Gonadal Malformations in Whitefish from Lake Thun: Defining the Case and Evaluating the Role of EDCs

The objectives of this project were to evaluate i) whether the gonad alterations of whitefish (Coregonus lavaretus spp.) in Lake Thun represent abnormal morphological variations specific to this lake, and, if so, ii) whether the malformations are related to chemical exposure, in particular to exposure to endocrine-disrupting compounds (EDCs). Large-scale monitoring data revealed that, although whitefish in other lakes display some background variation of gonad morphology, the situation in Lake Thun, is unique because of the significantly higher prevalence of gonad malformations. The abnormal variations of whitefish gonad morphology include aplasias, compartmentations, fusions, and intersex. In the search for the factor(s) causing the gonad malformations, coregonids were exposed from fertilization up to maturity to Lake Thun water and plankton or to contaminants possibly being present in the lake, including trinitrotoluenes, and naphtalene sulfonates. Since these experiments are still ongoing, a conclusive answer cannot be given yet, but initial observations point to a role of the lake plankton. The possible presence of EDCs in Lake Thun was assessed using bioanalytics and biomarkers. The bioanalytical studies found estrogenic activities in concentrated plankton extracts of Lake Thun, however, estrogenic activities occurred also in plankton extracts of reference lakes. Bioassay-directed fractionation of the plankton samples points to degradation products of natural substances as a cause of the estrogenic activity. Examination of Lake Thun whitefish for EDC biomarkers such as vitellogenin, sex steroid levels or intersex frequency yielded no indications of exposure to EDCs, neither in fish with normal nor in fish with abnormal gonad morphology. Long-term laboratory exposure of developing coregonids to the prototype estrogenic compound, 17?-estradiol, resulted in an increased frequency of intersex gonads, but did not induce the other gonad malformations typical for Lake Thun coregonids. In summing up, the currently available evidence does not support an EDC or chemical etiology of the gonad malformations, however, this preliminary conclusion needs to be substantiated in the ongoing investigations. The project also highlights the need for more detailed knowledge of natural variation in wildlife populations to be able to recognize anthropogenically caused variation

The Swiss Primary Hypersomnolence and Narcolepsy Cohort study (SPHYNCS): Study protocol for a prospective, multicentre cohort observational study

Narcolepsy type 1 (NT1) is a disorder with well-established markers and a suspected autoimmune aetiology. Conversely, the narcoleptic borderland (NBL) disorders, including narcolepsy type 2, idiopathic hypersomnia, insufficient sleep syndrome and hypersomnia associated with a psychiatric disorder, lack well-defined markers and remain controversial in terms of aetiology, diagnosis and management. The Swiss Primary Hypersomnolence and Narcolepsy Cohort Study (SPHYNCS) is a comprehensive multicentre cohort study, which will investigate the clinical picture, pathophysiology and long-term course of NT1 and the NBL. The primary aim is to validate new and reappraise well-known markers for the characterization of the NBL, facilitating the diagnostic process. Seven Swiss sleep centres, belonging to the Swiss Narcolepsy Network (SNaNe), joined the study and will prospectively enrol over 500 patients with recent onset of excessive daytime sleepiness (EDS), hypersomnia or a suspected central disorder of hypersomnolence (CDH) during a 3-year recruitment phase. Healthy controls and patients with EDS due to severe sleep-disordered breathing, improving after therapy, will represent two control groups of over 50 patients each. Clinical and electrophysiological (polysomnography, multiple sleep latency test, maintenance of wakefulness test) information, and information on psychomotor vigilance and a sustained attention to response task, actigraphy and wearable devices (long-term monitoring), and responses to questionnaires will be collected at baseline and after 6, 12, 24 and 36 months. Potential disease markers will be searched for in blood, cerebrospinal fluid and stool. Analyses will include quantitative hypocretin measurements, proteomics/peptidomics, and immunological, genetic and microbiota studies. SPHYNCS will increase our understanding of CDH and the relationship between NT1 and the NBL. The identification of new disease markers is expected to lead to better and earlier diagnosis, better prognosis and personalized management of CDH

