Publisher's announcement

On the national level in Ecuador in 1982 roughly 61 percent of elderly people 60 years and over lived in complex family households, but this was 70 percent in the Coastal region (Costa) compared with only 54 percent in the Mountain region (Sierra), these two regions comprising over 95 percent of Ecuador's 1982 population. The regional difference could not be explained by standard demographic or socioeconomic characteristics available in the 1982 Census, either among all elderly people or unmarried women elderly. Rather, the regional difference may reflect underlying value and attitude differences not measured in the Census. As the marital structure of the adult population in the two areas has been quite different, consensual union being much more common in the Costa than the Sierra, we are left to wonder if there might be two different family systems at play. Such speculation will need to be addressed by future research.     

Influence of naloxone on rectal sensorimotor function in health

Abstract  Abnormal rectal motor physiology and visceral hypersensitivity are implicated in the pathogenesis of irritable bowel syndrome. Endogenous opioids are involved in both the regulation of gut motility and the processing of sensory information. Our aim was to study the effect of suppression of endogenous opioid function by naloxone on rectal sensorimotor function in health. Eighteen healthy subjects participated in a rectal barostat study. Sensorimotor function was evaluated during two consecutive stepwise distensions separated by 30 min of basal tone recording, and with perception scoring on a 0–6 graded scale. Naloxone was administered, after 15 min of basal tone measurements, as an intravenous bolus (0.4 mg), followed by continuous infusion (20 μg kg⁻¹ h⁻¹) in a placebo-controlled, single-blinded and randomized fashion. Naloxone did not alter rectal sensitivity. Comparison of visual analogue scale scores between naloxone and saline did not reveal altered intensities of pain or discomfort. Compared to the baseline distension, a significant adaptive increase in compliance occurred during the second distension after saline (7.8 ± 0.7 vs 11.0 ± 0.6 mL mmHg⁻¹, P  = 0.0016). This dynamic change in rectal compliance did not occur after naloxone administration (8.8 ± 0.7 vs 10.1 ± 0.8 mL mmHg⁻¹, ns). Low intensity tonic distension induced a rectal adaptive relaxation, which was absent after naloxone. Naloxone does not alter rectal sensitivity but abolishes rectal adaptation in response to repeated balloon distention. These observations suggest that the endogenous opioid system is involved in control of rectal tone rather than rectal sensitivity.     

Mechanisms underlying duodeno-gastric reflux in man

BACKGROUND: Recent studies suggest that duodeno-gastro-oesophageal reflux (DGER) contributes to the occurrence of reflux oesophagitis and Barrett's oesophagus. The mechanisms underlying duodeno-gastric reflux (DGR), a prerequisite for DGER, are poorly understood. AIMS: To study the occurrence of DGR in relation to interdigestive and postprandial gastroduodenal motility. SUBJECTS AND METHODS: Ten healthy subjects underwent stationary gastroduodenal manometry with simultaneous duodenal and antral Bilitec recording 4 h before and 5 h after ingestion of a liquid meal. Eight volunteers underwent the same study, with administration of erythromycin postprandially. RESULTS: During the interdigestive phase II, all volunteers had short DGR episodes. Postprandially, DGR occurred in all subjects, on average 39 +/- 28 min after the start of the meal, and was cleared from the stomach after 242 +/- 23 min. Induction of increased antral motility and of a premature phase III, by administration of erythromycin, was associated with faster gastric DGR clearance. However, there was no direct temporal relationship between erythromycin-induced gastric phase III and erythromycin-induced DGR clearance. CONCLUSION: In healthy subjects, duodenogastric reflux occurs sporadically in the interdigestive state and is a normal phenomenon in the postprandial period. Erythromycin induces faster clearance of DGR from the stomach, which depends on enhanced antral contractile activity rather than premature phase III.     

