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1.
Int J Pediatr Otorhinolaryngol ; 162: 111267, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35988457

RESUMEN

OBJECTIVE: To assess and improve otoscopy examination skills across various medical specialities who perform otoscopy during their professional practice. METHODS: A pre-intervention survey was created using www.surveymonkey.com, which included several preliminary questions to clarify the participant's speciality and training level, followed by 25 individual otoscopy images. The participants were given 12 possible diagnoses for each otoscopy image and asked to choose the single best answer. After completing the survey, participants were asked to watch an otoscopy teaching session. This teaching session was created with multidisciplinary feedback, and the content included a demonstration video and a didactic lecture. Finally, a post-intervention survey was circulated four weeks later to the same cohort of doctors to assess improvement. RESULTS: A total of 79 pre-intervention surveys were collected with an average score of 53% (range 20-100%). The spectrum of medical specialities that completed the pre-intervention survey included paediatrics, ear, nose, and throat (ENT), emergency medicine, and general practice. The largest cohort of surveys came from senior house officers (SHO). In addition, 78.5% of responses were completed by doctors who had not worked in ENT before. After completing the otoscopy teaching session and at least four weeks after the initial survey, 23 post-intervention surveys were completed with an average score of 66% (range 32-100%), a 13% improvement. CONCLUSIONS: The results of the pre-intervention survey show that many doctors have difficulty diagnosing ear conditions. The implementation of a 25-min teaching session achieved a 13% improvement in the otoscopy knowledge of doctors across a variety of specialities.


Asunto(s)
Evaluación Educacional , Otolaringología , Niño , Competencia Clínica , Humanos , Otolaringología/educación , Otoscopía/métodos , Estudios Prospectivos
2.
Ir Med J ; 109(8): 450, 2016 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-28124850

RESUMEN

Surgical site infection (SSI) rates are used extensively by hospitals as a basis for quality improvement. A 30-day post-discharge SSI programme for Caesarean section operations has been implemented in Our Lady of Lourdes Hospital since 2011. It has been shown that skin antisepsis and antibiotic prophylaxis are key factors in the prevention of SSI. Using quality improvement methodology, an infection prevention bundle was introduced to address these two factors. Skin antisepsis was changed from povidone-iodine to chlorhexidine-alcohol. Compliance with choice of antibiotic prophylaxis increased from 89.6% in 2014 to 98.5% in 2015. Compliance with timing also improved. The SSI rate of 7.5% was the lowest recorded to date, with the majority of SSIs (64%) diagnosed after hospital discharge. The level of variation was also reduced. However, the continued presence of variation and possibility of lower infection rates from the literature imply that further improvements are required.


Asunto(s)
Antiinfecciosos Locales/administración & dosificación , Cesárea/efectos adversos , Mejoramiento de la Calidad , Infección de la Herida Quirúrgica/prevención & control , Clorhexidina/administración & dosificación , Femenino , Hospitales , Humanos , Povidona Yodada/administración & dosificación , Embarazo
3.
Allergy ; 68(12): 1598-604, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24410783

RESUMEN

BACKGROUND: Anaphylaxis is a life-threatening emergency. If promptly administered, adrenaline is potentially life-saving. Many food-allergic-children/carers are unsure when to use their adrenaline autoinjectors, contributing to a low quality of life and worse outcomes in the setting of an acute allergic reaction. OBJECTIVES: The aim of this study was to assess the effectiveness of 24-hour telephone access to specialist clinical advice on disease-specific quality of life. METHODS: A pragmatic two-arm, parallel-group randomized control trial was conducted. Children/carers (<16 years) with food allergy, trained in adrenaline auto-injector use, were recruited from a hospital-based paediatric allergy clinic. Baseline disease-specific quality of life was ascertained using the validated Food-Allergy-Related Quality-of-Life Questionnaire (FAQLQ), either Parent Form, Child Form or Teenager Form depending on child's age. Participants were then centrally randomized for a 6-month period to 24-hour telephone specialist support line or to usual care. The primary outcome measure was a change in FAQL scores, at one and 6 months postrandomization, compared with baseline. The minimum clinically important difference (MCID) in score is 0.5. RESULTS: Fifty two children/carers were recruited. FAQL scores remained static in the control group across the three time points. Scores gradually improved in the intervention group, with a significant difference seen at 6 months (T1-T3 Mean difference = -1.5, (CI 0.87-2.25) P < 0.005] Follow-up questionnaires, 6 months after the intervention was removed, T4, showed sustained significant difference between the groups (control M = 3.0; intervention M = 1.1[t = -4.113, P < 0.05]). CONCLUSION: The 24-hour helpline improved food-allergy-specific quality of life in children. Six-month intervention support resulted in sustained benefits for at least a further 6 months.