Surgery for benign insulinoma: An international review

In a multiinstitutional review, data on 396 patients with benign solitary or multiple insulinomas operated on in 15 centers were collected. In these 396 patients, 419 laparotomies (375 primary procedures and 44 reoperations) were performed. The rate of unnecessary laparotomies was 1.7%. Complications occurred after 132 operations (31.5%), requiring 27 reinterventions (6.4%). Ten (2%) patients died within 30 days of surgery. The success rate of first procedures in the centers was 94.9%. After reoperation, all but 2 (99.5%) of these patients were cured. The overall cure rate including those patients who had their primary operations elsewhere was 97.5% . Compilant les dossiers de 15 établissements internationaux, nous avons colligé les données concernant 396 patients présentant un insulinome bénin unique ou multiple, opérés. Chez ces 396 patients, 419 laparotomies (375 interventions de première intention et 44 reprises) ont été effectuées. Le taux de laparotomie inutile était de 1.7%. Des complications sont intervenues à la suite de 132 opérations (31.5%), nécessitant 27 réinterventions (6.4%). Dix (2%) patients sont morts dans les trente jours après l'acte chirurgical. Le taux de succès des interventions de première intention dans les centres de l'étude était de 94.9%. Après réinterventions, tous les patients sauf 2 (99.5%) ont été guéris. Le taux global de guérison, y compris les patients ayant été opérés une première fois ailleurs, était de 97.5%. En una revisión multiinstitucional se recolectaron los datos sobre 396 pacientes con insulinomas benignos solitarios o múltiples operados en 15 centros. En estos 396 pacientes se efectuaron 419 laparotomías (375 procedimientos primarios y 44 reoperaciones). Se registró una tasa de laparotomías innecesarias de 1.7%; se presentaron complicaciones después de 132 operaciones (31.5%), las cuales requirieron 27 reintervenciones (6.4%). Diez (2%) pacientes murieron dentro de los primeras 30 días después de la cirugía. La tasa de éxito del procedimiento primario realizado en estos centros fue 94.9%. Después de las reoperaciones la totalidad de los pacientes, menos 2 (99.5%), fueron curados. La tasa global de curación, incluyendo los que tuvieron su operación primaria por fuera de los centros del estudio, fue 97.5%.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41289/1/268_2005_Article_BF01658536.pd

Sympatric and Allopatric Divergence of MHC Genes in Threespine Stickleback

Parasites can strongly affect the evolution of their hosts, but their effects on host diversification are less clear. In theory, contrasting parasite communities in different foraging habitats could generate divergent selection on hosts and promote ecological speciation. Immune systems are costly to maintain, adaptable, and an important component of individual fitness. As a result, immune system genes, such as those of the Major Histocompatability Complex (MHC), can change rapidly in response to parasite-mediated selection. In threespine stickleback (Gasterosteus aculeatus), as well as in other vertebrates, MHC genes have been linked with female mating preference, suggesting that divergent selection acting on MHC genes might influence speciation. Here, we examined genetic variation at MHC Class II loci of sticklebacks from two lakes with a limnetic and benthic species pair, and two lakes with a single species. In both lakes with species pairs, limnetics and benthics differed in their composition of MHC alleles, and limnetics had fewer MHC alleles per individual than benthics. Similar to the limnetics, the allopatric population with a pelagic phenotype had few MHC alleles per individual, suggesting a correlation between MHC genotype and foraging habitat. Using a simulation model we show that the diversity and composition of MHC alleles in a sympatric species pair depends on the amount of assortative mating and on the strength of parasite-mediated selection in adjacent foraging habitats. Our results indicate parallel divergence in the number of MHC alleles between sympatric stickleback species, possibly resulting from the contrasting parasite communities in littoral and pelagic habitats of lakes

Interspecific Hybridization and Mitochondrial Introgression in Invasive Carcinus Shore Crabs

Interspecific hybridization plays an important role in facilitating adaptive evolutionary change. More specifically, recent studies have demonstrated that hybridization may dramatically influence the establishment, spread, and impact of invasive populations. In Japan, previous genetic evidence for the presence of two non-native congeners, the European green crab Carcinus maenas and the Mediterranean green crab C. aestuarii, has raised questions regarding the possibility of hybridization between these sister species. Here I present analysis based on both nuclear microsatellites and the mitochondrial cytochrome C oxidase subunit I (COI) gene which unambiguously argues for a hybrid origin of Japanese Carcinus. Despite the presence of mitochondrial lineages derived from both C. maenas and C. aestuarii, the Japanese population is panmictic at nuclear loci and has achieved cytonuclear equilibrium throughout the sampled range in Japan. Furthermore, analysis of admixture at nuclear loci indicates dramatic introgression of the C. maenas mitochondrial genome into a predominantly C. aestuarii nuclear background. These patterns, along with inferences drawn from the observational record, argue for a hybridization event pre-dating the arrival of Carcinus in Japan. The clarification of both invasion history and evolutionary history afforded by genetic analysis provides information that may be critically important to future studies aimed at assessing risks posed by invasive Carcinus populations to Japan and the surrounding region

