Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 229
Filtrar
1.
Ann R Coll Surg Engl ; 103(8): 553-560, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34464555

RESUMO

INTRODUCTION: Our study investigated how the standard of surgical care is assessed within the English and Welsh litigation process. The 'shadowline' represents the dividing line between acceptable and unacceptable standards of care. Our hypothesis was that different assessors risk adopting materially different interpretations regarding the acceptable standard of care. Any variation in the interpretation of where the shadowline falls will create uncertainty and unfairness to surgeons and patients alike. METHODS: We summarised the legal literature and suggested the factors affecting the assessment of surgical standards. We illustrated our findings on distribution curves. RESULTS: There was a risk that the shape of the curve and the location of the shadowline may vary according to the assessor. Importantly, a gap may have developed between the legal and clinical shadowlines in respect of the consenting process. DISCUSSION AND CONCLUSION: We suggested how a gap between the surgical and legal shadow lines could be narrowed. Clinical governance, balanced literature and realistic expert assessments were all part of the solution.


Assuntos
Padrão de Cuidado/legislação & jurisprudência , Procedimentos Cirúrgicos Operatórios/normas , Prática Clínica Baseada em Evidências/legislação & jurisprudência , Prova Pericial/legislação & jurisprudência , Humanos , Procedimentos Cirúrgicos Operatórios/legislação & jurisprudência
2.
Eur J Clin Nutr ; 70(2): 269-73, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26306566

RESUMO

BACKGROUND/OBJECTIVES: Vascular endothelial function declines with advancing age, due in part to increased oxidative stress and inflammation, and this age-related vascular dysfunction has been identified as an independent risk factor for cardiovascular diseases. This double-blind, placebo-controlled trial investigated the effects of a dietary supplement containing ß-hydroxy-ß-methylbutyrate (HMB), glutamine and arginine on endothelial-dependent vasodilation of older adults. SUBJECTS/METHODS: A total of 31 community-dwelling men and women aged 65-87 years were randomly assigned to two groups. The treatment group received two doses of the supplement daily (totaling 3 g HMB, 14 g glutamine and 14 g arginine) for 6 months, whereas the control group received an isocaloric placebo. At baseline and week 24, vascular endothelial function was measured by flow-mediated dilation of the brachial artery, and fasting blood samples were obtained to measure high-sensitivity C-reactive protein (hsCRP) and tumor necrosis factor-α (TNF-α). RESULTS: Paired sample t-tests revealed a 27% increase in flow-mediated dilation among the treatment group (P=0.003), whereas no change was observed in the placebo group (P=0.651). Repeated-measures analysis of variance verified a significant time by group interaction (P=0.038). Although no significant changes were observed for hsCRP or TNF-α, a trend was observed for increasing hsCRP among the placebo group only (P=0.059). CONCLUSIONS: These results suggest that dietary supplementation of HMB, glutamine and arginine may favorably affect vascular endothelial function in older adults. Additional studies are needed to elucidate whether reduced inflammation or other mechanisms may underlie the benefits of supplementation.


Assuntos
Envelhecimento/fisiologia , Arginina/administração & dosagem , Suplementos Nutricionais , Endotélio Vascular/efeitos dos fármacos , Glutamina/administração & dosagem , Valeratos/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/sangue , Artéria Braquial/fisiologia , Proteína C-Reativa/análise , Doenças Cardiovasculares/etiologia , Método Duplo-Cego , Endotélio Vascular/fisiologia , Jejum/sangue , Feminino , Humanos , Masculino , Fator de Necrose Tumoral alfa/sangue , Vasodilatação/efeitos dos fármacos
3.
Br J Cancer ; 111(1): 94-100, 2014 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-24867690

