PubMed Health⌕ Search

Biomedical subjects

G Siou

Publications and source records attributed to G Siou.

13 recordsLinked to original sources

Retropharyngeal abscess as a complication of oropharyngeal trauma in an 18-month-old child.

An 18-month-old boy presented to the accident and emergency department following trauma to the oropharynx by a doll's umbrella. Although no significant injury could be identified at first, it later transpired that he had developed retropharyngeal surgical emphysema with abscess. This case report aims to review the nature of retropharyngeal abscesses and to highlight and re-emphasize the fact that apparently non-serious pharyngeal injuries in children should be treated with suspicion.

Acute Disease↗

Toxicological aspects of vanadyl sulphate on diabetic rats: effects on vanadium levels and pancreatic B-cell morphology.

This study explored some toxicological aspects of vanadyl sulphate (VOSO4) treatment of rats made diabetic with a single intravenous injection of streptozotocin (60 mg/kg). Administered in drinking water (0.25, 0.5, 0.75 or 1 mg of VOSO4, 5H2O ml) VOSO4 treatment partially or totally corrected some of the alterations associated with the diabetic state (hyperglycaemia, polydipsia, polyphagia, high cholesterol and triglycerides levels) and did not produce any changes in various plasma or blood cell parameters which were not previously altered by diabetes. Measurement of vanadium levels indicated that tissues accumulated vanadium in the following order of concentrations: bone greater than kidney greater than spleen greater than liver greater than lung greater than or equal to muscle greater than blood. Histopathological studies did not reveal any difference in liver, stomach, ileum, spleen, heart and lung from control, non-treated diabetic or VOSO4-treated diabetic animals. Kidney of all non-treated diabetic animals showed an epithelial cellular swelling of distal tubules while only 2 of 6 VOSO4-treated diabetic animals showed this alteration. Cellular degeneration of pancreas B-cells was less marked in VOSO4-treated that in non-treated diabetic animals. The study indicates that VOSO4 may be a potential antidiabetic agent.

Animals↗

In vivo and in vitro effect of the Haemophilus influenzae lipopolysaccharide on ciliated respiratory epithelium.

The lipopolysaccharide of Haemophilus influenzae is presumed to have a toxic effect on the tracheal epithelium, and then induce a bronchial obstruction. This activity of LPS was studied in vitro on the ciliary beat using a photo-oscillographic apparatus, and in vivo on the rabbit trachea. Neither modification of ciliary beat frequency, nor epithelial damage in the rabbit trachea was observed after a single administration of LPS. In contrast, histopathologic changes were observed in vivo when the intratracheal administration of H. influenzae LPS was followed 24 h later by an intravenous injection of the same LPS. These experimental models seem thus to implicate a Shwartzman type cellular necrosis in the trachea in vivo in the absence of a direct toxic effect of endotoxin itself on trachea in vivo or in vitro.

Animals↗

[Experimental cadmium poisoning].

During the past years, many publications and reviews have described kidney and bone lesions observed after human chronic cadmium poisonings of food or occupational origin. In this experiment carried out in rat fed with normal diets or polydeprived of vitamin D3, calcium and proteins, with or without addition of cadmium, the bone lesions observed are as severe in all polydeprived animals, wether treated with cadmium or not.

Animals↗

Evaluation of the clastogenic action of benzene by oral administration with 2 cytogenetic techniques in mouse and Chinese hamster.

In previous studies, we found, using the micronucleus test, that the adult male mouse is about twice as sensitive as the female to the clastogenic action of orally administered benzene (Siou and Conan, 1978). For new-born mice suckling mothers receiving benzene orally (Siou and Conan, 1979), or for three-week-old mice receiving benzene orally (Siou and Conan, 1980), there was no significant difference in sensitivity between females and castrated males; castrated males treated with testosterone regained their original sensitivity. The objectives of the experiments described here were to confirm these findings by metaphase chromosome analysis of bone-marrow cells from mice and Chinese hamsters. Metaphase chromosome studies and micronucleus counts were performed on each animal to investigate the relationship between the 2 techniques.

Administration, Oral↗

[General schema for safety evaluation of residues of embryotoxic drugs (author's transl)].

Concerned with adapting the withdrawal time to real risks attributed to residues, the authors present a general schema of evaluation based on the metabolism-toxicity relationship. This schema takes into account: a) possible distinction between potentially toxic and atoxic metabolites for extractable residues, b) the more or less large biovailability of residues, c) the methodological evaluation difficulties of toxicity of bound residues. Without neglecting public health, this procedure leads to less constrained restrictions in use of veterinary drugs.

Abnormalities, Drug-Induced↗

[Experimental alpha-chymotrypsin model of glaucoma in the rabbit: histopathological studies (author's transl)].

The injection of alpha-chymotrypsin into the posterior chamber of the eye is known to produce an experimental ocular hypertension of long duration in animals. The present study reports the pathological changes which occur in the eye during the first nine months after the ocular injection of alpha-chymotrypsin in rabbits. Six weeks after treatment most of the eyes showed a buphthalmia and an intraocular pressure elevation which varied greatly from animal to animal. The anterior chamber angle of the treated eyes showed a progressive enlargement. Several days after the enzyme injection a transient increase in thickness of the cornea and Descemet membrane was noted. Cupping of the optic disc, characterized by a total disappearance of the optic nerve head fibers and an excavation beginning at margins of the retina appeared after four months and in most cases were present seven months after the treatment. More or less prominent retinal degeneration was also evidenced three months after enzyme injection. The results indicate alpha-chymotrypsin-induced occular hypertension in the rabbit leads after several months to pathological change in the eye analogous to that observed in human glaucoma.

Animals↗

[Toxicology of reproduction: predictive value of experimental models. Round Table No 1 at Giens XIII].

The carrying out of clinical trials with a view to the marketing of drugs for human use is directly related to results of some animal studies. This workshop was devoted to evaluation of the quality and interest of these experimental models in reproductive toxicology. The predictive ability of preclinical trials to make extrapolations from animals to man decreases from foetotoxic to tetratogenic risks respectively and from the effects on fertility in both sexes to postnatal risks. As a result of this workshop, we propose the following improvements: (1) standardization and generalization of fertility test evaluations, especially the spermogram, in order to improve animal and human correlations; (2) development of knowledge and standardization of the follow up of the oestral cycle; (3) improvement of standardization, harmonization and diffusion of postnatal tests that prove relevant in animals; (4) increase in initiatives aimed at better mutual understanding of all drug partners; (5) creation of registers for new drugs, as soon as possible during clinical trials, to study their effects on the whole reproductive process; (6) recommendations for the creation of guidelines for International Conference on Harmonisation (ICH) to enable classification of observed effects in experimental models. This could lead to specific (potentially for each phase of the reproductive cycle) guidelines, precautions for use and/or contraindications which are listed in the summary of product characteristics.

Animals↗