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1.
Diabet Med ; 40(9): e15126, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37171467

RESUMO

AIMS: Use of the CamAPS FX hybrid closed loop (CL) system is associated with improved time in range and glycated haemoglobin A1c across the age span, but little is known about its effects on patient-reported outcomes (PROs). METHODS: This open-label, randomized, multi-site study compared CamAPS FX to sensor-augmented pump (SAP) in a sample of older adults (≥60 years) with type 1 diabetes (T1D). Thirty-five older adults completed PROs surveys at the start of the study and after each period of 16 weeks using either CL or SAP. At the end of the study, 19 participated in interviews about their experiences with CL. RESULTS: Results examining the 16 weeks of CL use showed that the overall Diabetes Distress Scale score and two subscales (powerlessness and physician distress) improved significantly along with trust on the Glucose Monitoring Satisfaction Survey. User experience interview responses were consistent in noting benefits of 'improved glycaemic control' and 'worrying less about diabetes'. CONCLUSION: In this sample of older adults with T1D who have previously shown glycaemic benefit, there are indicators of improved PROs and subjective user experience benefits.


Assuntos
Diabetes Mellitus Tipo 1 , Idoso , Humanos , Glicemia , Automonitorização da Glicemia/métodos , Diabetes Mellitus Tipo 1/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Sistemas de Infusão de Insulina , Resultado do Tratamento , Pessoa de Meia-Idade
2.
BMC Pediatr ; 21(1): 160, 2021 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-33814007

RESUMO

AIMS: To synthesise the qualitative evidence on parents' experiences of caring for a child aged ≤8 years with type 1 diabetes to identify: the challenges they encounter; their views about support received; ways in which support could be improved; and, directions for future research. METHODS: We searched Medline, EMBASE, CINAHL, PsycINFO and Web of Science databases to identify qualitative studies reporting parents' views and experiences of caring for a child with type 1 diabetes aged ≤8 years. Key analytical themes were identified using thematic synthesis. RESULTS: Fourteen studies were included. The synthesis resulted in the generation of two overarching themes. Monopolisation of life describes the all-encompassing impact diabetes could have on parents due to the constant worry they experienced and the perceived need for vigilance. It describes how parents' caring responsibilities could affect their wellbeing, relationships and finances, and how a lack of trusted sources of childcare and a desire to enable a 'normal' childhood constrained personal choices and activities. However, use of diabetes technologies could lessen some of these burdens. Experiences of professional and informal support describes how encounters with healthcare professionals, while generally perceived as helpful, could lead to frustration and anxiety, and how connecting with other parents caring for a child with type 1 diabetes provided valued emotional and practical support. CONCLUSIONS: This synthesis outlines the challenges parents encounter, their views about support received and ways in which support might be improved. It also highlights significant limitations in the current literature and points to important areas for future research, including how sociodemographic factors and use of newer diabetes technologies influence parents' diabetes management practices and experiences. PROSPERO: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42019128710.


Assuntos
Diabetes Mellitus Tipo 1 , Criança , Diabetes Mellitus Tipo 1/terapia , Relações Familiares , Pessoal de Saúde , Humanos , Pais , Pesquisa Qualitativa
3.
Diabet Med ; 37(6): 1030-1037, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31989684

RESUMO

AIM: To explore health professionals' views about who would benefit from using a closed-loop system and who should be prioritized for access to the technology in routine clinical care. METHODS: Health professionals (n = 22) delivering the Closed Loop from Onset in type 1 Diabetes (CLOuD) trial were interviewed after they had ≥ 6 months' experience supporting participants using a closed-loop system. Data were analysed thematically. RESULTS: Interviewees described holding strong assumptions about the types of people who would use the technology effectively prior to the trial. Interviewees described changing their views as a result of observing individuals engaging with the closed-loop system in ways they had not anticipated. This included educated, technologically competent individuals who over-interacted with the system in ways which could compromise glycaemic control. Other individuals, who health professionals assumed would struggle to understand and use the technology, were reported to have benefitted from it because they stood back and allowed the system to operate without interference. Interviewees concluded that individual, family and psychological attributes cannot be used as pre-selection criteria and, ideally, all individuals should be given the chance to try the technology. However, it was recognized that clinical guidelines will be needed to inform difficult decisions about treatment allocation (and withdrawal), with young children and infants being considered priority groups. CONCLUSIONS: To ensure fair and equitable access to closed-loop systems, prejudicial assumptions held by health professionals may need to be addressed. To support their decision-making, clinical guidelines need to be made available in a timely manner.


