RESUMEN
In this work, a new method of analyzing noninvasive reflection spectra is presented. The approach explicitly models the inhomogeneity of chromophore distributions in living tissues and thus extracts not only apparent chromophore concentrations but also relative chromophore distributions in tissues. Furthermore, it works with spectra obtained with short source-detector separations where the diffusion theory of light transport through turbid media is not valid, and formerly presented methods thus fail. The effect of inhomogeneously distributed chromophores in a multicompartment model of tissues on measured reflection spectra is explained and an algorithm to deconvolute tissue spectra based on this model is presented. It is evaluated using simulated spectra and measurements on phantoms, which are made up of partially printed pieces of paper to simulate inhomogeneous dye distributions. Its applicability to real tissue is proven using reflection spectra obtained with 130 microm source-detector separation from a hemoperfusion stop experiment. The proposed model accurately determines apparent chromophore concentrations and corresponding distributions in simulated spectra and phantoms. Regarding real tissue spectra, the results correspond to former publications and the spectral reconstruction yields only minimal residuals, indicating a complete and accurate spectral deconvolution. In conclusion, the presented approach is a suitable extension and amendment to existing models of light transport through inhomogeneous samples.
Asunto(s)
Algoritmos , Pigmentos Biológicos/análisis , Pigmentos Biológicos/metabolismo , Refractometría/métodos , Pigmentación de la Piel/fisiología , Análisis Espectral/métodos , Animales , Bovinos , Simulación por Computador , Hemoglobinas/metabolismo , Modelos Biológicos , Distribución Tisular , beta Caroteno/metabolismoRESUMEN
BACKGROUND: Carotenoids and tocopherols, known to be efficient antioxidants and capable of scavenging reactive oxygen species generated during photooxidative stress, may protect the skin from ultraviolet light-induced erythema. beta-Carotene is widely used as an oral sun protectant but studies on its protective effects are scarce. OBJECTIVE: The objective of this study was to investigate the protective effects of oral supplementation with carotenoids and a combination of carotenoids and vitamin E against the development of erythema in humans. DESIGN: A carotenoid supplement (25 mg total carotenoids/d) and a combination of the carotenoid supplement and vitamin E [335 mg (500 IU) RRR-alpha-tocopherol/d] were given for 12 wk to healthy volunteers. Erythema was induced by illumination with a blue-light solar simulator. Serum beta-carotene and alpha-tocopherol concentrations and skin carotenoid levels were assessed by HPLC and reflection photometry. RESULTS: Serum beta-carotene and alpha-tocopherol concentrations increased with supplementation. Erythema on dorsal skin (back) was significantly diminished (P < 0.01) after week 8, and erythema suppression was greater with the combination of carotenoids and vitamin E than with carotenoids alone. CONCLUSION: The antioxidants used in this study provided protection against erythema in humans and may be useful for diminishing sensitivity to ultraviolet light.
Asunto(s)
Antioxidantes/uso terapéutico , Carotenoides/uso terapéutico , Eritema/etiología , Eritema/prevención & control , Rayos Ultravioleta , Vitamina E/uso terapéutico , Adulto , Antioxidantes/administración & dosificación , Carotenoides/administración & dosificación , Carotenoides/metabolismo , Suplementos Dietéticos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Piel/metabolismo , Vitamina E/administración & dosificación , Vitamina E/sangre , beta Caroteno/sangreRESUMEN
An investigation was undertaken in 9 male subjects of the effect of short exposure to moderate altitude on the oxygen affinity of haemoglobin and other parameters. Initial measurements were performed at 425 m and repeated 3 hours after ascent by cable car to an altitude of 1800 m (Untersberg, Salzburg), no muscular activity being allowed (first period). The same protocol was repeated 3 days subsequently except that after ascent the individuals were exercised on an ergometer bicycle (second part). Altitude exposure without exercise leads to a small, but significant increase in the pH corrected P50 value (= half-saturation tension), whereas the non-corrected P50 value showed no significant change. In the second part of the study the corrected and non-corrected P50 values both increased significantly. The whole body pH and the intraerythrocytic pH rose, whereas PCO2 decreased significantly. The intraerythrocytic 2,3-DPG concentration showed a significant increase (1.2 mumol/gHb) after 3 hours of altitude exposure with and without muscular exercise. The prealtitude DPG concentration and the P50 values in the second period were higher than the first control values. The red blood count and sodium and chloride concentration showed no changes. Potassium rose in both experimental periods, whereas inorganic plasma phosphates decreased. These findings show that 3 hours after cable-car ascent to a medium altitude a DPG increase occurs which is able to counteract the Bohr effect. This means that the expected impairment of tissue oxygenation, caused by the alkalosis-induced shift of the dissociation curve to the left, is prevented. These findings also indicate that a repeated "passive" ascent to moderate altitude can lead to an increased oxygen delivery to the tissue.
