Ischémie myocardique du diabétique : apports de la scintigraphie myocardique de perfusion

Diabetes is an important risk factor of myocardial ischemia. Myocardial perfusion imaging (MPI) is used for diagnostic, prognostic assessment and for post-therapeutic follow-up of coronary artery disease (CAD). Its usefulness has been documented extensively in the general population. However, in diabetic population, little studies have been published. CAD is more severe and more frequent among diabetic patients. The goal of this work was to assess usefulness of MPI among diabetic patients. This work includes 44 diabetic patients (22 women, 22 men), investigated by stress MPI in nuclear medicine department of Ibn Rochd UH of Casablanca. The studied parameters concerned: age, antecedents of CAD, risk factors of CAD associated to diabetes, duration of the diabetes, diabetes complications, diabetes treatment, indication of MPI, presence or not of anomaly on the ECG performed at rest, existence or not of typical or atypical clinical signs of CAD, investigations and therapy prescribed as well as the occurrence or not of cardiac event during monitoring after MPI. Results of MPI have been compared to clinical, therapeutic and monitoring data of patients. Mean age of patients was 55 years (39 to 75 years), mean diabetes duration was 8.6 years (1 to 30 years), at least one diabetes complication has been noted in 18 patients. The most frequent complication was diabetic retinopathy. MPI has been achieved for diagnosis of ischemia in 37 patients and assessment of anti-ischemic treatment in 7 cases. Treadmill exercise has been achieved in 34 cases and a pharmacological stress in 10 others. During follow-up, which was between 1 and 36 months (mean: 14.9 months), 6 cardiac events occurred among the 44 patients. Patients with abnormal findings at stress MPI had two cardiovascular risk factors or more associated to diabetes (91.3% vs. 9.5% among patients having normal findings, P < 0.001) and had diabetic retinopathy more often (56.5% vs. 9.5% among patients with normal findings, P < 0.001). Cardiac events were more frequent among men (100% vs. 43.2% of patients who did not have a coronary event, P < 0.01). Patients with stress MPI showing ischemia in 3/17 segments or more have presented a cardiac event more often during the follow-up (4/12 Vs 2/32 among patients with normal MPI or defect in less than 3/17 segments, P < 0.01). In this series, coronary artery disease was found more frequently among patients having more than 2 cardiovascular risk factors. In addition, risk of cardiac event seems related to extent of uptake decrease.     

Sur quelques sélaciens nouveauxdu Crétacé supérieur de Bolivie: Amérique du Sud

The locality of Torotoro (Puca Group, Upper Cretaceous of Bolivia) has yielded a small shark-fauna including a new genus and five new species: Pucabatis hoffstetteri nov. gen., nov. sp., Ischyrhiza hartenbergeri nov. sp., Dasyatis branisai nov. sp., D. molinoensis nov. sp. et D. schaefferi nov. sp. The genus Pucapristis, previously described on rostral teeth, is represented by numerous oral teeth unknown until this day. The occurence of the genus Schizorhiza, already pointed out, allows to attribute the El Molino formation to maestrichtian.     

Le débat macroévolutif : apports de la disparité morphologique

The macroevolutionary debate. Several historical as well as more recent aspects of macroevolutionary theory are discussed, in connection with a research program initiated by several working groups over the last ten years: it consists in dividing the taxonomic (diversity) and morphologic (disparity) components of biodiversity when studying its fluctuations through time. Studies have frequently shown a dissociation between the two metrics through the history of clades. Comparing diversity and disparity is a productive approach, which is leading to an exploration of large-scale biodiversity fluctuations in terms of both patterns and processes. To cite this article: P. Neige, C.R. Palevol 2 (2003).     

