Wyniki wyszukiwania - Biblioteka Nauki

1

Quick and efficient method for recovering of bacteriophages from soft agar after their propagation by the plate lysate technique

100%

Obuchowski M. , Stopa M.

Acta Biochimica Polonica

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1993

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tom 40

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nr 1

98-99

2

Multicellular behaviour and production of a wide variety of toxic substances support usage of Bacillus subtilis as a powerful biocontrol agent

80%

Nagórska K. , Bikowski M. , Obuchowski M.

Acta Biochimica Polonica

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2007

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tom 54

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nr 3

495-508

EN

Intensive cultivation of plants in the monoculture field system in order to feed the continuously growing human population creates a need for their protection from the variety of natural competitors such as: bacteria, fungi, insects as well as other plants. The increase in the use of chemical substances in the 20th century has brought many effective solutions for the agriculture. However, it was extremely difficult to obtain a substance, which would be directed solely against a specific plant pathogen and would not be harmful for the environment. In the late 1900's scientists began trying to use natural antagonisms between resident soil organism to protect plants. This phenomenon was named biocontrol. Biological control of plants by microorganisms is a very promising alternative to an extended use of pesticides, which are often expensive and accumulate in plants or soil, having adverse effects on humans. Nonpathogenic soil bacteria living in association with roots of higher plants enhance their adaptive potential and, moreover, they can be beneficial for their growth. Here, we present the current status of the use of Bacillus subtilis in biocontrol. This prevalent inhabitant of soil is widely recognized as a powerful biocontrol agent. Naturally present in the immediate vicinity of plant roots, B. subtilis is able to maintain stable contact with higher plants and promote their growth. In addition, due to its broad host range, its ability to form endospores and produce different biologically active compounds with a broad spectrum of activity, B. subtilis as well as other Bacilli are potentially useful as biocontrol agents.

3

Helicobacter pylori antigens, acetylsalicylic acid, LDL and 7-ketocholesterol - their potential role in destabilizing the gastric epithelial cell barrier. An in vitro model of Kato III cells

61%

Gajewski A. , Mnich E. , Szymański K. , Hinc K. , Obuchowski M. , Moran A. , Chmiela M.

Acta Biochimica Polonica

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2016

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tom 63

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nr 1

145-152

EN

Colonization of gastric tissue in humans by H. pylori Gram-negative bacteria initiates gastric and duodenal ulcers and even gastric cancers. Infections promote inflammation and damage to gastric epithelium which might be followed by the impairment of its barrier function. The role of H. pylori components in these processes has not been specified. H. pylori cytotoxicity may potentially increase in the milieu of anti-inflammatory drugs including acetylsalicylic acid (ASA). The lipid transport-associated molecule such as low density lipoprotein (LDL), which is a classic risk factor of coronary heart disease (CHD) and 7-ketocholesterol (7-kCh) a product of cholesterol oxidation, which may occur during the oxidative stress in LDL could also be considered as pro-inflammatory. The aim of this study was to evaluate the cytotoxicity of H. pylori antigens, ASA, LDL and 7-kCh towards Kato III gastric epithelial cells, on the basis of the cell ability to reduce tetrazolium salt (MTT) and morphology of cell nuclei assessed by 4',6-diamidino-2-phenylindole (DAPI) staining. Kato III cells were stimulated for 24 h, at 37°C and 5% CO2, with H. pylori antigens: cytotoxin associated gene A (CagA) protein, the urease A subunit (UreA), lipopolysaccharide (LPS) and ASA, LDL or 7-kCh. H. pylori LPS, ASA, LDL and 7-kCh, but not H. pylori glycine acid extract (GE), demonstrated cytotoxicity against Kato III cells, which was related to a diminished percentage of MTT reducing cells and to an increased cell population with the signs of DNA damage. The results suggest that damage to gastric epithelial cells can be induced independently by H. pylori antigens, ASA and endogenous lipid transport-associated molecules. During H. pylori infection in vivo, especially in CHD patients, synergistic or antagonistic interactions between these factors might possibly influence the disease course. Further study is necessary to explain these potential effects.

