Challenges during the realization of an international research project on leishmaniasis in Colombia.

Leishmaniasis is an infectious disease that belongs to the top 10 neglected tropical diseases. It mainly affects the poor population from tropical and subtropical areas of the World, which lacks sufficient resources and means to fight against this disease. With this in mind, the European Commission has funded an international collaborative research project in which are participating various institutions from South America, North Africa and Europe. The main objective of this project is the development of a fast, less expensive, non-invasive and easy to use alternative method for leishmaniasis diagnosis in dogs, one of the main reservoirs of leishmaniasis spread to humans. In this perspective article, we present our personal insight and opinion regarding the challenges of realizing a joint international research project on leishmaniasis in Colombia, a country where leishmaniasis is endemic, as well as regarding the involvement of the Public Health institutions and the local population from this country.

Cellular mechanisms linking to outdoor and indoor air pollution damage during pregnancy.

Pregnancies are a critical window period for environmental influences over the mother and the offspring. There is a growing body of evidence associating indoor and outdoor air pollution exposure to adverse pregnancy outcomes such as preterm birth and hypertensive disorders of pregnancy. Particulate matter (PM) could trigger oxi-inflammation and could also reach the placenta leading to placental damage with fetal consequences. The combination of strategies such as risk assessment, advise about risks of environmental exposures to pregnant women, together with nutritional strategies and digital solutions to monitor air quality can be effective in mitigating the effects of air pollution during pregnancy.

Effect of Mg-Gluconate on the Osmotic Fragility of Red Blood Cells, Lipid Peroxidation, and Ca2+-ATPase (PMCA) Activity of Placental Homogenates and Red Blood Cell Ghosts From Salt-Loaded Pregnant Rats.

Preeclampsia (PE) is a pregnancy-specific syndrome with multisystem involvement which leads to fetal, neonatal, and maternal morbidity and mortality. A model of salt-loaded pregnant rats has been previously studied, sharing several pathological characteristics of preeclamptic women. In this study, it was compared the effects of the treatment with an oral magnesium salt, magnesium gluconate (Mg-gluconate), on the osmotic fragility of red blood cells, lipid peroxidation, and PMCA activity of placental homogenates and red blood cell ghosts in salt-loaded pregnant rats. Mg-gluconate has a higher antioxidant capacity than MgSO4 due to the presence of several hydroxyl groups in the two anions of this salt. Salt-loaded pregnant rats received 1.8% NaCl solution ad libitum as a beverage during the last week of pregnancy. On day 22nd of pregnancy, the rats were euthanized and red blood cells and placenta were obtained. Salt-loaded pregnant rats showed an increased level of lipid peroxidation and a lowered PMCA activity in placental and red blood cell ghosts, as well as an increased osmotic fragility of their red blood cells. The treatment of the salt-loaded pregnant rats with Mg-gluconate avoids the rise in the level of lipid peroxidation and the concomitant lowering of the PMCA activity of their red blood cell membranes, reaching values similar to those from control pregnant rats. Also, this treatment prevents the increase of the osmotic fragility of their red blood cells, keeping values similar to those from control pregnant rats. Mg-gluconate seems to be an important candidate for the replacement of the MgSO4 treatment of preeclamptic women.

Effect of magnesium sulfate in oxidized lipid bilayers properties by using molecular dynamics.

