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1.
Ir Med J ; 111(2): 694, 2018 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-29952443

RESUMO

Correct technique with inhalers is vital for therapeutic effect. Efficacy of DVD inhaler instruction was investigated. Secondary aims were to examine feasibility of an inhaler technique outcome measure, and to compare knowledge and self-efficacy after DVD or individual education. This was a randomised controlled trial conducted in a regional hospital paediatric ward, involving new or existing paediatric inhaler users. Inhaler technique was assessed pre-education in existing inhaler users. Participants were then randomised to message equivalent education by DVD or individually with a physiotherapist. Inhaler technique, self-efficacy and knowledge were assessed immediately post- and three months after education. Twenty one participants received DVD or individual education. There were no significant differences between groups for technique, self-efficacy or knowledge at any time. The outcome measure was feasible for use in a research study. DVD education was equivalent to individual instruction to teach parents how to use inhalers with their child.


Assuntos
Nebulizadores e Vaporizadores , Educação de Pacientes como Assunto , Fisioterapeutas , Gravação em Vídeo , Criança , Estudos de Viabilidade , Humanos
2.
Ir Med J ; 109(10): 485, 2016 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-28644590

RESUMO

MUTYH is involved in DNA damage repair. Bi-allelic MUTYH mutations predispose to polyposis and gastrointestinal malignancies, distinct genetically from autosomal dominant familial adenomatous polyposis coli. Two common European MUTYH mutations account for 90% of MUTYH-associated polyposis (MAP). We aimed to examine the incidence of MAP in Ireland. A retrospective cohort study was undertaken. Patients undergoing MUTYH testing from 2003-2016 were identified by searching electronic databases using terms "MUTYH" and "MYH". Phenotypic and genotypic details were obtained by chart review. Bi-allelic mutations were confirmed in 26 individuals (17 families), of whom 16 (62%) developed colorectal malignancies, and 22(85%) polyposis. Eleven families had bi-allelic status for one/both common European mutations. Regional variation was noted, with over-representation of bi-allelic mutation carriers in the South-west of Ireland. MAP is under-diagnosed in Ireland. Increased awareness is required to facilitate appropriate identification and surveillance of bi-allelic mutation carriers for colorectal pathology.


Assuntos
Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/genética , DNA Glicosilases/genética , Pólipos Intestinais/epidemiologia , Pólipos Intestinais/genética , Mutação/genética , Polipose Adenomatosa do Colo/genética , Predisposição Genética para Doença , Genótipo , Humanos , Incidência , Irlanda/epidemiologia , Fenótipo , Estudos Retrospectivos
3.
Philos Trans A Math Phys Eng Sci ; 373(2035)2015 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-25583866

RESUMO

Understanding of dynamic behaviour of offshore wind floating substructures is extremely important in relation to design, operation, maintenance and management of floating wind farms. This paper presents assessment of nonlinear signatures of dynamic responses of a scaled tension-leg platform (TLP) in a wave tank exposed to different regular wave conditions and sea states characterized by the Bretschneider, the Pierson-Moskowitz and the JONSWAP spectra. Dynamic responses of the TLP were monitored at different locations using load cells, a camera-based motion recognition system and a laser Doppler vibrometer. The analysis of variability of the TLP responses and statistical quantification of their linearity or nonlinearity, as non-destructive means of structural monitoring from the output-only condition, remains a challenging problem. In this study, the delay vector variance (DVV) method is used to statistically study the degree of nonlinearity of measured response signals from a TLP. DVV is observed to create a marker estimating the degree to which a change in signal nonlinearity reflects real-time behaviour of the structure and also to establish the sensitivity of the instruments employed to these changes. The findings can be helpful in establishing monitoring strategies and control strategies for undesirable levels or types of dynamic response and can help to better estimate changes in system characteristics over the life cycle of the structure.

