Chromatin structures in ring-shaped nucleoli of human lymphocytes

The long-term monitoring of sympathetic ophthalmia in the diagnostic and terapeutic view. Review Department of Ophthalmology

AIM

To evaluate options of diagnostic and therapeutic procedures of sympathetic ophthalmia (SO) compared with literature data. Backgroud: SO is an ocular autoimmune disease. It is characterized by disbalance in the imunoregulatory T-subsets within cell mediated immune response.

METHODS

File examination of SO by evaluation humoral and cellular immunity was ranked nukleolar test (NT). It evaulates the current status of lymphocyte activation based on the nucleolar morphology and RNA transcription aktivity. The classical histological examination was supported by immunohistochemical analysis of lymphocytic subpopulations in the eyeball enucleated for. SO in one case.

MATERIAL

Five boys and men overall were monitored and treated in two studies from 1979 to 1994 and from 1999 to 2017 with SO In four cases it was subsequent after penetrating injuries and once after lensectomy with vitrectomy. The age of patients in the time of onset of SO was between 4 and 24 years (average 12 years). The time interval between insult and onset of SO varied between 10 days and 3 months (average 1.7 months). The relaps of disease appeared in the all cases in the time interval from 3 months to 38 years (average 15 years). Another two patients with SO were examined only in consultation: 16 years old boy with relaps of SO after cataract extraction and 71 years old women with SO subsequent after lensectomy and vitrectomy. There was examined and compared group of 19 patients with other types of uveitis in the same time. The lens-associated uveitis were caused after ocular contusion and penetrating eye injury in 16 patients (13 male patients). In another three cases (young women) with uveitid underlined by II. or III. type of hypersenzitivity the enucleation of dolorous eyeball calmed down the secondary uveitis on their second eye without any change of immunosupressive treatment and without change in NT.

RESULTS

There were changes in the complex immunological laboratory tests results in the SO cases in the counts of activated lymphocytes in the peripheral blood. The count of activated lymphocytes was increased in SO cases unlike in lens-associated uveitis. There was detected in NT statistically significant difference (p = 0,0134) between the two groups of uveitis. The histological examination (5 eyes with SO and 7 eyes without sympathetic uveitis) confirmed the diagnoses, supporting basically the clinical diagnosis. The immunohistochemical examination corfirmed the presence of populations of T-lymphocytes, macrophages and also B-lymphocytes. A basis of immunosuppressive therapy was the combination of prednisone and azathioprin at the first time. Effective therapy featured cyklosporine later.

CONCLUSION

The nucleolar test of lymphocytes draws attention of their up-to-day increased activity without the diferentiation of subpopulations and their absolute number increase related to the current activation of type IV. hypersensitivity (cell-mediated) in uveitis mechanism. The immunosupressive therapy calmes down this activation predominantly in SO, but also in other case sof uveitis with different types of hypersensivity. The immunohistochemical examination illustrates different presence of lymphocytic types according to the stage of SO.

Verticillium dahliae toxin induced alterations of cytoskeletons and nucleoli in Arabidopsis thaliana suspension cells

In plant cells, cytoskeletons play important roles in response to biotic and abiotic stresses. However, little is known about the dynamics of cytoskeletons when cells are attacked by unphysical stress factors such as elicitors and toxins. We report here that the toxin of Verticillium dahliae (VD toxin) induced changes of microfilaments (MFs) and microtubules (MTs) in Arabidopsis thaliana suspension-cultured cells. When cells were treated with a low concentration of VD toxin, MFs were disrupted ordinally from the cortex to the perinuclear region, and then recovered spontaneously; but the MTs persisted. The MFs in the perinuclear region showed more resistance to VD toxin than the cortical ones. In contrast, when cells were treated with a high concentration of VD toxin, MFs and MTs were disrupted sooner and more severely and did not recover spontaneously. Treatments with high concentrations of VD toxin also induced changes of nucleoli. At the early stages of treatment, a nucleus had a single ring-shaped nucleolus. At the later stages, multiple smaller and more brightly fluorescing nucleoli emerged in a single nucleus. Disrupted MFs could be recovered by removing the VD toxin before the ring-shaped nucleoli appeared. All these results showed that MFs and MTs play important roles in the early defense responses against VD toxin in Arabidopsis suspension cells. The cytoskeletons may be used as sensors and effectors monitoring the defense reactions. The changes of nucleoli induced by VD toxin should be important characteristics of cell death.

New Insights into Nucleolar Architecture and Activity

The nucleolus is the most obvious and clearly differentiated nuclear subcompartment. It is where ribosome biogenesis takes place and has been the subject of research over many decades. In recent years progress in our understanding of ribosome biogenesis has been rapid and is accelerating. This review discusses current understanding of how the biochemical processes of ribosome biosynthesis relate to an observable nucleolar structure. Emerging evidence is also described that points to other, unconventional roles for the nucleolus, particularly in the biogenesis of other RNA-containing cellular machinery, and in stress sensing and the control of cellular activity. Striking recent observations show that the nucleolus and its components are highly dynamic, and that the steady state structure observed by microscopical methods must be interpreted as the product of these dynamic processes. We still do not have detailed enough information to understand fully the organization and regulation of the various processes taking place in the nucleolus. However, the present power of light and electron microscopy (EM) techniques means that a description of nucleolar processes at the molecular level is now achievable, and the time is ripe for such an effort.

