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61.
Comparative distribution of nicotinic receptor subtypes during development, adulthood and aging: an autoradiographic study in the rat brain 总被引:6,自引:0,他引:6
The distribution in the rat brain of high affinity nicotinic heteromeric acetylcholine receptors and of low affinity nicotinic, alpha7-containing, homomeric receptors was studied using in vitro light microscopic autoradiography. As ligands, we used [3H]epibatidine, or [125I]epibatidine, and [125I]alpha-bungarotoxin, respectively. In adult animals, the two types of binding sites were widely distributed in many different brain structures, including the brainstem, cerebellum, mesencephalic structures, limbic system and cortex, but their anatomical distribution differed markedly. Only in rare instances could a co-localization be observed, for example in the superficial layer of the superior colliculus. In developing animals, both types of labeling were strongly expressed during embryonic and postnatal phases. Their distributions were qualitatively similar to those observed in adult animals, with a few noticeable exceptions in the cerebral cortex, hippocampus and brain stem. In aging animals, neither the distribution nor the density of nicotinic binding sites was significantly altered. Our conclusions are the following. (a) There is little overlap in the distribution of heteromeric and alpha7-containing homomeric nicotinic receptors in the rat brain. (b) The abundance of neuronal nicotinic receptors during embryonic and postnatal development suggests that they may play a role in the establishment of neuronal connectivity. (c) The expression of neuronal nicotinic receptors is unaltered in middle aged animals, suggesting that in the rat these receptors do not play any major role in aging process. 相似文献
62.
C. Sorlié O. Bertrand B. Yvert J. -C. Froment J. Pernier 《Medical & biological engineering & computing》1997,35(3):239-245
A method has been developed to match a standard digitised brain atlas onto MR images for identification of cerebral structures
in anatomical images. This method uses, first, a three-dimensional crude registration based on the proportional system of
Talairach. Then, a two-dimensional refined registration is performed using a deformation function based on a set of homologous
landmarks on both images (MR and atlas). Displacements vectors are computed between each corresponding landmark. These vectors
are interpolated by thin-plate splines, generating an unwarping function defined on the whole image. This function can then
be applied on any structure of the atlas. An evaluation of the matching procedure has been performed. First, the influence
of the choice of the landmarks has been evaluated for the fine registration method. The latter has been then compared to the
crude registration method considered as a classical reference method. These results show the advantages of the fine registration
approach. 相似文献
63.
Serotonin (5-HT) is a key modulator of neuronal excitability in the central and peripheral nervous system. In the enteric nervous system, 5-HT causes a slow depolarization in the intrinsic sensory neurons, but the receptor responsible for this has not been correlated with known gene products. The aim of this study was to determine whether the newly characterized 5-HT7 receptor may participate in the 5-HT-mediated depolarization of, and synaptic transmission to, the intrinsic sensory neurons of the guinea-pig ileum. Intracellular electrophysiological recordings were made from intrinsic sensory neurons identified as myenteric AH neurons from guinea-pig ileum. 5-HT (5 microM) applied to the cell body evoked both a fast depolarization (5-HT3 mediated) and/or a slow depolarization (5-HT1P-like). The 5-HT1/5/7 receptor agonist 5-carboxamidotryptamine (5-CT) (5 microM) evoked only a slow depolarization. When the fast depolarization evoked by 5-HT was blocked with granisetron (1 microM, 5-HT3 receptor antagonist), only a slow depolarization remained; this was abolished by the 5-HT7 receptor antagonist SB 269970 (1 microM, control: 14+/-2 mV, granisetron+SB 269970: -1+/-2 mV). The slow depolarization evoked by 5-CT was also significantly reduced by SB 269970 (control: 14+/-1 mV, SB 269970: 5+/-2 mV) suggesting a 5-HT7 receptor was activated by exogenous application of 5-CT and 5-HT. Slow excitatory postsynaptic potentials evoked by stimulating descending neural pathways (containing serotonergic fibers) were reduced by SB 269970 (control: 8+/-3 mV, SB 269970: 3+/-1 mV). However, SB 269970 had no effect on slow excitatory postsynaptic potentials evoked by stimulation of circumferential (tachykinergic) pathways (control: 7+/-1 mV, SB 269970: 6+/-1 mV). These data are consistent with the presence on enteric AH neurons of functional 5-HT7 receptors that participate in slow synaptic transmission. 相似文献
64.