Asunto(s)
Altitud , Hemoglobina A/metabolismo , Consumo de Oxígeno , Adulto , Alcalosis Respiratoria/etiología , Humanos , MasculinoRESUMEN
The skin activation and penetration capability of vitamin E acetate as an ingredient in a basic o/w cream (lamellar type), in liposomes (Rovisome) and microparticles (Roviparts), was investigated under in vitro conditions (BUS model) by the adhesive stripping method. The aim of the study was to compare the analytical results obtained by UV spectroscopy (transmission) and the conventional HPLC method. For the quantitative spectrometric assay, a classical least-squares evaluation of the spectra between 265 and 350 nm, based on the constituent spectra, was used. UV spectroscopy is an economic analytical method for evaluating a large population of samples of the horny layer taken by the adhesive tape stripping method, which is an established tool for depth profiling of substances within the stratum corneum. With regard to the irritation test, no cytotoxicity was recorded for all formulations tested. However, the Roviparts and Rovisome cream formulations induced a considerable activation of the epidermal cells that may contribute to the penetration efficiency of Rovisome-formulated vitamin E acetate. The Rovisome-formulated cream delivered a maximum amount of vitamin E acetate into the horny layer compared to the other formulations tested. The difference can be explained by an alteration of the plasticity of the horny layer inducing a strong reservoir capacity and an activation of upper epidermal cells. Moreover, the opening of the potential pathway for a follicular penetration may be part of the increased reservoir capacity.
Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Espectrofotometría Ultravioleta/métodos , alfa-Tocoferol/análogos & derivados , alfa-Tocoferol/farmacocinética , Animales , Bovinos , Técnicas In Vitro , Modelos Químicos , Tocoferoles , alfa-Tocoferol/análisisRESUMEN
BACKGROUND: Venepuncture-related blood loss is a common cause of neonatal anemia. Currently, this is the only way to obtain hemoglobin levels. This causes distress for the infant but can also lead to the need for blood transfusions. Recently, a new technique for measuring hemoglobin levels non-invasively has been developed to reduce iatrogenic blood loss and pain. OBJECTIVE: To compare hemoglobin levels obtained using a transcutaneous spectroscopic device (Mediscan 2000, MBR Optical Systems, Wuppertal, Germany) with venous or capillary blood samples in neonates. METHODS: Single-center prospective cohort study of term and preterm infants. The white light spectroscopic device was placed on the forearm for 60 s to measure hemoglobin content within 4 h of venous or capillary blood sampling. Pain reactions of the infants were assessed by using a neonatal pain assessment tool. Results were analyzed by Bland-Altman comparison and Wilcoxon signed-rank test. RESULTS: 80 infants (mean gestational age 29.8 +/- 3.8 weeks, mean birth weight 1,300 +/- 690 g) were enrolled into the study. A total of 313 spectroscopic recordings within 2 h of a clinically indicated blood sample (181 capillary, 142 venous) were taken. The correlation coefficient R(2) was 0.96 for capillary/spectroscopic and 0.99 for venous/spectroscopic pairs. Pain scores were significantly less for the spectroscopic measurements (p < 0.01). CONCLUSION: The results show good correlation between the hemoglobin blood levels and spectroscopic measurements. The slightly lower correlation coefficient for the capillary samples demonstrates a naturally higher variance in these values due to the laboratory method.
