Molecular analysis in cytological samples obtained by endobronchial or oesophageal ultrasound guided needle aspiration in non-small cell lung cancer.

INTRODUCTION: Cytological samples obtained by endobronchial ultrasound (EBUS) are capital for diagnosis, staging and molecular profile in non-small cell lung carcinoma (NSCLC). OBJECTIVE: To assess the success rate of complete, partial and individual of molecular analysis in samples obtained by EBUS-guided transbronchial needle aspiration (TBNA) and/or by oesophageal ultrasound-guided fine needle aspiration with an echobronchoscope (EUS-B-FNA) in patients with NSCLC. METHODS: Prospective study including 90 patients with non-squamous NSCLC, or non-smoking squamous. Cytological samples were classified into two groups. Group 1: PEN membrane slide and/or cell blocks for the determination of mutations of EGFR, KRAS, ERBB2 and BRAF. Group 2: silane coated slides or cell blocks for rearrangements of ALK, ROS1 and MET amplification. RESULTS: The success rate was 78.6% for 4 molecular alterations (EGFR, KRAS, ALK and ROS1), and 44% for 7 determinations. The individual success rate for EGFR was 97%, KRAS 96.3%, ALK 85%, ROS1 82.3%, ERBB2 71.4%, BRAF 67.7% and MET 81.1%. There were no significant differences (p=0.489) in the number of molecular analyses (1-3 vs. 4) in group 1, depending on the types of samples (cell block vs. PEN membrane slide vs. cell block and PEN membrane slide). CONCLUSIONS: In patients with NSCLC, the cytological material obtained by ultrasound-guided needle aspiration is sufficient for individual and partial molecular analysis in the vast majority of cases. Membrane slides such as cell blocks are valid samples for molecular analysis.

SEOM clinical guidelines for the treatment of small-cell lung cancer (SCLC) (2019).

Small-cell lung cancer (SCLC) accounts for 15% of lung cancers. Only one-third of patients are diagnosed at limited stage. The median survival remains to be around 15-20 months without significative changes in the strategies of treatment for many years. In stage I and IIA, the standard treatment is the surgery followed by adjuvant therapy with platinum-etoposide. In stage IIB-IIIC, the recommended treatment is early concurrent chemotherapy with platinum-etoposide plus thoracic radiotherapy followed by prophylactic cranial irradiation in patients without progression. However, in the extensive stage, significant advances have been observed adding immunotherapy to platinum-etoposide chemotherapy to obtain a significant increase in overall survival, constituting the new recommended standard of care. In the second-line treatment, topotecan remains as the standard treatment. Reinduction with platinum-etoposide is the recommended regimen in patients with sensitive relapse (≥ 3 months) and new drugs such as lurbinectedin and immunotherapy are new treatment options. New biomarkers and new clinical trials designed according to the new classification of SCLC subtypes defined by distinct gene expression profiles are necessary.

Effect of late preterm birth on lung clearance index and respiratory physiology in school-age children.

BACKGROUND: We hypothesized that former late preterm (LP) children have abnormal pulmonary physiology parameters, including uneven ventilation distribution, due to premature disruption of normal lung development. METHODS: A cross-sectional study evaluating former LP children at the age of 6 to 12 years as compared to term controls. Demographics and child's and family history of asthma/atopy/smoking were recorded. The outcome parameters were spirometry, multiple breath washout (MBW) measurement by lung clearance index (LCI), 6-minute walk test (6MWT), symptoms related to asthma and allergy, and Godin Leisure-Time Exercise Questionnaire. RESULTS: Twenty-nine former LP were compared to 30 term-control children (mean age, 8.2 ± 1.7 and 8.8 ± 1.8 years, respectively). LP had reduced forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) compared to term controls (FEV1 1.59 ± 0.48 vs 1.80 ± 0.39 L, P = 0.005 and FVC 1.73 ± 0.45 vs 1.99 ± 0.49 L, P = 0.009). There were no differences between the two groups regarding FEV1/FVC, forced expiratory flow between 25 and 75 (FEF25-75), LCI (7.10 ± 0.79 vs 6.96 ± 0.75, P = 0.50), 6MW distance, and weekly leisure-activity score. Former LP children had more episodes of wheezing and greater use of asthma medication. CONCLUSIONS: This pilot study suggests that LP have lower pulmonary function tests (PFTs) but not ventilation inhomogeneity measured by LCI or functional disturbance. It is unclear if the differences in PFTs are due to late prematurity by itself or are the consequence of maternal and neonatal factors associated with LP. Further larger studies are required to assess the long-term respiratory consequences of LP birth.

miRNA-197 and miRNA-184 are associated with brain metastasis in EGFR-mutant lung cancers.

