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1.
Dev Psychobiol ; 63(6): e22186, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34423851

RESUMO

Data in both humans and preclinical animal models clearly indicate drug exposure during adolescence, when the "reward" circuitry of the brain develops, increases the risk of substance use and other mental health disorders later in life. Human data indicate that different neural and behavioral sequelae can be observed in early versus late adolescence. However, most studies with rodent models examine a single adolescent age compared to a mature adult age, and often only in males. Herein, we sought to determine whether the acute response to the opioid morphine would also differ across adolescence, and by sex. By quantifying Fos positive cells, a proxy for neural activity, at different stages during adolescence (pre-, early, mid-, and late adolescence) and in multiple reward regions (prefrontal cortex, nucleus accumbens, caudate/putamen), we determined that the neural response to acute morphine is highly dependent on adolescent age, sex, and brain region. These data suggest that heterogeneity in the consequences of adolescent opioid exposure may be due to age- and sex-specific developmental profiles in individual reward processing regions. In future studies, it will be important to add age within adolescence as an independent variable for a holistic view of healthy or abnormal reward-related neural development.


Assuntos
Morfina , Núcleo Accumbens , Animais , Encéfalo , Feminino , Masculino , Morfina/farmacologia , Núcleo Accumbens/metabolismo , Córtex Pré-Frontal/fisiologia , Recompensa
2.
Mol Psychiatry ; 22(4): 625-633, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27166760

RESUMO

Contactin genes CNTN5 and CNTN6 code for neuronal cell adhesion molecules that promote neurite outgrowth in sensory-motor neuronal pathways. Mutations of CNTN5 and CNTN6 have previously been reported in individuals with autism spectrum disorders (ASDs), but very little is known on their prevalence and clinical impact. In this study, we identified CNTN5 and CNTN6 deleterious variants in individuals with ASD. Among the carriers, a girl with ASD and attention-deficit/hyperactivity disorder was carrying five copies of CNTN5. For CNTN6, both deletions (6/1534 ASD vs 1/8936 controls; P=0.00006) and private coding sequence variants (18/501 ASD vs 535/33480 controls; P=0.0005) were enriched in individuals with ASD. Among the rare CNTN6 variants, two deletions were transmitted by fathers diagnosed with ASD, one stop mutation CNTN6W923X was transmitted by a mother to her two sons with ASD and one variant CNTN6P770L was found de novo in a boy with ASD. Clinical investigations of the patients carrying CNTN5 or CNTN6 variants showed that they were hypersensitive to sounds (a condition called hyperacusis) and displayed changes in wave latency within the auditory pathway. These results reinforce the hypothesis of abnormal neuronal connectivity in the pathophysiology of ASD and shed new light on the genes that increase risk for abnormal sensory perception in ASD.


Assuntos
Percepção Auditiva/genética , Transtorno do Espectro Autista/genética , Contactinas/genética , Adolescente , Adulto , Transtorno do Deficit de Atenção com Hiperatividade/genética , Transtorno do Espectro Autista/metabolismo , Criança , Contactinas/metabolismo , Variações do Número de Cópias de DNA , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Mutação , Polimorfismo de Nucleotídeo Único
3.
Nat Mater ; 13(1): 74-80, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24270583

RESUMO

Combining functionalities in devices with high performances is a great challenge that rests on the discovery and optimization of materials. In this framework, layered oxides are attractive for numerous purposes, from energy conversion and storage to magnetic and electric properties. We demonstrate here the oxygen storage ability of ferroelectric LuFe2O4+x within a large x range (from 0 to 0.5) and its cycling possibility. The combination of thermogravimetric analyses, X-ray diffraction and transmission electron microscopy evidences a complex oxygen intercalation/de-intercalation process with several intermediate metastable states. This topotactic mechanism is mainly governed by nanoscale structures involving a shift of the cationic layers. The ferrite is highly promising because absorption begins at a low temperature (~=200 °C), occurs in a low oxygen pressure and the uptake of oxygen is reversible without altering the quality of the crystals. The storage/release of oxygen coupled to the transport and magnetic properties of LnFe2O4 opens the door to new tunable multifunctional applications.

