Scale-dependent patterns of intraspecific trait variations in two globally invasive species.

Animal species often show substantial intraspecific trait variability (ITV), yet evidence for its flexibility across multiple ecological scales remains poorly explored. Gaining this knowledge is essential to better understand the different processes maintaining ITV in nature. Due to their broad geographic ranges, widespread invasive species are expected to display strong phenotypic variations across their distribution. Here, we quantified the scale-dependent patterns of morphological variability among invasive populations of two global freshwater invaders-red swamp crayfish Procambarus clarkii and pumpkinseed sunfish Lepomis gibbosus-both established in American and European lakes. We quantified patterns in body morphology across different ecological (Individual and Population) and spatial scales (Region). We then analyzed the scale-dependency of morphological variations among lake populations that span a diversity of abiotic and biotic conditions. Next, we used stable isotope analyses to test the existence of ecomorphological patterns linking morphology and trophic niche of individuals. We found that trait variations mainly accounted for at the regional and individual levels. We showed that populations of both species strongly differed between United States and Europe whereas habitat characteristics had a relatively minor influence on morphological variations. Stable isotope analyses also revealed that ecomorphological pattern for the trophic position of L. gibbosus was region-dependent, whereas no ecomorphological patterns were observed for P. clarkii. Overall, our study strongly supports the notion that the patterns of phenotypic variability among invasive populations are likely to modulate the ecological impacts of invasive species on recipient ecosystems.

Contrasting ecological impacts of geographically close invasive populations.

Intraspecific trait variability is now well recognized as a key component of biodiversity explaining how individuals within a species can differentially interact with their environment. To date, however, this concept has rarely been incorporated in the study of biological invasions, despite its provision of new insights into invasive species management. Here, we used an experimental approach to investigate how invasive red swamp crayfish (Procambarus clarkii) derived from geographically close ecosystems can differentially impact prey community structure and relevant ecosystem processes. We also compared the magnitude of the effects induced by invasive species introduction with those induced by intraspecific variability. Our results showed that effects of intraspecific variability can be strong for direct interactions such as resource (e.g., leaf litter, snails) consumption and of similar magnitude to the effects induced by the introduction of the invasive species when considering indirect interactions (e.g., primary production, ecosystem metabolism). Overall, these results highlighted that invasive populations of the same species are not ecologically equivalent, with each population acting differently on their recipient ecosystem.

Accounting for intraspecific diversity when examining relationships between non-native species and functional diversity.

Quantifying changes in functional diversity, the facet of biodiversity accounting for the biological features of organisms, has been advocated as one of the most integrative ways to unravel how communities are affected by human-induced perturbations. The present study assessed how functional diversity patterns varied among communities that differed in the degree to which non-native species dominated the community in temperate lake fish communities and whether accounting for intraspecific functional variability could provide a better understanding of the variation of functional diversity across communities. Four functional diversity indices were computed for 18 temperate lake fish communities along a gradient of non-native fish dominance using morphological functional traits assessed for each life-stage within each species. First, we showed that intraspecific variability in functional traits was high and comparable to interspecific variability. Second, we found that non-native fish were functionally distinct from native fish. Finally, we demonstrated that there was a significant relationship between functional diversity and the degree to which non-native fish currently dominated the community and that this association could be better detected when accounting for intraspecific functional variability. These findings highlighted the importance of incorporating intraspecific variability to better quantify the variation of functional diversity patterns in communities facing human-induced perturbations.

Blastic plasmacytoid dendritic cell leukemia in a black malian.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare, clinically aggressive hematologic malignancy, that most commonly manifests as cutaneous lesions. A 19-year-old Malian female was admitted to the Unit of Medicine of Hopital du Mali with anemia, fever, weakness, and weight loss. On physical examination she was wasted, pale, febrile (37.4°C), and had inguinal and axillary lymphadenopathies. The complete blood count found pancytopenia with Hemoglobin level of 4.8 g/dL, Leucocytes count of 1900/µL (neutrophil: 300/µL), and platelets count of 56 000/µL. The ultrasonographic examination found hepatomegaly and splenomegaly. The bone marrow biopsy and flow cytometer analysis were in keeping with a diagnosis of BPDCN. The patient, unfortunately, was lost four months later after her hospital admission due to late diagnosis by septicemia. The early diagnosis and availability of specific drugs for acute leukemia could improve the clinical outcome of patients with BPDCN in Mali.

Kikuchi-Fujimoto disease, a rare cause of lymphadenopathy in Africa. Description of the first case in Senegal and review of the literature.

