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Biomedical subjects

W Inauen

Publications and source records attributed to W Inauen.

At least 37 records · Page 2Linked to original sources

Effects of ranitidine and cisapride on acid reflux and oesophageal motility in patients with reflux oesophagitis: a 24 hour ambulatory combined pH and manometry study.

The effect of ranitidine and cisapride on acid reflux and oesophageal motility was investigated in 18 patients with endoscopically verified erosive reflux oesophagitis. Each patient was treated with placebo, ranitidine (150 mg twice daily), and ranitidine (150 mg twice daily) plus cisapride (20 mg twice daily) in a double blind, double dummy, within subject, three way cross over design. Oesophageal acidity and motility were monitored under ambulatory conditions for 24 hours on the fourth day of treatment, after a wash out period of 10 days during which patients received only antacids for relief of symptoms. Acid reflux was monitored by a pH electrode located 5 cm above the lower oesophageal sphincter. Intraoesophageal pressure was simultaneously recorded from four transducers placed 20, 15, 10, and 5 cm above the lower oesophageal sphincter. Upright reflux was three times higher than supine reflux (median (range) 13.3 (3.7-35.0)% v 3.7 (0-37.6)% of the time with pH < 4.0, p < 0.01, n = 18). Compared with placebo, ranitidine decreased total reflux (from 10.0 (3.2-32.6)% to 6.4 (1.2-22.9)%, p < 0.01), upright reflux (p < 0.05), supine reflux (p < 0.001), and postprandial reflux (p < 0.01), but did not affect oesophageal motility. The combination of ranitidine with cisapride further diminished the acid reflux found with ranitidine--that is, cisapride led to an additional reduction of total reflux (from 6.4 (1.2-22.9)% to 3.7 (1.0-12.7)%, p < 0.01), supine reflux (p < 0.05), and postprandial reflux (p < 0.05). Cisapride also reduced both the number (p<0.01) and duration (p<0.05) of reflux episodes and significantly increased amplitude, duration, and propagation velocity of oesophageal contractions (p<0.05) but did not affect the number of contractions. The findings show that the 30% reduction of oesophageal acid exposure achieved by a conventional dose of ranitidine (150 mg twice daily) can be improved to more than 60% by combination with cisapride (20 mg twice daily). The cisapride induced increase in oesophageal contractile force and propagation velocity seems to enhance the clearance of gastro-oesophageal reflux. Combination of a histamine H2 receptor antagonist with a prokinetic agent may therefore provide an alternative treatment for reflux oesophagitis.

Adult↗

[Motility disorders and assessment methods of the esophagus].

Esophageal diseases frequently cause symptoms such as heartburn, epigastric pain and dysphagia. This article discusses the indications, techniques and limitations of currently available diagnostic procedures. Investigation of symptoms should proceed in a logical stepwise manner, beginning with endoscopy to exclude esophagitis or neoplasia. Symptoms due to acid reflux can be identified by 24h esophageal pH-metry to document a temporal association between symptoms and episodes of esophageal acidification. Stationary or ambulatory manometric recording of esophageal pressures can be used to diagnose esophageal motor disorders such as achalasia, nutcracker esophagus, diffuse esophageal spasm, or dysfunction of the upper or lower esophageal sphincter. Combined 24 h pH-manometry should be used to test the temporal association between pain, reflux, or abnormal motility in patients with non-cardiac chest pain. Video-fluoroscopy is the most appropriate technique to diagnose swallowing disorders. Pulmonary aspiration of gastro-esophageal reflux can be documented with scintigraphy.

Deglutition Disorders↗

Diagnostic assessment of gastroesophageal reflux disease: what is possible vs. what is practical?

