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.

Maintenance treatment with H2 receptor antagonists for duodenal ulcer disease: toward a rational use

Duodenal ulcer disease is a heterogenous condition characterized by episodes of recurrence and remission. Recurrences are often painful and may result in gross duodenal scarring and pyloric stenosis; bleeding and perforation can complicate the disease, requiring operative treatment and increasing mortality. Treatment should therefore maintain remission after ulcer healing, prevent possibly lethal complications, be safe and maintain efficacy over time. Maintenance treatment with H2 receptor antagonists reduces the rate of symptomatic relapse, but there is no evidence that it affects the complication rate. Tolerance develops in a subgroup of patients and seems to contribute to their poor response to long-term H2 antagonist therapy. It seems wise to prescribe maintenance treatment for 3 years following initial healing in patients with severe relapsing disease, or smokers with recurrent symptoms, and to continue it for life in selected individuals at increased risk of acute complications or of complication-related mortality.

Report of Balanorchis anastrophus in Pará State with surface topography by scanning electron microscopy

Balanorchis anastrophus Fischoeder, 1901, from the reticulum of Bos taurus is reported for the first time in the State of Pará, Brazil. The surface topography as revealed by scanning electron microscopy is presented.

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.

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.

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.

[Comparative study of helminth parasites of fishes from the Mogi Guassu river, collected during expeditions between 1927 and 1985]

This paper concerns the parasitism of Nematoda, Trematoda, Acanthocephala and Cestoda from 1027 fishes of 45 species from Mogi Guassu river, examined in the years 1927, 1946, 1947, 1962, 1983 and 1985 as a contribution to the knowledge of the parasitological fauna in 58 years. Thirty two species of nematodes, 21 of trematodes, 3 of acanthocephalans and 2 of cestodes are reported. New hosts are presented for the nematodes Cucullanus pinnai, Spirocamallanus inopinatus and Travnema travnema, for the trematode Pararhipidocotyle jeffersoni and for the acanthocephalan Gorytocephalus spectabilis. New measurements for the trematode Creptotrema lynchy, tables, graphics and a list of the examined hosts with their parasites are presented.

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.

Use of chicken and rabbit antibodies in a solid phase protein A radioimmunossay for virus detection

A new rapid indirect solid phase radioimmunoassay was developed for the detection of Sindbis virus. Chicken antibodies were adsorbed onto wells in microplates to serve as 'capture antibodies' and rabbit antibodies were used as the second antibody. 125I-labelled protein A that does not bind to chicken antibodies, but binds firmly to rabbit antibodies was used as the tracer. All the steps necessary for the development of the assay are described. The minimal amount of Sindbis virus detectable was around 3 x 10(5) PFU/ml and the interassay reproducibility was about +/- 30%.

Helminths parasites of freshwater fishes from Pirassununga, SP, Brazil

Twelve species of parasitic helminths, seven trematodes, four nematodes and one acanthocephalan are reported from various hosts. Creptotrema lynchi, a parasite from Bufo marinus in Colombia, is described for the first time in fish and from Brazil, parasitizing two different species. A list of the host species, measurements and figures of most parasites are included with particular reference to the tegument of Bellumcorpus major recovered from a new host. The genus Zonocotyloides Padilha, 1978 is considered a synonym of Zonocotyle and the new combination: Zonocotyle haroltravassosi is proposed to the species Zonocotyloides haroltravassosi Padilha, 1978. The nematodes Cucullanus pinnai and Procamallanus (Spirocamallanus) inopinatus and the trematode Pararhipidocotyle jeffersoni are reported in new hosts. The description of the acanthocephalan Neoechinorhynchus curemais (new locality record) is supplemented. Other parasites recovered include the nematodes Travnema travnema (new locality record), Rondonia rondoni and the digenetic trematodes Cladocystis intestinalis, Pseudosellacotyla lutzi (new locality record), Teratotrema sp. and Zonocotyle bicaecata.

Gastric acid and pancreatic polypeptide responses to modified sham feeding: indication of an increased basal vagal tone in a subgroup of duodenal ulcer patients

The effect of sham feeding upon gastric acid secretion and pancreatic polypeptide release was investigated in 28 patients with duodenal ulcer in order to evaluate whether high basal vagal activity is the cause of basal acid hypersecretion in patients with duodenal ulcer and basal secretion higher than 30% of their peak acid output. The patients were divided into two groups based on the ratio of basal/pentagastrin stimulated peak acid output (BAO/PAO) was higher or lower than 0.30: group A n = 19 (BAO/PAO less than or equal to 0.30) and group B n = 9 (BAO/PAO greater than 0.30). Gastric acid response to sham feeding (SAO) was significantly higher than basal level in group A (SAO: 11.4 mEq/h (2.5-20.1) vs BAO: 5.2 mEq/h (0.8-22.9), p less than 0.01, median (range)) while in group B the acid secretion did not increase with sham feeding (SAO: 9.6 mEq/h (4.5-13.6) vs BAO: 8.8 mEq/h (6.3-13.8) ns, median (range)). A negative correlation (r= -0.6118226, p less than 0.01) was found between acid increase expressed as basal subtracted sham feeding response (SAO-BAO) and BAO/PAO ratio of the entire group of duodenal ulcer patients (n = 28) suggesting that the greater is basal acid secretory capacity the smaller is acid increase in response to residual vagal activation. Pancreatic polypeptide response to sham feeding was higher in group A than in group B but no correlation (r = 0.20, n = 28) nor individual covariation was found between acid and pancreatic polypeptide secretions during vagal stimulation. sham feeding did not change serum gastrin. It is concluded that an increased vagal stimulation seems to be the cause of basal hypersecretion in a subgroup of patients with duodenal ulcer. The lact of correlation between the pancreatic polypeptide and acid responses to vagal stimulation interferes with the reliability of pancreatic polypeptide as indicator of vagal tone on gastric parietal cells.