RESUMO

BACKGROUND: Patients with malignant pleural effusions (MPEs) generally have advanced disease with poor survival and few therapeutic options. Cells within MPEs may be used to stratify patients for targeted therapy. Targeted therapy with poly(ADP ribose) polymerase inhibitors (PARPi) depends on identifying homologous recombination DNA repair (HRR)-defective cancer cells. We aimed to determine the feasibility of assaying HRR status in MPE cells. METHODS: A total of 15 MPE samples were collected from consenting patients with non-small-cell lung cancer (NSCLC), mesothelioma and ovarian and breast cancer. Primary cultures were confirmed as epithelial by pancytokeratin, and HRR status was determined by the detection of γH2AX and RAD51 foci following a 24-h exposure to rucaparib, by immunofluorescence microscopy. Massively parallel next-generation sequencing of DNA repair genes was performed on cultured MPE cells. RESULTS: From 15 MPE samples, 13 cultures were successfully established, with HRR function successfully determined in 12 cultures. Four samples - three NSCLC and one mesothelioma - were HRR defective and eight samples - one NSCLC, one mesothelioma, one sarcomatoid, one breast and four ovarian cancers - were HRR functional. No mutations in DNA repair genes were associated with HRR status, but there was probable loss of heterozygosity of FANCG, RPA1 and PARP1. CONCLUSIONS: HRR function can be successfully detected in MPE cells demonstrating the potential to stratify patients for targeted therapy with PARPi.


Assuntos
Derrame Pleural Maligno/genética , Reparo de DNA por Recombinação , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Estudos de Viabilidade , Feminino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Derrame Pleural Maligno/patologia
4.
Br J Cancer ; 110(8): 1977-84, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24556618

RESUMO

BACKGROUND: Poly(ADP-ribose) polymerase-1 (PARP) inhibitors (PARPi) exploit tumour-specific defects in homologous recombination DNA repair and continuous dosing is most efficacious. Early clinical trial data with rucaparib suggested that it caused sustained PARP inhibition. Here we investigate the mechanism of this durable inhibition and potential exploitation. METHODS: Uptake and retention of rucaparib and persistence of PARP inhibition were determined by radiochemical and immunological assays in human cancer cell lines. The pharmacokinetics and pharmacodynamics of rucaparib were determined in tumour-bearing mice and the efficacy of different schedules of rucaparib was determined in mice bearing homologous recombination DNA repair-defective tumours. RESULTS: Rucaparib accumulation is carrier mediated (Km=8.4±1.2 µM, Vmax=469±22 pmol per 10(6) cells per 10 min), reaching steady-state levels >10 times higher than the extracellular concentration within 30 min. Rucaparib is retained in cells and inhibits PARP ≥50% for ≥72 h days after a 30-min pulse of 400 nM. In Capan-1 tumour-bearing mice rucaparib accumulated and was retained in the tumours, and PARP was inhibited for 7 days following a single dose of 10 mg kg(-1) i.p or 150 mg kg(-1) p.o. by 70% and 90%, respectively. Weekly dosing of 150 mg kg(-1) p.o once a week was as effective as 10 mg kg(-1) i.p daily for five days every week for 6 weeks in delaying Capan-1 tumour growth. CONCLUSIONS: Rucaparib accumulates and is retained in tumour cells and inhibits PARP for long periods such that weekly schedules have equivalent anticancer activity to daily dosing in a pre-clinical model, suggesting that clinical evaluation of alternative schedules of rucaparib should be considered.


Assuntos
Inibidores Enzimáticos/administração & dosagem , Indóis/administração & dosagem , Poli(ADP-Ribose) Polimerases/genética , Animais , Linhagem Celular Tumoral , Reparo do DNA/efeitos dos fármacos , Esquema de Medicação , Inibidores Enzimáticos/sangue , Inibidores Enzimáticos/farmacocinética , Recombinação Homóloga/efeitos dos fármacos , Humanos , Indóis/sangue , Indóis/farmacocinética , Camundongos , Inibidores de Poli(ADP-Ribose) Polimerases , Ensaios Antitumorais Modelo de Xenoenxerto
5.
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
6.
Proc SPIE Int Soc Opt Eng ; 8668: 866830, 2013 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-25745539

