Publications by authors named "Mitchell V"

We have recently shown that the mRNA encoding for a type I receptor for transforming growth factor beta and activin - named B1 - is expressed in hypothalamic areas implicated in gonadotropin-releasing hormone regulation, particularly in estrogen-receptive regions. In the present study, we examined whether ovarian steroids may regulate expression of B1 mRNA in the hypothalamus. Comparing relative levels of B1 mRNA expression in ovariectomized (OVX), OVX + estradiol-treated, and OVX + estradiol + progesterone-treated female rats, we observed that estrogen significantly (p < 0.

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It has become apparent that galanin as well as proopiomelanocortin-derived peptides, such as beta-endorphin, play an important role in the hypothalamic circuitry that regulates neuroendocrine functions and appetite behavior. We have recently shown that GalR1 and GalR2 galanin receptor mRNAs are expressed in proopiomelanocortin neurons of the arcuate nucleus, suggesting a direct modulatory action of galanin on the proopiomelanocortin neuronal system. In the present study, we investigated the effect of galanin on beta-endorphin release and proopiomelanocortin mRNA expression from male rat mediobasal hypothalamic fragments incubated ex vivo.

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The presence of the iron-binding protein lactoferrin (Lf) in some specific areas of the central nervous system and particularly in the normal human substantia nigra, where it is found in dopaminergic (DA) neurons and some glial cells, led us to investigate Lf synthesis in this area. Lf mRNA were identified using in situ hybridization and found in small ameboid cells. These cells were identified using immunocytochemistry as activated microglia since they exhibited macrophage markers such as the CD68 and the CR1 antigens.

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The purpose of the present study was to determine whether TGF beta, a cytokine secreted by hypothalamic astrocytes, was able to regulate POMC neurons in the arcuate nucleus. In a first set of experiments, mediobasal hypothalamic fragments were exposed to TGF beta(1), and the relative POMC mRNA expression was assessed by in situ hybridization using a radiolabeled POMC riboprobe. The results showed that 4 x 10(-10) M TGF beta(1) was efficient in decreasing significantly the amounts of POMC mRNA (P < 0.

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In a attempt to improve the sensitivity of the simultaneous use of immunohistochemistry (IHC) with estrogen receptor (ER) and in situ hybridization (ISH) with a neuropeptide receptor, we first applied an existing microwave (MW) irradiation protocol for immunohistochemical detection of the estrogen receptor in frozen brain sections. Regions of interest were the preoptic area and the arcuate nucleus of the hypothalamus. ER signal was effective only after MW heating of sections in the two regions.

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Growth hormone secretagogues (GHSs) act at distinct levels to control growth hormone (GH) secretion. At the pituitary level they reinforce or extend a tonic GH-releasing-hormone (GHRH)-induced activated state by mobilizing intracellular Ca2+ store. At the hypothalamic level GHS actions are more complex than originally anticipated.

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Using the antibody microprobe method, the sites of spinal release of immunoreactive brain-derived neurotrophic factor (BDNF) was studied in normal rats, and rats with prior sciatic nerve transection. In normal rats, a significant basal release of immunoreactive BDNF was found in the superficial dorsal horn. Following sciatic nerve transection (performed 14 days previously), release of BDNF was found throughout the whole of the dorsal horn, extending into deeper laminae.

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The forebrain and pituitary sites of synthesis of growth hormone secretagogue-receptor mRNA were identified in four adult lemurs (Microcebus murinus) by in situ hybridisation performed with a radiolabeled cRNA probe transcribed from human Growth Hormone Secretagogue-Receptor cDNA. The cRNA sense and antisense probes were hybridised to cryostat sections containing structures extending from the rostral hypothalamus to its caudal limit as defined by the mammillary bodies. The pituitary gland and areas adjacent to the hypothalamus were also analyzed.

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Nitric oxide (NO) as well as beta-endorphin are involved in the neuroendocrine control of gonadotropin-releasing hormone (GnRH) secretion. Recently, morphological and microdialysis experiments have suggested that beta-endorphin may exert an inhibitory influence on NO release in the preoptic area of rat hypothalamus. The present study determines if the mu opioid receptor mRNA is expressed in neuronal NO synthase (nNOS)-immunopositive neurons and if this expression varies among the regions of the basal forebrain being examined.

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The present study was designed to determine whether transforming growth factor (TGF)beta and/or activin participate in the regulation of the gonadotropin releasing hormone (GnRH) neuroendocrine axis in vivo. Single-label in situ hybridization histochemistry was used to determine the anatomical distribution of a TGFbeta and activin type I receptor (B1) mRNA, in the adult female rat hypothalamic areas that are known to be important sites for the regulation of reproduction. Dual-label in situ hybridization histochemistry was performed to determine whether B1 mRNA was expressed in GnRH neurones.

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Previous studies have shown that galanin-containing fibers make synaptic contacts with POMC neurons in the arcuate nucleus. However, the ability of POMC neurons to express galanin receptors has never been assessed. The present study was designed to investigate whether POMC neurons express galanin receptor messenger RNA (mRNA) and whether testosterone could modulate galanin receptor gene expression.

