Sub-fossils of cladocerans in the surface sediment of 135 lakes as proxies for community structure of zooplankton,fish abundance and lake temperature

To elucidate the possibilities of using zooplankton remains in the surface sediment to describe present-days community structure and population dynamics of zooplankton, fish abundance and temperature, we compared contemporary data sampled in the pelagial during summer with the sediment record from the upper 1 cm of the sediment in 135 lakes covering a latitude gradient from Greenland in the north to New Zealand in the south. The abundance of three genera Bosmina, Daphnia and Ceriodaphnia of the total pool of ephippia was significantly related to the total abundance of the same taxa in the pelagic zone. However, in most lakes the abundance of Ceriodaphnia was higher in the sediment than in the water, which may be attributed to the overall preference by this genus for the littoral habitat. Using contemporary data from 27 Danish lakes sampled fortnightly during summer for 10 years, we found substantial inter-annual variations in the abundance of Daphnia spp., Ceriodaphnia spp., B. longirostris and B. coregoni. Yet, the sediment record mimicked the medium level well for most of the lakes, which suggests that the sediment record provides an integrated picture of the pelagic cladoceran community, which otherwise can be obtained only by long-term frequent contemporary sampling for several years. The contribution of Daphnia to the sum of Daphnia and Bosmina ephippia was negatively correlated with the abundance of fish expressed as catch per night in multi-mesh sized gill nets (CPUE). Yet, region-specific differences occurred, which partly could be eliminated by including nutrient state expressed as total phosphorus (TP) in a multiple regression. The average ratio of ephippia to the sum of ephippia and carapaces of Bosmina varied 40-fold between the sampling regions and was significantly negatively related to summer mean air temperature, and for Danish lakes also, albeit weakly, to fish CPUE but not to chlorophyll a. Apparently, temperature is the most important factor determining the ratio of parthenogenetic to ephippia producing specimens of Bosmina. We conclude that the sediment record of cladocerans is a useful indicator of community structure of pelagic cladocerans and the abundance of fish and temperature.     

The relationship between the transport of glucose and cations across cell membranes in isolated tissues XI. The effect of vanadate on 45Ca-efflux and sugar transport in adipose tissue and skeletal muscle

(1) The effects of vanadate of hexose transport, ⁴⁵Ca-exchange and (Na⁺, K⁺)-contents have been characterized in isolated adipose tissue and skeletal muscles of the rat. (2) In whole epididymal fat pads, vanadate (0.5–5.0 mM) markedly stimulated the uptake of 2-deoxyl[¹⁴C]glucose as well as the efflux of $\text{3-O-[}{}^{14}\text{C}\text{]}\text{methylglucose}$. (3) Within the same concentration range, vanadate induced an early increase in ⁴⁵Ca-washout from preloaded fat pads. The maximum increases in the fractional losses of $\text{3-O-[}{}^{14}\text{C}\text{]}\text{methylglucose}$ and ⁴⁵Ca were significantly correlated ($\text{P < 0.001}$, $\text{r = 0.98}$). (4) In extensor digitorum longus and soleus muscles, vanadate (0.5–5.0 mM) stimulated the efflux of $\text{3-O-[}{}^{14}\text{C}\text{]}\text{methylglucose}$ and this effect was preceded by a rise in the washout of ⁴⁵Ca. The maximum increases in the fractional losses of $\text{3-O-[}{}^{14}\text{C}\text{]}\text{methyglucose}$ and ⁴⁵Ca were significantly correlated ($\text{P < 0.005}$, $\text{r = 0.98}$). (5) In extensor digitorum longus and soleus muscles, vanadate increased K⁺-contents and decreased Na⁺ contents. (6) The stimulation of ⁴⁵Ca-washout presumably reflects an increase in the cytoplasmic Ca²⁺ level, brought about by an inhibitory effect of vanadate on the Ca²⁺-sensitive ATPase of the sarcoplasmic or the endoplasmic reticulum. As demonstrated for most other insulin-like agents (Sørensen, S.S., Christensen, F. and Clausen, T. (1980) Biochim. Biophys. Acta 602, 433–445), the stimulating effect of vanadate on glucose transport appears to be associated with or mediated by a rise in the cytoplasmic Ca²⁺ level.     

