Gastric dilatation in patients with restrictive eating disorders

OBJECTIVES

To better understand gastric dimensions in patients diagnosed with restrictive eating disorders (EDs).

METHOD

In this retrospective study, 56 patients, with restrictive EDs, and 60 gender/age/race-matched patients from an outpatient clinic, were studied. Difference in stomach size, between cohorts, was ascertained, and regression analyses were used to examine associations with stomach size in the ED cohort.

RESULTS

Patients with EDs were found to have significantly enlarged gastric dimensions when compared to the control group (M:14.8 cm [SD: 3.2] vs. 11.4 cm [SD: 2.9], p < .0001). Among the ED cohort, blood urea nitrogen (BUN), on the day of imaging, positively correlated with gastric dimensions (r = .43, p = .0009), while hypoalbuminemia negatively correlated with gastric dimensions (r = -.37, p = .005). BUN and albumin nadir were also significantly associated with stomach size (r²  = .26, F[2,53] = 9.46, p = .0003). There was no significant correlation between gastric dimensions and ED diagnosis, percent ideal body weight, gender, duration of illness, engagement in vomiting behaviors, diagnosis of superior mesenteric artery syndrome, or use of promotility agents.

DISCUSSION

Findings in this study suggest that malnutrition, secondary to EDs, may be associated with an enlarged stomach. The relationship between the gastric dimensions and reported GI symptoms in this population remain to be determined.

PUBLIC SIGNIFICANCE

There are many physiologic changes to the gastrointestinal system that develop with malnutrition but the contribution of these physiologic changes toward the reported GI symptoms and refeeding difficulties is unclear. This is the first study to suggest that patients with malnutrition, secondary to EDs, may be associated with an enlarged stomach, and this potential relationship requires further investigation.

A Traumatic Quinceañera: Acute Superior Mesenteric Artery Syndrome in an Adolescent Girl

ABSTRACT

A 15-year-old girl presented with 3 days of progressive abdominal distention, pain, and bilious hematemesis. Her symptoms began after her quinceañera, during which she wore a tight corset. On examination, she was thin and had significant abdominal distention and pain. A computed tomography revealed a massively dilated stomach and proximal duodenum to the region of the superior mesenteric artery (SMA) with distal decompression. An upper gastrointestinal fluoroscopy demonstrated marked dilation of the stomach through the mid third portion of the duodenum with distal decompression and an associated linear compression on her duodenal wall. We believe that she developed acute SMA syndrome. Superior mesenteric artery syndrome is a partial bowel obstruction caused when the third portion of the duodenum is compressed as it passes between the SMA and the aorta. Although the SMA syndrome is most commonly described as a condition associated with chronic, severe weight loss resulting in a narrowing of the SMA to aorta angle and subsequent duodenal compression, it can present acutely from causes such as a postoperative complication, blunt trauma, or external compression. Previously described acute SMA syndrome from external compression has been the result of medically necessary causes, such as body casting. In this case, the tight gown was likely the inciting factor for her development of SMA syndrome; however, she was placed at high risk for the condition by being underweight at baseline and experiencing food restriction for several days preceding her quinceañera. She was treated conservatively with nasogastric decompression and parenteral nutrition, and has since completely recovered.

The role of sensory C-fibers in response of vagal afferent stimulation by gastric distension in rats with experimental chronic gastric ulcer

There is growing evidence that gastric vagal afferent input may contribute to the altered sensations associated with gastrointestinal disorders. The aim of our study was to evaluate gastric vagal afferents (VA) activity in rats with experimental gastric ulcer and ulcer healing. The study was carried out on rats with gastric ulcer (GU), including, a group with perivagal capsaicin pretreatment (CAP), a group with capsaicin administration in gastric ulcer (CAP+GU) animals and control rats. In all rats electrical VA activity was recorded and analysed. In GU rats recordings were carried out in chronic ulcer and ulcer healing. In GU and CAP+GU groups gastric balloon distensions with vagal recording was performed on 3(rd) day after ulcer induction. Usually, experimental GU healed spontaneously within 2 weeks. Three days after acetic acid application when GU fully develop, the frequency of the basal VA activity was almost 3-times higher than in the control intact rats and remained elevayed until 4(th) week after ulcer induction. VA response to gastric distension increased concomitantly with increased balloon volume in both GU and control animals, but it was several times higher in GU rats. Perivagal capsaicin application decreased the frequency of spontaneous VA activity and decreased the response of VA to gastric distension. In CAP+GU, spontaneous activity as well as the response to gastric distension were higher than in CAP rats. Our study shows that GU induced inflammatory changes increase sensitivity of gastric VA. Capsaicin-sensitive vagal afferent fibers may play some role in this phenomenon. Peripheral sensitization of VA persists even when gastric ulcer is completely healed.

