La collection d’Invertébrés fossiles d’Alcide d’Orbigny et la salle d’Orbigny

Fossil invertebrates collected or received by Alcide d’Orbigny, all his life long, have been brought together in a renowned collection that is very rich in terms of both species and specimens. The collection has resulted from a huge palaeontological work. Study of faunas from numerous French sites led Alcide d’Orbigny to do biostratigraphical comparisons and to erect geological stages, the definitions of which rest on their stratotypes. His wide knowledge of European fossil faunas was strengthened by a more global palaeobiogeographical view derived from his travel in South America. The d’Orbigny collection is housed in the ‘Muséum’ of Paris and is often visited by experts.     

Note sur la découverte de nouvelles gravures dans le nord d’Akka (Maroc)

Beside the metallic weapon figures, the engravings of the sites of North Akka showed signs of the existence of cattle, mostly oxen cattle. The representation of anthropomorphs is also notable for its evolving aspects towards the schematic style of Libyco-Berber. Regarding wildlife, it is also represented encompassing elephants, rhinoceros, ostriches, antelopes, etc. Nevertheless, the figures of domestic cattle precede those of other subjects. The (peltiform) axes and the dagger, figured in two sites, attest to a mastered knowledge of metallurgy.     

Nouvelles données sur le déroulement de la mycose àNeozygites fumosa sur la cochenille du maniocPhenacoccus manihoti

Résumé Cet article présente les résultats obtenus en 1987 sur des points non encore abordés précédemment dans le cadre de l'étude des circonstances épidémiologiques favorisant le déroulement de l'Entomophthorose àNeozygites fumosa (Speare) Remaudière et Keller, pathogène de la cochenille du maniocPhenacoccus manihoti Matile-Ferrero (Hom.: Pseudococcidae). Il montre notamment que l'évolution de la maladie, très rapide, correspond à la succession de 2 phases: une première phase, d'implantation, fortement liée à la taille et à la structure des colonies et une deuxième phase (épizootique au sens strict) indépendante de leur taille et de leur structure. Son évolution appara?t plus liée à la régularité des pluies qu'à la quantité d'eau. Les conditions sont très favorables quand l'humidité relative est supérieure à 90% pendant au moins 5 heures par jour de fa?on régulière. Le r?le important joué par la durée d'humectation du feuillage est montré ici pour la première fois. La densité des conidies du pathogène dans l'air est proportionnelle aux taux de mycose observés dans les populations deP. manihoti.      

Sarcome d’Ewing agressif apparaissant comme une lésion froide sur la scintigraphie osseuse

Ewing's sarcoma classically presents as a hot spot on bone scan as a result of increased vascularity of the tumor and new bone formation.PurposeWe report and analyze an uncommon pattern of a “cold” lesion in Ewing's sarcoma on bone scan and its physiopathologic significance.Case reportA 15-year-old boy complaining of thigh pain. CT scan evocated Ewing's sarcoma or osteitis. MRI evocated chronic osteitis. Scintigraphy showed a fairly intense and heterogeneous uptake on the femoral lesion and no abnormal uptake elsewhere. Biopsy showed none pathologic pattern. Three months later, a second biopsy concluded to Ewing's sarcoma. Bone scan showed a larger lesion with peripheral intense uptake centered by enlarged “cold” area in the left femoral diaphysis and no evident bone metastasis. The patient underwent chemotherapy and surgery. Three months later, bone scan showed extensive skeletal metastasis.ConclusionEwing's sarcoma appears usually as an intense lesion on bone scan. Nevertheless, decreased radiopharmaceutical uptake or “cold” lesion may be seen in aggressive Ewing's sarcoma with lytic tumor, growth of which is very rapid and bony reaction is minimal.     

Impact du délai diagnostique sur la survie du cancer du testicule

Objectives

Testicular cancer is the leading cancer of young adults and its incidence is increasing in almost all industrialized countries. The survival rate after testicular cancer is 95%, all stages combined, but a group of patients with poor prognosis still fails to respond to treatment. The time to diagnosis is defined as the time in months between perception of the first symptoms of testicular cancer by the patient and the diagnosis of the disease by the doctor. The objective of this study is to determine whether the time to diagnosis has a prognostic value, particularly whether it is correlated with the stage of the disease and survival.

Material and Methods

The time to diagnosis was studied in 542 patients with a diagnosis of testicular cancer between 1983 and 2002 in the Midi-Pyrenées region. Information concerning the disease and treatments contained in medical files was collected on a summary document. The time to diagnosis was correlated with prognostic parameters, including stage and survival.

Results

The mean time to diagnosis was 3.7±5.1 months and was longer for seminomas (4.9±6.1 months) than for non-seminomatous germ cell tumours (NSGCT) (2.8 ±4.0 months). The time to diagnosis was correlated with the stage of the disease and the 5-year survival on the overall population and in the NSGCT group, but not in the seminoma group.

Conclusions

Early diagnosis has a prognostic value (correlation with stage of the disease and 5-year survival rate). Testicular cancer information campaigns should therefore be envisaged.     

Intérêt d’une semi-quantification et d’une analyse statistique automatique pour l’interprétation de la tomoscintigraphie cérébrale de perfusion dans la maladie d’Alzheimer

IntroductionAs the visual interpretation of the brain perfusion SPECT for the diagnosis of Alzheimer's disease might be difficult, it is wished to benefit from techniques allowing to improve the diagnostic accuracy especially for the inexperienced readers.Materials and methodsThree readers retrospectively interpreted 77 ^99mTc-ECD SPECT studies within the context of suspected neurodegenerative disease. The probability of Alzheimer's disease was quoted from 1 to 5, and the optimum sensitivity and specificity values were determined from ROC curves. The readers also attributed a hypoperfusion score to 13 brain regions; a diagnosis was obtained from this semi-quantification using a simple logic rule. The SPECT scans were also analyzed using the Planet Neuro software and a diagnosis was reached from a threshold for 2 of the 90 analyzed regions. The gold standard was established by a comprehensive neurological evaluation with at least 5 years of follow-up.ResultsThe sensitivities and specificities of the three readers were 50 %, 56 %, 28 % and 76 %, 83 % and 90 %, respectively. Using the semi-quantification they were 50 %, 67 %, 61 % and 54 %, 85 %, 69 %. The results of two readers were more in agreement. Using the automatic quantification, sensitivity was 78 % and specificity 81 %.ConclusionThe semi-quantification seems to ameliorate the results of and the agreement between certain readers. However, the automatic quantification seems to be the only way of assisting all of the readers to improve their diagnostic performances.     

Délocalisation de la biologie d’urgence et Assurance Qualité

La biologie délocalisée prend une importance croissante dans le fonctionnement des services traitant les urgences à l’h?pital. Elle devrait représenter une réele évolution pour la prise en charge du patient tout en améliorant l’organisation interne des unités de soins. Le biologiste occupe un r?le clé pour mener un tel projet et la mise en place d’un système d’assurance qualité adapté à cette pratique est indispensable.     

Optimisation du protocole d’acquisition de la TEP à la fluorocholine dans la détection des lésions parathyroïdiennes

