Aluminium speciation in forest soil solution--modelling the contribution of low molecular weight organic acids

The concentrations of Al bound to identified low molecular weight organic acids (LMWOAs), phosphate and humic compounds in soil solutions (O1, O2, E, B1 and B2 horizons) from Fennoscandinavian coniferous forest soils were calculated. Two models were evaluated: WHAM (Winderemere Humic Aqueous Model) and a model treating the natural organic acids as monoprotic. The WHAM model was calibrated to find an average charge balance of unity, and then used for Al speciation. This was achieved considering approximately 80% of the natural fulvic acid to be 'active'. For the monoprotic model, constants obtained from previous fitting of soil solution data were used and the model was calibrated using acid/base titrations. The modelling confirms that the low molecular weight acids are important complex formers, binding on average 11-42% (O), 19-20% (E), and 0-30% (B) of the total Al in solution depending on the model used. The monoprotic model yielded higher concentrations than WHAM. Both models predicted that the major part of Al in solution was organically complexed to humic substances and LMWOAs, which was consistent with analytical values of 'quickly reacting' Al (monomenc inorganic forms; 12-14% of Al(tot) on average in the E and B1 solutions). Both models could predict the magnitude of the analytical values (RMSD = 4-5 microM). On average the WHAM model showed a better fit for the E horizon solutions and the monoprotic model for the upper B horizon. The pH dependence of the low molecular weight fraction of Al was modelled in the pH range 3-5.5 for a 'typical' O1 and E solution assuming no other changes in soil solution composition. The extrapolation showed that the models had a different pH dependence. The concentration of Al bound to LMWOAs in WHAM decreased with higher pH while the opposite was seen for the monoprotic model. Also the influence of the concentration of total Al in solution was modelled. The models showed similar trends but for the 'typical' O1 horizon sample the monoprotic model yielded higher concentrations of Al bound to LMWOAs than WHAM.

Occurrence of esophageal granular cell tumors in The Netherlands between 1988 and 1994

Granular cell tumors (GCT) of the esophagus are rare. The tumor is generally beleived to be of neurogenic origin and shows a malignant course in 2-4% of cases. No unanimity has been reached regarding the management of this tumor. A national survey was conducted on the incidence of GCT of the esophagus, related symptoms, management, and follow-up. A national survey was performed on all newly registered esophageal GCTs in the PALGA system (Dutch register of all pathology diagnoses) for seven consecutive years (1988-1994). Fifty-two new cases (17 men, 35 women; median age 46 years, range 22-77 years) were registered. In 44 cases clinical data could be obtained (survey response 85%). The majority of the GCTs were solitary (42/44) and localized in the distal esophagus (33/44). At endoscopy the size of the tumor was estimated at <5 mm in 50%, 5-10 mm in 25%, and 10-30 mm in 18%. Most patients (40/44) presented with nonspecific gastrointestinal symptoms, only four had dysphagia (tumor size >1 cm). No malignancies were reported. Management of the tumor included excisional biopsy (1/44), endoscopic polypectomy (3/44), and surgical excision (1/44). Endoscopic follow up (1-60 months) in 16 out of 17 patients left untreated showed either a stable tumor size or regression of the tumor. In one case with multiple GCT's a slight tumor growth was seen after a follow-up period of 48 months. Esophageal GCTs in the Netherlands are rare, and mostly diagnosed incidentally. Most patients suffer from nonspecific symptoms; dysphagia occurs only with tumors >1 cm. The usual clinical course of esophageal GCTs is benign. Patients without dysphagia probably do not require routine endoscopic follow-up, provided they are instructed to contact their physician, once dysphagia develops.

Strongyloides stercoralis infection: how to diagnose best?

Four patients are described with a Strongyloides stercoralis infection. Several techniques to diagnose this infection are discussed. The so-called Baermann method is emphasised. Especially in chronic infections the combination of serology and the Baermann method seems the best diagnostic approach. Treatment with albendazole or ivermectin are suggested treatments.

