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1.
Pneumologie ; 75(3): 191-200, 2021 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-33728628

RESUMEN

The present addendum of the guideline for the diagnosis and treatment of asthma (2017) complements new insights into the diagnosis and management of asthma as well as for the newly approved drugs for the treatment of asthma. Current, evidence-based recommendations on diagnostic and therapeutic approaches are presented for children and adolescents as well as for adults with asthma.


Asunto(s)
Asma , Neumología , Adolescente , Adulto , Asma/diagnóstico , Asma/tratamiento farmacológico , Asma/epidemiología , Austria , Niño , Humanos , Sociedades Médicas
2.
BMC Med Res Methodol ; 20(1): 306, 2020 12 16.
Artículo en Inglés | MEDLINE | ID: mdl-33323110

RESUMEN

BACKGROUND: Although a variety of instruments are available that capture stress experience, the assessment of chronic stress has been hindered by the lack of economical screening instruments. Recently, an English-language version of the Trier Inventory for Chronic Stress (TICS-EN) consisting of 57 items according to a systemic-requirement-resource model of health in nine subdomains of the chronic stress experience has been introduced. METHODS: We constructed a new 9-item short version of the TICS covering all nine subdomains and evaluated it in two samples (total N = 685). We then used confirmatory factor analysis to check factorial validity. RESULTS: This version showed a highly satisfactory model fit, was invariant across participant gender, demonstrated a very high correlation with the original TICS (r = .94), and showed a moderate correlation (r = .58) with a measure of perceived stress in the past month. CONCLUSIONS: Therefore, this theoretically driven instrument can be recommended as a short version of the TICS in English language.


Asunto(s)
Lenguaje , Tamizaje Masivo , Análisis Factorial , Humanos , Psicometría , Reproducibilidad de los Resultados , Encuestas y Cuestionarios
3.
Photochem Photobiol Sci ; 19(3): 341-352, 2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-32065192

RESUMEN

Cryptochromes are highly conserved blue light-absorbing flavoproteins which function as photoreceptors during plant development and in the entrainment of the circadian clock in animals. They have been linked to perception of electromagnetic fields in many organisms including plants, flies, and humans. The mechanism of magnetic field perception by cryptochromes is suggested to occur by the so-called radical pair mechanism, whereby the electron spins of radical pairs formed in the course of cryptochrome activation can be manipulated by external magnetic fields. However, the identity of the magnetosensitive step and of the magnetically sensitive radical pairs remains a matter of debate. Here we investigate the effect of a static magnetic field of 500 µT (10× earth's magnetic field) which was applied in the course of a series of iterated 5 min blue light/10 min dark pulses. Under the identical pulsed light conditions, cryptochrome responses were enhanced by a magnetic field even when exposure was provided exclusively in the 10 min dark intervals. However, when the magnetic stimulus was given exclusively during the 5 min light interval, no magnetic sensitivity could be detected. This result eliminates the possibility that magnetic field sensitivity could occur during forward electron transfer to the flavin in the course of the cryptochrome photocycle. By contrast, radical pair formation during cryptochrome flavin reoxidation would occur independently of light, and continue for minutes after the cessation of illumination. Our results therefore provide evidence that a magnetically sensitive reaction is entwined with dark-state processes following the cryptochrome photoreduction step.


Asunto(s)
Arabidopsis/metabolismo , Criptocromos/metabolismo , Flavinas/metabolismo , Luz , Transporte de Electrón , Campos Magnéticos
4.
Pathologe ; 40(1): 85-92, 2019 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-30617605

RESUMEN

BACKGROUND: Biliary atresia (BA) is a rare disease of the newborn, resulting in liver cirrhosis due to obliterative cholangiopathy. Liver biopsies are commonly performed in order to confirm the diagnosis and in order to stage fibrosis. OBJECTIVES: The present study intended to analyze two established scores for evaluating liver fibrosis focusing on the interobserver variability as well as the prognostic reliability towards the time of liver transplantation. MATERIALS AND METHODS: Liver biopsies of BA patients between 2012 and 2015 were evaluated retrospectively by two pathologists at the Hannover Medical School (MHH) and the RWTH Aachen University Hospital. Fibrosis was measured using Ishak and Chevallier scores. Furthermore, a computerized automatically algorithm-based analyzation (ABAA) was performed. Results were evaluated towards the time point of liver transplantation and hepatoportoenterostomy (HPE). RESULTS: Overall, 34 liver biopsies were analyzed. The Ishak score showed a remarkable interobserver variability (ΚW = 0.68) while the Chevallier score was proven to have a poor interobserver variability (Fleiss' Κappa = -0.01). However, both scores were correlated positively, as was the ABAA (p < 0.001). Regarding prognostic reliability, ROC analyses of the Ishak score revealed the best validity towards an early liver transplantation within 12 months (AUC 0.813, p = 0.011). In addition, an increased Ishak score ≥4 reduced the survival time with the native liver (hazard ratio 6.6 [95% CI 1.9-23.3]). CONCLUSIONS: The Ishak score was revealed to have the best interobserver variability as well as prognostic validity towards an early liver transplantation in BA patients. Due to its easy applicability, the Ishak score was proven superior in comparison to the Chevallier score and ABAA. Therefore, use of the Ishak score is recommended in daily clinical routine for analyzing liver biopsies in BA patients.


Asunto(s)
Atresia Biliar , Cirrosis Hepática , Humanos , Hígado , Portoenterostomía Hepática , Reproducibilidad de los Resultados , Estudios Retrospectivos
5.
Pneumologie ; 71(12): 849-919, 2017 12.
Artículo en Alemán | MEDLINE | ID: mdl-29216678

RESUMEN

The present guideline is a new version and an update of the guideline for the diagnosis and treatment of asthma, which replaces the previous version for german speaking countries from the year 2006. The wealth of new data on the pathophysiology and the phenotypes of asthma, and the expanded spectrum of diagnostic and therapeutic options necessitated a new version and an update. This guideline presents the current, evidence-based recommendations for the diagnosis and treatment of asthma, for children and adolescents as well as for adults with asthma.


Asunto(s)
Asma/diagnóstico , Asma/terapia , Asma/clasificación , Asma/etiología , Austria , Alemania , Humanos , Pronóstico , Factores de Riesgo , Sociedades Médicas
6.
Clin Exp Allergy ; 47(4): 467-478, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28109164

RESUMEN

BACKGROUND AND OBJECTIVE: Inhaled corticosteroids (ICS) and inhaled corticosteroids combined with long-acting beta2-agonist (ICS/LABA) are standard treatments for asthma. However, factors that might help reduce medication in well-controlled asthma are unknown. We classified problems of asthma patients into biological, psychological and adherence factors, and investigated factors associated with the indication and failure of a medication step-down treatment. METHODS: Two hundred twenty two well-controlled asthma patients receiving ICS or ICS/LABA were assessed for physical and psychiatric problems and followed up for one year from adjustment of their treatment step. Factor B was defined as a presence of chronic upper airway complications. Factor P was defined as presence of psychiatric complications such as sleep disorder, depression, anxiety and somatoform disorders. Factor A was defined as poor adherence to ICS or ICS/LABA inhaler of 75% or less. Success in step-down treatment was defined as maintenance of well-controlled status for over one year after step-down. RESULTS: Factor B was the most important single negative predictive factor for indication for step-down treatment (Odds ratio; 0.19). Factor A increased the risk of failure to maintain step-down treatment most significantly by 23-fold, and factor B increased it by 11-fold. The combination of factors B and A increased failure by 24-fold, factors P and A by 21-fold, all three factors by 36-fold. Factor P only interacted with the other factors to reduce chances of stepping down, but did not constitute a problem factor when present alone. CONCLUSION AND CLINICAL RELEVANCE: The evaluation of biological, psychological and adherence problems may lead to a more proactive and targeted approach to step-down treatment for patients with well-controlled asthma.


Asunto(s)
Antiasmáticos/uso terapéutico , Asma/tratamiento farmacológico , Asma/psicología , Cumplimiento de la Medicación , Adolescente , Adulto , Anciano , Antiasmáticos/administración & dosificación , Asma/complicaciones , Asma/diagnóstico , Biomarcadores , Comorbilidad , Femenino , Estudios de Seguimiento , Humanos , Inmunoglobulina E/sangre , Inmunoglobulina E/inmunología , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Adulto Joven
9.
Clin Exp Allergy ; 43(9): 1000-8, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23957335

RESUMEN

Adequate asthma management depends on an accurate identification of asthma triggers. A review of the literature on trigger perception in asthma shows that individuals vary in their perception of asthma triggers and that the correlation between self-reported asthma triggers and allergy tests is only modest. In this article, we provide an overview of psychological mechanisms involved in the process of asthma triggers identification. We identify sources of errors in trigger identification and targets for behavioural interventions that aim to improve the accuracy of asthma trigger identification and thereby enhance asthma control.


