Dolphin leukocytes exhibit an attenuated cytokine response and increase heme oxygenase activity upon exposure to lipopolysaccharides.

Cetaceans exhibit physiological adaptations that allowed the transition to aquatic life, including a robust antioxidant defense system that prevents injury from repeated exposure to ischemia/reperfusion events associated with breath-hold diving. The signaling cascades that characterize ischemic inflammation in humans are well characterized. In contrast, cetaceans' molecular and biochemical mechanisms that confer tolerance to inflammatory events are poorly understood. Heme oxygenase (HO) is a cytoprotective protein with anti-inflammatory properties. HO catalyzes the first step in the oxidative degradation of heme. The inducible HO-1 isoform is regulated by various stimuli, including hypoxia, oxidant stress, and inflammatory cytokines. The objective of this study was to compare the response of HO-1 and cytokines to a proinflammatory challenge in leukocytes isolated from humans and bottlenose dolphins (Tursiops truncatus). We measured changes in HO activity, and abundance and expression of interleukin 1 beta (IL-1ß), interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), and heme oxygenase 1 (HMOX1) in leukocytes treated with lipopolysaccharide (LPS) for 24 and 48 h. HO activity increased (p < 0.05) in dolphin (48 h) but not human cells. TNF-α expression increased in human (24 h, 48 h), but not dolphin cells following LPS stimulation. LPS-induced cytokine expression was lower in dolphin than in human leukocytes, suggesting a blunted cytokine response in bottlenose dolphin leukocytes treated with LPS. Results suggest species-specific regulation of inflammatory cytokines in leukocytes treated with LPS, which may lead to differential responses to a pro-inflammatory challenge between marine and terrestrial mammals.

Spatial and Temporal Variability of Trace and Macro Elements in the Red Crab Pleuroncodes planipes in the Pacific Coast of the Baja California Peninsula, Mexico.

The red crab, Pleuroncodes planipes, is a decapod crustacean abundant off the Pacific coast of the Baja California Peninsula. This species is caught and used in preparing animal feed, such as flour, particularly for aquaculture. Levels of calcium (Ca), cadmium (Cd), copper (Cu), iron (Fe), lead (Pb), magnesium (Mg), manganese (Mn), nickel (Ni), phosphorus (P), and zinc (Zn) were measured in red crabs collected from three geographic zones during three cruises in different seasons. Significant differences were found in the levels of Ca, Cd, Cu, Fe, Mg, Ni, P, and Zn between the two El Niño years (cruises C1 and C3, based on a threshold of ±0.5 °C for the Oceanic Niño Index). The highest concentrations of most elements were observed in the south of the Baja California Peninsula, a highly productive area influenced by upwelling events. Our findings suggest that while environmental temperature plays a central role in the benthic or pelagic distribution of red crabs, their content and variability of trace and macro elements appear to be associated with the presence of oceanic conditions, such as upwelling and potential changes in the composition of their diet associated with the depth in which these crustaceans are collected.

"Oxidative stress induced by phthalates in mammals: State of the art and potential biomarkers".

BACKGROUND: Phthalates, plasticizers that are widely used in consumer products including toys, cosmetics, and food containers, have negative effects in liver, kidney, brain, lung and reproductive system of humans and other mammals. OBJECTIVES: To summarize, describe and discuss the available information on the effects of phthalate exposure in mammals, with emphasis on oxidative stress, and to suggest potential biomarkers of the health risks associated with phthalate exposure. METHODS: An assessment of scientific journals was performed using the PRISMA model for systematic reviews. Manuscripts reporting effects of phthalate exposure on mammalian health published in the last decade were selected according to originality, content, and association to health hazards. RESULTS AND DISCUSSION: We identified 25 peer-reviewed articles published between January 1st, 2010 and June 1st, 2021 that fit the aims and selection criteria. Phthalates induce oxidative stress and cell degenerative processes by increasing intracellular reactive species. Antioxidant cytoprotective systems decrease with time of exposure; conversely, oxidative damage markers, including thiobarbituric acid-reactive substances (TBARS), 8-hydroxy-2'-desoxyguanosine (8-OHdG) and malondialdehyde (MDA), increase. Phthalates were associated with endocrine system disfunction, metabolic disorders, infertility, nonviable pregnancy, cell degeneration, growth impairment, tumor development, and cognitive disorders. Phthalates can also aggravate health conditions such as asthma, hepatitis, diabetes, allergies, chronic liver and kidney diseases. Among humans, the more vulnerable subjects to phthalate exposure effects were children and individuals with a prior health condition. CONCLUSION: Chronic exposure to phthalates induces oxidative stress in mammals with concomitant adverse effects in reproductive, respiratory, endocrine, circulatory, and central nervous systems in both in vitro and in vivo trials. Oxidative damage markers and phthalate metabolites levels were the most common biomarkers of phthalate exposure effects. Studies in free-ranging and wild mammals are nil. Further studies on the pathways that lead to metabolic disruption are needed to identify potential treatments against phthalate-induced detrimental effects.

Morphological alterations in human skeletal muscle cells exposed to di-(2-Ethylhexyl) Phthalate (dehp) in primary cell culture conditions / Alteraciones morfológicas en células musculares esqueléticas humanas expuestas a Ftalato de di-(2-etilhexilo) (dehp) en condiciones de cultivo celular primario

SUMMARY: Di-(2-ethylhexyl) phthalate (DEHP) is among the most common plasticizer additives that humans are in contact with daily. DEHP can be released from plastic and enter the human body, whereby it is metabolized and transformed into oxidative hydrophilic molecules. Clinical follow-ups in patients exposed to this phthalate and investigations in cultures of several cell types have provided information on its effects. For example, it is associated with inhibition of diploid human cell development and morphological changes in cultured germ cells. Although skeletal muscle represents around 50 % of the human body mass, knowledge about the effects of DEHP on this tissue is poor. Cultured skeletal muscle cells were exposed to DEHP (1 mM) for 13 days with the aim of exploring and evaluating some of the potential morphological effects. Three culture development parameters and nine cell characteristics were monitored during the bioassay. At 13 days, growth area, cell viability, and concentration of total proteins were lower in DEHP exposed than in control cells. Cell width and area, as well as the diameter of the nucleus and nucleolus, were greater in exposed cells than in control cells. These are interpreted as signs of cytotoxicity and suggest potential adverse effects on the development of skeletal muscle cells from DEHP exposure, as reported for other cell types.

RESUMEN: Diariamente los seres humanos tenemos contacto con aditivos plastificantes, el di-(2-etilhexil) ftalato (DEHP) se encuentra entre los más comunes. El DEHP puede liberarse del plástico e ingresar al cuerpo humano, donde es metabolizado y transformando en moléculas hidrofílicas oxidativas. Seguimientos en pacientes expuestos a este ftalato e investigaciones en cultivos de varios tipos celulares han aportado información sobre sus efectos. El DEHP es asociado con la inhibición del desarrollo de células humanas diploides y cambios morfológicos en células germinales en cultivo. Sin embargo, aún es poco lo que se sabe sobre los efectos en el músculo esquelético, a pesar de que este tejido representa alrededor del 50 % de la masa corporal del humano. Para explorar y evaluar algunos efectos morfológicos en células de músculo esquelético, cultivos primarios fueron expuestos a DEHP (1 mM) durante 13 días. Se dio seguimiento a tres parámetros de desarrollo del cultivo y nueve características celulares. Al término de 13 días de exposición, los valores del área de crecimiento, viabilidad celular y concentración de proteínas totales fueron inferiores con respecto a los cultivos control. Se observaron cambios morfométricos en las células expuestas. Particularmente, el ancho y área celular, así como los diámetros del núcleo y nucleolos, fueron mayores a los registros en las células control. Estos resultados se interpretan como signos de citotoxicidad y sugieren efectos potencialmente adversos en el desarrollo de las células del músculo esquelético ante una exposición al DEHP, como se ha registrado para otros tipos celulares.

Morphometric characteristics of human skeletal muscle cells in primary culture / Características morfométricas de células musculares esqueléticas humanas en cultivo primario

SUMMARY: The study of cell morphology has contributed to the innovation of clinical techniques and biomedical research. Primary cell culture techniques are well standardized; however, knowledge about morphometric parameters under cell culture conditions is scarce. Variations in morphology can affect cell physiology and responses. The aim of this study was to use morphometric tools to describe the growth and development of skeletal muscle cells under standard cell culture conditions. A photographic database was generated, and morphometric data was obtained for nine cell characteristics (n = 559 cells). Four muscular cell shapes (spherical, irregular outline, triangular and spindle/fusiform) were characterized with wide ranges in variation. The maximum cell length (110-262 µm), width (35-66 µm), area (2,642 - 9,480 µm2), projection lengths (45 - 127 µm), and nucleus diameter (28 ± 11 µm) were obtained by day 23 of culture. A single centrally positioned nucleus was observed in each cell; nucleoli diameter (5 ± 2 µm) and number (1 - 5) varied. In general, cyclic changes in cell sizes were identified during culture, whereas cell length, width, and area increased in spurts. These results suggest that morphometric parameters can be used to monitor skeletal muscle cell development under standard culture conditions.

RESUMEN: A partir de células madre musculares, surgen los mioblastos que se dividen y fusionan entre sí para formar a los miocitos. Estas células ya diferenciadas son precursoras de miocitos que maduran en fibras musculares y posteriormente forman los músculos. La implementación de cultivos celulares de mioblastos ha permitido obtener conocimiento detallado del tejido muscular. Particularmente, algunas de las aportaciones morfológicas fueron el punto de partida de técnicas clínicas, terapias o investigaciones biomédicas. Sin embargo, los estudios morfométricos en condiciones de cultivo celular son escasos. Por lo cual, realizamos seguimientos fotográficos a cultivos desarrollados bajo condiciones estándar, registramos datos para nueve características celulares y aplicamos técnicas morfométricas para analizar estas células (n = 559). Se caracterizaron cuatro formas celulares adoptadas por los mioblastos (esférica, irregular, triangular y huso) y se registraron intervalos amplios de variación en los caracteres. Hacia el día 23 de cultivo se presentaron los valores máximos en la longitud (110-262 µm), el ancho (35-66 µm) y el área celular (2,642-9,480 µm2), así como en el tamaño máximo de las proyecciones celulares (45-127 µm) y el diámetro del núcleo (28±11 µm). El núcleo se observó como único y en posición central; los nucleolos variaron poco en diámetro (5±2 µm), aunque no en número (1 a 5). En términos generales, se identificaron cambios cíclicos en la talla de las células durante los cultivos, esto es, períodos intercalados de incremento y decremento en el largo, ancho y área celular. Debido a que estas características reflejaron los cambios generales sufridos por los mioblastos durante el cultivo, se proponen para monitorear sus etapas de desarrollo en cultivo.

Antibacterial effect of acetic acid during an outbreak of carbapenem-resistant Acinetobacter baumannii in an ICU (II).

INTRODUCTION: Acetic acid (AA) has been commonly used in medicine as an antiseptic agent for the past 6000 years. This study evaluated the antibacterial effect of AA during an outbreak in an intensive care unit (ICU) facility in Baja California Sur, México. METHODOLOGY: Thirty-five environmental samples were collected, subsequently, disinfection with AA (4%) was performed, and two days later the same areas were sampled inside the ICU facility. Carbapenem-resistant A. baumannii (CRAB) was detected with loop-mediated isothermal amplification assay (Garciglia-Mercado et al. companion paper), targeting blaOXA-23-like, blaOXA-24-like, blaOXA-51-like, blaOXA-58-like, blaIMP and blaVIM genes. CRAB isolates before and after disinfection were compared by PFGE. RESULTS: Eighteen (54.5%) and five (14.3%) of thirty-five environmental samples were identified as Acinetobacter baumannii before and after disinfection, respectively, showing a significant decrease of 85.7% (p < 0.05) both by Loop-mediated isothermal amplification (LAMP) and polymerase chain reaction (PCR). Furthermore, the presence of blaOXA-23-like and blaOXA-58-like genes significantly decreased (p < 0.05) both by LAMP and PCR methods. PFGE genotype showed high similarity among CRAB isolates before and after disinfection, suggesting wide clonal dissemination in the ICU facility. CONCLUSIONS: This study demonstrated the novel application of AA with the LAMP assays developed for detecting CRAB. AA promises to be a cheap and efficacious disinfectant alternative to both developed and especially developing countries, preventing the spread of this organism in the environment and to other susceptible patients in health care settings.

In silico Characterization of the Heme Oxygenase 1 From Bottlenose Dolphin (Tursiops truncatus): Evidence of Changes in the Active Site and Purifying Selection.

Cetacea is a clade well-adapted to the aquatic lifestyle, with diverse adaptations and physiological responses, as well as a robust antioxidant defense system. Serious injuries caused by boats and fishing nets are common in bottlenose dolphins (Tursiops truncatus); however, these animals do not show signs of serious infections. Evidence suggests an adaptive response to tissue damage and associated infections in cetaceans. Heme oxygenase (HO) is a cytoprotective protein that participates in the anti-inflammatory response. HO catalyzes the first step in the oxidative degradation of the heme group. Various stimuli, including inflammatory mediators, regulate the inducible HO-1 isoform. This study aims to characterize HO-1 of the bottlenose dolphin in silico and compare its structure to the terrestrial mammal protein. Upstream HO-1 sequence of the bottlenose dolphin was obtained from NCBI and Ensemble databases, and the gene structure was determined using bioinformatics tools. Five exons and four introns were identified, and proximal regulatory elements were detected in the upstream region. The presence of 10 α-helices, three 310 helices, the heme group lodged between the proximal and distal helices, and a histidine-25 in the proximal helix serving as a ligand to the heme group were inferred for T. truncatus. Amino acid sequence alignment suggests HO-1 is a conserved protein. The HO-1 "fingerprint" and histidine-25 appear to be fully conserved among all species analyzed. Evidence of positive selection within an α-helix configuration without changes in protein configuration and evidence of purifying selection were found, indicating evolutionary conservation of the coding sequence structure.

Mercury concentrations in Baja California Sur fish: Dietary exposure assessment.

Total mercury concentrations ([THg]) in muscle were determined in commercial finfish and elasmobranchs from Baja California Sur (BCS), Mexico to evaluate dietary Hg exposure for BCS communities, including the relationship of trophic ecology, length and mass with [THg] that might drive future consumption advice (e.g., recommend limited consumption of large fish for some species). The [THg] ranged from 0.06 to 528.02 µg kg-1 ww in finfish and 17.68-848.26 µg kg-1 ww in elasmobranchs. Relative to the consumption threshold set for predatory fish in Mexico, all species had a concentration below 1000 µg kg-1 ww. As expected, 16 (4.02%) and 75 (18.84%) individual fish were above advisory thresholds of 500 and 200 µg kg-1 ww, respectively. The hazard quotients (HQs) in most species were significantly <1.0, only banded guitarfish showed a significant median HQ > 1.0. Thus, the relative level of risk of high Hg exposure is low for most species.

Development of a LAMP method for detection of carbapenem-resistant Acinetobacter baumannii during a hospital outbreak.

INTRODUCTION: Carbapenem-resistant A. baumannii (CRAB) represents a public health threat increasing worldwide. We assess the suitability of a loop-mediated isothermal amplification (LAMP) method for on-site screening of CRAB in a hospital facility. METHODOLOGY: A set of six primers were designed for recognizing eight distinct sequences on six targets: blaOXA-23-like, blaOXA-24-like, blaOXA-51-like, blaOXA-58-like, blaIMP, and blaVIM. A LAMP method was developed, optimized and evaluated for the identification of CRAB in thirty-three environmental samples from an outbreak in an Intensive Care Unit (ICU) facility. RESULTS: The sensitivity of the LAMP assay for the detection of A. baumannii was ten-fold higher than the PCR assay (1.0 ng.µL-1). The LAMP assays showed a higher detection rate for CRAB samples and robust diagnosis performance in comparison to a conventional PCR, with clinical sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 100% for blaOXA-23-like, blaOXA-51-like and blaVIM. CONCLUSIONS: The developed LAMP assays are powerful tools that can be useful in on-site screening of CRAB causing local outbreaks in clinics and hospitals facilities where costs and equipment restraints are imperative.

Antioxidant response to cadmium exposure in primary skeletal muscle cells isolated from humans and elephant seals.

Cadmium (Cd) occurs naturally; however, its concentration can increase with anthropogenic activities. Excess Cd increases reactive oxygen species (ROS) production and oxidative damage, which can lead to pathological conditions. Marine mammals accumulate Cd in the liver and the kidney; yet, there are no reports of Cd-associated tissue damage in whales, seals or dolphins. Response to Cd exposure (0-5.0 µM CdCl2 for 1-12 h) was analyzed and compared in primary skeletal muscle cells isolated from northern elephant seals (Mirounga angustirostris) and humans (Homo sapiens). Antioxidant enzyme activities (glutathione S-transferase, glutathione reductase, glutathione peroxidase), glutathione concentration, and protein carbonyl levels (an indicator of oxidative damage) were quantified. Glutathione levels were higher in northern elephant seal than in human cells. Protein carbonyl content in cells exposed to Cd was lower and had a smaller variability range in elephant seals than in humans. Generalized linear models (GLIM) identified Cd exposure and antioxidant defenses as significant contributors to protein carbonyl variability in human but not in elephant seal cells. These results suggest that the previously observed differences in circulating and tissue glutathione levels between marine and terrestrial mammals are maintained under cell culture conditions and that northern elephant seal and human muscle cells respond differently to Cd exposure. The results also suggest that the observed differences could potentially be associated with the protective mechanisms that allow northern elephant seals to tolerate extreme conditions that result in increased ROS generation (e.g. diving, sleep apnea, fasting) with no oxidative damage.

Using carbon and nitrogen stable isotope modelling to assess dietary mercury exposure for pregnant women in Baja California Sur, Mexico.

INTRODUCTION: Previous studies of mercury (Hg) in pregnant women in the area of La Paz, Baja California Sur (BCS), Mexico found a proportion of individuals had concentrations of total Hg ([THg]) above some thresholds of concern set by health agencies. The [THg] were associated with fish and seafood consumption as well as other factors; although it was unclear which marine diet items could potentially be contributing to the concentrations observed. METHOD: We examined [THg] and monomethylmercury concentration ([MeHg+]) in the archived hair of 70 pregnant women from BCS as well as in diet items including fish, shellfish, and staple items (rice, beans, corn, and flour). We measured stable isotopes of carbon and nitrogen and employed a Bayesian stable isotope mixing model to investigate the proportion of fish and seafood in the isotopic profiles of archived hair samples. RESULTS: Concentrations of Hg species were low in staple foods and ranged from below detection limit to 5.71 parts per billion (ppb) wet weight. In hair, geometric mean [THg] was 658 ppb and [MeHg+] was 395 ppb, which were lower than previous reports. Percent MeHg+ was positively correlated with higher δ15N values. CONCLUSIONS: The largest carbon contributors to the diet of the study participants were corn and rice, and our analysis of fish contribution to diet varyingly agreed with the self-reported fish consumption. This report highlights the ability to discriminate potential sources of Hg from a diverse diet and the limitations of dietary recall studies.

The Neuroprotective Effect of Erythropoietin in Rat Hippocampus in an Endotoxic Shock Model.

BACKGROUND: Sepsis is characterized by an early systemic inflammation in response to infection. In the brain, inflammation is associated with expression of pro-inflammatory cytokines (e.g. tumor necrosis factor-α, interleukin-1ß and interleukin-6, among others) that may induce an overproduction of reactive oxygen and nitrogen species. The constitutive expression of cytokines in the brain is low, but may be induced by various stimuli, including lipopolysaccharide, which causes neuronal damage. Erythropoietin, among other effects, acts as a multifunctional neurotrophic factor implicated in neurogenesis, angiogenesis, vascular permeability, and immune regulation in the central nervous system. In an experimental model of endotoxic shock, we studied the neuroprotective capacity of erythropoietin in the rat hippocampus and compared with melatonin, a neurohormone with an important antioxidant and immunomodulatory effect. METHODS: In 21-day-old male Wistar rats divided into eight groups, we administered by intraperitoneal injection lipopolysaccharide, erythropoietin, melatonin, or combinations thereof. The hippocampus was dissected and morphological (histological analysis) and biochemical (cytokine levels) studies were conducted. RESULTS: The number of dead neuronal cells in histological sections in groups treated with lipopolysaccharide was higher compared to the erythropoietin group. There was a greater decrease (70%) in interleukin-1ß concentrations in rats with endotoxic shock that received erythropoietin compared to the lipopolysaccharide group. CONCLUSIONS: The neuronal cell loss caused by endotoxic shock and interleukin-1ß levels were reduced by the administration of the hematopoietic cytokine erythropoietin in this experimental model.

Purine nucleoside phosphorylase and the enzymatic antioxidant defense system in breast milk from women with different levels of arsenic exposure.

Purine nucleoside phosphorylase (PNP) is an ubiquitous enzyme which plays an important role in arsenic (As) detoxification. As is a toxic metalloid present in air, soil and water; is abundant in the environment and is readily transferred along the trophic chain, being found even in human breast milk. Milk is the main nutrient source for the growth and development of neonates. Information on breast milk synthesis and its potential defense mechanism against As toxicity is scarce. In this study, PNP and antioxidant enzymes activities, as well as glutathione (GSH) and total arsenic (TAs) concentrations, were quantified in breast milk samples. PNP, superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR) activities and GSH concentration were determined spectrophotometrically; TAs concentration ([TAs]) was measured by atomic absorption spectrometry. Data suggest an increase in PNP activity (median = 0.034 U mg protein-1) in the presence of TAs (median = 1.16 g L(-1)). To explain the possible association of PNP activity in breast milk with the activity of the antioxidant enzymes as well as with GSH and TAs concentrations, generalized linear models were built. In the adjusted model, GPx and GR activities showed a statistically significant (p<0.01) association with PNP activity. These results may suggest that PNP activity increases in the presence of TAs as part of the detoxification mechanism in breast milk.

Purina nucleósido fosforilasa (PNP) es una enzima ubicua que desempeña un papel importante en la desintoxicación del arsénico (As). As es un metaloide tóxico presente en el aire, el suelo y el agua; es abundante en el medio ambiente y se transfiere fácilmente a lo largo de la cadena trófica, encontrándose incluso en la leche materna humana. Información sobre la síntesis de la leche materna y su potencial mecanismo de defensa contra tóxicos es escasa. En este estudio, se cuantificó la actividad de PNP y de las enzimas antioxidantes así como la concentración de glutatión (GSH) y de arsénico total ([TAs]) en muestras de leche materna. La actividad de PNP, superóxido dismutasa (SOD), catalasa (CAT), glutatión S-transferasa (GST), glutatión peroxidasa (GPx), glutatión reductasa (GR) y la concentración de GSH se determinaron por espectrofotometría; la [TAs] se midió por espectrometría de absorción atómica. Los datos sugieren un incremento en la actividad de PNP (mediana= 0.034 U mg proteína-1) con la presencia de TAs (mediana= 1.16 g L-1). Para explicar la posible asociación de la actividad de las enzimas antioxidantes y la concentración de GSH, así como [TAs], con la actividad de PNP en la leche materna, se construyeron modelos lineales generalizados. En el modelo ajustado, la actividad de GPx y GR presentó una asociación estadística (p.

Oxidative stress in patients with rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis is an autoimmune disease of unknown etiology, characterized by articular inflammation. Oxidative damage induced by reactive oxygen species has been related to the pathophysiology of rheumatoid arthritis in several studies, although results have been inconsistent and contradictory. OBJECTIVE: To determine oxidative stress markers in patients with rheumatoid arthritis. METHODS: Descriptive cross-sectional study in rheumatoid arthritis patients and healthy controls. In peripheral blood samples from all study subjects, lipid peroxide (thiobarbituric acid reactive substances) and protein carbonyl levels were quantified as oxidative damage markers; superoxide dismutase and glutathione peroxidase activities, glutathione concentration, and the reduced glutathione/oxidized glutathione ratio were analyzed as antioxidant defense indicators. Mann-Whitney U tests were run. Statistical significance (a) was 0.05%. RESULTS: We included 29 rheumatoid arthritis patients, 10 with active disease, and 41 healthy controls. Age was higher in the rheumatoid arthritis group; there were no differences in female:male ratio between groups. Oxidative damage was higher in rheumatoid arthritis patients; however, there was no difference between patients with active or inactive rheumatoid arthritis. Antioxidant enzyme activities, glutathione concentration, and reduced glutathione/oxidized glutathione ratio were higher in rheumatoid arthritis patients than in controls. CONCLUSIONS: Antioxidant levels were higher in rheumatoid arthritis patients than in healthy controls; however, they were insufficient to prevent oxidative damage. This suggests an active oxidative process in rheumatoid arthritis patients.

Marine diet and tobacco exposure affects mercury concentrations in pregnant women (I) from Baja California Sur, Mexico.

Seafood provides essential polyunsaturated fatty acids (PUFA) and other nutrients to pregnant women and their fetus(es) while a diet rich in finfish can be a major pathway of monomethyl mercury (MeHg+) exposure. We measured total mercury concentration ([THg]) in hair samples provided by 75 women in Baja California Sur (BCS) to assess its relationship with age, parity, tobacco smoke exposure, and diet based on survey methodologies. Generalized linear models (GLM) were used to explain the possible association of the different variables with [THg] in hair. Median [THg] in hair was 1.52 µgg-1, ranging from 0.12 to 24.19 µgg-1 and varied significantly by segment. Approximately 72% (54/75) of those evaluated exceed 1 µgg-1 [THg] and 8% (6/75) exceed 5 µgg-1 [THg] in hair. Although frequency of fish consumption contributed significantly to explaining hair [THg], fish consumption only explained 43% of [THg] in a GLM incorporating tobacco exposure and body mass index. This study establishes possible relationships among multiple potential sources of exposure and other factors related to [THg] in hair of women in the prenatal period. A more detailed examination of other sources of exposure and factors contributing to [THg] is warranted.

Relationship between self-reported fish and shellfish consumption, carbon and nitrogen stable isotope values and total mercury concentrations in pregnant women (II) from Baja California Sur, Mexico.

Seafood is a valuable source of nutrients important for fetal development. However, seafood consumption is the main route of exposure to monomethyl mercury (MeHg+) for humans. MeHg+ is highly bioavailable and potentially adversely affects fetal neurodevelopment. MeHg+ exposure from fish consumption varies significantly by age and trophic level of fish consumed as well as the frequency and amount of fish consumed. This study investigates total Hg concentrations ([THg]) in hair segments of pregnant Mexican women in relation to (1) self-reported frequency of fish and shellfish consumption, (2) maternal trophic level and marine diet contributions, determined using hair carbon (C) and nitrogen (N) stable isotopes, and (3) relates [THg] to various hair advisory thresholds. We also examined whether variation in C and N isotope values is explained by self-reported frequency of fish and shellfish consumption. A significant proportion of hair samples had [THg] higher than suggested agency thresholds and, for women within the range of the various advisory thresholds (1-20 µg g-1), the specific statistic used and threshold applied are important considerations for assessing and communicating risk. Individuals enriched in 15N (δ15N values) had higher [THg] as did individuals that reported consuming fish and shellfish more frequently, suggesting that variation in [THg] can be explained by both consumer reported diet and diet as determined by C and N stable isotope assessment. However, at higher reported fish consumption levels the trophic level is maintained while [THg] is paradoxically lower. This suggests that THg exposure and assimilation are more complicated in higher fish frequency consumption categories. [THg] is more variable at the higher concentrations, possibly indicating some exposure to non-dietary Hg, heritable variations affecting Hg toxicodynamics, and BMI and tobacco exposure factors as outlined in our companion paper.

Incremento de la temperatura ambiental y su posible asociación al suicidio en Baja California Sur (BCS) 1985-2008 / Environmental temperature increase and its possible association with suicide in the population of Baja California Sur (BCS) 1985-2008

Introduction During the last decade we have observed important climate changes, especially in environmental temperatures. There is considerable information linking the increase in hot weather and human health. For example, hot weather is associated with an increased risk of suicide in different countries around the world. Objective To evaluate the relationship between suicide rates and the environmental temperature in Baja California Sur, Mexico, from 1985 to 2008. Method Suicide mortality data for Baja California Sur (BCS) were obtained for the years 1985-2008 from the Instituto Nacional de Estadística, Geografía e Informática (INEGI). The selected codes were: E950-E959 (ICD-9) and X60-X84, Y87.0 (ICD-10) for BCS. The BCS weather data used was the maximum temperature from 1985 to 2008, obtained from the Extractor Rápido de Información Climatológica (ERIC III). Lineal and quadratic models were used to assess the annual rate changes of suicide and generalized lineal models (GLM) to assess the effect of the climatological variables to the suicide rate. The p≤0.05 was considered significant. Results In BCS, 582 suicide deaths were reported from 1985 to 2008. The 9% (53) of the total reported were women with a yearly average rate 1.6/100 000; 91% (529) were men with a yearly average rate 16.3/100 000. Lineal and quadratic models explained the tendency of the annual increment observed in the number of suicides in both seasons. The quadratic model better explained such increment during the warmer months (R²=0.64 p<0.01). The temperature was positively correlated with the rate of suicides in both seasons (p<0.01). Two predictive GLMs were created by season. Discussion These results suggest a potential link between an increase in environmental temperature and the rates of suicide during 24 years in BCS. This relationship is clear during the hot season; however, a positive trend was found during the cold season, perhaps due to the result of warmer winters.

Introducción Durante las últimas décadas se ha podido apreciar un cambio en las variables climáticas, en especial en la temperatura ambiental. Hay evidencias que asocian el aumento de la temperatura ambiental con el incremento en las tasas de mortalidad por suicidio. Objetivo Evaluar la relación entre la tasa de suicidio y la temperatura ambiental en Baja California Sur (BCS) durante los años 1985-2008. Método Los datos de suicidio fueron obtenidos de las bases de Mortalidad del INEGI de 1985-2008. Se tabularon los registros con códigos: E950-E959 CIE-9 y X60-X84, Y87.0 CIE-10 para BCS. En el análisis climático se usaron las temperaturas máximas de 1985 al 2008 para BCS del Extractor Rápido de Información Climatológica (ERIC III). Para evaluar la tendencia, se utilizaron modelos de regresión lineal y cuadráticos. Los modelos lineales generalizados (GLM) se utilizaron para evaluar el efecto de las variables ambientales sobre la tasa de suicidios, con una significancia de p≤0.05. Resultados Un total de 582 suicidios ocurrieron en BCS de 1985 a 2008. Las mujeres representaron el 9% (53), con tasa anual promedio de 1.6/100 000. Los hombres 91% (529), con tasa promedio anual de 16.3/100 000. La tendencia de incremento anual se explicó con modelos lineales simples y cuadráticos en ambas temporadas. En los meses cálidos el modelo cuadrático explicó mejor dicho incremento (R²=0.64 p<0.01). La temperatura se correlacionó positivamente con la tasa en ambas temporadas (p<0.01). Se generaron dos modelos GLM predictivos por temporada. Discusión En este trabajo se observó una posible relación entre el incremento de la temperatura ambiental y el número de suicidios registrados durante 24 años en BCS. Esta relación se encuentra bien definida en los meses cálidos, pero con una tendencia en aumento para los meses fríos.

[Mercury concentration in breast milk of women from northwest Mexico; possible association with diet, tobacco and other maternal factors]. / Concentraciones de mercurio en leche de mujeres del noroeste de México; posible asociación a la dieta, tabaco y otros factores maternos.

OBJECTIVE: To determine THg levels in milk of women from Northwest Mexico and its potential association with maternal factors such as diet and tobacco smoke. METHOD: The study was performed in 108 milk samples donated by women in Baja California Sur. Data were stratified into three groups of 36 donors by number of pregnancies. General data, smoking, exposure to environmental tobacco smoke and seafood intake were explored. THg levels were measured using atomic absorption spectrophotometry. The difference between groups was evaluated with non-parametric statistics. To explain the possible association of the different variables with THg concentrations in milk, generalized linear models were performed. RESULTS: THg levels ranged from 1.23 µg/L in single-pregnancy women (GI) to 2.96 µg/L for women with 3 or more pregnancies (GIII) (p = 0.07). In the GI group THg concentration was 175% higher (p = 0.02) in women who do not eat fish, compared to those who eat fish. In the generalized linear model to adjust THg concentrations, the variables were: age, number of pregnancies, breastfeeding duration and exposure to tobacco smoke (p ≤ 0.05). CONCLUSIONS: Fish consumption was the factor that better adjusted models, relative to THg levels. The contribution associated to this factor was low; therefore, consumption of fish from the coast of Baja California Sur is safe. Tobacco increased Hg concentrations in breast milk; it is necessary to avoid the smoking habit during pregnancy and breast-feeding.

