Fire and burn severity assessment: Calibration of Relative Differenced Normalized Burn Ratio (RdNBR) with field data.

The assessment of burn severity is highly important in order to describe and measure the effects of fire on vegetation, wildlife habitat and soils. The estimation of burn severity based on remote sensing is a powerful tool that, to be useful, needs to be related and validated with field data. The present paper explores the relationships between field accessible variables and Relative Differenced Normalized Burn Ratio (RdNBR) index by using linear mixed-effects models and boosted regression trees, based on data from 28 large fires and 668 field measurements across three countries in southern Europe. The RdNBR clearly reflected the mean height of charred stem and loss of ligneous, living shrub and tree cover during the fire. The paper confirms that remote sensing indices provide an acceptable assessment of fire induced impact on forest vegetation but also highlights there are important between-fire variations due to specific contexts that modify these relationships. These variations can be effectively assessed and should be taken into account in future predictive efforts.

Oxidative stress, thyroid dysfunction & Down syndrome.

Down syndrome (DS) is one of the most common chromosomal disorders, occurring in one out of 700-1000 live births, and the most common cause of mental retardation. Thyroid dysfunction is the most typical endocrine abnormality in patients with DS. It is well known that thyroid dysfunction is highly prevalent in children and adults with DS and that both hypothyroidism and hyperthyroidism are more common in patients with DS than in the general population. Increasing evidence has shown that DS individuals are under unusual increased oxidative stress, which may be involved in the higher prevalence and severity of a number of pathologies associated with the syndrome, as well as the accelerated ageing observed in these individuals. The gene for Cu/Zn superoxide dismutase (SOD1) is coded on chromosome 21 and it is overexpressed (~50%) resulting in an increase of reactive oxygen species (ROS) due to overproduction of hydrogen peroxide (H 2 O 2 ). ROS leads to oxidative damage of DNA, proteins and lipids, therefore, oxidative stress may play an important role in the pathogenesis of DS.

Types and characteristics of drinking water for hydration in the elderly.

The role of hydration in the maintenance of health is increasingly recognized. Hydration requirements vary for each person, depending on physical activity, environmental conditions, dietary patterns, alcohol intake, health problems, and age. Elderly individuals have higher risk of developing dehydration than adults. Diminution of liquid intake and increase in liquid losses are both involved in causing dehydration in the elderly. The water used for drinking is provided through regular public water supply and the official sanitary controls ensure their quality and hygiene, granting a range of variation for most of its physical and chemical characteristics, being sometimes these differences, though apparently small, responsible for some disorders in sensitive individuals. Hence, the advantages of using bottled water, either natural mineral water or spring water, are required by law to specify their composition, their major components, and other specific parameters. It is essential to take this into account to understand the diversity of indications and favorable effects on health that certain waters can offer.

El ejercicio físico disminuye el estrés laboral y oxidativo en profesionales de Urgencias / Physical exercise reduces occupational and oxidative stress in Emergency Department staff

Fundamento. Situaciones estresantes conducen a la formación de un exceso de radicales libres, que constituyen la mayor amenaza para la homeostasis celular de organismos aerobios. El burnout es un síndrome de estrés crónico laboral. Objetivos. 1. Determinar tanto el estrés oxidativo como el estrés laboral al que se encuentran sometidos profesionales sanitarios de un servicio de urgencias. 2. Analizar la influencia que la práctica de ejercicio físico puede ejercer tanto sobre el estrés oxidativo como sobre el estrés laboral de estos profesionales. Material y métodos. Se han analizado 70 profesionales de un servicio de urgencias hospitalarias y un grupo control de 80 individuos sanos y edades similares. En todos se determinó la actividad de superóxido dismutasa (SOD) y catalasa (CAT), los niveles de malondialdehído (MDA) y del burnout y sus componentes. Resultados. No se han observado diferencias significativas entre varones y mujeres ni en la actividad de SOD y CAT, ni en los niveles de MDA ni en los niveles del burnout. Los niveles de MDA aumentan con la edad en profesionales sanitarios y en el grupo control, con diferencias significativas entre distintos grupos de edad. El estado civil no influye en las variables analizadas. Conclusiones. La peroxidación lipídica y el estrés laboral (niveles de burnout) disminuyen con la práctica de ejercicio físico, siendo los niveles más bajos para los que hacen ejercicio diariamente. Hacer deporte habitualmente, sobre todo cuando no es agotador, resulta una práctica beneficiosa para la prevención tanto del estrés oxidativo como del estrés laboral (AU)

