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181.
Transformation in Group H Streptococci: Blackburn Strain Transformable Mutants 总被引:1,自引:1,他引:0
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Transformable mutants of the nontransformable Blackburn strain group H streptococci have been isolated. In contrast with the wild strain, the cell surface extracts of these mutants contain the factor inactivating deoxyribonucleic acid in vitro. 相似文献
182.
Janusz Kömender Alina Gołaszewska Hanna Malczewska 《Histochemistry and cell biology》1973,35(3):219-225
Summary A method for the determination of hyaluronidase in histological sections is described. This method is based on incubation of tissue sections in a medium containing hyaluronic acid as substrate. Depolymerisation of the substrate during incubation as well as the total nitrogen content are measured in the same section. The comparison of these two values gives information concerning the hyaluronidase activity. This assay was tested in experiments with rat testis. It was also found that our procedure is sensitive enough for the estimation of hyaluronidase activity in sections from kidney. From these experiments with kidney sections it can be concluded that: 1. The pH optimum for renal hyaluronidase (3.5) differs from that in the testis (4.7). 2. In the renal cortex more hyaluronidase activity was detected than in the medulla.Department of Transplantology.Department of Histology and Embryology. 相似文献
183.
184.
Suppression of oxidative phosphorylation confers resistance against bevacizumab in experimental glioma
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Jule A. Eriksson Christina Wanka Michael C. Burger Hans Urban Ines Hartel Janusz von Renesse Patrick N. Harter Michel Mittelbronn Joachim P. Steinbach Johannes Rieger 《Journal of neurochemistry》2018,144(4):421-430
185.
Aneta Żabka Justyna Teresa Polit Konrad Winnicki Patrycja Paciorek Jolanta Juszczak Mateusz Nowak Janusz Maszewski 《Plant cell reports》2016,35(8):1655-1669
Key message
PIN2-like auxin transporters are expressed, preferentially in a polarized manner, in antheridial cells of freshwater green alga Chara vulgaris , considered to be the closest relative of the present-day land plants.Abstract
Chara vulgaris represents a group of advanced multicellular green algae that are considered as the closest relatives of the present-day land plants. A highly specialized structure of its male sex organs (antheridia) includes filaments consisting of generative cells, which after a series of synchronous divisions transform into mature sperm, and non-generative cells comprising outer shield cells, cylindrical manubria, and central complex of capitular cells from which antheridial filaments arise. Immunofluorescence observations indicate that PIN2-like proteins (PIN2-LPs), recognized by antibodies against PIN-FORMED2 (PIN2) auxin transporter in Arabidopsis thaliana, are expressed in both types of antheridial cells and, in most of them, preferentially accumulate in a polarized manner. The appearance of PIN2-LPs in germ-line cells is strictly confined to the proliferative period of spermatogenesis and their quantities increase steadily till antheridial filaments reach the 16-celled stage. An enhanced level of PIN2-LPs observed in the central cell walls separating two asynchronously developing parts of antheridial filaments (characterized by the plugged plasmodesmata) is correlated with an enhanced deposition of callose. Intense PIN2-LPs immunofluorescence maintained in the capitular cells and its altering polarity in manubria suggest a pivotal role of these cells in the regulation of auxin transport directionality during the whole time of antheridial ontogenesis. Immunohistochemical staining of IAA revealed a clear-cut correspondence between localization sites of auxins and PIN2-LPs. It seems probable then that a supplementary developmental mechanism has evolved in Chara, by which all antheridial elements may be integrated at the supra-cellular level via plasma membrane-targeted PIN2-LPs and auxin-mediated processes.186.
Janusz M. Gebicki 《Free radical research》2016,50(9):987-996
Amino acid and protein hydroperoxides can constitute a significant hazard if formed in vivo. It has been suggested that cysteine can form hydroperoxides after intramolecular hydrogen transfer to the commonly produced cysteine sulfur-centered radical. The resultant cysteine-derived carbon-centered radicals can react with oxygen at almost diffusion-controlled rate, forming peroxyl radicals which can oxidize other molecules and be reduced to hydroperoxides in the process. No cysteine hydroperoxides have been found so far. In this study, dilute air-saturated cysteine solutions were exposed to radicals generated by ionizing radiation and the hydroperoxides measured by an iodide assay. Of the three primary radicals present, the hydroxyl, hydrogen atoms and hydrated electrons, the first two were ineffective. However, electrons did initiate the generation of hydroperoxides by removing the –SH group and forming cysteine-derived carbon radicals. Under optimal conditions, 100% of the electrons reacting with cysteine produced the hydroperoxides with a 1:1 stoichiometry. Maximum hydroperoxide yields were at pH 5.5, with fairly rapid decline under more acid or alkaline conditions. The hydroperoxides were stable between pH 3 and 7.5, and decomposed in alkaline solutions. The results suggest that formation of cysteine hydroperoxides initiated by electrons is an unlikely event under physiological conditions. 相似文献
187.