The diagnosis of gastroesophageal reflux disease (GERD) entails the identification of patients with esophagitis and its complications as well as patients who have symptoms but no mucosal disease. Endoscopy is mandatory to establish a diagnosis of reflux esophagitis, to exclude other esophageal disease and to permit directed biopsy if columnar metaplasia, dysplasia or carcinoma is suspected. The lesions of reflux esophagitis--erosions, ulceration, stricturing and metaplasia--should be identified and graded independently, using a classification system such as the recently described "MUSE" (Metaplasia, Ulcer, Stricture, Erosions) system. Fluoroscopy can identify associated structural changes such as stricturing or esophageal shortening. Measures of esophageal acid exposure time may be used to quantify reflux before and after treatment; however, if the patient has typical symptoms but no esophagitis, a temporal association between symptoms and episodes of esophageal acidification should be sought. Ambulatory 24-hour esophageal pH-monitoring with accurate event-marking provides recordings suitable for an objective statistical analysis, which was evaluated prospectively in 14 patients. Computerized analysis of 24-hour esophageal pH recordings diagnosed 5 patients as having acid-related symptoms although only 3 of 5 patients fulfilling the criteria for pathological reflux had pH-related chest pain. This finding was confirmed by 5 experts who analyzed all recordings visually, unaware of the result of the computer analysis. The Bernstein test should be reserved for patients whose symptoms are too infrequent to permit an objective assessment of symptom occurrence during pH monitoring. In conclusion, i) endoscopy is the test of choice for the diagnosis of esophagitis but it should be supplemented by a standardized and reliable scoring system for disease severity; ii) ambulatory esophageal pH recording with accurate event-marking is the test of choice for the diagnosis of GER-related symptoms, but it should be supplemented by an objective assessment of the temporal relationship between symptoms and esophageal pH; and iii) esophageal manometry is the test of choice for evaluating esophageal peristalsis and LES (lower esophageal sphincter) function but, in the context of GERD, its main indication is the assessment of GERD patients who are being considered for surgery. The widespread use of other tests for clinical purposes must await a better understanding of the pathophysiological mechanisms which can lead to the development of GERD.

Esophagitis, Peptic↗

Effects of low and high dose oral contraceptives on blood coagulation and thrombogenesis induced by vascular subendothelium exposed to flowing human blood.

We investigated the effect of oral contraceptives with low and high estrogen concentration on blood coagulation and thrombogenesis, induced by vascular subendothelium of rabbit aorta exposed to flowing human blood. Twenty healthy women intending to take oral contraceptives were studied [1] before drug ingestion (control), and subsequently during the intake of oral contraceptives with [2] low estrogen content (20 micrograms ethinyl estradiol and 150 micrograms desogestrel per day) and [3] high estrogen content (50 micrograms ethinyl estradiol and 125 micrograms desogestrel per day). All experiments were performed between day 17 and 21 of the menstrual cycle and drug effects were studied during the third tablet cycle. Deposition of fibrin, platelets and platelet thrombi on vascular subendothelium was tested at a defined blood flow and wall shear rate (10 ml/min, 650 s-1) and was quantified by morphometrical techniques. Treatment with the low and high dose contraceptive increased the plasma levels of ethinyl estradiol (728 +/- 139 and 1438 +/- 212 vs. 0 fmol/l [low and high dose vs. control], means +/- SEM, P less than 0.001) and fibrinogen (2.3 +/- 0.1 and 2.6 +/- 0.1 vs. 2.0 +/- 0.1 g/l, P less than 0.05); and decreased antithrombin III activity (95 +/- 3 and 92 +/- 3 vs. 101 +/- 3 %, P less than 0.05). Fibrin deposition on vascular subendothelium was enhanced by the high dose contraceptive only (47 +/- 4 vs. 35 +/- 4 % coverage of the subendothelial surface with fibrin, high dose vs. control, P less than 0.05). The subendothelial deposition of platelets and platelet thrombi was not changed by contraceptive treatment. These results indicate that treatment with high dose contraceptives leads to an increase of fibrin-subendothelial interactions, whereas low dose contraceptives do not significantly alter the blood-subendothelium interactions. observed in this ex vivo model of thrombogenesis.

