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.

Partial purification of 3 alpha- and 3 beta-hydroxysteroid dehydrogenases from human hyperplastic prostate. Comparison between the two enzymes

3 alpha-Hydroxysteroid dehydrogenase (3 alpha-HSD) activity has been purified to homogeneity, the enzyme is a monomer with a Mw of 32,000 Da. 3 beta-Hydroxysteroid dehydrogenase (3 beta-HSD) activity has been partially purified and has an apparent Mw of 30,000 Da. Both enzymes have the same cofactor requirements, optimal pH. However, 3 beta-HSD appeared to be an integral protein dependent on protein environment for its activity while 3 alpha-HSD activity is a protein more loosely associated to membranes.

Pseudo-streaming potentials in Necturus gallbladder epithelium. I. Paracellular origin of the transepithelial voltage changes

Apparent streaming potentials were elicited across Necturus gallbladder epithelium by addition or removal of sucrose from the apical bathing solution. In NaCl Ringer's solution, the transepithelial voltage (Vms) change (reference, basolateral solution) was positive with sucrose addition and negative with sucrose removal. Bilateral Cl- removal (cyclamate replacement) had no effect on the polarity or magnitude of the Vms change elicited by addition of 100 mM sucrose. In contrast, bilateral Na+ removal (tetramethylammonium [TMA+] replacement) inverted the Vms change (from 2.7 +/- 0.3 to -3.2 +/- 0.2 mV). Replacement of Na+ and Cl- with TMA+ and cyclamate, respectively, abolished the change in Vms. Measurements of cell membrane voltages and relative resistances during osmotic challenges indicate that changes in cell membrane parameters do not explain the transepithelial voltage changes. The initial changes in Vms were slower than expected from concomitant estimates of the time course of sucrose concentration (and hence osmolality) at the membrane surface. Paired recordings of the time courses of paracellular bi-ionic potentials (partial substitution of apical Na+ with tetrabutylammonium [TBA+]) revealed much faster time courses than those produced by sucrose addition, although the diffusion coefficients of sucrose and TBACl are similar. Hyperosmotic and hypoosmotic challenges yielded initial Vms changes at the same rate; thereafter, the voltage increased with hypoosmotic solution and decreased with hyperosmotic solution. These late voltage changes appear to result from changes in width of the lateral intercellular spaces. The early time courses of the Vms changes produced by osmotic challenge are inconsistent with the expectations for water-ion flux coupling in the junctions. We propose that they are pseudo-streaming potentials, i.e., junctional diffusion potentials caused by salt concentration changes in the lateral intercellular spaces secondary to osmotic water flow.

Pseudo-streaming potentials in Necturus gallbladder epithelium. II. The mechanism is a junctional diffusion potential

The mechanisms of apparent streaming potentials elicited across Necturus gallbladder epithelium by addition or removal of sucrose from the apical bathing solution were studied by assessing the time courses of: (a) the change in transepithelial voltage (Vms). (b) the change in osmolality at the cell surface (estimated with a tetrabutylammonium [TBA+]-selective microelectrode, using TBA+ as a tracer for sucrose), and (c) the change in cell impermeant solute concentration ([TMA+]i, measured with an intracellular double-barrel TMA(+)-selective microelectrode after loading the cells with TMA+ by transient permeabilization with nystatin). For both sucrose addition and removal, the time courses of Vms were the same as the time courses of the voltage signals produced by [TMA+]i, while the time courses of the voltage signals produced by [TBA+]o were much faster. These results suggest that the apparent streaming potentials are caused by changes of [NaCl] in the lateral intercellular spaces, whose time course reflects the changes in cell water volume (and osmolality) elicited by the alterations in apical solution osmolality. Changes in cell osmolality are slow relative to those of the apical solution osmolality, whereas lateral space osmolality follows cell osmolality rapidly, due to the large surface area of lateral membranes and the small volume of the spaces. Analysis of a simple mathematical model of the epithelium yields an apical membrane Lp in good agreement with previous measurements and suggests that elevations of the apical solution osmolality elicit rapid reductions in junctional ionic selectivity, also in good agreement with experimental determinations. Elevations in apical solution [NaCl] cause biphasic transepithelial voltage changes: a rapid negative Vms change of similar time course to that of a Na+/TBA+ bi-ionic potential and a slow positive Vms change of similar time course to that of the sucrose-induced apparent streaming potential. We conclude that the Vms changes elicited by addition of impermeant solute to the apical bathing solution are pseudo-streaming potentials, i.e., junctional diffusion potentials caused by salt concentration changes in the lateral intercellular spaces secondary to osmotic water flow from the cells to the apical bathing solution and from the lateral intercellular spaces to the cells. Our results do not support the notion of junctional solute-solvent coupling during transepithelial osmotic water flow.

[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.