Asunto(s)
Anemia Neonatal/prevención & control , Recolección de Muestras de Sangre/efectos adversos , Hemoglobinas/análisis , Flebotomía/efectos adversos , Análisis de Varianza , Anemia Neonatal/etiología , Peso al Nacer , Capilares , Estudios de Cohortes , Femenino , Alemania , Humanos , Enfermedad Iatrogénica/prevención & control , Recién Nacido , Masculino , Dimensión del Dolor , Estudios Prospectivos , Análisis Espectral/instrumentación , Análisis Espectral/métodos , VenasAsunto(s)
Infarto del Miocardio/rehabilitación , Centros de Rehabilitación , Evaluación de la Discapacidad , Prueba de Esfuerzo , Terapia por Ejercicio , Educación en Salud , Humanos , Infarto del Miocardio/terapia , Servicio Ambulatorio en Hospital , Rehabilitación Vocacional , Evaluación de Capacidad de TrabajoRESUMEN
"Cures" prescribed in spas and health resorts are useful especially for patients who are chronically ill. The differences between pharmacotherapy and physiotherapy are discussed. The treatment in health resorts produces adaptations to repeated irritations, which need time, mostly four weeks. However, the changes of the function of circulatory system, lungs, metabolism etc. do not disappear after the end of the cure. To this extent, the principles of treatment in health resorts are comparable to sporting training. The days of incapacity to working are reduced to 50-60% in the following two years after a successful cure.
Asunto(s)
Enfermedad Crónica/rehabilitación , Colonias de Salud , Terapia Combinada , Humanos , Modalidades de FisioterapiaRESUMEN
In 7 patients suffering from heart infarction the electrocardiogram was telemetrically registered during telecast of the world championship in football 1974. The same patients were tested on a bicycle ergometer with standardized loads of 50, 75, 100 and 125 Watt for 3 minutes. Heart rate under psychial strain did not exceed the rate of 50 Watt on bicycle ergometer. Only 1 patient showed some extrasystoles during ergometry. Looking at television all patients developed extrasystoles, in one case 122. If the FRG took part in the game, ventricular extrasystoles were two times, auricular extrasystoles were four times more frequent than during games between foreign countries. It is concluded that psychical strain is able to produce dangerous arrhythmias in patients suffering from coronary heart disease. This danger cannot be proved by bicycle ergometry.
Asunto(s)
Enfermedad Coronaria/fisiopatología , Estrés Fisiológico/fisiopatología , Estrés Psicológico , Complejos Cardíacos Prematuros/etiología , Enfermedad Coronaria/diagnóstico , Electrocardiografía , Fútbol Americano , Humanos , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/fisiopatología , Esfuerzo Físico , Pulso ArterialRESUMEN
380 athletes in optimal performance were examinated within 10 years between 2 and 13 times (average: 4 times): ECG were taken at rest, during breathing tests and under maximal physical load by ergometry. 88 (23.2%) of them showed arrhythmias, 32 in the same examination different forms of premature beats. All kinds of arrhythmias were seen except atrial flatter, total av-block and paroxysmal tachycardias. Breathing tests provoked most of arrhythmias followed by the recovery after maximal physical load. Follow-up studies and clinical examinations proved that in 86 sportsmen these arrhythmias were not a symptom of heart disease. Only in 2 athletes heart injury could not be excluded. But in nearly 50% extracardial inflammations, like tonsillitis, bronchitis etc., were found. It is discussed that bradycardia and vagotonia of the highly trained sportsmen cause the arrhythmias. This vagotonia is intensified by breathing tests. But arrhythmias found in athletes should cause an examination for other chronical sicknesses.
Asunto(s)
Arritmias Cardíacas , Esfuerzo Físico , Medicina Deportiva , Adolescente , Adulto , Arritmias Cardíacas/fisiopatología , Niño , Prueba de Esfuerzo , Femenino , Pruebas de Función Cardíaca , Humanos , MasculinoRESUMEN
Left ventricular contractility of 20 patients, measured by heart catheterization was compared with simultaneously but unbloody registrated pulse wave of A. carotis. Furthermore the crest time of femoralis and dorsalis pedis pulse wave was correlated to ejection time, pulse wave velocity, blood pressure and the length of the arteries between heart and foot of 1112 patients suffering from hypertension, arteriosclerosis, circulatory dysregulation and of 182 healthy sportsmen. The indices of left ventricular contractility: dp/dtmax, dp/dtmax/IP and t-dp/dt correlated highly significant with the time between the onset of the systolic upstroke and the first peak in the carotis pulse wave. No correlation was found with ejection time and the last systolic peak of the carotis pulse. Crest time is always shorter in the pulse wave of the foot arteries than in the femoral artery. The crest time in the femoral- and foot pulse correlates in all groups significantly with ejection time, patients with hypertension have the shortest, patients with arteriosclerosis the longest crest times, the last independent from the ejection time. The time between the start of the systolic upstroke and the first systolic peak in the unbloody registrated carotis pulse wave gives indication to the pressure development in the left ventricle. A long crest time in the peripheral pulse (pulsus tardus) is a typical symptom of generalized arteriosclerosis. The combination of slow pulse wave velocity in the leg and long crest time in the foot arteries (quotient greater than 20.5) indicates a stenosis in the arteries of the leg.