4.
Eur J Hum Genet ; 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38355960

RESUMO

Genetic counselling education and training in Europe spans a continuum of 30 years. More master programs are opening due the demand for qualified genetic counselors. This report describes the evolution of training in Europe and the current state of genetic counselling training programs. Directors of master programs in Europe were invited to complete an online survey describing their program, including year of commencement, course duration, number of students and frequency of intake and number graduating. Results of the survey were presented at a closed meeting at the European Society of Human Genetics conference in 2022 along with a facilitated stakeholder engagement session in which 19 professionals participated to understand the challenges in delivering genetic counselling education in Europe. A total of 10 active programs exists in Europe with the first training program starting in 1992. The majority of training programs have a 2-year duration, with just over half of programs having an annual intake of students. Up to May 2022, 710 students have graduated from genetic counseling training programs across Europe. Of these, 670 students graduated from European Board of Medical Genetics-registered programs. Arranging clinical placements, clinical and counseling supervision of students, research collaboration for MSc research projects and incorporating genomics into the curriculum were identified as current challenges for genetic counseling education. Genetic counseling is still a developing profession in Europe and this historical and current view of the European genetic counselor pathways, allows for educational and professional standards to be examined as the profession evolves into the future.

5.
Nat Commun ; 12(1): 4303, 2021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34262037

RESUMO

Lipid droplets (LDs) are increasingly recognized as critical organelles in signalling events, transient protein sequestration and inter-organelle interactions. However, the role LDs play in antiviral innate immune pathways remains unknown. Here we demonstrate that induction of LDs occurs as early as 2 h post-viral infection, is transient and returns to basal levels by 72 h. This phenomenon occurs following viral infections, both in vitro and in vivo. Virally driven in vitro LD induction is type-I interferon (IFN) independent, and dependent on Epidermal Growth Factor Receptor (EGFR) engagement, offering an alternate mechanism of LD induction in comparison to our traditional understanding of their biogenesis. Additionally, LD induction corresponds with enhanced cellular type-I and -III IFN production in infected cells, with enhanced LD accumulation decreasing viral replication of both Herpes Simplex virus 1 (HSV-1) and Zika virus (ZIKV). Here, we demonstrate, that LDs play vital roles in facilitating the magnitude of the early antiviral immune response specifically through the enhanced modulation of IFN following viral infection, and control of viral replication. By identifying LDs as a critical signalling organelle, this data represents a paradigm shift in our understanding of the molecular mechanisms which coordinate an effective antiviral response.


Assuntos
Interferons/imunologia , Gotículas Lipídicas/imunologia , Viroses/imunologia , Animais , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Herpesvirus Humano 1/fisiologia , Humanos , Imunidade Inata , Interferons/genética , Interferons/metabolismo , Gotículas Lipídicas/metabolismo , Camundongos , Ácidos Nucleicos/metabolismo , Replicação Viral/efeitos dos fármacos , Zika virus/fisiologia
6.
Int J Pediatr Otorhinolaryngol ; 150: 110861, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34583300

RESUMO

INTRODUCTION: Corona-virus Disease 2019 (COVID-19) has had a huge impact on the delivery of healthcare worldwide, particularly elective surgery. There is a lack of data regarding risk of postoperative COVID-19 infection in children undergoing elective surgery, and regarding the utility of pre-operative COVID-19 testing, and preoperative "cocooning" or restriction of movements. The purpose of this present study was to examine the safety of elective paediatric Otolaryngology surgery during the COVID-19 pandemic with respect to incidence of postoperative symptomatic COVID-19 infection or major respiratory complications. MATERIALS AND METHODS: Prospective cohort study of paediatric patients undergoing elective Otolaryngology surgery between September and December 2020. Primary outcome measure was incidence of symptomatic COVID-19 or major respiratory complications within the 14 days after surgery. Parents of prospectively enrolled patients were contacted 14 days after surgery and enquiry made regarding development of postoperative symptoms, COVID-19 testing, or diagnosis of COVID-19. RESULTS: 302 patients were recruited. 125 (41.4%) underwent preoperative COVID-19 RT-PCR testing. 66 (21.8%) restricted movements prior to surgery. The peak 14-day COVID-19 incidence during the study was 302.9 cases per 100,000 population. No COVID-19 infections or major respiratory complications were reported in the 14 day follow-up period. CONCLUSION: The results of our study support the safety of elective paediatric Otolaryngology surgery during the pandemic, in the setting of community incidence not exceeding that observed during the study period.


