Central nervous system relapse in high-risk stage 4 neuroblastoma: The HR-NBL1/SIOPEN trial experience.

BACKGROUND: There is rising concern on the impact of new strategies, such as high-dose chemotherapy (HDC) and immunotherapy, on the pattern of relapse in high-risk neuroblastoma (HR-NBL). Our aim is to evaluate the incidence and identify risk factors for first recurrence in the central nervous system (CNS) in HR-NBL. PATIENTS AND METHODS: Data from patients with stage 4V HR-NBL included from February 2002 to June 2015 in the prospective HR-NBL trial of the European International Society of Pediatric Oncology Neuroblastoma Group were analysed. Characteristics at diagnosis, treatment and the pattern of first relapse were studied. CNS imaging at relapse was centrally reviewed. RESULTS: The 1977 included patients had a median age of 3 years (1 day-20 years); 1163 were boys. Among the 1161 first relapses, 53 were in the CNS, with an overall incidence of 2.7%, representing 6.2% of all metastatic relapses. One- and three-year post-relapse overall survival was 25 ± 6% and 8 ± 4%, respectively. Higher risk of CNS recurrence was associated with female sex (hazard ratio [HR] = 2.0 [95% confidence interval {CI}: 1.1-3.5]; P = 0.016), MYCN-amplification (HR = 2.4 [95% CI: 1.2-4.4]; P = 0.008), liver (HR = 2.5 [95% CI: 1.2-5.1]; P = 0.01) or >1 metastatic compartment involvement (HR = 7.1 [95% CI: 1.0-48.4]; P = 0.047) at diagnosis. Neither HDC nor immunotherapy was associated with higher risk of CNS recurrence. Stable incidence of CNS relapse was reported over time. CONCLUSIONS: The risk of CNS recurrence is linked to both patient and disease characteristics, with neither impact of HDC nor immunotherapy. These findings support the current treatment strategy and do not justify a CNS prophylactic treatment.

Functional Characterisation of Eel Dopamine D2 Receptors and Involvement in the Direct Inhibition of Pituitary Gonadotrophins.

In various vertebrate species, dopamine (DA) exerts an inhibitory action on reproduction. In the European eel, DA plays a pivotal role in the inhibitory control of gonadotroph function and the blockade of puberty. In vivo studies have suggested that this effect is mediated by receptors pharmacologically related to the D2 family. In the European eel, two distinct D2 receptor (D2-R) paralogous genes have been identified (D2A-R and D2B-R) and both were shown to be expressed in the pituitary. We investigated the potential role of each paralogue in the control of gonadotroph function in this species. Eel recombinant D2A-R or D2B-R were expressed in HEK 293 cells, with a universal Gα subunit, and receptor activation was followed by inositol phosphate production. Recombinant D2-Rs exhibited a comparable affinity for DA, although they had differential affinities for mammalian D2-R agonists and antagonists, supporting subtle structure/activity differences. Furthermore, using eel pituitary cell primary cultures, the expression by gonadotroph cells of both native eel D2-R paralogues was examined by in situ hybridisation of D2A-R or D2B-R transcripts, coupled with immunofluorescence of luteinising hormone (LH)ß or follicle-stimulating (FSH)ß. LH and to a lesser extent, FSH cells expressed both D2-R transcripts but with a clear predominance of D2B-R. Notably, D2B-R transcripts were detected for the majority of LH cells. Accordingly, using these cultures, we showed that DA potently inhibited basal and testosterone-stimulated LHß expression and less potently basal and activin-stimulated FSHß expression. We also tested some D2-R antagonists, aiming to select the most adequate one to be used in innovative protocols for induction of eel sexual maturation. We identified eticlopride as the most potent inhibitor of DA action on basal and stimulated LH expression in vitro. Our data suggest a differential functionalisation of the duplicated receptor genes and demonstrate that mainly D2B-R is involved in the dopaminergic inhibitory control of eel gonadotroph function.

Busulfan-melphalan in high-risk neuroblastoma: the 30-year experience of a single institution.

