The hydrographic properties of the Kongsfjorden-Krossfjorden system (79° N, Spitsbergen) are affected by Atlantic water incursions as well as glacier meltwater runoff. This results in strong physical ...gradients (temperature, salinity and irradiance) within the fjords. Here, we tested the hypothesis that glaciers affect phytoplankton dynamics as early as the productive spring bloom period. During two campaigns in 2007 (late spring) and 2008 (early spring) we studied hydrographic characteristics and phytoplankton variability along two transects in both fjords, using high-performance liquid chromatography (HPLC)-CHEMTAX pigment fingerprinting, molecular fingerprinting (denaturing gradient gel electrophoresis, or DGGE) and sequencing of 18S rRNA genes. The sheltered inner fjord locations remained colder during spring as opposed to the outer locations. Vertical light attenuation coefficients increased from early spring onwards, at all locations, but in particular at the inner locations. In late spring meltwater input caused stratification of surface waters in both fjords. The inner fjord locations were characterized by overall lower phytoplankton biomass. Furthermore HPLC-CHEMTAX data revealed that diatoms and Phaeocystis sp. were replaced by small nano- and picophytoplankton during late spring, coinciding with low nutrient availability. The innermost stations showed higher relative abundances of nano- and picophytoplankton throughout, notably of cyanophytes and cryptophytes. Molecular fingerprinting revealed a high similarity between inner fjord samples from early spring and late spring samples from all locations, while outer samples from early spring clustered separately. We conclude that glacier influence, mediated by early meltwater input, modifies phytoplankton biomass and composition already during the spring bloom period, in favor of low biomass and small cell size communities. This may affect higher trophic levels especially when regional warming further increases the period and volume of meltwater.
Like other reef-building corals, members of the genus Acropora form obligate endosymbioses with dinoflagellates (zooxanthellae) belonging to the genus Symbiodinium. Both Symbiodinium and its hosts ...are diverse assemblages, and the relationships between host and algal genotypes are unclear. In this study, we determined phylogenetic relationships between Symbiodinium isolates from a wide range of Acropora species and plotted the algal genotypes onto a molecular phylogeny of 28 Acropora species, using the same samples for the host and symbiont genotyping. In addition, we performed a preliminary survey of zooxanthella distribution in Acropora species from the central Great Barrier Reef. Three of the four known major zooxanthellae clades were represented in the 168 samples examined, and within the major clade C, three distinct subclades were identified. No evidence was found for coevolution, but several clear patterns of specificity were identified. Moreover, composition of the zooxanthella pool varied among locales and in one host species we found light-related patterns of zooxanthella distribution
In the Kongsfjorden–Krossfjorden system (Spitsbergen), increasing temperatures enhance glacier melting and concomitant intrusion of freshwater. These altered conditions affect the timing, intensity, ...and composition of the phytoplankton spring bloom in Kongsfjorden; yet, the effects on prokaryotes (bacteria and archaea) are not well understood. The aim of this study was to examine springtime prokaryote communities in both fjords as a function of hydrographic and phytoplankton variability. Prokaryote community composition was studied in two consecutive years by molecular fingerprinting of the 16S rRNA gene. In addition, we measured bacterial abundance, productivity (
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H-Leucine uptake), and single-cell activity using catalyzed reporter deposition fluorescence in situ hybridization combined with microautoradiography. Differences in bacterial and archaeal communities were found between Kongsfjorden and Krossfjorden. Furthermore, an increase in productivity, abundance, and proportion of active bacterial cells was observed during the course of spring. Bacteroidetes were the most abundant bacterial group among the assessed taxa in both Kongsfjorden and Krossfjorden. Multivariate analysis of the microbial community fingerprints revealed a strong temporal shaping of both the bacterial and archaeal communities in addition to a spatial separation between the two fjords. A significant part of the observed bacterial variation could be explained by cyanobacterial biomass, as deduced from pigment analysis, and by phosphate concentration. Archaea were mainly controlled by abiotic factors. We speculate that the bacterial response to hydrographic changes and glacier meltwater is mediated through shifts in phytoplankton abundance and composition, whereas archaea are directly influenced by abiotic environmental variables.
Tumor necrosis factor‐α (TNF‐α) may contribute to the progression of acute alcoholic hepatitis (AAH). The aim of this study was to evaluate the efficacy of an association of infliximab and ...prednisolone at reducing the 2‐month mortality rate among patients with severe AAH. Patients with severe AAH (Maddrey score ≥32) were randomly assigned to group A receiving intravenous infusions of infliximab (10 mg/kg) in weeks 0, 2, and 4; or group B receiving a placebo at the same times. All patients received prednisolone (40 mg/day) for 28 days. Blood neutrophil functional capacities were monitored over 28 days. After randomization of 36 patients, seven patients from group A and three from group B died within 2 months. The probability of being dead at 2 months was higher (not significant NS) in group A (39% ± 11%) than in group B (18% ± 9%). The study was stopped by the follow‐up committee and the sponsor (Assistance Publique‐Hôpitaux de Paris). The frequency of severe infections within 2 months was higher in group A than in group B (P < .002). This difference was potentially related to a significantly lower ex vivo stimulation capacity of neutrophils. There were no differences between the two groups in terms of Maddrey scores at any time point. In conclusion, three infusions of 10 mg/kg of infliximab in association with prednisolone may be harmful in patients with severe AAH because of the high prevalence of severe infections. (HEPATOLOGY 2004;39:1390–1397.)
Summary
Background
Malnutrition and jaundice are independent prognostic factors in cirrhosis.
Aim
To assess the impact of enteral nutrition on the survival of alcoholic cirrhotic patients with ...jaundice but without acute alcoholic hepatitis.