Background. Stressful conditions lead to the formation of excessive free radicals which represents the greatest threat to cellular homeostasis of aerobic organisms. Burnout is a syndrome of chronic occupational stress. Objectives. This work focuses on the determination of both oxidative stress and occupational stress in a medical emergency service staff, and to analyze the effect that performing physical exercise can have on oxidative and occupational stress in these professionals. Material and methods. The study sample consisted of 70 professionals working in a medical emergency service and a control group of 80 age-matched healthy individuals. Superoxide dismutase (SOD) and catalase (CAT) activities, and malondialdehyde (MDA) were determined, as well as burnout with its components. Results. No significant variations were observed in SOD, CAT, MDA, or burnout levels as regards to gender. MDA levels increased with age in both the medical emergency service staff and the control group, with significant differences between the medical emergency service staff and the control group for all age groups. Marital status does not influence the variables analyzed. Conclusions. Lipid peroxidation and occupational stress (burnout levels) decrease with physical exercise, being lower levels for those who practice it daily. Playing sports regularly, especially when it is not exhausting, is a beneficial practice for preventing both oxidative stress and occupational stress (AU)

Biomarkers of age effect on renal function in Down syndrome.

OBJECTIVE: To assess differences in kidney function between Down syndrome (DS) individuals and a control group related to aging. METHODS: Creatinine (Cr) and specific gravity (SG) were assessed by spectrophotometric and refractometric assays in urine samples of 103 individuals with DS and 82 age-matched controls. RESULTS: Significantly lower levels of Cr and SG were found in DS after puberty. Significant correlations were found between SG and age as well as between Cr and SG in DS and controls (p ≤ 0.05). CONCLUSIONS: Premature aging in kidneys of DS patients could lead to an impaired renal function.

Evaluation of urinary biomarkers of oxidative/nitrosative stress in children with Down syndrome.

AIMS: It has been suggested that oxidative stress plays a key role in the pathogenesis of Down syndrome (DS). However, urinary biomarkers of oxidative stress have been little studied in this condition. Thus, we aimed to assess a set of urinary oxidative/nitrosative stress biomarkers in children with DS, with and without hypothyroidism, which comprise: 8-hydroxy-2'-deoxyguanosine (8-OHdG), isoprostane 15-F(2t)-IsoP, thiobarbituric acid-reacting substances (TBARS), advanced glycation end products (AGEs), dityrosine (diTyr), hydrogen peroxide (H(2)O(2)) and nitrite/nitrate (NOx). MAIN METHODS: Fluorimetric and spectrophotometric assays were performed in children with DS (n=26), some of them taking levothyroxine for hypothyroidism (n=7), and their non-Down siblings (n=19). KEY FINDINGS: We found that only levels of diTyr were increased in DS, although no differences were obtained when hypothyroid DS children were excluded. Levels of 8-OHdG, 15-F(2t)-IsoP, TBARS, AGEs, H(2)O(2) and NOx did not differ neither between DS and controls nor between hypothyroid DS children and DS without hypothyroidism diagnosed. However, diTyr is increased in hypothyroid DS children compared with controls. Negative correlations with age were obtained for 8-OHdG, diTyr and NOx in DS and controls and for 8-OHdG, 15-F(2t)-IsoP, TBARS and AGEs in DS. SIGNIFICANCE: Increased oxidative stress in children with DS cannot be explained by the urinary levels of 8-OHdG, 15-F(2t)-IsoP, TBARS, AGEs, diTyr, H(2)O(2) and NOx, at least with the assays used. Nonetheless, urinary diTyr could be used as oxidative/nitrosative stress biomarker in hypothyroid DS children. The present work presents evidence of a probable renal impairment in children with DS receiving levothyroxine for hypothyroidism.

