Progenitor cells of the human erythroid and granulocytic cell lineages are characterized by the presence of several nucleoli. One of these nucleoli is larger and possesses more fibrillar centres than others. Such nucleolus is apparently dominant in respect of both size and main nucleolar function such as nucleolar-ribosomal RNA transcription. Such nucleolus is also visible in specimens using conventional visualization procedures, in contrast to smaller nucleoli. In the terminal differentiation nucleated stages of the erythroid and granulocytic development, dominant nucleoli apparently disappeared, since these cells mostly contained very small nucleoli of a similar size with one fibrillar centre. Thus, the easily visible dominant nucleoli appear to be useful markers of the progenitor cell state, such as proliferation, and differentiation potential.

• MeSH
• buněčná diferenciace MeSH
• buněčné dělení MeSH
• buněčné jadérko fyziologie   ultrastruktura   MeSH
• buněčné jádro ultrastruktura   MeSH
• buněčný rodokmen MeSH
• erytroidní prekurzorové buňky ultrastruktura   MeSH
• granulocyty ultrastruktura   MeSH
• lidé MeSH
• prekurzorové buňky granulocytů ultrastruktura   MeSH
• RNA ribozomální metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• RNA ribozomální MeSH

The present study was undertaken to provide more information on the differentiation and maturation of human granulocytes using computer-assisted image RNA densitometry at single-cell level. The bone marrow of patients suffering from chronic phase of chronic myeloid leukemia represents a very convenient model for such measurements because of the satisfactory number of early stages, as well as advanced stages, of the granulocytic cell lineage represented by neutrophils. In contrast to the erythroid cell lineage, similar nucleolar and cytoplasmic RNA density-concentration values were found only in early granulocytic progenitors such as myeloblasts and promyelocytes. In advanced stages of the granulocytic development starting with myelocytes, these cells were characterized by a larger decrease in the cytoplasmic RNA concentration in comparison with that of the nucleoli. Thus, the nucleolar to cytoplasmic RNA concentration ratio in these cells was above 1. On the other hand, it should be pointed out that late differentiation stages of granulocytes, starting with myelocytes, possessed nucleolar bodies (nucleoli without surrounding perinucleolar chromatin) of a markedly reduced size.

• MeSH
• biopsie MeSH
• buněčná diferenciace * MeSH
• buněčné jadérko ultrastruktura   MeSH
• buněčný rodokmen MeSH
• chronická nemoc MeSH
• cytoplazma metabolismus   ultrastruktura   MeSH
• denzitometrie MeSH
• lidé MeSH
• myeloidní leukemie krev   metabolismus   patologie   MeSH
• počítačové zpracování obrazu MeSH
• prekurzorové buňky granulocytů * metabolismus   ultrastruktura   MeSH
• RNA * analýza   MeSH
• velikost částic MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• RNA * MeSH

The present study was designed to provide more information on nucleoli in apoptotic cells,which were represented in the present study by cultured leukemic myeloblasts (Kasumi-1 cells). The apoptotic process in these cells was produced by trichostatin A (TSA) that is a histone deacetylase inhibitor with strong cytostatic effects. The selected TSA concentration added to cultures facilitated to study apoptotic and not-apoptotic cells in one and the same specimen. The nucleolar diameter and density were determined using computer assisted measurement and densitometry in specimens stained for RNA. In comparison with not-apoptotic cells, in apoptotic cells, nucleolar mean diameter did not change significantly and nucleolar RNA density was also not apparently different. On the other hand, the cytoplasmic RNA density in apoptotic cells was markedly reduced. Thus it seemed to be possible that the transcribed RNA remained "frozen"within the nucleolus but its transport to the cytoplasm decreased or stopped. However, the possibility of the RNA degradation in the cytoplasm of apoptotic cells based on the present study cannot be eliminated. At this occasion it should be added that AgNORs reflecting nucleolar biosynthetic and cell proliferation activity in apoptotic cells decreased in number or disappeared. The presented results also indicated that large nucleoli intensely stained for RNA need not be necessarily related to the high nucleolar biosynthetic or cell proliferation activity and may be also present in apoptotic cells responding to the cytostatic treatment.

• MeSH
• antigeny jaderné analýza   ultrastruktura   MeSH
• apoptóza * MeSH
• buněčné jadérko chemie   účinky léků   ultrastruktura   MeSH
• chronická myeloidní leukemie patologie   MeSH
• kyseliny hydroxamové farmakologie   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• prekurzorové buňky granulocytů účinky léků   ultrastruktura   MeSH
• RNA analýza   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny jaderné MeSH
• kyseliny hydroxamové MeSH
• nucleolar organizer region associated proteins MeSH Prohlížeč
• RNA MeSH
• trichostatin A MeSH Prohlížeč