Asunto(s)
Pulso Arterial , Adulto , Arteriopatías Oclusivas/diagnóstico , Arterias , Arteriosclerosis/diagnóstico , Arterias Carótidas , Trastornos Cerebrovasculares/diagnóstico , Enfermedad Coronaria/diagnóstico , Arteria Femoral , Pie/irrigación sanguínea , Humanos , Hipertensión/diagnóstico , Métodos , Persona de Mediana Edad , Contracción MiocárdicaRESUMEN
The period of inability to work after acute myocardial infarction was examined in follow-up studies. Without organized rehabilitation, 7.5% of patients past myocardial infarction returned to work after 6 months. After early mobilization in the hospital and intensive follow-up treatment in a rehabilitation center, 18% of the patients returned to work within 6 months. After the establishment of coronary groups in the vicinity of the patients' homes for the continuation of therapy, the percentage of patients able to return to work within 6 months rose to 42.5%, as shown in a later study. A further study checked the reliability of the rehabilitation clinic's prediction as to the expected date of return to work; only 24% of these predictions were correct. But this percentage rose to 82% after prolonged talks between physician and patient as to the motivation for return to work, modification of the conditions and a detailed report to the local physician.
Asunto(s)
Infarto del Miocardio/rehabilitación , Rehabilitación Vocacional , Adulto , Anciano , Humanos , Persona de Mediana Edad , Factores de TiempoRESUMEN
In 24 obese patients triglycerides, cholesterol, HDL- and LDL-cholesterol were determined repeatedly during a period of starvation up to 21 days, combined with kinesitherapy. The average loss of body weight was after 10 days 6.4 kg and after 21 days 10.5 kg. While the triglycerides decreased only in the first week significantly, cholesterol decreased highly significant in 21 days from an average of 224 mg/dl to an average of 160 mg/dl. LDL-cholesterol was reduced from the 4th to the 21st day of starvation highly significant to an average of 100 mg/dl. On the other hand HDL-cholesterol decreased only in the first days and showed later a tendency to increase. Therefore the quotient LDL/HDL-cholesterol changed from 3.0 to 2.0. It is discussed that starvation diminishes the atherogenic fractions of cholesterol much more than the fractions which may have a protective effect against coronary heart disease.
Asunto(s)
Lípidos/sangre , Obesidad/sangre , Inanición/sangre , Adulto , Colesterol/sangre , Terapia por Ejercicio , Femenino , Humanos , Masculino , Persona de Mediana Edad , Obesidad/terapia , Triglicéridos/sangreRESUMEN
In 25 patients suffering from coronary heart disease with myocardial infarction electrocardiograms were registered continuously during diving and under water swimming. The results are compared to findings in the same patients during bicycle ergometry. Submersion under water produced a highly significant bradycardia and an increase of arrhythmias. During under water swimming heart rate increased less than during 50 Watt ergometry and premature beats were very frequent. It is discussed that the diving bradycardia combined with breath holding provokes the accumulation of arrhythmias. After myocardial infarction patients should not submerge the head under water.
Asunto(s)
Arritmias Cardíacas/etiología , Enfermedad Coronaria/complicaciones , Buceo , Bradicardia/etiología , Complejos Cardíacos Prematuros/etiología , Electrocardiografía , Bloqueo Cardíaco/etiología , Infarto del Miocardio/complicaciones , Infarto del Miocardio/rehabilitación , NataciónRESUMEN
In 51 healthy young people the carotid arterial pulse wave was registered externally during bicycle-exercise in a lying position. The ejection time in relation to the duration of diastole (not pulse period or heart rate!) increased significantly. These results are compared with measurements made by Schulz (15) who found normal ejection times in tachycardia provoked by pacer-stimulation and shortened values during isoproterenol-induced tachycardia. Women have longer ejection times than men especially under physical stress. In 18 patients suffering from aortic insufficiency, ejection times were slightly prolonged and in 28 patients who had a systolic pressure gradient of more than 20 mm Hg between the left ventricle and the aorta ejection times were markedly prolonged. There is also a significant positive correlation between ejection time and pressure gradient. The authors consider that the autonomic innervation plays an important role in the duration of ejection time in normal subjects while in patients with aortic heart disease the ejection time is predominantly influenced by mechanical factors. For the diagnosis of the severity of aortic stenosis measurements of ejection time are only useful in connection with other clinical parameters (pulse pressure, creast time of the arterial pulse wave).
