Randomised clinical trial: mesalazine versus placebo in the prevention of diverticulitis recurrence.

BACKGROUND: Previous studies have reached conflicting conclusions regarding the efficacy of mesalazine in the prevention of recurrent diverticulitis. AIM: To investigate the efficacy and safety of mesalazine granules in the prevention of recurrence of diverticulitis after acute uncomplicated diverticulitis. METHODS: Two phase 3, randomised, placebo-controlled, double-blind multicentre trials (SAG-37 and SAG-51) investigated mesalazine granules in patients with prior episodes (<6 months) of uncomplicated left-sided diverticulitis. Patients were randomised to receive either 3 g mesalazine once daily or placebo (SAG-37, n=345) or to receive either 1.5 g mesalazine once daily, 3 g once daily or placebo for 96 weeks (SAG-51, n=330). The primary endpoint was the proportion of recurrence-free patients during 48 weeks (SAG-37 and SAG-51) or 96 weeks (SAG-51) of treatment. RESULTS: Mesalazine did not increase the proportion of recurrence-free patients over 48 or 96 weeks compared to placebo. In SAG-37, the proportion of recurrence-free patients during 48 weeks was 67.9% with mesalazine and 74.4% with placebo (P=.226). In SAG-51, the proportion of recurrence-free patients over 48 weeks was 46.0% with 1.5 g mesalazine, 52.0% with 3 g mesalazine and 58.0% with placebo (P=.860 for 3 g mesalazine vs placebo) and over 96 weeks 6.9%, 9.8% and 23.1% respectively (P=.980 for 3 g mesalazine vs placebo). Patients with only one diverticulitis episode in the year prior to study entry had a lower recurrence risk compared to >1 episode. Safety data revealed no new adverse events. CONCLUSION: Mesalazine was not superior to placebo in preventing recurrence of diverticulitis.

Synthesis and anti-HIV-1 activity of 4,5,6,7-tetrahydro-5-methylimidazo [4,5,1-jk][1,4]benzodiazepin-2(1H)-one (TIBO) derivatives. 3.

4,5,6,7-Tetrahydro-5-methylimidazo[4,5,1-jk][1,4]benzodiazepin-2 (1H)-ones (TIBO), 1, have been shown to significantly inhibit HIV-1 replication in vitro by interfering with the virus's reverse transcriptase enzyme. They have also demonstrated potential clinical efficacy in combating HIV-1, on the basis of a preliminary study. Our prior publications have discussed the discovery of this series of compounds and reported some preliminary chemical and biological studies around N-6 substitutions and 5-membered ring variations of 1. This manuscript describes our synthetic endeavors around 4, 5, and 7 mono- and disubstitutions of 1 and discusses related HIV-1 inhibitory structure-activity relationships. On the basis of inhibition of HIV-1's cytopathic effects in MT-4 cells, we found that 5-mono-Me-substituted analogues, the original substitution in the early lead compounds, and 7-mono-Me-substituted analogues of 1 were comparable as being consistently the most active compounds. Although generally less active, the 4,5,7-unsubstituted, 4-mono-substituted, cis- and trans-5,7-di-Me-substituted, and cis-4,5-di-Me-substituted analogues of 1 also exhibited some significant desired activity. The remaining trans-4,5-di-Me-substituted, cis- and trans-4,7-di-Me-substituted, and all 4,5-, 5,6-, 6,7-, and 7,8-fused disubstituted analogues of 1 possessed no noticeable desired activity.

Inhibition of leukotriene and thromboxane biosynthesis by a 9-(4-chlorophenyl) analogue of arachidonic acid.

