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1.
Occup Med (Lond) ; 71(6-7): 270-276, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34415353

RESUMO

BACKGROUND: Cardiovascular disease has a significant impact on public health and is largely preventable by addressing modifiable risk factors. As most adults spend on average half of their waking hours at work, this provides a significant opportunity to address modifiable risk factors through health promotion interventions. Healthcare professionals have the knowledge and skills to provide workplace interventions aimed at cardiovascular risk reduction. AIMS: This study was aimed to assess the literature regarding the effect of workplace interventions led by healthcare professionals on cardiovascular risk factors. METHODS: Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, MEDLINE, PsycINFO and SPORTDiscus were systematically searched from inception to March 2021. Included studies evaluated impact of workplace interventions by healthcare professionals on cardiovascular health. Data on study design, baseline characteristics, interventions, outcomes and conclusions were extracted and qualitatively analysed. RESULTS: Forty-five studies representing 77 633 participants were included in the analysis. Healthcare professionals involved included: nurses, nurse practitioners, physicians, dietitians, pharmacists, physician assistants, medical technicians/emergency medical technicians and physiotherapists. Workplace interventions by healthcare professionals generally improved surrogate markers of cardiovascular health. Success varied based on provider and nature of the intervention. Addressing motivation and including follow-up were key factors for successful intervention to reduce cardiovascular risk factors. CONCLUSIONS: Workplace health promotion initiatives delivered by healthcare professionals may improve cardiovascular risk markers if they are evidence based and customized for target populations. More research is needed to determine clinical relevance of interventions and ideal interventions for specific employee groups.


Assuntos
Doenças Cardiovasculares , Adulto , Doenças Cardiovasculares/prevenção & controle , Atenção à Saúde , Fatores de Risco de Doenças Cardíacas , Humanos , Fatores de Risco , Local de Trabalho
2.
Cereb Cortex ; 30(8): 4481-4495, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32244254

RESUMO

Many studies have implicated the basal forebrain (BF) as a potent regulator of sensory encoding even at the earliest stages of or cortical processing. The source of this regulation involves the well-documented corticopetal cholinergic projections from BF to primary cortical areas. However, the BF also projects to subcortical structures, including the thalamic reticular nucleus (TRN), which has abundant reciprocal connections with sensory thalamus. Here we present naturalistic auditory stimuli to the anesthetized rat while making simultaneous single-unit recordings from the ventral medial geniculate nucleus (MGN) and primary auditory cortex (A1) during electrical stimulation of the BF. Like primary visual cortex, we find that BF stimulation increases the trial-to-trial reliability of A1 neurons, and we relate these results to change in the response properties of MGN neurons. We discuss several lines of evidence that implicate the BF to thalamus pathway in the manifestation of BF-induced changes to cortical sensory processing and support our conclusions with supplementary TRN recordings, as well as studies in awake animals showing a strong relationship between endogenous BF activity and A1 reliability. Our findings suggest that the BF subcortical projections that modulate MGN play an important role in auditory processing.


Assuntos
Córtex Auditivo/fisiologia , Vias Auditivas/fisiologia , Percepção Auditiva/fisiologia , Prosencéfalo Basal/fisiologia , Corpos Geniculados/fisiologia , Animais , Feminino , Masculino , Ratos , Ratos Long-Evans
3.
J Phys Chem B ; 122(2): 933-946, 2018 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-28976197

RESUMO

We use dynamic atomic force microscopy (AFM) to investigate the forces involved in squeezing out thin films of aqueous electrolyte between an AFM tip and silica substrates at variable pH and salt concentration. From amplitude and phase of the AFM signal we determine both conservative and dissipative components of the tip sample interaction forces. The measured dissipation is enhanced by up to a factor of 5 at tip-sample separations of ≈ one Debye length compared to the expectations based on classical hydrodynamic Reynolds damping with bulk viscosity. Calculating the surface charge density from the conservative forces using Derjaguin-Landau-Verwey-Overbeek (DLVO) theory in combination with a charge regulation boundary condition we find that the viscosity enhancement correlates with increasing surface charge density. We compare the observed viscosity enhancement with two competing continuum theory models: (i) electroviscous dissipation due to the electrophoretic flow driven by the streaming current that is generated upon squeezing out the counterions in the diffuse part of the electric double layer, and (ii) visco-electric enhancement of the local water viscosity caused by the strong electric fields within the electric double layer. While the visco-electric model correctly captures the qualitative trends observed in the experiments, a quantitative description of the data presumably requires more sophisticated simulations that include microscopic aspects of the distribution and mobility of ions in the Stern layer.