Genetic heterogeneity of the NS3 protease gene in hepatitis C virus genotype 1 from untreated infected patients 总被引:3,自引:0,他引:3
Vallet S Gouriou S Nousbaum JB Legrand-Quillien MC Goudeau A Picard B 《Journal of medical virology》2005,75(4):528-537
NS3 protease is essential for hepatitis C Virus (HCV) replication, and is one of the most promising targets for specific anti-HCV therapy. Its natural polymorphism has not been studied at the quasispecies level. In the present work, the genetic heterogeneity of the NS3 protease gene was analyzed in 17 HCV genotype 1 (5 subtypes 1a and 12 subtypes 1b) samples collected from infected patients before anti-viral therapy. A total of 294 clones were sequenced. Although the protease NS3 is considered to be one of the less variable genes in the HCV genome, variability of both nucleotide and amino acid sequences was found. In variants belonging to 1a and 1b subtypes, 224 and 267 of 543 positions showed one or more nucleotide substitutions, respectively. Forty and 74 of the 181 NS3 amino acid positions showed at least one mutation in HCV-1a and HCV-1b isolates, respectively. Most substitutions were conservative. This substantial polymorphism of the NS3 protease produced by HCV-1a and HCV-1b suggests that, despite the numerous functional and structural constraints, the enzyme is sufficiently flexible to tolerate substitutions. 相似文献
65.
Jannot AS Meziani R Bertrand G Gérard B Descamps V Archimbaud A Picard C Ollivaud L Basset-Seguin N Kerob D Lanternier G Lebbe C Saiag P Crickx B Clerget-Darpoux F Grandchamp B Soufir N Melan-Cohort 《European journal of human genetics : EJHG》2005,13(8):913-920
The occuloalbinism 2 (OCA2) gene, localized at 15q11, encodes a melanosomal transmembrane protein that is involved in the most common form of human occulo-cutaneous albinism, a human genetic disorder characterized by fair pigmentation and susceptibility to skin cancer. We wondered whether allele variations at this locus could influence susceptibility to malignant melanoma (MM). In all, 10 intragenic single-nucleotide polymorphisms (SNPs) were genotyped in 113 patients with melanomas and in 105 Caucasian control subjects with no personal or family history of skin cancer. By comparing allelic distribution between cases and controls, we show that MM and OCA2 are associated (p value=0.030 after correction for multiple testing). Then, a recently developed strategy, the 'combination test' enabled us to show that a combination formed by two SNPs was most strongly associated to MM, suggesting a possible interaction between intragenic SNPs. In addition, the role of OCA2 on MM risk was also detected using a logistic model taking into account the presence of variants of the melanocortin 1 receptor gene (MC1R, a key pigmentation gene) and all pigmentation characteristics as melanoma risk factors. Our data demonstrate that a second pigmentation gene, in addition to MC1R, is involved in genetic susceptibility to melanoma. 相似文献
66.
P Gautier P Guiraudou F Pezziardi J P Bertrand J P Gagnol 《Journal of cardiovascular pharmacology》1987,9(5):601-610
The intracellular electrophysiologic properties of a new antiarrhythmic substance, penticainide, were studied in isolated rabbit, dog, and guinea pig myocardial preparations superfused or perfused with oxygenated Tyrode's solution. "Therapeutic" concentrations of penticainide (1.5 to 3 X 10(-5) M) had little effect on sinus node automaticity; sinoatrial conduction was slightly delayed. In atrial, Purkinje and ventricular fibers, amplitude, and maximal rate of rise of phase O (dV/dtmax) were decreased by penticainide; Purkinje-ventricle conduction velocity was depressed. Penticainide did not significantly modify action potential duration (APD) of rabbit atria and dog ventricle and reduced APD and effective refractory period (ERP) of dog Purkinje and guinea pig ventricular fibers. Penticainide reduced APD heterogeneity of Purkinje-ventricle junction with a preferential effect at the gate and decreased tension amplitude of perfused papillary muscle in dog heart. The effect of penticainide on dV/dtmax was voltage and rate dependent; the resting block was weak. Thus, penticainide is a class 1 antiarrhythmic agent with properties of class 1B agents such as APD reduction and properties of class 1C agents such as slow recovery kinetic of rate-dependent block. 相似文献
67.