INTRODUCTION: The prognostic value of EGFR mutation in lung cancer patients with brain metastases is uncertain and therapeutic efficacy with EGFR TKI is limited. Looking for biomarkers closely related with early tumor changes and brain metastases in non-small cell lung cancer is warranted. MicroRNAs (miRNAs) are frequently deregulated in lung cancer. The objective of this study was to investigate whether some miRNAs are related with brain metastasis risk in EGFR-mutant non-small cell lung cancer patients. MATERIALS AND METHODS: miRNA quantification was retrospectively performed in formalin-fixed, extracranial paraffin-embedded adenocarcinoma tumor tissue available from 17 human samples of advanced non-small cell lung cancer patients. Samples were classified as brain metastasis group (5 EGFR-mutant patients with initial BM, EGFRm-BM+; and 6 EGFR wild-type patients with initial BM) and the control group (6 EGFR-mutant NSCLC patients without BM). The RNA obtained was preamplified and retro-transcribed, and the miRNA was quantified with the TaqMan OpenArray Human MiRNA Panel in the QuantStudio™ 12 K Flex Real-Time PCR system. RESULTS: miRNA-197 and miRNA-184 showed a significant higher expression in EGFRm-BM+ group than in the control group (p = 0.017 and p = 0.01, for miRNA-197 and miRNA-184, respectively), with a trend toward overexpression in BM group compared with the control group (p = 0.08 and p = 0.065, for miRNA-197 and miRNA-184, respectively), without differences in expression in BM group according to EGFR mutational status (EGFR wild type vs. EGFR-mutant: p = 0.175 and p = 0.117, for miRNA-197, miRNA-184 respectively). CONCLUSIONS: miRNA-197 and miRNA-184 are overexpressed in EGFR-mutant patients with BM and they might be a new biomarker for stratifying the risk of BM in this subpopulation.

Effects of meal composition on postprandial incretin, glucose and insulin responses after surgical and medical weight loss.

BACKGROUND: Meal tolerance tests are frequently used to study dynamic incretin and insulin responses in the postprandial state; however, the optimal meal that is best tolerated and suited for hormonal response following surgical and medical weight loss has yet to be determined. OBJECTIVE: To evaluate the tolerability and effectiveness of different test meals in inducing detectable changes in markers of glucose metabolism in individuals who have undergone a weight loss intervention. METHODS: Six individuals who underwent surgical or medical weight loss (two Roux-en-Y gastric bypass, two sleeve gastrectomy and two medical weight loss) each completed three meal tolerance tests using liquid-mixed, solid-mixed and high-fat test meals. The tolerability of each test meal, as determined by the total amount consumed and palatability, as well as fasting and meal-stimulated glucagon-like peptide, glucose-dependent insulinotropic polypeptide, insulin and glucose were measured. RESULTS: Among the six individuals, the liquid-mixed meal was better and more uniformly tolerated with a median meal completion rate of 99%. Among the four bariatric surgical patients, liquid-mixed meal stimulated on average a higher glucagon-like peptide (percent difference: 83.7, 89), insulin secretion (percent difference: 155.1, 158.7) and glucose-dependent insulinotropic polypeptide (percent difference: 113.5, 34.3) compared with solid-mixed and high-fat meals. CONCLUSIONS: The liquid-mixed meal was better tolerated with higher incretin and insulin response compared with the high-fat and solid-mixed meals and is best suited for the evaluation of stimulated glucose homeostasis.

Two biomarker-directed randomized trials in European and Chinese patients with nonsmall-cell lung cancer: the BRCA1-RAP80 Expression Customization (BREC) studies.