Cinétiques de la fixation du 18F-FDG dans les structures cérébrales : faisabilité et résultats préliminaires

ObjectDynamic positron emission tomography (dyn-PET) acquisitions using the radiotracer ¹⁸F-deoxyglucose (¹⁸F-FDG) are mainly developed in research studies of brain PET in kinetic modelling to determine the local glucose consumption rate. This procedure is difficult to establish, due to its requirement for blood sampling. Here, we propose a simple approach to constructing time–activity curves (TACs) for four different brain structures (the arterial & venous regions and grey & white matter) based on direct image measurements on chronologically reconstructed image volumes of regions of interest.Materials and methodsWe applied our processing on 14 control subjects to extract their physiological state. We defined the reference ¹⁸F-FDG kinetic curves as a “population averaged TAC” for four structures. To increase the curves accuracy, our method included the evaluation of two normalization based on the integral of the activity curve in the arteries and the veins.ResultsThe method showed discrimination between artery, venous, grey and white matters. The two normalization methods significantly reduce the dispersion for the grey and white matter curves and that venous normalization showed the best overall efficiency.ConclusionWe have designed and evaluated an approach for directly defining PopAv_TACs which are representative of given anatomical structures.     

Apport du TDM en imagerie multimodalité : le point de vue du physicien médical

The recent introduction of hybrid systems SPECT/CT and PET/CT in nuclear medicine, greatly improved the diagnostic accuracy for particular clinical indications, due to the possible attenuation correction of functional images and the availability of helpful anatomic information. The introduction of CT in the nuclear diagnostic process results in a significant increase of the patient dose. This increase should be justified and optimized considering both the clinical question and the CT settings available on these systems. The choice of CT settings directly affects the effective dose. It varies basically as the square of the tube voltage, linearly with the length of the scan and the product of the current by the rotation time of the tube. It is also inversely proportional to the pitch. For attenuation correction, the literature shows that it is possible to use a low CT tube current without significant effect on tumor FDG uptake or lesion size. Conversely low CT voltage must be used with caution, depending on the algorithm implemented in the CT hybrid device to transform CT Hounsfield units to the attenuation map at the appropriate energy. The radiation dose for anatomic correlation can be substantially lower than for diagnostic-quality CT. It is possible to reduce the patient's radiation dose by a factor of 2 or 3 by acquiring a low-dose PET/CT scan for anatomic correlation of adequate image quality if compared with diagnostic ¹⁸FDG PET/CT. Using specific CT settings, the effective dose can range 7.3–11.3 mSv depending on the patient weight and age.     

Influence du piclorame sur l'activité phénylalanine-ammoniac lyase de Nicotiana tabacum induite par la réaction d'hypersensibilité au virus de la mosaïque du tabac

In Nicotiana tabacum var. Xanthi n.c. phenylalanine ammonia lyase (PAL) activity, which increases significantly during the hypersensitivity reaction to tobacco mosaic virus (TMV), is only partially affected when plants are treated with piclorame, which is known to be an inhibitor of PAL in vivo. Using piclorame together with TMV, it has been possible to distinguish between that increase in PAL activity due to the virus and that dependent on the photoperiod.     

Homogénéité ou hétérogénéité dans le métal des dépôts de l’Âge du Bronze : estimations sur leur formation à partir des isotopes du plomb

Lead isotope analysis was applied to three representative Late Bronze Age hoards from the Iberian Peninsula, for all of which compositional analyses are available. Unpublished isotopic evidence from the cave of Muricecs (Lleida) and the settlement of Las Lunas (Toledo) are compared to the published results for weapons from the Ría de Huelva, one of the most important Late Bronze Age hoards from Western Europe. Lead isotope analysis can tell us the sources of the metal used to make the artifacts in each hoard. The limited number of geologic reference points makes it difficult to determine all of the ore sources, but the analyses do give us evidence about the degree of homogeneity of the metal in the artifacts. As a result, one can separate metallic composition from artifact typology and thereby evaluate how the hoards were formed and what their functions were. Elemental analysis is unsuitable for this purpose because Late Bronze Age metals from Iberia are very homogenous and have few impurities.     