Magnesium sulfate (MgSO4) has been used as a protector agent for many diseases related to oxidative stress. The effect of MgSO4 on the oxidized lipid bilayer has not yet been studied using molecular dynamics calculations. In this work, the effects of oxidation were evaluated by using a POPC membrane model at different concentrations of its aldehyde (-CHO) and hydroperoxide (-OOH) derivatives with and without MgSO4. Several quantitative and qualitative properties were evaluated, such as membrane thickness, area per lipid, area compressibility modulus, snapshots after simulation finish, density distributions, time evolutions of oxidized group positions, and radial distributions of oxidized group concerning Mg. Results indicate that in the absence of MgSO4 the mobility of oxidized groups, particularly -CHO, toward the surface interface is high. At a low oxidation level of the bilayer there is an increase in the compressibility modulus as compared to the unoxidized bilayer. MgSO4, at a low oxidation level, tends to lessen the oxidation effects by lowering the dispersion in the distribution of oxidized species toward the membrane surface and the water region. However, MgSO4 does not change the trends of decreasing membrane thickness and area compressibility modulus and increasing area per lipid upon oxidation. In this regard, MgSO4 diminishes the electrostatic long-distance attractive interactions between the oxidized groups and the charged headgroups of the interface, owing to the Mg+2 and SO4 -2 screening effects and an electrostatic stabilization of the headgroups, preventing the pore formation, which is well-known to occur in oxidized membranes.

Metacyclogenesis of Trypanosoma cruzi in B. ferroae (Reduviidae: Triatominae) and feces infectivity under laboratory conditions / Metaciclogénesis de Trypanosoma cruzi en Belminus ferroae (Reduviidae: Triatominae) y capacidad infectiva de las heces en condiciones de laboratorio.

Introduction: Belminus ferroae is a triatominae with entomophagous behavior. However, it may occasionally feed on vertebrates. Currently, there is no evidence of natural infection with Trypanosoma cruzi or the occurrence of metacyclogenesis in this species. Objective: To test T. cruzi metacyclogenesis in B. ferroae and the infectivity of their feces or intestinal contents in rodents under laboratory conditions. Materials and methods: Twenty nymphs of B. ferroae were infected with an autochthonous strain of T. cruzi (M/HOM/VE/09/P6). Fecal and urine samples were collected from spontaneous droppings or by compressing the bugs' abdomens and, eventually, by removing their gut contents, and then examined at 10, 20, 30, 40, 50, and 60 days. We quantified T. cruzi parasitic load, as well as the evolutionary forms in feces, urine, and intestinal contents by Giemsa staining. Similarly, we evaluated the infectivity of T. cruzi metacyclic trypomastigotes in albino mice. Results: The parasitological analysis showed three insects (15%) infected with T. cruzi at 30 (n=1), 40 (n=1), and 50 (n=1) days post-infection. We observed parasitic loads of up to 1.62 x 105 trypanosomes/mm3 and metacyclogenesis percentages between 3.5% and 6.78%. Conclusions: This is the first time that T. cruzi metacyclogenesis is reported in a species of the genus Belminus under laboratory conditions and the infectivity of Belminus' feces is demonstrated on a vertebrate host.

Introducción. Belminus ferroae es un triatomino de comportamiento entomófago, sin embargo, puede alimentarse de vertebrados ocasionalmente. No se ha demostrado infección natural por Trypanosoma cruzi en esta especie, como tampoco la metaciclogénesis del parásito. Objetivo. Examinar la metaciclogénesis de T. cruzi en B. ferroae y la capacidad infectiva de las heces o sus contenidos intestinales en roedores. Materiales y métodos. Se analizaron las heces y la orina expulsadas espontáneamente por los insectos o mediante compresión abdominal o extracción del contenido intestinal a los 10, 20, 30, 40, 50 y 60 días. Se cuantificó la carga parasitaria de T. cruzi y sus formas evolutivas se identificaron con tinción de Giemsa. Asimismo, se evaluó en ratones albinos la apacidad infectiva de los tripomastigotes metacíclicos de T. cruzi obtenidos de las heces o contenidos intestinales de los especímenes infectados. Resultados. El análisis parasitológico reveló tres (15 %) insectos infectados con T. cruzi a los 30 (n=1), 40 (n=1) y 50 (n=1) días después de la infección con cargas parasitarias de hasta 1,62 x 105 tripanosomas/mm3 y porcentajes de metaciclogénesis entre el 3,5 y el 6,78 %. Conclusiones. Se demuestra por primera vez, en una especie del género Belminus, la metaciclogenésis de T. cruzi en condiciones de laboratorio y la capacidad infectiva de las heces para un huésped vertebrado.