Effects of gastric electric stimulation on gastric distention responsive neurons and expressions of CCK in rodent hippocampus

OBJECTIVE

Gastric electrical stimulation (GES) has been introduced for treating obesity. The hippocampus is known to be involved in the regulation of gastrointestinal motility. Changes in hypathalumus cholecystokinin (CCK) have been observed in genetically obese rodents. This experiment was to study the effect of GES on the activities of neurons and the expression of CCK in the hippocampus.

METHODS AND PROCEDURES

We investigated the effect of GES (GES-I: pulse train of standard parameters; GES-2: reduced train-on time; GES-3: increased pulse width; GES-4: reduced pulse frequency) on neurons responsive to gastric distention (GD) by recording extracellular potentials of single neurons and observing the expression of CCK in the rodent hippocampus by immunohistochemistry staining, radioimmunoassay, and real-time PCR.

RESULTS

92.1% of neurons in the CA2-3 region responded to GD, 53.2% of which showed excitation (GD-E), and 46.8% showed inhibition (GD-I). 64.8% GD-responsive neurons were excited by GES. The response was associated with stimulation strength, pulse width, and frequency; 70.6, 57.1, 94.4, and 66.7% of GD-E and 72.7, 57.1, 86.4, and 50% of GD-I neurons showed excitatory responses to GES-I, -2, -3, and -4, respectively. CCK immunoreactive positive neurons (P<0.001), the content of CCK-like materials (P<0.05) and the amount of CCK mRNA were significantly increased after GES (P<0.05).

DISCUSSION

These findings suggest the central, neuronal, and hormonal mechanisms of GES. GES may excite the activity of GD-sensitive neurons and increase the expression of CCK in the hippocampus. These excitatory effects of GES seem to be related to the parameters of stimulation.

Distension-induced gastric accommodation in functional dyspepsia: effect of autonomic manipulation

Functional dyspepsia (FD) is associated with impaired gastric accommodation and autonomic dysregulation. The aim of this study was to investigate the effects of autonomic manipulation on distension-induced gastric accommodation in subjects with and without FD, using a newly developed gastric barostat paradigm. Twelve healthy subjects (HS) and 18 subjects with FD had four barostat examinations each: no intervention, intravenous atropine (1 mg), vagal stimulation (mental relaxation with deep breathing) and acute stress stimulation (serial subtraction task). Intrabag pressure increased from 1 to 15 mmHg in 5 min (ramp phase), and was maintained at 15 mmHg for 5 min (tonic phase). Volume responses were analysed using predefined parameters. There were no significant group differences in accommodation variables between HS and subjects with FD. The FD group could be subdivided into two distinct subgroups: subgroup 1 (n = 7, 38%) with low maximum volume and accommodation rate, and subgroup 2 with normal accommodation (n = 11). In subgroup 1, but not in subgroup 2 atropine increased maximum volume and accommodation rate substantially. Neither mental stress nor mental relaxation changed any of the accommodation variables. In a subgroup of subjects with FD, impairment of distension-induced gastric accommodation can be improved by cholinergic blockade, but not by acute physiological autonomic manipulation.

Investigation of fundo-antral reflex in human beings

AIM: To examine the sensory and motor response(s) of the stomach following fundic distention and to assess whether cholinergic mechanisms influence these responses.

METHODS: Fundic tone, gastric sensory responses and antral motility were evaluated in eight healthy volunteers after a probe with two sensors was placed in the antrum and a highly compliant balloon in the fundus. Isobaric balloon distentions were performed with a barostat. Study was repeated in six volunteers after intravenous atropine was given.