Adolescent↗

Effects of the oral anticoagulant phenprocoumon on blood coagulation and thrombogenesis induced by rabbit aorta subendothelium exposed to flowing human blood: role of dose and shear rate.

We investigated the effect of oral anticoagulation on thrombogenesis induced by the subendothelium of rabbit aorta. Eighteen healthy volunteers underwent a 2-week treatment with the oral coumarin preparation phenprocoumon to a target international normalized ratio (INR) of 5. By using an ex-vivo perfusion chamber system, the interaction between flowing blood and exposed subendothelium was measured at low (50 sec-1) and high (650 sec-1) wall shear rates. The low shear rate simulated blood flow in venous vessels and the high shear rate simulated blood flow in arterial vessels. Deposition of fibrin, platelets, and platelet thrombi on subendothelium was quantified by morphometric and immunologic techniques. Fibrin deposition prevailed at the low shear rate (183 +/- 57 ng/mm2 vs 46 +/- 16 ng/mm2, low vs high shear rate; mean +/- SEM; p less than 0.01). In contrast, the interaction of platelets with subendothelium was more intense at high shear rates when compared with low shear rates, as indicated by higher platelet adhesion (44% +/- 2% vs 9% +/- 1% coverage of subendothelium with platelets, p less than 0.001) and platelet thrombus volumes (3.6 +/- 0.4 microns 3/microns 2 vs 1.3 +/- 0.3 microns 3/microns 2, p less than 0.001). Fibrin deposition on subendothelium was substantially reduced even at a low intensity of anticoagulation (reduction by 60% at INR 2.1 and by 75% at INR 3.7) and was abolished after high coumarin doses (INR 5.2). In contrast, a significant inhibition of platelet thrombus formation could be achieved only by high doses of phenprocoumon (INR 5.2). Our data indicate that relatively low doses of oral anticoagulants (INR between 2 and 3.5) substantially inhibit the fibrin formation on subendothelium prevailing at venous shear conditions, whereas a high intensity of anticoagulation (INR 4 to 5) is necessary to inhibit the formation of platelet-rich thrombi prevailing at arterial shear conditions.

Administration, Oral↗

Hypoxia/reoxygenation increases the permeability of endothelial cell monolayers: role of oxygen radicals.

We assessed the effect of hypoxia/reoxygenation on 14C-albumin flux across endothelial monolayers. Cultured bovine pulmonary artery endothelial cells were grown to confluence on nitrocellulose filters (pore size 12 microns). The endothelialized filters were mounted in Ussing-type chambers which were filled with cell culture medium (M 199). Equimolar amounts (33 nM) of 14C-labeled and unlabeled albumin were added to the "hot" and "cold" chambers, respectively. The monolayers were then exposed to successive periods (90 min) of normoxia (pO2 145 mmHg), hypoxia (pO2 20 mmHg), and reoxygenation (pO2 145 mmHg). A gas bubbling system was used to control media pO2 and to ensure adequate mixing. Four aliquots of culture media were taken during each period in order to calculate the 14C-albumin permeability across the endothelialized filter. In some experiments, either the xanthine oxidase inhibitor, oxypurinol (10 microM), or superoxide dismutase (600 U/mL), was added to the media immediately prior to the experiments. As compared to the normoxic control period, albumin permeability was 1.5 times higher during hypoxia (p less than 0.01) and 2.3 times higher during reoxygenation (p less than 0.01). The reoxygenation-induced increase in albumin permeability was prevented by either oxypurinol or superoxide dismutase. These data indicate that xanthine oxidase-derived oxygen radicals contribute to the hypoxia/reoxygenation-induced endothelial cell dysfunction. The altered endothelial barrier function induced by hypoxia/reoxygenation is consistent with the microvascular dysfunction observed following reperfusion of ischemic tissues.

Animals↗

An in vitro model of ischemia/reperfusion-induced microvascular injury.