Métastase du tissu mou révélant un carcinome folliculaire différencié de la thyroïde

Differentiated thyroid cancer occupies a very important place within the framework of thyroid pathology, representing 90% of thyroid cancers. A nodular goiter generally summarizes the clinical picture. Nevertheless, remote metastases can be revealing. The elective localizations of these metastases are by descending order of frequency: lung, bone, mediastinal lymph nodes, kidney, liver and adrenal glands. Soft tissue metastases are extremely rare and exceptionally revealing of the neoplasm. We report one case of follicular thyroid carcinoma revealed by soft tissue metastases of the arm.     

Assurance qualité du circuit des médicaments radiopharmaceutiques du service de médecine nucléaire de l’hôpital Ibn Sina de Rabat

Since Law n^o 17-04 of the national code of medicine and pharmacy, published in the official newspaper of November 22, 2006, radiotracers used in nuclear medicine in Morocco have become drugs or diagnostic radiopharmaceuticals. As such, radiopharamaceuticals must meet the requirements of pharmaceutical quality and control that apply to any drug (Payoux and Prigent, 2009 [5]). This task must be undertaken under the pharmacist's responsibility with a specific skill known as “radiopharmacist” (Morera et al., 1993 [6]). In the situation of Moroccan hospital, like Ibn Sina hospital for which the only law of the national code is partially applied, nevertheless the pharmacy department cannot ignore this issue. As part of this work, we present the proposed new quality installation service for 24 months. It aims to improve the proper use of radiopharmaceuticals, to contribute to the quality of diagnostic and therapeutic procedures and especially to ensure the optimal conditions of safety for staff and patients. This activity closely affects the pharmaceutical supply, preparation, dispensing and management of radioactive waste resulting from handling radiopharmaceutical drugs. Radiopharmaceutical quality control of was also integrated into the global quality control program, despite the technical constraints encountered during their day-to-day practice. Our basic documentation referred to European directives (Pharmacopée européenne, 2010 [8]), French Pharmacopoeia (Bonnot-Lours, 2000 [2]) and good preparation practise rules (Afssaps, 2006 [3]). The reflection was undertaken within a multidisciplinary framework: nuclear physician, physicists, a pharmacist working in hospitalpharmacy, chemists of the drug control department, computer and paramedical staff (technicians, nurses, and cleaners).     

Sélaciens nouveaux du London Clay de l'Essex (Yprésien du bassin de Londres)

The Ypresian locality of Burnham-on-Crouch(Essex) has yielded numerous Selachian species, some of which are new: Hexanchus agassizi sp. nov., Scyliorhinus burnhamensis sp. nov., S. casieri sp. nov., S. pattersoni sp. nov., S. woodwardi sp. nov., Pararhincodon ypresiensis sp. nov., Triakis wardi sp. nov., Mustelus whitei sp. nov. The Hexanchid teeth classicaly refered to Notidanus serratissimusAg. include in fact two separate species belonging to different genera: Notorhynchus serratissimus (Ag.) and Hexanchus agassizi sp. nov. Lamna affinis (Casier) is arranged in the genus Isurolamna nov. in consideration of his dental peculiarities. The genus Burnhamia nov. is created for Rhinoptera daviesiWoodward that can be regarded as a Mobulid. Oxyrhina sheppeyensisCasier must be classified in the genus Anomotodon. The genus Triakis, Mustelus, Anomotodon and Pararhincodon are pointed out for the first time in the Ypresian.     

