Catherine Bouland

The fine structure of the buccal tentacles of Holothuria forskali (Echinodermata, Holothuroidea)

SummaryUltrastructural study of the buccal tentacles of Holothuria forskali revealed that each tentacle bears numerous apical papillae. Each papilla consists of several differentiated sensory buds.The epidermis of the buds is composed of three cell types, i.e. mucus cells, ciliated cells, and glandular vesicular cells (GV cells). The GV cells have apical microvilli; they contain bundles of cross striated fibrillae associated with microtubules. Ciliated cells have a short non-motile cilium. Bud epidermal cells intimately contact an epineural nervous plate which is located slightly above the basement membrane of the epidermis. The epineural plate of each bud connects with the hyponeural nerve plexus of the tentacle. This nerve plexus consists of an axonic meshwork surrounded in places by sheath cells. The buccal tentacles have well-developed mesothelial muscles. Direct innervation of these muscles by the hyponeural nerve plexus was not seen.It is suggested that the buccal tentacles of H. forskali are sensory organs. They would recognize the organically richest areas of the sediment surface through the chemosensitive abilities of their apical buds. Tentacles presumably trap particles by wedging them between their buds and papillae.

Barriers and opportunities for return-to-work of cancer survivors: time for action—rapid review and expert consultation

BackgroundThe spread of early detection and the improvement of cancer treatment have led to an increased prevalence of cancer survivors, including in the working age population. Return-to-work (RTW) of cancer survivors has become a key issue for national cancer control plans. This study aims (1) to identify the factors that have an impact on RTW of cancer survivors and to draw a risk profile supporting health professionals in the screening of those at risk for barriers of RTW and (2) to sharpen these results with input from health, social security and academic Belgian experts and to provide evidence-based recommendations that facilitate RTW of cancer survivors.MethodsA rapid review was conducted, based on the methodology elaborated by The Knowledge to Action Research Programme and researchers from the University of York, including a quality assessment of retained studies. Next, the Delphi method was used to organize a consultation with experts in order to discuss, validate and complement the results.ResultsForty-three out of 1860 studies were included. We identified nine risk factors grouped into four categories: socio-demographic, disease and treatment-related, work-related, and personal and subjective factors. Experts suggested dividing them into two even groups: factors which are modifiable and those which are not. The awareness of health professionals regarding the identified factors, a better assessment of work capacities, clarity on the rights and obligations of employers and workers alike, and the setup of a positive discrimination employment policy for cancer survivors were acknowledged as factors facilitating RTW of cancer survivors.ConclusionsThe awareness of health professionals regarding barriers of RTW may improve the early identification of cancer survivors at risk for prolonged time to RTW and may allow early supportive intervention. Social and employment policies should be better tailored to support both employers and cancer survivors in the RTW process, providing incentives to positively discriminate cancer survivors on prolonged sick leave.

Collagen diversity in the sea urchin, strongylocentrotus purpuratus

Abstract 1. 1. Pepsin insensitive fragments of collalgen extracted from tube feet and peristome have α 1 and α 2 bands that differ in apparent molecular weights from each other and from human type 1 collagen. 2. 2. A monoclonal antibody that reacts with the ξ I band and a low molecular weight fragment of tube foot collagen does not react with either peristome collagen or human type I collagen. 3. 3. Measurements of the axial periodicity of native fibers of tube foot and peristone collagens indicate they have D values that differ significantly from each other and from reported values of vertebrate type I collagen. 4. 4. We propose that there are diverse and specialized types of collagen in sea urchins that are heterogeneously distributed in the extracellular matrix of different tissue.

Health effects of extremely low-frequency magnetic fields: reconsidering the melatonin hypothesis in the light of current data on magnetoreception

The so‐called ‘Melatonin Hypothesis’ proposed that decreased nocturnal production of melatonin (MLT) might explain the increased risk of breast cancer that has been formerly attributed to extremely low‐frequency (ELF) magnetic fields (MF) of weak intensity. Although the risk of ELF MF upon breast cancer was later dismissed, repeated reports were published of partial inhibition of MLT secretion in rats under long‐term (≥ 4 weeks) exposure to weak ELF MF. Since 2004, however, this topic has not been experimentally studied any more. In the present study, we propose to go back to the MLT hypothesis and apply it to childhood leukemia, for which an increased risk has been robustly associated with residential exposure to ELF MF. Contrary to the original hypothesis, however, we do not consider decreased MLT levels, but disruption of circadian rhythmicity per se as the effector mechanism. Indeed, the role of the circadian timing system in the development of childhood leukemia has been well established. Motivation for going back to the MLT hypothesis comes from recent data that suggest magnetosensory disruption by ELF MF in mammals, and magnetosensitivity in humans, together with current evidence for an influence on circadian rhythmicity from disruption of non‐photic sensory stimuli of various natures. We thus suggest further study on circadian rhythmicity in humans (children if possible) under long‐term exposure to weak ELF MF. Copyright

The ciliate Orchitophrya cf. stellarum and other parasites and commensals of the northern pacific seastar Asterias amurensis from Japan

To identify the pathogens and possible biological control agents for the introduced seastar Asterias amurensis, we examined seastars from source populations in central and northern Japan. In particular, we sought the scuticociliate Orchitophrya cf. stellarum. The ciliate was found in male A. amurensis from five sites. We also found the caprellid amphipod Caprella astericola on A. amurensis and Distolasterias nipon from Nemuro Bay. The copepod Scottomyzon gibberum was found on A. amurensis from Usujiri and polychaete scaleworms Arctonoe vittata were found on A. amurensis from Murohama and Nemuro Bay. Of these parasites and commensals, Orchitophrya cf. stellarum is the most likely agent for biological control of A. amurensis in Australian waters; however, its ability to regulate seastar populations is uncertain.