18F-Fluorocholine (FCH) PET/CT shows very promising potential for detection of hyperfunctioning parathyroid tumors. However, the optimal time to perform imaging after FCH administration has not yet been determined and protocols are highly variable. The aim of this study was to qualitatively and quantitatively compare 5, 10, 15, 20 and 60 min post-injection acquisition times in patients with primary hyperparathyroidism and equivocal traditional imaging. Thirty-one patients were included. Two observers retrospectively analyzed the five protocols. Any focal increase in FCH uptake was localized and graded on a discrete gradation scale between 1 and 5 to assess the likelihood of hyperfunctioning parathyroid tumors. Gold standard was histopathological findings for the 11 operated patients. Regarding quantitative analysis, ratio of SUVmax of parathyroid foci on SUVmean of thyroid background (as signal-to-noise ratio) were compared between protocols. After injection of 2.5 MBq/kg, FCH PET performed 60 min post-injection (2 min) had the best sensitivity and specificity by lesion (92% and 100% respectively and the best signal-to-noise ratio (median of 2). We suggest performing PET scan 60 min after injection, associated with early acquisition so as not to miss a wash-out hyperfunctioning parathyroid tumors.     

Conséquences de la chimiothérapie anticancéreuse sur la fertilité de la femme

Sterility is a potential toxic effect of chemotherapy. This risk is well established for alkylating agents, but is less clearly defined for anthracyclines, methotrexate and fluorouracil and poorly defined for alkaloids, platinum, etoposide and taxanes. The main predictive factors for ovarian toxicity are the additive effect of cytotoxic drugs, the cumulative dose of each drug and the patient’s age. This effect of chemotherapy is evaluated on menstrual cycles, hormonal assays and the number of pregnancies observed in patient cohorts. Chemotherapy induces destruction of oocytes and granulosa cells. In mice, it has been shown that adriamycin may induce oocyte apoptosis, which can be prevented by modulation of cycle cell signalling (dysregulation of Bax gene or, on the contrary, expression of its antagonist gene Bcl-2 or inhibition of apoptosis with sphingosine-1-phosphate or caspase inhibitors). Clinical data in the literature are usually based on retrospective studies and are somewhat confused: global fertility after MOPP chemotherapy for Hodgkin’s disease is about 20%, adjuvant chemotherapy with CMF, F(A)C or TAC for breast cancer induces amenorrhea in 50% to 70% of cases, PVB or BEP chemotherapy for ovarian germ cell tumors has little effect on fertility when the uterus and one ovary can be preserved, and the majority of women treated with methotrexate, actinomycin D or various combinations for persistent trophoblastic disease remain fertile. Preservation of fertility is a major goal for cancer patients receiving chemotherapy: in vitro fertilization could preserve the couple’s fertility, but is usually not feasible as it would delay initiation of chemotherapy until after stimulation of ovulation; oocyte or ovarian tissue cryopreservation is at the stage of research; oral contraceptives have not been demonstrated to be effective to preserve ovarian function; gonadotropin releasing hormone (GnRH) agonists prevent cyclophosphamide toxicity in rat and monkey ovaries, and a few pilot clinical studies suggest that chemotherapy-induced amenorrhea could be prevented by administration of GnRH analogues simultaneously to chemotherapy, but randomised studies are necessary.     

Conception et suites de la Paléontologie française d’Alcide d’Orbigny

The whole formed by his Paléontologie française, his Prodrome, and his Cours élémentaire, which are closely linked, constitutes one of the major parts of Alcide d’Orbigny’s scientific production, in which he exposed his concept of Palaeontology as a science closely related with Zoology and as an indispensable tool for Stratigraphy. The result was a remarkable impulsion for palaeontological and stratigraphical research, which from that time developed on new scientific foundations. Two annexes complete this communication, the first concerning the ‘Comité de la Paléontologie française’ (1860–1893), the second specifying the publication dates of four volumes of the Paléontologie française.     

Infection génitale à chlamydia chez l’homme et retentissement sur la fécondité

Chlamydia trachomatis is responsible for the most common sexually transmitted disease, up to 40% of the non gonococcal urethritis. It is a compulsary intracellular parasite. Its peculiar metabolism makes the bacteria interfere with the host cell immunity. Infection can become chronic and induce inflammation, if not properly treated, by permanent emission of antigens and heat shock proteins, and stimulation of Tcells. Autoimmunization against sperm can occur and impair fertilization and embryo implantation. Thus, Chlamydial infection can be associated with male infertility because of tissue damage, altered movement and antisperm immunization. PCR and LCR are to date the most sensitive detection techniques for c.trachomatis. Our study aim was to determine the prevalence of Chlamydial infection by PCR in 6 groups of men in andrologic practice. The highest prevalences have been found in the infertile men group and in the symptomatic group. No Chlamydia culture was found positive in any group. The association of PCR with anti C. trachomatis seminal IgA and seric IgG are useful tools for andrologic exploration.     

