TRPM8, ASIC1, and ASIC3 localization and expression in the human oropharynx.

BACKGROUND: Oropharyngeal dysphagia (OD) is a prevalent disease with poor prognosis among older people and has no pharmacological treatment. Polymodal sensory receptors like the TRP or ASIC family receptors are potential targets to treat OD. TRPM8 agonists and acidic solutions can improve the swallow response in patients with OD, but little is known about the expression of TRPM8, ASIC1, and ASIC3 in the human oropharynx. The aim of this study was to assess the expression and localization of TRPM8, ASIC1, and ASIC3 in human samples of the oropharynx to lay the basis for new pharmacological treatments for OD. METHODS: Pathology-free samples from oropharyngeal regions innervated by cranial nerves V, IX, and X were obtained during major ENT surgery and processed to obtain mRNA (20 patients) or to be used in immunohistochemical assays (12 patients). TRPM8, ASIC1, and ASIC3 expression and localization were studied with RT-qPCR and fluorescent immunohistochemistry. KEY RESULTS: ASIC3 was expressed in the 3 regions studied with similar levels and was localized on sensory fibers innervating the mucosa below the basal lamina of all studied regions. TRPM8 was also co-localized on the sensory fibers innervating the mucosa below the basal lamina of all studied regions. In contrast, ASIC1 was only found in the nerves innervating the tongue muscular fibers. CONCLUSIONS & INFERENCES: TRPM8 and ASIC3 are found on submucosal sensory nerves in the human oropharynx. Our study lays the basis to use oropharyngeal TRPM8 and ASIC3 receptors as therapeutic targets to develop new active pharmacological treatments for OD patients.

Pharyngeal Residue and Aspiration and the Relationship with Clinical/Nutritional Status of Patients with Oropharyngeal Dysphagia Submitted to Videofluoroscopy.

OBJECTIVES: The aim of this study was to investigate the association between the videofluoroscopic (VFS) signs of impaired efficacy (pharyngeal residue) and safety (aspiration) swallowing and the clinical/nutritional status of patients with suspect of dysphagia. DESIGN: A cross-sectional study was conducted with patients submitted to videofluoroscopy. SETTING AND PARTICIPANTS: Data of 76 patients were analyzed between March 2011 and December 2014. MEASUREMENTS: The clinical history and VFS exams of patients ≥ 38 years were retrospectively analyzed. RESULTS: 88% patients presented Oropharyngeal Dysphagia (OD), 44.7% presented laryngeal penetration and 32% presented aspiration. 78% patients presented pharyngeal residue. Aspiration was associated with Head Neck Cancer (HNC) [Prevalence Ratio (PR): 2.27, p = 0.028] and cardiovascular disease (PR 1.96, p = 0.027). Underweight [Body Mass Index < 18.5 kg/m2] was not associated with the presence of aspiration. Underweight patients with OD had a higher prevalence rate of pharyngeal residue than those normally nourished (100% vs. 78%) (PR 1.34, p = 0.011). Pharyngeal residue was associated with male sex (PR 1.32, p = 0.040), neurodegenerative disease (PR 1.57, p = 0.021), stroke (PR 1.62, p = 0.009), cerebral palsy (PR 1.76, p = 0.006) and HNC (PR 1.73, p = 0.002). CONCLUSION: In the present study, neurologic diseases, HNC, male sex and underweight were associated to impaired swallowing efficacy. Underweight, independently of the other variables, was not associated with impaired swallowing safety.

Nutritional Aspects of Dysphagia Management.

This chapter describes the nutritional aspects of dysphagia management by starting with the definition of these two conditions (dysphagia and malnutrition) that share three main clinical characteristics: (a) their prevalence is very high, (b) they can lead to severe complications, and (c) they are frequently underrecognized and neglected conditions. From an anatomical standpoint, dysphagia can result from oropharyngeal and/or esophageal causes; from a pathophysiological perspective, dysphagia can be caused by organic or structural diseases (either benign or malignant) or diseases causing impaired physiology (mainly motility and/or perception disorders). This chapter gathers up-to-date information on the screening and diagnosis of oropharyngeal dysphagia, the consequences of dysphagia (aspiration pneumonia, malnutrition, and dehydration), and on the nutritional management of dysphagic patients. Concerning this last topic, this chapter reviews the rheological aspects of swallowing and dysphagia (including shear and elongational flows) and its influence on the characteristics of the enteral nutrition for dysphagia management (solid/semisolid foods and thickened liquids; ready-to-use oral nutritional supplements and thickening powders), with special focus on the real characteristics of the bolus after mixing with human saliva.

