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Biomedical subjects

B Simon

Publications and source records attributed to B Simon.

At least 145 records · Page 8Linked to original sources

[Protective effect of ranitidine in the stomach and duodenum against piroxicam. An endoscopy controlled double-blind study].

Protective Effects of Ranitidine in Stomach and Duodenum against Piroxicam / An endoscopically controlled double-blind study In a randomized parallel double-blind study the gastroduodenal effects of 20 mg piroxicam (CAS 36322-90-4) daily in the presence and absence of 300 mg ranitidine nocte was evaluated in 28 healthy volunteers undergoing upper gastrointestinal endoscopy. Drugs were taken over a period of 14 days. Endoscopic controls were performed at entry, and repeated after 7 and 14 days of treatment. A damaging score according to Lanza et al. was used. At entry, both groups displayed comparable mucosal damages in the stomach (0.9 +/- 0.1) and in the duodenum (0.4 +/- 0.2). After 14 days the mean lesion score increased in the piroxicam/placebo group to 6.3 +/- 1.6 in the stomach and to 4.0 +/- 1.4 in the duodenum. The corresponding values in the piroxicam/ranitidine group were 3.4 +/- 1.0 (stomach) and 0.4 +/- 0.2 (duodenum). This protection afforded by ranitidine was significant when compared with placebo (p < 0.05). Our data suggest that 300 mg ranitidine at night markedly protect the stomach and the duodenum against piroxicam.

Adult↗

Dose-range finding study with the proton pump inhibitor pantoprazole in acute duodenal ulcer patients.

Pantoprazole is a newly developed benzimidazole derivative with strong inhibitory actions on gastric acid secretion by blocking H(+)-K(+)-ATPase. This randomized double-blind multicenter trial investigated the efficacy of 20 mg, 40 mg and 80 mg pantoprazole o.m. on ulcer healing and symptomatic relief in 219 out-patients with endoscopically assessed acute duodenal ulcer. After 2 weeks complete ulcer healing was achieved in 58%, 89% and 82% of the patients with 20 mg, 40 mg and 80 mg pantoprazole o.m., respectively. After 4 weeks, corresponding figures were 93%, 99% and 100%; the difference of the healing rates between the 20 mg and 40 mg groups at 2 weeks was statistically significant (p < 0.0001). A rapid pain relief was achieved in all treatment groups: 72% of the 20 mg group, 89% of the 40 mg group, and 84% of the 80 mg group were pain-free after 2 weeks. The difference between 20 mg and 40 mg was statistically significant (p < 0.05). Pantoprazole was well tolerated. Adverse events occurred in 13 patients; headache, skin alterations, and diarrhea were reported most frequently. Severity and frequency of adverse events did not reveal any dose-dependence. In conclusion, pantoprazole provides fast healing of acute duodenal ulcer as well as rapid improvement of ulcer symptoms. For further clinical trials in peptic ulcer disease a daily dose of pantoprazole 40 mg o.m. is recommended.

2-Pyridinylmethylsulfinylbenzimidazoles↗

[High-dose ranitidine protects stomach and duodenum completely against piroxicam. An endoscopic double-blind pilot study].

In a randomized placebo-controlled parallel and double-blind study the gastroduodenal effects of 20 mg piroxicam daily was evaluated endoscopically in the presence of ranitidine 150 mg bid or 300 mg bid in 31 healthy volunteers. Drugs were taken over a period of 14 days. Endoscopies were performed at entry and repeated after 14 days of treatment. A damage-score according to Lanza was used. At entry, all groups showed comparable mucosal damages in the stomach and in the duodenum. After 14 days the mean lesion score increased in the piroxicam/placebo group (group A) to 4.5 +/- 1.6 (+/- SEM) in the stomach and to 2.7 +/- 0.8 (+/- SEM) in the duodenum. The corresponding values in the piroxicam/ranitidine 150 mg bid group (group B) were 3.3 +/- 1.2 (stomach) (p > 0.05 vs. group A) and 1.4 +/- 0.7 (duodenum) (p < 0.05 vs. group A). The values in the piroxicam/ranitidine 300 mg bid group (group C) averaged 1.0 +/- 0.0 (stomach) and 0.3 +/- 0.1 (duodenum) (for both p < 0.05 vs. group A). Our data suggest that profound acid inhibition--achieved by doubling the usual dose--afforded complete protection of human stomach and duodenum against piroxicam.

