M.E. López-Fernández

Human aging brain disorders: role of antioxidant enzymes.

In order to investigate the role of two free radical detoxificant enzymes in patients with aging brain disorders, superoxide dismutase (SOD) and catalase (CAT) activities have been measured in blood from male and female human patients of different ages with several types of aging brain disorders. When compared with activities in the normal population, we have detected: 1) SOD and CAT activities are decreased in patients with Parkinson disease. 2) SOD activity seems to be normal and CAT activity is decreased in patients with dementia. 3) In the patients with stroke, SOD activity is normal, while CAT activity is decreased. SOD activity was measured in red blood cells using the Minami and Yoshikawa method. CAT activity was measured in hemolysates by the method of Aebi. We can conclude that SOD and CAT activities in patients with Parkinson disease are decreased.

Superoxide dismutase activity in the spanish population

Superoxide dismutase is an enzyme that catalyzes the dismutation of superoxide radicals to hydrogen peroxide and molecular oxygen. This superoxide radical is produced by all aerobic cells as a normal metabolic intermediate of molecular oxygen, and is dangerous for the cell because it induces the inactivation of various enzymes, lipid peroxidation and mutations. Superoxide dismutase can therefore be considered as a protective enzyme. The purpose of this work was to determine the level of superoxide dismutase activity in the Spanish population, and to study the factors that influence this activity. The superoxide dismutase activity of 2397 individuals was determined using the method described by Minami and Yoshikawa. The superoxide dismutase activity level in the adult Spanish population was found to be 4.16±0.89 Units/ml of blood. No significant variations with respect to sex were detected. But it was observed that the superoxide dismutase activity level was 9% higher in the young urban Spanish population.

Determination of oxidative and occupational stress in palliative care workers.

Abstract Background: In previous work, we demonstrated that some occupational workers in stressful conditions can have increases in several markers of oxidative stress when compared to other workers. We investigated two antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT) activities, and malondialdehyde (MDA) concentrations, according to demographics, lifestyle and occupational parameters in palliative care unit workers, and analyzed the relationship with occupational burnout. Methods: Fifty-two palliative care unit workers and 50 gender- and aged matched healthy individuals as controls were surveyed. Spectrophotometric and high-pressure liquid chromatography methods were used for biochemical determinations. Results: No significant variation with respect to gender were detected with respect to SOD and CAT activities, MDA concentrations or occupational burnout. MDA concentrations increased with age in controls and palliative care unit workers, and we observed significant differences in MDA between controls and palliative care unit workers for all age groups. Significant variation in MDA concentrations were detected between unmarried (287.22±8.31 nmol/mg hemoglobin) and married individuals (317.18±6.24 nmol/mg hemoglobin), but not with respect to divorced individuals (288.41±5.64 nmol/mg hemoglobin). Significant differences were detected between smokers and non-smokers for SOD, CAT and MDA, but not for alcohol, coffee, tea or cola consumption. Significant differences were seen in MDA concentrations between those who frequently practice some kind of sport (280.59±7.62 nmol/mg hemoglobin) and those who never practice any kind of sport (299.12±8.09 nmol/mg hemoglobin), and between those who frequently ate fruit and greens (291.05±8.11 nmol/mg hemoglobin) and those who never eat fruit and greens (316.31±7.42 nmol/mg hemoglobin). SOD activity and MDA concentrations are higher in palliative care workers who work the evening and night shifts (p<0.01), and these workers also show significantly higher levels of stress. Conclusions: Our findings suggest that oxidative stress, occupational stress and occupational burnout levels are similar in men and women. Occupational stress increases oxidative stress levels probably as a response to increased generation of reactive oxygen species. Working during the evening and night shifts increases oxidative levels and burnout levels.

Superoxide dismutase activity levels in a Spanish population 50-93 years.

Reports dealing with the free radical theory of aging have focused on the possibility that aging may be accelerated in elderly individuals due to lowering of antioxidant defenses. Accordingly, free radical processes involving oxygen continously damage cells and tissues in the body, leading to degeneration and aging. Scavenging enzymes represent one of the several natural defense mechanisms against free radical‐induced damage. These enzymes include superoxide dismutase. To investigate the role of this enzyme in aging, its activity was measured in 126 individuals 50–93 years of age. Cu/Zn superoxide dismutase (SOD1) was measured in red blood cells using the Minami and Yoshikawa method. The results were compared with those observed in a population between 18 and 65 years of age. SOD1 activity in males remains constant or slightly decreases with age, whereas in females SOD1 activity shows a significant increase in individuals between 68 and 93 years. Am. J. Hum. Biol. 11:45–47, 1999.

