1,721,015 research outputs found
Nucleolar morphological rearrangement related to transcriptional and replicative state in Burkitt lymphoma cells.
No full textThe specific silver staining of nucleolar region organizers was applied to Daudi lymphoma control and interferon alpha-treated cells. Isolated nuclei from control and treated samples were used for the kinetic analysis of in vitro RNA and DNA synthesis. Results have shown that interferon treatment induces a reduction of the transcriptional and replicative activities within 90 min. Concomitant to these results is the modification of the organization of nucleoli. Intensity and distribution of silver grains are, in fact, different in treated cells nucleoli as compared to those of controls. Thus, the number and the arrangement of granules could be related to the functional state of the cells suggesting that the transient cascade of interferon-generated signals involves also modulation of nucleolar structure and function in accordance with the hypothesis of a relationship of cell proliferation rate to silver-stained nucleolar protein quantity
Searching the point of no return in Helicobacter pylori life: necrosis and/or programmed death.
No full textAims: Ultrastructural and molecular studies to support the hypothesis of programmed cell
death in Helicobacter pylori were conducted.
Methods and Results: Evidence of programmed death in H. pylori is provided through
electron microscopic detection and cytochemical labelling of electrondense bodies (EDB),
1 containing packaged DNA in coccoid cells, resembling micronuclei of apoptotic eukaryotic
cells. This morphological evidence is also supported by DNA cleavage in homogeneous
fragments of about 100 base pairs. Programmed cell death was observed in H. pylori cultures at
37 °C, with a maximum of 37á5% of EDB coccoid cells after 7 days. The non-permissive
temperature of 4 °C anticipated this process, with 40% of EDB coccoid forms within 3 days,
and it remained substantially unaffected during the observation time of 14 days.
Conclusion: In these experiments, deprivation of nutrients and a non-permissive temperature
acted as a powerful trigger for programmed cell death.
Significance and Impact of the Study: Helicobacter pylori bacterial populations, under
2 stressing stimuli, can respond with programmed cell suicide as a means of species preservation
Relationship between nuclear ribonucleoprotein arrangement and cell proliferation in Burkitt lymphoma cells.
No full textThe presence of body-like structures in nuclei from interferon alpha-treated Daudi cells has been shown on the ultrastructural level, by the use of different staining methods. The degree of their rearrangement in the nucleoplasm seems to be dependent on the time of interferon treatment. Since this morphological evidence has been found to be preceded by a slowing down of RNA transcriptional machinery early upon the interferon administration, it is speculated that interferon generated signals might lead to RNP granule accumulation in the nucleus and a consequent arrangement into defined structures
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Human Herpesvirus 7 Induces the Down-Regulation of CD4 Antigen in Lymphoid T Cells Without Affecting p56lck Levels
No full textIn this study, we investigated the fate of the CD4 Ag during infection of CD4+ T cells with the T lymphotrophic human herpesvirus 7 (HHV-7), using the SupT1 lymphoblastoid T cell line as a model system. The following points were established: 1) productive infection with HHV-7 was required to obtain persistent down-modulation of surface CD4 (CD4SURF); 2) at 6 to 9 days postinfection, when approximately 50 to 60% of SupT1 cells still showed a CD4SURF dim positivity, a drastic loss of total CD4 protein was found by either Western blot or immunoprecipitation experiments; 3) a block in CD4 protein production was demonstrated by a radioimmunoprecipitation assay; 4) analysis of the mRNA steady-state levels and transfection studies performed with a plasmid containing the CD4 promoter/enhancer regions in front of the luciferase gene indicated that HHV-7 infection has a suppressive effect on CD4 transcription; 5) both CD4SURF and intracellular CD4 (CD4INTRA) were reduced in HHV-7-infected cells with respect to uninfected controls, but the loss of CD4SURF was more dramatic than that of CD4INTRA; 6) immunogold labeling and electron microscopy demonstrated that CD4INTRA co-localized with HHV-7 Ags within the same subcellular compartments of infected cells; and 7) the total amount of the tyrosine kinase p56lck and tyrosine phosphorylated p56lck levels were unchanged in HHV-7-infected versus uninfected cells
Metabolic alterations, aggressive hormone-naïve prostate cancer and cardiovascular disease: A complex relationship
Full text linkBackground: Epidemiological studies suggest a possible relationship between metabolic alterations, cardiovascular disease and aggressive prostate cancer, however, no clear consensus has been reached. Objective: The aim of the study was to analyze the recent literature and summarize our experience on the association between metabolic disorders, aggressive hormone-naïve prostate cancer and cardiovascular disease. Method: We identified relevant papers by searching in electronic databases such as Scopus, Life Science Journals, and Index Medicus/Medline. Moreover, we showed our experience on the reciprocal relationship between metabolic alterations and aggressive prostate cancer, without the influence of hormone therapy, as well the role of coronary and carotid vasculopathy in advanced prostate carcinoma. Results: Prostate cancer cells have an altered metabolic homeostatic control linked to an increased aggressivity and cancer mortality. The absence of discrimination of risk factors as obesity, systemic arterial hypertension, diabetes mellitus, dyslipidemia and inaccurate selection of vascular diseases as coronary and carotid damage at initial diagnosis of prostate cancer could explain the opposite results in the literature. Systemic inflammation and oxidative stress associated with metabolic alterations and cardiovascular disease can also contribute to prostate cancer progression and increased tumor aggressivity. Conclusions: Metabolic alterations and cardiovascular disease influence aggressive and metastatic prostate cancer. Therefore, a careful evaluation of obesity, diabetes mellitus, dyslipidemia, systemic arterial hypertension, together with a careful evaluation of cardiovascular status, in particular coronary and carotid vascular disease, should be carried out after an initial diagnosis of prostatic carcinoma
Effetto di campi elettromagnetici a frequenza estremamente bassa su cellule procariotiche
No full textHelicobacter Pylori ATCC 43629 outer membrane vesicles (OMVs): a vehicle for extracellular DNA (eDNA) transport.
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