Assuntos
COVID-19 , Pandemias , Teste para COVID-19 , Criança , Procedimentos Cirúrgicos Eletivos , Humanos , Estudos Prospectivos , SARS-CoV-2
7.
Clin Transl Radiat Oncol ; 21: 98-103, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32072031

RESUMO

There is an increasing need to measure treatment-related side effects in normal tissues following cancer therapy. The ALERT-B (Assessment of Late Effects of RadioTherapy - Bowel) questionnaire is a screening tool that is composed of four items related specifically to bowel symptoms. Those patients that respond with a "yes" to any of these items are referred on to gastroenterologist in order to improve the long-term consequences of these side effects of radiological treatment. Here we wish to test the ability of this questionnaire to identify these subsequent gastroenterological complications by tracking prostate cancer patients that were positive with respect to ALERT-B. We also carry out receiver-operator curve (ROC) analysis for baseline data for an overall ALERT-B questionnaire score with respect to subscale data for the Gastrointestinal Symptom Rating Scale (GSRS) and the Expanded Prostate Cancer Index Composite (EPIC-26) questionnaire. 84.4% and 95.7% of patients identified by the ALERT-B questionnaire demonstrated complications diagnosed at 6 and 12 months post-treatment, respectively. ROC curve analysis of baseline data showed that ALERT-B detected clinically relevant levels of side effects established at baseline by the GSRS diarrhoea subscale (AUC = 0.867, 95% CI = 0.795 to 0.926) and at the minimally important level of side effects for the EPIC bowel subscale (AUC = 0.765, 95% CI = 0.617 to 0.913). These results show that ALERT-B provides a simple and effective screening tool for identifying gastroenterological complications after treatment for prostate cancer.

9.
Fam Cancer ; 17(1): 123-128, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28509937

RESUMO

The increased availability of next generation sequencing (NGS) and multi gene panel testing has resulted in more frequent TP53 testing of families that do not meet classic testing criteria. We investigated testing criteria, family history and result outcome in a cohort of Irish probands undergoing TP53 full sequencing. All TP53 test requests processed through the national genetic testing laboratory between 2012 and 2014 were retrospectively reviewed. Personal and family cancer histories were collected, including tumour type and age at diagnosis, from two adult cancer genetic services in Ireland. Association between Li Fraumeni syndrome (LFS) or Li Fraumeni like syndrome (LFL) criteria and test result was examined. One hundred and 35 TP53 test requests were identified. Family history data and test results were available on 123 of the TP53 test requests (118 female; 5 male). 59/123 (48%) did not meet classic LFS or LFL criteria. Two individuals from this group harboured pathogenic TP53 mutations, giving a 3% mutation detection rate in those not meeting testing criteria. Both were female and had a personal history of early onset bilateral breast cancer with no reported LFS cancers in the family. 64/123 (52%) met LFS or LFL criteria and were all TP53 negative. 37/64 (57.8%) met Chompret criteria, 19/64 (29.7%) met Eeles and 7/64 (10.9%) met Eeles and Chompret and 1/64 (1.6%) met Classic LFS criteria. Stringent testing criteria miss germline mutations in TP53. Broadening the criteria for TP53 testing may improve our understanding of the phenotype and penetrance in the association syndrome.


Assuntos
Neoplasias da Mama/diagnóstico , Sequenciamento de Nucleotídeos em Larga Escala/estatística & dados numéricos , Síndrome de Li-Fraumeni/diagnóstico , Penetrância , Proteína Supressora de Tumor p53/genética , Adulto , Idoso , Neoplasias da Mama/genética , Análise Mutacional de DNA/estatística & dados numéricos , Feminino , Predisposição Genética para Doença , Testes Genéticos/métodos , Testes Genéticos/normas , Testes Genéticos/estatística & dados numéricos , Mutação em Linhagem Germinativa , Humanos , Irlanda , Síndrome de Li-Fraumeni/genética , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Estudos Retrospectivos
10.
J Psychiatr Res ; 100: 24-32, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29475018

RESUMO

Current first-line antidepressants can take weeks or months to decrease depressive symptoms. Low dose ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, shows potential for a more rapid antidepressant effect, with efficacy also evident in previously treatment-resistant populations. However, a greater understanding of the physiological mechanisms underlying such effects is required. We assessed the potential impact of ketamine infusion on neurobiological drivers of kynurenine pathway metabolism in major depression (HPA axis hyperactivity, inflammation) in patients with treatment-resistant depression compared to gender-matched healthy controls. Furthermore, we assessed these biomarkers before and after electroconvulsive therapy (ECT), which is currently the gold standard for management of treatment-resistant depression. As previously demonstrated, treatment with ketamine and ECT was associated with improved depressive symptoms in patients. At baseline, waking cortisol output was greater in the ECT cohort, kynurenine was greater in the ketamine cohort, and kynurenic acid was lower in patients compared to healthy controls, although inflammatory markers (IL-6, IL-8, IL-10 or IFN-γ) were similar in patients and controls. Furthermore, in patients who responded to ECT, the cortisol awakening response was decreased following treatment. Despite a trend towards reduced kynurenine concentrations in those who responded to ketamine, ketamine was not associated with significant alterations in any of the biomarkers assessed.


