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1.
Anaesthesia ; 78(2): 197-206, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36314294

RESUMO

The COVID-19 pandemic has imposed substantial burdens on clinicians and there is a need to better understand the impact on mental health and well-being. This scoping review investigates the prevalence of mental health concerns in anaesthetists, risk and protective factors for mental well-being, and anaesthetists' pandemic-related concerns and support. We searched online databases for articles published between January 2020 and May 2022, using search terms related to: anaesthesia; burnout, well-being, mental health or stress; and COVID-19. We identified 20 articles comprising 19 different populations of anaesthetists (n = 8680) from 14 countries. Studies identified the prevalence of the following condition in anaesthetists: burnout (14-59%); stress (50-71%); anxiety (11-74%); depression (12-67%); post-traumatic stress (17-25%); psychological distress (52%); and insomnia (17-61%). Significant risk factors for poorer mental health included: direct COVID-19-related issues (fear of self and family exposure to infection; requirement for quarantine); practitioner health factors (insomnia; comorbidities); psychosocial factors (loneliness; isolation; perceived lack of support at home and work); demographic factors (female gender; non-white ethnicity; LGBTQIA+); and workplace factors (redeployment outside area of clinical practice; increased work effort; personal protective equipment shortages). Protective factors identified included: job satisfaction; perceived organisational justice; older age; and male sex. Anaesthetists' self-reported concerns related to: personal protective equipment; resource allocation; fear of infection; fear of financial loss; increased workload; and effective communication of protocols for patient treatment. Support from family, colleagues and hospital management was identified as an important coping mechanism. Findings from this review may support the design of interventions to enhance anaesthetists' psychological health during pandemic conditions and beyond. Future research should include consistent psychological outcome measures and rigorous experimental design beyond cross-sectional studies.


Assuntos
Esgotamento Profissional , COVID-19 , Distúrbios do Início e da Manutenção do Sono , Masculino , Feminino , Humanos , COVID-19/epidemiologia , Saúde Mental , Pandemias , SARS-CoV-2 , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Estudos Transversais , Depressão/psicologia , Ansiedade/epidemiologia , Ansiedade/psicologia , Esgotamento Profissional/epidemiologia , Anestesistas
2.
Br J Anaesth ; 119(6): 1224-1230, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29045578

RESUMO

Background: Anaesthetists monitor auditory information about a patient's vital signs in an environment that can be noisy and while performing other cognitively demanding tasks. It can be difficult to identify oxygen saturation (SpO2) values using existing pulse oximeter auditory displays (sonifications). Methods: In a laboratory setting, we compared the ability of non-clinician participants to detect transitions into and out of an SpO2 target range using five different sonifications while they performed a secondary distractor arithmetic task in the presence of background noise. The control sonification was based on the auditory display of current pulse oximeters and comprised a variable pitch with an alarm. The four experimental conditions included an Alarm Only condition, a Variable pitch only condition, and two conditions using sonifications enhanced with additional sound dimensions. Accuracy to detect SpO2 target transitions was the primary outcome. Results: We found that participants using the two sonifications enhanced with the additional sound dimensions of tremolo and brightness were significantly more accurate (83 and 96%, respectively) at detecting transitions to and from a target SpO2 range than participants using a pitch only sonification plus alarms (57%) as implemented in current pulse oximeters. Conclusions: Enhanced sonifications are more informative than conventional sonification. The implication is that they might allow anaesthetists to judge better when desaturation decreases below, or returns to, a target range.


