The neuroendocrine system in hibernating mammals: present knowledge and open questions

The present review describes the distribution and the function-dependent reactivity pattern of those peptidergic and aminergic components of the neuroendocrine system of hibernating mammals that have been studied by histological, pharmacological and physiological techniques. Particular attention has been paid to the intrinsic connectivity of the peptidergic apparatus and its input systems. Since the reactivity patterns of the neuroendocrine system show remarkable fluctuations in relation to the various stages of hibernation and euthermia, these fluctuations have been analyzed with respect to (1) their causative role in the regulation of hibernation and (2) their secondary response to physiological changes during hibernation. The author's investigations described in this review have mainly been performed in European hedgehogs (Erinaceus europaeus), European and golden hamsters (Cricetus cricetus, Mesocricetus auratus), dormice (Glis glis), and in Richardson's and Columbian ground squirrels (Spermophilus richardsonii, Spermophilus columbianus), by the use of light- and electron-microscopic immunocytochemistry and histochemistry, in situ hybridization, radioimmunoassays and stereotaxically guided application techniques. These experiments were also performed in hypothermic animals. The (partially published) results obtained by the author and his associates are reviewed with reference to the body of evidence found in the recent literature. With respect to their reactivity patterns, several neuropeptide and transmitter systems can be regarded as candidates for control systems of hibernation. Neuronal complexes immunoreactive for endogenous opiates, in particular enkephalin, and also for vaspressin, somatostatin, substance P, corticotropin-releasing factor and serotonin are probably involved in the neuroendocrine control of hibernation.Dedicated to the memory of Dr. Gesa Merker     

Médicaments radiopharmaceutiques : du diagnostic au théranostique des tumeurs neuroendocrines

Neuroendocrine tumors (NET) are a heterogeneous group originating from endocrine cells, which have the ability to develop themselves on various organs. Most of NET are well differentiated and have the capacity to produce different hormones and biogenic amines. NETs usually appear sporadically and can also be associated with different syndromes (multiple endocrine neoplasia). For the majority of NETs, surgical resection is the treatment of choice requiring the precise location of the tumor before surgery as well as the determination of the stage, followed by monitoring the progression of the disease. In the diagnostic process, nuclear medicine with molecular imaging plays a fundamental role. The secretory functions of these tumors enable the use of molecular imaging by targeting specific metabolic pathways or receptors. In addition, nuclear medicine also plays an important role in the field of therapy by replacing in one radiopharmaceutical drugs, the imaging suited radionuclide by replacing with a radionuclide emitting radiation suitable for therapy, also called vectorized internal radiotherapy. The activity of nuclear medicine, which enables diagnosis and treatment to be carried out using the same structures specific to the molecular targets of neuroendocrine tumors, is fully integrated into the new theragnostic approach, and constitutes one of its main pillars. The objective of this work is to describe the molecular targets expressed by NETs and corresponding radiopharmaceuticals, validated for human use (diagnosis and therapy).     

Eliciting Low-Risk Thyroid Cancer Treatment Preferences Using Clinical Vignettes: A Pilot Study

ObjectiveWhile surgical resection has been the traditional standard treatment for small (≤1 cm), differentiated thyroid cancers, active surveillance (AS) and radiofrequency ablation (RFA) are increasingly considered. The aim of this study was to explore patient preferences in thyroid cancer treatment using a series of clinical vignettes.MethodsThyroid cancer survivors and general population volunteers were recruited to rank experience-driven clinical vignettes in order of preference. Rankings were compared using Wilcoxon signed rank. Formative qualitative methods were used to develop and refine clinical vignettes that captured 4 treatments—thyroid lobectomy (TL), total thyroidectomy (TT), AS, and RFA—along with 6 treatment complications. Content was validated via interviews with 5 academic subspecialists.ResultsNineteen volunteers participated (10 survivors, 9 general population). Treatment complications were ranked lower than uncomplicated counterparts in 99.0% of cases, indicating excellent comprehension. Counter to our hypothesis, among uncomplicated vignettes, median rankings were 1 for AS, 2 for RFA, 3.5 for TL, and 5 for TT. Trends were consistent between thyroid cancer survivors and the general population. AS was significantly preferred over RFA (P = .02) and TT (P < .01). Among surgical options, TL was significantly preferred over TT (P < .01).ConclusionWhen treatments for low-risk thyroid cancer are described clearly and accurately through clinical vignettes, patients may be more likely to choose less invasive treatment options over traditional surgical resection.     

Nucleolar organizer regions in the fine needle aspirates of lung tumours

Nucleolar organizer region associated proteins (AgNOR proteins) have been identified by means of an argyrophil technique in smears of 60 consecutive fine needle aspirates from lung tumours. AgNOR proteins were visualized as silver-positive granules distributed in loose, intranuclear aggregates. Variations in the number as well as differences in the distribution pattern of AgNOR granules were found among different types of tumours. Except for small cell lung carcinoma, the count of AgNOR granules increased when the differentiation of tumours decreased. In particular well differentiated tumours had relatively few AgNOR granules, distributed in cohesive aggregates. Poorly differentiated tumours had many AgNOR granules organized in loose clusters and small cell lung carcinoma had relatively few granules dispersed throughout the nucleoplasm, showing characteristics unique among all lung neoplasms. The application of the AgNOR technique in cyto-preparations is useful in discriminating between small cell and non-small cell lung carcinomas. Moreover, the pattern of distribution of AgNOR proteins may be of diagnostic value in the assessment of tumours displaying overlap in AgNOR counts.