Effects of neodymium incorporation on the structural and luminescence properties of the YAl(3)(BO(3))(4)-NdAl(3)(BO(3))(4) system.

The luminescence of Nd(3+) ions in Nd(x)Y(1-x)Al(3)(BO(3))(4) (Nd:YAB) single crystals has been investigated as a function of the neodymium concentration in order to evidence the relation between the structural and spectroscopic properties in this nonlinear laser system. The analysis of the experimental data allowed us to individuate four different composition ranges. For moderate concentrations (x<0.2) the lattice parameters are nearly constant, and the emission spectra arise from Nd(3+) ions in unperturbed crystal sites. For concentrations in the 0.20.9 the final formation of the NdAl(3)(BO(3))(4) (NAB) monoclinic phase is complete, and a new local ordering around Nd(3+) is very evident in the spectral features.

Characterization of acid and alkaline reflux in patients with Barrett's esophagus. G.O.S.P.E. Operative Group for the study of Esophageal Precancer.

Although the pathogenic role of gastroesophageal reflux in Barrett's esophagus is widely accepted, the pattern of gastric and esophageal pH profile of patients with Barrett's esophagus is not well documented. Moreover, the observation that a columnar-lined esophagus can also develop after gastrectomy implies that chronic irritation of the lower esophagus by duodenal juice can be as harmful as acid reflux. To test this hypothesis, we simultaneously monitored gastric and esophageal pH in 19 patients with endoscopically and histologically proven Barrett's esophagus, in 35 with slight-to-moderate esophagitis and in 10 healthy subjects. The gastroesophageal reflux pattern in both Barrett's esophagus and esophagitis was characterized by mainly acid refluxes. Esophageal acid exposure (% time pH < 4) was 39.4 in patients with Barrett's esophagus, 14.6 in patients with esophagitis (P < 0.05), and 3.1 in healthy subjects (P < 0.05). Seven of 19 patients with Barrett's esophagus and 7 of 35 with esophagitis had evidence of alkaline reflux too; but pure alkaline refluxes accounted for only 1.9% of total time in Barrett's esophagus and 0.3% in esophagitis patients. In conclusion, these results confirm the high prevalence and severity of acid reflux in patients with Barrett's esophagus and show that the reflux of pure alkaline material into the esophagus is a rare event in both Barrett's esophagus and esophagitis patients.

Nocturnal gastric acidity pattern in gastro-oesophageal reflux disease with or without oesophagitis.

The reasons why few patients with gastro-oesophageal reflux disease develop oesophagitis are not yet clear. One of the factors whose role is still debatable is the gastric acid secretory state. The aim of this study was to evaluate whether differences exist in nocturnal gastric acidity between patients with oesophagitis and refluxers without oesophageal lesions. We studied 65 patients with gastro-oesophageal reflux disease, 37 of whom presented erosive oesophagitis, while 28 had no oesophageal lesions. Thirty-one healthy volunteers were used as controls. In both patients and controls intragastric and intraoesophageal pH were measured continuously using 2 in-dwelling glass electrodes, placed in the gastric corpus and in the oesophagus. Mean intragastric pH was calculated over 3 nocturnal time periods: 11.00 p.m.-07.00 a.m.; 11.00 p.m.-03.00 a.m.; 03.00 a.m.-07.00 a.m. Patients with oesophagitis had a lower nocturnal gastric pH (1.6 +/- 0.2) than either refluxers without oesophagitis (2.2 +/- 0.3) (p = 0.05) or controls (2.6 +/- 0.4) (p = 0.02). The difference occurred entirely in the second part of the night. Furthermore, in the same time period, oesophagitis sufferers had a higher percentage of oesophageal acid exposure at pH < 2 (0.7 +/- 0.2) than refluxers without oesophagitis (0.2 +/- 0.1) (p = 0.05), suggesting that gastric findings are of pathogenetic relevance. Patients with reflux oesophagitis have a higher nocturnal intragastric acidity than refluxers without oesophagitis. This difference, confined to the second half of the night, may be due to an altered circadian pattern of gastric acid secretion and may partially explain why only some refluxers develop oesophagitis.

Epidemiology and etiology of "autonomous" nonspecific duodenitis.