4.
Behav Brain Res ; 429: 113919, 2022 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-35525338

RESUMO

Interest in the role of sex as a biological variable has increased, including a mandate for the study of both sexes in NIH-funded research. As sex differences exist in both human chronic pain conditions and rodent models of nociception, it is critical to understand the impact of sex in nociceptive assays. Choice-based thermal nociceptive tests permit the study of avoidance responses to thermal stimuli compared to traditional nociceptive assays, which measure nocifensive reactions. However, to date no comparison of male and female responses to choice-based tests has been published. Herein, we examined the effect of sex on two choice-based thermal nociceptive tests, the thermal gradient test and the temperature place preference test, in adult rats. The activation of a 10 °C-to-47 °C thermal gradient results in an increase in time spent in the 10 °C zone in females, compared to a reduction in males. Additionally, in a temperature place preference test pairing a surface temperature of 22 °C with either 5 °C, 10 °C, 47 °C, or 50 °C, females appeared to have overall greater tolerance for non-ambient temperatures. Males spent less than 50% of their time in every non-22 °C zone, whereas in females this was only observed when testing 5 °C and 50 °C. Together, these results suggest that male rats show more avoidance behavior than females to both hot and cold non-ambient temperatures when given free access to multiple zones, including at milder temperatures than those typically used to evoke a nociceptive response in traditional hot and cold plate tests.


Assuntos
Limiar da Dor , Caracteres Sexuais , Animais , Feminino , Temperatura Alta , Masculino , Nociceptividade/fisiologia , Medição da Dor/métodos , Limiar da Dor/fisiologia , Ratos
5.
J Neurosci Methods ; 348: 108982, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33091429

RESUMO

BACKGROUND: The use of immunohistochemistry to quantify neural markers in various brain regions is a staple of neuroscience research. Numerous programs exist to automate quantification, but manual assignment of regions of interest (ROIs) within individual brain sections remains time consuming and can introduce interobserver variability. NEW METHOD: We have developed a novel open source FIJI-based immunohistochemical data analysis pipeline, Atlas-Based Analysis (ABA). ABA uses landmark-based image warping to adjust the experimental image to closely align with a published rat brain atlas. c-Fos positive cells are then quantified within predetermined ROI coordinates derived from the brain atlas. Image warping adjusts for natural variation in brain sections to ensure reliable alignment of ROIs for data analysis. This pipeline can be adapted for new atlases, landmarks, ROIs, and quantification measurements. RESULTS: ABA permits rapid quantification of immunoreactivity in multiple ROIs and produces results with high levels of interobserver consistency. COMPARISON WITH EXISTING METHODS: Compared to manual ROI designation, ABA reduces total analysis time by ∼70%. With correct use of landmarks for image warping, ABA produces similar results to manually drawn ROIs, results in no interobserver variability, and maintains c-Fos+ pixel dimensions. CONCLUSIONS: ABA reduces time to obtain reliable results when performing automated immunoreactivity quantification and allows multiple users to analyze data without compromising the reliability of data obtained.


Assuntos
Mapeamento Encefálico , Encéfalo , Encéfalo/diagnóstico por imagem , Técnicas Histológicas , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Variações Dependentes do Observador , Reprodutibilidade dos Testes
6.
Phys Rev Lett ; 105(23): 237203, 2010 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-21231500

RESUMO

The electronic ferroelectric lutetium ferrite (LuFe(2)O(4)) was studied by x-ray diffraction as a function of pressure. Pressure is shown to induce an irreversible rhombohedral to orthorhombic transition leading to a supercell determined by the combination of electron and synchrotron x-ray diffraction. This new configuration is proposed to be charge ordered in agreement with the results of resistivity measurements.