Pigmented Follicle Cells and the Maturation of Oocytes in the Sand Dollar, Dendraster excentricus

Early in the spawning season female D. excentricus can be induced to spawn oocytes in the late stages of oogenesis. Observations with light microscopy indicate that pigment cells migrate in the jelly coat away from the surface of oocytes coincident with the final growth of the oocyte and its maturation. The pigment cells undergo a series of changes in shape and the oocyte elaborates arrays of long microvilli as the cells elevate from the surface of the oocyte. Transmission electron microscopy (TEM) observations of oocytes fixed within the ovary indicate that features of the sequence observed in the spawned oocytes normally take place within the ovary, prior to spawning. Extracts of the pigment cells induce a low level of germinal vesicle breakdown in asteroid oocytes. It is proposed that these cells are homologous to the follicle cells of other echinoderms and are involved in stimulating the maturation of oocytes.

Origin of germinal cells and the reproductive cycle of the asteroid Asterias rubens L. (Echinodermata)

Abstract A genital bud was observed in the aboral hemal system of Asterias rubens. Its structure is very similar to the parietal structure of a gonad. Three cell types are recognized, two of them (primordial germinal cells and ciliated somatic cells) border the periphery of the genital bud, the third type (pseudopodial cells) is found in the lumen. They form a cylindric structure surrounded by a thick and continuous basal lamina. The genital bud has a cyclical appearance and development within the aboral hemal system. Its major development coincides with the regression of the gonads that occurs after the natural spawning of gametes. The possible involvement of the genital bud in the initiation of the following years gametogenesis is considered. The complete regression of the gonad after spawning suggests an annual neoformation of the gonad preceding the initiation of the gametogenetic cycle.

BTEX air concentrations and self- reported common health problems in gasoline sellers from Cotonou, Benin

To examine the relation between BTEX exposure levels and common self-reported health problems in 140 gasoline sellers in Cotonou, Benin, a questionnaire documenting their socioeconomic status and their health problems was used, whereas 18 of them went through semi-directed qualitative individual interviews and 17 had air samples taken on their workplace for BTEX analysis. Median concentrations for BTEX were significantly lower on official (range of medians: 54–207 μg/m³, n = 9) vs unofficial (148–1449 μg/m³, n = 8) gasoline-selling sites (p < 0.05). Self-reported health problems were less frequently reported in sellers from unofficial vs official selling sites (p < 0.05), because, as suggested by the semi-directed interviews, of their fear of losing their important, but illegal, source of income. Concluding, this study has combined quantitative and qualitative methodological approaches to account for the complex socioeconomic and environmental conditions of the investigated sellers, leading to their, in some cases, preoccupying BTEX exposure.

How do social security schemes and labor market policies support the return-to-work of cancer survivors? A review article

Abstract Objective About 40% of new cancer diagnoses are detected among working age individuals. Cancer diagnosis and treatment have high impact on the work ability of workers and represent a real challenge for the healthcare and social security systems but also for employers and the labour market. This review aims at investigating the legal frameworks set up in EU Member States that support the retention and integration of workers with disability. Furthermore, we look at these initiatives or measures to see whether they fit the specific needs of workers with cancer. Methods We searched the PubMed database combining 4 key words: cancer, labour market, labour law and disability insurance or disability benefits. A total of 1.185 articles were found of which 10 were used for this review. In addition, grey literature, reports from the European Commission, the OECD and the WHO were searched and included in the material used for this review. Results Few peer reviewed articles discuss the impact of labor market law on the (re)integration of cancer survivors. Most measures and initiatives support workers with chronic diseases but present important limits when considering workers with cancer. Collaboration and coordination among health providers, social workers and employment decision makers is the mostly required and effective. Conclusion More research efforts should be made to systematically assess the impact of labor market and employment measures and initiatives on the (re)integration of workers with chronic diseases, with specific attention for workers with cancer. Legal frameworks need to be rethought for a better balance between productivity and equity, inclusion and social justice.

The use of the permanent sample (eps) to study the returnto- work after cancer. Challenges and opportunities for research

INTRODUCTION The introduction of early cancer detection and the improvement in treatment efficacy have led to a significant increase in the survival and the prevalence of (ex) cancer patients. Approximately 40 % of new cancer cases are diagnosed every year in the working age population (20-64 years). Maintaining their quality of life results, among others, in their retain on the labour market. Even though it is necessary to realize the scale of the phenomenon and to plan interventions, no measure allows assessing the rate of return to work among of (ex) cancer patients in Belgium nowadays. METHODS We observe during a five-year period the socio-professional status (inability, disability, unemployment or death) of 645 workers identified in the permanent sample (EPS), having had an oncological multidisciplinary consultation (MOC) in 2011. RESULTS By the end of follow-up, 24 % of the workers were deceased. Among those who survived 26 % are unable to work, 12 % are unemployed and 63 % do not receive any social benefit. Women and young workers (20-44 years) seemed to have encountered difficulties the most. CONCLUSIONS The results of this study allow giving a prudent first estimation of the return to work of socially insured Belgian citizens of almost 40 %, five years after the first MOC. Nevertheless, the structure of the EPS presents many limitations to the interpretation and reliability of results. We suggest some modifications of the EPS that might offer scientists better opportunities to improve the performance and reliability of such cohort studies.