Assuntos
Atitude do Pessoal de Saúde , Diabetes Mellitus Tipo 1/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Enfermeiras e Enfermeiros , Seleção de Pacientes , Médicos , Automonitorização da Glicemia , Alocação de Recursos para a Atenção à Saúde , Humanos , Bombas de Infusão Implantáveis , Sistemas de Infusão de Insulina , Monitorização Ambulatorial , Pesquisa Qualitativa , Ensaios Clínicos Controlados Aleatórios como Assunto
4.
Diabet Med ; 36(3): 279-286, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30183096

RESUMO

The artificial pancreas is now a viable treatment option for people with Type 1 diabetes and has demonstrated improved glycaemic outcomes while also reducing the onus of self-management of Type 1 diabetes. Closed-loop glucose-responsive insulin delivery guided by real-time sensor glucose readings can accommodate highly variable day-to-day insulin requirements and reduce the hypoglycaemia risk observed with tight glycaemic control in Type 1 diabetes. In 2011, the James Lind Alliance research priorities for Type 1 diabetes were produced and priority 3 was to establish whether an artificial pancreas (closed-loop system) for Type 1 diabetes is effective. This review focuses on the progress that has been made in the evolution of closed-loop systems as an effective treatment option for Type 1 diabetes. Development of closed-loop systems has advanced from feasibility evaluations in highly supervised settings over short periods, to clinical studies in free-living, unsupervised conditions lasting several months. The approval in the USA of the first hybrid closed-loop system (MiniMed® 670G pump, Medtronic, Northridge, CA, USA) in 2016 for use in Type 1 diabetes reflects these advancements. We discuss the evidence from clinical studies that closed-loop systems are effective with improved glycaemic outcomes, reduced hypoglycaemia and had positive end-user acceptance in children, adolescents, adults and pregnant women with Type 1 diabetes. We also present the outlook for future closed-loop systems in the treatment of Type 1 diabetes and identify the challenges facing the wide-spread clinical adoption of this technology.


Assuntos
Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/tratamento farmacológico , Sistemas de Infusão de Insulina , Insulina/administração & dosagem , Pâncreas Artificial , Adolescente , Adulto , Glicemia/análise , Glicemia/efeitos dos fármacos , Automonitorização da Glicemia/efeitos adversos , Automonitorização da Glicemia/instrumentação , Automonitorização da Glicemia/métodos , Criança , Feminino , Humanos , Sistemas de Infusão de Insulina/efeitos adversos , Sistemas de Infusão de Insulina/normas , Pâncreas Artificial/efeitos adversos , Pâncreas Artificial/normas , Gravidez , Gravidez em Diabéticas/sangue , Gravidez em Diabéticas/tratamento farmacológico , Resultado do Tratamento
5.
Diabet Med ; 36(12): 1711-1714, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31002426

RESUMO

BACKGROUND: Glucose management for people with diabetes approaching the end of life can be very challenging. The aim is to balance a minimally invasive approach with avoidance of symptomatic hypo- and hyperglycaemia. CASE REPORT: We present a case of a hospitalized individual whose glucose was managed with closed-loop insulin delivery within a randomized controlled trial setting during a period of terminal illness. During the time in which closed-loop insulin delivery was used, glucose control was safe, with no glucose-related harm. The mean ± sd sensor glucose for this individual was 11.3 ± 4.3 mmol/l, percentage of time spent in target glucose range between 6 and 15 mmol/l was 70.5%, time spent in hypoglycaemia was 2.0% and time spent in significant hyperglycaemia >20 mmol/l was 2.6%. CONCLUSION: Closed-loop systems can accommodate personalized glucose targets and highly variable insulin requirements. Factory-calibrated continuous glucose sensors and insulin pump therapy are less intrusive than finger-stick glucose measurements and insulin injections, respectively. Closed-loop systems may provide a safer and less burdensome approach to glucose management towards the end of life.