7.
J Cell Biol ; 79(1): 200-16, 1978 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-701372

RESUMO

Electroplaques dissected from the electric organ of Electrophorus electricus are labeled by tritiated alpha1-isotoxin from Naja nigricollis, a highly selective reagent of the cholinergic (nicotinic) receptor site. Preincubation of the cell with an excess of unlabeled alpha-toxin and with a covalent affinity reagent or labeling in the presence of 10(-4) M decamethonium reduces the binding of [3H]alpha-toxin by at least 75%. Absolute surface densities of alpha-toxin sites are estimated by high-resolution autoradiography on the basis of silver grain distribution and taking into account the complex geopmetry of the cell surface. Binding of [3H]alpha-toxin on the noninnervated face does not differ from background. Labeled sites are observed on the innervated membrane both between the synapses and under the nerve terminals but the density of sites is approx. 100 times higher at the level of the synapses than in between. Analysis of the distance of silver grains from the innervated membrane shows a symmetrical distribution centered on the postsynaptic plasma membrane under the nerve terminal. In extrasynaptic areas, the barycenter of the distribution lies approximately 0.5 micrometer inside the cell, indicating that alpha-toxin sites are present on the membrane of microinvaginations, or caveolae, abundant in the extrajunctional areas. An absolute density of 49,600 +/- 16,000 sites/micrometer2 of postsynaptic membrane is calculated; it is in the range of that found at the crest of the folds at the neuromuscular junction and expected from a close packing of receptor molecules. Electric organs were denervated for periods up to 142 days. Nerve transmission fails after 2 days, and within a week all the nerve terminals disappear and are subsequently replaced by Schwann cell processes, whereas the morphology of the electroplaque remains unaffected. The denervated electroplaque develops some of the electrophysiological changes found with denervated muscles (increases of membrane resting resistance, decrease of electrical excitability) but does not become hypersensitive to cholinergic agonists. Autoradiography of electroplaques dissected from denervated electric organs reveals, after labeling with [3H]alpha-toxin, patches of silver grains with a surface density close to that found in the normal electroplaque. The density of alpha-toxin binding sites in extrasynaptic areas remains close to that observed on innervated cells, confirming that denervation does not cause an increase in the number of cholinergic receptor sites. The patches have the same distribution, shape,and dimensions as in subneural areas of the normal electroplaque, and remnants of nerve terminal or Schwann cells are often found at the level of the patches. They most likely correspond to subsynaptic areas which persist with the same density of [3H]alpha-toxin sites up to 52 days after denervation. In the adult synapse, therefore, the receptor protein exhibits little if any tendency for lateral diffusion.


Assuntos
Órgão Elétrico/análise , Receptores Colinérgicos/análise , Potenciais de Ação , Animais , Membrana Celular/análise , Denervação , Venenos Elapídicos/metabolismo , Órgão Elétrico/inervação , Órgão Elétrico/fisiologia , Órgão Elétrico/ultraestrutura , Electrophorus , Receptores Colinérgicos/metabolismo , Sinapses/análise
8.
J Cell Biol ; 134(4): 1051-62, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8769426

RESUMO

A rat brain synaptosomal protein of 110,000 M(r) present in a fraction highly enriched in adenylyl cyclase activity was microsequenced (Castets, F., G. Baillat, S. Mirzoeva, K. Mabrouk, J. Garin, J. d'Alayer, and A. Monneron. 1994. Biochemistry. 33:5063-5069). Peptide sequences were used to clone a cDNA encoding a novel, 780-amino acid protein named striatin. Striatin is a member of the WD-repeat family (Neer, E.J., C.J. Schmidt, R. Nambudripad, and T.F. Smith. 1994. Nature (Lond.). 371:297-300), the first one known to bind calmodulin (CaM) in the presence of Ca++. Subcellular fractionation shows that striatin is a membrane-associated, Lubrol-soluble protein. As analyzed by Northern blots, in situ hybridization, and immunocytochemistry, striatin is localized in the central nervous system, where it is confined to a subset of neurons, many of which are associated with the motor system. In particular, striatin is conspicuous in the dorsal part of the striatum, as well as in motoneurons. Furthermore, striatin is essentially found in dendrites, but not in axons, and is most abundant in dendritic spines. We propose that striatin interacts, through its WD-repeat domain and in a CaM/Ca(++)-dependent manner, with one or several members of a surrounding cluster of molecules engaged in a Ca(++)-signaling pathway specific to excitatory synapses.