Methods
The study was a multicentre prospective randomised controlled trial comparing effects of enteral nutrition vs. a symptomatic support in patients with alcoholic cirrhosis and jaundice (bilirubin ≥51 µmol/L) but without severe acute alcoholic hepatitis. A total of 99 patients were randomised to receive either the conventional symptomatic treatment (55 patients) or the symptomatic support associated with 35 kcal/Kg/day of enteral nutrition during 4 weeks followed by an oral nutritional support during 2 months (44 patients). Randomisation was stratified on nutritional status. One‐year survival curves were compared using the Kaplan–Meier method and Logrank test.
Results
Populations in both arms were similar. One‐year survival was similar in the overall population (27/44 patients (61.4%) in the enteral nutrition arm vs. 36/55 (65.5%) in the control arm; Logrank P = 0.60) and in the subgroup suffering from malnutrition 18/29 patients (62.1%) in the enteral nutrition arm vs. 20/32 (62.5%) in the control arm; Logrank P = 0.99. There was no statistical difference for bilirubin, prothrombin rate, Child‐Pugh score, albumin or nutritional assessment. Complications during treatment (bleeding, encephalopathy, infection) occurred in 23% of patients in the enteral nutrition group (10/44) vs. 16% (9/55) of the control patients (P = 0.59).
Conclusion
Enteral nutrition does not improve the survival and hepatic or nutritional parameters of cirrhotic patients with jaundice.
Krossfjorden and Kongsfjorden are Arctic fjords on the western side of Spitsbergen. These fjords share a common mouth to the open sea, and both are influenced by the input of sediment-rich glacial ...meltwater leading to decreased surface salinity, increased turbidity and decreased light penetration during summer. Earlier classical taxonomic studies had described the pelagic protistan composition of the Kongsfjorden during summer, revealing the dominance of flagellates of often unresolved taxonomic origin. Only little information existed on microbial eukaryote composition of the Krossfjorden as well as the bacterial composition of both fjords. The aim of the present study was to analyze and compare surface summertime protistan and bacterial communities in both fjords, using molecular approaches (16S and 18S rRNA DGGE, sequencing). Samples were collected three times a week from the central Kongsfjorden over a 1-month period. Additionally, 10 marine and 2 freshwater sites were sampled within a 1-week period in both Kongsfjorden and Krossfjorden. The central Kongsfjorden revealed a relatively stable protistan community over time with dinoflagellates, chlorophytes and small heterotrophs dominating. In contrast, the bacterial community varied over time and appeared to be correlated with the inflow of glacial meltwater. The Kongsfjorden and Krossfjorden were found to harbor distinctive bacterial and eukaryotic communities. We speculate that differences in glacial meltwater composition and fjord bathymetry affect the surface water properties and therefore the observed spatial variability in the community fingerprints.
Mortality among patients with severe acute alcoholic hepatitis is high, even among those treated with glucocorticoids. We investigated whether combination therapy with glucocorticoids plus ...N-acetylcysteine would improve survival.
We randomly assigned 174 patients to receive prednisolone plus N-acetylcysteine (85 patients) or only prednisolone (89 patients). All patients received 4 weeks of prednisolone. The prednisolone-N-acetylcysteine group received intravenous N-acetylcysteine on day 1 (at a dose of 150, 50, and 100 mg per kilogram of body weight in 250, 500, and 1000 ml of 5% glucose solution over a period of 30 minutes, 4 hours, and 16 hours, respectively) and on days 2 through 5 (100 mg per kilogram per day in 1000 ml of 5% glucose solution). The prednisolone-only group received an infusion in 1000 ml of 5% glucose solution per day on days 1 through 5. The primary outcome was 6-month survival. Secondary outcomes included survival at 1 and 3 months, hepatitis complications, adverse events related to N-acetylcysteine use, and changes in bilirubin levels on days 7 and 14.
Mortality was not significantly lower in the prednisolone-N-acetylcysteine group than in the prednisolone-only group at 6 months (27% vs. 38%, P = 0.07). Mortality was significantly lower at 1 month (8% vs. 24%, P = 0.006) but not at 3 months (22% vs. 34%, P = 0.06). Death due to the hepatorenal syndrome was less frequent in the prednisolone-N-acetylcysteine group than in the prednisolone-only group at 6 months (9% vs. 22%, P = 0.02). In a multivariate analysis, factors associated with 6-month survival were a younger age (P<0.001), a shorter prothrombin time (P<0.001), a lower level of bilirubin at baseline (P<0.001), and a decrease in bilirubin on day 14 (P<0.001). Infections were less frequent in the prednisolone-N-acetylcysteine group than in the prednisolone-only group (P = 0.001); other side effects were similar in the two groups.
Although combination therapy with prednisolone plus N-acetylcysteine increased 1-month survival among patients with severe acute alcoholic hepatitis, 6-month survival, the primary outcome, was not improved. (Funded by Programme Hospitalier de Recherche Clinique; AAH-NAC ClinicalTrials.gov number, NCT00863785 .).
A new transformerless power supply for DBD application is presented here. The power supply is built with 10kV SiC MOSFET. This high voltage switches allow holding the high voltage required by the ...DBD. An analytical study of the converter's operation is presented to deduce the power transmitted to the DBD. A comparison between the experimental and theoretical electrical waveforms is shown. The experimental waveforms are particularly affected by all the parasitic capacitances. When all the switches are in OFF state, oscillations cause over-voltages across the switches. An analysis of the effect of each capacitance is presented and demonstrates that the parasitic capacitances of the switches and of the inductance play a key role in the actual power transfer.
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