Transcriptional Profiling of Whole Blood Identifies a Unique 5-Gene Signature for Myelofibrosis and Imminent Myelofibrosis Transformation

Identifying a distinct gene signature for myelofibrosis may yield novel information of the genes, which are responsible for progression of essential thrombocythemia and polycythemia vera towards myelofibrosis. We aimed at identifying a simple gene signature – composed of a few genes - which were selectively and highly deregulated in myelofibrosis patients. Gene expression microarray studies have been performed on whole blood from 69 patients with myeloproliferative neoplasms. Amongst the top-20 of the most upregulated genes in PMF compared to controls, we identified 5 genes (DEFA4, ELA2, OLFM4, CTSG, and AZU1), which were highly significantly deregulated in PMF only. None of these genes were significantly regulated in ET and PV patients. However, hierarchical cluster analysis showed that these genes were also highly expressed in a subset of patients with ET (n = 1) and PV (n = 4) transforming towards myelofibrosis and/or being featured by an aggressive phenotype. We have identified a simple 5-gene signature, which is uniquely and highly significantly deregulated in patients in transitional stages of ET and PV towards myelofibrosis and in patients with PMF only. Some of these genes are considered to be responsible for the derangement of bone marrow stroma in myelofibrosis. Accordingly, this gene-signature may reflect key processes in the pathogenesis and pathophysiology of myelofibrosis development.     

Arylsulfatase K,a Novel Lysosomal Sulfatase

The human sulfatase family has 17 members, 13 of which have been characterized biochemically. These enzymes specifically hydrolyze sulfate esters in glycosaminoglycans, sulfolipids, or steroid sulfates, thereby playing key roles in cellular degradation, cell signaling, and hormone regulation. The loss of sulfatase activity has been linked to severe pathophysiological conditions such as lysosomal storage disorders, developmental abnormalities, or cancer. A novel member of this family, arylsulfatase K (ARSK), was identified bioinformatically through its conserved sulfatase signature sequence directing posttranslational generation of the catalytic formylglycine residue in sulfatases. However, overall sequence identity of ARSK with other human sulfatases is low (18–22%). Here we demonstrate that ARSK indeed shows desulfation activity toward arylsulfate pseudosubstrates. When expressed in human cells, ARSK was detected as a 68-kDa glycoprotein carrying at least four N-glycans of both the complex and high-mannose type. Purified ARSK turned over p-nitrocatechol and p-nitrophenyl sulfate. This activity was dependent on cysteine 80, which was verified to undergo conversion to formylglycine. Kinetic parameters were similar to those of several lysosomal sulfatases involved in degradation of sulfated glycosaminoglycans. An acidic pH optimum (∼4.6) and colocalization with LAMP1 verified lysosomal functioning of ARSK. Further, it carries mannose 6-phosphate, indicating lysosomal sorting via mannose 6-phosphate receptors. ARSK mRNA expression was found in all tissues tested, suggesting a ubiquitous physiological substrate and a so far non-classified lysosomal storage disorder in the case of ARSK deficiency, as shown before for all other lysosomal sulfatases.     

