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Biomedical subjects

G Morel

Publications and source records attributed to G Morel.

197 records · Page 11Linked to original sources
PubMedDate not supplied

Critical period for styrene ototoxicity in the rat.

The current experiments were undertaken to determine whether or not styrene-induced hearing loss in the rat depends more on the existence of a critical period between 14 and 21 weeks of age than on body weight. For these purposes, two experiments were carried out with mature Long-Evans rats. In the first experiment, two groups of 5-month old rats, but having different body weight (slim: 314 g vs. fat: 415 g) were exposed to 700 ppm styrene for 4 consecutive weeks, 5 days per week, 6 hours per day. In the second experiment, two groups of rats having the same weight: 345 g, but different ages (14- vs. 21- week old) were exposed to styrene in strictly identical experimental conditions. Auditory sensitivity was tested by recording evoked potentials from the inferior colliculus. Surface preparations of the organ of Corti were also performed to complete the investigation. At the end of the six week recovery period following the styrene exposure, a 7 dB permanent threshold shift (PTS) was obtained with the same age animals regardless of the body weight. Consequently, weight was not a major factor in styrene-induced hearing loss. Age was a more critical factor in determining higher sensitivity to styrene. Indeed, the three months old group had 23.5 dB PTS, whereas the five months old group had only a 7.7 dB PTS at 16 kHz. Thus, a 15 dB difference of PTS was obtained between the rats having the same weight but different age. While the weight does not play a major role in styrene ototoxicity, there is a critical period whose duration lasts more than three months and for which the susceptibility to styrene is enhanced.

Age Factors↗
PubMedDate not supplied

[Immunologic comparison between some Wolbachiae and research of antigentic community with other members of the order of Rickettsiales].

The antigenic relationship between some rickettsiae of arthropods, which do not transmit germs pathogenic to vertebrates was investigated by agglutination and immunofluorescence techniques. The comparison of R. melolonthae, R. tipulae, R. cetonidarum, R. grylli and of the rickettsiae of the scorpion Buthus occitanus shows that the Wolbachiae are divided into three serological groups. The insect crystallogen rickettsiae belong to the first group, R. grylli and the scorpion Rickettsia are antigenically distinct (tables I and II). No antigenic relationship was found between these arthropod microorganisms and the following agents of vertebrate rickettsioses and chlamydioses : historical typhus, murine typhus, pustulous fever, Q-fever, epizootic absortion of sheep and psittacosis (tables III and IV). Bacteria of OX2 and OX19 strain of P. vulgaris when mixed with anti-Wolbachiae serums of I, II, III groups, give a negative Weil a Felix reaction. The OXK Proteus are however agglutinated by 4 out of 6 rabbit anti-Rickettsiella serums of the group. This fact calls for a further investigation regarding the comparison of these Rickettsiella with various strains of R. tsutsugamushi.

Antibodies, Bacterial↗
PubMedDate not supplied

[A single-day survey in pharmacies on the consumption of analgesics and antipyretics].

A one day long survey of antalgics and antipyretics consumption was carried out in 6 pharmacies of a middle-size city. It first shows the majority of medical prescription (62.2%) over self medication (29.4%) and over pharmaceutic advice (8.4%) at the drug delivery. Women are the main consumers, especially in the youngest ones (20-40 years old). Paracetamol is the most used drug; in this indication, the search for the less expensive drug seems usual. Drug abuse cannot be demonstrated in this survey; the consumption of this category of drugs appears as important although for a short duration; and most of the time for pain considered as moderate and trivial. The possibility to carry out such surveys and possibly clinical trials in private pharmacies appears as an opportunity.

Adolescent↗
PubMedDate not supplied

Retrospective review at skeletal maturity of the factors affecting the efficacy of Salter's innominate osteotomy in congenital dislocated, subluxed, and dysplastic hips.

This study reviewed at skeletal maturity 180 congenitally dislocated, subluxed, and dysplastic hips in 122 patients treated by the same surgeon by using Salter's innominate osteotomy (IO). The mean follow-up was 12 years. The sex of the patient, the laterality and height of the dislocation, the preoperative acetabular angle, the amount of femoral antetorsion, or the development of postoperative complications (except avascular necrosis of the femoral head), or a combination of these were not found to have a significant influence on the result. However, those patients who had a previous unsuccessful treatment of the hip, who developed pre- or postoperative avascular necrosis, who were unable to be restored by the osteotomy to a normal acetabular angle, or who required an open reduction of the hip joint (or who had a combination of these) were more likely to have an abnormal result. An important finding was that patients who underwent IO before age 4 years were the most likely candidates to receive a very satisfactory result.

Adolescent↗