RESUMO

The current Small Animal Radiation Research Platform (SARRP) is poor for localizing small soft tissue targets for irradiation or tumor models growing in a soft tissue environment. Therefore, an imaging method complementary to x-ray CT is required to localize the soft tissue target's Center of Mass (CoM) to within 1 mm. In this paper, we report the development of an integrated x-ray/bioluminescence imaging/tomography (BLI/BLT) system to provide a pre-clinical, high resolution irradiation system. This system can be used to study radiation effects in small animals under the conebeam computed tomography (CBCT) imaging guidance by adding the bioluminescence imaging (BLI) system as a standalone system which can also be docked onto the SARRP. The proposed system integrates two robotic rotating stages and an x-ray source rated at maximum 130 kVp and having a small variable focal spot. A high performance and low noise CCD camera mounted in a light-tight housing along with an optical filter assembly is used for multi-wavelength BL tomography. A three-mirror arrangement is implemented to eliminate the need of rotating the CCD camera for acquiring multiple views. The mirror system is attached to a motorized stage to capture images in angles between 0-90° (for the standalone system). Camera and CBCT calibration are accomplished.

7.
Med Phys ; 39(6Part14): 3767, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28517271

RESUMO

PURPOSE: Design and construct an integrated x-ray/bioluminescent tomography (BLT) system (with BLT being our initial focus) that can function as a standalone research apparatus and also on-board the SARRP to guide focal irradiation. In addition, it is aimed to enhance the BLT of the system to improve target localization by incorporating multi-projection, multi-spectral BL images, as well as CT 'priors'. METHODS: The SARRP system integrates a portable robotic translational/rotational stages system and an x-ray source which in the new system development the x-ray source is replaced with the PXS10-65 W model rated at maximum 130 kV having a variable small focal. A high performance, low noise, CCD camera mounted on a light-tight housing along is used for the aim of the BL imaging and tomography. In the new setup of the BLI system, the camera-filter-mirror assembly is attached to a motorized gantry to acquire images in angles between to while the position of the camera does not block the path of the x- ray beam. Innovatively, a 3-mirror arrangement is implemented to eliminate the need to rotate the CCD camera for capturing images. Furthermore, the robotic stage can be vertically adjusted to allow BLI imaging of multiple animals. RESULTS: To validate the accuracy with the on-board x-ray and BL tomography can be used to localize a BL tumor target and the minimum beam expansion to ensure radiation coverage of the target. The validation will employ phantoms and immunohistochemistry analysis of radiation damage in irradiated BL tumor models in vivo. The proposed system is currently under development and envisioned to be calibrated and evaluated along with the stand-alone radiation system. CONCLUSIONS: The novelty of embedded BLI guidance system is to enable the unprecedented focal irradiation of the small volumes of tumors which are more realistic in human disease.

8.
Health Technol Assess ; 14(51): 1-334, iv, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21050585

RESUMO

BACKGROUND: In recent years human resource management (HRM) has been seen as an important factor in the successful realisation of organisational change programmes. The UK NHS is undergoing substantial organisational change and there is a need to establish which human resource (HR) initiatives may be most effective. OBJECTIVES: To assess the results from a wide-ranging series of systematic reviews of the evidence on HRM and performance. The first part assesses evidence on use of HRM in the UK and fidelity of practice implemented. The second part considers evidence for the impact of HRM practices on intermediate outcomes, which can impact on final outcomes, such as organisational performance or patient care. DATA SOURCES: The following databases were searched: Applied Social Sciences Index and Abstracts (ASSIA), British Nursing Index (BNI), Business Source Premier, Campbell Collaboration, Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Database of Systematic Reviews (CDSR), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Database of Abstracts of Reviews of Effectiveness (DARE), DH-Data, EMBASE, Health Management Information Consortium (HMIC), International Bibliography of the Social Sciences (IBSS), King's Fund database, MEDLINE, NHS Economic Evaluation Database (NHS EED), National Research Register (NRR), PREMEDLINE, PsycINFO, ReFeR, Social Sciences Citation Index (SSCI) and Science Citation Index (SCI). The searches were conducted in May/June 2006. REVIEW METHODS: Broad categories of HRM interventions and intermediate outcomes were generated: 10 HRM categories and 12 intermediate outcome categories. Seven patient final outcomes were derived from the NHS Performance Indicators and the NHS Improvement Plan. The quality criteria used to select papers incorporated a longitudinal study design filter to provide evidence of the causal direction of relationships between HRM and relevant outcomes. Single HRM practices were considered. Within the health-specific literature, focus was on the impact of HRM on patient outcomes. Information is presented on the reliability of measures in each of the intermediate outcome areas. RESULTS: Work design practices that enhance employee autonomy and control influenced a number of outcomes and there was consistent evidence for the positive impact of increased job control on employee outcomes, such as job satisfaction, absence and health. For employee participation, the small number of studies reviewed supported the involvement of employees in design/implementation of changes that affect their work. In health literature in particular, employee involvement through quality improvement teams resulted in improved patient outcomes. Findings were positive for the impact of training on the intended outcomes of the initiatives. Support for the impact of performance management practices was apparent, in particular feedback on performance outcomes and the use of participative goal setting. Strong associations were found among all intermediate outcomes, and the relationship between most intermediate behaviours and outcomes were significant. LIMITATIONS: Limited evidence was available on the use of HRM and on the implementation of policy. Also, the specific practices studied within each HRM category differ so there was little evidence to show whether similar practices have the same effects in health and non-health settings. CONCLUSIONS: Some potentially effective practices for both health and non-health areas were identified, and HRM methods could be used to support change processes within the NHS; the findings relating to work organisation are particularly promising with regard to changes in methods of service delivery. Using training to support the implementation of change is highlighted. However, future multilevel studies that embrace the individual, team and organisational level are needed. Studies should look into interventions aimed at improving HR outcomes and performance, and allow for pre- and post-intervention measurement of practices and outcomes.