BACKGROUND: In a Spanish Lung Cancer Group (SLCG) phase II trial, the combination of BRCA1 and receptor-associated protein 80 (RAP80) expression was significantly associated with outcome in Caucasian patients with nonsmall-cell lung cancer (NSCLC). The SLCG therefore undertook an industry-independent collaborative randomized phase III trial comparing nonselected cisplatin-based chemotherapy with therapy customized according to BRCA1/RAP80 expression. An analogous randomized phase II trial was carried out in China under the auspices of the SLCG to evaluate the effect of BRCA1/RAP80 expression in Asian patients. PATIENTS AND METHODS: Eligibility criteria included stage IIIB-IV NSCLC and sufficient tumor specimen for molecular analysis. Randomization to the control or experimental arm was 1 : 1 in the SLCG trial and 1 : 3 in the Chinese trial. In both trials, patients in the control arm received docetaxel/cisplatin; in the experimental arm, patients with low RAP80 expression received gemcitabine/cisplatin, those with intermediate/high RAP80 expression and low/intermediate BRCA1 expression received docetaxel/cisplatin, and those with intermediate/high RAP80 expression and high BRCA1 expression received docetaxel alone. The primary end point was progression-free survival (PFS). RESULTS: Two hundred and seventy-nine patients in the SLCG trial and 124 in the Chinese trial were assessable for PFS. PFS in the control and experimental arms in the SLCG trial was 5.49 and 4.38 months, respectively [log rank P = 0.07; hazard ratio (HR) 1.28; P = 0.03]. In the Chinese trial, PFS was 4.74 and 3.78 months, respectively (log rank P = 0.82; HR 0.95; P = 0.82). CONCLUSION: Accrual was prematurely closed on the SLCG trial due to the absence of clinical benefit in the experimental over the control arm. However, the BREC studies provide proof of concept that an international, nonindustry, biomarker-directed trial is feasible. Thanks to the groundwork laid by these studies, we expect that ongoing further research on alternative biomarkers to elucidate DNA repair mechanisms will help define novel therapeutic approaches. TRIAL REGISTRATION: NCT00617656/GECP-BREC and ChiCTR-TRC-12001860/BREC-CHINA.

Beyond EGFR TKI in EGFR-mutant non-small cell lung cancer patients: main challenges still to be overcome.

First line epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) is the standard treatment in advanced EGFR-mutant Non Small Cell Lung Cancer (NSCLC) patients, with an improvement in response rate, progression free survival, and quality of life compared with upfront chemotherapy. However, in the real world, EGFR mutation results often return positive once chemotherapy has been started. Different clinical strategies have been tested in this situation: reserve the EGFR TKI until tumor become resistant beyond chemotherapy, stop chemotherapy and switch to EGFR TKI, introduce the EGFR TKI as a maintenance treatment, or combined strategies such as intercalated or concurrent EGFR TKI plus chemotherapy. In this review, we aim to summarize the clinical evidence of first line treatment strategy with EGFR TKI and discuss the potential options in the sequence of treatment in EGFR-mutant patients.

Acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors in EGFR-mutant non-small cell lung cancer: a new era begins.

The discovery of mutated oncogenes has opened up a new era for the development of more effective treatments for non-small cell lung cancer patients (NSCLC) harbouring EGFR mutations. However, patients with EGFR-activating mutation ultimately develop acquired resistance (AR). Several studies have identified some of the mechanisms involved in the development of AR to EGFR tyrosine kinase inhibitors (TKI) that can be potential therapeutic strategies, although in up to 30% of cases, the underlying mechanism of AR are still unexplained. In this review we aim to summarize the main mechanisms of AR to EGFR TKI and some clinical strategies that can be used in the daily clinical practice to overcome this resistance and try to prolong the outcomes in this subgroup of patients.

Palatable food avoidance and acceptance learning with different stressors in female rats.

Stress activates the hypothalamus-pituitary-adrenal (HPA) axis leading to the release of glucocorticoids (GC). Increased activity of the HPA axis and GC exposure has been suggested to facilitate the development of obesity and metabolic syndrome. Nonetheless, different stressors can produce distinct effects on food intake and may support different directions of food learning e.g. avoidance or acceptance. This study examined whether interoceptive (LiCl and exendin-4) and restraint stress (RS) support similar or distinct food learning. Female rats were exposed to different stressors after their consumption of a palatable food (butter icing). After four palatable food-stress pairings, distinct intakes of the butter icing were observed in rats treated with different stressors. Rats that received butter icing followed by intraperitoneal injections of LiCl (42.3mg/kg) and exendin-4 (10µg/kg) completely avoided the palatable food with subsequent presentations. In contrast, rats experiencing RS paired with the palatable food increased their consumption of butter icing across trials and did so to a greater degree than rats receiving saline injections. These data indicate that interoceptive and psychosocial stressors support conditioned food avoidance and acceptance, respectively. Examination of c-Fos immunoreactivity revealed distinct neural activation by interoceptive and psychosocial stressors that could provide the neural basis underlying opposite direction of food acceptance learning.

