Natural abundance of stable isotopes (15N and 13C) and isotopic fractionation of sea bream muscle as markers of food and culture conditions and its relationship with metabolic and proteomic analyses

Els isòtops estables com a traçadors de la cadena alimentària, s'han utilitzat per caracteritzar la relació entre els consumidors i els seus aliments, ja que el fraccionament isotòpic implica una discriminació en contra de certs isòtops. Però les anàlisis d'isòtops estables (SIA), també es poden dur a terme en peixos cultivats amb dietes artificials, com la orada (Sparus aurata), la especie más cultivada en el Mediterráneo. Canvis en l'abundància natural d'isòtops estables (13C i 15N) en els teixits i les seves reserves poden reflectir els canvis en l'ús i reciclatge dels nutrients ja que els enzims catabòlics implicats en els processos de descarboxilació i desaminació mostren una preferència pels isòtops més lleugers. Per tant, aquestes anàlisis ens poden proporcionar informació útil sobre l'estat nutricional i metabòlic dels peixos. L'objectiu d'aquest projecte va ser determinar la capacitat dels isòtops estables per ser utilitzats com a marcadors potencials de la capacitat de creixement i condicions de cria de l'orada. En aquest sentit, les anàlisis d'isòtops estables s'han combinat amb altres metabòlics (activitats citocrom-c-oxidasa, COX, i citrat sintasa, CS) i els paràmetres de creixement (ARN/ADN). El conjunt de resultats obtinguts en els diferents estudis realitzats en aquest projecte demostra que el SIA, en combinació amb altres paràmetres metabòlics, pot servir com una eina eficaç per discriminar els peixos amb millor potencial de creixement, així com a marcador sensible de l'estat nutricional i d'engreix. D'altra banda, la combinació de l'anàlisi d'isòtops estables amb les eines emergents, com ara tècniques de proteòmica (2D-PAGE), ens proporciona nous coneixements sobre els canvis metabòlics que ocorren en els músculs dels peixos durant l‟increment del creixement muscular induït per l'exercici.

Hepatitis B virus genotypes in Southeast Brazil and its relationship with histological features

Data concerning the relationship between hepatitis B virus (HBV) genotypes and liver histology are scarce. The aim of this study was to compare HBV non-B and non-C genotypes according to demographic features, clinical status, HBV-DNA levels and liver histology in Rio de Janeiro. One hundred twenty one consecutive chronic HBV-infected patients were enrolled during two-year period and data were prospectively collected. Sera were tested for HBV genotyping using restriction fragment length polymorphism. Liver biopsy was obtained from patients with either increased alanine aminotransferase (ALT) or HBV-DNA levels. Genotype A was the most common, found in 82 (68%) patients, followed by F in 19 (15%), D in 17 (14%), B in one (1%) and C in two (2%). There was no association between HBV genotypes A, D and F and gender (p = 0.37), age (p = 0.78), race (p = 0.22), mode of infection (p = 0.94), HB "e" antigen status (p = 0.37) and HBV-DNA levels (p = 0.47). The ALT levels were lower in genotype D (75%) compared with A (47%) and F (55%) (p = 0.05). Liver biopsy showed lower inflammation [histological activity index (HAI) = 4] and fibrosis (F) (= 0) scores in genotype D than in genotypes A (HAI = 5, p < 0.001; F = 2, p = 0.008) or F (HAI = 5, p = 0.009; F = 2, p = 0.01). Genotype A was the most prevalent in chronic HBV-infected patients and genotype D patients presented with less intense liver disease.

Efectos de la deficiencia de yodo sobre variables intelectuales en una población infantil.

An association between severe iodine deficiency and poor mental development has been found in many studies. We examined the relationship between moderate or mild iodine deficiency and intellectual capacity in order to determine whether problems common to severe iodine deficiency (including mental retardation) also emerge in a more subtle form. We also wished to know whether the classic methodology (comparing iodine-deficient zones with nondeficient zones) is the most adequate, and propose to combine this grouping by zones with urinary iodine presented by individuals in each zone. We measured IQ, manipulative and verbal capacity, attention, visual motor ability and disruptive behaviour, variables that have barely been studied in this kind of investigations. The sample comprised 760 schoolchildren from the province of Jaén (southern Spain). Our results show that children with low levels of iodine intake and with urinary iodine concentration lower than 100 microg/litre had a lower IQ and displayed more disruptive behaviour than children with high levels of the criteria. The other variables were not associated with iodine deficiency.