Asunto(s)
Asma/etiología , Asma/psicología , Percepción , Alérgenos/inmunología , Humanos , Pronóstico , Factores de Riesgo
10.
Int Arch Allergy Immunol ; 159(1): 83-93, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22573022

RESUMEN

BACKGROUND: It is unclear how far the superior efficacy of omalizumab, established in randomized controlled clinical trials of patients with severe allergic asthma (SAA), translates into routine practice and when compared to matched controls. METHODS: New-onset omalizumab-treated (OT) patients with SAA (n = 53) were compared to a matched control group of usual-care (UC) patients (n = 53). Treatment and procedures were naturalistic. Subsequent to a baseline assessment, patients were followed up over at least 6 months with at least two follow-up assessments. Primary clinical outcomes were the number of asthma attacks, persistence of asthma symptoms and degree of control [asthma control test (ACT), Global Initiative for Asthma]. Secondary outcome criteria were quality of life (Euro-Qol 5D) and number of medications. For each outcome we compared within-group effects from baseline to 6-month follow-up as well as between-group effects. RESULTS: OT patients showed significant improvements in number [effect size (ES) = 0.03] and frequency (ES = 0.04) of asthma attacks as well as asthma control (ES = 0.09), whereas controls revealed no significant improvements in these measures. Further improvements in the OT group were found for 'perceived control always' (ACT, p = 0.006), no impairment (ACT, p = 0.02), reduction of sickness days (p = 0.002) and number of medications needed (p = 0.001). CONCLUSIONS: Substantial beneficial effects of omalizumab, similar to those observed in controlled trials and after marketing studies, were confirmed, particularly with regard to the reduction of asthma attacks, persistence of symptoms, asthma control and reduction of concomitant asthma medications. This study provides a tougher test and generalizable evidence for the effectiveness of omalizumab in routine care.


Asunto(s)
Antiasmáticos/uso terapéutico , Anticuerpos Antiidiotipos/uso terapéutico , Anticuerpos Monoclonales Humanizados/uso terapéutico , Asma/tratamiento farmacológico , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Omalizumab , Estudios Prospectivos , Resultado del Tratamiento , Adulto Joven
11.
Curr Med Res Opin ; 27(9): 1835-47, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21824036

RESUMEN

BACKGROUND: Studies in the last decade showed high rates of poorly treated and poorly controlled asthma in the community. Extending these findings we describe the more recent situation in specialist respiratory care as the most frequent source of treatment provision using comprehensive clinical and patient assessments and exploring predictors for poor control. METHODS: This is a German cross-sectional, clinical epidemiological study in a nationally representative stratified treatment prevalence sample of N = 572 outpatients diagnosed with allergic asthma (AA; females 58.2%, aged 47.5 ± 16.3 (16-81 years). Treating physicians completed standardized clinical assessments (lung function, laboratory, clinical findings, severity, illness and treatment history, asthma control [GINA]), supplemented by patients' self-report measures (EQ5-D, AQLQ, ACT) and mental health module (CIDI-SF). RESULTS: A total of 65.4% of patients were rated (GINA) as controlled, 30.3% partially controlled, and 4.4% uncontrolled; the patient-rated ACT showed lower rates of control (19.9% controlled, 44.2% partial, 35.8% uncontrolled, kappa: 0.2). Consistent with findings of clinical measures, controlled asthma was highest among patients with pre-treatment stage I severity (83.6%) and decreased by pre-treatment severity (stage IV patients: 29.3%). Poorer control was associated with pre-treatment severity, nocturnal attacks, diminished adherence and comorbid anxiety/depression. Patients received complex multiple drug and non-drug interventions, largely consistent with guidelines. Degree of asthma control was associated with improved and even normalized quality of life findings. CONCLUSION: In this representative sample of longterm treated AA patients in specialist respiratory care we find better control rates and better adherence to guidelines as previous studies. Despite remarkable differences in clinician- vs patient-rated control ratings even the initially most severe stage IV patients (12.9% of patients) showed remarkable control rates and close to normal quality of life. Intensified treatment (e.g. omalizumab) was associated with improved control. Poorer control was associated with higher initial severity, diminished adherence, comorbid anxiety/depression and old age. LIMITATION: Findings apply to AA patients in respiratory specialist care sector which is likely to treat the more severely affected patients. Thus, findings cannot be generalized to the general population, other treatment settings or asthma types.


