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Biomedical subjects

G Celle

Publications and source records attributed to G Celle.

At least 109 records · Page 6Linked to original sources
PubMed1989

Gastric aspiration versus antimony and glass pH electrodes. A simultaneous comparative in vivo study.

To carry out a simultaneous comparison of the 24-h in vivo performance of antimony and glass electrodes and the findings of intermittent gastric aspiration, a triple-probe system with closely adjacent tips was positioned in the gastric corpus of 10 subjects representing different clinical and pharmacologic conditions. We showed that pH values measured with the antimony and the glass units were well correlated to those assessed in gastric aspirates (rs = 0.87; b = 1.079; a = -0.33; and rs = 0.85; b = 1.121; a = -0.38, respectively). A proportional correlation (rs = 0.86; b = 0.97; a = 0.02) was also found between the two intraluminal pH measurements. With regard to the error frequency distributions obtained by comparing the three measuring systems two at a time, the pH pairs differed by no more than 1 pH unit in most cases (greater than 90%). It can be concluded that antimony and glass pH electrodes can be used interchangeably in 24-h intragastric acidity studies in man.

Adolescent↗
PubMed1989

[Acid-related pathology and prolonged continuous gastric pH monitoring. Physiopathologic findings and therapeutic implications].

Long-term measurement of gastric acidity is useful for the investigation of acid-related disorders of the upper gastrointestinal tract and for the evaluation of antisecretory drugs. The assessment of this function with intragastric minielectrodes connected to ambulatory solid-state recorders is increasingly being used and is replacing the traditional aspirative methods. Antimony and glass electrodes provide equivalent results in vivo and thus they can be used interchangeably in every clinical condition. In normal subjects and in patients with acid-related disorders this technique has the great advantage to allow us an accurate knowledge not only of the level but also of the variations of gastric acidity over time, in relation to usual events of daily life. Clinical pharmacological studies permit to define exactly the potency and the duration of action of antisecretory compounds, the effects of various doses of the same drug and their best administration time.

Circadian Rhythm↗
PubMed1988

A comparison of the effects on intragastric acidity of bedtime or dinnertime administration of a once daily dose of famotidine.

In order to assess whether dinnertime administration of a once daily dose of famotidine is more advantageous than a bedtime dose in suppressing evening and nocturnal gastric acidity, we gave nine patients with a past history of duodenal ulcer in double-blind, randomized fashion either (1) placebo at 6 p.m. and 10 p.m., (2) famotidine 40 mg at 6 p.m. (Fam 6) + placebo at 10 p.m. or (3) placebo at 6 p.m. + famotidine at 10 p.m. (Fam 10) on three separate occasions. Comparison of the 24-h median pH values showed that the two administrations of famotidine were superior to placebo, while Fam 6 was significantly more effective than Fam 10. The gain in acid suppression of Fam 6 with respect to Fam 10 was particularly evident from 6 p.m. to midnight. Although the antisecretory effectiveness of Fam 6 was lower than that of Fam 10 from 4 a.m. to 8 a.m., it remained clearly higher than that of placebo and ensured virtual anacidity (median pH = 6.7) even in this time segment. We conclude that a once daily dose of famotidine at 6 p.m. is better than bedtime administration at covering the long period of continuous unbuffered intragastric acidity which extends from after the evening meal to breakfast.

Adult↗
PubMed1988

Evaluation of antisecretory activity of misoprostol in duodenal ulcer patients using long-term intragastric pH monitoring.

The effect of the new synthetic prostaglandin E1 analog, misoprostol, on intragastric acidity was evaluated by means of 24-hr intraluminal pH monitoring of 16 duodenal ulcer patients. They were randomly allocated into two groups: eight received no medication and misoprostol 400 micrograms bid and eight received ranitidine 150 mg and misoprostol 400 micrograms bid not less than one week apart. The comparison of the 24-hr areas under the curve related to the median pH values showed that no difference existed between misoprostol and untreated patients in the first group, while ranitidine was significantly more effective (P = 0.00003) than misoprostol in the second group. The analysis of arithmetic differences between the 24-hr median pH values showed that misoprostol increased pH values by at least one unit compared to the untreated subgroup for about 3.5 hr, while the antisecretory action of ranitidine was far superior to that of misoprostol throughout the whole 24-hr period. It can be concluded that the effect of twice daily doses of misoprostol 400 micrograms on 24-hr intragastric pH is small and not at all comparable to that of the well-known potent H2 blocker ranitidine.

