Evaluation of two fluorescent test kits for detection of selectedBacteroides species in clinical specimens

Two pools of isothiocyanate fluorescein-conjugated rabbit antisera toBacteroides fragilis, B. thetaiotaomicron, B. vulgatus, B. distasonis, B. ovatus, and toB. melaninogenicus, subsp.melaninogenicus andintermedius, andB. asaccharolyticus, respectively, were used in immunofluorescent (IF) tests of smears of 122 clinical specimens from a variety of sources, including abscesses and wounds. Smears of broth medium of 14 blood cultures were also tested. Bacteria of the species and subspecies mentioned were detected by the IF tests in 100 and by culture studies in 106 of the 136 speciments tested. Results of the culture studies indicated that 6 tests were false-negative by the IF test, while no false-positive tests were found. The sensitivities of the two test kits were 97% and 85%, respectively, while their specificities were 100%. The predicted value for a positive test with any of the two pools of antisera was 100%, while the predicted value for a negative test was 93% and 97%, respectively. The use of the two test kits (Fluoretec F and M) was found to be a valuable means for a rapid diagnosis of human infections with theBacteroides species mentioned.     

Potential importance of protozoan grazing on the accumulation of polychlorinated biphenyls (PCBs) in the pelagic food web

Experiments were conducted to study the distribution of three selectedpolychlorinated biphenyl (PCB) congeners within the microbial food web attwo different nutrient levels; control and nutrient enriched. The objectivewas to quantify the uptake of PCBs through grazing by protozoa. The¹⁴C-PCBs tested were 4-chlorobiphenyl (IUPAC # 3),2,2,5,5-tetrachlorobiphenyl (IUPAC # 52), and2,2,4,4,5,5-hexachlorobiphenyl (IUPAC # 153). EachPCB was incubated in triplicate seawater samples at 20 idref;Cover one week. Daily, samples were separated into four fractions; <0.2µm (dissolved), 0.2-2 µm (bacteria), 2-10 µm(flagellate), and > 10 µm (microplankton; phytoplankton andprotozoa) by selective filtration. Of the PCB fraction that initiallyadsorbed to particles, 60–100% was associated to the bacterialfraction and 0–5% to the microplankton fraction. The totaluptake was highest in the nutrient enriched samples, but when normalized tothe carbon biomass the concentration was lower or equal to the control inall particle fractions. The recovery of the PCBs in the particulatefractions depended on the degree of chlorination, as the highest values wereobserved for the 2,2,4,4,5,5-hexachlorobiphenyl and thelowest for the 4-chlorobiphenyl. The concentrations in the bacterial andflagellate fractions decreased over the first 48–96 hours whilst theconcentration increased in the highest trophic level (>10 µmfraction). Approximately 75% of the increase in concentration of the2,2,4,4,5,5-hexachlorobiphenyl in the > 10 µmfraction was estimated to be the result of bacterivory. Our results indicatethe microbial food web can contribute to a rapid uptake of higherchlorinated PCBs, particularly in oligotrophic ecosystems where thebacterial biomass dominates.     

Plant colonisation in small forest–floor patches: importance of plant group and disturbance traits

It has been proposed that the interaction between life–history attributes of different organisms and distrbance characteristics play an important role in determining the successional pattern following a disturbance event. We compared the responses of vascular plants and bryophytes (mosses and hepatics) to variation in disturbance size and severity in an old-growth boreal forest during a four–year period. The experiment included two patch sizes (0.25 and 2.5 m²) and two levels of severity: humus patches (removal of vegetation) and mineral soil patches (removal of both vegetation and humus layer). Treatments were chosen to reflect some aspects of disturbance by uprooting. Species richness was significantly affected by both disturbance size and severity but the response differed among plant groups. In vascular plants, species numbers were highest in humus patches while mosses were more numerous in mineral soil patches, the most severe disturbance. In contrast, severity had no effect on hepatics. Plant recovery was more rapid in bryophytes than in vascular plants. Species richness of bryophytes had exceeded that of adjacent, undisturbed vegetation after 2-3 yr. We attribute the contrasting response of the plant groups to differences in regeneration strategies. As a group, bryophytes had a greater variety of regeneration methods than vascular plants, with several types of asexual propagules and abundant production of spores in some species. In contrast, clonal ingrowth dominated in vascular plants while seedlings were rare. Thus, our analysis supports the view that plant response to patchy disturbance is strongly dependent on the interplay among disturbance traits and specific attribtites of different plant groups.     

In situ profiling of adipokines in subcutaneous microdialysates from lean and obese individuals

Adipose tissue (AT) had emerged as an endocrine organ and a key regulator of the metabolically triggered inflammation. The aims of this study were 1) to investigate the usefulness of a multiplexed bioassay in characterizing a panel of adipokines in subcutaneous (sc) microdialysate samples and 2) to determine whether lean and obese individuals differ in their interstitial adipokines levels following microdialysis (MD) probe insertion. Ultrafiltrating MD membranes were inserted in opposite sites of the sc abdominal AT of six lean (L) and six obese (OB) males at the beginning (M1) and during the last 120 min (M2) of the study. Interstitial and serum concentrations of adipokines were quantified using the Luminex technique and ELISA at 60-min intervals for 5 h. In comparison with L subjects, OB subjects exhibited elevated interstitial leptin (P < 0.001), IL-8 (P < 0.05), and IL-18 levels (P = 0.05), as well as higher serum concentrations of leptin (P < 0.0001), IL-6 (P < 0.0001), tumor necrosis factor-alpha (P < 0.001), IL-8 (P = 0.01) and interferon-gamma-inducible protein 10 (P < 0.05). In samples from the M1 membranes, leptin decreased and IL-1alpha, IL-18, and RANTES (regulated on activation, normal T-cell expressed and secreted) remained relatively stable, whereas IL-6, IL-8, and monocyte chemoattractant protein-1 significantly increased after the first hour (P < 0.0001 vs. baseline). Notably, either the magnitude of increase from the initial values or the time pattern of all the adipokines in M1 and M2 dialysates were similar between the groups. In conclusion, the current work provides valuable information on the optimal time frame to collect in situ AT microdialysate samples. Further studies are needed, however, to unravel the intricate interplay of cytokines in AT interstitial fluid.     

MSAP is a novel MIR-interacting protein that enhances neurite outgrowth and increases myosin regulatory light chain

Dynamic interactions between the actin cytoskeleton and specific proteins are crucial for changes in cell shape and motility. Here we describe a novel protein MSAP (MIR-interacting saposin-like protein) that is a positive regulator of neurite outgrowth. MSAP is expressed in different tissues, including brain, and has an apparent molecular weight of 21 kDa. MSAP interacts with the ezrin-radixin-moesin (ERM)-like myosin regulatory light chain-interacting protein (MIR), and the two proteins are co-localized in cell lines and in primary neurons. Overexpression of MSAP enhances neurite out-growth in neuroblastoma and PC12 cells, whereas down-regulation of MSAP using RNA silencing led to inhibition of neurite formation. The stimulation of neurite outgrowth by MSAP was abrogated by the overexpression of MIR, which induced a decrease in the levels of myosin regulatory light chain (MRLC). This reduction in MRLC by MIR was inhibited by blocking the activity of proteasome and by overexpression of MSAP, suggesting an effect on protein stability. Evidence was obtained that MIR decreases MRLC by inducing its ubiquitination. The results show that the levels of MRLC are controlled by MIR via ubiquitination and that the effect of MIR on MRLC is counteracted in the presence of MSAP. MSAP can stabilize MRLC and thus bring about an increase in neurite outgrowth.     

Uncertainties in the carbon footprint of refined wheat products: a case study on Swedish pasta

Purpose  

Calculating the carbon footprint (CF) of food is becoming increasingly important in climate change communication. To design effective CF labelling systems or reduction measures, it is necessary to understand the accuracy of the calculated CF values. This study quantified the uncertainty in the CF of wheat and of a common refined wheat-based product, pasta, for different resolutions of farm-level in-data to gain an increased understanding of the origins and magnitude of uncertainties in food CFs.