Biomedical subjects

L Antalíková

Publications and source records attributed to L Antalíková.

At least 19 recordsLinked to original sources

PubMed1996

Ultrastructural demonstration of glucose-6-phosphatase activity and glycogen in skeletal muscles of newborn piglets with the splayleg syndrome.

The ultrastructural localization of glucose-6-phosphatase activity and glycogen were investigated in the longissimus dorsi and biceps femoris muscles of normal and splaylegged newborn piglets. Significant differences were ascertained in the distribution of the reaction product of glucose-6-phosphatase activity between the two groups of animals. A fine precipitate was found in the sarcoplasmic reticulum and in the perinuclear cisternae of normal piglet muscles. In splaylegged muscles, variable deposits of coarse reaction product were observed within the extremely dilated cisternae of sarcoplasmic reticulum at their periphery. Moreover, both longitudinal and transversal ultrathin sections of these muscles showed a reduced number of myofibrils and an increased accumulation of glycogen (especially within the large extramyofibrillar spaces) in comparison with muscles of normal piglets.

Animals↗

PubMed1994

Cytoplasmic argyrophilic protein(s) in cumulus-oocyte complexes: a preliminary study.

The presence of acidic argyrophilic protein(s) in cumulus cells and oocytes was examined in bovine, ovine, porcine and murine cumulus-oocyte complexes (COCs) using a specific silver-staining method. The COCs were isolated from small (1 mm) or large (3-5 mm) antral follicles; they were fixed immediately after slaughter (first group) or after transfer to the laboratory (ca 60 min, second group) and then silver stained according to Likovskí and Smetana (1981). The argyrophilic proteins were accumulated mainly in foot processes of cumulus cells on oocytes isolated from large bovine follicles. The intensity of the reaction was less evident in small follicles. The intensity of staining gradually disappeared from cumulus cells as the maturation continued. Moreover, we were unable to detect similar strong labelling in mouse, pig and sheep COCs. Such a chronology suggests that argyrophilic protein(s) may play a role in the transition from meiotic arrest to resumption in bovine oocytes. Our results also suggest that preliminary events of maturation may occur just after slaughter, ie a relatively long time before the COCs are isolated and cultured in vitro.

Animals↗

PubMed1994

Localization of basic and acidic argyrophilic proteins in nuclear structures of elongating mouse spermatids.

Different cytochemical techniques at the electron microscopic level were used to investigate the presence of basic and acidic proteins during spermiogenesis in mice. Basic lysine rich proteins were demonstrated with an ethanolic solution of phosphotungstic acid, acidic agryrophilic proteins using two silver staining procedures applied en bloc and on the ultrathin lowicryl sections. Both types of proteins had very similar localization in the nucleoplasm and identical distribution within the postacrosomal dense lamina on the surface of late spermatid heads. The specificity of reactions is briefly discussed.

Acids↗

PubMed1993

Ultrastructural cytochemistry of the nucleus and nucleolus in growing rabbit oocytes.

Ultrastructural changes of the germinal vesicle during the growth of rabbit oocytes were studied by means of light and electron microscopy, 3H-uridine autoradiography, Ag-NOR staining and E-PTA staining. Particular interest was paid to the nucleologenesis and condensation of chromatin. In contrast to other mammalian species, chromosome condensation in rabbit oocytes occurred concomitantly with rRNA synthesis-dependent nucleolar compaction and preceded nuclear envelope breakdown and resumption of meiosis.

Animals↗

PubMed1993

Cytochemical and immunocytochemical ultrastructural study of nucleoproteins during nucleologenesis in 8-cell bovine embryos.