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We have shown previously at the ultrastructural level that morphological changes occur in the external zone of the median eminence allowing certain GnRH nerve terminals to contact the pericapillary space on the day of proestrus. The present study was designed to determine whether the intrinsic determinant of neuronal outgrowth, growth-associated protein-43 (GAP-43), was expressed in GnRH neurons of adult female rats, and whether its expression varied throughout the estrous cycle. To accomplish this, we perfusion-fixed groups of adult female rats at 0800 and 1600 h on diestrous day 2 (diestrous II), at 0800 h and 1600 h on proestrus, and at 0800 and 1600 h on estrus (n = 4 rats/group) and used double labeling in situ hybridization and quantification to compare the levels of GAP-43 messenger RNA (mRNA) in cells coexpressing GnRH mRNA.

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The presence of iron in brain tissue in increased concentrations in Parkinson's disease cases, where it might be responsible for oxidative stress, and the parallel observation that the iron transporter lactoferrin (Lf) was present in increased amounts in surviving neurons, led us to study the synthesis of Lf in a mouse model of Parkinson's disease. In this context, the origin and expression of brain Lf in normal, aged and MPTP (1-methyl-4-phenyl-1, 2,3,6-tetrahydropyridine)-treated mice were investigated. Lf immunostaining was observed mainly on microvessels in the cerebral cortex of the adult mice and to a greater extent in older mice.

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Previous studies have shown that galanin plays an important role in the regulation of gonadotropin releasing hormone (GnRH) release. At present, it is not known if this role is exerted by direct or indirect interactions between galanin producing neurones and GnRH neurones. The objective of this study was to determine whether or not GnRH neurones could express galanin receptor Gal-R1 mRNA.

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Unlabelled: Although local anesthetics can, in some situations, alleviate neuropathic pain, currently available preparations are short-acting and nonselective, producing, for example, motor dysfunction. Clinical studies report that a novel suspension preparation of butamben has the advantage of a prolonged duration of action, and it can be used epidurally, without impairment of motor function. In this behavioral study, we investigated the effect of the epidural administration of a 5% butamben suspension on nerve injury-induced allodynia.

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The distribution of galanin receptor subtype 2 (Gal-R2) mRNA-expressing cells was examined by in situ hybridization in the rat hypothalamus using a full-length rat 35S-riboprobe. Gal-R2 receptor mRNA-expressing cells were found at moderate to high levels of expression in most nuclei and regions of hypothalamus. The labeling was observed within well-defined anatomical nuclei: preoptic, suprachiasmatic, periventricular, paraventricular, arcuate, dorsomedial, mammillary nuclei.

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It has been previously demonstrated that the activity of proopiomelanocortin (POMC)-containing neurons in the rat arcuate nucleus is regulated by opiates, but the expression of opioid receptors in POMC neurons has never been reported. In the present study, we have applied a double-labeling in situ hybridization technique to investigate the occurrence of mu-opioid receptor mRNA on POMC neurons. We have found that 20+/-3% of arcuate POMC neurons express mu-opioid receptor mRNA and that the proportion of POMC neurons expressing mu-opioid receptor is higher in the caudal than in the rostral portion of the arcuate nucleus.

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By in situ hybridization, we show the ability of human neuroblastoma SY 5Y cells to synthesize apolipoprotein E (apoE) mRNA. This synthesis varied during cell NGF-differentiation: the mRNA level decreased during the first 4 days of NGF treatment (NGF 4 days) and then increased during the 3 following days (NGF 7 days). Furthermore, a treatment of 4-day NGF differentiated cells with exogenous apoE during 3 additional days induced a clear decrease in apoE mRNA synthesis when compared with control cells.

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Air, saline and a mixture of nitrous oxide and oxygen were used to inflate the cuffs of tracheal tubes inserted into three groups of patients, during nitrous oxide anaesthesia. Large increases in intracuff pressure were seen in the air group, but no morbidity resulted. The intracuff pressure decreased in the gas mix group and leaks occurred in some patients.

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The biological role and origin of human lactoferrin (Lf) within the brain in normal and disease processes are as yet uncharted. In this context the origin and expression of brain Lf in normal and MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine)-treated mice were investigated using immunohisto chemistry, PCR amplification and in situ hybridization. Lf immunostaining was observed both on sections of mouse lactating mammary gland, which was used as a positive control, and brains from young, adult and aged mice.

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Variations in the number of galanin receptor (Gal-R1)-expressing cells and levels of Gal-R1 messenger RNA (mRNA) were determined in the preoptic area in intact female rats throughout the phases of the estrous cycle and compared with those in the male. Female and male Wistar rats were fixed by perfusion with 4% paraformaldehyde. Cryostat sections were hybridized with a 35S-labeled antisense Gal-R1 riboprobe.

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We report a 23-year-old woman presenting with multiple cutaneous infarcts who was found to have spontaneous platelet aggregation (SPA). Her skin lesions showed a good response to aspirin therapy and platelet aggregation returned to normal. Subsequently, she was found to have and was treated for pulmonary tuberculosis.

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The relationship of subsyndromal depression to syndromal depression is unclear. Increased sensitivity of platelet serotonin type 2 receptor has been reported in depression using the Fura-2 technique. The sensitivity of the platelet serotonin type 2 receptor was assessed using the Fura-2 method in 16 patients with subsyndromal depression and 14 controls.

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Findings are presented from a thematic content analysis of individual and group interviews in which 26 lesbian mothers were asked about their concerns, values, and hopes regarding their children's sex education; about what they have done and plan to do with regard to sex education; and about how they evaluate their efforts to date. Themes, linked to the children's age, are described and illustrated with vignettes and observations from the participants.

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