Sentinel lymph node biopsy as a prognostic factor in non-metastatic colon cancer: a prospective study.

PURPOSE: Around a third of node-negative patients with colon cancer experience a recurrence after surgery, suggesting poor staging. Sentinel lymph node techniques combined with immunochemistry could improve colon cancer staging. We prospectively assessed the effect of Sentinel node mapping on staging and survival in patients with non-metastatic colon cancer. METHODS: An observational and prospective study was designed. 105 patients with colon cancer were selected. Patients were classified according to node involvement as: N1, with node invasion detected by the conventional techniques; up-staged, with node invasion detected only by sentinel node mapping; and N0, with negative lymph node involvement by both techniques. Five-year survival and disease-free survival rates were analysed. Multivariate regression analyses were performed to identify prognostic factors for disease-free and overall survival. RESULTS: Sentinel node mapping was successfully applied in 78 patients: 33 % were N1; 24.5 % were up-staged (18 patients with isolated tumour cells and 1 patient with micrometastases); and 42.5 % were N0. N1 patients had the poorest overall 5-year survival (65.4 %) and 5-year disease-free survival (69.2 %) rates compared with the other two groups. No significant 5-year survival differences were observed between N0 patients (87.9 %) and up-staged patients (84.2 %). CONCLUSIONS: Patients up-staged after sentinel node mapping do not have a poorer prognosis than patients without node involvement. Detection of isolated cancer cells was not a poor prognosis factor in these patients.

The effect of levosulpiride on in vitro motor patterns in the human gastric fundus, antrum, and jejunum.

BACKGROUND: Levosulpiride is a 5HT4 agonist/D2 antagonist prokinetic agent used to improve gastric emptying in patients with functional dyspepsia or gastroparesis. The aim of this study was to characterize its effect on the main in vitro motility patterns in the human fundus, antrum, and jejunum. METHODS: Circular muscle strips from human stomach (antrum and fundus) and jejunum, obtained from 46 patients undergoing bariatric surgery, were studied using organ baths. Enteric motor neurons (EMNs) were stimulated by electrical field stimulation (EFS). KEY RESULTS: Levosulpiride, caused an increase in the EFS-induced cholinergic contractions in the gastric antrum (+37 ± 15.18% at 100 µM, pEC50 = 4.46 ± 0.14; p < 0.05, n = 8) and jejunum (+45.4 ± 22.03% at 100 µM, pEC50 = 3.78 ± 6.81; p < 0.05, n = 5), but not in the gastric fundus. It also caused a slight decrease in tone and frequency of spontaneous contractions in the jejunum, but did not have any major effect on tone or spontaneous contractions in the stomach. It did not have any effect on EFS-induced relaxations mediated by nitric oxide (NO) in the stomach (antrum and fundus) and by NO and ATP in the jejunum. CONCLUSIONS & INFERENCES: Our results suggest that the prokinetic effects of levosulpiride in humans are mainly due to the facilitation of the release of acetylcholine by enteric motor neurons in the gastric antrum and the jejunum.

Localization and expression of TRPV1 and TRPA1 in the human oropharynx and larynx.

BACKGROUND: Previous studies have found that TRPV1 and TRPA1 receptor agonists improve swallow response in patients with oropharyngeal dysphagia (OD), but little is known about the expression of these receptors in the human oropharynx. The aim of this study was to assess the expression and localization of TRPV1 and TRPA1 in human samples from the oropharynx of healthy patients, to provide the basis for new pharmacological treatments for OD. METHODS: Samples from oropharyngeal regions innervated by cranial nerves V, IX, and X (tongue, pharynx, and epiglottis) were obtained during ENT surgery and processed either for mRNA (21 patients) or for immunohistochemical assays (seven patients). The expression analysis was performed with RT-qPCR using ACTBh as reference gene. Hemotoxylin and eosin staining was used to study the histology; the immunohistochemical assay used (i) neuron-specific enolase to detect nerve fibers or (ii) fluorescent probes to locate TRPV1 and TRPA1. RESULTS: TRPV1 was expressed in the three studied regions, with higher levels in CN V region (tongue) than in CN X region (epiglottis; p < 0.05), and was localized at epithelial cells and nociceptive fibers in all studied regions. TRPA1 was also expressed in all studied regions, but was always localized below the basal lamina. No immunoreactivity for TRPA1 was found on epithelial cells. CONCLUSIONS & INFERENCES: TRPV1 and TRPA1 are widely expressed in the human oropharynx with two distinct patterns. Our study further confirms that TRPV1/A1 receptors are promising therapeutic targets to develop active treatments for OD patients.

