排序方式: 共有283条查询结果,搜索用时 15 毫秒
41.
The poor efficacy of reference chemotherapy (fluorouracil -FU) in colon cancer has resulted in a constant search for agents which could augment the action of FU. Epidemiological data, such as the decreased risk of colorectal cancer among menopausal women receiving hormonal replacement therapy, indicate the role of oestrogen in the pathogenesis of this disease. The differences between normal and neoplastic colon cells in the expression of oestrogen receptor beta (ERbeta) could confirm this association. However, the direct influence of oestrogen or tamoxifen (SERM, selective oestrogen receptor modulator) on colon cancer growth has rarely been studied. The aim of the present study was to examine the direct effects of various concentrations of oestradiol and tamoxifen (10(-4) to 10(-12) M), applied alone or together with FU, on the growth of murine Colon 38 cancer in vitro as assessed by three colorimetric methods: Mosmann's method, incorporation of BrdU into cell nuclei and the TUNEL method. At high concentrations oestradiol and tamoxifen decreased the cancer growth in a dose- and time-dependent manner (the Mosmann and BrdU methods) and at some concentrations augmented the cytotoxic action of FU (Mosmann's method). Tamoxifen exerted a very early and potent inhibitory effect, inducing even total cancer growth inhibition at the concentration of 10(-4) M (the Mosmann and BrdU methods). All the substances studied at different concentrations and at different incubation time points increased the apoptosis of tumour cells (the TUNEL method). The results indicate that oestradiol and tamoxifen inhibit Colon 38 cancer growth and increase the cytotoxic effect of FU, which confirms the role of sex steroids in colon carcinogenesis and even suggests new therapeutic schemes. 相似文献
42.
Johann Schinnerl Ewelina A. Orlowska Eberhard Lorbeer Andreas Berger Lothar Brecker 《Phytochemistry letters》2012,5(3):586-590
Monoterpenoid indole alkaloids have frequently been isolated from the species-rich Psychotria alliance (Rubiaceae), a complex group including several tribes and genera. In our aim of understanding the chemical diversification within this remarkably heterogeneous group, members of two genera of the tribe Palicoureeae have been studied. Alstrostine A was isolated from Chassalia curviflora var. ophioxyloides, and a novel derivative, rudgeifoline from Rudgea cornifolia, respectively. Alstrostines, an unusual class of alkaloids comprising one tryptamine and two iridoid units, have recently been discovered in Alstonia rostrata (Apocynaceae). The presence of alstrostines in two rubiaceous species is remarkable but not unexpected as both families share similar biosynthetic pathways and are capable of synthesizing related alkaloids. 相似文献
43.
S100A6, a calcium-binding protein also known as calcyclin, was detected in human umbilical cord by immunoblotting. Immunohistochemical studies showed an intensive reaction for S100A6 in the walls of vessels and Wharton's jelly. In the latter, S100A6 was found not only in the myofibroblasts but also in the ECM (extracellular matrix) surrounding these cells. Affinity chromatography of S100A6 resin indicated that Wharton's jelly contains some proteins that could bind to S100A6. Thus these novel results show the presence of S100A6 in umbilical cord and suggest the involvement of this protein in intra- and extra-cellular signalling pathways in this tissue. 相似文献
44.
45.
Michał Bijok Ewelina Gruszczynska Adam Kowalczyk Katarzyna Sikorska Agnieszka Walewska Pawel F. Kukolowicz 《Reports of Practical Oncology and Radiotherapy》2018,23(5):341-345
Aim
The aim of the study was to analyze the long-term stability of electron beams generated by the Novac11? IORT accelerator.Background
Novac11? (NRT®) is a mobile electron accelerator designed to irradiate small areas of tissue, up to 10?cm in diameter, with electron beams during surgical procedures. It is characterized by a great mobility guaranteed by a number of degrees of freedom enabling irradiation in the conditions of an operating theatre.Materials and methods
Over the period of January 2013 and September 2016, the measurement sessions of the output of clinically used beam qualities (6, 8 and 10?MeV) were carried out 41 times. Because of the unsatisfactory long-term stability, an extra procedure of tuning of the magnetron, suggested by the manufacturer, was introduced in October 2015, 15 measurements were performed since then. The output of the Novac11? accelerator was measured in the reference conditions recommended by the IAEA Report 398, the measurements of the charge in the ionization chamber at the reference depth were carried out with a Dose1? electrometer and a plane-parallel chamber PPC05? from IBA®.Results
The introduction of the tuning of the magnetron procedure resulted in satisfactory long-term stability of the measured outputs below 2%.Conclusions
After the introduction of the STV parameter tuning procedure, the long-term stability of the Novac11? output increased considerably and is within the values declared by the manufacturer. 相似文献46.