Normal values for the satiety drinking test in healthy children between 5 and 15 years

Abstract  In adults, a slow caloric drinking test has been proposed as a non-invasive tool to estimate gastric accommodation and to quantify meal-induced symptoms in functional dyspepsia (FD). The same test has been proposed for paediatric FD, but normal values are only available for adolescents and adults. The aim of the study was (i) to establish normal values for the satiety drinking test in young children and (ii) to study the influence of demographic factors. In all, 59 healthy children [27 girls; age range 5–16 years, body mass index (BMI) 17.4 ± 2.5 kg m⁻²] were studied in the morning after an overnight fast. They drank a liquid nutrient meal (1.5 kcal mL⁻¹) from beakers that were filled by a peristaltic pump filled at a rate of 15 mL min⁻¹ with. For every 5 min, satiety was scored on a graphic rating scale grade 0–5 (1 = threshold, 5 = maximum), until a score of 5 was reached. Values are given as mean ± SEM and compared by t -test; correlation analysis was performed using Spearman rank test. All children performed the test as indicated except for one 5 years old who stopped prematurely for dislike of the taste. The endpoint was reached at 360 ± 23 mL (540 ± 34 kcal), and was age-dependent (Spearman r  = 0.28, P  = 0.03). No correlation was found between the maximum volume ingested and gender, weight, height or BMI. Age-dependent normal ranges were determined for ages 5–16 at 3-year intervals, and were found to increase with age. We established feasibility of and normal values for a non-invasive satiety drinking test in children with an age range of 5–15 years. This tool can now be used in the assessment of paediatric FD and eating disorders.     

Prolonged duodenal acid perfusion and dyspeptic symptom occurrence in healthy volunteers

Abstract  The pathophysiology of functional dyspepsia (FD) is unknown and several mechanisms associated with specific symptom patterns have been recently proposed. Increased duodenal acid exposure has been supposed to be associated with nausea, but recently an increase of severity of several dyspeptic symptoms was noted in a subset of dyspeptic patients. As its pathogenetic role is still unclear, we evaluated an involvement of duodenal acid exposure in symptom generation by inducing a hyperacidity status of the duodenum. Twelve young adult healthy volunteers in a randomized, double-blind protocol, underwent duodenal acid (0.2 N, 5 mL min⁻¹) or saline perfusion, antropyloroduodenal manometry and duodenal pH monitoring both during fasting and postprandially. Every 15 min, severity of discomfort, fullness, bloating, belching, nausea, heartburn, epigastric burning, satiety and pain were evaluated by visual analogue scale. During acid perfusion, symptom scores for discomfort, bloating, nausea, epigastric burning were significantly higher ( P  < 0.01) compared to saline. Postprandial antral motility index was lower (2.96 ± 1.8 vs 3.62 ± 1.8, P  = 0.01) and jejunal motility index higher (4.87 ± 1.0 vs 4.37 ± 1.4, P  = 0.01) during acid perfusion. Occurrence and duration of phases III of the migrating motor complex showed no difference. Duodenal acid perfusion causes a sensitization to dyspeptic symptoms and induces antral hypomotility and jejunal hypercontractility. Through these mechanisms, increased duodenal acid exposure may play a role in the pathophysiology of FD symptoms.     

Influence of ghrelin on the gastric accommodation reflex and on meal-induced satiety in man

Abstract  Ghrelin increases gastric tone in the fasting state and enhances gastric emptying in gastroparesis. The aims of the study were to evaluate the effect of ghrelin on postprandial gastric tone and on meal-induced satiety in health. Ten healthy volunteers underwent a barostat study on two occasions. After determination of intra-abdominal pressure (minimal distending pressure, MDP), isobaric volume measurement was performed for 90 min at MDP + 2 mmHg. After 20 min, ghrelin (40 μg) or saline was administered i.v. over 30 min in a double-blind-randomized cross-over design, followed 10 min later by a liquid meal (200 mL, 300 kcal). Stepwise isobaric distentions (+2 mmHg per 2 min) were performed 60 min after the meal. Data (mean ± SEM) were compared using paired Student's t -test and anova . Separately, a satiety drinking test (15 mL min⁻¹ until satiety score 5) was performed on 10 subjects twice, after treatment with placebo or ghrelin. Ghrelin infusion significantly inhibited gastric accommodation (mean volume increase adjusted means 108.0 ± 50 vs 23.0 ± 49 mL, P  = 0.03, ancova with the premeal postinfusion volume as covariate) and reduced postprandial gastric volumes (197.2 ± 24.6 vs 353.5 ± 50.0 mL, P  = 0.01). Pressures inducing perception or discomfort during postprandial gastric distentions were not altered. During satiety testing, ghrelin did not alter nutrient volume ingested till maximal satiety (637.5 ± 70.9 vs 637.5 ± 56.2 mL, ns). Ghrelin administered during the meal significantly inhibits gastric accommodation in health, but this is not associated with early satiation.     

