Efficacy and safety of rioprostil, 300 micrograms b.d., in the treatment of gastric ulcer: a comparison vs. ranitidine, 150 mg b.d., in a randomized multicentre study

The aim of this study is a double-blind evaluation of the efficacy and safety of rioprostil, 300 micrograms, compared with ranitidine, 150 mg, when given twice a day for 4 or 8 weeks in patients with active, uncomplicated gastric ulcer disease. A total of 194 patients are entered into the study, of which 182 are statistically evaluated for efficacy. Eighty-seven receive rioprostil and 95 receive ranitidine. All patients receive two oral doses of study medication daily. After 4 weeks' treatment, 47.1% of the patients receiving rioprostil are endoscopically healed compared with 53.7% of those receiving ranitidine. After 8 weeks' treatment, the cumulative cure rates are 76.2% and 80.9% respectively. Side effects occur in 26% of the patients receiving rioprostil and in 15% of the patients receiving ranitidine. Gastrointestinal side effects are most common. Changes in stool consistency (i.e. soft stools or mild diarrhoea) are the most reported symptoms in patients receiving rioprostil. These effects are generally self-limiting. Three patients on rioprostil and one patient on ranitidine discontinue treatment due to side effects. No clinically significant changes in biochemical variables occur in either group throughout the treatment period. Rioprostil, 300 micrograms b.d., is a safe and effective treatment for gastric ulcer disease. Healing rates and alleviation of pain are comparable for both treatment groups. The change in stool consistency with rioprostil is of only minor clinical importance, that is, it occurs on about 2% of treatment days.

Metabolism of androgens in human hyperplastic prostate: evidence for a differential localization of the enzymes involved in the metabolism

The subcellular distribution of 5 alpha-reductase, 17 beta-hydroxy steroid dehydrogenase, 3 alpha- and 3 beta-hydroxysteroid dehydrogenase activities was studied in human hyperplastic prostate. 5 alpha-reductase and 17 beta-hydroxysteroid dehydrogenase activities are located in the nuclear envelope. 3 alpha-hydroxysteroid dehydrogenase activity was almost equally distributed between cytosol and membranes, 3 beta-hydroxysteroid dehydrogenase activity was linked to all membranes. Direct testosterone metabolism (transformation into its active metabolite 5 alpha-DHT and into androstenedione, an inactive androgen) takes place only in the nucleus whereas indirect metabolism takes place mainly in the cytoplasm. These findings add new evidence for the mechanism of action of testosterone in prostatic tissue. Testosterone diffuses into the cell, migrates toward the nucleus and is transformed at the nuclear envelope level into two metabolites, DHT and androstenedione. After transformation into its active form, the hormone enters the nucleus whereas the inactive form is released into the cytoplasm. This metabolism could be seen as a control of the amount of active hormone entering the nucleus and being able to bind the androgen receptor.

The surreptitious observation design: An experimental paradigm for distinguishing artifact from essence in hypnosis

Administered a hypnotic induction and 5 standard hypnotic suggestions twice via audiotape to a group of high-hypnotizable subjects and a group of low-hypnotizable simulators. During the first administration, subjects were led to believe that they were alone. However, their behavior was surreptitiously recorded on videotape and observed on a video monitor. The second administration occurred in the presence of an experimenter who had not been informed of group assignment. When unaware that they were being observed, simulators were significantly less responsive to suggestions than they were when openly observed. In contrast, the behavior of nonsimulating subjects was not affected by the presence of an experimenter. These data indicate that the responses of highly hypnotizable subjects to standard hypnotic suggestions cannot be accounted for in terms of simple compliance with experimental demand.

