Evaluación fotohemolítica in vitro de Cissus sicyoides L y Achyranthes aspera L / In vitro photohemolytic assessment of Cissus sicyoides L y Achyranthes aspera

Los eritrocitos son células útiles para la identificación de agentes potencialmente fototóxicos administrados por vía sistémica, así como para el estudio de los mecanismos de fototoxicidad que involucran procesos de estrés oxidativo. OBJETIVO: evaluar el efecto fotohemolítico de extractos blandos de partes aéreas de Cissus sicyoides L (Vitaceae) y Achyranthes aspera L (Amaranthaceae). MÉTODOS: se utilizó un protocolo in vitro que emplea como modelo biológico eritrocitos humanos, los que se irradian con luz ultravioleta durante 90 min para evaluar el daño en las membranas eritrocitarias, por detección de hemoglobina liberada al medio. RESULTADOS: se observó un leve grado de hemólisis, el efecto fotohemolítico fue inferior a los controles positivos. CONCLUSIONES: los extractos de las plantas se clasificaron como no irritantes, lo cual sugiere que la hemólisis observada puede ser causada por la inestabilidad de la membrana del eritrocito, debido a la presencia de diferentes metabolitos en los extractos estudiados

Erythrocytes are useful cells to identify potentially phototoxic agents provided by systemic administration as well as to study the phototoxicity mechanisms involving oxidative stress processes. OBJECTIVE: to evaluate the photohemolytic effect of soft extracts from aerial parts of Cissus sicyoides L (Vitaceae) and Achyranthes aspera L (Amaranthaceae). METHODS: an in vitro protocol using human erythrocytes as biological model; they were ultraviolet light-radiated for 90 minutes to evaluate damage in erythrocyte membranes on the basis of detected hemoglobin released into the medium. RESULTS: mild hemolysis was observed, being the photohemolytic effect lower than that of positive controls. CONCLUSIONS: the extracts from these plants were rated as non-irritating, which suggests that observed hemolysis may be caused by unstable erythrocyte membranes resulting from the existence of different metabolites in the studied extracts

The effects of 201Tl myocardial perfusion scintigraphy studies on oxidative damage in patients / Efectos de los estudios de escintigrafía de perfusión miocárdica 201Tl sobre el daño oxidativo en los pacientes

The aim of this study was to investigate gamma radiation-induced oxidative damage in erythrocytes after 201Tl myocardial perfusion scintigraphy. Twenty patients (8 women and 12 men) who performed 201Tl myocardial perfusion scintigraphy were included in this study. The blood samples were taken from patients just before, 1 hour after and three hours after injection of the radiopharmaceutical. Malon-dialdehyde (MDA) and antioxidant enzymes such as glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (CAT) levels were measured to evaluate the gamma radiation induced oxidative damage. The enzyme activities of SOD, GPX and CAT were decreased 1 hour after (p = 0.042, p = 0. 697 and p = 0.653 respectively) and 3 hours after (p = 0.003, p = 0. 573 and p = 0.002 respectively) injection of the radiopharmaceutical. Malondialdehyde levels were increased 1 hour after (p = 0.10) and 3 hours after (p = 0.47) injection of the radiopharmaceutical. In this study, we found that radiation due to 201Tl myocardial perfusion scintigraphy decreased the erythrocyte antioxidant levels and increased MDA levels.

El objetivo de este estudio fue investigar el daño oxidativo inducido por radiaciones gamma, sobre los eritrocitos luego de realizada una escintigrafía de perfusión miocárdica 201Tl. Veinte pacientes (8 mujeres y 12 hombres) a quienes se les realizó escintigrafía por perfusión miocárdica 201Tl, fueron incluidos en este estudio. Las muestras de sangre fueron tomadas de los pacientes antes, 1 hora más tarde, y tres horas después de inyectar el radiofármaco. Se midieron los niveles del malondialdehido (MDA) y las enzimas antioxidantes tales como la glutationa peroxidasa (GPX), superóxido dismutasa (SOD), y la catalasa (CAT), a fin de evaluar el daño oxidativo inducido por la radiación gamma. Las actividades de las enzimas SOD, GPX y CAT fueron disminuidas 1 horas después (p = 0.042, p = 0. 697 y p = 0.653 respectivamente) y tres horas (p = 0.003, p = 0. 573 y p = 0.002 respectivamente) tras la inyección del radiofármaco. Los niveles de malondialdehido fueron aumentados 1 hora después (p = 0.10) y tres horas después (p = 0.47) de la inyección del radiofármaco. En este estudio, hallamos que la radiación a causa de la escintigrafía de perfusión miocárdica 201Tl disminuyó los niveles antioxidantes del eritrocito y aumentó los niveles de MDA.

