Praćenje promene broja bakterija familije enterobacteriaceae u pastrmci i odrescima šarana upakovanim u vakuum i modifikovanu atmosferu

Kvar ribe može se definisati kao bilo koja promena u mesu ribe koja proizvod čini neprihvatljivim za ljudsku ishranu i najčešće nastaje kao rezultat rasta mikroorganizama. Od toga koji su mikroorganizmi najzastupljeniji u ribi u trenutku ulova u velikoj meri zavisi i kolika će biti njena održivost tokom skladištenja. Bakterije koje pripadaju familiji Enterobacteriaceae su fakultativni anaerobi, gram negativni i katalaza pozitivni mikroorganizmi. Ovoj familiji pripadaju sledeći rodovi: Salmonelle, Escherichia, Proteus, Shigella, Serratia, Citrobacter, Klebsiella, Enterobacter i Erwinia, a neki od njih su izraziti patogeni i izazivači velikog broja različitih oboljenja kod ljudi, kao što su septikemija, pneumonija, meningitis, infekcije urinarnog trakta, bolesti organa za varenje i mnogih drugih bolesti. Široko su rasprostranjeni u spoljašnjoj sredini, a neki su saprofitski stanovnici digestivnog trakta. Cilj ovog eksperimenta je bio da se ispita rast bakterija familije Enterobacteriaceae u svežoj pastrmci i odrescima šarana upakovanim u vakuum i modifikovanu atmosferu. Uzorci su podeljeni u tri grupe. Grupa I je upakovana u modifikovanu atmosferu sa odnosom gasova 60%CO2 i 40%N2, grupa II je upakovana u modifikovanu atmosferu sa 40%CO2 i 60%N2 dok je III grupa upakovana u vakuum. Odnos gas/uzorak u pakovanju bio je 2:1. Svi uzorci su skladišteni pri istovetnim uslovima na temperaturi od +3˚C. Određivanje broja bakterija familije Enterobacteriaceae prema ISO 21528 -2:2004 obavljeno je 0, 7. i 14. dana skladištenja. U pastrmci i odrescima šarana upakovanim u modifikovanu atmosferu sa 60%CO2 i 40% N2 (I grupa), rast ukupnog broja enterobakterija bio je sporiji nego u pastrmci i odrescima šarana upakovanim u modifikovanu atmosferu sa 40%CO2 i 60%N2 (II grupa) ili pak u vakuum (III grupa). Ovo se može objasniti antimikrobnim dejstvom ugljen-dioksida, koji je procentualno najzastupljeniji u smeši gasova u koju su upakovani uzorci I grupe kao i činjenicom da ugljen-dioksid deluje inhibitorno pre svega na gram-negativne bakterije, kakvi i jesu mikroorganizmi iz familije Enterobacteriaceae. Najveću stopu rasta imale su enterobakterije u pastrmci i odrescima šarana III grupe tj. u uzorcima upakovanim u vakuum. Ovi rezultati ukazuju na sposobnost Enterobacteriaceae da rastu u anaerobnim uslovima, na temperaturi frižidera u proizvodima upakovanim u vakuum. Modifikovana atmosfera smanjuje ukupan broj enterobakterija, a najniža vrednost je dobijena kod odrezaka šarana upakovanih u modifikovanu atmosferu sa 60%CO2 i 40%N2

Murine B Cell Development and Antibody Responses to Model Antigens Are Not Impaired in the Absence of the TNF Receptor GITR