Neoadjuvant intraperitoneal chemotherapy with paclitaxel for the radical surgical treatment of peritoneal carcinomatosis in ovarian cancer: a prospective pilot study.

PURPOSE: The admitted benefits of intraperitoneal chemotherapy during postoperative administration for the treatment of peritoneal carcinomatosis from ovarian origin are limited by their associated morbidity and restricted diffusion by the presence of multiple intra-abdominal adherences. The purpose of the study was to evaluate the security, effectiveness, and cytoreduction optimization of intraperitoneal paclitaxel administration previously to radical surgery/peritonectomy/HIPEC (hyperthermic intraoperative intraperitoneal chemotherapy) either in monotherapy or combined with intravenous carboplatin. METHODS: Prospective pilot study of 10 patients with ovarian peritoneal carcinomatosis in stage IIIc-FIGO without previous treatment. After staging of the diseases by laparoscopy, five patients received paclitaxel by weekly intraperitoneal administration (60 mg/m(2), 10 cycles), and other five patients additionally received intravenous carboplatin every 21 days (AUC 6, 4 cycles). Subsequently radical surgery/peritonectomy with HIPEC was performed. RESULTS: The presence of moderate abdominal pain was the most common (70%) side effect associated with neoadjuvant paclitaxel intraperitoneal administration. The intravenous carboplatin administration was not associated with significant increase in adverse effects. It boosted intraperitoneal paclitaxel-associated antitumoral activity with a high average decrease in Index Cancer Peritoneal (21.2 vs. 14.4, P = 0.066) and CA 125(1,053 vs. 346, P = 0.043). All the patients who received combined neoadjuvant chemotherapy obtained R0 cytoreduction. Five-year overall survival was 62%. CONCLUSIONS: The intraperitoneal paclitaxel weekly administration combined with intravenous carboplatin administration prior to radical surgery/peritonectomy with HIPEC is a safe and effective option in the treatment of ovarian peritoneal carcinomatosis. This study shows the possibility to investigate other forms of intraperitoneal chemotherapy and their combinations thoroughly.

Urinary biomarkers of oxidative/nitrosative stress in healthy smokers.

OBJECTIVE: To evaluate the effect of cigarette smoking on oxidative and nitrosative stress, we assessed urinary levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), isoprostane 15-F(2t)-IsoP, thiobarbituric acid-reacting substances (TBARS), advanced glycation end-products (AGEs), dityrosine (diTyr), hydrogen peroxide, total nitrite and nitrate and trolox equivalent antioxidant capacity (TEAC) in healthy smokers. METHODS: Fluorimetric and spectrophotometric assays were performed in urine samples of 33 healthy smokers and 58 age-matched controls. RESULTS: Levels of 8-OHdG, 15-F(2t)-IsoP and AGES were found significantly higher in smokers than in controls (10.7 ng/mg Cr vs. 8.3 ng/mg Cr, 1.41 ng/mg Cr vs. 1.01 ng/mg Cr and 189 AFU/mg Cr vs. 143 AFU/mg Cr, respectively; P < 0.05 for all). Positive correlations were found between age and levels of AGEs and diTyr in smokers (r = 0.380, P < 0.035 and r = 0.418, P < 0.019, respectively) and also between age and AGEs, diTyr and TEAC in controls (r = 0.474, P < 0.001, r = 0.463, P < 0.001 and r = 0.576, P < 0.001, respectively), being this correlation negative for 8-OHdG in controls (r = -0.295, P = 0.041). Positive correlation between the number of cigarettes smoked per day and AGEs was also found (r = 0.355, P = 0.044). CONCLUSION: Urinary 8-OHdG, 15-F(2t)-IsoP and AGEs may represent a non-invasive quantitative index of oxidant stress in healthy smokers, being AGEs a possible indicator of tobacco toxin exposure. The increased oxidative stress in healthy smokers observed may be generated because of an excessive production of reactive oxygen species and not by exhaustion of antioxidant defenses.

Evaluation of urinary biomarkers of oxidative/nitrosative stress in adolescents and adults with Down syndrome.