4.
Neth Heart J ; 24(5): 308-16, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27043238

RESUMO

Biomedical scientific research in the Netherlands has a good reputation worldwide. Quantitatively, the university medical centres (UMCs) deliver about 40 % of the total number of scientific publications of this research. Analysis of the bibliometric output data of the UMCs shows that their research is highly cited. These output-based analyses also indicate the high impact of cardiovascular scientific research in these centres, illustrating the strength of this research in the Netherlands. A set of six joint national cardiovascular research topics selected by the UMCs can be recognised. At the top are heart failure, rhythm disorder research and atherosclerosis. National collaboration of top scientists in consortia in these three areas is successful in acquiring funding of large-scale programs. Our observations suggest that funding national consortia of experts focused on a few selected research topics may increase the international competitiveness of cardiovascular research in the Netherlands.

5.
Z Gerontol Geriatr ; 43(5): 317-23, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20198376

RESUMO

BACKGROUND: Dizziness as a geriatric syndrome needs to be assessed using a multi-dimensional, patient-centred approach in addition to a disease-orientated strategy. The aim of the study was to determine the priorities of elderly patients by a specific needs questionnaire, the"Dizziness Needs Assessment" (DiNA), and to evaluate its psychometric properties. METHODS: General practitioners (GPs) distributed questionnaires containing the DiNA as well as the Patients' Intentions Questionnaire (PIQ) to patients aged at least 65 years and suffering from dizziness. Items of both questionnaires were analysed by frequencies, means and rank correlations. Factor structure was explored by principal component analysis. RESULTS: A total of n=123 patients (mean age 76 years, 73% women) had suffered from dizziness on average for more than 3 years (57% chronic, i.e. >6 months). Knowing the cause of the dizziness was rated as very important by patients, and about half of them wished that their doctor would make more effort to investigate this. Among other differences, chronically dizzy patients ranked the risk of falling significantly higher than those with acute dizziness. Factor analysis revealed four subscales: "handicap and mobility" showed a very good reliability of 0.77 (Cronbach's α), indicating a "trait", whereas the other subscales rather indicated "state" characteristics. Validation coefficients showed that PIQ assesses general patient needs compared to the more specific dizziness-related needs revealed by the DiNA. CONCLUSION: The DiNA proved to be a valuable instrument to assess the specific priorities of elderly patients suffering from dizziness. Regarding the limited therapy options for dizziness in old age, a doctor-guided shift of patients' attention from causes to symptom-related implications could be a promising approach.


Assuntos
Tontura/etiologia , Avaliação das Necessidades , Acidentes por Quedas/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Estudos Transversais , Avaliação da Deficiência , Tontura/epidemiologia , Feminino , Medicina Geral , Alemanha , Humanos , Masculino , Limitação da Mobilidade , Satisfação do Paciente , Relações Médico-Paciente , Psicometria/estatística & dados numéricos , Reprodutibilidade dos Testes , Inquéritos e Questionários
6.
Clin Microbiol Infect ; 16(6): 704-10, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19624518

RESUMO

We developed a dermatophyte-specific single-tube real-time PCR assay based on internal transcribed sequences. This assay allows the rapid detection and identification of 11 clinically relevant species within the three dermatophyte genera Trichophyton, Microsporum and Epidermophyton in nail, skin and hair samples within a few hours. Analysis of 145 clinical samples (107 nail, 36 skin scale, and two hair) by both real-time PCR and a PCR-reverse line blot (PCR-RLB) assay described earlier revealed that 133 of the 145 samples had concordant real-time PCR and PCR-RLB detection results (83 positive, 49 negative, and one inhibited). Six samples were positive by real-time PCR and negative by PCR-RLB, and two were negative by real-time PCR and positive by PCR-RLB. Four samples demonstrated inhibition in one of the two PCR assays. Only one of 83 positive samples had discordant identification results between both assays (Trichophyton verrucosum and Trichophyton erinacei by real-time PCR and Trichophyton erinacei by PCR-RLB). Dermatophytes present in seven positive samples that were incompletely identified as Trichophyton sp. by PCR-RLB were identified to the species level by real-time PCR as Trichophyton interdigitale and Trichophyton rubrum in six cases and one case, respectively. One hundred and twenty of 145 samples were also analysed by conventional dermatophyte culture and by direct microscopy. Our single-tube real-time PCR assay proved to be suitable for direct detection and identification of dermatophytes in nail, skin and hair samples with minimal total assay time (4 h after overnight lysis) and hands-on time, without the need for post-PCR analysis, and with good sensitivity and specificity.


