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Biomedical subjects

F Levy

Publications and source records attributed to F Levy.

At least 73 records · Page 4Linked to original sources

Establishment of maternal bonding and its mediation by vaginocervical stimulation in goats.

To investigate the establishment of offspring recognition in mother goats, 11 females were subjected to two successive 5-min tests with their own kid and an alien, 2 h 30 min postpartum. All mothers accepted their own kid, while nine rejected the alien. This suggests that in goats, 2.5 h are sufficient for the development of an exclusive bond with the kid. We also studied the role of physiological factors mediating maternal bonding in this species. Eight of the nine goats that rejected alien kids were, therefore, submitted to 5 min of vaginocervical stimulation (VCS) immediately following the selectivity tests. Of these eight goats, five changed their behavior after VCS and accepted the alien kid (0/8 before VCS vs. 5/8 after VCS, p = 0.031). Thus, VCS appears to reduce rejection behavior towards alien kids while resulting in a significant increase in their rate of acceptance. Underlying physiological mechanisms by which VCS may act are discussed.

Animals↗

Neural networks and psychiatry: candidate applications in clinical decision making.

Neural networks comprise a fundamentally new type of computer system inspired by the functioning of neurons in the brain. Such networks are good at solving problems that involve pattern recognition and categorisation. An important difference between a neural network and a traditional computer system is that in developing an application, a neural network is not programmed; instead, it is trained to solve a particular type of problem. This ability to learn to solve a problem makes neural networks adaptable to solving a wide variety of problems, some of which have proved intractable using a traditional computing approach. Neural networks are particularly suited to tasks involving the categorisation of patterns of information, such as is required in diagnosis and clinical decision making. In the last three years reports of applications involving neural networks have begun to appear in the medical literature, and these are described in this paper. However, a comprehensive search of the literature has shown that there have not as yet been reports of any applications in psychiatry. This paper discusses the nature of clinical decision making, outlines the sorts of problems in psychiatry which neural networks applications might be developed to address, and gives examples of candidate applications in clinical decision making.

Adult↗

Occupational irritant contact dermatitis and fungal infection in construction workers.

We have examined 6 construction workers who developed chronic skin diseases on their hands over a period of 15 years (1970-1985). 4 developed a Trichophyton rubrum infection, and the other 2 an irritant contact dermatitis. All of them carried out jobs which caused traumatization of the skin, due to the presence of ethylene glycol and mineral oils during operation of pneumatic hammers in winter. They also suffered other types of skin trauma during their work. Construction workers may be at risk of developing an occupational skin disease involving fungal infection.

Chronic Disease↗

Medico-legal investigations of the Airbus, A320 crash upon Mount Ste-Odile, France.

The authors present the medico-legal investigations and identification after the aircrash of the Airbus A320 upon the Mount Sainte-Odile (France). The identification team comprising investigators from the gendarmerie, forensic pathologists, odontologists, and scientists of the Institute from Legal Medecine rapidly retrieved and identified 85 of the 87 victims, with 17 being identified through DNA typing, three through fingerprints and the remaining through dental records and specific physical or X-ray findings. Full autopsies were performed on all fatalities to determine patterns of injury and cause of death. Results lead us to point out the importance of a multidisciplinary team of forensic practitioners especially trained for managing medico-legal investigation in mass disaster and the ability of DNA technology to solve complex identification problems.

Accidents, Aviation↗

[Allergic reactions of the respiratory tract].

Allergic rhinoconjunctivitis and allergic asthma bronchiale are immunologically mediated diseases of the respiratory tract. Dependent on the allergen, they occur seasonally or perennially. Allergens can cause a specific reaction of the immune system, mediated by IgE-antibodies in individuals with a genetic predisposition. Different mediators are released from mast cells, and complex immunopathological mechanisms lead to inflammatory changes of the mucosa. A significant increase of allergies has been observed in the last decades. Indoor and outdoor allergens can be differentiated. Mites and animal dander are the most important indoor allergens. The pollens of birch, alder, hazel, different grasses and mugwort are the most important outdoor allergens. For diagnostic purposes skin tests, laboratory analyses and provocation tests are used. The best therapy is elimination of the offending allergen. As pharmacological agents histamine-receptor antagonists, topical corticosteroids and topical cromoglycate are currently used. Immune therapy is the most specific form of treatment.

Allergens↗

Serum IgG antibodies to mold spores in two Norwegian sawmill populations: relationship to respiratory and other work-related symptoms.

Wood trimmers and planing operators from two separate sawmill populations (N = 303 and 170) were studied by serology assessment and a self-administered questionnaire. IgG antibodies to Rhizopus microsporus ssp. rhizopodiformis, Paecilomyces variotii, and Aspergillus fumigatus were measured by ELISA. The questionnaire included questions about general respiratory symptoms and symptoms after handling moldy timber. Personal exposure of wood trimmers to mold spores and wood dust was measured in one part of the sawmills. R. microsporus was the most prevalent mold assessed by serology. Antibody levels were higher and symptoms suggestive of mucous membrane irritation, chronic nonspecific lung disease, allergic alveolitis, and organic dust toxic syndrome were more frequently reported by wood trimmers than by planing operators. The mean level of IgG antibodies to R. microsporus in sawmill workers working in the same work area was the best predictor of symptoms in both populations. The consistent results indicate that exposure to spores of R. microsporus may cause several respiratory symptoms in wood trimmers.

Adult↗

The cerebrovascular effects of physostigmine are not mediated through the substantia innominata.

This study sought to determine whether the cortical cholinergic projections from Meynert's nucleus are actually the target of the cholinesterase inhibitor physostigmine, which presents the ability to increase cortical blood flow. To this aim, the multiregional cerebrovascular effects of physostigmine in rats with and without lesion of the substantia innominata (SI), the equivalent of Meynert's nucleus of primates, were investigated. Unilateral SI lesions were made using ibotenic acid in three groups of rats. Four to 11 days later, the cortical choline acetyltransferase (ChAT) activity was measured in one group to assess the efficacy of the lesion. In the two other groups, the regional cerebral blood flow was measured using the [14C]iodoantipyrine technique, under physostigmine (0.2 mg/kg/h iv) or control conditions. SI lesion induced 27-59% fall in cortical ChAT activity in the ipsilateral hemisphere with the frontal area most affected. Despite these large biochemical differences, the lesion had little cerebrovascular effects. Side-to-side blood flow differences did not exceed 11% and did not strictly overlap the ChAT depletion. Physostigmine increased flow (38-66%) in all cortical areas, with no frontal predominance. Despite these considerable vasodilations, there were no significant differences between the lesioned and the intact hemisphere, nor any significant interaction between physostigmine and SI lesion. Thus, physostigmine does not actually activate the SI neuron terminals. This result suggests that cholinesterase inhibitors cannot be used as presynaptic markers of the cholinergic activity of this nucleus and casts doubts on their specificity as enhancement therapeutic agents in Alzheimer's disease.

Animals↗

Side effects of stimulant use.

The current literature on side effects of central nervous system (CNS) stimulant medications used in the treatment of attention deficit hyperactivity disorder (ADHD) is reviewed, with particular emphasis on dose-response effects on differing behavioural systems. The reasons for variation in findings may lie in individual differences in children, or in differing responses of target behavioural systems. These may be understood in terms of underlying pharmacological mechanisms. Social, educational and philosophical issues relating to medication use are discussed, and the need for ongoing critical clinical and research approaches, rather than polarization of professional attitudes, is emphasized.

Attention Deficit Disorder with Hyperactivity↗