Assuntos
Pessoal de Saúde/organização & administração , Gestão de Recursos Humanos/métodos , Qualidade da Assistência à Saúde/normas , Medicina Estatal/organização & administração , Pessoal de Saúde/psicologia , Humanos , Desenvolvimento de Pessoal/métodos , Desenvolvimento de Pessoal/normas , Gestão da Qualidade Total/métodos , Reino Unido
9.
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
10.
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
11.
Neurology ; 71(17): 1361-7, 2008 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-18936429

RESUMO

BACKGROUND: Histiocytosis, both Langerhans and non-Langerhans cell type, can be associated with cerebellar white matter abnormalities, thought to be paraneoplastic. The associated clinical picture consists of ataxia, spasticity, and cognitive decline. Hormonal dysfunction is frequent. MRI shows cerebellar white matter abnormalities, as well as brainstem and basal ganglia abnormalities. This so-called "neurodegenerative syndrome" may occur years before or during manifest histiocytosis and also years after cure. We discovered similar MRI abnormalities in 13 patients and wondered whether they could have the same syndrome. METHODS: We reviewed the clinical and laboratory information of these 13 patients and evaluated their brain MRIs. Seven patients underwent spinal cord MRI. RESULTS: All patients were isolated cases; 10 were male. They had signs of cerebellar and pyramidal dysfunction, behavioral problems, and cognitive decline. MRI showed abnormalities of the cerebellar white matter, brainstem, basal ganglia, and, to a lesser extent, cerebral white matter. Three patients had spinal cord lesions. Three patients had laboratory evidence of hormonal dysfunction. No evidence was found of an underlying metabolic defect. In two patients biopsy of nodular brain lesions revealed histiocytic infiltrates. CONCLUSIONS: Considering the striking clinical and MRI similarities between our patients and the patients with this neurodegenerative syndrome in the context of proven histiocytosis, it is likely that they share the same paraneoplastic syndrome, although we cannot exclude a genetic disorder with certainty. The fact that we found histiocytic lesions in two patients substantiates our conclusion. Patients with cerebellar white matter abnormalities should be monitored for histiocytosis.


Assuntos
Doenças Cerebelares/diagnóstico , Histiocitose/diagnóstico , Síndrome da Leucoencefalopatia Posterior/diagnóstico , Adulto , Ataxia Cerebelar/complicações , Ataxia Cerebelar/diagnóstico , Ataxia Cerebelar/patologia , Doenças Cerebelares/complicações , Doenças Cerebelares/patologia , Criança , Feminino , Histiocitose/complicações , Histiocitose/patologia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Síndrome da Leucoencefalopatia Posterior/complicações , Síndrome da Leucoencefalopatia Posterior/patologia , Estudos Retrospectivos
12.
Am J Physiol Endocrinol Metab ; 295(2): E278-86, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18492777