The major objective of this study was to develop an in vitro model of ischemia/reperfusion (I/R)-induced microvascular injury. Cultured venular endothelial cells were grown to confluency, labeled with 51Cr, and exposed to different durations of anoxia (0.5, 1, 2, 3, and 4 h). 51Cr release and cell detachment (indexes of cell injury) were determined at different times after reoxygenation (1, 2, 4, 6, 8, and 18 h). Because in vivo studies have implicated neutrophils in I/R injury, in some experiments human neutrophils were added to the endothelial cells upon reoxygenation. Periods of anoxia greater than or equal to 2 h resulted in 70-80% 51Cr release and 80-95% cell detachment upon reoxygenation. Under these conditions (near maximal injury), the addition of neutrophils produced negligible effects. Periods of anoxia less than or equal to 1 h resulted in 30-40% 51Cr release and 50-60% cell detachment. Under these conditions (moderate cell injury), addition of neutrophils enhanced endothelial cell injury. Using a 30-min period of anoxia, we also assessed the effects of superoxide dismutase (SOD; 300 U/ml) and allopurinol (20 microM) on anoxia/reoxygenation (A/R)-induced injury in the presence or absence of neutrophils. In the absence of neutrophils, SOD or allopurinol did not protect against A/R-induced injury. However, in the presence of neutrophils, both SOD and allopurinol attenuated the increases in 51Cr release. The results derived using this in vitro model of I/R injury are largely consistent with published in vivo studies. Thus this in vitro model may provide further insights regarding the mechanisms involved in I/R injury.

Allopurinol↗

Anoxia-reoxygenation-induced, neutrophil-mediated endothelial cell injury: role of elastase.

The aim of this study was to assess the role of neutrophilic elastase in anoxia-reoxygenation-induced, neutrophil-mediated injury to microvascular endothelium. Cultured bovine microvascular endothelial cells were grown to confluence and labeled with 51Cr. The endothelial cells were exposed to a 30-min period of anoxia and subsequently reoxygenated. Endothelial cell injury, quantitated as 51Cr release and cell detachment, was determined 8 h after reoxygenation. Addition of neutrophils upon reoxygenation enhanced the anoxia-reoxygenation-induced increase in 51Cr release and cell detachment. The neutrophil-mediated injury was associated with elastase release from the neutrophils. Four agents were used to inhibit neutrophilic elastase activity: Eglin C, methoxysuccunyl-Ala2-Pro-Val-CH2Cl, L658,758, and a monoclonal antibody against neutrophilic elastase. All elastase inhibitors attenuated the neutrophil-mediated endothelial cell detachment but not 51Cr release. Addition of purified human neutrophilic elastase, at a level that mimicked the release from neutrophils, increased cell detachment in endothelial cells exposed to anoxia-reoxygenation but did not affect 51Cr release. Our results indicate that elastase plays an important role in anoxia-reoxygenation-induced, neutrophil-mediated endothelial cell dysfunction.

Animals↗

Neutrophil-derived oxidants mediate formyl-methionyl-leucyl-phenylalanine-induced increases in mucosal permeability in rats.

The effects of several free radical scavengers and antioxidant enzymes on neutrophil-mediated changes in mucosal permeability (measured using blood-to-lumen clearance of 51Cr-labeled ethylene-diaminetetraactate) were assessed using ileal loops perfused with N-formyl-methionyl-leucyl-phenylalanine (FMLP). Neither superoxide dismutase nor catalase reduced the FMLP-induced increase in mucosal permeability. However, manganese-loaded desferrioxamine (a superoxide dismutase mimetic), PZ51 (a glutathione peroxidase analogue), desferrioxamine (an iron chelator), or dimethylsulfoxide (a hydroxyl radical scavenger) significantly attenuated FMLP-induced mucosal damage. The results of our experiments indicate that neutrophilic oxidants are responsible for a major portion of the mucosal permeability changes induced by FMLP.