Assuntos
Adenilil Ciclases/análise , Proteínas de Ligação a Calmodulina/análise , Sistema Nervoso Central/química , Dendritos/química , Adenilil Ciclases/química , Adenilil Ciclases/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Proteínas de Ligação a Calmodulina/química , Proteínas de Ligação a Calmodulina/genética , Fracionamento Celular , Clonagem Molecular , Corpo Estriado/química , AMP Cíclico/biossíntese , DNA Complementar/genética , Masculino , Dados de Sequência Molecular , Peso Molecular , Neurônios Motores/química , Peptídeos/química , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Análise de Sequência , Análise de Sequência de DNA , Solubilidade
9.
Science ; 232(4747): 232-5, 1986 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-3952506

RESUMO

Synapses develop concurrently and at identical rates in different layers of the visual, somatosensory, motor, and prefrontal areas of the primate cerebral cortex. This isochronic course of synaptogenesis in anatomically and functionally diverse regions indicates that the entire cerebral cortex develops as a whole and that the establishment of cell-to-cell communication in this structure may be orchestrated by a single genetic or humoral signal. This is in contrast to the traditional view of hierarchical development of the cortical regions and provides new insight into the maturation of cortical functions.


Assuntos
Córtex Cerebral/fisiologia , Sinapses/fisiologia , Animais , Córtex Cerebral/crescimento & desenvolvimento , Macaca mulatta , Córtex Motor/crescimento & desenvolvimento , Córtex Motor/fisiologia , Córtex Somatossensorial/crescimento & desenvolvimento , Córtex Somatossensorial/fisiologia , Córtex Visual/crescimento & desenvolvimento , Córtex Visual/fisiologia
10.
Science ; 241(4865): 567-70, 1988 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-17774578

RESUMO

At sites near the Brazos River, Texas, an iridium anomaly and the paleontologic Cretaceous-Tertiary boundary directly overlie a sandstone bed in which coarse-grained sandstone with large clasts of mudstone and reworked carbonate nodules grades upward to wave ripple-laminated, very fine grained sandstone. This bed is the only sandstone bed in a sequence of uppermost Cretaceous to lowermost Paleocene mudstone that records about 1 million years of quiet water deposition in midshelf to outer shelf depths. Conditions for depositing such a sandstone layer at these depths are most consistent with the occurrence of a tsunami about 50 to 100 meters high. The most likely source for such a tsunami at the Cretaceous-Tertiary boundary is a bolidewater impact.

11.
Nat Commun ; 9(1): 1476, 2018 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-29662058

RESUMO

The Northern Hemisphere experienced dramatic changes during the last glacial, featuring vast ice sheets and abrupt climate events, while high northern latitudes during the last interglacial (Eemian) were warmer than today. Here we use high-resolution aerosol records from the Greenland NEEM ice core to reconstruct the environmental alterations in aerosol source regions accompanying these changes. Separating source and transport effects, we find strongly reduced terrestrial biogenic emissions during glacial times reflecting net loss of vegetated area in North America. Rapid climate changes during the glacial have little effect on terrestrial biogenic aerosol emissions. A strong increase in terrestrial dust emissions during the coldest intervals indicates higher aridity and dust storm activity in East Asian deserts. Glacial sea salt aerosol emissions in the North Atlantic region increase only moderately (50%), likely due to sea ice expansion. Lower aerosol concentrations in Eemian ice compared to the Holocene are mainly due to shortened atmospheric residence time, while emissions changed little.

12.
Neurogastroenterol Motil ; 19(5): 349-64, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17509017

RESUMO

Crohn's disease associated dysmotility has been attributed to fibrosis and damage to enteric nerves but injury to interstitial cells of Cajal (ICC) could also be involved. We assessed ICC in specimens obtained from patients with Crohn's disease and determined the relation between ICC and the inflammatory infiltrate, particularly mast cells (MC) using quantitative immunohistochemistry and electron microscopy. Ultrastructural injury to ICC was patchy in all ICC subtypes but ICC-Auerbach's plexus (AP) showed damage more frequently, i.e. swelling of mitochondria, decreased electron density, autophagosomes and partial depletion of the cytoplasm. Light microscopy confirmed a significant decrease in c-kit immunoreactivity for ICC-AP and an increased number of MC in the muscularis externa. Electron microscopy showed MC exhibiting piecemeal degranulation and making frequent and selective membrane-to-membrane contact with all types of injured ICC which suggests chronic release of granule content to affect ICC. Extent of ICC injury was not associated with duration of the disease. In conclusion, ultrastructural injury and loss of ICC-AP is evident in Crohn's disease. Epidemiological and morphological data suggest that ICC have the capacity to regenerate in spite of the chronic insult. The muscularis hosts a marked number of MC that exhibit piecemeal degranulation associated with ICC and may facilitate ICC maintenance.