The aim of this study was to characterize embryonic nucleologenesis by determining the appearance and localization of acid argyrophilic, basic lysine-rich and histone proteins in 8-cell bovine embryos. Two silver staining techniques, ethanolic phosphotungstic acid (PTA) and immunocytochemical methods using specific antibodies, were applied at the ultrastructural level. The silver-stained proteins were detected at the onset of nucleologenesis on the periphery of the dense nucleolus precursor bodies (NPBs). The amounts of these proteins increased during the transformation of the NPBs into the fibrillogranular nucleolus. At this stage the well-developed dense fibrillar components encircling fibrillar centres showed intense staining. PTA-positive (basic lysine-rich) proteins were present within most nucleolar structures during nucleologenesis as well as in the chromatin. Histones H2B, H3 and H4 were concentrated throughout the chromatin including the nucleolus-associated chromatin. At the onset of nucleologenesis, histones were absent in the NPBs. The first weak histone labelling was detected in the multivacuolated NPBs, both in the fibrous mass as well as inside the vacuoles. Nucleolar histones appeared with the massive penetration of DNA into the NPBs. We suggest that nucleologenesis may serve as a criterion of normal early embryonic development and that the proteins involved in the process of nucleologenesis and transcription could be used as chemical markers of nucleolar function.

Animals↗

PubMed1992

Ultrastructural localization of basic lysine-rich proteins during the nucleologenesis in preimplantation bovine embryos.

The process of nucleologenesis was examined in preimplantation bovine embryos by using ethanolic phosphotungstic acid (E-PTA) at the electron microscopic level. E-PTA binds basic lysine-rich proteins and thus makes possible detection of their localization and distribution. In blastomere nuclei of 2-, 4- and early 8-cell embryos, only nucleolus precursor body/bodies (NPBs) appear, being formed from a mass which is homogeneously stained with E-PTA. In cow embryos, the whole nucleologenesis is situated in the 8-cell stage. During the following step of nucleologenesis, the NPB with a big central area (named NPB vacuole) is formed. Fibrillar mass around the central vacuole is intensively stained, especially in the regions in close vicinity to the central vacuole. Many clumps of E-PTA-positive, regularly dispersed material are found inside the vacuole. The next step of nucleologenesis is characterized by the presence of NPB with secondary vacuoles that are also filled with clumps of E-PTA-positive material. Small, intensively stained areas are visible at sites that are probably identical with those where a dense fibrillar component is formed. Until the end of the 8-cell stage, as well as in the morula and early blastocyst, typical fibrillogranular nucleoli are present. These nucleoli have 3 basic components--fibrillar centres (FC), dense fibrillar components (DFC) and granular components (GC) which stain with different increasing intensity. FC and DFC show a strong (particular) reaction while the GC are stained to a lesser degree. In all examined stages of embryonal development, the E-PTA positivity was found within the perinucleolar chromatin and on the clumps of heterochromatin. An analogical localization of basic and acidic regulatory proteins in the examined developmental stages is discussed.

Animals↗

PubMed1992

Ultrastructural and morphometric analysis of cytoplasmic structures in preimplantation pig embryos.

Preimplantation pig embryos (1-, 2-, 3/4-, 16-cell stage, blastocysts) were analysed morphologically and/or morphometrically by means of electron microscopy and computer-assisted image analysis. Qualitative and quantitative changes in localization, organization, number, and area of cytoplasmic inclusions were analysed on thin sections. The structure and number of mitochondria, number of endoplasmic reticulum profiles were recorded in several individual developmental stages. Three types of cytoplasmic inclusions were described (vesicles with yolk globules, vesicles with homogeneous light inclusions, lipid droplets), each having a different topographic distribution. Quantitatively, a gradual increase in the number of endoplasmic reticulum profiles and mitochondria occurred between 4-cell stage blastomeres and blastocyst trophectoderm cells. The significant differences recorded in number, morphology and distribution of organelles in different embryonic developmental stages are discussed in relation to physiological phenomena known to occur during cleavage and compaction.

Animals↗

PubMed1992

[Morphologic and cytochemical study of Sertoli cell nuclei in ruminants].

