Biomedical subjects

G Riezzo

Publications and source records attributed to G Riezzo.

36 records · Page 2Linked to original sources

PubMed1995

Gastric emptying and myoelectrical activity in children with nonulcer dyspepsia. Effect of cisapride.

We examined the effect of oral cisapride on gastric emptying time and myoelectrical activity using real-time ultrasonography and cutaneous electrogastrography in 10 children with nonulcer dyspepsia. A clear dominant frequency close to 3 cpm was present both at baseline and after eight weeks of cisapride. After cisapride, nine children had an increase in the normal slow wave percentage and the mean percentage of normal slow wave was significantly different (71.90 +/- 5.19% vs 79.16 +/- 5.54%; P < 0.01). Moreover, an increased stability of the dominant frequency, determined by computing the coefficient of variation before and after cisapride, was found (28.12 +/- 1.72% vs 23.61 +/- 3.47%; P < 0.01). At baseline the gastric emptying time, expressed as T1/2, was 139.76 +/- 40.04 min and at eight weeks 119.76 +/- 30.04 min (P = 0.06). As regards the relationship between EGG and gastric emptying, the proportion of children with improved normal slow wave percentage was similar to that with improved T1/2 emptying (Z = 0.57, P = 0.57). Thus, gastric electrical activity seems to be an important factor in the pathophysiology of nonulcer dyspepsia in children.

Adolescent↗

PubMed1995

Gallbladder motility before and after Billroth II gastric resection.

The aim of this study was to determine the effect of Billroth II gastric resection (BII) without vagotomy on gallbladder contraction in response to meal and CCK-OP infusion. Fourteen duodenal ulcer patients were studied before surgery and six months postoperatively. Gallbladder volume was measured by real-time ultrasonography. After surgery, there was a significant increase in fasting gallbladder volume (P < 0.05). Postprandial gallbladder emptying was not significantly affected by gastrectomy apart from a trend towards a shorter t1/2 and a larger ejection volume. In addition, postoperative gallbladder relaxation was more pronounced at time 120 min. In response to cholecystokinin-octapeptide (CCK-OP) infusion, there was a significant decrease of t1/2 after BII and a prolonged contraction with a significantly reduced gallbladder volume. Our data show that the gallbladder response both to meal and CCK-OP infusion is modified after BII and a larger postoperative gallbladder volume may play a role in the pathogenesis of gallstone disease after gastric surgery.

Adult↗

PubMed1994

Electrical activity recorded from abdominal surface before and after right hemicolectomy in man.

To explain the origin of the electrical signals obtained from the abdominal cutaneous surface (electrosplanchnogram, ESG), the ESG was recorded in 6 patients with carcinoma of the right colon without obstruction before and after right hemicolectomy. The analysis of colonic electrical activity was performed by means of spectral analysis that utilized fast Fourier transform method. Since the colonic electrical signal is highly complex and it may contain several frequencies concurrently the spectral frequency components were subdivided in ranges and the dominant frequency and power were calculated for each range before and after surgery. The pattern obtained from power profile, expressed as differences in power percentages before and after surgery, demonstrated that there were significant differences in power data from right hemicolectomized patients compared to cholecystectomized ones (p = 0.00001 and p = 0.001 in 2.5-3.5 and 3.6-7.5 cpm range, respectively). In particular, hemicolectomized patients showed a slight increase of power percentage in the 2.6-3.5 cpm range and a clear reduction in the 3.6-7.5 cpm range. These data suggest that there are several components of colonic origin in the cutaneous ESG signal which, in the right colon, are identifiable in the 3.6-7.5 cpm range.

Abdomen↗

PubMed1993

[Changes in slow and fast electrical activity of the gastro-duodeno-jejunal junction after cholecystectomy in humans].

The re-establishment of regular gastrointestinal electrical activity (Migrating Myoelectrical Complex-MMC- and slow wave) after cholecystectomy for gallstones was investigated in six female patients (50-77 years) by means of serosal electrodes implanted in the wall of the antrum, duodenum and jejunum during surgery. Five hour recordings were made on the first, third and fifth postoperative days, in patients who were on a liquid diet. The recordings were made after a twelve hour fast. On the fifth postoperative day, a test meal (250 g yoghurt) was given to the patients ant its effects on electrical activity were monitored for 2 hours. Even though MMC were present on the first and third postoperative days, a detailed study of their origin, the length of the Phase 3 and the speed of gastro-jejunal propagation showed that there existed an inhibition of gastric MMC until the fifth postoperative day and that intestinal MMC was slower than normal until the third postoperative day. On the fifth postoperative day, gastric inhibition disappeared since the length of the Phase 3 of the MMC of the stomach corresponds to those of the duodenum and jejunum, and the speed of propagation corresponded to that in normal subjects. Further, the slow wave frequency peculiar to each segment studied increased progressively from the first to the fifth postoperative day and the same was true of the slow waves with superimposed action potentials. In conclusion, notwithstanding the presence of MMC from the first postoperative day, it was only on the fifth day that normal coordination was restored and hence that patients were able to eat again.