Urinary biomarkers of oxidative stress have been little studied in adults with Down syndrome (DS), usually no more than two biomarkers have been measured in the population studied and controversial results are reported in literature. Thus, we aimed to assess a set of oxidative and nitrosative stress biomarkers in urine samples of adolescents and adults with DS, with and without hypothyroidism, which comprise: 8-hydroxy-2'-deoxyguanosine (8-OHdG), isoprostane 15-F(2t)-IsoP, thiobarbituric acid-reacting substances (TBARS), advanced glycation end products (AGEs), dityrosine (diTyr), hydrogen peroxide (H(2)O(2)) and nitrite/nitrate (NOx). Fluorimetric and spectrophotometric assays were performed in DS (n=78), some of them taking levothyroxine for hypothyroidism (n=24), and in their healthy age-matched controls (n=65). We found that levels of AGEs, diTyr, H(2)O(2) and NOx are increased in DS patients in any or in all age groups, whereas Cr levels were lower in DS than in controls in all age groups. Besides, correlations with age in DS were positive for diTyr and negative for Cr, TBARS, 15-F(2t)-IsoP and NOx. We also found lower levels of Cr from 15 to 19years, higher levels of TBARS and AGEs from 20 to 40years and higher levels of diTyr from 15 to 40years in DS patients receiving levothyroxine than in DS without hypothyroidism diagnosed. We conclude that AGEs, diTyr, H(2)O(2) and NOx could be used as oxidative stress biomarkers in DS in contrast to 8-OHdG, 15-F(2t)-IsoP and TBARS, at least with the methods used. However, renal impairment could occur in DS and Cr adjustment may bias the results, particularly in hypothyroid patients.

Determination of oxidative and occupational stress in palliative care workers.

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.

Urinary uric acid and antioxidant capacity in children and adults with Down syndrome.

OBJECTIVES: To evaluate the urinary levels of uric acid (UA) and total antioxidant capacity (TAC) with and without UA relative contribution (TAC(-UA)) in children and adults with Down syndrome (DS) and to prove the clinical use of TAC. DESIGN AND METHODS: Urine samples were obtained from 32 individuals with DS and 29 controls. Two age groups were established (children and adults). Spectrophotometric methods were used for biochemical determinations. RESULTS: Children with DS had significantly higher UA/Cr and TAC/Cr levels than controls, whereas levels of TAC(-UA)/Cr were lower in adults with DS than in controls (P<0.05 for all). In DS, levels of UA/Cr, TAC/Cr and TAC(-UA)/Cr were higher in children than in adults (P<0.05 for all). Positive correlations between UA/Cr and TAC/Cr were found for all groups studied. Negative correlations with age were found for UA/Cr and TAC/Cr in children of both groups. CONCLUSIONS: Our results proved that TAC is decreased in adults with DS. Besides, TAC(-UA) seems to provide more reliable information about the antioxidant status, at least in DS.

The role of hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC) in the treatment of peritoneal carcinomatosis in recurrent ovarian cancer.

BACKGROUND AND OBJECTIVES: Peritoneal carcinomatosis in women frequently has an ovarian origin. Hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC) along with radical surgery/peritonectomy could present a new therapeutic approach with curative intention. The purpose of this research is to evaluate the role of the administration of HIPEC. METHODS: A series of patients (N=26) diagnosed with peritoneal carcinomatosis for recurrent epithelial ovarian cancer (stage III) from January 1997 to December 2004 submitted to radical surgery/peritonectomy with optimal cytoreduction (R0-R1) were included in this study, 14 treated with HIPEC and 12 without HIPEC. RESULTS: The variables age, histologic type, peritonectomy procedures, peritoneal cancer index (PCI) and lymph node affectation were similar in both groups. The 5-year global survival was 58% and 17% (p=0.046), and 67% and 29% in patients with maximal cytoreduction (R0) (p=0.264), in the HIPEC- and non-HIPEC-treated patients, respectively. In patients with optimal cytoreduction and partial peritonectomy, 5-year global survival was also superior in the HIPEC group (75% vs. 11%, p=0.011). Average time free of disease was superior in the HIPEC group (48+/-42 vs. 24+/-21 months), with less reinterventions due to a new reappearance during the first three evolutionary years (2/14 vs. 4/12). Postoperative morbidity did not show substantial differences in both groups and there was no surgical mortality. CONCLUSIONS: HIPEC is a complement to radical surgery/ peritonectomy, which has been shown to be a surgical procedure with high tolerability, low morbimortality, enhanced survival and prolonged disease-free interval in patients with peritoneal carcinomatosis for recurrent ovarian cancer.