RESULTS: Fundic distention induced large amplitude antral contractions in all subjects. The area under the curve was higher (P<0.05) during fundic distention. First sensation was reported at 12±4 mmHg, moderate sensation at 18±4 mmHg and discomfort at 21±4 mmHg. Discomfort was associated with a decrease in antral motility. After atropine was given, the area under the curve of pressure waves and fundic tone decreased (P<0.05). Sensory thresholds were not affected.

CONCLUSIONS: Fundic balloon distention induces an antral motor response, the fundo-antral reflex, which in part may be mediated by cholinergic mechanisms.

Oral S(+)-ketamine does not change visceral perception in health

Application of N-methyl-D-aspartate (NMDA)-receptor antagonists may hold promise for the treatment of visceral pain. In this study we evaluated the effect of oral S(+)-ketamine (sKET), a non-competitive NMDA-receptor antagonist, on visceral sensitivity in healthy volunteers. Eight healthy volunteers (five male, three female) underwent a gastric barostat study following oral administration of placebo, 25 mg sKET, and 50 mg sKET. Studies were performed in a double-blind randomized crossover fashion. Sensations evoked by stepwise isobaric distension (2 mm Hg/2 min) were scored on a 100-mm visual analogue scale. In addition, fasting and postprandial fundic volume were measured at a fixed pressure level (MDP + 2 mm Hg). During gastric distension, sKET did not alter sensation scores for bloating, nausea, satiation, and pain compared to placebo. sKET had also no effects on the thresholds for pain/discomfort, fundic wall compliance, fundic tone, or meal-induced fundic relaxation. sKET does not reduce visceral perception or gastric motility in healthy volunteers. The role of sKET in conditions characterized by visceral hypersensitivity needs to be studied further.

Encoding meal in integrated vagal afferent discharge

Vagal afferents are integral part of the negative feedback loop induced by constitution and size of food stomach and jejunum. Aim of this study was to assess vagal discharge in response to food and gastric distension in rats. Electrophysiological recordings of vagal afferents in fasted (n=32), fed rats (n=20) and during gastric balloon distension (n=12) were performed. After 60 minutes of fasted nerve recording tube feeding was done. Fasted rats also underwent gastric distension via oesophagus. Vagal afferents discharges were analysed with dual time-amplitude window discriminator. Total vagal afferent discharge in fasted and fed rats revealed 0.3 +/- 0.12 vs 0.56 +/- 0.22 Hz (p<0.05). We observed two distinct discharge patterns: high amplitude low frequency (HALF) and low amplitude high frequency (LAHF). HALF spikes were observed more frequent in fasted than in fed rats (0.05 +/- 0.02 vs. 0.03 +/- 0.016 Hz (p<0.05). Conversely LAHF spikes in fed rats predominated over their occurrence in fasted rats: 0.52 +/- 0.2 vs. 0.25 +/- 0.12 Hz (p<0.05). Left vagal afferents discharge rises with gastric distension of 6, 8 and 10 ml and were: 0.46 +/- 0.22 Hz, 0.65 +/- 0.31 Hz, 0.86 +/- 0.33 Hz (p<0.05) respectively. Similar discharge showed right vagal afferents: 0.41 +/- 0.08 Hz, 0.51 +/- 0.13 Hz and 0.77 +/- 0.27 Hz (p<0.05) for 6, 8 and 10 ml of distension, respectively. We conclude that interdigestive information from gastrointestinal tract is encoded in high amplitude low frequency of spikes pattern in the vagus nerves.

Cholecystokinin and stomach distension combine to reduce food intake in humans

The aim of this study was to test the hypothesis that gastric distension can enhance the effect of cholecystokinin (CCK) on reduction of food intake in men and women. Eight normal-weight subjects of each gender were tested four times each with either CCK or saline infusion crossed with gastric distension or no distension. Intravenous infusion of a low dose of CCK octapeptide (CCK-8; 112 ng/min for 23 min) combined with a subthreshold gastric distension induced by a water-filled balloon (300 ml) resulted in a significant (means +/- SED: 191 +/- 61 g in men, 209 +/- 61 g in women, and 200 +/- 43 g combined) reduction in intake of a liquid meal compared with saline infusion and unfilled gastric balloon. This combined effect was the result of a large and significant CCK effect when the stomach was distended (CCK vs. saline with distension: 169 +/- 43 g) and a small and insignificant distension effect (distension vs. no distension without CCK: 31 +/- 43 g). The CCK effect alone on intake (CCK vs. saline) without distension was not significant in men (72 +/- 61 g) but was significant in women (121 +/- 61 g). These results are consistent with the hypothesis that CCK's suppression of food intake is enhanced when the stomach is distended.