Alprostadil↗
PubMed1988

24-hour study of intragastric acidity in duodenal ulcer patients and normal subjects using continuous intraluminal pH-metry.

The circadian pattern of intragastric acidity was assessed in 19 healthy subjects and 37 patients with active, endoscopically proven duodenal ulcer using 24-hr continuous intraluminal pH-metry. The median pH 24-hr profiles showed that ulcer patients had lower postprandial pH elevations and a smaller decline in acidity during the early morning hours when compared with controls. The after-lunch and -dinner area under the curve and maximum pH values were significantly higher in controls compared to ulcer patients. In the nighttime, the median pH values in controls were significantly higher during 9 PM to 12 PM (P = 0.02), 12 PM to 4 AM (P = 0.01), and 4 AM to 8 AM (P = 0.0008) compared to the ulcer patients. We conclude that the 24-hr acidity is higher in ulcer patients compared to healthy subjects and that the differences are particularly evident in the postprandial and nocturnal periods.

Adult↗
PubMed1988

Is hepatic ultrasonography a valid alternative tool to liver biopsy? Report on 507 cases studied with both techniques.

In order to evaluate the diagnostic potential of liver ultrasonography (US), the charts of 23 cases with normal liver, 424 patients with chronic widespread, and 60 patients with focal hepatic diseases, who had undergone both US and liver biopsy, were reviewed. The positive predictive value of US was good in all hepatic disorders (range 86.9-96.5%), while its negative predictive value was very low (range 14.1-42.5%) in the various forms of widespread liver disease and suitable for screening purposes (74%) in focal lesions. Of the 507 cases, 39 with an ultrasonically suspected liver mass also underwent an echo-guided fine-needle aspiration, which showed a high sensitivity (85%) in the 27 biopsy-proved malignant lesions and excluded tumor cells in the remaining 12 cirrhotic cases. As regards US tissue diagnosis, hepatic tumors, fatty infiltration, and fibrosis were detected in 88%, 60%, and 49% of cases, respectively. Fat and fibrous content on biopsy were similarly and significantly correlated with both echo pattern and sound attenuation. Overall results suggest that in the group of widespread hepatic disorders the usefulness of US is greatly reduced by the fact that the patient's actual condition is not likely to be negative if US examination is normal and by the impossibility of differentiating fat from fibrosis. In focal lesions, the diagnostic value of US appears high and the method may frequently provide conclusive proof of the tumor if a positive cytodiagnosis on echo-guided aspirated material is done.

Adolescent↗
PubMed1988

Propranolol reduces the response of serum bile acids to oral chenodeoxycholic acid, possibly as a reflex reaction to reduced portal blood flow in healthy and cirrhotic subjects.

To evaluate if a drug that affects splanchnic and portal flow reduces intestinal bile acid absorption, we studied the effect of propranolol (40 mg oral dose) both on the response of total bile acids (SBA) to oral chenodeoxycholic acid (CDCA 250 mg) and on the estimated hepatic flow by indocyanine green kinetics in 10 healthy and 14 cirrhotic subjects. In 18 subjects who showed a reduction in resting heart rate of almost -5%, propranolol significantly reduced the SBA area under the curve after CDCA in both healthy (mumol/l/h m +/- SD from 181.7 x 144.9 to 56.5 +/- 36.4 p less than 0.02) and cirrhotic (from 1412.1 +/- 1044.8 to 1129.2 +/- 978.8 p less than 0.01) subjects. Variable but not significant modifications were observed in estimated hepatic flow. These results suggest that the propranolol-induced changes in SBA response to CDCA could be a reflex reaction to changes in splanchnic/portal flow.

Bile Acids and Salts↗
PubMed1988

Different effects of intraperitoneal or subcutaneous administration of H2-antagonists on pancreatic response to chronic administration of caerulein in rats.

This study deals with the effect of H2-receptor antagonists on pancreatic response to chronic administration of caerulein. Caerulein was administered alone or combined with cimetidine, ranitidine or famotidine twice a day in various regimes. At the end of treatment, pure pancreatic juice was collected after hormonal stimulation. Then, the rats were killed, and growth and composition of the pancreatic tissue were determined. Caerulein increased pancreatic weight and enzyme content as well as volume and enzyme activity of pancreatic juice. When given alone the three H2-receptor antagonists were totally ineffective. Both ranitidine and famotidine, but not cimetidine, significantly reduced pancreatic response to chronic administration of caerulein only when given intraperitoneally together with caerulein. On the contrary, separate applications of caerulein and ranitidine (or famotidine) did not influence caerulein-stimulated pancreatic growth or enzyme secretion. Moreover, in rats treated both intraperitoneally and subcutaneously with caerulein, the H2-antagonists reduced the pancreatic response only partially and in proportion to the intraperitoneal dose of caerulein. The responsiveness of pancreatic tissue to subcutaneous caerulein was not modified. The results suggest that H2-receptor antagonists induce (1) impaired uptake of caerulein when given together with peptide, but (2) have no specific inhibitory effect on pancreatic response to caerulein.