Evaluation of the copper(II) reduction assay using bathocuproinedisulfonic acid disodium salt for the total antioxidant capacity assessment: the CUPRAC-BCS assay.

There is heightened interest in determining antioxidant status of individuals in experimental and clinical studies investigating progression of diseases or diverse aspects of oxidative stress, among others. The aim of this study was to evaluate the copper(II) reduction assay with bathocuproinedisulfonic acid disodium salt as chelating agent (the CUPRAC-BCS assay) for the total antioxidant capacity (TAC) assessment in human plasma and urine. Samples from 20 individuals were determined with four spectrophotometric assays-CUPRAC-BCS, ferric reducing ability of plasma (FRAP), trolox equivalent antioxidant capacity (TEAC), and 1,1-diphenyl-2-picrylhydrazyl assay (DPPH)-to compare these methods. CUPRAC-BCS was significantly correlated with FRAP and TEAC for plasma and urine samples (r>0.5, P<0.05 for all) and with DPPH for urine samples (r=0.925, P<0.001) but not with DPPH for plasma samples (r=0.366, P=0.112). However, the four methods do not agree given that lines of equality and regression were not matched up. The imprecision of the method is less than 6%, the detection limit is 41.8 micromol trolox equivalents/L, it is linear up to 2 mM trolox, and ethylenediaminetetraacetic acid dihydrate disodium salt (EDTA) binds to Cu(II), avoiding the formation of Cu(I)-BCS complex. This study shows that CUPRAC-BCS is a simple, fast, inexpensive, and suitable method for TAC assessment in human urine and heparinized plasma samples.

Relationship between oxidative and occupational stress and aging in nurses of an intensive care unit.

Stressful conditions lead to formation of excessive reactive oxygen species (ROS) and cause oxidative stress and aging. The aim of this study was to determine superoxide dismutase (SOD) and catalase (CAT) activity, and malondialdehyde (MDA) levels in nurses of a hospital intensive care unit according to demographic and occupational parameters, and to analyse the relationship with aging. Thirty-two nurses working in an intensive care unit and 35 aged-matched healthy individuals of both sexes as a control group were surveyed. No significant variations with respect to sex were detected in SOD, CAT, MDA and burnout levels. MDA levels increased with age in both the control group and the nurses, and we observed significant differences in MDA levels between the control group and nurses for all age groups. Significant variations in MDA levels were detected between single (286.12 +/- 8.41) and married (318.82 +/- 6.02), people, between those who frequently practice some kind of sport (281.41 +/- 7.32) and those who never participate in sport (298.24 +/- 8.11) ,and between those who frequently eat fruit and greens (289.75 +/- 8.41) and those who never eat them (315.12 +/- 7.21). Significant differences were detected between smokers and nonsmokers in SOD, CAT and MDA, but not for alcohol, coffee, tea or cola consumption. Higher SOD activity and MDA levels were detected in nurses on evening and night shifts (P < 0.01); these nurses also scored significantly higher on burnout subscales. These results suggest that: (1) occupational stress increases oxidative stress levels as a response to elevated ROS generation; (2) occupational stress increases MDA levels as a response to an elevation in free radical generation and can lead to aging; (3) working evening and night shifts increases oxidative and burnout levels. It is evident that preventive changes in job conditions and lifestyle are necessary to improve the quality of life of nurses who work in intensive care units.

Lipid peroxidation and antioxidant enzyme activities in vascular and Alzheimer dementias.