The synthesis of 9-(4-chlorophenyl)-7,7-dimethyl-5(Z), 8-nonadienoic acid (7) and its methyl ester 6, and their effects on arachidonic acid metabolism in vitro are described. The IC50 values of 19.6 and 20.6 microM were observed for inhibition of leukotriene synthesis in human granulocytes for 6 and 7, respectively. Additionally, the compounds inhibited thromboxane B2 (TxB2) synthesis, with respective IC50 values of 6.1 and 20 microM, while producing pronounced 3-8-fold increases in PGE2 synthesis in human mononuclear cells. Increased PGE2 synthesis may have reflected shunting of free arachidonic acid substrate at the thromboxane synthetase and endoperoxide E isomerase branchpoint of arachidonic acid metabolism.

Resolution of (+/-)-2-tetradecyloxiranecarboxylic acid. Absolute configuration and chiral synthesis of the hypoglycemic R enantiomer and biological activity of enantiomers.

The resolution of the hypoglycemic agent (+/-)-2-tetradecyloxiranecarboxylic acid (3) as its d- and l-ephedrine salts is presented. The active enantiomer (R)-(+)-3 was also synthesized by the Sharpless chiral epoxidation procedure and its methyl ester (R)-(+)-4 was shown to be identical with the corresponding ester from the resolved acid. Single-crystal X-ray structure analysis of the diastereomeric salt of (+)-3 and (-)-ephedrine allowed assignment of (+)-3 as the R configuration. The effects on fatty acid oxidation and glucose tolerance of the racemic and enantiomeric forms of 3, 4, and the CoA ester of 3 are presented. A postulated mechanism of action for the active enantiomer as an enantioselective, active-site-directed, irreversible inhibitor of carnitine palmitoyl transferase is suggested.

Alkylglycidic acids: potential new hypoglycemic agents.

A series of alkylglycidic acid analogues and derivatives were synthesized and tested for their ability to inhibit long-chain fatty acid oxidation in vitro and to lower blood sugar in rats. The extent of inhibition of carnitine acyl transferase, the enzyme at the mitochondrial membrane necessary to transport long-chain fatty acids into the mitochondria for subsequent beta-oxidation, was determined for the series. Structure-activity relationships using in vitro inhibition of [1-14C]palmitic acid oxidation in rat hemidiaphragm muscle indicate that potent activity resides mainly in 2-alkyl (C12-C16) glycidates. Replacement of the oxirane ring with cyclopropyl, thiirane, or other rings diminishes activity, as does substitution of the glycidate ring at the 3-position. In vivo potency in the rat glucose tolerance test roughly parallels the hemidiaphragm results. The lead compound, methyl 2-tetradecylglycidate (8), is a potent hypoglycemic agent following oral administration to several animal species. The hypoglycemic analogues interfere with fatty acid oxidation by specific and irreversible inhibition of mitochondrial carnitine palmitoyl transferase-A.

Diagnostic performance of enzymes in the discrimination of myocardial infarction.

We apply rigorous statistical methods to assess the diagnostic value of creatine kinase, creatine kinase-MB, aspartate aminotransferase, lactate dehydrogenase, and alpha-hydroxybutyrate dehydrogenase in realistic circumstances. The trade-off between false positives and false negatives obtained with various decision rules is examined with the receiver-operator characteristic function and with discriminant analysis. During the three days after an infarction, lactate and alpha-hydroxybutyrate dehydrogenase can provide diagnostic thresholds of constant sensitivity and specificity. By contrast, sensitivity progressively decays for creatine kinase, creatine kinase-MB, and aspartate aminotransferase. The diagnostic uncertainty introduced by the infarction's varying age at hospitalization is evaluated by subjecting the mixed patient population to discriminant analysis. For some enzymes, repeating the same assay on the second day contributes to sensitivity, while adding a different assay on the first day enhances specificity. The effects of lower or higher infarction prevalences on sensitivity and specificity are most favorable when creatine kinase-MB is combined with lactate or alpha-hydroxybutyrate dehydrogenase. Adding a third assay is ineffective. The further differentiation according to infarction stage produces only 81% correct classifications, even when five different assays are used on two consecutive days. As a general strategy, we recommend the assay of two enzymes on two consecutive days.

