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Biomedical subjects

A Kohn

Publications and source records attributed to A Kohn.

At least 55 records · Page 3Linked to original sources

Antimycobacterial therapy in Crohn's disease: results of a controlled, double-blind trial with a multiple antibiotic regimen.

UNLABELLED: Several recent reports have suggested an association of atypical mycobacteria with Crohn's disease. OBJECTIVES: The goal of this double-blind, placebo-controlled trial was to determine the efficacy of treatment with antimycobacterial drugs in maintaining clinical remission and in reducing active inflammatory lesions. METHODS: Forty patients (15 male) with refractory, steroid-dependent Crohn's disease were randomized to receive 2 months of tapering steroids plus either a 9-month regimen of ethambutol, clofazimine, dapsone and 1-day dose only of rifampicin (n = 22), or identical placebo. RESULTS: Three patients (two on active drug) were unable to discontinue steroids, and one patient on active drug was withdrawn for side effects during the first 2 months. Three of the remaining 19 patients on active drug relapsed during the study period, compared with 11 of 17 on placebo (log likelihood ratio = 4.6; p = 0.03). Another patient was withdrawn in remission at 5 months for anemia related to dapsone. Nine patients whose disease relapsed or persisted on placebo were crossed over to active drug; five achieved sustained remission, two failed, and two were withdrawn for side effects. Substantial endoscopic or radiologic healing did not occur. CONCLUSION: This study suggests that the treatment regimen with rifampicin, ethambutol, clofazimine, and dapsone is effective in relief of symptoms and maintenance of remission in some Crohn's disease patients.

Adult↗

Problems and conflicts in peer review.

The process of refereeing of scientific papers is essential in the course of their evaluation and selection for publication in a journal. Scientists who voluntarily and selflessly serve as referees may encounter situations which put them in conflict of interest. This review considers and analyses such conflicts.

Conflict of Interest↗

Reversible sustained increase of gastrin and gastric acid secretion in a subgroup of duodenal ulcer patients on long-term treatment with H2 antagonists.

We assessed the effect of long-lasting inhibition of gastric acid secretion on basal and meal-stimulated serum gastrin and gastric acid secretion in 37 patients on long-term maintenance treatment with H2 antagonists for severe relapsing and/or complicated duodenal ulcer disease. After a mean of 142 weeks (range, 28-324 weeks) of continuous treatment, gastric acid secretion, basal plasma gastrin, and gastrin response to a test meal were evaluated. All tests were performed a week after drug discontinuation to exclude rapidly reversible hypergastrinemia. Gastrin levels were above the normal range in seven patients (18.9%). After H2 antagonist were stopped for 6 weeks, basal gastrin returned to normal levels in all cases [from a median of 180 (range, 130-350) pg/ml to 58 (25-90) pg/ml] and peak meal-stimulated gastrin significantly decreased from a median of 500 pg/ml to 245 pg/ml (p = 0.02). In patients with hypergastrinemia, the discontinuation of H2 antagonists for 6 weeks led to a significant decrease of gastric acid secretion. Patients who developed hypergastrinemia spent more weeks on full-dose treatment and had more recurrences during therapy. The results of the present investigation demonstrate that a long-lasting inhibition of gastric acid secretion can induce, in a small percentage of patients, a reversible sustained hypergastrinemia and a consequent increase of acid secretion, which conceivably could lead to more frequent relapses of duodenal ulcer disease.

Adolescent↗

Activity of the artemether in experimental schistosomiasis mansoni.

The action of the ether of artemisinin (artemether) on Schistosoma mansoni in mice and hamsters experimentally infected with the LE strain was studied. In mice, the drug showed high schistosomicidal activity using a single intramuscular dose of 100 mg/kg/day. By the oral route, this dose showed a low activity. Mice treated with a single intramuscular dose of 200 mg/kg/day, and examined 15 days after treatment, presented 100% alteration of the oogram; when examined 45 days after treatment, the oogram was normal. With doses of 100 mg/kg/day, i.m., during 3 or 5 consecutive days, the death rate of mice was very high. Morphologic analysis of the worms collected by perfusion of mice treated with a single dose of 100 mg/kg/day, i.m., detected a marked decrease in the length of male and female worms, degenerative alterations in the parenchyma and in the reproductive system of the females, with the reduction of vitellinic material and in ovary volume; the intestinal contents presented a marked despigmentation. In the male worms significant alteration was not apparent by optical microscopy.

Animals↗

First record of Raphidascaris (Sprentascaris) hypostomi (Petter et Cassone, 1984) comb. n. and R. (S.) mahnerti (Petter et Cassone, 1984) comb. n. (Nematoda: Anisakidae) from Brazil with remarks on the taxonomic status of the genus Sprentascaris Petter et Cassone, 1984.

Large numbers of anisakid nematodes identified as Raphidascaris (Sprentascaris) hypostom (Petter et Cassone, 1984) were collected from the stomach and intestine of armoured catfishes P leco stomus albopunctatus, P. commersoni, P. derbyi, and Ancistrus cirrhosus (all representing new host records) from the three water reservoirs, Salto Osório, Salto Santiago and Passo Fundo, in southern Brazil. Another closely related species, R. (S.) mahnerti (Petter et Cassone, 1984), was recorded from the intestine of the armoured catfish Loricaria laticeps of the Paraná River. Since these are the first records of these parasites since their original descriptions, they are briefly redescribed and illustrated. The genus Sprentascaris Petter et Cassone, 1984, in which both these species were originally placed, is now considered only a subgenus of Raphidascaris Railliet et Henry, 1915 and, therefore, all Sprentascaris species are transferred to the latter genus as Raphidascaris (Sprentascaris) mahnerti (Petter et Cassone, 1984) comb. n., R. (S.) pimelodi (Petter et Cassone, 1984) comb. n., and R. (S.) hypostomi (Petter et Cassone, 1984) comb. n.

Animals↗

Detection of genotoxic substances in cancer patients receiving antineoplastic drugs.

A short-term bacterial mutation test, the SOS Chromotest, has been used to detect the excretion in urine of genotoxic metabolites of antineoplastic drugs administered to cancer patients. In this test, the damage to the DNA of the test bacteria is expressed by the production of beta-galactosidase, which can be quantitatively assessed and is proportional to the concentration of the drug. Kinetic curves of excretion for adriamycin, bleomycin, dacarbazine, cis-platinum and vincristine and their mixtures have been constructed from standard curves relating the intensity of the beta-galactosidase response to the concentration of drugs dissolved in normal urine. Comparative data on extraction and concentration of the drugs from urine or serum by means of selective resin or silica columns are presented.

Adenocarcinoma↗

EMC virus infection in baboons as a model for studies on antiviral substances.

EMC virus causes a lethal infection in baboon monkeys within 4-8 days following subcutaneous injection with 10(4)-10(8) pfu of virus. The infection is accompanied by viremia, invasion of heart muscle and of brain. Monkeys infected with 10(6) pfu of EMC virus were treated with human leukocyte interferon. The interferon was injected intramuscularly first 0, 0.5, 6 and 24 h post-infection, then twice daily with a dose of 3 X 10(6) units for 5 consecutive days. All the monkeys treated with interferon remained alive and healthy. Animals infected with EMC virus, but not treated with interferon died within 6 days with evidence of myocarditis. The EMC virus-interferon interaction in baboon monkeys seems to provide a useful primate model system for testing the prophylactic and therapeutic antiviral activity of interferons or other antiviral substances.

Animals↗