RESUMO

The hypothalamus plays a key role in the regulation of both energy homeostasis and reproduction. Evidence suggests that relaxin-3, a recently discovered member of the insulin superfamily, is an orexigenic hypothalamic neuropeptide. Relaxin-3 is thought to act in the brain via the RXFP3 receptor, although the RXFP1 receptor may also play a role. Relaxin-3, RXFP3, and RXFP1 are present in the hypothalamic paraventricular nucleus, an area with a well-characterized role in the regulation of energy balance that also modulates reproductive function by providing inputs to hypothalamic gonadotropin-releasing hormone (GnRH) neurons. Other members of the relaxin family are known to play a role in the regulation of reproduction. However, the effects of relaxin-3 on reproductive function are unknown. We studied the role of relaxin-3 in the regulation of the hypothalamo-pituitary-gonadal (HPG) axis. Intracerebroventricular (5 nmol) and intraparaventricular (540-1,620 pmol) administration of human relaxin-3 (H3) in adult male Wistar rats significantly increased plasma luteinizing hormone (LH) 30 min postinjection. This effect was blocked by pretreatment with a peripheral GnRH antagonist. Central administration of human relaxin-2 showed no significant effect on plasma LH. H3 dose-dependently stimulated the release of GnRH from hypothalamic explants and GT(1)-7 cells, which express RXFP1 and RXFP3, but did not influence LH or follicle-stimulating hormone release from pituitary fragments in vitro. We have demonstrated a novel role for relaxin-3 in the stimulation of the HPG axis, putatively via hypothalamic GnRH neurons. Relaxin-3 may act as a central signal linking nutritional status and reproductive function.


Assuntos
Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Relaxina/farmacologia , Animais , Linhagem Celular , Hormônio Foliculoestimulante/metabolismo , Hormônio Liberador de Gonadotropina/análogos & derivados , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Hormônio Liberador de Gonadotropina/farmacologia , Antagonistas de Hormônios/farmacologia , Humanos , Sistema Hipotálamo-Hipofisário/fisiologia , Hormônio Luteinizante/metabolismo , Masculino , Sistema Hipófise-Suprarrenal/fisiologia , Ratos , Ratos Wistar , Receptores Acoplados a Proteínas G/biossíntese , Receptores Acoplados a Proteínas G/genética , Relaxina/antagonistas & inibidores , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Testosterona/metabolismo
13.
Pharmacoepidemiol Drug Saf ; 16(6): 620-6, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17192840

RESUMO

PURPOSE: Case reports suggest that leukotriene modifier use may be associated with the onset of Churg-Strauss syndrome (CSS). Using pooled data from two nested case-control studies, we examined the association between asthma drug use and the development of CSS. METHODS: The study was performed in three US managed care organizations and a US national health plan with chart access and complete electronic pharmacy data, with a covered population of 13.9 million. There were 47 cases of possible or definite CSS and 4700 asthma drug user controls identified between January 1, 1995 and December 31, 2002. We examined exposure to asthma drugs in cases and controls, including leukotriene modifiers (6 cases and 202 controls), in the two to 6 months prior to the onset of adjudicated CSS. RESULTS: While the crude association between use of leukotriene modifiers and CSS was strong (odds ratio (OR) 4.00, 95% confidence interval (CI): 1.49-10.60), in a multivariable analysis controlling for use of oral corticosteroids, inhaled corticosteroids, and number of categories of asthma drugs dispensed, there was no significant association (OR 1.32, 95% CI: 0.44-3.96). Use of inhaled and oral corticosteroids, evaluated as markers of asthma severity, were associated with CSS (OR 3.07, 95% CI: 1.34-7.03 and OR 5.36, 95% CI: 2.51-11.45, respectively). CONCLUSIONS: No association was found between CSS and leukotriene modifiers after controlling for asthma drug use However, it is not possible to rule out modest associations with asthma treatments given CSS is so rare and so highly correlated with asthma severity, suggesting further investigation is warranted.