A Comparative Study Between Modified Starch and Xanthan Gum Thickeners in Post-Stroke Oropharyngeal Dysphagia.

Thickeners are used in post-stroke oropharyngeal dysphagia (OD) as a compensatory therapeutic strategy against aspirations. To compare the therapeutic effects of modified starch (MS) and xanthan gum (XG) thickeners on swallow safety and efficacy in chronic post-stroke OD patients using clinical and videofluoroscopic (VFS) assessment. Patients were studied by clinical assessment (volume-viscosity swallow test, V-VST) and VFS using 3 volumes (5, 10, 20 mL) and 3 viscosities (liquid, nectar and spoon thick), comparing MS and XG. We studied 122 patients (46MS, 76XG). (A) V-VST showed that both thickeners similarly improved safety of swallow. Prevalence of safe swallowing significantly increased with enhanced viscosity (P < 0.001 vs liquid), MS: 47.83 % at liquid, 84.93 % at nectar and 92.96 % at spoon thick; XG: 55.31 % at liquid, 77.78 % at nectar and 97.84 % at spoon thick. Patients on MS reported higher prevalence of pharyngeal residue at spoon-thick viscosities. (B) VFS: increasing bolus viscosity with either thickener increased prevalence of safe swallows (P < 0.001 vs liquid), MS: 30.25 % liquid, 61.07 % nectar and 92.64 % spoon thick; XG: 29.12 % liquid, 71.30 % nectar and 89.91 % spoon thick. Penetration-aspiration scale score was significantly reduced with increased viscosity with both thickeners. MS increased oral and pharyngeal residues at nectar and spoon-thick viscosities but XG did not. Timing of airway protection mechanisms and bolus velocity were not affected by either thickener. Increasing bolus viscosity with MS and XG thickeners strongly and similarly improved safety of swallow in chronic post-stroke OD by a compensatory mechanism; in contrast only MS thickeners increased oropharyngeal residue.

Mast cell degranulation inhibits motor patterns of human ileum and sigmoid colon in vitro: relevance for postoperative ileus.

BACKGROUND: Local release of mast cell proteases during gastrointestinal surgery is associated with the inhibition of motility and postoperative ileus (POI). We determined whether activation of intramuscular mast cell affects the motor patterns of the human ileum and colon and whether proteases are involved. METHODS: Motor response of ileal and colonic circular muscle strips was measured in organ bath. Mast cell degranulation was induced by compound 48/80 (c48/80; 25-675 µg/mL). Motor response was quantified as tone, rhythmic phasic contractions (RPCs) and contractions to electric field stimulation (EFS; 40 Hz), and bethanechol-evoked contractions. Ketotifen (10(-6) mol/L) and a protease inhibitor cocktail (P8340) were used to evaluate the role of mast cell mediators. KEY RESULTS: (a) c48/80 impaired the spontaneous and the electrically evoked motor response in small bowel and colonic strips (sigmoid colon EC50 : 460.0 µg/mL for RPCs and 8.9 µg/mL for electrically evoked contraction amplitudes) and bethanechol-evoked contractions. (b) Preincubation with ketotifen (10(-6) mol/L, 1 h) prevented the impairment of RPCs and EFS-evoked contractions in the sigmoid colon and ileum but not in the right colon. (c) Preincubation with P8340 also prevented the impairment of contractions in the sigmoid colon but not in the ileum or the right colon. CONCLUSIONS & INFERENCES: Mast cell degranulation by c48/80 inhibits the spontaneous and the nerve-mediated motor response in the human ileum and colon. The effect is partially mediated by mast cell proteases and could be relevant in the pathophysiology of POI.

Peritoneal mast cell degranulation and gastrointestinal recovery in patients undergoing colorectal surgery.