In this prospective study we looked for possible epidemiological and etiological factors in "autonomous" nonspecific duodenitis. Of 136 dyspeptic patients who entered the study, duodenitis was found in 25.6% (94.4% chronic duodenitis and 5.6% isolated active duodenitis). Men predominated with a significant prevalence of 74%; 49% of them had white-collar jobs, but age, psychological factors, and the season of the year played no role. We found that smoking and alcohol and coffee intake bore no relation to duodenitis. Helicobacter pylori (HP) was present in only 17.1% of patients with duodenitis, little different from the 10% prevalence in dyspeptic patients without duodenitis. HP was always associated with gastric metaplasia and inflammatory activity.

New provocative tests in the diagnosis of esophageal chest pain.

In the present experience, two new provocative tests are proposed in the diagnosis of chest pain. Exertional pHmetry, consisting in a standard ergometric test during esophago-gastric pHmetry, is employed in the diagnosis of chest pain by gastroesophageal reflux. 67 patients with non-cardiac chest pain were submitted to the test: 46 (group A) presenting pain only at rest, and 21 (group B) with exertional or mixed type of pain. Out of group A, 12 (25%) patients presented a positive response (both gastroesophageal reflux and typical pain during exercise). Out of group B, 6 (28.5%) patients responded positively, too. The diagnostic advantage of exertional pHmetry, compared to prolonged pHmetry, amounts to 21.7%. Exertional pHmetry, repeated on the following day, showed that occurrence of gastroesophageal reflux and pain are reproducible in all patients, with occurrence at the same threshold of the first test in 11 (61.1%) out of 18 patients. Endo-esophageal electrical stimulation is employed in the diagnosis of chest pain by motility disturbances: the technique is the same one of cardiological transesophageal atrial pacing. 6 healthy subjects and 21 patients with non-cardiac chest pain negative to other esophageal investigations (7 with and 14 without gastroesophageal reflux disease) were submitted to the test. 9 (43%) out of 21 patients showed a positive response, while in 2 patients (9%) we observed manometric changes without pain, and 10 (48%) showed a negative response. All the control subjects submitted to the test showed a completely negative response.(ABSTRACT TRUNCATED AT 250 WORDS)

Exertional gastroesophageal pH-metry: a new provocative physiological test in the diagnosis of chest pain.

With the aim of determining the value of physical exercise as a provocative test for chest pain associated with gastroesophageal reflux, 67 patients presenting non-cardiac chest pain (normal coronary angiograms and no functional coronary artery alterations) with different characteristics (group A: at rest; group B: exertional or mixed-type) underwent exercise tests during 24-hour gastroesophageal pH-metry associated with electrocardiographic (EKG) monitoring. Thirty-four patients in group A (73.4%), and 12 in group B (57%) showed pathological reflux on 24-hour gastroesophageal pH-metry. Twelve patients in group A (25%) and 6 in group B (28.5%) (total ratio: 26.8%) presented positive responses to exercise, with concomitant occurrence of gastroesophageal reflux, typical pain, without EKG ischemic signals. Exertional pH-metry allowed to reach diagnostic certitude in 10 (14.9%) of 67 patients, 9 presenting 24-hour pH-metry results that only suggested "possible" diagnosis, and 1 without either pathological reflux or pain during prolonged monitoring: all these patients belonged to group A. The repetition of the test showed total reproducibility of the results, with "fixed thresholds" of exercise in 11 of 18 subjects (61.1%). These data suggest the usefulness of grouping different diagnostics (24-hour EKG, pH-metry and exertional test) to increase diagnostic certitude, mainly in patients with primary angina. Exertional pH-metry shows to be an efficacious provocative test, and the only based on a physiological stimulus.

The duodenum in liver cirrhosis: endoscopic, morphological and clinical findings.