Human myeloblasts were studied in bone marrow of patients suffering from chronic phase of chronic myeloid leukaemia to provide more information on the nucleolar diameter in these early granulocytic progenitors. These cells are a convenient model for such study since the number of myeloblasts in diagnostic bone marrow smears of investigated patients is larger than in not-leukemic persons because of the increased granulopoiesis. The nucleolar diameter was measured in myeloblasts after various cytochemical procedures such as methods for visualisation of RNA, DNA and proteins of AgNORs using digitized images and image processing. The results clearly demonstrated that values of the nucleolar diameter depended on the procedures used for visualising nucleoli. It seems to be also clear that a close relationship exists between the diameter of nucleoli and their number since the larger the number of nucleoli per cell the smaller their mean size. However, one of multiple nucleoli present in the nucleus is usually significantly larger. Moreover, the possibility exists that the variability of nucleolar diameter of leukemic myeloblasts and thus the heterogeneity of these cells might depend on various stages of the cell cycle as supported by nucleolar measurements on aging leukemic myeloblasts (K 562 cells) in vitro. Since the staining density of small and large nucleoli did not differ substantially after staining for RNA, it seems to be likely that the nucleolar size is directly related to the total RNA content in myeloblasts. In addition, karyometry combined with RNA cytochemistry still appears to be an useful tool to study nucleoli at the single cell level.

• MeSH
• barvení a značení MeSH
• buněčné jadérko ultrastruktura   MeSH
• buňky K562 MeSH
• chronická myeloidní leukemie patologie   MeSH
• granulocyty patologie   MeSH
• hematopoetické kmenové buňky patologie   MeSH
• kultivované buňky MeSH
• lidé MeSH
• prekurzorové buňky granulocytů chemie   patologie   ultrastruktura   MeSH
• RNA analýza   MeSH
• velikost buňky MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• RNA MeSH

The diameter of nucleoli was measured in human bone marrow early granulocytic precursors after visualization by a simple cytochemical method for demonstration of RNA. Such method facilitated to clearly see nucleolar bodies without perinucleolar chromatin, including those of micronucleoli. The bone marrow of patients suffering from chronic myeloid leukaemia (untreated with cytostatics) provided a satisfactory number of both myeloblasts and promyelocytes for nucleolar measurements because of prevailing granulopoiesis. The direct nucleolar measurement was carried out on digitized and processed images on the screen at magnification 4,300x. It seems to be likely that the nucleolar size is directly related to the number of nucleoli per cell. The largest nucleoli were present in both myeloblasts and promyelocytes that possessed a single nucleolus. In contrast, the nucleolar diameter was significantly smaller in cells with multiple nucleoli. However, in cells with small multiple nucleoli, one of them was always larger and dominant with a large number of AgNORs. Such large nucleoli are possibly visible in specimens stained with panoptic procedures or methods staining nuclear chromatin or DNA. It should also be mentioned that both myeloblasts and promyelocytes mostly possessed two nucleoli with the mean diameter close to 1.5 microm. The incidence of early granulocytic precursors classified according to the nucleolar number and size strongly suggested that the various nucleolar number and nucleolar size in these cells might be related to the different stage of the cell cycle and might also explain their heterogeneity.

• MeSH
• buněčné jadérko ultrastruktura   MeSH
• histocytochemie MeSH
• karyometrie MeSH
• lidé MeSH
• organizátor jadérka ultrastruktura   MeSH
• prekurzorové buňky granulocytů ultrastruktura   MeSH
• RNA analýza   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• RNA MeSH

The present study was undertaken to provide missing information on the distribution of AgNORs in large nucleoli of human leukaemic early granulocytic precursors in vivo as well as in vitro. In vivo, the distribution of AgNORs was studied in early granulocytic precursors of patients suffering from chronic myeloid leukaemia who were both untreated and treated with imatinib mesylate. AgNORs were visualized by silver reaction under conditions which facilitated to see their distribution by light microscopy. In vitro, the distribution of AgNORs was studied in proliferating and ageing K 562 cells which originated from chronic myeloid leukaemia. In vitro, the ageing of K 562 cells produced intranucleolar translocation of AgNORs to the nucleolar periphery. Such translocation was also observed in some leukaemic early granulocytic precursors in vivo, e.g. in bone marrow myeloblasts and promyelocytes of leukaemic patients. As was expected, the intranucleolar translocation of AgNORs in early granulocytic precursors was more frequent in patients treated with the cytostatic therapy--imanitib mesylate. The abovementioned findings suggest that myeloblasts and promyelocytes with AgNORs translocated to the periphery of large nucleoli might be in the ageing state, similarly as blastic cells of leukaemic myeloid origin (K 562 cells) in ageing cultures. Thus, the translocation of AgNORs might be a useful marker of premature ageing in the future and might contribute to the evaluation of the single cell state under various experimental as well as clinical conditions. However, more clinically oriented studies are required in this direction.

• MeSH
• barvení stříbrem MeSH
• buněčné jadérko patologie   ultrastruktura   MeSH
• buňky K562 MeSH
• chronická myeloidní leukemie patologie   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• organizátor jadérka patologie   ultrastruktura   MeSH
• prekurzorové buňky granulocytů patologie   ultrastruktura   MeSH
• stárnutí buněk MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH