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1.
Rev Med Liege ; 77(12): 728-732, 2022 Dec.
Article in French | MEDLINE | ID: mdl-36484751

ABSTRACT

Complete androgen insensitivity syndrome is the most frequent cause of disorder of sexual development in 46 XY patients. It is caused by mutations of the AR gene coding for the androgen receptor. Transmission is X-linked and mutations are most of the time inherited. It leads to a complete lack of response to androgen resulting in the presence of female external genitalia in 46 XY patients, normal but undescended testes and lack of female internal genitalia due to the secretion of anti-Müllerian hormone by male gonads. Traditionally, gonadectomy was proposed before puberty to decrease the risk of gonadal malignancy. However, more recent studies underlined the benefits of postponing gonadectomy until after pubertal development. Benefits of deferred gonadectomy are spontaneous pubertal development through peripheral aromatization of testosterone into oestrogens and the chance for the patient to have an active role in the decision-making process. After gonadectomy, hormone replacement therapy is required in order to prevent complications due to hypogonadism such as osteoporosis, cardiovascular diseases and a reduction of life expectancy.


L'insensibilité aux androgènes est l'étiologie principale des troubles du développement sexuel chez des patientes 46 XY. Elle est due à des mutations du gène AR qui code pour le récepteur des androgènes. Le mode de transmission est lié à l'X et les mutations sont le plus souvent héritées. Il en résulte une absence d'action des androgènes sur leurs récepteurs entraînant la présence d'organes génitaux externes féminins chez des patientes 46 XY, de testicules normalement développés en position abdominale ou inguinale et en l'absence d'organes génitaux internes féminins due à la sécrétion d'hormone anti-müllérienne par les gonades masculines. La gonadectomie était auparavant effectuée en période pré-pubertaire en raison du risque suspecté de développement de néoplasie maligne. Des données récentes suggèrent la possibilité de postposer cette intervention après le développement pubertaire. Le risque de transformation maligne pré-pubertaire des gonades est faible, et différer la gonadectomie permet un développement pubertaire naturel grâce à l'aromatisation périphérique de la testostérone en œstradiol. Ce délai permet d'impliquer activement la patiente dans la prise en charge de sa pathologie. Après la gonadectomie, un traitement hormonal substitutif par œstrogènes est indiqué pour prévenir les complications dues à l'hypogonadisme telles que l'ostéoporose, les maladies cardio-vasculaires et la réduction de l'espérance de vie.


Subject(s)
Androgen-Insensitivity Syndrome , Neoplasms , Humans , Male , Female , Androgen-Insensitivity Syndrome/genetics , Androgen-Insensitivity Syndrome/surgery , Androgen-Insensitivity Syndrome/complications , Anti-Mullerian Hormone/genetics , Mutation
2.
Rev Med Liege ; 75(5-6): 406-409, 2020 May.
Article in French | MEDLINE | ID: mdl-32496688

ABSTRACT

These last few years, new advances in technologies and modern insulin regimens have improved diabetes care for children and adolescents and have led to the definition of new therapeutic goals.


Au cours de ces dernières années, les nouvelles avancées technologiques et thérapeutiques ont marqué la prise en charge du diabète de l'enfant et de l'adolescent amenant ainsi à définir de nouveaux objectifs thérapeutiques.


Subject(s)
Diabetes Mellitus, Type 1 , Hypoglycemic Agents , Insulin , Adolescent , Child , Diabetes Mellitus, Type 1/drug therapy , Humans , Hypoglycemic Agents/therapeutic use , Insulin/therapeutic use
3.
J Neural Transm (Vienna) ; 125(3): 279-290, 2018 03.
Article in English | MEDLINE | ID: mdl-28168621

ABSTRACT

This paper reviews the major organizational features of calretinin interneurons in the dorsal striatum of rodents and primates, with some insights on the state of these neurons in Parkinson's disease and Huntington's chorea. The rat striatum harbors medium-sized calretinin-immunoreactive (CR+) interneurons, whereas the mouse striatum is pervaded by medium-sized CR+ interneurons together with numerous small and highly immunoreactive CR+ cells. The CR interneuronal network is even more elaborated in monkey and human striatum where, in addition to the small- and medium-sized CR+ interneurons, a set of large CR+ interneurons occurs. The majority of these giant CR+ interneurons, which are unique to the primate striatum, also display immunoreactivity for choline acetyltransferase (ChAT), a faithful marker of cholinergic neurons. The expression of CR and/or ChAT by the large striatal interneurons appears to be seriously compromised in Parkinson's disease and Huntington's chorea. The species differences noted above have to be considered to better understand the role of CR interneurons in striatal organization in both normal and pathological conditions.


Subject(s)
Calbindin 2/metabolism , Corpus Striatum/pathology , Huntington Disease/metabolism , Interneurons/metabolism , Parkinson Disease/metabolism , Animals , Corpus Striatum/metabolism , Disease Models, Animal , Huntington Disease/pathology , Interneurons/pathology , Parkinson Disease/pathology , Primates , Rodentia
4.
Eur J Neurosci ; 44(12): 3001-3010, 2016 12.
Article in English | MEDLINE | ID: mdl-27740705

ABSTRACT

Neurogenesis in the dentate gyrus is sensitive to endogenous and exogenous factors that influence hippocampal function. Ongoing neurogenesis and the integration of these new neurons throughout life thus may provide a sensitive indicator of environmental stress. We examined the effects of Aroclor 1254 (A1254), a mixture of polychlorinated biphenyls (PCBs), on the development and function of newly generated dentate granule cells. Early exposure to A1254 has been associated with learning impairment in children, suggesting potential impact on the development of hippocampus and/or cortical circuits. Oral A1254 (from the 6th day of gestation to postnatal day 21) produced the expected increase in PCB levels in brain at postnatal day 21, which persisted at lower levels into adulthood. A1254 did not affect the proliferation or survival of newborn neurons in immature animals nor did it cause overt changes in neuronal morphology. However, A1254 occluded the normal developmental increase in sEPSC frequency in the third post-mitotic week without altering the average sEPSC amplitude. Our results suggest that early exposure to PCBs can disrupt excitatory synaptic function during a period of active synaptogenesis, and thus could contribute to the cognitive effects noted in children exposed to PCBs.


Subject(s)
/toxicity , Excitatory Postsynaptic Potentials/drug effects , Hippocampus/drug effects , Hippocampus/growth & development , Neurons/drug effects , Prenatal Exposure Delayed Effects/physiopathology , Synapses/drug effects , Animals , Cell Proliferation/drug effects , Cell Survival/drug effects , Female , Hippocampus/physiology , Mice , Mice, Inbred C57BL , Neurogenesis/drug effects , Neurons/physiology , Pregnancy , Prenatal Exposure Delayed Effects/chemically induced , Synapses/physiology , Thyroid Hormones/metabolism
5.
Rev Med Liege ; 69 Spec No: 25-30, 2014.
Article in French | MEDLINE | ID: mdl-25796794

ABSTRACT

Epidemiological and experimental data highlight the fetal and early postnatal life as critical periods for the effects of endocrine disrupting chemicals (EDCs), since exposure to EDCs during these periods can predispose to disease later in life. EDCs' effects include disorders of the reproductive system throughout life (abnormalities of sexual differentiation, infertility or subfertility and some neoplasia) and disorders of energy balance (obesity and metabolic syndrome). They could also influence the development of the cerebral cortex. However, the demonstration of the involvement of a single EDC remains difficult in human since we are virtually exposed to a mixture of several ubiquitous EDCs which are variably persistent in the environment and the body and have lifelong consequences. Moreover, since their dose-response relationship can be non-monotonic, setting a threshold dose for EDCs effects has become meaningless. Pregnant women, newborns and young children appear to be mostly at risk. However, the role of the physician remains difficult and raises several questions: how can we formulate justified, applicable and updated recommendations that are not counterproductive or alarmist...in a society that has to take the necessary steps to regulate production and protect the population?


Subject(s)
Biomedical Research , Endocrine Disruptors , Public Health , Humans
6.
Rev Med Liege ; 68(10): 531-6, 2013 Oct.
Article in French | MEDLINE | ID: mdl-24298728

ABSTRACT

Neonatal hyperthyroidism is a rare pathology, most often the consequence of Graves' disease in the mother. Around 0.2% of pregnant women have Graves disease and 1 to 2% of newborns of mother with Graves' disease. This article will describe the case of 4 newborns who have been diagnosed and treated in CHU-NDB between 2007 and 2011. The second part will focus on the new recommendations about the management of these young patients from foetal period to birth.


Subject(s)
Graves Disease/complications , Hyperthyroidism/etiology , Pregnancy Complications/physiopathology , Female , Humans , Hyperthyroidism/physiopathology , Hyperthyroidism/therapy , Infant, Newborn , Male , Pregnancy , Pregnancy Complications/epidemiology
7.
Gynecol Obstet Fertil Senol ; 50(1): 69-74, 2022 Jan.
Article in French | MEDLINE | ID: mdl-34656789

ABSTRACT

AIM: Endometriosis is a disabling gynecological pathology. Couples who face it frequently encounter sexual difficulties related to dyspareunia. This study aims to understand the sexual experiences of endometriosis patients and their partners. METHODS: A total of 13 patients and 13 partners were interviewed prior to surgery. Semi-structured interviews were conducted separately and explored their sexual experiences. The interviews were transcribed verbatim and analyzed using content analysis. RESULTS: Both members of the couple reported pain during intercourses; decreased sexual desire; adaptation during sexual intercourses; communication about sexuality, which can be either open or a source of conflict, and the search for explanations for endometriosis. As for the emotional sphere, patients report anticipatory anxiety while partners report frustration and hope. CONCLUSION: These couples are in difficulty regarding sexuality, it is necessary to take care of both members of the couple and to encourage communication between them.


Subject(s)
Dyspareunia , Endometriosis , Dyspareunia/etiology , Endometriosis/complications , Female , Humans , Sexual Behavior/psychology , Sexual Partners/psychology , Sexuality/psychology
8.
Eur J Obstet Gynecol Reprod Biol ; 274: 40-47, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35580530

ABSTRACT

OBJECTIVE: To develop a research database for mother-and-child clinical and laboratory data and digital foetal heart rate (FHR) recordings. METHODS: The Base Bien Naître (BBN) database was derived from a single-centre health data warehouse. It contains exhaustive data on all parturients with a singleton pregnancy, a vaginal or caesarean delivery in labour with a cephalic presentation after at least 37 weeks of amenorrhea, and a live birth between February 1st, 2011, and December 31st, 2018. On arrival in the delivery room, the FHR was recorded digitally for at least 30 min. A cord blood sample was always taken in order to obtain arterial pH (pHa). More than 6,000 recordings were analyzed visually for the risk of foetal acidosis and classified into five groups (according to the French College of Gynaecologists and Obstetricians (CNGOF) classification) or three groups (according to the International Federation of Gynaecology and Obstetrics (FIGO) classification). RESULTS: Of the 16,089 files in the health data warehouse, 11,026 were complete and met the BBN's inclusion criteria. The FHR digital recordings were of good quality, with low signal loss (median [interquartile range]: 7.0% [4.3;10.9]) and a median recording time of 304 min [190;438]). In 3.7% of the children, the pHa was below 7.10. We selected a subset of 6115 records with good-quality FHR recordings over 120 min and reliable cord blood gas data: 692 (11.3%) had at least a significant risk of acidosis (according to the CNGOF classification), and 1638 (26.8%) were at least suspicious (according to the FIGO classification). CONCLUSION: The BBN database has been designed as a searchable tool with data reuse. It currently contains over 11,000 records with comprehensive data.


Subject(s)
Acidosis , Fetal Diseases , Female , Fetal Blood , Heart Rate, Fetal/physiology , Humans , Pregnancy
9.
Brain Struct Funct ; 226(6): 1879-1891, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34018041

ABSTRACT

Interneurons play a significant role in the functional organization of the striatum and some of them display marked plastic changes in dopamine-depleted conditions. Here, we applied immunohistochemistry on brain sections from 6-hydroxydopamine (6-OHDA) mouse model of Parkinson's disease and sham animals to characterize the regional distribution and the morphological and neurochemical changes of striatal interneurons expressing the calcium-binding protein calretinin (CR). Two morphological subtypes of calretinin-immunostained (CR +) interneurons referred, respectively, as small- and medium-sized CR + interneurons were detected in 6-OHDA- and sham-lesioned animals. The small cells (9-12 µm) prevail in the anterior and dorsal striatal regions; they stain intensely for CR and display a single slightly varicose and moderately arborized process. The medium-sized CR + interneurons (15-20 µm) are more numerous than the small CR + cells and rather uniformly distributed within the striatum; they stain weakly for CR and display 2-3 long, slightly varicose and poorly branched dendrites. The density of medium CR + interneurons is significantly decreased in the dopamine-depleted striatum (158 ± 15 neurons/mm3), when compared to sham animals (370 ± 41 neurons/mm3), whereas that of the small-sized CR + interneurons is unchanged (174 ± 46 neurons/mm3 in 6-OHDA-lesioned striatum and 164 ± 22 neurons/mm3 in sham-lesioned striatum). The nucleus accumbens is populated only by medium-sized CR + interneurons, which are distributed equally among the core and shell compartments and whose density is unaltered after dopamine denervation. Our results provide the first evidence that the medium-sized striatal interneurons expressing low level of CR are specifically targeted by dopamine denervation, while the small and intensely immunoreactive CR + cells remain unaffected. These findings suggest that high expression of the calcium-binding protein CR might protect striatal interneurons against an increase in intracellular calcium level that is believed to arise from altered glutamate corticostriatal transmission in Parkinson's disease.


Subject(s)
Parkinson Disease , Animals , Calbindin 2/metabolism , Calcium-Binding Proteins , Corpus Striatum/metabolism , Interneurons/metabolism , Mice , Oxidopamine/toxicity
10.
Rev Med Liege ; 65(11): 634-41, 2010 Nov.
Article in French | MEDLINE | ID: mdl-21189530

ABSTRACT

Congenital Isolated hypogonadotropic hypogonadism (CIHH) is caused by an inherited mechanism of impairment of the pituitary-gonadal axis, interfering with gonads' control. Currently, different forms of HHCI with (Kallmann syndrome or KS) or without anosmia-hyposmia are known. There are six forms of KS already described but in several cases no genetic mutation is found. The genetic anomalies already described are: KAL1 (locus Xp23) coding for anosmine-1, KAL-2 or FGFRI (8p11. locus 2 - p11.1) coding for Fibroblast Growth Factor Receptor 1 (FGFR1), KAL4 or PROk2 (locus 3p21.1) and KAL3 or ProKR2 (locus 20p13) coding respectively for the Prokinecitin-2 and its receptor, KAL5 or CHD7 (locus_8q12.1) coding for a chromodomain helicase DNA-binding protein-7 gene (CHD7) and lastly KAL6 or FGF8 (10Q 24 loci) coding for Fibroblast Growth Factor 8. The other genetic anomalies without anosmia are less frequent. These are associated either with Gnrhl gene (8p2-11. 2), GnRHR (4q21.2), GPR54 (19p13),TAC3R or neurokinine receptor 3 (4 q 25), LH (19q13.32) or FSH (11p13). The isolated congenital hypogonadotrophic hypogonadism phenotype is variable depending on gender, the importance of the deficit, and ultimately, according to a specific regulatory mechanism of the axis, affected by an inherited genetic anomaly. In this review, we describe the essential aspects of the different phenotypes and genotypes of HHCI, in order to assess clinicians an early disease's diagnosis and management.


Subject(s)
Hypogonadism/congenital , Hypogonadism/genetics , Diagnosis, Differential , Genetic Counseling , Humans , Hypogonadism/diagnosis , Hypogonadism/therapy
11.
J Neurol Neurosurg Psychiatry ; 80(2): 213-7, 2009 Feb.
Article in English | MEDLINE | ID: mdl-18653551

ABSTRACT

OBJECTIVE: To evaluate and identify the risk factors associated with the pathogenesis of congenital hydrocephalus in a large specific population. METHODS: An International Classification of Diseases (ICD)-9 database search of patients with congenital hydrocephalus treated at the University of Mississippi Medical Center between 1998 and 2007 was performed. All recruited patients were interviewed, assessing maternal age, onset of prenatal care, geographic location of pregnancy, maternal diabetes and chronic hypertension, pregnancy induced hypertension, pre-eclampsia, eclampsia, single or multiparous gestation, maternal alcohol, tobacco and drug use, infection and trauma during gestation, trauma or sexually transmitted disease at parturition, and other family members with hydrocephalus. RESULTS: In this 10 year retrospective study, several significant risk factors were identified among 596 well defined cases of congenital hydrocephalus. The identified risk factors included lack of prenatal care, multiparous gestation, maternal diabetes, maternal chronic hypertension, maternal hypertension during gestation and alcohol use during pregnancy. Of these patients with congenital hydrocephalus, 12.1% identified an additional family member also diagnosed with hydrocephalus. No differences in risk factors were identified between sporadic and familial congenital hydrocephalus cases except for an increased incidence of multiparous pregnancies and prenatal care in the first trimester in familial cases. CONCLUSIONS: A number of key risk factors have been identified to be strongly associated with the development of congenital hydrocephalus in an infant. The prevalence of familial patterns of inheritance for congenital hydrocephalus suggests a broader role for genetic factors in the pathogenesis of congenital hydrocephalus.


Subject(s)
Hydrocephalus/diagnosis , Hydrocephalus/etiology , Demography , Female , Humans , Hydrocephalus/genetics , Hypertension/epidemiology , International Classification of Diseases , Male , Mothers/statistics & numerical data , Pregnancy , Pregnancy Complications , Prenatal Care/statistics & numerical data , Retrospective Studies , Risk Factors
12.
J Neural Transm Suppl ; (73): 49-58, 2009.
Article in English | MEDLINE | ID: mdl-20411767

ABSTRACT

This paper reviews two of the major features of the nigrostriatal pathway, its axonal collateralization, and compartmental specificity, as revealed by single-axon labeling experiments in rodents and immunocytological analysis of human postmortem tissue. The dorsal and ventral tiers of the substantia nigra pars compacta harbor various types of neurons the axons of which branch not only within the striatum but also in other major components of the basal ganglia. Furthermore, some nigrostriatal axons send collaterals both to thalamus and to brainstem pedunculopontine tegmental nucleus. In humans, the compartmental specificity of the nigrostriatal pathway is revealed by the fact that the matrix compartment is densely innervated by dopaminergic fibers, whereas the striosomes display different densities of dopaminergic terminals depending on their location within the striatum. The nigral neurons most severely affected in Parkinson's disease are the ventral tier cells that project to the matrix and form deep clusters in the substantia nigra pars reticulata.


Subject(s)
Axons/physiology , Corpus Striatum/pathology , Neurons/cytology , Substantia Nigra/cytology , Animals , Cell Adhesion Molecules, Neuronal/metabolism , Dopamine/metabolism , Enkephalins/metabolism , Humans , Neural Pathways/physiology , Neurons/classification
13.
Transl Med UniSa ; 19: 109-115, 2019.
Article in English | MEDLINE | ID: mdl-31360675

ABSTRACT

In February 2017, the "Programma Mattone Internazionale Salute" (ProMis), that is the Italian Program for Internationalization of Regional Health Systems of the Ministry of Health (MoH), presented the first version of its Position Paper on Health Tourism, which embeds a first shared approach to the recommendations expressed by the European Committee of Regions (CoR) on "Age-Friendly" tourism. The CoR stresses the importance of local and regional authorities in the coordination of multi-sectoral policies such as healthcare, social assistance, transport, urban planning and rural development in relation to the promotion of mobility, security, accessibility of services, including health care and social services. "Age-friendly" tourism is an example of an innovative tourist offer that strives to meet the health needs of the entire "traveling" population, with an integrated and cross-sector approach that involves various organizations operating in sectors such as healthcare, accessibility and transport. The aim of the workshop was to explore the interest of the stakeholders to participate in a systemic action in the field of "health" tourism, and to identify priority implementation areas that offer opportunities to take advantage of validated, innovative experiences that strengthen the accessibility to health and social services in regional, national and international contexts. This effort provides the opportunity to take advantage of aligning the European Structural and Investment Funds (ESIF) to the development of tourism, coherently with the needs and resources of local and regional health authorities.

14.
Neuron ; 20(6): 1199-210, 1998 Jun.
Article in English | MEDLINE | ID: mdl-9655507

ABSTRACT

Activation of adenylyl cyclase and the consequent production of cAMP is a process that has been shown to be central to invertebrate model systems of information storage. In the vertebrate brain, it has been suggested that a presynaptic cascade involving Ca influx, cAMP production, and subsequent activation of cAMP-dependent protein kinase is necessary for induction of long-term potentiation (LTP) at the cerebellar parallel fiber-Purkinje cell synapse. We have used mutant mice in which the major Ca-sensitive adenylyl cyclase isoform of cerebellar cortex (type I) is deleted to show that this results in an approximately 65% reduction in cerebellar Ca-sensitive cyclase activity and a nearly complete blockade of cerebellar LTP assessed using granule cell-Purkinje cell pairs in culture. This blockade is not accompanied by alterations in a number of basal electrophysiological parameters and may be bypassed by application of an exogenous cAMP analog, suggesting that it results specifically from deletion of the type I adenylyl cyclase.


Subject(s)
Adenylyl Cyclases/genetics , Long-Term Potentiation/physiology , Purkinje Cells/enzymology , Adenylyl Cyclases/metabolism , Animals , Cell Membrane/enzymology , Cells, Cultured , Cyclic AMP/analogs & derivatives , Cyclic AMP/metabolism , Cyclic AMP/pharmacology , Electrophysiology , Enzyme Inhibitors/pharmacology , Excitatory Postsynaptic Potentials/drug effects , Excitatory Postsynaptic Potentials/physiology , Gait/physiology , Glutamic Acid/pharmacology , Mice , Mice, Inbred C57BL , Mice, Knockout , Mutation/physiology , Nerve Fibers/enzymology , Psychomotor Performance/physiology , Purkinje Cells/cytology , Purkinje Cells/ultrastructure , Thionucleotides/pharmacology
15.
Neuron ; 10(5): 899-906, 1993 May.
Article in English | MEDLINE | ID: mdl-7684235

ABSTRACT

We have previously shown that the expression of somatostatin-like immunoreactivity in cultured ciliary ganglion neurons is stimulated by a macromolecule found in choroid cell-conditioned medium (ChCM). Here, we present the following evidence that this somatostatin-stimulating activity (SSA) is activin: human recombinant activin induces somatostatin-like immunoreactivity in CG neurons; ChCM induces hemoglobin synthesis in K562 cells, a biological activity characteristic of activin; activin A-specific antibodies recognize a protein in ChCM; cultured choroid cells contain activin RNA; and SSA is inhibited by follistatin, a specific activin-binding protein. Thus, activin is likely to be a neurodifferentiation factor for CG neurons in vivo.


Subject(s)
Choroid Plexus/metabolism , Culture Media, Conditioned , Ganglia, Parasympathetic/metabolism , Inhibins/pharmacology , Somatostatin/biosynthesis , Activins , Animals , Blotting, Northern , Blotting, Western , Cells, Cultured , Chick Embryo , Choroid Plexus/chemistry , Follistatin , Ganglia, Parasympathetic/drug effects , Glycoproteins/pharmacology , Growth Substances/pharmacology , Hemoglobins/biosynthesis , Humans , Inhibins/genetics , RNA/analysis , Recombinant Proteins/pharmacology
16.
Neuron ; 8(6): 1045-53, 1992 Jun.
Article in English | MEDLINE | ID: mdl-1610564

ABSTRACT

Ciliary ganglion (CG) neurons undergo a period of cell death during development that may be regulated by the limited availability of trophic factor produced by their target tissues. We have previously reported the purification of a ciliary neurotrophic factor from adult chick sciatic nerve that we called growth promoting activity (GPA). Here we demonstrate that GPA can be purified and cloned from embryonic day 15 (E15) chick eyes, which contain all the target tissues of the CG. Our studies show the following: GPA mRNA is induced in embryonic chick eyes during the period of CG neuron cell death; GPA mRNA is expressed specifically in the layer of the eye that contains the targets of the CG and in primary cultures of smooth muscle cells isolated from the choroid layer of the eye; and biologically active GPA is released from cells transfected with a GPA cDNA.


Subject(s)
Cloning, Molecular , Embryonic and Fetal Development , Ganglia, Sympathetic/embryology , Nerve Tissue Proteins/genetics , Neurons/metabolism , Amino Acid Sequence , Animals , Base Sequence , Chick Embryo , DNA/genetics , Ganglia, Sympathetic/cytology , Ganglia, Sympathetic/metabolism , Molecular Sequence Data , Nerve Growth Factors/genetics , Nerve Growth Factors/metabolism , Nerve Tissue Proteins/metabolism , RNA, Messenger/metabolism
17.
J Neuroendocrinol ; 19(3): 181-8, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17280591

ABSTRACT

The present study aimed to investigate the effects of leptin and ghrelin on pulsatile pulsatile gonadotrophin-releasing hormone (GnRH) secretion in vitro with emphasis on neuropeptide mediators and changes between prepuberty (15 days) and sexual maturity (50 days) in the male rat. When hypothalamic explants were studied 90 min after an intraperitoneal injection of leptin, ghrelin or agouti-related protein (AgRP) at 15 days, the GnRH interpulse interval (IPI) was significantly increased by ghrelin and AgRP and decreased by leptin. At 50 days, an increase in GnRH IPI was also caused by ghrelin and AgRP. When the peptides were directly incubated with the explants, the effects of leptin and AgRP in vitro were consistent with those seen after in vivo administration. By contrast, ghrelin resulted in a reduction of GnRH IPI and this was observed at 15 days only. To delineate the neuropeptide mediators of leptin and the effects of ghrelin in the hypothalamus, various hypothalamic neuropeptides and antagonists were used in vitro. At 15 days, the GnRH IPI was significantly decreased after incubation with cocaine and amphetamine-regulated transcript (CART), alpha-melanocyte-stimulating hormone, corticotrophin-releasing factor (CRF) and neuropeptide Y (NPY). The reduction of GnRH IPI caused by leptin was partially prevented by either an anti-CART antiserum or SHU 9119, a melanocortin MC3/MC4 receptor antagonist or a CRF receptor antagonist. The NPY-Y5 receptor antagonist did not influence the effects of leptin whereas that antagonist totally prevented the decrease in GnRH IPI caused by ghrelin. The ghrelin-induced reduction of GnRH IPI was partially prevented by SHU 9119. When used alone, SHU 9119 or a CRF-receptor antagonist resulted in increased GnRH IPI at 50 days while they had no effects at 15 days. The NPY-Y5 receptor antagonist resulted in increased GnRH IPI at 15 and 50 days. In conclusion, leptin and ghrelin show opposing effects on pulsatile GnRH secretion after administration in vivo whereas they both have stimulatory effects in vitro. Such effects involve consistently the anorectic peptides CART and CRF for leptin that are mainly active at 15 days. The melanocortigenic system appears to mediate the effects of both leptin and ghrelin. The effects of ghrelin also involve NPY receptors and operate effectively before and at sexual maturity.


Subject(s)
Gonadotropin-Releasing Hormone/metabolism , Hypothalamus/metabolism , Leptin/physiology , Peptide Hormones/physiology , Sexual Maturation/physiology , Agouti-Related Protein , Analysis of Variance , Animals , Corticotropin-Releasing Hormone/metabolism , Female , Ghrelin , In Vitro Techniques , Intercellular Signaling Peptides and Proteins/physiology , Male , Nerve Tissue Proteins/metabolism , Periodicity , Rats , Rats, Wistar , Receptors, Melanocortin/physiology , Signal Transduction/physiology , Statistics, Nonparametric
18.
J Neuroendocrinol ; 19(11): 847-59, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17927663

ABSTRACT

Although it is well established that gonadotrophin-releasing hormone (GnRH) neurones and astrocytes maintain an intimate contact throughout development and adult life, the cell-surface molecules that may contribute to this adhesiveness remain largely unknown. In the peripheral nervous system, the glycosylphosphatidyl inositol (GPI)-anchored protein contactin is a cell-surface neuronal protein required for axonal-glial adhesiveness. A glial transmembrane protein recognised by neuronal contactin is receptor-like protein tyrosine phosphatase beta (RPTP beta), a phosphatase with structural similarities to cell adhesion molecules. In the present study, we show that contactin, and its preferred in cis partner Caspr1, are expressed in GnRH neurones. We also show that the RPTP beta mRNA predominantly expressed in hypothalamic astrocytes encodes an RPTP beta isoform (short RPTP beta) that uses its carbonic anhydrase (CAH) extracellular subdomain to interact with neuronal contactin. Immunoreactive contactin is most abundant in GnRH nerve terminals projecting to both the organum vasculosum of the lamina terminalis and median eminence, implying GnRH axons as an important site of contactin-dependent cell adhesiveness. GT1-7 immortalised GnRH neurones adhere to the CAH domain of RPTPbeta, and this adhesiveness is blocked when contactin GPI anchoring is disrupted or contactin binding capacity is immunoneutralised, suggesting that astrocytic RPTP beta interacts with neuronal contactin to mediate glial-GnRH neurone adhesiveness. Because the abundance of short RPTP beta mRNA increases in the female mouse hypothalamus (but not in the cerebral cortex) before puberty, it appears that an increased interaction between GnRH axons and astrocytes mediated by RPTP beta-contactin is a dynamic mechanism of neurone-glia communication during female sexual development.


Subject(s)
Astrocytes/metabolism , Cell Adhesion Molecules, Neuronal/metabolism , Cell Adhesion/physiology , Cell Communication/physiology , Neurons/metabolism , Receptor-Like Protein Tyrosine Phosphatases, Class 5/metabolism , Animals , Astrocytes/cytology , Cell Adhesion Molecules, Neuronal/genetics , Cells, Cultured , Contactins , Female , Gonadotropin-Releasing Hormone/genetics , Gonadotropin-Releasing Hormone/metabolism , Hypothalamus/cytology , Hypothalamus/physiology , Mice , Neurons/cytology , Receptor-Like Protein Tyrosine Phosphatases, Class 5/genetics , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism
19.
Mol Cell Biol ; 7(1): 111-20, 1987 Jan.
Article in English | MEDLINE | ID: mdl-3031450

ABSTRACT

We examined the relationship between pre-mRNA splicing and the nuclear matrix by using an in vivo system that we have developed. Plasmids containing the inducible herpesvirus tk gene promoter linked to an intron-containing segment of the rabbit beta-globin gene were transfected into HeLa cells, and then the promoter was transactivated by infection with a TK- virus. Northern analysis revealed that the globin pre-mRNA and all its splicing intermediates and products are associated with the nuclear matrix prepared from such transfected cells. When the nuclear matrix was incubated with a HeLa cell in vitro splicing extract in the presence of ATP, the amount of matrix-associated precursor progressively decreased without a temporal lag in the reaction, with a corresponding increase in free intron lariat. Thus, most of the events of the splicing process (endonucleolytic cuts and branching) occur in this in vitro complementation reaction. However, ligation of exons cannot be monitored in this system because of the abundance of preexisting mature mRNA. Since the matrix is not a self-splicing entity, whereas the in vitro splicing system cannot process efficiently deproteinized matrix RNA, we conclude from our in vitro complementation results (which can be reproduced by using micrococcal nuclease-treated splicing extract) that the nuclear matrix preparation retains parts of preassembled ribonucleoprotein complexes that have the potential to function when supplemented with soluble factors (presumably other than most of the small nuclear ribonucleoproteins known to participate in splicing) present in the HeLa cell extract.


Subject(s)
Cell Nucleus/metabolism , Nucleic Acid Precursors/genetics , RNA Splicing , RNA, Messenger/genetics , Animals , DNA Restriction Enzymes , Genes , Genes, Viral , Globins/genetics , HeLa Cells/metabolism , Humans , Plasmids , Promoter Regions, Genetic , RNA Precursors , Rabbits , Simplexvirus/genetics , Thymidine Kinase/genetics , Vero Cells
20.
Phys Med Biol ; 52(15): 4541-52, 2007 Aug 07.
Article in English | MEDLINE | ID: mdl-17634649

ABSTRACT

Most IMRT techniques have been designed to treat targets smaller than the field size of conventional linac accelerators. In order to overcome the field size restrictions in applying IMRT, we developed a two isocenter IMRT technique to treat long volume targets. The technique exploits an extended dose gradient throughout a junction region of 4-6 cm to minimize the impact of field match errors on a junction dose and manipulates the inverse planning and IMRT segments to fill in the dose gradient and achieve dose uniformity. Techniques for abutting both conventional fields with IMRT ('Static + IMRT') and IMRT fields ('IMRT + IMRT') using two separate isocenters have been developed. Five long volume sarcoma cases have been planned in Pinnacle (Philips, Madison, USA) using Elekta Synergy and Varian 2100EX linacs; two of the cases were clinically treated with this technique. Advantages were demonstrated with well-controlled junction target uniformity and tolerance to setup uncertainties. The junction target dose heterogeneity was controlled at a level of +/-5%; for 3 mm setup errors at the field edges, the junction target dose changed less than 5% and the dose sparing to organs at risk (OARs) was maintained. Film measurements confirmed the treatment planning results.


Subject(s)
Models, Biological , Neoplasms/radiotherapy , Radiometry/methods , Radiotherapy Planning, Computer-Assisted/methods , Radiotherapy, Conformal/methods , Computer Simulation , Humans , Organ Size , Radiotherapy Dosage
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