Influence de passages répétés du virus de la polyèdrose nucléaire deAutographa californica chezSpodoptera littoralis [Lep.: Noctuidae]

Résumé Au cours de 7 passages du virus de la polyèdrose nucléaire deAutographa californica Speyer surSpodoptera littoralis (Boisd.) par la méthode d'ingestion libre des polyèdres il n'a pas été possible d'adapter ce virus à son nouvel h?te. Par contre les passages successifs du virus étranger permettent au virus occulte du nouvel h?te de se révéler, transformant ainsi la maladie latente en une infection caractérisée.

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Summary Adaptation of theAutographa californica Speyer nuclear polyhedrosis virus (Baculovirus) by successive passages of orally fed inclusion bodies, in a new host (Spodoptera littoralis) (Boisd) was unsuccessful. It is demonstrated, by using biochemical identification methods as well as specificity difference indices, that the occult virus ofS. littoralis is stressed by the artificial infection of theA. californica nuclear polyhedrosis virus. Thus it seems that NPV's are more stable than sometimes is suggested as far as natural routes of infection are used in the experimentation.

     

Évaluation de l’irradiation additionnelle des patients de médecine nucléaire en imagerie hybride TEMP/TDM

One hundred and ten consecutive patients and 130 SPECT/CT examinations were involved in this retrospective study that focused on the evaluation of the excess of dose contributed by the CT to the patient during the SPECT/CT explorations, for routine examinations in nuclear medicine. The average age of patients was 53 years. In this study, it appeared that irradiation induced by a low dose CT combined with a SPECT is low compared to that of a diagnostic CT. The main risk on patients is the occurrence of radiation-induced cancer. In our study, this increased risk induced by the additional CT with low dose settings in line with SPECT examination, is not significant and does not exceed 0.026%. By weighing the diagnostic value of SPECT/CT examination with that of a stand-alone SPECT examination dosimetric “incremental cost” is justified because of its direct clinical benefit conveyed to the patient.     

Étude de divers aspects de la prise en charge des acouphènes pour un sourd unilatéral avec le stimulateur électrique implantable extracochléaire Tinnelec RW®

Study of some aspects of the tinnitus treatment for unilateral deaf with an extracochlear electrical stimulation device. In France, there are about 6000 cases of sudden hearing loss, all of them bring with tinnitus. At present, the treatment of chronic tinnitus is based on the natural development or the facilitation of habituation. For the tinnitus, which resist to the habituation, the principle of the treatments consists in facilitating the habituation process. In a sound therapy the use of a sound generator, with a hearing aid if necessary, is proposed in order to facilitate habituation. But, in case of unilateral deafness acoustical habituation is not possible and tinnitus may cause a depression. Electrical stimulation offers a new therapeutic perspective, which overcomes the main problems to habituation. This approach is very promising that's why it seems essential to study some aspects. The project tries to answer to four questions: How do we have to stimulate electrically for a maximal efficiency? how can we fit the electric stimulation for maximal efficiency? When is it necessary to set up the stimulation? Can we intend to apply this technique to subjects having hearing residues? Recent experimental studies have proposed Tinnelec^® stimulator of the MXM Company as a therapeutic solution for the difficult tinnitus treatment in-patient with unilateral deafness. Many points will be examined through a clinical study and an animal study.     

Apport de l’iode 131 dans le traitement de la maladie de Basedow dans le service de médecine nucléaire de l’hôpital Ibn Sina de Rabat

One hundred and twenty-nine Grave's Basedow diseases in any gender and variable age patients, coming from several cities of Morocco, were randomized in a study of radio-iodine treatment who took place at the nuclear medicine department of Ibn Sina Hospital (Rabat, Morocco) during the period (from January 2001 to December 2008). The radio-iodine treatment was a first, second or third option and radio-iodine activities delivered varied (from 222 to 555 MBq 6 to 15 mCi) according to the age, the thyroid volume, the degree of hyperthyroidism and socio-economical situation. The high amounts of ¹³¹I were reserved especially to the patients who live far and whose socio-economic level is low with an aim of quickly obtaining an easily controllable state of hypothyroidism by a substitute treatment. The results showed that: (1) 57.36% of patients reverted to euthyroïdism (n = 74) with a patient having received two ¹³¹I cures. The second cure was justified by recurrence of hyperthyroidism after the first cure; (2) 34.88% passed in hypothyroidism (n = 45) with three patients having received two cures of ¹³¹I, the second cure was justified by recurrence of hyperthyroidism after the first cure in two patients and by the persistence of the hyperthyroidism after the first cure for the third patient. The average time of passage in hypothyroidism was 4.5 months; (3) 7.76% had remained in hyperthyroidism after the radioactive iodine treatment. Finally, 92.24% of our patients treated by radioactive iodine had passed in euthyroïdism or hypothyroidism against 7.76% whose hyperthyroidism had persisted or occurred.     

