Nitrogen inputs and microbial nitrogen cycling were investigated along a 79 km transect into the Greenland Ice Sheet (GrIS) during the main ablation season in summer 2010. The depletion of dissolved ...nitrate and production of ammonium (relative to icemelt) in cryoconite holes on Leverett Glacier, within 7.5 km of the ice sheet margin, suggested microbial uptake and ammonification respectively. Positive in situ acetylene assays indicated nitrogen fixation both in a debris-rich 100 m marginal zone and up to 5.7 km upslope on Leverett Glacier (with rates up to 16.3 μmoles C2H4 m−2 day−1). No positive acetylene assays were detected > 5.7 km into the ablation zone of the ice sheet. Potential nitrogen fixation only occurred when concentrations of dissolved and sediment-bound inorganic nitrogen were undetectable. Estimates of nitrogen fluxes onto the transect suggest that nitrogen fixation is likely of minor importance to the overall nitrogen budget of Leverett Glacier and of negligible importance to the nitrogen budget on the main ice sheet itself. Nitrogen fixation is however potentially important as a source of nitrogen to microbial communities in the debris-rich marginal zone close to the terminus of the glacier, where nitrogen fixation may aid the colonization of subglacial and moraine-derived debris.
The large diversity of marine microorganisms harboured by oceans plays an important role in planet sustainability by driving globally important biogeochemical cycles; all primary and most secondary ...production in the oceans is performed by microorganisms. The largest part of the planet is covered by cold environments; consequently, cold-adapted microorganisms have crucial functional roles in globally important environmental processes and biogeochemical cycles cold-adapted extremophiles are a remarkable model to shed light on the molecular basis of survival at low temperature. The indigenous populations of Antarctic and Arctic microorganisms are endowed with genetic and physiological traits that allow them to live and effectively compete at the temperatures prevailing in polar regions. Some genes, e.g. glycosyltransferases and glycosylsynthetases involved in the architecture of the cell wall, may have been acquired/retained during evolution of polar strains or lost in tropical strains. This present work focusses on temperature and its role in shaping microbial adaptations; however, in assessing the impacts of climate changes on microbial diversity and biogeochemical cycles in polar oceans, it should not be forgotten that physiological studies need to include the interaction of temperature with other abiotic and biotic factors.
•Semi-automatic method to standardize the study of Neutrophil Extracellular Traps.•Quantification of Neutrophil Extracellular Traps in paraffin-embedded tissues.•Extracellular Traps identified as ...colocalization of Myeloperoxidase and Histone.•Area of Neutrophil Extracellular Traps is calculated per μm2.•Confocal Microscopy provides information about the structure of Extracellular Traps.
Detection and quantification of Neutrophil Extracellular Traps (NETs) in tissue samples has become a topic of great interest to understand their pathological role in various diseases. We describe a semi-automatic method of visualization and quantification of NETs in paraffin-embedded intracoronary thrombus aspirate samples. This study is based on colocalization of myeloperoxidase (MPO) and citrullinated histone 3 (H3Cit) as hallmark of the presence of NETs. For the analysis we used the confocal immunofluorescence microscopy technology to quantify the number of fields and the total area (in μm2) containing NETs in each thrombus sample. This observer-independent quantification method could be a useful tool to standardize the study of NETs in paraffin-embedded tissues, enabling comparison of results among different laboratories.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Linear relationships between the mass of sediment present in a cryoconite hole and the hole area are described for a range of glacier and ice-sheet surfaces. The strong relationships found indicate ...that some mechanism regulates the thickness of the layer of sediment occupying the ‘floor’ of the hole. We find that this regulation process responds immediately to the addition of new debris to a hole and infer that it is caused by lateral thermal conduction from the debris to the hole wall. This causes hole widening by melt, and a redistribution of the debris within then takes place, usually resulting in 0.04–0.20 gcm−2 of debris in a layer of single cryoconite grains. The thinning of the debris layer during hole widening also reduces self-shading and thus maximizes the exposure of cryoconite to solar radiation. We explore the implications of the hole widening for biological production. Net photosynthesis (CO2 fixation) is shown to be favoured by thin debris layers, whilst net heterotrophy (CO2 respiration) occurs when debris layers are in excess of 2–4 mm. We conclude that the carbon balance of cryoconite holes is sensitive to the thickness of the debris and that the thermodynamic equilibration of the debris thickness helps the ecosystem to maximize primary production during the summer.
Les troubles des conduites des enfants Bellas-Cabane, C.
Neuropsychiatrie de l'enfance et de l'adolescence,
12/2007, Volume:
55, Issue:
8
Journal Article, Conference Proceeding
Peer reviewed
Dans le cadre de la prévention exercée par les services de PMI (Promotion de la santé de la mère et de l'enfant), le dépistage des troubles des conduites ne peut être isolé d'une approche globale du ...développement de l'enfant, considéré dans son contexte et son histoire. Au-delà de la reconnaissance d'un symptôme qui peut révéler une pathologie sous-jacente, il convient de s'interroger sur une démarche de prévention plus prédictive que prévenante qui tend à enfermer les enfants dans un destin tracé par leur capital génétique et leur milieu. Plus que d'étouffer les symptômes des enfants, il est urgent de chercher la cause profonde de troubles qui témoignent avant tout d'un problème de société.
