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Biomedical subjects

B Simon

Publications and source records attributed to B Simon.

At least 181 records · Page 10Linked to original sources
PubMed1990

[Endoscopic studies on the gastric tolerance of paracetamol and acetylsalicylic acid. A placebo-controlled, double-blind study in healthy volunteers].

Endoscopic Studies on the Gastric Tolerance Following 6 Days Treatment 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 a 6 day treatment with 3000 mg acetylsalicylic acid (ASA; as a commercially available preparation) and 3000 mg paracetamol (Tylenol) were directly compared in 12 healthy volunteers. An endoscopic evaluation of the gastric and duodenal mucosa was performed. 3000 mg ASA daily evoked significant more gastro-duodenal lesions than 3000 mg paracetamol daily and placebo. Difference between Paracetamol and placebo did not reach 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.

Acetaminophen↗
PubMed1989

[Lowering of the plasma lipid concentration with lovastatin. A clinical study in patients with primary hypercholesterolemia].

A study of 27 patients (18 males and 9 females; median age 57 [35-70] years) with hypercholesterolaemia examined the lipid-reducing effect, clinical reliability and tolerance of lovastatin, an HMG-CoA-reductase inhibitor, given in a single evening dose. After a four-week period on placebo and a lipid-reducing diet the patients received 20 mg lovastatin for four weeks. If, at the end of this period, total cholesterol levels were still above 200 mg/dl, the dose was increased to 40 mg, after a further four weeks to 80 mg. After a three-month treatment period total cholesterol concentration in lovastatin-treated patients was 28% lower than in the placebo group (289.4 +/- 42.2 vs 208.0 +/- 39.9 mg/dl; P less than 0.0001). LDL-cholesterol concentration had fallen by 40% (215.1 +/- 44.4 vs 130.1 +/- 24.7 mg/dl; P less than 0.0001), while plasma triglyceride concentrations had fallen by 15% (166.3 +/- 71.8 vs 141.8 +/- 69.8 mg/dl; P less than 0.01). At the same time, HDL-cholesterol levels had risen by 12% (42.9 +/- 12.4 vs 47.9 +/- 18.2 mg/dl; P less than 0.01). These results confirm the marked lipid-reducing effect of lovastatin.

Adult↗
PubMed1989

[Treatment of non-steroidal anti-inflammatory drug-induced damage to gastric mucosa using ranitidine. Comparison of the effectiveness of 2 dosages].

339 patients with rheumatic diseases suffering from dyspepsia and endoscopically proven gastroduodenal lesion entered an open multicenter study with ranitidine 150 mg bid or ranitidine 300 mg administered at night in a single dose over 4 weeks. For entry the patients had to have been treated for at least 3 months with the non-steroidal anti-inflammatory drugs diclofenac, indomethacin and piroxicam. During the trial all patients were continued on NSAID. The data of 248 patients were evaluable. At entry, patients in both treatment groups had a total gastric damage score of 2.0. The duodenal lesion score was on average 1.43 in the ranitidine 150 mg bid group, and 1.8 in the 300 mg single dose ranitidine at night group. After 4 weeks of treatment the mean lesion score was significantly reduced in the stomach as well as in the duodenum with both ranitidine regimens, no differences being seen between the groups. In addition, rapid symptomatic relief was observed in both groups. After 4 weeks of treatment more than 80% of the patients were symptom-free or markedly improved.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1989

[Inhibition of 24-hour acidity by nizatidine].

In a randomized, double-blind, placebo-controlled, comparative cross-over study, we studied the effect of four H2-receptor antagonists on intragastric 24-hour acidity, nocturnal volume and acid output. Ten healthy male volunteers were administered 300 mg or 150 mg nizatidine, 800 mg cimetidine, 300 mg ranitidine, 40 mg famotidine, or placebo on several days, in each case at 9:000 PM. Nocturnal intragastric H+ concentration (mmol/l) (11:00 PM to 7:00 AM) was significantly reduced by all H2 blockers compared with placebo. We obtained the following inhibition rates: Cimetidine 67%; ranitidine 95%; famotidine 89%; nizatidine 80% (300 mg) and 69% (150 mg). Nocturnal acid (mmol/l) and volume output (ml/h) were also significantly (compared with placebo) inhibited by all four H2-receptor antagonists. Inhibition of nocturnal acid secretion was almost identical on nizatidine 300 mg nocte, ranitidine 300 mg nocte, famotidine 40 mg nocte, and cimetidine 800 mg nocte. Nizatidine 300 mg nocte and 150 mg nocte exclusively reduced acid secretion at night, without an aftereffect into the following day (8:00 AM to 6:00 PM). These results suggest that the clinical efficacy of these H2-receptor antagonists is identical with respect to healing peptic ulcer disease and providing freedom from pain. It is generally accepted today that gastric acid inhibitors used in the treatment of peptic ulcer disease should interfere with daytime gastric acid secretion as little as possible, particularly since the acid protects the stomach from bacteria ingested with the food during the day.

Cimetidine↗
PubMed1989

Comparison of the gastroduodenal tolerance of tenoxicam and diclofenac Na. A double-blind, endoscopically controlled study in healthy volunteers.

The gastroduodenal tolerance of Tenoxicam and Diclofenac Na has been evaluated in a double-blind, parallel group study in 36 healthy male volunteers. The doses used were 20 mg Tenoxicam and 100 mg Diclofenac Na daily in a retard formulation for 14 days. Gastric tolerance was assessed by endoscopy, which was performed at base-line, after the 14 day dosing period and after a 14 day follow-up period without treatment. The mucosal lesions were scored using modified Lanza criteria. Tenoxicam was significantly better tolerated at the end of the 14 day dosing period (mean gastric score: Tenoxicam 1.3; Diclofenac Na 2.2). The two treatment groups had comparable scores at the base-line and post study assessments. Tenoxicam and Diclofenac Na were generally well tolerated. Only two volunteers reported intermittant lack of appetite, heartburn and a feeling of pressure in the stomach.

Adolescent↗
PubMed1989

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.

17-Hydroxysteroid Dehydrogenases↗
PubMed1989

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.

Humans↗
PubMed1989

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.

Animals↗
PubMed1989

Human gastric acid secretion following repeated doses of AG-1749.

The effect of increasing doses (15 mg, 30 mg and 60 mg) of the substituted benzimidazole, AG-1749, on gastric acid secretion and fasting serum gastrin concentration has been studied after repeated administration to healthy volunteers. AG-1749 produced a dose-dependent and profound decrease in basal and stimulated gastric acid secretion in all volunteers, with almost total suppression at the highest dose. The extent of inhibition increased between Day 2 and Day 8 with the 15 and 30 mg doses of AG-1749. The inhibitory effect of AG-1749 appears to be fully reversible as control levels of acid output were reached 7 days after drug withdrawal. Seven days' dosing with 60 mg AG-1749 induced a more than threefold increment of fasting serum gastrin concentration, but this increase was still within the normal range. Seven days after cessation of dosing, fasting serum gastrin concentration returned to a pre-dose level.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1989

Limiting dilution analysis of the T cell response to Plasmodium chabaudi chabaudi in mice.

A limiting dilution assay system was developed in order to measure the in-vitro T cell response to antigens of the erythrocytic stages of Plasmodium chabaudi. The conditions of the assay are such that only CD4+ T cells are able to respond. The assay allows the determination of the frequencies of T cells which proliferate and/or which develop into helper cells for antibody production during a primary infection. A specific response from splenic T cells can be measured as early as 7 days after infection, and is still significant 3 months after injection of P. chabaudi. At all times the frequency of proliferating cells was greater than the precursor frequency of T helper cells. This suggests that a proportion of CD4+ T cells in this assay, although they respond to malarial antigen, do not develop into helper cells for antibody production. This limiting dilution assay will be a useful method by which to evaluate the functional heterogeneity of the CD4+ T cell response to malaria antigens.

Animals↗
PubMed1989

Effects of long-term exposure to hydrostatic pressure per se (101 ATA) on eel metabolism.

Oxygen consumption, MO2, has been measured in yellow freshwater eels (Anguilla anguilla L.) exposed in normoxic conditions for 31 days at a hydrostatic pressure of 101 ATA (atmosphere absolute; 1 ATA = 0.1 MPa) using a high pressure water circulation system. The results (series I) show that from a maximal value observed at the end of compression, MO2 decreases exponentially with time (tau congruent to 1.4 days) then reaches a steady state (MO2 = 0.67 +/- 0.05 mmol.h-1.kg-1) at a lower level than observed at 1 ATA before compression (MO2 = 1.04 +/- 0.03 mmol.h-1.kg-1). These observations are in agreement with the hypothesis that shallow water fish are able to adapt to pressure; the possible mechanisms of this adaptation are discussed. Results from a second experimental series show that fish previously submitted to pressure for 1 month (then decompressed to 1 ATA) adjust faster to a new pressure exposure (4 days later) than fish that have never experienced pressure exposure. This observation suggests that the mechanisms triggered by long-term pressure exposure could persist, at least in part, for several days after decompression to atmospheric pressure.

Anguilla↗
PubMed1989

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.

Adult↗
PubMed1989

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.

Anti-Ulcer Agents↗
PubMed1989

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.

Anti-Ulcer Agents↗
PubMed1989

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.

Adult↗
PubMed1989

[Protective effect of an antacid against acetylsalicylic acid].

The protective action of an magnesium-aluminum-antacid (Mucal-Gel) against acute doses of acetylsalicylic acid (ASA) was studied in healthy subjects (n = 30) by a double-blind cross-over method. The severity of the lesion was determined by endoscopy. In the corresponding placebo experiments, severe lesions of the gastroduodenal mucosa were seen after administration of 1500 mg ASA. These lesions could be prevented only in the presence of high doses of the antacidum mixture. It is concluded from these studies that protective actions against ASA can be achieved only if the intragastric pH-level is adequately raised above 3.5 and higher.

Adult↗
PubMed1989

[Recall rate criteria in a periodontal office].

It was the objective of this study to identify parameters which influence the rate of recall. In 1987 a total of 845 recall treatments were given to 372 patients. Recorded variables were quality of oral hygiene, papilla bleeding index, and number of teeth with pockets greater than 3 mm. These results plus the number of capped teeth were related to the recall rate. Bad oral hygiene and a correspondingly higher papilla bleeding index require a more frequent recall. However, these variables show little influence on the number of teeth with deep pockets. A higher recall rate in patients with bad oral hygiene cannot always prevent gingivitis, but progression of the disease into periodontitis and loss of attachment.

Appointments and Schedules↗