Functional neuroimaging of gastric distention

This study aimed to measure brain activation during gastric distention as a way to investigate short-term satiety. We estimated regional cerebral blood flow with positron emission tomography (15O-water) during gastric balloon inflation and deflation in 18 healthy young women. The contrast between inflated minus deflated conditions showed activation in the following four key regions that were identified a priori: dorsal brain stem; left inferior frontal gyrus; bilateral insula; and right subgenual, anterior cingulate cortex. Extant neuroimaging literature provides context for these areas as follows: the brain stem represents vagal projection zones for visceral afferent processing; the inferior frontal gyrus serves as a convergence zone for processing food-related stimuli; and both the insula and subgenual anterior cingulate cortex respond to emotional stimulation. The identification of neural correlates of gastric distention is a key step in the discovery of new treatments for obesity. New therapies could intervene by modifying the perception of gastric distention, an important contributor to meal termination and short-term satiety. This first study of brain activation during nonpainful, proximal gastric distention provides the groundwork for future research to discover novel treatments for obesity.

The effects of solid food in prevention of intestinal activity in Tc-99m tetrofosmin myocardial perfusion scintigraphy

BACKGROUND

The aim of this study was to investigate the effect of a standardized meal on intestinal activity in technetium 99m tetrofosmin myocardial perfusion scintigraphy.

METHODS AND RESULTS

The study population consisted of 60 patients (42 men and 18 women; mean age, 56 +/- 8 years) referred for myocardial perfusion imaging. All patients underwent same-day exercise-rest Tc-99m tetrofosmin single photon emission computed tomography (SPECT) imaging. All patients were given 200 mL of milk 15 minutes after the injection for the exercise SPECT study and just after the injection for the first rest SPECT study. None of the patients ate or drank between the exercise and the first rest SPECT studies. After the first rest SPECT study, 30 patients (meal group) were given a standardized meal of solid food and liquid to increase the volume of the stomach, and a second rest SPECT image was obtained 30 minutes after the end of the first rest SPECT study. In 30 patients (control group) a second rest SPECT image was obtained 30 minutes after the end of the first rest SPECT study, but this group did not eat or drink in this interval. The effect of the meal on intestinal activity was evaluated both visually and quantitatively. Frequency of intestinal activity was assessed visually on SPECT images. Inferior myocardial wall and abdominal activity adjacent to the myocardium was quantitatively assessed on 3 different planar projections in the rest studies, and the mean inferior wall-to-abdomen count ratio was calculated. In the meal group, inferior wall-to-abdomen count ratios in the first and second rest studies were 1.48 +/- 0.3 and 2.09 +/- 0.4, respectively (P <.0001), and in the control group, 1.41 +/- 0.2 and 1.40 +/- 0.2 (P >.05), respectively. The frequency of intestinal activity was 63% (n = 19) in the first rest SPECT study and 10% (n = 3) in the second study in the meal group (P <.0001); it was 66% (n = 20) in the first rest SPECT study and 76% (n = 23) in the second study in the control group (P >.05).

CONCLUSIONS

Our results indicate that filling of the stomach with a meal of solid food and liquid before rest acquisition may provide a high target-to-nontarget ratio. This simple modification may reduce the frequency of intestinal activity of Tc-99m-labeled radiopharmaceuticals in myocardial perfusion imaging.

Effect of the low-affinity, noncompetitive N-methyl-d-aspartate receptor antagonist dextromethorphan on visceral perception in healthy volunteers

BACKGROUND

The use of N-methyl-d-aspartate (NMDA) receptor antagonists may hold promise for the treatment of pain of visceral origin, in particular in conditions characterized by visceral hypersensitivity.

AIM

To study the effect of dextromethorphan, a low affinity, non-competitive NMDA receptor antagonist, on visceral perception in healthy volunteers.