Assuntos
Arthrodermataceae/classificação , Arthrodermataceae/isolamento & purificação , Dermatomicoses/diagnóstico , Dermatomicoses/microbiologia , Micologia/métodos , Reação em Cadeia da Polimerase/métodos , Arthrodermataceae/genética , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Cabelo/microbiologia , Humanos , Unhas/microbiologia , Sensibilidade e Especificidade , Pele/microbiologia
7.
Clin Microbiol Infect ; 14(8): 778-88, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18727802

RESUMO

A dermatophyte-specific PCR-reverse line blot (PCR-RLB) assay based on internal transcribed sequences was developed. This assay allows the rapid detection and identification of nine clinically relevant species within the three dermatophyte genera Trichophyton, Microsporum and Epidermophyton in nail, skin and hair samples within 1 day. Analysis of 819 clinical samples (596 nail, 203 skin and 20 hair) revealed a positive PCR-RLB result in 93.6% of 172 culture-positive and microscopy-positive samples. PCR-RLB was superior to culture and direct microscopy, in both detection and species identification. Comparison of identification results of 208 PCR-positive and culture-positive clinical samples showed five discrepancies (2.4%) between PCR-RLB identification and classical microscopic/biochemical identification of isolates. Comparison of PCR-RLB identification and classical identification of 98 other isolates (dermatophytes and non-dermatophytes) revealed 13 discrepancies (13.3%) and five incomplete identifications of Trichophyton spp. Sequence analysis of ITS1 regions of 23 samples with discrepant or incomplete identification results (four Centraalbureau voor Schimmelcultures dermatophyte strains, four clinical samples and 15 clinical isolates) confirmed identification results of PCR-RLB in 21 of the 23 analyzed samples. PCR-RLB proved to be extremely suitable for routine detection and identification of dermatophytes directly in nail, skin and hair samples because it is rapid, sensitive, specific and accurate.


Assuntos
Arthrodermataceae/classificação , Arthrodermataceae/isolamento & purificação , Dermatomicoses/diagnóstico , Cabelo/microbiologia , Unhas/microbiologia , Hibridização de Ácido Nucleico/métodos , Reação em Cadeia da Polimerase/métodos , Pele/microbiologia , Arthrodermataceae/genética , Primers do DNA , DNA Fúngico/análise , DNA Fúngico/isolamento & purificação , DNA Espaçador Ribossômico/análise , Dermatomicoses/microbiologia , Humanos , Técnicas de Tipagem Micológica , Sensibilidade e Especificidade , Fatores de Tempo
8.
Tijdschr Psychiatr ; 50(3): 179-83, 2008.
Artigo em Holandês | MEDLINE | ID: mdl-18324605

RESUMO

BACKGROUND: Pipamperone is prescribed to prevent impulsive aggressive behaviour in patients with intermittent explosive disorder, personality disorders or mental retardation. AIM: To investigate the scientific basis of this treatment. METHOD: Various databases were searched using the terms 'pipamperon', 'pipamperone' and 'Dipiperon'. Located articles were reviewed in order to discover whether they dealt with the relationship between the drug and impulsiveness and aggression. results Six publications were found, all dating from before 1979. CONCLUSION: In view of the limited amount of research on the subject and the adverse side effects it is concluded that pipamperone is not the drug of first choice considering the treatment of impulsive aggressive behaviour.


Assuntos
Agressão/efeitos dos fármacos , Antipsicóticos/uso terapêutico , Butirofenonas/uso terapêutico , Comportamento Impulsivo/tratamento farmacológico , Medicina Baseada em Evidências , Humanos , Metanálise como Assunto , Resultado do Tratamento
9.
Neth Heart J ; 12(10): 480, 2004 Oct.
Artigo em Holandês | MEDLINE | ID: mdl-25696271
10.
Psychon Bull Rev ; 8(1): 73-80, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11340869

RESUMO

Recent evidence indicates that a central bottleneck causes much of the slowing that occurs when two tasks are performed at the same time. This bottleneck might reflect a structural limitation inherent in the cognitive architecture. Alternatively, the bottleneck might reflect strategic (i.e., voluntary) postponement, induced by instructions to emphasize one task over the other. To distinguish structural limitations from strategic postponement, we examine a new paradigm in which subjects are told to place equal emphasis on both tasks and to emit both responses at about the same time. An experiment using this paradigm demonstrated patterns of interference that cannot easily be attributed to strategic postponement, preparation effects, or conflicts in response production. The data conform closely to the predictions of structural central bottleneck models.


Assuntos
Atenção , Reconhecimento Visual de Modelos , Percepção da Altura Sonora , Tempo de Reação , Adulto , Feminino , Humanos , Masculino , Orientação , Resolução de Problemas , Desempenho Psicomotor , Aprendizagem Seriada
11.
Psychopharmacology (Berl) ; 136(3): 247-55, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9566810

RESUMO

The behavioral profile of corticotropin-releasing factor (CRF) in mediating anxiogenic-like and aversive responses to stressors may be particularly relevant for dependence and withdrawal in drug-experienced organisms. Moreover, stressful aspects of drug exposure in the drug naive organism may also induce CRF system activation. In the present studies, the dependence of aversive properties of cocaine on activation of endogenous CRF systems has been evaluated in rats using taste conditioning and runway self-administration paradigms. Systemic cocaine administration (20 mg/kg i.p.) produced a conditioned saccharin aversion which was dose-dependently potentiated by central administration of the CRF receptor antagonist, D-phe CRF (12 41). In addition, i.v. cocaine administration (0.75 mg/kg per injection i.v.) produced runway goal-box avoidance and conditioned place avoidance responses which were significantly accelerated by CRF antagonist treatment. In contrast, CRF receptor stimulation using CRF itself abolished cocaine-induced increases in goal latency in the runway paradigm. This generalized involvement of CRF systems in cocaine-related motivational/associative states is consistent with the comprehensive role of CRF in mediating emotional responses to non-drug stressors.


Assuntos
Aprendizagem da Esquiva/efeitos dos fármacos , Cocaína/farmacologia , Entorpecentes/farmacologia , Receptores de Hormônio Liberador da Corticotropina/antagonistas & inibidores , Animais , Hormônio Liberador da Corticotropina/análogos & derivados , Hormônio Liberador da Corticotropina/farmacologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Injeções Intravenosas , Injeções Intraventriculares , Veias Jugulares , Masculino , Fragmentos de Peptídeos/farmacologia , Ratos , Ratos Wistar , Paladar/efeitos dos fármacos
12.
Neurology ; 49(3): 711-3, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9305328

RESUMO

The levodopa (LD) dose-antiparkinsonian response relationship becomes progressively steeper with advancing Parkinson's disease (PD). To establish the dose-response profile for the dyskinesiogenic effect of LD, we administered intravenous LD over a wide dose range to 25 patients with advanced PD. As expected in these patients with nonexistent therapeutic windows, the threshold doses (TD) for both motor effects were similar. Just around the TD, the relationship between LD dose and the magnitude of antiparkinsonian and dyskinesiogenic responses inclined steeply, reaching a plateau above 1.5 x TD. Response duration, however, continued to increase. The findings suggest that attempts to ameliorate dyskinesias in advanced PD patients by giving smaller, more frequent LD doses may be counter-productive due to shorter motor responses, more "off" time, and dose failures, while some may, in fact, benefit from higher LD doses to assure a full response and prolong its duration.


Assuntos
Antiparkinsonianos/uso terapêutico , Levodopa/uso terapêutico , Transtornos dos Movimentos/tratamento farmacológico , Doença de Parkinson/tratamento farmacológico , Idoso , Antiparkinsonianos/administração & dosagem , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Feminino , Humanos , Infusões Intravenosas , Levodopa/administração & dosagem , Masculino , Pessoa de Meia-Idade , Transtornos dos Movimentos/diagnóstico , Doença de Parkinson/diagnóstico , Placebos , Índice de Gravidade de Doença
13.
Neuroreport ; 8(4): 1019-23, 1997 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-9141084

RESUMO

Intracellular recordings have shown that neocortical pyramidal neurones have an intrinsic capacity for regenerative firing. The cellular mechanism of this firing was investigated by computer simulations of a model neurone endowed with standard action potential and persistent sodium (gNaP) conductances. The firing mode of the neurone was determined as a function of leakage and NaP maximal conductances (gl and gNaP). The neurone had two stable states of activity (bistable) over wide range of gl and gNaP, one at the resting potential and the other in a regenerative firing mode, that could be triggered by a transient input. This model points to a cellular mechanism that may contribute to the generation and maintenance of long-lasting sustained neuronal discharges in the cerebral cortex.


Assuntos
Córtex Cerebral/fisiologia , Modelos Neurológicos , Células Piramidais/fisiologia , Potenciais de Ação , Animais , Condutividade Elétrica , Lobo Frontal/fisiologia , Matemática , Potenciais da Membrana , Memória/fisiologia , Canais de Sódio/fisiologia
16.
Rhinology ; 30(3): 177-81, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1448674

RESUMO

Normal values for the flow at a transnasal pressure of 150 Pa were established with active anterior rhinomanometry (with decongestion) in a group of 33 normal subjects. These values were used to detect abnormalities in a group of 193 patients whose septum anatomy had been evaluated with rhinoscopy. About 25% of the rhinoscopically normal patients were found to have significantly low ("abnormal") flow values on one side. The same was true for patients with a small septal deviation restricted to one anatomical area. An abnormal flow was measured in about 35% of the patients with a moderate (restricted) septal deviation. In the patients whose septal deviation was not restricted to one anatomical area, about 45% had an abnormal flow. The highest detection rate was about 80% in patients with major deviations in the region of the vestibule and the valve. Such deviations were found only in a minority of the patients with complaints of nasal obstruction, which limits the importance of rhinomanometric evaluation in clinical practice.


Assuntos
Obstrução Nasal/fisiopatologia , Septo Nasal/fisiologia , Adulto , Idoso , Resistência das Vias Respiratórias , Reações Falso-Positivas , Feminino , Humanos , Masculino , Manometria , Pessoa de Meia-Idade , Pressão , Valores de Referência
17.
J Allergy Clin Immunol ; 87(2): 521-9, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1993812

RESUMO

Cholinergic nasal hyperresponsiveness in nasal allergy may be due to changes of the characteristics in muscarinic cholinergic receptors. Radioligand receptor binding and in vitro autoradiographic studies of nasal mucosa in nonallergic (NA) and allergic patients were performed to investigate this hypothesis. The heterogeneous NA group was subdivided into control individuals and patients with chronic sinusitis and vasomotor rhinitis. The 3H-(-)-Quinuclidinylbenzilate binding to muscarinic receptors in human nasal mucosa membranes was saturable and of high affinity in all groups. No significant differences could be demonstrated between the subgroups of the NA patients. In allergic patients the dissociation constants and receptor densities were significantly decreased in comparison with those of NA and with those of control individuals. No differences in agonist binding or coupling of the muscarinic receptor to the effector system via the G protein could be observed in allergic patients. In vitro autoradiographic experiments demonstrated specific 3H-(-)-Quinuclidinylbenzilate labeling of the glandular acini in NA and allergic patients. No specific labeling could be observed in the epithelium, blood vessels, or connective tissue. In conclusion, the increased sensitivity and decreased muscarinic receptor number may reflect the cholinergic-induced hypersecretion in nasal allergy but are probably too small to explain the complex allergic reaction.


Assuntos
Acetilcolina/metabolismo , Hipersensibilidade/metabolismo , Mucosa Nasal/química , Receptores Muscarínicos/análise , Autorradiografia , Biópsia , Doença Crônica , Humanos , Hipersensibilidade/patologia , Mucosa Nasal/patologia , Quinuclidinil Benzilato/metabolismo , Ensaio Radioligante/métodos , Receptores Muscarínicos/metabolismo , Rinite Vasomotora/metabolismo , Rinite Vasomotora/patologia , Sinusite/metabolismo , Sinusite/patologia
18.
J Allergy Clin Immunol ; 87(2): 530-40, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1847157

RESUMO

Nasal hyperreactivity in nasal allergy may be due to changes of the characteristics in adrenergic receptors. Radioligand receptor-binding studies with the antagonists, 3H-prazosin (alpha 1-adrenoceptor), 3H-rauwolscine (alpha 2-adrenoceptor), and 125I-(-)-Cyanopindolol (beta-adrenoceptor) were performed in homogenates of nasal mucosa of allergic and nonallergic (NA) patients to investigate this hypothesis. The heterogeneous NA group was subdivided into control individuals and patients with chronic sinusitis and vasomotor rhinitis. No significant differences in affinities or densities of alpha 1- and alpha 2-adrenoceptors could be demonstrated in allergic patients in comparison with NA and control individuals. The beta-adrenoceptor density was significantly reduced in allergic patients in comparison with that of control individuals. Neither changes in agonist binding or in the effect of Gpp(NH)p on the agonist binding to beta-adrenoceptors could be observed in allergic patients. The subtype selective antagonist, LK203-030, demonstrated the presence of a homogeneous population of beta 2-adrenoceptors in human nasal mucosa of both NA and allergic patients. In vitro, autoradiography demonstrated specific 125I-(-)-Cyanopindolol labeling of the epithelium in NA and allergic patients. In conclusion, no changes in characteristics of alpha 1- or alpha 2-adrenoceptors in the nasal mucosa could be demonstrated in nasal allergy. However, a decreased number of beta-adrenoceptors may reflect a beta-adrenergic abnormality in nasal allergy.


Assuntos
Hipersensibilidade/metabolismo , Mucosa Nasal/química , Receptores Adrenérgicos alfa/análise , Receptores Adrenérgicos beta/análise , Autorradiografia , Biópsia , Doença Crônica , Humanos , Hipersensibilidade/patologia , Mucosa Nasal/patologia , Ensaio Radioligante/métodos , Receptores Adrenérgicos alfa/metabolismo , Receptores Adrenérgicos beta/metabolismo , Rinite Vasomotora/metabolismo , Rinite Vasomotora/patologia , Sinusite/metabolismo , Sinusite/patologia
19.
Eur J Pharmacol ; 182(3): 515-25, 1990 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-2171949

RESUMO

The specific binding of 125I-(-)-cyanopindolol (125I-(-)-CYP) to homogenates and cryostat sections of rat nasal mucosa was saturable, stereoselective and of high affinity (Kd = 5.0 +/- 0.4 pM. Bmax = 204 +/- 12 fmol/mg protein and Kd = 7.2 +/- 0.7 pM; Bmax = 15 +/- 1 fmol/mg protein respectively). The subtype-selective antagonists, LK203-030 and ICI118,551, inhibited specific 125I-(-)-CYP binding according to a two-binding site model, indicating the presence of 57 and 45% beta 1-adrenoceptors in homogenates and cryostat sections, respectively. Competition of isoprenaline for antagonist binding to homogenates demonstrated 30 +/- 3% high-affinity agonist binding sites. A steepening of the curve was observed in presence of guanine nucleotides. In vitro labelling of cryostat sections of rat nasal mucosa was combined with autoradiography. The autoradiographs generated after incubation with 20 pM 125I-(-)-CYP showed specific labelling of the epithelium and glandular excretory ducts. It appeared from autoradiographs generated with subtype-selective antagonists in addition to the radioligand that beta 1- and beta 2-adrenoceptors were present in both structures.


Assuntos
Mucosa Nasal/metabolismo , Receptores Adrenérgicos beta/análise , Animais , Autorradiografia , Técnicas In Vitro , Radioisótopos do Iodo , Iodocianopindolol , Isoproterenol/farmacologia , Cinética , Mucosa Nasal/anatomia & histologia , Pindolol/análogos & derivados , Ensaio Radioligante , Ratos , Ratos Endogâmicos , Estereoisomerismo
20.
Eur J Pharmacol ; 182(3): 561-7, 1990 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-2171951

RESUMO

The specific binding of [3H]rauwolscine to rat nasal mucosa membranes was saturable, stereoselective and of high affinity. The Scatchard plot pointed to a homogeneous population of binding sites (Kd = 3.6 +/- 0.6 nM; Bmax = 5.1 +/- 0.7 pmol/g). The non-specific binding appeared to be non-linear, probably due to filter binding. Inhibition of [3H]rauwolscine binding with the subtype-selective antagonist, prazosin, suggested the presence of alpha 2-adrenoceptor subclasses in rat nasal mucosa. The (-)-epinephrine inhibition curves demonstrated high- and low-affinity agonist binding sites. A monophasic (-)-epinephrine inhibition curve was obtained in the presence of guanine nucleotides.


Assuntos
Mucosa Nasal/metabolismo , Receptores Adrenérgicos alfa/metabolismo , Animais , Clonidina/farmacologia , Epinefrina/antagonistas & inibidores , Guanilil Imidodifosfato/farmacologia , Técnicas In Vitro , Cinética , Prazosina/farmacologia , Ratos , Ratos Endogâmicos , Estereoisomerismo , Ioimbina/metabolismo , Ioimbina/farmacologia
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