Endoscopic studies were performed to determine whether changes occurred in the duodenum related to portal hypertension in patients with liver cirrhosis. The total of 271 patients studied were subdivided into three groups: 83 patients with liver cirrhosis and portal hypertension, 53 with liver cirrhosis but no portal hypertension, and 135 controls. In the duodenum of cirrhotic patients with portal hypertension several changes were observed on endoscopy that were also present in the other two groups. Atrophy and vascular malformations, however, were present only in the duodenum of cirrhotic patients with portal hypertension, although in only a few patients and with statistical significance only for vascular malformations (p less than 0.01, phi = 0.21). Eleven percent of the patients had more than one endoscopic finding, but the associations of findings were without statistical significance. No statistically significant correlation was observed between the clinical severity of cirrhosis or the severity of esophageal varices and the endoscopic findings. Finally, there was no statistically significant difference between the histological findings of duodenitis in the three groups of patients.

A controlled study of 20 mg famotidine nocte vs. 150 mg ranitidine nocte for the prevention of duodenal ulcer relapse.

A 24-week, double-blind, randomized study at 13 centres compared the efficacy and safety of 20 mg famotidine nocte and 150 mg ranitidine h.s. for the prevention of duodenal ulcer recurrence. All participants had been successfully treated for an acute duodenal ulcer with 40 mg famotidine nocte. Patients were endoscoped at baseline and at 24 weeks, unless symptoms warranted earlier examination: of the 208 patients enrolled, 86 who received famotidine and 84 who received ranitidine met all protocol criteria and were considered evaluable. Intention to treat and per protocol analyses showed non-significant trends in favour of famotidine (P = 0.44 and 0.16, respectively). During the 24-week observation period, 16.3% of the famotidine group and 25% of the ranitidine group had an ulcer recurrence (95% CI of percentage difference -0.22 + 0.04). At 24 weeks, relief of day and night pain was reported by 81.2% and 91.8% of the famotidine-treated patients, respectively. The corresponding figures in the ranitidine group were 73.5% and 85.5%. No laboratory abnormalities related to the study-drugs were noted and only two drug related (possibly or probably) adverse experiences were reported, both in the famotidine group. The data from this study therefore, supports the conclusion that the efficacy of 20 mg famotidine nocte is comparable to that of ranitidine in preventing duodenal ulcer recurrence, with comparable tolerability for long-term therapy.

[Esophageal angina]. / Angina esofagea.

Angina-like chest pain, caused by alterations of esophageal function, is an increasingly common occurrence confronting cardiologists: advances in pathogenetic knowledge and in diagnostic possibilities in this field have in fact shed light on the prevalence of esophageal angina, which is present in approximately 60% of patients with angiographically intact coronaries (11% of anginal patients overall). Classically, esophageal chest pain is attributed to alterations of motility or to mucosal disease (pathologic gastro-esophageal reflux of the acid, mixed or alkaline type): this last cause prevails quantitatively. Little is known of the nociceptive mechanisms triggered by these alterations: as far as mucous disease is concerned, activation of the chemosensitive receptors has been postulated, while esophageal mechanoreceptors may be activated, in the course of a motor disorder, by distension of the wall. A recently proposed additional mechanism consists in the induction of parietal esophageal ischemia by chemical or mechanical injury: it is a fascinating and potentially resolvable mechanism, which however requires further investigation. Moreover, elements of psychological nature are also involved in the genesis of esophageal pain. A diagnosis of esophageal angina, heavily conditioned by obvious considerations of prognostic order, must necessarily aim for "certainty". Prolonged monitoring of the endoluminal pH and the adoption of provocative tests, in the course of pH monitoring and manometry, play an important role in achieving this aim (ergometric test, distension induced with a balloon, edrophonium, electrostimulation, seem most effective). A promising outlook is supported by the recent introduction of prolonged manometry. Finally, diagnostic attitude must necessarily abandon its limited specialistic horizon to consider the patient's profile in its entirety.

[Diagnostic evaluation of the patient with esophageal chest pain: our experience]. / Valutazione diagnostica del paziente con dolore toracico esofageo: la nostra esperienza.