Adult↗

Sodium fluoride-induced gastric mucosal lesions: comparison with sodium monofluorophosphate.

In a randomized double-blind study with two parallel groups of 10 male healthy volunteers each the response of gastric mucosa after a 7 days ingestion of sodium fluoride tablets (NaF) or sodium monofluorophosphate tablets (MFP) was compared. Gastroscopic evaluations were performed before treatment, day 1 and day 7. Simultaneously blood samples were collected for determination of laboratory data and serum fluoride values. In the MFP-group no severe gastric lesions were observed, whereas in the NaF-group in 7 of the 10 subjects significant gastric mucosal lesions including acute hemorrhages and free blood in the gastric lumen were found. The differences of the lesions scores in both groups were statistically significant (p = 0.0015). The serum fluoride content was comparable in both treatment groups. Possible adverse drug reactions were reported in 4 subjects with NaF and in 1 subject with MFP. In summary, under the experimental conditions used MFP is well tolerated by the stomach while NaF produces significant gastric mucosal lesions.

Adult↗

[Clinical studies on acid inhibition by ranitidine given simultaneously with pentagastrin].

In recent years there have been some reports of tolerance occurring in man with the antisecretory effect of H2 antagonists. We, therefore, studied the effect of 300 mg and 600 mg ranitidine (CAS 66357-35-5) daily and increasing i.v. doses of pentagastrin (0.37 microgram/kg, 0.75 microgram/kg, and 1.5 micrograms/kg body weight) on gastric acid output (mmol HCl/30 min) in 9 healthy volunteers. The study design was double-blind, randomized and cross-over. Pentagastrin stimulation was performed on day 1, day 8, and day 16. Increasing i.v. doses of pentagastrin induced an almost identical enhancement of volume secretion, total acid output as well as titratable acidity on the 3 study days. A 16-days treatment period with 300 mg and 600 mg ranitidine led to 80% and 90% inhibition of pentagastrin stimulated acid output. The degree of inhibition evoked by 300 mg and 600 mg ranitidine against pentagastrin was not statistically different during the 16-days treatment period; i.e. no significant tolerance did occur within 16 days. Our data suggest that, in contrast to intragastric acidity measurements, no significant decline of inhibitory effectiveness of ranitidine against i.v. pentagastrin could be observed in healthy male volunteers.

Adult↗

Ba2+ release from soda glass modifies single maxi K+ channel activity in patch clamp experiments.

Glasses used to fabricate patch pipettes may release components which affect ion channels (Cota, G., and C.M. Armstrong. 1988. Biophys. J. 53:107-109; Furman, R.E., and J.C. Tanaka. 1988. Biophys. J. 53:287-292; Rojas, L., and C. Zuazaga. 1988. Neurosci. Lett. 88:39-44). The gating properties of maxi K+ channels from Necturus gallbladder epithelium depend on whether borosilicate glass (BG) or blue tip hematocrit glass (SG) is used to construct the patch pipettes. The data are consistent with solubilization from SG of a component which exerts voltage-dependent, cytosolic-side specific block, closely resembling "slow block" by Ba2+ ions. Ringer's solution preincubated with SG, but not with BG, blocked inside-out maxi K+ channels when used as bathing solution. Mass spectrometry revealed that Ba2+ is released by the glass from fast and slow-release compartments (SG contains 3% wt/wt BaO), and is the only ion found in the solution at concentrations consistent with the observed channel block. Additionally, SG released O2-, Na+, Ca2+, and Mg2+, all to micromolar concentrations. These elements do not interfere with maxi K+ channels but they could in principle alter the properties of other ion channels. Thus, screening for channel-modifying substances released by the glass may be necessary for the adequate interpretation of patch-clamp results.

Animals↗

Dose-related healing of duodenal ulcer with the proton pump inhibitor lansoprazole.

Lansoprazole (AG 1749) is a novel substituted benzimidazole which inhibits gastric acid secretion by blocking H+,K(+)-ATPase. This randomized, double-blind multicentre trial studied the dose-response relationship of lansoprazole on ulcer healing and compared it with ranitidine in 314 out-patients with endoscopically assessed, symptomatic duodenal ulcer. Cumulative healing rates with Lansoprazole 7.5, 15, and 30 mg o.m. were 48, 59, and 74% at 2 weeks and 75, 84, and 95% at 4 weeks, respectively (intention-to-treat); the difference of the healing rates between 7.5 and 30 mg groups was significant (P less than 0.001). Corresponding healing rates for 300 mg ranitidine nocte were 51 and 89%. Pain relief was similar in all treatment groups. Lansoprazole was well tolerated. During a follow-up of 6 months relapse rates after lansoprazole 7.5, 15, and 30 mg were 21, 29, and 22%, respectively; the relapse rate after ranitidine 300 mg was 20%. In conclusion, lansoprazole provides faster healing of duodenal ulcer than ranitidine and a similar relapse pattern. For further trials in peptic ulcer disease a daily dose of lansoprazole 30 mg o.m. is recommended.

2-Pyridinylmethylsulfinylbenzimidazoles↗

Is the Oedipus complex still the cornerstone of psychoanalysis? Three obstacles to answering the question.

Current controversies about the centrality of the Oedipus complex in psychoanalysis are difficult to resolve unless we address three obstacles in the way of rational examination. The first is that the Oedipus complex, Freud's "shibboleth" of psychoanalysis, is politically controversial. Second is the great difficulty in agreeing upon the definition and boundaries of the Oedipus complex, especially the necessary complexities introduced with the negative Oedipus complex, female sexuality, the nature of the preoedipal, and counteroedipal fantasies and actions. The third obstacle involves basic questions of psychoanalytic epistemology: our criteria for evidence to prove or disprove any particular proposition. I conclude that the awareness of these difficulties signifies a certain maturation in our thinking and that the complexity introduced by these obstacles can in time provide the groundwork for a set of formulations that is richer and closer to the complexities and ambiguities of the clinical situation.

Ego↗

In vivo demonstration of the Haldane effect during extracorporeal gas exchange.

During the extracorporeal support (LFPPV-ECCO2R) of 11 patients suffering from severe lung failure (ARDS), we consistently noticed a higher arterial than mixed-venous PCO2 in blood samples drawn at the same time. Two explanations are possible: a) the Haldane effect (HE), b) CO2 from lung tissue metabolism. In order to distinguish changes in PCO2 due to the HE from those due to tissue CO2 production, CO2 content (CCO2) was calculated. The results were compared to animal experiments with hyperoxic apnea, after which arterial and mixed-venous samples were drawn simultaneously. All blood gas samples were analyzed for pH, PCO2, PO2, and O2-saturation, from which CCO2 was calculated. In both groups, PaCO2 was 2.15 mmHg (2.7 mmHg respectively) higher at a lower CaCO2 (-2.87 ml/l, -14.9 ml/l). Oxygen saturation increased by 8.1% in the human group and 17.8% in the animal group. A significant relationship was found between changes in PCO2 and changes in O2-saturation. This is a demonstration of the Haldane effect.

Animals↗

[75 mg roxatidine nocte protects human gastric mucosa against 300 mg acetylsalicylic acid nocte].

In a randomized double-blind parallel study the gastroduodenal tolerability of 300 mg ASS nocte (8 p.m.) has been evaluated in the presence of 75 mg roxatidine nocte (8 p.m.) or placebo in 20 healthy volunteers using upper GI-endoscopy. The treatment periods lasted 14 days. Endoscopic controls were performed at entry, and repeated at day 7 and day 14. At entry the mean endoscopic score averaged 0.9 +/- 0.1 in the ASS/placebo-group and 0.9 +/- 0.1 in the ASS/roxatidine-group. The median values were 1.0 and 1.0. 300 mg ASS nocte induced in the placebo-experiments marked gastroduodenal lesions both at day 7 and day 14 (6.5 +/- 1.2 and 7.9 +/- 0.7, respectively). The median values were 8.0 and 9.0, respectively. Concomitant administration of 75 mg roxatidine nocte afforded significant protection against 300 mg ASS nocte both on day 7 and day 14 (3.3 +/- 1.0 and 3.1 +/- 0.9, respectively) (p less than 0.05). The corresponding median values were 1.0 and 1.0. Our data suggest that coadministration of roxatidine nocte reduces significantly gastroduodenal lesions evoked by acetylsalicylic acid 300 mg nocte.

Adult↗

Hemodynamic variables and plasma levels of PGI2, TXA2 and IL-6 in a porcine model of recurrent endotoxemia.

The pulmonary and systemic hemodynamic effects of recurrent endotoxemia were studied in pigs over a 48-hr period. Six pigs of the test group were given 0.5 micrograms/kg of an E. coli endotoxin (WO111: B4) over 60 min at the beginning and in the middle (22 hr) of the experiment. Three pigs given the same amount of physiological saline solution served as controls. The hemodynamic response to the first LPS injection was characterized by severe pulmonary hypertension, a significant increase in systemic vascular resistance, and a marked decrease in cardiac output. Circulating TxB2 levels were higher than those of 6-keto-PGF1 alpha levels, so that the first response to LPS is influenced by the vasoconstrictive actions of TxA2. With the second LPS application, the pulmonary response was attenuated, although a significant increase of pulmonary artery pressure and pulmonary vascular resistance occurred. Once again systemic vascular resistance rose and cardiac output decreased, but this time plasma levels of 6-keto-PGF1 alpha were greater than those of TxB2. Toward the end of the experiment, we noted the progressive onset of a hyperdynamic and hypotensive state. Systemic vascular resistant index decreased to 50% of the baseline value. IL-6, a cytokine of systemic importance during the course of septic shock, markedly and significantly peaked after each LPS injection. Circulating plasma levels in response to recurrent endotoxemia are described.

Animals↗

[The effect of glycine on the gastroduodenal tolerability of acetylsalicylic acid. An endoscopic, controlled double-blind study in healthy subjects].

In a randomized double-blind study the gastroduodenal tolerability of daily 500 mg acetylsalicylic acid (ASA, CAS 50-78-2) in combination with 250 mg glycine (CAS 56-40-6) (Godamed) and 500 mg ASA without addition of glycine were evaluated in 20 healthy volunteers giving upper GI-endoscopy. Both ASA-preparations have been taken over a period of 4 weeks. Endoscopic controls were performed at entry, and repeated after 7, 14 and 28 days of treatment. Both ASA-preparations induced comparable gastroduodenal damages during the whole test period: The lesions score of both groups on day 7, 14 and day 28 was almost identical. In contrast to plain ASA, where 9 of 10 volunteers reported gastrointestinal side effects, all subjects receiving ASA in combination with glycine did not complain from any dyspeptic symptoms, i.e. epigastric pain etc. The reasons for the apparent better tolerability of ASA in combination with glycine are discussed.

Adult↗

[Effect of postmortem time on survival of corneal endothelium after cryopreservation].

In corneal cryopreservation and other preservation techniques, the donor tissue post-mortem time is believed to affect endothelial cell survival. In this study, porcine eyes were stored in a moist chamber at 4 degrees C for 2, 4, 8, 32, and 72 h. Then the corneas were subjected to cryopreservation. After thawing, a 24-h interval of organ culture was used as a viability test. The cell density of the central cornea and the percentage of Descemet's membrane denuded of endothelium were determined with vital staining and morphometric methods. Corneas stored 2-32 h before cryopreservation showed no difference in necrotic areas or cell density of surviving endothelium. Corneas stored 72 h before cryopreservation revealed no endothelial cell survival. We conclude that a post-mortem time of up to 32 h before corneal cryopreservation has no influence on endothelial cell survival.

Animals↗

[Long-term results of treated bi- and trifurcations in periodontitis profunda].

In 180 patients treated between 1971 and 1989 and subjected to regular follow-up checks, a total of 1111 molar teeth have been studied. 944 of them showed furcation involvement. Primarily 828 furcation involved teeth (87.7%) could be saved. The most frequently used method of treatment was flap surgery in primary treatment, and curettage in secondary treatment. Radectomy has gained ground in the past few years in the treatment of class III furcations. A treatment concept emphasizing the discriminating use of various treatment methods allows long-term preservation of molars with advanced furcation involvement.

Female↗

Prokinetic drug treatment (cisapride) is as effective as H2-blocking agent (ranitidine) in the treatment of gastric ulcer.

A double-blind, randomized, parallel-group multicenter study was conducted in 120 patients with gastric ulcer to compare cisapride, 10 mg t.i.d., and ranitidine, 150 mg b.i.d., administered over 8 weeks. No significant differences between the results of the two treatments were found in terms of ulcer healing or symptomatic relief. Endoscopy showed that the incidence of medium-sized or large ulcers was reduced from 85% at the start to 11% and 4%, respectively, after 4 and 8 weeks in the ranitidine group, and from 98% to 15% and 4%, respectively, in the cisapride group. By week 8, the ulcer was healed in 89% of the ranitidine patients, and in 86% of the cisapride patients. Moderate to severe diurnal epigastric pain--the predominant symptom--was reported by about 80% of the patients in week 8, and by less than 15% from week 4 on. The response to nocturnal epigastric pain, epigastric pressure, sensation of fullness and other symptoms was similar. Except for gastrointestinal symptoms in the cisapride patients--nearly always indicative of enhanced bowel contractions--the occurrence of adverse effects was similar in the two groups. The improvement in gastrointestinal motility under cisapride, would appear to be as effective as suppression of acid secretion in the treatment of gastric ulcer disease.

Adult↗

[Protection from gastroduodenal adverse effects of acetylsalicylic acid with ranitidine. An endoscopic controlled double-blind study of healthy subjects].

Ranitidine protects against gastroduodenal mucosal damage associated with low-dose ASA therapy/Endoscopically evaluated double-blind study in healthy volunteers In a randomized double-blind crossover study the gastroduodenal tolerability of 300 mg ASA mane (8 a.m.) has been evaluated in the presence of 300 mg ranitidine nocte (8 p.m.) or placebo in 10 healthy volunteers using upper GI-endoscopy. The treatment periods lasted 14 d. Endoscopic controls were performed at entry, and repeated at day 7 and day 14. At entry the mean endoscopic score averaged 0.9 +/- 0.1 in the ASA/placebo-group and 0.8 +/- 0.1 in the ASA/ranitidine-group. 300 mg ASA mane induced in the placebo-experiments marked gastroduodenal ulcerations both at day 7 and day 14 (7.3 +/- 1.3 and 8.2 +/- 2.1, respectively). Concommittant administration of 300 mg ranitidine nocte afforded almost full protection against 300 mg ASA mane both on day 7 and day 14 (1.6 +/- 0.4 and 1.7 +/- 0.5, respectively) (p less than 0.05). These data suggest that nocturnal coadministration of ranitidine 300 mg reduces almost completely gastroduodenal lesions evoked by acetylsalicylic acid 300 mg mane.

Adult↗

[Ranitidine in the therapy and prevention of NSAR-induced (non-steroidal anti-rheumatic agents) gastroduodenal lesions in patients with rheumatism].

178 patients with various rheumatic disorders who had been treated with non-steroidal anti-inflammatory drugs (NSAID) for at least 32 months, were enrolled in this open trial. Entry criteria were both the presence of endoscopic lesions in gastric and/or duodenal mucosa as well as dyspeptic symptoms. All patients were treated with ranitidine 150 mg bid for 4 weeks; 127 of them continued to take their original medication. Only in a small subgroup of 21 patients the NSAIDs were withdrawn. Mean gastric lesions scores averaged at entry in both treatment groups 2.2 and 2.0; the corresponding duodenal values were 2.2 and 2.6. After 4 weeks therapy a significant reduction of the mean gastric and duodenal damaging scores was observed (p less than 0.05). In addition, a marked symptomatic relief occurred. In the subsequent prophylactic trial 98 patients could be followed for 3 months and 59 patients for at least 6 months. 44 patients (3 months) and 36 patients (6 months) received in addition to their antirheumatic medication ranitidine 150 mg bid, whereas 54 patients (3 months) and 23 patients (6 months) were without any antiulcer therapy. The calculated relapse rates within 6 months were in the presence of ranitidine only 12% and without ranitidine 63% (p less than 0.05). Our data emphasize the efficacy of H2-receptor antagonist both in the therapy as well as in the prophylaxis of NSAID-induced lesions in the upper GI-tract.

Anti-Inflammatory Agents, Non-Steroidal↗