Assuntos
Sistemas de Infusão de Insulina , Insulina/administração & dosagem , Assistência Terminal/métodos , Glicemia/análise , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Evolução Fatal , Feminino , Humanos
7.
Diabetes Obes Metab ; 12(10): 883-90, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20920041

RESUMO

AIM: Cerebellin1 (Cbln1) is highly expressed in the hypothalamus, a region of the brain involved in appetite regulation. However, the effects of Cbn1 on food intake are not known. The present study aimed to investigate the effect of Cbln1 on appetite regulation in rats. METHODS: We determined the effect of (i) intracerebroventricular (ICV) injection of Cbln1 on food intake, behaviour and plasma pituitary hormone levels in male Wistar rats; (ii) Cbln1 on the release of hypothalamic neuropeptides known to modulate food intake from hypothalamic explants and (iii) fasting on hypothalamic Cbln1 mRNA expression. RESULTS: (i) ICV administration of Cbln1 significantly increased food intake in rats and caused no adverse behaviours. ICV administration of Cbln1 significantly reduced plasma thyroid stimulating hormone (TSH) levels 10 min postinjection in rats. (ii) Cbln1 significantly increased the release of neuropeptide Y (NPY) from hypothalamic explants. (iii) Cbln1 mRNA expression levels were increased in the ventromedial nucleus of the hypothalamus in fasted rats. CONCLUSIONS: These data suggest that Cbln1 is a novel orexigenic peptide, which may mediate its effects via hypothalamic NPY.


Assuntos
Depressores do Apetite/administração & dosagem , Regulação do Apetite/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Hipotálamo/efeitos dos fármacos , Proteínas do Tecido Nervoso/administração & dosagem , Precursores de Proteínas/administração & dosagem , Animais , Regulação do Apetite/fisiologia , Jejum , Hipotálamo/fisiologia , Injeções Intraventriculares , Masculino , Ratos
8.
9.
Br J Hosp Med (Lond) ; 80(11): 665-669, 2019 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-31707881

RESUMO

The prevalence of diabetes in the inpatient setting is increasing, and suboptimal glucose control in hospital is associated with increased morbidity and mortality. Attaining the recommended glucose levels is challenging with standard insulin therapy. Hypoglycaemia and hyperglycaemia are common and diabetes management in hospital can be a considerable workload burden for health-care professionals. Fully automated insulin delivery (closed-loop) has been shown to be safe, and achieves superior glucose control than standard insulin therapy in the hospital, including in those patients receiving haemodialysis and enteral or parenteral nutrition where glucose control can be particularly challenging. Evidence that the improved glucose control achieved using closed-loop systems can translate into improved clinical outcomes for patients is key to support widespread adoption of this technology. The closed-loop approach has the potential to provide a paradigm shift in the management of inpatient diabetes, particularly in the most challenging inpatient populations, and may reduce staff work burden and the health-care costs associated with inpatient diabetes.


Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Hiperglicemia/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Sistemas de Infusão de Insulina , Insulina/administração & dosagem , Adulto , Criança , Cuidados Críticos , Nutrição Enteral , Desenho de Equipamento , Hospitalização , Humanos , Nutrição Parenteral , Satisfação do Paciente , Diálise Renal , Assistência Terminal
11.
Sci Total Environ ; 374(2-3): 367-78, 2007 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-17258290

RESUMO

Metal and bioessential element concentrations were measured in three species of 17-year periodical cicadas (Magicicada spp.) to determine how cicada tissue chemistry is affected by soil chemistry, measure the bioavailability of metals from both uncontaminated and lead-arsenate-pesticide contaminated soils, and assess the potential risks of observed metal contamination for wildlife. Periodical cicada nymphs feed on root xylem fluids for 13 or 17 years of underground development. The nymphs then emerge synchronously at high densities, before leaving their nymphal keratin exoskeleton and molting into their adult form. Cicadas are an important food source for birds and animals during emergence events, and influence nutrient cycles in woodland ecosystems. Nymphal exoskeletons and whole adult cicadas were sampled in Clarke and Frederick Counties, Virginia and Berkeley and Jefferson Counties, West Virginia during the Brood X emergence in May and June, 2004. Elements, such as Al, Fe, and Pb, are strongly enriched in the nymphal exoskeleton relative to the adult body; Cu and Zn are enriched in bodies. Concentrations of Fe and Pb, when normalized to relatively inert soil constituents such as Al and Ce, are similar in both the molt exoskeleton and their host soil, implying that passive assimilation through prolonged soil contact (adhesion or adsorption) might control these metal concentrations. Normalized concentrations of bioessential elements, such as S, P, K, Ca, Mn, Cu, Zn, and Mo, and chalcophile (sulfur-loving) elements, such as As, Se, and Au, indicate strong enrichment in cicada tissues relative to soil, implying selective absorption and retention by xylem fluids, the cicada nymphs themselves, or both. Element enrichment patterns in cicada tissues are similar to enrichment patterns observed in xylem fluids from tree roots. Chalcophile elements and heavy metals accumulate in keratin-rich tissues and may bind to sulfhydryl groups. Metal concentrations in the nymphal exoskeleton show a positive correlation with soil metal concentrations, with Au exhibiting particularly strong enrichment in the exoskeleton relative to soil concentrations. Metal concentrations in adult bodies do not correlate with soil chemistry. Bioessential elements S, Ca, Mn, Fe, and Zn differed by sex in adults, whereas Na, Mg, K, Ca, Mn, Fe, Zn, and As differed by species. Body concentrations of Ca differed by site conditions (orchard or reference setting). The high Pb contents of orchard soils contaminated by arsenical pesticide residues might inhibit Ca uptake by cicada nymphs. The adult cicadas contain concentrations of metals similar to, or less than, other invertebrates, such as earthworms. There does not appear to be a dietary threat to birds or other consumers of adult cicadas based on Maximum Tolerable Dietary Level (MTDL) Guidelines developed for agricultural animals.


Assuntos
Hemípteros/metabolismo , Metais/análise , Poluentes do Solo/análise , Animais , Monitoramento Ambiental , Feminino , Larva/metabolismo , Masculino , Metais/metabolismo , Pele/metabolismo , Solo , Poluentes do Solo/metabolismo
12.
Obes Rev ; 18(9): 1061-1070, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28545166

RESUMO

Childhood obesity predicts the risk of adult adiposity, which is associated with the earlier onset of cardiovascular disease [adult atherosclerotic cardiovascular disease, ACVD: hypertension, increased carotid intima media thickness (CIMT) stroke, ischemic heart disease (IHD)] and dysglycaemia. Because it is not known whether childhood obesity contributes to these diseases, we conducted a systematic review of studies that examine the ability of measures of obesity in childhood to predict dysglycaemia and ACVD. Data sources were Web of Science, MEDLINE, PubMed, CINAHL, Cochrane, SCOPUS, ProQuest and reference lists. Studies measuring body mass index (BMI), skin fold thickness and waist circumference were selected; of 1,954 studies, 18 met study criteria. Childhood BMI predicted CIMT: odds ratio (OR), 3.39 (95% confidence interval (CI), 2.02 to 5.67, P < 0.001) and risk of impaired glucose tolerance in adulthood, but its ability to predict ACVD events (stroke, IHD; OR, 1.04; 95% CI, 1.02 to 1.07; P < 0.001) and hypertension (OR, 1.17, 95% CI 1.06 to 1.27, P = 0.003) was weak-moderate. Body mass index was not predictive of systolic BP (r -0.57, P = 0.08) and weakly predicted diastolic BP (r 0.21, P = 0.002). Skin fold thickness in childhood weakly predicted CIMT in female adults only (rs 0.09, P < 0.05). Childhood BMI predicts the risk of dysglycaemia and abnormal CIMT in adulthood, but its ability to predict hypertension and ACVD events was weak and moderate, respectively. Skin fold thickness was a weak predictor of CIMT in female adults.


Assuntos
Índice de Massa Corporal , Doenças Cardiovasculares/etiologia , Obesidade Infantil/complicações , Circunferência da Cintura/fisiologia , Pressão Sanguínea/fisiologia , Doenças Cardiovasculares/fisiopatologia , Humanos , Obesidade Infantil/fisiopatologia , Fatores de Risco , Dobras Cutâneas
13.
Am J Med ; 89(5): 561-8, 1990 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2146875

RESUMO

PURPOSE: The chronic fatigue syndrome (CFS) is characterized by profound fatigue, neuropsychiatric dysfunction, and frequent abnormalities in cell-mediated immunity. No effective therapy is known. PATIENTS AND METHODS: Forty-nine patients (40 with abnormal cell-mediated immunity) participated in a randomized, double-blind, placebo-controlled trial to determine the effectiveness of high-dose intravenously administered immunoglobulin G. The patients received three intravenous infusions of a placebo solution or immunoglobulin at a dose of 2 g/kg/month. Assessment of the severity of symptoms and associated disability, both before and after treatment, was completed at detailed interviews by a physician and psychiatrist, who were unaware of the treatment status. In addition, any change in physical symptoms and functional capacity was recorded using visual analogue scales, while changes in psychologic morbidity were assessed using patient-rated indices of depression. Cell-mediated immunity was evaluated by T-cell subset analysis, delayed-type hypersensitivity skin testing, and lymphocyte transformation with phytohemagglutinin. RESULTS: At the interview conducted by the physician 3 months after the final infusion, 10 of 23 (43%) immunoglobulin recipients and three of the 26 (12%) placebo recipients were assessed as having responded with a substantial reduction in their symptoms and recommencement of work, leisure, and social activities. The patients designated as having responded had improvement in physical, psychologic, and immunologic measures (p less than 0.01 for each). CONCLUSION: Immunomodulatory treatment with immunoglobulin is effective in a significant number of patients with CFS, a finding that supports the concept that an immunologic disturbance may be important in the pathogenesis of this disorder.


Assuntos
Síndrome de Fadiga Crônica/terapia , Imunoglobulina G/uso terapêutico , Adolescente , Adulto , Método Duplo-Cego , Esquema de Medicação , Síndrome de Fadiga Crônica/imunologia , Síndrome de Fadiga Crônica/fisiopatologia , Síndrome de Fadiga Crônica/psicologia , Feminino , Humanos , Imunoglobulina G/administração & dosagem , Infusões Intravenosas , Ativação Linfocitária , Linfopenia/patologia , Masculino , Pessoa de Meia-Idade , Placebos , Qualidade de Vida , Ajustamento Social , Subpopulações de Linfócitos T/patologia , Linfócitos T/imunologia , Linfócitos T Auxiliares-Indutores/patologia
14.
J Food Prot ; 67(9): 1834-9, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15453572

RESUMO

A national Salmonella control program in the pork industry was enacted in Ireland in August 2002. This study was undertaken as part of a larger project investigating the role of pork as a source of human salmonellosis in Ireland. The objective of this survey was to assess the prevalence of Salmonella in Irish pork sausage at retail level. Samples, comprising branded prepacked sausages and loose sausages from supermarket meat counters and butcher shops, were collected from selected retail sites in four cities from October to December 2001 and from June to August 2002. A three-tube most-probable-number method was used to enumerate Salmonella in a selected number of samples that were positive by enrichment. Salmonella serotypes were detected in 4.4 and 1.7% of samples at each of the respective sampling periods, a level similar to those reported in other U.S. and U.K. studies. Isolates were characterized by serotype, phage type, and antimicrobial susceptibility. Eighteen (70%) were resistant to at least one antimicrobial, and 15 (58%) were resistant to four or more antimicrobials. Most of the isolates exhibited resistance to tetracycline. Five different phage types were detected. DT104 was the predominant phage type among Salmonella Typhimurium isolates. This study revealed that multidrug-resistant salmonellae are present in a proportion of Irish sausages and that further risk analysis work is necessary in order to quantify the risk posed to public health.


Assuntos
Qualidade de Produtos para o Consumidor , Contaminação de Alimentos/análise , Produtos da Carne/microbiologia , Salmonella/isolamento & purificação , Animais , Tipagem de Bacteriófagos , Contagem de Colônia Microbiana , Farmacorresistência Bacteriana , Microbiologia de Alimentos , Humanos , Irlanda/epidemiologia , Testes de Sensibilidade Microbiana , Prevalência , Salmonella/classificação , Intoxicação Alimentar por Salmonella/prevenção & controle , Sorotipagem , Suínos
15.
BMJ ; 308(6931): 756-9, 1994 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-8142830

RESUMO

OBJECTIVE: To examine the predictors of long term outcome for patients with the chronic fatigue syndrome. DESIGN: Cohort study. SUBJECTS: 139 subjects previously enrolled in two treatment trials; 103 (74%) were reassessed a mean of 3.2 years after start of the trials. SETTING: University hospital referral centre. MAIN OUTCOME MEASURES: Age at onset, duration of illness, psychological and immunological status at initial assessment. Ongoing symptom severity, levels of disability, and immunological function at follow up. RESULTS: 65 subjects had improved but only six reported no current symptoms. An alternative medical diagnosis had been made in two and psychiatric illness diagnosed in 20. The assignment of a primary psychiatric diagnosis at follow up and the strength of the belief that a physical disease process explained all symptoms at entry to the trials both predicted poor outcome. Age at onset of illness, duration of illness, neuroticism, premorbid psychiatric diagnoses, and cell mediated immune function did not predict outcome. CONCLUSION: Though most patients with the chronic fatigue syndrome improve, a substantial proportion remain functionally impaired. Psychological factors such as illness attitudes and coping style seem more important predictors of long term outcome than immunological or demographic variables.


Assuntos
Síndrome de Fadiga Crônica/epidemiologia , Adaptação Psicológica , Adulto , Idade de Início , Idoso , Estudos de Coortes , Pessoas com Deficiência , Síndrome de Fadiga Crônica/imunologia , Síndrome de Fadiga Crônica/psicologia , Feminino , Humanos , Imunidade Celular , Imunoglobulinas/uso terapêutico , Avaliação de Estado de Karnofsky , Estudos Longitudinais , Linfopenia/epidemiologia , Masculino , Pessoa de Meia-Idade , Linfócitos T/imunologia , Resultado do Tratamento
16.
Br J Pharmacol ; 170(7): 1333-48, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23121386

RESUMO

UNLABELLED: Obesity is a major worldwide public health issue. The physiological systems that regulate body weight are thus of great interest as targets for anti-obesity agents. Peptidergic systems are critical to the regulation of energy homeostasis by key regions in the hypothalamus and brainstem. A number of neuropeptide systems have therefore been investigated as potential treatments for obesity. Blocking orexigenic peptide signals such as neuropeptide Y, melanin-concentrating hormone, orexins, relaxin-3 and galanin-like peptide or stimulating anorectic signalling pathways used by peptides such as the melanocortins, ciliary neurotrophic factor and brain-derived neurotrophic factor, are approaches that have shown some promise, but which have also highlighted possible concerns. Manipulation of central peptidergic systems poses a number of therapeutic problems, including brain access and side effects. Given that the homeostatic defence of body weight may limit the effectiveness of any single-target therapy developed, a combination therapy approach may offer the best hope for the effective prevention and treatment of obesity. LINKED ARTICLES: This article is part of a themed section on Neuropeptides. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2013.170.issue-7.


Assuntos
Fármacos Antiobesidade/uso terapêutico , Encéfalo/efeitos dos fármacos , Neuropeptídeos/uso terapêutico , Obesidade/tratamento farmacológico , Animais , Regulação do Apetite/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/fisiopatologia , Quimioterapia Combinada , Comportamento Alimentar/efeitos dos fármacos , Humanos , Neuropeptídeos/metabolismo , Obesidade/metabolismo , Obesidade/fisiopatologia , Transdução de Sinais/efeitos dos fármacos
17.
Regul Pept ; 187: 6-11, 2013 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-24120470

RESUMO

Neuromedin B (NMB) is a highly conserved bombesin-related peptide found in mammals. NMB mRNA is detected in the central nervous system (CNS) and is highly expressed in the rat hypothalamus, in particular the medial preoptic area and the arcuate nucleus. The mammalian bombesin family of receptors consists of three closely related G protein coupled receptors, BB1, BB2 and BB3. The BB1 receptor subtype has the highest affinity for NMB. NMB has well documented roles in the regulation of the thyroid axis and the stress axis in rats. However, there is little available data regarding the role of NMB in the regulation of the hypothalamic-pituitary-gonadal (HPG) axis. It is known that the NMB receptor is expressed in immortalised gonadotrophin releasing hormone (GnRH) releasing GT1-7 cells and murine forebrain GnRH neurons, and that anterior pituitary NMB-immunoreactivity is altered by changes in the sex steroid environment. The objective of these studies was thus to further investigate the effects of NMB on the HPG axis. Intracerebroventricular (ICV) administration of NMB (10 nmol) to adult male rats significantly increased plasma luteinising hormone (LH) levels 30 min after injection (plasma LH ng/ml; saline 0.69±0.07, 10 nmol NMB 1.33±0.17, P<0.01). In vitro, NMB stimulated GnRH release from hypothalamic explants from male rats and from hypothalamic GT1-7 cells. NMB had no significant effect on LH release from anterior pituitary explants from male rats, or from pituitary LßT2 cells in vitro. These results suggest a previously unreported role for NMB in the stimulation of the HPG axis via hypothalamic GnRH. Further work is now required to determine the receptor mediating the effects of NMB on the reproductive axis and the physiological role of NMB in reproduction.


Assuntos
Sistema Hipotálamo-Hipofisário , Neurocinina B/análogos & derivados , Sistema Hipófise-Suprarrenal , Animais , Linhagem Celular , Hormônio Liberador de Gonadotropina/metabolismo , Gonadotropinas/sangue , Humanos , Hipotálamo/metabolismo , Hormônio Luteinizante/metabolismo , Masculino , Neurocinina B/fisiologia , Hipófise/metabolismo , Ratos , Ratos Wistar , Testosterona/sangue , Técnicas de Cultura de Tecidos
18.
Br J Pharmacol ; 159(8): 1663-71, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20233222

