Publications by authors named "Landolt M"

Thirty-six normal subjects had to add two numbers ranging from 3 to 9 which were presented tachistoscopically. The two numbers were displayed either unilaterally to the left or right visual field, or bilaterally with one number to the left and one to the right visual field. They were represented as two word names, two dot clusters, or two bargraphs, or the two numbers were represented inconsistently in two different of these representations.

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Major advantages of the use of aquatic animals, such as trout, English sole, or sea urchins, for studying the mechanisms of reproductive toxicology are discussed. The remarkable synchrony of differentiation of gametes in large quantities for detailed morphologic and biochemical measurements enables research not readily done on mammalian nonseasonal breeders. Structural differences such as the absence of a fibrous sheath in the more simple structure of fish and sea urchin sperm flagella facilitates comparative study of the mechanism of action of microtubules in flagella movement and the coupling of mitochondrial energy production to microtubules movement.

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The genotoxicity of environmental contaminants and test compounds to aquatic and marine fish has primarily been assessed by in vivo techniques that require sacrifice of the test organism for analysis. The major objective of this research was to develop an in vitro sister chromatid exchange (SCE) assay which would utilize cultured peripheral blood leukocytes (PBLs) of a coldwater marine fish species. Use of PBLs in cytogenetic genotoxicity tests has several advantages, the major one being that the experimental fish need not be sacrificed for sample collection.

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Vertebrate fibroblasts grown in vitro and exposed to various concentrations of the mutagen/carcinogen benzo(a)pyrene (B(a)P) internalized the compound and recrystallized it in lysosomes by 6-18 h postexposure. This phenomenon occurred when B(a)P at or above 10 micrograms/ml was introduced to the culture medium in a solvent such as DMSO or acetone but not when introduced dissolved in serum. Likewise, high fetal bovine serum concentrations in the culture medium (greater than 20%) as well as human serum (10%) inhibited crystal formation, presumably owing to lipid competition for the compound.

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The ontogenetic effects of the environmental carcinogen benzo(a)pyrene (BAP) on three species of larval flatfish were investigated using concentrations (from 0.10 to 4.2 ppb) which were comparable to levels found in polluted harbors.

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Rainbow trout gonad cells (RTG-2) were cultured for various lengths of time in the presence of several classes of known mutagenic chemicals and several related compounds that possessed no known mutagenic/carcinogenic activity. During the course of exposure the cells were examined for the presence of abnormalities in the chromosome arrangement of anaphase figures during mitosis. Untreated and solvent-treated (dimethylsulfoxide-treated) cells exhibited a background abnormality rate of 12% with only minor chromosomal defects being observed.

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Fibroblast cells derived from juvenile bluegill sunfish were tested for their response the effects of known mutagens/carcinogens. The cells grew well and cloned in Eagle's minimal essential medium which contained fetal bovine serum. Growth rate was temperature dependent and increased steadily as temperature was raised from 15 to 33 degrees C.

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Accumulation of benzo[a]pyrene (BaP) by sexually mature flatfish gonad, its transfer to developing gametes, and its subsequent effects on developing embryos were studied. Thin-layer chromatography revealed both unmetabolized BaP and polar metabolites in the ovary, wolffian ducts, oocytes, and semen of English sole 24 h after ip injection with 200 microCi [3H]BaP. Concentrations of BaP and its metabolites were 3-11 times higher in oocytes and semen than in gonadal tissue.

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A double-blind crossover study in seven patients with glaucoma and obstructive lung disease revealed a considerable and significant bronchoconstrictive side effect on topically administered timolol maleat. Comparative treatment of these patients with an ophthalmic solution containing 3% carbachol did not yield a statistically significant bronchial reaction. However, the observation of serious lung function impairment in three patients suggests that carbachol is not a safe alternative for the treatment of glaucoma in patients with obstructive lung disease.

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A double blind controlled study on prophylaxis of postoperative gastrointestinal bleeding from stress lesions was performed. Both tragant sulfate, a pepsin inhibitor, and deglycyrrhizinized liquorice extract proved to be without prophylactic effect.

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Among 5776 patients operated on under general anaesthesia there was an increased risk of postoperative gastro-intestinal bleeding from stress lesions among those aged over 70 years, after major surgery, or with complications such as hypovolaemia, septicaemia or respiratory failure (n = 551). In this group of patients the incidence of fatal haemorrhage was 0.5%.

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In 90 patients with known extra-hepatic malignancy the liver was examined for metastases. The diagnostic value of clinical information, blood examinations, 99mTc scintiscan, and laparoscopy for the diagnosis of the liver metastases was evaluated. Clinical data (age, sex, time since onset of symptoms and localisation of primary tumor) are of no diagnostic value.

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Several wild species of birds, including starlings (Sturnus vulgaris), house sparrows (Passer domesticus) and pigeons (Columba livia) gained access to an aviary housing Rothchild's mynahs (Leucospar rothchildii) and over 100 additional birds representing a variety of species. Six of approximately 15 mynahs became infected with avian pox and all of them died. None of the other birds in the aviary developed lesions.

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Manometric, pH-metric, radiological and histological examinations were performed in 15 of 18 consecutive patients with gastro-esophageal reflux before and after fundoplication. In 13 of these 15 patients, reflux symptoms largely or completely disappeared after the operation. In the successfully operated patients, the reflux provocation test markedly improved but lower esophageal sphincter pressure did not rise.

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