[Urban density and psychosis - does living in a city cause schizophrenia?]. / Densité urbaine et psychose - est-ce que vivre en ville rend schizophrène ?

While it has often been stated that prevalence of schizophrenia is the same around the world, many publications have shown this illness is twice more frequent in urban areas. Although many hypotheses have been proposed, the mechanisms explaining this phenomenon are still unknown. Besides potential biological explanations, a certain number of hypotheses emerging from social sciences have recently enriched the debate. This article reviews the literature related to this issue and describes the development of a research projects conducted in collaboration between the Institut of Geography at the University of Neuchâtel, the Department of Psychiatry at the Lausanne University and the Swiss branch of ISPS, a society promoting the psychological treatment of schizophrenia and other psychoses.

Smell or taste disturbances, neurological symptoms, and hydrocarbon exposure.

A total of 264 workers participated in a cross-sectional study concerning the toxicity of hydrocarbons. The clinical examination shows an increased prevalence of smell and/or taste disturbances in the heavily exposed group. These symptoms appear to be generally transitory and reversible. They seem to be due to concentration peaks rather than to a long exposure duration. They are associated with acute depressor effects and not with symptoms which could belong to a hydrocarbon-induced chronic toxic encephalopathy.

Musculoskeletal and skin disorders in a population of floor-layers.

In the frame of a study on hydrocarbon-induced toxic effects, the knee morbidity and the prevalence of work-related arthralgias, gonalgias, myalgias and skin anomalies were investigated in a group a floor-layers. The results show that a previous history of knee morbidity is distinctly higher in floor-layers and that these workers have a higher prevalence of musculoskeletal and cutaneous disturbances than the comparison group. Owing to the fairly high prevalence of these troubles, it seems that this pathology deserves more attention and that more efficient preventive measures are indicated.

Relation between renal function tests and a retrospective organic solvent exposure score.

In case-control studies on glomerulonephritis and organic solvents several authors have assessed exposure to organic solvents with a score based on the self reported occupational history. The underlying principle is that all exposures can be weighted by an intensity factor and then added to get one number representative of lifetime exposure. As this score has hitherto not been validated the relation between this exposure score and kidney function tests in a population of workers with past or present exposure to organic solvents was examined. The results suggest that such relations do exist for the N-acetyl-beta-D-glucosaminidase (NAG) activity, erythrocyturia, and, perhaps, albuminuria but not for the protein creatinine ratio or for leucocyturia.

Beta-zeacarotene of the bovine ovary.

An investigation of the carotenoids from a bovine ovary extract has revealed the presence of three Porter-Lincoln pathway intermediates of which beta-zeacarotene is previously unreported. Analysis using spectrophotometric and chemical tests reveals beta-zeacarotene (2.14 micrograms/g), alpha-carotene (0.11 microgram/g), and beta-carotene (27 and 35 micrograms/g).