The effect of radiology guidelines for general practitioners in Plymouth

The impact of introducing guidelines to General Practitioners using the radiodiagnostic services in the Plymouth Health District has been analysed. The guidelines were advisory and issued to all General Practitioners in the area served by the Plymouth group of hospitals. There was no vetting of requests from Practitioners following their introduction. Three 6 month periods were considered; two before the guidelines were introduced and one after. An overall reduction of 23% in referrals was achieved. An analysis by examination showed that only those examinations specifically targeted in the guidelines showed a significant reduction. In the case of targeted examinations, a reduction of 28% (P less than 0.001) was demonstrated.     

Oesophageal tone and sensation in the transition zone between proximal striated and distal smooth muscle oesophagus

Abstract  Previous studies have shown that the proximal striated muscle oesophagus is less compliant and more sensitive than the distal smooth muscle oesophagus. Conventional and high resolution manometry described a transition zone between striated and smooth muscle oesophagus. We aimed to evaluate oesophageal tone and sensitivity at the transition zone of oesophagus in healthy volunteers. In 18 subjects (seven men, mean age: 28 years) an oesophageal barostat study was performed. Tone and sensitivity were assessed using stepwise isobaric distensions with the balloon located at transition zone and at distal oesophagus in random order. To study the effect induced on transition zone by a previous distension at the distal oesophagus and vice versa, identical protocol was repeated after 7 days with inverted order. Initial distension of a region is referred to as 'naïf' distension and distension of a region following the distension of the other segment as 'primed' distension. Assessment of three oesophageal symptoms (chest pain, heartburn and 'other') was obtained at the end of every distension step. Compliance was significantly higher in the transition zone than in the distal oesophagus (1.47 ± 0.14 vs 1.09 ± 0.09 mL mmHg⁻¹, P  = 0.03) after 'naif' distensions. This difference was not observed during 'primed' distensions. Higher sensitivity at transition zone level was found in 11/18 (61%) subjects compared to 6/18 (33%, P  < 0.05) at smooth muscle oesophagus. Chest pain and 'other' symptom were more often induced by distention of the transition zone, whereas heartburn was equally triggered by distension of either region. The transition zone is more complaint and more sensitive than smooth muscle oesophagus.     

Cortical deactivations during gastric fundus distension in health: visceral pain‐specific response or attenuation of ‘default mode’ brain function? A H215O‐PET study

Abstract Gastric distension activates a cerebral network including brainstem, thalamus, insula, perigenual anterior cingulate, cerebellum, ventrolateral prefrontal cortex and potentially somatosensory regions. Cortical deactivations during gastric distension have hardly been reported. To describe brain areas of decreased activity during gastric fundus distension compared to baseline, using data from our previously published study (Gastroenterology, 128, 2005 and 564). H₂¹⁵O‐brain positron emission tomography was performed in 11 healthy volunteers during five conditions (random order): (C₁) no distension (baseline); isobaric distension to individual thresholds for (C₂) first, (C₃) marked, (C₄) unpleasant sensation and (C₅) sham distension. Subtraction analyses were performed (in SPM2) to determine deactivated areas during distension compared to baseline, with a threshold of P_{uncorrected_voxel_level} < 0.001 and P_{corrected_cluster_level} < 0.05. Baseline–maximal distension (C₁–C₄) yielded significant deactivations in: (i) bilateral occipital, lateral parietal and temporal cortex as well as medial parietal lobe (posterior cingulate and precuneus) and medial temporal lobe (hippocampus and amygdala), (ii) right dorsolateral and dorso‐ and ventromedial PFC, (iii) left subgenual ACC and bilateral caudate head. Intragastric pressure and epigastric sensation score correlated negatively with brain activity in similar regions. The right hippocampus/amygdala deactivation was specific to sham. Gastric fundus distension in health is associated with extensive cortical deactivations, besides the activations described before. Whether this represents task‐independent suspension of ‘default mode’ activity (as described in various cognitive tasks) or an visceral pain/interoception‐specific process remains to be elucidated.