Metaciclogénesis de Trypanosoma cruzi en Belminus ferroae (Reduviidae: Triatominae) y capacidad infectiva de las heces en condiciones de laboratorio / Metacyclogenesis of Trypanosoma cruzi in B. ferroae (Reduviidae: Triatominae) and feces infectivity under laboratory conditions

Resumen | Introducción. Belminus ferroae es un triatomino de comportamiento entomófago, sin embargo, puede alimentarse de vertebrados ocasionalmente. No se ha demostrado infección natural por Trypanosoma cruzi en esta especie, como tampoco la metaciclogénesis del parásito. Objetivo. Examinar la metaciclogénesis de T. cruzi en B. ferroae y la capacidad infectiva de las heces o sus contenidos intestinales en roedores. Materiales y métodos. Se analizaron las heces y la orina expulsadas espontáneamente por los insectos o mediante compresión abdominal o extracción del contenido intestinal a los 10, 20, 30, 40, 50 y 60 días. Se cuantificó la carga parasitaria de T. cruzi y sus formas evolutivas se identificaron con tinción de Giemsa. Asimismo, se evaluó en ratones albinos la capacidad infectiva de los tripomastigotes metacíclicos de T. cruzi obtenidos de las heces o contenidos intestinales de los especímenes infectados. Resultados. El análisis parasitológico reveló tres (15 %) insectos infectados con T.cruzi a los 30 (n=1), 40 (n=1) y 50 (n=1) días después de la infección con cargas parasitarias de hasta 1,62 x 105 tripanosomas/mm3 y porcentajes de metaciclogénesis entre el 3,5 y el 6,78 %. Conclusiones. Se demuestra por primera vez, en una especie del género Belminus, la metaciclogenésis de T. cruzi en condiciones de laboratorio y la capacidad infectiva de las heces para un huésped vertebrado.

Abstract | Introduction: Belminus ferroae is a triatominae with entomophagous behavior. However, it may occasionally feed on vertebrates. Currently, there is no evidence of natural infection with Trypanosoma cruzi or the occurrence of metacyclogenesis in this species. Objective: To test T. cruzi metacyclogenesis in B. ferroae and the infectivity of their feces or intestinal contents in rodents under laboratory conditions. Materials and methods: Twenty nymphs of B. ferroae were infected with an autochthonous strain of T. cruzi (M/HOM/VE/09/P6). Fecal and urine samples were collected from spontaneous droppings or by compressing the bugs' abdomens and, eventually, by removing their gut contents, and then examined at 10, 20, 30, 40, 50, and 60 days. We quantified T. cruzi parasitic load, as well as the evolutionary forms in feces, urine, and intestinal contents by Giemsa staining. Similarly, we evaluated the infectivity of T. cruzi metacyclic trypomastigotes in albino mice. Results: The parasitological analysis showed three insects (15%) infected with T. cruzi at 30 (n=1), 40 (n=1), and 50 (n=1) days post-infection. We observed parasitic loads of up to 1.62 x 105 trypanosomes/mm3 and metacyclogenesis percentages between 3.5% and 6.78%. Conclusions: This is the first time that T. cruzi metacyclogenesis is reported in a species of the genus Belminus under laboratory conditions and the infectivity of Belminus' feces is demonstrated on a vertebrate host.

Complex ecological interactions across a focus of cutaneous leishmaniasis in Eastern Colombia: novel description of Leishmania species, hosts and phlebotomine fauna.