Additive feeding inhibitory and aversive effects of naltrexone and exendin-4 combinations.

OBJECTIVE: One developing strategy for obesity treatment has been to use combinations of differently acting pharmacotherapies to improve weight loss with fewer adverse effects. The purpose of this study was to determine whether the combination of naltrexone (Nal), an opioid antagonist acting on the reward system, and exendin-4 (Ex-4), a glucagon-like peptide 1 agonist acting on satiety signaling, would produce larger reductions in food intake than either alone in rats. Because the anorectic potencies of both compounds have been associated with nausea and malaise, the influence of these drug combinations on the acquisition of a conditioned taste aversion (CTA) was also determined. METHODS: In Experiment 1, the acute anorectic effects of Nal (0.32-3.2 mg kg(-1); intraperitoneally (i.p.)) and Ex-4 (1-10 µg kg(-1); i.p.) were assessed alone or in combination. Combinational doses were further investigated by the repeated daily administration of 1 mg kg(-1) Nal+3.2 µg kg(-1) Ex-4 for 4 days. In Experiment 2, both compounds alone or in combination were used as unconditioned stimuli in a series of CTA tests. RESULTS: Nal and Ex-4, alone or in combination, suppressed food intake in a dose-dependent manner, and the interaction on food intake between Nal and Ex-4 was additive. In the CTA paradigm, Nal (1 mg kg(-1)) alone did not support acquisition, whereas a CTA was evident with doses of Ex-4 (1 or 3.2 µg kg(-1)). Combinations of Nal and Ex-4 also resulted in a more rapid and robust acquisition of a CTA. CONCLUSION: Given that the Nal and Ex-4 combination produces additive effects on not only food intake reduction but also food aversion learning, this specific drug combination does not have the benefit of minimizing the adverse effects associated with each individual drug. These data suggest that it is necessary to evaluate both the positive and adverse effects at early stages of combinational drug development.

A novel obesity model: synphilin-1-induced hyperphagia and obesity in mice.

AIMS: The pathogenesis of obesity remains incompletely understood and the exploration of the role of novel proteins in obesity may provide important insights into its causes and treatments. Here, we report a previously unidentified role for synphilin-1 in the control of food intake and body weight. Synphilin-1, a cytoplasmic protein, was initially identified as an interaction partner of alpha-synuclein, and has implications in Parkinson's disease pathogenesis related to protein aggregation. SUBJECTS AND METHODS: To study the in vivo role of synphilin-1, we characterized a human synphilin-1 transgenic mouse (SP1) by assessing synphilin-1 expression, plasma parameters, food intake and spontaneous activity to determine the major behavioral changes and their consequences in the development of the obesity phenotype. RESULTS: Expression of human synphilin-1 in brain neurons in SP1 mice resulted in increased food intake, body weight and body fat. SP1 mice also displayed hyperinsulinemia, hyperleptinemia and impaired glucose tolerance. Pair-feeding SP1 mice to amounts consumed by non-transgenic mice prevented the increased body weight, adiposity, hyperinsulinemia and hyperleptinemia demonstrating that these were all the consequences of increased food intake. Transgenic expression of synphilin-1 was enriched in hypothalamic nuclei involved in feeding control, and fasting-induced elevated endogenous synphilin-1 levels at these sites, suggesting that synphilin-1 is an important player in the hypothalamic energy balance regulatory system. CONCLUSION: These studies identify a novel function of synphilin-1 in controlling food intake and body weight, and may provide a unique obesity model for future studies of obesity pathogenesis and therapeutics.

Preoperative tests: an Irish perspective.

INTRODUCTION: We sought to investigate whether hospital doctors in Ireland order too many expensive, unnecessary tests and analyse their motives for so doing. METHODS: A series of test patients modelled along guidelines as outlined by the National Institute for Clinical Excellence were presented to doctors in two university teaching hospitals. For each case, they were asked to identify the appropriate investigations. RESULTS: Fifty-three interns on a surgical rotation completed the questionnaires. Forty-four percent (n = 50) of interns ordered the tests based on influences from the consultant leading their team, with only 24% citing their medical training as the critical reason for ordering a preoperative investigation. No intern considered cost to have any influence on their decision to book preoperative tests. DISCUSSION: This study demonstrates that the previously well-documented international practice of overuse and unexplained variation in preoperative testing is also the norm in Ireland.

Synphilin-1 exhibits trophic and protective effects against Rotenone toxicity.