High-dose chemotherapy (HDC) was investigated in high-risk neuroblastoma (HR-NBL) to reduce the risk of relapse. We report the results of the 30-year experience of a cohort of patients with HR-NBL treated with high-dose (HD) busulfan (Bu)-containing regimens. From 1980 to 2009, 215 patients aged >1 year with stage 4 NBL were treated with HD Bu-containing regimens at Gustave Roussy. These data were prospectively recorded in the Pediatric Transplantation Database. The median age at diagnosis was 40 months (12-218 months). All patients had a stage 4 neuroblastoma. NMYC amplification was displayed in 24% of the tumors. The hematopoietic support consisted of bone marrow or PBSCs in 46% and 49% of patients, respectively. The 5-year event-free survival and overall survival rates of the whole cohort were 35.1% and 40%, respectively. Age at diagnosis, bone marrow involvement and tumor response after induction chemotherapy were significant prognostic factors. Toxicity was manageable and decreased over time, owing to both PBSC administration and better supportive care. Based on this experience, HD Bu-melphalan (Mel) has been implemented in Europe and compared with Carboplatin-Etoposide-Mel in the European SIOP Neuroblastoma (SIOPEN)/HR-NBL randomized protocol. It has now become the standard HDC in the SIOPEN HR strategy.

Tandem high-dose chemotherapy with thiotepa and busulfan-melphalan and autologous stem cell transplantation in very high-risk neuroblastoma patients.

High-risk neuroblastoma is characterised by poor long-term survival, especially for very high-risk (VHR) patients (poor response of metastases after induction therapy). We report the results of an intensified high-dose chemotherapy (HDC) strategy to improve the prognosis of VHR patients. This strategy was based on tandem HDC with thiotepa and busulfan-melphalan (Bu-Mel) followed by autologous stem cell transplantation (ASCT). All data were prospectively recorded in the Gustave Roussy Paediatric ASCT database. From April 2004 to August 2011, 26 patients were eligible for tandem HDC. The median age at diagnosis was 4.4 years (1-15.9). All patients had metastatic disease. MYCN was amplified in 5/26 tumours. Despite the cumulative toxicity of alkylating agents, the toxicity of the intensified HDC strategy was manageable. Thiotepa-related toxicity was mainly digestive, whereas sinusoidal obstruction syndrome was the main toxicity observed after Bu-Mel. The 3-year event-free survival of this cohort was 37.3% (21.3-56.7). This strategy will be compared with combined (131)I-mIBG/Bu-Mel in the upcoming SIOPEN VHR Neuroblastoma Protocol.

[Liver capillariasis (Calodium hepaticum) in rodents from Ituri (DRC) and Dakar (Senegal)]. / Capillariose hépatique (Calodium hepaticum) chez des rongeurs en Ituri (République démocratique du Congo) et à Dakar (Sénégal).

Human hepatic capillariosis due to Calodium hepaticum is rarely described in Africa, probably because of the lack of diagnosis tools. However, it is known that the animal reservoir is made up of rodents. During a study performed on 24 black rats (Rattus rattus) trapped in Rethy (CongoDR) and 20 Gambian pouched rats (Cricetomys gambianus) in Dakar (Senegal), macroscopic and histological hepatic lesions of capillariosis were found in 8 of these rodents (3 in Rethy and 5 in Dakar). These results led us to propose, besides hygiene measures, an epidemiologic survey of this serious parasitosis, particularly in children, in the course of serological and/or coproscopic investigations.

Neuroendocrine control by dopamine of teleost reproduction.

While gonadotropin-releasing hormone (GnRH) is considered as the major hypothalamic factor controlling pituitary gonadotrophins in mammals and most other vertebrates, its stimulatory actions may be opposed by the potent inhibitory actions of dopamine (DA) in teleosts. This dual neuroendocrine control of reproduction by GnRH and DA has been demonstrated in various, but not all, adult teleosts, where DA participates in an inhibitory role in the neuroendocrine regulation of the last steps of gametogenesis (final oocyte maturation and ovulation in females and spermiation in males). This has major implications for inducing spawning in aquaculture. In addition, DA may also play an inhibitory role during the early steps of gametogenesis in some teleost species, and thus interact with GnRH in the control of puberty. Various neuroanatomical investigations have shown that DA neurones responsible for the inhibitory control of reproduction originate in a specific nucleus of the preoptic area (NPOav) and project directly to the region of the pituitary where gonadotrophic cells are located. Pharmacological studies showed that the inhibitory effects of DA on pituitary gonadotrophin production are mediated by DA-D2 type receptors. DA-D2 receptors have now been sequenced in several teleosts, and the coexistence of several DA-D2 subtypes has been demonstrated in a few species. Hypophysiotropic DA activity varies with development and reproductive cycle and probably is controlled by environmental cues as well as endogenous signals. Sex steroids have been shown to regulate dopaminergic systems in several teleost species, affecting both DA synthesis and DA-D2 receptor expression. This demonstrates that sex steroid feedbacks target DA hypophysiotropic system, as well as the other components of the brain-pituitary gonadotrophic axis, GnRH and gonadotrophins. Recent studies have revealed that melatonin modulates the activity of DA systems in some teleosts, making the melatonin-DA pathway a prominent relay between environmental cues and control of reproduction. The recruitment of DA neurons for the neuroendocrine control of reproduction provides an additional brain pathway for the integration of various internal and environmental cues. The plasticity of the DA neuroendocrine role observed in teleosts may have contributed to their large diversity of reproductive cycles.

Impact of immigration and HIV infection on tuberculosis incidence in an area of low tuberculosis prevalence.

The aim of this study is to assess the effects of immigration from countries with a high prevalence of tuberculosis (HPCs), of HIV/AIDS prevalence, and the ageing of the indigenous population, on tuberculosis distribution in a low-prevalence area (LPCs), the Piedmont Region of Italy. Tuberculosis incidence and HIV cases were identified by linking records from the surveillance systems. Overall, 640 tuberculosis cases were identified and crude annual incidence was found to be 17.3/100000. The incidence rate ratio for HIV infection as a risk factor for tuberculosis (11.4 and 51.9 among individuals from HPCs and LPCs respectively) was greater than that for immigration from HPCs (6.7 and 30.9 among HIV+ and HIV- individuals). Immigration accounted for a larger number of incident cases [population attributable risk % (PAR %): 31.8 and 52.8% among HIV+ and HIV- individuals] than did HIV infection (PAR %: 5.4 and 11.1% among individuals from HPCs and LPCs). Efforts should be made to identify and treat young immigrants from HPCs.

Dopaminergic inhibition of reproduction in teleost fishes: ecophysiological and evolutionary implications.

In many teleosts, dopamine (DA) exerts direct inhibitory control on gonadotropes, counteracting the stimulatory effect of gonadotropin-releasing hormone (GnRH) on gonadotropin release. This dual control by GnRH and DA has been demonstrated in various adult teleosts and has major implications for aquaculture. Because of its unique life cycle, the European eel has provided a powerful model for demonstrating the key role of DA in the control of puberty. Data from tetrapods suggest that the inhibitory role of DA on reproduction is not restricted to the teleosts. Thus, DA inhibitory control could represent an ancient evolutionary component in the neuroendocrine regulation of reproduction that may have been differentially maintained throughout vertebrate evolution. The intensity of DA inhibition, its main site of action, and its involvement in the control of puberty, seasonal reproduction, ovulation, spermiation, or even sex change may differ among classes of vertebrates, as well as within smaller phylogenetic units such as teleosts or mammals. An inhibitory role for DA has been reported also in some invertebrates, indicating that neuronal DA pathways may have been recruited in various groups of metazoa to participate in the control of reproduction. In addition to the incontestable GnRH neurons, the recruitment of DA neurons for the neuroendocrine control of reproduction provides an additional brain pathway for the integration of various species-specific, internal, and environmental cues. In teleosts, the plasticity of the DA neuroendocrine role may have contributed to their large diversity of biological cycles and to their successful adaptation to various environments.

Brain expression of tyrosine hydroxylase and its regulation by steroid hormones in the European eel quantified by real-time PCR.

In the eel, dopamine inhibits pubertal development. To investigate the regulatory mechanisms involved, we developed a quantitative real-time RT-PCR assay for measurement of brain expression of tyrosine hydroxylase (TH), the rate-limiting enzyme in the biosynthesis of dopamine. TH expression was highest in the olfactory bulb, followed by the di-/mesencephalic areas and the telencephalon/preoptic area. TH expression in the optic lobes and hindbrain was low or below the detection limit. In vivo treatment with testosterone, but not estradiol, resulted in increased TH expression in the forebrain, except the optic tectum, but not in the hindbrain. The results were confirmed by in situ hybridization.

Differential subcellular distribution and transcriptional activity of sigmaE3, sigmaE4, and sigmaE3-4 isoforms of the rat estrogen receptor-alpha.

E3, E4, and E3-4 are naturally occurring estrogen receptor (ER) isoforms, generated through differential splicing of the ERalpha primary transcript and abundantly expressed in embryonic rat pituitary. Studies in COS cells transfected with full-length ERalpha or its three splice variants fused to green fluorescent protein (GFP), revealed a different subcellular localization for each isoform. In the absence of estradiol, full-length ERalpha-GFP was predominantly nuclear, and E3-GFP and E4-GFP were present both in cytoplasm and nucleus, whereas E3-4-GFP was predominantly cytoplasmic. Upon hormone treatment, a dramatic redistribution of full-length ERalpha-GFP and E3-GFP, from a diffuse to punctate pattern, occurred within the nucleus. In contrast, the distribution of E4-GFP and E3-4-GFP was unaffected. Nuclear fractionation studies showed that full-length ER-alpha and E3 displayed the same hormone-induced ability to tether to nuclear matrix, whereas nuclear E4 appeared to remain loosely associated to functional nuclear constituents. When cotransfected with an estrogen-inducible reporter plasmid (VIT-TK-CAT) in ER-negative (CHO k1) and ER-positive pituitary (GH4 C1) cells, E3-4 exhibited a very weak estrogen-dependent transactivation activity, whereas E3 had an inhibitory effect on full-length ER action. Conversely, E4 displayed estrogen-independent transcriptional activity in ER-negative cells, and in ER-positive cells, enhanced the estrogen-induced gene expression as efficiently as full-length ERalpha. In a gel mobility shift assay, phosphorylated E4 was able to form a specific complex with a consensus ERE, while E3 and E3-4 never did bind by themselves. The observed inhibitory action of E3 on estrogen-dependent transcription would rather involve protein-protein interactions such as formation of heterodimers with full-length ERalpha, as suggested by immunoprecipitation followed by Western blotting. These data suggest that E3 and E4 may play a physiologically relevant role as negative or constitutively positive modulators of transcription, in the developing rat pituitary.

Alterations during positive selection in the thymus of nackt CD4-deficient mice.

The T-cell repertoire is shaped by the positive and negative selection of immature CD4(+) CD8(+) double positive (DP) thymocytes. Positive selection of DP T cells to the CD4(+) CD8(-) and CD4(-) CD8(+) simple positive (SP) lineages is a multistep process which involves cellular interactions between thymocytes and stromal cells. Mutant nackt (nkt/nkt) mice have been shown to have a deficiency in the CD4(+) CD8(-) T-cell subset both in the thymus and in the periphery. The present report suggests that nkt/nkt mice present alterations in early steps of positive selection because they show decreases in the percentages of CD69(+) and CD5(+) cells within the DP subset. Experiments involving bone marrow transfer and thymic chimeras demonstrate that the thymic epithelium of nkt/nkt mice is involved in the alterations registered during positive selection and dictates the ultimate fate of CD4(+) SP cells.

Two different types of concomitant resistance induced by murine tumors: morphological aspects and intrinsic mechanisms.

Concomitant resistance (CR) is the phenomenon according to which a tumor-bearing host inhibits the growth of a secondary implant of the same tumor at a distant site. Confirming and extending previous results of our laboratory, histological studies have revealed that two temporally separate peaks of CR can be detected throughout tumor evolution. The first peak induced by immunogenic small tumors, in euthymic but not in nude mice, is associated with extensive necrosis of the secondary tumor implant and a profuse infiltration of polymorphonuclear granulocytes and mononuclear cells resulting in its final destruction; these features correspond to a typical immunological rejection. The second peak of CR induced by both immunogenic and non-immunogenic large tumors, in euthymic as well as in nude mice, is characterized by a dormant tumor stage with scarce or null mononuclear infiltration, associated with a significant reduction of tumor mitotic index and of the number of PCNA+ cells along with an increase in apoptosis and an arrest in S phase. In previous reports we suggested that a 1000 D serum fraction from mice bearing large tumors could be responsible for the induction of this dormant tumor stage. In this study tumor cells incubated in vitro with that serum factor mimicked the inhibition and cellular alterations observed in vivo in the secondary tumor inhibited by the second peak of CR. Moreover, the passive transfer of this factor by the intra-peritoneal (i.p.) route induced an in vivo inhibition of an i.p. tumor reproducing the image characteristic of the second peak of CR. This represents a direct proof that this serum factor can restrain tumor growth in vivo and that it is, most probably, the effector of the second peak of CR.