Juliana Chen Solne Bertrand Olivier Galy David Raubenheimer Margaret Allman-Farinelli Corinne Caillaud 《Nutrients》2021,13(5)
The food environment in New Caledonia is undergoing a transition, with movement away from traditional diets towards processed and discretionary foods and beverages. This study aimed to develop an up-to-date food composition database that could be used to analyze food and nutritional intake data of New Caledonian children and adults. Development of this database occurred in three phases: Phase 1, updating and expanding the number of food items to represent current food supply; Phase 2, refining the database items and naming and assigning portion size images for food items; Phase 3, ensuring comprehensive nutrient values for all foods, including saturated fat and total sugar. The final New Caledonian database comprised a total of 972 food items, with 40 associated food categories and 25 nutrient values and 615 items with portion size images. To improve the searchability of the database, the names of 593 food items were shortened and synonyms or alternate spelling were included for 462 foods. Once integrated into a mobile app-based multiple-pass 24-h recall tool, named iRecall.24, this country-specific food composition database would support the assessment of food and nutritional intakes of families in New Caledonia, in a cross-sectional and longitudinal manner, and with translational opportunities for use across the wider Pacific region. 相似文献
68.
69.
The effects of zinc gluconate have been studied on rat peritoneal mast cells and rat basophilic leukemia cells (RBL 2H3) stimulated by various secretagogues. The IC50's of zinc gluconate on peritoneal cells were (microM): 1.6, 1.9, 5.4 and 18 for ionophore A23187, phorbol 12-myristate 13-acetate, substance P and immunoglobulin E-antigen, respectively. Higher concentrations of zinc gluconate were required to inhibit histamine secretion from RBL 2H3 cells, i.e. 12 microM (ionophore A23187) and 140 microM (immunoglobulin E-antigen). Zinc gluconate (10(-4) to 10(-3) M) also inhibited the IgE-dependent contraction of guinea pig trachea but was unable to affect that induced by exogenous histamine. These results suggest that zinc gluconate acts intracellularly and is selective of "typical" or "connective tissue" mast cells. 相似文献
70.
Nausicaa Christodoulou Léa Bertrand Laura Palagini Justine Frija-Masson Marie-Pia d'Ortho Michel Lejoyeux Dieter Riemann Julia Maruani Pierre A. Geoffroy 《Journal of sleep research》2023,32(1):e13752
Insomnia is the most frequent sleep disorder and a public health concern that increased during the Covid 19 pandemic. Fully restrictive lockdowns during Covid are interesting periods to examine the impact of environmental and behavioural changes on the emergence of insomnia symptoms. In this cross-sectional study we aimed to (1) determine the main factors associated with insomnia symptoms during a Covid-19 fully restrictive lockdown examining the associated daily life alterations and (2) create a predictive model of insomnia symptoms. We used the data drawn from the “Covid-RythmE” study that reached volunteers from the general French population through an online survey during the last 2 weeks of the 2 month full lockdown. Associations with insomnia symptoms were tested and significant associations were entered in a Backward Stepwise Logistic Regression (BSLR) to assess the best combination to classify individuals with or without insomnia symptoms. From the 1624 participants, 50.64% suffered from mild to severe insomnia symptoms as assessed by the ISI. The best combination for explaining insomnia symptoms with 74.26% of accuracy included: age (OR = 1.15), females (OR = 1.26), smaller home sizes (OR = 0.77), environmental noises (OR = 1.59), anxiety symptoms (OR = 1.24), depressive symptoms (OR = 1.15), regularity of sleep–wake schedules (OR = 1.25), exposure to screen during the morning (OR = 1.13), and LED light during the evening (OR = 1.17). Thus, lifestyle schedule and exposure to natural synchronizers such as light, are primordial in considering in insomnia physiopathology, prevention and treatment, as well as the associated mental health status. 相似文献