Assuntos
Percepção Auditiva , Alarmes Clínicos , Oximetria/instrumentação , Oximetria/métodos , Oxigênio/metabolismo , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudantes de Medicina , Análise e Desempenho de Tarefas , Adulto Jovem
3.
Anaesthesia ; 71(5): 565-72, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26990198

RESUMO

UNLABELLED: Our study examined the effectiveness of pulse oximetry sonification enhanced with acoustic tremolo and brightness to help listeners differentiate clinically relevant oxygen saturation ranges. In a series of trials lasting 30 s each, 76 undergraduate participants identified final oxygen saturation range ( TARGET: 100% to 97%; Low: 96% to 90%; Critical: 89% and below), and detected threshold transitions into and out of the target range using conventional sonification (n = 38) or enhanced sonification (n = 38). Median (IQR [range]) accuracy for range identification with the conventional sonification was 80 (70-85 [45-95])%, whereas with the enhanced sonification it was 100 (99-100 [80-100])%; p < 0.001. Accuracy for detecting threshold transitions with the conventional sonification was 60 (50-75 [30-95])%, but with the enhanced sonification it was 100 (95-100 [75-100]%; p < 0.001. Participants can identify clinically meaningful oxygen saturation ranges and detect threshold transitions more accurately with enhanced sonification than with conventional sonification.


Assuntos
Oximetria/instrumentação , Oximetria/métodos , Oxigênio/sangue , Alarmes Clínicos , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Sonicação , Som , Estudantes de Medicina , Inquéritos e Questionários , Adulto Jovem
5.
J Eur Acad Dermatol Venereol ; 26(11): 1396-9, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22035130

RESUMO

BACKGROUND: The Fitzpatrick Skin Phototype Classification (FSPC) is the most commonly used measure of skin type. In questionnaire-based surveys, self-rated FSPC is often used as a measure of respondents' skin type. OBJECTIVE: The objective of this analysis was to assess test-retest reliability of the self-rated FSPC within a 12-month cohort study that examined the psychological sequelae of acne. METHODS: Participants were students aged 14-17 years in four Australian secondary schools; two-government system schools and two private schools. The primary outcomes were a number of psychological measures. The FSPC was assessed by a single concise questionnaire item. Test-retest agreement (as measured by quadratic weighted kappa) of participants' self-rated FSPC at three time-points (baseline, 6 and 12 months) was calculated. RESULTS: Of the 244 participating students, 209 students (86%) completed all three rounds of data collection. A further 26 students (11%) completed two rounds. Quadratic weighted kappa for Rounds 1 and 2 was 0.757 (95% CI 0.663-0.831). For Rounds 2 and 3 it was 0.805 (95% CI 0.659-0.893). Between Rounds 1 and 3 it was 0.767 (95% CI 0.698-0.832). This represents good-to-very-good agreement. Skin type was retained as an independent variable in 8 of the 16 regression models built to explain psychological outcomes in this study. CONCLUSION: Skin type appears to be a significant factor in psychological morbidity in acne. The FSPC is a reliable method for assessing skin phenotype, even when elicited via a concise questionnaire item suitable for assessing skin type as a potential confounder in studies of other outcome factors.


Assuntos
Autoavaliação (Psicologia) , Pele/fisiopatologia , Luz Solar , Adolescente , Austrália , Estudos de Coortes , Humanos , Reprodutibilidade dos Testes
6.
Clin Obes ; 6(4): 243-8, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27242175

RESUMO

This study assessed whether an obesity-related health status instrument (Edmonton obesity scoring system - EOSS) or body mass index (BMI) better predicted pregnancy rates in overweight women undergoing fertility treatments. A prospective cohort study was conducted on patients with a BMI ≥ 25 kg m(-2) undergoing a fertility treatment cycle (ovulation induction, superovulation, or in vitro fertilization). Obesity-related health status including blood pressure, blood work, health history, and functional assessment were assessed. A total of 101 patients were included in the study with an average age of 36.3 ± 4.2 years and a mean BMI of 31.8 ± 5.2 kg m(-2) . EOSS was found to be statistically predictive of pregnancy rate/cycle (OR 0.51, 95% CI 0.27-0.94; P = 0.03), whereas BMI was not (OR 0.95, 95% CI 0.86-1.05). A similar trend was seen for clinical pregnancy rate/cycle started. However, the association between clinical pregnancy rates and EOSS or BMI did not reach statistical significance (OR 0.53, P = 0.06 and OR 0.98, P = 0.62 respectively). Our results demonstrated that EOSS better predicted pregnancy rates after fertility treatments than BMI. In fact, for every EOSS stage increased by one unit, the odds of pregnancy were approximately halved. A multi-centre study powered for live birth is warranted to establish effective pre-fertility management of overweight women.