Assuntos
Antidepressivos/farmacologia , Citocinas/efeitos dos fármacos , Transtorno Depressivo Resistente a Tratamento/sangue , Transtorno Depressivo Resistente a Tratamento/tratamento farmacológico , Eletroconvulsoterapia/métodos , Hidrocortisona/sangue , Ketamina/farmacologia , Cinurenina/efeitos dos fármacos , Avaliação de Resultados em Cuidados de Saúde , Adulto , Antidepressivos/administração & dosagem , Biomarcadores/sangue , Humanos , Ketamina/administração & dosagem , Redes e Vias Metabólicas/efeitos dos fármacos
11.
Br J Pharmacol ; 150(1): 5-17, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17088867

RESUMO

L-Glutamate (Glu) is the major excitatory neurotransmitter in the mammalian CNS and five types of high-affinity Glu transporters (EAAT1-5) have been identified. The transporters EAAT1 and EAAT2 in glial cells are responsible for the majority of Glu uptake while neuronal EAATs appear to have specialized roles at particular types of synapses. Dysfunction of EAATs is specifically implicated in the pathology of neurodegenerative conditions such as amyotrophic lateral sclerosis, epilepsy, Huntington's disease, Alzheimer's disease and ischemic stroke injury, and thus treatments that can modulate EAAT function may prove beneficial in these conditions. Recent advances have been made in our understanding of the regulation of EAATs, including their trafficking, splicing and post-translational modification. This article summarises some recent developments that improve our understanding of the roles and regulation of EAATs.


Assuntos
Sistema X-AG de Transporte de Aminoácidos/fisiologia , Sistema X-AG de Transporte de Aminoácidos/classificação , Sistema X-AG de Transporte de Aminoácidos/efeitos dos fármacos , Animais , Transporte Biológico , Humanos
12.
Neurochem Int ; 51(8): 507-16, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17590480

RESUMO

While studies with [(3)H]D-aspartate ([(3)H]d-Asp) illustrate specific interactions with excitatory amino acid transporters (EAATs), new insights into the pharmacological characteristics and localization of specific EAAT subtypes depend upon the availability of novel ligands. One such ligand is [(3)H]-(2S,4R)-4-methylglutamate ([(3)H]4MG) which labels astrocytic EAATs in homogenate binding studies. This study examined the utility of [(3)H]4MG for binding and autoradiography in coronal sections of rat brain. Binding of [(3)H]4MG was optimal in 5mM HEPES buffer containing 96 mM NaCl, pH 7.5. Specific binding of [(3)H]4MG exhibited two components, but was to a single site when glutamate receptor (GluR) sites were masked with kainate (KA; 1 microM): t(1/2) approximately 5 min, K(d) 250 nM and B(max) 5.4 pmol/mg protein. Pharmacological studies revealed that [(3)H]4MG, unlike [(3)H]d-Asp, labeled both EAAT and ionotropic GluR sites. Further studies employed 6-cyano-7-nitroquinoxaline (30 microM) to block GluR sites, but selective EAAT ligands displayed lower potency than expected for binding to transporters relative to drugs possessing mixed transporter/receptor activities. Autoradiography in conjunction with densitometry with [(3)H]4MG and [(3)H]d-Asp revealed wide, but discrete distributions in forebrain; significant differences in binding levels were found in hippocampus, nucleus accumbens and cortical sub-areas. Although EAAT1 and EAAT2 components were detectable using 3-methylglutamate and serine-O-sulphate, respectively, the majority of [(3)H]4MG binding was to KA-related sites. Overall, in tissue sections [(3)H]4MG proved unsuitable for studying the autoradiographic localization of EAATs apparently due to its inability to selectively discriminate Na(+)-dependent binding to Glu transporters.