The Glucocorticoid-Induced Tumor necrosis factor Receptor GITR, a member of the tumor necrosis factor receptor superfamily, has been shown to be important in modulating immune responses in the context of T cell immunity. B lymphocytes also express GITR, but a role of GITR in humoral immunity has not been fully explored. To address this question, we performed studies to determine the kinetics of GITR expression on naïve and stimulated B cells and the capacity of B cells to develop and mount antibody responses in GITR−/− mice. Results of our studies indicate that all mature B cells express GITR on the cell surface, albeit at different levels. Expression of GITR on naïve mature B cells is upregulated by BCR signaling, but is counteracted by helper T cell-related factors and other inflammatory signals in vitro. In line with these findings, expression of GITR on germinal center and memory B cells is lower than that on naïve B cells. However, the expression of GITR is strongly upregulated in plasma cells. Despite these differences in GITR expression, the absence of GITR has no effect on T cell-dependent and T cell-independent antibody responses to model antigens in GITR−/− mice, or on B cell activation and proliferation in vitro. GITR deficiency manifests only with a slight reduction of mature B cell numbers and increased turnover of naïve B cells, suggesting that GITR slightly contributes to mature B cell homeostasis. Overall, our data indicate that GITR does not play a significant role in B cell development and antibody responses to T-dependent and independent model antigens within the context of a GITR-deficient genetic background

Doxorubicin versus doxorubicin and cisplatin in endometrial carcinoma: definitive results of a randomised study (55872) by the EORTC Gynaecological Cancer Group

Background: Combination chemotherapy yields better response rates which do not always lead to a survival advantage. The aim of this study was to investigate whether the reported differences in the efficacy and toxicity of monotherapy with doxorubicin (DOX) versus combination therapy with cisplatin (CDDP) in endometrial adenocarcinoma lead to significant advantage in favour of the combination. Patients and methods: Eligible patients had histologically-proven advanced and/or recurrent endometrial adenocarcinoma and were chemo-naïve. Treatment consisted of either DOX 60 mg/m2 alone or CDDP 50 mg/m2 added to DOX 60 mg/m2, every 4 weeks. Results: A total of 177 patients were entered and median follow-up is 7.1 years. The combination DOX-CDDP was more toxic than DOX alone. Haematological toxicity consisted mainly of white blood cell toxicity grade 3 and 4 (55% versus 30%). Non-haematological toxicity consisted mainly of grade 3 and 4 alopecia (72% versus 65%) and nausea/vomiting (36 % versus 12%). The combination DOX-CDDP provided a significantly higher response rate than single agent DOX (P <0.001). Thirty-nine patients (43%) responded on DOX-CDDP [13 complete responses (CRs) and 26 partial responses (PRs)], versus 15 patients (17%) on DOX alone (8 CR and 7 PR). The median overall survival (OS) was 9 months in the DOX-CDDP arm versus 7 months in the DOX alone arm (Wilcoxon P = 0.0654). Regression analysis showed that WHO performance status was statistically significant as a prognostic factor for survival, and stratifying for this factor, treatment effect reaches significance (hazard ratio = 1.46, 95% confidence interval 1.05-2.03, P = 0.024). Conclusions: In comparison to single agent DOX, the combination of DOX-CDDP results in higher but acceptable toxicity. The response rate produced is significantly higher, and a modest survival benefit is achieved with this combination regimen, especially in patients with a good performance statu

Network Centrality of Metro Systems

Whilst being hailed as the remedy to the world’s ills, cities will need to adapt in the 21st century. In particular, the role of public transport is likely to increase significantly, and new methods and technics to better plan transit systems are in dire need. This paper examines one fundamental aspect of transit: network centrality. By applying the notion of betweenness centrality to 28 worldwide metro systems, the main goal of this paper is to study the emergence of global trends in the evolution of centrality with network size and examine several individual systems in more detail. Betweenness was notably found to consistently become more evenly distributed with size (i.e. no “winner takes all”) unlike other complex network properties. Two distinct regimes were also observed that are representative of their structure. Moreover, the share of betweenness was found to decrease in a power law with size (with exponent 1 for the average node), but the share of most central nodes decreases much slower than least central nodes (0.87 vs. 2.48). Finally the betweenness of individual stations in several systems were examined, which can be useful to locate stations where passengers can be redistributed to relieve pressure from overcrowded stations. Overall, this study offers significant insights that can help planners in their task to design the systems of tomorrow, and similar undertakings can easily be imagined to other urban infrastructure systems (e.g., electricity grid, water/wastewater system, etc.) to develop more sustainable cities

Characterization of RNase MRP RNA and novel snoRNAs from Giardia intestinalis and Trichomonas vaginalis