4

The choice of the anchoring protein influences the interaction of recombinant Bacillus spores with the immune system

61%

Piekarska A. , Pełka P. , Peszyńska-Sularz G. , Negri A. , Hinc K. , Obuchowski M. , Iwanicki A.

Acta Biochimica Polonica

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2017

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tom 64

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nr 2

239-244

EN

The technology of display of heterologous proteins on the surface of Bacillus subtilis spores enables use of these structures as carriers of antigens for mucosal vaccination. Currently, there are no technical possibilities to predict whether a designed fusion will be efficiently displayed on the spore surface and how such recombinant spores will interact with cells of the immune system. In this study, we compared four variants of B. subtilis spores presenting a fragment of a FliD protein from Clostridium difficile in fusion with CotB, CotC, CotG or CotZ spore coat proteins. We show that these spores promote their own phagocytosis and activate both, the J774 macrophages and JAWSII dendritic cells of murine cell lines. Moreover, we used these spores for mucosal immunization of mice. We conclude that the observed effects vary with the type of displayed FliD-spore coat protein fusion and seem to be mostly independent of its abundance and localization in the spore coat structure.

5

The Escherichia coli RNA polymerase α subunit and transcriptional activation by bacteriophage λ CII protein

61%

Gabig M. , Obuchowski M. , Ciesielska A. , Latała B. , Alicja Węgrzyn2 , Thomas M. S. , Węgrzyn G.

Acta Biochimica Polonica

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1998

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tom 45

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nr 1

271-280

6

Eriochrome black T as a dye for agarose gel electrophoresis

60%

Obuchowski M. , Węgrzyn G.

Acta Biochimica Polonica

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1991

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tom 38

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nr 1

177-179

7

Immunoregulation of antigen presenting and secretory functions of monocytic cells by Helicobacter pylori antigens in relation to impairment of lymphocyte expansion

51%

Mnich E. , Gajewski A. , Rudnicka K. , Gonciarz W. , Stawerski P. , Hinc K. , Obuchowski M. , Chmiela M.

Acta Biochimica Polonica

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2015

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tom 62

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nr 4

641-650

EN

The role of Helicobacter pylori (H. pylori) antigens in driving a specific immune response against the bacteria causing gastroduodenal disorders is poorly understood. Using a guinea pig model mimicking the natural history of H. pylori infection, we evaluated the effectiveness of immature and mature macrophages in promoting the blastogenesis of splenocytes from H. pylori infected and uninfected animals, in response to H. pylori antigens: glycine acid extract (GE), cytotoxin associated gene A protein (CagA), urease A (UreA) and lipopolysaccharide (LPS). Lymphocyte expansion was assessed in 72 h cell cultures, containing: immature or mature macrophages derived from bone marrow monocytes, unstimulated or stimulated with H. pylori antigens for 2 h. The proliferation was expressed as a ratio of [3H]-thymidine incorporation into DNA of antigen-stimulated to unstimulated cells and the DNA damage was determined by DAPI cell staining. TGF-β and IFN-γ were assessed immunoenzymatically in cell culture supernatants. Lymphocytes of control and H. pylori-infected animals proliferated intensively in response to phytohaemagglutinin (PHA) and in co-cultures with immature or mature macrophages treated with CagA or UreA (significantly) and GE (slightly) exluding the cultures containing H. pylori or E. coli LPS. This lymphocyte growth inhibition was related to DNA damage of monocytic cells in response to H. pylori or E. coli LPS and secretion of regulatory TGF-β, but not proinflammatory IFN-γ. Impaired homeostasis of monocytic cell function related to DNA damage and TGF-β release, in response to H. pylori LPS may lead to the suppression of adaptive immune response against the bacteria and development of chronic infection.