Assuntos
Ligação Competitiva/efeitos dos fármacos , Ácido D-Aspártico/metabolismo , Transportador 1 de Aminoácido Excitatório/metabolismo , Glutamatos/metabolismo , Ácido Glutâmico/metabolismo , Ensaio Radioligante/métodos , Animais , Autorradiografia/métodos , Ligação Competitiva/fisiologia , Agonistas de Aminoácidos Excitatórios/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Transportador 1 de Aminoácido Excitatório/efeitos dos fármacos , Transportador 2 de Aminoácido Excitatório/efeitos dos fármacos , Transportador 2 de Aminoácido Excitatório/metabolismo , Feminino , Ligantes , Ratos , Ratos Sprague-Dawley , Receptores de Glutamato/efeitos dos fármacos , Receptores de Glutamato/metabolismo , Trítio/metabolismo
13.
Bioresour Technol ; 216: 238-49, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27240240

RESUMO

Four feedstocks were assessed for use in a demand driven biogas system. Biomethane potential (BMP) assays were conducted for grass silage, food waste, Laminaria digitata and dairy cow slurry. Semi-continuous trials were undertaken for all feedstocks, assessing biogas and biomethane production. Three kinetic models of the semi-continuous trials were compared. A first order model most accurately correlated with gas production in the pulse fed semi-continuous system. This model was developed for production of electricity on demand, and biomethane upgrading. The model examined a theoretical grass silage digester that would produce 435kWe in a continuous fed system. Adaptation to demand driven biogas required 187min to produce sufficient methane to run a 2MWe combined heat and power (CHP) unit for 60min. The upgrading system was dispatched 71min following CHP shutdown. Of the biogas produced 21% was used in the CHP and 79% was used in the upgrading system.


Assuntos
Biocombustíveis , Biotecnologia/métodos , Metano/biossíntese , Animais , Biocombustíveis/análise , Biotecnologia/instrumentação , Bovinos , Indústria de Laticínios , Eletricidade , Feminino , Alimentos , Cinética , Laminaria , Esterco , Modelos Teóricos , Poaceae , Silagem , Gerenciamento de Resíduos/instrumentação , Gerenciamento de Resíduos/métodos
14.
Bioresour Technol ; 202: 172-80, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26708485

RESUMO

A two-stage food waste digestion system involved a first stage hydrolysis reactor followed by a second stage methanogenic reactor. Organic loading rates (OLR) were increased from 6 to 15 g VS L(-1) d(-1) in the hydrolysis reactor and from 2 to 5 g VS L(-1) d(-1) in the methanogenic reactor. The retention time was fixed at 4 days (hydrolysis reactor) and 12 days (methane reactor). A single-stage digester was subjected to similar loading rates as the methanogenic reactor at 16 days retention. Increased OLR resulted in higher quantities of liquid fermentation products from the first stage hydrolysis reactor. Solubilisation of chemical oxygen demand peaked at 47% at the maximum loading. However, enhanced hydrolysis yields had no significant impact on the specific methane yields. The two-stage system increased methane yields up to 23% and enriched methane content by an average of 14% to levels of 71%.


Assuntos
Digestão , Alimentos , Resíduos , Anaerobiose , Análise da Demanda Biológica de Oxigênio , Reatores Biológicos/normas , Fermentação , Hidrólise , Metano/análise , Metano/metabolismo
15.
Neuroscience ; 53(2): 447-55, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8098512

RESUMO

The proto-oncogene c-jun is thought to play a role in the control of growth and differentiation of many cell types. It has been demonstrated previously that damage to axons of peripheral motor or sensory neurons resulted within 24 h in substantially increased levels of the c-jun gene in the parent cell bodies. These increased levels of c-jun protein and messenger RNA are maintained if the damaged nerve is ligated, but return to basal levels if the peripheral nerve is allowed to regenerate. We have examined the expression of immediate early genes in central neurons of the rat and now show that a 6-hydroxydopamine-induced axotomy of the dopaminergic nigrostriatal pathway results in a substantial increase in the levels of c-jun (but not c-fos) messenger RNA and protein within neurons of the substantia nigra pars compacta. However, the central neuronal response differs from the peripheral nerve response in that it becomes maximal at four to eight days post-lesion and is transient, declining to control levels in nigral neurons by 14 days post-lesion. These expression patterns may be related to the differential capacity of central and peripheral neurons to regenerate. The precise role of c-jun in these processes, or in the regenerative response, is unclear but it remains possible that c-jun activation following axon damage leads to an increased expression of genes which are essential for the regenerative response. The nature of the mechanism by which c-jun levels are attenuated in central neurons is also unclear, but inhibitory factors, generated by the central environment, may play a role.