INTRODUCTION: Kikuchi-Fujimoto disease, or histiocytic necrotizing lymphadenitis, is a benign disease most commonly affecting adult females. It generally presents in the form of febrile cervical lymphadenopathy. This diagnosis must be considered in the setting of tropical medicine, dominated by a high prevalence of tuberculous lymphadenitis and haematological malignancies. CASE REPORT: The authors report the case of a 33-year-old Senegalese woman who presented with subacute cervical lymphadenopathy associated with fever and laboratory signs of inflammation. Serological and tuberculosis screening tests were negative. Histopathological examination of a lymph node biopsy, following failure of nonspecific antibiotic therapy, concluded on a diagnosis of Kikuchi-Fujimoto disease. A favourable course was observed in response to corticosteroid therapy. CONCLUSION: In Sub-Saharan Africa, the association of polyadenitis and febrile syndrome, after excluding tuberculosis and lymphomas, must raise the suspicion of rare diseases such as Kikuchi-Fujimoto disease.

FishMORPH - An agent-based model to predict salmonid growth and distribution responses under natural and low flows.

Predicting fish responses to modified flow regimes is becoming central to fisheries management. In this study we present an agent-based model (ABM) to predict the growth and distribution of young-of-the-year (YOY) and one-year-old (1+) Atlantic salmon and brown trout in response to flow change during summer. A field study of a real population during both natural and low flow conditions provided the simulation environment and validation patterns. Virtual fish were realistic both in terms of bioenergetics and feeding. We tested alternative movement rules to replicate observed patterns of body mass, growth rates, stretch distribution and patch occupancy patterns. Notably, there was no calibration of the model. Virtual fish prioritising consumption rates before predator avoidance replicated observed growth and distribution patterns better than a purely maximising consumption rule. Stream conditions of low predation and harsh winters provide ecological justification for the selection of this behaviour during summer months. Overall, the model was able to predict distribution and growth patterns well across both natural and low flow regimes. The model can be used to support management of salmonids by predicting population responses to predicted flow impacts and associated habitat change.

Pleomorphic adenoma of the nasal septum.

INTRODUCTION: Pleomorphic adenoma is the most common benign tumour of the salivary glands. The major salivary glands are most commonly involved, or more rarely accessory salivary glands, especially the oral cavity. Other locations, such as the nasal cavity, paranasal sinuses or upper aerodigestive tract, are exceptional. CASE REPORT: A 26-year-old female presented with right-sided nasal obstruction. Radiology found a lesion involving the anterior third of the nasal septum. The patient underwent complete surgical resection of the tumour via an endonasal approach. Histological examination found a mixed cellular component (epithelial and myoepithelial) and mesenchymatous tissue with chondromyxoid stroma, enabling diagnosis of a typical pleomorphic adenoma. DISCUSSION/CONCLUSION: Pleomorphic adenoma is exceptional in the nasal cavity, with only a few cases reported in the literature. Although benign, the risk of local recurrence, malignant transformation and metastasis requires close long-term follow-up.

Morphological variability of black bullhead Ameiurus melas in four non-native European populations.

External morphology in black bullhead Ameiurus melas, a fish species considered to have high invasive potential, was studied in its four non-native European populations (British, French, Italian and Slovak). The aim of this study was to examine this species' variability in external morphology, including ontogenetic context, and to evaluate its invasive potential. Specimens from all non-native populations reached smaller body size compared to individuals from native populations. Juvenile A. melas were found to have a relatively uniform body shape regardless of the population's origin, whereas adults developed different phenotypes depending upon location. Specimens from the U.K., Slovak and French populations appeared to be rather similar to each other, whereas the Italian population showed the most distant phenotype. This probably results from the different thermal regime in the Italian habitat. Ameiurus melas from non-native European populations examined in this study showed some potential to alter the body shape both within and between populations. The phenotypic plasticity of A. melas, however, was not found to be as significant as in other invasive fish species. The results suggest that morphological variability itself is not necessarily essential for invasive success. The invasiveness of A. melas is therefore probably favoured by variations in its life-history traits and reproduction variables, together with some behavioural traits (e.g. voracious feeding and parental care) rather than by phenotypic plasticity expressed in external morphology.

Individual genetic tagging for teleosts: an empirical validation and a guideline for ecologists.

The efficiency of individual genetic tagging was determined by using passive integrated transponders (PIT) as a comparative conventional tagging method. Fifty-five common dace Leuciscus leuciscus were captured in the wild, PIT tagged and fin clipped (for DNA analysis). Thirty fish were recaptured on three occasions and tissue samples were collected. Using 18 microsatellite loci, 79-94% of the recaptures were correctly assigned. Experience with scoring L. leuciscus microsatellites led to more individuals correctly assigned. Allowing matches that differed by one or two alleles resulted in 100% of all recaptures successfully assigned irrespective of the observer. Reducing the set of loci to five to six loci appropriately selected did not affect the assignment rate, demonstrating that costs can be subsequently reduced. Despite their potential benefits, the application of genetic tags for teleosts has been limited. Here, it was demonstrated that genetic tagging could be applied, and a clear guideline (flowchart) is provided on how this method can be developed for teleosts and other organisms, with subsequent practical applications to ecology, evolutionary biology and conservation management.

Prognostic impact of microsatellite instability in colorectal cancer patients treated with adjuvant FOLFOX.

BACKGROUND: Colorectal cancer (CRC) patients whose tumours have microsatellite instability (MSI) do not benefit from adjuvant 5-fluorouracil. However, the predictive value of MSI is not known for FOLFOX, now recommended in adjuvant setting. PATIENTS AND METHODS: MSI phenotype was assessed by the pentaplex method. Three-year relapse and disease-free survival (DFS) of patients treated for CRC with FOLFOX 4 in an adjuvant setting were compared according to MSI phenotype. RESULTS: A total of 105 patients (19 MSI, 86 microsatellite stable, MSS) were included. Stage II patients more frequently exhibited MSI (58%) than MSS (21%); (p=0.002). Patients with MSI relapsed significantly less than those with MSS (10.5% vs. 35.0%; p=0.04). DFS was similar for MSI and MSS (p=0.1). In univariate analysis, stage (p=0.0006) and MSI status (p=0.017) were significant predictors of DFS. CONCLUSION: MSI status was associated with significantly fewer relapses and a better prognosis. FOLFOX4 did not alter survival of patients with MSI and can be administered to them.

Do native brown trout and non-native brook trout interact reproductively?

Reproductive interactions between native and non-native species of fish have received little attention compared to other types of interactions such as predation or competition for food and habitat. We studied the reproductive interactions between non-native brook trout (Salvelinus fontinalis) and native brown trout (Salmo trutta) in a Pyrenees Mountain stream (SW France). We found evidence of significant interspecific interactions owing to consistent spatial and temporal overlap in redd localizations and spawning periods. We observed mixed spawning groups composed of the two species, interspecific subordinate males, and presence of natural hybrids (tiger trout). These reproductive interactions could be detrimental to the reproduction success of both species. Our study shows that non-native species might have detrimental effects on native species via subtle hybridization behavior.

Microsatellite instability and sensitivitiy to FOLFOX treatment in metastatic colorectal cancer.

BACKGROUND: Microsatelite instability (MSI) is the consequence of the inactivation of a mismatch repair gene and is observed in approximately 15% of colon cancer cases. Patients with MSI colon cancer do not benefit from 5-fluorouracil (5-FU)-based chemotherapy. A current treatment of reference for colon cancer is a combination of 5-FU and oxaliplatin (FOLFOX). The aim of this study was to determine the efficiency of the FOLFOX treatment in patients with metastatic MSI colon cancer. PATIENTS AND METHODS: Tumour specimens were collected from patients with metastatic colon cancer treated with FOLFOX 4 modified or FOLFOX 6; these two regimens are based on 85 mg/m2 and 100 mg/m2 oxaliplatin, respectively. The MSI status was assessed by measuring the length of five monomorphic mononucleotide markers. The FOLFOX regimen was evaluated as a first-line treatment according to WHO criteria. RESULTS: Forty patients (22 men, 18 women), median age 63.5 years (27-83 years) were treated with FOLFOX 4 or 6. Nine patients had tumours exhibiting high MSI (MSI group) and 31 patients had tumours exhibiting microsatellite stability (MSS group). In the MSS group, 11 partial responses (36%) were observed, while there were only two in the MSI group (22%) (no significant difference). The two patients who were responders in the MSI group were treated with FOLFOX 6. The overall survival was not significantly different for MSI and MSS patients. CONCLUSION: No significant differences in the overall response rate or overall survival between the two groups of patients were observed. However, these results suggest that patients with MSI colon cancer are more sensitive to a higher dose of FOLFOX.

Comparison of liquid based cytology and histology for the evaluation of HER-2 status using immunostaining and CISH in breast carcinoma.

