Abdominal obesity and its association with socioeconomic factors among adolescents from different living environments.

BACKGROUND: Socioeconomic status has been associated with obesity in children and adolescents. This association may be dependent according with where adolescents lives. OBJECTIVE: The aim of this study was to evaluate the association between different socioeconomic indicators such as parental education and occupation and socioeconomic status with abdominal obesity in adolescents from two observational studies: the Healthy Lifestyle in Europe by Nutrition in Adolescence cross-sectional study (HELENA-CSS) and the Brazilian Cardiovascular Adolescent Health (BRACAH) study. METHODS: European (n = 3192, aged 12.5-17.5 years, with 53.1% girls from HELENA-CSS) and Brazilian (n = 991, aged 14-18 years, with 54.5% girls from BRACAH study) adolescents from two cross-sectional studies were included in this analysis. Complete data on waist circumference (WC), height, socioeconomic status indicators and several confounders were collected. Socioeconomic indicators were measured using a self-reported questionnaire in order to assess the family social status of the adolescents. Multilevel linear regression models were used to examine associations, and results were adjusted for potential confounders. RESULTS: Adjusted results showed inverse associations between mother's and father's education levels (p < 0.001) and father's occupation level (p < 0.001) with waist-to-height ratio (WHtR) and WC in HELENA-CSS girls. Similarly in European girls, socioeconomic indicators by socioeconomic status and maternal occupation level were associated with WHtR. In HELENA-CSS boys, the same significant association was found between WHtR and WC with maternal occupation level. Moreover, in European boys WHtR was also associated with parental education. In Brazilian adolescents, both indicators of abdominal obesity did not remain associated with the independents variables, after adjustment for potential confounders. CONCLUSIONS: Abdominal obesity was associated with socioeconomic indicators in higher-income countries, but this association was not observed in a lower-middle-income country.

Evolutionary dynamics of repetitive DNA in semaprochilodus (characiformes, prochilodontidae): a fish model for sex chromosome differentiation.

Distribution of 6 microsatellites and 5 transposable elements on the chromosomes of Semaprochilodus taeniurus and S. insignis, commonly referred to as Jaraqui, was performed using their physical mapping with fluorescence in situ hybridization. In this study, we aim to understand the evolutionary dynamics in genomes of S. taeniurus and S. insignis by comparing the position, abundance and contribution of the repetitive sequences in the origins and differentiation of a ZZ/ZW sex chromosome system in S. taeniurus. Results revealed that distribution patterns of repetitive DNAs along the chromosomes varied considerably. Hybridization signals were observed on several autosomes in both species; however, in S. taeniurus genome, the repetitive sequences were more abundant. In addition, large clusters of known repetitive sequences were detected in sex chromosomes of S. taeniurus. This observation is notable because the accumulation of repetitive DNAs could reflect the degradation of genetic activities and the differentiation of protosex chromosomes, evolving into the heteromorphic ZW pair observed in S. taeniurus.

Cryptic diversity in the mtDNA of the ornamental fish Carnegiella strigata.

Mitochondrial DNA ( mtDNA) sequences of the marbled hatchetfish Carnegiella strigata, an ornamental fish exported from the Negro River, was examined to determine its genetic diversity and population structure in blackwater rivers (Negro and Uatumã Rivers) in the central Amazon. Analyses of a 646 bp fragment of the ATPase 6/8 mtDNA gene revealed two monophyletic lineages of C. strigata with considerable genetic distance between them (10-12%), suggesting that these lineages should not be considered a single stock. Furthermore, there were strong differences in the geographical distribution of the lineages. These results indicate a past association between drainages of the Negro and Uatumã Rivers. They also suggest that, in the Negro River, its main tributary, the Branco River, may act as a geographical barrier and potentially an ecological barrier between populations of the middle and lower portions of the river.

Cytogenetics of Synbranchiformes: a comparative analysis of two Synbranchus Bloch, 1795 species from the Amazon.

Synbranchidae belongs to the Synbranchiformes and occurs in Africa, Asia, Australia, Mexico, and Central and South America. This family comprises four genera: Synbranchus, Ophisternon, Monopterus, and Macrotrema. Only two are known from the neotropical region, Ophisternon and Synbranchus. According to current classification, Synbranchus has three valid species: S. marmoratus (Bloch 1795), S. madeirae (Rosen and Rumney 1972), and S. lampreia (Favorito, Zanata and Assumpção 2005). Thus the present research is aimed to cytogenetically characterize (by classical and molecular methods) two syntopic species-S. aff. lampreia and S. madeirae-from the central Amazon basin to validate the taxonomy of both species and provide a revisionary discussion on the cytogenetics of Synbranchiformes. Synbranchus aff. lampreia was found to possess 2n = 44 chromosomes (6 m + 2st + 36a, NF = 50), while S. madeirae had 2n = 46 chromosomes (6 m + 2st + 38a, NF = 52). Constitutive heterochromatin was dominant in the centromeric and terminal regions of most of the chromosomes in both species, although the precise distribution patterns were species-specific. The nucleolar organizing region was single in S. aff. lampreia and multiple in S. madeirae, as indicated by both AgNO(3) and hybridization using 18S rDNA probes. The 5S rDNA sites were located interstitially on the long arms of an acrocentric pair in both species, and the telomeric probe did not show any interstitial sites in either species. These data indicate the occurrence of interspecific karyotypic variability in Synbranchus and suggest that taxonomic review for this genus is necessary.

CompCytogen of two of the smallest Amazonian fishes: Fluviphylax simplex Costa, 1996 and Fluviphylax zonatus Costa, 1996 (Cyprinodontiformes, Poeciliidae).

The genus Fluviphylax Whitley, 1965is comprized of five valid species (Fluviphylax pygmaeus Myers et Carvalho, 1955, Fluviphylax zonatus, Fluviphylax simplex, Fluviphylax obscurus Costa, 1996,and Fluviphylax palikur Costa et Le Bail, 1999), which are endemic to the Amazon region. These fishes are the smallest known South American vertebrates and among the smallest know vertebrates on Earth. All species but the type Fluviphylax pygmaeus have been described in late 1990's, and much remains unknown about the biology, taxonomy and systematics of this group of fishes. The aims of the present study were to establish the diploid and haploid number of Fluviphylax zonatus and Fluviphylax simplex, and to find species-specific markers for the discrimination of taxa. The diploid number for both species was 48 chromosomes, with no sex chromosome heteromorphism. Fluviphylax zonatus exhibited the karyotypic formula 4m+8sm+22st+14a and FN=82, and Fluviphylax simplex exhibited 4m+16sm+18st+10a and FN=86. The determination of the total mean length of the chromosomes and their grouping into five size classes demonstrated different chromosome composition of the two species. This difference was further supported by the distribution of constitutive heterochromatin. The meiotic analysis revealed 24 bivalents in both species, but Fluviphylax zonatus exhibited chromosomes with late pairing of the telomeric portions in the pachytene. These data reveal that cytogenetic characterization is useful and important for the discrimination of these species. Our study further indicates that this method could be employed in the analysis of other species of small fishes that are difficult to distinguish using traditional morphological traits or are morphologically cryptic.

Variability of 18S rDNA locus among Symphysodon fishes: chromosomal rearrangements.

Three species of cichlids belonging to the genus Symphysodon have demonstrated interspecific and intraspecific variation in nucleolus organizer regions (NOR) detected with silver nitrate. In order to understand the evolution of this marker in the genus, the structural variability of these sequences in mitotic chromosomes from Symphysodon aequifasciatus, Symphysodon discus and Symphysodon haraldi was investigated using both silver nitrate impregnation and hybridization of the 18S rRNA gene probe. For the three species, the two markers were intraspecifically and interspecifically variable both in the number and in the size of the sites. This polymorphism may stem from duplications and translocations, which suggests that structural chromosome rearrangements effectively act in the karyoevolution of wild Symphysodon species and may have favoured the adaptability of these fishes to diverse aquatic environments in the Amazon.

Importancia del manejo del ductus arterioso persistente en la XII Región al implementar el diagnóstico ecográfico y tratamiento quirúrgico a nivel local / Surgical management of persistent ductus arteriosus in the Xllth Region of Chile

Introducción: El Ductus Arterioso Persistente (DAP) representa un problema muy importante en los Recién Nacidos de Pretérmino (RNPT) menores de 1500 g. Diversos adelantos en el Servicio de Pediatría del Hospital Regional de Punta Arenas desde 1997 hicieron posible que iniciáramos la resolución local de ésta patología, tanto en Neonatos como en pacientes Pediátricos. Objetivo: Mostrar la experiencia obtenida después de 9 a±os de iniciado el diagnóstico y cirugía del DAP a nivel regional. Metodología: Evaluación prospectiva-retrospectiva de todos los pacientes operados de DAP desde Septiembre de 1997 hasta Agosto de 2006, recolectando información clínica, técnica quirúrgica y complicaciones, seguimiento y sobrevida. Se separan los pacientes en 2 grupos, los RNPT (Grupo A) y los niños de edad pediátrica (Grupo B). Resultados: Se han intervenido quirúrgicamente 16 pacientes del Grupo A y 10 pacientes del Grupo B. La edad al momento de la operación fluctuó entre 9 días y los 6 años 3 meses. En el grupo A, el peso al momento de la cirugía se encontraba entre 527 g y 2062 g. Para el diagnóstico ecocardiográfico se utilizó desde envío de imágenes por video hasta telemedicina con ecocardiografistas experimentados, hasta lograr la experiencia local. El equipo quirúrgico fue apoyado inicialmente por Cirujano Infantil con experiencia en cirugía Ductal, siendo parte del equipo en el 20 por ciento de las cirugías en el grupo A y en el 60 por ciento del grupo B. Se abordó el tórax por vía transpleural en 4 casos y extrapleural en 22 casos, sin dejar drenajes pleurales. No hubo complicaciones significativas. El tiempo de seguimiento varió entre 2 meses y 9 años, y la sobrevida fue de un 96 por ciento, con 1 paciente fallecido hasta Diciembre 2006. Conclusiones: La resolución quirúrgica de ésta patología es posible en el ámbito local, lo cual tiene gran importancia en los casos en que el traslado sea imposible o riesgoso por las condiciones de los enfermos...

Patent ductus arteriosus (PDA) accounts is a very important problem for extreme premature newborns < 1500 g due to a high associated morbi-mortality in this group of patients. After the arrival of a pediatric cardiac surgeon and training in appropriate echocardiography diagnosis, surgical treatment of this condition began at the Regional Hospital in Punta Arenas, Chile. Aim. to repon local results of PDA surgical treatment in neonates and children during a 9 year period. Method. All patients operated on for closure of PDA from September 1997 to August 2006 were included. A retrospective recollection of data, age weight at time of surgery (preterm neonates), means used to diagnose PDA, co-morbidity, surgical technique, complications and survival, was performed. A separate analysis of preterm neonates (PTN) and pediatric age patients (PA) was carried out. Results. 16 PTN and 10 PA patients were operated on. Overall, age at operation ranged from 9 days to 6 years. Weight of PTN ranged from 572 to 2062 g. Diagnosis was confirmed by echocardiography in all but one patient. Echocardiographic findings were discussed via tele-medicine with experienced specialists in many cases. The local surgical team was supported by an experienced surgeon in 20 percent of PTN and 60 percent of PA patients. A transpleural approach was used in 4 and an extrapleural approach in 22 patients; no pleural drainage was used. There were no significant complications. Only 1 patients has died in follow-up ranging from 2 months to 9 years. Conclusions. Local resolution of PDA in neonates and small children has been made possible in Punta Arenas, avoiding dangerous transfer of these patients. Assistance by trained specialists was essential to accomplish this goal. Use of tele-medicine proved to be an important factor to increase safety in the management of PDA.

Intriguing evidence of translocations in Discus fish (Symphysodon, Cichlidae) and a report of the largest meiotic chromosomal chain observed in vertebrates.

As part of a program to understand the genetics of Amazonian ornamental fish, classical cytogenetics was used to analyze Symphysodon aequifasciatus, S. discus and S. haraldi, popular and expensive aquarium fishes that are endemic to the Amazon basin. Mitotic analyses in Symphysodon have shown some odd patterns compared with other Neotropical cichlids. We have confirmed that Symphysodon species are characterized by chromosomal diversity and meiotic complexity despite the fact that species share the same diploid number 2n=60. An intriguing meiotic chromosomal chain, with up to 20 elements during diplotene/diakinesis, was observed in S. aequifasciatus and S. haraldi, whereas S. discus only contains typical bivalent chromosomes. Such chromosomal chains with a high number of elements have not been observed in any other vertebrates. We showed that the meiotic chromosomal chain was not sex related. This observation is unusual and we propose that the origin of meiotic multiples in males and females is based on a series of translocations that involved heterochromatic regions after hybridization of ancestor wild Discus species.

Comparative cytogenetic analysis of the genus symphysodon (discus fishes, cichlidae): chromosomal characteristics of retrotransposons and minor ribosomal DNA.

As part of a genetic screening program for wild Discus fishes, we analyzed karyotypes and cytogenetic characteristics of Symphysodon aequifasciatus, S. discus and S. haraldi using C-banding and fluorescent in situ hybridization (FISH) with the Rex3 retrotransposon and 5S rDNA probes in mitotic and meiotic chromosomes. In the 3 species, diploid chromosome number was 2n = 60 and karyotypes contained predominantly meta-submetacentric chromosomes. C-banding showed blocks of constitutive heterochromatin mainly in the pericentromeric region. Physical mapping of repetitive 5S rDNA sequences and Rex3 retrotransposons in mitotic and meiotic chromosomes showed partial colocalization of constitutive heterochromatin and repetitive elements. Correlations among the accumulation of repetitive elements, heterochromatinization and chromosome rearrangements have been hypothesized to explain the karyotype differentiation in the Symphysodon genus. The role of repetitive elements in adaptation to highly diverse habitats, as well as in the generation of the phenotypic and genetic variability found in wild Discus populations, needs to be further investigated.

Has repetitive transcranial magnetic stimulation (rTMS) treatment for depression improved? A systematic review and meta-analysis comparing the recent vs. the earlier rTMS studies.

OBJECTIVE: To investigate whether the recent repetitive transcranial magnetic stimulation (rTMS) studies on depression using new parameters of stimulation have shown improved clinical results. METHOD: We performed a systematic review and a meta-analysis of the rTMS studies on depression published in the past 12 months comparing these results with an earlier meta-analysis that analyzed the results of the initial rTMS studies on depression. RESULTS: Using our inclusion criteria, we selected the meta-analysis of Martin [Br J Psychiatry (2003) Vol. 182, 480-491] that included 13 studies (324 patients) and five studies for the recent meta-analysis (274 patients). The pooled effect size (standardized mean difference between pretreatment vs. post-treatment) from the random effects model was -0.76 (95% confidence interval, CI, -1.01 to -0.51). This result was significantly larger than that of the earlier meta-analysis (-0.35, 95% CI -0.66 to -0.04). CONCLUSION: Our findings suggest that recent rTMS clinical trials have shown larger antidepressant effects when compared with the earlier studies.

Possible roles of magnesium on the immune system.

During the last few years, magnesium (Mg) has been subject of research due to its functionality in the organism. It is one of the most important micronutrients, and therefore its role in biological systems has been extensively investigated. Particularly, Mg has a strong relation with the immune system, in both nonspecific and specific immune response, also known as innate and acquired immune response. The aim of this paper is to review the state of the art about the interactions between Mg and the immune system. We discuss the link between dietary Mg and inflammation, apoptosis and alterations in number and function of innate immune cell populations, described in animal models. Furthermore, the immune system can be compromised in human populations under certain circumstances, including athletes and elderly people. The importance of a balanced Mg homeostasis and its interaction with the immune system in these groups has also been reviewed. Although emerging data support the relevant role of Mg in the immune response, further research is needed; and special efforts should be made to establish the most adequate dose in nutritional supplements to reach beneficial effects on health.

[Nutrition in the sport practice: adaptation of the food guide pyramid to the characteristics of athletes diet]. / La nutrición en la práctica deportiva: adaptación de la pirámide nutricional a las características de la dieta del deportista.

In spite of all the advances in sport nutrition and the importance of an adequate food intake in order to improve sport performance, both recreational and professional athletes forget frequently to include planning an optimum diet and fluid intake in their global strategy for performance. Physiological and metabolic adaptations produced as a consequence of physical exercise lead to the necessity of increasing caloric (in accordance to energy output) and protein (based on the trophic needs of the organism) intake. Likewise, paying major attention to vitamin and mineral intake, specifically B vitamins and zinc and chromium, is required, in order to optimize carbohydrate metabolism, the ultimate limiting factor for sport performance. During the training phase, 60% of calories should come from carbohydrates, protein intake should be 1.2-2 g/kg/day and athletes should follow the recommendations of the food guide pyramid. During the pre-, per- and post-competition phase the healthy aspect of the diet passes to a second level, in order to obtain good sport performance and to guarantee a fast and effective recovery. Again, carbohydrates with a high or medium glycaemic index and water are the nutrients which have to be calculated more thoroughly. In conclusion, athletes have to follow a diet that is adequate to their higher energy output and to their higher metabolic turnover. The food guide pyramid is a graphic expression which facilitates the comprehension and following of a healthy diet. In the present article, the authors introduce the pyramid adapted to the characteristics of sports nutrition, with easy-to-follow practical recommendations regarding the kind and amounts of foodstuffs that should be consumed in order to cover nutrient needs of people who exercise regularly.

Diagnóstico del conducto peritoneo vaginal persistente contralateral en pacientes con hernia inguinal / Diagnosis of persistent contralateral vagino-peritoneal duct in patients with inguinal hernia

Actualmente la exploración laparoscópica del orificio inguinal profundo es la mejor forma de diagnosticar la persistencia del conducto peritoneo vaginal coantralateral en pacientes con hernia inguinal unilateral. Se realizó dicha exploración en 20 pacientes examinando quirúrgicamente el trayecto inguinal contralateral luego de la evaluación endoscópica. En 15 casos (75 por ciento) la visión endoscópica no reveló signos sugerentes de persistencia del conducto, lo cual fue corroborado quirúrgicamente. En cinco pacientes (25 por ciento) se encontraron signos anatómicos sugerentes de persistencia, confirmándose dicha observación en todos ellos al explorar en forman quirúrgica el trayecto inguinal. En esta serie no hubo falsos (+) ni falsos (-). La exploración laparoscópica del orificio inguinal profundo es una técnica simple, rápida, segura y sensible en el diagnóstico de la persistencia del conducto peritoneo vaginal contralateral en pacientes con hernia inguinal unilateral

[Women's opinion on abortion legalization in a middle size county in southern Brazil]. / Opinião de mulheres sobre a legalização do aborto em município de porte médio no Sul do Brasil.

INTRODUCTION: Induced abortion is the main cause of maternal death in Brazil. Question of its legalization has been the subject of frequent discussion. MATERIAL AND METHOD: In order to assess the influence of the variables affecting the opinion of women of reproductive age, a population-based systematic sample in the county of Rio Grande (Southern Brazil) was examined. RESULTS: Of a total of 1,456 interviews 30% endorsed the legalization, whatever the circumstances; this percentage was directly associated with age, schooling, family income and previous induced abortion (p < 0.01). Adjusted analysis using logistic regression showed a significant effect of schooling and previous induced abortion on favourable opinion. CONCLUSION: Schooling and previous induced abortion were the main determinants of women's favorable opinions regarding abortion legalization.

[Influence of iron status on attention and intellectual performance of a population of Spanish adolescents]. / Influencia del status en hierro en la atención y rendimiento intelectual de un colectivo de adolescentes españoles.

Dietetic, hematologic and biochemical data were used to asses the iron status of a group of 64 adolescents (37 males and 27 females), aged 15 to 18 (mean age 15.94 +/- 0.76 years), who study in a High School in the comunidad Autónoma de Madrid. All were asked to keep a dietary record during 5 days, one of which had to be a sunday. Iron intake was estimated using the Food Composition Tables of the Instituto de Nutrición (1990). The hematologic survey determined hemoglobin hematocrit mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), serum iron and serum ferritin. These data were correlated with the scores obtained in the attention and school capability test (AT), that gave information about the verbal (V), reasoning (R) and calculus (C) capabilities. There is a positive correlation between MCV (r = 0.2705), MCH (r = 0.3370) ferritin (r = 0.3383) and attention. MCV (r = 0.2995), MCH (r = 0.3998), MCHC (r = 0.3134) and ferritin (r = 0.3970) were also correlated with the speed capability shown on the attention test and the hemoglobin level was correlated with the calculus capability (r = 0.2905). The students who obtained higher scores in the school capability test had also better blood parameter values. This was statistically significant for serum ferritin in males students and for hemoglobin and MCHC in female students. 19.6% of the adolescents had ferritin levels lower than 12 ng/ml. Their intelligence test scores were lower to those who had serum ferritin > or = 12 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effect of nutrition on the functional capacity of a group of elderly Spaniards]. / Influencia de la nutrición en la capacidad funcional de un grupo de ancianos españoles.

The present study analyzes the influence of the nutritional status on the functional capability of 11 institutionalized elderly living in Madrid (Spain). Nutritional status was evaluated by dietetic, anthropometric, hematological and biochemical data and functional status was evaluated considering adiposity, strength in hands and legs bent and stretched and flexibility. The most important nutritional problems that conditional functional wastages are obesity, hypercholesterolemia and protein and micronutrient deficiency. The adverse influence of obesity and hypercholesterolemia on the functional capacity of the elderly is shown by the inverse relationship between flexibility and strength in hands and legs with the adiposity degree, with the thickness of skin folds and the cholesterolemia. In reference to the diet's influence, there are positive correlations between food intake and most of the nutrients with hand and legs strength, and there are statistical significances for proteins, iron, zinc, magnesium and pyridoxine, and also for vitamin C, niacin, thiamin, folic acid and vitamin E. For blood values, the mayor correlation exists between functional parameters and iron, ferritin and vitamin C levels. Our results contribute to confirm the influence of nutrition on the functional capacity of the influence of nutrition on the functional capacity of the elderly and manifest the necessity of improving the elderly's diet, to prevent micronutrient deficiency and also the necessity of increasing their physical activity. Both measures will mean an important help for sanitary and functional improvement of the elderly.

Identification of a novel protein capable of interacting with the IL-3 receptor.

IL-3 has numerous functions in hematopoiesis yet its receptor has not been fully characterized. We have developed two mAb, 4G8 and 2F2, that markedly inhibited IL-3-dependent proliferation whereas only marginally affecting IL-2 or IL-4-induced proliferation. On Western blots, both antibodies identified the same protein, which varied in size from 115 to 145 kDa in six cell lines tested. The 4G8/2F2 Ag was detected at moderate density, on a wide variety of cells including IL-3-dependent cell lines and T lymphocytes. Radioligand binding studies revealed that 4G8, but not 2F2, could inhibit the binding of 125I-IL-3 to the high affinity IL-3R. These data suggest that the mAb 4G8 and 2F2 recognize different epitopes on the same Ag, and suggest furthermore that the inhibition of IL-3-dependent proliferation mediated by 2F2, in particular, does not occur via inhibition of ligand binding. Neither antibody showed an enhanced level of fluorescent staining of Cos 7 cells transfected with the low affinity IL-3R cDNA. In addition, 4G8 did not inhibit IL-3 binding to L cells transfected with the cloned IL-3R or IL-4R despite the fact that 4G8 was expressed on these cells. These data suggest that the 4G8/2F2 Ag is a unique cell surface protein that can interact with the endogenous functional IL-3R.

Fast atom bombardment and collision-induced dissociation of prostaglandins and thromboxanes: Some examples of charge remote fragmentation.

The mass spectra of products found by collisional activation of selected prostaglandins and thromboxanes were studied by tandem mass spectrometry as barium carboxylate salts and as carboxylate anions. Collision-induced dissociation (CID) of these closed shell ions generated by fast atom bombardment mass spectrometry reveals a wealth of structural information for these hydroxy acids. Decomposition reactions were found to be dependent upon the eicosanoid ring structure and the type of ion being studied, either positive or negative ion. The bariated carboxylate salts undergo reactions by processes that are similar to those previously characterized as charge remote mechanisms in which neutral species are lost as in thermal and photolytic decompositions. The most abundant ion is formed by loss of water from each of the hydroxyl groups present on the prostaglandin or thromboxane structure. For these multifunctionalized eicosanoids, typical patterns of decomposition emerge as characteristic of the oxygen substituents present along the carbon chain of the eicosanoid structure. The structural information obtained from the barium salts along with those from the carboxylate anions is substantially different, yet the structural information from each process is complementary. The CIDs of positive ions (metalated salts) provide structural information concerning the substituents between the carboxyl group and C12 of the eicosanoid structure, whereas the decompositions of the carboxylate anions (negative ion mode) provide data concerning structure alterations of the eicosanoid structure between C15 and C20.