Asunto(s)
Anafilaxia/etiología , Anafilaxia/prevención & control , Consultores , Hipersensibilidad a los Alimentos/complicaciones , Líneas Directas , Calidad de Vida , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Evaluación del Resultado de la Atención al Paciente , Adulto Joven
4.
Arch Dis Child ; 94(8): 633-5, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19465583

RESUMEN

OBJECTIVES: To establish the information-seeking behaviours of paediatricians in answering every-day clinical queries. DESIGN: A questionnaire was distributed to every hospital-based paediatrician (paediatric registrar and consultant) working in Ireland. RESULTS: The study received 156 completed questionnaires, a 66.1% response. 67% of paediatricians utilised the internet as their first "port of call" when looking to answer a medical question. 85% believe that web-based resources have improved medical practice, with 88% reporting web-based resources are essential for medical practice today. 93.5% of paediatricians believe attempting to answer clinical questions as they arise is an important component in practising evidence-based medicine. 54% of all paediatricians have recommended websites to parents or patients. 75.5% of paediatricians report finding it difficult to keep up-to-date with new information relevant to their practice. CONCLUSIONS: Web-based paediatric resources are of increasing significance in day-to-day clinical practice. Many paediatricians now believe that the quality of patient care depends on it. Information technology resources play a key role in helping physicians to deliver, in a time-efficient manner, solutions to clinical queries at the point of care.


Asunto(s)
Actitud del Personal de Salud , Actitud hacia los Computadores , Educación Médica Continua/métodos , Internet/estadística & datos numéricos , Pediatría/educación , Encuestas y Cuestionarios , Adulto , Anciano , Femenino , Humanos , Irlanda , Masculino , Persona de Mediana Edad
5.
Ir J Med Sci ; 177(3): 225-31, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18584271

RESUMEN

BACKGROUND: Streptococcus pneumoniae is an important cause of childhood illness. Recently a safe and effective 7-valent conjugate pneumococcal vaccine for children has been licensed in the EU. AIMS: To calculate the incidence of invasive pneumococcal disease (IPD) in children in Ireland, to estimate the burden of disease and to anticipate the protective effect of the conjugate vaccine. METHODS: Retrospective review of data from children with IPD. RESULTS: Ninety-six cases of IPD in 95 children including two related deaths were identified. All childhood IPD incidence was estimated at 10.6/100,000. We anticipate that the 7-valent conjugate vaccine could prevent up to 90% of sepsis and up to 82.5% of meningitis cases. CONCLUSIONS: IPD is an important cause of mortality and morbidity in children in Ireland. Routine use of conjugate pneumococcal vaccine would have a significant impact on pneumococcal disease, especially in vaccinated children but also in unvaccinated children and older adults.


Asunto(s)
Infecciones Neumocócicas/prevención & control , Vacunas Neumococicas , Vacunas Conjugadas , Adolescente , Antibacterianos/uso terapéutico , Niño , Preescolar , Femenino , Humanos , Incidencia , Lactante , Recién Nacido , Irlanda/epidemiología , Masculino , Pruebas de Sensibilidad Microbiana , Infecciones Neumocócicas/tratamiento farmacológico , Infecciones Neumocócicas/epidemiología , Vigilancia de la Población , Estudios Retrospectivos , Factores de Riesgo
6.
Arch Dis Child Fetal Neonatal Ed ; 91(4): F268-71, 2006 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16790729