Gas-liquid chromatography of undervatized drugs after chromatographic extraction from blood.

We have developed an integrated method that overcomes the two main procedural difficulties of gas-liquid chromatography, namely, solvent-solvent extraction and chemical derivatization. Drugs are extracted from serum by column chromatography on granular diatomaceous earth (kieselguhr). Subsequent gas-liquid chromatography of underivatized samples can be performed on either of two liquid phases. A mixed liquid phase, used for quantitative gas-chromatographic assay on patients with a known therapeutic regimen, has enabled quantitation of 12 drugs in serum. Alternatively, a single liquid phase, used with the mixed liquid phase, permits the gas-chromatographic identification of unknown drugs on the basis of the characteristic pattern of the two relative retention times; by this approach more than 40 drugs have been identified in cases of suspected intoxication, both in serum and in gastric aspirate. Besides providing ease of performance and wide applicability, the proposed procedure offers a degree of precision and accuracy that compares favorably with established methods.

Aids to the evaluation of diagnostic performance, as applied to immunological creatine kinase-MB assay in myocardial infarction.

Immunoassay of creatine kinase-MB provides numerical information, which makes it possible to estimate quantitatively the diagnostic performance following myocardial infarction. Two graphical methods for such an evaluation are presented. The relationship between technical sensitivity and specificity was analyzed using a continuous function, the receiver-operator characteristic curve. Using this function, a diagnostic threshold ("upper normal limit") was chosen, which balances both technical specificity and sensitivity on the first day following infarction. On the second and third days this threshold caused a progressive loss of technical sensitivity. The relationship between effectiveness and the prevalence of myocardial infarction in the tested population was evaluated with a nomogram correlating these two quantities. With the chosen diagnostic threshold, effectiveness is independent of prevalence on the first day, but the loss in technical sensitivity on subsequent days causes effectiveness to decay when the prevalence is high.

Immobilized enzymes in continuous-flow analysis.

Glucose oxidase, uricase, and urease were immobilized on the interior surface of activated polyamide tubing. The shelf-life of such enzyme bearing tubes was at least six months. The tubes were used for continuous-flow analysis of glucose, uric acid, and urea with conventional systems and with hybrid micro-scale systems in which modules of different manufacture were combined. The length of enzyme-bearing tube required for each system was ascertained empirically. Each tube could be used for several thousand assays, but glucose oxidase-bearing tubes were more stable than urease- or uricase-bearing tubes. Results for patients' samples correlated well with results obtained by accepted methods.

Pharmacologic profile of methyl 2-tetradecylglycidate (McN-3716)--an orally effective hypoglycemic agent.

A specific inhibitor of fatty acid oxidation, methyl 2-tetradecylglycidate (McN-3716) has been found to produce a dose dependent hypoglycemic effect when administered orally to rats, mice, and dogs. In addition to being more potent than other inhibitors of fatty acid oxidation, McN-3716 was also found to be 15--20 times more potent than tolbutamide in lowering the blood glucose of fasting rats. Furthermore, evidence is presented that McN-3716 produces hypoglycemia by a mechanism which differs from that of other oral hypoglycemic agents, the biguanides and the sulfonylureas. As predicted by the Randle glucose-fatty acid cycle, McN-3716 lowered glucose concentrations only under conditions where fatty acids were being used as the major energy substrates (fasting, diabetes, and feeding of high fat diets) but not under conditions where energy was derived mainly from carbohydrate (fed state or following hypophysectomy). Administration of McN-3716 produced a remarkable lowering of the plasma glucose and the glycosuria of depancreatized dogs but did not result in complete normalization of glucose, especially the excursions of blood glucose following feeding. It did, however, produce virtually complete reversal of the ketoacidosis of alloxan diabetic rats and depancreatized dogs without worsening the plasma lipid profile. Thus, McN-3716 may have potential utility as an oral therapeutic agent for the treatment of ketosis-prone juvenile or maturity-onset diabetes.