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Biomedical subjects

A M Ravelli

Publications and source records attributed to A M Ravelli.

11 recordsLinked to original sources
PubMed2001

Endoscopic features of celiac disease in children.

BACKGROUND: Endoscopic abnormalities have been described in adult patients with celiac disease that may suggest the diagnosis, especially when the presentation is atypical. METHODS: The duodenum of 140 children undergoing EGD for various different indications was evaluated macroscopically and histologically. RESULTS: Histology revealed total villous atrophy in 80 patients, 79 of whom had celiac disease. Among these, 100% had a mucosal mosaic pattern in the duodenum (sensitivity 98.7%, specificity 96.7%, positive predictive value 97.5%, negative predictive value 98.3%), 70% had scalloped duodenal folds (sensitivity 68.7%, specificity 98.3%, positive predictive value 98.2%, negative predictive value 70.2%), 15% had visible vasculature, and 6% had reduction of duodenal folds. Sensitivity and specificity of endoscopic findings were not modified by chromoendoscopy. Except for the mosaic pattern, the frequency of endoscopic abnormalities increased with age; reduction of duodenal folds was never seen in children with celiac disease who were less than 5 years of age. CONCLUSIONS: The frequency and diagnostic value of endoscopic abnormalities are different in children with celiac disease compared with adults with this disease. Because indications for endoscopy, such as abdominal pain, dyspepsia, and unexplained anemia, can be manifestations of celiac disease, and villous atrophy may have a patchy distribution, awareness of these endoscopic abnormalities is important in the diagnosis of celiac disease in children.

Adolescent↗
PubMed2001

Vomiting and gastric motility in infants with cow's milk allergy.

BACKGROUND: Regurgitation and vomiting are common manifestations of cow's milk protein allergy (CMPA) in infants and are usually ascribed to gastroesophageal reflux (GER). Gastric anaphylaxis can induce antral dysmotility in the rat, and therefore the hypothesis for the current study was that cow's milk in sensitized infants may impair antral motility, thereby promoting GER and reflex vomiting. METHODS: Seven vomiting infants with CMPA and nine with primary GER underwent a challenge with cow's milk formula. Electrogastrography (EGG) was used to measure the spectral frequency (bradygastria = 1.5-2.4 cycles per minute [cpm], normogastria = 2.5-3.9 cpm, tachygastria = 4.0-9.0 cpm) and the postprandial-to-fasting power ratio of gastric electrical activity, whereas gastric half-emptying time (T1/2) was measured by electrical impedance tomography (EIT). RESULTS: In CMPA and GER, respectively, during fasting, the frequency distribution (mean +/- SD) of the EGG was as follows: normogastria 47.9%+/-12.5% versus 52.2%+/-9.8%, bradygastria 24.1%+/-5.7% versus 22.8%+/-8.3%, and tachygastria 28.0% 8.5% versus 25.0% 8.3%. In contrast, after the cow's milk challenge, the difference between the two groups was statistically significant: normogastria 33.1%+/-8.8% versus 70.6%+/-8.6% (P < 0.0001). bradygastria 38.0%+/-15.5% versus 15.7%+/-5.2% (P = 0.002), and tachygastria 28.9%+/-10.6% versus 13.4%+/-4.6% (P = 0.001. The postprandial/ fasting power ratio (mean +/- SD) was 3.2+/-1.9 in CMPA and 8.1+/-2.1 in GER (P < 0.0001). Gastric T1/2 (mean +/- SD) of the cow's milk meal was 89.0+/-26.3 minutes versus 54.0+/-12.6 minutes (P = 0.003). In infants with GER all EGG parameters and gastric T1/2 were similar to that in 10 healthy control infants. CONCLUSIONS: In sensitized infants, cow's milk induces severe gastric dysrhythmia and delayed gastric emptying, which in turn may exacerbate GER and induce reflex vomiting. Electrogastrography and EIT can be useful in the assessment of vomiting, GER, and CMPA in infants.

Electric Impedance↗
PubMed1998

Vomiting and gastroesophageal motor activity in children with disorders of the central nervous system.

BACKGROUND: Vomiting is common in children with disorders of the central nervous system (CNS) and is usually ascribed to gastroesophageal reflux (GER). However, recent acquisitions on the pathophysiology of vomiting suggest that the dysmotility of the foregut may be more widespread. METHODS: Fifty-five children with CNS disorders, 50 of whom suffered from retching and/or vomiting (18 following fundoplication) were studied. We assessed GER by 24 hour pH monitoring and endoscopy, gastric electrical activity by electrogastrography, and gastric half-emptying time (T1/2) of a milk meal be electrical impedance tomography. RESULTS: Of the 50 vomiting patients, 29 had GER (reflux index of 5.7%-87.4%; controls: < 5%), and 31 had gastric dysrhythmias (12 tachyarrhythmia at 5.5-11.2 cpm, 4 bradyarrhythmia at 1.7-1.9 cpm, 15 unstable electrical activity; controls; 2.2-4.0 cpm). Sixteen patients had GER and gastric dysrhythmias. Eleven of 18 patients with fundoplication had gastric dysrhythmias. Gastric T1/2 was delayed in 12 of 13 patients with gastric dysrhythmia (6 with GER), versus 2 of 5 with GER alone. No abnormalities were detected in the 5 patients who did not suffer from vomiting. CONCLUSIONS: Children with CNS disorders who vomit have abnormal gastric motility as often as GER. Following fundoplication, many patients continue to have symptoms possibly related to gastric dysrhythmias, the effects of which may be unmasked by fundoplication. Foregut dysmotility may be related to abnormal modulation of the enteric nervous system by the CNS or to involvement of the enteric nervous system by the same process affecting the brain.