BACKGROUND: Degranulation of peritoneal mast cells (MCs) induced by intestinal manipulation has been proposed as a pathophysiological factor in postoperative ileus (POI). We aimed to explore the relationship between peritoneal and colonic MC degranulation and gastrointestinal (GI) recovery following colectomy. METHODS: Patients undergoing elective laparoscopic cholecystectomy (using a laparoscope and small abdominal incisions, n = 14), and elective laparoscopic (n = 32) or open partial colectomy (through a large abdominal incision, n = 10) were studied. MC protease tryptase and chymase were studied in peritoneal fluid at the beginning, middle, and end of each surgical intervention. Density of MCs in colectomy samples were examined and oro-caecal transit time by breath test, GI function recovery by clinical composite endpoint GI-2 and association between MC proteases and clinical recovery. KEY RESULTS: Open and laparoscopic colectomy caused greater peritoneal release of tryptase and chymase (323.0 ng/mL [IQR: 53.05-381.4] and 118.6 ng/mL [IQR: 53.60-240.3]), than cholecystectomy (41.64 ng/mL [IQR: 11.17-90.93]) at the end of the surgical intervention. However, there were no differences between laparoscopic and open colectomy. Increased peritoneal protease release during surgery was observed in patients who developed POI after colectomy. CONCLUSIONS & INFERENCES: Colorectal surgery causes protease release from peritoneal MCs. Protease release does not differ between both types of colectomy (laparoscopy vs laparotomy). However, MC activation is increased in colectomy patients developing POI. Therefore, degranulation of peritoneal MCs as a factor contributing to human POI after colectomy might be considered in future studies as a target to avoid POI.

Potential role of the gaseous mediator hydrogen sulphide (H2S) in inhibition of human colonic contractility.

BACKGROUND: Hydrogen sulphide (H2S) is an endogenous signalling molecule that might play a physiologically relevant role in gastrointestinal motility. Cystathionine ß-synthase (CBS) and cystathionine γ-lyase (CSE) are two enzymes responsible for H2S production. d,l-Propargylglycine (PAG) is a CSE inhibitor whereas both aminooxyacetic acid (AOAA) and hydroxylamine (HA) are CBS inhibitors. The characterization of H2S responses and its mechanism of action are crucial to define H2S function. METHODS: Human colonic strips were used to investigate the role of H2S on contractility (muscle bath) and smooth muscle electrophysiology (microelectrodes). NaHS was used as a H2S donor. RESULTS: Combination of PAG and AOAA depolarized the smooth muscle (5-6mV, n=4) and elicited a transient increase in tone (260.5±92.8mg, n=12). No effect was observed on neural mediated inhibitory junction potential or relaxation. In the presence of tetrodotoxin 1µM, NaHS concentration-dependently inhibited spontaneous contractions (EC50=329.2µM, n=18). This effect was partially reduced by the guanylyl cyclase inhibitor ODQ 10µM (EC50=2.6µM, n=12) and by l-NNA 1mM (EC50=1.4mM, n=8). NaHS reversibly blocked neural mediated cholinergic (EC50=2mM) and tachykinergic (EC50=5.7mM) contractions. NaHS concentration-dependently reduced the increase in spontaneous mechanical activity (AUC) induced by carbachol (EC50=1.9mM) and NKA (EC50=1.7mM AUC). CONCLUSIONS: H2S might be an endogenous gasomediator regulating human colonic contractility. Its inhibitory effect is observed at high concentrations and could be mediated by a direct effect on smooth muscle with a possible synergistic effect with NO, as well as by an interaction with the cholinergic and tachykinergic neural mediated pathways.

Differential functional role of purinergic and nitrergic inhibitory cotransmitters in human colonic relaxation.