Our experience in the field of the "cardio-esophageal" differential diagnosis of angina-like pain derives from the close cooperation between the Divisions of Gastroenterology and Cardiology. Commonly applied tests of esophageal function, always performed during electrocardiographic monitoring, are prolonged gastro-esophageal pH monitoring plus the adoption, as provocative tests, of the stress test in the course pH monitoring, of endo-esophageal distension and of electrostimulation in the course of manometry. An evaluation of prolonged pH monitoring tracings is performed not solely to locate a quantitatively pathological reflux, but especially to identify temporal correlations between the symptoms and the reflux. This explains how we were able to relate pain to reflux in 63% of the patients who took the test. Furthermore, use of esophagogastric monitoring makes it possible to identify the critical share of the non-acid reflux, i.e. mixed (21%) or alkaline (6%). Episodes of non-acid reflux feature a significantly higher rate of association with pain than acid reflux (12.5% of symptomatic acid refluxes, versus 6% of symptomatic acid refluxes, versus 6% of mixed refluxes and 7.15% of alkaline refluxes). Execution of an ergometric test, performed according to routine cardiologic procedures during pH monitoring, constitutes a valid stimulation for reflux-dependent pain, enabling us to achieve a diagnostic gain of 15.5% compared to pH monitoring alone. As stated, elicitation of pain by motor causes is performed using endo-esophageal distension (positive in 30% of cases) and with electrostimulation, a new test studied at our center.(ABSTRACT TRUNCATED AT 250 WORDS)

Famotidine vs ranitidine h.s. in acute duodenal ulcer. A multicentre endoscopic trial.

A double-blind, randomized, active drug-controlled study was conducted in order to evaluate the efficacy and safety of famotidine vs ranitidine h.s. in promoting the healing of acute duodenal ulcers. Two hundred and eighty patients participated in the trial and received either famotidine 40mg h.s. or ranitidine, 300mg h.s. The two groups were not significantly different with regard to sex and risk factors such as alcohol consumption and family history of peptic ulcer disease, while in the famotidine group, there was a slightly higher number of patients who smoked. Endoscopy was performed at the end of 4 and 6 weeks in 248 patients (128 in the famotidine group and 120 in the ranitidine group). The healing rate in those receiving famotidine was 73.4% at the end of 4 weeks and increased to 93% at the end of 6 weeks, while in the ranitidine group, the rate was 75.8% and 92.5% respectively. Day and night pain markedly reduced in both groups and therapy was generally well tolerated.

Famotidine in the management of acid-reflux oesophagitis: a multicentre study.

The management of gastro-oesophageal reflux still presents a considerable problem mostly because of its multifactorial pathogenesis. In this study, we tested the response to treatment with famotidine for 8 weeks in patients with reflux oesophagitis, taking into consideration, however, only cases with pathological gastro-oesophageal reflux of the acidic type. All the patients participating in the multicentre study underwent gastro-oesophageal 24-hr pH-metry. The results show a good response to the H2 antagonist treatment with regards to both symptomatology (improvement/healing in 98% of cases, asymptomatic in 68%) and the endoscopic and histological picture. In fact, endoscopy showed complete remission of the lesions in 60% of cases and an improvement in 21%. The histological picture of oesophagitis improved in 64% of cases, 36% of which were completely healed, with no modifications in the remaining 36%. These data, which are globally better than those reported in the literature, can probably be attributed to the original selection of patients treated by means of prolonged gastro-oesophageal pH-metry, who had exclusively pathological gastro-oesophageal reflux of the acidic type. For these patients the use of the H2 antagonist drug is more appropriate even as monotherapy, than it is for those patients who have combined or isolated alkaline gastrooesophageal reflux.

Epidemiology of duodenal erosions.

The epidemiological characters of 142 patients, 121 males and 21 females, with duodenal erosions were evaluated. They were predominantly between 30 and 60 years old. During the observation time, 125 of them were complaining of dyspeptic symptoms while the remaining 17 had haematemesis and/or melena. Duodenal erosions were single in 9 cases, zonally distributed in 51 and disseminated in 82. Erosions were associated with duodenal ulcer in 25% of cases, with ulcer scar in 4%, and with gastric ulcer in 2%. The intake of alcohol, coffee, anti-inflammatory drugs and the smoking habit were similar in patients with duodenal erosions and the general population subjected to endoscopy. These results suggest a relationship between duodenal erosions and peptic ulcer.

Tripotassium dicitrate bismuthate and ranitidine in duodenal ulcer. Healing and influence on recurrence.