Nuclei and nucleoli were examined at an ultrastructural level in the testicular tissue of bulls and rams. In the two species there occurs a morphologically interesting so called multivesicular nuclear body; the interpretation of its function is not quite clear. The tissue was processed by a routine electron microscope technique and than a cytochemical demonstration of several types of proteins was used. Acidic argyrophilic proteins were demonstrated by a silver-staining technique, basic lysine-rich proteins by means of ethanolic PTA, and ribonucleoproteins (RNP) by the method of Bernhard's regressive preferential staining. Multivesicular nuclear bodies in bull Sertoli's cells are composed of a greater number of membrane bound vesicles with granules on the outer surface (Fig. 1). The results of cytochemistry reactions show that the granules contain acidic argyrophilic proteins (Fig. 3) and RNP (Fig. 7). The intervesicular material is an analogy of the dense fibrillar component of normal nucleoli of somatic cells. This component contains the three types of investigated proteins (Figs. 2, 3, 5, 7). In the nuclear bodies of ram Sertoli's cells the number of vesicles is much lower, the fibrillar component is prevailing, in form of clusters and striae of filamentous material around the vesicles. The cytochemistry reactions proved that this material contains acidic argyrophilic proteins (Fig. 4) and basic PTA positive (Fig. 6) proteins. The presence of acidic and basic regulatory proteins in the fibrillar component of multivesicular nuclear bodies indicates the active synthesis of RNA occurring in this material. It is therefore possible to consider this special type of nuclear bodies as a full equivalent of nucleoli of somatic cells as to the function.

Animals↗

PubMed1991

Ultrastructural localization of basic lysine-rich proteins during the nucleologenesis in preimplantation mouse embryos.

The paper describes nucleologenesis in preimplantation mouse embryos studied by electron microscopy after staining with ethanolic phosphotungstic acid (E-PTA), a substance which binds to basic lysine-rich proteins and makes it thus possible to follow their localization and distribution. A nucleolar precursor body (NPB) homogeneously stained with E-PTA first appears in pronuclei of a fertilized oocyte. In 2-cell stage embryos, the staining intensity of the central part of NPB is reduced, whereas the outer zone retains the PTA positivity. In the course of further development, reticulation takes place in the peripheral zone and all structures of a functional nucleolus are gradually formed. Tiny spherical bodies, called "remnant NPBs", can still be observed in reticular nucleoli of cells at the morula stage. The similarities in reaction and morphological appearance of the NPB and the corresponding structures in oocytes of the mouse and rat antral follicle are discussed.

Animals↗

PubMed1990

Ultrastructural localization of silver-staining nuclear proteins at the onset of transcription in early bovine embryos.

Argyrophilic nuclear proteins, known to be functionally associated with ribosomal genes, were localized, in four-, eight-, and 16-cell bovine embryo blastomere nuclei using two different silver-staining procedures. Within the eight-cell cleavage stage by the process of embryonal nucleologenesis in the cow embryo the full-capacity ribosome-producing machinery is established. In the four-cell embryo, many patches and islands of argyrophilic (Ag+) material were detected in the nucleoplasm. The nucleolus-precursor bodies (NPBs), composed uniformly of a homogeneous compact mass, were completely devoid of any silver staining. On the other hand, clear-cut localization of argyrophilic proteins was detected during the eight-cell stage either inside the transforming NPBs or in the close vicinity, or in the already differentiated nucleolus. In compact, nonvacuolated NPB, an intensive Ag+ area was detected, in the form of a lenticle, at the periphery of the NPB. During and following vacuolation of the NPB, no Ag+ was detected inside these vacuoles. It was seen, however, in the dense fibrillar nucleolar component surrounding the smaller vacuoles formed at the time of the establishment of nucleolar structure. Ag+ areas were seen repeatedly in the vicinity of NPBs, probably a part of the nucleolus-associated chromatin or, alternatively, representing the extranucleolar bodies. In blastomere nuclei of 16-cell embryos, already possessing reticulated nucleoli known from intensively synthesizing somatic cells, the silver-staining pattern corresponded to the usual situation in differentiated cells: slight staining of fibrillar centers, heavy labelling in the dense fibrillar component, and absence of silver deposits in the granular component.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Ultrastructural cytochemical methods in the study of mouse testicular tissue.