It has been reported that oxidative stress may play a role in the pathogenesis of dementia of the Alzheimer type (AD) and the cerebral ischemia which causes vascular dementia (VD). We measured malondialdehyde (MDA) levels and superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) activities in blood samples from patients with AD and VD and in healthy non-demented controls (CTR) which similar ages to the patients, in order to evaluate the degree of oxidative stress in patients with AD and VD. A sample of 150 subjects consisting of 50 patients with AD; 50 patients with VD and 50 CTR, aged from 65 to 85 years on, was analyzed. Most of the changes observed were in SOD activity and MDA levels. Catalase activity were least affected. Significant differences were observed in SOD and GR activity between males and females in CRT and in patients with AD, but not in VD. We have found a decrease in antioxidant enzymes activities (SOD, CAT, GPx and GR) in patients with AD and VD and significant differences were observed between CRT and AD patients for ages from 65 to 74, 75 to 84 and from 85 years to 94 years in SOD activity and MDA levels (P < 0.001). MDA levels increase with age in VD, AD and CTR. No significant variation with respect to sex were detected, but significant variations in MDA levels were detected between CRT and patients with VD and AD (P < 0.001). We conclude that oxidative stress plays an important role in the brain damage for both AD and VD, being observed higher levels of oxidative stress for AD that for VD.

Copper/zinc superoxide dismutase activity in newborns & young people in Spain.

BACKGROUND & OBJECTIVE: There is evidence that reactive oxygen species (ROS) plays an important role in the pathophysiology of many paediatric disorders. We carried out this study to see whether superoxide dismutase (SOD) activity was associated with age, sex and rural or urban status in three groups of Spanish people (newborns, children and young). METHODS: SOD activity was measured in red blood cells in newborns, children and young Spanish people (n=1212, divided in six groups) using the Minami and Yoshikawa method. RESULTS: The newborns had high levels of SOD activity, but among all age groups studied, SOD showed the highest activity in groups 1 and 2. We also observed that this activity decreased gradually with age until achieving adult levels. No significant variations with respect to sex were detected, except for the >or=14 to 18 yr age group, in which SOD activity decreased significantly in females. INTERPRETATION & CONCLUSION: Our findings show that SOD activity in newborns, children and young Spanish people is affected by age but not by gender (except from >or=14-18 yr) or rural or urban status.

Lipid peroxidation in Down syndrome caused by regular trisomy 21, trisomy 21 by Robertsonian translocation and mosaic trisomy 21.

BACKGROUND: It has been suggested that an increase in oxidative stress in individuals with Down syndrome (DS) may cause adverse effects in the cell membranes through the oxidation of polyunsatured fatty acids. METHODS: We examined erythrocyte malondialdehyde (MDA) levels in 100 individuals of both sexes (34 males and 66 females) with DS, aged from newborn to 29 years. The cytogenetic analysis revealed 90 individuals with regular trisomy 21, four individuals with trisomy 21 by Robertsonian (Rb) translocation, and six individuals with mosaic trisomy 21. DS individuals were divided into six age groups. The control group consisted of 100 healthy individuals of both sexes (40 males and 60 females) who were age-matched with DS subjects. RESULTS: No significant differences were found in erythrocyte MDA levels between the sexes in any of the age groups for the DS group and the control group. We confirmed significantly higher erythrocyte levels of MDA in individuals with DS compared to the control group. A significant difference was observed in erythrocyte MDA levels between DS individuals with trisomy and controls for all age groups, and in individuals with DS due to Rb translocation trisomy. However, in DS individuals with mosaicism, MDA levels depended on the percentage of diploid and trisomy cells. CONCLUSIONS: Our results confirm an increase in lipid peroxidation in patients with DS.