Adolescent↗
PubMed1995

Gastrointestinal function in chronic renal failure.

Feeding problems, anorexia and vomiting are common in infants and children with chronic renal failure (CRF), and play a major role in the growth failure often found in this condition. However, the gastroenterological and nutritional aspects of CRF in children have received little attention, hence therapeutic interventions are usually empirical and often ineffective. Gastritis, duodenitis and peptic ulcer are often found in adults with CRF on regular haemodialysis and following renal transplantation. Despite persistent hypergastrinaemia, gastric acid secretion is decreased rather than increased in most of these patients, and active peptic disease appears to be promoted by the removal of the acid output inhibition (neutralisation of gastric acid by ammonia) that follows active treatment. Helicobacter pylori, on the other hand, does not seem to play a significant role in the pathogenesis of peptic disease in CRF. Gastro-oesophageal reflux has been found in about 70% of infants and children with CRF suffering from vomiting and feeding problems, and thus appears to be a major problem in these patients. In a number of symptomatic patients with CRF, gastric dysrhythmias and delayed gastric emptying have also been found; hence there appears to be a complex disorder of gastrointestinal motility in CRF. Serum levels of several polypeptide hormones involved in the modulation of gastrointestinal motility [e.g. gastrin, cholecystokinin (CCK), neurotensin] and the regulation of hunger and satiety (e.g. glucagon, CCK) are significantly raised as a consequence of renal insufficiency, and can be reverted to normal by renal transplantation. Furthermore, several other humoral abnormalities (e.g. hypercalcaemia, hypokalaemia, acidosis, etc.) are not uncommon in CRF. By directly affecting the smooth muscle of the gut or stimulating particular areas within the central nervous system, all these humoral alterations may well play a major role in the gastrointestinal dysmotility, anorexia, nausea and vomiting in patients with CRF. Specific pharmacological and nutritional interventions should thus be considered for the treatment of vomiting and feeding problems in CRF.

Child↗
PubMed1994

Detection of gastroesophageal reflux by electrical impedance tomography.

In children with vomiting, dyspepsia, and feeding problems, gastroesophageal reflux (GOR) and altered gastric emptying are common. We have used electrical impedance tomography (EIT) to study children with suspected gastric emptying disorders. Abnormalities of the gastric emptying curve suggestive of GOR were seen in some, with marked negative or positive shifts related to sharp increases or decreases in intragastric resistance. These findings could represent fluid leaving or entering the stomach, as might occur in GOR. To confirm the origin of the abnormal EIT curves, we devised and in vitro tank test system, and we performed simultaneous 2-h EIT and intraoesophageal pH monitoring after a glucose meal on six patients. In vitro, reflux of > or = 25 ml produced clearly detectable changes on the emptying curves. In vivo, the overall correlation between the times of 42 GOR episodes lasting > or = 1 min detected by pH study and the times of 38 negative peaks due to > or = 15% changes of the maximum intragastric resistivity detected by simultaneous EIT was significant; the correlation was highly significant in four of six patients. When the peaks were used to define GOR episodes on EIT gastric emptying curves, the two methods still showed good agreement. Retrospective examination of 50 patients who had undergone both EIT and 24-h intraoesophageal pH study during their diagnostic workup showed that EIT had a sensitivity of 94.6% and a specificity of 76.9% (with positive and negative predictive values of 0.92 and 0.83, respectively) for the detection of pathological GOR.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1994

Gastric emptying in children with gastric transposition.