Marcadores de estrés oxidativo en el síndrome de Down

Resumen Introduccion El estres oxidativo, generado por un desequilibrio celular entre agentes oxidantes y antioxidantes, puede originar alteraciones celulares, causantes de diversas patologias, y conducir a un envejecimiento prematuro. Objetivo Analizar la actividad de Cu/Zn superoxido dismutasa (Cu/ZnSOD), catalasa (CAT), glutation peroxidasa (GPx) y glutation reductasa (GR) (principal mecanismo de defensa enzimatica frente a la accion nociva de radicales libres y especies reactivas de oxigeno) y los niveles de malondialdehido (MDA), producto final de la peroxidacion lipidica, en individuos con sindrome de Down (SD), con la finalidad de contribuir al conocimiento de un nuevo aspecto de la patologia de este sindrome. Pacientes y metodos Se analizaron 100 individuos con SD (34 varones, 66 mujeres), con edades desde recien nacidos a 29 anos: 90 presentaban trisomia regular del cromosoma 21, 6 presentaban un mosaicismo y 4 presentaban una translocacion robertsoniana. El estudio incluyo tambien un grupo de 100 individuos sin patologias, (40 varones, 60 mujeres) con edades similares a los individuos con SD. En todos se determino: 1) la actividad de los enzimas antioxidantes: Cu/ZnSOD, CAT, GPx, y GR, y 2) los niveles de MDA. Resultados Se observo: a) aumento del estres oxidativo en individuos con SD, causado por exceso de Cu/ZnSOD, que tienden a compensar incrementando la actividad de GPx y CAT; b) altos niveles de peroxidacion lipidica; c) no existen diferencias entre varones y mujeres con SD; d) menor estres oxidativo en individuos con SD por mosaicismo. Conclusion Las celulas trisomicas son mas sensibles al estres oxidativo, sensibilidad que podria deberse al desequilibrio del metabolismo del peroxido de hidrogeno.

Prevalence and significance of HBeAg and isolated anti-HBc in several institutions for the mentally retarded in the autonomous community of madrid

Hepatitis B virus (HBV) surface antigen (HBsAg) and antibody to HBsAg (antiHBs) are excellent markers for HBV infection and its immunity. A total of 414 patients, 312 Down syndrome and 102 non‐Downs syndrome, were studied, and 142 were residents of an institution (RI), whereas 272 were in nonresidential care (NRC). Of the total, 28 (6.8%) were HBsAg positive, and of these, 16 (57.1%) had a positive test for the Hepatitis Be antigen (HBeAg). Proportionately more Down syndrome chronic carriers of HBsAg acquired the persistent Hepatitis Be antigen (HBeAg) than non‐Down syndrome patients 15 (65.2%) vs. 1 (20%). The presence of HBeAg was correlated with abnormal liver function and high titres of HBsAg. Testing for the IgM antibody to the hepatitis B core antigen (IgM AntiHBc) facilitated the identification of acute and chronic hepatitis infection in both RI and NRC individuals. The significance of isolated antiHBc seropositivity in Down syndrome patients remains unclear. It is not certain whether the isolated antiHBc seropositivity represents chronic “low levels” of HBV, past infection, or false‐positive tests, and whether this test should be employed as a vaccine screening test. Am. J. Hum. Biol. 9:29–33

PREVALENCE OF HEPATITIS B VIRUS MARKERS IN SEVERAL INSTITUTIONS FOR THE MENTALLY HANDICAPPED IN THE AUTONOMOUS COMMUNITY OF MADRID

In order to determine the prevalence of hepatitis B virus (HBV) markers, 400 patients were studied: 134 residents of an institution (RI) for the mentally retarded and 266 under non‐residential care (NRC). In the residential institutions, all markers were absent in 69 (65.7%) of 105 patients with Down syndrome and 20 (69.0%) of 29 clients without Down syndrome. In the NRC clients, 167 (85.6%) of 195 patients with Down syndrome and 65 (91.5%) of 71 clients with other mental defects (psychologically and physically handicapped, autism) had negative tests for HBV markers. The prevalence of the hepatitis B surface antigen (HBsAg) was higher in institutionalized mentally retarded (RI) and older patients (21+ years). Examination of 195 Down patients revealed a higher frequency (1.4 times) of surface antigen carriers as strictly matched non‐Down syndrome cases (point prevalences 14.2% and 10.3%, respectively). The higher prevalence in affected cases appears to be primarily associated with a longer persistence of antigenemia. Results related to the sex of the patients were less clear. Neither affected nor non‐affected patients showed significant differences in prevalence among males and females.