La eliminación urinaria de productos de lipoperoxidación depende de un ritmo biológico anual / Annual rhythm of urinary excretion of lipoperoxidation products

Introducción: existen numerosos rasgos biológicos ligados a ritmos diarios, anuales o estacionales. Uno de estos rasgos podría ser la producción y eliminación urinaria de productos de lipoperoxidación (sustancias reactivas al ácido tiobarbitúrico [TBARS]) eliminados por orina que son modificados por la crenoterapia con diferentes aguas mineromedicinales. El objetivo del presente artículo es analizar si la eliminación urinaria de TBARS depende de la época del año en que se determina. Material y métodos: se han obtenido muestras de orina de 230 voluntarios del Programa de Termalismo Social del IMSERSO (edad 52-81 años), 115 varones y 115 mujeres que se adscribieron a 2 balnearios diferentes en 6 épocas distintas del año: 110 al primero y 120 al segundo. A la llegada al balneario se determinó la concentración de TBARS mediante espectrofotometría; paralelamente se realizó a los pacientes historia clínica que incluyó registros de la presión arterial. Resultados: la media de eliminación total de TBARS a la llegada al balneario en la población del primero fue de 0,418 ± 0,025 nmol/mg de creatinina; en la segunda fue de 0,368 ± 0,01 nmol/mg de creatinina. Una de las posibles razones de los diferentes valores de ambas poblaciones, con un máximo de excreción urinaria en julio y un mínimo en noviembre, fue el hecho de que las determinaciones se realizaron en diferentes meses del año en ambas poblaciones. Conclusión: este estudio muestra que las tasas de eliminación de productos de lipoperoxidación siguen un ritmo anual

Introduction: many biological features are linked to daily, annual, or seasonal rhythms. One of these features could be the production and urinary excretion of lipoperoxidation products (TBARS), which are modified by crenotherapy with different mineromedicinal waters. The objective of the present article was to analyse whether urinary excretion of TBARS depends on the time of the year in which it is determined. Material and methods: urinary samples were obtained from 230 volunteers from the Social Thermalism Program of the Institute for the Elderly and Social Services (Instituto de Mayores y Servicios Sociales [IMSERSO]). There were 115 men and 115 women (aged 52-81years) who where assigned to two different spas at six different times of the year: 110 were assigned to the first spa and 120 to the second. TBARS concentration was determined on arrival at the spa by means of spectrophotometry; a clinical history was also taken, including blood pressure measurement. Results: the mean total TBARS excretion on arrival was 0.418 ± 0.025 nmol/mg of creatinine for the population from the first spa and 0.368 ± 0.01 nmol/mg of creatinine for the second. One of the reasons why these values differed between the two populations was that they were determined in different months of the year, showing a maximum excretion in July and a minimum in November. Conclusion: this study shows that excretion rates of lipid peroxidation products follows an annual rhythm

Lipid peroxidation, occupational stress and aging in workers of a prehospital emergency service.

BACKGROUND: Stressful conditions lead to formation of excessive free radicals, and lipid peroxidation is one of the major outcomes of free radical-mediated injury that directly damages membranes and generates a number of secondary products. OBJECTIVES: To determine the levels of malondialdehyde, an end product of lipid peroxidation, according to demographic and occupational variables in workers of a prehospital emergency service and to analyse the relationship between malondialdehyde levels and burnout. MATERIAL AND METHODS: One hundred and eleven healthy workers of a prehospital emergency service and eighty aged-matched healthy individuals of both sexes as a control group were surveyed. Malondialdehyde levels were measured by the Bull and Marnett method. To measure burnout, the Maslach Burnout Inventory was used. RESULTS: Professional category is associated with lipid peroxidation and burnout levels (Malondialdehyde levels were: physicians 338.10+/-14.47, nurses 329.17+/-12.62 and technicians 296.74+/-14.28; burnout levels were: physicians 41.29+/-3.59, nurses 37.38+/-6.05 and technicians 35.33+/-5.87). Working at night and in the evening increased malondialdehyde and burnout levels. Malondialdehyde levels increase with age. No significant variations with respect to sex were detected. Significant variations in malondialdehyde levels were detected between singles (303.13+/-12.74) and married people (344.43+/-13.43) but not with respect to divorcees (326.44+/-11.74). Significant differences were detected in erythrocyte malondialdehyde levels between smokers (341.37+/-17.09) and nonsmokers (302.21+/-12.38), but not for alcohol consumption. CONCLUSIONS: These findings suggest a positive correlation between malondialdehyde, a biomarker of lipid peroxidation and occupational stress, as estimated by elements of the Maslach Burnout Inventory, and oxidative stress.