Low-amplitude distal esophageal spasm as a cause of severe dysphagia for solid food

This case report presents a patient with progressive dysphagia, accompanied by weight loss, in the absence of organic disease. Esophageal motility studies initially failed to reveal a diagnosis. At simultaneous manometry and fluoroscopy, with bread/barium boluses, the diagnosis of esophageal spasm in a relatively weak esophagus was made. All conservative treatment modalities failed. Thoracoscopic myotomy resulted in partial field of symptoms. Finally, an esophagectomy was performed because of sever dysphagia accompanied by persisting weight loss.

Comparison of the efficacy and safety of 1.5 compared with 3.0 g oral slow-release mesalazine (Pentasa) in the maintenance treatment of ulcerative colitis. Dutch Pentasa Study Group

OBJECTIVE

To investigate a possible dose-effect relationship with two dosages of oral slow-release mesalazine in patients with quiescent ulcerative colitis.

METHOD

One hundred and sixty-nine patients with ulcerative colitis in remission were treated with either 1.5 or 3.0 g/day mesalazine for 1 year or until relapse into active colitis.

RESULTS

Fewer of the 3.0 g dose group relapsed than of the 1.5 g dose group (33 compared with 46%). This difference failed to reach statistical significance (P = 0.057). A significant relationship between age and relapse rate was established. No dose-related adverse events were found. Three serious drug-related adverse events were, however, reported. All of the serious adverse reactions resolved after the medication was discontinued.

CONCLUSION

There is a trend for high doses of oral mesalazine to be more effective in prevention of relapse of ulcerative colitis. These higher doses are not associated with a higher incidence of adverse reactions.

Sulphasalazine-induced eosinophilic pneumonia

Eosinophilic pneumonia and skin rash developed in a 21-yr-old man while taking sulphasalazine. After discontinuation of the drug and treatment with steroids the pulmonary infiltrates and rash resolved completely. A short review of the literature concerning sulphasalazine-induced lung disease is presented.

Bacterial acetylation of 5-aminosalicylic acid in faecal suspensions cultured under aerobic and anaerobic conditions

After oral administration of 5-aminosalicylic acid a substantial proportion of the acetylated form is excreted in the faeces. We have studied the role of the faecal microflora in acetylating 5-aminosalicylic acid. In faeces incubated under both aerobic and anaerobic conditions there was acetylation of 5-aminosalicylic acid. Of the anaerobic bacteria isolated from a 10(8) faecal dilution 44% were able to acetylate 5-aminosalicylic acid. We conclude that the normal faecal microflora contribute to the acetylation of 5-aminosalicylic acid.

The endoscopic spectrum of colonic mucosal injury following aortic aneurysm resection

Ischemic colitis is a serious complication of aortic aneurysm resection. A knowledge of the endoscopic appearance and the clinical course of various forms of colonic mucosal injury is important for the clinician who has to decide which patient should be carefully monitored after aneurysm resection. This article reports on 48 patients with colonic mucosal injury, subdivided into non-specific lesions and ischemic colitis. Details are given of the endoscopic picture and the clinical course. It is concluded that only the gangrenous form of ischemic colitis is of clinical significance, and is related to bowel perforation and late stricture formation.

Stability of disodium azodisalicylate (olsalazine) and metabolites in urine and faeces stored at different temperatures

METHODS

The stability of disodium azodisalicylate, 5-aminosalicylic acid and acetyl-5-aminosalicylic acid dissolved in distilled water and in urine or mixed with faeces to which HgCl2 was added, was studied at -20 degrees C, 4 degrees C and room temperature.

RESULTS

In water, no marked differences were found between the three storage regimens. In urine, disodium azodisalicylate and acetyl-5-aminosalicylic acid were stable, while the 5-ASA concentration decreased when stored at 4 degrees C and room temperature. In faeces stored during seven days, a marked decrease in 5-aminosalicylic acid concentration to about zero was found when it was kept at 4 degrees C and room temperature. No marked change in the concentration of disodium azodisalicylate and 5-aminosalicylic acid added to the faeces-HgCl2-mixtures appeared.