This study aimed to analyse the patterns of diversity, blood sources and Leishmania species of phlebotomines in a focus of cutaneous leishmaniasis in Arboledas, Eastern Colombia. In total, 1729 phlebotomines were captured in two localities (62.3% Siravita and 37.7% Cinera) and five environments of Norte de Santander. We identified 18 species of phlebotomines: Pintomyia ovallesi (29.8%), Psychodopygus davisi (20.3%), Pi. spinicrassa (18.5%) and Lutzomyia gomezi (15.8%) showed the highest abundance. Species diversities were compared between Cinera (15.00) and Siravita (20.00) and among five microenvironments: forest remnants (19.49), coffee plantations (12.5), grassland (12.99), cane plantations (11.66) and citrus plantations (12.22). Leishmania DNA was detected in 5.8% (80/1380) of females, corresponding mainly to Pi. ovallesi (22/80; 27.2%), Lu. gomezi (17/80; 21.3%) and Pi. spinicrassa (11/80; 13.8%). Leishmania species were 63.1% L. braziliensis, 18.5% L. panamensis, 13.2% L. infantum and 6.1% L. amazonensis. The most frequent feeding sources were Homo sapiens (50%), Bos taurus (13.8%) and Canis lupus familiaris (10.3%). This focus of cutaneous leishmaniasis has a high diversity of Leishmania-carrying phlebotomines that feed on domestic animals. The transmission of leishmaniasis to human hosts was mainly associated with Lu. gomezi, Pi. ovallesi and L. braziliensis.

Correction to 'Complex ecological interactions across a focus of cutaneous leishmaniasis in Eastern Colombia: novel description of Leishmania species, hosts and phlebotomine fauna'.

[This corrects the article DOI: 10.1098/rsos.200266.].

Oxidative stress: Normal pregnancy versus preeclampsia.

The role of oxidative stress in the physiopathology of human pregnancy is of particular interest. Pregnancy is well-known to increase the oxidative stress, mainly produced by a normal systemic inflammatory response, which results in high amounts of circulating reactive oxygen species (ROS) and reactive nitrogen species (RNS). Both ROS and RNS play an important role as secondary messengers in many intracellular signalling cascades. However, they can also exert critical effects on pathological processes involving the pregnant woman. ROS, RNS and antioxidants establish a balance that determines the oxidation status of animals and humans. This review focuses on the mechanism of oxidative stress in pregnancy as well as its involvement and consequences on the human pregnancy-specific clinical syndrome preeclampsia.

Efectos psicosociales de la cirugía intraocular en una unidad oftalmológica / Psychosocial effects of intraocular surgery in an Ophthalmology Unit

RESUMEN Introducción: como resultado de la elevada incidencia de la baja visión, así como sus consecuencias negativas en la esfera biológica, psicológica y social, los autores tienen en cuenta la escasez de estudios interdisciplinares que recojan los efectos psicosociales de la cirugía intraocular para la mejoría de los pacientes. Presentación del caso: paciente masculino de 20 años de edad, de raza negra, con antecedentes patológicos personales de catarata congénita bilateral, nistagmo horizontal y baja visión; antecedentes patológicos familiares oftalmológicos de catarata congénita por la línea materna. Es remitido desde su área de salud a consulta de baja visión por deterioro progresivo de la visión bilateral. Anteriormente, durante su infancia, el paciente había sido atendido en consulta de baja visión en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer" donde fue rehabilitado, se insertó en el Centro de diagnóstico y orientación donde terminó sus estudios primarios, más tarde el paciente pasó a la enseñanza regular para culminar la secundaria básica. Conclusiones: puede ser un facilitador motivador que hace posible dirigir las acciones que llevan a un estudio en profundidad con respecto a las particularidades de cada uno de los casos.

ABSTRACT Introduction: as a result of the high incidence of low vision, as well as its negative consequences in the biological, psychological and social spheres, the authors take into account the insufficiency of interdisciplinary studies that collect the psychosocial effects of intraocular surgery for the improvement of the patients. Case presentation: 20-year-old black male patient with a personal pathologic history of bilateral congenital cataract, horizontal nystagmus and low vision; family ophthalmologic-pathologic history of congenital cataract through the maternal line. He was referred from his health area to a low vision consultation for progressive deterioration of bilateral vision. Previously, during his childhood, the patient had been treated in low vision consultation at Ramon Pando Ferrer Cuban Institute of Ophthalmology, where he was rehabilitated, inserted in the Diagnostic and Orientation Center where he finished his primary studies, later the patient went on to regular education to complete basic secondary education. Conclusions: it can be a motivational facilitator that makes possible to direct the actions that lead to an in-depth study regarding the particularities of each of the cases.