Assuntos
Antiasmáticos/efeitos adversos , Asma/tratamento farmacológico , Síndrome de Churg-Strauss/induzido quimicamente , Adolescente , Corticosteroides/efeitos adversos , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Antagonistas de Leucotrienos/efeitos adversos , Masculino , Pessoa de Meia-Idade
14.
Diabetes Metab Res Rev ; 23(4): 299-303, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-16952199

RESUMO

BACKGROUND: Weight loss is difficult to achieve in type 2 diabetes and many therapies are associated with weight gain, an effect attenuated by metformin. We studied the effects of metformin on energy expenditure, appetite and the regulation of PYY and ghrelin in type 2 diabetes. METHODS: Plasma peptide YY (PYY), ghrelin, resting metabolic rate (RMR), postprandial thermogenesis (PPTG), and appetite ratings were measured at baseline and following a mixed meal in 11 type 2 diabetic subjects treated with diet alone (T2D) and 10 treated with metformin monotherapy (T2MF). The groups were similar in age, gender and adiposity. RESULTS: There were no differences in baseline anthropometric, or metabolic variables between the groups. Postprandially, plasma ghrelin fell equally in both groups (23% versus 24.5%, p < 0.05 versus baseline, p = NS between groups) but were reduced for longer in T2MF (below baseline 60-240 min T2MF versus 60-180 min T2D) coincidentally with a prolonged sensation of fullness and suppression of hunger in the metformin-treated group. There were no differences in PYY concentrations, RMR or PPTG. CONCLUSIONS: Metformin prolongs the postprandial fall in ghrelin concentrations. These effects may prolong the inter-meal interval, thereby decreasing snack intake and daily energy intake, promoting weight loss.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Hormônios Peptídicos/sangue , Adulto , Apetite , Diabetes Mellitus Tipo 2/fisiopatologia , Metabolismo Energético/efeitos dos fármacos , Feminino , Grelina , Humanos , Masculino , Pessoa de Meia-Idade , Concentração Osmolar , Peptídeo YY/sangue , Período Pós-Prandial , Resposta de Saciedade , Termogênese
15.
Am J Physiol Endocrinol Metab ; 292(3): E913-9, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17132825

RESUMO

The insulin superfamily, characterized by common disulphide bonds, includes not only insulin but also insulin-like peptides such as relaxin-1 and relaxin-3. The actions of relaxin-3 are largely unknown, but recent work suggests a role in regulation of food intake. Relaxin-3 mRNA is highly expressed in the nucleus incertus, which has extensive projections to the hypothalamus, and relaxin immunoreactivity is present in several hypothalamic nuclei. In the rat, relaxin-3 binds and activates both relaxin family peptide receptor 1, which also binds relaxin-1, and a previously orphaned G protein-coupled receptor, RXFP3. These receptors are extensively expressed in the hypothalamus. The aims of these studies were twofold: 1) map the hypothalamic site(s) of the orexigenic action of relaxin-3 and 2) examine the site(s) of neuronal activation following central relaxin-3 administration. After microinjection into hypothalamic sites, human relaxin-3 (H3; 180 pmol) significantly stimulated 0- to 1-h food intake in the supraoptic nucleus (SON), arcuate nucleus (ARC), and the anterior preoptic area (APOA) [SON 0.4+/-0.2 (vehicle) vs. 2.9+/-0.5 g (H3), P<0.001; ARC 0.7+/-0.3 (vehicle) vs. 2.7+/-0.2 g (H3), P<0.05; and APOA 0.8+/-0.1 (vehicle) vs. 2.2+/-0.2 g (H3), P<0.05]. Cumulative food intake was significantly increased

Assuntos
Mapeamento Encefálico , Hipotálamo/efeitos dos fármacos , Hipotálamo/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas do Tecido Nervoso/farmacologia , Neuropeptídeos/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Relaxina/farmacologia , Animais , Ingestão de Alimentos/efeitos dos fármacos , Imuno-Histoquímica , Masculino , Modelos Biológicos , Orexinas , Ratos , Ratos Wistar
16.
Br J Surg ; 93(11): 1418-23, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17016792