<p>Abstract</p> <p>Background</p> <p>Eukaryotic cells possess a complex network of RNA machineries which function in RNA-processing and cellular regulation which includes transcription, translation, silencing, editing and epigenetic control. Studies of model organisms have shown that many ncRNAs of the RNA-infrastructure are highly conserved, but little is known from non-model protists. In this study we have conducted a genome-scale survey of medium-length ncRNAs from the protozoan parasites <it>Giardia intestinalis </it>and <it>Trichomonas vaginalis</it>.</p> <p>Results</p> <p>We have identified the previously 'missing' <it>Giardia </it>RNase MRP RNA, which is a key ribozyme involved in pre-rRNA processing. We have also uncovered 18 new H/ACA box snoRNAs, expanding our knowledge of the H/ACA family of snoRNAs.</p> <p>Conclusions</p> <p>Results indicate that <it>Giardia intestinalis </it>and <it>Trichomonas vaginalis</it>, like their distant multicellular relatives, contain a rich infrastructure of RNA-based processing. From here we can investigate the evolution of RNA processing networks in eukaryotes.</p

Identification of Zoonotic Genotypes of Giardia duodenalis

Giardia duodenalis, originally regarded as a commensal organism, is the etiologic agent of giardiasis, a gastrointestinal disease of humans and animals. Giardiasis causes major public and veterinary health concerns worldwide. Transmission is either direct, through the faecal-oral route, or indirect, through ingestion of contaminated water or food. Genetic characterization of G. duodenalis isolates has revealed the existence of seven groups (assemblages A to G) which differ in their host distribution. Assemblages A and B are found in humans and in many other mammals, but the role of animals in the epidemiology of human infection is still unclear, despite the fact that the zoonotic potential of Giardia was recognised by the WHO some 30 years ago. Here, we performed an extensive genetic characterization of 978 human and 1440 animal isolates, which together comprise 3886 sequences from 4 genetic loci. The data were assembled into a molecular epidemiological database developed by a European network of public and veterinary health Institutions. Genotyping was performed at different levels of resolution (single and multiple loci on the same dataset). The zoonotic potential of both assemblages A and B is evident when studied at the level of assemblages, sub-assemblages, and even at each single locus. However, when genotypes are defined using a multi-locus sequence typing scheme, only 2 multi-locus genotypes (MLG) of assemblage A and none of assemblage B appear to have a zoonotic potential. Surprisingly, mixtures of genotypes in individual isolates were repeatedly observed. Possible explanations are the uptake of genetically different Giardia cysts by a host, or subsequent infection of an already infected host, likely without overt symptoms, with a different Giardia species, which may cause disease. Other explanations for mixed genotypes, particularly for assemblage B, are substantial allelic sequence heterogeneity and/or genetic recombination. Although the zoonotic potential of G. duodenalis is evident, evidence on the contribution and frequency is (still) lacking. This newly developed molecular database has the potential to tackle intricate epidemiological questions concerning protozoan diseases

The antigen-specific CD8+ T cell repertoire in unimmunized mice includes memory phenotype cells bearing markers of homeostatic expansion

Memory T cells exhibit superior responses to pathogens and tumors compared with their naive counterparts. Memory is typically generated via an immune response to a foreign antigen, but functional memory T cells can also be produced from naive cells by homeostatic mechanisms. Using a recently developed method, we studied CD8 T cells, which are specific for model (ovalbumin) and viral (HSV, vaccinia) antigens, in unimmunized mice and found a subpopulation bearing markers of memory cells. Based on their phenotypic markers and by their presence in germ-free mice, these preexisting memory-like CD44hi CD8 T cells are likely to arise via physiological homeostatic proliferation rather than a response to environmental microbes. These antigen-inexperienced memory phenotype CD8 T cells display several functions that distinguish them from their CD44lo counterparts, including a rapid initiation of proliferation after T cell stimulation and rapid IFN-γ production after exposure to proinflammatory cytokines. Collectively, these data indicate that the unprimed antigen-specific CD8 T cell repertoire contains antigen-inexperienced cells that display phenotypic and functional traits of memory cells