Assuntos
Doença de Crohn/patologia , Sistema Nervoso Entérico/ultraestrutura , Íleo/ultraestrutura , Mastócitos/metabolismo , Plexo Mientérico/ultraestrutura , Adolescente , Adulto , Animais , Humanos , Íleo/metabolismo , Mastócitos/ultraestrutura , Microscopia Eletrônica de Transmissão , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-kit/metabolismo
13.
Can J Gastroenterol ; 21(7): 453-5, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17637949

RESUMO

The present report describes a young woman with no previous gastrointestinal complaints who was initially diagnosed with postinfective irritable bowel syndrome (IBS) after a confirmed case of Campylobacter jejuni enteritis. However, because of persistent diarrhea, new-onset bloating and the development of iron and vitamin deficiencies, serological markers for celiac disease (CD) were evaluated. A positive tissue transglutaminase immunoglobulin A antibody test and repeat endoscopy with duodenal biopsy showing a Marsh IIIa lesion confirmed the diagnosis of CD. Infectious gastroenteritis is a well-established risk factor for the development of IBS, and there is recent evidence that it could play a role in the initiation and exacerbation of inflammatory bowel disease. The present case suggests that the clinical expression of CD can be unmasked by an acute gastrointestinal infection and supports the hypothesis that environmental factors other than gliadin may play a role in the clinical onset of CD in a genetically susceptible host. The increasing availability of serological testing and upper endoscopy has led to increasingly frequent diagnoses of CD and recognition that it may mimic IBS. The present case findings suggest that CD should be considered in the differential diagnosis of persistent IBS-like symptoms after an episode of infectious gastroenteritis.


Assuntos
Infecções por Campylobacter/diagnóstico , Campylobacter jejuni , Doença Celíaca/diagnóstico , Enterite/diagnóstico , Síndrome do Intestino Irritável/diagnóstico , Adulto , Infecções por Campylobacter/complicações , Doença Celíaca/complicações , Diagnóstico Diferencial , Dieta , Duodenoscopia , Enterite/complicações , Fezes/microbiologia , Feminino , Humanos , Síndrome do Intestino Irritável/complicações
14.
J Natl Cancer Inst ; 89(11): 790-5, 1997 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-9182977

RESUMO

BACKGROUND: Approximately 20% of patients with colorectal cancer die of metastases confined to the liver. A meta-analysis recently performed by our group confirmed that in these patients hepatic arterial infusion of 5-fluoro-2'-deoxyuridine, compared with intravenous chemotherapy with fluoropyrimidines or supportive care (including symptom palliation when necessary), improved tumor response. PURPOSE: Because of the high cost of hepatic arterial infusion, we undertook a cost-effectiveness analysis that related the cost of such therapy to its medical efficacy. METHODS: The patient population was drawn from the seven randomized clinical trials included in the meta-analysis and included individual data on 654 patients. Of these seven trials, five compared hepatic arterial infusion and intravenous chemotherapy and two compared hepatic arterial infusion and a control group in which some patients could be left untreated. Patients assigned to receive hepatic arterial infusion made up the hepatic arterial infusion group; the other patients constituted the control group. The measures of efficacy were survival and tumor response. Health-care costs (in 1995 U.S. dollars) were computed over the duration of patient follow-up and were derived from actual costs in two centers, one at Henri Mondor Hospital (Paris, France) and the other at Stanford University Medical Center (Palo Alto, CA). The total cost of treatment included the initial procedure, chemotherapy cycles, and main complications. RESULTS: The mean gain in life expectancy in the hepatic arterial infusion group compared with the control group was 3.2 months (standard error = 1.0 month). For patients treated by hepatic arterial infusion in Paris, the hepatic arterial infusion pump, initial hospitalization, and the entire process (including follow-up and complications) cost, on average, $8400, $15172, and $29562, respectively; in Palo Alto, these costs were $4700, $13784, and $25 208, respectively. For patients in the control groups in Paris and Palo Alto, the total treatment costs were, on average, $9926 and $5928. The additional costs of hepatic arterial infusion over control treatment were $19636 in Paris and $19280 in Palo Alto. The cost-effectiveness (i.e., the additional cost divided by the additional benefit) with respect to survival of the patients in the hepatic arterial infusion group compared with the patients in the control group was $73635 per life-year in Paris and $72300 per life-year in Palo Alto. CONCLUSIONS AND IMPLICATIONS: The cost-effectiveness of localized chemotherapy for colorectal liver metastases is within the range of accepted treatments for serious medical conditions, although it might be considered borderline by policy-makers in some countries. Prospective clinical trials should be conducted to more definitively answer this question.