RESUMO

BACKGROUND: Most injured children are appropriately treated at a district general hospital (DGH), but some require transfer to a specialist centre. The objectives of this study were to develop, implement and evaluate triage guidelines for the rapid recognition of injured children who require transfer. METHODS: This was a prospective, interventional cohort study of the 592 seriously injured children who presented to five regional DGHs during a 51-month period. A multispecialty steering group representing all participating DGHs developed and implemented the guidelines. Data were collected for 24 months before the guidelines were introduced, over the 3-month implementation period and for 24 months afterwards. Outcome measures were referral and management patterns before and after introduction of the guidelines. RESULTS: For level I (unstable) patients, after the implementation of guidelines there was a 29 per cent increase in the proportion of transfers to a specialist centre (from 40 (68 per cent) of 59 to 32 (97 per cent) of 33; P = 0.003), no admissions to a DGH intensive care unit and all 12 operations were performed at a specialist centre. Guideline users indicated that they were familiar with the guidelines. CONCLUSION: The introduction of triage guidelines within an effective communication network was associated with changes in the management of severely injured children.


Assuntos
Transferência de Pacientes/normas , Guias de Prática Clínica como Assunto/normas , Triagem/normas , Ferimentos e Lesões/terapia , Adolescente , Criança , Pré-Escolar , Feminino , Fidelidade a Diretrizes , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Masculino , Encaminhamento e Consulta , Resultado do Tratamento
18.
Neurology ; 66(9): 1361-6, 2006 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-16682668

RESUMO

OBJECTIVE: To examine one model of research advance directive as a possible way to reduce the mismatch between patient and proxy choices and also to learn more about how patients with mild to moderate dementia may want to keep decision making or cede it to their proxies in the future. METHODS: Separate interviews were conducted with 149 dyads of dementia patients and family proxies about future enrollment in five types of research. Subsequent joint interviews were conducted with 69 of those dyads to discuss their separately articulated decisions and ask whether the patient prefers future enrollment decisions to be made as he or she directs today or as the proxy deems best in the future. RESULTS: Patients chose to cede future decision making to their proxies in 82.9% of the trials. Patients ceded decisions to their proxies in 80.7% of those trials about which the dyad had given opposite answers (n = 74, 49.7%). Patients who had expressed discomfort about the prospect of the proxy making an enrollment decision in a trial (n = 49, 32.9%) ceded decision making to their proxies in 45.7% of those trials. CONCLUSIONS: Both patients and proxies were willing to discuss future research enrollment in the context of an advance directive for research. Such a document may be helpful to proxies and researchers in the future to judge the types of research and associated risks patients are willing to enroll in. Although most patients willingly cede future decisions to their proxies, a sizeable minority do not wish to do so.


Assuntos
Diretivas Antecipadas , Ensaios Clínicos como Assunto/psicologia , Tomada de Decisões , Demência/psicologia , Competência Mental , Pacientes/psicologia , Procurador , Consentimento do Representante Legal , Administração Oral , Diretivas Antecipadas/ética , Diretivas Antecipadas/psicologia , Negro ou Afro-Americano/psicologia , Idoso , Idoso de 80 Anos ou mais , Encéfalo , Ensaios Clínicos como Assunto/ética , Comunicação , Avaliação Pré-Clínica de Medicamentos/psicologia , Feminino , Testes Genéticos/psicologia , Humanos , Relações Interpessoais , Masculino , Pessoa de Meia-Idade , Direitos do Paciente , Autonomia Pessoal , Flebotomia/psicologia , Testes Psicológicos , Risco , Punção Espinal/psicologia , Transplante de Células-Tronco/psicologia , População Branca/psicologia
19.
J Neuroendocrinol ; 18(5): 349-54, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16629833