Effets d’une exposition à la Vinclozoline et à la Génistéine de la gestation à l’âge adulte sur la fonction de reproduction du ratWistar mâle: protocole et résultats préliminaires

Current evidence indicates that endocrine disrupters (EDs) can induce adverse effects on the male reproductive tract in various mammalian species. Recent reports indicate deterioration in male reproductive health in several human populations, but the evidence for a causal link with endocrine disruption is still weak. In addition, the experimental conditions of most of the reportedin vivo studies are not representative of environmental exposures (for example, high doses, short-term exposure, a single ED) and the mechanisms by which EDs disrupt the reproductive system are poorly understood. The objective of the present study is to develop an animal model to assess the reproductive effects and study the putative cellular and molecular mechanisms involved after exposure to genistein (phytoestrogen) and vinclozolin (fungicide with a known antiandrogenic potential) alone or in combination. The study will be performed in male Wistar rats, with administration of low and high doses of the compounds from conception to adulthood and a subset of the males in each treatment group will be mated with unexposed females. We plan to assess the level of sperm production, histology of the reproductive organs, motility and morphometry of spermatozoa and hormone levels, as well as DNA fragmentation of spermatozoa and determination of the number of germ cells, Sertoli cells and the diameters of seminiferous tubules. Estrogen, androgen, progesterone and FSH receptors will be detected and quantified and the level of testicular apoptosis and several apoptosis pathways will be studied to determine the putative cellular and molecular mechanisms involved. The preliminary results confirmed the developmental effects previously reported for high doses of vinclozolin. More interestingly, they indicated a number of deleterious effects for male rats exposed to low dosages alone or mixtures of low and high dosages compared to controls and rats exposed to high dosages alone. For example, a number of developmental anomalies of the genitalia were observed and a significant decrease of sperm motility and motion and fertilizing ability were observed. These preliminary results provide evidence that chronic exposure to environmental levels of EDs or mixtures of EDs have a detrimental impact on the male reproductive tract. The next step involves assessment of the anatomical disorders and the study of some of the cellular and molecular mechanisms possibly involved.     

Réflexions sur la place des médecins spécialistes en médecine nucléaire dans le dispositif d’annonce en cancérologie

Nuclear medicine physicians are very involved in French's oncology announcement procedure. However, their role needs to be analysed and evaluated. Before diagnosis’ announcement, information provided by nuclear medicine physicians are never neutral for patients. Information must not increase patient's anxiety or false patient's sense of reassurance. In this context, it seems necessary to engage in ethical reflexions about nuclear medicine physicians communication challenges.     

Effets de l’âge et du genre sur la perfusion cérébrale régionale étudiée par deux méthodes d’analyse statistique voxel-par-voxel