Action Potentials↗

PubMed1992

Reversal of gastric electrical dysrhythmias by cisapride in children with functional dyspepsia. Report of three cases.

Three children (ages 5, 7.6, and 8 years), with recurrent unexplained upper abdominal symptoms such as vomiting, epigastric pain, anorexia, early satiety and without structural or mucosal abnormalities of gastrointestinal tract, underwent electrogastrography (EGG)--recording of gastric electrical activity using cutaneous electrodes positioned on the epigastric region and connected to a recording polygraph. Frequency of EGG signals was analyzed by fast Fourier transform. Significant changes of fasting and fed gastric myoelectrical activity (tachygastria, bradygastria, flatline pattern) were recorded in the three patients; furthermore, gastric emptying (GE) of a solid-liquid mixed meal, measured by ultrasonography, was significantly prolonged in them. A follow-up study was carried out after an eight-week course with oral cisapride: in all patients symptoms improved, GE time normalized, and EGG analysis showed normal electrical rhythm. It is suggested that gastric dysrhythmias can play a pathogenetic role in patients with functional gastrointestinal symptoms and that symptomatic improvement is accompanied by normalization of gastric electrical rhythm.

Child↗

PubMed1992

Electrogastrography in non-ulcer dyspepsia.

Fasting and fed gastric electrical activity was recorded by cutaneous electrodes (electrogastrography) in 14 children with unexplained recurrent symptoms of upper intestinal dysfunction, and in 10 controls. The unexplained symptoms included vomiting, epigastric pain, fullness, and early satiety. Mean (SD) age was 7.0 (3) and 7.5 (2) years, respectively. Gastric emptying time of a solid-liquid meal was also measured by real time ultrasonography in all subjects (patients and controls). In all patients radiography and endoscopy excluded structural and focal abnormalities of the gastrointestinal tract. Gastric emptying time was significantly more prolonged in patients than in controls. It was also found that there were appreciable irregularities of gastric electrical rhythm (tachygastria, bradygastria, flat line pattern, and mixed arrhythmia) in 12 fasting and 10 fed patients, whereas controls showed short and rare episodes of arrhythmia during both fasting and fed recording periods. The percentage distribution of the total electrogastrographic energy power across three frequency bands of electrical activity (low, normal, and high) showed that patients were different from controls both for reduced activity of normal frequency and for increased incidence of high and low abnormal frequencies. It is concluded that gastric electrical abnormalities are found in a high proportion of children with recurrent unexplained upper gastrointestinal symptoms. Electrogastrography can be a valuable tool in the assessment of these patients.

Child↗

PubMed1992

Reproducibility of cutaneous electrogastrography in the fasting state in man.

Cutaneous electrogastrography (EGGc), the recording of gastric electrical activity from the cutaneous abdominal surface, still presents a series of difficulties connected with the interpretation of signals. In this study, the authors evaluated the reproducibility of electrogastrographic data over a period of time by making recordings on three consecutive days in a group of healthy subjects. The recordings (lasting 1 hour) were made in the morning on fasting subjects. Three sets of bipolar cutaneous electrodes were placed on the abdomen around the pyloric radiological projection and the couple 3-6 corresponded to the antral axis. The spectral analysis of data was computed by fast Fourier transform. Their data confirmed that the 3-6 couple, corresponding to the antral axis, provides the strongest EGG signal. Each subject's mean gastric frequency and power were evaluated on the three consecutive recording days. The mean frequency was 2.83 +/- 0.22, 2.89 +/- 0.23, and 2.86 +/- 0.16 cpm on day I, day II and day III respectively. The mean power was 54.80 +/- 21.34, 46.86 +/- 21.52 and 49.25 +/- 19.55 microV 2 on day I, day II and day III respectively. The analysis of variance showed that the mean gastric frequency and power were not significantly different on the three days (p > 0.05). This shows that the frequency of the EGGc signal remains stable in the course of time and hence that EGGc is a reliable method of studying disorders in gastric electrical rhythm.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Gastric myoelectrical activity in the first trimester of pregnancy: a cutaneous electrogastrographic study.