Research letter: is neuroticism a risk factor for postpartum depression?

Although the relationship between personality and depressive illness is complex (Shea, 2005), there is empirical evidence that some personality features such as neuroticism, harm avoidance, introversion, dependency, self-criticism or perfectionism are related to depressive illness risk (Gunderson et al. 1999).

Relationship of mating systems and metabolic rate with cycle length of spermatogenesis and sperm production rate in shrews

SUMMARY : The shrews are among the most ancient of living eutherian mammals. They represent an interesting comparative model because of their extreme divergent species. The two shrew subfamilies, Soricinae and Crocidurinae are characterized by fundamental differences concerning their metabolic rates, litter size, period of gestation and different mating pattern. In this study we established and compared the sperm characteristics in four species of different genera of shrews (Sorex araneus, Neomys fodiens, Crocidura russula and Suncus murinus) in the context of the sperm competition hypothesis. The sperm competition concerns the competition between ejaculates of different males for fertilization of ova of a female within a single estrus period. As expected, a greater relative testis size (indicating the importance of polyandry) was associated with a higher number of cauda epididymal spermatozoa, higher level of circulating testosterone and a higher percentage of progressive sperm motility. In addition, we investigated if the basal metabolic rate (BMR) and relative testis size (RTS) may be correlated with the cycle length of spermatogenesis. In this purpose, we determined and compared the cycle length of spermatogenesis in six species of shrews belonging to two subfamilies: Soiricinae (Sorex araneus, Sorex coronatus, Sorex minutus, Neomys fodiens) and Crocidurinae (Crocidura russula, Sunctes murinus). Our results indicate that sperm competition and metabolic rate may act independently or together reducing cycle length of spermatogenesis and thus increase sperm production. We finally investigated this correlation across 32 mammalian species. After testing the data for phylogenetic independence, our results showed that BMR explained only 21 % of the variation, while the RTS explained 44% of the variation of the cycle length of spermatogenesis. The level of the sperm competition, indicated by RTS, is thus to our knowledge the most important factor influencing the speed of spermatogenesis in mammals. RESUME : Les musaraignes sont parmi les plus anciens mammifères vivants. Grâce à leurs extrêmes divergences, ils sont souvent utilisés comme modèles dans des études comparatives. Les deux sous-familles Soricinae et Crocidurinae sont caractérisées par des différences fondamentales, notamment en termes d'intensité du métabolisme, des stratégies de reproduction et du comportement social. Dans la première partie de cette étude, nous avons établi et comparé certaines "caractéristiques des spermatozoïdes chez quatre espèces de musaraignes appartenant à des genres différents (Sorex araneus, Neomys fodiens, Crocidura russula et Suncus murinus). Les résultats ont été interprétés dans le contexte de la théorie de la compétition spermatique, c'est-à-dire la compétition entre le sperme de deux ou plusieurs mâles pour féconder un maximum d'ovules de la même femelle. Cette compétition spermatique peut amener à certaines adaptations biologiques afin de produire plus de sperme. Comme attendu, une grande taille relative des testicules est associée à un nombre élevé de spermatozoïdes, dont la majorité présente une mobilité progressive. Un taux élévé de testostérone a également été observé. De plus, nous avons étudié l'influence du métabolisme basal ainsi que l'intensité de la compétition spermatique sur la durée du cycle de la spermatogenèse. Dans ce but, nous avons déterminé et comparé les durées de la spermatogenèse chez six espèces de musaraignes appartenant à deux sous-familles : Soricinae (Sorex araneus, Sorex coronatus, Sorex minutus, Neomys fodiens) et Crocidurinae (Crocidura russula, Suncus murinus). Les résultats obtenus indiquent que ces deux facteurs (l'intensité du métabolisme basal et de la compétition spermatique) agissent d'une manière dépendante ou indépendante dans le même sens. La conséquence de ces actions est une diminution de la durée de la spermatogenèse entraînant une augmentation de la production de spermatozoïdes. Nous avons finalement étudié ce phénomène dans l'ensemble des mammifères. Après avoir testé l'indépendance phylogénétique, nos résultats montrent que l'intensité de la compétition spermatique indiquée par le RTS est mieux corrélée avec la régulation de la durée de la spermatogenèse qu'avec l'intensité du métabolisme.