Asunto(s)
Insuficiencia de la Válvula Aórtica/fisiopatología , Contracción Miocárdica , Esfuerzo Físico , Adulto , Femenino , Corazón/fisiología , Corazón/fisiopatología , Humanos , MasculinoRESUMEN
The aim of this study was to demonstrate that modification of the cellular redox-equilibrium occurs as a consequence of antioxidant nutrients intake (carotenoids, vitamine E and vitamine C) and that these nutrients play a role in the pigmentation of the skin without any UV exposure. We conducted a randomized, double-blind study in 20 healthy subjects to evaluate and to compare the efficacy of two mixtures of dietary antioxidants with regard to direct determination of melanin and carotenes by chromametry at selected skin sites and multiple reflection spectrometry from a 1 cm2 region of skin of different parts of the body. Efficacy was assessed by a significant improvement of these parameters, in comparison with measurements performed on the day of randomization, before dietary supplement intake. The formulations per capsule of study dietary supplements are: 13 mg of beta-carotene, 2 mg of lycopene, 5 mg of vitamine E and 30 mg of vitamine C (B13/L2) or 3 mg of beta-carotene, 3 mg of lycopene, 5 mg of vitamine E and 30 mg of vitamine C (B3/L3). A 8-week B13/L2-supplementation lead to a detectable carotenodermia whereas the B3/L3-supplementation not. Signicative increase of melanin concentrations in skin were found after 4, 5, 6 and 8 weeks of dietary antioxidant intake in both groups (p < 0.05). These results are discussed with regard to the redox control theory of melanocytes which regulates the tyrosinase activity.
Asunto(s)
Antioxidantes/administración & dosificación , Ácido Ascórbico/administración & dosificación , Carotenoides/administración & dosificación , Melaninas/metabolismo , Pigmentación de la Piel/efectos de los fármacos , Vitamina E/administración & dosificación , Adulto , Dieta , Método Doble Ciego , Humanos , Persona de Mediana Edad , Piel/metabolismoRESUMEN
In 50 patients with coronary heart disease (CHD), 44 of them with a recent history of myocardial infarction, 2 tests on the bicycle-ergometer in the supine position, one with the crankshaft on the level of the examination cot and one with an elevation of the pedal axle by 30 cm were carried out within 30-minute intervals after initiating a flow directed right heart catheterization. In chronological sequence of the recruitment the patients began the ergometric tests alternately with a low or an elevated crank. The applied exercise loads of 50 and 75 watts lasted 3 minutes each. The results show clinically relevant differences between the 2 positions of the pedal axle, being in many cases statistically significant (p less than or equal to 0.01). The pressure of the pulmonary artery (PAP) was elevated at rest and under exercise load when the pedal axle was elevated. The changes of the pressure of the pulmonary artery through the exercise load are greater in patients with an impaired left ventricular function at rest with both pedal axle positions than in patients with a normal left ventricular function. We observed under increasing exercise load a diverging more pronounced elevation of PAP-curves only as a trend in the group of patients with an impaired left ventricular function. Heart rate and systolic blood pressure were on average likewise higher with the elevated crank then with the low one, however the mean variations were considerable. The oxygen saturation of the blood was somewhat less at rest and during exercise load when the pedal axle was elevated compared to the findings with the low pedal axle. The decrease of the oxygen saturation under exercise load was most pronounced in patients having already at rest an impaired left ventricular function. However, with both positions of the pedal axle the behaviour was identical.
Asunto(s)
Enfermedad Coronaria/fisiopatología , Prueba de Esfuerzo/instrumentación , Hemodinámica , Función Ventricular Izquierda , Adulto , Anciano , Presión Sanguínea , Electrocardiografía , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/fisiopatología , Oxígeno/sangre , Presión Esfenoidal Pulmonar , Posición SupinaRESUMEN
Three and six months after joining the outpatient coronary groups in their area, follow-up studies became possible in 543 patients after their myocardial infarction. The subjective complaints had fallen in this six months, the physical performance measured ergometrically, had distinctly increased. Patients who had joined the coronary group were able to work again significantly earlier. At the time of the.follow-up 5% were pensioners, 76.2% were able to work, 51% fully active at their old workplace.