METHODS

Nine healthy volunteers (5 female, median age 22 years) underwent a gastric barostat study after oral administration of placebo, dextromethorphan 10 mg or dextromethorphan 30 mg, on three separate days in a double-blind, randomised order. Sensations induced by step-wise isobaric gastric distension (2 mmHg/2 min) were studied during fasting and 30 min after a meal. In addition, proximal gastric tone was measured during fasting and postprandially.

RESULTS

Compared to placebo, dextromethorphan 30 mg significantly increased the distension-evoked sensation scores for nausea (P=0.004) and satiation (P=0.004) during fasting; and for bloating (P= 0.001), nausea (P=0.000) and satiation (P=0.01) 30 min postprandially. Dextromethorphan did not alter pain scores, proximal gastric tone or gastric compliance.

CONCLUSIONS

Dextromethorphan increases the perception of non-painful sensations during gastric distension, without altering the perception of pain. Therefore, application of dextromethorphan as a visceral analgesic is questionable. Future studies with more specific NMDA receptor antagonist are warranted.

Intestinal volvulus: aetiology, morbidity, and mortality in Nigerian children

In developed countries, intestinal volvulus in children is most frequently due to malrotation. To review the experience in Nigeria, a retrospective analysis of 28 patients managed over 25 years at the Ahmadu Bello University Teaching Hospital, Zaria, Nigeria, was undertaken. There were 22 boys and 6 girls with an age range of 4 days to 14 years (median 4 years). There were equal numbers over and less than 5 years of age. Vomiting (89%) and abdominal distension (79%) were the most prominent features. Thirteen children (46%) had fever, associated with bowel gangrene in 5, while 8 (29%) presented with severe dehydration and shock. A plain abdominal radiograph was the only investigation performed, but the features were not specific for volvulus. In 11 children (39%) the volvulus was idiopathic, in 9 (32%) due to adhesions or bands, in 5 (18%) to malrotation, and in 1 each a Meckel's diverticulum, internal herniation, and ventriculoperitoneal shunt. Twenty-three patients had a small-bowel, 4 sigmoid, and 1 caecal volvulus. The bowel resection rate for gangrene was 46% (small bowel 9, sigmoid 3, caecum 1). All patients with malrotation had Ladd's procedure performed. Wound infections occurred in 10 patients (36%), complete wound dehiscence in 1, and recurrence in 1 (idiopathic terminal ileal volvulus). The mortality was 21%, mostly from overwhelming infection (2 neonates, 11-year-old, 3 >/= 5 years). Intestinal volvulus in our environment differs in aetiology from other reports. The resection rates are similar, however. This condition carries high morbidity and mortality.

Sigmoid volvulus in childhood: report of six cases

Sigmoid volvulus is a common cause of large-bowel obstruction in elderly individuals, but is quite rare in childhood. We report six cases in patients under 20 years of age. One had Hirschprung's disease. Gangrenous sigmoid colon was found in three cases and resection was performed. Sigmoidopexy (one case) and extraperitonealization (two cases) were performed for viable sigmoid colon. There were no recurrences after 5.7 years of follow-up.

Roles of gastrin release and neural reflexes during the gastric phase of acid secretion in dogs

The acid secretion from the main stomachs and from denervated Heidenhain pouches in response to peptone meals infused in the stomach was determined in 4 dogs. When expressed as percent of the maximal acid response to histamine, the acid secretion from the innervated and from the denervated fundic mucosa was similar, but the response from the Heidenhain pouch was larger when expressed as percent of the maximal response to pentagastrin. These studies indicate that, under the conditions used, short (gastrogastric) and long (vagovagal) reflexes during the gastric phase, are of minor importance in inducing the acid response to the meal.

Effect of gastric distension on human pancreatic secretion

The effect of gastric distension on pancreatic secretion of bicarbonate and trypsin was studied in 10 individuals in the basal state or during stimulation with low and high doses of secretin or secretin plus cholecystokinin (CCK). Gastric distension augmented the pancreatic response to secretin but had no consistent effect on the pancreatic response to combination of secretin and CCK. We conclude that gastropancratic reflexes do not have much functional significance in man.

Vagotomy and experimental duodenal ulcers

Truncal vagotomy prevents secretagogue-induced duodenal ulcers in the rat. Without a drainage procedure it results in gastric stasis which predisposes to hypersecretory produced gastric ulcers.