RESUMEN
Around volcanic carbon dioxide (CO2) seeps in Papua New Guinea, partial pressures of CO2 (pCO2) approximate those as predicted for the end of this century, and coral communities have low diversity and low structural complexity. To assess the mechanisms for such community shifts in response to ocean acidification, we examined the physiological performance of two hard corals that occur with increased or unaltered abundance at a seep site (mean pHTotal=7.8, pCO2=862 µatm) compared to a control site (mean pHTotal=8.1, pCO2=323 µatm), namely massive Porites spp. and Pocillopora damicornis, and two species with reduced abundance, Acropora millepora and Seriatopora hystrix. Oxygen fluxes, calcification, and skeletal densities were analyzed in corals originating from the seep and control site. Net photosynthesis rates increased considerably in Porites spp. and A. millepora and slightly in P. damicornis at increased pCO2, but remained unaltered in S. hystrix. Dark respiration rates remained constant in all corals investigated from both sites. Rates of light calcification declined in S. hystrix at high pCO2, but were unaffected by pCO2 in the other three coral taxa. Dark and net calcification rates remained unchanged in massive Porites and P. damicornis, but were drastically reduced at high pCO2 in A. millepora and S. hystrix. However, skeletal densities were similar at both seep and control sites in all coral taxa investigated. Our data suggest that the pCO2-tolerant corals were characterized by an increased ability to acclimatize to ocean acidification, e.g. by maintaining net calcification. Thus, robust corals, such as Porites spp. and P. damicornis, are more likely to persist for longer in a future high pCO2 world than those unable to acclimatize.
Asunto(s)
Antozoos/fisiología , Dióxido de Carbono/metabolismo , Ecología , Erupciones Volcánicas , AnimalesRESUMEN
65 patients after previous myocardial infarction well documented by electrocardiography were investigated by 201-Tl scintigraphy after submaximal ergometry. Topographic results of the scintigraphy in three planes were compared with the location of previous infarction demonstrated by standard electrocardiography. 30% of disagreements and partial agreements in more than half the patients were caused predominantly by inability of electrocardiography to qualify a true ischaemic necrosis in the interventricular septum, by limited ability to localize exactly the site of myocardial infarction and by underestimating its size, in particular in the posterior left ventricular wall, where the lesion often extends to the lateral wall. Some principal disagreements of both methods in different findings on the anterior and posterior left ventricular walls stress the low value of standard electrocardiography for exact topographic diagnosis of the infarct site. The authors express their opinion that the size of myocardial infarction and its influence on left ventricular function measured by non-invasive methods in the acute state would be more important for the prognosis of the patient.
Asunto(s)
Electrocardiografía , Corazón/diagnóstico por imagen , Infarto del Miocardio/complicaciones , Daño por Reperfusión Miocárdica/patología , Adulto , Anciano , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Daño por Reperfusión Miocárdica/diagnóstico por imagen , Daño por Reperfusión Miocárdica/fisiopatología , Miocardio/patología , Cintigrafía , Radioisótopos de TalioRESUMEN
The study presents data regarding the functional assessment and prognosis of acute myocardial infarction survivors resident in Prague 4 and an industrial region in north Bohemia. No demonstrable differences between the incidence of myocardial infarction in various professions were found. Acute myocardial infarction occurred in 0.52-0.73% of the total number of workers enrolled in the study. Rehabilitation programmes succeeded in significantly increasing working tolerance, overall performance, and in decreasing the heart rate/blood pressure index within the first six months after acute myocardial infarction. In patients resuming their original jobs, all these parameters were substantially more favourable than in those not seeking re-employment. Prognosis was assessed in 1072 patients. The 10-year mortality was 52.1%. Of the survivors, 30% of patients returned to work, and 24% and 46% remained in partial and full-time retirement, respectively.
Asunto(s)
Infarto del Miocardio/rehabilitación , Tolerancia al Trabajo Programado , Trabajo , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Capacidad de TrabajoRESUMEN
The authors propose a dynamic 'man-work system' model, centered around the bodily strain, which is determined jointly by the momentary efficiency of the organism and the sum of stresses acting at a given point of time, i.e. integrated along various durations. With regard to stresses, they call attention to the heuristic significance of a separate subgroup, that of physiological stresses and also to the necessity of the distinction of a physiological subclass in the class of information stresses. The 'man-work system' is completed by positive and negative feedback from the strain and the components of efficiency, thereby providing the basis of successful or unsuccessful adaptation of the organism to the short- and long-term challenges. The authors are of the opinion that the system offers a sounder foundation for rehabilitative as well as preventive cardiology.
Asunto(s)
Infarto del Miocardio/psicología , Estrés Psicológico/psicología , Humanos , Tolerancia al Trabajo ProgramadoRESUMEN
One hundred and seven patients registered in the secondary preventive programme in Prague 4 were followed up for an average period of 3 years. The endpoints of the study were taken as criteria of the progression of clinical atherosclerosis (non-fatal myocardial infarction, cardiovascular death). The authors tried to detect the causes responsible for the high prevalence of impaired glucose tolerance, diabetes and hyperlipoproteinaemia. They analyzed the interrelationships of food intake, insulin secretion, serum fatty acids and lipoprotein phenotypes. There were 6% of non-fatal myocardial reinfarctions and 13% of cardiovascular death after 3 years. Multiple regression analysis identified the following 3 factors closely associated with cardiovascular death: 1) history of myocardial infarction 2) low proportion of linoleic acid in total lipids 3) hyperlipoproteinaemia. The authors show that analysis of the relationships of triglycerides, insulin and serum fatty acids could be of value for identifying the factors involved in a faster progression of atherosclerosis.
Asunto(s)
Infarto del Miocardio/sangre , Glucemia/análisis , Colesterol/sangre , Dieta , Prueba de Tolerancia a la Glucosa , Humanos , Insulina/sangre , Masculino , Persona de Mediana Edad , Triglicéridos/sangre , Ácido Úrico/sangreAsunto(s)
Prueba de Tolerancia a la Glucosa , Infarto del Miocardio/sangre , Glucemia/análisis , Complicaciones de la Diabetes , Diabetes Mellitus/diagnóstico , Humanos , Insulina/sangre , Lípidos/sangre , Masculino , Persona de Mediana Edad , Infarto del Miocardio/complicaciones , Ácido Úrico/sangreAsunto(s)
Enfermedad Coronaria/epidemiología , Enfermedad Aguda , Adulto , Anciano , Checoslovaquia , Urgencias Médicas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores SexualesRESUMEN
The incidence of some risk factors of ischaemic heart disease in men aged 40-55 years is compared with the presence and absence of angina pectoris (AP). Patients with positive AP had significantly higher values of the blood pressure, serum cholesterol level, and ponderal index. The frequency of probably pathological and possibly ischaemic changes was likewise significantly higher in the group with AP. Intermittent claudication was more frequent in this group as well. No significant difference in consumption of cigarettes was found between the two groups.