RESUMO

Kisspeptin-54 is the peptide product of the KiSS-1 gene and an endogenous agonist of the GPR54 receptor. KiSS-1 was initially discovered as a metastasis suppressor gene, but recent studies demonstrate that the kisspeptin/GPR54 system is a key regulator of the reproductive system. Disrupted GPR54 signalling causes hypogonadotrophic hypogonadism in rodents and man. Intracerebroventricular or peripheral administration of kisspeptin potently stimulates the hypothalamic-pituitary-gonadal (HPG) axis via the hypothalamic gonadotrophin-releasing hormone system. We have investigated the effect of injection of kisspeptin-54 into discrete hypothalamic regions on the HPG axis. To construct a dose-response curve for the effects of intrahypothalamic kisspeptin administration, adult male Wistar rats were cannulated into the medial preoptic area (MPOA) at the level of the organum vasculosum laminae terminalis (OVLT). Kisspeptin-54 was injected into the MPOA at doses of 0.01, 0.1, 1, 10 and 100 pmol. At 60 min following injection of 1, 10 or 100 pmol kisspeptin-54, plasma luteinising hormone (LH) and total testosterone levels were significantly increased. Adult male Wistar rats were then cannulated into the rostral preoptic area at the level of the OVLT (RPOA), the MPOA, the paraventricular (PVN), dorsomedial (DMN) and arcuate hypothalamic nuclei, and the lateral hypothalamic area. A dose of 1 pmol kisspeptin-54 was administered into all areas. The circulating levels of LH and total testosterone were significantly increased 60 min postinjection of kisspeptin-54 into the RPOA, MPOA, PVN and arcuate nucleus. Our results suggest that kisspeptin may mediate its effects on the HPG axis via these regions of the hypothalamus.


Assuntos
Hipotálamo/fisiologia , Hormônio Luteinizante/sangue , Testosterona/sangue , Proteínas Supressoras de Tumor/fisiologia , Análise de Variância , Animais , Núcleo Arqueado do Hipotálamo/efeitos dos fármacos , Núcleo Arqueado do Hipotálamo/fisiologia , Relação Dose-Resposta a Droga , Humanos , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/metabolismo , Hipotálamo/efeitos dos fármacos , Kisspeptinas , Masculino , Microinjeções , Núcleo Hipotalâmico Paraventricular/efeitos dos fármacos , Núcleo Hipotalâmico Paraventricular/fisiologia , Área Pré-Óptica/efeitos dos fármacos , Área Pré-Óptica/fisiologia , Ratos , Ratos Wistar , Testículo/efeitos dos fármacos , Testículo/metabolismo , Proteínas Supressoras de Tumor/administração & dosagem
20.
Vet Pathol ; 43(1): 2-14, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16407482

RESUMO

Helicobacter spp. have been implicated in a variety of gastrointestinal tract diseases, including peptic ulcer disease, gastric cancer, and inflammatory bowel disease (IBD), in humans and animals. Although most models of IBD are experimentally induced, spontaneous or natural models of IBD are rare. Herein, we describe a long-term study of chronic, progressive lesions that develop in the distal portion of the large bowel of unmanipulated Syrian hamsters naturally infected with Helicobacter spp. Twenty-four Syrian hamsters of three age groups (group A, 1 month [n = 4], group B, 7-12 months [n = 12], group C, 18-24 months [n = 12]), underwent complete postmortem examination. Results of microbial isolation and polymerase chain reaction and restriction fragment length polymorphism analyses confirmed the presence of Helicobacter spp. infection in the distal portion of the large bowel of all animals. Additionally, confounding pathogens, such as Clostridium difficile, Lawsonia intracellularis, and Giardia spp. that can cause proliferative enteritis, were absent in the hamsters of this study. Histopathologic scores for inflammation (P < 0.01), hyperplasia (P < 0.01), and dysplasia (P < 0.05) were significantly higher in the ileocecocolic (ICC) junction of animals in group C, relative to group A. Dysplastic lesions of various grades were detected in 5 of 11 hamsters in group C. Interestingly, the segment of the bowel that is usually colonized by Helicobacter spp. in hamsters had the most severe lesions. One hamster of group C developed a malignant fibrous histiocytoma, whereas another hamster developed a round cell sarcoma originating from the ICC junction. Thus, lesions in the distal portion of the large bowel of aging hamsters naturally colonized with Helicobacter spp. warrants developing the hamster as an animal model of IBD and potentially IBD-related cancer.


Assuntos
Cricetinae , Modelos Animais de Doenças , Enterocolite Necrosante/patologia , Infecções por Helicobacter/patologia , Helicobacter/genética , Doenças Inflamatórias Intestinais/patologia , Animais , Testes Imunológicos de Citotoxicidade , Enterocolite Necrosante/microbiologia , Células HeLa , Humanos , Imuno-Histoquímica , Doenças Inflamatórias Intestinais/microbiologia , Intestino Grosso/microbiologia , Intestino Grosso/patologia , Mesocricetus , Polimorfismo de Fragmento de Restrição
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA