First analysis of the proteome in two nematomorph species, Paragordius tricuspidatus (Chordodidae) and Spinochordodes tellinii (Spinochordodidae).

The proteome of most parasite species is currently unknown. Hairworms (Nematomorpha), 300 species distributed around the world, are parasitic in arthropods (mainly terrestrial species) when juveniles, but they are free-living in aquatic environments when adult. Most aspects of their systematics and biology are currently unknown. The aim of this paper was (i) to report a novel and reproducible protocol for the analysis of the proteome of hairworms using two-dimensional gel electrophoresis (2-DGE) and mass spectrometry (matrix laser desorption ionization-time of flight mass spectrometry (MALDI-TOF)) and (ii) to determine the level of proteomic divergence between two sympatric but taxonomically unrelated nematomorph species in the adult stage, Paragordius tricuspidatus Dufour (Nematomorpha, Gordiidae) and Spinochordodes tellinii Camerano (Nematomorpha, Gordiidae). In total, 689 protein spots were observed for P. tricuspidatus, 575 for S. tellinii. Only 36.2% spots were shared between the two species. Quantitative analysis of the proteins which are common to both parasite species reveals substantial differences in the pattern of protein expression. These results suggest a rapid evolutionary divergence between these two nematomorph families. Also, to test the value of our MALDI-TOF protocol, we used Actin-2 (Act-2), a protein highly conserved in the course of evolution. Peptide mass fingerprint (PMF) data obtained for Act-2 of P. tricuspidatus and S. tellinii suggest a very high homology with Act-2 of different worms species belonging to the Bilateria phylum (Annelida and Nematoda) and more specifically to Lumbricus terrestris (Annelida, Lumbricidae) and Caenorhabditis elegans (Nematoda, Rhabditidae). We discuss our results in relationship with current ideas concerning the use of proteomics in systematics.     

Developing the occupational stress indicator (OSI) for use in Brazil: A report on the reliability and validity of the translated OSI

The Occupational Stress Indicator (OSI) was translated into Brazilian Portuguese and administered to a sample of 84 white-collar workers in Brazil. Five of the six scales of the OSI (job satisfaction, mental and physical health, coping, type A behaviour, sources of stress) showed acceptable reliability. The reliability of the sixth scale (locus of control) was disappointing, in keeping with earlier findings that suggest that this scale requires further development. Alternative measures of the stress outcomes — job satisfaction, mental health and physical health — were taken in order to assess the construct validity of these three scales. These measures included translations of the Hackman-Oldham job satisfaction measure and the Crown–Crisp Experiential Index, as well as subjective measures of health-related behaviours. Correlational and multivariate analyses of these data suggested that the job satisfaction, mental health and physical health scales of the OSI had good validity, with the physical health measure probably including a psychosomatic component. These findings are promising for the development of a new version of the OSI designed for use in South America.     

Lifestyle Intervention in Pregnant Women With Obesity Impacts Cord Blood DNA Methylation,Which Associates With Body Composition in the Offspring

Maternal obesity may lead to epigenetic alterations in the offspring and might thereby contribute to disease later in life. We investigated whether a lifestyle intervention in pregnant women with obesity is associated with epigenetic variation in cord blood and body composition in the offspring. Genome-wide DNA methylation was analyzed in cord blood from 208 offspring from the Treatment of Obese Pregnant women (TOP)-study, which includes pregnant women with obesity randomized to lifestyle interventions comprised of physical activity with or without dietary advice versus control subjects (standard of care). DNA methylation was altered at 379 sites, annotated to 370 genes, in cord blood from offspring of mothers following a lifestyle intervention versus control subjects (false discovery rate [FDR] <5%) when using the Houseman reference-free method to correct for cell composition, and three of these sites were significant based on Bonferroni correction. These 370 genes are overrepresented in gene ontology terms, including response to fatty acids and adipose tissue development. Offspring of mothers included in a lifestyle intervention were born with more lean mass compared with control subjects. Methylation at 17 sites, annotated to, for example, DISC1, GBX2, HERC2, and HUWE1, partially mediates the effect of the lifestyle intervention on lean mass in the offspring (FDR <5%). Moreover, 22 methylation sites were associated with offspring BMI z scores during the first 3 years of life (P < 0.05). Overall, lifestyle interventions in pregnant women with obesity are associated with epigenetic changes in offspring, potentially influencing the offspring’s lean mass and early growth.     

Neuropathy in two cobalamin-deficient breast-fed infants of vegetarian mothers

We describe the electrophysiological findings in 2 infants with deficient cobalamin intake. After normal development, psychomotor regression appeared after the 6th month, leading to severe hypotonia and apathy before the 12th month. Electrodiagnostic evaluation showed sensory neuropathy in both cases, associated with motor neuropathy in 1 case. Thus, in an acquired floppy infant syndrome, electrophysiological signs of peripheral neuropathy contributed to the diagnosis of a curable metabolic disorder.     

ERPs and PET analysis of time perception: spatial and temporal brain mapping during visual discrimination tasks

ERPs were recorded from 12 subjects performing duration and intensity visual discrimination tasks which have been previously used in a PET study. PET data showed that the same network was activated in both tasks [P. Maquet et al., NeuroImage 3:119-126, 1996]. Different ERP waveforms were observed for the late latency components depending on the dimension of the stimulus to be processed: frontal negativity (CNV) for the duration task and parieto-occipital positivity (P300) for the intensity task. Using BESA software, the sources were first modelled with a "PET dipolar model" (right prefrontal, right parietal, anterior cingulate, left and right fusiforms). To obtain a better fit for ERPs recorded in each task, two sources (cuneus, left prefrontal area) had to be added. Consistently with PET findings, dipole modelling indicates that duration and intensity dimensions of a visual stimulus are processed in the same areas. However, ERPs also reveal prominent differences between the time course of the dipole activations for each task, particularly for sources contributing to the late latency ERP components. In the intensity task, dipoles located in the cuneus, the anterior cingulate, and the left prefrontal area yield largest activity within the P300 interval, then activity diminishes rapidly as the stimulus ends, whereas in the duration task, the cuneus and anterior cingulate are still active several hundred milliseconds following stimulus offset. Moreover, in the duration task, the activity of the right frontal dipole parallels the CNV waveform, whereas in the intensity task, this dipole is largely inactive. We assume that the right frontal area plays a specific role in the formation of temporal judgments.     

Alterations of rat hepatoma cell genomes induced by copper deficiency

Copper deficiency imposed on a variant rat hepatoma cell line inhibits cell growth and results in genesis of stable well‐differentiated, tumorigenic revertants. The treatment caused a substantial increase in DNA content (up to 20%) of G1 and G2/M cells and inhibition of cell proliferation. This phenomenon was correlated with an enhancement of DNA replication. The excess DNA was unstable and rapidly lost with reinitiation of cell growth and mitosis. Minute and double‐minute extrachromosomal material was detected by metaphase analysis, suggesting widespread DNA amplification in copper‐deficient conditions. Although transitory, these genetic events were associated with genesis of drug‐resistant cells and induction of tumorigenicity of the variant hepatoma cells. The data reveal a novel aspect of the consequences of trace element deficiency.