Adolescent survivors of childhood cancer: are they vulnerable for psychological distress?

OBJECTIVES: We aimed to (i) evaluate psychological distress in adolescent survivors of childhood cancer and compare them to siblings and a norm population; (ii) compare the severity of distress of distressed survivors and siblings with that of psychotherapy patients; and (iii) determine risk factors for psychological distress in survivors. METHODS: We sent a questionnaire to all childhood cancer survivors aged <16 years when diagnosed, who had survived ≥ 5 years and were aged 16-19 years at the time of study. Our control groups were same-aged siblings, a norm population, and psychotherapy patients. Psychological distress was measured with the Brief Symptom Inventory-18 (BSI-18) assessing somatization, depression, anxiety, and a global severity index (GSI). Participants with a T-score ≥ 57 were defined as distressed. We used logistic regression to determine risk factors. RESULTS: We evaluated the BSI-18 in 407 survivors and 102 siblings. Fifty-two survivors (13%) and 11 siblings (11%) had scores above the distress threshold (T ≥ 57). Distressed survivors scored significantly higher in somatization (p=0.027) and GSI (p=0.016) than distressed siblings, and also scored higher in somatization (p ≤ 0.001) and anxiety (p=0.002) than psychotherapy patients. In the multivariable regression, psychological distress was associated with female sex, self-reported late effects, and low perceived parental support. CONCLUSIONS: The majority of survivors did not report psychological distress. However, the severity of distress of distressed survivors exceeded that of distressed siblings and psychotherapy patients. Systematic psychological follow-up can help to identify survivors at risk and support them during the challenging period of adolescence.

Maternal and paternal contributions to pathogen resistance dependent on development stage in a whitefish (Salmonidae)

It is often assumed that maternal and paternal contributions to offspring phenotype change over the lifetime of an individual. However, studies on parental effects typically suffer from the problems that heritabilities and maternal environmental effects are difficult to separate, and that both may depend on environmental factors and developmental stage. In order to experimentally disentangle maternal from paternal contributions and the likely effects of developmental stage from ecological effects, we sampled a natural population of the whitefish Coregonus palaea, used gametes for full-factorial in vitro fertilizations, raised over 10000 of the resulting offspring singly at controlled conditions, and exposed them at different points during embryonic development to one of two strains of Pseudomonas fluorescens that differed in their virulence characteristics (only one caused mortality, while both delayed hatching and reduced growth). Vulnerability to infection increased markedly over embryo development. This change coincided with a distinct shift in the importance of maternal to additive genetic effects on survival. Timing of exposure also affected the variance components for hatching time and larval length, but in a less consistent direction than the variance components for mortality. No significant genetic variation was found for any reaction norms across time points of exposure, indicating a uniformity among genotypes in how susceptibility changed over development. Phenotypes were also typically correlated across time points, which could constrain the evolution of the reaction norms. Our experiment demonstrates that the relative maternal and paternal contributions to susceptibility to an infection, and hence the evolutionary potential to respond to pathogen-induced selection, depends not only on the kind of pathogenic stress but also on the timing of the challenge.

Selective integration of auditory-visual looming cues by humans.

An object's motion relative to an observer can confer ethologically meaningful information. Approaching or looming stimuli can signal threats/collisions to be avoided or prey to be confronted, whereas receding stimuli can signal successful escape or failed pursuit. Using movement detection and subjective ratings, we investigated the multisensory integration of looming and receding auditory and visual information by humans. While prior research has demonstrated a perceptual bias for unisensory and more recently multisensory looming stimuli, none has investigated whether there is integration of looming signals between modalities. Our findings reveal selective integration of multisensory looming stimuli. Performance was significantly enhanced for looming stimuli over all other multisensory conditions. Contrasts with static multisensory conditions indicate that only multisensory looming stimuli resulted in facilitation beyond that induced by the sheer presence of auditory-visual stimuli. Controlling for variation in physical energy replicated the advantage for multisensory looming stimuli. Finally, only looming stimuli exhibited a negative linear relationship between enhancement indices for detection speed and for subjective ratings. Maximal detection speed was attained when motion perception was already robust under unisensory conditions. The preferential integration of multisensory looming stimuli highlights that complex ethologically salient stimuli likely require synergistic cooperation between existing principles of multisensory integration. A new conceptualization of the neurophysiologic mechanisms mediating real-world multisensory perceptions and action is therefore supported.