Les recherches sur les lépidoptères foreurs des graminées et leurs antagonistes : bilan et perspectives

Ancistrocerus, Discoelius and Symmorphus are xylicolous predatory wasps, the former two genera hunting caterpillars, the last one using both caterpillars and larvae of Chrysomelidae beetles. One of the aims of this study was to compare the stinging pattern of species from these genera with the ancestral “complete four-sting pattern” (C4SP) and reduced “two-sting pattern” (C2SP). Another aim was to clarify whether stinging pattern of predatory wasps depends mostly on the prey type or on the systematic position of the wasp. Sting traces on 6123 paralysed prey specimens, taken from 409 fresh wasp nests made by 10 wasp species in reed (Phragmites australis) trap-nests in three localities of Lithuania, were studied. The total number of stings applied to a prey specimen, the number and the share of stings directed to its body segments and the probability of stinging the segments were considered. The main conclusions of the study are: (1) the total number of stings delivered to a prey is species-specific, in some cases it may be used to distinguish fresh nests of related wasp species, as those of Symmorphus crassicornis and S. murarius and those of Discoelius dufourii and D. zonalis. (2) The distribution of stings is significantly different from the basic patterns C4SP and C2SP in all ten studied wasps; however, four caterpillar-hunting species have the distribution close to the C2SP The stinging pattern of three Symmorphus species hunting Chrysomelidae larvae included regular stings to the throat, three thoracic and the first abdominal segment; it could be abbreviated as C5SP (a complete five-sting pattern). (3) The distribution of stings among the segments of prey was found to be more dependent on the taxonomic position of the wasp species than on the prey type, thus it might be used as a behavioural character in comparative and phylogenetic studies. (4) The stinging pattern depended on the prey type as well: in the caterpillar-hunting S. debilitatus, it was quite different from the stinging pattern of the Symmorphus that hunt Chrysomelidae larvae.     

Prothèses orthopédiques et médecine nucléaire : le cas particulier de l’infection. Cas cliniques d’infection chronique sur prothèse de hanche

The diagnosis of chronic orthopedic infections relies on the combination of clinical, laboratory and imaging findings. Although there is no perfect imaging examination, the various nuclear medicine techniques are a useful help for clinicians. Performance and image quality have improved dramatically since the development of hybrid cameras. The choice of the most appropriate examination for underlying infections is sometimes difficult as well as its interpretation. It is often essential to know the patient's history (surgical history, biology, etc.). We have tried to illustrate the sometimes-complex management of chronic infections of hip prostheses through these clinical cases from multidisciplinary staff committee of osteoarticular infections.     

Aspects moléculaires de la spermatogenèse: la réparation post-réplication de l’ADN et le système ubiquitine

Ubiquitin is a ubiquitous and highly conserved protein of 76 amino acid residues, that can be covalently attached to cellular acceptor proteins through a multi-step enzymatic pathway. Mono- or poly-ubiquitination of proteins can lead to protein degradation or modification of protein activity. The ubiquitin system is essential to all eukaryotic cells. Many components of the complex ubiquitin system show remarkable evolutionary conservation, from yeast to mammalian species. Interestingly, during gametogenesis, many specialized and important aspects of the ubiquitin system become apparent. TheHR6B gene is a mammalian, autosomal homolog of theSaccharomyces cerevisiae geneRAD6 encoding a ubiquitin-conjugating enzyme.RAD6 in yeast is required for a variety of cellular functions, including sporulation, DNA repair, and mutagenesis. Male infertility inHR6B knockout mice is associated with impairment of spermatogenesis. Components of the ubiquitin system appear to be involved in different steps and processes during gametogenesis, including control of meiosis, and reorganization of chromatin structure.     

Étude de l’action pathogène éventuelle duBaculovirus d’Oryctes pour le porc

Résumé Après avoir étudié l’action duBaculovirus d’Oryctes sur cultures cellulaires de vertébrés en lignée continue, en particulier sur cellules rénales de porc, nous avons cherché à confirmer l’innocuité observée en effectuant des test de pathogénie sur l’animal vivant en lui administrant le virus soit par intubations gastriques, uniques ou répétées, soit par injections intrapéritonéales répétées. Ces observations confirment les résultats obtenus sur les lignées cellulaires.

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Summary Pathogenicity tests ofOryctes Baculovirus on adult pigs were carried out by contamination through different routes including unique and repeated gastric intubations and repeated intraperitoneal injections. The virus appeared to be devoid of pathogenic effect with the exception of hepatic parenchyme where lesions could be observed. These results confirm our previous studies on the safety of this virus toward different vertebrate cell lines, including pig kidney cells.