Asunto(s)
Asma/epidemiología , Asma/terapia , Hipersensibilidad/epidemiología , Hipersensibilidad/terapia , Terapia Respiratoria/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Asma/complicaciones , Estudios Transversales , Estudios Epidemiológicos , Femenino , Alemania/epidemiología , Humanos , Hipersensibilidad/complicaciones , Masculino , Persona de Mediana Edad , Pautas de la Práctica en Medicina , Prevalencia , Terapia Respiratoria/estadística & datos numéricos , Especialización , Adulto Joven
12.
Clin Exp Allergy ; 40(1): 143-52, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19793085

RESUMEN

BACKGROUND: Allergy contributes significantly to asthma exacerbation, yet avoidance of triggers, in particular allergens, is rarely addressed in detail in regular asthma review in primary care. OBJECTIVE: To determine whether structured, individually tailored allergen and trigger avoidance advice, given as part of a primary care asthma review, improves lung function and asthma control. METHODS: In a randomized-controlled trial 214 adults with asthma in six general practices were either offered usual care during a primary care asthma review or usual care with additional allergen and trigger identification (by skin prick testing and structured allergy assessment) and avoidance advice according to a standardized protocol by trained practice nurses. Main outcome measures were lung function, asthma control, asthma self-efficacy. RESULTS: Both intervention groups were equivalent in demographic and asthma-related variables at baseline. At 3-6-month follow-up, patients receiving the allergen and trigger avoidance review showed significant improvements in lung function (assessed by blinded research nurses) compared with those receiving usual care. Significantly more patients in the intervention group than in the control group showed improvements in forced expiratory volume in 1 s > or =15%. No significant differences were found in self-report measures of asthma control. Asthma-specific self-efficacy improved in both groups but did not differ between groups. CONCLUSIONS: Allergen and trigger identification and avoidance advice, given as part of a structured asthma review delivered in primary care by nurses results in clinically important improvements in lung function but not self-report of asthma control. TRIAL REGISTRATION: ISRCTN45684820.


Asunto(s)
Alérgenos/uso terapéutico , Asma/terapia , Asma/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas de Función Respiratoria , Prevención Secundaria , Resultado del Tratamiento
13.
Phys Biol ; 3(3): 220-31, 2006 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-17021386

RESUMEN

Behavioral researchers have attached magnets to birds during orientation experiments, assuming that such magnets will disrupt their ability to obtain magnetic information. Here, we investigate the effect of an attached magnet on the ability to derive directional information from a radical-pair based compass mechanism. We outline in some detail the geometrical symmetries that would allow a bird to identify magnetic directions in a radical-pair based compass. We show that the artificial field through an attached magnet will quickly disrupt the birds' ability to distinguish pole-ward from equator-ward headings, but that much stronger fields are necessary to disrupt their ability to detect the magnetic axis. Together with estimates of the functional limits of a radical-pair based compass, our calculations suggest that artificial fields of comparable size to the geomagnetic field are not generally sufficient to render a radical-pair based compass non-functional.


Asunto(s)
Aves/fisiología , Magnetismo , Migración Animal , Animales , Planeta Tierra , Orientación
14.
J Psychosom Res ; 51(5): 639-45, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11728504

RESUMEN

OBJECTIVES: We studied the structure of symptom report in a sample of British asthma patients using the Asthma Symptom Checklist (ASC). METHODS: The ASC was administered to 193 patients, together with a questionnaire on demographics and asthma-related information and the Perceived Control of Asthma Questionnaire. RESULTS: Principal Component Analysis yielded evidence for a six-dimensional structure of the ASC, with positively correlated subscales for panic-fear, irritation, obstruction-dyspnea, obstruction-congestion, fatigue, and hyperventilation symptoms. Individual subscales showed good to excellent item characteristics and internal consistencies in individual subscales. Panic-fear and obstruction-congestion were related to self-reported duration of oral corticosteroid intake. Other ASC subscales were positively related to aspects of health care utilization, limitations in daily activity, and lower perceived control of asthma mainly in women. The dyspnea subscale of the ASC showed only little relationship with either of these variables. CONCLUSION: The ASC can reliably assess the multidimensional structure of asthma symptom report. Its subscales are associated with important aspects of asthma management behavior.