BACKGROUND: HER-2 amplification is an important prognostic biomarker and treatment determinant in breast carcinoma. AIMS: To correlate immunocytochemical (ICC) expression of HER-2 and gene amplification determined by chromogenic in situ hybridisation (CISH) using liquid based cytology (LBC) with immunohistochemistry (IHC) and CISH using histological samples of the same breast carcinomas. METHODS: Frozen sections and cytobrushings of 103 breast carcinomas were analysed. Four techniques were performed on each tumour: two on LBC samples (ICC, and CISH, both graded as positive, indeterminate, or negative) and two on histological samples (IHC and CISH). Two cell lines (MCF-7, negative; BT 474, positive) were used as controls for cytological analysis. A complementary fluorescence in situ hybridisation technique was carried out in histological samples with low amplification (4-10 dots/nucleus). RESULTS: Interobserver agreement for the four techniques calculated by the kappa coefficient indicated a substantial agreement. Nine cases failed in cytology because of poor cellularity. Among 94 cases, 19 were amplified; 73, 12, and 9 tumours were scored 0 or 1+, 2+, and 3+, respectively by IHC and 75, 13, and 6, respectively, by ICC. CISH found no amplification in 72 tumours. Correlations between the IHC and CISH results in the histological and cytological samples were always significant. CONCLUSIONS: Her-2 status could be determined in LBC samples and correlated well with reference histological methods using in situ hybridisation. ICC was less reliable because of the presence of the cytoplasmic membrane. However, these results should be confirmed by a large multicentre study.

[Anatomohistologic study of von Oort's vestibulocochlear anastomosis]. / Etude anatomo-histologique de l'anastomose vestibulo-cochléaire de von Oort.

OBJECTIVES: The vestibulocochlear anastomosis was first described in 1918 by von Oort. It is situated deeply at the bottom of the internal acoustic meatus, and spreads from the saccular nerve before its terminal ramifications, to the cochlear nerve before its penetration into the cochlea. Nerve fibers of the cochlear efferent system are thought to pass through it. The aim of our study was to investigate the anatomy of the vestibulocochlear anastomosis and characterize its histological features. METHOD: [corrected] Ten human temporal bones were dissected. Serial sections were obtained for histological evaluation. RESULTS: The vestibulocochlear anastomosis was found in seven of the specimens, perfectly visualized in six. Average diameter was 0.5 mm with lengths varying from 0.5 to 1 mm. Serial histological sections demonstrated the nervous nature of the anastomosis and its relations with the saccular and cochlear nerves. The epinevrium of the saccular nerve was continuous with the supposed anastomosis in five of the specimens, demonstrating the distinct nature of the anastomosis from the saccular and cochlear nerves. We did not find any evidence linking these fibers to the cochlear efferent system. DISCUSSION: The vestibulocochlear anastomosis was found in seven of our ten dissections. The anastomosis is probably an anatomic reality composed of nerve fibers. The efferent function of these fibers remains to be demonstrated.

Negative human papillomavirus testing in normal smears selects a population at low risk for developing high-grade cervical lesions.

High-risk human papillomaviruses (HR-HPV) are the necessary cause of cervical carcinomas and there is an increasing interest in using HR-HPV DNA detection in adjunction to cytological examination for primary cervical screening. To determine whether women with a normal smear negative for HR-HPV DNA detection with the Hybrid Capture II assay might represent a low-risk population for developing a high-grade squamous intraepithelial lesion (HSIL), 4401 women have been followed in a period of 12-72 months (median=34 months). During this follow-up, four HSIL and one microinvasive carcinoma have been detected in this cohort (three in the cohort of 3526 women >29 years). The global negative predictive value (NPV) of double-negative tests is thus of 99.9% (ninety-five percent confidence interval (95% CI): 99.8-100%), whereas cytology alone gives an NPV of 99.2% (95% CI: 98.9-99.5%). If we obtain a second negative HR-HPV test 1-2 years after the initial test, the NPV is 100%. The NPV is also of 100% in the cohort of women >49 years. We conclude that all these women could be safely screened at longer intervals between 3 and 5 years. This policy will offset the increased costs induced by an additional HR-HPV testing in primary screening.

[Two benign vascular tumors of the kidney capsule]. / Deux tumeurs vasculaires bénignes de la capsule du rein.

Capsular tumors of the kidney are uncommon or poorly documented. The authors report two cases of benign vascular tumors: a so-called "vascular leiomyoblastoma" and a glomus tumor. An ultrastructural study of the first tumor demonstrated smooth muscular characteristics. Obvious histological features of glomus were seen in the second. Immunohistochemical study revealed positive immunoreactivity for epithelial and mesenchymal antibodies in the two tumors. Glomus tumor originates from the particular system of vessels in the capsule. Histogenesis of the vascular leiomyoblastoma is more controversial. This tumor could be akin to leiomyomas of the renal capsule and intra parenchymatous leiomyomas; lymphatic origin and even a glomangiomatous nature are also possible explanations.