[ effect of extremely low frequency electromagnetic field[50Hz] on induction of chromosomal damages on bone marrow erythrocytes of male Balb/C mouse]

The increasing use of the electromagnetic field producer sets in daily living causes concerns about these waves on human health. The effects of extremely low frequency electromagnetic field [50 Hz] on induction of chromosomal damages on bone marrow erythrocytes of male Balb/C mouse has been investigated in this research. This is an experimental study in which the laboratory system of producing electromagnetic field with low frequency [50 Hz] was used. Five week old male Balb/C mice were divided into three controls, Sham-exposed and experimental groups. The experimental mice exposed were exposed to electromagnetic field [50 gauss] for 4 days [12 hours/day]. After treatment, the chromosomal damages were assessed using micronucleus test in polychromatic erythrocytes and resultant quantity data were analyzed using t and Mann-Whitney test. Results showed that frequency of micronucleated polychromatic erythrocytes of experimental group [14/35 +/- 1/589] was more than Sham-exposed [8/958 +/- 1/049] and control group [7/65 +/- 0/768] significantly [p<0/05]. Extremely low frequency electromagnetic field [50 Hz] causes chromosomal damages induction in polychromatic erythrocytes of bone marrow male Balb/C mouse

Effect of pre-storage gamma irradiation on red blood cells.

BACKGROUND & OBJECTIVE: The irradiation of blood components has received increased attention due to increasing categories of patients eligible to receive such blood to prevent transfusion-associated graft versus host disease. Irradiation leads to enhancement of storage lesions, which could have deleterious effects when such blood is transfused. The aim of the present study was to assess the biochemical changes during conventional preservation of irradiated and non-irradiated whole blood. METHODS: Ten units of whole blood were taken from healthy donors and divided into two parts. One aliquot was subjected to gamma irradiation and then stored under conventional blood banking conditions. Sampling was done from these irradiated and non-irradiated blood bags and tests for free plasma haemoglobin, plasma potassium and lactate dehydrogenase (LDH) were performed. RESULTS: A progressive increase in the mean values of plasma Hb, K+ and LDH was seen in both the groups. The increase was statistically significant. INTERPRETATION & CONCLUSION: Our findings indicated that the gamma irradiation of blood resulted in increased plasma haemoglobin, potassium and LDH. These biochemical changes might not have clinical significance when irradiated blood is transfused to a select group of patients. There is a need for further in vivo studies to follow up the consequences of transfusion of irradiated blood in patients.

role of ultrasound exposure in erythrocytes defense against hemolysis

In the present work, the effect of continuous wave ultrasound with different frequencies and different intensities on erythrocytes defense against hemolysis has been studied. Ultrasound exposure to erythrocytes suspended in saline during hemolysis caused with low different concentrations of HC1, resulted in deceleration of hemolysis relative to control value of HC1. The calculated hemolysis parameter: relative hemolysis rate [H.R][R], showed a critical concentration of KCl below which the hemolysis is decelerated, which means that the ultrasound plays a role in protecting erythrocytes from hemolysis. Also, ultrasound caused some mechanical changes in erythrocytes, and these changes were frequency and intensity dependant

Comparative study of different methods used to isolated Trypanosoma cruzi from defibrinated blood of irradiated mice

Different methods are being used for the isolation and purification of Trypanosoma cruzi blood forms from infected vertebrate hosts. In this study we compare four of these methods (differential centrifugation, Ficoll-Hypaque, Histopaque 1077 and metrizamide) in terms of parasite recovery rates, contamination with cells, duration of the process and role of host irradiation. male albino Swins mice irradiated in a Gamma Cell 220 (500 rads) were inoculated with CL and VL-10 T. cruzi strains and bled at the peak of parasitemia. Infected defibrinated blood was then used for the isolation. Although all methods permitted the recovery of viable trypomastigotes, the best results were obtained with Ficoll-Hypaque and Histopaque 1077. Recovery rates ranged between 71% to 88% and parasite-enriched preparations were obtained in approximately 75 min. irradiation and blood defibrination drastically reduced platelet and leukocyte contamination of the preparations

Cambios inducidos en la actividad antigénica de los hematíes por la luz blanca polarizada / Induced changes in erithrocyte antigenic activity by polarized white light

Poblaciones de eritrocitos obtenidos por punción venosa de dadores sanos fueron irradiados con luz blanca linealmente polarizada hasta niveles de 140J/cm**2 y enfrentados luego con antisueros tipificadores del sistema ABO y con una lectina monoespecífica anti-H. Simultáneamente alícuotas de cada muestra fueron mantenidas, en oscuridad, como testigos y luego enfrentadas con los mismos antisueros y lectinas. Los resultados muestran una significativa activación antigénica de las células, aunque diferenciada de acuerdo al grupo del sistema ABO al que pertenecíam. Esta activación resultó máxima para el grupo A y mínima para el AB