AIM: ATP and nitric oxide (NO) are released from enteric inhibitory motor neurones and are responsible for colonic smooth muscle relaxation. However, how frequency of neural stimulation affects this cotransmission process and the post-junctional responses has not been systematically characterized in the human colon. METHODS: The dynamics of inhibitory cotransmission were studied using different protocols of electrical field stimulation (EFS) to characterize the inhibitory junction potentials (IJP) and the corresponding relaxation in colonic strips obtained from 36 patients. RESULTS: Single pulses elicited a fast IJP (IJPf(MAX) = -27.6 ± 1.6 mV), sensitive to the P2Y1 antagonist MRS2500 1 µm, that ran down with frequency increase leaving a residual hyperpolarization at high frequencies (IJPf∞ = -3.7 ± 0.6 mV). Accordingly, low frequencies of EFS caused purinergic transient relaxations that cannot be maintained at high frequencies. Addition of the P2Y1 agonist MRS2365 10 µm during the purinergic rundown did not cause any hyperpolarization. Protein kinase C (PKC), a putative P2Y1 desensitizator, was able to reduce the amplitude of the IJPf when activated, but the rundown was not modified by PKC inhibitors. Frequencies higher than 0.60 ± 0.15 Hz were needed to evoke a sustained nitrergic hyperpolarization that progressively increased reaching IJPs∞ = -13 ± 0.4 mV at high frequencies and leading to a sustained inhibition of spontaneous motility. CONCLUSION: Changes in frequency of stimulation possibly mimicking neuronal firing will post-junctionally determine purinergic vs. nitrergic responses underlying different functional roles. NO will be responsible for sustained relaxations needed in physiological processes such as storage, while purinergic neurotransmission evoking sharp transient relaxations will be dominant in processes such as propulsion.

Pharmacological characterization of purinergic inhibitory neuromuscular transmission in the human colon.

BACKGROUND: In the present study, we further characterize the purinergic receptors mediating the inhibitory junction potential (IJP) and smooth muscle relaxation in the human colon using a new, potent and selective agonist (MRS2365), and antagonists (MR2279 and MRS2500) of the P2Y(1) receptor. The P2Y(12) antagonist AR-C66096 was tested as well. Using this pharmacological approach, we tested whether ß-nicotinamide adenine dinucleotide (ß-NAD) fulfilled the criteria to be considered an inhibitory neurotransmitter in the human colon. METHODS: We carried out muscle bath and microelectrode experiments on circular strips from the human colon and calcium imaging recordings on HEK293 cells, which constitutively express the human P2Y(1) receptor. KEY RESULTS: Both the fast component of IJP and non-nitrergic relaxation was concentration-dependently inhibited by MRS2279 and MRS2500. This antagonism was confirmed in HEK293 cells. However, AR-C66096 did not modify either inhibitory response. Adenosine 5'-Ο-2-thiodiphosphate and MRS2365 caused a smooth muscle hyperpolarization and transient inhibition of spontaneous motility that was antagonized by MRS2279 and MRS2500. ß-Nicotinamide adenine dinucleotide inhibited the spontaneous motility (IC(50) = 3.3 mmol L(-1) ). Nevertheless, this effect was not antagonized by high concentrations of P2Y(1) antagonists. CONCLUSIONS & INFERENCES: Inhibitory purinergic neuromuscular transmission in the human colon was pharmacologically assessed by the use of new P2Y(1) receptor antagonists MRS2179, MRS2279, and MRS2500. The rank order of potency of the P2Y(1) antagonists is MRS2500 > MRS2279 > MRS2179. We found that ß-NAD partially fulfills the criteria to be considered an inhibitory neurotransmitter in the human colon, but the relative contribution of each purine (ATP/ADP vsß-NAD) requires further studies.

Regional functional specialization and inhibitory nitrergic and nonnitrergic coneurotransmission in the human esophagus.

The aim of this study was to explore the myenteric mechanisms of control of human esophageal motility and the effect of nitrergic and nonnitrergic neurotransmitters. Human circular esophageal strips were studied in organ baths and with microelectrodes. Responses following electrical field stimulation (EFS) of enteric motoneurons (EMNs) or through nicotinic acetylcholine receptors were compared in the esophageal body (EB) and in clasp and sling regions in the lower esophageal sphincter (LES). In clasp LES strips: 1) sodium nitroprusside (1 nM to 100 µM), adenosine-5'-[ß-thio]diphosphate trilithium salt (1-100 µM), and vasoactive intestinal peptide (1 nM to 1 µM) caused a relaxation; 2) 1 mM N(ω)-nitro-L-arginine (L-NNA) shifted the EFS "on"-relaxation to an "off"-relaxation, partly antagonized by 10 µM 2'-deoxy-N(6)-methyladenosine 3',5'-bisphosphate tetrasodium salt (MRS2179) or 10 U/ml α-chymotrypsin; and 3) nicotine-relaxation (100 µM) was mainly antagonized by L-NNA, and only partly by MRS2179 or α-chymotrypsin. In sling LES fibers, EFS and nicotine relaxation was abolished by L-NNA. In the EB, L-NNA blocked the latency period, and MRS2179 reduced "off"-contraction. The amplitude of cholinergic contraction decreased from the EB to both LES sides. EFS induced a monophasic inhibitory junction potential in clasp, sling, and EB fibers abolished by L-NNA. Our study shows a regional specialization to stimulation of EMNs in the human esophagus, with stronger inhibitory responses in clasp LES fibers and stronger cholinergic excitatory responses in the EB. Inhibitory responses are mainly triggered by nitrergic EMNs mediating the inhibitory junction potentials in the LES and EB, EFS on-relaxation in clasp and sling LES sides, and latency in the EB. We also found a minor role for purines (through P2Y(1) receptors) and vasoactive intestinal peptide-mediating part of nonnitrergic clasp LES relaxation.

