A standardized method for identifying and counting the vagile and sessile periphyton

Summary A technique adapting the traditional slide method for quantitative study of periphyton populations is described. A substrate of known area and composition (a microscope slide) is exposed to colonization by periphyton in a body of water. At the end of the exposure time the periphyton is fixed while still on the slide and (as suggested by Bodian) impregnated with protargol. This impregnation reveals clearly all the autotrophic and heterotrophic forms in the periphyton population. The entire population is thus permanently preserved for study.Dedicated to Prof. Rolf Danneel on the occasion of his 75th birthday     

Aging induces cardiac diastolic dysfunction, oxidative stress, accumulation of advanced glycation endproducts and protein modification

Evidence suggests that aging, per se, is a major risk factor for cardiac dysfunction. Oxidative modification of cardiac proteins by non-enzymatic glycation, i.e. advanced glycation endproducts (AGEs), has been implicated as a causal factor in the aging process. This study was designed to examine the role of aging on cardiomyocyte contractile function, cardiac protein oxidation and oxidative modification. Mechanical properties were evaluated in ventricular myocytes from young (2-month) and aged (24-26-month) mice using a MyoCam system. The mechanical indices evaluated were peak shortening (PS), time-to-PS (TPS), time-to-90% relengthening (TR90) and maximal velocity of shortening/relengthening (+/- dL/dt). Oxidative stress and protein damage were evaluated by glutathione and glutathione disulfide (GSH/GSSG) ratio and protein carbonyl content, respectively. Activation of NAD(P)H oxidase was determined by immunoblotting. Aged myocytes displayed a larger cell cross-sectional area, prolonged TR90, and normal PS, +/- dL/dt and TPS compared with young myocytes. Aged myocytes were less tolerant of high stimulus frequency (from 0.1 to 5 Hz) compared with young myocytes. Oxidative stress and protein oxidative damage were both elevated in the aging group associated with significantly enhanced p47phox but not gp91phox expression. In addition, level of cardiac AGEs was approximately 2.5-fold higher in aged hearts than young ones determined by AGEs-ELISA. A group of proteins with a molecular range between 50 and 75 kDa with pI of 4-7 was distinctively modified in aged heart using one- or two-dimension SDS gel electrophoresis analysis. These data demonstrate cardiac diastolic dysfunction and reduced stress tolerance in aged cardiac myocytes, which may be associated with enhanced cardiac oxidative damage, level of AGEs and protein modification by AGEs.     

Multivitamin production in Lactococcus lactis using metabolic engineering

The dairy starter bacterium Lactococcus lactis has the potential to synthesize both folate (vitamin B11) and riboflavin (vitamin B2). By directed mutagenesis followed by selection and metabolic engineering we have modified two complicated biosynthetic pathways in L. lactis resulting in simultaneous overproduction of both folate and riboflavin: Following exposure to the riboflavin analogue roseoflavin we have isolated a spontaneous mutant of L. lactis strain NZ9000 that was changed from a riboflavin consumer into a riboflavin producer. This mutant contained a single base change in the regulatory region upstream of the riboflavin biosynthetic genes. By the constitutive overproduction of GTP cyclohydrolase I in this riboflavin-producing strain, the production of folate was increased as well. Novel foods, enriched through fermentation using these multivitamin-producing starters, could compensate the B-vitamin-deficiencies that are common even in highly developed countries and could specifically be used in dietary foods for the large fraction of the Caucasian people (10-15%) with mutations in the methylene tetrahydrofolate reductase (MTHFR).     

Effects of recombinant adenovirus-mediated expression of IL-2 and IL-12 in human B lymphoma cells on co-cultured PBMC

Background  

Modulation of the immune system by genetically modified lymphoma cell vaccines is of potential therapeutic value in the treatment of B cell lymphoma. However, the anti-tumor effect of any single immunogene transfer has so far been limited. Combination treatment of recombinant IL-2 and IL-12 has been reported to be synergistic for inducing anti-tumor responses in solid tumors but the potential of IL-2/IL-12 gene modified B cell lymphoma cells has not been explored yet.     