RESUMO

BACKGROUND AND PURPOSE: The functional characterization of secreted peptides can provide the basis for the development of novel therapeutic agents. Augurin is a recently identified secreted peptide of unknown function expressed in multiple endocrine tissues, and in regions of the brain including the hypothalamus. We therefore investigated the effect of hypothalamic injection of augurin on the hypothalamo-pituitary-adrenal (HPA) axis in male Wistar rats. EXPERIMENTAL APPROACH: Augurin was given as a single injection into the third cerebral ventricle (i.c.v.) or into the paraventricular nucleus (iPVN) of the hypothalamus. Circulating hormone levels were then measured by radioimmunoassay. The effect of augurin on the release of hypothalamic neuropeptides was investigated ex vivo using hypothalamic explants. The acute effects of iPVN augurin on behaviour were also assessed. KEY RESULTS: i.c.v. injection of augurin significantly increased plasma ACTH and corticosterone, compared with vehicle-injected controls, but had no effect on other hypothalamo-pituitary axes hormones. Microinjection of lower doses of augurin into the PVN caused a similar increase in plasma ACTH and corticosterone, without significant alteration in behavioural patterns. Incubation of hypothalamic explants with increasing doses of augurin significantly elevated corticotrophin-releasing factor (CRF) and arginine vasopressin release. In vivo, peripheral injection of a CRF(1/2) receptor antagonist prevented the rise in ACTH and corticosterone caused by i.c.v. augurin injection. CONCLUSIONS AND IMPLICATIONS: These data suggest that augurin stimulates the release of ACTH via the release of hypothalamic CRF. Pharmacological manipulation of the augurin system may therefore be a novel target for regulation of the HPA axis.


Assuntos
Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Proteínas de Neoplasias/farmacologia , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Hormônio Liberador da Corticotropina , Hormônios/sangue , Humanos , Injeções Intraventriculares , Masculino , Proteínas de Neoplasias/administração & dosagem , Ratos , Ratos Wistar , Proteínas Supressoras de Tumor
19.
Br J Pharmacol ; 161(3): 601-13, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20880399

RESUMO

BACKGROUND AND PURPOSE: Alarin is a recently discovered member of the galanin peptide family encoded by a splice variant of galanin-like peptide (GALP) mRNA. Galanin and GALP regulate energy homeostasis and reproduction. We therefore investigated the effects of alarin on food intake and gonadotrophin release. EXPERIMENTAL APPROACH: Alarin was administered into the third cerebral ventricle (i.c.v.) of rats, and food intake or circulating hormone levels were measured. The effect of alarin on the hypothalamo-pituitary-gonadal axis was investigated in vitro using hypothalamic and anterior pituitary explants, and immortalized cell lines. Receptor binding assays were used to determine whether alarin binds to galanin receptors. KEY RESULTS: The i.c.v. administration of alarin (30 nmol) to ad libitum fed male rats significantly increased acute food intake to 500%, and plasma luteinizing hormone (LH) levels to 170% of responses to saline. In vitro, 100 nM alarin stimulated neuropeptide Y (NPY) and gonadotrophin-releasing hormone (GnRH) release from hypothalamic explants from male rats, and 1000 nM alarin increased GnRH release from GT1-7 cells. In vivo, pretreatment with the GnRH receptor antagonist cetrorelix prevented the increase in plasma LH levels observed following i.c.v. alarin administration. Receptor binding studies confirmed alarin did not bind to any known galanin receptor, or compete with radiolabelled galanin for hypothalamic binding sites. CONCLUSIONS AND IMPLICATIONS: These results suggest alarin is a novel orexigenic peptide, and that it increases circulating LH levels via hypothalamic GnRH. Further work is required to identify the receptor(s) mediating the biological effects of alarin.


Assuntos
Ingestão de Alimentos/efeitos dos fármacos , Peptídeo Semelhante a Galanina/farmacologia , Hormônio Liberador de Gonadotropina/metabolismo , Gonadotropinas/sangue , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Linhagem Celular , Peptídeo Semelhante a Galanina/administração & dosagem , Peptídeo Semelhante a Galanina/antagonistas & inibidores , Hormônio Liberador de Gonadotropina/análogos & derivados , Hormônio Liberador de Gonadotropina/farmacologia , Sistema Hipotálamo-Hipofisário/metabolismo , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Injeções Intraventriculares , Hormônio Luteinizante/sangue , Masculino , Neuropeptídeo Y/metabolismo , Ensaio Radioligante , Ratos , Ratos Wistar , Receptores de Galanina/metabolismo , Testosterona/sangue
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