Olsalazine as an alternative therapy in a patient with sulfasalazine-induced eosinophilic pneumonia

A man with Crohn's colitis developed eosinophilic pneumonia after treatment with sulfasalazine. Challenge with sulfapyridine revealed that this component of sulfasalazine was the likely causative agent. Treatment with olsalazine, a 5-aminosalicylic acid compound (disodium-azodisalicylate), was well tolerated without recurrence of pulmonary symptoms.

Double-blind comparison of 5-aminosalicylic acid and acetyl-5-aminosalicylic acid suppositories in patients with idiopathic proctitis

Suppositories containing 300 mg 5-aminosalicylic acid (1.96 mmol) or 425 mg acetyl-5-aminosalicylic acid (1.96 mmol) were used in 40 patients with idiopathic proctitis to determine the efficacy of acetyl-5-aminosalicylic acid in treating this bowel inflammation. Each patient was treated with 5-aminosalicylic acid or acetyl-5-aminosalicylic acid suppositories twice daily for 4 weeks in a double-blind trial. Four patients were included twice in the trial. The second time they were treated with the alternative regimen. Six patients in the acetyl-5-aminosalicylic acid group did not complete the trial, four of them because of diarrhoea. Complete clinical remission with normal rectal mucosa on sigmoidoscopy was achieved in 10 out of 18 patients on 5-aminosalicylic acid and in only two out of 15 in the acetyl-5-aminosalicylic acid group (P = 0.03). A favourable histological improvement was demonstrated with 5-aminosalicylic acid suppositories, but the difference with acetyl-5-aminosalicylic acid was not significant (P = 0.059). Three of the four patients who received both drugs recovered with 5-aminosalicylic acid; in none of them was acetyl-5-aminosalicylic acid effective. The results from this study and from previous investigations show that acetyl-5-aminosalicylic acid is not superior to placebo.

Disposition of disodium azodisalicylate in healthy subjects. A possible new drug for inflammatory bowel disease

The disposition of disodium azodisalicylate and salicylazosulfapyridine was studied in 6 healthy volunteers. After a single oral dose (1.0 g disodium azodisalicylate; 2.3 g salicylazosulfapyridine) maximum serum concentrations of the intact compound ranged between 1.4 and 6.8 mumol/L and 32 and 114 mumol/L, respectively. Mean residence time and serum half-life of disodium azodisalicylate were considerably longer than those of salicylazosulfapyridine, probably because of a higher apparent volume of distribution. Both compounds were largely split by colonic bacteria and comparable amounts of the active moiety, (acetyl-)5-aminosalicylic acid, were recovered in feces. During long-term ingestion of disodium azodisalicylate (1.0 g/day) it took 6-19 days to reach a steady state. Serum concentrations of disodium azodisalicylate at steady state were low: 2.2-8.4 mumol/L. The serum half-life was 6-10 days. It is concluded that the disposition of disodium azodisalicylate is similar, in important respects, to that of salicylazosulfapyridine. Disodium azodisalicylate, therefore, deserves therapeutic trial.

[Current developments in the field of endoscopy in the treatment of digestive system disorders]

A review is given of new developments of endoscopic treatment of diseases of the gastrointestinal tract. Endoscopic treatment is possible in patients with peptic stricture or inoperable tumors of the oesophagus, achalasia of the oesophagus, oesophageal varices, polyps and angiodysplasia of the large bowel, stomach and duodenum, choledocholithiasis and unresectable stenosing tumors of the bile ducts. In comparison with surgical therapy endoscopic treatment is relatively simple and has a much lower morbidity and mortality, especially in patients with an increased surgical risk.

Compliance to therapy in patients on a maintenance dose of sulfasalazine

In patients with inflammatory bowel disease using a maintenance dose of sulfasalazine (SASP), compliance to therapy was studied by measuring serum sulfapyridine (SP) levels. Serum SP levels were determined in 51 patients both during hospitalization and at outpatient follow-up 1-6 months later. In 21 patients (41.2%) the serum SP level was considerably lower at outpatient follow-up than the serum level before discharge. In 21 (12%) of 175 outpatients taking a maintenance dose of SASP, SP in serum was not detectable at all at repeated determination during follow-up. These results indicate that a substantial number of patients on maintenance therapy with SASP do not take the prescribed dose. Drug trials in these patients should therefore incorporate methods of detecting defaulters.