Asunto(s)
Asma/diagnóstico , Encuestas y Cuestionarios , Administración Oral , Adolescente , Adulto , Anciano , Obstrucción de las Vías Aéreas/epidemiología , Obstrucción de las Vías Aéreas/psicología , Antiinflamatorios/uso terapéutico , Asma/tratamiento farmacológico , Disnea/diagnóstico , Disnea/epidemiología , Femenino , Humanos , Hiperventilación/diagnóstico , Hiperventilación/epidemiología , Masculino , Persona de Mediana Edad , Trastorno de Pánico/epidemiología , Trastorno de Pánico/psicología , Reproducibilidad de los Resultados , Autoadministración , Esteroides
15.
Psychophysiology ; 38(5): 858-62, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11577909

RESUMEN

We tested the assumption that the slope of the within-individual regression equation of respiratory sinus arrhythmia (RSA) normalized by tidal volume (V(T)) upon respiratory cycle length (T(TOT)) can characterize ventilatory RSA modulation independent of cardiac vagal tone, whereas the intercept is varying as a function of vagal tone. We also explored whether a variation of V(T) is necessary to estimate slopes reliably. Four 3-min sequences paced at 8-18 cycles/min were performed supine and standing. Participants also breathed the same sequences in supine posture with voluntarily varying V(T). The mean slope of RSA/V(T) upon T(TOT) was identical, and the mean intercept was lower for standing than supine (spontaneous V(T)) conditions. Stability of slopes was low between body postures, and was higher between spontaneous V(T) versus varying V(T) at the same body posture. The regression of RSA/V(T) upon T(TOT) allows for a valid estimation of ventilatory influences on RSA.


Asunto(s)
Arritmias Cardíacas/fisiopatología , Postura/fisiología , Mecánica Respiratoria/fisiología , Volumen de Ventilación Pulmonar/fisiología , Adulto , Femenino , Humanos , Masculino
16.
Behav Modif ; 25(4): 640-66, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11530720

RESUMEN

Studies of relaxation training for adult asthma patients were reviewed for the period between 1980 and 2000. Six controlled and three uncontrolled studies were identified, employing a variety of methods, such as progressive relaxation, functional relaxation, autogenic training, or yoga. Most studies had low sample sizes and suffered from one or more methodological deficiencies, such as suboptimal data analysis, high dropout rates, problematic measurement procedures, or insufficient descriptions of methodology and results. Overall effects on parameters of lung function, symptoms, medication consumption, and health care use were generally negligible. Problems with the underlying rationale of relaxation therapy in asthma are discussed from a psychophysiological viewpoint. Examples are given of potential beneficial and detrimental effects of these techniques on lung function with respect to emotional processes, the musculoskeletal system, and ventilation as targets of a relaxation intervention. It remains to be demonstrated that relaxation training can significantly contribute to the standard treatment of asthma in adult patients.


Asunto(s)
Asma/terapia , Terapia por Relajación , Adulto , Asma/psicología , Ensayos Clínicos como Asunto , Terapia Combinada , Humanos , Resultado del Tratamiento
17.
Br J Med Psychol ; 74(Pt 2): 167-82, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11453169

RESUMEN

We studied the effects of emotion induction on total respiratory resistance, and their relationship with cardiac vagal activity and facial muscle activity in asthma. Groups of 20 asthmatic and 20 non-asthmatic participants were exposed to series of happy and depressing pictures or self-referent Velten statements. Facial electromyographic activity over corrugator supercilii, orbicularis oculi, and zygomaticus major regions was recorded during periods of presentation and imagery of each stimulus. Following each stimulus series, mood, respiratory resistance, ventilation, and cardiac activity including respiratory sinus arrhythmia (RSA) were recorded. Significant increases of respiratory resistance were observed in asthmatic patients following depressing stimulation. Resistance increases were positively correlated with RSA and heart period. No substantial group differences were found in facial response to emotional stimuli. Changes in facial target muscle sites during positive stimulation were inversely correlated with RSA following stimulation. We conclude that respiratory resistance increases in asthmatics following depressing stimulation are dependent on vagal activity. Greater facial muscle activation during emotional stimulation can reduce vagal activation, which is consistent with claims in the clinical literature of the benefits of emotional expression in asthma.


