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Abstract  

The elemental composition of various synthetic crystalline sodium-boroaluminosilicates, especially the Al content and the silicon to aluminium bulk ratio, were determined by means of the combination of PIGE (Proton-Induced Gamma-Ray Emission Spectrometry) and PIXE (Proton-Induced X-Ray Emission Spectrometry). Light elements (B, O, Na, Al) were determined by means of gamma-ray emission. Proton-induced X-ray emission provided information on heavy elements present down to impurities. The Si/Al ratios, which mainly determine the catalytic and adsorptive properties of the zeolites, are compared with those obtained with other methods (EPMA, H2O sorption capacity) and show good agreement.

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Abstract

Campylobacter (C.) jejuni is among the leading bacterial agents causing enterocolitis worldwide. Despite the high prevalence of C. jejuni infections and its significant medical and economical consequences, intestinal pathogenesis is poorly understood. This is mainly due to the lack of appropriate animal models. In the age of 3 months, adult mice display strong colonization resistance (CR) against C. jejuni. Previous studies underlined the substantial role of the murine intestinal microbiota in maintaining CR. Due to the fact that the host-specific gut flora establishes after weaning, we investigated CR against C. jejuni in 3-week-old mice and studied intestinal and extra-intestinal immunopathogenesis as well as age dependent differences of the murine colon microbiota. In infant animals infected orally immediately after weaning C. jejuni strain B2 could stably colonize the gastrointestinal tract for more than 100 days. Within six days following infection, infant mice developed acute enterocolitis as indicated by bloody diarrhea, colonic shortening, and increased apoptotic cell numbers in the colon mucosa. Similar to human campylobacteriosis clinical disease manifestations were self-limited and disappeared within two weeks. Interestingly, long-term C. jejuni infection was accompanied by distinct intestinal immune and inflammatory responses as indicated by increased numbers of T- and B-lymphocytes, regulatory T-cells, neutrophils, as well as apoptotic cells in the colon mucosa. Strikingly, C. jejuni infection also induced a pronounced influx of immune cells into extra-intestinal sites such as liver, lung, and kidney. Furthermore, C. jejuni susceptible weaned mice harbored a different microbiota as compared to resistant adult animals. These results support the essential role of the microflora composition in CR against C. jejuni and demonstrate that infant mouse models resemble C. jejuni mediated immunopathogenesis including the characteristic self-limited enterocolitis in human campylobacteriosis. Furthermore, potential clinical and immunological sequelae of chronic C. jejuni carriers in humans can be further elucidated by investigation of long-term infected infant mice. The observed extraintestinal disease manifestations might help to unravel the mechanisms causing complications such as reactive arthritis or Guillain-Barré syndrome.

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Abstract

Campylobacter jejuni is one of the predominant causes for foodborne bacterial infections worldwide. We investigated whether signaling of C. jejuni-lipoproteins and -lipooligosaccharide via Toll-like-receptor (TLR) -2 and -4, respectively, is inducing intestinal and extra-intestinal immune responses following infection of conventional IL-10-/- mice with chronic colitis. At day 3 following oral infection, IL-10-/- mice lacking TLR-2 or TLR-4 harbored comparable C. jejuni strain ATCC 43431 loads in their colon. Interestingly, infected TLR-4-/- IL-10-/- mice displayed less compromized epithelial barrier function as indicated by lower translocation rates of live gut commensals into mesenteric lymphnodes (MLNs), and exhibited less distinct B lymphocyte responses in their colonic mucosa as compared to naïve IL-10-/- controls. Furthermore, in extra-intestinal compartments such as MLNs and spleens, abundance of myeloid cells was less distinct whereas relative percentages of activated T helper cells and cytotoxic T cells were higher in spleens and dendritic cells more abundant in MLNs of infected IL-10-/- animals lacking TLR-4 as compared to IL-10-/- controls. Taken together, in conventionally colonized IL-10-/- mice, TLR-4, but not TLR-2, is involved in mediating extra-intestinal pro-inflammatory immune responses following C. jejuni infection. Thus, conventional IL-10-/- mice are well suited to further dissect mechanisms underlying Campylobacter infections in vivo.

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Acta Veterinaria Hungarica
Authors: Adam Šuluburić, Svetlana Milanović, Sanja Vranješ-Đurić, Ivan B. Jovanović, Tomislav Barna, Milica Stojić, Natalija Fratrić, Ottó Szenci and Dragan Gvozdić

Early embryonic development may be negatively affected by insufficient progesterone (P4) production. Therefore, the aim of our study was to increase P4 by gonadotropin-releasing hormone (GnRH) and/or human chorionic gonadotropin (hCG) treatments after inducing oestrus by prostaglandin (PG) treatment. Lactating Simmental dairy cows (n = 110), between 1 to 5 lactations, with an average milk production of 6,500 1/305 days, at 40–80 days postpartum were used and grouped as follows: (1) PG + GnRH treatment at AI (GnRH group), (2) PG + hCG treatment at day 7 after AI (hCG group), (3) PG + GnRH at AI + hCG treatment at day 7 after AI (GnRH/hCG group), and (4) spontaneous oestrus (C: control group). All animals were double inseminated (at the time of oestrus detection and 12 ± 2 h thereafter). Blood serum and milk samples were collected at the day of observed oestrus (day 0), and 14, 21 and 28 days after AI. Serum P4 was determined using a commercial radioimmunoassay (RIA) test (INEP, Zemun), and milk P4 was determined using enzyme-linked immunoassay (ELISA) test (NIV Novi Sad). Pregnancy status was confirmed by ultrasonography between days 28 and 35 after AI. Differences of serum or milk P4 medians, pregnancy (and calving) rate were determined using Dunn’s Multiple Comparison Tests and Z test, respectively. Serum P4 medians were significantly higher at days 14, 21 and 28 after AI in the hCG-treated animals, indicating increased luteal activity, with a similar tendency in whole milk P4 values. Treatment with hCG during the early luteal phase significantly contributed to the maintenance of gestation at days 28–35 after AI, and also increased the calving rate in Simmental dairy cows.

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European Journal of Microbiology and Immunology
Authors: Markus M. Heimesaat, Lea-Maxie Haag, André Fischer, Bettina Otto, Anja A. Kühl, Ulf B. Göbel and Stefan Bereswill

Abstract

Campylobacter jejuni is among the most frequently reported bacterial pathogens causing diarrhea in humans worldwide. We recently reported a murine infection model mimicking key features of human campylobacteriosis. Six days following oral C. jejuni infection immediately after weaning, infant mice developed acute enterocolitis resolving within 2 weeks. Thereafter, C. jejuni could still be isolated from the intestines of asymptomatic mice at low levels accompanied by distinct immune responses, both at intestinal and extra-intestinal locations. We here show that, at day 103 post infection (p.i.), long-term C. jejuni-infected mice exhibited higher numbers of T lymphocytes in liver, lung, kindneys, and cardiac muscle as compared to uninfected controls. In addition, B lymphocytes were slightly higher, but macrophage numbers were significantly lower in liver and lung of C. jejuni-infected versus naive mice. As compared to uninfected control animals, proliferating cells were significantly lower in liver, lung, kidneys, cardiac muscle, and spleen at day 103 p.i., whereas more apoptotic cells were abundant in the spleen with predominance in the red pulp. This study underlines that post-infectious, immunological sequelae at extra-intestinal locations are of importance even in asymptomatic long-term C. jejuni carriers and need to be further studied in order to unravel the underlying molecular mechanisms.

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