An experiment of fish spillover from a marine reserve in Cuba

Several studies on adult fish movement from marine protected areas to zones open to fishing activity conclude spillover is present, but most of these investigations use indirect evidence and small-sized species of little commercial importance. This paper reports the effects of manipulating a density gradient on movements of large-sized and commercially-important fish across “Jardines de la Reina” Marine Reserve boundaries, using tagging methods and visual census. Tagging was carried out using dart tags and modified spearguns at an experimental and a control site. Density of fish was experimentally manipulated on the unprotected side of the boundary. Before experimental manipulation, fish density was similar in both experimental and control sites and on both sides of the boundaries. After manipulation, fish density in the unprotected side of experimental site declined dramatically and a strong gradient was established through the boundary. One month later, this forced gradient disappeared, returning to the situation at the beginning of the study. This last result is due to spillover effect: the mean distance traveled by fish increased 1.5 times (mean from below 200 m to more than 300 m), the mean emigration rate doubled and the immigration rate decreased, allowing density levels to recover after manipulation.     

A refined method for the photoaffinity labelling of the nitrobenzylthioinosine-sensitive nucleoside transport protein: application to cell membranes of calf lung tissue

A refined method for the photoaffinity labelling of the NBI-sensitive nucleoside transport protein is described. It involves the use of low concentrations of the photolabile probe [3H]nitrobenzylthioinosine ([3H]NBI), whereas the usual inclusion of dithiothreitol in the protocol is omitted. The method was successfully applied to cell membranes of calf lung tissue, which was shown to be a rich source of this physiologically important protein with all the characteristics (both in membrane bound and solubilized form) known from similar proteins on other cell types. Specific covalent incorporation of radioactivity appeared to be pH independent. SDS-polyacrylamide gel electrophoresis revealed a specifically labelled protein with an apparent molecular weight of 55 kDa.     

Experimentelle untersuchungen über material-kompensation bei der entwicklung von insekten

Ohne Zusammenfassung     

Towards the human colorectal cancer microbiome

Multiple factors drive the progression from healthy mucosa towards sporadic colorectal carcinomas and accumulating evidence associates intestinal bacteria with disease initiation and progression. Therefore, the aim of this study was to provide a first high-resolution map of colonic dysbiosis that is associated with human colorectal cancer (CRC). To this purpose, the microbiomes colonizing colon tumor tissue and adjacent non-malignant mucosa were compared by deep rRNA sequencing. The results revealed striking differences in microbial colonization patterns between these two sites. Although inter-individual colonization in CRC patients was variable, tumors consistently formed a niche for Coriobacteria and other proposed probiotic bacterial species, while potentially pathogenic Enterobacteria were underrepresented in tumor tissue. As the intestinal microbiota is generally stable during adult life, these findings suggest that CRC-associated physiological and metabolic changes recruit tumor-foraging commensal-like bacteria. These microbes thus have an apparent competitive advantage in the tumor microenvironment and thereby seem to replace pathogenic bacteria that may be implicated in CRC etiology. This first glimpse of the CRC microbiome provides an important step towards full understanding of the dynamic interplay between intestinal microbial ecology and sporadic CRC, which may provide important leads towards novel microbiome-related diagnostic tools and therapeutic interventions.     

Life cycle assessment of side stream removal and recovery of nitrogen from wastewater treatment plants

In the light of a circular economy, the Nijhuis Ammonia Recovery system (AECO‐NAR) was developed to not only remove nitrogen from wastewater streams, but also produce ammonium sulfate (AS), used as fertilizer, in a single plant. The goal of this paper was to quantify the environmental impacts of side stream ammonia recovery with the AECO‐NAR system and compares them with the impacts of side stream nitrogen removal combined SHARON (partly nitrification)‐anammox plant. For this, an environmental life cycle assessment was performed with a functional unit (FU) of the treatment of 1 kg of total dissolved nitrogen inflow. Since AS obtained by the AECO‐NAR is a by‐product of the ammonia removal process, allocation was based on system expansion. Foreground inventory data were obtained from a full‐scale plant. ReCiPe2016 was used to determine human health and biodiversity impacts. Results show that due to the production of AS in an integrated water treatment and production system, the AECO‐NAR avoids impacts of current AS production, leading to negative impact scores. Impacts per FU decrease with increasing inflow concentrations of ammonia. Main improvement options are the use of renewable energy and the replacement of the cleaning chemical citric acid with a sustainable alternative. Total impacts of the AECO‐NAR system diminish when comparing the system to the biological SHARON‐Anammox system, due to production of AS fertilizer product. Due to the fertilizer production step being integrated in the side stream treatment, the complete system is beneficial over ammonia recovery and wastewater treatment as separate systems.