Frequencies of CD4+ T cells reactive with Plasmodium chabaudi chabaudi: distinct response kinetics for cells with Th1 and Th2 characteristics during infection

The functional heterogeneity of the CD4+ T cell response to Plasmodium chabaudi has been evaluated. Using a limiting dilution assay system and a variety of assays to detect gamma-interferon (IFN-gamma), interleukin-2 (IL-2), IL-3, and T helper (Th) cells for malaria-specific antibody production, the precursor frequencies of P. chabaudi-reactive T cells have been calculated. The patterns of lymphokines produced by individual microcultures of the limiting dilution assay generally supported the idea of two functionally distinct CD4+ subsets: one which produces IFN-gamma and IL-2 (Th1) and one which is an effective helper cell for antibody production (Th2). However, it could not be determined whether the overlapping functions observed in some cultures represented T cells which could produce all factors or separate clones which were developing in the same wells. During the first 14 days of an erythrocytic infection of P. chabaudi the predominant T cell response was of the Th1-type. The frequency of these cells decreased after 14 days. By 3 weeks after infection the CD4+ T cell response was characterized by Th2 cells, as defined by their ability to act as helper cells in the production of malaria-specific antibody. These data support the hypothesis that early clearance of P. chabaudi may be antibody-independent but that the final clearance mechanism coincides with the appearance of helper cells and antibody.

Rioprostil in the acute and long-term treatment of peptic ulcers: a review

The new prostaglandin E1 analogue, rioprostil, significantly accelerates healing and the elimination of pain in cases of peptic ulcer. The anti-ulcerous potency of this prostaglandin is equivalent to that of cimetidine. In comparison with ranitidine, there is a positive trend in favour of the H2-receptor antagonist, ranitidine, which has a more pronounced antisecretory effect than rioprostil. The differences in the healing rates during treatment with rioprostil and ranitidine are statistically significant in some cases, whereas those relating to pain alleviation are not. In contrast, the therapeutic efficacy of the two substances is almost identical in cases of Ulcus ventriculi. Rioprostil can be used with much the same success as ranitidine for preventing the recurrence of duodenal ulcers. The frequency of diarrhoea during rioprostil treatment, 300 micrograms b.d. and 600 micrograms nocte, is approximately 10%. In only about 1% of the patients does the rioprostil treatment have to be discontinued because of this adverse reaction.

A single evening dose of rioprostil, 600 micrograms, in the treatment of acute duodenal ulcers

When administered as 300 micrograms b.d. or as 600 micrograms once in the evening, the new prostaglandin E1 analogue, rioprostil, is capable of reducing nocturnal H+ activity (1200 h to 0800 h) by 52% and 74%, respectively (p less than 0.01). Diurnal acidity (0900 h to 1800 h), on the other hand, is only reduced by 33% and 15% (not significant). A single evening dose of rioprostil, 600 micrograms, is used successfully on 208 patients suffering from acute duodenal ulcer. After 2 weeks and 4 weeks of treatment, the healing rates are comparable to the high values obtained with ranitidine, 300 mg nocte (rioprostil, 600 micrograms nocte: 54.1% and 84.1%; ranitidine, 300 mg nocte: 54.4% and 89.9%). There are also no significant differences between the groups as regards symptomatic improvement. Severe diarrhoea and abdominal complaints do not occur with rioprostil, 600 micrograms nocte.

Sucralfate in the treatment of reflux esophagitis in adults: an update

Sucralfate was evaluated in several clinical studies on reflux esophagitis, a total of over 400 patients were studied worldwide. In this study 49 patients with reflux esophagitis of stage I-III acc. to Savary and Miller were included. The evaluation was based on 41 patients, 22 received sucralfate suspension 1 g in 5 ml qid, 19 ranitidine 150 mg bid. The patients were treated for 8 weeks, endoscopic controls were performed before treatment and after 8 weeks. The healing rates were 64% in the sucralfate group and 68% in the ranitidine group and exhibited no significant difference (p greater than 0.05). Antacid consumption and symptomatic improvement were comparable in both groups. Sucralfate seems to be a valid alternative to H2-blockers in the treatment of reflux esophagitis.