Dorota Kregiel Steve A. James Anna Rygala Joanna Berlowska Hubert Antolak Ewelina Pawlikowska 《Antonie van Leeuwenhoek》2018,111(3):373-383
Yeast strains and acetic acid bacteria were isolated from spoiled soft drinks with characteristic flocs as a visual defect. Polymerase chain reaction and amplification of a partial region of the LSU rRNA gene identified the bacteria as Asaia spp. Sequence analysis of the D1/D2 region of the 26S rDNA in turn identified the yeast isolates as Wickerhamomyces anomalus, Dekkera bruxellensis and Rhodotorula mucilaginosa. The hydrophobicity and adhesion properties of the yeasts were evaluated in various culture media, taking into account the availability of nutrients and the carbon sources. The highest hydrophobicity and best adhesion properties were exhibited by the R. mucilaginosa cells. Our results suggest that Asaia spp. bacterial cells were responsible for the formation of flocs, while the presence of yeast cells may help to strengthen the structure of co-aggregates. 相似文献
47.
Aneta Blat Ewelina Wiercigroch Marta Smeda Adrianna Wislocka Stefan Chlopicki Kamilla Malek 《Journal of biophotonics》2019,12(10)
Despite advanced diagnostic techniques used for detecting cancer, this disease still remains a leading cause of death in the developed world. What is more, the greatest danger for patients is not related with growing of tumor but rather with metastasis of cancer cells to the distant organs. In this study, Fourier transform infrared (FTIR) spectroscopy was used to track chemical changes in blood plasma to find spectral markers of metastatic breast cancer during the disease progression. Plasma samples were taken 1‐5 weeks after orthotropic inoculation of 4T1 metastatic breast cancer cells to mice. The earliest changes detected by FTIR spectroscopy in plasma were correlated with unsaturation of phospholipids and secondary structures of proteins that appeared 2 and 3 weeks, respectively, after 4T1 cells inoculation (micrometastatic phase). Significant alternations in the content and structure of lipids and carbohydrates were identified in plasma at the later stages (macrometastatic phase). When large primary tumors in breast and macrometastases in lung were developed, all bands in FTIR spectra significantly differed from those at earlier phases of the cancer progression. In conclusion, we showed that each phase of the breast cancer progression and its pulmonary metastasis can be characterized by a specific panel of spectral markers. 相似文献
48.
Branicki W Liu F van Duijn K Draus-Barini J Pośpiech E Walsh S Kupiec T Wojas-Pelc A Kayser M 《Human genetics》2011,129(4):443-454
Predicting complex human phenotypes from genotypes is the central concept of widely advocated personalized medicine, but so
far has rarely led to high accuracies limiting practical applications. One notable exception, although less relevant for medical
but important for forensic purposes, is human eye color, for which it has been recently demonstrated that highly accurate
prediction is feasible from a small number of DNA variants. Here, we demonstrate that human hair color is predictable from
DNA variants with similarly high accuracies. We analyzed in Polish Europeans with single-observer hair color grading 45 single
nucleotide polymorphisms (SNPs) from 12 genes previously associated with human hair color variation. We found that a model
based on a subset of 13 single or compound genetic markers from 11 genes predicted red hair color with over 0.9, black hair
color with almost 0.9, as well as blond, and brown hair color with over 0.8 prevalence-adjusted accuracy expressed by the
area under the receiver characteristic operating curves (AUC). The identified genetic predictors also differentiate reasonably
well between similar hair colors, such as between red and blond-red, as well as between blond and dark-blond, highlighting
the value of the identified DNA variants for accurate hair color prediction. 相似文献
49.
50.
Ewelina Węglarz-Tomczak Marcin Poręba Anna Byzia Łukasz Berlicki Bogusław Nocek Rory Mulligan Andrzej Joachimiak Marcin Drąg Artur Mucha 《Biochimie》2013
Neisseria meningitides is a gram-negative diplococcus bacterium and is the main causative agent of meningitis and other meningococcal diseases. Alanine aminopeptidase from N. meningitides (NmAPN) belongs to the family of metallo-exopeptidase enzymes, which catalyze the removal of amino acids from the N-terminus of peptides and proteins, and are found among all the kingdoms of life. NmAPN is suggested to be mostly responsible for proteolysis and nutrition delivery, similar to the orthologs from other bacteria. 相似文献