Objetivo: Determinar los niveles de mercurio total (THg) en leche de mujeres del Noroeste de México y su posible asociación con factores maternos, la dieta y el tabaco. Método: El estudio se realizó en leches donadas por 108 mujeres de Baja California Sur. Se estratificaron en tres grupos de 36 donantes según el número de gesta. Se exploraron datos generales, hábito tabáquico, exposición al humo de tabaco ambiental, ingesta de mariscos y pescados. Los niveles de THg fueron cuantificados utilizando espectrofotometría de absorción atómica. La diferencia entres grupos se evaluó con estadística no paramétrica. Para explicar la posible asociación de las diferentes variables estudiadas y las concentraciones de THg en la leche, se realizaron modelos lineales generalizados. Resultados: Los niveles de THg fueron desde 1.23 ?g/L en las primigestas (GI) a 2,96 ?g/L para las mujeres con 3 o más gestas (GIII) (p = 0,07). En el grupo de GI encontramos una concentración del THg 175% mayor (p = 0,02) entre las mujeres que no comen pescado, en comparación con las que si comen pescado. En el modelo lineal generalizado ajustado por las concentraciones de THg, las variables fueron: edad, número de embarazos, duración de la lactancia y exposición al tabaco (p =?0,05). Conclusiones: El consumo de pescado fue el factor que mejor ajustó los modelos en relación a los niveles de THg. El aporte de Hg por la dieta que se pudo asociar fue bajo, por lo que el consumo de pescado de las costas de Baja California Sur es seguro. El tabaco, incrementa las concentraciones de Hg en la leche materna, por lo que debe de limitarse su hábito durante el embarazo y la lactancia.

Mortality trend by dengue in Mexico 1980 to 2009.

OBJECTIVE: To describe the mortality of dengue in Mexico during 1980 to 2009. MATERIAL AND METHODS: Dengue mortality data for Mexico were obtained from Instituto Nacional de Estadistica, Geografía e Informática. We used standardized and non-standardized dengue mortality rates per 1,000,000 people and determined the mortality trend. The groups were based on International Classification of Diseases coding criteria (ICD-9 E061 and ICD-10 A91X). The results were stratified by age groups and the frequencies of dengue deaths were compared using relative risk (RR) with its 95% confidence interval. RESULTS: During 1980 to 2009 in Mexico, 549 deaths due to dengue were reported. We found an important variation in the mortality rates during the years studied. We were able to identify three periods: 1980 to 1992, 1994 to 2000, and 2001 to 2009. The mortality rates found are from 0.88/1,000,000 through 0.00/1,000,000. The average mortality rates by decade: 1980 to 1989: 0.53/1,000,000; 1990 to 1999: 0.06/1,000,000; 2000 to 2009: 0.12/1,000,000. In the analysis of mortality by community size during 2000 to 2009, we observed in the small communities with < 2,499 people, the risk is 1.25 times higher than in those with more than 20,000 people. CONCLUSIONS: We found, in general, a sustained decline in the number of deaths by dengue over the last 30 years in Mexico. However, a slow increase was observed since 1994, which may be related to the circulation of DENV2 and DENV3, among other factors. We need to strengthen prevention programs in smaller communities (< 2,499) where we found a higher risk of mortality due to dengue.

[Civil status and suicide]. / El estado civil y el suicidio en Baja California Sur.

OBJECTIVE: To determine if civil status acts as a risk factor in suicide and how it modifies according to gender, age and population size. METHODS: A retrospective study which analyzes information from the mortality data from the National Institute of Statistics, Geography and Information, from 1998 to 2002. Variables like suicides age, sex, cause of death, federal entity, population size and civil status were registered. RESULTS: Single men showed twofold risk for committing suicide. Women did not show any associated risk for suicide according to civil status. The risk of married men for committing suicide increased gradually with age. Medium-sized communities with less than 19,999 habitants presented the highest risk for habitants to commit suicide. CONCLUSIONS: Suicide is associated to gender especially to men who are not married and living in small and medium-sized communities. One explanation could be the lack of integrated behavior as defined by Emile Durkheim, where the physical density of society will determine behavior and ideas. This social structure phenomenon is called the "moral cocoon." This works around the individual being less individualistic and granting him/her the feeling of belonging to a group.