Size diversity and species diversity relationships in fish assemblages of Western Palearctic lakes

Body size, coupled with abundance and taxonomy, may help to understand the mechanisms shaping community structure. Since the body size of fish is closely related to their trophic niche, size diversity (based on individual body size) of fish communities may capture intraspecific variations in fish trophic niches that are not detected by species diversity. Thus, the relationship between size diversity and species diversity may help to integrate variation at both intraspecific and interspecific levels. We studied the relationship between species diversity and size diversity as a measure of the degree of overlap in size among species and thereby the potential overlap in niches in a community. We hypothesized that the relationship between size diversity and species would be different across the European continent due to different levels of size overlap in fish communities. The data were derived from samplings of fish communities using standardised benthic gill nets in 363 lakes. At the continental scale, size diversity increased with species diversity; at the ecoregion scale, the slope of the relation changed across the continent, with the greatest mismatch occurring in northern Europe where communities comprised only one or a few species, but each of which exhibited a great range in size. There was an increase in slope towards the south with significant relations for four out of six ecoregions. The steeper size diversity‐species diversity slope at lower latitudes is attributable to a lower overlap in fish size and thus likely to finer niche separation. Our results also suggest that size diversity is not a strong surrogate for species diversity in European lake fish communities. Thus, particularly in fish communities composed of few species, measuring size diversity may help to detect potential functional variation which may be neglected by measuring species diversity alone.     

The Prognostic Value of Tumor-Infiltrating lymphocytes in Stage II Colon Cancer. A Nationwide Population-Based Study

BACKGROUND: Additional prognostic markers are needed for better treatment stratification of stage II colon cancer (CC). We investigated the prognostic value of tumor-infiltrating lymphocytes (TILs) in a true population-based cohort of patients with stage II CC. MATERIAL AND METHODS: A total of 573 patients were included. Tumor blocks representing the deepest invasive part of the primary tumor were used for analysis. CD3+ and CD8+ TILs at the invasive front were evaluated by immunohistochemistry on whole tumor sections. The invasive area was manually outlined, and Visiopharm Integrator System software was used for quantification. Data were dichotomized for comparison with clinical data. The prognostic value was investigated in Cox proportional-hazard models for recurrence-free survival (RFS) and overall survival (OS). RESULTS: Low CD3+ or CD8+ TILs were significantly associated with poor RFS and OS (P?=?.0021 and P?≤?.0009, respectively, log-rank test). In multiple Cox regression analysis, low CD3+ and CD8+ TILs were associated with reduced RFS with hazard ratio (HR)?=?1.386 (95% CI 1.039-1.850), P?=?.026, and HR?=?1.394 (95% CI 1.029-1.890), P?=?.032, respectively, independent of age, T-stage, localization, perforation, and microsatellite instability (MSI). In the subgroups of patients with low CD3+ or CD8+ TILs, there was no difference in survival between patients with MSI and microsatellite-stable tumors, (P?=?.821 and P?=?.907, respectively). CONCLUSION: Low CD3+ and CD8+ TILs in the invasive area are both related to inferior prognosis of stage II CC, and we recommend either of these parameters to be considered as additional high-risk factor.     

The impact of polychaete (Nereis virens Sars) burrows on nitrification and nitrate reduction in estuarine sediments

The influence of Nereis virens Sars burrows on nitrification, denitrification and total nitrate reduction was assessed in poor (0.7% organic matter) and rich (2.0% organic matter) sediment from the estuary, Norsminde Fjord. The experiments were performed as assays of potential activity, since natural conditions proved impossible to simulate in the unpredictable burrow environment. The measurements were made in two microprofiles, extending 15 mm into the sediment from the surface and from the burrow wall lining. Both sediment types showed higher potential nitrification in the wall linings than in the surface sediment. This was positively correlated with the content of silt + clay particles and organic matter (i.e. the mucous lining of burrow walls). An elevated nitrate reduction activity was evident in the oxic layer of surface sediment. No such activity pattern was observed in the burrow walls. Denitrification accounted for 27–53 % of the total nitrate reduction. An empirical relationship between the ratio of predicted oxygen penetration into surface and wall sediment and the contribution of nereid burrows to bulk actual nitrification and nitrate reduction is presented. The burrow contribution to bulk nitrification was, in contrast to bulk nitrate reduction, very sensitive to variable oxygen penetrations. Thus, possible short-time changes in nitrate exchange across the wall lining will apparently be regulated by changes in nitrification activity rather than nitrate reduction activity.