Animals↗
PubMed1988

Once and twice daily doses of H2 antagonists revisited, using continuous intragastric pH monitoring.

Eight patients with previous duodenal ulcer in symptomatic remission underwent continuous intraluminal pH monitoring on five separate occasions to compare the effects on 24-h intragastric acidity of placebo, 300 mg ranitidine at night, 150 mg ranitidine twice daily, 40 mg famotidine at night, and 20 mg famotidine twice daily. All H2 blocker treatments were superior to placebo (p congruent to 0), whereas the twice daily doses of both ranitidine and famotidine were significantly better (p congruent to 0 and p = 0.00006, respectively) than the single ones in reducing 24-h intragastric acidity. The higher acid inhibitory effect of the twice daily dose regimens than of the single ones was evident during the daytime, whereas no difference between them was found during the nighttime (from 2200 to 0800 h). These data are at variance with those previously published, and the slight effect of the single nightly doses of H2 blockers on daytime acidity seems to confirm further that the suppression of nocturnal acidity may really be the decisive factor in the success of this dosing schedule in treating duodenal ulcer.

Adult↗
PubMed1988

Overnight comparable anacidity by standard large and half-single bedtime doses of H2 antagonists in duodenal ulcer patients: a clinical pharmacological study.

We continuously monitored 24-h intragastric pH in eight ulcer patients--who received orally at 10 PM in double-blind, randomized fashion either placebo, ranitidine 150 mg and 300 mg, or famotidine 20 mg and 40 mg, on five separate occasions--in order to determine whether half the commonly used bedtime doses of the H2 antagonists would suppress overnight acidity to the same extent as the large doses. Our results show that, during the nocturnal period (from 11 PM to 8 AM), significantly higher pH values were obtained with the large doses than with the half doses of both ranitidine (p = 0.00005) and famotidine (p = 0.00004). However, hydrogen ion activity was virtually nil with each H2 blocker dose regimen, and the percent inhibition of acidity over placebo was 100% for all of them (p = approximately equal to 0). Further more, with regard to the nocturnal period elapsed in min above 5.0 pH units, there was no significant difference between the two ranitidine doses (p = 0.39) and the two famotidine doses (p = 0.81). Therefore, the two dosing schedules of each H2 antagonist increased intragastric pH differently, but both the half and the standard large regimens produced similar overnight virtual anacidity. It is suggested that ranitidine and famotidine should be evaluated in the acute treatment of duodenal ulcer, using single bedtime doses half those commonly employed.

Adult↗
PubMed1988

Famotidine has no significant effect on gonadal function in man.

The effect of a single bedtime dose of famotidine 40 mg on gonadal function was studied in 8 male duodenal ulcer patients. The drug was orally administered for 4 weeks. Our results show that this new H2 blocker influences basal and stimulated serum levels of neither testosterone nor gonadotrophins (LH, FSH). Besides, no significant variations were observed before and after famotidine treatment in seminal fluid characteristics evaluated in 5 out of 8 cases. It can be concluded that famotidine appears to leave gonadal function unaffected in man.

Administration, Oral↗
PubMed1987

Single bedtime dose of famotidine: assessment of its antisecretory action by 24-hour intragastric pH monitoring.

The antisecretory efficacy of a single bedtime dose of famotidine, a new potent H2-receptor antagonist, was evaluated by means of continuous 24-hour intragastric pH monitoring. Of 20 patients with duodenal ulcers, ten randomly received famotidine 40 mg at 10 PM and ten were monitored without medication for control. Famotidine regimen led to a remarkable reduction of gastric acidity in patients who were treated for duodenal ulcer and the drug-induced pH levels were significantly different (P less than .0001) from those of untreated controls. The antisecretory action lasted for 12 hours, which comprised the nocturnal period, whereas no important difference was found between the two groups for the most part of the daytime. The drug was able to keep intragastric pH above 4 units during almost 50% of the whole 24-hour period. These results confirm that famotidine is a powerful and long-acting H2 blocker that relieves gastric acidity during the night and morning hours when administered as a single bedtime dose of 40 mg.

Adult↗