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71.
72.
Halina Miller-Podraza Jorgen Bergstrom Maan Abul Milh Karl-Anders Karlsson 《Glycoconjugate journal》1997,14(4):467-471
Helicobacter pylori expresses separate binding characteristics depending on growth conditions, as documented by binding to
human erythrocyte glycoconjugates. Cells grown in Ham's F12 liquid medium exhibited a selective sialic acid-dependent binding
to polyglycosylceramides, PGCs (Miller-Podraza et al. (1996) Glycoconjugate J 13:453–60). There was no binding to traditional
sialylated glycoconjugates like shorter-chain gangliosides, glycophorin or fetuin. However, cells grown on Brucella agar bound
both to PGCs and other sialylated glycoconjugates. Fetuin was an effective inhibitor of haemagglutination caused by agar-grown
cells, but had no or a very weak inhibitory effect on haemagglutination by F12-grown bacteria. PGCs were strong inhibitors
in both cases, while asialofetuin was completely ineffective. The results indicate that H. pylori is able to express two separate
sialic acid-dependent specificities, one represented by binding to fetuin, as described before, and another represented by
a selective binding to PGCs. Abbreviations: PGCs, polyglycosylceramides; TLC, thin-layer chromatography; SDS PAGE, sodium
dodecylsulfate polyacrylamide gel electrophoresis; BSA, bovine serum albumin; C, chloroform; M, methanol. The carbohydrate
and glycosphingolipid nomenclatures are according to recommendations of IUPAC-IUB Commission on Biochemical Nomenclature (Lipids
(1977) 12:455–68; J Biol Chem (1982) 257:3347–51 and J Biol Chem (1987) 262:13–18).
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
73.
Tritium labelling and cytochemistry of extra DNA in Acheta 总被引:3,自引:1,他引:2
Females of Acheta domesticus were injected with H3-thymidine and H3-uridine at various stages of development in order to study DNA and RNA synthesis in the DNA body present in the oocytes. Staining with alkaline fast green, azure B and the Feulgen reaction were employed as cytochemical tests. The following main results were obtained.
- The DNA body appears in the oogonia at interphase as a Feulgen positive spherical structure 2 microns in diameter and is seen in subsequent mitotic divisions as a slightly smaller structure of variable shape. H3-thymidine autoradiography discloses that the DNA present in this body is synthesised at a different time from the chromosomal DNA.
- At interphase and during the early prophase of meiosis the DNA body increases in size becoming a large Feulgen positive sphere 6 microns in diameter. Small nucleoli are present within this body. The DNA of the body is complexed with histone as revealed by alkaline fast green staining. H3-thymidine labelling discloses that it is at these stages that the bulk of the DNA synthesis takes place in the body.
- Every oocyte contains a DNA body, and no body of comparable size or shape seems to be present in the male meiotic prophase.
- At pachytene and diplotene the DNA body acquires the appearance of a “puff”. Two zones can be distinguished inside the DNA body: (1) an inner core of DNA and an outer shell of RNA. The inner core is Feulgen positive and stains light green with azure B, the outer shell is Feulgen negative and stains purple-violet with azure B, as does the cytoplasm. From the inner DNA core many Feulgen positive fibrils radiate into the outer RNA shell. These fibrils appear unstained or slightly greenish with Azure B, forming a transparent network in a purple-violet background. This gives the body the typical appearance of a “puff”. H3-uridine incorporation reveals that the RNA synthesis occurs in the outer RNA shell of the body and in the chromosomes. RNase treatment removes the H3-uridine incorporated into these regions.
- At the end of diplotene the DNA body starts to disintegrate. The DNA core breaks up into minor components and the outer RNA zone also begins to disintegrate. By late diplotene the whole body has vanished, releasing DNA, histone and RNA into the nucleus. Subsequently the nuclear envelope disintegrates as it regularly does at the end of prophase of meiosis.
- The simplest interpretation of the above results is that the DNA body represents hundreds of copies of the genes of the nucleolar organizing region.
74.
The non-cytotoxic concentration (20 microM) of menadione (2-methyl-1,4-naphthoquinone), after 1 h of incubation, leads to loss of the activity of rhodanese by 33%, 3-mercaptopyruvate sulfurtransferase by 20%, as well as the level of sulfane sulfur by about 23% and glutathione by 12%, in the culture of U373 cells, in comparison with the control culture. Reactive oxygen species generated by menadione oxidize sulfhydryl groups in active centers of the investigated enzymes, inhibiting them and saving cysteine for glutathione synthesis. A decreased sulfane sulfur level can be correlated with an oxidative stress. 相似文献
75.
Four species of the moss genusRacomitrium Brid. are reported from Brazil:R. subsecundum (Harv.) Wils,R. didymum (Mont.) Lorentz,R. crispipilum (Taylor) A. Jaeger, andR. visnadiae W. R. Buck.Racomitrium subsecundum is reported for the first time from South America in Brazil and Colombia. The species is fully described and illustrated.Racomitrium didymum is recorded for the first time from Brazil; the specimens previously assigned toR. crispulum (Hook.f. & Wils.) Hook.f. & Wils. represent this species.Racomitrium cucullatifolium Hampe andR. crispulum (Hook. f. & Wils.) Hook.f. & Wils. are excluded from the Brazilian bryophyte flora. All Brazilian species ofRacomitrium are briefly assessed taxonomically and bryogeographically and illustrated, and a key to their determination is given. A lectotype
is selected forGrimmia didyma Mont. 相似文献
76.