Animals↗

Enprostil reduces the increase of gastric corpus mucosal mass induced by the hydrogen-potassium-stimulated adenosine triphosphatase inhibitor BY 831-78 in the rat.

We studied whether enprostil, a synthetic prostaglandin E2 derivative, might inhibit gastrin release and the trophic effects on gastric oxyntic mucosa induced by prolonged treatment with an inhibitor of hydrogen-potassium-stimulated adenosine triphosphatase, the substituted benzimidazole BY 831-78. Rats were treated intragastrically with enprostil (1 or 15 micrograms/kg b.i.d.), BY 831-78 (15 mumol/kg once daily), the combination of enprostil and BY 831-78, ranitidine (300 mumol/kg b.i.d.), and placebo. Plasma gastrin and somatostatin levels and gastric acid secretion were measured during a 1-day treatment in animals fitted with chronic gastric fistulas and repeatedly during 9 wk of treatment in intact rats. Despite inhibiting acid secretion, enprostil did not increase plasma gastrin. When combined with BY 831-78, enprostil transiently reduced the BY 831-78-induced increase of integrated plasma gastrin (1375 +/- 206 vs. 2137 +/- 256 pmol/L.12 h, p less than 0.05) in fasted rats with fistulas, but failed to prevent the marked hypergastrinemia following 9 wk of treatment with BY 831-78 (717 +/- 80 vs. 731 +/- 56 pmol/L) in intact rats. However, enprostil reduced the BY 831-78-induced increase of oxyntic mucosal volume (458 +/- 31 vs. 567 +/- 33 mm3, p less than 0.01), whereas BY 831-78 prevented the enprostil-induced increase of antral mucosal volume (42 +/- 3 vs. 56 +/- 3 mm3, p less than 0.01). These results demonstrate that some of the trophic effects induced by a hydrogen-potassium-stimulated adenosine triphosphatase inhibitor are not exclusively governed by gastrin.

Adenosine Triphosphatases↗

Xanthine oxidase-induced injury to endothelium: role of intracellular iron and hydroxyl radical.

The major objective of the present study was to characterize the sequence of events leading to endothelial cytotoxicity induced by oxidants generated extracellularly by xanthine oxidase. 51Cr-labeled monolayers of calf pulmonary artery endothelial cells were exposed to a reaction mixture containing hypoxanthine, xanthine oxidase, and chelated iron (HX/XO) and endothelial cell injury was quantitated as 51Cr release into the media. Catalase, but not mannitol or superoxide dismutase, prevented endothelial cell injury induced by HX/XO, indicating that H2O2 was the mediator of the cytotoxicity. Pretreatment of the cells with free deferoxamine (an iron chelator), but not with deferoxamine bound to dextran (mol wt 40,000), prevented endothelial cell injury induced by HX/XO or H2O2. Of the membrane-permeant hydroxyl radical scavengers dimethylsulfoxide and dimethylthiourea, only dimethylthiourea prevented 1) HX/XO or H2O2-induced endothelial cytotoxicity and 2) deoxyribose degradation by hydroxyl radicals (.OH) generated by an iron-catalyzed reaction on the sugar (site-specific reaction). The concentration of ferritin required to produce significant quantities of .OH was much greater than that present in endothelial cells, and ferritin-catalyzed .OH formation was not affected by deferoxamine, indicating that ferritin-bound iron is most likely not the physiologically active catalyst. We conclude that extracellularly generated H2O2 can enter the cell and interact with nonferritin iron to produce the cytotoxic .OH via a site-specific reaction.

Animals↗

Superoxide mediates reperfusion-induced leukocyte-endothelial cell interactions.