Mise en évidence de la reproduction naturelle du saumon atlantique (Salmo salar L.) dans un affluent français du Rhin par analyse génétique d'oeufs prélevés dans des frayères

En utilisant la réaction de polymérisation en chaîne, nous avons pu amplifier des régions spécifiques des ADN nucléaire (région conservée des gènes du rARN 5S) et mitochondrial (région ND-5/6) extraits d'oeufs prélevés sur quatre frayères de salmonidés dans un tributaire du Rhin. Trois frayères abritaient des descendances de saumon atlantique et la quatrième une descendance de truite commune. Ces résultats prouvent que les techniques de biologie moléculaire permettent une identification des espèces de salmonidés à des stades très précoces de développement, et que les programmes de réintroduction de saumon atlantique dans le bassin du Rhin se sont traduits par une reprise de la reproduction naturelle du saumon atlantique dans la partie française de ce bassin

REPRODUCTION DE LA TRUITE (Salmo trutta L.) DANS LETORRENT DE CHEVENNE, HAUTE-SAVOIE.UN FONCTIONNEMENT ORIGINAL ?

La reproduction d’une population de truite (Salmo trutta L.) de forme essentiellement méditerranéenne est décrite dans le ruisseau du Chevenne, un torrent à forte pente (10 %) entrecoupé d’obstacles et limité en substrat de frai, situé dans les Alpes savoyardes. Les reproducteurs (résidents du torrent ou migrants issus du cours principal) diffèrent en taille et sexe-ratio. La majorité (58 %) des femelles migrantes entrent dans l’affluent déjà ovulées. Il existe une fort gradient décroissant aval-amont dans la répartition des géniteurs et des frayères. Les 157 frayères décrites montrent une grande diversité de microhabitats (5 types principaux) utilisés pour la reproduction, avec un pourcentage élevé (65 %) de frayères construites dans des sites protégés ayant une faible vitesse de courant (< 20 cm/s). La reproduction débute en radier, l’habitat de frai classique, puis elle s’étend ensuite aux autres microhabitats avant que le frai en milieu radier ne soit achevé. Une évaluation de la disponibilité et de l’utilisation du substrat favorable au frai (taille de 1 à 3 cm) dans les divers microhabitats a été réalisée a posteriori. Le microhabitat « côté de pool » (inhabituel pour le frai) est autant utilisé que le milieu radier. Les lentilles de substrat favorable, abritées en bordure de berge ou dans les courants sont préférées alors que les lentilles de substrat non protégées dans les courants sont évitées. Une crue en fin de la période de frai a totalement détruit 36 % des frayères avec un taux de destruction totale très variable selon le type de microhabitat de frai. Les frayères creusées en côté de pool et en bordure de berge protégées du courant ont été moins détruites (15-17 % de destruction totale) que dans les autres microhabitats (50 à 67 % de destruction totale). La diversité des sites de frai pourrait donc être une composante essentielle à la survie de la population de truite en milieu « torrent exposé à des crues hivernales »

Experimentelle retroperitoneoskopische lumbale Sympathektomie. [Experimental retroperitoneoscopic lumbar sympathectomy]

The present study was designed to support the hypothesis that lumbar sympathectomy could be performed by minimal invasive surgery. In a porcine experiment, under laparoscopic vision control, a pneumoretroperitoneum was established through a direct retroperitoneal access for dissecting the retroperitoneal tissue layers and resecting the lumbar sympathetic trunc. The connective tissue septae were separated without any problems by blunt dissection under vision through the retroperitoneally inserted laparoscope. After exposure of the retroperitoneal organs and identification of specific landmarks, the resection of the lumbar sympathetic trunk was performed. We conclude that lumbar sympathectomy can be easily performed by minimal invasive surgery