Different cytochemical and immunocytochemical techniques employed in processing of mouse testicular tissue at ultrastructural level were compared. Two silver staining procedures applied en block and on ultrathin Lowicryl sections were used to demonstrate acidic argyrophilic nuclear proteins. Both methods give standard results. Silver staining en block gives positivity in the form of fine silver precipitate. Coarser silver aggregates and fine nonspecific reactions of the background result from silver staining on ultrathin sections. The method with alcoholic phosphotungstic acid applied en block was used to demonstrate basic nuclear proteins rich in lysine. The results are confirmed and specified by immunocytochemical demonstration of histones and protamine. Specificity of the reactions is briefly discussed.

Acrylic Resins↗

PubMed1990

Contribution to the morphometry of limb bud structures in the normodactylous and polydactylous rat. I. Apical ectodermal ridge.

The height of the apical ectodermal ridge on limb buds of the embryo laboratory rat was studied in the polydactyly-luxate syndrome and compared with the controls. The following findings were obtained: (a) On the 14th embryonal day, prior to the development of the anlage of mesenchymal condensates, the AER is higher in polydactylous animals as compared with the controls. (b) On the 15th, 16th and 17th embryonal day the height of the AER in the praeaxial region of the polydactylous limb bud largely predominates over the controls. A comparison of the height of the AER above digital rays and interdigital grooves of polydactylous and normodactylous animals does not thus exhibit any marked differences. This fact is attributed to the existence of more powerful induction processes of the underlying mesenchymal component where rudiments of supernumerary digital rays are formed.

Animals↗

PubMed1990

Contribution to the morphometry of limb bud structures in the normodactylous and polydactylous rat. II. Density of filopodia in the subectodermal zone.

In hindlimb buds of normodactylous and polydactylous embryos in the stage of the 16th and 17th embryonal day the mesenchymal region, closely adjoining the site below the AER, was investigated. This space is called the subridge zone and is filled with a large amount of variously formed processes of mesenchymal cells, chiefly with filopodia. With the use of the morphometric point-couting method it was found that in normodactylous limb buds the density of filopodia in the given area of the subridge zone was 2.15% as compared with the 6.48% representation of filopodia in the same zone of polydactylous animals. Numerous filopodia localized right under the AER established connection between the mesenchyma and the intact basal membrane, and their higher density is undoubtedly related to the existence of the maintenance factor.

Animals↗

PubMed1989

Patterns of physiological cell death and mitoses in the apical ectodermal ridge in normodactylous and polydactylous rat limb buds. A quantitative evaluation.

Limb buds in normally developing foetal rats and rats with the polydactyly-luxate syndrome at day 14 and 15 of intrauterine growth were studied at the optical and electron microscopic levels. Four sets of limb buds were collected and evaluated: 14th e.d.N., 14th e.d.P., 15th e.d.N., and 15th e.d.P. (e.d. embryonic day, N - normodactylous, P - polydactylous); they were studied for apical ectodermal ridge development with reference to the rates of cell death and mitosis. Both phenomena were evaluated quantitatively. A significant difference was found in the rate of physiological cell death, which was far lower in polydactylous (4.33 and 28.73) as compared with normodactylous individuals (62.40 and 82.11 cell deaths per 300 cells in the ridge on days 14 and 15). The difference found documents a considerable retardation in cell death rate in the polydactylous apical ectodermal ridge epithelium. Physiological cell death is associated with a process called apoptosis, which is characterized by the presence of "apoptotic bodies" in the cytoplasm of epithelial cells and in the intercellular space. The total number of mitoses in the ridge epithelium was relatively low (4.63 - 6.33 per 300 cells) and the differences between norm and polydactyly were not statistically significant.

Animals↗

PubMed1988