality of life, and caregivers' burden. Sixty-two patients were included at baseline: mean age 72.2 years (SD ± 7.0), 42% women. Median duration of PD symptoms was 13.5 years (IQR 5.5-21.5) and median time with motor fluctuations was 5.0 years (IQR 1.0-9.0). Treatment with LCIG infusion was associated with progressive and significant improvements in ICDs symptoms over the study period (64.4% reduction in the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's disease-Rating Scale score). Psychotic and other neuropsychiatric symptoms were also significantly reduced, and patients' sleep quality and psychosocial function improved. Caregivers' burden remained unchanged. There was a significant improvement in the daily "Off" time [7.4 h (SD ± 4.0) vs 1.5 h (SD ± 1.8); p < 0.0001] at the end of follow-up, whereas duration of dyskinesias was not affected. ICDs significantly improved after 6-month LCIG treatment in a group of PD patients with mild-to-moderate neuropsychiatric disturbances.

Response of the Tail of the Ventral Tegmental Area to Aversive Stimuli.

The GABAergic tail of the ventral tegmental area (tVTA), also named rostromedial tegmental nucleus (RMTg), exerts an inhibitory control on dopamine neurons of the VTA and substantia nigra. The tVTA has been implicated in avoidance behaviors, response to drugs of abuse, reward prediction error, and motor functions. Stimulation of the lateral habenula (LHb) inputs to the tVTA, or of the tVTA itself, induces avoidance behaviors, which suggests a role of the tVTA in processing aversive information. Our aim was to test the impact of aversive stimuli on the molecular recruitment of the tVTA, and the behavioral consequences of tVTA lesions. In rats, we assessed Fos response to lithium chloride (LiCl), ß-carboline, naloxone, lipopolysaccharide (LPS), inflammatory pain, neuropathic pain, foot-shock, restraint stress, forced swimming, predator odor, and opiate withdrawal. We also determined the effect of tVTA bilateral ablation on physical signs of opiate withdrawal, and on LPS- and LiCl-induced conditioned taste aversion (CTA). Naloxone-precipitated opiate withdrawal induced Fos in µ-opioid receptor-positive (15%) and -negative (85%) tVTA cells, suggesting the presence of both direct and indirect mechanisms in tVTA recruitment during withdrawal. However, tVTA lesion did not impact physical signs of opiate withdrawal. Fos induction was also present with repeated, but not single, foot-shock delivery. However, such induction was mostly absent with other aversive stimuli. Moreover, tVTA ablation had no impact on CTA. Although stimulation of the tVTA favors avoidance behaviors, present findings suggest that this structure may be important to the response to some, but not all, aversive stimuli.

Liquid Biopsy in Non-Small Cell Lung Cancer.

Liquid biopsy analyses are already incorporated in the routine clinical practice in many hospitals and oncology departments worldwide, improving the selection of treatments and monitoring of lung cancer patients. Although they have not yet reached its full potential, liquid biopsy-based tests will soon be as widespread as "standard" biopsies and imaging techniques, offering invaluable diagnostic, prognostic, and predictive information. This review summarizes the techniques available for the isolation and analysis of circulating free DNA and RNA, exosomes, tumor-educated platelets, and circulating tumor cells from the blood of cancer patients, presents the methodological challenges associated with each of these materials, and discusses the clinical applications of liquid biopsy testing in lung cancer.

In vivo gastric detection of α-synuclein inclusions in Parkinson's disease.

α-Synuclein inclusions have been identified in the brain and some parts of the enteric nervous system in Parkinson's disease cases. We aimed to assess these inclusions in gastric mucosa samples from patients with symptomatic Parkinson's disease. Random biopsies were performed by gastroscopy in 28 patients with Parkinson's disease and in 29 age- and sex-matched controls. Gastroscopy was performed to start enteral levodopa (L-dopa) therapy in cases and for diagnostic purposes in controls (gastroesophageal reflux, anemia, and abdominal pain were the main indications). The clinical definition of cases and controls was made a priori. Six controls had data suggestive of "mild presymptomatic parkinsonism". Biopsy specimens were immunostained for α-synuclein. The neuropathological diagnosis was established post hoc. No differences were found in the baseline characteristics of the groups. Positive fibers for the α-synuclein protein were observed in 17 of 28 (60.7%) Parkinson's disease patients, 1 of 23 controls (4.3%), and 1 of 6 (16.7%) cases of incident "mild presymptomatic parkinsonism." Neuropathological diagnosis based on α-synuclein immunostaining showed a sensitivity of 85% (95% confidence interval [CI] 62.1-96.8), specificity of 95% (95% CI 76.2-99.9) and area under the receiver operating characteristics curve (AUC) of 0.90 (95% CI 0.80-1.00). No adverse events occurred. Detection of α-synuclein inclusions in the gastric mucosa is a useful and safe tool providing in vivo evidence of the underlying neurodegenerative peripheral involvement linked to Parkinson's disease. Further studies are warranted to determine its pathophysiological implications.

Identification of natural dyes used in works of art by pyrolysis-gas chromatography/mass spectrometry combined with in situ trimethylsilylation.

Samples of four natural dyes from different organic families--natural madder (anthraquinonoid), curcuma (curcuminoid), saffron (carotenoid) and indigo (indigotic)--were analysed using a new procedure based on pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), which includes the on-line derivatisation of the natural dyes using hexamethyldisilazane (HMDS). In addition, a previous procedure involving the addition of a 10% H2SO4 aqueous solution to the dye and further separation with ethyl acetate has been tested. This procedure enhances the sensitivity of the method by extracting the colouring compounds from the rest of the compounds present in the natural dye. Two possible derivatising reagents--HMDS and tetramethylammonium hydroxide (TMAH)--were compared in order to assess their effectiveness in the proposed method. Characteristic peaks from trimethylsilyl derivatives of alizarin, quinizarin, xanthopurpurin and purpurin were obtained for madder; peaks from safranal, isophorone and trimethylsilyl derivative of crocetin for saffron; peaks from 4-(4-hydroxy-3-methoxy)phenyl-3-buten-2-one and 4-(4-hydroxy-3-methoxy)phenyl-2-butanone, which are primary pyrolysis products of curcuma, and peaks from indole, 2-methylindole and 2,3-dihydroindol-2-one, which are primary pyrolysis products of indigo, among others, were obtained. The reported procedure leads to the unambiguous identification of the four studied dyes from solid samples formed by individual dyes.