Assuntos
Corpo Estriado/fisiologia , Expressão Gênica/efeitos dos fármacos , Genes jun , Neurônios/metabolismo , Oxidopamina/toxicidade , Substância Negra/metabolismo , Animais , Autorradiografia , Corpo Estriado/efeitos dos fármacos , Feminino , Ácido Ibotênico/farmacologia , Imuno-Histoquímica , Hibridização In Situ , Mazindol/metabolismo , Proteínas Proto-Oncogênicas c-jun/biossíntese , Proteínas Proto-Oncogênicas c-jun/genética , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Receptores Dopaminérgicos/efeitos dos fármacos , Receptores Dopaminérgicos/metabolismo , Tirosina 3-Mono-Oxigenase/imunologia , Tirosina 3-Mono-Oxigenase/metabolismo
16.
Invest Ophthalmol Vis Sci ; 35(1): 313-7, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8300359

RESUMO

PURPOSE: To compare binocularity in central and peripheral vision of people with early-onset strabismus and people with normal binocular vision. METHODS: Ten subjects with early-onset strabismus, and nine subjects with normal binocular vision were tested. To assess binocularity, interocular transfer (IOT) of a rotary movement aftereffect (MAE) was measured. The MAE stimuli were either confined to the central 2.8 degrees of the visual field or were presented 10 degrees into peripheral vision. RESULTS: In peripheral vision, there was no significant difference in IOT for the two groups of subjects. In central vision, there was a significant decrease of IOT in subjects with early-onset strabismus. Their IOT was, however, significantly greater than zero. CONCLUSIONS: Early-onset strabismus appears to spare binocularity in peripheral vision but reduces it in central vision. It does not abolish binocularity assessed by IOT of MAE, suggesting that some binocular connections survive early-onset strabismus, even in central vision.


Assuntos
Pós-Imagem/fisiologia , Percepção de Movimento/fisiologia , Estrabismo/fisiopatologia , Visão Binocular/fisiologia , Adolescente , Adulto , Feminino , Humanos , Luz , Masculino , Movimento , Retina/fisiologia
17.
J Neuroendocrinol ; 3(1): 11-4, 1991 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-19215440

RESUMO

The distribution of messenger ribonucleic acid (mRNA) encoding preproneuropeptide Y (prepro-NPY) in the hypothalamus of rats subjected to food deprivation or dehydration has been investigated by quantitative in situ hybridization. Levels of prepro-NPY mRNA in the arcuate nucleus (ARC) were selectively increased by both treatments. The very high concentration of prepro-NPY mRNA seen following 96 h of food deprivation had returned towards control levels after 24 h of refeeding. Levels of preprogalanin (prepro-GAL) mRNA throughout the hypothalamus were essentially unaffected by both regimes. These results demonstrate that hypothalamic NPY gene expression is regulated by peripheral metabolic status (and osmolality), and confirm the key physiological role of NPY in controlling ingestive behaviour.

18.
J Neuroendocrinol ; 8(6): 417-25, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8809671

RESUMO

Nitric oxide (NO) is produced by the enzyme NO synthase (NOS) and may be involved in the regulation of nutrient and endocrine homeostasis via actions on neurones of the hypothalamic supraoptic (SON) and paraventricular (PVN) nuclei. The effects of water deprivation or food deprivation for 4 days on the abundance of messenger RNA encoding NOS in these nuclei in rats were examined using in situ hybridization. Water deprivation markedly increased the abundance of NOS mRNA in both the SON and PVN (225 +/- 11% of control, P < 0.05 and 261 +/- 34% of control, P < 0.01 respectively). NOS mRNA abundance also appeared to be increased in magnocellular accessory nuclei. Food deprivation decreased NOS mRNA abundance in the SON and PVN (42 +/- 6% and 52 +/- 7% of control respectively, both P < 0.05), while withdrawal of both food and water produced no significant net changes in the abundance of NOS mRNA. Treatment-induced alterations in NOS mRNA abundance were reflected by changes in NOS activity, as assessed by NADPH-diaphorase histochemistry, and NADPH-diaphorase staining was observed in neurones both positive and negative for oxytocin-like immunoreactivity. These findings suggest that NOS mRNA abundance, NOS enzymatic activity and presumably NO production are modulated in an activity-dependent manner in hypothalamic (magnocellular and parvocellular) neurones by alterations in fluid and nutrient homeostasis, and support data from other studies suggesting a role for NO in the central regulation of water and food intake in the rat.


Assuntos
Privação de Alimentos , Expressão Gênica , Hipotálamo/enzimologia , Neurossecreção , Óxido Nítrico Sintase/metabolismo , Privação de Água , Animais , Hipotálamo/fisiologia , Imuno-Histoquímica , Hibridização In Situ , Masculino , NADPH Desidrogenase/análise , Neurônios/enzimologia , Óxido Nítrico Sintase/genética , Ocitocina/análise , Núcleo Hipotalâmico Paraventricular/química , Núcleo Hipotalâmico Paraventricular/enzimologia , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Núcleo Supraóptico/química , Núcleo Supraóptico/enzimologia
19.
J Neuroendocrinol ; 5(6): 697-704, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8680444

RESUMO

Cholecystokinin (CCK) has been suggested to mediate satiety in a number of non-primate species via its peripheral actions as well as a possible central mechanism involving magnocellular and parvocellular oxytocin release. Quantitative in vitro autoradiography employing [125I]-Bolton-Hunter labelled CCK-8S ([125I]-CCK-8S) was used to examine the distribution and density of CCK receptors in sections of brain from normal rats and rats deprived of food, water or both food and water for 4 days. In food-deprived rats, specific [125I]-CCK-8S binding was reduced by 64 +/- 5% in the hypothalamic supraoptic nucleus (SON) and by 44 +/- 13% in the paraventricular nucleus of the hypothalamus (PVN). In contrast, water deprivation increased binding of [125I]-CCK-8S by 128 +/- 15% in the SON and by 196% +/- 24% in the PVN, while combined food and water deprivation produced smaller increases in both nuclei (30 +/- 5% and 98 +/- 26% in SON and PVN respectively). Changes in receptor density in the PVN appeared to be most prominent in the magnocellular (especially oxytocin-rich) subdivisions. None of the treatments employed produced changes in [125I]-CCK-8S binding in the ventromedial hypothalamic nucleus or the reticular thalamic nucleus. Both CCK-A and CCK-B receptor subtypes were visualized in the nucleus of the solitary tract and the area postrema of normal rats, but levels of binding to both of these subtypes were unaffected by the experimental treatments. These selective alterations demonstrate the plasticity of CCK receptors in the SON and PBN, and are probably associated with changes in the level of neurochemical activity of magnocellular oxytocinergic neurones in these areas. These results, together with reports of changes in the level of CCK synthesis in cells of the SON and PVN after hyperosmotic stimuli, suggest that CCK may act in an autocrine fashion on these neurones and that both CCK receptors and peptide levels are altered in the same direction following cellular activation or inhibition.


Assuntos
Desidratação/fisiopatologia , Privação de Alimentos/fisiologia , Hipotálamo/metabolismo , Receptores da Colecistocinina/metabolismo , Animais , Autorradiografia , Peso Corporal/fisiologia , Hipotálamo/anatomia & histologia , Processamento de Imagem Assistida por Computador , Radioisótopos do Iodo , Masculino , Núcleo Hipotalâmico Paraventricular/fisiologia , Ratos , Ratos Sprague-Dawley , Núcleo Supraóptico/fisiologia
20.
Neuroreport ; 5(16): 2113-6, 1994 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-7865757

RESUMO

Hypothalamic neuropeptide Y (NPY) and 5-hydroxytryptamine (5-HT) may interact to regulate food intake. This study investigated the effects of the 5-HT reuptake blocker and secretagogue D-fenfluramine (D-FEN) on preproNPY mRNA abundance in the hypothalamic arcuate nucleus (ARC) of free-feeding and food-deprived (FD) rats in two treatment regimens. ARC preproNPY mRNA levels were significantly increased in FD rats, to the same extent as in combined FD/D-FEN animals. D-FEN treatments producing different-sized reductions in food intake (and body weight) produced corresponding changes in ARC preproNPY mRNA abundance. These findings suggest that ARC preproNPY mRNA levels are not directly altered by D-FEN, and that D-FEN-induced anorexia does not involve effects on the hypothalamic NPY system at the level of NPY gene transcription.


Assuntos
Núcleo Arqueado do Hipotálamo/efeitos dos fármacos , Fenfluramina/farmacologia , Neuropeptídeo Y/genética , Precursores de Proteínas/genética , RNA Mensageiro/metabolismo , Animais , Núcleo Arqueado do Hipotálamo/metabolismo , Peso Corporal/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Masculino , Ratos , Ratos Sprague-Dawley
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