Assuntos
Antimetabólitos Antineoplásicos/administração & dosagem , Neoplasias Colorretais/patologia , Floxuridina/administração & dosagem , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/secundário , Antimetabólitos Antineoplásicos/economia , Neoplasias Colorretais/economia , Análise Custo-Benefício , Tomada de Decisões , Ensaios de Seleção de Medicamentos Antitumorais , Tratamento Farmacológico/economia , Floxuridina/economia , Artéria Hepática , Humanos , Infusões Intra-Arteriais , Neoplasias Hepáticas/economia
15.
J Nutr Health Aging ; 20(1): 48-55, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26728933

RESUMO

This study examined the effectiveness of three different learning methods: trial and error learning (TE), errorless learning (EL) and learning by modeling with spaced retrieval (MR) on the relearning process of IADL in mild-to-moderately severe Alzheimer's Dementia (AD) patients (n=52), using a 6-weeks randomized controlled trial design. The participants had to relearn three IADLs. Repeated-measure analyses during pre-intervention, post-intervention and 1-month delayed sessions were performed. All three learning methods were found to have similar efficiency. However, the intervention produced greater improvements in the actual performance of the IADL tasks than on their explicit knowledge. This study confirms that the relearning of IADL is possible with AD patients through individualized interventions, and that the improvements can be maintained even after the intervention.


Assuntos
Atividades Cotidianas , Doença de Alzheimer/reabilitação , Aprendizagem , Idoso , Idoso de 80 Anos ou mais , Demência , Feminino , Humanos , Masculino , Memória
17.
J Comp Neurol ; 208(1): 1-15, 1982 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-7119151

RESUMO

The distribution of the innervation to the anterior latissimus dorsi (ALD) and posterior latissimus dorsi (PLD) muscles of the chicken are described on the day of hatching and 6 weeks later using electron microscopy. In the ALD muscle, there are 5,000 muscle fibres and 374,000 endplates supplied by about 169 skeletomotor axons; in the PLD muscle, there are 12,000 focally innervated muscle fibers supplied by about 20 skeletomotor axons. On the cell surface of the muscle fibers the mean total subsynaptic area contacted by each motor axon is comparable in the ALD and PLD muscles. The growth pattern of the axons in the PLD motor nerve was described from the ninth day in ovo up to 6 weeks after hatching. The axons arrive in the PLD muscle in two successive waves: first, the large somatic axons which are already present before the ninth day in ovo and second, the small autonomic axons which continue to accumulate until hatching. The total number of somatic axons decreases from the ninth day until the hatching day when it reaches its definitive value. This decrease takes place during a period when the numbers of myofibers and of endplates dramatically increase, and it coincides with the axonal segregation by the Schwann cells. The myelination of the axons starts on the 15th day in ovo and is essentially complete upon hatching. Despite the decreasing number of somatic axons in the PLD nerve, the decrease in number of nerve endings per PLD endplate and the increasing number of PLD endplates per PLD muscle, it was found that between the 16th day in ovo and 6 weeks after hatching the mean number of axonal branches per PLD motor axon does not decrease.


Assuntos
Envelhecimento , Axônios/ultraestrutura , Plexo Braquial/embriologia , Neurônios Motores/ultraestrutura , Músculos/inervação , Animais , Plexo Braquial/anatomia & histologia , Embrião de Galinha , Galinhas , Microscopia Eletrônica , Placa Motora/anatomia & histologia , Fibras Nervosas Mielinizadas/ultraestrutura , Sinapses/ultraestrutura
18.
J Comp Neurol ; 360(2): 363-76, 1995 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-8522653