Specific and complementary roles for nitric oxide and ATP in the inhibitory motor pathways to rat internal anal sphincter.

BACKGROUND: The neurotransmitters mediating inhibitory pathways to internal anal sphincter (IAS) have not been fully characterized. Our aim was to assess the putative release of nitric oxide, purines and vasoactive intestinal peptide (VIP) from inhibitory motor neurons (MNs) and their role in the myogenic tone, resting membrane potential (RMP) of smooth muscle cells (SMC), spontaneous inhibitory junction potentials (sIJP), mechanical relaxation, and IJP induced by electrical field stimulation (EFS) or nicotine. METHODS: Rat IAS strips were studied using organ baths, microelectrodes, and immunohistochemistry. KEY RESULTS: Internal anal sphincter strips developed active myogenic tone (0.31 g), enhanced and stabilized by prostaglandin F(2α) (PGF2α). L-NNA (1 mmol L(-1)) depolarized SMC and increased tone but did not modify sIJP. In contrast, the specific P2Y(1) receptor antagonist MRS2500 (1 µmol L(-1)) did not modify the RMP or the basal tone but abolished sIJP. Electrical field stimulation and nicotine (10 µmol L(-1)) caused IAS relaxation (-45.9%VS-52.2%), partially antagonized by L-NNA (35%-45%, P ≤ 0.05) and fully abolished by MRS2500 (P ≤ 0.001). Electrical field stimulation induced a biphasic inhibitory junction potential (IJP), the initial fast component was selectively blocked by MRS2500 and the sustained slow component was blocked by L-NNA. Vasoactive intestinal peptide 6-28 (0.1 µmol L(-1)) or α-chymotrypsin (10 U mL(-1)) did not modify the RMP, sIJP, EFS-induced IJP, or relaxation. P2Y(1) receptors were immunolocalized in the circular SMC of IAS. CONCLUSIONS & INFERENCES: The effects of inhibitory MNs on rat IAS are mediated by a functional co-transmission process involving nitrergic and purinergic pathways through P2Y(1) receptors with specific and complementary roles on the control of tone, sIJP, and hyperpolarization and relaxation of IAS following stimulation of inhibitory MNs.

Effects of excitatory and inhibitory neurotransmission on motor patterns of human sigmoid colon in vitro.

BACKGROUND AND PURPOSE: To characterize the in vitro motor patterns and the neurotransmitters released by enteric motor neurons (EMNs) in the human sigmoid colon. EXPERIMENTAL APPROACH: Sigmoid circular strips were studied in organ baths. EMNs were stimulated by electrical field stimulation (EFS) and through nicotinic ACh receptors. KEY RESULTS: Strips developed weak spontaneous rhythmic contractions (3.67+/-0.49 g, 2.54+/-0.15 min) unaffected by the neurotoxin tetrodotoxin (TTX; 1 microM). EFS induced strong contractions during (on, 56%) or after electrical stimulus (off, 44%), both abolished by TTX. Nicotine (1-100 microM) inhibited spontaneous contractions. Latency of off-contractions and nicotine responses were reduced by N(G)-nitro-L-arginine (1 mM) and blocked after further addition of apamin (1 microM) or the P2Y(1) receptor antagonist MRS 2179 (10 microM) and were unaffected by the P2X antagonist NF279 (10 microM) or alpha-chymotrypsin (10 U mL(-1)). Amplitude of on- and off-contractions was reduced by atropine (1 microM) and the selective NK(2) receptor antagonist Bz-Ala-Ala-D-Trp-Phe-D-Pro-Pro-Nle-NH(2) (1 microM). MRS 2179 reduced the amplitude of EFS on- and off-contractions without altering direct muscular contractions induced by ACh (1 nM-1 mM) or substance P (1 nM-10 microM). CONCLUSIONS AND IMPLICATIONS: Latency of EFS-induced off-contractions and inhibition of spontaneous motility by nicotine are caused by stimulation of inhibitory EMNs coreleasing NO and a purine acting at muscular P2Y(1) receptors through apamin-sensitive K(+) channels. EFS-induced on- and off-contractions are caused by stimulation of excitatory EMNs coreleasing ACh and tachykinins acting on muscular muscarinic and NK(2) receptors. Prejunctional P2Y(1) receptors might modulate the activity of excitatory EMNs. P2Y(1) and NK(2) receptors might be therapeutic targets for colonic motor disorders.