"Incest--see under Oedipus complex": the history of an error in psychoanalysis

This paper is intended as a contribution to the understanding of errors in our field. The title refers to the index entries "incest" in several classic psychoanalytic texts. In a way that is analogous to the defenses utilized by survivors of incest, psychoanalysis has both known and not known, avowed and disavowed, the traumatic impact of actual incest. It is argued that psychoanalysis erred in (a) focusing too heavily on the implications of incest for the Oedipus complex instead of its implications for every stage of development, and (b) missing out on the full and detailed description of the clinical pictures of incest victims and of treatment issues, including transference and countertransference. The author presents an overview of the history prompted by Masson's original attack on Freud for abandoning the "seduction hypothesis." Topics covered are: Freud's early papers, the Freud-Ferenczi controversy (1932), and the state of psychoanalytic awareness in the 1960's of the importance of actual incest. Certain features of our field make it all too likely that new errors can be generated that may similarly take decades to recognize and undo. These include the politics of our discipline, and negative attitudes toward systematic gathering and assessment of evidence.

Adaptation and renewal of the endocrine stomach

At present at least seven different endocrine cell types have been identified in the stomach. According to their relative frequency and secretion products the antral gastrin producing G cell and somatostatin producing D cell and the fundic histamine producing ECL cell are the best characterized cell types. Total endocrine cell mass is controlled by various factors from inside and outside the stomach. Density of antral G and D cells depends on the presence and absence of food, on the antral pH and on additional humoral and/or neural factors. Gastrin and not gastric pH has been identified as the most important factor regulating the density of fundic ECL cells. Adaptation of gastric endocrine cells to gastric pH and to the presence, abundance or absence of humoral and neural regulators are well known phenomena though only partially understood. Antral G cells increase and antral D cells decrease during long-term achlorhydria which as a consequence leads to hypergastrinaemia. Examples are pernicious anaemia in man and drug-induced acid suppression under experimental conditions. Interestingly, achlorhydria-induced G cell hyperplasia never progresses to gastrinomas. Fundic ECL cell density increases markedly in the presence of long-lasting hypergastrinaemia independently of gastric pH. In contrast to G cells ECL cell hyperplasia may progress to rarely occurring ECLomas. However, this depends on additional conditioning factors as the presence of severe atrophic gastritis as in pernicious anaemia or a specific genetic trait present in patients with gastrinomas associated with the MEN I syndrome.

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.

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.

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.

[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.

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.

[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.

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.

[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.

[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.

[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.

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.

[Pharmacokinetics and tolerability of telenzepine in patients with compensated liver cirrhosis]

Pharmacokinetics and Tolerability of Telenzepine in Patients with Chronic Liver Diseases. The pharmacokinetics and tolerability of the new selective muscarinic M1-antagonist telenzepine (BY 803; CAS 80880-90-6) were studied in 10 patients with compensated liver cirrhosis who were treated over 4 weeks with 3 mg at night. 3 mg telenzepine was well tolerated. There was no deterioration of laboratory parameters during the 4 weeks treatment course. Following a single oral dose of 3 mg telenzepine the mean maximal plasma level (cmax) averaged 5.7 (1.9-10.1) ng/ml. After repeated dosing 3 patients displayed different kinetic behaviour resulting in higher values of AUC on day 14/15 in comparison to day 1/2. tmax and cmax remained unchanged. It can be concluded that even in patients with compensated liver cirrhosis no significant accumulation of the compound will occur.

Pentagastrin-stimulated gastric acid secretion and pharmacokinetics following single and repeated intravenous administration of the gastric H+, K(+)-ATPase-inhibitor pantoprazole (BY1023/SK&F96022) in healthy volunteers

The objective of the study was to investigate the pharmacodynamics and pharmacokinetics of the gastric H+, K(+)-ATPase inhibitor pantoprazole in man following repeated i.v. dosing. 8 healthy male volunteers aged from 25 to 31 years (median: 29 years), body weight between 72 and 95 kg (median: 82 kg) entered this single-blind two-period cross-over study. Each subject underwent two treatment periods of 5 days each with daily infusion of 15 mg or 30 mg pantoprazole, respectively. A placebo day preceeded the trial. On the placebo day as well as on days 1, 4 and 5 of each treatment period, gastric secretion was stimulated submaximally by a pentagastrin infusion of 0.6 micrograms/h/kg over a period of 4 h, starting one hour before administration of drug or placebo. Repeated once-daily infusion (15 min) of pantoprazole resulted in a rapidly increasing pharmacodynamic effect: as compared to placebo the mean percent inhibition of acid output measured from 1 to 3 h after start of infusion was 22%, 63% and 78% for the 15 mg dose, and 56%, 97% and 99% for the 30 mg dose on days 1, 4 and 5, respectively. The pH also increased in relation to the dose and the duration of treatment. Mean fasting gastrin serum concentrations increased by about 50%, yet remained within the normal range. Only in one subject, one of the individual values was above the upper limit of the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)