The objective of this study was to determine whether superoxide mediates the leukocyte-endothelial cell interactions elicited by reperfusion (reoxygenation) of ischemic (hypoxic) tissues. Mesenteric and intestinal blood flows were reduced to 20% of control for 1 h, followed by 1 h of reperfusion. Sixty minutes after reperfusion, red blood cell velocity (Vr), leukocyte rolling velocity (Vw), and the number of adherent leukocytes were measured in mesenteric venules. Then, either human superoxide dismutase (hSOD), hydrogen peroxide-inactivated hSOD, or MoAb IB4 (a monoclonal antibody against the leukocyte adhesion molecule CD18) was injected intravenously. Ten minutes later, repeat measurements were obtained and compared with pretreatment values. hSOD attenuated reperfusion-induced neutrophil adherence and increased Vw/Vr, an index of the fracture stress between leukocytes and endothelium. Peroxide-inactivated hSOD did not alter any parameter. MoAb IB4 attenuated reperfusion-induced adherence but did not alter Vw/Vr. In a correlate study, cultured bovine microvascular endothelium was exposed to 30 min of anoxia, followed by 60 min of reoxygenation. Cat neutrophils were added during reoxygenation. Reoxygenation-induced leukocyte adherence was attenuated by either hSOD or MoAb IB4 but not by inactivated hSOD. Adherence of phorbol 12-myristate 13-acetate-activated cat neutrophils to plastic was unaffected by hSOD or inactive hSOD, yet MoAb IB4 virtually abolished the response. These results indicate that superoxide mediates reperfusion-induced leukocyte adherence and that endothelial cells are required for this superoxide-mediated adherence.

Animals↗

Influence of prostaglandins, omeprazole, and indomethacin on healing of experimental gastric ulcers in the rat.

We investigated whether the trophic actions of prostaglandins, omeprazole, and indomethacin on gastric mucosa lead to accelerated healing of gastric ulcers in the rat. Cryoulcers were produced in the corpus area and treated with 16,16-dimethyl prostaglandin E2 (5 or 100 micrograms/kg b.i.d., intragastrically), omeprazole (40 mumol/kg once daily, subcutaneously), indomethacin (2 mg/kg b.i.d., subcutaneously), or placebo. At the end of the treatment, plasma gastrin, cell labeling index (autoradiography with [3H]thymidine), and the size and depth of mucosal defects were measured. Compared with placebo, omeprazole accelerated ulcer healing as indicated by a smaller ulcer area [1.1 +/- 0.2 vs. 4.8 +/- 1.2 mm2 (mean +/- SEM)] and smaller ulcer depth (383 +/- 31 vs. 488 +/- 41 microns) after 10 days of treatment. Prostaglandins did not affect ulcer healing despite thickening of gastric corpus mucosa. Indomethacin delayed ulcer healing and reduced the labeling index. Omeprazole induced a marked hypergastrinemia (208 +/- 12 vs. 66 +/- 12 pmol/L on day 5, and 469 +/- 23 vs. 58 +/- 16 pmol/L on day 10). The results indicate that abolishment of acid secretion by omeprazole accelerates healing. Trophic actions and "cytoprotective" effects by prostaglandins are not relevant for ulcer healing in this model.

16,16-Dimethylprostaglandin E2↗

Excessive deposition of fibrin, platelets and platelet thrombi on vascular subendothelium during contraceptive drug treatment.

We investigated the effect of oral contraceptives on thrombogenesis induced by subendothelium of rabbit aorta (SE), exposed to flowing non-anticoagulated blood in an annular flow chamber. Six healthy women on sequential contraceptive drugs (0.05 mg aethinylestradiol/day, 0.125 mg desogestrel/day) were compared with 6 women without hormonal contraception and 6 men. On contraceptive drug treatment, blood values were significantly increased for fibrinogen (2.6 +/- 0.2 vs 1.9 +/- 0.1 g/l) and fibrinopeptide A (3.9 +/- 0.9 vs 0.9 +/- 0.1 ng/ml), whereas antithrombin III was decreased (81 +/- 4 vs 97 +/- 6%). Fibrin deposition on vascular subendothelium was more than four-fold increased when measured morphologically (63.4 +/- 2.5 vs 14.6 +/- 6.8% coverage of SE surface with fibrin) as well as immunologically (29.3 +/- 2.2 vs 4.5 +/- 1.9 micrograms fibrin/cm2 of SE). Thrombus volumes were more than two-fold increased in women with contraceptives (9.0 +/- 1.4 vs 3.7 +/- 1.0 micron 3/micron 2). Our study shows that during contraceptive drug treatment the exposure of flowing blood to vascular subendothelium leads to excessive deposition of fibrin and platelet thrombi. Measurement of blood interactions with subendothelium might be of predictive value in hypercoagulable states such as contraceptive treatment.