Long-term prevalence of oropharyngeal dysphagia in head and neck cancer patients: Impact on quality of life.

BACKGROUND & AIMS: To determine the prevalence of dysphagia in head and neck cancer patients treated with surgery and radiotherapy or chemoradiotherapy. To study the impact of dysphagia on food habits, nutritional status, and quality of life. METHODS: Retrospective cross-sectional study of 87 head and neck cancer patients treated with surgery and radiotherapy or chemoradiotherapy from January 2000 through May 2005. Time since surgery was 28.5+/-17.8 months. A clinical test was used to detect dysphagia. A nutritional assessment was performed in all patients. A questionnaire was used to evaluate quality of life. RESULTS: Oropharyngeal dysphagia was present in 50.6% of patients, mostly to solid foods (72.4%). Patients with total glossectomy and chemoradiotherapy had the highest rate of dysphagia. Nutritional support was necessary in 57.1% of patients. Malnutrition was present in 20.3% of patients, mainly marasmus (81%). Fifty-one percent of patients reported a decrease in their quality of life due to dysphagia. CONCLUSIONS: We found a high prevalence of dysphagia in head and neck cancer patients treated with surgery and coadjuvant treatment. This problem negatively affects their quality of life. It is important that nutritional surveillance be provided to detect it and to prevent malnutrition.

Mechanisms controlling function in the clasp and sling regions of porcine lower oesophageal sphincter.

BACKGROUND: Characterization of functional differences between lower oesophageal sphincter (LOS) clasp and sling muscles might aid the development of more specific pharmacological and surgical approaches for the treatment of motility disorders. METHODS: Circular LOS strips from 25 adult pigs were studied in organ baths to compare the physiology of clasp and sling fibres. RESULTS: Sling strips developed greater tone than clasp fibres (mean(s.e.m.) 7.59(0.89) versus 4.72(0.67) g; P = 0.017). LOS tone was more dependent on extracellular calcium in clasp strips and on the activity of cholinergic enteric motor neurones (EMNs) in sling strips. The amplitude of maximal relaxation caused by electrical field stimulation (EFS, 3Hz) of EMNs was greater in clasp strips (mean(s.e.m.) 74.5(2.3) versus 58.1(2.2) per cent of tone; P < 0.001). EFS-induced relaxation was reduced in clasp fibres and fully blocked in sling fibres by nitrergic blockade with 10 micromol/l 1H-[1,2,4]oxadiazole-[4,3-alpha]quinoxalin-1-one (ODQ). The amplitude of EFS cholinergic responses was significantly greater in sling fibres. In the clasp region, relaxation caused by stimulation of EMNs with 100 micromol/l nicotine was reduced by ODQ. In sling fibres, nicotine induced relaxation at rest and cholinergic contraction following ODQ. CONCLUSION: Clasp and sling fibres of the porcine LOS show marked intrinsic functional differences. This should be considered when developing more specific approaches to human LOS motility disorders.

Effect of cholecystokinin-A receptor blockade on postprandial insulinaemia and gastric emptying in humans.