Using the noninvasive technique of electrical impedance tomography (EIT), gastric emptying was studied in 12 children, aged 9 months to 17 years, who had undergone gastric transposition (six with pyloroplasty) for oesophageal replacement (seven oesophageal atresia, five severe caustic or peptic damage). In two patients, gastric antral electrical control activity was also studied using surface electrogastrography. Nine patients had problems on oral feeds (respiratory symptoms, feeding difficulties, vomiting, abdominal pain, symptoms suggesting dumping), whilst three were asymptomatic. All 12 patients were tested with a milk meal; in addition four (two with and two without dumping symptoms) were tested with a hypertonic glucose drink; gastric emptying of the milk meal was expressed as the percentage of the meal remaining in the stomach at 60 min (R60). Mean (+/- 2 SD) R60 was 54.6% (+/- 17.4%) in 12 healthy controls and 59.8% (+/- 83.2%) in the 12 patients. Gastric emptying was normal in one patient (R60, 42.6%), delayed in seven (mean R60, 91.2%; range, 74.4-100%), and accelerated in four (R60, 0%). The emptying rate was unrelated to the presence or absence of pyloroplasty. Furthermore, the emptying pattern was extremely irregular, suggesting that gastroesophageal as well as duodenogastric reflux episodes occurred in all patients. The hypertonic glucose drink induced dumping (50% of the meal emptied at 1-3 min) in all four patients, two of whom had delayed emptying of the milk meal, but the gastric antral electrical control activity occurred at the normal frequency of 0.05 Hz.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Normal gastric antral myoelectrical activity in early onset anorexia nervosa.

Anorexia, epigastric discomfort, nausea, and vomiting may result from disordered gastric motility and emptying. These features have been found in many adults with anorexia nervosa, but have never been investigated in early onset anorexia nervosa. In 14 patients with early onset anorexia nervosa (eight of whom had upper gastrointestinal tract symptoms), six children with other eating disorders, four children with non-ulcer dyspepsia, and 10 controls matched for age and sex, the non-invasive technique of surface electrogastrography was used to measure fasting and postprandial gastric antral electrical control activity, which underlies antral motility. The electrical signal was recorded by four bipolar silver/silver chloride electrodes attached to the upper abdomen, amplified and low pass filtered at 0.33 Hz before being displayed on a polygraph, digitised at 1 Hz, and stored on the hard disk of a personal computer for later offline analysis. Patients with non-ulcer dyspepsia had gastric antral dysrhythmias. No significant difference was found in the mean (SD) dominant frequency of the antral electrical control activity between patients with early onset anorexia nervosa (2.86 (0.35) cycles/minute (cpm)), patients with other eating disorders (3.14 (0.65) cpm), and controls (3.00 (0.46) cpm). The amplitude of electrical control activity increased postprandially in all but one subject and the fasting/postprandial amplitude ratio did not significantly differ between patients with early onset anorexia nervosa and controls, though patients with longer established disease had a smaller increase in amplitude. Gastric antral electrical dysrhythmias are not a feature of early onset anorexia nervosa and therefore do not induce or perpetuate food refusal in this disorder.

Adolescent↗
PubMed1992

Foregut motor function in chronic renal failure.

In children with chronic renal failure (CRF) anorexia, nausea, and vomiting are common yet poorly understood symptoms. We studied oesophageal and gastric motor function in 12 children (age 7 months-6.8 years) with severe CRF not undergoing dialysis who had persistent anorexia and vomiting. Eight of 12 patients had significant gastro-oesophageal reflux (reflux index 5.2% to 21.9%, mean 11.3%; controls < 5%), 7/10 had altered gastric half emptying times (T1/2) for 5% glucose or milk (glucose meal--controls: 8-14 min, two CRF patients: 18-25 min; milk meal--controls: 48-72 min, five CRF patients 27, 28, 82, 83, and 110 min). Gastric antral electrical control activity was abnormal in 6/11 patients, with different types of gastric dysrhythmias whereas the remainder and controls showed a regular dominant frequency of 0.05 Hz. In 7/9 patients fasting serum gastrin concentration was raised (53 to > 400, mean 168 pmol/l, controls < 40 pmol/l). All CRF patients with anorexia and vomiting had one or more disorder of foregut motility. The nature and variety of the motor disorders and the raised concentrations of circulating gastrin suggest that the normal environment generated by CRF affects the function of the smooth muscle of the foregut.

Child↗
PubMed1992

Gastric antral dysrhythmias in children with chronic idiopathic intestinal pseudoobstruction.

Chronic idiopathic intestinal pseudoobstruction is a serious disorder of intestinal neuromuscular function resulting in recurrent episodes of intestinal obstruction, and is caused by primary disease of the enteric nerves or enteric smooth muscle. Gastric electrical control activity detected by the non-invasive technique of surface electrogastrography was investigated in 11 children (0.1-16 years) with proven chronic idiopathic intestinal pseudoobstruction (four with known disease of the enteric nerves, three with disease of smooth muscle cells, and four without defined pathology), to determine whether abnormalities were present and whether these were useful in detecting the underlying pathology. Abnormalities were present in eight of 11 patients. Persistent tachygastria (electrical control activity frequency > 5 cycles/minute) was found in three patients, all with a proven neuropathy. A continuously irregular frequency was found in five patients, three with a proven myopathy and two with undefined pathology. A normal electrical control activity frequency was present in three patients, one with a proven neuropathy and two with undefined pathology. It is suggested that this non-invasive technique may provide a useful screening test of the pathophysiological basis of the functional obstruction in children with chronic idiopathic intestinal pseudoobstruction.

Adolescent↗