Synphilin-1 is a cytoplasmic protein with unclear function. Synphilin-1 has been identified as an interaction partner of alpha-synuclein. The interaction between synphilin-1 and alpha-synuclein has implications in Parkinson's disease. In this study, we stably overexpressed human synphilin-1 in mouse N1E-115 neuroblastoma cells. We found that overexpression of synphilin-1 shortened cell growth doubling time and increased neurite outgrowth. Knockdown of endogenous synphilin-1 caused neuronal toxicity and shortened neurite outgrowth. We further found that synphilin-1 increased activation of the extracellular signal-regulated kinases (ERK1/2) and mediated neurite outgrowth. Rotenone, mitochondrial complex I inhibitor, has been shown previously to induce dopaminergic neurodegeneration and Parkinsonism in rats and Drosophila. We found that Rotenone induced apoptotic cell death in N1E-115 cells via caspase-3 activation and poly (ADP-ribose) polymerase (PARP) cleavage. Overexpression of synphilin-1 significantly reduced Rotenone-induced cell death, caspase-3 activation and PARP cleavage. The results indicate that synphilin-1 displays trophic and protective effects in vitro, suggesting that synphilin-1 may play a protective role in Parkinson's disease (PD) pathogenesis and may lead to a potential therapeutic target for PD intervention.

Endobronchial ultrasound-guided transbronchial needle aspiration for identifying EGFR mutations.

The presence of somatic mutations of the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) gene in patients with advanced nonsmall cell lung cancer (NSCLC) correlates with a good response to tyrosine kinase inhibitors. The usefulness of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for the detection of EGFR mutations in cells recovered from malignant mediastinal nodes in patients with NSCLC was assessed. All patients with lung adenocarcinoma or unspecified NSCLC referred for staging with EBUS-TBNA were included. Nodes with a short-axis diameter of >5 mm were sampled, and genomic DNA from metastatic tumour cells was obtained for analysis of exons 19 and 21. The impact of sampling on management was assessed. EGFR gene analysis of the EBUS-TBNA sample was feasible in 26 (72.2%) out of the 36 patients with lymph node metastasis. Somatic mutations of the EGFR gene were detected in tissue obtained through EBUS-TBNA in two (10%) out of 20 patients with metastasic lung adenocarcinoma. Malignant tissue samples obtained by EBUS-TBNA from patients with nodal metastasis of NSCLC are suitable for the detection of EGFR mutations in most cases, and this technique demonstrates mutated neoplastic cells in a tenth of patients with adenocarcinoma.

Multifocal Langerhans' cell histiocytosis: a case report.

OBJECTIVES: Langerhans' cell histiocytosis (LCH) is a rare disorder of unknown aetiology, characterised by the proliferation of histiocytic cells in various tissues and organs. The role of the otolaryngologist is important in the early and accurate evaluation, staging and diagnosis of LCH, as it may mimic more common otological disorders. METHOD: We report the case of a 2-year-old child presenting with LCH and review the literature concerning this rare disease. RESULTS: Presentation in our case was with a common aural polyp, refractory to medical treatment, which when biopsied, revealed LCH. Radiological evaluation showed multifocal disease. CONCLUSION: A sound knowledge of the disease process in vital to the otolaryngologist, thus enabling rapid diagnosis and early treatment for a commonly fatal condition.

Gut peptides in the control of food intake.

Multiple gut peptides are involved in the overall control of food intake. Plasma levels of gut peptides are differentially affected by food intake, and the different patterns of release around meals provides an indication of a peptide's specific role in feeding control. Ghrelin is a gastric peptide whose plasma levels are high before meals and are suppressed in response to food intake. Consistent with this pattern, ghrelin has been shown to stimulate food intake by hastening meal initiations. Cholecystokinin (CCK) is released from upper intestinal sites in response to food intake. CCK inhibits eating in a manner consistent with a role in satiety. Pancreatic glucagon and amylin play similar roles in meal termination. In contrast, the lower gut peptides, peptide YY (3-36) and glucagon-like peptide 1, are released more slowly in response to food intake and levels remain elevated for hours after a meal. This pattern of release suggests effects across multiple meals, and these peptides have been shown to inhibit food intake by both decreasing meal size and increasing the satiating potency of consumed nutrients. Together, these actions indicate multiple roles for gut peptides in feeding control.

A bioassay for metals utilizing a human cell line.