Performing masculinity, influencing health: a qualitative mixed-methods study of young Spanish men

Background: The literature shows how gender mandates contribute to differences in exposure and vulnerability to certain health risk factors. This paper presents the results of a study developed in the south of Spain, where research aimed at understanding men from a gender perspective is still limited. Objective: The aim of this paper is to explore the lay perceptions and meanings ascribed to the idea of masculinity, identifying ways in which gender displays are related to health. Design: The study is based on a mixed-methods data collection strategy typical of qualitative research. We performed a qualitative content analysis focused on manifest and latent content. Results: Our analysis showed that the relationship between masculinity and health was mainly defined with regard to behavioural explanations with an evident performative meaning. With regard to issues such as driving, the use of recreational drugs, aggressive behaviour, sexuality, and body image, important connections were established between manhood acts and health outcomes. Different ways of understanding and performing the male identity also emerged from the results. The findings revealed the implications of these aspects in the processes of change in the identity codes of men and women. Conclusions: The study provides insights into how the category ‘man’ is highly dependent on collective practices and performative acts. Consideration of how males perform manhood acts might be required in guidance on the development of programmes and policies aimed at addressing gender inequalities in health in a particular local context.

Accumulation of scandium in plasma in patients with chronic renal failure.

Scandium (Sc) is an element with many industrial applications, but relatively little is known about its physiological and/or toxicological effects, and very little data are available concerning the role of Sc in chronic renal failure (CRF). This paper examines the changes in plasma levels of Sc in predialysis patients with CRF and the relationship with blood parameters. The participants in this trial were 48 patients with CRF in predialysis and 53 healthy controls. Erythrocyte, haemoglobin, and haematocrit counts in blood were determined, and levels of creatinine, urea, uric acid, albumin, total protein and Sc were measured in plasma. The glomerular filtration rate (GFR) was calculated using the Cockcroft-Gault index. The CRF patients were found to have higher plasma levels of creatinine, urea, uric acid, albumin, total protein, and Sc and a lower GFR than that the controls. Scandium in plasma was positively correlated with creatinine and plasma urea and negatively correlated with GFR, haemoglobin, and haematocrit and was associated with the risk of lower levels of erythrocytes, haemoglobin, and haematocrit. CRF was associated with increases in the circulating levels of scandium.

La formulation de cas : un modèle d'évaluation psychologique de l'enfant et de l'adolescent

L'article présente le modèle de la formulation de cas pour l'évaluation psychologique de l'enfant et de l'adolescent. La formulation de cas s'est développée en réponse au diagnostic psychiatrique qui peut être perc ̧u comme une approche réductionniste du fonctionnement psychique. En Europe, de nombreux psychologues cliniciens ont adopté ce modèle, qui a initialement été développé par les psychothérapeutes d'orientation cognitivo-comportementale, et l'ont adapté à leur pratique respective. Ce modèle, aujourd'hui bien ancré dans la pratique clinique quotidienne, consiste à élaborer différents regards théoriques intégrant les résultats de la recherche scientifique pour favoriser la compréhension d'un cas clinique. Ce modèle s'inscrit parallèlement dans une approche centrée sur les preuves et dans une pratique réflexive de la clinique. L'objectif de la formulation de cas est d'élaborer des hypothèses et de proposer des traitements adéquats. La famille est toutefois intégrée dans le processus de discussion et de prise de décision, ce qui permet de renforcer l'alliance thérapeutique. Cet article présente les trois courants théoriques les plus utilisés dans la formulation de cas : les approches cognitivo-comportementale, psychodynamique et systémique. L'utilisation d'une seule et même vignette permettra de montrer la pertinence du modèle et la complémentarité des différentes approches cliniques.