Zannatul Ferdous Muhammad Anwar Qureshi Petrilla Jayaprakash Khatija Parekh Annie John Murat Oz Haider Raza Halina Dobrzynski Thomas Edward Adrian Frank Christopher Howarth 《PloS one》2016,11(4)
BackgroundExperiments in isolated perfused heart have shown that heart rate is lower and sinoatrial node (SAN) action potential duration is longer in streptozotocin (STZ)–induced diabetic rat compared to controls. In sino-atrial preparations the pacemaker cycle length and sino-atrial conduction time are prolonged in STZ heart. To further clarify the molecular basis of electrical disturbances in the diabetic heart the profile of mRNA encoding a wide variety of proteins associated with the generation and transmission of electrical activity has been evaluated in the SAN of STZ-induced diabetic rat heart.Conclusions/SignificanceCollectively, this study has demonstrated differences in the profile of mRNA encoding a variety of proteins that are associated with the generation, conduction and regulation of electrical signals in the SAN of STZ-induced diabetic rat heart. Data from this study will provide a basis for a substantial range of future studies to investigate whether these changes in mRNA translate into changes in electrophysiological function. 相似文献
77.
Skała E Wysokińska H 《Zeitschrift für Naturforschung. C, Journal of biosciences》2005,60(7-8):583-586
Production of tanshinones (tanshinone I and IIA) was determined in roots of Salvia przewalskii micropropagated plants. It was found that the total tanshinone content (tashinone I and tashinone IIA) was dependent on the age of the analyzed plants. The roots of 2-year-old in vitro regenerated plants at flowering stage produced highest tanshinone levels (3.8 mg/g dry weight of tanshinone I and 7.6 mg/g dry weight of tanshinone IIA). 相似文献
78.
Guillaume Maucort Ravikiran Kasula Andreas Papadopulos Timo A. Nieminen Halina Rubinsztein-Dunlop Frederic A. Meunier 《PloS one》2014,9(1)
How neurosecretory cells spatially adjust their secretory vesicle pools to replenish those that have fused and released their hormonal content is currently unknown. Here we designed a novel set of image analyses to map the probability of tracked organelles undergoing a specific type of movement (free, caged or directed). We then applied our analysis to time-lapse z-stack confocal imaging of secretory vesicles from bovine Chromaffin cells to map the global changes in vesicle motion and directionality occurring upon secretagogue stimulation. We report a defined region abutting the cortical actin network that actively transports secretory vesicles and is dissipated by actin and microtubule depolymerizing drugs. The directionality of this “conveyor belt” towards the cell surface is activated by stimulation. Actin and microtubule networks therefore cooperatively probe the microenvironment to transport secretory vesicles to the periphery, providing a mechanism whereby cells globally adjust their vesicle pools in response to secretagogue stimulation. 相似文献
79.
Drake PM Schilling B Niles RK Prakobphol A Li B Jung K Cho W Braten M Inerowicz HD Williams K Albertolle M Held JM Iacovides D Sorensen DJ Griffith OL Johansen E Zawadzka AM Cusack MP Allen S Gormley M Hall SC Witkowska HE Gray JW Regnier F Gibson BW Fisher SJ 《Journal of proteome research》2012,11(4):2508-2520
We used a lectin chromatography/MS-based approach to screen conditioned medium from a panel of luminal (less aggressive) and triple negative (more aggressive) breast cancer cell lines (n=5/subtype). The samples were fractionated using the lectins Aleuria aurantia (AAL) and Sambucus nigra agglutinin (SNA), which recognize fucose and sialic acid, respectively. The bound fractions were enzymatically N-deglycosylated and analyzed by LC-MS/MS. In total, we identified 533 glycoproteins, ~90% of which were components of the cell surface or extracellular matrix. We observed 1011 glycosites, 100 of which were solely detected in ≥3 triple negative lines. Statistical analyses suggested that a number of these glycosites were triple negative-specific and thus potential biomarkers for this tumor subtype. An analysis of RNaseq data revealed that approximately half of the mRNAs encoding the protein scaffolds that carried potential biomarker glycosites were up-regulated in triple negative vs luminal cell lines, and that a number of genes encoding fucosyl- or sialyltransferases were differentially expressed between the two subtypes, suggesting that alterations in glycosylation may also drive candidate identification. Notably, the glycoproteins from which these putative biomarker candidates were derived are involved in cancer-related processes. Thus, they may represent novel therapeutic targets for this aggressive tumor subtype. 相似文献
80.
Joanna Kamińska Olga M. Koper Edyta Siedlecka-Czykier Joanna Matowicka-Karna Jerzy Bychowski Halina Kemona 《Saudi Journal of Biological Sciences》2018,25(7):1263-1271