Fully automated analysis programs have been applied more and more to aid for the reading of regional cerebral blood flow SPECT study. They are increasingly based on the comparison of the patient study with a normal database. In this study, we evaluate the ability of Three-Dimensional Stereotactic Surface Projection (3D-SSP) to isolate effects of age and gender in a previously studied normal population. The results were also compared with those obtained using Statistical Parametric Mapping (SPM99).MethodsEighty-nine ^99mTc-ECD-SPECT studies performed in carefully screened healthy volunteers (46 females, 43 males; age 20–81 years) were analysed using 3D-SSP. A multivariate analysis based on the general linear model was performed with regions as intrasubject factor, gender as intersubject factor and age as covariate.ResultsBoth age and gender had a significant interaction effect with regional tracer uptake. An age-related decline (p < 0.001) was found in the anterior cingulate gyrus, left frontal association cortex and left insula. Bilateral occipital association and left primary visual cortical uptake showed a significant relative increase with age (p < 0.001). Concerning the gender effect, women showed higher uptake (p < 0.01) in the parietal and right sensorimotor cortices. An age by gender interaction (p < 0.01) was only found in the left medial frontal cortex. The results were consistent with those obtained with SPM99.Conclusion3D-SSP analysis of normal rCBF variability is consistent with the literature and other automated voxel-based techniques, which highlight the effects of both age and gender.     

Analyse de l’algorithme décisionnel basé sur la testostérone totale et recommandé pour le diagnostic de l’hypogonadisme acquis

Introduction

The diagnosis of acquired hypogonadism is still an important issue for laboratory medicine. Hypogonadism is defined as a sustained decrease of total testosterone confirmed by the biochemistry laboratory and total testosterone measurement is proposed as the initial step in the investigation of hypogonadism. If TT is over 12 nmol/l, the probability of hypogonadism is considered low and it is suggested that patients be referred to others methods of investigation. Only a small percentage of men aged 50 and over are treated for hypogonadism. Seventy percent of men investigated for hypogonadism have a TT of over 12 nmol/l and there is an unpredictable increase of SHBG during this period, reducing the bioavailability of circulating testosterone. The hypothalamic-pituitary gonadal axis is modified with age and contributes to hypogonadism. The efficacy of biochemical investigation of hypogonadism needs to be reassessed.

Materials and methods

Total testosterone and LH were measured on the Centaur immunoanalyser (Siemens) and SHBG was analysed on the Immulite 2000 (Siemens). Bioavailable testosterone was calculated using the formula provided by ISSAM.

Results

Using the algorithm based on TT, only 27.9% of men would have been investigated for hypogonadism. Of the 638 patients considered as normal, 325 showed an index of hypothalamic-pituitary gonadal axis stimulation and possible hypogonadism, revealed by an elevated LH. In these patients with TT superior to 12 nmol/l and a LH superior to 7 UI/l, SHBG level was at the upper limit of or over the reference range. No correlation was observed between calculated BT and the abnormal LH level found in these patients. Calculated BT was not considered a good marker of hypogonadism for these patients.

Conclusion

Elevated LH is a biochemical marker of hypogonadism and should be interpreted in the context of stimulation of the hypothalamic-pituitary gonadal axis. Based on our data, an initial step in the investigation of hypogonadism based only on TT does not seem suitable for the identification of all patients who might experience hypogonadism. A complete investigation should be offered to all patients with clinical evidence of hypogonadism whatever their TT level. In patients who might benefit from hormonal treatment, calculated BT should be interpreted with caution. A definition of hypogonadism based on TT does not seem appropriate and a new definition based on bioavailable testosterone and the hypothalamopituitary gonadal axis should be considered.     

Recherches sur la conservation du virus de la densonucléose

Résumé Le virus de la densonucléose (VDN) conserve une partie de sa virulence en solution aqueuse entre 0°C et 30°C pendant deux mois. Son pouvoir infectieux se maintient à—10°C pendant deux mois mais est supprimé après dix jours de dessication. On peut done considérer ceParvovirus d’Insectes comme un virus relativement résistant aux températures que l’on rencontre ordinairement dans la nature et au laboratoire.

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Summary The persistence of DNV is described. This virus retains a part of its infectivity in aqueous solution between 0°C and 30°C. The log LD₅₀ initially 7,15 drops to 2 after two months. The virus keeps its infectivity at 10°C but it loses all its pathogenicity after 10 days in dry conditions.

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Ce travail a été réalisé en partie dans le cadre d’une convention I.N.R.A.-D.R.M.E.