Our aim was determine the relationship between cholecystokinin (CCK)-A receptor blockade, glucose levels, insulin secretion and gastric emptying in humans, and to assess the effect of CCK-A blockade on pancreatic polypeptide secretion. After a 12-h fast, six healthy volunteers were given [99mTc]iminodiacetic acid monosodium salt (IDA) intravenously (5 mCi). One hour later they were offered a 577 kcal liquid meal containing [99mTc]diethylenetriaminepentaacetic acid (DTPA) (2 mCi) and glucose (105 g). Scintigraphic gastric and gallbladder activity, and plasma glucose, insulin and pancreatic polypeptide responses were monitored. In a second experiment, a continuous intravenous infusion of loxiglumide (7.5 mg kg h(-1)) was started 60 min before and continued until 120 min after test meal ingestion to block the CCK-A receptors. Gallbladder emptying was blocked by loxiglumide. Loxiglumide accelerated gastric emptying, increased insulin secretion without alteration of glucose profiles, and abolished all phases of the postprandial pancreatic polypeptide response. Blockade of peripheral CCK-A receptors accelerates gastric emptying of liquids with an increase in postprandial insulin levels. The lack of changes in glycaemia suggests that alternative homeostatic mechanisms also control postprandial glucose levels. Inhibition of pancreatic polypeptide release may reflect an independent effect of loxiglumide on vagal control involved in pancreatic polypeptide release.

[Accuracy of imaging techniques and tumor markers in the diagnosis of pancreatic cancer]. / Precisión diagnóstica de los métodos de imagen y de los marcadores tumorales séricos en el cáncer de páncreas.

OBJECTIVE: The aim of this study was to evaluate the diagnostic accuracy of: a) three imaging techniques: ultrasonography (US), computed tomography (CT) and endoscopic retrograde cholangiopancreatography (ERCP), and b) the serum tumor markers CEA, CA 19-9 and CA 125, in the diagnosis of pancreatic cancer. PATIENTS AND METHODS: A total of 137 patients were prospectively evaluated. Pancreatic cancer was diagnosed in 25 patients; chronic pancreatitis in 24; acute pancreatitis in 22; extrapancreatic malignancies in 24, and benign digestive disease in 42. The reference interval for each marker was determined in 36 healthy volunteers. Diagnostic accuracy was determined using receiver operating characteristic (ROC) curves. Each diagnostic test was used in order: a) to diagnose pancreatic cancer when the disease was clinically suspected, and b) to differentiate between pancreatic cancer and chronic pancreatitis. RESULTS: CT (0.976-0.888) and US (0.857) diagnostic accuracy resulted greater than the best serum tumor marker CA 19-9 (0.755-0.786) (p = NS), in both diagnostic conditions. To obtain a diagnostic specificity of 90% in pancreatic cancer, the CA 19-9 cutoff level should increase up to 3 and 7.5 folds being in this case better than CEA and CA 125 (p < 0.05). CONCLUSIONS: CT scan offers the greatest accuracy in the diagnosis of PC. Among the tumor markers, CA 19-9 offers the best accuracy in the diagnosis of pancreatic cancer.

[The use of anorectal manometry and dynamic proctography in patients for diagnosis of solitary rectal ulcer syndrome]. / Utilidad de la manometría ano-rectal y de la proctografía dinámica en pacientes con diagnóstico de síndrome de úlcera rectal solitaria.

BACKGROUND: Solitary rectal ulcer syndrome is caused by rectal prolapse and/or anismus. The diagnosis by physical examination, or using endoscopy or radiology alone is difficult. AIM: To evaluate the diagnostic utility of videoproctography and anorectal manometry in solitary rectal ulcer syndrome. PATIENTS AND METHODS: We studied six patients (5 women/1 man; 21-66 years) with rectal lesions suggestive of solitary rectal ulcer. By videoproctography, we measured the changes in the anorectal angle and the shape of the rectal wall during voiding. By manometry, we measured the resting pressure of the anal canal, and the pressure during maximal voluntary contraction and during straining. RESULTS: Proctography showed a rectal prolapse in 5 patients (non-exteriorized in 4). Both manometry and proctography demonstrated the normal relaxation of puborectalis and external sphincter during straining in 4 patients, manometry found sphincteric weakness in two of these patients. Both manometry and proctography evidenced anismus in a patient with rectal prolapse. CONCLUSION: The high prevalence of rectal prolapse in our patients allows us to recommend proctography in patients with morphological lesions suggestive of solitary rectal ulcer. The manometric examination identifies patients at risk of developing incontinence. Both techniques contribute to ascertain the presence of anismus and are indispensable in the selection of the adequate treatment for patients with solitary rectal ulcer.