Recently, it has been shown that changes in gastric electrical rhythm can be connected with clinical syndromes characterized by nausea and vomiting, among these the nausea of pregnancy. We studied gastric electrical activity during the first trimester of pregnancy in nine women with nausea and vomiting (study group) by means of cutaneous electrogastrography. Recordings were made before and after a standardized meal in the 6th-8th wk of gestation, and 2 months after voluntary interruption of pregnancy (VIP). The control group consisted of eight pregnant women without a history of nausea and vomiting. In the women in the study group there was more unstable cutaneous electrogastrographic (EGGc) activity and a reduced increase in postprandial power during pregnancy than after VIP, when a normal pattern with regular 3-cpm EGGc waves was reestablished. The coefficient of variation of gastric frequency during pregnancy was significantly higher than after VIP (p less than 0.01), whereas the postprandial to preprandial power ratio was lower (p less than 0.01). During the recording sessions, none of the subjects had clear episodes of tachygastria or bradygastria, and none of them had nausea, vomiting, or epigastric discomfort. Comparison of the EGGc data for the pregnant women in the study and control groups revealed a similar pattern of gastric electrical activity in the two, the only exception being the power ratio, which was lower in the study group (p less than 0.01). We conclude that pregnant women without symptoms of nausea and vomiting at the time of EGG recordings have normal 3-cpm myoelectrical activity, and that EGGc activity is more unstable and less responsive to the ingestion of food during pregnancy than after VIP. Furthermore, in pregnant women with a history of nausea and vomiting, EGGc activity is less responsive to the ingestion of food than it is in symptom-free pregnant women.

Adult↗

PubMed1991

Gastric electrical dysrhythmia following cholecystectomy in humans.

In order to observe the incidence of dysrhythmia in 20 patients who had undergone cholecystectomy, we recorded gastric electrical activity by means of serosal electrodes from the day of surgery to the 6th postoperative day. The difference between the incidence of dysrhythmia on the day of the operation and the other days is statistically significant (t test: p less than 0.001). Bradygastria was the most frequently observed dysrhythmia, both on the day of surgery and on the following days. It had a frequency of around 1.0-1.5 cpm and the episodes lasted for a minimum of 10 min to a maximum of 105 min (mean duration 32.6 min). Episodes of tachygastria were of varying duration, ranging from a minimum of 3 min to a maximum of 60 min (mean duration 18.5 min), whereas episodes of gastric tachyarrhythmia lasted between 2 min and 21 min (mean duration 5.4 min). Only 1 patient had an episode of nausea and biliary vomiting, associated with an episode of gastric tachyarrhythmia on the 1st postoperative day. None of the other patients had symptoms of impaired gastric function, such as nausea, vomiting, bloating and epigastric pain, at any time during the recording sessions. These findings suggest that in most cases, gastric electrical rhythm returns to normal within 24 h of cholecystectomy and further that gastric dysrhythmia is not related to symptoms of impaired gastric function. The etiological mechanism and clinical significance of gastric dysrhythmia, therefore, are still unclear.

Adult↗

PubMed1991

In vitro gallbladder motility in patients with radiolucent and radiopaque stones.

Twenty-five gallbladders were studied in vitro. Sixteen had radiolucent gallstones and 9 had radiopaque gallstones. The radiolucent gallstones had a cholesterol content of 94.17 +/- 3.76% and the radiopaque gallstones had a cholesterol content of 56.6 +/- 4.46%. Half the maximal response (ED50) to cholecystokinin octapeptide (CCK-OP) and to carbachol in strips from patients with radiolucent gallstones was 0.8 +/- 0.15 and 27.01 +/- 3.74 x 10(-7) M, respectively. In strips from patients with radiopaque gallstones, the ED50 was 0.4 +/- 0.08 and 14.92 +/- 3.07 x 10(-7) M, respectively. The ED50 values to CCK-OP and carbachol were greater in strips from specimens with radiolucent gallstones than in strips from specimens with radiopaque gallstones (p less than 0.05). There was no significant difference in the maximal contractile response of the two groups. It can be concluded that gallbladder sensitivity to CCK-OP and carbachol can be modified in relation to differences in the cholesterol and calcium content of the stones.