Assuntos
Índice de Massa Corporal , Nível de Saúde , Infertilidade Feminina/tratamento farmacológico , Obesidade , Adulto , Estudos de Coortes , Feminino , Humanos , Indução da Ovulação , Gravidez , Taxa de Gravidez , Resultado do Tratamento
7.
J Clin Endocrinol Metab ; 71(1): 34-9, 1990 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2370299

RESUMO

In human blood, cortisol is transported by a plasma protein known as corticosteroid-binding globulin (CBG). As anticipated from primary structure comparisons of CBG and alpha 1-proteinase inhibitor (A1-PI), CBG acts as a substrate for neutrophil elastase. However, unlike A1-PI, CBG does not alter the activity of this enzyme, but is cleaved by it at a single location close to its carboxy-terminus, and this reduces its molecular size by 5 kDa with the concomitant release of more than 80% of CBG-bound cortisol. Three small molecular size fragments are detected after elastase cleavage, and carbohydrate analysis of these fragments suggests that they represent the same polypeptide fragment which has been differentially glycosylated. To assess the biological significance of these observations, CBG was incubated with either mononuclear cells or granulocytes obtained from patients with acute inflammation (sepsis) and from a normal volunteer. Only granulocytes from septic patients reduced the mol wt of CBG by about 5 kDa and destroyed its steroid-binding activity. Preincubation with A1-PI prevented this, which demonstrates that neutrophil elastase plays a key role in this event. These results suggest a physiological role for CBG in the delivery of cortisol to sites of inflammation.


Assuntos
Hidrocortisona/metabolismo , Neutrófilos/metabolismo , Transcortina/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Transporte Biológico , Metabolismo dos Carboidratos , Eletroforese em Gel de Poliacrilamida , Ativação Enzimática/efeitos dos fármacos , Feminino , Granulócitos/metabolismo , Humanos , Inflamação/metabolismo , Leucócitos Mononucleares/metabolismo , Masculino , Elastase Pancreática/metabolismo , Fragmentos de Peptídeos/metabolismo , alfa 1-Antitripsina/metabolismo
8.
Radiother Oncol ; 60(3): 267-72, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11514006

RESUMO

We measured pulmonary function in 21 patients, after craniospinal irradiation with a posterior spinal electron beam. The median age at treatment was 7.5 years. Nine patients (43%) demonstrated abnormal pulmonary function tests, five with restrictive changes, one with isolated diminished diffusion capacity, and three with obstructive disease. These changes were mild and predominantly asymptomatic.


Assuntos
Neoplasias do Sistema Nervoso Central/radioterapia , Irradiação Craniana/efeitos adversos , Pneumonite por Radiação , Radioterapia de Alta Energia/efeitos adversos , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Meduloblastoma/radioterapia , Dosagem Radioterapêutica , Testes de Função Respiratória , Coluna Vertebral
9.
Plant Cell Environ ; 10(1): 1-10, 1987 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28692151

RESUMO

A definition of plant hormone sensitivity is proposed which is based on the initial rates of responses at different hormone concentrations. By analogy with enzyme kinetics, it is concluded that simple concentration-response curves can be described by a function containing three 'sensitivity parameters'. Objective methods for determining the values of these parameters and for comparing curves are described. These methods are used to describe the responses of Commelina communis L. stomata to abscisic acid. If certain assumptions are valid, the sensitivity parameters can be assigned physicochemical meanings. To validate the assumptions, certain experimental criteria must be fulfilled and these are discussed.