RESUMO

In the neocortex, the onset of the rapid phase (phase 3) of synaptogenesis occurs after the end of neurogenesis. However, we still do not know whether or not these two developmental events are causally related. The present study compares the time-course and tempo of neurogenesis and synaptogenesis in the anterior cingulate cortex (area 24 of Brodmann) and in the primary visual cortex (area 17) in a series of pre- and postnatal rhesus monkeys. Autoradiographic analysis of animals fetally injected with 3H-thymidine showed that all neurons destined for area 24 are generated by embryonic day 70, which is 30 days earlier than in area 17. The rapid phase of synaptogenesis in area 24 starts during the third embryonic month and continues at the same rate through the remainder of gestation and the first 2 months after birth, as has been seen in neocortical areas examined previously. Statistical analysis of the linear portions of the rapid phase indicates that, although neurogenesis in area 24 is completed 1 month earlier than in area 17, the rapid phase of synaptogenesis occurs 41 days later. Moreover, the tempo of synaptic accretion was remarkably similar to that in motor, somatosensory, visual, or associational areas. All were grouped within the same time window of about 40 days, centered at birth. After the second postnatal month, synaptic density in area 24 remains at a high level until sexual maturity. This work shows that the rapid phase of synaptogenesis in the cingulate mesocortex is not linked temporally to the end of neurogenesis. We suggest that it is regulated by the same genetic or humoral factors that control synaptogenesis in the phylogenetically newer neocortical areas.


Assuntos
Córtex Cerebral/ultraestrutura , Giro do Cíngulo/ultraestrutura , Vias Neurais/ultraestrutura , Sinapses/ultraestrutura , Animais , Sistema Límbico/ultraestrutura , Macaca mulatta , Microscopia Eletrônica
19.
Eur J Cancer ; 30A(5): 590-6, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8080672

RESUMO

The management of breast cancer in elderly women was analysed by a retrospective study of 150 women over 70 years old referred to our department between 1984 and 1988. 80 were T1-T2, 33 were T3 and 34 were T4. 107 were N0 and 43 were N1-N2. 16 women (11%) were in poor health, preventing conventional treatment. Treatment choice varied with age: 60% of the women aged 70-79 (group 1) and 23% of the oldest women (group 2) were treated conventionally. The use of surgery decreased with age and surgical procedures were conventional in only 85% of the group 1 women and in 56% of the group 2 women. Definitive radiation therapy was used more frequently in the oldest women, as was primary hormone therapy. Quality of follow-up also varied with age. Five-year survival rates were still high in both groups while relapses were frequent. Breast cancer was consequently a frequent cause of death. The increase in the proportion of elderly people with breast cancers over the next few years will require validated guidelines. Specific protocols and specific rules of management must be drawn up.


Assuntos
Neoplasias da Mama/terapia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Terapia Combinada , Feminino , Seguimentos , Humanos , Estudos Retrospectivos , Tamoxifeno/uso terapêutico , Resultado do Tratamento
20.
Int J Radiat Oncol Biol Phys ; 9(9): 1313-9, 1983 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6885544

RESUMO

From May 1978 to May 1981, a total of 20 patients (18 patients with Non Hodgkin Lymphomas + 2 patients with Stage IV Hodgkin's disease) were treated with chemotherapy and whole or upper abdominal radiotherapy. All the patients were in complete remission at the time of irradiation. Shielding of the kidneys was effected at the start of treatment and the right lobe of the liver was shielded after a dose of 20 Gy was delivered. As of January 1982, 17 of the patients were alive and free of disease with a follow-up ranging from 6 to 32 months (mean follow-up of 18.5 months). Two patients were dead from their disease. Alterations in liver chemistry were observed in 5 patients, clinical jaundice or transient hepatomegaly along with changes in liver chemistry in 4 patients, classical veno-occlusive disease in 2 patients and 7 of the patients did not develop any complication. No death from complications were observed. The contribution of the following factors such as radiotherapy dose to the liver, drugs, nutritional status and associated medical conditions, towards the development of complications have been analyzed in detail.


Assuntos
Fígado/efeitos dos fármacos , Linfoma/complicações , Adulto , Idoso , Doxorrubicina/administração & dosagem , Quimioterapia Combinada , Feminino , Doença de Hodgkin/complicações , Doença de Hodgkin/tratamento farmacológico , Doença de Hodgkin/radioterapia , Humanos , Fígado/efeitos da radiação , Lomustina/administração & dosagem , Linfoma/tratamento farmacológico , Linfoma/radioterapia , Masculino , Pessoa de Meia-Idade , Aceleradores de Partículas , Dosagem Radioterapêutica , Fatores de Tempo
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