Cancer différencié de la thyroïde métastatique à propos de 70 cas : impact des nouvelles recommandations de 2017

IntroductionMetastatic differentiated thyroid carcinoma (MDT) represents an average of 10% of patients with CDT. Metastases are prognostic factors. Their care is multidisciplinary.ObjectiveTo study the epidemiological, clinical, histological, therapeutic and evolutionary aspects of metastatic CDT and to study the impact of new recommendations.Patients and methodsRetrospective study of 70 patients followed for a metastatic CDT collected between June 2007 and June 2017, in the nuclear medicine department of Hassan II University Hospital of Fez.ResultsMean age 51.34 ± 15.96 years, sex ratio F:H: 2.5. Age > 45 years old at 65.7% of whom 42.8% > 55 years old. Circumstances of discovery: nodule 15.8%, multi-hetero-nodular goiter 17.1%, metastases 65.7%. Multivariate analysis shows a significant correlation of age greater than 45 years (P: 0,001) and revealing metastasis. Histology: papillary carcinoma 72.9%, vesicular carcinoma 22.8% and carcinoma poorly differentiated 4.3%. Tumor > 4 cm in 45.7%, the TNM classification (2010) vs. TNM classification (2017): 31.4% vs. 48.6% in stage I, 12.9% vs. 28.6% in stage II, the stage III in 17.1% vs. 0% and 38.6% vs. 22.8% in stage IV. Complementary investigations: localization of metastases: 40% at the bone level, 31.4% lung, 14.3% ganglionnaires and others 9.9%. Hormonal braking treatment was administered in all patients and the « irathérapie » (ATA vs. French recommendation 2017).EvolutionSeven cases of cure, 1 case of recurrence, 4.3% refractory to iodine.ConclusionThe presence of metastases, worsens the prognosis. Therapeutic de-escalation with French recommendations. Bone localization was predominant, its management is multidisciplinary, and radioactive iodine as a complementary treatment does not allow their healing.     

Variations de l'incidence des fractures de l'extrémité supérieure du fémur chez les personnes agées de la région de Québec.

To estimate the incidence of fracture of the proximal end of the femur in people aged 50 years or older living in the Quebec area in 1971, 1976 and 1981 we determined the number of admissions for such fractures to the 15 acute care hospitals in the region. From 1971 to 1981 the number of fractures increased by 71%; the increases for those aged 75 to 84 years and 85 years or over were 98% and 118% respectively. The variation is only partly explained by changes in sex and age distribution of the population; the incidence rates also increased. Among men aged 75 to 84 years the incidence rate per 1000 person-years rose from 2.63 in 1971 to 5.22 in 1981, an increase of 98%; the corresponding figures for men aged 85 years or more were 9.76 and 16.91, an increase of 73%. Among women aged 75 to 84 years the rate rose from 7.28 to 8.81, an increase of 21%; the corresponding figures for women aged 85 years or more were 20.40 and 24.27, an increase of 21% and 19% respectively.     

Influence de la rhTSH sur la fixation du 18 FDG dans une population de 42 patients avec cancer différencié de la thyroïde suspect de récidive

PurposeThe role of positron emission tomography with 18 fluoro-deoxy-glucose (FDG-PET) in case of differentiated thyroid carcinoma recurrence is established. However, the influence of TSH levels on 18 FDG is still discussed. Our study aims at comparing respective performances of FDG-PET performed at low TSH levels and under rhTSH stimulation, when a recurrence of a thyroid carcinoma is suspected.Material and methodsForty-two patients have been included, in a prospective way; each of them has been explored by FDG-PET at low (PET1) and high TSH levels with Thyrogen^® (PET2). The number of hypermetabolic foci, the intensity of uptake, both visual and with Standardized Uptake Values (SUV) have been compared.ResultsPET1: 82 foci were detected, including 75 true positive (TP) and seven false positive (FP). Sensitivity by lesion is 85.23 and 58.6% on a patient basis. Twelve pathological sites, not visualized (false negative) in PET1, were seen under stimulation. PET2: 89 foci were detected, including 87 TP and two FP; two tumoral sites visualized with PET1 are not detected. Sensitivity by lesion is 97.75 and 75.9% on a patient basis. SUV are significantly higher under stimulation. In three patients, therapeutic strategy has been modified, based on PET2 data.ConclusionStimulation by rhTSH improves FDG-PET performances. Therefore, it is justified to resort to it in case of recurrence of differentiated thyroid carcinoma, when the usual workup is negative.