Anna Bochenek Agnieszka Synowiec Bożena Kondrat Milena Szymczak Lesław B. Lahuta Janusz Gołaszewski 《Acta Physiologiae Plantarum》2016,38(6):159
Solidago gigantea Ait. (goldenrod) belongs to the most expansive environmental weeds, and it is the most dangerous plant-invader of American origin in Europe. The species easily propagates vegetatively, but it also produces large amounts of wind-disseminated achenes that contribute to the colonization of new areas. A sound knowledge of the germination biology of goldenrods is required to control the spread of this invasive species. The objective of this study was to investigate selected aspects of germination of giant goldenrod achenes and to determine: the influence of temperature and humidity on seed dormancy and germination, the content of soluble carbohydrates in seeds and the sensitivity of seeds to selected phytohormones. Unlike native weed species of the same family, S. gigantea seeds did not display symptoms of innate dormancy, and high seed vigor was maintained after storage in a wide range of temperatures, in both dry and moist conditions. The physiological mechanisms behind those traits have not yet been fully explored, but they could be associated with the relatively high sucrose-to-hexose ratio in seeds and significant sensitivity to abscisic acid. More extensive research is required to explain the internal causes for the atypical behavior of goldenrod seeds during dry and moist storage, especially in the context of its invasiveness, because the species has a preference for sites located close to river banks. 相似文献
188.
Tysarowski A Fabisiewicz A Paszkiewicz-Kozik E Kulik J Walewski J Siedlecki JA 《Acta biochimica Polonica》2007,54(1):135-142
The aim of this study was to evaluate the usefulness of quantitative real-time PCR (RQ-PCR) for the monitoring of molecular remission in follicular lymphoma (FL) patients during long-term follow-up. RQ-PCR by the use of TaqMan detection system is a sensitive tool to monitor minimal residual disease (MRD) in FL through amplification of the t(14;18) fusion gene during and post-therapy. In most cases the breakpoint region occurs within the major breakpoint region (MBR). Among 75 patients diagnosed with FL, cells harboring the fusion gene BCL2/JH were found in peripheral blood of 31 patients (41%). We further monitored 30 of these patients in a period varying from 6 months to 5 years by RQ-PCR. In our study the level indicating the possibility of the presence of MRD was established at more than five t(14;18)-positive cells in the background of 83,000 normal cells. The results of this work also confirmed that the presence of MRD detected by RQ-PCR is an indication for careful observation of patients because of a higher risk of disease recurrence. 相似文献
189.
Małgorzata Pleszczyńska Marta K. Lemieszek Marek Siwulski Adrian Wiater Wojciech Rzeski Janusz Szczodrak 《World journal of microbiology & biotechnology》2017,33(5):83
Higher Basidiomycota have been used in natural medicine throughout the world for centuries. One of such fungi is Fomitopsis betulina (formerly Piptoporus betulinus), which causes brown rot of birch wood. Annual white to brownish fruiting bodies of the species can be found on trees in the northern hemisphere but F. betulina can also be cultured as a mycelium and fruiting body. The fungus has a long tradition of being applied in folk medicine as an antimicrobial, anticancer, and anti-inflammatory agent. Probably due to the curative properties, pieces of its fruiting body were carried by Ötzi the Iceman. Modern research confirms the health-promoting benefits of F. betulina. Pharmacological studies have provided evidence supporting the antibacterial, anti-parasitic, antiviral, anti-inflammatory, anticancer, neuroprotective, and immunomodulating activities of F. betulina preparations. Biologically active compounds such as triterpenoids have been isolated. The mushroom is also a reservoir of valuable enzymes and other substances such as cell wall (1→3)-α-d-glucan which can be used for induction of microbial enzymes degrading cariogenic dental biofilm. In conclusion, F. betulina can be considered as a promising source for the development of new products for healthcare and other biotechnological uses. 相似文献
190.
Kai Kaarniranta Paulina Tokarz Ali Koskela Jussi Paterno Janusz Blasiak 《Cell biology and toxicology》2017,33(2):113-128
Age-related macular degeneration (AMD) is an eye disease underlined by the degradation of retinal pigment epithelium (RPE) cells, photoreceptors, and choriocapillares, but the exact mechanism of cell death in AMD is not completely clear. This mechanism is important for prevention of and therapeutic intervention in AMD, which is a hardly curable disease. Present reports suggest that both apoptosis and pyroptosis (cell death dependent on caspase-1) as well as necroptosis (regulated necrosis dependent on the proteins RIPK3 and MLKL, caspase-independent) can be involved in the AMD-related death of RPE cells. Autophagy, a cellular clearing system, plays an important role in AMD pathogenesis, and this role is closely associated with the activation of the NLRP3 inflammasome, a central event for advanced AMD. Autophagy can play a role in apoptosis, pyroptosis, and necroptosis, but its contribution to AMD-specific cell death is not completely clear. Autophagy can be involved in the regulation of proteins important for cellular antioxidative defense, including Nrf2, which can interact with p62/SQSTM, a protein essential for autophagy. As oxidative stress is implicated in AMD pathogenesis, autophagy can contribute to this disease by deregulation of cellular defense against the stress. However, these and other interactions do not explain the mechanisms of RPE cell death in AMD. In this review, we present basic mechanisms of autophagy and its involvement in AMD pathogenesis and try to show a regulatory role of autophagy in RPE cell death. This can result in considering the genes and proteins of autophagy as molecular targets in AMD prevention and therapy. 相似文献