In the frame of prevention exercised by the PMI (Promotion of mother's and child's health) the track of behaviour trouble can't be isolated from a global approach of the child's development, considerated in its context and in its history. Beyond the recognizing of a symptom, which can reveal a subjacent pathology, it is reasonable to inquire about the proceeding for a prevention more predictive than preventive, which tends to confine the children in a destiny traced as well by their genetical fund as their social environment. In stead suppressing children's symptoms, it's urgent to search for the profound causes of the trouble, which are, at first, the sign of the problem of the society.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Background: Localized low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma can regress after Helicobacter pylori eradication, but IgVH gene monoclonality may persist. We studied the ...long-term histological and molecular follow-up of 24 patients and the possible association of t(11;18) with the persistent monoclonality. Patients and methods: From January 1994, 24 untreated patients with stage I low-grade gastric MALT lymphoma associated with H. pylori were prospectively studied. They all received eradication treatment and were sequentially followed-up with endoscopies for histological and molecular studies. Rearrangement of the IgVH gene was studied by PCR analysis. MALT1 locus alterations were studied by FISH. Results: Twenty-two of the 24 patients (91%) achieved disappearance of the lymphoma. Eighteen (82%) of the 22 histologically cured patients and 16 of the 19 (84%) with long follow-up had monoclonality. Three patterns of development of IgVH gene rearrangements were observed: four patients (21%) had polyclonal rearrangements; eight (58%) had maintained/intermittent monoclonality and four (21%) had occasional monoclonality, mostly after H. pylori reinfection. Only one patient (6%) with persistent monoclonality relapsed. The remaining 18 patients maintained the remission, despite the persistent monoclonality in 15, for a median of 66 months (range 20–113). t(11;18) was not found in any of the patients with persistent monoclonality. Time and the number of endoscopies performed were not related with the occurrence of monoclonality. Conclusions: In stage I low-grade gastric MALT lymphoma eradication of H. pylori achieves prolonged histological remission in 90% of patients, but molecular remission is not accomplished in most cases. Molecular disease persists for years, but is not associated with t(11;18).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
BACKGROUND Most low grade gastric lymphomas arising from the mucosa associated lymphoid tissue (MALT) are related to Helicobacter pylori colonisation. Cases with disease limited to the stomach can be ...cured after H pylori eradication and remain in remission for years. In contrast, high grade lymphomas of the stomach, although also related toH pylori, do not usually respond to eradication treatment. CASE REPORT A 36 year old patient was referred from another hospital with a diagnosis of a low grade gastric MALT lymphoma associated with H pylori. The patient was in stage I and while waiting for the biopsies to be reviewed H pylori eradication therapy was given as the first step of treatment. Review of the biopsies showed a high grade immunoblastic lymphoma with areas of low grade gastric MALT lymphoma (high grade gastric MALT lymphoma or diffuse large B cell lymphoma with areas of MALT type lymphoma of the WHO classification). The patient received no further treatment but has been closely followed up for 32 months with sequential endoscopies to obtain biopsies for histological studies, H pylori cultures, and polymerase chain reaction analysis of the IgH gene. RESULTS AfterH pylori eradication the patient had a complete histological response that has been maintained for 32 months. Monoclonal IgH gene rearrangement persisted for 32 months. CONCLUSION The response of this patient indicates the possibility that some cases of high grade gastric MALT lymphoma (possibly patients in stage I with a superficial or limited disease) may still be responsive toH pylori antigenic drive and may be cured with eradication therapy. Prospective studies should be performed to identify patients with high grade gastric MALT lymphomas that may respond to eradication therapy and be spared of other more aggressive treatments.
Transformation of CLL into a large cell lymphoma has an incidence of 3-5%. We have studied 101 cases of CLL treated with fludarabine over a 10-year period (1990-2000) and observed a 12% incidence of ...transformation. In six of 12 patients, transformation was documented within 4 months following treatment with fludarabine. Pathological material, available in nine cases, was investigated for latent EBV by staining for LMP-1 by immunohistochemistry and EBERs-1 and 2 by in situ hybridisation. LMP-1 and EBERs were demonstrated in three of the nine samples. In two cases there was a different pattern of immunoglobulin gene rearrangement in the transformed cells assessed by PCR (FR3 fragment) compared to the original CLL clone. One of these two cases showed evidence of latent EBV. The other seven cases, of which two were EBV positive, showed identical pattern of Ig gene rearrangement in both the CLL and the transformed cells. We suggest that the relatively high incidence of transformation in this series may be due to immunosuppression mainly related to fludarabine, although other agents and prior therapies may have also contributed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Aims: Differential diagnosis between multiple myeloma (MM), monoclonal gammopathy of uncertain significance (MGUS), and polyclonal plasmacytosis may be difficult in cases with not much bone marrow ...infiltration. Normal plasma cells express the antigens CD138, CD38, CD19, CD10 and D‐related human leucocyte antigen (HLA‐DR). Myelomatous plasma cells lack B lymphoid‐associated markers and may express cell surface antigens associated with other haematopoietic lineages such as NCAM/CD56 (neural cell adhesion molecule). Recently, a monoclonal antibody, anti‐CD56, has become available that can be used in fixed tissues embedded in paraffin, and it has been reported that osteoblastic cells of trabecular bone strongly express NCAM/CD56.
Methods and results: We analysed NCAM molecule expression in 35 samples from patients with plasma cell disorders: 14 cases of MM, 16 cases of MGUS, and five cases of polyclonal plasmacytosis using immunohistochemistry in parallel in bone marrow core biopsies processed routinely and in bone marrow smears from the same patients. Of the MM samples 78% were CD56+ in smears and 92% positive in biopsies. We did not find strong CD56 expression in MGUS samples. One of five samples of polyclonal plasmacytosis was CD56+. A case was considered to be positive for CD56 expression if >50% of the CD138+ plasma cells expressed NCAM with an intensity on a par with that of the osteoblasts.
Conclusion: We conclude that CD56 antibody is a very useful marker in the study of plasma cell proliferation in bone marrow biopsies and in bone marrow aspirates and is a great help in discriminating between MM, MGUS, and polyclonal plasmacytosis, especially in those cases with low infiltration.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
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