The purpose of this study was to assess the ability of the HepG2 cell line to function as a bioassay for metal contamination in sediments, using metallothionein (MT) as a biomarker of exposure. Sediments were collected from the eastern and western ends of Lake Erie, extracted using EPA method 200.7, and analyzed for cadmium (Cd), mercury (Hg) and lead (Pb) levels using ICP-AES. Sediment extracts were neutralized then used at a 2.5% final concentration in the exposure medium. MT levels were measured using the cadmium-hemoglobin affinity assay after a 48 h exposure. Fortified blanks from the ICP protocol served as positive controls. Also, HepG2 cells were exposed to Cd, Pb or combinations of Cd and Pb to determine whether or not induction of MT observed in cells exposed to sediment extracts was due to a single metal, combinations of metals, pH, or some other factor. Additionally, cells were exposed to a range of Cd concentrations approximating the levels found in the extracts (0.0005-0.1mg/L) to determine if a concentration-response occurred. Total metal levels ranged from 527 to 33.5mg/kg with lead the predominant metal, accounting for 100-88.9% of the total quantifiable metals in the sediments. The biomarker response (MT induction) was strongly correlated (r2=0.9919, r2=0.990) with total metal and lead levels in the sediments, respectively, which supports recent field studies indicating the biomarker can discern differences in the strength of the inducing agent. Statistically significant MT induction was associated with sediments which contained measurable Cd concentrations and no significant differences were observed when comparing Cd only and Cd+Pb exposed cells indicating no interactions between Cd and Pb were occurring and supporting our finding that Cd was the main inducing agent in sediment extracts. MT levels also increased significantly in a concentration-dependent manner when cells were exposed only to Cd. Results suggest this human bioassay and the MT biomarker of exposure may be useful for monitoring complex metal mixtures in aquatic sediments.

The Rossetti-Nissen fundoplication--effective in managing gastro-oesophageal reflux disease.

BACKGROUND: The report herein details a prospective audit of a unit's eight-year experience of the Rossetti-Nissen fundoplication using a predominantly laparoscopic technique, selective hiatal repair, no bougie and a standardised protocol of pre- and post-operative functional endoscopic and symptom assessment. METHODS: Three hundred and seventy-eight patients underwent the Rossetti-Nissen fundoplication. All patients had documented data on endoscopy, health related quality of life (HR-QoL), surgical details and complications pre-operatively and at six months post-operatively. Repeat physiological testing was performed at six months. RESULTS: At a median follow-up of six (range 3-13) months there was improved symptom scoring and HR-QoL after fundoplication with an 89% patient satisfaction rate. Ninety-five patients (25%) reported some early dysphagia, and 91 of these reported the outcome of surgery to be excellent or good. Thirty-eight patients (10%) had recurrent heartburn and 28 (7%) were back on medication at six months post-operatively. At follow-up pH study at a median of six months, 89% of patients had normalised acid reflux scores. CONCLUSIONS: Rossetti-Nissen fundoplication, with no use of an oesophageal bougie and no division of short gastric vessels, is an effective procedure giving 89% patient satisfaction and significant improvement in QoL parameters and physiological measurements.

Characterization of the feeding inhibition and neural activation produced by dorsomedial hypothalamic cholecystokinin administration.

Within the dorsomedial hypothalamus (DMH), cholecystokinin (CCK) has been proposed to modulate neuropeptide Y (NPY) signaling to affect food intake. However, the neural circuitry underlying the actions of this CCK-NPY signaling system in the controls of food intake has yet to be determined. We sought to characterize the feeding inhibition and brain neural activation produced by CCK administration into the DMH of rats. We determined the time course of feeding inhibitory effects of exogenous DMH CCK, assessed NPY gene expression in the DMH in response to DMH CCK administration, and characterized c-Fos activation in the entire brain induced by CCK injection into the DMH using c-Fos like immunohistochemistry. We found that parenchymal injection of CCK into the DMH decreased food intake during the entire 22 h observation period, with a primary effect in the first 4 h, and down-regulated NPY gene expression in the DMH. c-Fos immunohistochemistry revealed that DMH CCK increased the number of c-Fos positive cells in the paraventricular nucleus (PVN), arcuate nucleus, suprachiasmatic nucleus and retrochiasmatic area as well as in the contralateral DMH. This pattern of activity is different from that produced by peripherally administered CCK which is short acting and primarily activates neurons in the nucleus of the solitary tract and area postrema, as well as the PVN and DMH. Together, these data suggest that DMH CCK plays an important role in the control of food intake, and does so by activating different pathways from those activated by peripheral CCK.