10.
Chest ; 106(3): 672-6, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8082336

RESUMO

The clinical, functional, radiologic, and pathologic characteristics of seven cases of necrotizing sarcoid granulomatosis (NSG) are presented. The population consisted of five women and two men, with an average age of 36 years. Each patient's predominant presenting complaint was pleuritic chest pain. Pulmonary function testing demonstrated a variety of abnormal patterns. Computed tomography (CT) of the chest showed solitary or multiple nodules in all patients, occasionally associated with pulmonary infiltrates in the lower lobes. Pleural involvement was seen on CT scanning in six patients and mediastinal adenopathy was present in five. Biopsy specimens of the lung lesions revealed confluent epithelioid granulomata associated with necrosis and vasculitis. Pleural involvement by confluent granulomata was a prominent feature in four patients. Follow-up has ranged from 6 months to 4 years. All patients are now asymptomatic, the majority having received prednisone. One patient received methotrexate as a steroid-sparing measure. We conclude that NSG is distinguishable from sarcoidosis as a clinicopathologic entity in which pleural involvement is a frequent finding. Treatment with steroids appears to hasten recovery.


Assuntos
Doenças Pleurais/patologia , Sarcoidose Pulmonar/patologia , Adulto , Biópsia , Terapia Combinada , Feminino , Seguimentos , Humanos , Pulmão/diagnóstico por imagem , Pulmão/patologia , Linfonodos/patologia , Masculino , Pessoa de Meia-Idade , Necrose , Pleura/diagnóstico por imagem , Pleura/patologia , Doenças Pleurais/diagnóstico por imagem , Doenças Pleurais/epidemiologia , Doenças Pleurais/terapia , Testes de Função Respiratória , Estudos Retrospectivos , Sarcoidose Pulmonar/diagnóstico por imagem , Sarcoidose Pulmonar/epidemiologia , Sarcoidose Pulmonar/terapia , Tomografia Computadorizada por Raios X , Resultado do Tratamento
11.
Chest ; 82(3): 300-5, 1982 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6213382

RESUMO

In two groups of patients, 15 with asthma and 15 with chronic bronchitis, the bronchodilator effects of ipratropium bromide, of fenoterol plus theophylline, and of the combination of the three drugs, were compared using a double-blind, single-dose, placebo-controlled format. Ipratropium bromide caused rapid bronchodilatation which was not significantly different in asthmatic patients and patients with bronchitis (delta FEV1 = .29 L in one hour in asthmatic patients, .18 L in patients with bronchitis). In contrast, fenoterol plus theophylline induced a considerably greater effect in asthmatic patients (delta FEV1 = .41 L in one hour) than in those with bronchitis (delta FEV1 = .07 in one hour). The use of the three drugs in combination compared with ipratropium bromide alone, or fenoterol plus theophylline alone, resulted in a significant additional bronchodilatation in asthmatic patients. In the patients with bronchitis, the triple combination was clearly superior to fenoterol plus theophylline. A similar trend was present in comparing the triple combination to ipratropium bromide, but the difference did not reach statistical significance. There was no evidence of synergism when ipratropium bromide was combined with fenoterol plus theophylline in that the total bronchodilator effect was approximately additive. Asthmatic patients and the physician were able to distinguish the triple combination from placebo. No such ability was demonstrated with respect to those with bronchitis. All three drugs were well tolerated. Side effects were mostly mild, and none was related to the use of ipratropium.


Assuntos
Asma/tratamento farmacológico , Derivados da Atropina/uso terapêutico , Bronquite/tratamento farmacológico , Ipratrópio/uso terapêutico , Teofilina/uso terapêutico , Administração Oral , Adolescente , Adulto , Aerossóis , Idoso , Doença Crônica , Ensaios Clínicos como Assunto , Método Duplo-Cego , Quimioterapia Combinada , Fenoterol/administração & dosagem , Fenoterol/uso terapêutico , Humanos , Ipratrópio/administração & dosagem , Pessoa de Meia-Idade , Placebos
12.
Chest ; 73(5): 583-91, 1978 May.
Artigo em Inglês | MEDLINE | ID: mdl-648208

RESUMO

To examine the relative roles of passive factors (flow; filling pressures of left side of heart) and active factors (acidosis; arterial unsaturation) in the genesis of pulmonary hypertension when associated with sepsis, 37 patients with sepsis and 24 patients without sepsis were examined. Pulmonary hypertension was measured by the pulmonary arterial diastolic-pulmonary wedge pressure gradient (PAd-PWP gradient) and correlated reasonably with a standard formula for calculated resistance ([PA--PWP]/CI, where PA is mean pulmonary artery pressure and CI is cardiac index). In 22 of 37 patients, sepsis was associated with a significant degree of resistance to flow in the pulmonary circulation, as measured by the PAd-PWP gradient: and the higher the PAd--PWP gradient, the greater the likelihood of early death. None of the examined passive or active factors appeared to be adequate to explain pulmonary hypertension when present. By the use of previously derived formulae to estimate the compliance of the elastic pulmonary arteries, factors affecting this part of the pulmonary microcirculation could not be held accountable for apparent pulmonary hypertension. Therefore, the presence of pulmonary hypertension in sepis appears to be an active, rather than a passive, phenomenon and unrelated to arterial oxygen saturation or acid-base imbalance. Although the exact cause is unknown, pulmonary hypertension in sepis is associated with a high mortality and may be clinically followed by measurement of the PAd-PWP gradient.


Assuntos
Hipertensão Pulmonar/etiologia , Sepse/complicações , Infecções Bacterianas/complicações , Pressão Sanguínea , Débito Cardíaco , Humanos , Hipertensão Pulmonar/diagnóstico , Hipertensão Pulmonar/fisiopatologia , Pessoa de Meia-Idade , Circulação Pulmonar , Síndrome do Desconforto Respiratório/complicações , Síndrome do Desconforto Respiratório/fisiopatologia , Sepse/fisiopatologia , Resistência Vascular
13.
Chest ; 115(1): 38-48, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9925061

RESUMO

STUDY OBJECTIVE: To compare quality of life and exercise capacity (primary aim), and drug usage (secondary aim), between groups of patients with irreversible chronic airflow limitation (CAL) who were undergoing theophylline Theo-Dur; Key Pharmaceuticals; Kenilworth, NJ) therapy guided by n of 1 trials or standard practice. DESIGN: Randomized study of n of 1 trials vs standard practice. SETTING: Outpatient departments in two tertiary care centers. PATIENTS: Sixty-eight patients with irreversible CAL who were symptomatic despite the use of inhaled bronchodilators, and who were unsure whether theophylline was helping them following open treatment, were randomized into n of 1 trials (N=34) or standard practice. INTERVENTIONS: The n of 1 trials (single-patient, randomized, double-blind, multiple crossover comparisons of the effect on dyspnea of theophylline vs a placebo) followed published guidelines. Standard practice patients stopped taking theophylline but resumed it if their dyspnea worsened. If their dyspnea then improved, theophylline was continued. In both groups, a decision about continuing or stopping the use of theophylline was made within 3 months of randomization. MEASUREMENTS AND RESULTS: The primary outcomes (the chronic respiratory disease questionnaire [CRQ] and 6-min walk) were measured at baseline, 6 months, and 12 months by personnel blinded to treatment group allocation. No between-group differences (n of 1 minus standard practice) were seen in within-group changes over time (1 year minus baseline) in the CRQ Physical Function score (point estimate on the difference, -2.8; 95% confidence limits [CLs], -8.2, 2.5), CRQ Emotional Function score (point estimate on the difference, 0.5; 95% CLs, -4.7, 5.7), or 6-min walk (point estimate on the difference, 8 m; 95% CLs, -26, 44 m). No differences between groups were seen in the secondary outcome of the proportion of patients taking theophylline at 6 and 12 months. In 7 of 34 n of 1 trial patients (21%), dyspnea improved during theophylline treatment compared with placebo treatment. CONCLUSIONS: Using n of 1 trials to guide theophylline therapy in patients with irreversible CAL did not improve their quality of life or exercise capacity, or reduce drug usa e, over 1 year compared to standard practice. Under the objective conditions of an n of 1 trial, 21% of patients with CAL responded to theophylline. There remains a rationale for considering theophylline in patients with irreversible CAL who remain symptomatic despite the use of inhaled bronchodilators, but the use of n of 1 trials to guide this decision did not yield clinically important advantages over standard practice.


Assuntos
Broncodilatadores/administração & dosagem , Pneumopatias Obstrutivas/tratamento farmacológico , Teofilina/administração & dosagem , Idoso , Broncodilatadores/efeitos adversos , Estudos Cross-Over , Método Duplo-Cego , Teste de Esforço/efeitos dos fármacos , Feminino , Volume Expiratório Forçado/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Teofilina/efeitos adversos , Resultado do Tratamento , Capacidade Vital/efeitos dos fármacos
14.
Psychopharmacology (Berl) ; 152(4): 440-6, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11140337

RESUMO

RATIONALE: The study of the effects of repeated amphetamine administration and withdrawal on brain reward function has relevance to both amphetamine dependence and non-drug-induced depressions. OBJECTIVES: The purpose of this study was to investigate the effects of continuous amphetamine administration and withdrawal on brain stimulation reward thresholds, and the changes that occur with repeated amphetamine exposures. METHODS: Rats were prepared with bipolar electrodes in the lateral hypothalamus and trained in a discrete-trial reward threshold procedure. Then, rats underwent two separate periods of amphetamine administration via subcutaneous osmotic mini-pumps. RESULTS: Continuous amphetamine administration was associated with lowering in brain reward thresholds and decreases in response latencies, while withdrawal was associated with threshold elevations. These effects changed with subsequent amphetamine administration and withdrawal. CONCLUSIONS: The results of this study indicated that with the amphetamine administration regime used here, rats developed increased sensitivity to the effects of acute amphetamine administration and tolerance to the effects of amphetamine withdrawal.


Assuntos
Transtornos Relacionados ao Uso de Anfetaminas/psicologia , Anfetamina/administração & dosagem , Encéfalo/efeitos dos fármacos , Estimulantes do Sistema Nervoso Central/administração & dosagem , Depressão/etiologia , Síndrome de Abstinência a Substâncias/psicologia , Animais , Encéfalo/fisiologia , Masculino , Ratos , Ratos Wistar , Recompensa , Autoestimulação
15.
J Appl Physiol (1985) ; 61(5): 1790-5, 1986 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2430931

RESUMO

The ability of hypoxia (PO2 57 Torr) and anoxia (PO2 0 Torr) to induce the release of histamine or sulfidopeptide leukotrienes from dispersed porcine parenchymal lung cells was examined. Spontaneous release of histamine (9.2 +/- 1.3%) was not significantly increased during hypoxia or anoxia, and spontaneous leukotriene release was not detected under any conditions. The release of leukotriene induced by A23187 (78 +/- 11 pmol leukotriene D4 equivalent/10(7) parenchymal lung cells) was unchanged during hypoxia and was significantly reduced (55.4 +/- 7.7% control leukotriene release) during anoxia, whereas A23187-induced histamine release (63.2 +/- 4.2% total cell histamine) was unaffected by reduced oxygenation. Reduction of final buffer pH from 7.4 to 7.0 did not affect mediator release. High-pressure liquid chromatographic analysis of the released leukotrienes revealed a mixture of leukotrienes C4 and D4, with a symmetrical reduction in product during anoxia. Although leukotriene release in response to hypoxia was not demonstrated, the findings do not preclude limited local release of leukotrienes, perhaps in association with increased smooth muscle responsiveness.


Assuntos
Liberação de Histamina , Hipóxia/fisiopatologia , Pulmão/fisiopatologia , SRS-A/metabolismo , Animais , Soluções Tampão , Calcimicina/farmacologia , Cromatografia Líquida de Alta Pressão , Técnicas In Vitro , Pulmão/efeitos dos fármacos , Suínos
16.
J Appl Physiol (1985) ; 64(1): 435-40, 1988 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3356661

RESUMO

The aim of the present study was to compare the effect of reduced oxygenation on the contractions of pulmonary vascular and airway smooth muscle induced by leukotriene D4 (LTD4) with those induced by histamine (an agonist with similar mechanisms of smooth muscle contraction) and KCl (a voltage-dependent stimulus). During hypoxia (PO2: 40 +/- 4 Torr) the responses of isolated porcine pulmonary artery and vein spiral strips to LTD4 increased approximately three- and two-fold, respectively, and the vein also exhibited an augmented response to histamine. The augmentation was blunted (LTD4) or reversed (histamine) during anoxia (PO2: 0 +/- 2 Torr). Responses to KCl were not systematically altered by reduced oxygenation. In contrast, the contractions of the guinea pig parenchymal lung strip by all three agonists were generally suppressed by reduced oxygenation. After reoxygenation, the contractile responses of each of the three smooth muscle preparations were generally increased compared with previous and concurrent base-line observations, particularly the LTD4-induced pulmonary vein contraction that increased approximately sevenfold after reoxygenation after anoxia. The contribution (if any) of leukotrienes to hypoxic pulmonary vasoconstriction may reflect increased vascular responsiveness to leukotrienes during hypoxia as well as (or instead of) increased leukotriene release.


Assuntos
Histamina/farmacologia , Hipóxia/fisiopatologia , Pulmão/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , SRS-A/farmacologia , Animais , Cobaias , Técnicas In Vitro , Contração Muscular/efeitos dos fármacos , Oxigênio/fisiologia , Artéria Pulmonar/efeitos dos fármacos , Veias Pulmonares/efeitos dos fármacos , Suínos
17.
J Appl Physiol (1985) ; 67(5): 2147-53, 1989 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2600043

RESUMO

Because small pulmonary arteries are believed to be the major site of hypoxic pulmonary vasoconstriction (HPV), pulmonary venular responses to hypoxia have received little attention. Therefore the responses of isolated guinea pig pulmonary venules to hypoxia (bath PO2, 25 Torr) and anoxia (bath PO2, 0 Torr) were characterized. Pulmonary venules [effective lumen radius (ELR), 116 +/- 2 microns] with an adherent layer of parenchyma responded to hypoxia and anoxia with a graded sustained contraction (hypoxia, 0.03 +/- 0.01; anoxia, 0.26 +/- 0.03 mN/mm), whereas paired femoral venules (ELR, 184 +/- 7 microns) contracted to anoxia only (0.05 +/- 0.02 mN/mm). Repeated challenges with hypoxia and anoxia continued to elicit sustained pulmonary venular contractions; femoral venule contractions to anoxia were not repeatable. Hypoxia- and anoxia-induced pulmonary venular contractions were calcium and pH dependent. Dissection of the parenchyma from pulmonary venules did not alter contractions to decreased PO2. Anoxic contractions of pulmonary venules were variably reduced by replacement of the bath fluid; however, the release of a contractile mediator(s) from pulmonary venules during hypoxia or anoxia was not demonstrated. Pulmonary venular responses to hypoxia and anoxia are similar to those induced by hypoxia in vivo, and results obtained from this model may be useful in predicting mechanisms of HPV.


Assuntos
Oxigênio/fisiologia , Veias Pulmonares/fisiologia , Vasoconstrição/fisiologia , Animais , Cálcio/fisiologia , Capilares/fisiologia , Veia Femoral/fisiologia , Cobaias , Concentração de Íons de Hidrogênio , Hipóxia , Técnicas In Vitro , Masculino , Veias Pulmonares/anatomia & histologia , Veias Pulmonares/efeitos dos fármacos , Vasoconstrição/efeitos dos fármacos
18.
Eur J Pharmacol ; 70(4): 489-99, 1981 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-6113148

RESUMO

Spirally cut tracheae from actively sensitized guinea pigs were challenged with antigen in the presence and absence of indomethacin. In the absence of indomethacin, the SRS-A antagonist FPL55712, added 30 min before challenge had no effect on antigen-induced contraction (ATC) when added in concentrations less than or equal to 1.7 X 10(-6) M. However with the highest concentration employed (5.2 X 10(-6) M) the duration of ATC was reduced by 45%. Furthermore the enhancement by indomethacin of the peak height of ATC was reduced even by lower (5.2 X 10(-7) M) concentrations of FPL55712. The inhibition of FPL55712 was time-dependent, suggesting that its action was not confined to competitive receptor antagonism. Hence, although our previous data indicate that a lipoxygenase product is involved in ATC, the current findings suggest that lipoxygenase products in addition to SRS-A contribute to the response. THe H1-antagonists mepyramine, chlorpheniramine and diphenhydramine inhibited ATC only in the first minute, and the peak height was reduced only by diphenhydramine. The H2-antagonist cimetidine had no effect on ATC. These data suggest that the contribution of histamine to ATC is small, confined to the first minute following antigen challenge and mediated via H1-receptors. Reduction of the peak height by diphenhydramine may be unrelated to its H1-antagonist properties.


Assuntos
Resistência das Vias Respiratórias/efeitos dos fármacos , Antígenos , Autacoides/antagonistas & inibidores , Antagonistas dos Receptores Histamínicos H1/farmacologia , Antagonistas dos Receptores H2 da Histamina/farmacologia , Traqueia/efeitos dos fármacos , Animais , Atropina/farmacologia , Cromonas/farmacologia , Interações Medicamentosas , Éteres/farmacologia , Cobaias , Indometacina/farmacologia , Masculino , Contração Muscular/efeitos dos fármacos , Traqueia/imunologia
19.
Ann Clin Biochem ; 22 ( Pt 6): 606-11, 1985 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-4073792

RESUMO

The LKB 'Delfia, immunofluorometric assay for serum TSH has been evaluated. The assay is simple and rapid to perform and is capable of processing in excess of 100 specimens within a working day. The sensitivity of the assay is 0.05 microU/L, with a working range extending beyond 324 microU/L. The change in signal at each point over the standard curve approaches 1000-fold, significantly greater than that of a typical immunoradiometric assay. Mean figures for intra-assay and inter-assay precision were 4.7% and 8.6% CV, respectively. Mean recovery of added TSH was 98.3%, and samples containing high levels of endogenous TSH diluted parallel to the standard curve. The method showed good correlation with an immunoradiometric assay for TSH. The reference ranges for clinically defined groups of subjects were euthyroid 0.47-3.84 microU/L (n = 83); primary hypothyroidism 15--greater than 324 microU/L (n = 28); thyrotoxicosis less than 0.05 microU/L (n = 46). It is concluded that the 'Delfia' assay offers the clinical biochemistry laboratory an attractive and reliable alternative to a sensitive immunoradiometric assay for serum TSH.


Assuntos
Tireotropina/sangue , Estudos de Avaliação como Assunto , Feminino , Fluorometria , Humanos , Hipertireoidismo/sangue , Hipotireoidismo/sangue , Imunoensaio , Gravidez , Valores de Referência
20.
Ann Clin Biochem ; 24 ( Pt 4): 408-10, 1987 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-3662390

RESUMO

Digoxin requesting patterns were studied prospectively over a 6-month period. Clinicians were not forewarned that the study was being undertaken. Many samples received in the laboratory were taken at incorrect times after the drug had been given. This led to inappropriate action being taken in some cases. Appropriate action was taken on most patients who had toxic serum digoxin levels together with clinical signs. The role of subtherapeutic digoxin levels seems unclear as these elicit a wide variety of responses.


Assuntos
Digoxina/sangue , Digoxina/efeitos adversos , Humanos , Monitorização Fisiológica , Estudos Prospectivos
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