RESUMEN

BACKGROUND: Death remains a common event in the neonatal intensive care unit, and often involves limitation or withdrawal of life sustaining treatment. OBJECTIVE: To document changes in the causes of death and its management over the last two decades. METHODS: An audit of infants dying in the neonatal intensive care unit was performed during two epochs (1985-1987 and 1999-2001). The principal diagnoses of infants who died were recorded, as well as their apparent prognoses, and any decisions to limit or withdraw medical treatment. RESULTS: In epoch 1, 132 infants died out of 1362 admissions (9.7%), and in epoch 2 there were 111 deaths out of 1776 admissions (6.2%; p<0.001). Approximately three quarters of infants died after withdrawal of life sustaining treatment in both epochs. There was a significant reduction in the proportion of deaths from chromosomal abnormalities, and from neural tube defects in epoch 2. CONCLUSIONS: There have been substantial changes in the illnesses leading to death in the neonatal intensive care unit. These may reflect the combined effects of prenatal diagnosis and changing community and medical attitudes.


Asunto(s)
Mortalidad Hospitalaria/tendencias , Mortalidad Infantil/tendencias , Cuidado Intensivo Neonatal/tendencias , Cuidado Terminal/tendencias , Causas de Muerte/tendencias , Aberraciones Cromosómicas , Humanos , Recién Nacido , Recien Nacido Prematuro , Enfermedades del Prematuro/mortalidad , Unidades de Cuidado Intensivo Neonatal/tendencias , Auditoría Médica , Defectos del Tubo Neural/mortalidad , Pronóstico , Victoria/epidemiología , Privación de Tratamiento/tendencias
8.
Aquat Toxicol ; 52(3-4): 229-39, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11239684

RESUMEN

Early mortality syndrome (EMS) is a non-infectious disease affecting lake trout and other salmonids in the Great Lakes and in inland lakes. It is characterised by loss of equilibrium, hyperexcitability, anorexia, and eventually death. EMS is associated with low thiamine and treatment of eggs or fry with thiamine-HCl eliminates symptoms and mortality. To verify the role of the active form of the vitamin as the prophylactic agent, we used thiamine pyrophosphate (TPP) to reverse EMS symptoms. We also investigated the ability of specific thiamine antagonists that either block TPP production or interfere with its function to induce EMS. When graded doses of TPP were administered to EMS-susceptible sac-fry, there was a dose-dependent reduction in EMS. The egg concentration of TPP that was associated with reduced EMS was similar to the threshold thiamine concentration found in feral lake trout stocks where EMS occurs. A thiamine deficient stock from Lake Ontario was very sensitive to the thiamine antagonist oxythiamine (OXY) with total mortality associated with developmental arrest occurring at an antagonist to thiamine molar ratio (ATR) above 7:1. The threshold ATR with OXY for development of EMS-like neurological signs in this stock was 1.6:1. In addition to EMS-like neurological signs, OXY caused dose-dependent increases in hydrocephalus, developmental arrest, and vitelline congestion in the Lake Ontario stock. These signs are consistent with those observed in feral fish exhibiting EMS. Much higher doses of antagonists were required (both pyrithiamine (PT) and OXY) to induce EMS-like clinical signs in the thiamine replete Lake Manitou stock. PT was a more potent inducer in this stock as the ATR associated with development of clinical signs was 111:1 for PT compared with 892:1 for OXY. These data provide experimental evidence supporting the hypothesis that a thiamine deficiency in the natural environment is the cause of EMS.