Osmotic fragility of red blood cells, lipid peroxidation and Ca²âº-ATPase activity of placental homogenates and red blood cell ghosts in salt-loaded pregnant rats.

OBJECTIVE: To evaluate the osmotic fragility of red blood cells and the level of lipid peroxidation, the Ca(2+)-ATPase activity of red cell ghosts and placental homogenates from salt-loaded pregnant rats. METHODS: Salt-loaded pregnant rats received 1.8% NaCl solution ad libitum as a beverage for seven days, starting on 15th day of pregnancy. Then, it was evaluated the level of lipid peroxidation and the Ca(2+)-ATPase activity of placental homogenates and red blood cell ghosts from control and experimental rats. Furthermore, the osmotic fragility of the red blood cells was evaluated by measuring the lysis of these cells when incubated with a NaCl solution with different osmolarities. RESULTS: It was found that placental homogenates and red blood cell ghosts from experimental pregnant rats showed an increased level of lipid peroxidation and a lowered Ca(2+)-ATPase activity, as compared to control pregnant rats. They also presented an increased osmotic fragility of their red blood cells. CONCLUSIONS: Salt-loaded pregnant rats showed, similar to preeclamptic women, an increased level of lipid peroxidation and a lowered Ca(2+)-ATPase activity in placental and red blood cells membranes, as well as an increased osmotic fragility of the red blood cells.

ATPases, ion exchangers and human sperm motility.

Human sperm has several mechanisms to control its ionic milieu, such as the Na,K-ATPase (NKA), the Ca-ATPase of the plasma membrane (PMCA), the Na(+)/Ca(2) (+)-exchanger (NCX) and the Na(+)/H(+)-exchanger (NHE). On the other hand, the dynein-ATPase is the intracellular motor for sperm motility. In this work, we evaluated NKA, PMCA, NHE, NCX and dynein-ATPase activities in human sperm and investigated their correlation with sperm motility. Sperm motility was measured by Computer Assisted Semen Analysis. It was found that the NKA activity is inhibited by ouabain with two Ki (7.9 × 10(-9) and 9.8 × 10(-5) M), which is consistent with the presence of two isoforms of α subunit of the NKA in the sperm plasma membranes (α1 and α4), being α4 more sensitive to ouabain. The decrease in NKA activity is associated with a reduction in sperm motility. In addition, sperm motility was evaluated in the presence of known inhibitors of NHE, PMCA and NCX, such as amiloride, eosin, and KB-R7943, respectively, as well as in the presence of nigericin after incubation with ouabain. Amiloride, eosin and KB-R7943 significantly reduced sperm motility. Nigericin reversed the effect of ouabain and amiloride on sperm motility. Dynein-ATPase activity was inhibited by acidic pH and micromolar concentrations of Ca(2) (+). We explain our results in terms of inhibition of the dynein-ATPase in the presence of higher cytosolic H(+) and Ca(2) (+), and therefore inhibition of sperm motility.

Effect of hypoxia on the calcium and magnesium content, lipid peroxidation level, and Ca²âº-ATPase activity of syncytiotrophoblast plasma membranes from placental explants.

In the current study the possible relationship between the Ca(2+)/Mg(2+) ratio of human syncytiotrophoblast plasma membranes and their lipid peroxidation and Ca(2+)-ATPase activity was determined. Syncytiotrophoblast plasma membranes of placental explants cultured under hypoxia increased their lipid peroxidation and Ca(2+) content, diminished their Ca(2+)-ATPase activity, and kept their Mg(2+) content unchanged. Membranes preincubated with different concentrations of Ca(2+) increased their Ca(2+) content without changes in their Mg(2+) content. There is a direct relationship between Ca(2+) content and lipid peroxidation of the membranes, as well as an inverse relationship between their Ca(2+) content and Ca(2+)-ATPase activity. On the contrary, preincubation of membranes with different concentrations of Mg(2+) showed a higher Mg(2+) content without changing their lipid peroxidation and Ca(2+)-ATPase activity. Explants cultured under hypoxia in the presence of 4 mM MgSO4 showed similar values of lipid peroxidation and Ca(2+)-ATPase activity of their membranes compared to those of explants cultured under normoxia. Increased Ca(2+) content of the membranes by interacting with negatively charged phospholipids could result in destabilizing effects of the membrane structure, exposing hydrocarbon chains of fatty acids to the action of free radicals. Mg(2+) might exert a stabilizing effect of the membranes, avoiding their exposure to free radicals.

Preeclampsia, placenta, oxidative stress, and PMCA.

OBJECTIVE: The aim of this study is to summarize the reported evidence on the possible relationship between preeclampsia, placenta, oxidative stress and plasma membrane Ca-ATPase (PMCA) activity, responsible for fine control of intracellular calcium concentration. METHODS: Literature search was conducted in MEDLINE/PubMed and several unpublished results from our laboratory were included. RESULTS: Lipid peroxidation in placental and red blood cell plasma membranes during preeclampsia and a concomitant diminution of their PMCA activity are described. CONCLUSIONS: Uteroplacental hypoperfusion raises lipid peroxidation by-products in the blood plasma that could alter structure and functionality of the cell membranes of the endothelium and several tissues.

Effect of ultraviolet C irradiation on human sperm motility and lipid peroxidation.

PURPOSE: Ultraviolet C (UVC) irradiation of aqueous solutions is known to be a good source of reactive oxygen species (ROS). The aim of this study is to examine the effect of increasing doses of UVC irradiation, in the presence and absence of the antioxidant butylated hydroxytoluene (BHT), on human sperm motility and lipid peroxidation of its membranes. MATERIALS AND METHODS: Human sperm samples were irradiated with UVC light (254 nm) for different periods of time. A computer-assisted semen analysis of sperm motility was carried out after UV irradiation. The percentage of motile sperm (%MOT), progressive motility, straight line velocity (VSL), curvilinear velocity (VCL) and the percentage of linearity (%LIN) were evaluated. The level of lipid peroxidation of sperm membranes was estimated by measurement of the thiobarbituric acid reactive substances (TBARS). RESULTS: UVC irradiation of human spermatozoa produced a diminution of the sperm motility (%MOT, progressive motility, VSL, VCL, %LIN), viability and, concomitantly, an increase of the level of lipid peroxidation of the sperm membranes. The observed effects of the UVC irradiation were prevented by addition of the antioxidant BHT, indicating that the effects of UVC on the tested sperm parameters are mediated by an important rise in lipid peroxidation of the sperm membrane. CONCLUSION: Lipid peroxidation of the human sperm plasma membrane leads to a decrease in the sperm motility (%MOT, progressive motility, VSL, VCL, %LIN) and viability. The protective effect of BHT on the UVC-irradiated sperm cells indicates the effects of ROS on sperm function.

Effect of magnesium sulfate on the osmotic fragility and lipid peroxidation of intact red blood cells from pregnant women with severe preeclampsia.

OBJECTIVE: To evaluate the osmotic fragility and level of lipid peroxidation of red blood cells from pregnant women with severe preeclampsia, treated or not with MgSO(4). METHODS: Osmotic fragility and lipid peroxidation of red blood cells was evaluated in 11 normotensive pregnant women and eleven pregnant women with severe preeclampsia. RESULTS: MgSO(4) therapy, either in vivo or in vitro, leads to a reduction of the osmotic fragility and the level of lipid peroxidation of red blood cells from pregnant women with severe preeclampsia. CONCLUSIONS: Interaction of MgSO(4) with free radicals, by avoiding an excessive lipid peroxidation of the red blood cell membrane, would protect the membrane structure, avoiding in this way the increase in osmotic fragility.