Preferential silver reaction of nucleolar regions adjacent to fibrillar centers in ring shaped nucleoli of leukemic lymphocytes

Silver stained proteins (SSPs) characteristic for interphasic nucleolus organizer regions (NORs) associated with fibrillar centers (FCs) and adjacent nucleolar regions of ring shaped nucleoli in leukemic lymphocytes exhibit a different sensitivity to the mild acid extraction including that with HCl. Such extractions permit a preferential visualization of fibrillar centers adjacent regions (FCARs) which are believed to represent sites of the ribosomal RNA (rRNA) transcription. The resistance of SSPs in FCARs to the extraction with HCl seems to be due to their binding to other components present in these regions. The extractibility of SSPs with HCl was influenced by the fixatives used. The largest resistance of SSPs to the extraction with HCl was noted after fixation with glutaraldehyde. In contrast, the largest extractibility of these proteins was observed after fixation with unbuffered formaldehyde.

Immunocytochemistry of the cell nucleus

This electron microscopic review addresses in situ immunocytochemistry of the mammalian cell nucleus with special reference to the use of autoantibodies, which are the major source of antinuclear antibodies. The localization of many key nuclear antigens is documented and immunocytochemical data are related to the major functional processes of transcription and processing of RNA and to replication of DNA.

Analysis of ring-shaped nucleoli in serially sectioned human lymphocytes

Serial section analysis has demonstrated that ring-shaped nucleoli of mature human lymphocytes are spherical structures consisting of a peripheral ribonucleoprotein shell that surrounds one large fibrillar center. The shell exhibits usually one or, less frequently, two openings. The fibrillar center is in contact with the nucleoplasm and perinucleolar condensed chromatin, which frequently appears as a pedicle-like structure. Several chromocenters are associated with the ring-shaped nucleolus.

Cytochemistry of the microtrabecular network in compact nucleoli of hepatocytes treated with cycloheximide

Compact nucleoli without the segregation of nucleolar components were produced in hepatocytes by the treatment of experimental rats with cycloheximide to facilitate a cytochemical study on the organization of nucleolar components in such nucleoli. The extraction of pepsin pretreated specimens with nucleases (deoxyribonuclease and ribonuclease) demonstrated that compact nucleoli are characterized by a relatively uniform distribution of RNP components which mask a microtrabecular intranucleolar network. This network apparently consists of proteins and contains fine DNA filaments.

A cytological method for the simultaneous staining of nucleoproteids and some cathionic proteins

A cytochemical method is suggested for the simultaneous and differential staining of cellular nucleoproteids [ribonucleoproteids (RNP) and desoxyribonucleoproteids (DNP)], as well as for the simultaneous contrast staining of some basic (arginine- and lysin-containing) proteins. The staining technique is based on DNA-denaturation procedures and the application of mixtures of basic dye--methylene blue and acid dyes--eosin or fast green at low concentrations. The combination of methylene blue with eosin is used for the staining of ribonucleoproteids (RNP) whereas methylene blue-fast green for the simultaneous detection of ribonucleoproteids and desoxyribonucleoproteids (RNP and DNP), as well as for the differential staining of nuclear DNP (after cold hydrolysis with 5 N HCl). The acid dyes eosin and fast green stain in pink resp. in green some cathionic proteins in the lysosomal (specific) granules of the neutrophilic and eosinophilic leucocytes in the cytoplasm of erythrocytes, and after cold hydrolysis in the cytoplasm of lymphocytes. A fluorescent variant of the method with sulfaflavin is also suggested for the fluorochromation of cytoplasmic cathionic granules in the luecocytes. Acid mucopolysaccharide components in the granules of basophilic leucocytes, tissue mastocytes and thrombocyres are stained intensively pink-violet (gamma-metachromatic). The possibilities for the application of the method in the quantitative analysis of blood and exfoliated cells, as well as for purpose of haematology, immunology and exfoliative cytology are discussed.

The fine structure of the lymphocyte nucleus under conditions of phytohaemagglutinin stimulation

The nucleus of PHA (phytohaemagglutinin) cultured lymphocytes is studied by EDTA, Thalium-Schiff and uranyl-lead techniques. Scattering of the dense chromatin, increase in the number of NB (nuclear bodies) and nucleolar modifications are established. Transportation is seen of granules similar to perichromatin ones from the nucleus into the cytoplasm. Morphometric investigation reveals a decrease between 7,7 and 26,3% of the dense chromatin and also that the number of PCG (perichromatin granules) to be the greatest in the untransformed PHA lymphocytes, e.g. B lymphocytes. It is established in new born chickens that the lymphocytes of the bourse of Fabricius are richer in PCG than these of the thymus.