Adult↗

PubMed1991

Effects of age and obesity on fasting gastric electrical activity in man: a cutaneous electrogastrographic study.

We investigated the effects of age and obesity on the fasting cutaneous electrogastrogram (EGGc) by studying both young and aged, healthy men. All subjects underwent an electrogastrographic recording lasting 1 h, and frequency and power data were obtained by means of spectral analysis. In order to make a precise comparison of the data, each subject's body mass index (BMI) was calculated and each age group was subdivided into nonobese subjects, those with a BMI of less than 24.9 kg/m2, and obese subjects, those with a BMI of more than 25 kg/m2. Comparison of the mean frequency values of the gastric spectral peak did not reveal statistically significant differences among the groups (young vs. old, nonobese vs. obese). Comparison of the mean power values of the gastric spectral peak, on the other hand, showed that there was a statistically significant reduction in spectral power in the aged subjects compared with the young (p = 0.017 in the aged vs. young nonobese subjects and p = 0.009 in the aged vs. young obese subjects), and in the obese subjects compared with the nonobese (p = 0.00021 in the young and p = 0.00029 in the aged). Frequency, therefore, is the parameter of gastric electrical activity which may best be studied by means of EGGc as it is only very slightly affected by physiological parameters, such as age and the adiposity of subjects. EGGc, therefore, could be useful in the study of those gastric diseases associated with disorders in gastric electrical rhythm and rate.

Adult↗

PubMed1989

Electrical activity recorded from abdominal surface after gastrectomy or colectomy in humans.

The visceral electrical activity recorded from the abdominal surface was studied before and after either total gastrectomy or colectomy. The patterns obtained from fast Fourier transform analysis demonstrated the disappearance of the power peak of approximately 3 cpm after gastrectomy, whereas colectomy did not result in the disappearance of the power peak of approximately 3 and 8-12 cpm. Only the frequencies of approximately 3.5-7.5 cpm were not present after colon surgery. These data demonstrate that the spectral power peaks at frequencies of approximately 3 cpm are entirely related to the stomach because they disappear after gastrectomy; the power peaks between 3.5 and 7.5 cpm are related to the colon because they are present after gastrectomy but not after colectomy; the power peaks between 7.5 and 11 cpm are related to the small intestine because they are present after either gastrectomy or colectomy. The authors conclude that the electrical activity recorded from the abdominal surface and analyzed by fast Fourier transform gives reliable information concerning the electrical activity of the stomach and small intestine, although it is less reliable concerning the electrical activity of the colon.

Abdomen↗

PubMed1989

[New method of non invasive examination of the gastroenteric tract].

A new non-invasive method for studying the gastrointestinal tract. The Authors, after a critical evaluation of the methods used to study gastrointestinal motility, evaluate the diagnostic power of electrical activity recorded from the abdominal surface. Physiological principles of gastrointestinal electrical activity, recording methods and statistical analyses of the signal are discussed. A review of the literature is included. It is suggested that this method represents a more accurate, non-invasive diagnostic tool for gastrointestinal disorders.

Electrodiagnosis↗

PubMedDate not supplied

In vitro electro-mechanical activity of the human colon. Simultaneous recording of the electrical patterns of the two muscle layers.

Electrical and mechanical activity on longitudinal and circular layers of the human sigmoid colon were simultaneously studied. Recordings were obtained from two electrode sites spaced 3 cm apart in a piece of colon which had been resected surgically and perfused in an organ bath. Spontaneous electrical activity of the colon showed slow waves and spikes. Slow waves were present for only 24.5% and 12% of the recording time on the longitudinal and circular layers, respectively, and they appeared as localized activity which was irregular in amplitude and varying in frequency. Electrical coupling between the two muscle layers was rarely seen and slow waves were not associated with pressure changes. Spiking activity were recorded as short and long spike bursts on both muscle layers. Short spike bursts were localized activity superimposed on slow waves. The associated mechanical activity, which consisted of single weak pressure changes or prolonged contractions with summation, was determined by slow wave frequency. Long spike bursts were seen at irregular intervals and were either propagated or not propagated activity associated with electrical oscillations ranging from 24 to 46 cpm. Mechanical activity consisted of sustained tonic contractions propagated or not propagated in the same way as the electrical pattern. Coordinated electrical activity of the two muscle layers seldom occurred when spontaneous activity was being recorded. Electrical activity on both muscle layers was very sensitive to stretching and could be initiated or modulated by pharmacological agents. In particular, our findings showed that stimulation induced coordinated spiking activity on the two muscle layers and caused mechanical activity, propagated orally or aborally, which consisted of long lasting, high amplitude contractions.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗

PubMedDate not supplied

Effect of cimetidine and ranitidine on gastric electrical activity in man.