Trypanosoma evansi: Effect of experimental infection on the osmotic fragility, lipid peroxidation and calcium-ATPase activity of rat red blood cells.

Trypanosoma evansi is the causative agent of equine trypanosomoses. The disease is characterized by fever, anemia, and cachexia. Peroxidative damage of the red blood cells caused by the parasite, may contribute to the pathogenesis of the anemia seen in trypanosomoses. Consequently, we evaluated the hematocrit, the osmotic fragility of the red blood cells, the level of lipid peroxidation and the activity of the Ca-ATPase of red blood cell ghosts from rats experimentally infected with T. evansi. After 72 h inoculation, the hematocrit decreased from 49.5% to 33%; the osmotic fragility of the red blood cells was approximately 40% higher as compared to the healthy animals; and the red blood cell ghosts showed a higher level of lipid peroxidation and a lower Ca-ATPase activity than the red cell ghosts from the healthy animals. In vitro incubations of red blood cells from healthy animals with T. evansi, produced also a significant increase of the osmotic fragility of the red blood cells.

Biochemical identification of dynein-ATPase activity in human sperm.

Dynein-ATPase is the intracellular motor for sperm motility. In the present work we assayed the dynein-ATPase activity in an axoneme-containing fraction of human sperm, free of plasma membranes, in normozoospermic and asthenozoospermic donors. Axoneme-containing fractions were isolated from semen samples obtained from healthy donors with either normozoospermia or asthenozoospermia, as indicated by a sperm motility lower than 50% (WHO grade a + b). The dynein-ATPase activity was assayed and partially characterized. The dynein-ATPase activity in the axoneme-containing fractions was identified as Mg2+-dependent ATPase activity inhibited by 10 microM vanadate. This inhibition was not seen when the assay was done in the presence of 1 mM norepinephrine. The dynein-ATPase activity is Mg2+-dependent, Li+-sensitive, and insensitive to 2 mM ouabain, 1 microM oligomycin, and 1 microM thapsigargin. The dynein-ATPase activity was significantly lower (p < 0.001) for asthenozoospermic donors as compared to normozoospermic donors. This is a straightforward dynein-ATPase assay that can be used to obtain data of functional interest in clinical or experimental settings.

Ca-ATPase activity of human red cell ghosts: preeclampsia, lipid peroxidation and MgSO4.

The increased level of lipid peroxidation of red blood cells during preeclampsia is considered to be responsible for the diminished Ca-ATPase activity in these cells. The level of lipid peroxidation and the Ca-ATPase activity of red blood cells from preeclamptic women, return to their normal values after in vivo and in vitro treatment with MgSO4 for 24 h. In order to evaluate whether or not cell intactness is essential for these changes, we used either intact red blood cells or red cell ghosts from normotensive pregnant women. The intact red blood cells were treated with Fenton's reagent and then incubated with 4 mM MgSO4. The red cells ghosts were irradiated with UV light and afterwards incubated with MgSO4 at 4 degrees C. Lipid peroxidation and Ca-ATPase activity were determined for all the preparations. Both, Fenton's reagent and UV irradiation increased the level of lipid peroxidation and diminished the Ca-ATPase activity of the red cell membranes. Incubation of the cells treated with Fenton's reagent, or the ghosts irradiated with UV, with 4 mM MgSO4, returned Ca-ATPase activity and lipid peroxidation levels to normal values. The presence of MgSO4 blocked the effects in the ghosts of UV irradiation. MgSO4 seems to better protect the red cell membrane against lipid peroxidation than other SO4= and Cl- salts. These results indicate that the changes in the lipid peroxidation of the red cell ghosts and their Ca-ATPase activity are a result of changes to the cell membranes.