One hundred patients were entered into a double-blind, double-dummy comparison of tripotassium dicitrate bismuthate (TDB) versus ranitidine, to evaluate short-term healing rates, and successfully healed patients were then entered into a follow-up phase to observe relapse rates. At 4 weeks 84% of patients treated with TDB and 68% of those treated with ranitidine had healed. At 8 weeks these figures had risen to 96% and 90%, respectively (p = NS). After a year's follow-up study 84% of patients healed initially with ranitidine had relapsed, whereas in the case of patients healed initially with TDB the relapse rate was 67% (p less than 0.05). The results confirm that in the short term, TDB is as effective as ranitidine, whereas the significantly better protection against relapse offered by TDB compared with ranitidine underlines the importance of restoring mucosal defence, an approach that to date has been somewhat overlooked.

Manometric evaluation of esophageal motility in patients submitted to prophylactic variceal sclerosis.

Sclerotherapy of esophageal varices is an effective hemostatic treatment and may also prevent bleeding. In our study, we examined the effects of prophylactic sclerotherapy on esophageal motility in 15 patients with Child's A cirrhosis of the liver. All the patients underwent three manometric measurements, performed respectively before the sclerotherapy, 1 week after the eradication of varices, and 3 months later. The results of our study show that prophylactic sclerotherapy of esophageal varices does not significantly change the resting pressure and length of the lower esophageal sphincter. Neither the amplitude nor the duration of the postswallowing esophageal peristaltic waves is significantly influenced by sclerotherapy. However, sclerotherapy produces a significant increase in tertiary contractions in the distal esophagus, which could explain the onset of dysphagia among patients in whom postsclerotherapy stricture is not evident.

Nizatidine in the short-term treatment of duodenal ulcer--an Italian Multicenter Study.

One hundred and seventy three patients suffering from duodenal ulcer, were selected for a double-blind, controlled and randomized parallel multicenter study, with interval endoscopic examinations. This study was undertaken to compare the efficacy and safety of nizatidine administered at a single dose (300 mg "nocte") versus ranitidine (300 mg "nocte") in the treatment of acute duodenal ulcer. One hundred and sixty five patients were found to meet every admission criterion and completed the study (86 on nizatidine and 79 on ranitidine). On admission to the study, both groups were seen to have been correctly selected and epidemiologically well-distributed as to history of duodenal ulcer, previous treatments and pre-study symptoms. The ulcer was considered healed when complete re-epithelialization had occurred in areas of ulcerated mucosa. Healing rates of duodenal ulcer proved to be globally similar in the two groups, both in the 4th week (nizatidine, 78%; ranitidine, 78%) and in the 8th week (nizatidine, 91%; ranitidine, 95%). After four weeks of treatment, 67% of the patients treated with nizatidine no longer had any symptoms, while 87% patients no longer suffered from day pain, and 91% had no nocturnal pain. As a result, intake of antacids quickly decreased during the first four weeks. A similar response was observed in the group receiving ranitidine. After administration at a single dose of 300 mg in the evening, nizatidine proved to be at least as effective and safe as 300 mg of ranitidine administered in the same way, with respect both to ulcer healing and symptom response.

Short-term treatment of reflux oesophagitis with ranitidine 300 mg nocte. Italian multicentre study.

A multicentre study involving 9 Italian institutions was carried out to compare the efficacy and safety of ranitidine 150 mg b.i.d. and ranitidine 300 mg nocte in the treatment of reflux oesophagitis. 117 patients with histologically proven oesophagitis were randomly allocated to two comparable treatment groups. Efficacy and reliability were evaluated by clinical and laboratory tests at the beginning of the study, and at 3 and 6 weeks; endoscopy and biopsies were performed at the beginning and at 6 weeks. Treatment with ranitidine for 6 weeks led to total disappearance of gastro-oesophageal reflux symptoms in 60% of patients, with percentages of partial improvement varying between 85% and 95% of cases. Improvement in the results of endoscopic examination was 85%, of which 55% were cured. Microscopic examination revealed an improvement of 36% and 44%, with a cure rate of 18% and 26% respectively. With regard neither to the regression of symptoms nor to the macroscopic and microscopic inflammation of the oesophageal mucosa did statistical examination show significant differences in the therapeutic efficacy of ranitidine 150 mg b.i.d. or 300 mg nocte for treatment of reflux oesophagitis.