Asunto(s)
Enfermedades de los Peces/etiología , Tiamina/antagonistas & inhibidores , Trucha , Animales , Femenino , Enfermedades de los Peces/mortalidad , Agua Dulce , Great Lakes Region , Masculino , Oxitiamina , Piritiamina , Tiamina Pirofosfoquinasa/metabolismo , Tiamina Pirofosfato
10.
Physiol Rev ; 78(3): 583-686, 1998 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9674690

RESUMEN

Angiotensin (ANG) II is a powerful and phylogenetically widespread stimulus to thirst and sodium appetite. When it is injected directly into sensitive areas of the brain, it causes an immediate increase in water intake followed by a slower increase in NaCl intake. Drinking is vigorous, highly motivated, and rapidly completed. The amounts of water taken within 15 min or so of injection can exceed what the animal would spontaneously drink in the course of its normal activities over 24 h. The increase in NaCl intake is slower in onset, more persistent, and affected by experience. Increases in circulating ANG II have similar effects on drinking, although these may be partly obscured by accompanying rises in blood pressure. The circumventricular organs, median preoptic nucleus, and tissue surrounding the anteroventral third ventricle in the lamina terminalis (AV3V region) provide the neuroanatomic focus for thirst, sodium appetite, and cardiovascular control, making extensive connections with the hypothalamus, limbic system, and brain stem. The AV3V region is well provided with angiotensinergic nerve endings and angiotensin AT1 receptors, the receptor type responsible for acute responses to ANG II, and it responds vigorously to the dipsogenic action of ANG II. The nucleus tractus solitarius and other structures in the brain stem form part of a negative-feedback system for blood volume control, responding to baroreceptor and volume receptor information from the circulation and sending ascending noradrenergic and other projections to the AV3V region. The subfornical organ, organum vasculosum of the lamina terminalis and area postrema contain ANG II-sensitive receptors that allow circulating ANG II to interact with central nervous structures involved in hypovolemic thirst and sodium appetite and blood pressure control. Angiotensin peptides generated inside the blood-brain barrier may act as conventional neurotransmitters or, in view of the many instances of anatomic separation between sites of production and receptors, they may act as paracrine agents at a distance from their point of release. An attractive speculation is that some are responsible for long-term changes in neuronal organization, especially of sodium appetite. Anatomic mismatches between sites of production and receptors are less evident in limbic and brain stem structures responsible for body fluid homeostasis and blood pressure control. Limbic structures are rich in other neuroactive peptides, some of which have powerful effects on drinking, and they and many of the classical nonpeptide neurotransmitters may interact with ANG II to augment or inhibit drinking behavior. Because ANG II immunoreactivity and binding are so widely distributed in the central nervous system, brain ANG II is unlikely to have a role as circumscribed as that of circulating ANG II. Angiotensin peptides generated from brain precursors may also be involved in functions that have little immediate effect on body fluid homeostasis and blood pressure control, such as cell differentiation, regeneration and remodeling, or learning and memory. Analysis of the mechanisms of increased drinking caused by drugs and experimental procedures that activate the renal renin-angiotensin system, and clinical conditions in which renal renin secretion is increased, have provided evidence that endogenously released renal renin can generate enough circulating ANG II to stimulate drinking. But it is also certain that other mechanisms of thirst and sodium appetite still operate when the effects of circulating ANG II are blocked or absent, although it is not known whether this is also true for angiotensin peptides formed in the brain. Whether ANG II should be regarded primarily as a hormone released in hypovolemia helping to defend the blood volume, a neurotransmitter or paracrine agent with a privileged role in the neural pathways for thirst and sodium appetite of all kinds, a neural organizer especially in sodium appetit


Asunto(s)
Angiotensina II/fisiología , Apetito/fisiología , Conducta de Ingestión de Líquido/fisiología , Sodio en la Dieta/farmacología , Sed/fisiología , Animales , Conducta de Ingestión de Líquido/efectos de los fármacos
11.
J Hered ; 89(1): 8-16, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9487675

RESUMEN

MtDNA sequencing was used to assess the phylogeographic structure of four species of Hawaiian freshwater fishes: Lentipes concolor, Stenogobius hawaiiensis, Sicyopterus stimpsoni, and Awaous guamensis. Samples of each species were collected from streams on the northeast side of Kauai, Maui, Molokai, Oahu, and Hawaii. We sequenced segments from both coding and noncoding regions (638-1391 bp) in each species. Sequence analysis uncovered genetic variability in these fishes but no evidence of strong geographic structure among island populations. This result is most readily explained by the fishes' larval marine life stage (amphidromy), which likely facilitates gene flow among island populations. By constraining genetic differentiation among populations, amphidromy may impede speciation in these fishes, possibly explaining why the Hawaiian freshwater fish fauna is depauperate compared to other species-rich Hawaiian faunas. It may also provide them with a kind of evolutionary flexibility atypical of other, more isolated island faunas and allow natural restocking to occur in streams that have been restored to suitable conditions. Comparisons of restriction site and sequence data suggested similar population genetic conclusions for all species except S. stimpsoni, for which the restriction site data is questioned.


Asunto(s)
ADN Mitocondrial , Peces/genética , Variación Genética , Animales , Sitios de Unión , Peces/clasificación , Agua Dulce , Hawaii , Filogenia , Mapeo Restrictivo , Análisis de Secuencia de ADN
12.
Neuroscience ; 78(4): 1167-76, 1997 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9174082

RESUMEN

The relation between c-fos expression in the forebrain of Lister hooded rats and water and NaCl intakes was examined in response to systemic injection of angiotensin II, desoxycorticosterone, angiotensin II and desoxycorticosterone together, frusemide or low sodium diet, all treatments that induce a sodium appetite. Angiotensin II (1 mg/kg subcutaneously) caused significant increases in the 1-h intakes of water and 1.8% NaCl compared to controls, the effect on water intake being the greater. There was a similar increase in NaCl intake after four days' treatment with desoxycorticosterone (20 mg pellet subcutaneously) but water intake was not increased. The NaCl intake of rats given angiotensin II following desoxycorticosterone treatment was approximately the sum of the intakes after angiotensin II or desoxycorticosterone alone, but the water intake was slightly less than after angiotensin II alone. Frusemide pretreatment (4 mg/kg subcutaneously) caused an NaCl intake similar to that following angiotensin II and desoxycorticosterone but water intake was little affected. Low dietary sodium also increased salt appetite, as expected. These treatments were repeated in rats that were not allowed to drink NaCl, after which the brains were processed for c-fos immunocytochemistry. This showed intense staining of the subfornical organ, median preoptic nucleus, organum vasculosum of the laminal terminalis, paraventricular nucleus and supraoptic nucleus after subcutanous angiotensin II. Animals given angiotensin II following desoxycorticosterone pretreatment showed patterns of c-fos expression that did not differ from those of angiotensin II alone. Treatment with desoxycorticosterone alone produced intense staining in the organum vasculosum of the laminal terminalis and some staining in the median preoptic nucleus. Frusemide gave a similar pattern of staining to desoxycorticosterone, stimulating c-fos expression in the same regions but to a lesser extent. A low salt diet resulted in increased c-fos expression only in the organum vasculosum of the laminal terminalis. Therefore, five different treatments that induced increased sodium appetite evoked distinct patterns of c-fos expression in the anteroventral region of the third ventricle of the rat forebrain. Since the common feature was induction of c-fos in the organum vasculosum of the laminal terminalis, these results suggest a key role for this structure in the development of increased sodium appetite.


Asunto(s)
Apetito/fisiología , Hipotálamo/metabolismo , Proteínas Proto-Oncogénicas c-fos/metabolismo , Sodio , Angiotensina II/farmacología , Animales , Desoxicorticosterona/farmacología , Conducta de Ingestión de Líquido/efectos de los fármacos , Furosemida/farmacología , Masculino , Ratas , Ratas Endogámicas , Cloruro de Sodio
13.
Regul Pept ; 66(1-2): 127-33, 1996 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-8899907

RESUMEN

In the rat, blocking 11 beta-OHSD with the active ingredient of liquorice, glycyrrhizic acid (GZA) or its hydrolytic product, 18 beta-glycyrrhetinic acid (GTA), caused potassium loss, increased water intake and a primary increase in salt appetite that was specific for sodium and not secondary to sodium loss. Intracerebroventricular injection of angiotensin II enhanced the sodium appetite but carbachol did not. The stimulating effects of GZA or GTA on intakes of water and NaCl resembled those caused by the administration of excessive amounts of mineralocorticoid. The results suggest that GZA- or GTA-induced drinking behaviour is mediated by circulating glucocorticoids. After liquorice blockade of 11 beta-OHSD, the peripheral and central mineralocorticoid receptors are no longer protected from glucocorticoid action.


Asunto(s)
Regulación del Apetito/fisiología , Ingestión de Líquidos/fisiología , Ácido Glicirretínico/análogos & derivados , Ácido Glicirretínico/farmacología , Glycyrrhiza/química , Plantas Medicinales , Cloruro de Sodio/administración & dosificación , Sed/fisiología , Angiotensina II/administración & dosificación , Animales , Regulación del Apetito/efectos de los fármacos , Arachis/química , Carbacol/administración & dosificación , Ingestión de Líquidos/efectos de los fármacos , Ácido Glicirretínico/administración & dosificación , Ácido Glicirrínico , Inyecciones Intraventriculares , Inyecciones Subcutáneas , Masculino , Aceite de Cacahuete , Aceites de Plantas/administración & dosificación , Potasio/metabolismo , Ratas , Ratas Wistar , Solución Salina Hipertónica , Sodio/metabolismo , Sed/efectos de los fármacos
14.
Vet Rec ; 138(14): 327-9, 1996 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-8730674

RESUMEN

An outbreak of polioencephalomalacia affected 16 of 46 Swaledale lambs and five of 25 Scottish blackface lambs 15 to 32 days after they were introduced to an ad libitum concentrate ration containing 0.43 per cent sulphur. The clinical signs were acute and included depression central blindness and head-pressing, but no hyperaesthesia, nystagmus, dorsiflexion of the neck or opisthotonos were observed. Treatment of the affected lambs with vitamin B1, dexamethasone and antibiotics was associated with a prolonged recovery period, though no further cases were identified after vitamin B1 had been given parenterally to all the lambs at risk.


Asunto(s)
Brotes de Enfermedades/veterinaria , Encefalomalacia/veterinaria , Enfermedades de las Ovejas/inducido químicamente , Azufre/efectos adversos , Alimentación Animal/efectos adversos , Alimentación Animal/análisis , Animales , Dexametasona/uso terapéutico , Encefalomalacia/tratamiento farmacológico , Encefalomalacia/fisiopatología , Ovinos , Enfermedades de las Ovejas/tratamiento farmacológico , Enfermedades de las Ovejas/fisiopatología , Tiamina/uso terapéutico
15.
Neuroscience ; 69(1): 199-208, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8637618

RESUMEN

The effect intracerebroventricular injections of angiotensin II (0.1 nm), angiotensin-(1-7) (1 or 100 nm) and carbachol (500 ng) on c-fos expression was examined in the forebrain of Lister hooded rats. Intense staining of the c-Fos protein was found in the median preoptic nucleus, organum vasculosum of the lamina terminalis, subfornical organ, paraventricular nucleus and supraoptic nucleus after angiotensin II and carbachol Angiotensin II caused significantly more c-fos expression in the ventral median preoptic nucleus and organum vasculosum of the lamina terminalis than carbachol, whereas in the paraventricular and supraoptic nuclei this was reversed, with carbachol having a greater effect on c-fos expression in these areas. Angiotensin-(1-7), however, only induced c-Fos protein in the organum vasculosum of the lamina terminalis and median preoptic nucleus with the number and the intensity of staining of the nuclei significantly less in both areas than after angiotensin II or carbachol. Separate groups of Lister rats were given i.c.v. injections of the same substances at the same doses, but excluding the lower dose of angiotensin-(1-7), and the intakes of water and 1.8% NaCl over 60 min were measured. Angiotensin II stimulated intakes of both water and NaCl. The effect on water intake was almost immediate (<1 min), whereas NaCl intake did not usually start until at least 5 min after injection. Over 60 min, water (12.4 +/- 1.0 ml) and NaCl (4.2 +/- 0.9 ml) intakes were significantly greater than water (1.1 +/- 0.2 ml) and NaCl (0.6 +/- 0.5 ml) intakes of the controls. Carbachol caused less drinking than angiotensin II, the water intake over 60 min being significantly less (4.8 +/- 0.7 ml) and the latency of response greater (>5 min). Carbachol, unlike angiotensin II, had little effect on NaCl intake (0.7 +/- 0.4 ml). Angiotensin-(1-7) had no effect on water (1.1 +/- 0.3 ml) or NaCl (0.3 +/- 0.3 ml) intakes. The plasma levels of vasopressin were measured after i.c.v. injection of the same three substances in the same doses, again excluding the lower dose of angiotensin-(1-7), in further groups of rats. Angiotensin II and carbachol caused an approximate five-fold increase in plasma vasopressin levels compared to cerebrospinal fluid-injected rats, but angiotensin-(1-7) had no effect on vasopressin release. Therefore, three compounds with widely differing effects on thirst, sodium appetite and vasopressin release induce distinctive patterns of c-fos protein expression in the forebrain. By combining experimental approaches in this way it is possible to determine areas of the brain which are involved in certain behavioural and endocrine responses.


Asunto(s)
Apetito/fisiología , Prosencéfalo/metabolismo , Proteínas Proto-Oncogénicas c-fos/metabolismo , Sodio , Sed/fisiología , Vasopresinas/metabolismo , Angiotensina I , Angiotensina II/farmacología , Animales , Carbacol/farmacología , Conducta de Ingestión de Líquido/efectos de los fármacos , Inyecciones Intraventriculares , Masculino , Fragmentos de Péptidos/farmacología , Ratas , Ratas Endogámicas
16.
J Neuroendocrinol ; 7(3): 165-9, 1995 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7606241

RESUMEN

Of the reproductive hormones it has been suggested that relaxin may play an important role in the increased sodium appetite of pregnancy. ICV injection of porcine relaxin caused water-replete male and female Wistar rats with access to water and 0.9% or 2.7% NaCl to drink on average about 3 to 8 ml of water within 1 h of injection. By 24 h the cumulative intake of water was no different from the control intake. The amounts of water drunk were similar after doses of 50, 100, 250 and 500 ng of relaxin. A dose of 5 ng was ineffective. Male rats generally drank more water than female rats after ICV injection of angiotensin or relaxin. Male SH rats which drink more water than male WKY rats in response to ICV angiotensin also drank more after ICV relaxin. Intakes of 0.9% or 2.7% NaCl were unaffected for up to 24 h after injection of relaxin, whereas angiotensin-injected rats showed a significant increase in 0.9% NaCl 1 h after injection though this difference was no longer evident in the 24 h cumulative intake. Relaxin did not cause any increase in NaCl intake in SH rats. Insulin, which is similar in structure and molecular weight to relaxin, was without effect on drinking when doses comparable to dipsogenically effective doses of relaxin were injected ICV. In male Wistar rats treated with DOCA for 5-15 days, relaxin retained its weak stimulatory action on water intake but did not affect NaCl intake despite the increased baseline NaCl intake during DOCA. These results indicate that relaxin is a dipsogen in the rat but that it seems to have little short-term effect on sodium appetite.


Asunto(s)
Conducta de Ingestión de Líquido/efectos de los fármacos , Relaxina/farmacología , Sed/efectos de los fármacos , Animales , Apetito/efectos de los fármacos , Femenino , Hipertensión/psicología , Inyecciones Intraventriculares , Masculino , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKY , Ratas Wistar , Caracteres Sexuales , Cloruro de Sodio/administración & dosificación , Porcinos
17.
Exp Physiol ; 78(6): 767-74, 1993 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8311944

RESUMEN

Intracerebroventricular injection of the putative AT2 agonist, p-aminophenylalanine6 angiotensin II (p-NH2Phe6-Ang II), caused dose-dependent increases in intakes of water and NaCl similar to those produced by angiotensin II but requiring more than one thousand times the dose. Very large doses of another AT2 agonist, angiotensin(1-7) heptapeptide (Ang(1-7)), had no effect on intakes of water and NaCl up to 24 h after injection, nor did Ang(1-7) affect angiotensin II-induced drinking when the two peptides were given together. The AT1 antagonist, losartan, but not the AT2 antagonist, CGP 42112B, inhibited p-NH2Phe6-Ang II- and angiotensin II-induced drinking, suggesting that p-NH2Phe6-Ang II, like angiotensin II, acts on AT1 but not AT2 receptors. However, large doses of the AT2 antagonist, PD 123319, inhibited drinking in response to both dipsogens. Since p-NH2Phe6-Ang II- and angiotensin II-induced drinking were unaffected by CGP 42112B, this could mean that there are different AT2 receptor subtypes of which only the PD 123319-sensitive one is involved in drinking. But because of the very large doses of PD 123319 used it is also likely that there was loss of receptor specificity resulting in cross-reaction of PD 123319 with AT1 receptors. The results do not favour involvement of AT2 receptors in angiotensin-induced thirst and sodium appetite in the short term.


Asunto(s)
Angiotensina II/análogos & derivados , Apetito/efectos de los fármacos , Receptores de Angiotensina/efectos de los fármacos , Cloruro de Sodio Dietético/administración & dosificación , Sed/efectos de los fármacos , Angiotensina I , Angiotensina II/administración & dosificación , Angiotensina II/farmacología , Antagonistas de Receptores de Angiotensina , Animales , Apetito/fisiología , Compuestos de Bifenilo/farmacología , Ingestión de Líquidos/efectos de los fármacos , Ingestión de Líquidos/fisiología , Imidazoles/farmacología , Inyecciones Intraventriculares , Losartán , Masculino , Oligopéptidos/farmacología , Fragmentos de Péptidos/farmacología , Piridinas/farmacología , Ratas , Ratas Wistar , Receptores de Angiotensina/fisiología , Tetrazoles/farmacología , Sed/fisiología
19.
Sci Total Environ ; 94(1-2): 125-41, 1990 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-2163105

RESUMEN

In order to investigate the putative association between chemical contamination in western Lake Ontario and high prevalences of fish tumors, sediments from Hamilton Harbour and Oakville Creek in Lake Ontario and reference sites in non-polluted areas of Ontario, Canada were collected and extracted for organic contaminants. Sediment extracts from Hamilton Harbour had the highest concentrations of polychlorinated biphenyls and organochlorine insecticides (ppb) and contained very high concentrations of polynuclear aromatic hydrocarbons (ppm); although the levels of these compounds varied widely with sampling location in the harbor. A sediment extract from Hamilton Harbour was mutagenic in the Ames bacterial assay, both with and without microsomal activation. High levels of aromatic DNA adducts were induced in cultured mouse C3H1OT1/2 cells after in vitro exposure to Hamilton Harbour sediment extract. In two separate carcinogenicity experiments involving a sac fry microinjection assay with rainbow trout (Oncorhynchus mykiss), Hamilton Harbour sediment extract induced hepatocellular carcinomas in fish. No hepatic neoplasms were observed in fish that had been treated with sediment extract from Oakville Creek, or with extract from a reference sediment. The significance of these results is discussed in relation to the distribution of neoplasms in feral fish within western Lake Ontario.


Asunto(s)
Carcinógenos/análisis , Carcinoma Hepatocelular/veterinaria , Enfermedades de los Peces/inducido químicamente , Neoplasias Hepáticas/veterinaria , Mutágenos/análisis , Neoplasias/veterinaria , Contaminantes Químicos del Agua/análisis , Contaminantes del Agua/análisis , Animales , Pruebas de Carcinogenicidad , Carcinoma Hepatocelular/inducido químicamente , Carcinoma Hepatocelular/patología , Células Cultivadas , ADN/metabolismo , Enfermedades de los Peces/patología , Peces , Agua Dulce , Neoplasias Hepáticas/inducido químicamente , Neoplasias Hepáticas/patología , Pruebas de Mutagenicidad , Mutágenos/farmacología , Neoplasias/inducido químicamente , Neoplasias/patología , Ontario , Salmonella typhimurium/efectos de los fármacos , Trucha
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