Asunto(s)
Afecto , Asma/psicología , Músculos Faciales/fisiología , Respiración , Adulto , Antiasmáticos/uso terapéutico , Asma/tratamiento farmacológico , Electromiografía , Femenino , Humanos , Masculino , Encuestas y Cuestionarios , Nervio Vago/fisiología
18.
Biol Psychol ; 55(2): 119-35, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11118679

RESUMEN

We investigated the effects of forehead temperature stimulation on total respiratory resistance in healthy individuals. In two experiments involving a total of 38 participants we studied the time course and stability of the response at moderate temperature (20-23 degrees C). Small plastic bags filled with water were positioned on the forehead for a duration of 60 s. Oscillatory resistance (R(os)), heart period (HP), respiratory sinus arrhythmia (RSA), and ventilatory parameters were measured continuously. Experiment 1 showed similar phasic increases in R(os) during the first 20 s of stimulation with moderate (20-23 degrees C) as compared to cold (8-11 degrees C) temperature. Phasic increases by moderate temperature were replicated in Experiment 2 over five successive stimulation trials. Within-session stability of individual differences in response was only modest. Ventilatory adjustments did not facilitate the phasic R(os) increases. As increases were mainly due to the inspiratory component of R(os), a substantial contribution of upper airway artifacts was less likely. Increases in HP were the most pronounced responses to all stimulation conditions, while RSA did not increase significantly.


Asunto(s)
Resistencia de las Vías Respiratorias/fisiología , Nivel de Alerta/fisiología , Frente/inervación , Temperatura Cutánea/fisiología , Adulto , Sistema Nervioso Autónomo/fisiología , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Nervio Vago/fisiología
19.
Biophys J ; 79(4): 1695-705, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11023878

RESUMEN

Peridinin-chlorophyll-protein (PCP) is a unique light-harvesting protein that uses carotenoids as its primary light-absorbers. This paper theoretically investigates excitation transfer between carotenoids and chlorophylls in PCP of the dinoflagellate Amphidinium carterae. Calculations based on a description of the electronic states of the participating chromophores and on the atomic level structure of PCP seek to identify the mechanism and pathways of singlet excitation flow. After light absorption the optically allowed states of peridinins share their electronic excitation in excitonic fashion, but are not coupled strongly to chlorophyll residues in PCP. Instead, a gateway to chlorophyll Q(y) excitations is furnished through a low-lying optically forbidden excited state, populated through internal conversion. Carbonyl group and non-hydrogen side groups of peridinin are instrumental in achieving the respective coupling to chlorophyll. Triplet excitation transfer to peridinins, mediated by electron exchange, is found to efficiently protect chlorophylls against photo-oxidation.


Asunto(s)
Carotenoides/química , Carotenoides/metabolismo , Clorofila/química , Clorofila/metabolismo , Dinoflagelados/metabolismo , Proteínas Protozoarias/química , Proteínas Protozoarias/metabolismo , Animales , Fenómenos Biofísicos , Biofisica , Sustancias Macromoleculares , Modelos Moleculares , Fotoquímica , Fotosíntesis , Proteínas del Complejo del Centro de Reacción Fotosintética/química , Proteínas del Complejo del Centro de Reacción Fotosintética/metabolismo
20.
Psychosom Med ; 62(3): 401-12, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10845354

RESUMEN

OBJECTIVES: Clinical reports suggest that various emotions and types of stress can precipitate asthmatic symptoms, but there is little experimental evidence to substantiate this claim. We studied the impact of different emotional states and stress on respiratory resistance in asthmatic and nonasthmatic individuals. METHODS: Participants (24 asthmatic and 24 nonasthmatic patients) viewed short film sequences selected to induce anxiety, anger, depression, elation, happiness, contentment, or a neutral affective state and completed two stressful tasks, mental arithmetic to induce active coping efforts and viewing of medical slides to induce passive coping efforts. Oscillatory resistance, heart rate, blood pressure, baroreflex sensitivity, skin conductance level, respiration rate and volume, and self-reported affective state were measured throughout the session. RESULTS: Uniform increases in oscillatory resistance were found in all emotional states compared with the neutral state and during mental arithmetic in both groups. Asthmatic patients showed stronger reactions to the medical slides than healthy control subjects, with significant increases in oscillatory resistance, blood pressure, skin conductance level, and minute volume, as well as higher levels of self-reported depression, arousal, and shortness of breath. Changes in oscillatory resistance were inconsistently correlated with other physiological indices. CONCLUSIONS: Various emotional states and stress increase oscillatory resistance largely independently of concurrent increases in autonomic or ventilatory activity. The particular sensitivity of asthmatics to passive coping demand requires additional research.


Asunto(s)
Asma/psicología , Emociones , Mecánica Respiratoria/fisiología , Estrés Psicológico/psicología , Adulto , Asma/diagnóstico , Barorreflejo/fisiología , Presión Sanguínea/fisiología , Femenino , Respuesta Galvánica de la Piel/fisiología , Humanos , Masculino , Índice de Severidad de la Enfermedad
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