Partial suppression of anchorage-independent growth and tumorigenicity in immunodeficient mice by transfection of the H-2 class I gene H-2Ld into a human colon cancer cell line (HCT)

Many human tumors, particularly those of epithelial origin, appear to express greatly reduced levels of major histocompatibility complex class I antigens on their surface. It has been previously reported that the class I gene H-2Ld, introduced into adenovirus type 12-transformed mouse cells, induces reversal of oncogenesis in immunocompetent BALB/c mice. We have tested the hypothesis that the H-2Ld gene, when transfected into HCT colon cancer cells, may alter their transformed phenotype. Two H-2Ld transfectants, HCT-Ii and HCT-If, were found to exhibit a markedly reduced-to-virtually suppressed ability to form colonies in soft agar in comparison to a transfectant (HCTh) carrying only the neomycin-resistance gene. We also compared the tumorigenicity of HCTh vs. HCT-If cells in two different strains of immunodeficient mice: nude (T-) and triple-deficient mutants (T-, NK-, B-). At 28 days postinjection of 10(7) and 10(6) cells, the size and growth rate of HCT-If tumors were greatly reduced compared to HCTh cells. Therefore, as assayed in immunodeficient animals, expression of the class I H-2Ld gene in HCT cells appears to correlate with partial suppression of the tumorigenic phenotype, suggesting that the expression of a transfected class I gene may by itself alter the phenotype of the recipient cell and that such phenotypic changes may be independent of the immune system.

Esterase-16 (ES-16) of the rat (Rattus norvegicus): identification and genetic characterization

Esterase-16, an esterase present in lung and other tissues of the laboratory rat, has been characterized by its biochemical properties (electrophoretic mobility, substrate pattern, sensitivity to inhibitors) and genetic variation in 107 inbred strains and substrains including 14 RI strains. It was classified as a carboxylesterase (EC 3.1.1.1). The phenotype ES-16A (BN/Han and 63 other strains) was defined as a narrow electrophoretic band migrating between ES-1A and ES-13A, ES-16B (LEW/Han and 42 other strains) exhibited the same electrophoretic mobility as ES-16A but was distinguished by its extremely weak activity. Segregation of ES-16 in RI strains and backcrosses indicated linkage to linkage group V (LGV). The Es-16 locus was tentatively placed into esterase cluster 2 and homology with Es-7 of the house mouse is proposed.

[Endoscopic study of gastric tolerance of paracetamol and acetylsalicylic acid. A placebo-controlled double-blind study on healthy subjects]

Endoscopic Studies on the Gastric Tolerance of Paracetamol and Acetylsalicylic Acid/A placebo-controlled double-blind study in healthy volunteers. In placebo-controlled randomized double-blind cross-over fashion the gastric and duodenal tolerance of 1000 mg acetylsalicylic acid (ASA; as a commercially available preparation and 1000 mg paracetamol (Tylenol) were directly compared in 12 healthy volunteers. An endoscopic evaluation of the gastric and duodenal mucosa was performed. 1000 mg ASA evoked a lesion score of 2.5 whereas 1000 mg paracetamol and placebo displayed a score of 1.0 and 0.92, respectively. This difference between paracetamol and ASA reached a statistical significance. Based on the comparable analgetic potency of both compounds and the apparently better gastro-duodenal tolerability paracetamol is the drug of choice when a non-inflammatory problem requires an analgesic.

[Ranitidine in the treatment of non-steroidal anti-inflammatory agent-induced damage of the stomach and duodenal mucosa. Results of a randomized, placebo-controlled double-blind study in patients with rheumatic diseases]

46 patients with rheumatic diseases suffering from dyspepsia and endoscopically proven gastroduodenal lesions entered a double-blind placebo-controlled study with ranitidine 150 mg b.i.d. over 4-8 weeks. The patients had to be treated for at least 3 months with the non-steroidal antiinflammatory drugs (NSAID) Diclofenac, Indomethacin, and Piroxicam before entering the study. During the trial all patients had to continue on NSAID. At entry patients in the placebo group (n = 23) had a total number of 33 gastrointestinal lesions of grade 1-3. In the ranitidine group (n = 23) a total number of 28 gastrointestinal lesions had been counted. After 4 weeks of treatment the number of lesions had been reduced in the placebo group to 20 and in the ranitidine group to 6 (p less than 0.05). The total damaging score at entry averaging 2.0 under placebo and 1.0 under ranitidine had been reduced to 1.3 (placebo) and 0.3 (ranitidine). (p less than 0.05). Our results underline the efficacy of ranitidine in the treatment of NSAID-induced gastroduodenal mucosal lesions.

Effect of omeprazole on ethanol oxidation and aniline hydroxylation in rat hepatic microsomes

Omeprazole, a substituted benzimidazole, is a potent gastric acid antisecretory drug, which inhibits the hepatic oxidative drug metabolism in vitro and in vivo. The effect of omeprazole on the microsomal ethanol oxidizing system (MEOS) and, since ethanol-induced cytochrome P-450 reveals a high activity for aniline hydroxylation, on aniline hydroxylase (AH) has been investigated in rat liver microsomes. Omeprazole inhibits microsomal AH activity significantly in a dose dependent manner, while this was not the case for MEOS activity. These data give indirect evidence that the microsomal metabolism of both ethanol and aniline is mediated by different isoenzymes of cytochrome P-450 and that omeprazole exhibits a different affinity to both compounds. Therefore, it must be emphasized that drug interactions with omeprazole have to be tested experimentally in each individual case, since it is impossible to predict such interactions solely on the knowledge of the drug's metabolic pathway.

Optimal reduction of gastric acid secretion in the treatment of peptic ulceration

Pronounced and sustained inhibition of acid secretion is currently the therapeutic principle most frequently applied in the treatment of peptic ulcer disease. Since theoretically short term risks of complete inhibition of acid secretion cannot be totally ruled out, anti-secretory anti-ulcer drugs should interfere as little as possible in the physiology of gastric acid secretion. This concept is presently best achieved through the single bedtime dose of H2-blockers, which has been shown to be as effective as a twice daily dosage regimen in peptic ulcer disease. This reduces only nocturnal acid secretion, while daytime acidity remains unaffected. But there is a close correlation between the extent of the reduction of nocturnal acid secretion, healing rates and pain relief. Additionally, large clinical trials with peptic ulcer patients have shown that after 14 days' treatment with H2-blockers 30 to 50% of patients still complain about ulcer pain and about 20 to 40% of patients take supplementary antacids. As a result of this there is undoubtedly a need for an additional medication that produces a more pronounced reduction of acidity than current treatment with H2-receptor antagonists as a single evening dose. Obviously this dosage regimen does not always fulfil the therapeutic requirements (i.e. pain relief) of the individual patient. Therefore a more flexible form of application should be introduced. In general clinical use it is not feasible to identify patients with a higher treatment requirement by acid secretion analysis. However, what is feasible is the recommendation to increase the dose and frequency of administration of H2-blockers in relation to the symptoms of pain.

Comparison of the effect of sucralfate and ranitidine in reflux esophagitis

A total of 49 patients with primary reflux esophagitis were treated in a randomized controlled study at six trial centers. Treatment was given for eight weeks and consisted of daily doses of either 1 g of sucralfate suspension four times daily or one 150-mg ranitidine film-coated tablet twice daily. The evaluation of effect was based on data from 41 patients; 22 of these had received sucralfate, and 19 had received ranitidine. Reflux esophagitis was healed after eight weeks of treatment in 14 sucralfate-treated patients and in 13 ranitidine-treated patients. Alterations in the esophageal mucosa were established by endoscopic examination; the severity of these alterations was expressed in degrees using the Savary-Miller method of classification. The greater the degree of severity as assessed before treatment, the lower were the chances of the condition being completely healed. The endoscopic findings after treatment did not show any difference in the effect of the sucralfate and ranitidine treatments (p greater than 0.05). Both forms of treatment were also found to have a similar positive effect on the subjective symptoms recorded. Overall tolerance of the two forms of treatment was good. One patient treated with ranitidine had to discontinue treatment because of an allergic rash. Based on these results, sucralfate seems to be an effective alternative for the treatment of reflux esophagitis.

[Endoscopic studies of the stomach tolerance of ibuprofen: comparison of 2 galenically different preparations]

In randomised crossover fashion, the gastric and duodenal tolerability of two different ibuprofen galenic formulations were directly compared in ten healthy volunteers. An endoscopic evaluation was performed after 7 and 14 days treatment. 300 mg Ibuprofen q.i.d. as pellets, as well as 600 mg Ibuprofen b.i.d. as dragees, evoked a lesion score of 1.6 +/- 0.3 and 1.7 +/- 0.4 after 7 days of treatment (n.s.). After 14 days, the lesion score under ibuprofen dragees was slightly higher (1.9 +/- 0.3) when compared with the pellet formulation (1.6 +/- 0.3). This difference did not reach statistical significance. Both ibuprofen preparations were well tolerated.

[H2 receptor antagonists in the therapy of peptic ulcer disease]

Today histamine-H2-receptor antagonists are the most intensively investigated drugs in the therapy of acid related diseases. They are characterized by a clear mechanism of action, a convenient application form, a high tolerability, a low incidence of side effects, and a large therapeutic window. The single nocturnal dosage regimen of H2-blockers follows the concept to reduce substantially night time acidity only, which is believed to play a decisive pathogenetic role in peptic ulcer disease, while during day time physiological acid secretion remains unaffected. The clinical efficacy of this application form has been well documented in the healing and symptomatic relief of acute peptic ulcers. However, about 30% of patients still suffer from ulcer pain after a 2 weeks treatment period. A more flexible dosage regimen, which is more adapted to the ulcer symptoms of the patient will probably lead to even better clinical results.

[Therapy and prevention of peptic lesions by prostaglandins]

Prostaglandin-E-analogues inhibit gastric acid secretion after oral administration. Therefore, these drugs are tested in clinical trials and two of them- misoprostol and rosaprostol-has recently been registered. With regard to healing rate of peptic ulcer and improvement of clinical signs and symptoms the prostaglandin analogues are superior to placebo but only equally effective or even slightly inferior to H2-receptor blockers. The relapse rates following successful therapy with prostaglandin analogues are similar to that with H2-blockers. Side effects such as diarrhea or uterotropic actions will probably limit their broad application. The exact therapeutic effectiveness of prostaglandin analogues in treatment of peptic ulcer remains to be evaluated in greater detail. As in the treatment of peptic ulcer disease prostaglandin-analogues are only effective in preventing NOSAC-induced peptic lesions when given in antisecretory doses.

An alprostadil analogue and human gastric secretion. A double-blind placebo-controlled study of the effects of a tablet and lyovial formulation

The effects of single doses of 800 micrograms and 1200 micrograms of the new alprostadil analogue (prostaglandin E1 16-methyl-16-methoxy derivative) MDL 646, presented as tablet and lyovial formulations, on basal and pentagastrin-stimulated gastric acid secretion, were studied in 10 normal male volunteers using a randomised, double-blind placebo-controlled cross-over design. Compared to placebo, both doses of MDL 646 significantly decreased acid output during the basal and pentagastrin-stimulated periods. No difference between the tablet and lyovial formulations was found. Total basal output (tablet and lyovial data pooled) was reduced by 58% and 68% following 800 micrograms and 1200 micrograms MDL 646, respectively. Stimulated output was reduced to a lesser degree (15% and 27%). Inhibition of the stimulated acid secretion was observed up to 1.5 to 1.75 h after drug administration. Tolerance was good with only one subject reporting nocturnal abdominal pain following each dose of the drug and placebo.

[Omeprazole in the therapy of acid-induced diseases]

Omeprazole is a substituted benzimidazole which inhibits profoundly and long-lasting human acid secretion. The maximum inhibition effect of omeprazole begins after 3-5 days treatment. Even after 28 days application no significant rebound effects were seen after withdrawal from the medication. Omeprazole was clinically tested on several thousand patients. The daily doses of 20 mg to 60 mg in cases of duodenal ulcer led to healing rates of 60-100% after 14 days. In direct comparative studies omeprazole was superior in cases of duodenal ulcers to cimetidine and ranitidine. With regard to gastric ulcers identical successful results were seen with 20 mg omeprazole daily as with 2 X 150 mg ranitidine daily. Omeprazole was also superior to H2-blockers in the treatment of erosive reflux-oesophagitis. Results from long-term therapy with the exception of Zollinger-Ellison syndrome are not yet available. In the clinical studies, omeprazole proved to be well tolerated. Its definite place in the management of peptic ulcer disease, however, remains to clearly established.

Selective inhibition of endothelium-dependent dilation in resistance-sized vessels in vivo

In vivo experiments were performed in autoperfused hindlimbs of rabbits to investigate the role of endothelium-mediated vasomotion in resistance-sized vessels. The flow responses to the vasodilators acetylcholine (ACh), ATP, and substance P (SP), all of which have been shown to act in an endothelium-dependent manner in large conduit arteries, were studied before and after exposure of the hindleg vasculature to gossypol (a potent inhibitor of endothelium-mediated vasodilation in vitro). The flow responses to adenosine (ADO), nitroglycerin (GTN), and prostaglandin E2 (PGE2), which induce relaxation by a direct effect on vascular smooth muscle, were tested in the same manner. All vasodilators induced dose-dependent increases in femoral flow up to two- to threefold when administered intra-arterially. After gossypol, the flow responses to the endothelium-dependent compounds (ACh, ATP, and SP) were severely reduced (by 88 +/- 3%, P less than 0.01) or sometimes were converted to constrictions (ATP). The flow increases induced by ADO, PGE2, and GTN remained largely unaffected. Sham treatment (gossypol solute only), exposure to indomethacin (10 microM), and ganglionic blockade had no differential effect on the flow responses. The selective action of gossypol in suppressing the flow responses to the endothelium-dependent compounds ACh, ATP, and SP is consistent with a vasomotor role for endothelial cells in resistance-sized vessels in vivo.

Famotidine once-a-day in the therapy of acute, benign gastric ulcer: a worldwide experience

Three hundred thirty-six patients with endoscopically diagnosed benign gastric ulcers, randomly allocated to treatment with 40 mg famotidine at night or placebo, were evaluated in a double-blind multicenter trial conducted in 14 countries worldwide. After 4 weeks, 294 patients qualified for a "per protocol" analysis. Complete ulcer healing was observed in 70 of 149 patients (47%) treated with famotidine 40 mg at night and in 45 of 145 patients (31%) receiving placebo. Cumulative healing rates at 6 weeks were 65 and 46%, and at 8 weeks 80 and 54%, respectively. There were statistically significant differences between the healing rates at each time point (p less than 0.01). The famotidine treatment was significantly more effective at rapidly reducing the incidence of ulcer-related symptoms. Adverse side effects reported were minor and equally distributed between the two groups. The results of this trial show that 40 mg famotidine administered at night is significantly superior to placebo in both accelerating the healing of benign gastric ulcers and in relieving ulcer symptoms. Since 40 mg famotidine administered at night suppresses exclusively nocturnal acid secretion, these findings support the hypothesis that this factor is also of particular importance in the pathogenesis of gastric ulcers.