Electrical activity was recorded in six post-cholecystectomy patients using bipolar serosal electrodes. Three patients were treated with intravenous cimetidine bolus in doses of 200 mg every four hours. Another three patients were treated with intravenous ranitidine bolus in doses of 50 mg every six hours. The frequency and the amplitude of the gastric electrical control activity (ECA) and the incidence of electrical response a activity (ERA) were evaluated before and after the administration of the drugs. The administration of cimetidine and ranitidine did not produce any statistically significant variation in the frequency and amplitude of the gastric ECA and the incidence of ERA. These results show that the effects of the H2-antagonists on gastric electrical activity had no clinical relevance.

Cimetidine↗

PubMedDate not supplied

[Recovery of gastroduodenojejunal electric activity after cholecystectomy. In situ study in mam].

The recovery of gastrointestinal electrical activity--migrating myoelectrical complex (MMC) and slow waves--was studied in six women (50-77 years) after cholecystectomy for gallstones: serosal electrodes in pairs are implanted in the wall of the antrum, duodenum and jejunum during surgery. Five hour recordings were made on the first, third and fourth postoperative days (pOD), in starvation condition with hydric intake only. The recordings were made after a twelve hour fast. On the fourth postoperative day, a test meal (250 g yogurt) was given to the patients and its effects on electrical activity were recorded for 2 hours. Even though MMC were present on the first and third postoperative days, a detailed study of their origin, the length of the phase 3 and the speed of gastro-jejunal propagation showed an inhibition of gastric MMC until the fourth pOD, moreover that intestinal MMC was slower than normal until the third pOD. On the fourth postoperative day, gastric inhibition disappeared since the length of the phase 3 of the MMC in the gastric level corresponded to those of the duodenum and jejunum. Furthermore the speed of propagation corresponded to that in normal subjects. Further, the slow wave frequency peculiar to each segment studied increased progressively from the first to the fourth pOD just like the slow waves with action potentials. In conclusion, notwithstanding the presence of MMC from the first postoperative day, it was only on the fourth day that normal coordination was restored and hence that patients were able to eat again.

Action Potentials↗

PubMedDate not supplied

[Restarting of electric gastric activity in situ after a minor gastric intervention].

The restarting of the electrical gastric activity after an extramucous myotomy according to the Heller's techniques with Dor's fundoplicatio was observed in a woman by 3 pairs of electrodes implanted in the wall of the gastric fundus, corpus and antrum at 3, 11 and 20 cm from the pylorus. The electrical activity was recorded on the day of surgery and on the 1st, 3rd and 5th postoperative day. Feeding was allowed on the 5th day. The gastric frequency decreased significantly on the 1st (2.92 +/- 0.09 c/min), increased on the 3rd (3.29 +/- 0.04 c/min.) and appeared normal on the day of surgery and on the 5th day (3.10 +/- 0.09 c/min). The pattern of the Potential Pacesetter (PP) changed during the observation: it appeared with a great amplitude on the day of surgery, slowed on the 1st, was polyphasic on the 3rd and shorter and weaker on the 5th day. The spiking activity was observed on the 3rd day for 20 minutes and it allowed to establish the restoration of the normal migrating complexes. A decrease of the gastric frequency and an increase of the slow wave progression was induced by the first alimentary resumption (yoghurt). The gastric frequency increased and the velocity of the slow wave progression decreased as soon as the ingestion was over. The receptive relaxation of stomach should be related to these latter phenomena.

Action Potentials↗

PubMedDate not supplied

Electrogastrography: possibilities and limits.

A cutaneous electrogastrogram (EGG) is a recording of the electrical activity of the stomach by means of electrodes placed on the abdominal skin surface. Recently, there has been an increased interest in the cutaneous EGG due to the development of new recording techniques and improved methods of signal analysis, and as a result of these developments recent studies have been able to demonstrate that alterations in gastric electrical activity may be accompanied by unexplained nausea and vomiting. In spite of the diagnostic potential of the cutaneous EGG, there are numerous problems which must be resolved before widespread clinical use is possible. The authors review the current status of the cutaneous EGG and describe their own experience of its use in the study of certain organic gastric diseases.

Electrodiagnosis↗