Adult↗

Effect of acid inhibition on the growth of parietal cells.

Studies in the rat have shown that prolonged inhibition of acid secretion by high doses of a histamine H2 antagonist is followed by a 20-30% increase in the number of parietal cells, and that this is paralleled by an augmentation of the maximum acid output. A similar effect has been shown after prolonged acid neutralization with high doses of an antacid. These trophic effects are not unexpected. An increase in gastric pH is followed by gastrin release, and the parietal cell mass may be augmented by repeated exogenous administration of gastrin or by endogenous hypergastrinaemia following surgery. To further evaluate whether a direct correlation exists between the magnitude of drug-induced hypergastrinaemia and parietal cell hyperplasia, rats were treated for 24 days with two acid inhibitors which differ markedly in the degree of acid inhibition and acute or chronic gastrin release. Six animals each were treated with either omeprazole (40 mumol/kg once daily), or atropine (3 mg/kg twice daily), or omeprazole combined with atropine or with placebo. On day 24, plasma gastrin was elevated more than 10-fold in both groups of rats treated with omeprazole but not in animals given atropine alone. As compared to placebo treatment, total parietal cell volume was significantly higher in animals treated with atropine (102 +/- 9 mm3 versus 140 +/- 18 mm3), but was unchanged in the other two groups. These studies demonstrate that marked prolonged drug-induced hypergastrinaemia does not necessarily exert trophic effects on parietal cells. Furthermore, the finding that omeprazole abolishes the effect of atropine suggests that omeprazole interferes with trophic actions on parietal cells.

Animals↗

Clinical relevance of mucosal protection.

An inquiry was made among 70 of the 76 participants of an international symposium entitled 'Future Directions in Peptic Ulcer Research', held in Bellagio, Italy, in April 1986. There was almost unanimous agreement that research in the development of protective drugs should be intensified. The participants felt that in future studies the prevention of ulcer relapse, concomitant administration with potentially ulcerogenic drugs, prevention of stress ulceration, and treatment of ulcer hemorrhage should be emphasized rather than the healing of uncomplicated ulcers. They were not generally satisfied with the performance of available prostaglandin analogues in ulcer treatment. The moderate commercial success of sucralfate was attributed mainly to the complicated mode of intake, but also to the unknown mechanism of action of this substance. It was felt likely that antacids have a clinically relevant protective effect on gastroduodenal mucosa.

Anti-Ulcer Agents↗

Erythrocyte deformability in dialysed and non-dialysed uraemic patients.

In thirty-one uraemic patients, fourteen on conservative treatment and seventeen on long-term haemodialysis, erythrocyte deformability, measured as filtration half-time in a paper filtration experiment, was studied. The two groups were comparable concerning age, sex and kidney disease. Although the mean filtration half-time for erythrocyte suspensions was normal in non-dialysed patients there was a positive linear correlation (P less than 0.01) between serum creatinine and filtration half-time in this group. Filtration half-time was increased in dialysed patients, indicating impaired deformability in the latter (P less than 0.001). Filtration half-time showed a good inverse correlation with the packed red cell volume in the non-dialysed (P less than 0.001) and in the dialysed group (P less than 0.01). As pre- and post-dialysis filtration half-times were the same, it appeared that the more severe uraemic state of dialysed patients was responsible for the impairment of erythrocyte deformability and not the dialysis procedure itself.

Adult↗