Effect of sulphapyridine, 5-aminosalicylic acid, and placebo in patients with idiopathic proctitis: a study to determine the active therapeutic moiety of sulphasalazine

Suppositories of sulphapyridine, 5-aminosalicylic acid, and placebo were used in 45 patients with idiopathic proctitis to determine the active part of sulphasalazine. Each patient used one of the suppositories twice daily for four weeks in a double-blind controlled trial. Complete clinical remission with normal rectal mucosa on sigmoidoscopy occurred in 60% of patients given 5-aminosalicylic acid, but in only 13% and 27% of those given sulphapyridine and placebo respectively. Twelve patients were included twice. In eight of these patients 5-aminosalicylic acid was given one time and sulphapyridine (two patients) or placebo (six patients) another time. Clinical remission occurred in each patient with 5-aminosalicylic acid, but in only one patient during other therapy. The results suggest that 5-aminosalicylic acid is the active therapeutic moiety of sulphasalazine.

An index of inflammatory activity in patients with Crohn's disease

An objective and quantitative standard of inflammatory activity for patients with Crohn's disease was developed. This Activity Index (AI) was derived from data of 63 patients with Crohn's disease who had been submitted to a total of 85 clinical examinations. On the basis of 18 predictor variables three physicians gave an overall evaluation of the severity of inflammatory activity in each patient. Stepwise multiple regression analysis was used to investigate which combination of variables contributed most to the overall evaluation. The combination of the following nine variables gave a very good correlation (r = 0.95) with the overall evaluation: serum albumin, ESR, body weight related to length, abdominal mass, sex, temperature, stool consistency, bowel resection, and extraintestinal symptoms related to Crohn's disease. This combination of variables expressed in a score that was used as an activity index proved to be very useful in the assessment of disease activity and of the effect of therapy. Index values below 100 are associated with inactive disease, values between 100 and 150 can be regarded as indicating slight inflammatory activity, values between 150 and 210 as indicating moderate, and values above 210 as indicating severe-to-very-severe inflammatory activity.

Influence of intestinal transit time on azo-reduction of salicylazosulphapyridine (Salazopyrin)

During a normal and an accelerated intestinal transit, in seven healthy volunteers, the recoveries of salicylazosulphapyridine (SASP) and its split products sulphapyridine (SP) and 5-aminosalicylic acid (5-ASA) were determined in urine and faeces. The azo-reduction of SASP and consequently the recovery of 5-ASA in the faeces was found to be substantially decreased during an accelerated intestinal transit. In addition, in 18 patients with inflammatory disease of the colon during maintenance therapy of SASP it could be demonstrated that the serum SP levels were related to the diarrhoeal state and did not correlate with disease activity. As recent studies have reported that 5-ASA is possibly the active therapeutic moiety of SASP, the ineffectiveness of SASP therapy in patients with active colitis may be ascribed to the reduced azo reduction of SASP as the result of profuse diarrhoea.

Hemolysis during salicylazosulfapyridine therapy

In 36 unselected patients with ulcerative colitis or Crohn's disease taking 4.5-6 gm. salicylazosulfapyridine per day the incidence of hemolysis and its relation to the serum level of salicylazosulfapyridine (Salazopyrin, Azulfidline, SASP), free sulfapyridine (SP) and acetyl sulfapyridine (ac-SP) was investigated. In 19 patients hemolysis was present. Serum levels of free SP were significantly higher in these patients (P less than 0.001). All patients with a serum SP level higher than 37 microgram./ml. had hemolysis as compared to only four of 21 patients with a serum SP level below 37 microgram./ml. Four patients had evidence of hemolytic anemia. In these patients the serum SP level was higher than 55 microgram./ml. Eighteen of the 19 patients with hemolysis were slow acetylators while six of the 17 patients without hemolysis belonged to the slow acetylator phenotype.